Facile Synthesis of Bowl-Like LiFePO4/C Composite with High Rate-Performance

NASA Astrophysics Data System (ADS)

Jing, Peng; Yao, Lei; Xiang, Mingwu; Wang, Yan; Wu, Jinhua; Wang, Boya; Zhang, Yun; Wu, Hao; Liu, Heng

2018-07-01

Olivine-structured LiFePO4/C composites with high rate-performance were synthesized via an industrial spray-drying technique using a low cost Fe3O4 as iron source. The as-obtained LiFePO4/C exhibits a unique bowl-like morphology with a particle size of 2-5 μm in diameter. A continuous uniform carbon coating layer on the surface of LiFePO4/C cathodes promotes fast electron transport, whilst it guarantees the favorable electrochemical reaction. Especially the formation of porous structure leads to an average pore volume of 0.127 cm3 g-1 and a high specific surface area of 34.46 m2 g-1, which is conducive to facilitating the penetration of electrolyte and providing the more contact area of electrolyte with LiFePO4/C. As a result, the as-prepared LiFePO4/C cathode material delivers an outstanding discharge capacity of 102.1 mAh g-1, 94.2% of the initial capacity (108.3 mAh g-1), after 1000 cycles at 10 C. Even at an ultrahigh current rate of 50 C, it still shows an initial discharge capacity of 58 mAh g-1.

Facile Synthesis of Bowl-Like LiFePO4/C Composite with High Rate-Performance

NASA Astrophysics Data System (ADS)

Jing, Peng; Yao, Lei; Xiang, Mingwu; Wang, Yan; Wu, Jinhua; Wang, Boya; Zhang, Yun; Wu, Hao; Liu, Heng

2018-03-01

Olivine-structured LiFePO4/C composites with high rate-performance were synthesized via an industrial spray-drying technique using a low cost Fe3O4 as iron source. The as-obtained LiFePO4/C exhibits a unique bowl-like morphology with a particle size of 2-5 μm in diameter. A continuous uniform carbon coating layer on the surface of LiFePO4/C cathodes promotes fast electron transport, whilst it guarantees the favorable electrochemical reaction. Especially the formation of porous structure leads to an average pore volume of 0.127 cm3 g-1 and a high specific surface area of 34.46 m2 g-1, which is conducive to facilitating the penetration of electrolyte and providing the more contact area of electrolyte with LiFePO4/C. As a result, the as-prepared LiFePO4/C cathode material delivers an outstanding discharge capacity of 102.1 mAh g-1, 94.2% of the initial capacity (108.3 mAh g-1), after 1000 cycles at 10 C. Even at an ultrahigh current rate of 50 C, it still shows an initial discharge capacity of 58 mAh g-1.

Dust and Diffuse Interstellar Bands in the za = 0.524 Absorption System toward AO 0235+164

NASA Astrophysics Data System (ADS)

Junkkarinen, V. T.; Cohen, Ross D.; Beaver, E. A.; Burbidge, E. M.; Lyons, R. W.; Madejski, G.

2004-10-01

We present new Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) NUV-MAMA and STIS CCD observations of the BL Lac object AO 0235+164 and the intervening damped Lyα (DLA) line at za=0.524. The line profile gives N(HI)=(5+/-1)×1021 cm-2 and, combined with the H I 21 cm absorption data, leads to a spin temperature of Ts=220+/-60 K. Those spectra also show a strong, broad feature at the expected position of the 2175 Å graphitic dust feature at za=0.524. Assuming a Galactic-type dust extinction curve at za=0.524 gives a dust-to-gas ratio of 0.19 times the Galactic value, but the fit, assuming that the underlying, unreddened spectrum is a single power law, is poor in the far-UV. A dust-to-gas ratio of 0.19 times the Galactic value is similar to the LMC, but the AO 0235+164 spectrum does not fit either the LMC extinction curve or the SMC extinction curve (which has practically no 2175 Å feature). A possible interpretation includes dust similar to that in the Galaxy, but with fewer of the small particles that produce the far-UV extinction. The metallicity of the za=0.524 absorber, estimated from the observed N(HI) and excess X-ray absorption (beyond Galactic) derived from contemporaneous and archival ASCA and ROSAT X-ray data, is Z=0.72+/-0.28 Zsolar, implying in turn a dust-to-metals ratio of 0.27 times the Galactic value. If the dust mass density is the same in the za=0.524 DLA system as in our Galaxy, only 14% (+/-6%) of the metals (by mass) are in dust, compared to 51%, 36%, and 46% for the Galaxy, LMC, and SMC, respectively. Such a dusty za=0.524 AO 0235+164 absorption system is a good example of the kind of DLA system that will be missed because of selection effects, which in turn can bias the measurement of the comoving density of interstellar gas (in units of the closure density), Ωg, as a function of z. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by

Hexamethylenetetramine assisted hydrothermal synthesis of BiPO4 and its electrochemical properties for supercapacitors

NASA Astrophysics Data System (ADS)

Nithya, V. D.; Kalai Selvan, R.; Vasylechko, Leonid

2015-11-01

The well defined microstructures of BiPO4 were successfully synthesized by the facile hexamethylenetetramine (HMT) assisted hydrothermal method. The low temperature monoclinic BiPO4 structure with space group P21/n, were obtained from X-ray diffraction (XRD) for the pristine and HMT-assisted BiPO4 with 1, 3, 5 and 10 mmole concentration. A transformation from low temperature monazite-type phase to the high temperature SbPO4-type phase of BiPO4 was observed at the 10 mmole concentration. There was a variation in the morphology from polyhedron to octahedra-like and finally into cube shape upon an increase in concentration of HMT. The role of reaction time in the morphology of BiPO4 particles was investigated. The selected area electron diffraction (SAED) pattern elucidated the ordered dot pattern and the calculated d-spacing revealed the formation of BiPO4. An increased specific capacitance of HMT assisted materials (202 F/g) compared with pristine BiPO4 (89 F/g) at 5 mA/cm2 was observed upon morphological variation due to HMT addition.

Short-lived isomers in 192Po and 194Po

NASA Astrophysics Data System (ADS)

Andel, B.; Andreyev, A. N.; Antalic, S.; Heßberger, F. P.; Ackermann, D.; Hofmann, S.; Huyse, M.; Kalaninová, Z.; Kindler, B.; Kojouharov, I.; Kuusiniemi, P.; Lommel, B.; Nishio, K.; Page, R. D.; Sulignano, B.; Van Duppen, P.

2016-06-01

Isomeric states in 194Po and 192Po were studied at the velocity filter SHIP. The isotopes were produced in the fusion-evaporation reactions 141Pr(56Fe, p 2 n )194Po and 144Sm(51V, p 2 n )192Po . Several new γ -ray transitions were attributed to the isomers and γ -γ coincidences for both isomers were studied for the first time. The 459-keV transition earlier, tentatively proposed as de-exciting the isomeric level in 194Po, was replaced by a new 248-keV transition, and the spin of this isomer was reassigned from (11-) to (10-). The de-excitation of the (11-) isomeric level in 192Po by the 154-keV transition was confirmed and a parallel de-excitation by a 733-keV (E 3 ) transition to (8+) level of the ground-state band was suggested. Moreover, side feeding to the (4+) level of the ground-state band was proposed. The paper also discusses strengths of transitions de-exciting 11- isomers in neighboring Po and Pb isotopes.

Synthesis and Electrochemical Properties of LiFePO4/C for Lithium Ion Batteries.

PubMed

Gao, Hong; Wang, Jiazhao; Yin, Shengyu; Zheng, Hao; Wang, Shengfu; Feng, Chuanqi; Wang, Shiquan

2015-03-01

LiFePO4/C was prepared through a facile rheological phase reaction method by using Fe3(PO4)2, Li3PO4 · 8H2O, and glucose as reactants. The LiFePO4/C samples were characterized by X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis. The electrochemical properties of the samples were investigated. The results show that the LiFePO4/C samples have single-phase olivine-type structure, and their particles feature a spherical shape. The carbon coating on the particles of LiFePO4 is about 1.8% of the LiFePO4/C by weight. The particle size was distributed from 0.2 to 1 µm. The initial discharge capacity of LiFePO4/C reached 154 mA h/g at 0.1 C. The retained discharge capacity of LiFePO4/C was 152.9 mA h g(-1) after 50 cycles. The LiFePO4/C also showed better cycling performance than that of the bare LiPeO4 at a higher charge/discharge rate (1 C). The LIFePO4/C prepared in this way could be a promising cathode material for lithium ion battery application.

[Collation between Za Liao of Qian Jin Yi Fang and Xin Xiu Ben Cao].

PubMed

Liang, Fei; Jiang, Li-Sheng; Li, Jian; Zhang, Wei; Zhang, Rui-Xian

2012-10-01

To analyze specific content of Za Liao of Qian Jin Yi Fang, this essay compares its content with related content of Xin Xiu Ben Cao, finding that Za Liao of Qian Jin Yi Fang is derived from the part of Jin An of Xin Xiu Ben Cao, which complements with herbal chapters from volume II to IV of Qian Jin Yi Fang. The texts in Za Liao can verify and collate part of Jin An, and thereby showing important literature value and great help for further studies on traditional Chinese medicines of Tang dynasty.

Conversational Russian in Russkij Jazyk Za Rubezom

ERIC Educational Resources Information Center

Morgan, Thomas W.

1976-01-01

Reviews materials relating to Russian speech which have appeared in the journal "Russkij Jazyk Za Rubezom" since its first issue in 1967. The articles reviewed are divided into three categories: the stylistics of Russian speech, specific conversation expressions, and methodology. (CLK)

Study on feed forward neural network convex optimization for LiFePO4 battery parameters

NASA Astrophysics Data System (ADS)

Liu, Xuepeng; Zhao, Dongmei

2017-08-01

Based on the modern facility agriculture automatic walking equipment LiFePO4 Battery, the parameter identification of LiFePO4 Battery is analyzed. An improved method for the process model of li battery is proposed, and the on-line estimation algorithm is presented. The parameters of the battery are identified using feed forward network neural convex optimization algorithm.

LiFePO4/C nanocomposites for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Eftekhari, Ali

2017-03-01

LiFePO4, as the most famous member of the family of olivine-type lithium transition metal phosphates, is one of the promising candidates for the cathodes of lithium-ion batteries. However, its battery performance is limited by its low electrical conductivity and slow Li solid-state diffusion. Various methods have been attempted to improve the battery performance of lithium iron phosphate. Among them, compositing the LiFePO4 with carbon nanomaterials seems to be the most promising, as it is facile and efficient. Carbon nanomaterials usually serve as a conductive agent to improve the electrical conductivity while increasing the material porosity in which the solid-state diffusion distances are significantly shortened. Owing to the popularity of various carbonaceous nanomaterials, there is no straightforward line of research for comparing the LiFePO4/C nanocomposites. This review aims to provide a general perspective based on the research achievements reported in the literature. While surveying the research findings reported in the literature, controversial issues are also discussed. The possible contribution of pseudocapacitance as a result of functionalized carbon or LiFePO4 lattice defects is described, since from a practical perspective, a LiFePO4/C electrode can be considered as a supercapacitor at high C rates (with a specific capacitance as large as 200 F g-1). The Li diffusion in LiFePO4 has not been well understood yet; while the Li diffusion within the LiFePO4 lattice seems to be quite fast, the peculiar interfacial electrochemistry of LiFePO4 slows down the diffusion within the entire electrode by a few orders of magnitude.

Three-Dimensional LiMnPO4·Li3V2(PO4)3/C Nanocomposite as a Bicontinuous Cathode for High-Rate and Long-Life Lithium-Ion Batteries.

PubMed

Luo, Yanzhu; Xu, Xu; Zhang, Yuxiang; Pi, Yuqiang; Yan, Mengyu; Wei, Qiulong; Tian, Xiaocong; Mai, Liqiang

2015-08-12

Olivine-type LiMnPO4 has been extensively studied as a high-energy density cathode material for lithium-ion batteries. To improve both the ionic and electronic conductivities of LiMnPO4, a series of carbon-decorated LiMnPO4·Li3V2(PO4)3 nanocomposites are synthesized by a facile sol-gel method combined with the conventional solid-state method. The optimized composite presents a three-dimensional hierarchical structure with active nanoparticles well-embedded in a conductive carbon matrix. The combination of the nanoscale carbon coating and the microscale carbon network could provide a more active site for electrochemical reaction, as well as a highly conductive network for both electron and lithium-ion transportation. When cycled at 20 C, an initial specific capacity of 103 mA h g(-1) can be obtained and the capacity retention reaches 68% after 3000 cycles, corresponding to a capacity fading of 0.013% per cycle. The stable capacity and excellent rate capability make this carbon-decorated LiMnPO4·Li3V2(PO4)3 nanocomposite a promising cathode for lithium-ion batteries.

Dynamic PROOF clusters with PoD: architecture and user experience

NASA Astrophysics Data System (ADS)

Manafov, Anar

2011-12-01

PROOF on Demand (PoD) is a tool-set, which sets up a PROOF cluster on any resource management system. PoD is a user oriented product with an easy to use GUI and a command-line interface. It is fully automated. No administrative privileges or special knowledge is required to use it. PoD utilizes a plug-in system, to use different job submission front-ends. The current PoD distribution is shipped with LSF, Torque (PBS), Grid Engine, Condor, gLite, and SSH plug-ins. The product is to be extended. We therefore plan to implement a plug-in for AliEn Grid as well. Recently developed algorithms made it possible to efficiently maintain two types of connections: packet-forwarding and native PROOF connections. This helps to properly handle most kinds of workers, with and without firewalls. PoD maintains the PROOF environment automatically and, for example, prevents resource misusage in case when workers idle for too long. As PoD matures as a product and provides more plug-ins, it's used as a standard for setting up dynamic PROOF clusters in many different institutions. The GSI Analysis Facility (GSIAF) is in production since 2007. The static PROOF cluster has been phased out end of 2009. GSIAF is now completely based on PoD. Users create private dynamic PROOF clusters on the general purpose batch farm. This provides an easier resource sharing between interactive local batch and Grid usage. The main user communities are FAIR and ALICE.

Z-scheme Ag3PO4/POM/GO heterojunction with enhanced photocatalytic performance for degradation and water splitting.

PubMed

Liu, Guodong; Zhao, Xinfu; Zhang, Jian; Liu, Shaojie; Sha, Jingquan

2018-05-01

To develop solar light-driven photocatalysts with high activity and structural stability, Ag3PO4/POM/GO heterojunction has been successfully prepared by a facile method at room temperature. Ag3PO4/POM/GO shows remarkably enhanced activity and stability for photocatalytic degradation and H2 production from water-splitting under simulated solar light. The degradation rate of Ag3PO4/POM/GO is 1.8 times and 1.2 times those of Ag3PO4 and Ag3PO4/POMs, respectively. H2 production using Ag3PO4/POM/GO is 2.0 times that of Ag3PO4/GO. The enhanced photocatalytic performance of Ag3PO4/POM/GO is attributed to the increased surface area, electronegativity and structure stability. The Z-scheme system of Ag3PO4/POM/GO effectively promotes charge separation, resulting in enhanced photocatalytic performance under simulated solar light.

Sedimentation survey of Lago Loíza, Trujillo Alto, Puerto Rico, July 2009

USGS Publications Warehouse

Soler-López, Luis R.; Licha-Soler, N.A.

2014-01-01

Lago Loíza is a reservoir formed at the confluence of Río Gurabo and Río Grande de Loíza in the municipality of Trujillo Alto in central Puerto Rico, about 10 kilometers (km) north of the town of Caguas, about 9 km northwest of Gurabo, and about 3 km south of Trujillo Alto (fig. 1). The Carraizo Dam is owned and operated by the Puerto Rico Aqueduct and Sewer Authority (PRASA), and was constructed in 1953 as a water-supply reservoir for the San Juan Metropolitan area. The dam is a concrete gravity structure that is located in a shallow valley and has a gently sloping left abutment and steep right abutment. Non-overflow sections flank the spillway section. Waterways include an intake structure for the pumping station and power plant, sluiceways, a trash sluice, and a spillway. The reservoir was built to provide a storage capacity of 26.8 million cubic meters (Mm3) of water at the maximum pool elevation of 41.14 meters (m) above mean sea level (msl) for the Sergio Cuevas Filtration Plant that serves the San Juan metropolitan area. The reservoir has a drainage area of 538 square kilometers (km2) and receives an annual mean rainfall that ranges from 1,600 to 5,000 millimeters per year (mm/yr). The principal streams that drain into Lago Loíza are the Río Grande de Loíza, Río Gurabo, and Río Cañas. Two other rivers, the Río Bairoa and Río Cagüitas, discharge into the Río Grande de Loíza just before it enters the reservoir. The combined mean annual runoff of the Río Grande de Loíza and the Río Gurabo for the 1960–2009 period of record is 323 Mm3. Flow from these streams constitutes about 89 percent of the total mean annual inflow of 364 Mm3 to the reservoir (U.S. Geological Survey, 2009). Detailed information about Lago Loíza reservoir structures, historical sediment accumulation, and a dredge conducted in 1999 are available in Soler-López and Gómez-Gómez (2005). During July 8–15, 2009, the U.S. Geological Survey (USGS) Caribbean Water Science

Oblique view of Facility No. S362 showing the profile of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Oblique view of Facility No. S362 showing the profile of the ramp. Note the mooring cleat fixed to the top edge of the curb at left - U.S. Naval Base, Pearl Harbor, Seaplane Ramps - World War II Type, Southwest and west shore of Ford Island, near Wasp Boulevard, Pearl City, Honolulu County, HI

Lidar sprectroscopy instrument (LISSI): An infrastructure facility for chemical aerosol profiling at the University of Hertfordshire

NASA Astrophysics Data System (ADS)

Tesche, Matthias; Tatarov, Boyan; Noh, Youngmin; Müller, Detlef

2018-04-01

The lidar development at the University of Hertfordshire explores the feasibility of using Raman backscattering for chemical aerosol profiling. This paper provides an overview of the new facility. A high-power Nd:YAG/OPO setup is used to excite Raman backscattering at a wide range of wavelengths. The receiver combines a spectrometer with a 32-channel detector or an ICCD camera to resolve Raman signals of various chemical compounds. The new facility will open new avenues for chemical profiling of aerosol pollution from measurements of Raman scattering by selected chemical compounds, provide data that allow to close the gap between optical and microphysical aerosol profiling with lidar and enables connecting lidar measurements to parameters used in atmospheric modelling.

Post-test analysis of PIPER-ONE PO-IC-2 experiment by RELAP5/MOD3 codes

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

Bovalini, R.; D`Auria, F.; Galassi, G.M.

1996-11-01

RELAP5/MOD3.1 was applied to the PO-IC-2 experiment performed in PIPER-ONE facility, which has been modified to reproduce typical isolation condenser thermal-hydraulic conditions. RELAP5 is a well known code widely used at the University of Pisa during the past seven years. RELAP5/MOD3.1 was the latest version of the code made available by the Idaho National Engineering Laboratory at the time of the reported study. PIPER-ONE is an experimental facility simulating a General Electric BWR-6 with volume and height scaling ratios of 1/2,200 and 1./1, respectively. In the frame of the present activity a once-through heat exchanger immersed in a pool ofmore » ambient temperature water, installed approximately 10 m above the core, was utilized to reproduce qualitatively the phenomenologies expected for the Isolation Condenser in the simplified BWR (SBWR). The PO-IC-2 experiment is the flood up of the PO-SD-8 and has been designed to solve some of the problems encountered in the analysis of the PO-SD-8 experiment. A very wide analysis is presented hereafter including the use of different code versions.« less

ZaP-HD: High Energy Density Z-Pinch Plasmas using Sheared Flow Stabilization

NASA Astrophysics Data System (ADS)

Golingo, R. P.; Shumlak, U.; Nelson, B. A.; Claveau, E. L.; Doty, S. A.; Forbes, E. G.; Hughes, M. C.; Kim, B.; Ross, M. P.; Weed, J. R.

2015-11-01

The ZaP-HD flow Z-pinch project investigates scaling the flow Z-pinch to High Energy Density Plasma, HEDP, conditions by using sheared flow stabilization. ZaP used a single power supply to produce 100 cm long Z-pinches that were quiescent for many radial Alfven times and axial flow-through times. The flow Z-pinch concept provides an approach to achieve HED plasmas, which are dimensionally large and persist for extended durations. The ZaP-HD device replaces the single power supply from ZaP with two separate power supplies to independently control the plasma flow and current in the Z-pinch. Equilibrium is determined by diagnostic measurements of the density with interferometry and digital holography, the plasma flow and temperature with passive spectroscopy, the magnetic field with surface magnetic probes, and plasma emission with optical imaging. The diagnostics fully characterize the plasma from its initiation in the coaxial accelerator, through the pinch, and exhaust from the assembly region. The plasma evolution is modeled with high resolution codes: Mach2, WARPX, and NIMROD. Experimental results and scaling analyses are presented. This work is supported by grants from the U.S. Department of Energy and the U.S. National Nuclear Security Administration.

[The life and work of Zaíra Cintra Vidal].

PubMed

Lopes, G T; Caldas, N P; Lima, T C; Martingil, I C

2001-01-01

This is a social-historical study that aims at describing the trajectory of Zaíra Cintra Vidal, her participation in the Nursing School Rachel Haddock Lobo and in the Brazilian Association of Nursing (ABEn). The study is based on the concepts of symbolic power, habitus and symbolic struggle of Pierre Bourdieu. The primary sources are documents which were collected in the Documentation Center of Escola de Enfermagem Ana Neri (EEAN--Ana Neri School of Nursing) in the Federeal University of Rio de Janeiro (UFRJ) and at the Memory Center of the Faculty of Nursing (FENF) in the State University of Rio de Janeiro (UERJ). The data was collected between August 2000 and April 2001 by means of document analysis script. The outcomes showed that Zaíra Cintra Vidal was born on 5 May 1903; graduated from the Nursing School of the National Public Health Department in 1926; studied and post-graduated in the United States from 1927 until 1929 and returned to Brazil in 1943. Zaíra Cintra Vidal was the founder of the Nursing School Rachel Haddock Lobo and was its first director for nine years. She also and took part in ABEn's Direction Board and in the Revista Anais de Enfermagem (Nursing Magazine).

Design of LaPO4:Nd3+ materials by using ionic liquids

NASA Astrophysics Data System (ADS)

Cybinska, J.; Guzik, M.; Lorbeer, C.; Zych, E.; Guyot, Y.; Boulon, G.; Mudring, A.-V.

2017-01-01

Monoclinic monazite-type Nd3+-doped lanthanum orthophosphate (LaPO4:Nd3+) nanoparticles were prepared by microwave treatment of simple lanthanide precursors such as Nd(OAc)3•xH2O, OAc = acetate) with task-specific dihydrogen phosphate ionic liquids (ILs) 1-butyl-1-methylpyrrolidinium dihydrogenphosphate- BmPyrH2PO4 (IL1) and 2-hydroxyethyl-N,N,N-trimethylammonium, [choline][H2PO4] (IL2) as the reaction medium, reactant and in-situ nanoparticle stabilizer. This synthesis route possesses many advantages as it is a fast and facile preparation method of the desired phosphate nanomaterials without the necessity for post-reaction heat treatment to obtain the anhydrous high temperature monazite phosphate phase. The nano-sized phosphors Nd3+:LaPO4 were carefully analyzed by the powder X-ray diffraction, electron microscopy and spectroscopic techniques taking advantage of the Nd3+ spectroscopic probe to analyze in detail the structural properties. Applied high resolution low temperature absorption and emission techniques allowed to complete the structural information unavailable from the XRD powder patterns. A clear influence of the used task-specific dihydrogen phosphate ILs on the structure, morphology, luminescence intensity and lifetimes of the obtained Nd3+:LaPO4 was found. It is worth noting that the Nd3+ luminescence in LaPO4 has never been reported up to now.

Effects on asylum seekers of ill treatment in Zaïre.

PubMed Central

Peel, M. R.

1996-01-01

To describe the health effects of the political system in Zaïre on asylum seekers seen at the Medical Foundation for the Care of Victims of Torture a retrospective study was performed of the records of 92 asylum seekers from Zaïre who were seen for medical reports at the medical foundation in 1993 and 1994. Eighty one had been imprisoned; the others had been severely treated at home by the security services. Sixty six had been detained for up to one year. Prison conditions were invariably unsanitary, and food of poor quality when provided. All had been beaten on arrest, and all but two had been beaten repeatedly in prison. Nearly all the women and some of the men described sexual abuse. Almost all left prison through bribery or because a guard had a similar background. Seventy two asylum seekers had scarring, consider to be consistent with the history, and 70 were considered to have suffered persistent psychological damage. Asylum seekers from Zaïre will have health effects from experiences unimaginable to the ordinary Briton. An understanding of the background will help clinicians manage them. PMID:8611788

Effects on asylum seekers of ill treatment in Zaïre.

PubMed

Peel, M R

1996-02-03

To describe the health effects of the political system in Zaïre on asylum seekers seen at the Medical Foundation for the Care of Victims of Torture a retrospective study was performed of the records of 92 asylum seekers from Zaïre who were seen for medical reports at the medical foundation in 1993 and 1994. Eighty one had been imprisoned; the others had been severely treated at home by the security services. Sixty six had been detained for up to one year. Prison conditions were invariably unsanitary, and food of poor quality when provided. All had been beaten on arrest, and all but two had been beaten repeatedly in prison. Nearly all the women and some of the men described sexual abuse. Almost all left prison through bribery or because a guard had a similar background. Seventy two asylum seekers had scarring, consider to be consistent with the history, and 70 were considered to have suffered persistent psychological damage. Asylum seekers from Zaïre will have health effects from experiences unimaginable to the ordinary Briton. An understanding of the background will help clinicians manage them.

High-pressure structural and vibrational properties of monazite-type BiPO4, LaPO4, CePO4, and PrPO4

NASA Astrophysics Data System (ADS)

Errandonea, D.; Gomis, O.; Rodríguez-Hernández, P.; Muñoz, A.; Ruiz-Fuertes, J.; Gupta, M.; Achary, S. N.; Hirsch, A.; Manjon, F. J.; Peters, L.; Roth, G.; Tyagi, A. K.; Bettinelli, M.

2018-02-01

Monazite-type BiPO4, LaPO4, CePO4, and PrPO4 have been studied under high pressure by ab initio simulations and Raman spectroscopy measurements in the pressure range of stability of the monazite structure. A good agreement between experimental and theoretical Raman-active mode frequencies and pressure coefficients has been found which has allowed us to discuss the nature of the Raman-active modes. Besides, calculations have provided us with information on how the crystal structure is modified by pressure. This information has allowed us to determine the equation of state and the isothermal compressibility tensor of the four studied compounds. In addition, the information obtained on the polyhedral compressibility has been used to explain the anisotropic axial compressibility and the bulk compressibility of monazite phosphates. Finally, we have carried out a systematic discussion on the high-pressure behavior of the four studied phosphates in comparison to results of previous studies.

Synthesis of g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} heterojunction with enhanced photocatalytic performance

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

He, Peizhi; Song, Limin; Zhang, Shujuan, E-mail: songlmnk@sohu.com

2014-03-01

Graphical abstract: g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} heterojunction photocatalyst with visible-light response was prepared by a facile coprecipitation method. The results show that g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} possesses a much higher activity for the decomposition of RhB than that of the pure Ag{sub 3}PO{sub 4} particles. The most mechanism is that g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} heterojunction photocatalyst can efficiently separate the photogenerated electron–hole pairs, enhancing the photocatalytic activity of g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} composites. - Highlights: • g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} heterojunction showed much higher activity than that of Ag{sub 3}PO{sub 4}. • The high activitymore » could be attributed to g-C{sub 3}N{sub 4} for modifying Ag{sub 3}PO{sub 4}. • More ·OH radicals may be significant reason to improve Ag{sub 3}PO{sub 4} activity. - Abstract: g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} heterojunction photocatalyst with visible-light response was prepared by a facile coprecipitation method. The photocatalysts were characterized by X-ray powder diffraction, transmission electron microscopy, UV–vis absorption spectroscopy and Fourier transform infrared spectroscopy. The photocatalytic activities of the obtained samples were tested by using Rhodamine B (RhB) as the degradation target under visible light irradiation. g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} decomposed RhB more effectively than the pure Ag{sub 3}PO{sub 4} particles did, and 2 wt.% g-C{sub 3}N{sub 4} had the highest activity. Furthermore, 2 wt.% g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} degraded high-concentration RhB more potently than unmodified Ag{sub 3}PO{sub 4} did, probably because g-C{sub 3}N{sub 4}/Ag{sub 3}PO{sub 4} heterojunction photocatalyst enhanced the photocatalytic activity by efficiently separating the photogenerated electron–hole pairs.« less

New nematotoxic indoloditerpenoid produced by Gymnoascus reessii za-130

USDA-ARS?s Scientific Manuscript database

Chemical investigation of the fungal strain Gymnoascus reessii za-130, which was previously isolated from the rhizosphere of tomato plants infected by the root-knot nematode Meloidogyne incognita, led to the isolation and identification of a new indoloditerpenoid metabolite designated gymnoascole ac...

One-pot, facile fabrication of a Ag3PO4-based ternary Z-scheme photocatalyst with excellent visible-light photoactivity and anti-photocorrosion performance

NASA Astrophysics Data System (ADS)

Xie, Mingyuan; Zhang, Tailiang

2018-04-01

Ag3PO4 can-not be widely used as an efficient photocatalyst in practical applications because of its susceptibility to photocorrosion. In this study, a novel, ternary Z-scheme photocatalytic system containing graphene oxide (GO), Ag3PO4 and SnS2 was fabricated by a one-pot, mild, in-situ precipitation method successfully. Using Rhodamine B (RhB) as the target of elimination, GO/Ag3PO4/SnS2 exhibited outstanding photocatalytic and anti-photocorrosion properties compared with those of Ag3PO4, Ag3PO4/SnS2 and GO/Ag3PO4. RhB was thoroughly degraded over the optimized GO/Ag3PO4/SnS2 nanocomposite after only 15 min under visible-light irradiation; this result is approximately 2.14, 3.33 and 5.83 times faster than that of GO/Ag3PO4, Ag3PO4/SnS2 and Ag3PO4, respectively. After three reuses, the photocatalytic activity of the ternary composite slightly decreased but remained 2.36, 4.08 and 12.70 times higher than those of the reused GO/Ag3PO4, Ag3PO4/SnS2 and Ag3PO4, respectively. In this system, the efficient separation and migration of the photoinduced current carriers in Ag3PO4 was realized through a double Z-scheme electron-transfer mechanism in which the GO nanosheets acted as the photocatalyst and electron mediator, thereby enhancing the photoactivity and stability of Ag3PO4. The present study provides a new perspective for enhancing photocatalytic and anti-photocorrosion performances in perishable photocatalysts for organic sewage and other environmental contamination treatments.

Evolution of LiFePO4 thin films interphase with electrolyte

NASA Astrophysics Data System (ADS)

Dupré, N.; Cuisinier, M.; Zheng, Y.; Fernandez, V.; Hamon, J.; Hirayama, M.; Kanno, R.; Guyomard, D.

2018-04-01

Many parameters may control the growth and the characteristics of the interphase, such as surface structure and morphology, structural defects, grain boundaries, surface reactions, etc. However, polycrystalline surfaces contain these parameters simultaneously, resulting in a quite complicated system to study. Working with model electrode surfaces using crystallographically oriented crystalline thin films appears as a novel and unique approach to understand contributions of preferential orientation and rugosity of the surface. In order to rebuild the interphase architecture along electrochemical cycling, LiFePO4 epitaxial films offering ideal 2D (100) interfaces are here investigated through the use of non-destructive depth profiling by Angular Resolved X-ray Photoelectron Spectroscopy (ARXPS). The composition and structure of the interphase is then monitored upon cycling for samples stopped at the end of charge and discharge for various numbers of cycles, and discussed in the light of combined XPS and X-ray reflectivity (XRR) measurements. Such an approach allows describing the interphase evolution on a specific model LiFePO4 crystallographic orientation and helps understanding the nature and evolution of the LiFePO4/electrolyte interphase forming on the surface of LiFePO4 poly-crystalline powder.

Morbidity profile of elderly outpatients attending selected sub-district Siddha health facilities in Tamil Nadu, India

PubMed Central

Selvaraj, Kalaiselvi; Srinivasan, Manikandan; Duraisamy, Venkatachalam; Ramaswamy, Gomathi; Venugopal, Vinayagamurthy; Chinnakali, Palanivel

2016-01-01

Background: Recently, under National Health Mission alternate systems of Medicine are mainstreamed in public health care system. Effective action plan generation, logistic arrangement and roll out of these alternate systems of Medicine needs understanding on profile of morbidities among attendees who come to these facilities. Objectives: This study was planned to report profile of morbidities, age and sex differentials in specific morbidities among geriatric attendees in secondary level siddha health facilities. Materials and Methods: A facility based cross sectional study was conducted among elderly person (60 years and above) attending Siddha outpatient department (OPD) from two of the randomly selected sub district level siddha facilities in Erode district, Tamil Nadu, India. Information on socio-demographic variables like age, gender, education and clinical profile (diagnosis) were collected from records already maintained in the siddha OPD. Morbidities were summarized in terms of proportions based on age and gender. Age and sex specific differentials on specific morbidities were compared using ‘z’ test. Results: Of 2710 patients who visited these two siddha facilities during the reference period, 763 (28.1%) patients were elderly. Arthritis (45.2%), neuritis (8.8%), diabetes (6.6%), bronchial asthma (5.2%), hemiplegia (3.7%) were the top five morbidities diagnosed and treated among elderly attending the siddha OPD. There was a predilection towards elderly male for morbidities such as bronchial asthma and hemiplegia compared to elderly female. Similarly, higher proportions of lumbar spondylosis, hypertension and fungal skin diseases were reported among aged 80 years or more compared to elderly aged 60-79 years. Conclusion: Elderly constitute more than one fourth of outpatients load from siddha health facilities. Degenerative diseases like arthritis and non-communicable diseases were the common morbidities in this age group. Geriatric clinics and mobile

Morphology and conductivity study of solid electrolyte Li{sub 3}PO{sub 4}

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

Prayogi, Lugas Dwi, E-mail: ldprayodi@gmail.com; Faisal, Muhamad; Kartini, Evvy, E-mail: kartini@batan.go.id

2016-02-08

The comparison between two different methods of synthesize of solid electrolyte Li{sub 3}PO{sub 4} as precursor material for developing lithium ion battery, has been performed. The first method is to synthesize Li{sub 3}PO{sub 4} prepared by wet chemical reaction from LiOH and H{sub 3}PO{sub 4} which provide facile, abundant available resource, low cost, and low toxicity. The second method is solid state reaction prepared by Li{sub 2}CO{sub 3} and NH{sub 4}H{sub 2}PO{sub 4.} In addition, the possible morphology identification of comparison between two different methods will also be discussed. The composition, morphology, and additional identification phase and another compound ofmore » Li{sub 3}PO{sub 4} powder products from two different reaction are characterized by SEM, EDS, and EIS. The Li{sub 3}PO{sub 4} powder produced from wet reaction and solid state reaction have an average diameter of 0.834 – 7.81 µm and 2.15 – 17.3 µm, respectively. The density of Li{sub 3}PO{sub 4} prepared by wet chemical reaction is 2.238 gr/cm{sup 3}, little bit lower than the sample prepared by solid state reaction which density is 2.3560 gr/cm{sup 3}. The EIS measurement result shows that the conductivity of Li{sub 3}PO{sub 4} is 1.7 x 10{sup −9} S.cm{sup −1} for wet chemical reaction and 1.8 x 10{sup −10} S.cm{sup −1} for solid state reaction. The conductivity of Li{sub 3}PO{sub 4} is not quite different between those two samples even though they were prepared by different method of synthesize.« less

Scintillation properties of rare-earth doped NaPO3-Al(PO3)3 glasses

NASA Astrophysics Data System (ADS)

Kuro, Tomoaki; Okada, Go; Kawaguchi, Noriaki; Fujimoto, Yutaka; Masai, Hirokazu; Yanagida, Takayuki

2016-12-01

We systematically investigated photoluminescence (PL), scintillation and dosimeter properties of rare-earth (RE) doped NaPO3-Al(PO3)3 (NAP) glasses. The NAP glasses doped with a series of RE ions (La-Yb, except Pm) with a consistent concentration (0.3 wt%) were prepared by the conventional melt-quenching method. The PL and scintillation decay time profiles showed fast (ns) and slow (μs or ms) components: the fast components from 15 to 100 ns were due to the host or 5d-4f transition emission, and the slow components from 15 μs to 5 ms were due to the 4f-4f transitions of RE. The thermally stimulated luminescence (TSL) was evaluated as a dosimeter property, and glow peaks appeared around 400 °C in all the samples. The TSL dose response function was examined in the dose range from 10 mGy to 10 Gy. Among the samples tested, Nd and Tb doped glasses showed higher signal by at least one order of magnitude than those of non-doped and other RE-doped samples. Over the dose range tested, the TSL signals are linearly related with the incident X-ray dose, showing a potential for practical applications.

First Reprocessing of Southern Hemisphere ADditional OZonesondes Profile Records: 3. Uncertainty in Ozone Profile and Total Column

NASA Astrophysics Data System (ADS)

Witte, Jacquelyn C.; Thompson, Anne M.; Smit, Herman G. J.; Vömel, Holger; Posny, Françoise; Stübi, Rene

2018-03-01

Reprocessed ozonesonde data from eight SHADOZ (Southern Hemisphere ADditional OZonesondes) sites have been used to derive the first analysis of uncertainty estimates for both profile and total column ozone (TCO). The ozone uncertainty is a composite of the uncertainties of the individual terms in the ozone partial pressure (PO3) equation, those being the ozone sensor current, background current, internal pump temperature, pump efficiency factors, conversion efficiency, and flow rate. Overall, PO3 uncertainties (ΔPO3) are within 15% and peak around the tropopause (15 ± 3 km) where ozone is a minimum and ΔPO3 approaches the measured signal. The uncertainty in the background and sensor currents dominates the overall ΔPO3 in the troposphere including the tropopause region, while the uncertainties in the conversion efficiency and flow rate dominate in the stratosphere. Seasonally, ΔPO3 is generally a maximum in the March-May, with the exception of SHADOZ sites in Asia, for which the highest ΔPO3 occurs in September-February. As a first approach, we calculate sonde TCO uncertainty (ΔTCO) by integrating the profile ΔPO3 and adding the ozone residual uncertainty, derived from the McPeters and Labow (2012, doi:10.1029/2011JD017006) 1σ ozone mixing ratios. Overall, ΔTCO are within ±15 Dobson units (DU), representing 5-6% of the TCO. Total Ozone Mapping Spectrometer and Ozone Monitoring Instrument (TOMS and OMI) satellite overpasses are generally within the sonde ΔTCO. However, there is a discontinuity between TOMS v8.6 (1998 to September 2004) and OMI (October 2004-2016) TCO on the order of 10 DU that accounts for the significant 16 DU overall difference observed between sonde and TOMS. By comparison, the sonde-OMI absolute difference for the eight stations is only 4 DU.

Levels and transfer of 210Po and 210Pb in Nordic terrestrial ecosystems.

PubMed

Brown, J E; Gjelsvik, R; Roos, P; Kålås, J A; Outola, I; Holm, E

2011-05-01

Recent developments regarding environmental impact assessment methodologies for radioactivity have precipitated the need for information on levels of naturally occurring radionuclides within and transfer to wild flora and fauna. The objectives of this study were therefore to determine activity concentrations of the main dose forming radionuclides (210)Po and (210)Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell exhibited an approximately exponential fall in (210)Pb activity concentrations from elevated levels in humus/surface soils to "supported" levels at depth. Activity concentrations of (210)Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg(-1)d.w. and in plants and lichens between 20 and 138 Bq kg(-1)d.w. The results showed that soil humus is an important reservoir for (210)Po and (210)Pb and that fauna in close contact with this media may also exhibit elevated levels of (210)Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations of (210)Po in invertebrates and vertebrates. Biokinetic models may provide a tool to explore in a more mechanistic way the behaviour of (210)Po in this system. Copyright © 2010 Elsevier Ltd. All rights reserved.

Unusually large sup 210 Po deficiencies relative to sup 210 Pb in the Kuroshio Current of the East China and Philippine seas

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

Yoshiyuki Nozaki; Naoko Ikuta; Mayumi Yashima

1990-04-15

Three vertical water profiles of {sup 210}Pb and {sup 210}Po have been measured in the East China and Philippine seas. All the profiles show a large {sup 210}Po deficiency of {approximately} 8 dpm/cm{sup 2} relative to {sup 210}Pb in the top {approximately} 1,000 m of the water column. Based on the {sup 210}Po deficiency, the steady state flux for {sup 210}Po removal from the surface water is estimated to be 14 dpm cm{sup {minus}2}/yr. The {sup 210}Po/{sup 210}Pb ratio of sinking particles will be too high unless an additional source of {sup 210}Pb into the surface is accounted for. Thusmore » the large {sup 210}Po deficit is probably caused by the increased atmospheric input of {sup 210}Pb without any significant {sup 210}Po, which is focused in the Kuroshio region by isopycnal transport, and the preferential scavenging of {sup 210}Po relative to {sup 210}Pb by settling particles. The transient model calculations indicate that the model can account for the observed high excess {sup 210}Pb inventory and large {sup 210}Po deficiency in the water column if focusing of atmospherically derived {sup 210}Pb in the Kuroshio water is a factor of 2-3 more than the local input. Such lateral redistribution by the western North Pacific gyre circulation is not inconsistent with the deeper penetration and the high water column inventories of anthropogenic substances observed in this region.« less

Enhanced photocatalytic activity and structural stability by hybridizing Ag3PO4 nanospheres with graphene oxide sheets.

PubMed

Liang, Qinghua; Shi, Yao; Ma, Wangjing; Li, Zhi; Yang, Xinmin

2012-12-05

Graphene oxide (GO)-Ag(3)PO(4) nanocomposites synthesized through a facile solution approach via electrostatic interaction were investigated as excellent photocatalysts for the degradation of rhodamine B (RhB) under visible light irradiation. SEM and TEM observations indicate that Ag(3)PO(4) nanospheres of ~120 nm in diameter were well dispersed and anchored onto the exfoliated GO sheets. The characterizations of FTIR and Raman demonstrated the existence of strong charge interactions between GO sheets and Ag(3)PO(4) nanospheres. As compared to Ag(3)PO(4) nanospheres alone, the attachments of GO sheets led to a band gap narrowing (2.10 eV) and a strong absorbance in the near infrared region (NIR). The photoluminescence (PL) analysis indicates a more efficient separation of electron-hole pairs in the GO-Ag(3)PO(4) nanocomposites. Notably, the incorporation of GO sheets not only significantly enhances the photocatalytic activity but also improves the structural stability of Ag(3)PO(4). The positive synergistic effects between Ag(3)PO(4) nanospheres and GO sheets are proposed to contribute to the improved photocatalytic properties. A possible photocatalytic mechanism of the GO-Ag(3)PO(4) nanocomposites was assumed as well. The integration of these advantages enables such GO-Ag(3)PO(4) hybrid material to be a nice photocatalyst for broad applications in a sewage treatment system.

Analysis of Ozone And CO2 Profiles Measured At A Diary Facility

NASA Astrophysics Data System (ADS)

Ogunjemiyo, S. O.; Hasson, A. S.; Ashkan, S.; Steele, J.; Shelton, T.

2015-12-01

Ozone and carbon dioxide are both greenhouse gasses in the planetary boundary layer. Ozone is a harmful secondary pollutant in the troposphere produced mostly during the day when there is a photochemical reaction in which primary pollutant precursors such as nitrous oxide (NOx) or volatile organic compounds (VOC's) mix with sunlight. As with most pollutants in the lower troposphere, both ozone and carbon dioxide vary in spatial and temporal scale depending on sources of pollution, environmental conditions and the boundary layer dynamics. Among the several factors that influence ozone variation, the seasonal changes in meteorological parameters and availability of ozone precursors are crucial because they control ozone formation and decay. Understanding how the difference in emission sources affect vertical transport of ozone and carbon dioxide is considered crucial to the improvement of their regional inventory sources. The purpose of this study is to characterize vertical transport of ozone and carbon at a diary facility. The study was conducted in the summer of 2011 and 2012 at a commercial dairy facility in Central California and involved profile measurements of ozone and CO2 using electrochemical ozonesondes, meteorological sondes and CO2 probe tethered to a 9 cubic meters helium balloon. On each day of the data collection, multiple balloon launches were made over a period representing different stages of the boundary layer development. The results show ozone and CO2 profiles display different characteristics. Regardless of the time of the day, the CO2 concentration decreases with height with a sharp gradient near the surface that is strengthened by a stable atmospheric condition, a feature suggesting the surface as the source. On the other hand, ozone profiles show greater link to the evolution of the lower boundary layer. Ozone profiles display unique features indicating ozone destruction near the surface. This unusual near the surface, observed even in the

Synthesis and luminescent properties of uniform monodisperse LuPO4:Eu3+/Tb3+ hollow microspheres

PubMed Central

Gao, Yu; Yu, He; Shi, Cheng; Zhao, Guiyan; Bi, Yanfeng; Ding, Fu; Sun, Yaguang; Xu, Zhenhe

2017-01-01

Uniform monodisperse LuPO4:Eu3+/Tb3+ hollow microspheres with diameters of about 2.4 µm have been successfully synthesized by the combination of a facile homogeneous precipitation approach, an ion-exchange process and a calcination process. The possible formation mechanism for the hollow microspheres was presented. Furthermore, the luminescence properties revealed that the LuPO4:Eu3+ and LuPO4:Tb3+ phosphors show strong orange-red and green emissions under ultraviolet excitation, respectively, which endows this material with potential application in many fields, such as light display systems and optoelectronic devices. Since the synthetic process can be carried out at mild conditions, it should be straightforward to scale up the entire process for large-scale production of the LuPO4 hollow microspheres. Furthermore, this general and simple method may be of much significance in the synthesis of many other inorganic materials. PMID:29308268

Synthesis and luminescent properties of uniform monodisperse LuPO4:Eu3+/Tb3+ hollow microspheres

NASA Astrophysics Data System (ADS)

Gao, Yu; Yu, He; Shi, Cheng; Zhao, Guiyan; Bi, Yanfeng; Xu, Baotong; Ding, Fu; Sun, Yaguang; Xu, Zhenhe

2017-12-01

Uniform monodisperse LuPO4:Eu3+/Tb3+ hollow microspheres with diameters of about 2.4 µm have been successfully synthesized by the combination of a facile homogeneous precipitation approach, an ion-exchange process and a calcination process. The possible formation mechanism for the hollow microspheres was presented. Furthermore, the luminescence properties revealed that the LuPO4:Eu3+ and LuPO4:Tb3+ phosphors show strong orange-red and green emissions under ultraviolet excitation, respectively, which endows this material with potential application in many fields, such as light display systems and optoelectronic devices. Since the synthetic process can be carried out at mild conditions, it should be straightforward to scale up the entire process for large-scale production of the LuPO4 hollow microspheres. Furthermore, this general and simple method may be of much significance in the synthesis of many other inorganic materials.

Enhancement of the Rate Capability of LiFePO4 by a New Highly Graphitic Carbon-Coating Method.

PubMed

Song, Jianjun; Sun, Bing; Liu, Hao; Ma, Zhipeng; Chen, Zhouhao; Shao, Guangjie; Wang, Guoxiu

2016-06-22

Low lithium ion diffusivity and poor electronic conductivity are two major drawbacks for the wide application of LiFePO4 in high-power lithium ion batteries. In this work, we report a facile and efficient carbon-coating method to prepare LiFePO4/graphitic carbon composites by in situ carbonization of perylene-3,4,9,10-tetracarboxylic dianhydride during calcination. Perylene-3,4,9,10-tetracarboxylic dianhydride containing naphthalene rings can be easily converted to highly graphitic carbon during thermal treatment. The ultrathin layer of highly graphitic carbon coating drastically increased the electronic conductivity of LiFePO4. The short pathway along the [010] direction of LiFePO4 nanoplates could decrease the Li(+) ion diffusion path. In favor of the high electronic conductivity and short lithium ion diffusion distance, the LiFePO4/graphitic carbon composites exhibit an excellent cycling stability at high current rates at room temperature and superior performance at low temperature (-20 °C).

Microwave synthesis of molybdenum doped LiFePO4/C and its electrochemical studies.

PubMed

Naik, Amol; P, Sajan C

2016-05-10

A Mo-doped LiFePO4 composite was prepared successfully from an iron carbonyl complex by adopting a facile and rapid microwave assisted solid state method. The evolution of gases from the iron precursor produces a highly porous product. The formation and substitution of Mo in LiFePO4 were confirmed by X-ray diffraction; surface analysis was carried out by scanning electron microscopy, field emission scanning electron microscopy, and transmission electron microscopy. The electrochemical properties of the substituted LiFePO4 were examined by cyclic voltammetry, electrochemical impedance spectroscopy and by recording charge-discharge cycles. It was observed that the as prepared composites consisted of a single phase orthorhombic olivine-type structure, where Mo(6+) was successfully introduced into the M2(Fe) sites. Incorporation of supervalent Mo(6+) introduced Li(+) ion vacancies in LiFePO4. The synthesized material facilitated lithium ion diffusion during charging/discharging due to the charge compensation effect and porosity. The battery performance studies showed that LiMo0.05Fe0.095PO4 exhibited a maximum capacity of 169.7 mA h g(-1) at 0.1 C current density, with admirable stability retention. Even at higher current densities, the retention of the specific capacity was exceptional.

Oxygen uptake and local Po2 profiles in submerged larvae of phaeoxantha klugii (Coleoptera: Cicindelidae), as well as their metabolic rate in air.

PubMed

Zerm, M; Zinkler, D; Adis, J

2004-01-01

We studied whether oxygen uptake from the surrounding water might enhance survival in submerged third instar larvae of Phaeoxantha klugii, a tiger beetle from the central Amazonian floodplains. Local oxygen partial pressures (Po(2)) were measured with microcoaxial needle electrodes close to larvae submerged in initially air-saturated still water. The Po(2) profiles showed that the larvae exploit oxygen from the aquatic medium. Metabolism in the air of more or less resting larvae was determined by measuring the rate of CO(2) production (sV dot co2) with an infrared gas analyzer at 29 degrees C. The sV dot co2 was around 1.8 mu L g(-1) min(-1), equivalent to an oxygen consumption rate (sV dot o2) of 1.8-2.6 mu L g(-1) min(-1). Oxygen consumption (V dot o2) of individually submerged larvae measured in closed respiration chambers at 19-10.3 kPa Po(2) (initially air saturated, 29 degrees C) ranged between 0.05 and 0.2 mu L min(-1) and was not correlated with body mass. The sV dot o2 ranged between 0.1 and 0.4 mu L min(-1), that is, 4%-22% of the metabolic rate measured in air. Mean V dot o2 decreased with declining Po(2); however, some individuals showed contrary patterns. V dot o2 was additionally measured in dormant larvae, in larvae submerged for 1-2 d in open water or for 30-49 d within sediment, as well as in larvae exposed to anoxia before the measurements. The range of V dot o2 was similar in all groups, indicating that the larvae exploit oxygen from the water whenever available. Similar V dot o2 across the whole range of body mass investigated (0.31-0.76 g) suggests that oxygen uptake occurs by spiracular uptake. Assuming that larvae survive for some time at rates comparable to depressed metabolic rates reported for other insect species, it can be concluded that oxygen uptake from water can sustain aerobic metabolism even under quite severe hypoxia. It might therefore play an important role for survival during inundation periods.

Cubic KTi2(PO4)3 as electrode materials for sodium-ion batteries.

PubMed

Han, Jin; Xu, Maowen; Niu, Yubin; Jia, Min; Liu, Ting; Li, Chang Ming

2016-12-01

A novel cubic KTi2(PO4)3 is successfully synthesized via a facile hydrothermal method combined with a subsequent annealing treatment and further used as electrode material for sodium-ion batteries for the first time. For comparison, carbon-coated KTi2(PO4)3 obtained by a normal cane sugar-assisted method reveals superior electrochemical performances in sodium-ion battery. Besides of the high coulombic efficiency of nearly 100% after 100 cycles, a stable capacity of 112mAhg(-1) can be achieved at 0.5C after 100 cycles, and still maintains to 105mAhg(-1) after 500 cycles with capacity retention of approximately 90%. Copyright © 2016 Elsevier Inc. All rights reserved.

Facile solvothermal synthesis of NaTi2(PO4)3/C porous plates as electrode materials for high-performance sodium ion batteries

NASA Astrophysics Data System (ADS)

Huang, Zhifeng; Liu, Li; Yi, Lingguang; Xiao, Wei; Li, Min; Zhou, Qian; Guo, Guoxiong; Chen, Xiaoying; Shu, Hongbo; Yang, Xiukang; Wang, Xianyou

2016-09-01

NaTi2(PO4)3/C porous plates have been successfully synthesized via solvothermal approach with ammonia as inductive agent combined in-situ carbon coating. It reveals that the inductive agent plays a critical role in morphology-controllable fabrication. The morphology, structure, and electrochemical properties of NaTi2(PO4)3/C composites with multilayered plates, single-layered plate, porous multilayered plates all have been investigated, which are prepared by using urea, triethylamine, and ammonia, respectively. Among these samples, NaTi2(PO4)3/C porous multilayered plates with ammonia addition exhibit the best electrochemical properties due to their unique mesoporous structure. NaTi2(PO4)3/C porous multilayered plates deliver an initial specific capacity of 125 and 110 mAh g-1 at 0.1 and 1 C, respectively. Furthermore, NaTi2(PO4)3/C porous multilayered plates show a good rate capability, whose capacity and corresponding capacity retention reach 85 mAh g-1 and 82.4%, respectively, after 120 cycles under the high rate of 10 C. The excellent results indicate that the NaTi2(PO4)3/C porous multilayered plates are a promising electrode candidate for sodium ion battery.

Outstanding Li-storage performance of LiFePO4@MWCNTs cathode material with 3D network structure for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Sun, Xiaodong; Zhang, Le

2018-05-01

In this work, the MWCNTs-decorated LiFePO4 microspheres (LiFePO4@MWCNTs) with a 3D network structure have been synthesized by a facile and efficient spray-drying approach followed by solid-state reaction in a reduction atmosphere. In the as-prepared composite, the MWCNTs around LiFePO4 nanoparticles can provide 3D conductive networks which greatly facilitate the transport of Li+-ion and electron during the electrochemical reaction. Compared to the pure LiFePO4 material, the LiFePO4@MWCNTs composite as cathode for lithium-ion batteries exhibits significantly improved Li-storage performance in terms of rate capability and cyclic stability. Therefore, we can speculate that the spray-drying approach is a promising route to prepare the high-performance electrode materials with 3D network structure for electrochemical energy storage.

The Synthesis of LiMnxFe1−xPO4/C Cathode Material through Solvothermal Jointed with Solid-State Reaction

PubMed Central

He, Xiangming; Wang, Jixian; Dai, Zhongjia; Wang, Li; Tian, Guangyu

2016-01-01

LiMnxFe1−xPO4/C material has been synthesized through a facile solid-state reaction under the condition of carbon coating, using solvothermal-prepared LiMnPO4 and LiFePO4 as precursors and sucrose as a carbon resource. XRD and element distribution analysis reveal completed solid-state reaction of precursors. LiMnxFe1−xPO4/C composites inherit the morphology of precursors after heat treatment without obvious agglomeration and size increase. LiMnxFe1−xPO4 solid solution forms at low temperature around 350 °C, and Mn2+/Fe2+ diffuse completely within 1 h at 650 °C. The LiMnxFe1−xPO4/C (x < 0.8) composite exhibits a high-discharge capacity of over 120 mAh·g−1 (500 Wh·kg−1) at low C-rates. This paves a way to synthesize the crystal-optimized LiMnxFe1−xPO4/C materials for high performance Li-ion batteries. PMID:28773887

Effect of organic additives on characteristics of carbon-coated LiCoPO4 synthesized by hydrothermal method

NASA Astrophysics Data System (ADS)

Maeyoshi, Yuta; Miyamoto, Shohei; Noda, Yusaku; Munakata, Hirokazu; Kanamura, Kiyoshi

2017-01-01

Carbon-coated LiCoPO4 particles are synthesized by one-pot hydrothermal process using three different organic additives (carboxymethylcellulose sodium salt (CMC), glucose, and ascorbic acid). The effect of the organic additives on particle size, morphology, nature of carbon coating, and electrochemical property of the resulting LiCoPO4 is investigated. CMC plays important roles to decrease the particle size and form well-covered carbon coating on the surface. Carbon-coated LiCoPO4 prepared using CMC delivers higher initial discharge capacity of 135 mA h g-1 at 0.1 C, and shows superior rate capability and cyclic performance than the other samples. The improved electrochemical characteristics are attributed to not only the fine particle which allows facile electronic and ionic transport, but also the high coverage of carbon coating which improves the electrical conductivity and prevents the irreversible reactions of the charged LiCoPO4 with electrolyte.

Enhanced photo-stability and photocatalytic activity of Ag3PO4 via modification with BiPO4 and polypyrrole

NASA Astrophysics Data System (ADS)

Cai, Li; Jiang, Hui; Wang, Luxi

2017-10-01

Ag3PO4 photocatalysts modified with BiPO4 and polypyrrole (PPy) were successfully synthesized via a combination of co-precipitation hydrothermal technique and oxidative polymerization method. Their morphologies, structures and optical and electronic properties were characterized by means of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscope (TEM), Brunauer-Emmett-Teller (BET) surface areas, X-ray diffraction (XRD), fourier transform infrared spectra (FT-IR), X-ray photo-electron spectroscopy (XPS), UV-vis diffuse reflection spectra (UV-vis DRS), photocurrent technique and electrochemical impedance spectra (EIS). The typical triphenylmethane dye (malachite green) was chosen as a target organic contaminants to estimate the photocatalytic activities and photo-stabilities of Ag3PO4-BiPO4-PPy heterostructures under visible light irradiation. The results indicated that the existence of BiPO4 and PPy not only showed great influences on the photocatalytic activity, but also significantly enhanced photo-stability of Ag3PO4 in repeated and long-term applications. The degradation conversion of Ag3PO4-BiPO4-PPy heterostructures (ABP-3) was 1.58 times of that of pure Ag3PO4. The photo-corrosion phenomenon of Ag3PO4 was effectively avoided. The photocatalytic activity of up to 87% in the Ag3PO4-BiPO4-PPy heterostructures (ABP-3) can be remained after five repeated cycles, while only about 33% of the degradation efficiency can be reserved in pure Ag3PO4. The possible mechanism of enhanced photo-stability and photocatalytic activity of Ag3PO4-BiPO4-PPy heterostructures was also discussed in this work.

First heat flow density determinations from Southeastern Zaïre (Central Africa)

NASA Astrophysics Data System (ADS)

Sebagenzi, M. N.; Vasseur, G.; Louis, P.

1993-05-01

First heat flow density determinations from southeastern Zaïre are presented. Sites are located in the late Proterozoic metasedimentary cover of the Pan-African belt (600 Ma.). For each individual boreholes, heat flow ranges between 48 and 72 mWm -2. The average value of 62 mW m -2 for the sites is similar to that of 66 mW m -2 observed in Zambia. Both values are higher than what is expected for Pan-African terranes. These heat flow determinations in Shaba province of southeastern Zaïre, together with gravity and seismological observations, support the hypothesis of lithospheric thinning for this area. As already suggested for Zambia, this lithospheric thinning may be associated with a southwestern extension of the East African Rift System from Tanganyika across the central African plateau.

Tailored surface structure of LiFePO4/C nanofibers by phosphidation and their electrochemical superiority for lithium rechargeable batteries.

PubMed

Lee, Yoon Cheol; Han, Dong-Wook; Park, Mihui; Jo, Mi Ru; Kang, Seung Ho; Lee, Ju Kyung; Kang, Yong-Mook

2014-06-25

We offer a brand new strategy for enhancing Li ion transport at the surface of LiFePO4/C nanofibers through noble Li ion conducting pathways built along reduced carbon webs by phosphorus. Pristine LiFePO4/C nanofibers composed of 1-dimensional (1D) LiFePO4 nanofibers with thick carbon coating layers on the surfaces of the nanofibers were prepared by the electrospinning technique. These dense and thick carbon layers prevented not only electrolyte penetration into the inner LiFePO4 nanofibers but also facile Li ion transport at the electrode/electrolyte interface. In contrast, the existing strong interactions between the carbon and oxygen atoms on the surface of the pristine LiFePO4/C nanofibers were weakened or partly broken by the adhesion of phosphorus, thereby improving Li ion migration through the thick carbon layers on the surfaces of the LiFePO4 nanofibers. As a result, the phosphidated LiFePO4/C nanofibers have a higher initial discharge capacity and a greatly improved rate capability when compared with pristine LiFePO4/C nanofibers. Our findings of high Li ion transport induced by phosphidation can be widely applied to other carbon-coated electrode materials.

Redetermination of AgPO(3).

PubMed

Terebilenko, Katherina V; Zatovsky, Igor V; Ogorodnyk, Ivan V; Baumer, Vyacheslav N; Slobodyanik, Nikolay S

2011-02-09

Single crystals of silver(I) polyphosphate(V), AgPO(3), were prepared via a phospho-ric acid melt method using a solution of Ag(3)PO(4) in H(3)PO(4). In comparison with the previous study based on single-crystal Weissenberg photographs [Jost (1961 ▶). Acta Cryst. 14, 779-784], the results were mainly confirmed, but with much higher precision and with all displacement parameters refined anisotropically. The structure is built up from two types of distorted edge- and corner-sharing [AgO(5)] polyhedra, giving rise to multidirectional ribbons, and from two types of PO(4) tetra-hedra linked into meandering chains (PO(3))(n) spreading parallel to the b axis with a repeat unit of four tetra-hedra. The calculated bond-valence sum value of one of the two Ag(I) ions indicates a significant strain of the structure.

High Performance Solid Polymer Electrolytes for Rechargeable Batteries: A Self-Catalyzed Strategy toward Facile Synthesis.

PubMed

Cui, Yanyan; Liang, Xinmiao; Chai, Jingchao; Cui, Zili; Wang, Qinglei; He, Weisheng; Liu, Xiaochen; Liu, Zhihong; Cui, Guanglei; Feng, Jiwen

2017-11-01

It is urgent to seek high performance solid polymer electrolytes (SPEs) via a facile chemistry and simple process. The lithium salts are composed of complex anions that are stabilized by a Lewis acid agent. This Lewis acid can initiate the ring opening polymerization. Herein, a self-catalyzed strategy toward facile synthesis of crosslinked poly(ethylene glycol) diglycidyl ether-based solid polymer electrolyte (C-PEGDE) is presented. It is manifested that the poly(ethylene glycol) diglycidyl ether-based solid polymer electrolyte possesses a superior electrochemical stability window up to 4.5 V versus Li/Li + and considerable ionic conductivity of 8.9 × 10 -5 S cm -1 at ambient temperature. Moreover, the LiFePO 4 /C-PEGDE/Li batteries deliver stable charge/discharge profiles and considerable rate capability. It is demonstrated that this self-catalyzed strategy can be a very effective approach for high performance solid polymer electrolytes.

A research on shape-controllable synthesis of Ag3PO4/AgBr and its degradation of ciprofloxacin.

PubMed

Chen, Jingran; Yang, Xingyu; Zhu, Chenyu; Xie, Xin; Lin, Cuiping; Zhao, Yalei; Yan, Qishe

2018-03-01

Antibiotic ciprofloxacin is one of the commonly used broad spectrum fluoroquinolone human and veterinary drugs. Because of the overuse of human beings, the presence of ciprofloxacin has been detected in a variety of environmental matrices. To solve this problem, a facile, environmentally-friendly Ag 3 PO 4 /AgBr composite photocatalyst was synthesized by a simple precipitation method at room temperature in the presence of cetyltrimethyl ammonium bromide (CTAB). CTAB was served as surfactant and the source of bromide ions. The as-prepared Ag 3 PO 4 /AgBr microspheres were characterized by means of powder X-ray diffraction (XRD), scanning electron microscope (SEM) and UV-visible diffuse reflectance spectroscopy (UV-vis DRS). The results revealed that the Ag 3 PO 4 /AgBr sample (synthesized with CTAB, 0.8 g) exhibited the highest photocatalytic activity to the photodegradation rate of 96.36%. Moreover, mechanism detection experiment indicated that h + was the major active species in the degradation process. So the enhanced photocatalytic activity of Ag 3 PO 4 /AgBr composites is attributed to its excellent separation of photogenerated electron-hole pairs through Ag 3 PO 4 /AgBr heterojunction. Also, Ag 3 PO 4 /AgBr heterojunction has a lower band gap compared to pure Ag 3 PO 4 and pure AgBr, so higher efficiency of light harvesting is equipped.

Redetermination of AgPO3

PubMed Central

Terebilenko, Katherina V.; Zatovsky, Igor V.; Ogorodnyk, Ivan V.; Baumer, Vyacheslav N.; Slobodyanik, Nikolay S.

2011-01-01

Single crystals of silver(I) polyphosphate(V), AgPO3, were prepared via a phospho­ric acid melt method using a solution of Ag3PO4 in H3PO4. In comparison with the previous study based on single-crystal Weissenberg photographs [Jost (1961 ▶). Acta Cryst. 14, 779–784], the results were mainly confirmed, but with much higher precision and with all displacement parameters refined anisotropically. The structure is built up from two types of distorted edge- and corner-sharing [AgO5] polyhedra, giving rise to multidirectional ribbons, and from two types of PO4 tetra­hedra linked into meandering chains (PO3)n spreading parallel to the b axis with a repeat unit of four tetra­hedra. The calculated bond-valence sum value of one of the two AgI ions indicates a significant strain of the structure. PMID:21522230

Why Baby Why: Howard Broomfield's Documentation of the Dunne-za Soundscape.

ERIC Educational Resources Information Center

Ridington, Robin

1988-01-01

Examines the acoustic environment and aural culture of the Dunne-za of northeastern British Columbia. Discusses the changing soundscape of a northern hunting people, techniques for recording and cataloging an ethnographic soundscape archive, and the use of audio actualities in producing ethnographic audio documentaries. (Author/SV)

Soil phosphorus forms and profile distributions in the tidal river network region in the Yellow River Delta estuary.

PubMed

Yu, Junbao; Qu, Fanzhu; Wu, Huifeng; Meng, Ling; Du, Siyao; Xie, Baohua

2014-01-01

Modified Hedley fraction method was used to study the forms and profile distribution in the tidal river network region subjected to rapid deposition and hydrologic disturbance in the Yellow River Delta (YRD) estuary, eastern China. The results showed that the total P (Pt) ranged from 612.1 to 657.8 mg kg(-1). Dilute HCl extractable inorganic P (Pi) was the predominant form in all profiles, both as absolute values and as a percentage of total extracted Pi. The NaOH extractable organic P (Po) was the predominant form of total extracted Po, while Bicarb-Pi and C.HCl-Po were the lowest fractions of total extracted Pi and Po in all the P forms. The Resin-P concentrations were high in the top soil layer and decreased with depth. The Pearson correlation matrix indicated that Resin-P, Bicarb-Pi, NaOH-Pi, and C.HCl-Pi were strongly positively correlated with salinity, TOC, Ca, Al, and Fe but negatively correlated with pH. The significant correlation of any studied form of organic P (Bicarb-Po, NaOH-Po, and C.HCl-Po) with geochemical properties were not observed in the study. Duncan multiple-range test indicated that the P forms and distribution heterogeneity in the profiles could be attributed to the influences of vegetation cover and hydrologic disturbance.

H2O2 rejuvenation-mediated synthesis of stable mixed-morphology Ag3PO4 photocatalysts.

PubMed

Agbe, Henry; Raza, Nadeem; Dodoo-Arhin, David; Chauhan, Aditya; Kumar, Ramachandran Vasant

2018-04-01

Ag 3 PO 4 photocatalyst has attracted interest of the scientific community in recent times due to its reported high efficiency for water oxidation and dye degradation. However, Ag 3 PO 4 photo-corrodes if electron accepter such as AgNO 3 is not used as scavenger. Synthesis of efficient Ag 3 PO 4 followed by a simple protocol for regeneration of the photocatalyst is therefore a prerequisite for practical application. Herein, we present a facile method for the synthesis of a highly efficient Ag 3 PO 4 , whose photocatalytic efficiency was demonstrated using 3 different organic dyes: Methylene Blue (MB), Methyl orange (MO) and Rhodamine B (RhB) organic dyes for degradation tests. Approximately, 19 % of Ag 3 PO 4 is converted to Ag 0 after 4.30 hours of continuous UV-Vis irradiation in presence of MB organic dye. We have shown that the Ag/Ag 3 PO 4 composite can be rejuvenated by a simple chemical oxidation step after several cycles of photocatalysis tests. At an optimal pH of 6.5, a mixture of cubic, rhombic dodecahedron, nanosphere and nanocrystals morphologies of the photocatalyst was formed. H 2 O 2 served as the chemical oxidant to re-insert the surface metallic Ag into the Ag 3 PO 4 photocatalyst but also as the agent that can control morphology of the regenerated as-prepared photocatalyst without the need for any other morphology controlling Agent (MCA). Surprisingly, the as- regenerated Ag 3 PO 4 was found to have higher photocatalytic reactivity than the freshly made material and superior at least 17 times in comparison with the conventional Degussa TiO 2 , and some of TiO 2 composites tested in this work.

A facile route to modify ferrous phosphate and its use as an iron-containing resource for LiFePO4 via a polyol process.

PubMed

Li, Shaomin; Liu, Xichuan; Mi, Rui; Liu, Hao; Li, Yinchuan; Lau, Woon-min; Mei, Jun

2014-06-25

This study introduces an economical and environmentally friendly way of synthesizing LiFePO4/C to be used as cathode material in lithium ion batteries via two processes: (1) the synthesis of LiFePO4/C cathode material using a low cost divalent precursor ferrous phosphate, Fe3 (PO4)2·8H2O, as iron source in a polyol process and (2) the modification of the morphology of this precursor by varying the reaction time in a coprecipitation process. The study examines the effects of different structures and morphologies of the precursor on the structure and electrochemical performance of the as-synthesized LiFePO4/C. The LiFePO4/C shows an excellent rate capability and cycle performance, with initial discharge capacities of 153, 128, and 106 mA h g(-1) at 1 C, 5 C, and 10 C. The capacity retention is respectively 98.7%, 98.2%, and 98.7%, after 10 cycles at the corresponding rates. The capacity retention remains at 97% even after 300 cycles at the rate of 10 C. The outstanding electrochemical performance can be attributed to the improved rate of Li(+) diffusion and the excellent crystallinity of synthesized LiFePO4/C powders through the modified precursor. Therefore, this is an economical and environmentally friendly way of synthesizing LiFePO4/C to be used as cathode material in lithium ion batteries.

Investigation of sodium insertion–extraction in olivine Na x FePO 4 (0 ≤ x ≤ 1) using first-principles calculations

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

Saracibar, A.; Carrasco, J.; Saurel, D.

Olivine NaFePO4 has recently attracted the attention of the scientific community as a promising cathode material for Na-ion batteries. In this work we combine density functional theory (DFT) calculations and high resolution synchrotron X-ray diffraction (HRXRD) experiments to study the phase stability of NaxFePO4 along the whole range of sodium compositions (0 ≤ x ≤ 1). DFT calculations reveal the existence of two intermediate structures governing the phase stability at x = 2/3 and x = 5/6. This is in contrast to isostructural LiFePO4, which is a broadly used cathode in Li-ion batteries. Na2/3FePO4 and Na5/6FePO4 ground states both alignmore » vacancies diagonally within the ab plane, coupled to a Fe2+/Fe3+ alignment. HRXRD data for NaxFePO4 (2/3 < x < 1) materials show common superstructure reflections up to x = 5/6 within the studied compositions. The computed intercalation voltage profile shows a voltage difference of 0.16 V between NaFePO4 and Na2/3FePO4 in agreement with the voltage discontinuity observed experimentally during electrochemical insertion.« less

Pak4 Is Required during Epithelial Polarity Remodeling through Regulating AJ Stability and Bazooka Retention at the ZA

PubMed Central

Walther, Rhian F.; Nunes de Almeida, Francisca; Vlassaks, Evi; Burden, Jemima J.; Pichaud, Franck

2016-01-01

Summary The ability of epithelial cells to assemble into sheets relies on their zonula adherens (ZA), a circumferential belt of adherens junction (AJ) material, which can be remodeled during development to shape organs. Here, we show that during ZA remodeling in a model neuroepithelial cell, the Cdc42 effector P21-activated kinase 4 (Pak4/Mbt) regulates AJ morphogenesis and stability through β-catenin (β-cat/Arm) phosphorylation. We find that β-catenin phosphorylation by Mbt, and associated AJ morphogenesis, is needed for the retention of the apical determinant Par3/Bazooka at the remodeling ZA. Importantly, this retention mechanism functions together with Par1-dependent lateral exclusion of Par3/Bazooka to regulate apical membrane differentiation. Our results reveal an important functional link between Pak4, AJ material morphogenesis, and polarity remodeling during organogenesis downstream of Par3. PMID:27052178

Pak4 Is Required during Epithelial Polarity Remodeling through Regulating AJ Stability and Bazooka Retention at the ZA.

PubMed

Walther, Rhian F; Nunes de Almeida, Francisca; Vlassaks, Evi; Burden, Jemima J; Pichaud, Franck

2016-04-05

The ability of epithelial cells to assemble into sheets relies on their zonula adherens (ZA), a circumferential belt of adherens junction (AJ) material, which can be remodeled during development to shape organs. Here, we show that during ZA remodeling in a model neuroepithelial cell, the Cdc42 effector P21-activated kinase 4 (Pak4/Mbt) regulates AJ morphogenesis and stability through β-catenin (β-cat/Arm) phosphorylation. We find that β-catenin phosphorylation by Mbt, and associated AJ morphogenesis, is needed for the retention of the apical determinant Par3/Bazooka at the remodeling ZA. Importantly, this retention mechanism functions together with Par1-dependent lateral exclusion of Par3/Bazooka to regulate apical membrane differentiation. Our results reveal an important functional link between Pak4, AJ material morphogenesis, and polarity remodeling during organogenesis downstream of Par3. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

High Performance Solid Polymer Electrolytes for Rechargeable Batteries: A Self‐Catalyzed Strategy toward Facile Synthesis

PubMed Central

Cui, Yanyan; Liang, Xinmiao; Chai, Jingchao; Cui, Zili; Wang, Qinglei; He, Weisheng; Liu, Xiaochen; Feng, Jiwen

2017-01-01

Abstract It is urgent to seek high performance solid polymer electrolytes (SPEs) via a facile chemistry and simple process. The lithium salts are composed of complex anions that are stabilized by a Lewis acid agent. This Lewis acid can initiate the ring opening polymerization. Herein, a self‐catalyzed strategy toward facile synthesis of crosslinked poly(ethylene glycol) diglycidyl ether‐based solid polymer electrolyte (C‐PEGDE) is presented. It is manifested that the poly(ethylene glycol) diglycidyl ether‐based solid polymer electrolyte possesses a superior electrochemical stability window up to 4.5 V versus Li/Li+ and considerable ionic conductivity of 8.9 × 10−5 S cm−1 at ambient temperature. Moreover, the LiFePO4/C‐PEGDE/Li batteries deliver stable charge/discharge profiles and considerable rate capability. It is demonstrated that this self‐catalyzed strategy can be a very effective approach for high performance solid polymer electrolytes. PMID:29201612

Influence of temperature and frequency on ionic conductivity of Li{sub 3}PO{sub 4}–Pb{sub 3}(PO{sub 4}){sub 2}–BiPO{sub 4} phosphate glasses

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

El Moudane, M., E-mail: m.elmoudane@gmail.com; El Maniani, M.; Sabbar, A.

2015-12-15

Highlights: • Results of ionic conductivities of Li{sub 3}PO{sub 4}–Pb{sub 3}(PO{sub 4}){sub 2}–BiPO{sub 4} phosphate glasses. • Determination of glass transition temperature using DSC method. • Study of temperature and frequency on ionic conductivity of Li{sub 3}PO{sub 4}–Pb{sub 3}(PO{sub 4}){sub 2}–BiPO{sub 4} phosphate glasses. - Abstract: Lithium–Lead–Bismuth phosphates glasses having, a composition 30Li{sub 3}PO{sub 4}–(70 − x)Pb{sub 3}(PO{sub 4}){sub 2}–xBiPO{sub 4} (45 ≤ x ≤ 60 mol%) were prepared by using the melt quenching method 1000 °C. The thermal stability of theses glasses increases with the substitution of Bi{sub 2}O{sub 3} with PbO. The ionic conductivity of all compositions havemore » been measured over a wide temperature (200–500 °C) and frequency range (1–106 Hz). The ionic conductivity data below and above T{sub g} follows Arrhenius and Vogel–Tamman–Fulcher (VTF) relationship, respectively. The activation energies are estimated and discussed. The dependence in frequency of AC conductivity is found to obey Jonscher’s relation.« less

Encapsulation of LiFePO4 by in-situ graphitized carbon cage towards enhanced low temperature performance as cathode materials for lithium ion batteries

NASA Astrophysics Data System (ADS)

Yao, Bin; Ding, Zhaojun; Zhang, Jianxin; Feng, Xiaoyu; Yin, Longwei

2014-08-01

The severe capacity decay of LiFePO4 at low temperatures (≤0 °C) limits its wide applications as cathode materials for energy storage batteries. Creating comprehensive carbon network between particles with improved electronic conductivity is a well known solution to this problem. Here, a novel structured LiFePO4/C composite was prepared by a facile solid state route, in which nanosized LiFePO4 spheres were encapsulated by in-situ graphitized carbon cages. With the enhancement in electronic conductivity (2.15e-1 S cm-1), the composite presented excellent rate performance at room temperature and remarkable capacity retention at -40 °C, with charge transfer resistance much lower than commercial LiFePO4.

Ralstonia eutropha's Poly(3-hydroxybutyrate)(PHB) polymerase PhaC1 and PHB depolymerase PhaZa1 are phosphorylated in vivo.

PubMed

Jüngert, Janina R; Patterson, Cameron; Jendrossek, Dieter

2018-04-20

In this study, we screened PHB synthase PhaC1 and PHB depolymerase PhaZa1 of Ralstonia eutropha for the presence of phosphorylated residues during the PHB accumulation and PHB degradation phase. Thr373 of PHB synthase PhaC1 was phosphorylated in the stationary growth phase but was not modified in the exponential and PHB accumulation phases. Ser35 of PHB depolymerase PhaZa1 was identified in phosphorylated form both in the exponential and in the stationary growth phase. Additional phosphosites were identified for both proteins in sample-dependent forms. Site-directed mutagenesis of the codon for Thr373 and other phosphosites of PhaC1 revealed a strong negative impact on PHB synthase activity. Modification of Thr26 and Ser35 of PhaZa1 reduced the ability of R. eutropha to mobilize PHB in the stationary growth phase. Our results show that phosphorylation of PhaC1 and PhaZa1 can be important for modulation of the activities of PHB synthase and PHB depolymerase. Importance Polyhydroxybutyrate (PHB) and related polyhydroxyalkanoates (PHAs) are important intracellular carbon and energy storage compounds in many prokaryotes. The accumulation of PHB or PHAs increases the fitness of cells during periods of starvation and other stress conditions. The simultaneous presence of poly(3-hydroxybutyrate) (PHB) synthase (PhaC1) and PHB depolymerase (PhaZa1) on synthesized PHB granules in Ralstonia eutropha (alternative designation Cupriavidus necator ) has been previously shown in several laboratories. These findings imply that the activities of PHB synthase and PHB depolymerase should be regulated to avoid a futile cycle of simultaneous synthesis and degradation of PHB. Here, we addressed this question by identifying phosphorylation sites on PhaC1 and PhaZa1 and by site-directed mutagenesis of identified residues. Furthermore, we conducted in vitro and in vivo analysis of PHB synthase activity and PHB contents. Copyright © 2018 American Society for Microbiology.

Profile of hepatitis B and C virus infection in prisoners in Lubuk Pakam correctional facilities

NASA Astrophysics Data System (ADS)

Rey, I.; Saragih, R. H.; Effendi-YS, R.; Sembiring, J.; Siregar, G. A.; Zain, L. H.

2018-03-01

Prisoners in correctional facilities are predisposed to chronic viral infections because of their high-risk behaviors or unsafe lifestyle. The economic and public health burden of chronic hepatitis B and C and its sequelae need to be addressed, such as by finding the risk factors and therefore reducing the spread of HCV and HBV infection in prisons. This study aimed to see the profile of Hepatitis B and C Virus Infection in prisoners in Lubuk Pakam Correctional Facilities. This cross-sectional study was in Lubuk Pakam Correctional Facilities in 2016. From 1114 prisoners in Lubuk Pakam correctional facility, we randomly examined 120 prisoners for HBV and HCV serology markers. From 120 prisoners, six prisoners were HBV positive, 21 prisoners were HCV positive and one prisoner positive for both HCV and HBV infection. The most common risk factors for prisoners getting HBV infection are tattoos and free sex (36.4% and 36.4%, respectively). The most common risk factors for HCV infection in prisoners are tattoos and free sex (40% and 35%, respectively).

Study on LOC for modern facility agriculture automatic walking equipment LiFePO4 battery

NASA Astrophysics Data System (ADS)

Liu, Xuepeng; Zhao, Dongmei

2017-08-01

LiFePO4 battery LOC (life Of Charge) is the assessment of the ability to work within a cycle of battery charge and discharge period, which likes the miles for vehicle. LOC is related with battery capacity, working condition and stress. LOC consists of the model of the battery's SOC online prediction model, the analysis of RBSOC and the LOC model of multi-condition and multi-stress.

Relating the 3D electrode morphology to Li-ion battery performance; a case for LiFePO4

NASA Astrophysics Data System (ADS)

Liu, Zhao; Verhallen, Tomas W.; Singh, Deepak P.; Wang, Hongqian; Wagemaker, Marnix; Barnett, Scott

2016-08-01

One of the main goals in lithium ion battery electrode design is to increase the power density. This requires insight in the relation between the complex heterogeneous microstructure existing of active material, conductive additive and electrolyte providing the required electronic and Li-ion transport. FIB-SEM is used to determine the three phase 3D morphology, and Li-ion concentration profiles obtained with Neutron Depth Profiling (NDP) are compared for two cases, conventional LiFePO4 electrodes and better performing carbonate templated LiFePO4 electrodes. This provides detailed understanding of the impact of key parameters such as the tortuosity for electron and Li-ion transport though the electrodes. The created hierarchical pore network of the templated electrodes, containing micron sized pores, appears to be effective only at high rate charge where electrolyte depletion is hindering fast discharge. Surprisingly the carbonate templating method results in a better electronic conductive CB network, enhancing the activity of LiFePO4 near the electrolyte-electrode interface as directly observed with NDP, which in a large part is responsible for the improved rate performance both during charge and discharge. The results demonstrate that standard electrodes have a far from optimal charge transport network and that significantly improved electrode performance should be possible by engineering the microstructure.

Three-Dimensional Ordered Macroporous FePO4 as High-Efficiency Catalyst for Rechargeable Li-O2 Batteries.

PubMed

Li, Chao; Guo, Ziyang; Pang, Ying; Sun, Yunhe; Su, Xiuli; Wang, Yonggang; Xia, Yongyao

2016-11-23

The Li-O 2 battery is receiving much recent attention because of its superhigh theoretical energy density. However, its performance is limited by the irreversible formation/decomposition of Li 2 O 2 on the cathode and the undesired electrolyte decomposition. In this work, low-cost three-dimensional ordered macroporous (3DOM) FePO 4 is synthesized by using polystyrene (PS) spheres template in a facile experimental condition and applied as a high-efficiency catalyst for rechargeable Li-O 2 batteries, including good rate performance, high specific capacity, and perfect cycling stability. The superior performances can be attributed to the unique structure of 3DOM FePO 4 cathodes, which can provide an efficient buffer space for O 2 /Li 2 O 2 conversion. In addition, it is demonstrated that the Li + intercalation/deintercalation behavior of 3DOM FePO 4 in ether-based electrolyte can contribute to capacity for Li-O 2 batteries over cycling. As a result, when there is no O 2 in the environment, the Li-O 2 cell can also be operated as a rechargeable Li-FePO 4 cell with a perfect cycle capability.

210Po secretion from sweat glands.

PubMed

Romańczyk, Grzegorz; Boryło, Alicja

2017-02-01

The results of the research indicated that the 210 Po activity concentration in sweat samples was between 0.22 ± 0.03 to 2.10 ± 0.15 mBq·g -1 d.w. The obtained results of the studies showed that smoking and eating fish led to higher activity concentrations of 210 Po in sweat in comparison to the control group. Statistical analysis of 210 Po activity concentrations in sweat samples showed significant differences between control, smoking, fish eating and age groups, while no significant differences was found for 210 Po between volunteers as far as gender is concerned. Copyright © 2016. Published by Elsevier Ltd.

Application of genetic algorithm in the evaluation of the profile error of archimedes helicoid surface

NASA Astrophysics Data System (ADS)

Zhu, Lianqing; Chen, Yunfang; Chen, Qingshan; Meng, Hao

2011-05-01

According to minimum zone condition, a method for evaluating the profile error of Archimedes helicoid surface based on Genetic Algorithm (GA) is proposed. The mathematic model of the surface is provided and the unknown parameters in the equation of surface are acquired through least square method. Principle of GA is explained. Then, the profile error of Archimedes Helicoid surface is obtained through GA optimization method. To validate the proposed method, the profile error of an Archimedes helicoid surface, Archimedes Cylindrical worm (ZA worm) surface, is evaluated. The results show that the proposed method is capable of correctly evaluating the profile error of Archimedes helicoid surface and satisfy the evaluation standard of the Minimum Zone Method. It can be applied to deal with the measured data of profile error of complex surface obtained by three coordinate measurement machines (CMM).

DOSE PROFILE MODELING OF IDAHO NATIONAL LABORATORY’S ACTIVE NEUTRON INTERROGATION TEST FACILITY

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

D. L. Chichester; E. H. Seabury; J. M. Zabriskie

2009-06-01

A new research and development laboratory has been commissioned at Idaho National Laboratory for performing active neutron interrogation research and development. The facility is designed to provide radiation shielding for DT fusion (14.1 MeV) neutron generators (2 x 108 neutrons per second), DD fusion (2.5 MeV) neutron generators (up to 2 x 106 neutrons per second), and 252Cf spontaneous fission neutron sources (6.7 x 107 neutrons per second, 30 micrograms). Shielding at the laboratory is comprised of modular concrete shield blocks 0.76 m thick with tongue-in-groove features to prevent radiation streaming, arranged into one small and one large test vault.more » The larger vault is designed to allow operation of the DT generator and has walls 3.8 m tall, an entrance maze, and a fully integrated electrical interlock system; the smaller test vault is designed for 252Cf and DD neutron sources and has walls 1.9 m tall and a simple entrance maze. Both analytical calculations and numerical simulations were used in the design process for the building to assess the performance of the shielding walls and to ensure external dose rates are within required facility limits. Dose rate contour plots have been generated for the facility to visualize the effectiveness of the shield wall and entrance maze and to illustrate the spatial profile of the radiation dose field above the facility and the effects of skyshine around the vaults.« less

K2Ho(PO4)(WO4)

PubMed Central

Terebilenko, Katherina V.; Zatovsky, Igor V.; Baumer, Vyacheslav N.; Slobodyanik, Nikolay S.; Shishkin, Oleg V.

2008-01-01

A new compound, dipotassium holmium(III) phosphate(V) tungstate(VI), K2Ho(PO4)(WO4), has been obtained during investigation of the K2O–P2O5–WO3–HoF3 phase system using the flux technique. The compound is isotypic with K2Bi(PO4)(WO4). Its framework structure consists of flat ∞ 2[HoPO4] layers parallel to (100) that are made up of ∞ 1[HoO8] zigzag chains inter­linked via slightly distorted PO4 tetra­hedra. WO4 tetra­hedra are attached above and below these layers, leaving space for the K+ counter-cations. The HoO8, PO4 and WO4 units exhibit 2 symmetry. PMID:21580811

Internet-Based Injury Profile Developer (IPD) User’s Manual, Version 1.0

DTIC Science & Technology

2002-10-01

NAVAL HEALTH RESEARCH CENTER Internet-based Injury Profile Developer (IPD) User’s Manual Version 1.0 M. Knapp M. Galarneau...NAVAL HEALTH RESEARCH CENTER P. O. BOX 85122 SAN DIEGO, CA 92186-5122...Kizakevich2 1Naval Health Research Center P.O. Box 85122 San Diego, CA 92182-5122 2Research Triangle Institute P.O. Box 12194

Nanocomposite of exfoliated bentonite/g-C3N4/Ag3PO4 for enhanced visible-light photocatalytic decomposition of Rhodamine B.

PubMed

Ma, Jianfeng; Huang, Daiqin; Zhang, Wenyi; Zou, Jing; Kong, Yong; Zhu, Jianxi; Komarneni, Sridhar

2016-11-01

Novel visible-light-driven heterojunction photocatalyst comprising exfoliated bentonite, g-C3N4 and Ag3PO4 (EB/g-C3N4/Ag3PO4) was synthesized by a facile and green method. The composites EB/g-C3N4/Ag3PO4 were characterized by X-ray diffraction, Transmission electron microscopy, Fourier transform infrared spectroscopy, UV-Vis diffuse reflectance spectroscopy and the Brunauer, Emmett, and Teller (BET) surface area method. Under visible light irradiation, EB/g-C3N4/Ag3PO4 composites displayed much higher photocatalytic activity than that of either pure g-C3N4 or pure Ag3PO4 in the degradation of Rhodamine B (RhB). Among the hybrid photocatalysts, EB/g-C3N4/Ag3PO4 composite containing 20 wt% Ag3PO4 exhibited the highest photocatalytic activity for the decolorization of RhB. Under the visible-light irradiation, the RhB dye was completely decolorized in less than 60 min. The enhanced photocatalytic performance is attributed to the stable structure, enlarged surface area, strong adsorbability, strong light absorption ability, and high-efficiency separation rate of photoinduced electron-hole pairs. Our finding paves a way to design highly efficient and stable visible-light-induced photocatalysts for practical applications in wastewater treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhancing visible light photocatalytic activity of direct Z-scheme SnS{sub 2}/Ag{sub 3}PO{sub 4} heterojunction photocatalysts

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

Luo, Jin, E-mail: lj328520504@126.com; Zhou, Xiaosong; Ma, Lin

Highlights: • Novel direct Z-scheme SnS{sub 2}/Ag{sub 3}PO{sub 4} heterojunction photocatalysts are synthesized. • SnS{sub 2}/Ag{sub 3}PO{sub 4} exhibits much higher photocatalytic activity than pure SnS{sub 2} and Ag{sub 3}PO{sub 4}. • A possible photocatalytic mechanism was discussed in detail. - Abstract: Novel direct Z-scheme SnS{sub 2}/Ag{sub 3}PO{sub 4} heterojunction photocatalysts were successfully fabricated with SnS{sub 2} nanoplates hybridized by Ag{sub 3}PO{sub 4} nanoparticals via a facile hydrothermal and precipitation method and applied for the photocatalytic degradation of methyl orange in aqueous solution under visible light irradiation (λ > 420 nm). It was found that the photocatalytic performance of themore » SnS{sub 2} (2.0 wt%)/Ag{sub 3}PO{sub 4} heterojunction photocatalyst with 2.0 wt% SnS{sub 2} content was much higher than that of individual SnS{sub 2} and Ag{sub 3}PO{sub 4}. The enhanced photocatalytic activity could be ascribed to the efficient separation of photogenerated electrons and holes through the formation of direct Z-scheme system composed of SnS{sub 2} and Ag{sub 3}PO{sub 4}. Furthermore, the recycling experiments revealed that the photocorrosion behavior of Ag{sub 3}PO{sub 4} was strongly inhibited by SnS{sub 2}, it may be due to the photogenerated electrons of Ag{sub 3}PO{sub 4} would be quickly combined with the photogenerated holes of SnS{sub 2}. This work will be useful for the design of other direct Z-scheme visible-light-driven photocatalytic systems for application in energy conversion and environmental remediation.« less

PO2 cycling reduces diaphragm fatigue by attenuating ROS formation.

PubMed

Zuo, Li; Diaz, Philip T; Chien, Michael T; Roberts, William J; Kishek, Juliana; Best, Thomas M; Wagner, Peter D

2014-01-01

Prolonged muscle exposure to low PO2 conditions may cause oxidative stress resulting in severe muscular injuries. We hypothesize that PO2 cycling preconditioning, which involves brief cycles of diaphragmatic muscle exposure to a low oxygen level (40 Torr) followed by a high oxygen level (550 Torr), can reduce intracellular reactive oxygen species (ROS) as well as attenuate muscle fatigue in mouse diaphragm under low PO2. Accordingly, dihydrofluorescein (a fluorescent probe) was used to monitor muscular ROS production in real time with confocal microscopy during a lower PO2 condition. In the control group with no PO2 cycling, intracellular ROS formation did not appear during the first 15 min of the low PO2 period. However, after 20 min of low PO2, ROS levels increased significantly by ∼30% compared to baseline, and this increase continued until the end of the 30 min low PO2 condition. Conversely, muscles treated with PO2 cycling showed a complete absence of enhanced fluorescence emission throughout the entire low PO2 period. Furthermore, PO2 cycling-treated diaphragm exhibited increased fatigue resistance during prolonged low PO2 period compared to control. Thus, our data suggest that PO2 cycling mitigates diaphragm fatigue during prolonged low PO2. Although the exact mechanism for this protection remains to be elucidated, it is likely that through limiting excessive ROS levels, PO2 cycling initiates ROS-related antioxidant defenses.

Structural and Electrochemical Characterization of Pure LiFePO 4 and Nanocomposite C- LiFePO 4 Cathodes for Lithium Ion Rechargeable Batteries

DOE PAGES

Kumar, Arun; Thomas, R.; Karan, N. K.; ...

2009-01-01

Pure limore » thium iron phosphate ( LiFePO 4 ) and carbon-coated LiFePO 4 (C- LiFePO 4 ) cathode materials were synthesized for Li-ion batteries. Structural and electrochemical properties of these materials were compared. X-ray diffraction revealed orthorhombic olivine structure. Micro-Raman scattering analysis indicates amorphous carbon, and TEM micrographs show carbon coating on LiFePO 4 particles. Ex situ Raman spectrum of C- LiFePO 4 at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of LiFePO 4 and C- LiFePO 4 showed only a pair of peaks corresponding to the anodic and cathodic reactions. The first discharge capacities were 63, 43, and 13 mAh/g for C/5, C/3, and C/2, respectively for LiFePO 4 where as in case of C- LiFePO 4 that were 163, 144, 118, and 70 mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pure LiFePO 4 was 69% after 25 cycles where as that of C- LiFePO 4 was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating.« less

Facile solution-precipitation assisted synthesis and luminescence property of greenish-yellow emitting Ca{sub 6}Ba(PO{sub 4}){sub 4}O:Eu{sup 2+} phosphor

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

Ji, Haipeng; Huang, Zhaohui, E-mail: huang118@cugb.edu.cn; Xia, Zhiguo, E-mail: xiazg@ustb.edu.cn

2016-03-15

Highlights: • Ca{sub 6}Ba(PO{sub 4}){sub 4}O:Eu{sup 2+} phosphor was prepared by the solution-precipitation assisted route. • The phosphors have satisfactory smooth grain surface and particle size. • It shows greenish-yellow color emission (maximum at 540 nm) upon blue light excitation. • Eu{sup 2+} is coordinated with isolated oxygen atoms and those from PO{sub 4} polyhedra. - Abstract: Greenish-yellow emitting microcrystalline Ca{sub 6}Ba(PO{sub 4}){sub 4}O:Eu{sup 2+} phosphor was successfully prepared by a solution-precipitation assisted high temperature reaction method. Phase structure, morphology and/or luminescence properties of the precursor and the as-prepared phosphors were characterized. The phase-pure Ca{sub 6}Ba(PO{sub 4}){sub 4}O:Eu{sup 2+} phosphorsmore » were obtained with smooth grain surface and particle size of 2–8 μm. Ca{sub 6}Ba(PO{sub 4}){sub 4}O:Eu{sup 2+} exhibits bright greenish-yellow color emission with its maximum at 540 nm upon UV-blue light excitation. The maximum position of the broad emission band is independent on the calcination temperature. The emission intensity increases with increasing calcination temperature due to improved crystallinity. Besides, the presence of two Eu{sup 2+} emission centers in the Ca{sub 6}Ba(PO{sub 4}){sub 4}O crystal lattice was confirmed and the coordination effects are considered concerning the roles of isolated O atoms and those from the PO{sub 4} tetrahedra.« less

Structural and {sup 31}P NMR investigation of Bi(MM'){sub 2}PO{sub 6} statistic solid solutions: Deconvolution of lattice constraints and cationic influences

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

Colmont, Marie; Delevoye, Laurent; Ketatni, El Mostafa

2006-07-15

Two solid solutions BiM{sub x} Mg{sub (2-x)}PO{sub 6} (with M {sup 2+}=Zn or Cd) have been studied through {sup 31}P MAS NMR. The analysis has been performed on the basis of refined crystal structures through X-ray diffraction and neutron diffraction. The BiZn {sub x} Mg{sub (2-x)}PO{sub 6} does not provide direct evidence for sensitive changes in the phosphorus local symmetry. This result is in good agreement with structural data which show nearly unchanged lattices and atomic separations through the Zn{sup 2+} for Mg{sup 2+} substitution. On the other hand, the Cd{sup 2+} for Mg{sup 2+} substitution behaves differently. Indeed, upmore » to five resonances are observed, each corresponding to one of the five first-cationic neighbour distributions, i.e. 4Mg/0Cd, 3Mg/1Cd, 2Mg/2Cd, 1Mg/3Cd and 0Mg/4Cd. Their intensities match rather well the expected weight for each configuration of the statistical Cd{sup 2+}/Mg{sup 2+} mixed occupancy. The match is further improved when one takes into account the influence of the 2nd cationic sphere that is available from high-field NMR data (18.8 T). Finally, the fine examination of the chemical shift for each resonance versus x allows to de-convolute the mean Z/a {sup 2} effective field into two sub-effects: a lattice constraint-only term and a chemical-only term whose effects are directly quantifiable. - Graphical abstract: First (CdMg){sub 4} cationic sphere influence on the {sup 31}P NMR signal in Bi(Cd,Mg){sub 2}PO{sub 6}. Display Omitted.« less

Density functional theory study of lithium diffusion at the interface between olivine-type LiFePO4 and LiMnPO4

NASA Astrophysics Data System (ADS)

Shi, Jianjian; Wang, Zhiguo; Qing Fu, Yong

2016-12-01

Coating LiMnPO4 with a thin layer of LiFePO4 shows a better electrochemical performance than the pure LiFePO4 and LiMnPO4, thus it is critical to understand Li diffusion at their interfaces to improve the performance of electrode materials. Li diffusion at the (1 0 0)\\text{LiFeP{{\\text{O}}4}} //(1 0 0)\\text{LiMnP{{\\text{O}}4}} , (0 1 0)\\text{LiFeP{{\\text{O}}4}} //(0 1 0)\\text{LiMnP{{\\text{O}}4}} , and (0 0 1)\\text{LiFeP{{\\text{O}}4}} //(0 0 1)\\text{LiMnP{{\\text{O}}4}} interfaces between LiFePO4 and LiMnPO4 was investigated using density functional theory. The calculated diffusion energy barriers are 0.55 eV for Li to diffuse along the (0 0 1) interface, 0.44 and 0.49 eV for the Li diffusion inside the LiMnPO4 and along the (1 0 0) interface, respectively. When Li diffuses from the LiFePO4 to LiMnPO4 by passing through the (0 1 0) interfaces, the diffusion barriers are 0.45 and 0.60 eV for the Li diffusions in both sides. The diffusion barriers for Li to diffuse in LiMnPO4 near the interfaces decrease compared with those in the pure LiMnPO4. The calculated diffusion coefficient of Li along the (1 0 0) interface is in the range of 3.65  ×  10-11-5.28  ×  10-12 cm2 s-1, which is larger than that in the pure LiMnPO4 with a value of 7.5  ×  10-14 cm2 s-1. Therefore, the charging/discharging rate performance of the LiMnPO4 can be improved by surface coating with the LiFePO4.

Direct observation of antisite defects in LiCoPO4 cathode materials by annular dark- and bright-field electron microscopy.

PubMed

Truong, Quang Duc; Devaraju, Murukanahally Kempaiah; Tomai, Takaaki; Honma, Itaru

2013-10-23

LiCoPO4 cathode materials have been synthesized by a sol-gel route. X-ray diffraction analysis confirmed that LiCoPO4 was well-crystallized in an orthorhombic structure in the Pmna space group. From the high-resolution transmission electron microscopy (HR-TEM) image, the lattice fringes of {001} and {100} are well-resolved. The HR-TEM image and selected area electron diffraction pattern reveal the highly crystalline nature of LiCoPO4 having an ordered olivine structure. The atom-by-atom structure of LiCoPO4 olivine has been observed, for the first time, using high-angle annular dark-field (HAADF) and annual bright-field scanning transmission electron microscopy. We observed the bright contrast in Li columns in the HAADF images and strong contrast in the ABF images, directly indicating the antisite exchange defects in which Co atoms partly occupy the Li sites. The LiCoPO4 cathode materials delivered an initial discharge capacity of 117 mAh/g at a C/10 rate with moderate cyclic performance. The discharge profile of LiCoPO4 shows a plateau at 4.75 V, revealing its importance as a potentially high-voltage cathode. The direct visualization of atom-by-atom structure in this work represents important information for the understanding of the structure of the active cathode materials for Li-ion batteries.

"Artificial lymphatic system": a new approach to reduce interstitial hypertension and increase blood flow, pH and pO2 in solid tumors.

PubMed

DiResta, G R; Lee, J; Healey, J H; Levchenko, A; Larson, S M; Arbit, E

2000-05-01

A mechanical drainage system, the "artificial lymphatic system" (ALS), consisting of a vacuum source and drain, is evaluated for its ability to aspirate the interstitial fluids responsible for the elevated interstitial fluid pressure (IFP) observed in solid tumors. IFP, pH, and pO2 radial profiles were measured before and after aspiration using wick-in-needle (WIN) probes, needle pH and oxygen electrodes, respectively. Laser Doppler flowmetry measured temporal changes in blood flow rate (BFR) at the tumor surface during aspiration. The WIN probe and IFP profile data were analyzed using numerical simulation and distributed mathematical models, respectively. The model parameter, P(E), reflecting central tumor IFP, was reduced from 15.3 to 5.7 mm Hg in neuroblastoma and from 13.3 to 12.1 mm Hg in Walker 256, respectively, following aspiration. The simulation demonstrated that spatial averaging inherent in WIN measurements reduced the calculated magnitude of the model parameter changes. IFP was significantly lower (p<0.05), especially in regions surrounding the drain, and BFR was significantly higher (p<0.05) following 25 and 45 min of aspiration, respectively; pH and pO2 profiles increased following aspiration. The experimental and mathematical findings suggest that ALS aspiration may be a viable way of reducing IFP and increasing BFR, pO2, and pH and should enhance solid tumor chemo and radiation therapy.

Temporal changes of 210Po in temperate coastal waters.

PubMed

Wildgust, M A; McDonald, P; White, K N

1998-06-18

The temporal variation of Polonium-210 (210Po) was examined in coastal sea water, the mussel Mytilus edulis, the winkle Littorina littorea and green alga Ulva lactuca in order to investigate the entry of 210Po into the marine food chain. More than 99% of 210Po in the water column occurred in the particulate phase. Dissolved 210Po concentrations peaked during the spring phytoplankton bloom and it is suggested this is related to preferential scavenging of 210Po by the increased numbers of bacteria, viruses and small dissolved particulates. Changes in L. littorea 210Po specific activity are thought not to be related to food, but to a drop in body weight following spawning. Much of the 210Po accumulated by M. edulis was located in the digestive gland. The specific activity of 210Po in the digestive gland of M. edulis was shown to be strongly correlated with changes in sea water suspended particulate specific activity. Examination of other trace metal (Ag, Al, As, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Sb, Se, Sn and Zn) variations in the digestive gland revealed that class B and borderline metals had a strong positive correlation with 210Po. On-going work is investigating whether the accumulation and loss of 210Po is affected by the presence of metallothioneins.

Aspects on the analysis of 210Po.

PubMed

Henricsson, F; Ranebo, Y; Holm, E; Roos, P

2011-05-01

There has been little development regarding analysis of polonium (Po) in environmental samples since the 1960 ies. This is due to the straightforward spontaneous deposition of this element on silver (Ag), nickel (Ni) or copper (Cu) without any radiochemical separation. For many years, no radiochemical yield determinant was used and it was generally supposed that the yield was 100% after two depositions. Counting was often done using ZnS scintillation counter coupled to a photomultiplier tube. However, the use of the yield determinants (208)Po and (209)Po and the development of alpha spectrometry showed that the yield was lower. Furthermore, the tendency of Po to volatilize at low temperatures constrains the sample preparation techniques; dry-ashing cannot be used. But during the wet-ashing procedure, there are still some losses. The aim of this study was to evaluate the Po losses during wet-ashing by the use of a double-tracer technique. We have found that the losses were about 30% when open glass beakers were used and about 17% when the samples were digested in microwave oven. When long-necked bottles (Kjeldahl flasks) were used, a loss of about 20% was registered. It has also been observed that (210)Pb to some extent is plating out together with its daughter nuclide Po during the electrochemical deposition. This will result in a systematic error since an unknown amount of supported (210)Po will be produced from the (210)Pb decay depending on the fraction of (210)Pb being deposited on the disc and the waiting time between deposition and measurement of the sample. A further consequence of this is that in the assessment of the (210)Pb content in the sample, very often the remaining liquid is stored after deposition for build-up of (210)Po. Since some (210)Pb is lost on the disc, the result for (210)Pb will be too low. Both these systematic errors give rise to a too high (210)Po/(210)Pb ratio. The fraction of (210)Pb which is plating out has been assessed in this

A chemical bath deposition route to facet-controlled Ag{sub 3}PO{sub 4} thin films with improved visible light photocatalytic activity

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

Gunjakar, Jayavant L.; Jo, Yun Kyung; Kim, In Young

A facile, economic, and reproducible chemical bath deposition (CBD) method is developed for the fabrication of facet-controlled Ag{sub 3}PO{sub 4} thin films with enhanced visible light photocatalytic activity. The fine-control of bath temperature, precursor, complexing agent, substrate, and solution pH is fairly crucial in preparing the facet-selective thin film of Ag{sub 3}PO{sub 4} nanocrystal. The change of precursor from silver nitrate to silver acetate makes possible the tailoring of the crystal shape of Ag{sub 3}PO{sub 4} from cube to rhombic dodecahedron and also the bandgap tuning of the deposited films. The control of [Ag{sup +}]/[phosphate] ratio enables to maximize themore » loading amount of Ag{sub 3}PO{sub 4} crystals per the unit area of the deposited film. All the fabricated Ag{sub 3}PO{sub 4} thin films show high photocatalytic activity for visible light-induced degradation of organic molecules, which can be optimized by tailoring the crystal shape of the deposited crystals. This CBD method is also useful in preparing the facet-controlled hybrid film of Ag{sub 3}PO{sub 4}–ZnO photocatalyst. The present study clearly demonstrates the usefulness of the present CBD method for fabricating facet-controlled thin films of metal oxosalt and its nanohybrid. - Highlights: • The crystal facet of Ag{sub 3}PO{sub 4} films can be tuned by chemical bath deposition. • The crystal shape of Ag{sub 3}PO{sub 4} is tailorable from cube to rhombic dodecahedron. • Facet-tuned Ag{sub 3}PO{sub 4} film shows enhanced visible light photocatalyst activity.« less

Rate-dependent, Li-ion insertion/deinsertion behavior of LiFePO4 cathodes in commercial 18650 LiFePO4 cells.

PubMed

Liu, Qi; He, Hao; Li, Zhe-Fei; Liu, Yadong; Ren, Yang; Lu, Wenquan; Lu, Jun; Stach, Eric A; Xie, Jian

2014-03-12

We have performed operando synchrotron high-energy X-ray diffraction (XRD) to obtain nonintrusive, real-time monitoring of the dynamic chemical and structural changes in commercial 18650 LiFePO4/C cells under realistic cycling conditions. The results indicate a nonequilibrium lithium insertion and extraction in the LiFePO4 cathode, with neither the LiFePO4 phase nor the FePO4 phase maintaining a static composition during lithium insertion/extraction. On the basis of our observations, we propose that the LiFePO4 cathode simultaneously experiences both a two-phase reaction mechanism and a dual-phase solid-solution reaction mechanism over the entire range of the flat voltage plateau, with this dual-phase solid-solution behavior being strongly dependent on charge/discharge rates. The proposed dual-phase solid-solution mechanism may explain the remarkable rate capability of LiFePO4 in commercial cells.

Production and decay spectroscopy of {sup 192}Po and {sup 194}Po

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

Andel, B., E-mail: boris.andel@fmph.uniba.sk

2015-10-15

A γ-ray spectroscopy study of the (11{sup −}) isomers in {sup 194}Po and {sup 192}Po was performed at the velocity filter SHIP at GSI (Germany). Nuclei were produced in fusion-evaporation reactions and investigated in the detection set-up at the focal plane after the separator. Several new γ transitions were attributed to the isomers and detailed analysis of the first γ-γ coincidences for both isomers is being prepared. For the reaction {sup 56}Fe + {sup 141}Pr → {sup 197}At*, excitation functions for astatine and polonium isotopes were measured and compared with HIVAP calculations.

Degradation of microcystin-LR by highly efficient AgBr/Ag3PO4/TiO2 heterojunction photocatalyst under simulated solar light irradiation

NASA Astrophysics Data System (ADS)

Wang, Xin; Utsumi, Motoo; Yang, Yingnan; Li, Dawei; Zhao, Yingxin; Zhang, Zhenya; Feng, Chuanping; Sugiura, Norio; Cheng, Jay Jiayang

2015-01-01

A novel photocatalyst AgBr/Ag3PO4/TiO2 was developed by a simple facile in situ deposition method and used for degradation of mirocystin-LR. TiO2 (P25) as a cost effective chemical was used to improve the stability of AgBr/Ag3PO4 under simulated solar light irradiation. The photocatalytic activity tests for this heterojunction were conducted under simulated solar light irradiation using methyl orange as targeted pollutant. The results indicated that the optimal Ag to Ti molar ratio for the photocatalytic activity of the resulting heterojunction AgBr/Ag3PO4/TiO2 was 1.5 (named as 1.5 BrPTi), which possessed higher photocatalytic capacity than AgBr/Ag3PO4. The 1.5 BrPTi heterojunction was also more stable than AgBr/Ag3PO4 in photocatalysis. This highly efficient and relatively stable photocatalyst was further tested for degradation of the hepatotoxin microcystin-LR (MC-LR). The results suggested that MC-LR was much more easily degraded by 1.5 BrPTi than by AgBr/Ag3PO4. The quenching effects of different scavengers proved that reactive h+ and •OH played important roles for MC-LR degradation.

Cs2Bi(PO4)(WO4)

PubMed Central

Terebilenko, Kateryna V.; Zatovsky, Igor V.; Baumer, Vyacheslav N.; Slobodyanik, Nikolay S.

2009-01-01

Dicaesium bis­muth(III) phosphate(V) tungstate(VI), Cs2Bi(PO4)(WO4), has been synthesized during complex investigation in a molten pseudo-quaternary Cs2O–Bi2O3–P2O5–WO3 system. It is isotypic with K2Bi(PO4)(WO4). The three-dimensional framework is built up from [Bi(PO4)(WO4)] nets, which are organized by adhesion of [BiPO4] layers and [WO4] tetra­hedra above and below of those layers. The inter­stitial space is occupied by Cs atoms. Bi, W and P atoms lie on crystallographic twofold axes. PMID:21577386

49 CFR 604.36 - Powers of a PO.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Powers of a PO. 604.36 Section 604.36 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CHARTER SERVICE Hearings. § 604.36 Powers of a PO. A PO may: (a) Give notice of...

LiFePO4 nanoparticles enveloped in freestanding sandwich-like graphitized carbon sheets as enhanced remarkable lithium-ion battery cathode.

PubMed

Zhang, Yan; Zhang, Huijuan; Li, Xiao; Xu, Haitao; Wang, Yu

2016-04-15

A novel nanostructure where LiFePO4 nanoparticles are enveloped in sandwich-like carbon sheets as an enhanced cathode in lithium-ion batteries has successfully been synthesized for the first time. Compared to previous carbon-based nanocomposites, the achieved sandwich-like LiFePO4 nanocomposites exhibit totally different architecture, in which LiFePO4 nanoparticles are tightly entrapped between two carbon layers, instead of being anchored on the carbon sheet surfaces. In other words, the achieved sandwich-like LiFePO4 nanocomposite carbon layers are actually freestanding and can be operated and separated from each other. This is a great breakthrough in the design and synthesis of carbon-based functional materials. The obtained sandwich-like LiFePO4 nanocomposites present excellent electrochemical performance, which is rationally ascribed to the superb and unique structure and architecture. Of particular note is that the freestanding sandwich-like LiFePO4 nanocomposites exhibit enhanced cyclability and rate capability. At a high current density of 0.1 A g(-1), a stable specific capacity of approximately 168.5 mAh g(-1) can be delivered over 1000 cycles, and when the charge-discharge rates increase to 0.6, 2, 5 and 10 A g(-1), the specific capacities still survive at 149, 129, 114 and 91 mAh g(-1), respectively. Meanwhile, the sandwiched nanocomposite demonstrates a significantly improved low-temperature electrochemical energy storage performance. With respect to the excellent Li storage performance, and facility and reliability of production, the freestanding sandwich-like LiFePO4 nanocomposites are reasonably believed to have a great potential for multiple electrochemical energy storage applications.

Multi-heteroatom doped carbon coated Na3V2(PO4)3 derived from ionic liquids.

PubMed

Zhang, Lu-Lu; Zhou, Ying-Xian; Li, Tao; Ma, Di; Yang, Xue-Lin

2018-03-28

Multi-heteroatom (N, S and F) doped carbon coated Na 3 V 2 (PO 4 ) 3 (labeled as NVP/C-ILs) derived from an ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM]TF2N) has been successfully fabricated. The as-prepared Na 3 V 2 (PO 4 ) 3 particles are well dispersed and closely coated with a multi-heteroatom (N, S and F) doped carbon layer. As a cathode for sodium-ion batteries, the NVP/C-ILs electrode exhibits high reversible specific capacity (117.5 mA h g -1 at 1C), superior rate performance (93.4 mA h g -1 at 10C) and excellent cycling stability (∼95% capacity retention ratio at 10C over 1000 cycles). The impressive electrochemical performance of NVP/C-ILs can be attributed to effectively conductive networks for electrons and Na + ions induced by a joint effect of N, S and F doping on carbon. The use of multi-heteroatom doped carbon coated Na 3 V 2 (PO 4 ) 3 provides a facile and effective strategy for the fabrication of high performance electrode materials with low intrinsic electrical conductivity.

Carbon nanostructures modified LiFePO4 cathodes for lithium ion battery applications: optimized porosity and composition

NASA Astrophysics Data System (ADS)

Mahmoud, Lama; Singh Lalia, Boor; Hashaikeh, Raed

2016-12-01

Lithium iron phosphate (LiFePO4) battery cathode was fabricated without using any metallic current collector and polymeric binder. Carbon nanostructures (CNS) were used as microbinders for LiFePO4 particles and at the same time as a 3D current collector. A facile and cost effective method of fabricating composite cathodes of CNS and LiFePO4 was developed. Thick electrodes with high loading of active material (20-25 mg cm-2) were obtained that are almost 2-3 folds higher than commercial electrodes. SEM images confirm that the 3D CNS conductive network encapsulated the LiFePO4 particles homogenously facilitating the charge transfer at the electrode-CNS interface. The composition, scan rate and porosity of the paper-like cathode were sequentially varied and their influence was systematically monitored by means of linear sweep cyclic voltammetry and AC electrochemical impedance spectroscopy. Addition of CNS improved the electrode’s bulk electronic conductivity, mechanical integrity, surface area and double layer capacitance, yet compromised the charge transfer resistance at the electrode-electrolyte interface. Based on a range of the tested binder-free electrodes, this study proposes that electrodes with 20 wt% CNS having 49 ± 2.5% porosity had realized best improvements of two folds and four folds in the electronic conductivity and diffusion coefficient, respectively.

Micro-Raman observation on the H2PO4- association structures in a supersaturated droplet of potassium dihydrogen phosphate (KH2PO4)

NASA Astrophysics Data System (ADS)

Syed, Kamran Ajmal; Pang, Shu-Feng; Zhang, Yun; Zhang, Yun-Hong

2013-01-01

The efflorescence of an individual KH2PO4 droplet on Teflon substrate was investigated by micro-Raman spectroscopy. With the decrease of relative humidity (RH) from 98.0% to 73.0%, the KH2PO4 droplet lost water gradually and entered into supersaturated state, which was reflected by the area ratio between the water stretching band to the sum of νs-PO2 and νs-P(OH)2 bands of the H2PO4- (A_{H_2 O} /(A_{(ν _s -PO_2 } {+ A}_{ν _s -P(OH)_2 {)}} {)}). In 1.0 mol l-1 KH2PO4 solution, the νs-P(OH)2 and νs-PO2 bands appeared at 877 and 1077 cm-1. In the KH2PO4 droplet, the two bands shifted to 894 and 1039 cm-1 at 98.0% RH, to 899 and 1031 cm-1 at 89.6% RH, and then to 904 and 997 cm-1 at 73.0% RH. Moreover, the aggregation process between the H2PO4- ions was observed from the spectral characteristic of the νs-P(OH)2 band in the concentration process, including the transitions of the H2PO4- ions from monomer in bulk solutions (0.5-1.0 mol l-1) to possible dimers at 98.0% RH and then further to oligomers in the droplet with the RH decrease, which were indicated by the blueshift of the νs-P(OH)2 band and its full width at half-height as a function of the RH. When the RH reached at 72.0%, the anhydrous crystal was obtained. A strong peak appeared at 928 cm-1, implying that the four oxygen atoms of the H2PO4- were all hydrogen bonding through the bridge hydrogen atoms to get the extensive hydrogen-bonded network structure of the H2PO4- association, leading to the symmetric increase of the H2PO4- ion from C2v in dilute solution to quasi-Td in the anhydrous crystal.

Study of phase relationships in the Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system. Phase diagram and thermal characteristics of phases

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

Matraszek, Aleksandra, E-mail: aleksandra.matraszek@ue.wroc.pl

2013-07-15

A diagram representing phase relationships in the Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} phosphate system has been developed on the basis of results obtained by thermal analysis (DTA/DSC/TGA) and X-ray diffraction (XRD) methods. One intermediate compound with the formula Sr{sub 3}Ce(PO{sub 4}){sub 3} occurs in the Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system at temperatures exceeding 1045 °C. The compound has a eulytite structure with the following structural parameters: a=b=c=10.1655(8) Å, α=β=γ=90.00°, V=1050.46(6) Å{sup 3}. It's melting point exceeds 1950 °C. A limited solid solution exists in the system, which possesses the structure of a low-temperature form of Sr{sub 3}(PO{sub 4}){sub 2}.more » At 1000 °C the maximal concentration of CePO{sub 4} in the solid solution is below 20 mol%. The solid solution phase field narrows with increased temperature. There is a eutectic point in the (Sr{sub 3}(PO{sub 4}){sub 2}+Sr{sub 3}Ce(PO{sub 4}){sub 3}) phase field at 1765 °C and 15 mol% of CePO{sub 4}. The melting temperature of Sr{sub 3}(PO{sub 4}){sub 2} is 1882±15 °C. - Graphical abstract: The phase diagram of Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system showing the stability ranges of limited solid solution and Sr{sub 3}Ce(PO{sub 4}){sub 3} phases. - Highlights: • Sr{sub 3}(PO{sub 4}){sub 2} melts at 1882 °C. • Phase diagram of Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system has been proposed. • Limited solid solution of CePO{sub 4} in Sr{sub 3}(PO{sub 4}){sub 2} forms in the system. • The Sr{sub 3}Ce(PO{sub 4}){sub 2} phosphate is stable at temperatures above 1045 °C.« less

210Po and 210Pb activity in Chinese cigarettes.

PubMed

Schayer, Stephen; Nowak, Barbara; Wang, Yanling; Qu, Qingshan; Cohen, Beverly

2009-05-01

The radon decay products lead-210 ((210)Pb) and polonium-210 ((210)Po) are known components of tobacco. China is the world's largest producer and consumer of cigarettes, yet no comprehensive published reports of the (210)Pb and (210)Po activity concentrations in Chinese cigarettes are available. Twelve brands of cigarettes that were commonly smoked within a group of 184 Chinese smokers were selected for (210)Pb and (210)Po activity analysis. For each brand, the tobacco from two cigarettes was isolated, dried, weighed, spiked with a (209)Po tracer for yield, and digested with concentrated HNO3, followed by HCl. The polonium in each digested solution was spontaneously deposited onto a nickel disc. The polonium activity was then counted using alpha spectroscopy. The mean (range) (210)Po activity for all brands was 23 (18-29) mBq cig(-1). The state of radioactive equilibrium between (210)Po and (210)Pb in each cigarette was verified in three brands of cigarettes. Cigarettes from two brands were smoked on a machine in order to estimate the fraction of (210)Pb and (210)Po inhaled. An average of 8% of the (210)Pb and 13% of the (210)Po in the tobacco of the cigarettes was transferred to the mainstream smoke. It is thus estimated that a person smoking 20 of these cigarettes per day in China would inhale a mean (range) of 37 (29-46) mBq d(-1) of (210)Pb and 60 (47-75) mBq d(-1) of (210)Po. Cigarette smoking in China may therefore be a large source of a person's daily intake of (210)Pb and (210)Po.

Targeted partial surface modification with nano-SiO2@Li2CoPO4F as high-voltage cathode material for LIBs

NASA Astrophysics Data System (ADS)

Chang, Caiyun; Huang, Zhipeng; Tian, Runsai; Jiang, Xinyu; Li, Chunsheng; Feng, Jijun

2017-10-01

Tuning whole/partial surface modification on cathode material with oxide material is a sought-after method to enhance the electrochemical performance in power storage field. Herein, nano-SiO2 targeted partial surface modified high voltage cathode material Li2CoPO4F has been successfully fabricated via a facile self-assembly process in silica dispersion at ambient temperature. With the aid of polar -OH groups attracted on the surface of SiO2 micelles, the nano-SiO2 preferentially nestle up along the borders and boundaries of Li2CoPO4F particles, where protection should be deployed with emphasis against the undesirable interactions between materials and electrolytes. Compared with pristine Li2CoPO4F, the SiO2 selectively modified Li2CoPO4F cathode materials, especially LCPF-3S, exhibit desirable electrochemical performances with higher discharge capacity, more outstanding cycle stability and favorable rate capability without any additional carbon involved. The greatly enhanced electrochemical properties can be attributed to the improved lithium-ion diffusion kinetics and structure tolerance during repeated lithiation/delithiation process. Such findings reveal a great potential of nano-SiO2 modified Li2CoPO4F as high energy cathode material for lithium ion batteries.

The Growth of Berlinite (AlPO4) Single Crystals.

DTIC Science & Technology

1980-03-01

Solubility of AlPO 4 18 6. Solubility Data of Jahn and Kordes on AlPO4 19 7. AlPO 4 Seed Crystal 23 8. Tem-Pres Hydrothermal Research Unit 25 9...Since the vapor pressure of water rises rapidly with temperature, a closed hydrothermal system was used. In a seeded hydrothermal growth process, the...to investigate the hydrothermal growth of Berlinite (AlPO4 ) to determine the optimum growth conditions for large high quality crystals. Over thirty

Na(7)Mg(13)Nd(PO(4))(12).

PubMed

Jerbi, Hasna; Hidouri, Mourad; Mongi, Ben Amara

2012-06-01

Investigations of the quasi-ternary system Na(3)PO(4)-Mg(3)(PO(4))(2)-NdPO(4) allowed us to obtain the new phosphate hepta-sodium trideca-magnesium neodymium dodeca-kis-phosphate, Na(7)Mg(13)Nd(PO(4))(12), by applying a flux method. The crystal structure is isotypic with that of the previously reported Na(7)Mg(13)Ln(PO(4))(12) (Ln = Eu, La) compounds. It consists of a complex three-dimensional framework built up from an NdO(8) polyhedron (m symmetry), an MO(6) octa-hedron statistically occupied by M = Mg and Na, and eight MgO(x) (x = 5, 6) polyhedra (four with site symmetry m), linked either directely by sharing corners, edges and faces, or by one of the eight unique PO(4) tetra-hedra through common corners. Two of the PO(4) tetra-hedra are statisticaly disordered over a mirror plane. The whole structure can be described as resutling from an assembly of two types of structural units, viz [Mg(4)MP(4)O(22)](∞) (2) layers extending parallel to (100) and stacked along [100], and [Mg(4)NdP(4)O(36)](∞) (1) undulating chains running along the [010] direction. The six different Na(+) cations (five with site symmetry m and one with 0.5 occupancy) are situated in six distinct cavities delimited by the framework. The structure was refined from data of a racemic twin.

Identification of Phosphorus Monoxide (X2Πr) in VY Canis Majoris: Detection of the First PO Bond in Space

NASA Astrophysics Data System (ADS)

Tenenbaum, E. D.; Woolf, N. J.; Ziurys, L. M.

2007-09-01

A new interstellar molecule, PO (X2Πr), has been detected toward the envelope of the oxygen-rich supergiant star VY Canis Majoris (VY CMa) using the Submillimeter Telescope of the Arizona Radio Observatory. The J=5.5-->4.5 and J=6.5-->5.5 rotational transitions of PO at 240 and 284 GHz were observed, each of which consisted of well-defined lambda-doublets. The line profiles are roughly parabolic in shape, analogous to PN, and suggest that this species arises from the spherical wind in VY CMa, as opposed to the collimated blue- and redshifted outflows. Comparison of line intensities indicates that PO arises from a confined source roughly 1" in extent, with a column density of Ntot ~= 2.8 × 1015 cm-2, which corresponds to a fractional abundance of f~9×10-8, relative to H2. Consequently, PO and PN have similar concentrations in VY CMa, a result not predicted by either LTE or kinetic models of circumstellar chemistry. These phosphorus compounds may arise from shock-induced reactions in this active envelope. Phosphorus monoxide is the first interstellar molecule detected that contains a PO bond, a moiety essential in biochemical compounds. It is also the first new species to be identified in an oxygen-rich, as opposed to a carbon-rich, circumstellar envelope.

Assessment of ²¹⁰Po in Italian diet.

PubMed

Meli, Maria Assunta; Desideri, Donatella; Roselli, Carla; Feduzi, Laura

2014-07-15

This research was dedicated to the study, in the Italian daily diet, of the background activity concentration of (210)Po, a radionuclide with a high radiotoxicity. (210)Po was determined by alpha spectrometry. For food products of vegetable origin, the (210)Po activity concentration follows the trend: leafy vegetable>flour>rice>fruits>pasta>other vegetables>fruit vegetable; for those of animal origin: eggs>cheese>milk. The (210)Po activity concentration was also compared with that found by the same authors in meat, sea food, water and beverages in a previous study. The committed effective doses to individuals of three population groups (infants, children and adults) were 379, 222 and 151 μSv y(-1), respectively. The intake of foods of marine origin contributed about 67% of the total dose due to (210)Po ingestion. The effective dose, from (210)Po ingested by total diet, accounts for only 5-12% of the natural radiation exposure in Italy. Copyright © 2014 Elsevier Ltd. All rights reserved.

210Po and 210Pb variations in fish species from the Aegean Sea and the contribution of 210Po to the radiation dose.

PubMed

Çatal, Ebru Mat; Uğur, Aysun; Ozden, Banu; Filizok, Işik

2012-04-01

In recent years, there has been increasing interest in the significance of natural radionuclides, particularly (210)Po, in the marine environment. (210)Po, a naturally occurring alpha emitter, accumulates in marine organisms and reflects differences in their diets. In the literature, there is no data for (210)Po and (210)Pb activity concentrations for fish species on the Turkish coast of Aegean Sea. Therefore, in this study, multiple fish species were collected from six stations seasonally on the Turkish coast of Aegean Sea and were analyzed for their (210)Po and (210)Pb content. The (210)Po and (210)Pb concentrations in the fish samples were found to vary from undetectable levels to 499 ± 44 Bq kg(-1) dry weight (dw) and from 1.0 ± 0.3 Bq kg(-1) to 35 ± 4.0 Bq kg(-1) (dw), respectively. There were no significant differences in the activity concentrations of (210)Po and (210)Pb in fish samples between seasons (ANOVA, P>0.05). The highest dose contribution of (210)Po to humans was calculated to be 10,530 μSv year(-1). Copyright © 2012 Elsevier Ltd. All rights reserved.

Integration of bicycling and walking facilities into the infrastructure of urban communities : [research brief].

DOT National Transportation Integrated Search

2012-02-01

Many manuals, handbooks and web resources exist that provide guidance on planning for and designing bicycle and pedestrian facilities. However few of these resources emphasize program and infrastructure characteristics most desired by current (and po...

Synthesis, structure and NMR characterization of a new monomeric aluminophosphate [ dl-Co(en) 3] 2[Al(HPO 4) 2(H 1.5PO 4) 2(H 2PO 4) 2](H 3PO 4) 4 containing four different types of monophosphates

NASA Astrophysics Data System (ADS)

Chen, Peng; Li, Jiyang; Xu, Jun; Duan, Fangzheng; Deng, Feng; Xu, Ruren

2009-03-01

A new zero-dimensional (0D) aluminophosphate monomer [ dl-Co(en) 3] 2[Al(HPO 4) 2(H 1.5PO 4) 2(H 2PO 4) 2](H 3PO 4) 4 (designated AlPO-CJ38) with Al/P ratio of 1/6 has been solvothermally prepared by using racemic cobalt complex dl-Co(en) 3Cl 3 as the template. The Al atom is octahedrally linked to six P atoms via bridging oxygen atoms, forming a unique [Al(HPO 4) 2(H 1.5PO 4) 2(H 2PO 4) 2] 6- monomer. Notably, there exists intramolecular symmetrical O⋯H⋯O bonds, which results in pseudo-4-rings stabilized by the strong H-bonding interactions. The structure is also featured by the existence of four different types of monophosphates that have been confirmed by 31P NMR and 1H NMR spectra. The crystal data are as follows: AlPO-CJ38, [ dl-Co(en) 3] 2[Al(HPO 4) 2(H 1.5PO 4) 2(H 2PO 4) 2](H 3PO 4) 4, M = 1476.33, monoclinic, C2/ c (No. 15), a = 36.028(7) Å, b = 8.9877(18) Å, c = 16.006(3) Å, β = 100.68(3)°, U = 5093.2(18) Å 3,Z = 4, R1 = 0.0509 ( I > 2 σ( I)) and wR2 = 0.1074 (all data). CCDC number 689491.

Neutron diffraction studies of the Na-ion battery electrode materials NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3}

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

Yahia, H. Ben; Essehli, R., E-mail: ressehli@qf.org.qa; Avdeev, M.

The new compounds NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} were synthesized by sol-gel method and their crystal structures were determined by using neutron powder diffraction data. These compounds were characterized by galvanometric cycling and cyclic voltammetry. NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} crystallize with a stuffed α-CrPO{sub 4}-type structure. The structure consists of a 3D-framework made of octahedra and tetrahedra that are sharing corners and/or edges generating channels along [100] and [010], in which the sodium atoms are located. Of significance, in the structuresmore » of NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} a statistical disorder Ni{sup 2+}/Cr{sup 3+} was observed on both the 8g and 4a atomic positions, whereas in NaCoCr{sub 2}(PO{sub 4}){sub 3} the statistical disorder Co{sup 2+}/Cr{sup 3+} was only observed on the 8g atomic position. When tested as negative electrode materials, NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} delivered specific capacities of 352, 385, and 368 mA h g{sup −1}, respectively, which attests to the electrochemical activity of sodium in these compounds. - Highlights: • NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} were synthesized by sol-gel method. • The crystal structures were determined by using neutron powder diffraction data. • The three compounds crystallize with a stuffed α-CrPO{sub 4}-type structure. • The three compounds were tested as anodes in sodium-ion batteries. • Relatively high specific capacities were obtained for these compounds.« less

Vertical profiles of pollutant gases measured with passive DOAS in the Po Valley devoted to satellite and chemical model data comparison

NASA Astrophysics Data System (ADS)

Masieri, S.; Petritoli, A.; Kostadinov, I.; Bortoli, D.; Premuda, M.; Ravegnani, F.; Giovanelli, G.

2009-04-01

In the frame of QUITSAT Italian pilot project (Air QUality with InTegration of ground-based and SAtellite measurement and chemical Transport model), two field campaigns were made in S.Pietro Capofiume (44.65˚ N; 11.37˚ E) and Bologna (44.52˚ N; 11.34˚ E) to provide concentration of ground particular matter and gaseous pollutants, namely nitrogen dioxide (NO2), formaldehyde (HCHO), sulphur dioxide (SO2) and ozone (O3). The aim of the campaigns was to provide experimental data need for tests and improvement of algorithms developed for integration of satellite and ground-based data together with chemical transport model data in order to retrieve air quality in the QUITSAT domain. Ground based measurements were carried out within a network of in-situ analyser in the Po Valley and with a scanning multi-axis DOAS (Differential Optical Absorption Spectroscopy) spectrometer system developed at ISAC-CNR institute [1], in collaboration with Geophysics Center of Evora [2]. TropoGAS (TROPOspheric Gas Analyser Spectrometer) spectrometer permits active and passive DOAS measurements at the chosen angles: α =1,2,3,6,10,15,20,90 and another measurement was taken along the sun direction. A Xenon lamp installed at 1km of distance from spectrometer was used as a reference concentration measured in the same place, and these values shows good agreement with in-situ analyser concentration. Gas spectral absorption was evaluated with DOAS [3] algorithms from 430 to 500 nm in two different windows: first from 436 to 460 nm for NO2 retrieval; second from 460 to 500 nm for O4 (best line at 477 nm) and NO2. Air Mass Factor (AMF) was calculated using PROMSAR (PROcessing of Multi-Scattered Atmospheric Radiation) model [4], that is a backward Montecarlo Radiative Transfer Model (RTM). An apposite inversion method [5][6], was applied to retrieve profiles of the target gases from their Slant Column Densities (SCD), using advanced approaches involving measurement of the atmospheric O4

LiFePO4 Nanostructures Fabricated from Iron(III) Phosphate (FePO4 x 2H2O) by Hydrothermal Method.

PubMed

Saji, Viswanathan S; Song, Hyun-Kon

2015-01-01

Electrode materials having nanometer scale dimensions are expected to have property enhancements due to enhanced surface area and mass/charge transport kinetics. This is particularly relevant to intrinsically low electronically conductive materials such as lithium iron phosphate (LiFePO4), which is of recent research interest as a high performance intercalation electrode material for Li-ion batteries. Many of the reported works on LiFePO4 synthesis are unattractive either due to the high cost of raw materials or due to the complex synthesis technique. In this direction, synthesis of LiFePO4 directly from inexpensive FePO4 shows promise.The present study reports LiFePO4 nanostructures prepared from iron (III) phosphate (FePO4 x 2H2O) by precipitation-hydrothermal method. The sintered powder was characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Inductive coupled plasma-optical emission spectroscopy (ICP-OES), and Electron microscopy (SEM and TEM). Two synthesis methods, viz. bulk synthesis and anodized aluminum oxide (AAO) template-assisted synthesis are reported. By bulk synthesis, micro-sized particles having peculiar surface nanostructuring were formed at precipitation pH of 6.0 to 7.5 whereas typical nanosized LiFePO4 resulted at pH ≥ 8.0. An in-situ precipitation strategy inside the pores of AAO utilizing the spin coating was utilized for the AAO-template-assisted synthesis. The template with pores filled with the precipitate was subsequently subjected to hydrothermal process and high temperature sintering to fabricate compact rod-like structures.

LiFePO4 mesocrystals for lithium-ion batteries.

PubMed

Popovic, Jelena; Demir-Cakan, Rezan; Tornow, Julian; Morcrette, Mathieu; Su, Dang Sheng; Schlögl, Robert; Antonietti, Markus; Titirici, Maria-Magdalena

2011-04-18

Olivine LiFePO(4) is considered one of the most promising cathode materials for Li-ion batteries. A simple one-step, template-free, low-temperature solvothermal method is developed for the synthesis of urchinlike hierarchical mesocrystals of pristine LiFePO(4) as well as carbon-coated LiFePO(4) composites. Each urchinlike mesocrystal consists of LiFePO(4) sheets self-assembled via a dipolar field in spheres during a solvothermal process under the influence of Cl(-) anions. The obtained primary sheets of LiFePO(4) are single crystalline in nature and can be coated in situ with an amorphous nitrogen-doped carbonaceous layer several nanometers in thickness. To increase the conductivity of the carbon coating, the materials are subjected to further temperature treatment (700 °C) under an inert atmosphere. The lithium storage performance of the pure LiFePO(4) is compared with that of its carbon-coated counterparts. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radionuclides (210Po and 210Pb) and Some Heavy Metals in Fish and Sediments in Lake Bafa, Turkey, and the Contribution of 210Po to the Radiation Dose.

PubMed

Manav, Ramazan; Uğur Görgün, Aysun; Filizok, Işık

2016-11-09

The pollution level of Lake Bafa was investigated by collecting fish samples { Dicentrarchus labrax (sea bass), Liza ramada (mullet) and Anguilla anguilla (eel)}, surface sediment, and core samples. In all these samples, 210 Po and 210 Pb concentrations were estimated, and total annual dose rates were obtained for each species. Some heavy metal (Cr, Ni, Pb, Cd, Mn, Fe, and Zn) concentration levels were obtained for the fish and a core sample. The sediment mass accumulation rate was found to be 3.27 g·m -2 ·day -1 (0.119 g·cm -2 ·y -1 ) from a core sample. The heavy metal concentrations in the vertical profile of samples from the core were also observed. The measured concentration of Zn, Pb, Cd, and Cr were between the ERL (effects range low) and ERM (effects range median) limits, while Ni concentrations were higher than the ERM limit. The observed concentrations of Cd, Pb, and Zn in fish samples did not exceed the limits in accordance with Turkish Food Regulations. Further, the maximum effective dose equivalent of 210 Po in the area was found to be 1.169 µSv·y -1 .

Ag{sub 3}PO{sub 4}/ZnO: An efficient visible-light-sensitized composite with its application in photocatalytic degradation of Rhodamine B

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

Liu, Wei; School of Chemistry and Material Science, Huaibei Normal University, Huaibei 235000; Wang, Mingliang, E-mail: wangmlchem@263.net

2013-01-15

Graphical abstract: The free OH radicals generated in the VB of ZnO play the primary role in the visible-light photocatalytic degradation of RhB in Ag{sub 3}PO{sub 4}/ZnO system. The accumulated electrons in the CB of Ag{sub 3}PO{sub 4} can be transferred to O{sub 2} adsorbed on the surface of the composite semiconductors and H{sub 2}O{sub 2} yields. H{sub 2}O{sub 2} reacts with electrons in succession to produce active ·OH to some extent. Display Omitted Highlights: ► Efficient visible-light-sensitized Ag{sub 3}PO{sub 4}/ZnO composites were successfully prepared. ► Effect of Ag{sub 3}PO{sub 4} content on the catalytic activity of Ag{sub 3}PO{sub 4}/ZnOmore » is studied in detail. ► Rate constant of RhB degradation over Ag{sub 3}PO{sub 4}(3.0 wt.%)/ZnO is 3 times that of Ag{sub 3}PO{sub 4}. ► The active species in RhB degradation are examined by adding a series of scavengers. ► Visible light degradation mechanism of RhB over Ag{sub 3}PO{sub 4}/ZnO is systematically studied. -- Abstract: The efficient visible-light-sensitized Ag{sub 3}PO{sub 4}/ZnO composites with various weight percents of Ag{sub 3}PO{sub 4} were prepared by a facile ball milling method. The photocatalysts were characterized by XRD, DRS, SEM, EDS, XPS, and BET specific area. The ·OH radicals produced during the photocatalytic reaction was detected by the TA–PL technique. The photocatalytic property of Ag{sub 3}PO{sub 4}/ZnO was evaluated by photocatalytic degradation of Rhodamine B under visible light irradiation. Significantly, the results revealed that the photocatalytic activity of the composites was much higher than that of pure Ag{sub 3}PO{sub 4} and ZnO. The rate constant of RhB degradation over Ag{sub 3}PO{sub 4}(3.0 wt.%)/ZnO is 3 times that of single-phase Ag{sub 3}PO{sub 4}. The optimal percentage of Ag{sub 3}PO{sub 4} in the composite is 3.0 wt.%. It is proposed that the ·OH radicals produced in the valence band of ZnO play the leading role in the photocatalytic

Desired crystal oriented LiFePO4 nanoplatelets in situ anchored on a graphene cross-linked conductive network for fast lithium storage.

PubMed

Wang, Bo; Liu, Anmin; Abdulla, Wael Al; Wang, Dianlong; Zhao, X S

2015-05-21

Electron transfer and lithium ion diffusion rates are the key factors limiting the lithium ion storage in anisotropic LiFePO4 electrodes. In this work, we employed a facile solvothermal method to synthesize a "platelet-on-sheet" LiFePO4/graphene composite (LFP@GNs), which is LiFePO4 nanoplatelets in situ grown on graphene sheets with highly oriented (010) facets of LiFePO4 crystals. Such a two-phase contact mode with graphene sheets cross-linked to form a three-dimensional porous network is favourable for both fast lithium ion and electron transports. As a result, the designed LFP@GNs displayed a high rate capability (∼56 mA h g(-1) at 60 C) and long life cycling stability (∼87% capacity retention over 1000 cycles at 10 C). For comparison purposes, samples ex situ modified with graphene (LFP/GNs) as well as pure LiFePO4 platelets (LFP) were also prepared and investigated. More importantly, the obtained LFP@GNs can be used as a basic unit for constructing more complex structures to further improve electrochemical performance, such as coating the exposed LFP surface with a thin layer of carbon to build a C@LFP@GN composite to further enhance its cycling stability (∼98% capacity retention over 1000 cycles at 10 C).

Get Involved in Education and Public Outreach! The Science Mission Directorate Science E/PO Forums Are Here to Help

NASA Astrophysics Data System (ADS)

Shipp, S. S.; Buxner, S.; Schwerin, T. G.; Hsu, B. C.; Peticolas, L. M.; Smith, D.; Meinke, B. K.

2013-12-01

programs in context (e.g., Beyond IYA, Sun-Earth Day, launch events, 50 Years of Solar System Exploration, Earth Science Week), and get your programs and products disseminated. 4) Connections to education professionals to collaborate with you on educational programs, involve intended audience members as partners to guide your programs, reach a broader audience, and insure impact with external partners through the E/PO community contact database and workspace profiles, conferences, meetings, and SMD E/PO community annual retreats. Recently developed, the NASA SMD Scientist Speaker's Bureau (http://www.lpi.usra.edu/education/speaker) offers an online portal to connect scientists interested in getting involved in E/PO projects - giving public talks, classroom visits, and virtual connections - with audiences. Learn more about the Forums and the opportunities to become involved in E/PO and to share your science with students, educators, and the general public at http://smdepo.org.

Facility Management's Role in Organizational Sustainability

ERIC Educational Resources Information Center

Adams, Gregory K.

2013-01-01

Facility managers have questions about sustainability. How do an organization's physical facilities--its built environment--and the management of them, influence the sustainability of the organization or institution as a whole? How important is Facility Management (FM) to the overall sustainability profile of an organization? Facility managers…

Designing of luminescent GdPO4:Eu@LaPO4@SiO2 core/shell nanorods: Synthesis, structural and luminescence properties

NASA Astrophysics Data System (ADS)

Ansari, Anees A.; Labis, Joselito P.; Aslam Manthrammel, M.

2017-09-01

GdPO4:Eu3+ (core) and GdPO4:Eu@LaPO4 (core/shell) nanorods (NRs) were successfully prepared by urea based co-precipitation process at ambient conditions which was followed by coating with amorphous silica shell via the sol-gel chemical route. The role of surface coating on the crystal structure, crystallinity, morphology, solubility, surface chemistry and luminescence properties were well investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis, Fourier Transform Infrared (FTIR), UV-Vis, and photoluminescence spectroscopy. XRD pattern revealed highly purified, well-crystalline, single phase-hexagonal-rhabdophane structure of GdPO4 crystal. The TEM micrographs exhibited highly crystalline and narrow size distributed rod-shaped GdPO4:Eu3+ nanostructures with average width 14-16 nm and typical length 190-220 nm. FTIR spectra revealed characteristic infrared absorption bands of amorphous silica. High absorbance in a visible region of silica modified core/shell/Si NRs in aqueous environment suggests the high solubility along with colloidal stability. The photoluminescence properties were remarkably enhanced after growth of undoped LaPO4 layers due to the reduction of nonradiative transition rate. The advantages of presented high emission intensity and high solubility of core/shell and core/shell/Si NRs indicated the potential applications in monitoring biological events.

Baseline concentration of 210Po in Kuwait's commercial fish species.

PubMed

Uddin, S; Al-Ghadban, A N; Behbehani, M; Aba, A; Al Mutairi, A; Karam, Q

2012-11-01

This baseline study highlights the (210)Po variation in whole fishes with different feeding habits. Whole-body (210)Po concentrations were determined in ten important commercial fish species found in the northern Arabian Gulf to serve as baseline data. Primarily, (210)Po is absorbed from water, concentrated by phytoplankton and microzooplankton, and then transferred to the next trophic level along the marine food chain. The lowest concentration of (210)Po was measured in larger carnivorous fishes like hamoor (0.089 Bq kg(-1)), while the highest was found in the fishes that feed on algae, zooplanktons and detritus, like battan (3.30 Bq kg(-1)). The baseline data can be used to understand both the trophic transfer of (210)Po in the marine food chain and the (210)Po concentration factors in fish from the Arabian Gulf. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Establishment and activity of PoKuNyoKwan].

PubMed

Lee, Bang Weon

2008-06-01

PoKuNyoKwan was established in 1887 by Meta Howard, a female doctor who was dispatched from Woman's Foreign Missionary Society, an evangelical branch affiliated with U.S. North Methodist Church. PoKuNyoKwan was equipped with dispensaries, waiting rooms, pharmacies, warehouses, operating rooms, and wards for about 30 patients. It used a traditional Korean house, which was renovated for its medical purpose, in Ewha Haktang. Residing in Chung Dong, the medical institution had taken care of women's mental and physical health for about 25 years, until it was merged with East Gate Lillian Harris Memorial Hospital in 1912, and then its dispensary function was abolished in 1913. Medical missionaries (Meta Howard, Rosetta Sherwood, Mary M. Cutler, Emma Ernsberger, Esther K. Pak, Amanda F. Hillman) and nurse missionaries (Ella Lewis, Margaret J. Edmunds, Alta I. Morrison, Naomi A. Anderson), who were professionally trained in the United States, and their helpers, who were trained by those missionaries, managed PoKuNyoKwan. Nurses who were educated in Nurses' Training School, which was also established by PoKuNyoKwan, helped to run the institution as well. At the beginning, they usually had worked as a team of one medical missionary and three helpers. Since its establishment in 1903, however, the helpers began to enter the Nurses' Training School to become professional nurses, and the helpers eventually faded out because of the proliferation of those nurses. PoKuNyoKwan did not only offer medical services but also executed educational and evangelical activities. Medical missionaries struggled to overcome Koreans' ignorance and prejudice against westerners and western medical services, while they took care of their patients at office, for calls, and in hospital dispensaries. Enlightening the public by criticizing Korean traditional medical treatments including fork remedies, acupuncture, and superstitions, they helped modernization of medical systems in Korea. In the area of

Searching for “LiCr{sup II}PO{sub 4}”

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

Mosymow, E.; Glaum, R., E-mail: rglaum@uni-bonn.de; Kremer, R.K.

The two new phosphates LiCr{sup II}{sub 4}(PO{sub 4}){sub 3} and Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4} are discovered as equilibrium phases (ϑ=800 °C) in the quarternary system Li/Cr/P/O. Their crystal structures have been determined from single-crystal X-ray diffraction data (LiCr{sup II}{sub 4}(PO{sub 4}){sub 3}: violet-blue, Pnma (no. 62), Z=4, a=6.175(1) Å, b=14.316(3) Å, c=10.277(2) Å, 100 parameters, R{sub 1}=0.028, wR{sub 2}=0.08, 2060 unique reflections with F{sub o}>4σ(F{sub o}); Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4}: greyish-green, P1{sup ¯} (no. 2), Z=1, a=4.9379(7) Å, b=7.917(2) Å, c=8.426(2) Å, α=109.98(2)°, β=90.71(1)°, γ=104.91(1)°, 131 parameters, R{sub 1}=0.022, wR{sub 2}=0.067, 1594 unique reflectionsmore » with F{sub o}>4σ(F{sub o})). Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4} adopts an hitherto unknown structure type. The crystal structure of LiCr{sup II}{sub 4}(PO{sub 4}){sub 3} is isotypic to that of NaCd{sup II}{sub 4}(PO{sub 4}){sub 3} and related to that of the mineral silicocarnotite Ca{sub 5}(PO{sub 4}){sub 2}(SiO{sub 4}). Significant disorder between Li{sup +} and Cr{sup 2+} is observed for both crystal structures. The oxidation states assigned to chromium in these two phosphates are in agreement with UV/vis/NIR absorption spectra and magnetic susceptibility data recorded for both compounds. Instead of “LiCr{sup II}PO{sub 4}” mixtures of LiCr{sup II}{sub 4}(PO{sub 4}){sub 3}, Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4}, Cr{sub 2}O{sub 3}, and CrP are observed at equilibrium. Instead of “Li{sub 2}Cr{sup II}P{sub 2}O{sub 7}” four-phase mixtures consisting of Li{sub 9}Cr{sup III}{sub 3}(P{sub 2}O{sub 7}){sub 3}(PO{sub 4}){sub 2}, Li{sub 3}Cr{sup III}{sub 2}(PO{sub 4}){sub 3}, LiCrP{sub 2}O{sub 7}, and CrP were obtained. - Graphical abstract: Investigations on the equilibrium relations in the system Li/Cr/P/O revealed the two hitherto unknown phosphates

Rapid determination of 210Po in water samples

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

Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.

2013-08-02

A new rapid method for the determination of 210Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that can be used for emergency response or routine water analyses. If a radiological dispersive device (RDD) event or a radiological attack associated with drinking water supplies occurs, there will be an urgent need for rapid analyses of water samples, including drinking water, ground water and other water effluents. Current analytical methods for the assay of 210Po in water samples have typically involved spontaneous auto-deposition of 210Po onto silver or other metal disks followed by counting by alphamore » spectrometry. The auto-deposition times range from 90 minutes to 24 hours or more, at times with yields that may be less than desirable. If sample interferences are present, decreased yields and degraded alpha spectrums can occur due to unpredictable thickening in the deposited layer. Separation methods have focused on the use of Sr Resin, often in combination with 210Pb analysis. A new rapid method for 210Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that utilizes a rapid calcium phosphate co-precipitation method, separation using DGA Resin (N,N,N,N-tetraoctyldiglycolamide extractant-coated resin, Eichrom Technologies or Triskem-International), followed by rapid microprecipitation of 210Po using bismuth phosphate for counting by alpha spectrometry. This new method can be performed quickly with excellent removal of interferences, high chemical yields and very good alpha peak resolution, eliminating any potential problems with the alpha source preparation for emergency or routine samples. A rapid sequential separation method to separate 210Po and actinide isotopes was also developed. This new approach, rapid separation with DGA Resin plus microprecipitation for alpha source preparation, is a significant advance in radiochemistry for the rapid determination of 210Po.« less

Co11Li[(OH)5O][(PO3OH)(PO4)5], a Lithium-Stabilized, Mixed-Valent Cobalt(II,III) Hydroxide Phosphate Framework.

PubMed

Ludwig, Jennifer; Geprägs, Stephan; Nordlund, Dennis; Doeff, Marca M; Nilges, Tom

2017-09-18

A new metastable phase, featuring a lithium-stabilized mixed-valence cobalt(II,III) hydroxide phosphate framework, Co 11.0(1) Li 1.0(2) [(OH) 5 O][(PO 3 OH)(PO 4 ) 5 ], corresponding to the simplified composition Co 1.84(2) Li 0.16(3) (OH)PO 4 , is prepared by hydrothermal synthesis. Because the pH-dependent formation of other phases such as Co 3 (OH) 2 (PO 3 OH) 2 and olivine-type LiCoPO 4 competes in the process, a pH value of 5.0 is crucial for obtaining a single-phase material. The crystals with dimensions of 15 μm × 30 μm exhibit a unique elongated triangular pyramid morphology with a lamellar fine structure. Powder X-ray diffraction experiments reveal that the phase is isostructural with the natural phosphate minerals holtedahlite and satterlyite, and crystallizes in the trigonal space group P31m (a = 11.2533(4) Å, c = 4.9940(2) Å, V = 547.70(3) Å 3 , Z = 1). The three-dimensional network structure is characterized by partially Li-substituted, octahedral [M 2 O 8 (OH)] (M = Co, Li) dimer units which form double chains that run along the [001] direction and are connected by [PO 4 ] and [PO 3 (OH)] tetrahedra. Because no Li-free P31m-type Co 2 (OH)PO 4 phase could be prepared, it can be assumed that the Li ions are crucial for the stabilization of the framework. Co L-edge X-ray absorption spectroscopy demonstrates that the cobalt ions adopt the oxidation states +2 and +3 and hence provides further evidence for the incorporation of Li in the charge-balanced framework. The presence of three independent hydroxyl groups is further confirmed by infrared spectroscopy. Magnetization measurements imply a paramagnetic to antiferromagnetic transition at around T = 25 K as well as a second transition at around 9-12 K with a ferromagnetic component below this temperature. The metastable character of the phase is demonstrated by thermogravimetric analysis and differential scanning calorimetry, which above 558 °C reveal a two-step decomposition to CoO, Co 3 (PO 4 ) 2

PoSSUM: Polar Suborbital Science in the Upper Mesosphere

NASA Astrophysics Data System (ADS)

Reimuller, J. D.; Fritts, D. C.; Thomas, G. E.; Taylor, M. J.; Mitchell, S.; Lehmacher, G. A.; Watchorn, S. R.; Baumgarten, G.; Plane, J. M.

2013-12-01

Project PoSSUM (www.projectpossum.org) is a suborbital research project leveraging imaging and remote sensing techniques from Reusable Suborbital Launch Vehicles (rSLVs) to gather critical climate data through use of the PoSSUM Observatory and the PoSSUM Aeronomy Laboratory. An acronym for Polar Suborbital Science in the Upper Mesosphere, PoSSUM grew from the opportunity created by the Noctilucent Cloud Imagery and Tomography Experiment, selected by the NASA Flight Opportunities Program as Experiment 46-S in March 2012. This experiment will employ an rSLV (e.g. the XCOR Lynx Mark II) launched from a high-latitude spaceport (e.g. Eielson AFB, Alaska or Kiruna, Sweden) during a week-long deployment scheduled for July 2015 to address critical questions concerning noctilucent clouds (NLCs) through flights that transition the cloud layer where the clouds will be under direct illumination from the sun. The 2015 Project PoSSUM NLC campaign will use the unique capability of rSLVs to address key under-answered questions pertaining to NLCs. Specifically, PoSSUM will answer: 1) What are the small-scale dynamics of NLCs and what does this tell us about the energy and momentum deposition from the lower atmosphere? 2) What is the seasonal variability of NLCs, mesospheric dynamics, and temperatures? 3) Are structures observed in the OH layer coupled with NLC structures? 4) How do NLCs nucleate? and 5) What is the geometry of NLC particles and how do they stratify? Instrumentation will include video and still-frame visible cameras (PoSSUMCam), infrared cameras, a mesospheric temperatures experiment, a depolarization LiDAR, a mesospheric density and temperatures experiment (MCAT), a mesospheric winds experiment, and a meteoric smoke detector (MASS). The instrument suite used on PoSSUM will mature through subsequent campaigns to develop an integrated, modular laboratory (the ';PoSSUM Observatory') that will provide repeatable, low cost, in-situ NLC and aeronomy observations as well

Synthesis and performances of 2LiFePO4·Li3V2(PO4)3/C cathode materials via spray drying method with double carbon sources

NASA Astrophysics Data System (ADS)

Zhang, Jia-feng; Shen, Chao; Zhang, Bao; Zheng, Jun-chao; Peng, Chun-li; Wang, Xiao-wei; Yuan, Xin-bo; Li, Hui; Chen, Guo-min

2014-12-01

The 2LiFePO4·Li3V2(PO4)3/C samples are synthesized through spray drying method. Glucose and oxalic acid are used as collaborative carbon sources to improve the electrochemical performance of 2LiFePO4·Li3V2(PO4)3/C composites. XRD results reveal the LiFePO4·Li3V2(PO4)3/C samples are composed of orthorhombic LiFePO4 and monoclinic Li3V2(PO4)3 phases. SEM results reveal that the nano-spherical Fe4(VO4)4·5H2O are about 80 nm and the 2LiFePO4·Li3V2(PO4)3/C composites possess a micro-nano spherical morphology with carbon coating layer. The samples show the best electrochemical performance when the mass ration of glucose and oxalic is 6:4, it can deliver a capacity of 147.6 mAh g-1, 145.0 mAh g-1, 134.1 mAh g-1 and 123.0 mAh g-1 at the rates of 0.1C, 1C, 5C and 10C, respectively.

Estimation of ²¹⁰Po and ²¹⁰Pb and its dose to human beings due to consumption of marine species of Ennore Creek, South India.

PubMed

Musthafa, M Saiyad; Krishnamoorthy, R

2012-10-01

A systemic study on the natural radionuclides such as (210)Po and (210)Pb in the environmental matrices and biota of Ennore Creek has been undertaken to establish a baseline data on the radiation profile of Ennore Creek environment. The environmental samples such as water, sediment, and biota (seaweeds, molluscs, crustaceans, and fishes) have been subjected to analyses. It has been observed that the concentration of (210)Po and (210)Pb in the water samples of Ennore Creek as 2.7 and 1.63 m Bq L(-1), respectively. The activity concentration of (210)Po and (210)Pb in the sediment sample was 17.9 and 28.9 Bq kg(-1), respectively. The bivalve mollusk Perna viridis have been identified to accumulate higher concentrations of (210)Po and (210)Pb suggesting that they could serve as bioindicator of radionuclides in the Ennore Creek environment. The committed effective dose for human beings was found at 81.13-216.8 and 2.1-297.2 μSv year(-1) for (210)Po and (210)Pb, respectively.

Florida Educational Facilities, 1999.

ERIC Educational Resources Information Center

Florida State Dept. of Education, Tallahassee. Office of Educational Facilities.

This publication describes Florida school and community college facilities completed in 1999, including photographs and floor plans. The facilities profiled are: Buchholz High School (Alachua County); Gator Run Elementary School (Broward); Corkscrew Elementary School (Collier); The 500 Role Models Academy of Excellence (Miami-Dade); Caribbean…

Florida Educational Facilities, 2000.

ERIC Educational Resources Information Center

Florida State Dept. of Education, Tallahassee. Office of Educational Facilities.

This publication describes Florida school and community college facilities completed in 2000, including photographs and floor plans. The facilities profiled are:J. R. Arnold High School (Bay County); Falcon Cove Middle School (Broward); Floranada Elementary School (Broward); Lyons Creek Middle School (Broward); Parkside Elementary School…

The Legacy of NASA Astrophysics E/PO: Conducting Professional Development, Developing Key Themes & Resources, and Broadening E/PO Audiences

NASA Astrophysics Data System (ADS)

Lawton, Brandon L.; Smith, Denise A.; Meinke, Bonnie K.; Bartolone, Lindsay; Manning, Jim; Schultz, Gregory R.; NASA Astrophysics E/PO Community

2016-01-01

For the past six years, NASA's Science Mission Directorate (SMD) has coordinated the work of its mission- and program-embedded education and public outreach (E/PO) efforts through four forums representing its four science divisions. The Astrophysics Forum, as the others, has built on SMD's long-standing principle of partnering scientists and educators and embedding E/PO in its missions to encourage and coordinate collaborative efforts to make the most efficient and effective use of NASA resources, personnel, data and discoveries in leveraged ways, in support of the nation's science education. Three priorities established early in the Forum's period of activity were to collaboratively enhance professional development for formal and informal educators, develop key themes & resources centered on astrophysics topics, and broaden the reach of astrophysics E/PO to traditionally underserved audiences in STEM subjects. This presentation will highlight some of the achievements of the Astrophysics E/PO community and Forum in these priority areas. This work constitutes an ongoing legacy--a firm foundation on which the new structure of NASA SMD education efforts will go forward.

Phase equilibrium relations in the binary systems LiPO 3CeP 3O 9 and NaPO 3CeP 3O 9

NASA Astrophysics Data System (ADS)

Rzaigui, Mohamed; Ariguib, Najia Kbir

1981-10-01

The LiPO 3CeP 3O 9 and NaPO 3CeP 3O 9 systems have been investigated for the first time by DTA, X-ray diffraction, and infrared spectroscopy. Each system forms a single 1:1 compound. LiCe(PO 3) 4 melts in a peritectic reaction at 980°C. NaCe(PO 3) 4 melts incongruently, too, at 865°C. These compounds have a monoclinic unit cell with the parameters: a = 16.415(6), b = 7,042(6), c = 9.772(7)Å; β = 126.03(5)°; Z = 4; space group {C 2}/{c} for LiCe (PO 3) 4; and a = 9.981(4), b = 13.129(6), c = 7.226(5) Å, β = 89.93(4)°, Z = 4, space group {P2 1}/{n} for NaCe(PO 3) 4. It is established that both compounds are mixed polyphosphates with chain structure of the type | MIIMIIIII (PO 3) 4| ∞MII: alkali metal, MIIIII: rare earth.

Biogeochemical factors affecting the presence of 210Po in groundwater

USGS Publications Warehouse

Seiler, R.L.; Stillings, L.L.; Cutler, N.; Salonen, L.; Outola, I.

2011-01-01

The discovery of natural 210Po enrichment at levels exceeding 500 mBq/L in numerous domestic wells in northern Nevada, USA, led to a geochemical investigation of the processes responsible for its mobilization. 210Po activities in 63 domestic and public-supply wells ranged from below 1 mBq/L to 6590 ± 590 mBq/L, among the highest reported levels in the USA. There is little spatial or depth variability in 210Pb activity in study-area sediments and mobilization of a few percent of the 210Po in the sediments would account for all of the 210Po in water. Stable-isotope measurements indicate SO4 reduction has occurred in all 210Po contaminated wells. Sulfide species are not accumulating in the groundwater in much of Lahontan Valley, probably because of S cycling involving microbial SO4 reduction, abiotic oxidation of H2S to S0 by Mn(IV), followed by microbial disproportionation of S0 to H2S and SO4. The high pH, Ca depletion, MnCO3 saturation, and presence of S0 in Lahontan Valley groundwater may be consequences of the anaerobic S cycling. Consistent with data from naturally-enriched wells in Florida, 210Po activities begin to decrease when aqueous sulfide species begin to accumulate. This may be due to formation and precipitation of PoS, however, Eh–pH diagrams suggest PoS would not be stable in study-area groundwater. An alternative explanation for the study area is that H2S accumulation begins when anaerobic S cycling stops because Mn oxides are depleted and their reduction is no longer releasing 210Po. Common features of 210Po-enriched groundwater were identified by comparing the radiological and geochemical data from Nevada with data from naturally-enriched wells in Finland, and Florida and Maryland in the USA. Values of pH ranged from 9 in Nevada wells, indicating that pH is not critical in determining whether 210Po is present. Where U is present in the sediments, the data suggest 210Po levels may be elevated in aquifers with (1) SO4-reducing waters with low H2S

Stability of luminescence in LaPO4, LaPO4 :RE(3+) (RE = Dy, Eu) nanophosphors.

PubMed

Pimpalshende, D M; Dhoble, S J

2015-03-01

The property of high refractive index, low solubility in water as well as stability to high temperature variation of lanthanum phosphate (LaPO4 ) proved it was the most effective candidate for the production of display lamps, and plasma display panel devices and sensors. The morphological and nanostructural characteristics play a key role in the working efficiency of the luminescent material. These properties can be controlled by the synthesis method, which we have adopted in this paper. We have prepared LaPO4 nanoparticles at a relatively low temperature (110 ºC) in polyethylene glycol medium by using a wet chemical one-step synthesis. The phase composition and structural properties of the sample have been characterized by X-ray diffraction, Fourier transform infrared, transmission electron microscopy and the luminescent property by photoluminescence and thermoluminescence. The samples were well crystallized and the average crystallite size of 15 nm has been calculated for pure LaPO4 using the Debye-Scherrer equation. The result from heat-treated samples shows the phase combination and morphological structure of the powder depend on the annealing temperature. The heat treatment changes the structure of LaPO4 from cuboid rods to fine grains at about 600 °C. The emission spectrum of LaPO4 shows the broad emission band at 368 nm and shoulder at 465 nm with emission of blue color when monitored at an excitation wavelength at 256 nm. The stability of phosphor has been studied with respect to humidity, temperature, doping, doping concentration, γ-ray exposures, etc. The prepared nanosized phosphors were thermally stable and may be a promising blue phosphor for lighting technology as well as radiation dosimetry. Copyright © 2014 John Wiley & Sons, Ltd.

Prediction of Wind Energy Resources (PoWER) Users Guide

DTIC Science & Technology

2016-01-01

ARL-TR-7573● JAN 2016 US Army Research Laboratory Prediction of Wind Energy Resources (PoWER) User’s Guide by David P Sauter...not return it to the originator. ARL-TR-7573 ● JAN 2016 US Army Research Laboratory Prediction of Wind Energy Resources (PoWER...2016 2. REPORT TYPE Final 3. DATES COVERED (From - To) 09/2015–11/2015 4. TITLE AND SUBTITLE Prediction of Wind Energy Resources (PoWER) User’s

210Po in Nevada groundwater and its relation to gross alpha radioactivity

USGS Publications Warehouse

Seiler, R.L.

2011-01-01

Polonium-210 (210Po) is a highly toxic alpha emitter that is rarely found in groundwater at activities exceeding 1 pCi/L. 210Po activities in 63 domestic and public-supply wells in Lahontan Valley in Churchill County in northern Nevada, United States, ranged from 0.01 ± 0.005 to 178 ± 16 pCi/L with a median activity of 2.88 pCi/L. Wells with high 210Po activities had low dissolved oxygen concentrations (less than 0.1 mg/L) and commonly had pH greater than 9. Lead-210 activities are low and aqueous 210Po is unsupported by 210Pb, indicating that the 210Po is mobilized from aquifer sediments. The only significant contributors to alpha particle activity in Lahontan Valley groundwater are 234/238U, 222Rn, and 210Po. Radon-222 activities were below 1000 pCi/L and were uncorrelated with 210Po activity. The only applicable drinking water standard for 210Po in the United States is the adjusted gross alpha radioactivity (GAR) standard of 15 pCi/L. 210Po was not volatile in a Nevada well, but volatile 210Po has been reported in a Florida well. Additional information on the volatility of 210Po is needed because GAR is an inappropriate method to screen for volatile radionuclides. About 25% of the samples had 210Po activities that exceed the level associated with a lifetime total cancer risk of 1× 10−4 (1.1 pCi/L) without exceeding the GAR standard. In cases where the 72-h GAR exceeds the uranium activity by more than 5 to 10 pCi/L, an analysis to rule out the presence of 210Po may be justified to protect human health even though the maximum contaminant level for adjusted GAR is not exceeded.

Oxygen exchange profile in rat muscles of contrasting fibre types.

PubMed

Behnke, Brad J; McDonough, Paul; Padilla, Danielle J; Musch, Timothy I; Poole, David C

2003-06-01

To determine whether fibre type affects the O2 exchange characteristics of skeletal muscle at the microcirculatory level we tested the hypothesis that, following the onset of contractions, muscle comprising predominately type I fibres (soleus, Sol, 86 % type I) would, based on demonstrated blood flow responses, exhibit a blunted microvascular PO2 (PO2,m, which is determined by the O2 delivery (QO2) to O2 uptake (VO2) ratio) profile (assessed via phosphorescence quenching) compared to muscle of primarily type II fibres (peroneal, Per, 84 % type II). PO2,m was measured at rest, and following the rest-contractions (twitch, 1 Hz, 2-4 V for 120 s) transition in Sol (n = 6) and Per (n = 6) muscles of Sprague-Dawley rats. Both muscles exhibited a delay followed by a mono-exponential decrease in PO2,m to the steady state. However, compared with Sol, Per demonstrated (1) a larger change in baseline minus steady state contracting PO2,m (DeltaPO2,m) (Per, 13.4 +/- 1.7 mmHg; Sol, 8.6 +/- 0.9 mmHg, P < 0.05); (2) a faster mean response time (i.e. time delay (TD) plus time constant (tau); Per, 23.8 +/- 1.5 s; Sol, 39.6 +/- 4.3 s, P < 0.05); and therefore (3) a greater rate of PO2,m decline (DeltaPO2,m/tau; Per, 0.92 +/- 0.08 mmHg s-1; Sol, 0.42 +/- 0.05 mmHg s-1, P < 0.05). These data demonstrate an increased microvascular pressure head of O2 at any given point after the initial time delay for Sol versus Per following the onset of contractions that is probably due to faster QO2 dynamics relative to those of VO2.

Magnetic Flyer Facility Correlation and UGT Simulation

DTIC Science & Technology

1978-05-01

AND UGT SIMULATION (U) Kaman Sciences Corporation L ~ P.O. Box 7463 I Colorado Springs, Colcerado 80933 ý4 May 1978DC Final Report CONTRACT No. DNA O01...selected underground test ( UGT ) environment on 3DQP; and, (2) To correlate the magnetically driven flyer plate facilities of VKSC with those of the...tailored to matcb the pressure vs. time anid total impulse measurements obtained on UGT events. This matching of experi- mental data required considerable

Synthesis and characterization of CdS/BiPO{sub 4} heterojunction photocatalyst

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

Chen, Daimei, E-mail: chendaimei@cugb.edu.cn; Kuang, Zheng; Zhu, Qian

2015-06-15

Highlights: • A CdS/BiPO{sub 4} heterojunction was prepared by the solvothermal method. • The CdS/BiPO{sub 4} composite has the higher photocatalytic activity than the individual ones. • The optimal mass ratio of CdS to BiPO{sub 4} was 0.5. • The heterojunction structure of CdS/BiPO{sub 4} induces an effective electron–hole separation. - Abstract: A series of CdS/BiPO{sub 4} heterojunction photocatalysts with the visible-light response were synthesized by the solvothermal method. The resulting products were characterized by X-ray diffraction, Transmission electron microscopy, X-ray photoelectron spectroscopy, and UV–vis diffuse reflection spectroscopy. CdS nanoparticles with the size at range of 5–7 nm were immobilizedmore » on the surface of BiPO{sub 4} nanorods. The CdS/BiPO{sub 4} composite exhibited much higher photodegradation rate of methylene blue under visible light irradation compared to the pure CdS and BiPO{sub 4}. The optimal mass ratio of CdS to BiPO{sub 4} was 0.5, the photodegradation rate of which is 2.1 times higher than that of CdS. The enhancement of photocatalytic activity is attributed to the heterojunction structure of CdS/BiPO{sub 4} composite which induced the effective electron–hole separation between CdS and BiPO{sub 4}.« less

Electroweak Higgs production with HiggsPO at NLO QCD

NASA Astrophysics Data System (ADS)

Greljo, Admir; Isidori, Gino; Lindert, Jonas M.; Marzocca, David; Zhang, Hantian

2017-12-01

We present the HiggsPO UFO model for Monte Carlo event generation of electroweak VH and VBF Higgs production processes at NLO in QCD in the formalism of Higgs pseudo-observables (PO). We illustrate the use of this tool by studying the QCD corrections, matched to a parton shower, for several benchmark points in the Higgs PO parameter space. We find that, while being sizable and thus important to be considered in realistic experimental analyses, the QCD higher-order corrections largely factorize. As an additional finding, based on the NLO results, we advocate to consider 2D distributions of the two-jet azimuthal-angle difference and the leading jet p_T for new physics searches in VBF Higgs production. The HiggsPO UFO model is publicly available.

Systematic Analysis of the Pleurotus ostreatus Laccase Gene (PoLac) Family and Functional Characterization of PoLac2 Involved in the Degradation of Cotton-Straw Lignin.

PubMed

Jiao, Xiaoyu; Li, Guoqing; Wang, Yan; Nie, Fan; Cheng, Xi; Abdullah, Muhammad; Lin, Yi; Cai, Yongping

2018-04-11

Fungal laccases play important roles in the degradation of lignocellulose. Although some PoLac s have been reported in several studies, still no comprehensive bioinformatics study of the LAC family in Pleurotus ostreatus has been reported. In this study, we identified 12 laccase genes in the whole genome sequence of P. ostreatus and their physical characteristics, gene distribution, phylogenic relationships, gene structure, conserved motifs, and cis-elements were also analyzed. The expression patterns of 12 PoLac genes at different developmental stages and under different culture substrates were also analyzed. The results revealed that PoLac2 and PoLac12 may be involved in the degradation of lignin and the formation of the fruiting body, respectively. Subsequently, we overexpressed PoLac2 in P. ostreatus by the Agrobacterium tumefaciens -mediated transformation (ATMT) method. The transformants' laccase activity increased in varying degrees, and the gene expression level of PoLac2 in transformants was 2-8 times higher than that of the wild-type strain. Furthermore, the lignin degradation rate by transgenic fungus over 30 days was 2.36-6.3% higher than that of wild-type. Our data show that overexpression of PoLac2 significantly enhanced the lignin degradation of cotton-straw. To our knowledge, this study is the first report to demonstrate the functions of PoLac2 in P. ostreatus .

Unlocking the energy capabilities of micron-sized LiFePO4.

PubMed

Guo, Limin; Zhang, Yelong; Wang, Jiawei; Ma, Lipo; Ma, Shunchao; Zhang, Yantao; Wang, Erkang; Bi, Yujing; Wang, Deyu; McKee, William C; Xu, Ye; Chen, Jitao; Zhang, Qinghua; Nan, Cewen; Gu, Lin; Bruce, Peter G; Peng, Zhangquan

2015-08-03

Utilization of LiFePO4 as a cathode material for Li-ion batteries often requires size nanonization coupled with calcination-based carbon coating to improve its electrochemical performance, which, however, is usually at the expense of tap density and may be environmentally problematic. Here we report the utilization of micron-sized LiFePO4, which has a higher tap density than its nano-sized siblings, by forming a conducting polymer coating on its surface with a greener diazonium chemistry. Specifically, micron-sized LiFePO4 particles have been uniformly coated with a thin polyphenylene film via the spontaneous reaction between LiFePO4 and an aromatic diazonium salt of benzenediazonium tetrafluoroborate. The coated micron-sized LiFePO4, compared with its pristine counterpart, has shown improved electrical conductivity, high rate capability and excellent cyclability when used as a 'carbon additive free' cathode material for rechargeable Li-ion batteries. The bonding mechanism of polyphenylene to LiFePO4/FePO4 has been understood with density functional theory calculations.

Unlocking the energy capabilities of micron-sized LiFePO4

PubMed Central

Guo, Limin; Zhang, Yelong; Wang, Jiawei; Ma, Lipo; Ma, Shunchao; Zhang, Yantao; Wang, Erkang; Bi, Yujing; Wang, Deyu; McKee, William C.; Xu, Ye; Chen, Jitao; Zhang, Qinghua; Nan, Cewen; Gu, Lin; Bruce, Peter G.; Peng, Zhangquan

2015-01-01

Utilization of LiFePO4 as a cathode material for Li-ion batteries often requires size nanonization coupled with calcination-based carbon coating to improve its electrochemical performance, which, however, is usually at the expense of tap density and may be environmentally problematic. Here we report the utilization of micron-sized LiFePO4, which has a higher tap density than its nano-sized siblings, by forming a conducting polymer coating on its surface with a greener diazonium chemistry. Specifically, micron-sized LiFePO4 particles have been uniformly coated with a thin polyphenylene film via the spontaneous reaction between LiFePO4 and an aromatic diazonium salt of benzenediazonium tetrafluoroborate. The coated micron-sized LiFePO4, compared with its pristine counterpart, has shown improved electrical conductivity, high rate capability and excellent cyclability when used as a ‘carbon additive free' cathode material for rechargeable Li-ion batteries. The bonding mechanism of polyphenylene to LiFePO4/FePO4 has been understood with density functional theory calculations. PMID:26235395

Unlocking the energy capabilities of micron-sized LiFePO4

NASA Astrophysics Data System (ADS)

Guo, Limin; Zhang, Yelong; Wang, Jiawei; Ma, Lipo; Ma, Shunchao; Zhang, Yantao; Wang, Erkang; Bi, Yujing; Wang, Deyu; McKee, William C.; Xu, Ye; Chen, Jitao; Zhang, Qinghua; Nan, Cewen; Gu, Lin; Bruce, Peter G.; Peng, Zhangquan

2015-08-01

Utilization of LiFePO4 as a cathode material for Li-ion batteries often requires size nanonization coupled with calcination-based carbon coating to improve its electrochemical performance, which, however, is usually at the expense of tap density and may be environmentally problematic. Here we report the utilization of micron-sized LiFePO4, which has a higher tap density than its nano-sized siblings, by forming a conducting polymer coating on its surface with a greener diazonium chemistry. Specifically, micron-sized LiFePO4 particles have been uniformly coated with a thin polyphenylene film via the spontaneous reaction between LiFePO4 and an aromatic diazonium salt of benzenediazonium tetrafluoroborate. The coated micron-sized LiFePO4, compared with its pristine counterpart, has shown improved electrical conductivity, high rate capability and excellent cyclability when used as a `carbon additive free' cathode material for rechargeable Li-ion batteries. The bonding mechanism of polyphenylene to LiFePO4/FePO4 has been understood with density functional theory calculations.

Identifying the Structure of the Intermediate, Li 2/3CoPO 4, Formed during Electrochemical Cycling of LiCoPO 4

DOE PAGES

Strobridge, Fiona C.; Clément, Raphaële J.; Leskes, Michal; ...

2014-11-03

In situ synchrotron diffraction measurements and subsequent Rietveld refinements are used to show that the high energy density cathode material LiCoPO 4 (space group Pnma) undergoes two distinct two-phase reactions upon charge and discharge, both occurring via an intermediate Li 2/3(Co 2+) 2/3(Co 3+) 1/3PO 4 phase. Two resonances are observed for Li 2/3CoPO 4 with intensity ratios of 2:1 and 1:1 in the 31P and 7Li NMR spectra, respectively. An ordering of Co 2+/Co 3+ oxidation states is proposed within a (a × 3b × c) supercell, and Li +/vacancy ordering is investigated using experimental NMR data in combinationmore » with first-principles solid-state DFT calculations. In the lowest energy configuration, both the Co 3+ ions and Li vacancies are found to order along the b-axis. Two other low energy Li +/vacancy ordering schemes are found only 5 meV per formula unit higher in energy. All three configurations lie below the LiCoPO 4–CoPO 4 convex hull and they may be readily interconverted by Li + hops along the b-direction.« less

Point Intercept (PO)

Treesearch

John F. Caratti

2006-01-01

The FIREMON Point Intercept (PO) method is used to assess changes in plant species cover or ground cover for a macroplot. This method uses a narrow diameter sampling pole or sampling pins, placed at systematic intervals along line transects to sample within plot variation and quantify statistically valid changes in plant species cover and height over time. Plant...

Low collectivity of the first 2+ states of 212,210Po

NASA Astrophysics Data System (ADS)

Kocheva, D.; Rainovski, G.; Jolie, J.; Pietralla, N.; Blazhev, A.; Astier, A.; Altenkirch, R.; Bast, M.; Beckers, M.; Ansari, S.; Braunroth, Th.; Cappellazzo, M.; Cortés, M. L.; Dewald, A.; Diel, F.; Djongolov, M.; Fransen, C.; Gladnishki, K.; Goldkuhle, A.; Hennig, A.; Karayonchev, V.; Keatings, J. M.; Kluge, E.; Kröll, Th.; Litzinger, J.; Moschner, K.; Müller-Gatermann, C.; Petkov, P.; Rudigier, M.; Scheck, M.; Spagnoletti, P.; Scholz, Ph.; Schmidt, T.; Spieker, M.; Stahl, C.; Stegmann, R.; Stolz, A.; Vogt, A.; Stoyanova, M.; Thöle, P.; Warr, N.; Werner, V.; Witt, W.; Wölk, D.; Zamora, J. C.; Zell, K. O.; Van Isacker, P.; Ponomarev, V. Yu.

2018-05-01

The lifetimes of the first 2+ excited states of 212,210Po were measured in two transfer reactions 208Pb(12C,8Be)212Po and 208Pb(12C,10Be)210Po by the Recoil Distance Doppler Shift (RDDS) method and by the Doppler Shift Attenuation method (DSAM), respectively. The derived absolute B(E2) values of 2.6(3) W.u. for 212Po and 1.83(28) W.u. for 210Po indicate low collectivity. It is shown that the properties of the yrast {2}1+, {4}1+, {6}1+ and {8}1+ states in both nuclei cannot be described consistently in the framework of nuclear shell models. It is also demonstrated in the case of 210Po that Quasi-particle Phonon Model (QPM) calculations cannot overcome this problem thus indicating the existence of a peculiarity which is neglected in both theoretical approaches.

210Po in nevada groundwater and its relation to gross alpha radioactivity.

PubMed

Seiler, Ralph L

2011-01-01

Polonium-210 ((210) Po) is a highly toxic alpha emitter that is rarely found in groundwater at activities exceeding 1 pCi/L. (210) Po activities in 63 domestic and public-supply wells in Lahontan Valley in Churchill County in northern Nevada, United States, ranged from 0.01 ± 0.005 to 178 ± 16 pCi/L with a median activity of 2.88 pCi/L. Wells with high (210) Po activities had low dissolved oxygen concentrations (less than 0.1 mg/L) and commonly had pH greater than 9. Lead-210 activities are low and aqueous (210) Po is unsupported by (210) Pb, indicating that the (210) Po is mobilized from aquifer sediments. The only significant contributors to alpha particle activity in Lahontan Valley groundwater are (234/238) U, (222) Rn, and (210) Po. Radon-222 activities were below 1000 pCi/L and were uncorrelated with (210) Po activity. The only applicable drinking water standard for (210) Po in the United States is the adjusted gross alpha radioactivity (GAR) standard of 15 pCi/L. (210) Po was not volatile in a Nevada well, but volatile (210) Po has been reported in a Florida well. Additional information on the volatility of (210) Po is needed because GAR is an inappropriate method to screen for volatile radionuclides. About 25% of the samples had (210) Po activities that exceed the level associated with a lifetime total cancer risk of 1× 10(-4) (1.1 pCi/L) without exceeding the GAR standard. In cases where the 72-h GAR exceeds the uranium activity by more than 5 to 10 pCi/L, an analysis to rule out the presence of (210) Po may be justified to protect human health even though the maximum contaminant level for adjusted GAR is not exceeded. Journal compilation © 2010 National Ground Water Association. No claim to original US government works.

Enhanced lithium storage capability of Li3V2(PO4)3@C co-modified with graphene and Ce3+ doping as high-power cathode for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Tong, Junjie; Fang, Yunhui

2017-12-01

As a high-voltage cathode material, monoclinic Li3V2(PO4)3 has been proposed as the next-generation commercial electrode for lithium-ion batteries. Nevertheless, it remains a practical challenge to improve the poor electronic conductivity of Li3V2(PO4)3. Herein, we first design and fabricate the Li3V2(PO4)3@C (LVP@C) nanocrystals further modified by graphene and doped with Ce3+-ion via a facile sol-gel method. The Ce3+ doping can form a continuous conductive pathway in the electrode and thus improve the intrinsic electronic conductivity of Li3V2(PO4)3 material. Meanwhile, the residual carbon layer and graphene can also construct a conductive network, which is helpful to enhance the apparent conductivity of Li3V2(PO4)3. Therefore, the graphene and Ce3+ doping co-decorated LVP@C (G-LVCeP@C) composite exhibits better lithium storage capability than the LVP@C and Ce3+-doped LVP@C (LVCeP@C) materials. This novel design provides an effective strategy for the preparation of other electrodes for lithium-ion batteries.

Thermal profiles, crystallization behaviors and microstructure of diacylglycerol-enriched palm oil blends with diacylglycerol-enriched palm olein.

PubMed

Xu, Yayuan; Zhao, Xiaoqing; Wang, Qiang; Peng, Zhen; Dong, Cao

2016-07-01

To elucidate the possible interaction mechanisms between DAG-enriched oils, this study investigated how mixtures of DAG-enriched palm-based oils influenced the phase behavior, thermal properties, crystallization behaviors and the microstructure in binary fat blends. DAG-enriched palm oil (PO-DAGE) was blended with DAG-enriched palm olein (POL-DAGE) in various percentages (0%, 10%, 30%, 50%, 70%, 90%, 100%). Based on the observation of iso-solid diagram and phase diagram, the binary mixture of PO-DAGE/POL-DAGE showed a better compatibility in comparison with their corresponding original blends. DSC thermal profiles exhibited that the melting and crystallization properties of PO-DAGE/POL-DAGE were distinctively different from corresponding original blends. Crystallization kinetics revealed that PO-DAGE/POL-DAGE blends displayed a rather high crystallization rate and exhibited no spherulitic crystal growth. From the results of polarized light micrographs, PO-DAGE/POL-DAGE blends showed more dense structure with very small needle-like crystals than PO/POL. X-ray diffraction evaluation revealed when POL-DAGE was added in high contents to PO-DAGE, above 30%, β-polymorph dominated, and the mount of β' forms crystals was decreasing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Relational Aggression in Children with Preschool Onset (PO) Psychiatric Disorders

PubMed Central

Belden, Andy C.; Gaffrey, Michael S.; Luby, Joan L.

2012-01-01

Objective The role of preschool onset (PO) psychiatric disorders as correlates and/or risk factors for relational aggression during kindergarten or 1st grade was tested in a sample of N = 146 preschool-age children (3 to 5.11). Method Axis-I diagnoses and symptom scores were derived using the Preschool Age Psychiatric Assessment. Children’s roles in relational aggression as aggressor, victim, aggressive-victim, or non-aggressor/non-victim were determined at preschool and again 24 months later at elementary school entry. Results Preschoolers diagnosed with PO-psychiatric disorders were 3 times as likely as the healthy preschoolers to be classified aggressors, victims, or aggressive-victims. Children diagnosed with PO-disruptive, depressive, and/or anxiety disorders were at least 6 times as likely as children without PO-psychiatric disorders to become aggressive-victims during elementary school after covarying for other key risk factors. Conclusions Findings suggested that PO-psychiatric disorders differentiated preschool and school-age children’s roles in relational aggression based on teacher-report. Recommendations for future research and preventative intervention aimed at minimizing the development of relational aggression in early childhood by identifying and targeting PO-psychiatric disorders are made. PMID:22917202

On the synthesis of AlPO4-21 molecular sieve by vapor phase transport method and its phase transformation to AlPO4-15 molecular sieve

NASA Astrophysics Data System (ADS)

Shao, Hui; Chen, Jingjing; Chen, Xia; Leng, Yixin; Zhong, Jing

2015-04-01

An experimental design was applied to the synthesis of AlPO4-21 molecular sieve (AWO structure) by vapor phase transport (VPT) method, using tetramethylguanidine (TMG) as the template. In this study, the effects of crystallization time, crystallization temperature, phosphor content, template content and water content in the synthesis gel were investigated. The materials obtained were characterized by X-ray diffraction, scanning electron microscopy and fourier transform infrared spectroscopy (FT-IR). Microstructural analysis of the crystal growth in vapor synthetic conditions revealed a revised crystal growth route from zeolite AlPO4-21 to AlPO4-15 in the presence of the TMG. Homogenous hexagonal prism AlPO4-21 crystals with size of 7 × 3 μm were synthesized at a lower temperature (120 °C), which were completely different from the typical tabular parallelogram crystallization microstructure of AlPO4-21 phase. The crystals were transformed into AlPO4-21 phase with higher crystallization temperature, longer crystallization time, higher P2O5/Al2O3 ratio and higher TMG/Al2O3 ratio.

Scientist-Educator Partnerships: the Cornerstone of Astrophysics E/PO

NASA Astrophysics Data System (ADS)

Meinke, Bonnie K.; Smith, Denise A.; Lawton, Brandon; Eisenhamer, Bonnie; Jirdeh, Hussein

2015-11-01

For nearly two decades, NASA has partnered scientists and educators by embedding Education and Public Outreach (E/PO) programs and funding in its science missions and research activities. This enables scientist and educators to work side-by-side in translating cutting-edge NASA science and technology for classrooms, museums, and public venues.The Office of Public Outreach at the Space Telescope Science Institute (STScI) is uniquely poised to foster collaboration between scientists with content expertise and educators with pedagogy expertise. As home to both Hubble Space Telescope and the future James Webb Space Telescope, STScI leverages the expertise of its scientists to create partnerships with its collocated Education Team to translate cutting-edge NASA science into new and effective learning tools. In addition, STScI is home of the NASA Science Mission Directorate (SMD) Astrophysics Science E/PO Forum, which facilitates connections both within the SMD E/PO community and beyond to scientists and educators across all NASA Astrophysics missions. These collaborations strengthen partnerships, build best practices, and enhance coherence for NASA SMD-funded E/PO missions and programs.We will present examples of astronomers’ engagement in our E/PO efforts, such as NASA Science4Girls.

PoET: Polarimeters for Energetic Transients

NASA Technical Reports Server (NTRS)

McConnell, Mark; Barthelmy, Scott; Hill, Joanne

2008-01-01

This presentation focuses on PoET (Polarimeters for Energetic Transients): a Small Explorer mission concept proposed to NASA in January 2008. The principal scientific goal of POET is to measure GRB polarization between 2 and 500 keV. The payload consists of two wide FoV instruments: a Low Energy Polarimeter (LEP) capable of polarization measurements in the energy range from 2-15 keV and a high energy polarimeter (Gamma-Ray Polarimeter Experiment - GRAPE) that will measure polarization in the 60-500 keV energy range. Spectra will be measured from 2 keV up to 1 MeV. The PoET spacecraft provides a zenith-pointed platform for maximizing the exposure to deep space. Spacecraft rotation will provide a means of effectively dealing with systematics in the polarization response. PoET will provide sufficient sensitivity and sky coverage to measure statistically significant polarization for up to 100 GRBs in a two-year mission. Polarization data will also be obtained for solar flares, pulsars and other sources of astronomical interest.

Infrared-active optical phonons in LiFePO4 single crystals

NASA Astrophysics Data System (ADS)

Stanislavchuk, T. N.; Middlemiss, D. S.; Syzdek, J. S.; Janssen, Y.; Basistyy, R.; Sirenko, A. A.; Khalifah, P. G.; Grey, C. P.; Kostecki, R.

2017-07-01

Infrared-active optical phonons were studied in olivine LiFePO4 oriented single crystals by means of both rotating analyzer and rotating compensator spectroscopic ellipsometry in the spectral range between 50 and 1400 cm-1. The eigenfrequencies, oscillator strengths, and broadenings of the phonon modes were determined from fits of the anisotropic harmonic oscillator model to the data. Optical phonons in a heterosite FePO4 crystal were measured from the delithiated ab-surface of the LiFePO4 crystal and compared with the phonon modes of the latter. Good agreement was found between experimental data and the results of solid-state hybrid density functional theory calculations for the phonon modes in both LiFePO4 and FePO4.

Structure for Storing Properties of Particles (PoP)

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

Patel, N. R.; Mattoon, C. M.; Beck, B. R.

2014-06-01

Some evaluated nuclear databases are critical for applications such as nuclear energy, nuclear medicine, homeland security, and stockpile stewardship. Particle masses, nuclear excitation levels, and other “Properties of Particles” are essential for making evaluated nuclear databases. Currently, these properties are obtained from various databases that are stored in outdated formats. Moreover, the “Properties of Particles” (PoP) structure is being designed that will allow storing all information for one or more particles in a single place, so that each evaluation, simulation, model calculation, etc. can link to the same data. Information provided in PoP will include properties of nuclei, gammas andmore » electrons (along with other particles such as pions, as evaluations extend to higher energies). Presently, PoP includes masses from the Atomic Mass Evaluation version 2003 (AME2003), and level schemes and gamma decays from the Reference Input Parameter Library (RIPL-3). The data are stored in a hierarchical structure. An example of how PoP stores nuclear masses and energy levels will be presented here.« less

Structure for Storing Properties of Particles (PoP)

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

Patel, N.R., E-mail: infinidhi@llnl.gov; Mattoon, C.M.; Beck, B.R.

2014-06-15

Evaluated nuclear databases are critical for applications such as nuclear energy, nuclear medicine, homeland security, and stockpile stewardship. Particle masses, nuclear excitation levels, and other “Properties of Particles” are essential for making evaluated nuclear databases. Currently, these properties are obtained from various databases that are stored in outdated formats. A “Properties of Particles” (PoP) structure is being designed that will allow storing all information for one or more particles in a single place, so that each evaluation, simulation, model calculation, etc. can link to the same data. Information provided in PoP will include properties of nuclei, gammas and electrons (alongmore » with other particles such as pions, as evaluations extend to higher energies). Presently, PoP includes masses from the Atomic Mass Evaluation version 2003 (AME2003), and level schemes and gamma decays from the Reference Input Parameter Library (RIPL-3). The data are stored in a hierarchical structure. An example of how PoP stores nuclear masses and energy levels will be presented here.« less

PoMiN: A Post-Minkowskian N-Body Solver

NASA Astrophysics Data System (ADS)

Feng, Justin; Baumann, Mark; Hall, Bryton; Doss, Joel; Spencer, Lucas; Matzner, Richard

2018-05-01

PoMiN is a lightweight N-body code based on the Post-Minkowskian N-body Hamiltonian of Ledvinka, Schafer, and Bicak, which includes General Relativistic effects up to first order in Newton's constant G, and all orders in the speed of light c. PoMiN is a single file written in C and uses a fourth-order Runge-Kutta integration scheme. PoMiN has also been written to handle an arbitrary number of particles (both massive and massless) with a computational complexity that scales as O(N^2).

[Immobilization technology and mechanism of fly ash using H3PO4].

PubMed

Wang, Jun; Jiang, Jian-Guo; Sui, Ji-Chao; Yang, Shi-Jian

2006-08-01

Chemical composition and toxicity leaching characteristics of fly ash was analyzed. The experiment results show that many heavy metals were contained; leaching concentration of Pb is 67.03 mg/L, which exceeds the limit of identification standard for hazardous wastes. Effect of input mass of H3PO4 on immobilization of heavy metals and its long-term environmental stability was studied. The results show that when input 8% - 14% (H3PO4 mass/ fly ash mass) of H3PO4 sound immobilization effect can be achieved; 8% and 12% of H3PO4 will bring a satisfactory environmental stability of heavy metals, while more H3PO4 led to less buffer capacity to acid conditions. In fly ash treated by 12% H3PO4, a small quantity of crystal Cr2P2O7, ZnP2, Pb3P4O13, Pb3P2O7, NaZnPO4, NaPbP3O9, Ca2ZnSi2O7 can be detected by XRD; many independent fly ash particles and bar-shaped Pb5 (PO4)3Cl with a diameter of 0.3 - 0.5 microm were observed by SEM; concentrated heavy metal materials were not obtained by CHBr3 floatation. Conclusions can be drawn that, through neutralization reaction of H3PO4 with strongly alkaline fly ash, stabilization reaction conditions were improved, entrapped heavy metals were chemically activated and PO4(3-) needed in stabilization was produced. Activated heavy metals combined with PO4(3-) on surface of fly ash,generated phosphates existing as forms of solid solution in SiO2, CaCO3, CaSO4, KCl, NaCl.

Anode property of carbon coated LiFePO4 nanocrystals

NASA Astrophysics Data System (ADS)

Ni, Jiangfeng; Jiang, Jiaxing; Savilov, S. V.; Aldoshin, S. M.

2016-10-01

Nanostructured LiFePO4 is appealing cathode material for rechargeable lithium batteries. Herein, however, we report the intriguing anode properties of carbon coated LiFePO4 nanocrystals. In the potential range of 0-3.0 V, the LiFePO4 nanocrystal electrodes afford high reversible capacity of 373 mAhg-1 at a current rate of 0.05 Ag-1 and retains 239 mAhg-1 at a much higher rate of 1.25 Ag-1. In addition, it is capable of sustaining 1000 cycles at 1.25 Ag-1 without any capacity fading. Such superior properties indicate that nanostructured LiFePO4 could also be promising anode for rechargeable battery applications.

The PoGO+ Ballon-Borne Hard X-ray Polarimetry Mission

NASA Astrophysics Data System (ADS)

Friis, Mette; Kiss, Mózsi; Mikhalev, Victor; Pearce, Mark; Takahashi, Hiromitsu

2018-03-01

The PoGO mission, including the PoGOLite Pathfinder and PoGO+, aims to provide polarimetric measurements of the Crab system and Cygnus X-1 in the hard X-ray band. Measurements are conducted from a stabilized balloon-borne platform, launched on a 1 million cubic meter balloon from the Esrange Space Center in Sweden to an altitude of approximately 40 km. Several flights have been conducted, resulting in two independent measurements of the Crab polarization and one of Cygnus X-1. Here, a review of the PoGO mission is presented, including a description of the payload and the flight campaigns, and a discussion of some of the scientific results obtained to date.

The half-life of 218Po.

PubMed

Martz, D E; Harris, R T; Langner, G H

1989-07-01

Direct observation of the 218Po alpha-peak decay with a microcomputer-controlled alpha-spectrometer yielded a mean half-life value of 3.040 +/- 0.008 min, where the error quoted represents twice the standard deviation of the means from 38 separate decay measurements. The 1912 and 1924 218Po half-life measurements, which provided the 3.05-min value listed in nuclear tables for the past 60 y, are critically reviewed. Two more recent experiments, which yielded longer values of 3.11 min (Van Hise et al. 1982) and 3.093 min (Potapov and Soloshenkov 1986), are also discussed.

Core-shell LiFePO4 /carbon-coated reduced graphene oxide hybrids for high-power lithium-ion battery cathodes.

PubMed

Ha, Sung Hoon; Lee, Yun Jung

2015-01-26

Core-shell carbon-coated LiFePO4 nanoparticles were hybridized with reduced graphene (rGO) for high-power lithium-ion battery cathodes. Spontaneous aggregation of hydrophobic graphene in aqueous solutions during the formation of composite materials was precluded by employing hydrophilic graphene oxide (GO) as starting templates. The fabrication of true nanoscale carbon-coated LiFePO4 -rGO (LFP/C-rGO) hybrids were ascribed to three factors: 1) In-situ polymerization of polypyrrole for constrained nanoparticle synthesis of LiFePO4 , 2) enhanced dispersion of conducting 2D networks endowed by colloidal stability of GO, and 3) intimate contact between active materials and rGO. The importance of conducting template dispersion was demonstrated by contrasting LFP/C-rGO hybrids with LFP/C-rGO composites in which agglomerated rGO solution was used as the starting templates. The fabricated hybrid cathodes showed superior rate capability and cyclability with rates from 0.1 to 60 C. This study demonstrated the synergistic combination of nanosizing with efficient conducting templates to afford facile Li(+) ion and electron transport for high power applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Infrared-active optical phonons in LiFePO 4 single crystals

DOE PAGES

Stanislavchuk, T. N.; Middlemiss, D. S.; Syzdek, J. S.; ...

2017-07-28

Infrared-active optical phonons were studied in olivine LiFePO 4 oriented single crystals by means of both rotating analyzer and rotating compensator spectroscopic ellipsometry in the spectral range between 50 and 1400 cm -1. The eigenfrequencies, oscillator strengths, and broadenings of the phonon modes were determined from fits of the anisotropic harmonic oscillator model to the data. Optical phonons in a heterosite FePO 4 crystal were measured from the delithiated ab-surface of the LiFePO 4 crystal and compared with the phonon modes of the latter. Good agreement was found between experimental data and the results of solid-state hybrid density functional theorymore » calculations for the phonon modes in both LiFePO 4 and FePO 4.« less

Vitamins A, C, and E may reduce intestinal Po-210 levels after ingestion

PubMed Central

Kemp, Francis W; Portugal, Frank; Akudugu, John M.; Neti, Prasad VSV; Ferraris, Ronaldo P.; Howell, Roger W.

2016-01-01

Damage to the gut mucosa is a probable contributory cause of death from ingested 210Po. Therefore, medical products are needed that can prevent, mitigate, and/or repair gastrointestinal (GI) damage caused by high-LET radiation emitted by 210Po. The present studies investigated the capacity of a diet highly enriched with vitamins A, C, and E (vitamin ACE) to protect against intestinal mucosal damage indicated by functional reductions in nutrient transport caused by orally ingested 210Po. Mice were gavaged with 0 or 18.5 kBq 210Po-citrate and fed a control or vitamin ACE-enriched diet (the latter beginning either 96 h before or immediately after gavage). Mouse intestines significantly retained 210Po on day 8 post-gavage. The concentration of 210Po in intestinal tissues was significantly (p<0.05) lower in all vitamin ACE groups compared to control. There were borderline significant 210Po-induced reductions in intestinal absorption of D-fructose. The combination of vitamins A, C, and E may reduce 210Po incorporation in the intestines when given before, or enhance decorporation when provided after, 210Po gavage. PMID:27218295

Structure of C3PO and Mechanism of Human RISC Activation

PubMed Central

Ye, Xuecheng; Huang, Nian; Liu, Ying; Paroo, Zain; Huerta, Carlos; Li, Peng; Chen, She; Liu, Qinghua; Zhang, Hong

2011-01-01

Assembly of the RNA-induced silencing complex (RISC) consists of loading duplex (guide/passenger) siRNA onto and removing the passenger strand from Argonaute (Ago2). Ago2 contributes critically to RISC activation by nicking the passenger strand. Here, we reconstituted duplex siRNA-initiated RISC activity using recombinant human (h)Ago2 and C3PO, indicating a critical role for C3PO in hAgo2-RISC activation. Consistently, genetic depletion of C3PO compromised RNA silencing in mammalian cells. We determined the crystal structure of hC3PO, which reveals an asymmetric octamer barrel consisting of six Translin and two TRAX subunits. This asymmetric assembly is critical for the function of C3PO as a novel endonuclease that cleaves RNA at the interior surface. The current work supports a Dicer-independent mechanism for human RISC activation: 1) Ago2 directly binds duplex siRNA and nicks the passenger strand; 2) C3PO activates RISC by degrading Ago2-nicked passenger strand. PMID:21552258

Direct synthesis and characterization of mixed-valent Li 0.5$-$δCoPO 4, a Li-deficient derivative of the Cmcm polymorph of LiCoPO 4

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

Ludwig, Jennifer; Alarcon-Suesca, Carlos; Geprags, Stephan

While the majority of research activities on LiCoPO 4 is focussed on the thermodynamically stable olivine-type Pnma polymorph, the metastable Pna2 1 and Cmcm modifications have recently attracted considerable attention due to their interesting material properties. In this study, we present the first Li-deficient structural derivative of the Cmcm modification with the nominal composition Li 0.5–δCoPO 4. As opposed to the substoichiometric olivine ( Pnma) phases Li xCoPO 4 (x = 0; 2/3), which are exclusively accessible by electrochemical or chemical Li extraction techniques, this is also the first time that a direct soft-chemical synthesis route towards a Li xCoPOmore » 4-type material is accomplished. X-ray and neutron diffraction studies indicate that Cmcm-type Li 0.5–δCoPO 4 shows vacancies on both the Li and Co sites, whereas X-ray absorption spectra demonstrate that the structure features heterovalent Co ions (+2/+3) to compensate for the Li deficit. Magnetic measurements reveal a long-range antiferromagnetic order below 10.5 K. A thorough investigation of the thermal stability using thermogravimetric analysis, differential scanning calorimetry, and temperature-dependent in situ X-ray powder diffraction demonstrates that Li 0.5–δCoPO 4 is metastable and exhibits a complex, multi-step thermal decomposition mechanism. In the first step at 394 °C, it decomposes to α-Co 2P 2O 7 ( P2 1/c) and LiCoPO 4 ( Cmcm) upon O 2 release. The LiCoPO 4 ( Cmcm) intermediate is then irreversibly transformed to olivine-type LiCoPO 4 (Pnma) at 686 °C. Furthermore, the material properties of Li 0.5–δCoPO 4 are further compared to the fully lithiated, isostructural LiCoPO 4 ( Cmcm) phase, for which an improved structure solution as well as Co L 2,3-edge X-ray absorption spectra are reported for the first time.« less

Direct synthesis and characterization of mixed-valent Li 0.5$-$δCoPO 4, a Li-deficient derivative of the Cmcm polymorph of LiCoPO 4

DOE PAGES

Ludwig, Jennifer; Alarcon-Suesca, Carlos; Geprags, Stephan; ...

2017-05-26

While the majority of research activities on LiCoPO 4 is focussed on the thermodynamically stable olivine-type Pnma polymorph, the metastable Pna2 1 and Cmcm modifications have recently attracted considerable attention due to their interesting material properties. In this study, we present the first Li-deficient structural derivative of the Cmcm modification with the nominal composition Li 0.5–δCoPO 4. As opposed to the substoichiometric olivine ( Pnma) phases Li xCoPO 4 (x = 0; 2/3), which are exclusively accessible by electrochemical or chemical Li extraction techniques, this is also the first time that a direct soft-chemical synthesis route towards a Li xCoPOmore » 4-type material is accomplished. X-ray and neutron diffraction studies indicate that Cmcm-type Li 0.5–δCoPO 4 shows vacancies on both the Li and Co sites, whereas X-ray absorption spectra demonstrate that the structure features heterovalent Co ions (+2/+3) to compensate for the Li deficit. Magnetic measurements reveal a long-range antiferromagnetic order below 10.5 K. A thorough investigation of the thermal stability using thermogravimetric analysis, differential scanning calorimetry, and temperature-dependent in situ X-ray powder diffraction demonstrates that Li 0.5–δCoPO 4 is metastable and exhibits a complex, multi-step thermal decomposition mechanism. In the first step at 394 °C, it decomposes to α-Co 2P 2O 7 ( P2 1/c) and LiCoPO 4 ( Cmcm) upon O 2 release. The LiCoPO 4 ( Cmcm) intermediate is then irreversibly transformed to olivine-type LiCoPO 4 (Pnma) at 686 °C. Furthermore, the material properties of Li 0.5–δCoPO 4 are further compared to the fully lithiated, isostructural LiCoPO 4 ( Cmcm) phase, for which an improved structure solution as well as Co L 2,3-edge X-ray absorption spectra are reported for the first time.« less

PO*WW*ER mobile treatment unit process hazards analysis

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

Richardson, R.B.

1996-06-01

The objective of this report is to demonstrate that a thorough assessment of the risks associated with the operation of the Rust Geotech patented PO*WW*ER mobile treatment unit (MTU) has been performed and documented. The MTU was developed to treat aqueous mixed wastes at the US Department of Energy (DOE) Albuquerque Operations Office sites. The MTU uses evaporation to separate organics and water from radionuclides and solids, and catalytic oxidation to convert the hazardous into byproducts. This process hazards analysis evaluated a number of accident scenarios not directly related to the operation of the MTU, such as natural phenomena damagemore » and mishandling of chemical containers. Worst case accident scenarios were further evaluated to determine the risk potential to the MTU and to workers, the public, and the environment. The overall risk to any group from operation of the MTU was determined to be very low; the MTU is classified as a Radiological Facility with low hazards.« less

AgPO2F2 and Ag9(PO2F2)14: the first Ag(i) and Ag(i)/Ag(ii) difluorophosphates with complex crystal structures.

PubMed

Malinowski, Przemysław J; Kurzydłowski, Dominik; Grochala, Wojciech

2015-12-07

The reaction of AgF2 with P2O3F4 yields a mixed valence Ag(I)/Ag(II) difluorophosphate salt with AgAg(PO2F2)14 stoichiometry - the first Ag(ii)-PO2F2 system known. This highly moisture sensitive brown solid is thermally stable up to 120 °C, which points at further feasible extension of the chemistry of Ag(ii)-PO2F2 systems. The crystal structure shows a very complex bonding pattern, comprising of polymeric Ag(PO2F2)14(4-) anions and two types of Ag(I) cations. One particular Ag(II) site present in the crystal structure of Ag9(PO2F2)14 is the first known example of square pyramidal penta-coordinated Ag(ii) in an oxo-ligand environment. Ag(i)PO2F2 - the product of the thermal decomposition of Ag9(PO2F2)14 - has also been characterized by thermal analysis, IR spectroscopy and X-ray powder diffraction. It has a complicated crystal structure as well, which consists of infinite 1D [Ag(I)O4/2] chains which are linked to more complex 3D structures via OPO bridges. The PO2F2(-) anions bind to cations in both compounds as bidentate oxo-ligands. The terminal F atoms tend to point inside the van der Waals cavities in the crystal structure of both compounds. All important structural details of both title compounds were corroborated by DFT calculations.

H-PoP and H-PoPG: heuristic partitioning algorithms for single individual haplotyping of polyploids.

PubMed

Xie, Minzhu; Wu, Qiong; Wang, Jianxin; Jiang, Tao

2016-12-15

Some economically important plants including wheat and cotton have more than two copies of each chromosome. With the decreasing cost and increasing read length of next-generation sequencing technologies, reconstructing the multiple haplotypes of a polyploid genome from its sequence reads becomes practical. However, the computational challenge in polyploid haplotyping is much greater than that in diploid haplotyping, and there are few related methods. This article models the polyploid haplotyping problem as an optimal poly-partition problem of the reads, called the Polyploid Balanced Optimal Partition model. For the reads sequenced from a k-ploid genome, the model tries to divide the reads into k groups such that the difference between the reads of the same group is minimized while the difference between the reads of different groups is maximized. When the genotype information is available, the model is extended to the Polyploid Balanced Optimal Partition with Genotype constraint problem. These models are all NP-hard. We propose two heuristic algorithms, H-PoP and H-PoPG, based on dynamic programming and a strategy of limiting the number of intermediate solutions at each iteration, to solve the two models, respectively. Extensive experimental results on simulated and real data show that our algorithms can solve the models effectively, and are much faster and more accurate than the recent state-of-the-art polyploid haplotyping algorithms. The experiments also show that our algorithms can deal with long reads and deep read coverage effectively and accurately. Furthermore, H-PoP might be applied to help determine the ploidy of an organism. https://github.com/MinzhuXie/H-PoPG CONTACT: xieminzhu@hotmail.comSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Ag3PO4 nanocrystals deposited on monoclinic olive-like BiVO4 with efficient photodegradation of organic dyes under visible light irradiation

NASA Astrophysics Data System (ADS)

Chen, Jingshuai; Jiang, Liang-Liang; Liu, Xing-Pei; Mao, Chang-Jie; Song, Ji-Ming; Niu, Helin; Zhang, Shengyi

2017-05-01

Olive-like BiVO4 microstructures with lengths of 600-1000 nm and widths of 300-600 nm have been synthesized via a facile and additive-free solvothermal method. Studies find that the type of solvent plays an important role in the morphology of the final products. Furthermore, Ag3PO4 nanocrystals are successfully deposited on monoclinic olive-like BiVO4 via in situ precipitation method. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), photoluminescence (PL) spectra, and UV-vis diffuse reflectance spectra (DRS). The photocatalytic activities of the catalysts are evaluated by degradation of rhodamine B (RhB) and methylene blue (MB) under visible light (≥420 nm) irradiation. The experimental results suggest that catalytic activity of the composite photocatalysts is greatly influenced by the loading level of Ag3PO4. The molar ratio of 0.8:1.0 Ag3PO4-loaded BiVO4 exhibits higher photocatalytic activity in both the decolorization of RhB and MB than that of individual BiVO4 and P25. The observed improvement in photocatalytic activity is associated with the extended absorption in the visible light region resulting from the Ag3PO4 nanoparticles, and the effective separation of photogenerated carriers at the Ag3PO4/BiVO4 interfaces through the formation of heterojunction structure. The study provides a general and effective method in the fabrication of composite with sound heterojunctions that may show a variety of applications.

Folic acid-conjugated GdPO4:Tb3+@SiO2 Nanoprobe for folate receptor-targeted optical and magnetic resonance bi-modal imaging

NASA Astrophysics Data System (ADS)

Xu, Xianzhu; Zhang, Xiaoying; Wu, Yanli

2016-11-01

Both fluorescent and magnetic nanoprobes have great potential applications for diagnostics and therapy. In the present work, a folic acid-conjugated and silica-modified GdPO4:Tb3+ (GdPO4:Tb3+@SiO2-FA) dual nanoprobe was strategically designed and synthesized for the targeted dual-modality optical and magnetic resonance (MR) imaging via a facile aqueous method. Their structural, optical, and magnetic properties were determined using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), ultraviolet-visible spectra (UV-Vis), photoluminescence (PL), and superconducting quantum interference device (SQUID). These results indicated that GdPO4:Tb3+@SiO2-FA were uniform monodisperse core-shell structured nanorods (NRs) with an average length of 200 nm and an average width of 25 nm. The paramagnetic property of the synthesized GdPO4:Tb3+@SiO2-FA NRs was confirmed with its linear hysteresis plot (M-H). In addition, the NRs displayed an obvious T1-weighted effect and thus it could potentially serve as a T1-positive contrast agent. The NRs emitted green lights due to the 5D4 → 7F5 transition of the Tb3+. The in vitro assays with NCI-H460 lung cancer cells and human embryonic kidney cell line 293T cells indicated that the GdPO4:Tb3+@SiO2-FA nanoprobe could specifically bind the cells bearing folate receptors (FR). The MTT assay of the NRs revealed that its cytotoxicity was very low. Further in vivo MRI experiments distinctively depict enhanced anatomical features in a xenograft tumor. These results suggest that the GdPO4:Tb3+@SiO2-FA NPs have excellent imaging and cell-targeting abilities for the folate receptor-targeted dual-modality optical and MR imaging and can be potentially used as the nanoprobe for bioimaging.

Curcumin-Eudragit® E PO solid dispersion: A simple and potent method to solve the problems of curcumin.

PubMed

Li, Jinglei; Lee, Il Woo; Shin, Gye Hwa; Chen, Xiguang; Park, Hyun Jin

2015-08-01

Using a simple solution mixing method, curcumin was dispersed in the matrix of Eudragit® E PO polymer. Water solubility of curcumin in curcumin-Eudragit® E PO solid dispersion (Cur@EPO) was greatly increased. Based on the results of several tests, curcumin was demonstrated to exist in the polymer matrix in amorphous state. The interaction between curcumin and the polymer was investigated through Fourier transform infrared spectroscopy and (1)H NMR which implied that OH group of curcumin and carbonyl group of the polymer involved in the H bonding formation. Cur@EPO also provided protection function for curcumin as verified by the pH challenge and UV irradiation test. The pH value influenced curcumin release profile in which sustained release pattern was revealed. Additionally, in vitro transdermal test was conducted to assess the potential of Cur@EPO as a vehicle to deliver curcumin through this alternative administration route. Copyright © 2015 Elsevier B.V. All rights reserved.

Quantum-Chemical Approach to NMR Chemical Shifts in Paramagnetic Solids Applied to LiFePO4 and LiCoPO4.

PubMed

Mondal, Arobendo; Kaupp, Martin

2018-04-05

A novel protocol to compute and analyze NMR chemical shifts for extended paramagnetic solids, accounting comprehensively for Fermi-contact (FC), pseudocontact (PC), and orbital shifts, is reported and applied to the important lithium ion battery cathode materials LiFePO 4 and LiCoPO 4 . Using an EPR-parameter-based ansatz, the approach combines periodic (hybrid) DFT computation of hyperfine and orbital-shielding tensors with an incremental cluster model for g- and zero-field-splitting (ZFS) D-tensors. The cluster model allows the use of advanced multireference wave function methods (such as CASSCF or NEVPT2). Application of this protocol shows that the 7 Li shifts in the high-voltage cathode material LiCoPO 4 are dominated by spin-orbit-induced PC contributions, in contrast with previous assumptions, fundamentally changing interpretations of the shifts in terms of covalency. PC contributions are smaller for the 7 Li shifts of the related LiFePO 4 , where FC and orbital shifts dominate. The 31 P shifts of both materials finally are almost pure FC shifts. Nevertheless, large ZFS contributions can give rise to non-Curie temperature dependences for both 7 Li and 31 P shifts.

Annual dose of Taiwanese from the ingestion of 210Po in oysters.

PubMed

Lee, Hsiu-wei; Wang, Jeng-Jong

2013-03-01

Oysters around the coast of Taiwan were collected, dried, spiked with a (209)Po tracer for yield, digested with concentrated HNO(3) and H(2)O(2), and finally dissolved in 0.5 N HCl. The polonium was then spontaneously deposited onto a silver disc, and the activity of (210)Po was measured using an alpha spectrum analyzer equipped with a silicon barrier detector. Meanwhile, the internal effective dose of (210)Po coming from the intake of oysters by Taiwanese was evaluated. The results of the present study indicate that (210)Po average activity concentrations ranged from 23.4 ± 0.4 to 126 ± 94 Bq kg(-1) of fresh oysters. The oysters coming from Penghu island and Kinmen island regions contain higher concentrations of (210)Po in comparison with oysters from other regions of Taiwan. The value of (210)Po weighted average activity concentrations for all oyster samples studied is 25.9 Bq kg(-1). The annual effective dose of Taiwanese due to the ingestion of (210)Po in oysters was estimated to be 4.1 × 10(-2) mSv y(-1). Copyright © 2013. Published by Elsevier Ltd.

Direct comparison of 210Po, 234Th and POC particle-size distributions and export fluxes at the Bermuda Atlantic Time-series Study (BATS) site.

PubMed

Stewart, Gillian; Moran, S Bradley; Lomas, Michael W; Kelly, Roger P

2011-05-01

Particle-reactive, naturally occurring radionuclides are useful tracers of the sinking flux of organic matter from the surface to the deep ocean. Since the Joint Global Ocean Flux Study (JGOFS) began in 1987, the disequilibrium between (234)Th and its parent (238)U has become widely used as a technique to measure particle export fluxes from surface ocean waters. Another radionuclide pair, (210)Po and (210)Pb, can be used for the same purpose but has not been as widely adopted due to difficulty with accurately constraining the (210)Po/(210)Pb radiochemical balance in the ocean and because of the more time-consuming radiochemical procedures. Direct comparison of particle flux estimated in different ocean regions using these short-lived radionuclides is important in evaluating their utility and accuracy as tracers of particle flux. In this paper, we present paired (234)Th/(238)U and (210)Po/(210)Pb data from oligotrophic surface waters of the subtropical Northwest Atlantic and discuss their advantages and limitations. Vertical profiles of total and particle size-fractionated (210)Po and (234)Th activities, together with particulate organic carbon (POC) concentrations, were measured during three seasons at the Bermuda Atlantic Time-series Study (BATS) site. Both (210)Po and (234)Th reasonably predict sinking POC flux caught in sediment traps, and each tracer provides unique information about the magnitude and efficiency of the ocean's biological pump. Copyright © 2010 Elsevier Ltd. All rights reserved.

Indoor tanning facility density in eighty U.S. cities.

PubMed

Palmer, Richard C; Mayer, Joni A; Woodruff, Susan I; Eckhardt, Laura; Sallis, James F

2002-06-01

The purpose of this study was to examine the number of tanning facilities in select U.S. cities. The twenty most populated cities from each of 4 U.S. regions were selected for the sample. For each city, data on the number of tanning facilities, climate, and general demographic profile were collected. Data for state tanning facility legislation also were collected. A tanning facility density variable was created by dividing the city's number of facilities by its population size. The 80 cities had an average of 50 facilities each. Results of linear regression analysis indicated that higher density was significantly associated with colder climate, lower median income, and higher proportion of Whites. These data indicate that indoor tanning facilities are prevalent in the environments of U.S. urban-dwellers. Cities having the higher density profile may be logical targets for interventions promoting less or safer use of these facilities.

KMg0.09Fe1.91(PO4)2

PubMed Central

Yatskin, Michael M.; Zatovsky, Igor V.; Baumer, Vyacheslav N.; Ogorodnyk, Ivan V.; Slobodyanik, Nikolay S.

2012-01-01

KMg0.09Fe1.91(PO4)2, potassium [iron(II)/magnesium] iron(III) bis(orthophosphate), is a solid solution derived from compounds with general formula KM IIFe(PO4)2 (M II = Fe, Cu), in which the Mg atoms substitute Fe atoms only in the octa­hedrally surrounded sites. The framework of the structure is built up from [FeO5] trigonal bipyramids and [MO6] (M = (Fe, Mg) octa­hedra sharing corners and edges and connected by two types of bridging PO4 tetra­hedra. The K+ cations are nine-coordinated and are situated in channels running along [101]. PMID:22719280

Efficient UV-emitting X-ray phosphors: octahedral Zr(PO 4) 6 luminescence centers in potassium hafnium-zirconium phosphates K 2Hf 1- xZr x(PO 4) 2 and KHf 2(1- x) Zr 2 x(PO 4) 3

NASA Astrophysics Data System (ADS)

Torardi, C. C.; Miao, C. R.; Li, J.

2003-02-01

Potassium hafnium-zirconium phosphates, K 2Hf 1- xZr x(PO 4) 2 and KHf 2(1- x) Zr 2 x(PO 4) 3, are broad-band UV-emitting phosphors. At room temperature, they have emission peak maxima at approximately 322 and 305 nm, respectively, under 30 kV peak molybdenum X-ray excitation. Both phosphors demonstrate luminescence efficiencies that make them up to ˜60% as bright as commercially available CaWO 4 Hi-Plus. The solid-state and flux synthesis conditions, and X-ray excited UV luminescence of these two phosphors are discussed. Even though the two compounds have different atomic structures, they contain zirconium in the same active luminescence environment as that found in highly efficient UV-emitting BaHf 1- xZr x(PO 4) 2. All the three materials have hafnium and zirconium in octahedral coordination via oxygen-atom corner sharing with six separate PO 4 tetrahedra. This octahedral Zr(PO 4) 6 moiety appears to be an important structural element for efficient X-ray excited luminescence, as are the edge-sharing octahedral TaO 6 chains for tantalate emission.

Synthesis of superior fast charging-discharging nano-LiFePO4/C from nano-FePO4 generated using a confined area impinging jet reactor approach.

PubMed

Liu, Xiao-min; Yan, Pen; Xie, Yin-Yin; Yang, Hui; Shen, Xiao-dong; Ma, Zi-Feng

2013-06-14

LiFePO4/C nanocomposites with excellent electrochemical performance is synthesized from nano-FePO4, generated by a novel method using a confined area impinging jet reactor (CIJR). When discharged at 80 C (13.6 Ag(-1)), the LiFePO4/C delivers a discharge capacity of 95 mA h g(-1), an energy density of 227 W h kg(-1) and a power density of 34 kW kg(-1).

Electrochemical performances of LiMnPO4 synthesized from non-stoichiometric Li/Mn ratio.

PubMed

Xiao, Jie; Chernova, Natasha A; Upreti, Shailesh; Chen, Xilin; Li, Zheng; Deng, Zhiqun; Choi, Daiwon; Xu, Wu; Nie, Zimin; Graff, Gordon L; Liu, Jun; Whittingham, M Stanley; Zhang, Ji-Guang

2011-10-28

In this paper, the influences of the lithium content in the starting materials on the final performances of as-prepared Li(x)MnPO(4) (x hereafter represents the starting Li content in the synthesis step which does not necessarily mean that Li(x)MnPO(4) is a single phase solid solution in this work.) are systematically investigated. It has been revealed that Mn(2)P(2)O(7) is the main impurity when Li < 1.0 while Li(3)PO(4) begins to form once x > 1.0. The interactions between Mn(2)P(2)O(7) or Li(3)PO(4) impurities and LiMnPO(4) are studied in terms of the structural, electrochemical, and magnetic properties. At a slow rate of C/50, the reversible capacity of both Li(0.5)MnPO(4) and Li(0.8)MnPO(4) increases with cycling. This indicates a gradual activation of more sites to accommodate a reversible diffusion of Li(+) ions that may be related to the interaction between Mn(2)P(2)O(7) and LiMnPO(4) nanoparticles. Among all of the different compositions, Li(1.1)MnPO(4) exhibits the most stable cycling ability probably because of the existence of a trace amount of Li(3)PO(4) impurity that functions as a solid-state electrolyte on the surface. The magnetic properties and X-ray absorption spectroscopy (XAS) of the MnPO(4)·H(2)O precursor, pure and carbon-coated Li(x)MnPO(4) are also investigated to identify the key steps involved in preparing a high-performance LiMnPO(4). This journal is © the Owner Societies 2011

Sky Fest: A Model of Successful Scientist Participation in E/PO

NASA Astrophysics Data System (ADS)

Dalton, H.; Shipp, S. S.; Shaner, A. J.; LaConte, K.; Shupla, C. B.

2014-12-01

Participation in outreach events is an easy way for scientists to get involved with E/PO and reach many people with minimal time commitment. At the Lunar and Planetary Institute (LPI) in Houston, Texas, the E/PO team holds Sky Fest outreach events several times a year. These events each have a science content theme and include several activities for children and their parents, night sky viewing through telescopes, and scientist presentations. LPI scientists have the opportunity to participate in Sky Fest events either by helping lead an activity or by giving the scientist presentation (a short lecture and/or demonstration). Scientists are involved in at least one preparation meeting before the event. This allows them to ask questions, understand what activity they will be leading, and learn the key points that they should be sharing with the public, as well as techniques for effectively teaching members of the public about the event topic. During the event, each activity is run by one E/PO specialist and one scientist, enabling the scientist to learn about effective E/PO practices from the E/PO specialist and the E/PO specialist to get more science information about the event topic. E/PO specialists working together with scientists at stations provides a more complete, richer experience for event participants. Surveys of event participants have shown that interacting one-on-one with scientists is often one of their favorite parts of the events. Interviews with scientists indicated that they enjoyed Sky Fest because there was very little time involved on their parts outside of the actual event; the activities were created and/or chosen by the E/PO professionals, and setup for the events was completed before they arrived. They also enjoyed presenting their topic to people without a background in science, and who would not have otherwise sought out the information that was presented.

Velocity profile development for a poultry facility acid scrubber

USDA-ARS?s Scientific Manuscript database

Determination of the air velocity profile for 12 experimental configurations (ECs) of an acid scrubber was carried out using an equal area traverse method with a vane axial anemometer. Four velocity profile plots were created for each configuration to determine the four optimal ECs. ECs were selecte...

CsMgPO4

PubMed Central

Strutynska, Nataliya Yu.; Zatovsky, Igor V.; Baumer, Vyacheslav N.; Slobodyanik, Nikolay S.

2009-01-01

Caesium magnesium orthophosphate is built up from MgO4 and PO4 tetra­hedra (both with . m. symmetry) linked together by corners, forming a three-dimensional framework. The Cs atoms have .m. site symmetry and are located in hexa­gonal channels running along the a- and b-axis directions. PMID:21583294

Discrimination of magnoliae officinalis cortex based on the quantitative profiles of magnolosides by two-channel liquid chromatography with electrochemical detection.

PubMed

Xue, Zhenzhen; Kotani, Akira; Yang, Bin; Hakamata, Hideki

2018-05-31

A two-channel liquid chromatography with electrochemical detection system (2LC-ECD) was newly designed for the simultaneous determination of magnolosides A, B, F, H, and L in the first channel and other magnolosides D and M in the second channel, respectively. Peak heights had linear relationships to the magnoloside concentrations in a range of 0.02-16 μmol/L for H, 0.01-12 μmol/L for A, 0.02-12 μmol/L for F and L, 0.01-8 μmol/L for B, 0.002-6 μmol/L for D, and 0.002-4 μmol/L for M, respectively. Seven magnolosides in magnoliae officinalis cortex (MOC) were determined by the 2LC-ECD, and the obtained quantitative profiles of magnolosides were applied to the discrimination between the MOC samples harvested from Hubei and Sichuan (called Chuan po) and from Zhejiang and Fujian (called Wen po). By principal component analysis (PCA) and supervised partial least squares discriminant analysis (PLS-DA) based on the quantitative profiles of the magnolosides, Chuan po were clearly discriminated from Wen po on the plots obtained from our multivariable analyses. Copyright © 2018 Elsevier B.V. All rights reserved.

Supplemental multilayer insulation research facility

NASA Technical Reports Server (NTRS)

Dempsey, P. J.; Stochl, R. J.

1995-01-01

The Supplemental Multilayer Insulation Research Facility (SMIRF) provides a small scale test bed for conducting cryogenic experiments in a vacuum environment. The facility vacuum system is capable of simulating a Space Shuttle launch pressure profile as well as providing a steady space vacuum environment of 1.3 x 10(exp -4) Newton/sq meter (1 x 10(exp -6) torr). Warm side boundary temperatures can be maintained constant between 111 K (200 R) and 361 K (650 R) using a temperature controlled shroud. The shroud can also simulate a typical lunar day-night temperature profile. The test hardware consists of a cryogenic calorimeter supported by the lid of the vacuum chamber. A 0.45 cu meter (120 gallon) vacuum jacketed storage/supply tank is available for conditioning the cryogen prior to use in the calorimeter. The facility was initially designed to evaluate the thermal performance of insulation systems for long-term storage in space. The facility has recently been used to evaluate the performance of various new insulation systems for LH2 and LN2 ground storage dewars.

The influence of temperature on a nutty-cake structural material: LiMn1-xFexPO4 composite with LiFePO4 core and carbon outer layer for lithium-ion battery

NASA Astrophysics Data System (ADS)

Huo, Zhen-Qing; Cui, Yu-Ting; Wang, Dan; Dong, Yue; Chen, Li

2014-01-01

The extremely low electronic conductivity, slow ion diffusion kinetics, and the Jahn-Teller effect of LiMnPO4 limit its electrochemical performance. In this work, a nutty-cake structural C-LiMn1-xFexPO4-LiFePO4 cathode material is synthesized by hydrothermal method and further calcined at different temperatures. The influence of calcination temperature on the electrochemical behavior is investigated by X-ray diffractometer, scanning electron microscope, field-emission high-resolution transmission electron microscope, energy-dispersive X-ray spectroscopy, electrochemical impedance spectroscopy and charge-discharge tests. And the performance of C-LiMn1-xFexPO4-LiFePO4 materials has a relationship with its crystal structure. The well-crystallized Sample-600 calcined at 600 °C shows the smallest charge transfer resistance, the largest lithium ion diffusion coefficient (DLi) and the best cycling stability. The discharge capacity of Sample-600 holds around 112 mAh g-1 after the 3rd cycle at 0.1 C rate. The performances improvement of C-LiMn1-xFexPO4-LiFePO4 material can be mainly attributed to the iron diffusion from the LiFePO4 core to the outer LiMnPO4 layer under appropriate calcination temperature.

PoMiN: A Post-Minkowskian N-body Solver

NASA Astrophysics Data System (ADS)

Feng, Justin; Baumann, Mark; Hall, Bryton; Doss, Joel; Spencer, Lucas; Matzner, Richard

2018-06-01

In this paper, we introduce PoMiN, a lightweight N-body code based on the post-Minkowskian N-body Hamiltonian of Ledvinka et al., which includes general relativistic effects up to first order in Newton’s constant G, and all orders in the speed of light c. PoMiN is written in C and uses a fourth-order Runge–Kutta integration scheme. PoMiN has also been written to handle an arbitrary number of particles (both massive and massless), with a computational complexity that scales as O(N 2). We describe the methods we used to simplify and organize the Hamiltonian, and the tests we performed (convergence, conservation, and analytical comparison tests) to validate the code.

Ultralong Lifespan and Ultrafast Li Storage: Single-Crystal LiFePO4 Nanomeshes.

PubMed

Zhang, Yan; Zhang, Hui Juan; Feng, Yang Yang; Fang, Ling; Wang, Yu

2016-01-27

A novel LiFePO4 material, in the shape of a nanomesh, has been rationally designed and synthesized based on the low crystal-mismatch strategy. The LiFePO4 nanomesh possesses several advantages in morphology and crystal structure, including a mesoporous structure, its crystal orientation that is along the [010] direction, and a shortened Li-ion diffusion path. These properties are favorable for their application as cathode in Li-ion batteries, as these will accelerate the Li-ion diffusion rate, improve the Li-ion exchange between the LiFePO4 nanomesh and the electrolyte, and reduce the Li-ion capacitive behavior during Li intercalation. So the LiFePO4 nanomesh exhibits a high specific capacity, enhanced rate capability, and strengthened cyclability. The method developed here can also be extended to other similar systems, for instance, LiMnPO4 , LiCoPO4 , and LiNiPO4 , and may find more applications in the designed synthesis of functional materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Liquid Metal Fast Breeder Reactor Program: Argonne facilities

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

Stephens, S. V.

1976-09-01

The objective of the document is to present in one volume an overview of the Argonne National Laboratory test facilities involved in the conduct of the national LMFBR research and development program. Existing facilities and those under construction or authorized as of September 1976 are described. Each profile presents brief descriptions of the overall facility and its test area and data relating to its experimental and testing capability. The volume is divided into two sections: Argonne-East and Argonne-West. Introductory material for each section includes site and facility maps. The profiles are arranged alphabetically by title according to their respective locationsmore » at Argonne-East or Argonne-West. A glossary of acronyms and letter designations in common usage to describe organizations, reactor and test facilities, components, etc., involved in the LMFBR program is appended.« less

234Th, 210Pb, 210Po and stable Pb in the central equatorial Pacific: Tracers for particle cycling

USGS Publications Warehouse

Murray, J.W.; Paul, B.; Dunne, J.P.; Chapin, T.

2005-01-01

Samples were collected during the 1992 US JGOFS EqPac Survey I and II cruises from 12??N to 12??S at 140??W in the central equatorial Pacific for water column profiles of dissolved, particulate and total 234Th, 210Pb and 210Po and total acid soluble stable Pb and sediment trap fluxes of 234Th, 210Pb and 210Po. Survey I occurred in February/March with moderate El Nino conditions while Survey II was conducted in September/October when there was a well developed cold-tongue. 234Th, 210Pb and 210Po are all particle reactive yet they partition differently between dissolved and particulate phases. Fractionation factors (the ratios of the distribution coefficients) show that the selectivity for suspended and sediment trap particles follows Th>Po>Pb. Scavenging residence times (??) for 234Th, 210Pb and 210Po ranged from 25 to 100 d, 3 to 8 years and 100 to 500 d, respectively. These particle reactive tracers have very different distributions in the water column, which reflect differences in their sources and sinks. The deficiency of 234Th relative to 238U was fairly uniformly distributed meridionally, though deficiencies were higher during Survey II when there was higher new production. Excess 210Pb relative to 226Ra was very asymmetrical with much higher excess values north of the equator. The distributions were similar for Surveys I and II. The deficiency of 210Po relative to 210Pb had a symmetrical distribution about the equator for both Survey I and II but the deficiencies were larger during Survey I when upwelling was smaller. Stable Pb was generally higher at the surface than at 250 m and there was no meridional trend from 12??N to 12??S. A mass balance for 210Pb was used to determine the atmospheric input of 210Pb. The average values for Surveys I and II were 0.12 and 0.32 dpm cm-2 year-1, respectively. There was no general increase in atmospheric input of 210Pb north of the equator but there was a strong maximum at 2-3??N during Survey I coincident with the

Synergetic effect of MoS2 and graphene as cocatalysts for enhanced photocatalytic activity of BiPO4 nanoparticles

NASA Astrophysics Data System (ADS)

Lv, Hua; Liu, Yumin; Tang, Haibo; Zhang, Peng; Wang, Jianji

2017-12-01

The photodegradation of organic pollutants is an attractive green chemistry technology for water pollution control. Here we prepared a new composite material consisting of BiPO4 nanocrystals grown on layered graphene and MoS2 as a high-performance photocatalyst for the photodegradation of organic pollutants. This composite material was synthesized by a facile one-pot microwave-assisted hydrothermal technique in the presence of layered graphene and MoS2. Through optimizing the loading content of each component, the BiPO4-MoS2/graphene nanocomposite exhibited the highest photocatalytic activity for the degradation of Rhodamine (RhB) when the content of MoS2 and graphene was 2 wt% and 7 wt%, respectively. The enhanced photocatalytic activity of the new composite photocatalyst was attributed to the positive synergetic effect of the layered graphene and MoS2 as cocatalyst, which acted as electron collector and transporter for the interfacial electron transfer from BiPO4 to electron acceptor in the aqueous solution and thus suppressed the charge recombination and made the photogenerated holes more available to participated in the oxidation process. Moreover, the presence of layered MoS2/graphene hybrid could offer more reactive sites and activated the O2 molecular in water to form superoxide radical, thereby resulting in the enhanced photocatalytic activity.

Occurrence of 210Po and Biological Effects of Low-Level Exposure: The Need for Research

PubMed Central

Wiemels, Joseph L.

2012-01-01

Background: Polonium-210 (210Po) concentrations that exceed 1 Bq/L in drinking-water supplies have been reported from four widely separated U.S. states where exposure to it went unnoticed for decades. The radionuclide grandparents of 210Po are common in sediments, and segments of the public may be chronically exposed to low levels of 210Po in drinking water or in food products from animals raised in contaminated areas. Objectives: We summarized information on the environmental behavior, biokinetics, and toxicology of 210Po and identified the need for future research. Methods: Potential linkages between environmental exposure to 210Po and human health effects were identified in a literature review. Discussion: 210Po accumulates in the ovaries where it kills primary oocytes at low doses. Because of its radiosensitivity and tendency to concentrate 210Po, the ovary may be the critical organ in determining the lowest injurious dose for 210Po. 210Po also accumulates in the yolk sac of the embryo and in the fetal and placental tissues. Low-level exposure to 210Po may have subtle, long-term biological effects because of its tropism towards reproductive and embryonic and fetal tissues where exposure to a single alpha particle may kill or damage critical cells. 210Po is present in cigarettes and maternal smoking has several effects that appear consistent with the toxicology of 210Po. Conclusions: Much of the important biological and toxicological research on 210Po is more than four decades old. New research is needed to evaluate environmental exposure to 210Po and the biological effects of low-dose exposure to it so that public health officials can develop appropriate mitigation measures where necessary. PMID:22538346

The sources and fate of (210)Po in the urban air: A review.

PubMed

Długosz-Lisiecka, Magdalena

2016-09-01

The origin of (210)Po activity and its fluctuations in the air are discussed in this paper. In the case of atmospheric aerosol samples, a comparison of the (210)Po/(210)Pb and (210)Bi/(210)Pb activity ratios makes it possible not only to determine aerosol residence times but also to appraise the contribution of the unsupported (210)Po coming from other sources than (222)Rn decay, such as human industrial activities, especially coal combustion. A simple mathematical method makes it possible to observe the seasonal fluctuations of the anthropogenic excess of (210)Po in the urban air. The average doses of (210)Po intake with food (including drinking water) and inhalation of urban aerosols are usually lower than those from (210)Po intake by cigarette smokers and negligible in comparison to total natural radiation exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pnicogen bonded complexes of PO2X (X = F, Cl) with nitrogen bases.

PubMed

Alkorta, Ibon; Elguero, José; Del Bene, Janet E

2013-10-10

An ab initio MP2/aug'-cc-pVTZ study has been carried out on complexes formed between PO2X (X = F and Cl) as the Lewis acids and a series of nitrogen bases ZN, including NH3, H2C═NH, NH2F, NP, NCH, NCF, NF3, and N2. Binding energies of these complexes vary from -10 to -150 kJ/mol, and P-N distances from 1.88 to 2.72 Å. Complexes ZN:PO2F have stronger P(...)N bonds and shorter P-N distances than the corresponding complexes ZN:PO2Cl. Charge transfer from the N lone pair through the π-hole to the P-X and P-O σ* orbitals leads to stabilization of these complexes, although charge-transfer energies can be evaluated only for complexes with binding energies less than -71 kJ/mol. Complexation of PO2X with the strongest bases leads to P···N bonds with a significant degree of covalency, and P-N distances that approach the P-N distances in the molecules PO2NC and PO2NH2. In these complexes, the PO2X molecules distort from planarity. Changes in (31)P absolute chemical shieldings upon complexation do not correlate with changes in charges on P, although they do correlate with the binding energies of the complexes. EOM-CCSD spin-spin coupling constants (1p)J(P-N) are dominated by the Fermi-contact term, which is an excellent approximation to total J. (1p)J(P-N) values are small at long distances, increase as the distance decreases, but then decrease at short P-N distances. At the shortest distances, values of (1p)J(P-N) approach (1)J(P-N) for the molecules PO2NC and PO2NH2.

CeRuPO: A rare example of a ferromagnetic Kondo lattice

NASA Astrophysics Data System (ADS)

Krellner, C.; Kini, N. S.; Brüning, E. M.; Koch, K.; Rosner, H.; Nicklas, M.; Baenitz, M.; Geibel, C.

2007-09-01

We have determined the physical ground state properties of the compounds CeRuPO and CeOsPO by means of magnetic susceptibility χ(T) , specific heat C(T) , electrical resistivity ρ(T) , and thermopower S(T) measurements. χ(T) reveals a trivalent 4f1 cerium state in both compounds. For CeRuPO a pronounced decrease of ρ(T) below 50K indicates the onset of coherent Kondo scattering, which is confirmed by enhanced S(T) . The temperature and magnetic field dependence of χ(T) and C(T) evidence ferromagnetic (FM) order at TC=15K . Thus, CeRuPO seems to be one of the rare examples of a FM Kondo lattice. In contrast, CeOsPO shows antiferromagnetic order at TN=4.5K despite only minor changes in lattice parameters and electronic configuration. Additional P31 NMR results support these scenarios. LSDA+U calculations evidence a quasi-two-dimensional electronic band structure, reflecting a strong covalent bonding within the CeO and RuP layers and a weak ioniclike bonding between the layers.

Association Between Hospital Admission Risk Profile Score and Skilled Nursing or Acute Rehabilitation Facility Discharges in Hospitalized Older Adults.

PubMed

Liu, Stephen K; Montgomery, Justin; Yan, Yu; Mecchella, John N; Bartels, Stephen J; Masutani, Rebecca; Batsis, John A

2016-10-01

To evaluate whether the Hospital Admission Risk Profile (HARP) score is associated with skilled nursing or acute rehabilitation facility discharge after an acute hospitalization. Retrospective cohort study. Inpatient unit of a rural academic medical center. Hospitalized individuals aged 70 and older from October 1, 2013 to June 1, 2014. Participant age at the time of admission, modified Folstein Mini-Mental State Examination score, and self-reported instrumental activities of daily living 2 weeks before admission were used to calculate HARP score. The primary predictor was HARP score, and the primary outcome was discharge disposition (home, facility, deceased). Multivariate analysis was used to evaluate the association between HARP score and discharge disposition, adjusting for age, sex, comorbidities, and length of stay. Four hundred twenty-eight individuals admitted from home were screened and their HARP scores were categorized as low (n = 162, 37.8%), intermediate (n = 157, 36.7%), or high (n = 109, 25.5%). Participants with high HARP scores were significantly more likely to be discharged to a facility (55%) than those with low HARP scores (20%) (P < .001). After adjustment, participants with high HARP scores were more than four times as likely as those with low scores to be discharged to a facility (odds ratio = 4.58, 95% confidence interval = 2.42-8.66). In a population of older hospitalized adults, HARP score (using readily available admission information) identifies individuals at greater risk of skilled nursing or acute rehabilitation facility discharge. Early identification for potential facility discharges may allow for targeted interventions to prevent functional decline, improve informed shared decision-making about post-acute care needs, and expedite discharge planning. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

High pressure experimental studies on Na3Fe(PO4)(CO3) and Na3Mn(PO4)(CO3): Extensive pressure behaviors of carbonophosphates family

NASA Astrophysics Data System (ADS)

Gao, Jing; Huang, Weifeng; Wu, Xiang; Qin, Shan

2018-04-01

Carbon-bearing phases in the Earth's interior have profound implications for the long-term Earth carbon cycle. Here we investigate high-pressure behaviors of carbonophosphates bonshtedtite Na3Fe(PO4)(CO3) and sidorenkite Na3Mn(PO4)(CO3) in diamond anvil cells up to ∼12 GPa at room temperature. Modifications in in situ synchrotron X-ray diffraction patterns and Raman spectra confirm the structural stability of carbonophosphates within the pressure region. Fitting the third-order Birch-Murnaghan equation of state to the volume compression curve, the isothermal bulk modulus parameters are obtained to be K0 = 56(1) GPa, K0' = 3.3(1), V0 = 303.3(3) Å3 for Na3Fe(PO4)(CO3) and K0 = 54(1) GPa, K0' = 3.4(1), V0 = 313.4(2) Å3 for Na3Mn(PO4)(CO3). Crystallographic axes exhibit an elastic anisotropy with a more compressible c-axis relative to the ab-plane. An inverse linear correlation between the K0 value and the ionic radius of M2+ (M = Mg, Fe, Mn) is well determined for carbonophosphates. The pressure-dependence responsiveness of [PO4] and [CO3] in carbonophosphates show a negative relationship to the M2+ radius. We also discussed the effect of [PO4] group on the structural variations and high-pressure behaviors of carbonates. Furthermore, the geochemical properties of carbonophosphates hold implications to diamond genesis.

Visible light assisted degradation of organic dye using Ag{sub 3}PO{sub 4}

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

Dhanabal, R.; Bose, A. Chandra, E-mail: acbose@nitt.edu; Velmathi, S.

2015-06-24

The study of visible light photodegradation of organic dye Methylene Blue (MB) have been investigated using silver phosphate (Ag{sub 3}PO{sub 4}) as a photocatalyst which is good efficient material for photocatalytic reaction. The simple ion-exchange method is used to prepare Ag{sub 3}PO{sub 4}. The structure of the material have been confirmed using X-ray diffraction which shows cubic structure of Ag{sub 3}PO{sub 4}. The functional group of the Ag{sub 3}PO{sub 4} has been verified by Fourier transform infrared spectroscopy. The bandgap of Ag{sub 3}PO{sub 4} is calculated using kubelka-munk function from the ultra violet-visible diffuse reflectance spectroscopy, the absorption of Ag{submore » 3}PO{sub 4} starts from 470 nm. Under simulated visible light irradiation, Ag{sub 3}PO{sub 4} catalyst exhibits good catalytic ability for degrading MB dye.« less

Highly-efficient photocatalytic degradation of methylene blue by PoPD-modified TiO 2 nanocomposites due to photosensitization-synergetic effect of TiO2 with PoPD.

PubMed

Yang, Chuanxi; Dong, Wenping; Cui, Guanwei; Zhao, Yingqiang; Shi, Xifeng; Xia, Xinyuan; Tang, Bo; Wang, Weiliang

2017-06-21

Poly-o-phenylenediamine modified TiO 2 nanocomposites were successfully synthesized via an 'in situ' oxidative polymerization method. The modified nanocomposites were characterized by BET, XRD, TEM, FT-IR, TGA, XPS, EA and UV-Vis DRS. The photocatalytic degradation of methylene blue was chosen as a model reaction to evaluate the photocatalytic activities of TiO 2 and PoPD/TiO 2 . The results indicated that PoPD/TiO 2 nanocomposites exhibited good photocatalytic activity and stability. The photocatalytic activity of PoPD/TiO 2 increased as the initial pH increased because of electrostatic adsorption between the photocatalyst and MB as well as the generation of ·OH, whereas it exhibited an earlier increasing and later decreasing trend as the concentration of the photocatalyst increased owing to the absorption of visible light. The photocatalytic stability of the PoPD/TiO 2 nanocomposite was dependent on the stability of its structure. Based on radical trapping experiments and ESR measurements, the origin of oxidizing ability of PoPD/TiO 2 nanocomposites on photocatalytic degradation of MB was proposed, which taking into account of ·OH and ·O 2 - were the first and second important ROS, respectively. The possible photocatalytic mechanism and photocatalytic activity enhanced mechanism has been proposed, taking into account the photosensitization effect and synergetic effect of TiO 2 with PoPD.

Super, Red Palm and Palm Oleins Improve the Blood Pressure, Heart Size, Aortic Media Thickness and Lipid Profile in Spontaneously Hypertensive Rats

PubMed Central

Boon, Chee-Meng; Ng, Mei-Han; Choo, Yuen-May; Mok, Shiueh-Lian

2013-01-01

Background Oleic acid has been shown to lower high blood pressure and provide cardiovascular protection. Curiosity arises as to whether super olein (SO), red palm olein (RPO) and palm olein (PO), which have high oleic acid content, are able to prevent the development of hypertension. Methodology/Principal Findings Four-week-old male spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats were fed 15% SO, RPO or PO supplemented diet for 15 weeks. After 15 weeks of treatment, the systolic blood pressure (SBP) of SHR treated with SO, RPO and PO were 158.4±5.0 mmHg (p<0.001), 178.9±2.7 mmHg (p<0.001) and 167.7±2.1 mmHg (p<0.001), respectively, compared with SHR controls (220.9±1.5 mmHg). Bradycardia was observed with SO and PO. In contrast, the SBP and heart rate of treated WKY rats were not different from those of WKY controls. The SO and PO significantly reduced the increased heart size and thoracic aortic media thickness observed in untreated SHR but RPO reduced only the latter. No such differences, however, were observed between the treated and untreated WKY rats. Oil Red O enface staining of thoracic-abdominal aorta did not show any lipid deposition in all treated rats. The SO and RPO significantly raised serum alkaline phosphatase levels in the SHR while body weight and renal biochemical indices were unaltered in both strains. Serum lipid profiles of treated SHR and WKY rats were unchanged, with the exception of a significant reduction in LDL-C level and total cholesterol/HDL ratio (atherogenic index) in SO and RPO treated SHR compared with untreated SHR. Conclusion The SO, RPO and PO attenuate the rise in blood pressure in SHR, accompanied by bradycardia and heart size reduction with SO and PO, and aortic media thickness reduction with SO, RPO and PO. The SO and RPO are antiatherogenic in nature by improving blood lipid profiles in SHR. PMID:23409085

Tools for Scientist Engagement in E/PO: NASA SMD Community Workspace and Online Resources

NASA Astrophysics Data System (ADS)

Dalton, H.; Shipp, S. S.; Grier, J.; Gross, N. A.; Buxner, S.; Bartolone, L.; Peticolas, L. M.; Woroner, M.; Schwerin, T. G.

2014-12-01

The Science Mission Directorate (SMD) Science Education and Public Outreach (E/PO) Forums are here to help you get involved in E/PO! The Forums have been developing several online resources to support scientists who are - or who are interested in becoming - involved in E/PO. These include NASA Wavelength, EarthSpace, and the SMD E/PO online community workspace. NASA Wavelength is the one-stop shop of all peer-reviewed NASA education resources to find materials you - or your audiences - can use. Browse by audience (pre-K through 12, higher education, and informal education) or topic, or choose to search for something specific by keyword and audience. http://nasawavelength.org. EarthSpace, an online clearinghouse of Earth and space materials for use in the higher education classroom, is driven by a powerful search engine that allows you to browse the collection of resources by science topic, audience, type of material or key terms. All materials are peer-reviewed before posting, and because all submissions receive a digital object identifier (doi), submitted materials can be listed as publications. http://www.lpi.usra.edu/earthspace. The SMD E/PO online community workspace contains many resources for scientists. These include one-page guides on how to get involved, tips on how to make the most of your time spent on E/PO, and sample activities, as well as news on funding, policy, and what's happening in the E/PO community. The workspace also provides scientists and the public pathways to find opportunities for participation in E/PO, to learn about SMD E/PO projects and their impacts, to connect with SMD E/PO practitioners, and to explore resources to improve professional E/PO practice, including literature reviews, information about the Next Generation Science Standards, and best practices in evaluation and engaging diverse audiences. http://smdepo.org.

Synthesis of national risk profile

NASA Technical Reports Server (NTRS)

1979-01-01

The methodology used and results obtained in computing the national risk profile for carbon fibers (CF) released after an aircraft accident (fire or explosion) are presented. The computation was performed by use of twenty-six individual conditional risk profiles, together with the extrapolation of these profiles to other U.S. airports. The risk profile was obtained using 1993 CF utilization forecasts, but numbers of facilities were taken from 1972 and 1975 census data, while losses were expressed in 1977 dollars.

Silica-modified luminescent LaPO4 :Eu@LaPO4 @SiO2 core/shell nanorods: Synthesis, structural and luminescent properties.

PubMed

Ansari, Anees A

2018-02-01

Monoclinic-type tetragonal LaPO 4 :Eu (core) and LaPO 4 :Eu@LaPO 4 (core/shell) nanorods (NRs) were successfully prepared using a urea-based co-precipitation process under ambient conditions. An amorphous silica layer was coated around the luminescent core/shell NRs via the sol-gel process to improve their solubility and colloidal stability in aqueous and non-aqueous media. The prepared nano-products were systematically characterized by X-ray diffraction pattern, transmission electron microscopy, energy dispersive X-ray analysis, and FTIR, UV/Vis, and photoluminescence spectroscopy to examine their phase purity, crystal phase, surface chemistry, solubility and luminescence characteristics. The length and diameter of the nano-products were in the range 80-120 nm and 10-15 nm, respectively. High solubility of the silica-modified core/shell/Si NRs was found for the aqueous medium. The luminescent core NRs exhibited characteristic excitation and emission transitions in the visible region that were greatly affected by surface growth of insulating LaPO 4 and silica layers due to the multiphonon relaxation rate. Our luminescence spectral results clearly show a distinct difference in intensities for core, core/shell, and core/shell/Si NRs. Highly luminescent NRs with good solubility could be useful candidates for a variety of photonic-based biomedical applications. Copyright © 2017 John Wiley & Sons, Ltd.

210Pb and 210Po in Finnish cereals.

PubMed

Turtiainen, Tuukka; Kostiainen, Eila; Hallikainen, Anja

2011-05-01

A survey was carried out on the activity concentrations of (210)Pb and (210)Po in cereal grains produced in Finland. The cereal species were wheat (Triticum aestivum), rye (Secale cereale), oats (Avena sativa) and barley (Hordeum vulgare), which account for 90% of the Finnish consumption of cereal products. The survey consisted of 18 flour and 13 unprocessed cereal samples and one hulled grain sample from 22 flour mills. According to the results, the mean (210)Pb/(210)Po concentrations in wheat grains, wheat flour, rye flour, oat grains and barley grains were 0.29, 0.12, 0.29, 0.36 and 0.36 Bq kg(-1), respectively. Combined with the consumption rates of the products, we assess that the mean effective doses from (210)Pb and (210)Po in cereal products for the adult male and female population are 22 and 17 μSv per year, respectively. Copyright © 2010 Elsevier Ltd. All rights reserved.

Synthesis, crystal structure and spectroscopy properties of Na 3AZr(PO 4) 3 ( A=Mg, Ni) and Li 2.6Na 0.4NiZr(PO 4) 3 phosphates

NASA Astrophysics Data System (ADS)

Chakir, M.; El Jazouli, A.; de Waal, D.

2006-06-01

Na 3AZr(PO 4) 3 ( A=Mg, Ni) phosphates were prepared at 750 °C by coprecipitation route. Their crystal structures have been refined at room temperature from X-ray powder diffraction data using Rietveld method. Li 2.6Na 0.4NiZr(PO 4) 3 was synthesized through ion exchange from the sodium analog. These materials belong to the Nasicon-type structure. Raman spectra of Na 3AZr(PO 4) 3 ( A=Mg, Ni) phosphates present broad peaks in favor of the statistical distribution in the sites around PO 4 tetrahedra. Diffuse reflectance spectra indicate the presence of octahedrally coordinated Ni 2+ ions.

On a framework for generating PoD curves assisted by numerical simulations

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

Subair, S. Mohamed, E-mail: prajagopal@iitm.ac.in; Agrawal, Shweta, E-mail: prajagopal@iitm.ac.in; Balasubramaniam, Krishnan, E-mail: prajagopal@iitm.ac.in

2015-03-31

The Probability of Detection (PoD) curve method has emerged as an important tool for the assessment of the performance of NDE techniques, a topic of particular interest to the nuclear industry where inspection qualification is very important. The conventional experimental means of generating PoD curves though, can be expensive, requiring large data sets (covering defects and test conditions), and equipment and operator time. Several methods of achieving faster estimates for PoD curves using physics-based modelling have been developed to address this problem. Numerical modelling techniques are also attractive, especially given the ever-increasing computational power available to scientists today. Here wemore » develop procedures for obtaining PoD curves, assisted by numerical simulation and based on Bayesian statistics. Numerical simulations are performed using Finite Element analysis for factors that are assumed to be independent, random and normally distributed. PoD curves so generated are compared with experiments on austenitic stainless steel (SS) plates with artificially created notches. We examine issues affecting the PoD curve generation process including codes, standards, distribution of defect parameters and the choice of the noise threshold. We also study the assumption of normal distribution for signal response parameters and consider strategies for dealing with data that may be more complex or sparse to justify this. These topics are addressed and illustrated through the example case of generation of PoD curves for pulse-echo ultrasonic inspection of vertical surface-breaking cracks in SS plates.« less

On a framework for generating PoD curves assisted by numerical simulations

NASA Astrophysics Data System (ADS)

Subair, S. Mohamed; Agrawal, Shweta; Balasubramaniam, Krishnan; Rajagopal, Prabhu; Kumar, Anish; Rao, Purnachandra B.; Tamanna, Jayakumar

2015-03-01

The Probability of Detection (PoD) curve method has emerged as an important tool for the assessment of the performance of NDE techniques, a topic of particular interest to the nuclear industry where inspection qualification is very important. The conventional experimental means of generating PoD curves though, can be expensive, requiring large data sets (covering defects and test conditions), and equipment and operator time. Several methods of achieving faster estimates for PoD curves using physics-based modelling have been developed to address this problem. Numerical modelling techniques are also attractive, especially given the ever-increasing computational power available to scientists today. Here we develop procedures for obtaining PoD curves, assisted by numerical simulation and based on Bayesian statistics. Numerical simulations are performed using Finite Element analysis for factors that are assumed to be independent, random and normally distributed. PoD curves so generated are compared with experiments on austenitic stainless steel (SS) plates with artificially created notches. We examine issues affecting the PoD curve generation process including codes, standards, distribution of defect parameters and the choice of the noise threshold. We also study the assumption of normal distribution for signal response parameters and consider strategies for dealing with data that may be more complex or sparse to justify this. These topics are addressed and illustrated through the example case of generation of PoD curves for pulse-echo ultrasonic inspection of vertical surface-breaking cracks in SS plates.

Effects of Posidonia oceanica banquettes on intake, digestibility, nitrogen balance and metabolic profiles in sheep.

PubMed

Castillo, Cristina; Hernández, Joaquín; Sotillo Mesanza, Juan; Gutiérrez, Cándido; Montes, Ana M; Mantecón, Ángel Ruiz

2018-05-01

The marine plant Posidonia oceanica (L.) (PO) has been demonstrated in goats to be a source of fibre. The aim of the present study was to assess the effects of introducing this marine plant as a substitute for barley straw in the feed of mature ewes, assessing the effects of its addition on intake, digestibility and ruminal fermentation and on the ewes' metabolic profiles (energy and protein). PO was used at 75 g day -1 per ewe (15% of the total forage), 150 g day -1 per ewe (30% of the total forage) and 300 g day -1 per ewe (60% of the total forage). Substitution of 15% of the forage with PO has no negative consequences on dry matter intake, final live weight and metabolic status in mature ewes; in addition, PO may improve the animal's nitrogen utilisation. The upper limit of substitution was 30%, where only few changes were noted without metabolic consequences. Substitution of 60% impaired performance and affects tissue functions in the animal's body. Moderate quantities of barley straw (between 75 and 150 g day -1 per ewe) can be replaced by PO in feed rations for mature ewes. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Development of a Portable Motor Learning Laboratory (PoMLab)

PubMed Central

Shinya, Masahiro

2016-01-01

Most motor learning experiments have been conducted in a laboratory setting. In this type of setting, a huge and expensive manipulandum is frequently used, requiring a large budget and wide open space. Subjects also need to travel to the laboratory, which is a burden for them. This burden is particularly severe for patients with neurological disorders. Here, we describe the development of a novel application based on Unity3D and smart devices, e.g., smartphones or tablet devices, that can be used to conduct motor learning experiments at any time and in any place, without requiring a large budget and wide open space and without the burden of travel on subjects. We refer to our application as POrtable Motor learning LABoratory, or PoMLab. PoMLab is a multiplatform application that is available and sharable for free. We investigated whether PoMLab could be an alternative to the laboratory setting using a visuomotor rotation paradigm that causes sensory prediction error, enabling the investigation of how subjects minimize the error. In the first experiment, subjects could adapt to a constant visuomotor rotation that was abruptly applied at a specific trial. The learning curve for the first experiment could be modeled well using a state space model, a mathematical model that describes the motor leaning process. In the second experiment, subjects could adapt to a visuomotor rotation that gradually increased each trial. The subjects adapted to the gradually increasing visuomotor rotation without being aware of the visuomotor rotation. These experimental results have been reported for conventional experiments conducted in a laboratory setting, and our PoMLab application could reproduce these results. PoMLab can thus be considered an alternative to the laboratory setting. We also conducted follow-up experiments in university physical education classes. A state space model that was fit to the data obtained in the laboratory experiments could predict the learning curves

Development of a Portable Motor Learning Laboratory (PoMLab).

PubMed

Takiyama, Ken; Shinya, Masahiro

2016-01-01

Most motor learning experiments have been conducted in a laboratory setting. In this type of setting, a huge and expensive manipulandum is frequently used, requiring a large budget and wide open space. Subjects also need to travel to the laboratory, which is a burden for them. This burden is particularly severe for patients with neurological disorders. Here, we describe the development of a novel application based on Unity3D and smart devices, e.g., smartphones or tablet devices, that can be used to conduct motor learning experiments at any time and in any place, without requiring a large budget and wide open space and without the burden of travel on subjects. We refer to our application as POrtable Motor learning LABoratory, or PoMLab. PoMLab is a multiplatform application that is available and sharable for free. We investigated whether PoMLab could be an alternative to the laboratory setting using a visuomotor rotation paradigm that causes sensory prediction error, enabling the investigation of how subjects minimize the error. In the first experiment, subjects could adapt to a constant visuomotor rotation that was abruptly applied at a specific trial. The learning curve for the first experiment could be modeled well using a state space model, a mathematical model that describes the motor leaning process. In the second experiment, subjects could adapt to a visuomotor rotation that gradually increased each trial. The subjects adapted to the gradually increasing visuomotor rotation without being aware of the visuomotor rotation. These experimental results have been reported for conventional experiments conducted in a laboratory setting, and our PoMLab application could reproduce these results. PoMLab can thus be considered an alternative to the laboratory setting. We also conducted follow-up experiments in university physical education classes. A state space model that was fit to the data obtained in the laboratory experiments could predict the learning curves

Target design optimization for an electron accelerator driven subcritical facility with circular and square beam profiles.

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

Gohar, M. Y. A; Sofu, T.; Zhong, Z.

2008-10-30

A subcritical facility driven by an electron accelerator is planned at the Kharkov Institute of Physics and Technology (KIPT) in Ukraine for medical isotope production, materials research, training, and education. The conceptual design of the facility is being pursued through collaborations between ANL and KIPT. As part of the design effort, the high-fidelity analyses of various target options are performed with formulations to reflect the realistic configuration and the three dimensional geometry of each design. This report summarizes the results of target design optimization studies for electron beams with two different beam profiles. The target design optimization is performed viamore » the sequential neutronic, thermal-hydraulic, and structural analyses for a comprehensive assessment of each configuration. First, a target CAD model is developed with proper emphasis on manufacturability to provide a basis for separate but consistent models for subsequent neutronic, thermal-hydraulic, and structural analyses. The optimizations are pursued for maximizing the neutron yield, streamlining the flow field to avoid hotspots, and minimizing the thermal stresses to increase the durability. In addition to general geometric modifications, the inlet/outlet channel configurations, target plate partitioning schemes, flow manipulations and rates, electron beam diameter/width options, and cladding material choices are included in the design optimizations. The electron beam interactions with the target assembly and the neutronic response of the subcritical facility are evaluated using the MCNPX code. the results for the electron beam energy deposition, neutron generation, and utilization in the subcritical pile are then used to characterize the axisymmetric heat generation profiles in the target assembly with explicit simulations of the beam tube, the coolant, the clad, and the target materials. Both tungsten and uranium are considered as target materials. Neutron spectra from

Nanocomposite Electrodes for Advanced Lithium Batteries: The LiFePO4 Cathode

DTIC Science & Technology

2001-11-01

The LiFePO4 Cathode DISTRIBUTION: Approved for public release, distribution unlimited This paper is part of the following report: TITLE: Nanophase and...Nanocomposite Electrodes for Advanced Lithium Batteries: The LiFePO4 Cathode Shoufeng Yang, Yanning Song, Peter Y. Zavalij and M. Stanley Whittingham...Institute for Materials Research, Binghamton University, Binghamton, NY 13902-1600, U.S.A. ABSTRACT LiFePO4 was successfully synthesized by high temperature

Kinetic Monte Carlo Study of Li Intercalation in LiFePO4.

PubMed

Xiao, Penghao; Henkelman, Graeme

2018-01-23

Even as a commercial cathode material, LiFePO 4 remains of tremendous research interest for understanding Li intercalation dynamics. The partially lithiated material spontaneously separates into Li-poor and Li-rich phases at equilibrium. Phase segregation is a surprising property of LiFePO 4 given its high measured rate capability. Previous theoretical studies, aiming to describe Li intercalation in LiFePO 4 , include both atomic-scale density functional theory (DFT) calculations of static Li distributions and entire-particle-scale phase field models, based upon empirical parameters, studying the dynamics of the phase separation. Little effort has been made to bridge the gap between these two scales. In this work, DFT calculations are used to fit a cluster expansion for the basis of kinetic Monte Carlo calculations, which enables long time scale simulations with accurate atomic interactions. This atomistic model shows how the phases evolve in Li x FePO 4 without parameters from experiments. Our simulations reveal that an ordered Li 0.5 FePO4 phase with alternating Li-rich and Li-poor planes along the ac direction forms between the LiFePO 4 and FePO 4 phases, which is consistent with recent X-ray diffraction experiments showing peaks associated with an intermediate-Li phase. The calculations also help to explain a recent puzzling experiment showing that LiFePO 4 particles with high aspect ratios that are narrower along the [100] direction, perpendicular to the [010] Li diffusion channels, actually have better rate capabilities. Our calculations show that lateral surfaces parallel to the Li diffusion channels, as well as other preexisting sites that bind Li weakly, are important for phase nucleation and rapid cycling performance.

Crystal structures of lazulite-type oxidephosphates Ti IIITi IV3O 3(PO 4) 3 and MIII4Ti IV27O 24(PO 4) 24 ( MIII=Ti, Cr, Fe)

NASA Astrophysics Data System (ADS)

Schöneborn, M.; Glaum, R.; Reinauer, F.

2008-06-01

Single crystals of the oxidephosphates Ti IIITi IV3O 3(PO 4) 3 (black), Cr III4Ti IV27O 24(PO 4) 24 (red-brown, transparent), and Fe III4Ti IV27O 24(PO 4) 24 (brown) with edge-lengths up to 0.3 mm were grown by chemical vapour transport. The crystal structures of these orthorhombic members (space group F2 dd ) of the lazulite/lipscombite structure family were refined from single-crystal data [Ti IIITi IV3O 3(PO 4) 3: Z=24, a=7.3261(9) Å, b=22.166(5) Å, c=39.239(8) Å, R1=0.029, w R2=0.084, 6055 independent reflections, 301 variables; Cr III4Ti IV27O 24(PO 4) 24: Z=1, a=7.419(3) Å, b=21.640(5) Å, c=13.057(4) Å, R1=0.037, w R2=0.097, 1524 independent reflections, 111 variables; Fe III4Ti IV27O 24(PO 4) 24: Z=1, a=7.4001(9) Å, b=21.7503(2) Å, c=12.775(3) Å, R1=0.049, w R2=0.140, 1240 independent reflections, 112 variables). For Ti IIITi IVO 3(PO 4) 3 a well-ordered structure built from dimers [Ti III,IV2O 9] and [Ti IV,IV2O 9] and phosphate tetrahedra is found. The metal sites in the crystal structures of Cr 4Ti 27O 24(PO 4) 24 and Fe 4Ti 27O 24(PO 4) 24, consisting of dimers [ MIIITi IVO 9] and [Ti IV,IV2O 9], monomeric [Ti IVO 6] octahedra, and phosphate tetrahedra, are heavily disordered. Site disorder, leading to partial occupancy of all octahedral voids of the parent lipscombite/lazulite structure, as well as splitting of the metal positions is observed. According to Guinier photographs Ti III4Ti IV27O 24(PO 4) 24 ( a=7.418(2) Å, b=21.933(6) Å, c=12.948(7) Å) is isotypic to the oxidephosphates MIII4Ti IV27O 24(PO 4) 24 ( MIII: Cr, Fe). The UV/vis spectrum of Cr 4Ti 27O 24(PO 4) 24 reveals a rather small ligand-field splitting Δ o=14,370 cm -1 and a very low nephelauxetic ratio β=0.72 for the chromophores [Cr IIIO 6] within the dimers [Cr IIITi IVO 9].

Development of an Ultra-Pure, Carrier-Free 209Po Solution Standard

PubMed Central

Collé, R.; Fitzgerald, R. P.; Laureano-Perez, L.

2015-01-01

Ultra-pure, carrier-free 209Po solution standards have been prepared and standardized for their massic alpha-particle emission rate. The standards, which will be disseminated by the National Institute of Standards and Technology (NIST) as Standard Reference Material SRM 4326a, have a mean mass of (5.169 ± 0.003) g of a solution of polonium in nominal 2.0 mol▪L−1 HCl (having a solution density of (1.032 ± 0.002) g▪ mL−1 at 20 °C) that are contained in 5 mL, flame-sealed, borosilicate glass ampoules. They are certified to contain a 209Po massic alpha-particle emission rate of (39.01 ± 0.18) s−1▪g−1 as of a reference time of 1200 EST, 01 December 2013. This new standard series replaces SRM 4326 that was issued by NIST in 1994. The standardization was based on 4πα liquid scintillation (LS) spectrometry with two different LS counting systems and under wide variations in measurement and counting source conditions. The methodology for the standardization, with corrections for detection of the low-energy conversion electrons from the delayed 2 keV isomeric state in 205Pb and for the radiations accompanying the small 0.45 % electron-capture branch to 209Bi, involves a unique spectral analysis procedure that is specific for the case of 209Po decay. The entire measurement protocol is similar, but revised and improved from that used for SRM 4326. Spectroscopic impurity analyses revealed that no photon-emitting or alpha-emitting radionuclidic impurities were detected. The most common impurity associated with 209Po is 208Po and the activity ratio of 208Po/209Po was < 10−7. PMID:26958444

Thermal expansion of phosphates with the NaZr2(PO4)3 structure containing lanthanides and zirconium: R 0.33Zr2(PO4)3 ( R = Nd, Eu, Er) and Er0.33(1- x) Zr0.25 x Zr2(PO4)3

NASA Astrophysics Data System (ADS)

Volgutov, V. Yu.; Orlova, A. I.

2015-09-01

Phosphates R 0.33Zr2(PO4)3 ( R = Nd, Eu, or Er) and Er0.33(1- х)Zr0.25Zr2(PO4)3 ( х = 0, 0.25, 0.5, 0.75, 1.0) of the NaZr2(PO4)3 family have been synthesized and investigated by high-temperature X-ray diffraction. The crystallochemical approach is used to obtain compounds with expected small and controllable thermal-expansion parameters. Phosphates with close-to-zero thermal-expansion parameters, including those with low thermal-expansion anisotropy, have been obtained: Nd0.33Zr2(PO4)3 with α a =-2.21 × 10-6 °С-1, α c = 0.81 × 10-6 °С-1, and Δα = 3.02 × 10-6 °С-1 and Er0.08Zr0.19Zr2(PO4)3 with α a =-1.86 × 10-6 °С-1, α c = 1.73 × 10-6 °С-1, and Δα = 3.58 × 10-6 °С-1.

Effect of the synthesis conditions on the electrochemical properties of LiFePO{sub 4} obtained from NH{sub 4}FePO{sub 4}

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

Prosini, Pier Paolo, E-mail: pierpaolo.prosini@enea.it; Gislon, Paola; Cento, Cinzia

Graphical abstract: - Highlights: • Four different samples of FAP were synthesized by precipitation techniques. • The samples were used as precursors to synthesize electrochemical active LiFePO{sub 4}. • Their morphology, composition, structure and electrochemical performance were studied. • The LiFePO{sub 4} electrochemical performance resulted affected by the preparation method - Abstract: In this paper the morphological, structural and electrochemical properties of crystalline lithium iron phosphate (LiFePO{sub 4}) obtained from ferrous ammonium phosphate (FAP) have been studied. The FAP was obtained following four different processes, namely: (1) homogeneous phase precipitation, (2) heterogeneous phase precipitation from stoichiometric sodium phosphate, (3) heterogeneousmore » phase precipitation from stoichiometric ammonium phosphate, and (4) heterogeneous phase precipitation from over stoichiometric ammonium phosphate. Lithium iron phosphate was prepared by solid state reaction of FAP with lithium hydroxide. In order to evaluate the effect of reaction time and synthesis temperature the LiFePO{sub 4} was prepared varying the heating temperatures (550, 600 and 700 °C) and the reaction times (1 or 2 h). The morphology of the materials was evaluated by scanning electron microscopy while the chemical composition was determined by electron energy loss spectroscopy. X-ray diffraction was used to evaluate phase composition, crystal structure and crystallite size. The so obtained LiFePO{sub 4}'s were fully electrochemical characterized and a correlation was found between the crystal size and the electrochemical performance.« less

Surfactant mediated hydrothermal synthesis, characterization and luminescent properties of GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} @ GdPO{sub 4} core shell nanorods

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

Khajuria, Heena; Ladol, Jigmet; Khajuria, Sonika

Highlights: • Core shell nanorods were synthesised by surfactant assisted hydrothermal method. • Morphology of core shell nanorods resembles those of core nanorods indicating coating of shell on cores. • More uniform and non-aggregated core shell nanorods were prepared in presence of surfactants. • Surfactant assisted prepared core shell nanorods show intense emission as compared to uncoated core nanorods. - Abstract: Core shell GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} @ GdPO{sub 4} nanorods were synthesized via hydrothermal route in the presence of different surfactants [cetyltrimethyl ammonium bromide (CTAB) and Sodium dodecyl sulphate (SDS)]. The nanorods were characterized by powder X-ray diffractionmore » (PXRD), fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and photoluminescence (PL) studies. The X-ray diffraction results indicate good crystallinity and effective doping in core and core shell nanorods. SEM and TEM micrographs show that all of the as prepared gadolinium phosphate products have rod like shape. The compositional analysis of GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} core was done by EDS. The emission intensity of the GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} @ GdPO{sub 4} core shell increased significantly with respect to those of GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} core nanorods. The effect of surfactant on the uniformity, thickness and luminescence of the core shell nanorods was investigated.« less

High-pressure structural, elastic, and thermodynamic properties of zircon-type HoPO 4 and TmPO 4

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

Gomis, O.; Lavina, B.; Rodríguez-Hernández, P.

2017-01-20

Zircon-type holmium phosphate (HoPO 4) and thulium phosphate (TmPO 4) have been studied by single-crystal x-ray diffraction and ab initio calculations. We report on the influence of pressure on the crystal structure, and on the elastic and thermodynamic properties. The equation of state for both compounds is accurately determined. We have also obtained information on the polyhedral compressibility which is used to explain the anisotropic axial compressibility and the bulk compressibility. Both compounds are ductile and more resistive to volume compression than to shear deformation at all pressures. Furthermore, the elastic anisotropy is enhanced upon compression. Finally, the calculations indicatemore » that the possible causes that make the zircon structure unstable are mechanical instabilities and the softening of a silent B 1u mode.« less

Laser safety at high profile projects

NASA Astrophysics Data System (ADS)

Barat, K.

2011-03-01

Laser Safety at high profile laser facilities tends to be more controlled than in the standard laser lab found at a research institution. The reason for this is the potential consequences for such facilities from incidents. This ranges from construction accidents, to equipment damage to personnel injuries. No laser user wants to sustain a laser eye injury. Unfortunately, many laser users, most commonly experienced researchers and inexperienced graduate students, do receive laser eye injuries during their careers. . More unforgiveable is the general acceptance of this scenario, as part of the research & development experience. How do senior researchers, safety personnel and management stop this trend? The answer lies in a cultural change that involves institutional training, user mentoring, hazard awareness by users and administrative controls. None of these would inhibit research activities. As a matter of fact, proper implementation of these controls would increase research productivity. This presentation will review and explain the steps needed to steer an institution, research division, group or individual lab towards a culture that should nearly eliminate laser accidents. As well as how high profile facilities try to avoid laser injuries. Using the definition of high profile facility as one who's funding in the million to billions of dollars or Euros and derives form government funding.

210Po bioaccumulation and trophic transfer in marine food chains in the northern Arabian Gulf.

PubMed

Uddin, S; Fowler, S W; Behbehani, M; Metian, M

2017-08-01

The tendency of 210 Po to concentrate in body tissue poses a serious concern of radiological safety. This study compiles available information and presents recent 210 Po data for the marine food web in the northern Gulf waters. Since 210 Po is concentrated in marine biota, a large number of samples of various marine organisms covering several trophic levels, from microalgae to sharks, were analyzed. 210 Po was found to be highly concentrated in several marine species with the highest 210 Po concentrations found in yellowfin tuna, i.e. 37.3-44.9, 451-548, and 1511-1693 Bq kg -1 wwt in muscle, digestive system and liver, respectively. In most dissected fish samples, 210 Po showed increasing concentrations in the following order: edible tissue, gills, digestive system, liver and fecal matter. Fish feces had 210 Po concentrations several orders of magnitude higher than that in seawater, fish muscle, and the fishes' ingested food. The high 210 Po concentration in fish fecal matter suggests that the bulk of 210 Po content in fish is eventually excreted back into the environment as fecal pellets. In most fish high concentrations were noted in liver, with the highest 210 Po concentration recorded in yellowfin tuna liver. Moreover, 210 Po concentration in the soft tissue of tunicate and bryozoan samples were 872-1012 and 402-527 Bq kg -1 wwt, respectively, far higher than that in fish muscle (0.04-44.9 Bq kg -1 wwt). It was observed that the maximum 210 Po concentration in edible fish tissue among the fish in trophic level 2 was an order of magnitude lower than those in trophic level 3 and two orders of magnitude lower compared to fish in trophic level 4. The highest concentrations in the muscle tissue were observed in the following order: tunicate > bryozoan > mollusc > crustacean > algae > fish. Among all the biota analyzed, the highest overall concentration of 210 Po was noted in yellowfin tuna (Thunnus albacores) indicating a potential biomagnification of 210

Role of nitric oxide of the median preoptic nucleus (MnPO) in the alterations of salivary flow, arterial pressure and heart rate induced by injection of pilocarpine into the MnPO and intraperitoneally.

PubMed

Saad, Wilson A; Guarda, I F M S; Camargo, L A A; Santos, T A F B; Guarda, R S; Saad, Willian A; Simões, S; Rodrigues, J Antunes

2003-07-01

We investigated the effect of L-NAME, a nitric oxide (NO) inhibitor and sodium nitroprusside (SNP), an NO-donating agent, on pilocarpine-induced alterations in salivary flow, mean arterial blood pressure (MAP) and heart rate (HR) in rats. Male Holtzman rats (250-300 g) were implanted with a stainless steel cannula directly into the median preoptic nucleus (MnPO). Pilocarpine (10, 20, 40, 80, 160 g) injected into the MnPO induced an increase in salivary secretion (P<0.01). Pilocarpine (1, 2, 4, 8, 16 mg/kg) ip also increased salivary secretion (P<0.01). Injection of L-NAME (40 g) into the MnPO prior to pilocarpine (10, 20, 40, 80, 160 g) injected into the MnPO or ip (1, 2, 4, 8, 16 mg/kg) increased salivary secretion (P<0.01). SNP (30 g) injected into the MnPO or ip prior to pilocarpine attenuated salivary secretion (P<0.01). Pilocarpine (40 g) injection into the MnPO increased MAP and decreased HR (P<0.01). Pilocarpine (4 mg/kg body weight) ip produced a decrease in MAP and an increase in HR (P<0.01). Injection of L-NAME (40 g) into the MnPO prior to pilocarpine potentiated the increase in MAP and reduced HR (P<0.01). SNP (30 g) injected into the MnPO prior to pilocarpine attenuated (100%) the effect of pilocarpine on MAP, with no effect on HR. Administration of L-NAME (40 g) into the MnPO potentiated the effect of pilocarpine injected ip. SNP (30 g) injected into the MnPO attenuated the effect of ip pilocarpine on MAP and HR. The present study suggests that in the rat MnPO 1) NO is important for the effects of pilocarpine on salivary flow, and 2) pilocarpine interferes with blood pressure and HR (side effects of pilocarpine), that is attenuated by NO.

Synthesis and magnetic properties of LiFePO4 substitution magnesium

NASA Astrophysics Data System (ADS)

Choi, Hyunkyung; Kim, Min Ji; Hahn, Eun Joo; Kim, Sam Jin; Kim, Chul Sung

2017-06-01

LiFe0.9Mg0.1PO4 sample was prepared by using a solid-state reaction method, and the temperature-dependent magnetic properties of the sample were studied. The X-ray diffraction (XRD) pattern showed an olivine-type orthorhombic structure with space group Pnma based on Rietveld refinement method. The effect of Mg substitution in antiferromagnetic LiFe0.9Mg0.1PO4 was investigated using a vibrating sample magnetometer (VSM) and Mössbauer spectroscopy. The temperature-dependence of the magnetization curves of LiFe0.9Mg0.1PO4 shows abnormal antiferromagnetic behavior with ordering temperature. Sudden changes in both the magnetic hyperfine field (Hhf) and its slope below 15 K suggest that magnetic phase transition associated to the abrupt occurrence of spin-reorientation. The Néel temperature (TN) and spin-reorientation temperature (TS) of LiFe0.9Mg0.1PO4 are lower than those of pure LiFePO4 (TN = 51 K, TS = 23 K). This is due to the Fe-O-Fe superexchange interaction being larger than that of the Fe-O-Mg link. Also, we have confirmed a change in the electric quadrupole splitting (ΔEQ) by the spin-orbit coupling effect and the shape of Mössbauer spectrum has provided the evidence for TS and a strong crystalline field. We have found that Mg ions in LiFe0.9Mg0.1PO4 induce an asymmetric charge density due to the presence of Mg2+ ions at the FeO6 octahedral sites.

Facile and Reliable in Situ Polymerization of Poly(Ethyl Cyanoacrylate)-Based Polymer Electrolytes toward Flexible Lithium Batteries.

PubMed

Cui, Yanyan; Chai, Jingchao; Du, Huiping; Duan, Yulong; Xie, Guangwen; Liu, Zhihong; Cui, Guanglei

2017-03-15

Polycyanoacrylate is a very promising matrix for polymer electrolyte, which possesses advantages of strong binding and high electrochemical stability owing to the functional nitrile groups. Herein, a facile and reliable in situ polymerization strategy of poly(ethyl cyanoacrylate) (PECA) based gel polymer electrolytes (GPE) via a high efficient anionic polymerization was introduced consisting of PECA and 4 M LiClO 4 in carbonate solvents. The in situ polymerized PECA gel polymer electrolyte achieved an excellent ionic conductivity (2.7 × 10 -3 S cm -1 ) at room temperature, and exhibited a considerable electrochemical stability window up to 4.8 V vs Li/Li + . The LiFePO 4 /PECA-GPE/Li and LiNi 1.5 Mn 0.5 O 4 /PECA-GPE/Li batteries using this in-situ-polymerized GPE delivered stable charge/discharge profiles, considerable rate capability, and excellent cycling performance. These results demonstrated this reliable in situ polymerization process is a very promising strategy to prepare high performance polymer electrolytes for flexible thin-film batteries, micropower lithium batteries, and deformable lithium batteries for special purpose.

210Po Log-normal distribution in human urines: Survey from Central Italy people

PubMed Central

Sisti, D.; Rocchi, M. B. L.; Meli, M. A.; Desideri, D.

2009-01-01

The death in London of the former secret service agent Alexander Livtinenko on 23 November 2006 generally attracted the attention of the public to the rather unknown radionuclide 210Po. This paper presents the results of a monitoring programme of 210Po background levels in the urines of noncontaminated people living in Central Italy (near the Republic of S. Marino). The relationship between age, sex, years of smoking, number of cigarettes per day, and 210Po concentration was also studied. The results indicated that the urinary 210Po concentration follows a surprisingly perfect Log-normal distribution. Log 210Po concentrations were positively correlated to age (p < 0.0001), number of daily smoked cigarettes (p = 0.006), and years of smoking (p = 0.021), and associated to sex (p = 0.019). Consequently, this study provides upper reference limits for each sub-group identified by significantly predictive variables. PMID:19750019

The bioaccumulation of210Po and210Pb in the southern Baltic organisms

NASA Astrophysics Data System (ADS)

Stepnowski, P.; Skwarzec, B.

1999-01-01

The paper presents the results of210Po and210Pb determinations in three species of Baltic invertebrates, crustacean Saduria entomon, molluscs Mya arenaria and Mytilus trossulus Obtained data show significant differences in activity concentrations of both radionuclides in the tissues and organs examined. The highest values for210Po were found in hepatopancreas of Mytlius trossulus. Similar concentration effect is observed in the same organ of Saduria entomon.210Po is not significantly accumulated in haemolymph and gonads of crustacean as well as shell and fat of molluscs. Great disproportion between210Po and210Pb is observed in the hard tissues of Saduria entomon.

210Po and 210Pb in Forest Soil and in Wild Berries in Finland

NASA Astrophysics Data System (ADS)

Vaaramaa, Kaisa; Solatie, Dina; Aro, Lasse; Lehto, Jukka

2008-08-01

The behaviour of 210Po and 210Pb was investigated in forests in the Southern Finland site and in the Northern Finland site. Sampling sites were in Scots pine (Pinus sylvestris) forests. Maximum activities of 210Po and 210Pb in soil columns were found in organic layers. According to preliminary results of wild berry samples, the lowest 210Po concentrations were found in berries. The highest concentration of 210Po was found in stems of the blueberry (Vaccinium myrtillus) and the lingonberry (Vaccinium vitis-idaea) samples.

Systematic vertical and lateral changes in quality and time resolution of the macrofossil record: insights from Holocene transgressive deposits, Po coastal plain, Italy

NASA Astrophysics Data System (ADS)

Azzarone, Michele; Scarponi, Daniele; Kusnerik, Kristopher; Amorosi, Alessandro; Bohacs, Kevin M.; Drexler, Tina M.; Kowalewski, Michał

2017-04-01

In siliciclastic marine settings, skeletal concentrations are a characteristic feature of transgressive intervals that provide insights into paleobiology and sequence stratigraphy. To investigate taphonomic signatures of transgressive intervals, we analyzed three cores from a Holocene depositional profile of the Po coastal plain, in northern Italy. Coupled multivariate taphonomic and bathymetric trends delineate spatial and temporal gradients in sediment starvation/bypassing, suggesting that quality and resolution of the fossil record vary predictably along the studied depositional profile. Moreover, joint consideration of taphonomic, bathymetric, and fossil density trends across the study area reveals distinctive signatures that are useful in characterizing facies associations and recognizing surfaces and intervals of sequence stratigraphic significance. Within the southern Po plain succession, taphonomic degradation of macroskeletal remains increases from proximal—nearshore to distal—offshore locations. This trend is discernible for both biologically-driven (bioerosion) and chemically/physically-driven (e.g., dissolution, abrasion) shell alterations. Compared to the up-dip (most proximal) core, the down-dip core is distinguished by shell-rich lithosomes affected by ecological condensation (co-occurrence of environmentally non-overlapping taxa) and by higher taphonomic alteration. The onshore-offshore taphonomic trend likely reflects variation in sediment-supply along the depositional profile of the Holocene Northern Adriatic shelf, with surface/near-surface residence-time of macroskeletal remains increasing down dip due to lower accumulation rates. These results indicate that, during transgressive phases, changes in sea-level (base level) are likely to produce down-dip taphonomic gradients across shelves, where the quality and resolution of the fossil record both deteriorate distally. The amino acid radiometrically calibrated dates on bivalves and the

Novel phosphate halides BaMn{sup III}[PO{sub 4}]FCl and BaMn{sup III}[PO{sub 4}]F{sub 2}: Effects of mixed halides on crystal structures and magnetic properties

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

Pei, Da-Ting, E-mail: pdtcug@gmail.com; Sun, Wei, E-mail: 421221789@qq.com; Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Canada SK S7N 5E2

2016-02-15

Two new phosphate halides BaMn{sup III}[PO{sub 4}]FCl (1) and BaMn{sup III}[PO{sub 4}]F{sub 2} (2), have been synthesized under hydrothermal conditions. Structural characterizations show that both new compounds adopt layered structures but with different polyhedral linkages. Introduction of Cl into Compound (1) results in isolated hemimorphic [MnO{sub 4}FCl] octahedra, different from the chain of [MnO{sub 4}F{sub 2}]/[MnO{sub 2}F{sub 4}] octahedra in Compound (2). These compounds have significantly different molecular vibration modes and thermal stabilities. Magnetic measurements reveal that Compound (2) has larger antiferromagnetic interactions than Compound (1), because the former has strong interactions between Mn{sup 3+}-Mn{sup 3+} ions within corner-shared Mn{supmore » 3+}-octahedral chains whereas the latter only possesses isolated Mn{sup 3+}-octahedra. Both compounds transform to a new orthorhombic compound BaMn{sup II}(PO{sub 4})F (3) after thermal decomposition. - Graphical abstract: The large radius of Cl{sup -} ions makesBaMn{sup III}[PO{sub 4}]FCl to adopt isolated [MnO{sub 4}FCl] rather than corner-sharing octahedra as observed in BaMn{sup III}[PO{sub 4}]F{sub 2}. - Highlights: • Two novel phosphate halides BaMn[PO{sub 4}]FCl and BaMn[PO{sub 4}]F{sub 2} have been prepared. • These new compounds adopt different types of layered structures. • They have different molecular vibration modes and thermal stabilities. • BaMn[PO{sub 4}]FCl has weaker antiferromagnetic interactions than BaMn[PO{sub 4}]F{sub 2}. • The former adopts isolated octahedra whereas the latter adopts octahedral chains.« less

Chemically grafted carbon-coated LiFePO4 using diazonium chemistry

NASA Astrophysics Data System (ADS)

Delaporte, Nicolas; Perea, Alexis; Amin, Ruhul; Zaghib, Karim; Bélanger, Daniel

2015-04-01

The effect of surface functionalization of aminophenyl and bromophenyl groups on carbon-coated LiFePO4 and the electrochemical properties of composite electrode containing these materials are reported. The functionalization was performed by spontaneous reduction of the corresponding in situ generated diazonium ions. The resulting chemically grafted LiFePO4/C materials were characterized by energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) to confirm the presence of the surface organic species. XRD analyses indicated the cathode material was partially oxidized. Thermogravimetric and elemental analyses revealed the loading of grafted molecules was between 0.2 and 1.1 wt.% depending on the reaction conditions. Interestingly, the electrochemical performances of the modified LiFePO4/C are not adversely affected by the presence of either aminophenyl and bromophenyl groups at the carbon surface, and in fact the grafted LiFePO4/C displayed slightly superior discharge capacity at the highest C rate investigated for a low loading of organic molecules.

A chemically activated graphene-encapsulated LiFePO4 composite for high-performance lithium ion batteries.

PubMed

Ha, Jeonghyun; Park, Seung-Keun; Yu, Seung-Ho; Jin, Aihua; Jang, Byungchul; Bong, Sungyool; Kim, In; Sung, Yung-Eun; Piao, Yuanzhe

2013-09-21

A composite of modified graphene and LiFePO4 has been developed to improve the speed of charging-discharging and the cycling stability of lithium ion batteries using LiFePO4 as a cathode material. Chemically activated graphene (CA-graphene) has been successfully synthesized via activation by KOH. The as-prepared CA-graphene was mixed with LiFePO4 to prepare the composite. Microscopic observation and nitrogen sorption analysis have revealed the surface morphologies of CA-graphene and the CA-graphene/LiFePO4 composite. Electrochemical properties have also been investigated after assembling coin cells with the CA-graphene/LiFePO4 composite as a cathode active material. Interestingly, the CA-graphene/LiFePO4 composite has exhibited better electrochemical properties than the conventional graphene/LiFePO4 composite as well as bare LiFePO4, including exceptional speed of charging-discharging and excellent cycle stability. That is because the CA-graphene in the composite provides abundant porous channels for the diffusion of lithium ions. Moreover, it acts as a conducting network for easy charge transfer and as a divider, preventing the aggregation of LiFePO4 particles. Owing to these properties of CA-graphene, LiFePO4 could demonstrate enhanced and stably long-lasting electrochemical performance.

Continuous flame aerosol synthesis of carbon-coated nano-LiFePO4 for Li-ion batteries

PubMed Central

Waser, Oliver; Büchel, Robert; Hintennach, Andreas; Novák, Petr; Pratsinis, Sotiris E.

2013-01-01

Core-shell, nanosized LiFePO4-carbon particles were made in one step by scalable flame aerosol technology at 7 g/h. Core LiFePO4 particles were made in an enclosed flame spray pyrolysis (FSP) unit and were coated in-situ downstream by auto thermal carbonization (pyrolysis) of swirl-fed C2H2 in an O2-controlled atmosphere. The formation of acetylene carbon black (ACB) shell was investigated as a function of the process fuel-oxidant equivalence ratio (EQR). The core-shell morphology was obtained at slightly fuel-rich conditions (1.0 < EQR < 1.07) whereas segregated ACB and LiFePO4 particles were formed at fuel-lean conditions (0.8 < EQR < 1). Post-annealing of core-shell particles in reducing environment (5 vol% H2 in argon) at 700 °C for up to 4 hours established phase pure, monocrystalline LiFePO4 with a crystal size of 65 nm and 30 wt% ACB content. Uncoated LiFePO4 or segregated LiFePO4-ACB grew to 250 nm at these conditions. Annealing at 800 °C induced carbothermal reduction of LiFePO4 to Fe2P by ACB shell consumption that resulted in cavities between carbon shell and core LiFePO4 and even slight LiFePO4 crystal growth but better electrochemical performance. The present carbon-coated LiFePO4 showed superior cycle stability and higher rate capability than the benchmark, commercially available LiFePO4. PMID:23407817

Occurrence of ²¹⁰Po and biological effects of low-level exposure: the need for research.

PubMed

Seiler, Ralph L; Wiemels, Joseph L

2012-09-01

Polonium-210 (²¹⁰Po) concentrations that exceed 1 Bq/L in drinking-water supplies have been reported from four widely separated U.S. states where exposure to it went unnoticed for decades. The radionuclide grandparents of ²¹⁰Po are common in sediments, and segments of the public may be chronically exposed to low levels of ²¹⁰Po in drinking water or in food products from animals raised in contaminated areas. We summarized information on the environmental behavior, biokinetics, and toxicology of ²¹⁰Po and identified the need for future research. Potential linkages between environmental exposure to ²¹⁰Po and human health effects were identified in a literature review. ²¹⁰Po accumulates in the ovaries where it kills primary oocytes at low doses. Because of its radiosensitivity and tendency to concentrate ²¹⁰Po, the ovary may be the critical organ in determining the lowest injurious dose for ²¹⁰Po. ²¹⁰Po also accumulates in the yolk sac of the embryo and in the fetal and placental tissues. Low-level exposure to ²¹⁰Po may have subtle, long-term biological effects because of its tropism towards reproductive and embryonic and fetal tissues where exposure to a single alpha particle may kill or damage critical cells. ²¹⁰Po is present in cigarettes and maternal smoking has several effects that appear consistent with the toxicology of ²¹⁰Po. Much of the important biological and toxicological research on ²¹⁰Po is more than four decades old. New research is needed to evaluate environmental exposure to ²¹⁰Po and the biological effects of low-dose exposure to it so that public health officials can develop appropriate mitigation measures where necessary.

Direct sunlight facility for testing and research in HCPV

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

Sciortino, Luisa, E-mail: luisa.sciortino@unipa.it; Agnello, Simonpietro, E-mail: luisa.sciortino@unipa.it; Bonsignore, Gaetano

2014-09-26

A facility for testing different components for HCPV application has been developed in the framework of 'Fotovoltaico ad Alta Efficienza' (FAE) project funded by the Sicilian Regional Authority (PO FESR Sicilia 2007/2013 4.1.1.1). The testing facility is equipped with an heliostat providing a wide solar beam inside the lab, an optical bench for mounting and aligning the HCPV components, electronic equipments to characterize the I-V curves of multijunction cells operated up to 2000 suns, a system to circulate a fluid in the heat sink at controlled temperature and flow-rate, a data logging system with sensors to measure temperatures in severalmore » locations and fluid pressures at the inlet and outlet of the heat sink, and a climatic chamber with large test volume to test assembled HCPV modules.« less

pO(2) measurements by phosphorescence quenching: characteristics and applications of an automated system.

PubMed

Kerger, Heinz; Groth, Gesine; Kalenka, Armin; Vajkoczy, Peter; Tsai, Amy G; Intaglietta, Marcos

2003-01-01

An automated system for pO(2) analysis based upon phosphorescence quenching was tested. The system was calibrated in vitro with capillary samples of saline and blood. Results were compared to a conventional measuring procedure wherein pO(2) was calculated off-line by computer fitting of phosphorescence decay signals. PO(2) measurements obtained by the automated system were correlated (r(2) = 0.98) with readings simultaneously generated by a blood gas analyzer, accuracy being highest in the low (0-20 mm Hg) and medium pO(2) ranges (21-70 mm Hg). Measurements in in vivo studies in the hamster skin-fold preparation were similar to previously reported results. The automated system fits the phosphorescence decay data to a single exponential and allows repeated pO(2) measurements in rapid sequence.

Uniform Free-Energy Profiles of the P-O Bond Formation and Cleavage Reactions Catalyzed by DNA Polymerases β and λ.

PubMed

Klvaňa, Martin; Bren, Urban; Florián, Jan

2016-12-29

Human X-family DNA polymerases β (Polβ) and λ (Polλ) catalyze the nucleotidyl-transfer reaction in the base excision repair pathway of the cellular DNA damage response. Using empirical valence bond and free-energy perturbation simulations, we explore the feasibility of various mechanisms for the deprotonation of the 3'-OH group of the primer DNA strand, and the subsequent formation and cleavage of P-O bonds in four Polβ, two truncated Polλ (tPolλ), and two tPolλ Loop1 mutant (tPolλΔL1) systems differing in the initial X-ray crystal structure and nascent base pair. The average calculated activation free energies of 14, 18, and 22 kcal mol -1 for Polβ, tPolλ, and tPolλΔL1, respectively, reproduce the trend in the observed catalytic rate constants. The most feasible reaction pathway consists of two successive steps: specific base (SB) proton transfer followed by rate-limiting concerted formation and cleavage of the P-O bonds. We identify linear free-energy relationships (LFERs) which show that the differences in the overall activation and reaction free energies among the eight studied systems are determined by the reaction free energy of the SB proton transfer. We discuss the implications of the LFERs and suggest pK a of the 3'-OH group as a predictor of the catalytic rate of X-family DNA polymerases.

Single-crystalline LiFePO4 nanosheets for high-rate Li-ion batteries.

PubMed

Zhao, Yu; Peng, Lele; Liu, Borui; Yu, Guihua

2014-05-14

The lithiation/delithiation in LiFePO4 is highly anisotropic with lithium-ion diffusion being mainly confined to channels along the b-axis. Controlling the orientation of LiFePO4 crystals therefore plays an important role for efficient mass transport within this material. We report here the preparation of single crystalline LiFePO4 nanosheets with a large percentage of highly oriented {010} facets, which provide the highest pore density for lithium-ion insertion/extraction. The LiFePO4 nanosheets show a high specific capacity at low charge/discharge rates and retain significant capacities at high C-rates, which may benefit the development of lithium batteries with both favorable energy and power density.

Concentrations, profiles, and estimated human exposures for polychlorinated dibenzo-p-dioxins and dibenzofurans from electronic waste recycling facilities and a chemical industrial complex in Eastern China

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

Ma, J.; Kannan, K.; Cheng, J.

2008-11-15

Electronic shredder waste and dust from e-waste facilities, and leaves and surface soil collected in the vicinity of a large scale e-waste recycling facility in Taizhou, Eastern China, were analyzed for total dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) including 2,3,7,8-substituted congeners. We also determined PCDD/Fs in surface agricultural soils from several provinces in China for comparison with soils from e-waste facilities. Concentrations of total PCDD/Fs were high in all of the matrices analyzed and ranged from 30.9 to 11,400 pg/g for shredder waste, 3460 to 9820 pg/g dry weight for leaves, 2560 to 148,000 pg/g dry weight for workshop-floor dust, and 854more » to 10200 pg/g dry weight for soils. We also analyzed surface soils from a chemical industrial complex (a coke-oven plant, a coal-fired power plant, and a chlor-alkali plant) in Shanghai. Concentrations of total PCDD/Fs in surface soil from the chemical industrial complex were lower than the concentrations found in soils from e-waste recycling plants, but higher than the concentrations found in agricultural soils. Agricultural soils from six cities in China contained low levels of total PCDD/Fs. Profiles of dioxin toxic equivalents (TEQs) of 2,3,7,8-PCDD/Fs in soils from e-waste facilities in Taizhou differed from the profiles found in agricultural soils. The estimated daily intakes of TEQs of PCDD/Fs via soil/dust ingestion and dermal exposure were 2 orders of magnitude higher in people at e-waste recycling facilities than in people at the chemical industrial site, implying greater health risk for humans from dioxin exposures at e-waste recycling facilities. The calculated TEQ exposures for e-waste workers from dust and soil ingestion alone were 2-3 orders of magnitude greater than the exposures from soils in reference locations. 37 refs., 1 fig., 2 tabs.« less

210Po in Human Saliva of Smokeless Tobacco Users.

PubMed

Meli, Maria Assunta; Desideri, Donatella; Roselli, Carla; Feduzi, Laura

2017-01-01

The occurrence and mobility of Po in oral smokeless tobacco products (STPs) were determined because its effects on human health must be taken into account. This research was subdivided into two parts: determination by alpha spectrometry of the Po activity concentration in 16 oral smokeless tobacco products of different brands purchased in local specialty stores in Europe and evaluation of its percent extraction into an artificial salivary gland during sucking or chewing operations. Polonium-210 was detected in all samples, and its concentrations ranged from 3.46 to 14.8 Bq kg (mean value of 7.45 ± 3.82 Bq kg). The highest concentration was found in chewing tobacco. The samples showed no significant difference in the content of Po level. The data obtained in this study show that the polonium, although poorly extracted (12.8 ± 8.96%) by artificial saliva, is not totally retained within the smokeless tobacco products, with a consequent potential health hazard associated with oral use of these products.

Origin of the charge gap in LaMnPO

DOE PAGES

McNally, D. E.; Simonson, Jack W.; Post, K. W.; ...

2014-11-18

In this paper, we present high temperature inelastic neutron scattering and magnetic susceptibility measurements of the antiferromagnetic insulator LaMnPO that are consistent with the presence of two-dimensional magnetic correlations up to a temperature T max≈700K»T N=375 K, the Néel temperature. Optical transmission measurements show the T=300 K direct charge gap Δ=1 eV has decreased only marginally by 500 K and suggest it decreases by only 10% at T max. Density functional theory and dynamical mean-field theory calculations reproduce a direct charge gap in paramagnetic LaMnPO only when a strong Hund's coupling J H=0.9 eV is included, as well as on-sitemore » Hubbard U=8 eV. In conclusion, our results show that LaMnPO is a Mott-Hund's insulator, in which the charge gap is rather insensitive to antiferromagnetic exchange coupling.« less

Effects of middle-term land reclamation on nickel soil-water interaction: a case study from reclaimed salt marshes of Po River Delta, Italy.

PubMed

Di Giuseppe, Dario; Melchiorre, Massimiliano; Faccini, Barbara; Ferretti, Giacomo; Coltorti, Massimo

2017-09-26

Reclaimed salt marshes are fragile environments where water salinization and accumulation of heavy metals can easily occur. This type of environment constitutes a large part of the Po River Delta (Italy), where intensive agricultural activities take place. Given the higher Ni background of Po River Delta soils and its water-soluble nature, the main aim of this contribution is to understand if reclamation can influence the Ni behavior over time. In this study, we investigated the geochemical features of 40 soils sampled in two different localities from the Po River Delta with different reclamation ages. Samples of salt marsh soils reclaimed in 1964 were taken from Valle del Mezzano while soils reclaimed in 1872 were taken nearby Codigoro town. Batch solubility tests and consecutive determination of Ni in pore-water were compared to bulk physicochemical compositions of soils. Bulk Ni content of the studied soils is naturally high, since these soils originated from Po River sediments derived from the erosion of ultramafic rocks. Moreover, it seems that Ni concentration increases during soil evolution, being probably related to the degradation of serpentine. Instead, the water-soluble Ni measured in the leaching tests is greater in soils recently reclaimed compared to the oldest soils. Soil properties of two soil profiles from a reclaimed wetland area were examined to determine soil evolution over one century. Following reclamation, pedogenic processes of the superficial horizons resulted in organic matter mineralization, pH buffer, and a decrease of Ni water solubility from recently to evolved reclaimed soil.

Highly efficient photocatalytic degradation of methylene blue by PoPD/TiO2 nanocomposite

PubMed Central

Dong, Wenping; Cui, Guanwei; Ren, Zongming

2017-01-01

The poly-o-phenylenediamine (PoPD)/TiO2 nanocomposite was successfully synthesized via ‘in situ’ oxidative polymerization method. The modified photocatalysts were characterized by BET, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrarad spectra (FT-IR), thermogravimrtic analysis (TGA), X-ray photoelectron spectroscopy (XPS), Ultraviolet-visible diffuse reflectance spectrum (UV-Vis DRS) and Photocurrent Test. The results showed that the PoPD exists on the surface of TiO2, the presence of PoPD does not impact on the lattice structure and grain size of TiO2, and the presence of PoPD enhances the visible response and photoelectric property. The photocatalytic degradation of methylene blue (MB) was chosen as a model reaction to evaluate the photocatalytic activities of TiO2 and PoPD/TiO2. The optimal preparation condition was the molar ratio of oPD to TiO2 = 3:1, HCl concentration = 1.2 mol/L, the molar ratio of APS to oPD = 1:1. The apparent first-order rate constant kapp of PoPD/TiO2 nanocomposite was 0.0098 min-1, which is 6 times higher than TiO2 (0.0016 min-1). Meanwhile, the PoPD/TiO2 nanocomposites showed excellent photocatalytic stability, and the photocatalytic stability was depended on the stability of structure. At last, the photocatalytic mechanism of POPD/TiO2 nanocomposites was also proposed based on the synergetic effect between TiO2 and PoPD. PMID:28329007

Phase equilibria in the NaF-CdO-NaPO{sub 3} system at 873 K and crystal structure and physico-chemical characterizations of the new Na{sub 2}CdPO{sub 4}F fluorophosphate

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

Aboussatar, Mohamed; Laboratoire de Physico-Chimie de l’État Solide, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax; Mbarek, Aïcha

Isothermal sections of the diagram representing phase relationships in the NaF-CdO-NaPO{sub 3} system have been investigated by solid state reactions and powder X-ray diffraction. This phase diagram investigation confirms the polymorphism of the NaCdPO{sub 4} side component and the structure of the ß high temperature polymorph (orthorhombic, space group Pnma and unit cell parameters a=9.3118(2), b=7.0459(1), c=5.1849(1) Å has been refined. A new fluorophosphate, Na{sub 2}CdPO{sub 4}F, has been discovered and its crystal structure determined and refined from powder X-ray diffraction data. It exhibits a new 3D structure with orthorhombic symmetry, space group Pnma and unit cell parameters a=5.3731(1), b=6.8530(1),more » c=12.2691(2) Å. The structure is closely related to those of the high temperature polymorph of the nacaphite Na{sub 2}CaPO{sub 4}F and the fluorosilicate Ca{sub 2}NaSiO{sub 4}F but differs essentially in the cationic repartition since the structure is fully ordered with one Na site (8d) and one Cd site (4c). Relationships with other Na{sub 2}M{sup II}PO{sub 4}F (M{sup II}=Mg, Ca, Mn, Fe, Co, Ni) have been examined and the crystal-chemical and topographical analysis of these fluorophosphates is briefly reviewed. IR, Raman, optical and {sup 19}F, {sup 23}Na, {sup 31}P MAS NMR characterizations of Na{sub 2}CdPO{sub 4}F have been investigated. - Graphical abstract: The structure of the compound Na{sub 2}CdPO{sub 4}F, discovered during the study of the phase relationships in the NaF-CdO-NaPO{sub 3} system, has been determined and compared with other Na{sub 2}M{sup II}PO{sub 4}F fluorophosphates. - Highlights: • XRD analysis of the isothermal section of the NaF-CdO-NaPO{sub 3} system at 923 K. • Rietveld refinement of the high temperature polymorph β-NaCdPO{sub 4}. • Crystal structure of the new Na{sub 2}CdPO{sub 4}F fluorophosphate determined from powder XRD. • Crystal structure - composition relationships of Na{sub 2}M{sup II}PO{sub 4}F

In pursuit of the rhabdophane crystal structure: from the hydrated monoclinic LnPO{sub 4}.0.667H{sub 2}O to the hexagonal LnPO{sub 4} (Ln = Nd, Sm, Gd, Eu and Dy)

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

Mesbah, Adel, E-mail: adel.mesbah@cea.fr; Clavier, Nicolas; Elkaim, Erik

The dehydration process of the hydrated rhabdophane LnPO{sub 4}.0.667H{sub 2}O (Ln = La to Dy) was thoroughly studied over the combination of in situ high resolution synchrotron powder diffraction and TGA experiments. In the case of SmPO{sub 4}.0.667H{sub 2}O (monoclinic, C2), a first dehydration step was identified around 80 °C leading to the formation of SmPO{sub 4}.0.5H{sub 2}O (Monoclinic, C2) with Z =12 and a =17.6264(1) Å, b =6.9704(1) Å, c =12.1141(1) Å, β=133.74(1) °, V =1075.33(1) Å{sup 3}. In agreement with the TGA and dilatometry experiments, all the water molecules were evacuated above 220 °C yielding to the anhydrousmore » form, which crystallizes in the hexagonal P3{sub 1}21 space group with a =7.0389(1) Å, c =6.3702(1) Å and V =273.34(1) Å{sup 3}. This study was extended to selected LnPO{sub 4}.0.667H{sub 2}O samples (Ln= Nd, Gd, Eu, Dy) and the obtained results confirmed the existence of two dehydration steps before the stabilization of the anhydrous form, with the transitory formation of LnPO{sub 4}.0.5H{sub 2}O. - Graphical abstract: The dehydration process of the rhabdophane SmPO{sub 4}.0.667H{sub 2}O was studied over combination of in situ high resolution synchrotron powder diffraction and TGA techniques, a first dehydration was identified around 80 °C leading to the formation of SmPO{sub 4}.0.5H{sub 2}O (Monoclinic, C2). Then above 220 °C, the anhydrous form of the rhabdophane SmPO{sub 4} was stabilized and crystallizes in the hexagonal P3{sub 1}21 space group. - Highlights: • In situ synchrotron powder diffraction was carried out during the dehydration of the rhabdopahe LnPO{sub 4}.0.667H{sub 2}O. • The heat of the rhabdophane LnPO{sub 4}.0.667H{sub 2}O leads to LnPO{sub 4}.0.5H{sub 2}O then to anhydrous rhabdophane LnPO{sub 4}. • LnPO{sub 4}.0.5H{sub 2}O (monoclinic, C2) and LnPO{sub 4} (Hexagonal, P3{sub 1}21) were solved over the use of direct methods.« less

Spatial distribution of 214Po ions in the electrostatic collection.

PubMed

Barlas, E; Bayrak, A; Emirhan, E; Haciomeroglu, S; Ozben, C S

2013-10-01

A low cost Si-PIN photodiode-based radon monitor was successfully designed and produced to monitor precursory earthquake indicators in the Northern Anatolian Fault Line. The spatial distribution of (214)Po ions was determined by comparing the 7.69 MeV (214)Po peak in the MCA spectrum and the Geant4 energy distribution of alpha particles at various detector source distances. Copyright © 2013 Elsevier Ltd. All rights reserved.

Rietveld refinement of AgCa10(PO4)7 from X-ray powder data

PubMed Central

Strutynska, Nataliya Yu.; Zatovsky, Igor V.; Ogorodnyk, Ivan V.; Slobodyanik, Nikolay S.

2013-01-01

Polycrystalline silver(I) deca­calcium heptakis(orthophos­phate), AgCa10(PO4)7, was obtained by solid-state reaction. It is isotopic with members of the series MCa10(PO4)7 (M = Li, Na, K and Cs), and is closely related to the structure of β-Ca3(PO4)2. The crystal structure of the title compound is built up from a framework of [CaO9] and two [CaO8] polyhedra, one [CaO6] octa­hedron (site symmetry 3.) and three PO4 tetra­hedra (one with site symmetry 3.). The Ag+ cation is likewise located on a threefold rotation axis and resides in the cavities of the rigid [Ca10(PO4)7]− framework. It is surrounded by three O atoms in an almost regular triangular environment. PMID:23723747

Is ecological food also radioecological? - 210Po and 210Pb studies.

PubMed

Strumińska-Parulska, Dagmara; Olszewski, Grzegorz

2018-01-01

Presented are results of a study on accumulation of naturally occurring 210 Po and 210 Pb in ecological and conventional farming food products in Poland: fruits, vegetables and cereals. The main idea behind this research was to determine the activity concentrations of 210 Po and 210 Pb in ecological and commercial food as well as calculate and compare the effective dose (radiation) connected to different origin of analyzed food products consumption. The studies showed the majority of all compared food samples contained similar 210 Po and 210 Pb activities and statistically, the consumption of organic and commercial food would give similar annual effective dose. Copyright © 2017 Elsevier Ltd. All rights reserved.

AgI/Ag{sub 3}PO{sub 4} hybrids with highly efficient visible-light driven photocatalytic activity

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

Katsumata, Hideyuki, E-mail: hidek@chem.mie-u.ac.jp; Hayashi, Takahiro; Taniguchi, Masanao

Highlights: • AgI/Ag{sub 3}PO{sub 4} hybrid was prepared via an in situ anion-exchange method. • AgI/Ag{sub 3}PO{sub 4} displays the excellent photocatalytic activity under visible light. • AgI/Ag{sub 3}PO{sub 4} readily transforms to be Ag@AgI/Ag{sub 3}PO{sub 4} system. • h{sup +} and O{sub 2}{sup ·−} play the major role in the AO 7 decolorization over AgI/Ag{sub 3}PO{sub 4}. • The activity enhancement is ascribed to a Z-scheme system composed of Ag{sub 3}PO{sub 4}, Ag and AgI. - Abstract: Highly efficient visible-light-driven AgI/Ag{sub 3}PO{sub 4} hybrid photocatalysts with different mole ratios of AgI were prepared via an in situ anion-exchange methodmore » and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) technique. Under visible light irradiation (>420 nm), the AgI/Ag{sub 3}PO{sub 4} photocatalysts displayed the higher photocatalytic activity than pure Ag{sub 3}PO{sub 4} and AgI for the decolorization of acid orange 7 (AO 7). Among the hybrid photocatalysts, AgI/Ag{sub 3}PO{sub 4} with 80% of AgI exhibited the highest photocatalytic activity for the decolorization of AO 7. X-ray photoelectron spectroscopy (XPS) results revealed that AgI/Ag{sub 3}PO{sub 4} readily transformed to be Ag@AgI/Ag{sub 3}PO{sub 4} system while the photocatalytic activity of AgI/Ag{sub 3}PO{sub 4} remained after 5 recycling runs. In addition, the quenching effects of different scavengers displayed that the reactive h{sup +} and O{sub 2}{sup ·−} play the major role in the AO 7 decolorization. The photocatalytic activity enhancement of AgI/Ag{sub 3}PO{sub 4} hybrids can be ascribed to the efficient separation of electron–hole pairs through a Z-scheme system composed of Ag{sub 3}PO{sub 4}, Ag and AgI, in which Ag nanoparticles act as the charge separation center.« less

Spontaneous Fluctuations of PO2 in the Rabbit Somatosensory Cortex.

PubMed

Linsenmeier, Robert A; Aksenov, Daniil P; Faber, Holden M; Makar, Peter; Wyrwicz, Alice M

2016-01-01

In many tissues, PO2 fluctuates spontaneously with amplitudes of a few mmHg. Here we further characterized these oscillations. PO2 recordings were made from the whisker barrel cortex of six rabbits with acutely or chronically placed polarographic electrodes. Measurements were made while rabbits were awake and while anesthetized with isoflurane, during air breathing, and during 100% oxygen inspiration. In awake rabbits, 90% of the power was between 0 and 20 cycles per minute (cpm), not uniformly distributed over this range, but with a peak frequently near 10 cpm. This was much slower than heart or respiratory rhythms and is similar to the frequency content observed in other tissues. During hyperoxia, total power was higher than during air-breathing, and the dominant frequencies tended to shift toward lower values (0-10 cpm). These observations suggest that at least the lower frequency fluctuations represent efforts by the circulation to regulate local PO2. There were no consistent changes in total power during 0.5 or 1.5% isoflurane anesthesia, but the power shifted to lower frequencies. Thus, both hyperoxia and anesthesia cause characteristic, but distinct, changes in spontaneous fluctuations. These PO2 fluctuations may be caused by vasomotion, but other factors cannot be ruled out.

Synthesis, characterization and optical properties of NH4Dy(PO3)4

NASA Astrophysics Data System (ADS)

Chemingui, S.; Ferhi, M.; Horchani-Naifer, K.; Férid, M.

2014-09-01

Polycrystalline powders of NH4Dy(PO3)4 polyphosphate have been grown by the flux method. This compound was found to be isotopic with NH4Ce(PO3)4 and RbHo(PO3)4. It crystallizes in the monoclinic space group P21/n with unit cell parameters a=10.474(6) Å, b=9.011(4) Å, c=10.947(7) Å and β=106.64(3)°. The title compound has been transformed to triphosphate Dy(PO3)3 after calcination at 800 °C. Powder X-ray diffraction, infrared and Raman spectroscopies and the differential thermal analysis have been used to identify these materials. The spectroscopic properties have been investigated through absorption, excitation, emission spectra and decay curves of Dy3+ ion in both compounds at room temperature. The emission spectra show the characteristic emission bands of Dy3+ in the two compounds, before and after calcination. The integrated emission intensity ratios of the yellow to blue (IY/IB) transitions and the chromaticity properties have been determined from emission spectra. The decay curves are found to be double-exponential. The non-exponential behavior of the decay rates was related to the resonant energy transfer as well as cross-relaxation between the donor and acceptor Dy3+ ions. The determined properties have been discussed as function of crystal structure of both compounds. They reveal that NH4Dy(PO3)4 is promising for white light generation but Dy(PO3)3 is potential candidates in field emission display (FED) and plasma display panel (PDP) devices.

Connected Lighting Systems Efficiency Study$-$ PoE Cable Energy Losses, Part 1

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

Tuenge, Jason; Kelly, Karsten; Poplawski, Michael

First report in a study of the efficiency of connected lighting systems. The report summarizes the results of an exploratory study investigating power losses in Ethernet cables used between PoE switches and luminaires in PoE connected lighting systems. Testing was conducted at the Pacific Northwest National Laboratory (PNNL) Connected Lighting Test Bed in September 2017. The results were analyzed to explore the impact of cable selection on PoE lighting system energy efficiency, as well as the effectiveness of guidelines recently introduced by the American National Standards Institute (ANSI) C137 Lighting Systems Committee.

Important Variation in Vibrational Properties of LiFePO4 and FePO4 Induced by Magnetism

PubMed Central

Seifitokaldani, Ali; Gheribi, Aïmen E.; Phan, Anh Thu; Chartrand, Patrice; Dollé, Mickaël

2016-01-01

A new thermodynamically self-consistent (TSC) method, based on the quasi-harmonic approximation (QHA), is used to obtain the Debye temperatures of LiFePO4 (LFP) and FePO4 (FP) from available experimental specific heat capacities for a wide temperature range. The calculated Debye temperatures show an interesting critical and peculiar behavior so that a steep increase in the Debye temperatures is observed by increasing the temperature. This critical behavior is fitted by the critical function and the adjusted critical temperatures are very close to the magnetic phase transition temperatures in LFP and FP. Hence, the critical behavior of the Debye temperatures is correlated with the magnetic phase transitions in these compounds. Our first-principle calculations support our conjecture that the change in electronic structures, i.e. electron density of state and electron localization function, and consequently the change in thermophysical properties due to the magnetic transition may be the reason for the observation of this peculiar behavior of the Debye temperatures. PMID:27604551

Important Variation in Vibrational Properties of LiFePO4 and FePO4 Induced by Magnetism

NASA Astrophysics Data System (ADS)

Seifitokaldani, Ali; Gheribi, Aïmen E.; Phan, Anh Thu; Chartrand, Patrice; Dollé, Mickaël

2016-09-01

A new thermodynamically self-consistent (TSC) method, based on the quasi-harmonic approximation (QHA), is used to obtain the Debye temperatures of LiFePO4 (LFP) and FePO4 (FP) from available experimental specific heat capacities for a wide temperature range. The calculated Debye temperatures show an interesting critical and peculiar behavior so that a steep increase in the Debye temperatures is observed by increasing the temperature. This critical behavior is fitted by the critical function and the adjusted critical temperatures are very close to the magnetic phase transition temperatures in LFP and FP. Hence, the critical behavior of the Debye temperatures is correlated with the magnetic phase transitions in these compounds. Our first-principle calculations support our conjecture that the change in electronic structures, i.e. electron density of state and electron localization function, and consequently the change in thermophysical properties due to the magnetic transition may be the reason for the observation of this peculiar behavior of the Debye temperatures.

Important Variation in Vibrational Properties of LiFePO4 and FePO4 Induced by Magnetism.

PubMed

Seifitokaldani, Ali; Gheribi, Aïmen E; Phan, Anh Thu; Chartrand, Patrice; Dollé, Mickaël

2016-09-08

A new thermodynamically self-consistent (TSC) method, based on the quasi-harmonic approximation (QHA), is used to obtain the Debye temperatures of LiFePO4 (LFP) and FePO4 (FP) from available experimental specific heat capacities for a wide temperature range. The calculated Debye temperatures show an interesting critical and peculiar behavior so that a steep increase in the Debye temperatures is observed by increasing the temperature. This critical behavior is fitted by the critical function and the adjusted critical temperatures are very close to the magnetic phase transition temperatures in LFP and FP. Hence, the critical behavior of the Debye temperatures is correlated with the magnetic phase transitions in these compounds. Our first-principle calculations support our conjecture that the change in electronic structures, i.e. electron density of state and electron localization function, and consequently the change in thermophysical properties due to the magnetic transition may be the reason for the observation of this peculiar behavior of the Debye temperatures.

Structure determination and optical properties of CsSm(PO{sub 3}){sub 4}

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

Ben Hassen, N.; Ferhi, M., E-mail: ferhi.mounir@gmail.com; Horchani-Naifer, K.

2015-03-15

Graphical abstract: Projection of the CsSm(PO{sub 3}){sub 4} structure viewing along the a axis. - Highlights: • Single crystal of a new polyphosphate CsSm(PO{sub 3}){sub 4} has been synthesized. • The obtained compound has been characterized by several techniques. • The crystal structure of CsSm(PO{sub 3}){sub 4} has been resolved. • Spectroscopic properties of Sm{sup 3+} in CsSm(PO{sub 3}){sub 4} have been performed. - Abstract: A new alkali metal-rare earth polyphosphate CsSm(PO{sub 3}){sub 4} has been synthesized by flux method. The obtained compound has been characterized by means of single crystal X-ray diffraction, Fourier transform infrared (FTIR) and Raman scatteringmore » spectroscopies. It crystallizes in the monoclinic space group P2{sub 1}/n with the following unit-cell parameters: a = 10.382(2), b = 8.978(6), c = 11.205(4) Å, β = 106.398(3)° and Z = 4. The structure of CsSm(PO{sub 3}){sub 4} is an infinite three-dimensional framework made up of double spiral (PO{sub 3}){sub n} chains linked with neighboring SmO{sub 8} and CsO{sub 11} polyhedra. Spectroscopic properties of Sm{sup 3+} in this new compound including excitation, emission, and kinetic measurement have been performed. The emission spectrum shows four transitions characteristics of Sm{sup 3+} in the orange–red region by excitation wavelength at 400 nm. The decay time curve of {sup 4}G{sub 5/2} → {sup 6}H{sub 7/2} transition has been also registered and fitted to a single exponential function.« less

Optical Properties and Electrochemical Performance of LiFePO4 Thin Films Deposited on Transparent Current Collectors.

PubMed

Lee, HyunSeok; Yim, Haena; Kim, Kwang-Bum; Choi, Ji-Won

2015-11-01

LiFePO4 thin film cathodes are deposited on various transparent conducting oxide thin films on glass, which are used as cathode current collectors. The XRD patterns show that the thin films have the phase of LiFePO4 with an ordered olivine structure indexed to the orthorhombic Pmna space group. LiFePO4 thin film deposited on various TCO glass substrates exhibits transmittance of about 53%. The initial specific discharge capacities of LiFePO4 thin films are 25.0 μAh/cm2 x μm on FTO, 33.0 μAh/cm2 x μm on ITO, and 13.0 μAh/cm2 x μm on AZO coated glass substrates. Interestingly, the retention capacities of LiFePO4 thin films are 76.0% on FTO, 31.2% on ITO, and 37.7% on AZO coated glass substrates at 20th cycle. The initial specific discharge capacity of the LiFePO4/FTO electrode is slightly lower, but the discharge capacities of the LiFePO4/FTO electrode relatively decrease less than those of the others such as LiFePO4/ITO and LiFePO4/AZO with cycling. The results reported here provide the high transparency of LiFePO4 thin films cathode materials and the good candidate as FTO current collector of the LiFePO4 thin film cathode of transparent thin film rechargeable batteries due to its high transparency and cyclic retention.

Synthesis, characterization and optical properties of NH{sub 4}Dy(PO{sub 3}){sub 4}

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

Chemingui, S.; Ferhi, M., E-mail: ferhi.mounir@gmail.com; Horchani-Naifer, K.

2014-09-15

Polycrystalline powders of NH{sub 4}Dy(PO{sub 3}){sub 4} polyphosphate have been grown by the flux method. This compound was found to be isotopic with NH{sub 4}Ce(PO{sub 3}){sub 4} and RbHo(PO{sub 3}){sub 4}. It crystallizes in the monoclinic space group P2{sub 1/n} with unit cell parameters a=10.474(6) Å, b=9.011(4) Å, c=10.947(7) Å and β=106.64(3)°. The title compound has been transformed to triphosphate Dy(PO{sub 3}){sub 3} after calcination at 800 °C. Powder X-ray diffraction, infrared and Raman spectroscopies and the differential thermal analysis have been used to identify these materials. The spectroscopic properties have been investigated through absorption, excitation, emission spectra and decaymore » curves of Dy{sup 3+} ion in both compounds at room temperature. The emission spectra show the characteristic emission bands of Dy{sup 3+} in the two compounds, before and after calcination. The integrated emission intensity ratios of the yellow to blue (I{sub Y}/I{sub B}) transitions and the chromaticity properties have been determined from emission spectra. The decay curves are found to be double-exponential. The non-exponential behavior of the decay rates was related to the resonant energy transfer as well as cross-relaxation between the donor and acceptor Dy{sup 3+} ions. The determined properties have been discussed as function of crystal structure of both compounds. They reveal that NH{sub 4}Dy(PO{sub 3}){sub 4} is promising for white light generation but Dy(PO{sub 3}){sub 3} is potential candidates in field emission display (FED) and plasma display panel (PDP) devices. - Graphical abstract: The CIE color coordinate diagrams showing the chromatic coordinates of Dy{sup 3+} luminescence in NH{sub 4}Dy(PO{sub 3}){sub 4} and Dy(PO{sub 3}){sub 3}. - Highlights: • The polycrystalline powders of NH{sub 4}Dy(PO{sub 3}){sub 4} and Dy(PO{sub 3}){sub 3} are synthesized. • The obtained powders are characterized. • The spectroscopic properties of Dy

Online Workspace to Connect Scientists with NASA's Science E/PO Efforts and Practitioners

NASA Astrophysics Data System (ADS)

Shipp, Stephanie; Bartolone , Lindsay; Peticolas, Laura; Woroner, Morgan; Dalton, Heather; Schwerin, Theresa; Smith, Denise

2014-11-01

There is a growing awareness of the need for a scientifically literate public in light of challenges facing society today, and also a growing concern about the preparedness of our future workforce to meet those challenges. Federal priorities for science, technology, engineering, and math (STEM) education call for improvement of teacher training, increased youth and public engagement, greater involvement of underrepresented populations, and investment in undergraduate and graduate education. How can planetary scientists contribute to these priorities? How can they “make their work and findings comprehensible, appealing, and available to the public” as called for in the Planetary Decadal Survey?NASA’s Science Mission Directorate (SMD) Education and Public Outreach (E/PO) workspace provides the SMD E/PO community of practice - scientists and educators funded to conduct SMD E/PO or those using NASA’s science discoveries in E/PO endeavors - with an online environment in which to communicate, collaborate, and coordinate activities, thus helping to increase effectiveness of E/PO efforts. The workspace offers interested scientists avenues to partner with SMD E/PO practitioners and learn about E/PO projects and impacts, as well as to advertise their own efforts to reach a broader audience. Through the workspace, scientists can become aware of opportunities for involvement and explore resources to improve professional practice, including literature reviews of best practices for program impact, mechanisms for engaging diverse audiences, and large- and small-scale program evaluation. Scientists will find “how to” manuals for getting started and increasing impact with public presentations, classroom visits, and other audiences, as well as primers with activity ideas and resources that can augment E/PO interactions with different audiences. The poster will introduce the workspace to interested scientists and highlight pathways to resources of interest that can help

210Po in the marine environment with emphasis on its behaviour within the biosphere.

PubMed

Fowler, Scott W

2011-05-01

The distribution and behaviour of the natural-series alpha-emitter polonium-210 in the marine environment has been under study for many years primarily due to its enhanced bioaccumulation, its strong affinity for binding with certain internal tissues, and its importance as a contributor to the natural radiation dose received by marine biota as well as humans consuming seafoods. Results from studies spanning nearly 5 decades show that (210)Po concentrations in organisms vary widely among the different phylogenic groups as well as between the different tissues of a given species. Such variation results in (210)Po concentration factors ranging from approximately 10(3) to over 10(6) depending upon the organism or tissue considered. (210)Po/(210)Pb ratios in marine species are generally greater than unity and tend to increase up the food chain indicating that (210)Po is preferentially taken up by organisms compared to its progenitor (210)Pb. The effective transfer of (210)Po up the food chain is primarily due to the high degree of assimilation of the radionuclide from ingested food and its subsequent strong retention in the organisms. In some cases this mechanism may lead to an apparent biomagnification of (210)Po at the higher trophic level. Various pelagic species release (210)Po and (210)Pb packaged in organic biodetrital particles that sink and remove these radionuclides from the upper water column, a biogeochemical process which, coupled with scavenging rates of this radionuclide pair, is being examined as a possible proxy for estimating downward organic carbon fluxes in the sea. Data related to preferential bioaccumulation in various organisms, their tissues, resultant radiation doses to these species, and the processes by which (210)Po is transferred and recycled through the food web are discussed. In addition, the main gaps in our present knowledge and proposed areas for future studies on the biogeochemical behaviour of (210)Po and its use as a tracer of

Atomic-Scale Observations of (010) LiFePO4 Surfaces Before and After Chemical Delithiation.

PubMed

Kobayashi, Shunsuke; Fisher, Craig A J; Kato, Takeharu; Ukyo, Yoshio; Hirayama, Tsukasa; Ikuhara, Yuichi

2016-09-14

The ability to view directly the surface structures of battery materials with atomic resolution promises to dramatically improve our understanding of lithium (de)intercalation and related processes. Here we report the use of state-of-the-art scanning transmission electron microscopy techniques to probe the (010) surface of commercially important material LiFePO4 and compare the results with theoretical models. The surface structure is noticeably different depending on whether Li ions are present in the topmost surface layer or not. Li ions are also found to migrate back to surface regions from within the crystal relatively quickly after partial delithiation, demonstrating the facile nature of Li transport in the [010] direction. The results are consistent with phase transformation models involving metastable phase formation and relaxation, providing atomic-level insights into these fundamental processes.

Rural Incubator Profile.

ERIC Educational Resources Information Center

Weinberg, Mark L.

This profile summarizes the responses of 20 managers of rural business incubators, reporting on their operations, entry and exit policies, facility promotion, service arrangements and economic development outcomes. Incubators assist small businesses in the early stages of growth by providing them with rental space, shared services, management and…

Improvement of the mechanical properties and corrosion resistance of biodegradable β-Ca3(PO4)2/Mg-Zn composites prepared by powder metallurgy: the adding β-Ca3(PO4)2, hot extrusion and aging treatment.

PubMed

Yan, Yang; Kang, Yijun; Li, Ding; Yu, Kun; Xiao, Tao; Deng, Youwen; Dai, Han; Dai, Yilong; Xiong, Hanqing; Fang, Hongjie

2017-05-01

In this study, 10%β-Ca 3 (PO 4 ) 2 /Mg-6%Zn (wt.%) composites with Mg-6%Zn alloy as control were prepared by powder metallurgy. After hot extrusion, the as-extruded composites were aged for 72h at 150°C. The effects of the adding β-Ca 3 (PO 4 ) 2 , hot extrusion and aging treatment on their microstructure, mechanical properties and corrosion resistance were investigated. The XRD results identified α-Mg, MgZn phase and β-Ca 3 (PO 4 ) 2 phase in these composites. After hot extrusion, grains were significantly refined, and the larger-sized β-Ca 3 (PO 4 ) 2 particles and coarse MgZn phases were broken into linear-distributed β-Ca 3 (PO 4 ) 2 and MgZn phases along the extrusion direction. After aging treatment, the elements of Zn, Ca, P and O presented a more homogeneous distribution. The compressive strengths of the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites were approximately double those of natural bone, and their densities and elastic moduli matched those of natural bone. The immersion tests and electrochemical tests revealed that the adding β-Ca 3 (PO 4 ) 2 , hot extrusion and aging treatment could promote the formation of protective corrosion product layer on the sample surface in Ringer's solution, which improved corrosion resistance of the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites. The XRD results indicated that the corrosion product layer contained Mg(OH) 2 , β-Ca 3 (PO 4 ) 2 and hydroxyapatite (HA). The cytotoxicity assessments showed the as-extruded β-Ca 3 (PO 4 ) 2 /Mg-Zn composite aged for 72h was harmless to L-929 cells. These results suggested that the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites prepared by powder metallurgy were promising to be used for bone tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

MW-assisted synthesis of LiFePO 4 for high power applications

NASA Astrophysics Data System (ADS)

Beninati, Sabina; Damen, Libero; Mastragostino, Marina

LiFePO 4/C was prepared by solid-state reaction from Li 3PO 4, Fe 3(PO 4) 2·8H 2O, carbon and glucose in a few minutes in a scientific MW (microwave) oven with temperature and power control. The material was characterized by X-ray diffraction, scanning electron microscopy and by TGA analysis to evaluate carbon content. The electrochemical characterization as positive electrode in EC (ethylene carbonate)-DMC (dimethylcarbonate) 1 M LiPF 6 was performed by galvanostatic charge-discharge cycles at C/10 to evaluate specific capacity and by sequences of 10 s discharge-charge pulses, at different high C-rates (5-45C) to evaluate pulse-specific power in simulate operative conditions for full-HEV application. The maximum pulse-specific power and, particularly, pulse efficiency values are quite high and make MW synthesis a very promising route for mass production of LiFePO 4/C for full-HEV batteries at low energy costs.

Increase of 210Po levels in human semen fluid after mussel ingestion.

PubMed

Kelecom, Alphonse; Gouvea, Rita de Cássia dos Santos

2011-05-01

Polonium-210 ((210)Po) radioactive concentrations were determined in human semen fluid of vasectomized non-smoker volunteers. The (210)Po levels ranged from 0.10 to 0.39 mBq g(-1) (mean: 0.23 ± 0.08 mBq g(-1)). This value decreased to 0.10 ± 0.02 mBq g(-1) (range from 0.07 to 0.13 mBq g(-1)) after two weeks of a controlled diet, excluding fish and seafood. Then, volunteers ate during a single meal 200 g of the cooked mussel Perna perna L., and (210)Po levels were determined again, during ten days, in semen fluid samples collected every morning. Volunteers continued with the controlled diet and maintained sexual abstinence through the period of the experiment. A 300% increase of (210)Po level was observed the day following mussel consumption, with a later reduction, such that the level returned to near baseline by day 4. Copyright © 2011 Elsevier Ltd. All rights reserved.

Three new d10 transition metal selenites containing PO4 tetrahedron: Cd7(HPO4)2(PO4)2(SeO3)2, Cd6(PO4)1.34(SeO3)4.66 and Zn3(HPO4)(SeO3)2(H2O)

NASA Astrophysics Data System (ADS)

Ma, Yun-Xiang; Gong, Ya-Ping; Hu, Chun-li; Mao, Jiang-Gao; Kong, Fang

2018-06-01

Three new d10 transition metal selenites containing PO4 tetrahedron, namely, Cd7(HPO4)2(PO4)2(SeO3)2 (1), Cd6(PO4)1.34(SeO3)4.66 (2) and Zn3(HPO4)(SeO3)2(H2O) (3), have been synthesized by hydrothermal reaction. They feature three different structural types. Compound 1 exhibits a novel 3D network composed of 3D cadmium selenite open framework with phosphate groups filled in the 1D helical tunnels. The structure of compound 2 displays a new 3D framework consisted of 2D cadmium oxide layers bridged by SeO3 and PO4 groups. Compound 3 is isostructural with the reported solids of Co3(SeO3)3-x(PO3OH)x(H2O) when x is equal to 1.0. Its structure could be viewed as a 3D zinc oxide open skeleton with SeO3 and HPO4 polyhedra attached on the wall of the tunnels. They represent the only examples in metal selenite phosphates in addition to the above cobalt compounds. Optical diffuse reflectance spectra revealed that these solids are insulators, which are consistent with the results of band structure computations based on DFT algorithm.

Synthesis, characterization and vibrational spectroscopic study of Co, Mg co-doped LiMnPO4

NASA Astrophysics Data System (ADS)

Sronsri, Chuchai; Noisong, Pittayagorn; Danvirutai, Chanaiporn

2016-01-01

The isostructural olivine-like LiM(II)PO4 compounds [M(II) = Mn, Mn0.9Co0.1, Mn0.8Co0.1Mg0.1] were successfully generated through the solid state reaction from the synthesized NH4M(II)PO4• H2O precursors. The TG/DTG/DTA, AAS/AES, FTIR and XRD methods were employed to confirm both NH4M(II)PO4• H2O and LiM(II)PO4 compounds. Their morphologies were studied by SEM method. The shift of two theta angle of XRD to higher values was observed in metal doping compounds, which indicate the formation of the single phase of isodivalent doping of Co2 + and Mg2 + ions according to the change in the lattice parameters and cell volumes. Their infrared spectra are reported and discussed with respect to the normal vibrations of NH4+, PO43 -, P2O74 - and H2O molecules using factor group analysis. The correlation field splitting analysis of PO43 - in NH4M(II)PO4• H2O (orthorhombic system, Pmn21, C2v7 and Z = 2, [(3 × 5) - 6] × 2 = 18 internal modes) symbolized as Td - Cs - C2v7 suggested the number of vibrational modes to be: ΓVib = A1(6) + A2(3) + B1(6) + B2(3) and A1(6) + A2(3) + B1(3) + B2(6) for zx and yz plane respectively. While, LiM(II)PO4 crystallizes in the orthorhombic system the space group Pnma (D2h16), Z = 4 and the site symmetry of PO43 - is Cs. The correlation field splitting of type Td - Cs - D2h16 were reported in relation to [(3 × 5) - 6] × 4 = 36 internal modes for PO43 - unit in the structure.

Sodium intercalation in the phosphosulfate cathode NaFe2(PO4)(SO4)2

NASA Astrophysics Data System (ADS)

Ben Yahia, Hamdi; Essehli, Rachid; Amin, Ruhul; Boulahya, Khalid; Okumura, Toyoki; Belharouak, Ilias

2018-04-01

The compound NaFe2(PO4)(SO4)2 is successfully synthesized via a solid state reaction route and its crystal structure is determined using powder X-ray diffraction data. NaFe2(PO4)(SO4)2 phase is also characterized by cyclic voltammetry, galvanostatic cycling and electrochemical impedance spectroscopy. NaFe2(PO4)(SO4)2 crystallizes with the well-known NASICON-type structure. SAED and HRTEM experiments confirm the structural model, and no ordering between the PO4-3 and SO4-2 polyanions is detected. The electrochemical tests indicate that NaFe2(PO4)(SO4)2 is a 3 V sodium intercalating cathode. The electrical conductivity is relatively low (2.2 × 10-6 Scm-1 at 200 °C) and the obtained activation energy is ∼0.60eV. The GITT experiments indicate that the diffusivity values are in the range of 10-11-10-12 cm2/s within the measured sodium concentrations.

The effect of heat preservation time on the electrochemical properties of LiFePO4

NASA Astrophysics Data System (ADS)

He, Rui; Zhang, Lihui; Bai, Xue; Liu, Zhenfa

2017-12-01

LiFePO4 was prepared via high temperature solid-state method at different heat preservation time. XRD and SEM was used to test the structure and morphology of LiFePO4. Land 2001 was used to test the electrochemical performance of LiFePO4. The results illustrated that well-crystallized LiFePO4 composite with homogeneous small particles was obtained by XRD and SEM. And the optimum heat preservation time was 4 hour. From charge/discharge test, it can be seen that at 0.2C, LiFePO4 has initial discharge capacities of 159.1mAh/g at the heat preservation time 4 hour. From the rate capacity, it can be seen that the discharge capacity was of optimum sample remains above 99% after 200 cycles.

Investigation of structural and luminescent properties of Ce{sup 3+}/Mn{sup 2+} ions-doped Ca{sub 5}(PO{sub 4}){sub 3}F

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

Zhang, Lei; Fu, Zuoling, E-mail: zlfu@jlu.edu.cn; Wu, Zhijian

Graphical abstract: The structural and luminescent properties FAP: Ce{sup 3+} and FAP: Ce{sup 3+}, Mn{sup 2+} were investigated in detail by the spectral measurement and theoretical calculation. The emission of Ce{sup 3+} is fitted by two Gaussian functions dashed lines in wavenumber to further confirm the Ce{sup 3+} ion simultaneously occupy the 4f and 6h sites Ca{sub 5}(PO{sub 4})F host. - Highlights: • A simple hydrothermal method has been used to prepare Ca{sub 5}(PO{sub 4}){sub 3}F: Ce{sup 3+}, Mn{sup 2+} powders with structural and luminescent analysis. • The emission of Ce{sup 3+} is fitted by two Gaussian functions to confirmmore » the Ce{sup 3+} ion simultaneously to occupy the 4f and 6h sites in Ca{sub 5}(PO{sub 4}){sub 3}F host. • Due to an efficient energy transfer, the existence of Ce{sup 3+} (sensitizer) can dramatically enhance the green emission of Mn{sup 2+} (activator) in co-doped samples. - Abstract: Ce{sup 3+}/Mn{sup 2+} ions-doped oxyapatite calcium fluorapatite [Ca{sub 5}(PO{sub 4}){sub 3}F, FAP] has been successfully synthesized by a facile one-step hydrothermal method. The luminescent properties of Ce{sup 3+}- and Ce{sup 3+}/Mn{sup 2+}- activated FAP phosphors were investigated using the photoluminescence (PL) and photoluminescence excitation (PLE) spectra. The emission of Ce{sup 3+} was fitted by two Gaussian functions with dashed lines in wavenumber to confirm the Ce{sup 3+} ion simultaneously to occupy the 4f and 6h sites in Ca{sub 5}(PO{sub 4}){sub 3}F host, which was consistent with the calculated results of crystal field based on chemical bond theory. In addition, the existence of Ce{sup 3+} (sensitizer) can dramatically enhance the green emission of Mn{sup 2+} (activator) in Ce{sup 3+}/Mn{sup 2+} ions co-doped samples due to an efficient energy transfer from Ce{sup 3+} to Mn{sup 2+}. All of these results could help us understand the site assignments and optical properties of the rare earth ions doped in hexagonal Ca{sub 5}(PO

Structural Transformation of LiFePO4 during Ultrafast Delithiation.

PubMed

Kuss, Christian; Trinh, Ngoc Duc; Andjelic, Stefan; Saulnier, Mathieu; Dufresne, Eric M; Liang, Guoxian; Schougaard, Steen B

2017-12-21

The prolific lithium battery electrode material lithium iron phosphate (LiFePO 4 ) stores and releases lithium ions by undergoing a crystallographic phase change. Nevertheless, it performs unexpectedly well at high rate and exhibits good cycling stability. We investigate here the ultrafast charging reaction to resolve the underlying mechanism while avoiding the limitations of prevailing electrochemical methods by using a gaseous oxidant to deintercalate lithium from the LiFePO 4 structure. Oxidizing LiFePO 4 with nitrogen dioxide gas reveals structural changes through in situ synchrotron X-ray diffraction and electronic changes through in situ UV/vis reflectance spectroscopy. This study clearly shows that ultrahigh rates reaching 100% state of charge in 10 s does not lead to a particle-wide union of the olivine and heterosite structures. An extensive solid solution phase is therefore not a prerequisite for ultrafast charge/discharge.

Structural Transformation of LiFePO 4 during Ultrafast Delithiation

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

Kuss, Christian; Trinh, Ngoc Duc; Andjelic, Stefan

The prolific lithium battery electrode material lithium iron phosphate (LiFePO 4) stores and releases lithium ions by undergoing a crystallographic phase change. Nevertheless, it performs unexpectedly well at high rate and exhibits good cycling stability. Here we investigate here the ultrafast charging reaction to resolve the underlying mechanism while avoiding the limitations of prevailing electrochemical methods by using a gaseous oxidant to deintercalate lithium from the LiFePO 4 structure. Oxidizing LiFePO 4 with nitrogen dioxide gas reveals structural changes through in situ synchrotron X-ray diffraction and electronic changes through in situ UV/vis reflectance spectroscopy. This study clearly shows that ultrahighmore » rates reaching 100% state of charge in 10 s does not lead to a particle-wide union of the olivine and heterosite structures. An extensive solid solution phase is therefore not a prerequisite for ultrafast charge/discharge.« less

Structural Transformation of LiFePO 4 during Ultrafast Delithiation

DOE PAGES

Kuss, Christian; Trinh, Ngoc Duc; Andjelic, Stefan; ...

2017-12-05

The prolific lithium battery electrode material lithium iron phosphate (LiFePO 4) stores and releases lithium ions by undergoing a crystallographic phase change. Nevertheless, it performs unexpectedly well at high rate and exhibits good cycling stability. Here we investigate here the ultrafast charging reaction to resolve the underlying mechanism while avoiding the limitations of prevailing electrochemical methods by using a gaseous oxidant to deintercalate lithium from the LiFePO 4 structure. Oxidizing LiFePO 4 with nitrogen dioxide gas reveals structural changes through in situ synchrotron X-ray diffraction and electronic changes through in situ UV/vis reflectance spectroscopy. This study clearly shows that ultrahighmore » rates reaching 100% state of charge in 10 s does not lead to a particle-wide union of the olivine and heterosite structures. An extensive solid solution phase is therefore not a prerequisite for ultrafast charge/discharge.« less

A frogspawn-inspired hierarchical porous NaTi2(PO4)3-C array for high-rate and long-life aqueous rechargeable sodium batteries

NASA Astrophysics Data System (ADS)

Zhao, Baidan; Lin, Bo; Zhang, Sen; Deng, Chao

2015-11-01

Hollow micro/nano-arrays have attracted tremendous attention in the field of energy conversion and storage, but such structures usually compromise the volumetric energy density of the electrode materials. Frogspawn consists of a spawn core and a transparent jelly shell organized in a hierarchical porous array, which exhibits superior mechanical strength and high-efficiency oxygen permeability. It can be used as a model for designing a new high-performance electrode material, which has advantages such as a high surface area, fast mass transport and superior durability. Herein, we report a frogspawn-like NaTi2(PO4)3/C array prepared by a facile preform impregnation strategy. The framework is formed by a hollow carbon sphere connected by the NaTi2(PO4)3/C skeleton, and its hollow is filled with the NaTi2(PO4)3 nanospheres. The whole hierarchical porous three-dimensional array copies the structure of a frogspawn. This unique structure not only enables easy electrolyte percolation and fast electron/ion transport, but also enhances the reversible capacity and cycling durability. When it is applied as an anode of the aqueous sodium ion battery, it exhibits favorable high rate capability and superior cycling stability, and retains 89% of the initial capacity after two thousand cycles at 20 C. Moreover, the full cell using the frogspawn-inspired NaTi2(PO4)3-C as the anode and Na0.44MnO2 as the cathode is capable of ultralong cycling up to one thousand cycles at alternate 10 and 60 C, which is among the best of state-of-the-art aqueous sodium ion systems. Therefore, the frogspawn-inspired architecture provides a new strategy to the tailored design of polyanion materials for high-power applications.Hollow micro/nano-arrays have attracted tremendous attention in the field of energy conversion and storage, but such structures usually compromise the volumetric energy density of the electrode materials. Frogspawn consists of a spawn core and a transparent jelly shell organized in

Fission fragment mass distributions from 210Po and 213At

NASA Astrophysics Data System (ADS)

Sen, A.; Ghosh, T. K.; Bhattacharya, S.; Banerjee, K.; Bhattacharya, C.; Kundu, S.; Mukherjee, G.; Asgar, A.; Dey, A.; Dhal, A.; Shaikh, Md. Moin; Meena, J. K.; Manna, S.; Pandey, R.; Rana, T. K.; Roy, Pratap; Roy, T.; Srivastava, V.; Bhattacharya, P.

2017-12-01

Background: The influence of shell effect on the dynamics of the fusion fission process and its evolution with excitation energy in the preactinide Hg-Pb region in general is a matter of intense research in recent years. In particular, a strong ambiguity remains for the neutron shell closed 210Po nucleus regarding the role of shell effect in fission around ≈30 -40 MeV of excitation energy. Purpose: We have measured the fission fragment mass distribution of 210Po populated using fusion of 4He+206Pb at different excitation energies and compare the result with recent theoretical predictions as well as with our previous measurement for the same nucleus populated through a different entrance channel. Mass distribution in the fission of the neighboring nuclei 213At is also studied for comparison. Methods: Two large area multiwire proportional counters (MWPC) were used for complete kinematical measurement of the coincident fission fragments. The time of flight differences of the coincident fission fragments were used to directly extract the fission fragment mass distributions. Results: The measured fragment mass distribution for the reactions 4He+206Pb and 4He+209Bi were symmetric and the width of the mass distributions were found to increase monotonically with excitation energy above 36.7 MeV and 32.9 MeV, respectively, indicating the absence of shell effects at the saddle. However, in the fission of 210Po, we find minor deviation from symmetric mass distributions at the lowest excitation energy (30.8 MeV). Conclusion: Persistence of shell effect in fission fragment mass distribution of 210Po was observed at the excitation energy ≈31 MeV as predicted by the theory; at higher excitation energy, however, the present study reaffirms the absence of any shell correction in the fission of 210Po.

In vivo PO2 imaging in the porcine model with perfluorocarbon F-19 NMR at low field.

PubMed

Thomas, S R; Pratt, R G; Millard, R W; Samaratunga, R C; Shiferaw, Y; McGoron, A J; Tan, K K

1996-01-01

Quantitative pO2 imaging in vivo has been evaluated utilizing F-19 NMR in the porcine model at 0.14 T for the lungs, liver, and spleen following i.p. administration of the commercial perfluorotributylamine (FC-43)-based perfluorocarbon (PFC) emulsion, Oxypherol-ET. Calculated T1 maps obtained from a two spin-echo saturation recovery/inversion recovery (SR/IR) pulse protocol are converted into quantitative pO2 images through a temperature-dependent calibration curve relating longitudinal relaxation rate (1/T1) to pO2. The uncertainty in pO2 for a T1 measurement error of +/- 5% as encountered in establishing the calibration curves ranges from +/- 10 torr (+/- 40%) at 25 torr to +/- 16 torr (+/- 11%) at 150 torr for FC-43 (37 degrees C). However, additional uncertainties in T1 dependent upon the signal-to-noise ratio may be introduced through the SR/IR calculated T1 pulse protocol, which might severely degrade the pO2 accuracy. Correlation of the organ image calculated pO2 with directly measured pO2 in airway or blood pools in six pigs indicate that the PFC resident in lung is in near equilibrium with arterialized blood and not with airway pO2, suggesting a location distal to the alveolar epithelium. For the liver, the strongest correlation implying equilibrium was evident for venous blood (hepatic vein). For the spleen, arterial blood pO2 (aorta) was an unreliable predictor of pO2 for PFC resident in splenic tissue. The results have demonstrated the utility and defined the limiting aspects quantitative pO2 imaging in vivo using F-19 MRI of sequestered PFC materials.

A Case of Severe, Prolonged, Refractory Hypophosphatemia After Zoledronic Acid Administration.

PubMed

Clark, Sarah L; Nystrom, Erin M

2016-04-01

Zoledronic acid (ZA) administration has been associated with electrolyte abnormalities, including hypocalcemia, hypomagnesemia, hypokalemia, and hypophosphatemia. We describe a case of severe, refractory hypophosphatemia in a patient who received ZA for hypercalcemia of malignancy (HCM). Little data are available that describe the incidence or degree of severity of hypophosphatemia that can occur following ZA administration. In addition, no formal recommendations exist to guide monitoring for or management of electrolyte derangements in the setting of bisphosphonate use. Our patient required daily, high-dose phosphorus replacement beginning day 4 following ZA administration. The average daily dose of phosphorus, including both intravenous and enteral administration, was highest in the first 2 weeks after ZA, averaging 77 mmol/d days 4 through 15, and does not include sources of phosphorus from the patient's nutrition support. Despite this high amount of supplementation, which was well beyond what meets normal daily requirements and the amount expected to treat "usual" hypophosphatemia, the patient did not achieve sustained normal serum phosphorus levels for over 30 days after ZA. ZA is a favorable option for treating HCM because of its longer duration of action, potent serum calcium-lowering effects, and favorable safety profile. The risk of hypophosphatemia with ZA use is reviewed. © The Author(s) 2016.

Vertical distribution of aerosol optical properties in the Po Valley during the 2012 summer campaigns

NASA Astrophysics Data System (ADS)

Bucci, Silvia; Cristofanelli, Paolo; Decesari, Stefano; Marinoni, Angela; Sandrini, Silvia; Größ, Johannes; Wiedensohler, Alfred; Di Marco, Chiara F.; Nemitz, Eiko; Cairo, Francesco; Di Liberto, Luca; Fierli, Federico

2018-04-01

Studying the vertical distribution of aerosol particle physical and chemical properties in the troposphere is essential to understand the relative importance of local emission processes vs. long-range transport for column-integrated aerosol properties (e.g. the aerosol optical depth, AOD, affecting regional climate) as well as for the aerosol burden and its impacts on air quality at the ground. The main objective of this paper is to investigate the transport of desert dust in the middle troposphere and its intrusion into the planetary boundary layer (PBL) over the Po Valley (Italy), a region considered one of the greatest European pollution hotspots for the frequency that particulate matter (PM) limit values are exceeded. Events of mineral aerosol uplift from local (soil) sources and phenomena of hygroscopic growth at the ground are also investigated, possibly affecting the PM concentration in the region as well. During the PEGASOS 2012 field campaign, an integrated observing-modelling system was set up based on near-surface measurements (particle concentration and chemistry), vertical profiling (backscatter coefficient profiles from lidar and radiosoundings) and Lagrangian air mass transport simulations by FLEXPART model. Measurements were taken at the San Pietro Capofiume supersite (44°39' N, 11°37' E; 11 m a.s.l.), located in a rural area relatively close to some major urban and industrial emissive areas in the Po Valley. Mt. Cimone (44°12' N, 10°42' E; 2165 m a.s.l.) WMO/GAW station observations are also included in the study to characterize regional-scale variability. Results show that, in the Po Valley, aerosol is detected mainly below 2000 m a.s.l. with a prevalent occurrence of non-depolarizing particles ( > 50 % throughout the campaign) and a vertical distribution modulated by the PBL daily evolution. Two intense events of mineral dust transport from northern Africa (19-21 and 29 June to 2 July) are observed, with layers advected mainly above 2000 m

Annual Data Summary for 1986 CERC (Coastal Engineering Research Center) Field Research Facility. Volume 1. Main Text and Appendix A

DTIC Science & Technology

1988-08-01

Waterways Experiment Station, Corps of Engineers PO Box 631, Vicksburg, Mississippi 39180-0631 DTI ~;~c~v ~ jAUG 291988 : H Ke August 1988 Final Report...PART I: INTRODUCTION ................................................ 3 Background ........................................................ 3...Information Service, 5285 Port Royal Road, Springfield, VA. 22161. 2 ANNUAL DATA SUMMARY FOR 1986 CERC FIELD RESEARCH FACILITY PART I: INTRODUCTION

Interdependence of arterial PO2 and O2 consumption in the fetal sheep.

PubMed

Asakura, H; Ball, K T; Power, G G

1990-04-01

These experiments were undertaken to measure the effects of changing arterial oxygen tension (PaO2) on oxygen use by the fetal body (VO2). Six fetal sheep at 130-140 days gestation were prepared with an endotracheal tube, carotid artery catheter, body-core thermistor, cooling coil and loosely-applied umbilical cord snare. The next day the cord was occluded and the fetal lungs were ventilated with gas mixtures containing different concentrations of oxygen. While fetal core temperature was kept constant, fetal arterial PO2 was cycled between high and low values (span = 7 to 359 mmHg, n = 103) and O2 consumption was measured by the rate of O2 uptake from a closed-rebreathing circuit. VO2 changed directly with changes in PO2 from 10 to 40 mmHg but became insensitive to changes in PO2 above about 50 mmHg. The results were well described over the entire range by the equation: VO2 (ml/min per kg fetal wt) = -9.62 + 6.99 ln PO2(mmHg)-0.66 ln2 PO2. Thus the oxygen consumption of the near-term fetal sheep varies with changes in arterial PO2 in the physiologic range. This finding is distinctly different than the adult at rest but resembles adult tissues such as exercising muscle at VO2max. This finding is consistent with differences in fetal metabolic controls, limited cardiac reserve, and limited tissue diffusion rates in actively metabolizing tissues.

Na3Tb(PO4)2: Synthesis, crystal structure and greenish emitting properties

NASA Astrophysics Data System (ADS)

Zhao, Dan; Ma, Zhao; Liu, Bao-Zhong; Zhang, Rui-Juan; Wu, Zhi-Qiang; Wang, Jian; Duan, Pei-Gao

2018-03-01

A anhydrous orthoborate Na3Tb(PO4)2 has been prepared and its crystal structure was determined by X-Ray diffraction of a non-merohedral twinned single crystal. The results show that the compound crystallizes in monoclinic space group C2/c and the structure features a 3D framework containing PO4, NaO6, NaO7, NaO8 and TbO8 polyhedra. Under near-UV excitation (370 nm), Na3Tb(PO4)2 shows intense characteristic emission bands of Tb3+ (490 nm, 543 nm, 585 nm and 620 nm) with the CIE coordinate of (0.3062, 0.5901), corresponding to greenish color. The excitation spectrum covers a wide range from 340 nm to 390 nm, which indicates that phosphor Na3Tb(PO4)2 can be efficiently activated by near-UV LED ship.

Determination of Po-210 content in cigarette smoke using a smoking machine: A case study of Iranian cigarettes.

PubMed

Horváth, Mária; Shahrokhi, Amin; Bátor, Péter; Tóth-Bodrogi, Edit; Kovács, Tibor

2017-08-01

The Po-210 content of tobacco has been known for a long time, however, different results can be found about the estimated amount of Po-210 that is inhaled by humans as a result of smoking cigarettes. Because of the unique properties of Po-210, the smoking machines available on the market are not suitable because of their failure to quantitatively collect Po-210 for measurement. Therefore, to estimate precisely the amount of Po-210 entering the lungs as a result of smoking, a smoking machine and sampling protocol based on relevant ISO standards - ISO-3308, ISO-3402 and ISO-4387 - was developed. A 5% HCl solution was found to be the best absorber of Po-210 from smoke. Seventeen different brands of cigarettes distributed in Iran were used to validate the new machine and sampling protocol. The Po-210 concentration was determined by alpha spectrometry; the cigarette smoke solution underwent combined acid treatment after adding a Po-209 tracer. The Po-210 activity concentration of cigarettes sold in Iran was between 9.7 ± 1.2 and 26.5 ± 4.6 mBq/cigarette and it was determined that there was no relationship between the Po-210 and nicotine contents of cigarette smoke. Additionally, it was found that 15 ± 10% of the cigarette Po-210 was transferred to the mainstream smoke. Copyright © 2017 Elsevier Ltd. All rights reserved.

Al(0.5)Nb(1.5)(PO(4))(3).

PubMed

Zhao, Dan; Liang, Peng; Su, Ling; Chang, Huan; Yan, Shi

2011-02-12

Single crystals of the title compound, aluminium niobium triphosphate, Al(0.5)Nb(1.5)(PO(4))(3), have been synthesized by a high-temperature reaction in a platinium crucible. The Al(III) and Nb(V) atoms occupy the same site on the axis, with disorder in the ratio of 1:3. The fundamental building units of the title structure are isolated Al/NbO(6) octa-hedra and PO(4) tetra-hedra (. 2 symmetry), which are further inter-locked by corner-sharing O atoms, leading to a three-dimensional framework structure with infinite channels along the a axis.

Ionothermal synthesis, crystal structure, and magnetic study of Co2PO4OH isostructural with caminite.

PubMed

Wang, Guangmei; Valldor, Martin; Spielberg, Eike T; Mudring, Anja-Verena

2014-03-17

A new framework cobalt(II) hydroxyl phosphate, Co2PO4OH, was prepared by ionothermal synthesis using 1-butyl-4-methyl-pyridinium hexafluorophosphate as the ionic liquid. As the formation of Co2PO4F competes in the synthesis, the synthesis conditions have to be judiciously chosen to obtain well-crystallized, single phase Co2PO4OH. Single-crystal X-ray diffraction analyses reveal Co2PO4OH crystallizes with space group I41/amd (a = b = 5.2713(7) Å, c = 12.907(3) Å, V = 358.63(10) Å(3), and Z = 4). Astonishingly, it does not crystallize isotypically with Co2PO4F but rather isotypically with the hydroxyl minerals caminite Mg1.33[SO4(OH)0.66(H2O)0.33] and lipscombite Fe(2–y)PO4(OH) (0 ≤ y ≤ 2/3). Phosphate tetrahedra groups interconnect four rod-packed face-sharing ∞(1){CoO(6/2)} octahedra chains to form a three-dimensional framework structure. The compound Co2PO4OH was further characterized by powder X-ray diffraction, Fourier transform–infrared, and ultraviolet–visible spectroscopy, confirming the discussed structure. The magnetic measurement reveals that Co2PO4OH undergoes a magnetic transition and presents at low temperatures a canted antiferromagnetic spin order in the ground state.

Detoxification of diphenyl ether herbicide lactofen by Bacillus sp. Za and enantioselective characteristics of an esterase gene lacE.

PubMed

Zhang, Jing; Lu, Luyao; Chen, Feng; Chen, Lingling; Yin, Jingang; Huang, Xing

2018-01-05

A bacterial strain Za capable of degrading diphenyl ether herbicide lactofen was isolated and identified as Bacillus sp. This strain could degrade 94.8% of 50mgL -1 lactofen after 4days of inoculation in flasks. It was revealed that lactofen was initially hydrolyzed to desethyl lactofen, which was further transformed to acifluorfen, followed by the reduction of the nitro group to yield aminoacifluorfen. The phytotoxicity of the transformed product aminoacifluorfen to maize was decreased significantly compared with the lactofen. A gene lacE, encoding an esterase responsible for lactofen hydrolysis to desethyl lactofen and acifluorfen continuously, was cloned from Bacillus sp. Za. The deduced amino acid belonging to the esterase family VII contained a typical Ser-His-Asp/Glu catalytic triad and the conserved motifs GXSXG. The purified recombinant protein LacE displayed maximal esterase activity at 40°C and pH 7.0. Additionally, LacE had broad substrate specificity and was capable of hydrolyzing p-nitrophenyl esters. The enantioselectivity of LacE during lactofen degradation was further studied, and the results indicated that the (S)-(+)-lactofen was degraded faster than the (R)-(-)-lactofen, which could illustrate the reported phenomenon that (S)-(+)-lactofen was preferentially degraded in soil and sediment. Copyright © 2017 Elsevier B.V. All rights reserved.

A new method for the preparation of a [Sn2(H2PO2)3]Br SHG-active polar crystal via surfactant-induced strategy.

PubMed

Xie, Jie-Ling; Zhou, Yu-Hua; Li, Long-Hua; Zhang, Jian-Han; Song, Jun-Ling

2017-07-25

Herein, unprecedented NLO-brominated tin hypophosphites, namely [Sn 2 (H 2 PO 2 ) 3 ]Br, were discovered via a facile surfactant-induced method, which displayed a moderate powder SHG intensity (3.0 × KDP) in type - I phase matching behavior. This complex has high chemical and thermal stability at room temperature. DFT calculations and SHG coefficient analyses revealed that the alignment of the SHG-active-units SnO 3 trigonal pyramids and Br - anions in its structure mainly contribute to the macroscopical SHG behaviors.

Surprising luminescent properties of the polyphosphates Ln(PO3)3:Eu (Ln = Y, Gd, Lu).

PubMed

Höppe, Henning A; Kazmierczak, Karolina; Kacprzak, Sylwia; Schellenberg, Inga; Pöttgen, Rainer

2011-10-21

The optical emission properties of the lanthanoid catena-polyphosphates Ln(PO(3))(3) (Ln = Y, Gd, Lu) doped with europium were investigated. Incommensurately modulated β-Y(PO(3))(3):Eu (super space group Cc (0|0.364|0)0) and Gd(PO(3))(3):Eu (space group I2/a) show the usual emission characteristics of Eu(3+), while in Lu(PO(3))(3):Eu (space group Cc) the europium is unprecedentedly partially reduced to the divalent state, as proven by both a broad emission band at 406 nm excited at 279 nm and an EPR spectroscopic investigation. (151)Eu-Mössbauer spectroscopy showed that only a very small part of the europium is reduced in Lu(PO(3))(3):Eu. An explanation for this unusual behaviour is given. This journal is © The Royal Society of Chemistry 2011

Enhancement of white-light-emission from single-phase Sr5(PO4)3F:Eu(2+),Mn(2+) phosphors for near-UV white LEDs.

PubMed

Feng, Yaomiao; Huang, Jinping; Liu, Lili; Liu, Jie; Yu, Xibin

2015-09-07

A series of single-phase broadband white-light-emitting Sr5(PO4)3F:Eu(2+),Mn(2+) phosphors were prepared by a solid state reaction. The luminescence property, and the crystal and electronic structures of the fluorophosphates were studied by photoluminescence analysis, XRD Rietveld refinement and density functional theory calculation (DFT), respectively. Under near ultraviolet excitation in the 250 to 430 nm wavelength range, the phosphors exhibit two emission bands centered at 440 and 556 nm, caused by the Eu(2+) and Mn(2+) ions. By altering the relative ratios of Eu(2+) and Mn(2+) in the compounds, the emission color could be modulated from blue to white. The efficient energy transfer from the Eu(2+) to Mn(2+) ions could be ascribed to the well crystallized host lattice and the facile substitution of Eu(2+) and Mn(2+) for Sr(2+) sites due to similar ionic radii. A series of fluxes were investigated to improve the photoluminescence intensity. When KCl was used as flux in the synthesis, the photoluminescence intensity of Sr5(PO4)3F:Eu(2+),Mn(2+) was enhanced by 85% compared with no fluxes added. These results demonstrate that the single-phase Sr5(PO4)3F:Eu(2+),Mn(2+) with enhanced luminescence efficiency could be promising as a near UV-convertible direct white-light-emitting phosphor for WLED applications.

21 CFR 868.1200 - Indwelling blood oxygen partial pressure (PO2) analyzer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Indwelling blood oxygen partial pressure (PO2... Indwelling blood oxygen partial pressure (PO2) analyzer. (a) Identification. An indwelling blood oxygen... electrode) and that is used to measure, in vivo, the partial pressure of oxygen in blood to aid in...

21 CFR 868.1200 - Indwelling blood oxygen partial pressure (PO2) analyzer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Indwelling blood oxygen partial pressure (PO2... Indwelling blood oxygen partial pressure (PO2) analyzer. (a) Identification. An indwelling blood oxygen... electrode) and that is used to measure, in vivo, the partial pressure of oxygen in blood to aid in...

21 CFR 868.1200 - Indwelling blood oxygen partial pressure (PO2) analyzer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Indwelling blood oxygen partial pressure (PO2... Indwelling blood oxygen partial pressure (PO2) analyzer. (a) Identification. An indwelling blood oxygen... electrode) and that is used to measure, in vivo, the partial pressure of oxygen in blood to aid in...

21 CFR 868.1200 - Indwelling blood oxygen partial pressure (PO2) analyzer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Indwelling blood oxygen partial pressure (PO2... Indwelling blood oxygen partial pressure (PO2) analyzer. (a) Identification. An indwelling blood oxygen... electrode) and that is used to measure, in vivo, the partial pressure of oxygen in blood to aid in...

21 CFR 868.1200 - Indwelling blood oxygen partial pressure (PO2) analyzer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Indwelling blood oxygen partial pressure (PO2... Indwelling blood oxygen partial pressure (PO2) analyzer. (a) Identification. An indwelling blood oxygen... electrode) and that is used to measure, in vivo, the partial pressure of oxygen in blood to aid in...

Synthesis and electrochemical properties of olivine LiFePO 4 prepared by a carbothermal reduction method

NASA Astrophysics Data System (ADS)

Liu, Hui-ping; Wang, Zhi-xing; Li, Xin-hai; Guo, Hua-jun; Peng, Wen-jie; Zhang, Yun-he; Hu, Qi-yang

LiFePO 4/C composite cathode material was prepared by carbothermal reduction method, which uses NH 4H 2PO 4, Li 2CO 3 and cheap Fe 2O 3 as starting materials, acetylene black and glucose as carbon sources. The precursor of LiFePO 4/C was characterized by differential thermal analysis and thermogravimetry. X-ray diffraction (XRD), scanning electron microscopy (SEM) micrographs showed that the LiFePO 4/C is olivine-type phase, and the addition of the carbon reduced the LiFePO 4 grain size. The carbon is dispersed between the grains, ensuring a good electronic contact. The products sintered at 700 °C for 8 h with glucose as carbon source possessed excellent electrochemical performance. The synthesized LiFePO 4 composites showed a high electrochemical capacity of 159.3 mAh g -1 at 0.1 C rate, and the capacity fading is only 2.2% after 30 cycles.

Co3(PO4)2·4H2O

PubMed Central

Lee, Young Hoon; Clegg, Jack K.; Lindoy, Leonard F.; Lu, G. Q. Max; Park, Yu-Chul; Kim, Yang

2008-01-01

Single crystals of Co3(PO4)2·4H2O, tricobalt(II) bis­[ortho­phosphate(V)] tetra­hydrate, were obtained under hydro­thermal conditions. The title compound is isotypic with its zinc analogue Zn3(PO4)2·4H2O (mineral name hopeite) and contains two independent Co2+ cations. One Co2+ cation exhibits a slightly distorted tetra­hedral coordination, while the second, located on a mirror plane, has a distorted octa­hedral coordination environment. The tetra­hedrally coordinated Co2+ is bonded to four O atoms of four PO4 3− anions, whereas the six-coordinate Co2+ is cis-bonded to two phosphate groups and to four O atoms of four water mol­ecules (two of which are located on mirror planes), forming a framework structure. In addition, hydrogen bonds of the type O—H⋯O are present throughout the crystal structure. PMID:21200978

Preparation and characterization of SnO2 and Carbon Co-coated LiFePO4 cathode materials.

PubMed

Wang, Haibin; Liu, Shuxin; Huang, Yongmao

2014-04-01

The SnO2 and carbon co-coated LiFePO4 cathode materials were successfully synthesized by solid state method. The microstructure and morphology of LiFePO4 composites were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscope. The results showed that the SnO2 and carbon co-coated LiFePO4 cathode materials exhibited more uniform particle size distribution. Compared with the uncoated LiFePO4/C, the structure of LiFePO4 with SnO2 and carbon coating had no change. The existence of SnO2 and carbon coating layer effectively enhanced the initial discharge capacity. Among the investigated samples, the one with DBTDL:LiFePO4 molar ratios of 7:100 exhibited the best electrochemical performance.

New Nematotoxic Indoloditerpenoid Produced by Gymnoascus reessii za-130.

PubMed

Liu, Ting; Meyer, Susan L F; Chitwood, David J; Chauhan, Kamlesh R; Dong, Dan; Zhang, TaoTao; Li, Jun; Liu, Wei-Cheng

2017-04-19

Chemical investigation of the fungal strain Gymnoascus reessii za-130, which was previously isolated from the rhizosphere of tomato plants infected by the root-knot nematode Meloidogyne incognita, led to the isolation and identification of a new indoloditerpenoid metabolite designated gymnoascole acetate. Its structure was established by spectroscopic methods including 1D- and 2D-NMR and MS analyses. Gymnoascole acetate demonstrated strong adverse effects on M. incognita second-stage juvenile (J2) viability; exposure to 36 μg/mL for 24 h induced 100% paralysis of J2 (EC 50 = 47.5 μg/mL). Gymnoascole acetate suppressed M. incognita egg hatch relative to controls by >90% at 133 μg/mL after 7 days of exposure. The numbers of root galls and J2 in both soil and roots were significantly reduced (p = 0.05) by treatment with 2-200 μg/mL gymnoascole acetate/kg soil, compared to untreated control plants; nematode suppression increased with gymnoascole acetate concentration. This study demonstrated the nematotoxicity of gymnoascole acetate and indicates that it might be a potential biobased component in integrated management of M. incognita.

C-PCM based calculation of energy profiles for proton transfer in phosphorus-containing acid- N, N-dimethylformamide complexes

NASA Astrophysics Data System (ADS)

Fedorova, I. V.; Khatuntseva, E. A.; Krest'yaninov, M. A.; Safonova, L. P.

2016-02-01

Proton transfer along the hydrogen bond in complexes of DMF with H3PO4, H3PO3, CH3H2PO3, and their dimers has been investigated by the B3LYP/6-31++G** method in combination with the C-PCM model. When the Oacid···ODMF distance ( R) in the scanning procedure is not fixed, the energy profile in all cases has a single well. When this distance is fixed, there can be a proton transfer in all of the complexes in the gas phase at R > 2.6 Å; if solvation is taken into account, proton transfer can take place at R > 2.4 Å ( R > 2.5 Å for DMF complexes with CH3H2PO3 and its dimer). The height of the energy barrier to proton transfer increases with increasing R. Proton transfer is energetically most favorable in the DMF-phosphoric acid complexes. The structural and energetic characteristics of the hydrogen-bonded complexes calculated on the basis of the solvation model are compared with the same parameters for the complexes in the gas phase.

The role of ZA channel water-mediated interactions in the design of bromodomain-selective BET inhibitors.

PubMed

Bharatham, Nagakumar; Slavish, Peter J; Shadrick, William R; Young, Brandon M; Shelat, Anang A

2018-05-01

The Bromodomain and Extra-Terminal domain (BET) family of proteins are involved in the regulation of gene transcription, and their dysregulation is implicated in several diseases including cancer. BET proteins contain two tandem bromodomains (BD1 and BD2) that independently recognize acetylated-lysine residues and appear to have distinct biological roles. We compared several published co-crystal structures and found five positions near the substrate binding pocket that vary between BET bromodomains. One position located in the ZA loop has unique properties. In BRD2-4, this residue is glutamine in BD1 and lysine in BD2; in BRDT, this residue is arginine in BD1 and asparagine in BD2. Using molecular modeling, we identified differences in the water-mediated network at this position between bromodomains. Molecular dynamics simulations helped rationalize the observed bromodomain selectivity for exemplar BET inhibitors and a congeneric series of tetrahydroquinolines (THQ) that differed by a single heteroatom near the ZA channel. The 2-furan SJ830599, the most BD2-selective THQ analog, did not disrupt the water-mediated networks in either domain, but was electrostatically-repulsed by the specific arrangement of the W5 water dipole in BD1. Our work underscores the value of exploring water-mediated interactions to study ligand binding, and highlights the difficulty of optimizing polar interactions due to high desolvation penalties. Finally, we suggest further modifications to THQ-based BET inhibitors that would increase BD2-selectivity in BRD2-4, while minimizing affinity for one or both bromodomains of BRDT. Copyright © 2018 Elsevier Inc. All rights reserved.

Mechanistic insights of Li+ diffusion within doped LiFePO4 from Muon Spectroscopy.

PubMed

Johnson, Ian D; Ashton, Thomas E; Blagovidova, Ekaterina; Smales, Glen J; Lübke, Mechthild; Baker, Peter J; Corr, Serena A; Darr, Jawwad A

2018-03-07

The Li + ion diffusion characteristics of V- and Nb-doped LiFePO 4 were examined with respect to undoped LiFePO 4 using muon spectroscopy (µSR) as a local probe. As little difference in diffusion coefficient between the pure and doped samples was observed, offering D Li values in the range 1.8-2.3 × 10 -10  cm 2 s -1 , this implied the improvement in electrochemical performance observed within doped LiFePO 4 was not a result of increased local Li + diffusion. This unexpected observation was made possible with the µSR technique, which can measure Li + self-diffusion within LiFePO 4 , and therefore negated the effect of the LiFePO 4 two-phase delithiation mechanism, which has previously prevented accurate Li + diffusion comparison between the doped and undoped materials. Therefore, the authors suggest that µSR is an excellent technique for analysing materials on a local scale to elucidate the effects of dopants on solid-state diffusion behaviour.

Regulation of the activity of the promoter of RNA-induced silencing, C3PO.

PubMed

Sahu, Shriya; Williams, Leo; Perez, Alberto; Philip, Finly; Caso, Giuseppe; Zurawsky, Walter; Scarlata, Suzanne

2017-09-01

RNA-induced silencing is a process which allows cells to regulate the synthesis of specific proteins. RNA silencing is promoted by the protein C3PO (component 3 of RISC). We have previously found that phospholipase Cβ, which increases intracellular calcium levels in response to specific G protein signals, inhibits C3PO activity towards certain genes. Understanding the parameters that control C3PO activity and which genes are impacted by G protein activation would help predict which genes are more vulnerable to downregulation. Here, using a library of 10 18 oligonucleotides, we show that C3PO binds oligonucleotides with structural specificity but little sequence specificity. Alternately, C3PO hydrolyzes oligonucleotides with a rate that is sensitive to substrate stability. Importantly, we find that oligonucleotides with higher Tm values are inhibited by bound PLCβ. This finding is supported by microarray analysis in cells over-expressing PLCβ1. Taken together, this study allows predictions of the genes whose post-transcriptional regulation is responsive to the G protein/phospholipase Cβ/calcium signaling pathway. © 2017 The Protein Society.

Application of an in vitro digestion model for 210Po bioaccessibility assessment in seafood.

PubMed

Roselli, Carla; Desideri, Donatella; Feduzi, Laura; Ugolini, Lucia; Meli, Maria Assunta

2017-12-01

This study aims to investigate the bioaccessibility of 210 Po in seafood and the impact of food preparation on this radionuclide. Polonium bioaccessibility is the fraction of 210 Po mobilised from food matrices into digestive extractants when applying an in vitro digestion model. The degree of bioaccessibility of 210 Po in food has important implications for estimating ingestion doses from this radionuclide. The simulation of gastrointestinal digestion was divided into three stages through the use of synthetic saliva, gastric and bile-pancreas solutions. Following pre-treatment with a saliva solution, raw and cooked seafood samples underwent one of the following treatments: (a) simulated gastric digestion only or (b) simulated complete gastrointestinal digestion (gastric digestion followed by bile-pancreas digestion). No significant difference (P > 0.05) in 210 Po mobility was found between samples that underwent gastric digestion compared to those that only underwent gastro-intestinal digestion. However, a significant difference (P < 0.05) in 210 Po bioaccessibility was found between raw and cooked seafood undergoing both gastric and gastro-intestinal digestion.

3.0 V High Energy Density Symmetric Sodium-Ion Battery: Na4V2(PO4)3∥Na3V2(PO4)3.

PubMed

Yao, Xuhui; Zhu, Zixuan; Li, Qi; Wang, Xuanpeng; Xu, Xiaoming; Meng, Jiashen; Ren, Wenhao; Zhang, Xinhe; Huang, Yunhui; Mai, Liqiang

2018-03-28

Symmetric sodium-ion batteries (SIBs) are considered as promising candidates for large-scale energy storage owing to the simplified manufacture and wide abundance of sodium resources. However, most symmetric SIBs suffer from suppressed energy density. Here, a superior congeneric Na 4 V 2 (PO 4 ) 3 anode is synthesized via electrochemical preintercalation, and a high energy density symmetric SIB (Na 3 V 2 (PO 4 ) 3 as a cathode and Na 4 V 2 (PO 4 ) 3 as an anode) based on the deepened redox couple of V 4+ /V 2+ is built for the first time. When measured in half cell, both electrodes show stabilized electrochemical performance (over 3000 cycles). The symmetric SIBs exhibit an output voltage of 3.0 V and a cell-level energy density of 138 W h kg -1 . Furthermore, the sodium storage mechanism under the expanded measurement range of 0.01-3.9 V is disclosed through an in situ X-ray diffraction technique.

Synthesis and Performance of LiFe1-xMnxPO4 in Lithium-ion Battery

NASA Astrophysics Data System (ADS)

Bazzi, Khadije; Nazri, Maryam; Vaishnava, Prem; Naik, Vaman; Nazri, Gholam-Abbas; Naik, Ratna

2013-03-01

Olivine-type lithium transition metal phosphates (i.e. LiFePO4) have been intensively investigated as promising electrode materials for rechargeable lithium-ion batteries. There have been attempts to improve energy density and voltage quality of phosphate based electrode. In this study, we have partially substituted FeII/FeIII redox center with MnII/MnIII in LiFePO4 that provides over 600 mV higher voltage. We prepared various compositions of LiFe1-xMnxPO4 (x =0, 0.2, 0.4, 0.6, 0.8 and 1) between the two end members (LiFePO4 - LiMnPO4) . Due to intrinsic low electronic conductivity of lithium transition metal phosphates, we coat these materials with a uniform conductive carbon through a unique sol-gel process developed in our laboratory. In addition, we made a composite of the carbon coated phosphate with carbon nano-tubes to develop a highly conductive matrix electrode. We report the materials structure, morphology, electrical conductivity and electrochemical performances of LiFe1-xMnxPO4 using XRD, Raman spectroscopy, SEM, TEM, XPS, electrical conductivity and galvanostatic charge/discharge measurements.

LiFePO4 nanoparticles encapsulated in graphene nanoshells for high-performance lithium-ion battery cathodes.

PubMed

Fei, Huilong; Peng, Zhiwei; Yang, Yang; Li, Lei; Raji, Abdul-Rahman O; Samuel, Errol L G; Tour, James M

2014-07-11

LiFePO4 encapsulated in graphene nanoshells (LiFePO4@GNS) nanoparticles were synthesized by solid state reaction between graphene-coated Fe nanoparticles and LiH2PO4. The resulting nanocomposite was demonstrated to be a superior lithium-ion battery cathode with improved cycle and rate performances.

{sup 210}Po and {sup 210}Pb in Forest Soil and in Wild Berries in Finland

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

Vaaramaa, Kaisa; Lehto, Jukka; Solatie, Dina

2008-08-07

The behaviour of {sup 210}Po and {sup 210}Pb was investigated in forests in the Southern Finland site and in the Northern Finland site. Sampling sites were in Scots pine (Pinus sylvestris) forests. Maximum activities of {sup 210}Po and {sup 210}Pb in soil columns were found in organic layers. According to preliminary results of wild berry samples, the lowest {sup 210}Po concentrations were found in berries. The highest concentration of {sup 210}Po was found in stems of the blueberry (Vaccinium myrtillus) and the lingonberry (Vaccinium vitis-idaea) samples.

Temperature dependence of single-crystal elastic constants of flux-grown alpha-GaPO(4).

PubMed

Armand, P; Beaurain, M; Rufflé, B; Menaert, B; Papet, P

2009-06-01

The lattice parameter change with respect to temperature (T) has been measured using high-temperature powder X-ray diffraction techniques for high-temperature flux-grown GaPO(4) single crystals with the alpha-quartz structure. The lattice and the volume linear thermal expansion coefficients in the temperature range 303-1173 K were computed from the X-ray data. The percentage linear thermal expansions along the a and c axes at 1173 K are 1.5 and 0.51, respectively. The temperature dependence of the mass density rho of flux-grown GaPO(4) single crystals was evaluated using the volume thermal expansion coefficient alpha(V)(T) = 3.291 x 10(-5) - 2.786 x 10(-8) [T] + 4.598 x 10(-11)[T](2). Single-crystal high-resolution Brillouin spectroscopy measurements have been carried out at ambient pressure from 303 to 1123 K to determine the elastic constants C(IJ) of high-temperature flux-grown GaPO(4) material. The single-crystal elastic moduli were calculated using the sound velocities via the measured Brillouin frequency shifts Deltanu(B). These are, to our knowledge, the highest temperatures at which single-crystal elastic constants of alpha-GaPO(4) have been measured. Most of the room-temperature elastic constant values measured on flux-grown GaPO(4) material are higher than the ones found for hydrothermally grown GaPO(4) single crystals. The fourth-order temperature coefficients of both the Brillouin frequency shifts T(nuB)((n)) and the single-crystal elastic moduli T(C(IJ))((n)) were obtained. The first-order temperature coefficients of the C(IJ) are in excellent agreement with previous reports on low-temperature hydrothermally grown alpha-GaPO(4) single crystals, while small discrepancies in the higher-order temperature coefficients are observed. This is explained in terms of the OH content in the GaPO(4) network, which is an important parameter in the crystal thermal behavior.

Mechanical properties and in vitro bioactivity of Ca5(PO4)2SiO4 bioceramic.

PubMed

Lu, Wenhao; Duan, Wei; Guo, Yaping; Ning, Congqin

2012-02-01

Pure Ca(5)(PO(4))(2)SiO(4) bioceramic was first prepared by a sol-gel method using triethyl phosphate, tetraethoxysilane, and calcium nitrate tetrahydrate as original materials. Simulated body fluid (SBF) immersion tests revealed that Ca(5)(PO(4))(2)SiO(4) samples had a greater in vitro apatite-forming ability than hydroxyapatite (HA). After soaking Ca(5)(PO(4))(2)SiO(4) samples in the SBF for 1 day, bone-like apatite precipitated on the surfaces and the apatite layer became thicker with increasing the soaking time. However, few bone-like apatites precipitated on the HA samples even after soaking in the SBF for 7 days. The good in vitro bioactivity of Ca(5)(PO(4))(2)SiO(4) samples was attributed to the silanol (Si-OH) groups and greater solubility of Ca(5)(PO(4))(2)SiO(4). In addition, hot-pressed Ca(5)(PO(4))(2)SiO(4) ceramic exhibited lower bending strength and elastic modulus than hot-pressed HA, since the former had a lower relative density than the latter. The results have shown that Ca(5)(PO(4))(2)SiO(4) is a potential candidate material for bone repair. © The Author(s), 2010.

Linking the distribution of (210)Po and (210)Pb with plankton community along Line P, Northeast Subarctic Pacific.

PubMed

Choi, Hiu Yan; Stewart, Gillian M; Lomas, Michael W; Kelly, Roger P; Moran, S Bradley

2014-12-01

Depth profiles of (210)Po and (210)Pb activity and phytoplankton and zooplankton abundance were collected during two cruises along the Canadian time-series Line P in the Northeast Subarctic Pacific (ranging from 48o39 N to 50o00 N and 126o40 W to 145o00 W) in August 2010 and February 2011 to evaluate connections between the planktonic community and distributions of these radionuclides in the upper 500 m of the water column. Statistical analysis indicates that (210)Po is more effectively removed from the surface ocean when large (>0.1 mg ind(-1) dry wt) zooplankton dominate, and is less effectively scavenged when the picoplankton Synechococcus is present at high concentrations (>1 × 10(5) cells ml(-1)). While the zooplankton field data are consistent with previous lab studies and field observations, the phytoplankton results seem to conflict with recent evidence that small cells may contribute significantly to export in other oligotrophic regions. Differences in ecosystem mechanisms between the Subarctic Pacific and other oligotrophic systems that limit the contribution of small cells to sinking flux remain to be identified. Copyright © 2014 Elsevier Ltd. All rights reserved.

Photocatalytic activity of Ag3PO4 nanoparticle/TiO2 nanobelt heterostructures

NASA Astrophysics Data System (ADS)

Liu, Ruoyu; Hu, Peiguang; Chen, Shaowei

2012-10-01

Heterostructures based on Ag3PO4 nanoparticles and TiO2 nanobelts were prepared by a coprecipitation method. The crystalline structures were characterized by X-ray diffraction measurements. Electron microscopic studies showed that the Ag3PO4 nanoparticles and TiO2 nanobelts were in intimate contact which might be exploited to facilitate charge transfer between the two semiconductor materials. In fact, the heterostructures exhibited markedly enhanced photocatalytic activity as compared with unmodified TiO2 nanobelts or commercial TiO2 colloids in the photodegradation of methyl orange under UV irradiation. This was accounted for by the improved efficiency of interfacial charge separation thanks to the unique alignments of their band structures. Remarkably, whereas the photocatalytic activity of the heterostructure was comparable to that of Ag3PO4 nanoparticles alone, the heterostructures exhibited significantly better stability and reusability in repeated tests than the Ag3PO4 nanoparticles.

Facile method for modulating the profiles and periods of self-ordered three-dimensional alumina taper-nanopores.

PubMed

Li, Juan; Li, Congshan; Chen, Cheng; Hao, Qingli; Wang, Zhijia; Zhu, Jie; Gao, Xuefeng

2012-10-24

We report a facile nanofabrication method, one-step hard anodizing and etching peeling (OS-HA-EP) of aluminum foils followed by multistep mild anodizing and etching pore-widening (MS-MA-EW), for the controllable tailoring of hexagonally packed three-dimensional alumina taper-nanopores. Their profiles can be precisely tailored by the synergistic control of anodizing time, etching time and cyclic times at the MS-MA-EW stage, exemplified by linear cones, whorl-embedded cones, funnels, pencils, parabolas, and trumpets. Meantime, their periods can also be modulated in the range of 70-370 nm by choosing matched anodizing electrolytes (e.g., H(2)C(2)O(4), H(2)SO(4), H(2)C(2)O(4)-H(2)SO(4), and H(2)C(2)O(4)-C(2)H(5)OH mixture) and anodizing voltages at the OS-HA-EP stage. We also demonstrated that the long-range ordering of nanopits and the peak voltage of stable self-ordered HA, which are unachievable in a single H(2)C(2)O(4) electrolyte system, can be effectively tuned by simply adding tiny quantity of H(2)SO(4) and C(2)H(5)OH to keep an appropriate HA current density, respectively. This method of using the combination of simple pure chemical nanofabrication technologies is very facile and efficient in realizing the controllable tailoring of large-area alumina membranes containing self-ordered taper-nanopores. Our work opens a door for exploring the novel physical and chemical properties of different materials of nanotaper arrays.

A review of the Delta Po evolution (Italy) related to climatic changes and human impacts

NASA Astrophysics Data System (ADS)

Simeoni, Umberto; Corbau, Corinne

2009-06-01

Climate changes and sea-level rise are important issues, especially for deltas such as the Po Delta, Italy. The evolution of the Po Delta shows a succession in space and a superposition in time of complex environmental natural processes. During the last few centuries, anthropogenic action has played a major role. The formation of the Po Delta began about 2000 years ago and has undergone many phases of development. Between 1500 AD and 1600 AD, the Venetian technicians diverted the Po river course. With these interventions, the "Renaissance delta" was cut off from the hydraulic network and the "modern delta" began to form. Until the middle of the 20th century, progradation of the delta was noticeable due to the abundant sediment supply. In the following decades coastal erosion occurred, this was caused by the reduction of the solid supply of the Po, due to dam and barrier construction and to river bed excavation. These and other interventions (e.g. reclamation, methane extractions from superficial ground water table) have deeply modified the physical and ecological characteristics of the Po Delta. The morphological characteristics of the Po Delta make the largest Italian wetland particularly unstable and very fragile when subjected to human pressure. Furthermore, the delta evidences multiple threats that will probably be exacerbated in the following decades by the effects of expected climatic changes. Only the application of careful policies concerning coastal defence, flood mitigation, anthropogenic subsidence reduction and salt wedge intrusion control will allow reduction of the present or predicted negative effects. This paper reviews how natural and human factors have controlled the Po Delta through time and discusses management strategies taking into account the importance of the human factor and the potential effects of climatic changes.

Energy Systems Integration Facility Insight Center | Energy Systems

Science.gov Websites

simulation data. Photo of researchers studying data on a 3-D power system profile depicting the interaction of renewable energy resources on the grid. Capabilities The Insight Center offers the following Integration Facility Insight Center Located adjacent to the Energy System Integration Facility's High

Combustion Synthesis of Ca3(PO4)2 Net-Shape Surgical Implants

NASA Technical Reports Server (NTRS)

Ayers, Reed A.; Castillo, Martin; Gottoli, Guglielmo; Moore, John J.; Simske, Steven J.

2006-01-01

Self-propagating high-temperature combustion synthesis (SHS) is the basis of a method of making components of porous tricalcium phosphate [Ca3(PO4)2] and related compounds in net sizes and shapes for use as surgical implants that are compatible with bone. The SHS method offers advantages over prior methods of manufacturing Ca3(PO4)2-based surgical implants.

Validation of aerosol extinction and water vapor profiles from routine Atmospheric Radiation Measurement Program Climate Research Facility measurements

NASA Astrophysics Data System (ADS)

Schmid, Beat; Flynn, Connor J.; Newsom, Rob K.; Turner, David D.; Ferrare, Richard A.; Clayton, Marian F.; Andrews, Elisabeth; Ogren, John A.; Johnson, Roy R.; Russell, Philip B.; Gore, Warren J.; Dominguez, Roseanne

2009-11-01

The accuracy with which vertical profiles of aerosol extinction σep(λ) can be measured using routine Atmospheric Radiation Measurement Program (ARM) Climate Research Facility (ACRF) measurements and was assessed using data from two airborne field campaigns, the ARM Aerosol Intensive Operation Period (AIOP, May 2003), and the Aerosol Lidar Validation Experiment (ALIVE, September 2005). This assessment pertains to the aerosol at its ambient concentration and thermodynamic state (i.e., σep(λ) either free of or corrected for sampling artifacts) and includes the following ACRF routine methods: Raman lidar, micropulse lidar (MPL), and in situ aerosol profiles (IAP) with a small aircraft. Profiles of aerosol optical depth τp(λ), from which the profiles of σep(λ) are derived through vertical differentiation, were measured by the NASA Ames Airborne Tracking 14-channel Sun photometer (AATS-14); these data were used as benchmark in this evaluation. The ACRF IAP σep(550 nm) were lower by 11% (during AIOP) and higher by 1% (during ALIVE) when compared to AATS-14. The ACRF MPL σep(523 nm) measurements were higher by 24% (AIOP) and 19-21% (ALIVE) compared to AATS-14, but the correlation improved significantly during ALIVE. In the AIOP, a second MPL operated by NASA showed a smaller positive bias (13%) with respect to AATS-14. The ACRF Raman lidar σep(355 nm) measurements were larger by 54% (AIOP) and by 6% (ALIVE) compared to AATS-14. The large bias in the Raman lidar measurements during AIOP stemmed from a gradual loss of Raman lidar sensitivity starting about the end of 2001 going unnoticed until after AIOP. A major refurbishment and upgrade of the instrument and improvements to a data processing algorithm led to the significant improvement and very small bias in ALIVE. Finally, we find that during ALIVE the Raman lidar water vapor densities ρw are 8% larger when compared to AATS-14, whereas in situ measured ρw aboard two different aircraft are smaller than the

A cell wall-bound anionic peroxidase, PtrPO21, is involved in lignin polymerization in Populus trichocarpa

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

Lin, Chien-Yuan; Li, Quanzi; Tunlaya-Anukit, Sermsawat

2016-03-11

Class III peroxidases are members of a large plant-specific sequence-heterogeneous protein family. Several sequence-conserved homologs have been associated with lignin polymerization in Arabidopsis thaliana, Oryza sativa, Nicotiana tabacum, Zinnia elegans, Picea abies, and Pinus sylvestris. In Populus trichocarpa, a model species for studies of wood formation, the peroxidases involved in lignin biosynthesis have not yet been identified. To do this, we retrieved sequences of all PtrPOs from Peroxibase and conducted RNA-seq to identify candidates. Transcripts from 42 PtrPOs were detected in stem differentiating xylem (SDX) and four of them are the most xylem-abundant (PtrPO12, PtrPO21, PtrPO42, and PtrPO64). PtrPO21 showsmore » xylem-specific expression similar to that of genes encoding the monolignol biosynthetic enzymes. Using protein cleavage-isotope dilution mass spectrometry, PtrPO21 is detected only in the cell wall fraction and not in the soluble fraction. Downregulated transgenics of PtrPO21 have a lignin reduction of ~20% with subunit composition (S/G ratio) similar to wild type. The transgenics show a growth reduction and reddish color of stem wood. The modulus of elasticity (MOE) of the stems of the downregulated PtrPO21-line 8 can be reduced to ~60% of wild type. Differentially expressed gene (DEG) analysis of PtrPO21 downregulated transgenics identified a significant overexpression of PtPrx35, suggesting a compensatory effect within the peroxidase family. No significant changes in the expression of the 49 P. trichocarpa laccases (PtrLACs) were observed.« less

Morphology-controlled synthesis of Ag{sub 3}PO{sub 4} nano/microcrystals and their antibacterial properties

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

Wu, Aiping; Tian, Chungui, E-mail: tianchungui@yahoo.com.cn; Chang, Wei

Graphical abstract: The Ag{sub 3}PO{sub 4} with rhombic dodecahedral, spherical and small size particles were controllable fabricated just by changing the types of the solvent. The materials possess good antibacterial properties toward different kinds of bacteria. - Highlights: • The Ag{sub 3}PO{sub 4} with three morphologies were controllable fabricated. • The Ag{sub 3}PO{sub 4} as-prepared possess obvious antibacterial properties in the dark. • The antibacterial ability of Ag{sub 3}PO{sub 4} could be greatly improved under the visible light irradiation. - Abstract: We reported the controllable fabrication of Ag{sub 3}PO{sub 4} nano/microcrystals through a simple solution-based precipitation reaction. The samples weremore » characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and infrared spectroscopy. The results indicated that the Ag{sub 3}PO{sub 4} crystals with three different morphology, including the rhombic dodecahedron of 500 nm, the sphere of 100 nm and the particles with small-size of 20 nm, could be obtained in the solvents of water, ethylene glycol (EG) and dimethyl sulfoxide (DMSO). The antibacterial assay showed that all samples possess obvious antibacterial properties. In addition, the Ag{sub 3}PO{sub 4} with small size of 20 nm showed better activity due to their high specific surface areas. Notably, we have found that the antibacterial ability of Ag{sub 3}PO{sub 4} could be greatly improved under the visible light irradiation, which are superior to that in the dark and commercial streptomycin.« less

Crystalline maricite NaFePO4 as a positive electrode material for sodium secondary batteries operating at intermediate temperature

NASA Astrophysics Data System (ADS)

Hwang, Jinkwang; Matsumoto, Kazuhiko; Orikasa, Yuki; Katayama, Misaki; Inada, Yasuhiro; Nohira, Toshiyuki; Hagiwara, Rika

2018-02-01

Maricite NaFePO4 (m-NaFePO4) was investigated as a positive electrode material for intermediate-temperature operation of sodium secondary batteries using ionic liquid electrolytes. Powdered m-NaFePO4 was prepared by a conventional solid-state method at 873 K and subsequently fabricated in two different conditions; one is ball-milled in acetone and the other is re-calcined at 873 K after the ball-milling. Electrochemical properties of the electrodes prepared with the as-synthesized m-NaFePO4, the ball-milled m-NaFePO4, and the re-calcined m-NaFePO4 were investigated in Na[FSA]-[C2C1im][FSA] (C2C1im+ = 1-ethyl-3-methylimidazolium, FSA- = bis(fluorosulfonyl)amide) ionic liquid electrolytes at 298 K and 363 K to assess the effects of temperature and particle size on their electrochemical properties. A reversible charge-discharge capacity of 107 mAh g-1 was achieved with a coulombic efficiency >98% from the 2nd cycle using the ball-milled m-NaFePO4 electrode at a C-rate of 0.1 C and 363 K. Electrochemical impedance spectroscopy using m-NaFePO4/m-NaFePO4 symmetric cells indicated that inactive m-NaFePO4 becomes an active material through ball-milling treatment and elevation of operating temperature. X-ray diffraction analysis of crystalline m-NaFePO4 confirmed the lattice contraction and expansion upon charging and discharging, respectively. These results indicate that the desodiation-sodiation process in m-NaFePO4 is reversible in the intermediate-temperature range.

Identifying compatibility of lithium salts with LiFePO4 cathode using a symmetric cell

NASA Astrophysics Data System (ADS)

Tong, Bo; Wang, Jiawei; Liu, Zhenjie; Ma, Lipo; Zhou, Zhibin; Peng, Zhangquan

2018-04-01

The electrochemical performance of lithium-ion batteries is dominated by the interphase electrochemistry between the electrolyte and electrode materials. A multitude of efforts have been dedicated to the solid electrolyte interphase (SEI) formed on the anode. However, the interphase on the cathode, namely the cathode electrolyte interphase (CEI), is left aside, partially due to the fact that it is hard to single out the CEI considering the complicated anode-cathode inter-talk. Herein, a partially delithiated lithium iron phosphate (Li0.25FePO4) electrode is used as the anode. Owing to a high voltage plateau (≈3.45 V vs. Li/Li+), negligible reduction reactions of electrolyte occur on the L0.25FePO4 anode. Therefore, the CEI can be investigated exclusively. Using a LiFePO4|Li0.25FePO4 symmetric cell configuration, we scrutinize the compatibility of the electrolytes containing a wide spectrum of lithium salts, Li[(FSO2)(Cm F2m+1SO2)N] (m = 0, 1, 2, 4), with the LiFePO4, in both cycling and calendar tests. It is found that the Li[(FSO2)(n-C4F9SO2)N] (LiFNFSI)-based electrolyte exhibits the highest compatibility with LiFePO4.

PO-58 - Cardiovascular risk profile in survivors of adult cancer - results from the general population study.

PubMed

Panova-Noeva, M; Hermanns, I M; Schulz, A; Laubert-Reh, D; Zeller, T; Blankenberg, S; Spronk, H M; Münzel, T; Lackner, K J; Ten Cate, H; Wild, P S

2016-04-01

The advancements in cancer treatment and detection of early cancer have resulted in steady increase of adult cancer survivors over the years. However, due to the long term toxic effects of chemotherapy and radiotherapy, the incidence of cardiovascular diseases (CVD) is increasing in survivors. Identifying risk factors and interventions to reduce the excess burden of CVD in this vulnerable population is urgently needed. To investigate the cardiovascular risk factors (CVRFs), inflammation and coagulation profile in cancer survivors from a large population-based study. Presence of CVRFs and laboratory markers have been compared in individuals with (n=1,359) and without (n=13,626) history of cancer. Standard laboratory profile, including blood glucose and lipid profile, has been evaluated in 15,010 individuals from the Gutenberg Health Study (GHS). Coagulation factors, D-dimer and von Willebrand factor (vWF) activity were available in N=4,993. The individuals with history of cancer were older compared to no history of cancer with mean age of 61,5years and 54.4years, respectively (p<0.001). Traditional CVRFs as diabetes (14% vs 8.8%), dyslipidemia (49.6% vs 43.7%) and hypertension (60.3 vs 48.7%) were more frequent whereas smoking was less frequent (14.5% vs 19.9%) in cancer survivors (p<0.001). The standard laboratory profile showed cancer survivors with lower erythrocyte, platelet and white blood cell counts and higher C-reactive protein (CRP), glucose, HbA1c and triglycerides levels (p<0.001). Multivariable logistic regression analysis adjusted for age, sex and CVRFs demonstrated an independent association with diabetes (odds ratio, OR: 1.24, 1.02-1.50; p=0.027) and higher CRP (OR: 1.01, 1.01-1.02; p=0.00071). Fibrinogen, FV, FVII, FVIII and FXI, D-dimer and vWF activity were higher in cancer survivors (p<0.001). Multivariable logistic regression confirmed an independent association with higher fibrinogen (OR: 1.002, 1.000-1.003) and vWF activity (OR: 1.005, 1

Linear-to-λ-Shape P-O-P Bond Transmutation in Polyphosphates with Infinite (PO3)∞ Chain.

PubMed

Wang, Ying; Li, Lin; Han, Shujuan; Lei, Bing-Hua; Abudoureheman, Maierhaba; Yang, Zhihua; Pan, Shilie

2017-09-05

A new metal polyphosphate, α-CsBa 2 (PO 3 ) 5 , exhibiting the first example of a linear P-O-P bond angle in a one-dimensional (PO 3 ) ∞ chain has been reported. Interestingly, α → β phase transition occurs in CsBa 2 (PO 3 ) 5 along with the P-O-P bonds varying from linear to λ-shape, suggesting that α-CsBa 2 (PO 3 ) 5 with unfavorable linear P-O-P bonds is more stable at ambient temperature.

Additional of polyethylene glycol on the preparation of LaPO4:Eu3+ phosphor

NASA Astrophysics Data System (ADS)

Panatarani, Camellia; Joni, I. Made

2013-09-01

Solution phase method was used to synthesis nanocrystal LaPO4:Eu3+. Polyethylene glycol with vary molecular weight (MW) was added to allow an exothermic reaction to get a high crystalinity of LaPO4:Eu3+. The x-ray pattern of as prepared LaPO4 was obtained by using an X'pert PANalytical diffractometer with CuKα radiation (λ = 1.5406 Å) and the photoluminescent measurement spectra is obtained by using Fluorescence Spectrometer LS55, Perkin Elmer. The additional of various MW of polyethylene glycol into the precursor solution of LaPO4:Eu3+ affected the crystal structure and luminescent properties. Higher MW of PEG depressing the luminescent spectra. The emission origin from 5D0-7F4 transition vanished by additional 500,000 and 2,000,000 MW of PEG.

Unusually high (210)Po activities in the surface water of the Zhubi Coral Reef Lagoon in the South China Sea.

PubMed

Yang, Weifeng; Huang, Yipu; Chen, Min; Qiu, Yusheng; Li, Hongbin; Zhang, Lei

2011-10-01

Recent researches revealed the exciting application of (210)Po in tracing carbon and nitrogen cycling in the coral reef system. In order to quantify the recycling of particulate organic nitrogen (PON), both (210)Po and (210)Pb were examined at both high and low tides in the Zhubi Coral Reef lagoon, the South China Sea. Unusually, much higher (210)Po activities and (210)Po/(210)Pb ratios, in comparison with those found in the open seawater and the lagoon subsurface water, showed additional input of (210)Po besides production from in situ(210)Pb in the lagoon surface water. Statistical analysis identified that the reef flat seawater was the additional (210)Po source. Based on a mass balance model, the input rates of (210)Po varied from 0.04 Bq m(-3)year(-1) to 8.41 Bq m(-3)year(-1). On average, the additional (210)Po contributed more than 60% of the total (210)Po. The particulate (210)Po significantly correlated with the concentrations of PON, indicating that diffusion of (210)Po from sediment could be used to quantify the recycling of nitrogen. The average input rate of nitrogen was 16 mmol m(-3)year(-1), which can support up to 11% of the primary production rate. These results suggested that the unusual behavior of (210)Po could provide new insight into the nitrogen recycling in the coral reef system. Copyright © 2011 Elsevier B.V. All rights reserved.

An exploration of the socio-economic profile of women and costs of receiving abortion services at public health facilities of Madhya Pradesh, India.

PubMed

Banerjee, Sushanta K; Kumar, Rakesh; Warvadekar, Janardan; Manning, Vinoj; Andersen, Kathryn Louise

2017-03-21

Maternal mortality, which primarily burdens developing countries, reflects the greatest health divide between rich and poor. This is especially pronounced for access to safe abortion services which alone avert 1 of every 10 maternal deaths in India. Primarily due to confidentiality concerns, poor women in India prefer private services which are often offered by untrained providers and may be expensive. In 2006 the state government of Madhya Pradesh (population 73 million) began a concerted effort to ensure access to safe abortion services at public health facilities to both rural and urban poor women. This study aims to understand the socio-economic profile of women seeking abortion services in public health facilities across this state and out of pocket cost accessing abortion services. In particular, we examine the level of access that poor women have to safe abortion services in Madhya Pradesh. This study consisted of a cross-sectional client follow-up design. A total of 19 facilities were selected using two-stage random sampling and 1036 women presenting to chosen facilities with abortion and post-abortion complications were interviewed between May and December 2014. A structured data collection tool was developed. A composite wealth index computed using principal component analysis derived weights from consumer durables and asset holding and classified women into three categories, poor, moderate, and rich. Findings highlight that overall 57% of women who received abortion care at public health facilities were poor, followed by 21% moderate and 22% rich. More poor women sought care at primary level facilities (58%) than secondary level facilities and among women presenting for postabortion complications (67%) than induced abortion. Women reported spending no money to access abortion services as abortion services are free of cost at public facilities. However, poor women spend INR 64 (1 USD) while visiting primary level facilities and INR 256 (USD 4) while

Na7Cr4(P2O7)4PO4

PubMed Central

Bourguiba Fakhar, Noura; Zid, Mohamed Faouzi; Driss, Ahmed

2013-01-01

The title compound, hepta­sodium tetra­chromium(III) tetra­kis­(diphosphate) orthophosphate, was synthesized by solid-state reaction. Its structure is isotypic with that of Na7 M 4(P2O7)4PO4 (M = In, Al) compounds and is made up from a three-dimensional [(CrP2O7)4PO4]7− framework with channels running along [001]. The three Na+ cations are located in the voids of the framework. One of the cations is situated on a general position, one is equally disordered around a twofold rotation axis and one is on a fourfold rotoinversion axis. The isolated PO4 tetra­hedron of the anionic framework is also situated on the -4 axis. Structural relationships between the title compound and different diphosphates containing MP2O11 units (M = Mo, V) are discussed. PMID:23723751

Ultra-high power capabilities in amorphous FePO4 thin films

NASA Astrophysics Data System (ADS)

Gandrud, Knut B.; Nilsen, Ola; Fjellvåg, Helmer

2016-02-01

Record breaking electrochemical properties of FePO4 have been found through investigation of the thickness dependent electrochemical properties of amorphous thin film electrodes. Atomic layer deposition was used for production of thin films of amorphous FePO4 with highly accurate thickness and topography. Electrochemical characterization of these thin film electrodes revealed that the thinner electrodes behave in a pseudocapacitive manner even at high rates of Li+ de/intercalation, which enabled specific powers above 1 MW kg-1 FePO4 to be obtained with minimal capacity loss. In addition, a self-enhancing kinetic effect was observed during cycling enabling more than 10,000 cycles at current rates approaching that of a supercapacitor (11s charge/discharge). The current findings may open for construction of ultra-high power battery electrodes that combines the energy density of batteries with the power capabilities of supercapacitors.

Study on SOC wavelet analysis for LiFePO4 battery

NASA Astrophysics Data System (ADS)

Liu, Xuepeng; Zhao, Dongmei

2017-08-01

Improving the prediction accuracy of SOC can reduce the complexity of the conservative and control strategy of the strategy such as the scheduling, optimization and planning of LiFePO4 battery system. Based on the analysis of the relationship between the SOC historical data and the external stress factors, the SOC Estimation-Correction Prediction Model based on wavelet analysis is established. Using wavelet neural network prediction model is of high precision to achieve forecast link, external stress measured data is used to update parameters estimation in the model, implement correction link, makes the forecast model can adapt to the LiFePO4 battery under rated condition of charge and discharge the operating point of the variable operation area. The test results show that the method can obtain higher precision prediction model when the input and output of LiFePO4 battery are changed frequently.

A history of calcium orthophosphates (CaPO4) and their biomedical applications.

PubMed

Dorozhkin, S V

2017-09-01

The historical development of a scientific knowledge on calcium orthophosphates (CaPO 4 ) from 1770-s till 1950 is described. Many forgotten and poorly known historical facts and approaches have been extracted from old publications and then they have been analyzed, systematized and reconsidered from the modern point of view. The chosen time scale starts with the earliest available studies of 1770-s (to the best of my findings, CaPO 4 had been unknown before), passes through the entire 19th century and finishes in 1950, because since then the amount of publications on CaPO 4 rapidly increases and the subject becomes too broad. Furthermore, since publications of the second half of the 20th century are easily accessible, the substantial amount of them has been already reviewed by other researchers. The reported historical findings clearly demonstrate that the substantial amount of the scientific facts and experimental approaches has been known for very many decades and, in fact, the considerable quantity of relatively recent investigations on CaPO 4 is just either a further development of the earlier studies or a rediscovery of the already forgotten knowledge. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Po2 cycling protects diaphragm function during reoxygenation via ROS, Akt, ERK, and mitochondrial channels.

PubMed

Zuo, Li; Pannell, Benjamin K; Re, Anthony T; Best, Thomas M; Wagner, Peter D

2015-12-01

Po2 cycling, often referred to as intermittent hypoxia, involves exposing tissues to brief cycles of low oxygen environments immediately followed by hyperoxic conditions. After experiencing long-term hypoxia, muscle can be damaged during the subsequent reintroduction of oxygen, which leads to muscle dysfunction via reperfusion injury. The protective effect and mechanism behind Po2 cycling in skeletal muscle during reoxygenation have yet to be fully elucidated. We hypothesize that Po2 cycling effectively increases muscle fatigue resistance through reactive oxygen species (ROS), protein kinase B (Akt), extracellular signal-regulated kinase (ERK), and certain mitochondrial channels during reoxygenation. Using a dihydrofluorescein fluorescent probe, we detected the production of ROS in mouse diaphragmatic skeletal muscle in real time under confocal microscopy. Muscles treated with Po2 cycling displayed significantly attenuated ROS levels (n = 5; P < 0.001) as well as enhanced force generation compared with controls during reperfusion (n = 7; P < 0.05). We also used inhibitors for signaling molecules or membrane channels such as ROS, Akt, ERK, as well as chemical stimulators to close mitochondrial ATP-sensitive potassium channel (KATP) or open mitochondrial permeability transition pore (mPTP). All these blockers or stimulators abolished improved muscle function with Po2 cycling treatment. This current investigation has discovered a correlation between KATP and mPTP and the Po2 cycling pathway in diaphragmatic skeletal muscle. Thus we have identified a unique signaling pathway that may involve ROS, Akt, ERK, and mitochondrial channels responsible for Po2 cycling protection during reoxygenation conditions in the diaphragm. Copyright © 2015 the American Physiological Society.

Self-assembly of red-blood-cell-like (NH4)[Fe2(OH)(PO4)2]·2H2O architectures from 2D nanoplates by sonochemical method.

PubMed

Wu, Kaipeng; Liu, Diwei; Tang, Yun

2018-01-01

Red-blood-cell-like (RBC-like) (NH 4 )[Fe 2 (OH)(PO 4 ) 2 ]·2H 2 O architectures assembled from 2D nanoplates are successfully synthesized via a facile sonochemical method. XRD measurement indicates that the as-prepared sample is well crystallized with a monoclinic structure. The morphology of the sample is characterized by SEM analysis, which shows that the (NH 4 )[Fe 2 (OH)(PO 4 ) 2 ]·2H 2 O particles exhibit a unique biconcave red blood cell morphology with an average diameter of 4um and thickness of 1.5um. The detailed time-dependent experiments are conducted to investigate the morphological evolution process. It reveals that the ultrasonic time is crucial to the morphology of the products, and the RBC-like (NH 4 )[Fe 2 (OH)(PO 4 ) 2 ]·2H 2 O proceeds in steps of crystallization, formation of thin plates, and the subsequent self-assembly. Compared to the available methods that are typically time-consuming and complicated, this smart sonochemical strategy proposed herein is efficient and simple. Moreover, these obtained special RBC-like architectures will be more fascinating for application in many areas. Copyright © 2017 Elsevier B.V. All rights reserved.

Tunable morphology synthesis of LiFePO4 nanoparticles as cathode materials for lithium ion batteries.

PubMed

Ma, Zhipeng; Shao, Guangjie; Fan, Yuqian; Wang, Guiling; Song, Jianjun; Liu, Tingting

2014-06-25

Olivine LiFePO4 with nanoplate, rectangular prism nanorod and hexagonal prism nanorod morphologies with a short b-axis were successfully synthesized by a solvothermal in glycerol and water system. The influences of solvent composition on the morphological transformation and electrochemical performances of olivine LiFePO4 are systematically investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and galvanostatic charge-discharge tests. It is found that with increasing water content in solvent, the LiFePO4 nanoplates gradually transform into hexagonal prism nanorods that are similar to the thermodynamic equilibrium shape of the LiFePO4 crystal. This indicates that water plays an important role in the morphology transformation of the olivine LiFePO4. The electrochemical performances vary significantly with the particle morphology. The LiFePO4 rectangular prism nanorods (formed in a glycerol-to-water ratio of 1:1) exhibit superior electrochemical properties compared with the other morphological particles because of their moderate size and shorter Li(+) ion diffusion length along the [010] direction. The initial discharge capacity of the LiFePO4@C with a rectangular prism nanorod morphology reaches to 163.8 mAh g(-1) at 0.2 C and over 75 mAh g(-1) at the high discharging rate of 20 C, maintaining good stability at each discharging rate.

[100]-Oriented LiFePO4 Nanoflakes toward High Rate Li-Ion Battery Cathode.

PubMed

Li, Zhaojin; Peng, Zhenzhen; Zhang, Hui; Hu, Tao; Hu, Minmin; Zhu, Kongjun; Wang, Xiaohui

2016-01-13

[100] is believed to be a tough diffusion direction for Li(+) in LiFePO4, leading to the belief that the rate performance of [100]-oriented LiFePO4 is poor. Here we report the fabrication of 12 nm-thick [100]-oriented LiFePO4 nanoflakes by a simple one-pot solvothermal method. The nanoflakes exhibit unexpectedly excellent electrochemical performance, in stark contrast to what was previously believed. Such an exceptional result is attributed to a decreased thermodynamic transformation barrier height (Δμb) associated with increased active population.

Paleomagnetic constrains in the reconstruction of the recent stratigraphic evolution of the Po delta

NASA Astrophysics Data System (ADS)

Correggiari, Annamaria; Vigliotti, Luigi; Remia, Alessandro; Perini, Luisa; Calabrese, Lorenzo; Luciani, Paolo

2014-05-01

The delta and prodelta deposits are characterized by a complex stratigraphic architecture that can be approached with several multidisciplinary tools. We present an example from the Po delta system characterized by alternating phases of rapid advance and abandonment of its multiple deltaic lobes that has been investigated through: (1) a review of historical cartography extending back several centuries; (2) integrated surveys of VHR seismic profiles recorded offshore of the modern delta from water depths as shallow as 5 m to the toe of the prodelta in about 30 m; and (3) sedimentological and geochronological data from precisely positioned sediment cores. Within this well known stratigraphic framework we have acquired seismic data and sediment cores in the area of the post roman Po delta system. However a precise dating of the recent evolution of depositional delta lobes is difficult because of the lack of suitable dating methods. To constrain the emplacement timing of the Renaissance lobes a paleomagnetic studies was carried out on a sedimentary sequence representing a seismic facies well correlated in the cores by whole core magnetic susceptibility profile. Forty eight samples were collected from a core section (RER96-1) characterized by a fine grained lithology suitable for paleomagnetic investigations. The characteristic remanent magnetization (ChRM) of the sediments has been obtained by applying an AF cleaning between 10 and 30 millitesla. The results have been compared with the directions recorded by the historical lavas of the Etna and Vesuvius. The combination of the trends observed in the declination and inclination suggests that the results can be compatible with the directions of the secular variation of the earth magnetic field occurring during the XVII century. This allow to date the sismic unit as representative of the beginning of the new delta following the Porto Viro avulsion made by the Venice Republic in 1604 AD. This delta history reflects the

Effect of saturated fatty acid-rich dietary vegetable oils on lipid profile, antioxidant enzymes and glucose tolerance in diabetic rats

PubMed Central

Kochikuzhyil, Benson Mathai; Devi, Kshama; Fattepur, Santosh Raghunandan

2010-01-01

Objective: To study the effect of saturated fatty acid (SFA)-rich dietary vegetable oils on the lipid profile, endogenous antioxidant enzymes and glucose tolerance in type 2 diabetic rats. Materials and Methods: Type 2 diabetes was induced by administering streptozotocin (90 mg/kg, i.p.) in neonatal rats. Twenty-eight-day-old normal (N) and diabetic (D) male Wistar rats were fed for 45 days with a fat-enriched special diet (10%) prepared with coconut oil (CO) – lauric acid-rich SFA, palm oil (PO) – palmitic acid-rich SFA and groundnut oil (GNO) – control (N and D). Lipid profile, endogenous antioxidant enzymes and oral glucose tolerance tests were monitored. Results: D rats fed with CO (D + CO) exhibited a significant decrease in the total cholesterol and non-high-density lipoprotein cholesterol. Besides, they also showed a trend toward improving antioxidant enzymes and glucose tolerance as compared to the D + GNO group, whereas D + PO treatment aggravated the dyslipidemic condition while causing a significant decrease in the superoxide dismutase levels when compared to N rats fed with GNO (N + GNO). D + PO treatment also impaired the glucose tolerance when compared to N + GNO and D + GNO. Conclusion: The type of FA in the dietary oil determines its deleterious or beneficial effects. Lauric acid present in CO may protect against diabetes-induced dyslipidemia. PMID:20871763

Diurnal variations of (218)Po, (214)Pb, and (214)Po and their effect on atmospheric electrical conductivity in the lower atmosphere at Mysore city, Karnataka State, India.

PubMed

Pruthvi Rani, K S; Paramesh, L; Chandrashekara, M S

2014-12-01

The short-lived radon daughters ((218)Po, (214)Pb, (214)Bi and (214)Po) are natural tracers in the troposphere, in particular near the ground surface. They are electrically charged particles and are chemically reactive. As soon as they are formed they get attached to the aerosol particles of the atmosphere. The behavior of radon daughters is similar to that of aerosols with respect to their growth, transport and removal processes in the atmosphere. The electrical conductivity of the atmosphere is mainly due to the presence of highly mobile ions. Galactic cosmic rays are the main source of ionization in the planetary boundary layer; however, near the surface of the earth, ions are produced mainly by decays of natural radioactive gases emanating from the soil surface and by radiations emitted directly from the surface. Hence the electrical conductivity of air near the surface of the earth is mainly due to radiations emitted by (222)Rn, (218)Po, (214)Pb, (214)Bi and (214)Po, and depends on aerosol concentrations and meteorological parameters. In the present work the diurnal and seasonal variations of radon and its progeny concentrations are studied using Low Level Radon Detection System and Airflow Meter respectively. Atmospheric electrical conductivity of both positive and negative polarities is measured using a Gerdien Condenser. All the measurements were carried out simultaneously at one location in Mysore city (12°N, 76°E), India. The diurnal variation of atmospheric electrical conductivity was found to be similar to that of ion pair production rate estimated from radon and its progeny concentrations with a maximum in the early morning hours and minimum during day time. The annual average concentrations of (222)Rn, (218)Po, (214)Pb, and (214)Po at the study location were found to be 21.46, 10.88, 1.78 and 1.80 Bq m(-3) respectively. The annual average values of positive and negative atmospheric electrical conductivity were found to be 18.1 and 16.6 f S m(-1

Used Fuel Cask Identification through Neutron Profile

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

Rauch, Eric Benton

2015-11-20

Currently, most spent fuel is stored near reactors. An interim consolidated fuel storage facility would receive fuel from multiple sites and store it in casks on site for decades. For successful operation of such a facility there is need for a way to restore continuity of knowledge if lost as well as a method that will indicate state of fuel inside the cask. Used nuclear fuel is identifiable by its radiation emission, both gamma and neutron. Neutron emission from fission products, multiplication from remaining fissile material, and the unique distribution of both in each cask produce a unique neutron signature.more » If two signatures taken at different times do not match, either changes within the fuel content or misidentification of a cask occurred. It was found that identification of cask loadings works well through the profile of emitted neutrons in simulated real casks. Even casks with similar overall neutron emission or average counts around the circumference can be distinguished from each other by analyzing the profile. In conclusion, (1) identification of unaltered casks through neutron signature profile is viable; (2) collecting the profile provides insight to the condition and intactness of the fuel stored inside the cask; and (3) the signature profile is stable over time.« less

Improving the electrochemical performances of Li-rich Li1.20Ni0.13Co0.13Mn0.54O2 through a cooperative doping of Na+ and PO43- with Na3PO4

NASA Astrophysics Data System (ADS)

Liu, Yi; Ning, De; Zheng, Lirong; Zhang, Qinghua; Gu, Lin; Gao, Rui; Zhang, Jicheng; Franz, Alexandra; Schumacher, Gerhard; Liu, Xiangfeng

2018-01-01

Li-rich layered oxide cathodes suffer from poor rate capability, voltage decay and inferior cycling stability. Herein, we propose a novel synergistic strategy to improve the electrochemical performances of Li-rich Li1.20Ni0.13Co0.13Mn0.54O2 by the co-doping of Na+ and PO43-. The co-doping of Na+ for Li and PO43- for Mn is simultaneously achieved using Na3PO4 as a dopant. The co-doping of Na+ and PO43- not only enhances the high-rate performance (106.4 mAhg-1@10C) and capacity retention (93.8%@1C@100 cycles) but also mitigates the voltage decay owing to the synergistic effect of Na+ and PO43- co-doping. The synergistic mechanism is unraveled based on neutron diffraction, aberration-corrected scanning transmission electron microscope, X-ray photoelectron spectroscopy, ex-situ X-ray absorption spectra, ex-situ X-ray diffraction, electrochemical impedance spectroscopy and electrochemical measurements. The co-doping of Na+ and PO43- enlarges the interlayer spacing and suppresses Li/Ni mixing which increases Li+ diffusivity and enhances the rate capability. Meanwhile, the co-doping of Na+ and PO43- shrinks the thickness of the slabs, weakens the TM-O covalency and alleviates the volume change in the charge/discharge process which improves the layered structure stability and the cycling performances. This study presents some new insights into designing high performance cathode materials through a cooperative modulation of different crystal sites doping.

CdZnTe Background Measurements at Balloon Altitudes with PoRTIA

NASA Technical Reports Server (NTRS)

Parsons, A.; Barthelmy, S.; Bartlett, L.; Gehrels, N.; Naya, J.; Stahle, C. M.; Tueller, J.; Teegarden, B.

2003-01-01

Measurements of the CdZnTe internal background at balloon altitudes are essential to determine which physical processes make the most important background contributions. We present results from CdZnTe background measurements made by PoRTIA, a small CdZnTe balloon instrument that was flown three times in three different shielding configurations. PoRTIA was passively shielded during its first flight from Palestine, Texas and actively shielded as a piggyback instrument on the GRIS balloon experiment during its second and third flights from Alice Springs, Australia, using the thick GRIS Nal anticoincidence shield. A significant CdZnTe background reduction was achieved during the third flight with PoRTIA placed completely inside the GRIS shield and blocking crystal, and thus completely surrounded by 15 cm of Nal. A unique balloon altitude background data set is provided by CdZnTe and Ge detectors simultaneously surrounded by the same thick anticoincidence shield; the presence of a single coxial Ge detector inside the shield next to PoRTIA allowed a measurement of the ambient neutron flux inside the shield throughout the flight. These neutrons interact with the detector material to produce isomeric states of the Cd, Zn and Te nuclei that radiatively decay; calculations are presented that indicate that these decays may explain most of the fully shielded CdZnTe background.

In pursuit of the rhabdophane crystal structure: from the hydrated monoclinic LnPO4.0.667H2O to the hexagonal LnPO4 (Ln = Nd, Sm, Gd, Eu and Dy)

NASA Astrophysics Data System (ADS)

Mesbah, Adel; Clavier, Nicolas; Elkaim, Erik; Szenknect, Stéphanie; Dacheux, Nicolas

2017-05-01

The dehydration process of the hydrated rhabdophane LnPO4.0.667H2O (Ln = La to Dy) was thoroughly studied over the combination of in situ high resolution synchrotron powder diffraction and TGA experiments. In the case of SmPO4.0.667H2O (monoclinic, C2), a first dehydration step was identified around 80 °C leading to the formation of SmPO4.0.5H2O (Monoclinic, C2) with Z =12 and a =17.6264(1) Å, b =6.9704(1) Å, c =12.1141(1) Å, β=133.74(1) °, V =1075.33(1) Å3. In agreement with the TGA and dilatometry experiments, all the water molecules were evacuated above 220 °C yielding to the anhydrous form, which crystallizes in the hexagonal P3121 space group with a =7.0389(1) Å, c =6.3702(1) Å and V =273.34(1) Å3. This study was extended to selected LnPO4.0.667H2O samples (Ln= Nd, Gd, Eu, Dy) and the obtained results confirmed the existence of two dehydration steps before the stabilization of the anhydrous form, with the transitory formation of LnPO4.0.5H2O.

Importance of E/PO Activity in Lunar Science

NASA Astrophysics Data System (ADS)

Terazono, J.

2018-04-01

Upon rise of momentum for lunar science and explorations, we should regard importance of E/PO (Education and Public Outreach) in this area. The author will show significance of strategy and human resource cultivation of this area.

Photoluminescence properties of Eu(3+)/ Sm(3+) activated CaZr4(PO4)6 phosphors.

PubMed

Nair, Govind B; Dhoble, S J

2016-09-01

Solid state reaction method was employed for the synthesis of a series of CaZr4(PO4)6: Eu(3+)/Sm(3+) phosphors. The red-emitting CaZr4(PO4)6:Eu(3+) phosphors can be efficiently excited at 396 nm and thereby, exhibit a strong red luminescence predominantly corresponding to the electric dipole transition at 615 nm. Under 405 nm excitation, CaZr4(PO4)6:Sm(3+) phosphors display orange emission with color temperatures approximately around 2200 K. The acquired results reveal that CaZr4(PO4)6: RE(3+) (RE = Eu, Sm) phosphors could be potential candidates for red and orange emitting phosphor, respectively, for UV/blue-pump LEDs.

Profiling a multiplex short tandem repeat loci from human urine with use of low cost on-site technology for verification of sample authenticity.

PubMed

Pires, Nuno M M; Tao Dong; Berntzen, Lasse; Lonningdal, Torill

2017-07-01

This work focuses on the development of a sophisticated technique via STR typing to unequivocally verify the authenticity of urine samples before sent to laboratories. STR profiling was conducted with the CSF1PO, TPOX, TH01 Multiplex System coupled with a smartphone-based detection method. The promising capability of the method to identify distinct STR profiles from urine of different persons opens the possibility to conduct sample authenticity tests. On-site STR profiling could be realized with a self-contained autonomous device with an integrated PCR microchip shown hereby.

Luminescence and energy transfer properties of Ca2Ba3(PO4)3Cl and Ca2Ba3(PO4)3Cl:A (A = Eu2+/Ce3+/Dy3+/Tb3+) under UV and low-voltage electron beam excitation.

PubMed

Shang, Mengmeng; Geng, Dongling; Yang, Dongmei; Kang, Xiaojiao; Zhang, Yang; Lin, Jun

2013-03-18

Pure Ca2Ba3(PO4)3Cl and rare earth ion (Eu(2+)/Ce(3+)/Dy(3+)/Tb(3+)) doped Ca2Ba3(PO4)3Cl phosphors with the apatite structure have been prepared via a Pechini-type sol-gel process. X-ray diffraction (XRD) and structure refinement, photoluminescence (PL) spectra, cathodoluminescence (CL) spectra, absolute quantum yield, as well as lifetimes were utilized to characterize samples. Under UV light excitation, the undoped Ca2Ba3(PO4)3Cl sample shows broad band photoluminescence centered near 480 nm after being reduced due to the defect structure. Eu(2+) and Ce(3+) ion doped Ca2Ba3(PO4)3Cl samples also show broad 5d → 4f transitions with cyan and blue colors and higher quantum yields (72% for Ca2Ba3(PO4)3Cl:0.04Eu(2+); 67% for Ca2Ba3(PO4)3Cl:0.016Ce(3+)). For Dy(3+) and Tb(3+) doped Ca2Ba3(PO4)3Cl samples, they give strong line emissions coming from 4f → 4f transitions. Moreover, the Ce(3+) ion can transfer its energy to the Tb(3+) ion in the Ca2Ba3(PO4)3Cl host, and the energy transfer mechanism has been demonstrated to be a resonant type, via a dipole-quadrupole interaction. However, under the low voltage electron beam excitation, Tb(3+) ion doped Ca2Ba3(PO4)3Cl samples present different luminescence properties compared with their PL spectra, which is ascribed to the different excitation mechanism. On the basis of the good PL and CL properties of the Ca2Ba3(PO4)3Cl:A (A = Ce(3+)/Eu(2+)/Tb(3+)/Dy(3+)), Ca2Ba3(PO4)3Cl might be promising for application in solid state lighting and field-emission displays.

Effect of synthesizing method on the properties of LiFePO4/C composite for rechargeable lithium-ion batteries

NASA Astrophysics Data System (ADS)

Yoon, Man-Soon; Islam, Mobinul; Park, Young Min; Ur, Soon-Chul

2013-03-01

Olivine-type LiFePO4/C cathode materials are fabricated with FePO4 powders that are pre-synthesized by two different processes from iron chloride solution. Process I is a modified precipitation method which is implemented by the pH control of a solution using NH4OH to form FePO4 precipitates at room temperature. Process II is a conventional precipitation method, of which H3PO4 (85%) solution is gradually added to a FeCl3 solution during the process to maintain a designated mole ratio. The solution is subsequently aged at 90°C in a water bath until FePO4 precipitates appear. In order to synthesize LiFePO4/C composites, each batch of FePO4 powders is then mixed with pre-milled lithium carbonate and glucose (8 wt. %) as a carbon source in a ball-mill. The structural characteristics of both LiFePO4/C composites fabricated using iron phospates from two different routes have been examined employing XRD and SEM. The modified precipitation process is considered to be a relatively simple and effective process for the preparation of LiFePO4/C composites owing to their excellent electrochemical properties and rate capabilities.

Double Carbon Nano Coating of LiFePO4 Cathode Material for High Performance of Lithium Ion Batteries.

PubMed

Ding, Yan-Hong; Huang, Guo-Long; Li, Huan-Huan; Xie, Hai-Ming; Sun, Hai-Zhu; Zhang, Jing-Ping

2015-12-01

Double carbon-coated LiFePO4 (D-LiFePO4/C) composite with sphere-like structure was synthesized through combination of co-precipitation and solid-state methods. Cetyl-trimethyl-ammonium bromide (CTAB) and citric acid served as two kinds of carbon sources in sequence. SEM images demonstrated that double carbon coating had certain influence on the morphology. The thickness of carbon coating on D-LiFePO4/C was about 1.7 nm and the content of carbon was 2.48 wt%, according to HRTEM and TG analysis. The electrochemical impedance spectroscopy analysis indicated that the D-LiFePO4/C composite presented the charge-transfer resistance of 68 Ω and Li ion diffusion coefficient of 2.68 x 10(-13) cm2 S(-1), while the single carbon-coated LiFePO4 (S-LiFePO4/C) exhibited 135.5Ω and 4.03 x 10(-14) cm2 S(-1). Especially, the prepared D-LiFePO4/C electrode showed discharge capacities of 102.9 (10C) and 87.1 (20C) mA h g(-1), respectively, with almost no capacity lost after 400 cycles at 10C, which were much better than those of S-LiFePO4/C composite.

C3PO, an endoribonuclease that promotes RNAi by facilitating RISC activation.

PubMed

Liu, Ying; Ye, Xuecheng; Jiang, Feng; Liang, Chunyang; Chen, Dongmei; Peng, Junmin; Kinch, Lisa N; Grishin, Nick V; Liu, Qinghua

2009-08-07

The catalytic engine of RNA interference (RNAi) is the RNA-induced silencing complex (RISC), wherein the endoribonuclease Argonaute and single-stranded small interfering RNA (siRNA) direct target mRNA cleavage. We reconstituted long double-stranded RNA- and duplex siRNA-initiated RISC activities with the use of recombinant Drosophila Dicer-2, R2D2, and Ago2 proteins. We used this core reconstitution system to purify an RNAi regulator that we term C3PO (component 3 promoter of RISC), a complex of Translin and Trax. C3PO is a Mg2+-dependent endoribonuclease that promotes RISC activation by removing siRNA passenger strand cleavage products. These studies establish an in vitro RNAi reconstitution system and identify C3PO as a key activator of the core RNAi machinery.

Using the nutrient ratio NO/PO as a tracer of continental shelf waters in the central Arctic Ocean

NASA Astrophysics Data System (ADS)

Wilson, Cara; Wallace, Douglas W. R.

1990-12-01

Historical nitrate, phosphate, and dissolved oxygen data from the central Arctic Ocean are examined with particular emphasis on the conservative parameters NO (9 * NO3 + O2) and PO (135 * PO4 + O2). The NO/PO ratio is shown to increase with depth in the Canada Basin, being ˜0.78 in Surface and Upper Halocline Waters and ˜1.0 in the Atlantic Layer and Deep Waters. Lower Halocline Water is marked by NO and PO minima and intermediate NO/PO. NO/PO ratios from the Arctic shelf seas are examined to determine possible source regions for the various water masses. The NO/PO ratio of Canada Basin Deep Water implies an upper bound of ˜11% shelf water contribution to this water mass. A slight oxygen maximum core in the Lower Halocline Water is identified at a salinity of S = 34.5 in the vicinity of the Alpha Ridge. This core appears to be diminished by diapycnal mixing and does not extend into the Beaufort Gyre.

Room-temperature synthesis and photoluminescence of hexagonal CePO4 nanorods

NASA Astrophysics Data System (ADS)

Zhu, J.; Zhang, K.; Zhao, H. Y.

2018-01-01

Hexagonal CePO4 nanorods were synthesized via a simple chemical precipitation route at room-temperature without the presence of surfactants and then characterized by powder X-ray diffraction (XRD), energy-dispersive X-ray (EDX) spectrometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption and photoluminescence (PL) spectroscopy. Hexagonal CePO4 nanorods exhibit strong ultraviolet absorption and ultraviolet luminescence, which correspond to the electronic transitions between 4f and 5d state of Ce3+ ions.

Implementation of the MPC and A Operations Monitorying (MOM) System at JSC PO Sevmas

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

Monogarov, A.; Taranenko, V.; Serov,A

The Material Protection, Control and Accounting (MPC&A) Program has been working since 1994 with nuclear sites in Russia to upgrade the physical protection (PP) and material control and accounting (MC&A) functions at facilities containing weapons usable nuclear material. In early 2001, the MPC&A program initiated the MPC&A Operations Monitoring (MOM) Project to monitor facilities where MPC&A upgrades have been installed to provide increased confidence that personnel are present and vigilant, provide confidence that security procedures are being properly performed and provide additional assurance that nuclear materials have not been stolen. The MOM project began as a pilot project at themore » Moscow State Engineering Physics Institute (MEPhI) and a MOM system was successfully installed in October 2001. Following the success of the MEPhI pilot project, the MPC&A Program expanded the installation of MOM systems to several other Russian facilities, including the JSC 'PO' Sevmash', Severodvinsk, Russia. The MOM system was made operational at Sevmash in September, 2008. This paper will discuss the objectives of the MOM system installed at Sevmash and indicate how the objectives influenced the development of the conceptual design. The paper will also describe activities related to installation of the infrastructure and the MOM system at Sevmash. Experience gained from operation of the system and how the objectives are being met will also be discussed. The paper will describe how the MOM system is used at Sevmash and, in particular, how the data is analyzed. Finally, future activities including potential expansion of the MOM system, operator training, data sharing and analysis, procedure development, repair and maintenance will be included in the paper.« less

Effects of Mg doping on the remarkably enhanced electrochemical performance of Na 3V 2(PO 4) 3 cathode materials for sodium ion batteries

DOE PAGES

Li, Hui; Yu, Xiqian; Bai, Ying; ...

2015-01-01

Na 3V 2-xMg x(PO 4) 3/C composites with different Mg 2+ doping contents (x=0, 0.01, 0.03, 0.05, 0.07 and 0.1) were prepared by a facile sol-gel method. The doping effects on the crystal structure were investigated by XRD, XPS and EXAFS. The results show that low dose doping Mg 2+ does not alter the structure of the material, and magnesium is successfully substituted for vanadium site. The Mg doped Na 3V 2-xMg x(PO 4) 3/C composites exhibit significant improvements on the electrochemistry performances in terms of the rate capability and cycle performance, especially for the Na 3V 1.95Mg 0.05(PO 4)more » 3/C. For example, when the current density increased from 1 C to 30 C, the specific capacity only decreased from 112.5 mAh g-1 to 94.2 mAh g -1 showing very good rate capability. Moreover, even cycling at a high rate of 20 C, an excellent capacity retention of 81% is maintained from the initial value of 106.4 mAh g-1 to 86.2 mAh g-1 at the 50th cycle. Enhanced rate capability and cycle performance can be attributed to the optimized particle size, structural stability and enhanced ionic and electronic conductivity induced by Mg doping.« less

PoLi: A Virtual Screening Pipeline Based On Template Pocket And Ligand Similarity

PubMed Central

Roy, Ambrish; Srinivasan, Bharath; Skolnick, Jeffrey

2015-01-01

Often in pharmaceutical research, the goal is to identify small molecules that can interact with and appropriately modify the biological behavior of a new protein target. Unfortunately, most proteins lack both known structures and small molecule binders, prerequisites of many virtual screening, VS, approaches. For such proteins, ligand homology modeling, LHM, that copies ligands from homologous and perhaps evolutionarily distant template proteins, has been shown to be a powerful VS approach to identify possible binding ligands. However, if we want to target a specific pocket for which there is no homologous holo template protein structure, then LHM will not work. To address this issue, in a new pocket based approach, PoLi, we generalize LHM by exploiting the fact that the number of distinct small molecule ligand binding pockets in proteins is small. PoLi identifies similar ligand binding pockets in a holo-template protein library, selectively copies relevant parts of template ligands and uses them for VS. In practice, PoLi is a hybrid structure and ligand based VS algorithm that integrates 2D fingerprint-based and 3D shape-based similarity metrics for improved virtual screening performance. On standard DUD and DUD-E benchmark databases, using modeled receptor structures, PoLi achieves an average enrichment factor of 13.4 and 9.6 respectively, in the top 1% of the screened library. In contrast, traditional docking based VS using AutoDock Vina and homology-based VS using FINDSITEfilt have an average enrichment of 1.6 (3.0) and 9.0 (7.9) on the DUD (DUD-E) sets respectively. Experimental validation of PoLi predictions on dihydrofolate reductase, DHFR, using differential scanning fluorimetry, DSF, identifies multiple ligands with diverse molecular scaffolds, thus demonstrating the advantage of PoLi over current state-of-the-art VS methods. PMID:26225536

21 CFR 862.1120 - Blood gases (PCO2, PO2) and blood pH test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Blood gases (PCO2, PO2) and blood pH test system... Test Systems § 862.1120 Blood gases (PCO2, PO2) and blood pH test system. (a) Identification. A blood gases (PCO2, PO2) and blood pH test system is a device intended to measure certain gases in blood, serum...

Experimental ammonia-free phosphate-bonded investments using Mg(H2PO4)2.

PubMed

Zhang, Z; Tamaki, Y; Miyazaki, T

2001-12-01

In previous study, we found that Mg(H2PO4)2 instead of NH4H2PO4 was available as a binder material for phosphate-bonded investments and possibly could be used to develop the phosphate-bonded investment without ammonia gas release. The purpose of the present study was to develop the experimental ammonia-free phosphate-bonded investments by investigating suitable refractories. Mg(H2PO4)2.nH2O and MgO were prepared as a binder. Cristobalite and quartz were selected as refractories. The power ratio of MgO/Mg(H2PO4)2.nH2O was set constant at 1.2 according to our previous findings. Fundamental properties of dental investment such as strength, manipulation and expansion were evaluated. Using cristobalite as the refractory material, further investigations were performed. The refractory/binder ratio was definitely effective. The increase of this ratio led to low mold strength and large mold expansion. The present findings suggested that C5 was desirable for dental investment.

Particle Scavenging and Tidal Exchange of Po-210 and Th-234 in a Mesotidal Embayment in Southern California

NASA Astrophysics Data System (ADS)

Peng, J.; Ku, T.; Luo, S.

2002-12-01

San Diego Bay (SDB) is a semi-closed shallow embayment that sustains semidiurnal tides and continuous tidal flows. We measured Po-210 and Th-234 activities in water samples collected from across north SDB, coastal waters immediately outside SDB, and from several rivers in the vicinity of SDB. A station in north SDB was sampled multiple times during a complete flooding-ebbing cycle. The major findings are as follows. 1) Compared to the outer sea, SDB water has much higher Th-234 deficiency (1.3-2.0 dpm/l, vs. 0.4-0.8dpm/l for outer sea) and considerably lower Po-210 activities (averaging 0.05dpm/l vs. 0.07dpm/l for outer sea) due to stronger particle scavenging. There is higher particulate Po-210 vs. total Po-210 ratio in SDB water (68%, vs. 34% for outer sea). 2) Inside SDB, an increasing Po-210 activities towards the bay mouth clearly indicates the effect of tidal exchange. Po-210 activity near the Bay mouth exceeds that of the outer sea due to higher particulate Po-210, which may come from tidal-induced sediment resuspension. 3) Rivers flowing into or near SDB have 8-12 times higher Po-210 activities than the bay water. But the input of Po-210 to SDB from rivers should be insignificant because of the negligible flow in the dry season. 4) In a tidal cycle, both Po-210 and Th-234 activities in North Bay covary with tidal pattern, which can be readily explained by the exchange between two waters inside and outside SDB with distinct TSS levels and Po-210/Th-234 activities. Sediment resuspension plays an important role during the peak tidal flow, resulting in an asymmetrical time-evolution curve of Po-210/Th-234 activities. These observations correspond well with our previous finding of systematic variations of Po-210 and Th-234 activities in water and sediment columns across SDB. This study manifests the significance of hydrodynamic processes such as advection, mixing and particle movement in the study of geochemistry of particle-reactive radionuclides in a tidal

EvoDB: a database of evolutionary rate profiles, associated protein domains and phylogenetic trees for PFAM-A

PubMed Central

Ndhlovu, Andrew; Durand, Pierre M.; Hazelhurst, Scott

2015-01-01

The evolutionary rate at codon sites across protein-coding nucleotide sequences represents a valuable tier of information for aligning sequences, inferring homology and constructing phylogenetic profiles. However, a comprehensive resource for cataloguing the evolutionary rate at codon sites and their corresponding nucleotide and protein domain sequence alignments has not been developed. To address this gap in knowledge, EvoDB (an Evolutionary rates DataBase) was compiled. Nucleotide sequences and their corresponding protein domain data including the associated seed alignments from the PFAM-A (protein family) database were used to estimate evolutionary rate (ω = dN/dS) profiles at codon sites for each entry. EvoDB contains 98.83% of the gapped nucleotide sequence alignments and 97.1% of the evolutionary rate profiles for the corresponding information in PFAM-A. As the identification of codon sites under positive selection and their position in a sequence profile is usually the most sought after information for molecular evolutionary biologists, evolutionary rate profiles were determined under the M2a model using the CODEML algorithm in the PAML (Phylogenetic Analysis by Maximum Likelihood) suite of software. Validation of nucleotide sequences against amino acid data was implemented to ensure high data quality. EvoDB is a catalogue of the evolutionary rate profiles and provides the corresponding phylogenetic trees, PFAM-A alignments and annotated accession identifier data. In addition, the database can be explored and queried using known evolutionary rate profiles to identify domains under similar evolutionary constraints and pressures. EvoDB is a resource for evolutionary, phylogenetic studies and presents a tier of information untapped by current databases. Database URL: http://www.bioinf.wits.ac.za/software/fire/evodb PMID:26140928

Advanced carbon materials/olivine LiFePO4 composites cathode for lithium ion batteries

NASA Astrophysics Data System (ADS)

Gong, Chunli; Xue, Zhigang; Wen, Sheng; Ye, Yunsheng; Xie, Xiaolin

2016-06-01

In the past two decades, LiFePO4 has undoubtly become a competitive candidate for the cathode material of the next-generation LIBs due to its abundant resources, low toxicity and excellent thermal stability, etc. However, the poor electronic conductivity as well as low lithium ion diffusion rate are the two major drawbacks for the commercial applications of LiFePO4 especially in the power energy field. The introduction of highly graphitized advanced carbon materials, which also possess high electronic conductivity, superior specific surface area and excellent structural stability, into LiFePO4 offers a better way to resolve the issue of limited rate performance caused by the two obstacles when compared with traditional carbon materials. In this review, we focus on advanced carbon materials such as one-dimensional (1D) carbon (carbon nanotubes and carbon fibers), two-dimensional (2D) carbon (graphene, graphene oxide and reduced graphene oxide) and three-dimensional (3D) carbon (carbon nanotubes array and 3D graphene skeleton), modified LiFePO4 for high power lithium ion batteries. The preparation strategies, structure, and electrochemical performance of advanced carbon/LiFePO4 composite are summarized and discussed in detail. The problems encountered in its application and the future development of this composite are also discussed.

Relaxation-Induced Memory Effect of LiFePO4 Electrodes in Li-Ion Batteries.

PubMed

Jia, Jianfeng; Tan, Chuhao; Liu, Mengchuang; Li, De; Chen, Yong

2017-07-26

In Li-ion batteries, memory effect has been found in several commercial two-phase materials as a voltage bump and a step in the (dis)charging plateau, which delays the two-phase transition and influences the estimation of the state of charge. Although memory effect has been first discovered in olivine LiFePO 4 , the origination and dependence are still not clear and are critical for regulating the memory effect of LiFePO 4 . Herein, LiFePO 4 has been synthesized by a home-built spray drying instrument, of which the memory effect has been investigated in Li-ion batteries. For as-synthesized LiFePO 4 , the memory effect is significantly dependent on the relaxation time after phase transition. Besides, the voltage bump of memory effect is actually a delayed voltage overshooting that is overlaid at the edge of stepped (dis)charging plateau. Furthermore, we studied the kinetics of LiFePO 4 electrode with electrochemical impedance spectroscopy (EIS), which shows that the memory effect is related to the electrochemical kinetics. Thereby, the underlying mechanism has been revealed in memory effect, which would guide us to optimize two-phase electrode materials and improve Li-ion battery management systems.

Behavior of LiFe1-yMnyPO4/C cathode materials upon electrochemical lithium intercalation/deintercalation

NASA Astrophysics Data System (ADS)

Novikova, Svetlana; Yaroslavtsev, Sergey; Rusakov, Vyacheslav; Chekannikov, Andrey; Kulova, Tatiana; Skundin, Alexander; Yaroslavtsev, Andrey

2015-12-01

LiFe1-yMnyPO4/C (y = 0-0.3) nanocomposites are prepared by the sol-gel method, and their properties are characterized with the use of the XRD analysis, SEM, impedance spectroscopy, charge/discharge tests, and Mössbauer spectroscopy. The samples with a low manganese content, LiFe1-yMnyPO4 (y = 0.1, 0.2) are characterized by an increased conductivity. In LiFe1-yMnyPO4 (x = 0.1-0.3), electrochemical lithium deintercalation/intercalation proceeds in two stages which due to the subsequent oxidation/reduction of iron and manganese ions. The LiFe1-yMnyPO4/С (y = 0.1, 0.2) samples show enhanced charge/discharge capacity, especially, at high current density (for LiFe0.9Mn0.1PO4/C, the discharge capacity is equal to 142 and 55 mAh g-1 at a current density of 20 and 1600 mA g-1, respectively). Mn2+ ↔ Mn3+ transition in LiFe1-yMnyPO4 proceeds via the solid solutions formation under gradual changes in the potential. For LiFe0.7Mn0.3PO4, oxidation and reduction of iron ions follow the same scenario. According to the Mössbauer spectroscopy data, manganese is orderly distributed in LixFeIII1-yMnyPO4: iron contains not more than one manganese cation in its nearest neighborhood. Moreover, combination of the Mössbauer spectroscopy and X-ray analysis data indicates that, in the interval where solid solutions exist in LixFe0.7Mn0.3PO4, the regions with an inhomogeneous distribution of divalent and trivalent manganese ions are formed.

Evidence for a pressure-induced spin transition in olivine-type LiFePO4 triphylite

NASA Astrophysics Data System (ADS)

Núñez Valdez, Maribel; Efthimiopoulos, Ilias; Taran, Michail; Müller, Jan; Bykova, Elena; McCammon, Catherine; Koch-Müller, Monika; Wilke, Max

2018-05-01

We present a combination of first-principles and experimental results regarding the structural and magnetic properties of olivine-type LiFePO4 under pressure. Our investigations indicate that the starting P b n m phase of LiFePO4 persists up to 70 GPa. Further compression leads to an isostructural transition in the pressure range of 70-75 GPa, inconsistent with a former theoretical study. Considering our first-principles prediction for a high-spin to low-spin transition of Fe2 + close to 72 GPa, we attribute the experimentally observed isostructural transition to a change in the spin state of Fe2 + in LiFePO4. Compared to relevant Fe-bearing minerals, LiFePO4 exhibits the largest onset pressure for a pressure-induced spin state transition.

Carbon coatings with olive oil, soybean oil and butter on nano-LiFePO 4

NASA Astrophysics Data System (ADS)

Kim, Ketack; Jeong, Ji Hwa; Kim, Ick-Jun; Kim, Hyun-Soo

Kitchen oils (olive, soybean and butter) are selected for carbon coatings on LiFePO 4. The surface properties of LiFePO 4 are unknown or vary depending on synthetic methods. The multi-functional groups of fatty acids in the oils can orient properly to cope with the variable surface properties of LiFePO 4, which can lead to dense carbon coatings. The low price and low toxicity of kitchen oils are other advantages of the coating process. LiFePO 4 (D 50 = 121 nm)combined with the carbon coating enhances the rate capability. Capacities at the 2 C rate reach 150 mAh g -1 or higher. The charge retention values of 2.0 C/0.2 C are between 94.4 and 98.9%.

Improved GO/PO method and its application to wideband SAR image of conducting objects over rough surface

NASA Astrophysics Data System (ADS)

Jiang, Wang-Qiang; Zhang, Min; Nie, Ding; Jiao, Yong-Chang

2018-04-01

To simulate the multiple scattering effect of target in synthetic aperture radar (SAR) image, the hybrid method GO/PO method, which combines the geometrical optics (GO) and physical optics (PO), is employed to simulate the scattering field of target. For ray tracing is time-consuming, the Open Graphics Library (OpenGL) is usually employed to accelerate the process of ray tracing. Furthermore, the GO/PO method is improved for the simulation in low pixel situation. For the improved GO/PO method, the pixels are arranged corresponding to the rectangular wave beams one by one, and the GO/PO result is the sum of the contribution values of all the rectangular wave beams. To get high-resolution SAR image, the wideband echo signal is simulated which includes information of many electromagnetic (EM) waves with different frequencies. Finally, the improved GO/PO method is used to simulate the SAR image of targets above rough surface. And the effects of reflected rays and the size of pixel matrix on the SAR image are also discussed.

Accelerated Removal of Fe-Antisite Defects while Nanosizing Hydrothermal LiFePO4 with Ca(2).

PubMed

Paolella, Andrea; Turner, Stuart; Bertoni, Giovanni; Hovington, Pierre; Flacau, Roxana; Boyer, Chad; Feng, Zimin; Colombo, Massimo; Marras, Sergio; Prato, Mirko; Manna, Liberato; Guerfi, Abdelbast; Demopoulos, George P; Armand, Michel; Zaghib, Karim

2016-04-13

Based on neutron powder diffraction (NPD) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), we show that calcium ions help eliminate the Fe-antisite defects by controlling the nucleation and evolution of the LiFePO4 particles during their hydrothermal synthesis. This Ca-regulated formation of LiFePO4 particles has an overwhelming impact on the removal of their iron antisite defects during the subsequent carbon-coating step since (i) almost all the Fe-antisite defects aggregate at the surface of the LiFePO4 crystal when the crystals are small enough and (ii) the concomitant increase of the surface area, which further exposes the Fe-antisite defects. Our results not only justify a low-cost, efficient and reliable hydrothermal synthesis method for LiFePO4 but also provide a promising alternative viewpoint on the mechanism controlling the nanosizing of LiFePO4, which leads to improved electrochemical performances.

Conjugation of TbPO4·H2O-Based Nanowires with Immunoglobulin G for Bioimaging

NASA Astrophysics Data System (ADS)

Huong, Nguyen Thanh; Lien, Pham Thi; Hung, Nguyen Manh; Van, Nguyen Duc; Thuy, Tran Thi; Binh, Nguyen Thanh; Minh, Le Quoc

2016-05-01

The surface modification, functionalization, and conjugation of undoped and 11 at.% Eu3+-doped TbPO4 ·H2O nanowires by using silica, a thyocyanate functional group, and immunoglobulin G, respectively, are described in this paper. For the core layer of obtained conjugated nanowires, the undoped TbPO4 ·H2O exhibited characteristic photoluminescent green emission corresponding to 5 D 4 → 7 F J transitions ( J = 6, 5, 4, 3) while the incorporation of Eu3+ into TbPO4 ·H2O lattice was evidenced by Starks splitting transitions at 590, 615, 693 nm of Eu3+ ions for the case of 11 at.% Eu3+-doped TbPO4 ·H2O. The results also indicated that both immunoglobulin G-conjugated undoped and Eu3+-doped TbPO4 ·H2O nanowires can be used in the fluorescent immune analysis as a biomedical label maker to identify measles viruses in vaccine testing.

Determination of (210)Po in calcium supplements and the possible related dose assessment to the consumers.

PubMed

Strumińska-Parulska, Dagmara I

2015-12-01

The aim of this pioneer study was to investigate the most popular calcium supplements as a potential additional source of polonium (210)Po in human diet. The analyzed calcium pharmaceutics contained organic or inorganic calcium compounds; some from natural sources as mussels' shells, fish extracts, or sedimentary rocks. The objectives of this research were to investigate the naturally occurring (210)Po activity concentrations in calcium supplements, find the correlations between (210)Po concentration in medicament and calcium chemical form, and calculate the effective radiation dose connected to analyzed calcium supplement consumption. As results showed, (210)Po concentrations in natural origin calcium supplements (especially sedimentary rocks) were higher than the other analyzed. Also the results of (210)Po analysis obtained for inorganic forms of calcium supplements were higher. The highest (210)Po activity concentrations were determined in mineral tablets made from sedimentary rocks: dolomite and chalk - 3.88 ± 0.22 and 3.36 ± 0.10 mBq g(-1) respectively; while the lowest in organic calcium compounds: calcium lactate and calcium gluconate - 0.07 ± 0.02 and 0.17 ± 0.01 mBq g(-1). The annual effective radiation doses from supplements intake were estimated as well. The highest annual radiation dose from (210)Po taken with 1 tablet of calcium supplement per day was connected to sample made from chalk - 2.5 ± 0.07 μSv year(-1), while the highest annual radiation dose from (210)Po taken with 1 g of pure calcium per day was connected to dolomite - 12.7 ± 0.70 μSv year(-1). Copyright © 2015 Elsevier Ltd. All rights reserved.

Short-Term Safety of Zoledronic Acid in Young Patients With Bone Disorders: An Extensive Institutional Experience.

PubMed

George, Sobenna; Weber, David R; Kaplan, Paige; Hummel, Kelly; Monk, Heather M; Levine, Michael A

2015-11-01

Zoledronic acid (ZA) is increasingly used in young patients with bone disorders. However, data related to the safety of ZA administration in this population are limited. The study aimed to characterize the short-term safety profile of ZA and identify risk factors for ZA-related adverse events (AEs) in young patients. This was a retrospective chart review of inpatients and outpatients less than 21 years old who received at least one ZA infusion between July 2010 and January 2014 at The Children's Hospital of Philadelphia. Eighty-one patients (56% male; median age, 12 y; age at first infusion, 0.5 to 20 y) with diverse skeletal disorders received a total of 204 infusions. The most common indications were osteoporosis (33% of cohort) and osteogenesis imperfecta (27.2%). The median ZA dose was 0.025 mg/kg (interquartile range, 0.025-0.05); the median dosing interval was 6 months (range, 1 to 25.6 mo). AEs were mild and more common after the first ZA infusion in patients with no previous bisphosphonate exposure: hypophosphatemia (25.2% of infusions), acute phase reactions (19.1%), and hypocalcemia (16.4%). Symptomatic hypocalcemia requiring iv calcium occurred after two infusions. ZA dose was significantly associated with hypophosphatemia, but not other AEs. Hypocalcemia was more common in patients with high bone turnover as assessed by preinfusion alkaline phosphatase levels. AEs were not associated with diagnosis, baseline serum calcium, or calcium/calcitriol supplementation. Acute AEs related to ZA infusion in youths are common, occur principally after the first ZA infusion in bisphosphonate-naive patients, and are typically mild and easily managed. Future prospective studies are needed to determine the potential long-term risks, as well as benefits, of ZA therapy in the pediatric population.

Short-Term Safety of Zoledronic Acid in Young Patients With Bone Disorders: An Extensive Institutional Experience

PubMed Central

George, Sobenna; Weber, David R.; Kaplan, Paige; Hummel, Kelly; Monk, Heather M.

2015-01-01

Context: Zoledronic acid (ZA) is increasingly used in young patients with bone disorders. However, data related to the safety of ZA administration in this population are limited. Objective: The study aimed to characterize the short-term safety profile of ZA and identify risk factors for ZA-related adverse events (AEs) in young patients. Design, Setting, and Participants: This was a retrospective chart review of inpatients and outpatients less than 21 years old who received at least one ZA infusion between July 2010 and January 2014 at The Children's Hospital of Philadelphia. Results: Eighty-one patients (56% male; median age, 12 y; age at first infusion, 0.5 to 20 y) with diverse skeletal disorders received a total of 204 infusions. The most common indications were osteoporosis (33% of cohort) and osteogenesis imperfecta (27.2%). The median ZA dose was 0.025 mg/kg (interquartile range, 0.025–0.05); the median dosing interval was 6 months (range, 1 to 25.6 mo). AEs were mild and more common after the first ZA infusion in patients with no previous bisphosphonate exposure: hypophosphatemia (25.2% of infusions), acute phase reactions (19.1%), and hypocalcemia (16.4%). Symptomatic hypocalcemia requiring iv calcium occurred after two infusions. ZA dose was significantly associated with hypophosphatemia, but not other AEs. Hypocalcemia was more common in patients with high bone turnover as assessed by preinfusion alkaline phosphatase levels. AEs were not associated with diagnosis, baseline serum calcium, or calcium/calcitriol supplementation. Conclusion: Acute AEs related to ZA infusion in youths are common, occur principally after the first ZA infusion in bisphosphonate-naive patients, and are typically mild and easily managed. Future prospective studies are needed to determine the potential long-term risks, as well as benefits, of ZA therapy in the pediatric population. PMID:26308295

PoPSat: The Polar Precipitation Satellite Mission

NASA Astrophysics Data System (ADS)

Binder, Matthias J.; Agten, Dries; Arago-Higueras, Nadia; Borderies, Mary; Diaz-Schümmer, Carlos; Jamali, Maryam; Jimenez-Lluva, David; Kiefer, Joshua; Larsson, Anna; Lopez-Gilabert, Lola; Mione, Michele; Mould, Toby JD; Pavesi, Sara; Roth, Georg; Tomicic, Maja

2017-04-01

The terrestrial water cycle is one of many unique regulatory systems on planet Earth. It is directly responsible for sustaining biological life on land and human populations by ensuring sustained crop yields. However, this delicate balanced system continues to be influenced significantly by a changing climate, which has had drastic impacts particularly on the polar regions. Precipitation is a key process in the weather and climate system, due to its storage, transport and release of latent heat in the atmosphere. It has been extensively investigated in low latitudes, in which detailed models have been established for weather prediction. However, a gap has been left in higher latitudes above 65°, which show the strongest response to climate changes and where increasing precipitations have been foreseen in the future. In order to establish a global perspective of atmospheric processes, space observation of high-latitude areas is crucial to produce globally consistent data. The increasing demand for those data has driven a critical need to devise a mission which fills the gaps in current climate models. The authors propose the Polar Precipitation Satellite (PoPSat), an innovative satellite mission to provide enhanced observation of light and medium precipitation, focusing on snowfall and light rain in high latitudes. PoPSat is the first mission aimed to provide high resolution 3D structural information about snow and light precipitation systems and cloud structure in the covered areas. The satellite is equipped with a dual band (Ka and W band) phased-array radar. These antennas provide a horizontal resolution of 2 km and 4 km respectively which will exceed all other observations made to date at high-latitudes, while providing the additional capability to monitor snowfall. The data gathered will be compatible and complementary with measurements made during previous missions. PoPSat has been designed to fly on a sun-synchronous, dawn-dusk orbit at 460 km. This orbit

Ab-initio Calculation of the XANES of Lithium Phosphates and LiFePO4

NASA Astrophysics Data System (ADS)

Yiu, Y. M.; Yang, Songlan; Wang, Dongniu; Sun, Xueliang; Sham, T. K.

2013-04-01

Lithium iron phosphate has been regarded as a promising cathode material for the next generation lithium ion batteries due to its high specific capacity, superior thermal and cyclic stability [1]. In this study, the XANES (X-ray Absorption Near Edge Structure) spectra of lithium iron phosphate and lithium phosphates of various compositions at the Li K, P L3,2, Fe M3,2 and O K-edges have been simulated self-consistently using ab-initio calculations based on multiple scattering theory (the FEFF9 code) and DFT (Density Functional Theory, the Wien2k code). The lithium phosphates under investigation include LiFePO4, γ-Li3PO4, Li4P2O7 and LiPO3. The calculated spectra are compared to the experimental XANES recorded in total electron yield (TEY) and fluorescence yield (FLY). This work was carried out to assess the XANES of possible phases presented in LiFePO4 based Li ion battery applications [2].

Reproductive performance of peranakan ongole (PO) bull at different altitudes areas in Lampung province

NASA Astrophysics Data System (ADS)

Suretno, N. D.; Supriyatna, I.; Purwanto, B.; Priyanto, R.

2018-01-01

Peranakan Ongole (PO) cattle are famous for their bulls and known for their toughness, rapid growth and natural tolerance to tropical heat and disease resistance. This study was conducted to determine the reproductive performance of PO bull in some altitude in Lampung Province. A total of PO bulls used were 48 heads, with age three to four years. The variables observed were volume, consistency, pH, semen colour, concentration, mass movement, motility, percentage of living spermatozoa and abnormality. Data were collected during the rainy season and dry season, calculated with the average and standard deviation and then analyzed descriptively. Based on the macroscopic examination, Peranakan Ongole bull living in low temperature place had a normal semen volume, the consistency mostly watery to moderate, fresh semen pH is in the normal range and the color of semen are all normal both in the rainy and dry seasons. The results of microscopic examination showed that PO cattle had a good reproduction conditions at all three

Comparative Costs and Staffing Report for Educational Facilities, 1997-1998.

ERIC Educational Resources Information Center

Glazner, Steve, Ed.

This report presents comparative data on facility management costs and staffing based on responses from 193 U.S. postsecondary educational facilities and K-12 institutions during 1997-98. It also lists data from both private and public institutions. Section 1 contains general data on the survey response tally and institutional profiles listed by…

The National QAAMS Program – A Practical Example of PoCT Working in the Community

PubMed Central

Shephard, Mark DS; Gill, Janice P

2010-01-01

The Quality Assurance for Aboriginal and Torres Strait Islander Medical Services (QAAMS) Program is the largest and longest-standing national point-of-care testing (PoCT) program in Australia. With a focus on PoCT for diabetes management, it now operates in 115 Indigenous medical services and has been funded continuously by the Australian Government for 11 years. A recent independent evaluation of the QAAMS Program concluded that the program continues to meet best practice standards for Indigenous healthcare, diabetes management and PoCT. PMID:24150514

Preparation of V-Doped LiFePO4/C as the Optimized Cathode Material for Lithium Ion Batteries.

PubMed

Sun, Pingping; Zhang, Haiyang; Shen, Kai; Fan, Qi; Xu, Qingyu

2015-04-01

LiFe1-x,Vx,PO4/C composites were synthesized by solid state reaction. The effect of carbon coating and V doping on the performance of LiFePO4 has been systematically investigated by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), charge/discharge and cyclic voltammetry (CV) measurement. The results show that carbon coating and proper amount of V incorporation do not significantly change the host crystal structure of LiFePO4, while the electrochemical performance of LiFePO4 can be significantly improved. Particularly, the LiFe0.96V0.04PO4/C exhibits the best performance with a specific discharge capacity of 105.5 mA h/g at 5.0 C, 90.3 mA h/g at 10 C and 66.7 mA h/g at 30 C with stable cycle performance, which is significantly improved compared with the pure LiFePO4/C. The cyclic voltammograms result reveals that V doping could decrease the resistance of LiFePO4/C composite electrode drastically and improve its reversibility.

Surface Modification of the LiFePO4 Cathode for the Aqueous Rechargeable Lithium Ion Battery.

PubMed

Tron, Artur; Jo, Yong Nam; Oh, Si Hyoung; Park, Yeong Don; Mun, Junyoung

2017-04-12

The LiFePO 4 surface is coated with AlF 3 via a simple chemical precipitation for aqueous rechargeable lithium ion batteries (ARLBs). During electrochemical cycling, the unfavorable side reactions between LiFePO 4 and the aqueous electrolyte (1 M Li 2 SO 4 in water) leave a highly resistant passivation film, which causes a deterioration in the electrochemical performance. The coated LiFePO 4 by 1 wt % AlF 3 has a high discharge capacity of 132 mAh g -1 and a highly improved cycle life, which shows 93% capacity retention even after 100 cycles, whereas the pristine LiFePO 4 has a specific capacity of 123 mAh g -1 and a poor capacity retention of 82%. The surface analysis results, which include X-ray photoelectron spectroscopy and transmission electron microscopy results, show that the AlF 3 coating material is highly effective for reducing the detrimental surface passivation by relieving the electrochemical side reactions of the fragile aqueous electrolyte. The AlF 3 coating material has good compatibility with the LiFePO 4 cathode material, which mitigates the surface diffusion obstacles, reduces the charge-transfer resistances and improves the electrochemical performance and surface stability of the LiFePO 4 material in aqueous electrolyte solutions.

PoMaMo--a comprehensive database for potato genome data.

PubMed

Meyer, Svenja; Nagel, Axel; Gebhardt, Christiane

2005-01-01

A database for potato genome data (PoMaMo, Potato Maps and More) was established. The database contains molecular maps of all twelve potato chromosomes with about 1000 mapped elements, sequence data, putative gene functions, results from BLAST analysis, SNP and InDel information from different diploid and tetraploid potato genotypes, publication references, links to other public databases like GenBank (http://www.ncbi.nlm.nih.gov/) or SGN (Solanaceae Genomics Network, http://www.sgn.cornell.edu/), etc. Flexible search and data visualization interfaces enable easy access to the data via internet (https://gabi.rzpd.de/PoMaMo.html). The Java servlet tool YAMB (Yet Another Map Browser) was designed to interactively display chromosomal maps. Maps can be zoomed in and out, and detailed information about mapped elements can be obtained by clicking on an element of interest. The GreenCards interface allows a text-based data search by marker-, sequence- or genotype name, by sequence accession number, gene function, BLAST Hit or publication reference. The PoMaMo database is a comprehensive database for different potato genome data, and to date the only database containing SNP and InDel data from diploid and tetraploid potato genotypes.

Hierarchical LiFePO4 with a controllable growth of the (010) facet for lithium-ion batteries.

PubMed

Guo, Binbin; Ruan, Hongcheng; Zheng, Cheng; Fei, Hailong; Wei, Mingdeng

2013-09-27

Hierarchically structured LiFePO4 was successfully synthesized by ionic liquid solvothermal method. These hierarchically structured LiFePO4 samples were constructed from nanostructured platelets with their (010) facets mainly exposed. To the best of our knowledge, facet control of a hierarchical LiFePO4 crystal has not been reported yet. Based on a series of experimental results, a tentative mechanism for the formation of these hierarchical structures was proposed. After these hierarchically structured LiFePO4 samples were coated with a thin carbon layer and used as cathode materials for lithium-ion batteries, they exhibited excellent high-rate discharge capability and cycling stability. For instance, a capacity of 95% can be maintained for the LiFePO4 sample at a rate as high as 20 C, even after 1000 cycles.

Effect of precursor concentration on the electrical properties of LiFePO{sub 4} prepared by solvothermal method

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

Rabbani, Ahmad Yasin; Fakhri, Hafizh A.; Arifin, Muhammad

2016-02-08

Lithium iron phosphate (LiFePO{sub 4}) is frequently used for Li-ion battery cathode. LiFePO{sub 4} has the high specific capacity at 170 mAhg{sup −1}, stable voltage at 3.45 V, stable structure, cheap, and low toxicity. The objective of this research is investigating the effect of precursor concentration on the electrical properties of LiFePO{sub 4} prepared by solvothermal method. LiOH, FeSO{sub 4}, H{sub 3}PO{sub 4}, and citric acid were used as the precursors. The LiOH concentration was varied from 0.3 M to 1.8 M. The Fourier Transform Infrared Spectroscopy (FTIR) measurement identified the Fe-O, O-P-O, and P-O bonds which corresponding to LiFePO{sub 4}.more » The result of 4-point probe measurement shows that, among the prepared samples, the sample from the precursor concentration of 1.8 M has the highest electrical conductivity.« less

TL-OSL study of Li3PO4: Mg, Cu phosphor

NASA Astrophysics Data System (ADS)

Rahangdale, S. R.; Wankhede, S. P.; Dhabekar, B. S.; Palikundwar, U. A.; Moharil, S. V.

2015-08-01

In the present work, we report the thermoluminescence and optically stimulated luminescence properties of Mg and Cu doped Li3PO4 phosphor. The phosphor was synthesized by precipitation method. The thermoluminescence dosimetric peak temperature for the phosphor varies with concentrations of Mg and Cu. Li3PO4 shows good response to 470nm optical stimulation. The OSL sensitivity of the phosphor is approximately 12 times than that of standard Lithium magnesium phosphate. This study may help to develop this material for the application in real time dosimetry using optically stimulated luminescence.

Synthesis and photoluminescence in Yb doped cerium phosphate CePO4

NASA Astrophysics Data System (ADS)

Bhonsule, S. U.; Wankhede, S. P.; Moharil, S. V.

2018-05-01

This paper presents the preparation of CePO4 and Yb doped CePO4 using simple solid state reaction method. PL measurements indicated significant energy transfer from Ce3+ to Yb3+ ions. Further evidence of energy transfer was provided by analysis of Luminescence Decay measurements. Energy transfer efficiency of 50% was obtained for 5%Yb doping. Energy transfer from Ce3+ to Yb3+ ions takes place by Cooperative energy transfer mechanism. Such phosphors can be used in white LED's, Lasers and energy saving fluorescent lamps.

A novel method for preparing pomegranate-structured FePO{sub 4}/C composite materials as cathode for lithium-ion batteries

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

Hao, Guan-nan; State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029; Zhang, Hao, E-mail: dr.h.zhang@hotmail.com

2012-12-15

Graphical abstract: Display Omitted Highlights: ► We designed and synthesized a pomegranate-structured FePO{sub 4}/C composite. ► We used a combination of electrospinning and solid-state reaction for preparation. ► We showed how the performance of pomegranate-structured FePO{sub 4} is highly enhanced. -- Abstract: A pomegranate-structured FePO{sub 4}/C composite was synthesized via a combination of electrospinning and high temperature reaction using micron-level FePO{sub 4} and polyacrylonitrile (PAN). Systematic studies on synthesis, modification, and characterization of FePO{sub 4}/C composites were conducted. The FePO{sub 4}/C composites delivered a specific discharge capacity of 109 mAh g{sup −1} at 0.2 C and 39 mAh g{sup −1}more » at 10 C, which were comparable with the reported nanometer-level FePO{sub 4}. We demonstrated that the three-dimensional net-like structure covered by porous carbon layers could highly enhance the electrochemical performance of FePO{sub 4}.« less

Nanosized LiFePO4-decorated emulsion-templated carbon foam for 3D micro batteries: a study of structure and electrochemical performance

NASA Astrophysics Data System (ADS)

Asfaw, Habtom D.; Roberts, Matthew R.; Tai, Cheuk-Wai; Younesi, Reza; Valvo, Mario; Nyholm, Leif; Edström, Kristina

2014-07-01

In this article, we report a novel 3D composite cathode fabricated from LiFePO4 nanoparticles deposited conformally on emulsion-templated carbon foam by a sol-gel method. The carbon foam is synthesized via a facile and scalable method which involves the carbonization of a high internal phase emulsion (polyHIPE) polymer template. Various techniques (XRD, SEM, TEM and electrochemical methods) are used to fully characterize the porous electrode and confirm the distribution and morphology of the cathode active material. The major benefits of the carbon foam used in our work are closely connected with its high surface area and the plenty of space suitable for sequential coating with battery components. After coating with a cathode material (LiFePO4 nanoparticles), the 3D electrode presents a hierarchically structured electrode in which a porous layer of the cathode material is deposited on the rigid and bicontinuous carbon foam. The composite electrodes exhibit impressive cyclability and rate performance at different current densities affirming their importance as viable power sources in miniature devices. Footprint area capacities of 1.72 mA h cm-2 at 0.1 mA cm-2 (lowest rate) and 1.1 mA h cm-2 at 6 mA cm-2 (highest rate) are obtained when the cells are cycled in the range 2.8 to 4.0 V vs. lithium.In this article, we report a novel 3D composite cathode fabricated from LiFePO4 nanoparticles deposited conformally on emulsion-templated carbon foam by a sol-gel method. The carbon foam is synthesized via a facile and scalable method which involves the carbonization of a high internal phase emulsion (polyHIPE) polymer template. Various techniques (XRD, SEM, TEM and electrochemical methods) are used to fully characterize the porous electrode and confirm the distribution and morphology of the cathode active material. The major benefits of the carbon foam used in our work are closely connected with its high surface area and the plenty of space suitable for sequential coating

Photodegradation applied to the treatment of phenol and derived substances catalyzed by TiO2/BiPO4 and biological toxicity analysis.

PubMed

Zaidan, Léa Elias Mendes Carneiro; de Lima Sales, Renata Vitória; de Almeida Salgado, Júlia Barbosa; da Silva, Ana Maria Ribeiro Bastos; Napoleão, Daniella Carla; Rodríguez-Díaz, Joan Manuel; Marques, Olga Martins; Benachour, Mohand; da Silva, Valdinete Lins

2017-03-01

For this work, a phenol solution model was treated by an advanced oxidation process (AOPs), using the heterogeneous catalyst TiO 2 /BiPO 4 and hydrogen peroxide combined with UVA for 240 min. An annular reactor containing a UVA lamp (80 W) was employed. A central composite rotacional design was developed employing a TiO 2 /BiPO 4 concentration of 87 mg L -1 and a hydrogen peroxide concentration of 1800 mg L -1 , being evaluated by the degradation percentage and phenol mineralization percentage as responses; 94.30 and 67.00 % were obtained for the phenol degradation and total organic carbon (TOC) conversion, respectively. The lumped kinetic model (LKM) was applied and a satisfactory profile of the residual fractions of the organic compounds present in the liquid phase as a time function with a determination coefficient (R 2  = 0.9945). The toxicity tests employing microbiological species indicated that the organisms tested for the evaluation of the toxic compounds present in the contaminated samples presented a practical low cost test, rapid execution, and high sensibility as an indicator of the presence of toxic substances in liquid effluents.

Ab initio identification of the Li-rich phase in LiFePO4.

PubMed

Zeng, Hua; Gu, Yue; Teng, Gaofeng; Liu, Yimeng; Zheng, Jiaxin; Pan, Feng

2018-06-27

A recent discovery of anionic redox activity in Li-rich layered compounds opens a new direction for the design of high-capacity cathode materials for lithium-ion batteries. Here using extensive ab initio calculations, the thermodynamic existence of the Li-rich phase in LiFePO4 to form Li1+xFe1-xPO4 with x not exceeding 12.5% has been proved. Anionic redox activity and structural stability during delithiation are further investigated. Interestingly, it is found that Li1+xFe1-xPO4 cannot be delithiated completely and thus cannot achieve extra capacity by anionic redox activity, because the local oxygen-ion redox will cause the fracture of the rigid framework formed by phosphate tetrahedral polyanions. Although an extra capacity cannot be realized, the excess Li-ions at Fe sites can enhance the Li-ion diffusivity along the adjacent [010] channel and contribute to the shift from 1D to 2D/3D diffusion. This study provides a fresh perspective on olivine-type LiFePO4 and offers some important clues on designing Li-rich cathode materials with high energy density.

Negative regulation of prophenoloxidase (proPO) activation by a clip-domain serine proteinase homolog (SPH) from endoparasitoid venom.

PubMed

Zhang, Guangmei; Lu, Zhi-Qiang; Jiang, Haobo; Asgari, Sassan

2004-05-01

Most parasitic wasps inject maternal factors into the host hemocoel to suppress the host immune system and ensure successful development of their progeny. Melanization is one of the insect defence mechanisms against intruding pathogens or parasites. We previously isolated from the venom of Cotesia rubecula a 50 kDa protein that blocked melanization in the hemolymph of its host, Pieris rapae [Insect Biochem. Mol. Biol. 33 (2003) 1017]. This protein, designated Vn50, is a serine proteinase homolog (SPH) containing an amino-terminal clip domain. In this work, we demonstrated that recombinant Vn50 bound P. rapae hemolymph components that were recognized by antisera to Tenebrio molitor prophenoloxidase (proPO) and Manduca sexta proPO-activating proteinase (PAP). Vn50 is stable in the host hemolymph-it remained intact for at least 72 h after parasitization. Using M. sexta as a model system, we found that Vn50 efficiently down-regulated proPO activation mediated by M. sexta PAP-1, SPH-1, and SPH-2. Vn50 did not inhibit active phenoloxidase (PO) or PAP-1, but it significantly reduced the proteolysis of proPO. If recombinant Vn50 binds P. rapae proPO and PAP (as suggested by the antibody reactions), it is likely that the molecular interactions among M. sexta proPO, PAP-1, and SPHs were impaired by this venom protein. A similar strategy might be employed by C. rubecula to negatively impact the proPO activation reaction in its natural host.

Stability of sunscreens containing CePO4: proposal for a new inorganic UV filter.

PubMed

Seixas, Vitor C; Serra, Osvaldo A

2014-07-09

Inorganic UV filters have become attractive because of their role in protecting the skin from the damage caused by continuous exposure to the sun. However, their large refractive index and high photocatalytic activity have led to the development of alternative inorganic materials such as CePO4 for application as UV filters. This compound leaves a low amount of white residue on the skin and is highly stable. The aim of this study was to evaluate the physical and chemical stability of a cosmetic formulation containing ordinary organic UV filters combined with 5% CePO4, and, to compare it with other formulations containing the same vehicle with 5% TiO2 or ZnO as inorganic materials. The rheological behavior and chemical stability of the formulations containing these different UV filters were investigated. Results showed that the formulation containing CePO4 is a promising innovative UV filter due to its low interaction with organic filters, which culminates in longer shelf life when compared with traditional formulations containing ZnO or TiO2 filters. Moreover, the recognized ability of CePO4 to leave a low amount of white residue on the skin combined with great stability, suggests that CePO4 can be used as inorganic filter in high concentrations, affording formulations with high SPF values.

The existence of a temperature-driven solid solution in LixFePO4 for 0 <= x <= 1

NASA Astrophysics Data System (ADS)

Delacourt, Charles; Poizot, Philippe; Tarascon, Jean-Marie; Masquelier, Christian

2005-03-01

Lithium-ion batteries have revolutionized the powering of portable electronics. Electrode reactions in these electrochemical systems are based on reversible insertion/deinsertion of Li+ ions into the host electrode material with a concomitant addition/removal of electrons into the host. If such batteries are to find a wider market such as the automotive industry, less expensive positive electrode materials will be required, among which LiFePO4 is a leading contender. An intriguing fundamental problem is to understand the fast electrochemical response from the poorly electronic conducting two-phase LiFePO4/FePO4 system. In contrast to the well-documented two-phase nature of this system at room temperature, we give the first experimental evidence of a solid solution LixFePO4 (0 <= x <= 1) at 450 °C, and two new metastable phases at room temperature with Li0.75FePO4 and Li0.5FePO4 composition. These experimental findings challenge theorists to improve predictive models commonly used in the field. Our results may also lead to improved performances of these electrodes at elevated temperatures.

NIR emission using Ce3+→Nd3+ energy transfer in Ba3Ce(PO4)3:Nd3+ phosphor

NASA Astrophysics Data System (ADS)

Tumram, P. V.; Moharil, S. V.

2018-05-01

In the System CePO4-Ba3(PO4)2, the intermediate compound Ba3Ce(PO4)3, is well known. In recent years, luminescence of rare earths has been studied in this host. However, there are no reports on the NIR emission in Ba3Ce(PO4)3. Here, NIR emission resulting from Ce3+→Nd3+ energy transfer in Ba3Ce(PO4)3 host is reported. This could be relevant for applications in bioimaging, telecommunication, solar photovoltaics, Photodynamic therapy, photostimulated localized hyperthermia, etc.

A hydrothermally synthesized LiFePO4/C composite with superior low-temperature performance and cycle life

NASA Astrophysics Data System (ADS)

Wu, Guan; Liu, Na; Gao, Xuguang; Tian, Xiaohui; Zhu, Yanbin; Zhou, Yingke; Zhu, Qingyou

2018-03-01

The LiFePO4/C composites have been successfully synthesized by a hydrothermal process, with the combined carbon sources of fructose and calcium lignosulfonate. The morphology and microstructure of LiFePO4/C were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The electrochemical properties were evaluated by the constant-current charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. The uniform carbon coating layer derived from calcium lignosulfonate can effectively improve the electronic conductivity, lithium-ion diffusivity and surface stability of the LiFePO4/C composites and prevent the side reactions between the LiFePO4 particles and electrolytes. The LiFePO4/C composites display excellent rate capability, superior cycle life and outstanding low temperature performance, which are promising for lithium-ion battery applications in electrical vehicles and electrical energy storage systems.

Synthesis, structures and properties of the new lithium cobalt(II) phosphate Li{sub 4}Co(PO{sub 4}){sub 2}

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

Glaum, R., E-mail: rglaum@uni-bonn.de; Gerber, K.; Schulz-Dobrick, M.

2012-04-15

{alpha}-Li{sub 4}Co(PO{sub 4}){sub 2} has been synthesized and crystallized by solid-state reactions. The new phosphate crystallizes in the monoclinic system (P2{sub 1}/a, Z=4, a=8.117(3) Angstrom-Sign , b=10.303(8) Angstrom-Sign , c=8.118(8) Angstrom-Sign , {beta}=104.36(8) Angstrom-Sign ) and is isotypic to {alpha}-Li{sub 4}Zn(PO{sub 4}){sub 2}. The structure of {alpha}-Li{sub 4}Co(PO{sub 4}){sub 2} has been determined from single-crystal X-ray diffraction data {l_brace}R{sub 1}=0.040, wR{sub 2}=0.135, 2278 unique reflections with F{sub o}>4{sigma}(F{sub o}){r_brace}. The crystal structure, which might be regarded as a superstructure of the wurtzite structure type, is build of layers of regular CoO{sub 4}, PO{sub 4} and Li1O{sub 4} tetrahedra. Lithium atomsmore » Li2, Li3 and Li4 are located between these layers. Thermal investigations by in-situ XRPD, DTA/TG and quenching experiments suggest decomposition followed by formation and phase transformation of Li{sub 4}Co(PO{sub 4}){sub 2}: {alpha}-Li{sub 4}Co(PO{sub 4}){sub 2} Long-Rightwards-Double-Arrow {sup 442 Degree-Sign C}{beta}-Li{sub 3}PO{sub 4}+LiCoPO{sub 4} Rightwards-Harpoon-Over-Leftwards-Harpoon {sup 773 Degree-Sign C}{beta}-Li{sub 4}Co(PO{sub 4}){sub 2} Long-Rightwards-Double-Arrow {sup quenchingto25 Degree-Sign C}{alpha}-Li{sub 4} Co(PO{sub 4}){sub 2} According to HT-XRPD at {theta}=850 Degree-Sign C{beta}-Li{sub 4}Co(PO{sub 4}){sub 2} (Pnma, Z=2, 10.3341(8) A, b=6.5829(5) A, c=5.0428(3) Angstrom-Sign ) is isostructural to {gamma}-Li{sub 3}PO{sub 4}. The powder reflectance spectrum of {alpha}-Li{sub 4}Co(PO{sub 4}){sub 2} shows the typical absorption bands for the tetrahedral chromophore [Co{sup II}O{sub 4}]. - Graphical abstract: The complex formation and decomposition behavior of Li{sub 4}Co(PO{sub 4}){sub 2} with temperature has been elucidated. The crystal structure of its {alpha}-phase was determined from single crystal data, HT-XRPD allowed derivation of a structure model for the {beta

Baseline concentration of ²¹⁰Po and ²¹⁰Pb in Sargassum from the northern Gulf.

PubMed

Uddin, S; Aba, A; Bebhehani, M

2015-01-15

This baseline study highlights the (210)Po and (210)Pb concentration in two species of the benthic macroalgae Sargassum from northern Gulf, also known as the ROPME Sea Area (RSA). Within the marine environment, (210)Po is initially absorbed from water and concentrated by phytoplankton and macroalgae, and this concentrated (210)Po can then readily be passed along to the higher trophic level of the marine food web. The (210)Po concentration measured in Sargassum boveanum (22.5-25.6 Bq kg(-1)) was higher than that in Sargassum oligocystum (20.2-22.5 Bq kg(-1)), but is not statistically significant (p>0.064), where as the difference between (210)Pb concentrations in Sargassum boveanum (15.3-16.8 Bq kg(-1)) and Sargassum oligocystum (18.4-22.0 Bq kg(-1)) was statistically significant (p>0.019). The measured concentration factor for (210)Po in Sargassum in the northern Gulf varied between 0.55 and 1.2×10(4), values higher to the IAEA recommended value of 1×10(3). The (210)Po enrichment is observed in both the species of Sargassum,(210)Po/(210)Pb ratio was >1 at all the stations for all the samples. Copyright © 2014 Elsevier Ltd. All rights reserved.

PoMo: An Allele Frequency-Based Approach for Species Tree Estimation

PubMed Central

De Maio, Nicola; Schrempf, Dominik; Kosiol, Carolin

2015-01-01

Incomplete lineage sorting can cause incongruencies of the overall species-level phylogenetic tree with the phylogenetic trees for individual genes or genomic segments. If these incongruencies are not accounted for, it is possible to incur several biases in species tree estimation. Here, we present a simple maximum likelihood approach that accounts for ancestral variation and incomplete lineage sorting. We use a POlymorphisms-aware phylogenetic MOdel (PoMo) that we have recently shown to efficiently estimate mutation rates and fixation biases from within and between-species variation data. We extend this model to perform efficient estimation of species trees. We test the performance of PoMo in several different scenarios of incomplete lineage sorting using simulations and compare it with existing methods both in accuracy and computational speed. In contrast to other approaches, our model does not use coalescent theory but is allele frequency based. We show that PoMo is well suited for genome-wide species tree estimation and that on such data it is more accurate than previous approaches. PMID:26209413

We Need You! The Importance of Scientist Involvement in Education and Public Outreach (E/PO)

NASA Astrophysics Data System (ADS)

Buxner, S.; Hsu, B. C.; Meinke, B. K.; Shipp, S. S.; Schwerin, T. G.; Peticolas, L. M.; Smith, D.; Dalton, H.

2013-12-01

Active engagement of scientists in education and public outreach (E/PO) activities is beneficial for scientists, classrooms, and the general public. Scientist visibility in the public arena is important to garner public support, whose tax dollars fund scientific programs. Scientists are important disseminators of current, accurate scientific knowledge. They also, perhaps more importantly, understand the nature and process of science and have the means of understanding and addressing many of the issues facing society. Research has shown that while the public is interested in science, not all members are necessarily scientifically literate; additionally there is evidence than many students are not prepared for, or choosing to participate in science careers. And yet, a scientifically engaged, literate, and supportive public is a necessary partner in addressing important global challenges of the future. E/PO is a wonderful opportunity for scientists to demonstrate that science is interesting, exciting, fun, challenging, and relevant to society. In doing so, they can transfer ownership of science to the public through a variety of vehicles by increasing access to scientific thought and discovery. Through partnerships with E/PO professionals, teachers, or journalists, scientists can improve their communication and teaching skills, whether in an E/PO setting or their higher education careers. Sharing with the public what scientists do is an effective way to engage people in the scientific process and to express scientists' enthusiasm for what they do. Scientist involvement in E/PO also shows the public that scientists are real people and provides important role models for the next generation of scientists. There are many opportunities to get involved in E/PO! Find information on EarthSpace, a national clearinghouse for higher education materials in Earth and space science through an abstract by Nicholas Gross, et al. Learn about NASA Science Mission Directorate (SMD

Phase equilibria in the NaF-CdO-NaPO3 system at 873 K and crystal structure and physico-chemical characterizations of the new Na2CdPO4F fluorophosphate

NASA Astrophysics Data System (ADS)

Aboussatar, Mohamed; Mbarek, Aïcha; Naili, Houcine; El-Ghozzi, Malika; Chadeyron, Geneviève; Avignant, Daniel; Zambon, Daniel

2017-04-01

Isothermal sections of the diagram representing phase relationships in the NaF-CdO-NaPO3 system have been investigated by solid state reactions and powder X-ray diffraction. This phase diagram investigation confirms the polymorphism of the NaCdPO4 side component and the structure of the ß high temperature polymorph (orthorhombic, space group Pnma and unit cell parameters a=9.3118(2), b=7.0459(1), c=5.1849(1) Å has been refined. A new fluorophosphate, Na2CdPO4F, has been discovered and its crystal structure determined and refined from powder X-ray diffraction data. It exhibits a new 3D structure with orthorhombic symmetry, space group Pnma and unit cell parameters a=5.3731(1), b=6.8530(1), c=12.2691(2) Å. The structure is closely related to those of the high temperature polymorph of the nacaphite Na2CaPO4F and the fluorosilicate Ca2NaSiO4F but differs essentially in the cationic repartition since the structure is fully ordered with one Na site (8d) and one Cd site (4c). Relationships with other Na2MIIPO4F (MII=Mg, Ca, Mn, Fe, Co, Ni) have been examined and the crystal-chemical and topographical analysis of these fluorophosphates is briefly reviewed. IR, Raman, optical and 19F, 23Na, 31P MAS NMR characterizations of Na2CdPO4F have been investigated.

Synthesis of LiFePO4/Li2SiO3/reduced Graphene Oxide (rGO) Composite via Hydrothermal Method

NASA Astrophysics Data System (ADS)

Arifin, M.; Iskandar, F.; Aimon, A. H.; Munir, M. M.; Nuryadin, B. W.

2016-08-01

LiFePO4 is a type of cathode active material used for lithium ion batteries. It has a high electrochemical performance. However, it suffers from certain disadvantages such as a very low intrinsic electronic conductivity and low ionic diffusion. This study was conducted to increase the conductivity of LiFePO4. We have investigated the addition of Li2SiO3 and reduced graphene oxide (rGO) to LiFePO4. The objective of this research was to synthesize LiFePO4/Li2SiO3/rGO via hydrothermal method. Fourier transform infrared spectroscopy (FTIR) measurement showed that the peaks corresponded to the vibration of LiFePO4/Li2SiO3. Further, X-ray diffraction (XRD) measurement confirmed a single phase of LiFePO4. Finally, scanning electron microscopy (SEM) images showed that rGO was distributed on the LiFePO4/Li2SiO3 structure.

Structural and Electrical Properties of Lithium-Ion Rechargeable Battery Using the LiFePO4/Carbon Cathode Material.

PubMed

Kim, Young-Sung; Jeoung, Tae-Hoon; Nam, Sung-Pill; Lee, Seung-Hwan; Kim, Jea-Chul; Lee, Sung-Gap

2015-03-01

LiFePO4/C composite powder as cathode material and graphite powder as anode material for Li-ion batteries were synthesized by using the sol-gel method. An electrochemical improvement of LiFePO4 materials has been achieved by adding polyvinyl alcohol as a carbon source into as-prepared materials. The samples were characterized by elemental analysis (EA), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-EM). The chemical composition of LiFePO4/C powders was in a good agreement with that of the starting solution. The capacity loss after 500 cycles of LiFePO4/C cell is 11.1% in room temperature. These superior electrochemical properties show that LiFePO4/C composite materials are promising candidates as cathode materials.

Three-dimensional hollow graphene efficiently promotes electron transfer of Ag3PO4 for photocatalytically eliminating phenol

NASA Astrophysics Data System (ADS)

Song, Shaoqing; Meng, Aiyun; Jiang, Shujuan; Cheng, Bei

2018-06-01

The effective transport of photo-induced carriers over semiconductor photocatalyst is critical for enhancing the photocatalytic performance under light excitation. Although oxidized graphene (GO) and/or reduced graphene oxide (rGO) has been used as cocatalyst to promote the transfer and utilization of electrons, however, random diffusion and transfer of photo-induced charges are inevitable from all sides over these actual graphene owing to the limitation of the preparation process and theory. Herein, we utilized three-dimensional hollow carbon graphene (HCG) to promote the efficient electron transfer of Ag3PO4 in the photocatalytic process. Owing to the confinement-induced electron field of HCG, the constructed HCG-Ag3PO4 photocatalytic system demonstrated the enhanced visible-light adsorption, improved transfer of photo-induced charges, and suitable redox potentials as revealed by transient photo-current spectroscopic, surface photovoltage spectroscopy, and electron paramagnetic resonance (EPR). EPR spectra of oxygen species and gas chromatography-mass spectra exhibited high efficiency activity over HCG-Ag3PO4 with Z-scheme photocatalytic mechanism for phenol decomposition by reaction between hexanoic acid and radOH and radO2-. It is noteworthy that photocatalytic performance over optimal HCG-Ag3PO4 is 6, 3.43, 1.92 times of pristine Ag3PO4, GO-Ag3PO4, and rGO-Ag3PO4, respectively. The results may supply a novel perspective to enhance transfer of photo-induced charges for the promotion of photocatalytic technology.

High-Capacity and Long-Cycle Life Aqueous Rechargeable Lithium-Ion Battery with the FePO4 Anode.

PubMed

Wang, Yuesheng; Yang, Shi-Ze; You, Ya; Feng, Zimin; Zhu, Wen; Gariépy, Vincent; Xia, Jiexiang; Commarieu, Basile; Darwiche, Ali; Guerfi, Abdelbast; Zaghib, Karim

2018-02-28

Aqueous lithium-ion batteries are emerging as strong candidates for a great variety of energy storage applications because of their low cost, high-rate capability, and high safety. Exciting progress has been made in the search for anode materials with high capacity, low toxicity, and high conductivity; yet, most of the anode materials, because of their low equilibrium voltages, facilitate hydrogen evolution. Here, we show the application of olivine FePO 4 and amorphous FePO 4 ·2H 2 O as anode materials for aqueous lithium-ion batteries. Their capacities reached 163 and 82 mA h/g at a current rate of 0.2 C, respectively. The full cell with an amorphous FePO 4 ·2H 2 O anode maintained 92% capacity after 500 cycles at a current rate of 0.2 C. The acidic aqueous electrolyte in the full cells prevented cathodic oxygen evolution, while the higher equilibrium voltage of FePO 4 avoided hydrogen evolution as well, making them highly stable. A combination of in situ X-ray diffraction analyses and computational studies revealed that olivine FePO 4 still has the biphase reaction in the aqueous electrolyte and that the intercalation pathways in FePO 4 ·2H 2 O form a 2-D mesh. The low cost, high safety, and outstanding electrochemical performance make the full cells with olivine or amorphous hydrated FePO 4 anodes commercially viable configurations for aqueous lithium-ion batteries.

A semantic proteomics dashboard (SemPoD) for data management in translational research.

PubMed

Jayapandian, Catherine P; Zhao, Meng; Ewing, Rob M; Zhang, Guo-Qiang; Sahoo, Satya S

2012-01-01

One of the primary challenges in translational research data management is breaking down the barriers between the multiple data silos and the integration of 'omics data with clinical information to complete the cycle from the bench to the bedside. The role of contextual metadata, also called provenance information, is a key factor ineffective data integration, reproducibility of results, correct attribution of original source, and answering research queries involving "What", "Where", "When", "Which", "Who", "How", and "Why" (also known as the W7 model). But, at present there is limited or no effective approach to managing and leveraging provenance information for integrating data across studies or projects. Hence, there is an urgent need for a paradigm shift in creating a "provenance-aware" informatics platform to address this challenge. We introduce an ontology-driven, intuitive Semantic Proteomics Dashboard (SemPoD) that uses provenance together with domain information (semantic provenance) to enable researchers to query, compare, and correlate different types of data across multiple projects, and allow integration with legacy data to support their ongoing research. The SemPoD platform, currently in use at the Case Center for Proteomics and Bioinformatics (CPB), consists of three components: (a) Ontology-driven Visual Query Composer, (b) Result Explorer, and (c) Query Manager. Currently, SemPoD allows provenance-aware querying of 1153 mass-spectrometry experiments from 20 different projects. SemPod uses the systems molecular biology provenance ontology (SysPro) to support a dynamic query composition interface, which automatically updates the components of the query interface based on previous user selections and efficiently prunes the result set usinga "smart filtering" approach. The SysPro ontology re-uses terms from the PROV-ontology (PROV-O) being developed by the World Wide Web Consortium (W3C) provenance working group, the minimum information required for

Bottom-up substitution assembly of AuF4-n0,-+nPO3 (n = 1-4): a theoretical study of novel oxyfluoride hyperhalogen molecules and anions AuF4-n(PO3)n0,-

NASA Astrophysics Data System (ADS)

Yang, Yi-fan; Cui, Zhong-hua; Ding, Yi-hong

2014-06-01

Compounds with high electron affinity, i.e. superhalogens, have continued to attract chemists' attention, due to their potential importance in fundamental chemistry and materials science. It has now proven very effective to build up novel superhalogens with multi-positively charged centres, which are usually called 'hyperhalogens'. Herein, using AuF4- and PO3 as the model building blocks, we made the first attempt to design the Au,P-based hyperhalogen anions AuF4-n(PO3)n- (n = 1-4) at the B3LYP/6-311+G(d)&SDD and CCSD(T)/6-311+G(d)&SDD (single-point) levels (6-311+G(d) for O, F, P and SDD for Au). Notably, for all the considered Au,P systems, the ground state bears a dioxo-bonded structure with n ≤ 3, which is significantly more stable than the usually presumed mono-oxo-bonded one. Moreover, the clustering of the -PO3 moieties becomes energetically favoured for n ≥ 3. The ground states of AuP4O120,- are the first reported cage-like oxide hyperhalogens. Thus, the -PO3 moiety cannot be retained during the 'bottom-up' assembly. The vertical detachment energy (VDE) value of the most stable AuF4-n(PO3)n- (n = 1-4) ranges from 7.16 to 8.20 eV, higher than the VDE values of the corresponding building blocks AuF4- (7.08 eV) and PO3- (4.69 eV). The adiabatic detachment energy values of these four hyperhalogens exceed 6.00 eV. Possible generation routes for AuF4-n(PO3)n- (n = 1-4) were discussed. The presently designed oxyfluorides not only enriches the family of hyperhalogens, but also demonstrates the great importance of considering the structural transformation during the superhalogen → hyperhalogen design such as for the present Au-P based systems.

Speciation of 210Po and 210Pb in air particulates determined by sequential extraction.

PubMed

Al-Masri, M S; Al-Karfan, K; Khalili, H; Hassan, M

2006-01-01

Speciation of (210)Po and (210)Pb in air particulates of two Syrian phosphate sites with different climate conditions has been studied. The sites are the mines and Tartous port at the Mediterranean Sea. Air filters were collected during September 2000 until February 2002 and extracted chemically using different selective fluids in an attempt to identify the different forms of these two radionuclides. The results have shown that the inorganic and insoluble (210)Po and (210)Pb (attached to silica and soluble in mineral acids) portion was found to be high in both sites and reached a maximum value of 94% and 77% in the mine site and Tartous port site, respectively. In addition, only 24% of (210)Pb in air particulates was found to be associated with organic materials probably produced from the incomplete burning of fuel vehicle and similar activities. Moreover, the (210)Po/(210)Pb activity ratio in air particulates was higher than that in all samples at both sites and varied between 3.85 in November 2000 at Tartous port site and 20 in April 2001 at the mine area. These activity ratios were also higher than the natural levels. The (210)Po/(210)Pb activity ratio was also determined in each portion resulting from the selective extraction and found to be higher than that in most samples. The sources of (210)Po excess in these portions are discussed. Soil suspension, which is common in the dry climate dominant in the area, sea water spray and heating of phosphate ores were considered; polonium is more volatile than the lead compounds at even moderate temperature. Furthermore, variations in the chemical forms of (210)Po and (210)Pb during the year were also investigated. However, the results of this study can also be utilized for dose assessment to phosphate industry workers.

The large-scale distribution and internal geometry of the fall 2000 Po River flood deposit: Evidence from digital X-radiography

USGS Publications Warehouse

Wheatcroft, R.A.; Stevens, A.W.; Hunt, L.M.; Milligan, T.G.

2006-01-01

Event-response coring on the Po River prodelta (northern Adriatic Sea) coupled with shipboard digital X-radiography, resistivity profiling, and grain-size analyses permitted documentation of the initial distribution and physical properties of the October 2000 flood deposit. The digital X-radiography system comprises a constant-potential X-ray source and an amorphous silicon imager with an active area of 29??42 cm and 12-bit depth resolution. Objective image segmentation algorithms based on bulk density (brightness), layer contacts (edge detection) and small-scale texture (fabric) were used to identify the flood deposit. Results indicate that the deposit formed in water depths of 6-29 m immediately adjacent to the three main distributary mouths of the Po (Pila, Tolle and Gnocca/Goro). Maximal thickness was 36 cm at a 20-m site off the main mouth (Pila), but many other sites hadthicknesses >20 cm. The Po flood deposit has a complex internal stratigraphy, with multiple layers, a diverse suite of physical sedimentary structures (e.g., laminations, ripple cross bedding, lenticular bedding, soft-sediment deformation structures), and dramatic changes in grain size that imply rapid deposition and fluctuations in energy during emplacement. Based on the flood deposit volume and well-constrained measurements of deposit bulk density the mass of the flood deposit was estimated to be 16??109 kg, which is about two-thirds of the estimated suspended sediment load delivered by the river during the event. The locus of deposition, overall thickness, and stratigraphic complexity of the flood deposit can best be explained by the relatively long sediment throughput times of the Po River, whereby sediment is delivered to the ocean during a range of conditions (i.e., the storm responsible for the precipitation is long gone), the majority of which are reflective of the fair-weather condition. Sediment is therefore deposited proximal to the river mouths, where it can form thick, but

NASA's Science Education and Public Outreach Forums: Bringing Communities and Resources Together to Increase Effectiveness and Sustainability of E/PO

NASA Astrophysics Data System (ADS)

Sharma, Mangala; Smith, D.; Mendez, B.; Shipp, S.; Schwerin, T.; Stockman, S.; Cooper, L.

2010-03-01

The AAS-HEAD community has a rich history of involvement in education and public outreach (E/PO). HEAD members have been using NASA science and educational resources to engage and educate youth and adults nationwide in science, technology, engineering, and mathematics topics. Four new Science Education and Public Outreach Forums ("Forums") funded by NASA Science Mission Directorate (SMD) are working in partnership with the research and education community to ensure that current and future SMD-funded E/PO activities form a seamless whole, with easy entry points for scientists, engineers, faculty, students, K-12 formal and informal science educators, general public, and E/PO professionals alike. These Forums support the astrophysics, heliophysics, planetary and Earth science divisions of NASA SMD in three core areas: 1) E/PO community engagement and development to facilitate clear paths of involvement for scientists, engineers and others interested - or potentially interested - in participating in SMD-funded E/PO activities. Collaborations with science professionals are vital for infusing current, accurate SMD mission and research findings into educational products and activities. Forum activities will yield readily accessible information on effective E/PO strategies, resources, and expertise; context for individual E/PO activities; and opportunities for collaboration. 2) A rigorous analysis of SMD-funded E/PO products and activities to help understand how the existing collection supports education standards and audience needs and to identify areas of opportunity for new materials and activities. K-12 formal, informal, and higher education products and activities are included in this analysis. 3) Finally, to address E/PO-related systemic issues and coordinate related activities across the four SMD science divisions. By supporting the NASA E/PO community and facilitating coordination of E/PO activities within and across disciplines, the SMD-Forum partnerships will

Baseline concentration of Polonium-210 ((210)Po) in tuna fish.

PubMed

Khan, M Feroz; Wesley, S Godwin

2016-06-15

Several species of tuna fish were analyzed for (210)Po content in their edible muscle tissues. This study was carried out as a part of baseline data generation around a large nuclear power plant situated at Kudankulam, southeast coast of India. The concentration of (210)Po in the muscle tissue ranged from 40.9±5.2 to 92.5±7.9Bq/kg of fresh fish, and the highest activity was recorded for the tuna Euthynnus affinis and the lowest for Auxis thazard. The committed effective dose to the local residents was calculated to be 62.7-141.8μSvyear(-1). Copyright © 2016 Elsevier Ltd. All rights reserved.

Preventing structural degradation from Na3V2(PO4)3 to V2(PO4)3: F-doped Na3V2(PO4)3/C cathode composite with stable lifetime for sodium ion batteries

NASA Astrophysics Data System (ADS)

Chen, Yanjun; Xu, Youlong; Sun, Xiaofei; Zhang, Baofeng; He, Shengnan; Li, Long; Wang, Chao

2018-02-01

A prospective NASICON-type F-doped Na3V2(PO4)2.93F0.07/C (F-0.07-NVP/C) composite is synthesized by a solid-state reaction method. F-doping can restrain the structural degradation from Na3V2(PO4)3 to V2(PO4)3 and enhance the structural stability. Meanwhile, it can decrease the particle size to diminish the pathway of Na+ diffusion, which can increase ionic conductivity efficiently. The kinetic behavior is significantly improved and it is beneficial to reinforcing the electrochemical performance of F-doping composites. Compared with Undoped-NVP/C sample, F-0.07-NVP/C composite delivers a 113 mAh g-1 discharge capacity at 10 mA g-1, which is very close to the theoretical capacity (117 mAh g-1). As for cycle performance, a reversible capacity of 97.8 mAh g-1 can be obtained and it retains 86% capacity after 1000 cycles at 200 mA g-1. F-0.07-NVP/C composite presents the highest DNa+ (2.62 × 10-15 cm2s-1), two orders of magnitude higher than the undoped sample (4.8 × 10-17 cm2s-1). This outstanding electrochemical performance is ascribed to the synergetic effect from improved kinetic behavior and enhanced structural stability due to F-doping. Hence, the F-doped composite would be a promising cathode material in SIB for energy storage and conversion.

Electrochemical and XPS study of LiFePO4 cathode nanocomposite with PPy/PEG conductive network

NASA Astrophysics Data System (ADS)

Fedorková, A.; Oriňáková, R.; Oriňák, A.; Kupková, M.; Wiemhöfer, H.-D.; Audinot, J. N.; Guillot, J.

2012-08-01

High performance PPy/PEG-LiFePO4 nanocomposites as cathode materials were synthesized by solvothermal method and simple chemical oxidative polymerization of pyrrole (Py) monomer on the surface of LiFePO4 particles. The samples were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectrometry (XPS) and charge-discharge tests. PPyPEG hybrid layers decrease particle to particle contact resistance while the impedance measurements confirmed that the coating of PPy-PEG significantly decreases the charge transfer resistance of the electrode material. The initial discharge capacities of this sample at C/5 and 1C are 150 and 128 mAh/g, respectively. The results show that PPy/PEGLiFePO4 composites are more effective than bare LiFePO4 as cathode material.

Source inversion of the 1570 Ferrara earthquake and definitive diversion of the Po River (Italy)

NASA Astrophysics Data System (ADS)

Sirovich, L.; Pettenati, F.

2015-08-01

An 11-parameter, kinematic-function (KF) model was used to retrieve the approximate geometrical and kinematic characteristics of the fault source of the 1570 Mw 5.8 Ferrara earthquake in the Po Plain, including the double-couple orientation (strike angle 127 ± 16°, dip 28 ± 7°, and rake 77 ± 16°). These results are compatible with either the outermost thrust fronts of the northern Apennines, which are buried beneath the Po Plain's alluvial deposits, or the blind crustal-scale thrust. The 1570 event developed to the ENE of the two main shocks on 20 May 2012 (M 6.1) and 29 May 2012 (M 5.9). The three earthquakes had similar kinematics and are found 20-30 km from each other en echelon in the buried chain. Geomorphological and historical evidence exist which suggest the following: (i) the long-lasting uplift of the buried Apenninic front shifted the central part of the course of the Po River approximately 20 km northward in historical times and (ii) the 1570 earthquake marked the definitive diversion of the final part of the Po River away from Ferrara and the closure of the Po delta 40 km south of its present position.

Concentrations, profiles, and estimated human exposures for polychlorinated dibenzo-p-dioxins and dibenzofurans from electronic waste recycling facilities and a chemical industrial complex in Eastern China.

PubMed

Ma, Jing; Kannan, Kurunthachalam; Cheng, Jinping; Horii, Yuichi; Wu, Qian; Wang, Wenhua

2008-11-15

Environmental pollution arising from electronic waste (e-waste) disposal and recycling has received considerable attention in recent years. Treatment, at low temperatures, of e-wastes that contain polyvinylchloride and related polymers can release polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Although several studies have reported trace metals and polybrominated diphenyl ethers (PBDEs) released from e-waste recycling operations, environmental contamination and human exposure to PCDD/Fs from e-waste recycling operations are less well understood. In this study, electronic shredder waste and dust from e-waste facilities, and leaves and surface soil collected in the vicinity of a large scale e-waste recycling facility in Taizhou, Eastern China, were analyzed for total PCDD/ Fs including 2,3,7,8-substituted congeners. We also determined PCDD/Fs in surface agricultural soils from several provinces in China for comparison with soils from e-waste facilities. Concentrations of total PCDD/Fs were high in all of the matrices analyzed and ranged from 30.9 to 11400 pg/g for shredder waste, 3460 to 9820 pg/g dry weight for leaves, 2560 to 148000 pg/g dry weight for workshop-floor dust, and 854 to 10200 pg/g dry weight for soils. We also analyzed surface soils from a chemical industrial complex (a coke-oven plant, a coal-fired power plant, and a chlor-alkali plant) in Shanghai. Concentrations of total PCDD/Fs in surface soil (44.5-531 pg/g dry wt) from the chemical industrial complex were lower than the concentrations found in soils from e-waste recycling plants, but higher than the concentrations found in agricultural soils. Agricultural soils from six cities in China contained low levels (3.44-33.8 pg/g dry wt) of total PCDD/Fs. Profiles of dioxin toxic equivalents (TEQs) of 2,3,7,8-PCDD/Fs in soils from e-waste facilities in Taizhou differed from the profiles found in agricultural soils. The estimated daily intakes of TEQs of PCDD/ Fs via soil/dust ingestion

AgCl/Ag3PO4: A stable Ag-Based nanocomposite photocatalyst with enhanced photocatalytic activity for the degradation of parabens.

PubMed

Guo, Jianhao; Shi, Huixian; Huang, Xiaobo; Shi, Huifang; An, Zhongfu

2018-04-01

An AgCl/Ag 3 PO 4 composite has been successfully fabricated by a simple desorption-precipitation method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV/Vis), and photoluminescence (PL) have been used to study the structural and physicochemical characteristics of the AgCl/Ag 3 PO 4 composite. The photocatalytic activity of the AgCl/Ag 3 PO 4 composite has been tested by the degradation of parabens under visible-light irradiation. 100% of MPB was degraded within 40 min in the AgCl/Ag 3 PO 4 -visible light system. Moreover, the photocatalytic activity of AgCl/Ag 3 PO 4 remained at 94% of the original level after five runs, which was much higher than that of pure Ag 3 PO 4 (25%). The obtained results confirmed that the AgCl/Ag 3 PO 4 composite exhibited significantly higher photocatalytic performance and improved stability compared with bare Ag 3 PO 4 . The enhanced photocatalytic performance of the AgCl/Ag 3 PO 4 composite could be mainly attributed to highly efficient charge separation through a synergistic effect of AgCl, Ag 3 PO 4 , and in situ photo-reduced Ag nanoparticles. Trapping experiments confirmed h + and ·O 2 - to be the two main active species in the photocatalytic process. Finally, a possible photocatalytic mechanism for the charge-transfer process is proposed to account for the enhanced photocatalytic performance of the AgCl/Ag 3 PO 4 composite. Copyright © 2018 Elsevier Inc. All rights reserved.

In-situ synthesis of monodisperse micro-nanospherical LiFePO4/carbon cathode composites for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Gong, Hao; Xue, Hairong; Wang, Tao; He, Jianping

2016-06-01

The LiFePO4 is recognized as the promising cathode material, due to its high specific capacity, excellent, structural stability and environmental benignity. However, it is blamed for the low tap density and poor rate performance when served as the cathode materials for a long time. Here, the microspheric LiFePO4/C composites are successfully synthesized through a one-step in-situ solvothermal method combined with carbothermic reduction. These LiFePO4/C microspheres are assembled by LiFePO4 nanoparticles (∼100 nm) and uniformly coated by the carbon, which show a narrow diameter distribution of 4 μm. As a cathode material for lithium ion batteries, the LiFePO4/C composites can deliver an initiate charge capacity of 155 mAh g-1 and retain 90% of initial capacity after 200 cycles at 0.1 C. When cycled at high current densities up to 20 C, it shows a discharge capacity of ∼60 mAh g-1, exhibiting superior rate performance. The significantly improved electrochemical performance of LiFePO4/C composites material can be attributed to its special micro-nano hierarchical structure. Microspheric LiFePO4/C composites exhibit a high tap density about 1.3 g cm-3. What's more, the well-coated carbon insures the high electrical conductivity and the nano-sized LiFePO4/C particles shorten lithium ion transport, thus exhibiting the high specific capacity, high cycling stability and good rate performance.

PoMaMo—a comprehensive database for potato genome data

PubMed Central

Meyer, Svenja; Nagel, Axel; Gebhardt, Christiane

2005-01-01

A database for potato genome data (PoMaMo, Potato Maps and More) was established. The database contains molecular maps of all twelve potato chromosomes with about 1000 mapped elements, sequence data, putative gene functions, results from BLAST analysis, SNP and InDel information from different diploid and tetraploid potato genotypes, publication references, links to other public databases like GenBank (http://www.ncbi.nlm.nih.gov/) or SGN (Solanaceae Genomics Network, http://www.sgn.cornell.edu/), etc. Flexible search and data visualization interfaces enable easy access to the data via internet (https://gabi.rzpd.de/PoMaMo.html). The Java servlet tool YAMB (Yet Another Map Browser) was designed to interactively display chromosomal maps. Maps can be zoomed in and out, and detailed information about mapped elements can be obtained by clicking on an element of interest. The GreenCards interface allows a text-based data search by marker-, sequence- or genotype name, by sequence accession number, gene function, BLAST Hit or publication reference. The PoMaMo database is a comprehensive database for different potato genome data, and to date the only database containing SNP and InDel data from diploid and tetraploid potato genotypes. PMID:15608284

Vibrational spectroscopy of the phosphate mineral kovdorskite - Mg2PO4(OH)ṡ3H2O

NASA Astrophysics Data System (ADS)

Frost, Ray L.; López, Andrés; Xi, Yunfei; Granja, Amanda; Scholz, Ricardo; Lima, Rosa Malena Fernandes

2013-10-01

The mineral kovdorskite Mg2PO4(OH)ṡ3H2O was studied by electron microscopy, thermal analysis and vibrational spectroscopy. A comparison of the vibrational spectroscopy of kovdorskite is made with other magnesium bearing phosphate minerals and compounds. Electron probe analysis proves the mineral is very pure. The Raman spectrum is characterized by a band at 965 cm-1 attributed to the PO43- ν1 symmetric stretching mode. Raman bands at 1057 and 1089 cm-1 are attributed to the PO43- ν3 antisymmetric stretching modes. Raman bands at 412, 454 and 485 cm-1 are assigned to the PO43- ν2 bending modes. Raman bands at 536, 546 and 574 cm-1 are assigned to the PO43- ν4 bending modes. The Raman spectrum in the OH stretching region is dominated by a very sharp intense band at 3681 cm-1 assigned to the stretching vibration of OH units. Infrared bands observed at 2762, 2977, 3204, 3275 and 3394 cm-1 are attributed to water stretching bands. Vibrational spectroscopy shows that no carbonate bands are observed in the spectra; thus confirming the formula of the mineral as Mg2PO4(OH)ṡ3H2O.

Synthesis and characterization of LiFePO4/C cathode materials by sol-gel method.

PubMed

Liu, Shuxin; Yin, Hengbo; Wang, Haibin; Wang, Hong

2014-09-01

The carbon coated LiFePO4 cathode materials (LiFePO4/C) were successfully synthesized by sol-gel method with glucose, citric acid and PEG-4000 as dispersant and carbon source, respectively. The microstructure and grain size of LiFePO4/C composite were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy. The results showed that the carbon source and calcination temperature had important effect on the graphitization degree of carbon; the carbon decomposed by citric acid had higher graphitization degree; with calcination temperature rising, the graphitization degree of carbon increased and the particles size increased. The graphitization degree and grain size were very important for improving the electrochemical performance of LiFePO4 cathode materials, according to the experimental results, the sample LFP-700 (LFP-C) which was synthesized with citric acid as dispersant at 700 degree C had lower polarization and larger discharge capacity.

DNA@Mn3(PO4)2 Nanoparticles Supported with Graphene Oxide as Photoelectrodes for Photoeletrocatalysis

NASA Astrophysics Data System (ADS)

Gao, Lixia; Xie, Jiale; Ma, Xiaoqing; Li, Man; Yu, Ling

2017-01-01

A novel deoxyribose nucleic acid (DNA)-based photoelectrode consisting of DNA@Mn3(PO4)2 nanoparticles on graphene oxide (GO) sheets was successfully fabricated for photoelectrocatalysis. DNA served as a soft template to guide the nucleation and growth of Mn3(PO4)2 nanoparticles in the synthesis of Mn3(PO4)2 nanoparticles. More importantly, the DNA also serves as semiconductor materials to adjust charge transport. Under UV light irradiation (180-420 nm, 15 mW/cm2), the photocurrent density of DNA@ Mn3(PO4)2/GO electrodes reached 9 μA/cm2 at 0.7 V bias (vs. SCE). An applied bias photon-to-current efficiency (ABPE) of 0.18% can be achieved, which was much higher than that of other control electrodes (<0.04%). In this DNA-based photoelectrode, well-matched energy levels can efficiently improve charge transfer and reduce the recombination of photogenerated electron-hole pairs.

Zoledronic acid induces micronuclei formation, mitochondrial-mediated apoptosis and cytostasis in kidney cells.

PubMed

Singireesu, Soma Shiva Nageswara Rao; Mondal, Sujan Kumar; Yerramsetty, Suresh; Misra, Sunil

2018-06-15

Zoledronic acid (ZA), a FDA approved drug has used widely in the treatment of bone metastasis complications, has been linked to renal toxicity with unclear mechanism. The present study is aimed at investigating the genotoxic and cytotoxic effects of ZA in renal epithelial cells. The genotoxic effect of ZA in Vero and MDCK cells determined by cytokinesis block micronucleus (CBMN) assay. The cytotoxic effect assessed by analysing cell cycle profile, cell death and mitochondrial membrane potential by flow cytometry using propidium iodide, AnnexinV-FITC/PI and JC1 dye staining, respectively, BAX and Bcl-2 expression by Western blotting and caspase activity by spectrofluorimetry. The cytotoxic effect of ZA based on MTT assay revealed variable sensitivities of Vero and MDCK cells, with IC 50 values of 7.41 and 109.58 μM, respectively. The CBMN assay has shown prominent dose-dependent (IC 10-50 ) induction of micronuclei formation in both cells, indicating ZA's clastogenic and aneugenic potential. Further, the ZA treatment led the cells to apoptosis, evident from dose-dependent increase in the percentage of cells in subG1 phase and display of membranous phosphatidylserine translocation. Studies also confirmed apoptosis through mitochondria, evident from the prominent increase in BAX/Bcl-2 ratio, mitochondrial membrane depolarization and caspase-3/7 activity. In addition, ZA reduces cytokinetic activity of renal cells, evident from dose-wise lowered replicative indices. The study depict ZA's potential genotoxic effect along with cytotoxic effect in renal epithelial cells, could be key factors for the development of renal complications associated with it, which prompts renal safety measures in lieu with ZA usage. Copyright © 2018 Elsevier Inc. All rights reserved.

Synthesis and Electrocatalytic Activity of Ammonium Nickel Phosphate, [NH4]NiPO4·6H2O, and β-Nickel Pyrophosphate, β-Ni2P2O7: Catalysts for Electrocatalytic Decomposition of Urea.

PubMed

Meguerdichian, Andrew G; Jafari, Tahereh; Shakil, Md R; Miao, Ran; Achola, Laura A; Macharia, John; Shirazi-Amin, Alireza; Suib, Steven L

2018-02-19

Electrocatalytic decomposition of urea for the production of hydrogen, H 2, for clean energy applications, such as in fuel cells, has several potential advantages such as reducing carbon emissions in the energy sector and environmental applications to remove urea from animal and human waste facilities. The study and development of new catalyst materials containing nickel metal, the active site for urea decomposition, is a critical aspect of research in inorganic and materials chemistry. We report the synthesis and application of [NH 4 ]NiPO 4 ·6H 2 O and β-Ni 2 P 2 O 7 using in situ prepared [NH 4 ] 2 HPO 4 . The [NH 4 ]NiPO 4 ·6H 2 O is calcined at varying temperatures and tested for electrocatalytic decomposition of urea. Our results indicate that [NH 4 ]NiPO 4 ·6H 2 O calcined at 300 °C with an amorphous crystal structure and, for the first time applied for urea electrocatalytic decomposition, had the greatest reported electroactive surface area (ESA) of 142 cm 2 /mg and an onset potential of 0.33 V (SCE) and was stable over a 24-h test period.

Dosimetry of {sup 210}Po in humans, caribou, and wolves in northern Canada

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

Thomas, P.A.

1994-06-01

Effective doses from {sup 210}Po intake with caribou meat were determined for human residents in Baker Lake and Snowdrift in the Northwest Territories of Canada and compared to doses calculated from reported {sup 210}Po tissue activities in Alaskan and British residents. Effective doses were calculated to separate body tissues, using ICRP 60 human weighting factors and the ICRP 30 metabolic model for {sup 210}Po. Baker Lake and Alaskan effective doses were similar at 0.4 mSv y{sup {minus}1} and slightly higher than Snowdrift doses (0.3 mSv y{sup {minus}1}). Alaskan tissue activities indicated higher effective doses to liver, bone surfaces and redmore » marrow and lower doses to spleen than the {sup 210}Po metabolic model (ICRP 1979a) predicts. Effective doses to Baker Lake and Snowdrift caribou and wolves, calculated from tissue activities, ranged from 7-20 mSv y{sup {minus}1} using human weighting factors for comparison to human doses only. Effective doses to northern Canadians and wildlife were, respectively, 7-11% and 1.8-5 times an estimated human background of 4 mSv y{sup {minus}} from all sources. 51 refs., 2 figs., 9 tabs.« less

In vitro corrosion behavior and in vivo biodegradation of biomedical β-Ca3(PO4)2/Mg-Zn composites.

PubMed

Yu, Kun; Chen, Liangjian; Zhao, Jun; Li, Shaojun; Dai, Yilong; Huang, Qiao; Yu, Zhiming

2012-07-01

In this study 5, 10 and 15% β-Ca(3)(PO(4))(2)/Mg-Zn composites were prepared through powder metallurgy methods, and their corrosion behavior and mechanical properties were studied in simulated body fluid (SBF) at 37°C. The 10% β-Ca(3)(PO(4))(2)/Mg-Zn composite was selected for cytocompatibility assessment and in vivo biodegradation testing. The results identified the α-Mg, MgZn and β-Ca(3)(PO(4))(2) phases in these sintered composites. The density and elastic modulus of the β-Ca(3)(PO(4))(2)/Mg-6% Zn composite match those of natural bone, and the strength is approximately double that of natural bone. The 10% β-Ca(3)(PO(4))(2)/Mg-6% Zn composites exhibit good corrosion resistance, as determined by a 30 day immersion test and electrochemical measurements in SBF at 37°C. The 10% β-Ca(3)(PO(4))(2)/Mg-6% Zn composite is safe for cellular applications, with a cytotoxicity grade of ∼0-1 against L929 cells in in vitro testing. The β-Ca(3)(PO(4))(2)/Mg-6% Zn composite also exhibits good biocompatibility with the tissue and the important visceral organs the heart, kidney and liver of experimental rabbits. The composite has a suitable degradation rate and improves the concrescence of a pre-broken bone. The corrosion products, such as Mg(OH)(2) and Ca(5)(PO(4))(6)(OH)(2), can improve the biocompatibility of the β-Ca(3)(PO(4))(2)/Mg-Zn composite. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Heterometallic cerium(IV) perrhenate, permanganate, and molybdate complexes supported by the imidodiphosphinate ligand [N(i-Pr2PO)2]-.

PubMed

Wang, Guo-Cang; Sung, Herman H Y; Dai, Feng-Rong; Chiu, Wai-Hang; Wong, Wai-Yeung; Williams, Ian D; Leung, Wa-Hung

2013-03-04

Heterometallic cerium(IV) perrhenate, permanganate, and molybdate complexes containing the imidodiphosphinate ligand [N(i-Pr2PO)2](-) have been synthesized, and their reactivity was investigated. Treatment of Ce[N(i-Pr2PO)2]3Cl (1) with AgMO4 (M = Re, Mn) afforded Ce[N(i-Pr2PO)2]3(ReO4) (2) or Ce2[N(i-Pr2PO)2]6(MnO4)2 (3). In the solid state, 3 is composed of a [Ce2{N(i-Pr2PO)2}6(MnO4)](+) moiety featuring a weak Ce-OMn interaction [Ce-OMn distance = 2.528(8) Å] and a noncoordinating MnO4(-) counteranion. While 3 is stable in the solid state and acetonitrile solution, it decomposes readily in other organic solvents, such as CH2Cl2. 3 can oxidize ethylbenzene to acetophenone at room temperature. Treatment of 1 with AgBF4, followed by reaction with [n-Bu4N]2[MoO4], afforded [Ce{N(i-Pr2PO)2}3]2(μ-MoO4) (4). Reaction of trans-Ce[N(i-Pr2PO)2]2(NO3)2 (5), which was prepared from (NH4)2Ce(NO3)6 and K[N(i-Pr2PO)2], with 2 equiv of [n-Bu4N][Cp*MoO3] yielded trans-Ce[N(i-Pr2PO)2]2(Cp*MoO3)2 (6). 4 can catalyze the oxidation of methyl phenyl sulfide with tert-butyl hydroperoxide with high selectivity. The crystal structures of complexes 3-6 have been determined.

210Po in the marine biota of Korean coastal waters and the effective dose from seafood consumption.

PubMed

Kim, S H; Hong, G H; Lee, H M; Cho, B E

2017-08-01

The activity concentrations of 210 Po were determined in plankton and selected species of macroalgae, crustaceans, molluscs, and fish from Korean coastal waters to understand 210 Po distribution in these trophic levels and to assess the effective dose of 210 Po from seafood ingested by the average Korean. The activity concentration of 210 Po in macroalgae, mixed plankton, anchovy (whole body), abalone muscle, and abalone viscera was 0.97-1.43, 32-137, 59-392, 2.93 ± 0.86, and 1495 ± 484 Bq kg -1 (w.w.), respectively. Polonium-210 concentration in the whole flesh of mussel and oyster were 47.8 ± 5.9 and 45.3 ± 7.1 Bq kg -1 (w.w.), respectively. Polonium-210 concentration in the muscle of the five tested species of fish other than anchovy ranged from 0.51 to 5.56 Bq kg -1 (w.w.), with the lowest amount in a demersal species. In fish, 210 Po activity concentration was as much as three orders of magnitude higher in viscera than in muscle. The average annual effective 210 Po dose per average Korean adult, who consumes 42.8 kg of seafood a year (excluding anchovy), was estimated to be 94 μSv y -1 , with 42-71% of this attributed to shellfish. Further studies are required to assess the dose of 210 Po from anchovy owing to its high activity concentration and the manner in which anchovy is consumed. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Occurrence of 210Po in marine macroalgae inhabiting a coastal nuclear zone, southeast coast of India.

PubMed

Praveen Pole, R P; Feroz Khan, M; Godwin Wesley, S

2017-04-01

The activity concentration of 210 Po in 26 species of marine macroalgae found along coast near to a nuclear installation in southeast coast of India was studied. Phaeophytes were found to accumulate the maximum 210 Po concentration and chlorophytes the minimum. The average 210 Po activity concentration values in the three groups were 6.2 ± 2.5 Bq kg -1 (Chlorophyta), 14.4 ± 5.2 Bq kg -1 (Phaeophyta) and 11.3 ± 3.9 Bq kg -1 (Rhodophyta). A statistically significant variation in accumulation was found between groups (p < 0.05). The un-weighted dose rate to these algae due to 210 Po was calculated to be well below the benchmark dose limit of 10 μGy h -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

Using Eu(3+) as an atomic probe to investigate the local environment in LaPO4-GdPO4 monazite end-members.

PubMed

Huittinen, Nina; Arinicheva, Yulia; Schmidt, Moritz; Neumeier, Stefan; Stumpf, Thorsten

2016-12-01

In the present study, we have investigated the luminescent properties of Eu(3+) as a dopant in a series of synthetic lanthanide phosphates from the monazite group. Systematic trends in the spectroscopic properties of Eu(3+) depending on the size of the host cation and the dopant to ligand distance have been observed. Our results show that the increasing match between host and dopant radii when going from Eu(3+)-doped LaPO4 toward the smaller GdPO4 monazite decreases both the full width at half maximum of the Eu(3+) excitation peak, as well as the (7)F2/(7)F1 emission band intensity ratio. The decreasing Ln⋯O bond distance within the LnPO4 series causes a systematic bathochromic shift of the Eu(3+) excitation peak, showing a linear dependence of both the host cation size and the Ln⋯O distance. The linear relationship can be used to predict the energy band gap for Eu(3+)-doped monazites for which no Eu(3+) luminescent data is available. Finally, mechanisms for metal-metal energy transfer between host and dopant lanthanides have been explored based on recorded luminescence lifetime data. Luminescence lifetime data for Eu(3+) incorporated in the various monazite hosts clearly indicated that the energy band gap between the guest ion emission transition and the host ion absorption transition can be correlated to the degree of quenching observed in these materials with otherwise identical geometries and chemistries. Copyright © 2016 Elsevier Inc. All rights reserved.

Transfer of {sup 210}Po and {sup 210}Pb through the lichen-caribou-wolf food chain of northern Canada

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

Thomas, P.A.; Sheard, J.W.; Swanson, S.

1994-06-01

Natural background activity and food chain transfer of the uranium decay products, {sup 210}Po and {sup 210}Pb, were examined in the lichen-caribou-wolf food chain at two locations in the Northwest Territories of Canada. {sup 210}Po and {sup 210}Pb activities in lichens differed with species and location. Both {sup 210}Po and {sup 210}Pb were markedly higher in caribou bone than in wolf bone. {sup 210}Po activities in liver, kidney, and muscle were similar in both species. Caribou fetuses had lower activities of {sup 210}Po but higher activities of {sup 210}Pb than maternal muscle and placenta, suggesting greater placental transport of {supmore » 210}Pb than {sup 210}Po. Concentration ratios (CR = Bq kg{sup {minus}1} in consumer/Bq kg{sup {minus}1} in its food source) and f{sub f} values (f{sub f} in d kg{sup {minus}1} = Bq kg{sup {minus}1} in muscle/Bq d{sup {minus}1} ingested) showed that wolves retain more {sup 210}Po and less {sup 210}Pb from their diet than do caribou. {sup 210}Po CRs averaged 0.38 for caribou/lichens, 0.26 for caribou/rumen contents, and 0.40 for wolves/caribou. {sup 210}Pb CRs averaged 0.36 for caribou/lichens, 0.57 for caribou/rumen contents, and 0.13 for wolves/caribou. 43 refs., 4 figs., 5 tabs.« less

Comparative Costs and Staffing Report for College and University Facilities, 1993-94.

ERIC Educational Resources Information Center

Silberman, Gil, Ed.; Glazner, Steve, Ed.

This report presents comparative data on facility management costs and staffing based on responses from 516 U.S. postsecondary educational facilities during 1993-94. It lists statistics from both private and public institutions, beginning with statistical reductions presenting the survey response tally, institutional profiles, and mean costs per…

NASICON-related Na3.4Mn0.4Fe1.6(PO4)3

PubMed Central

Yatskin, Michael M.; Strutynska, Nataliya Yu.; Baumer, Vyacheslav N.; Ogorodnyk, Ivan V.; Slobodyanik, Nikolay S.

2012-01-01

The solid solution, sodium [iron(III)/manganese(II)] tris­(orthophosphate), Na3.4Mn0.4Fe1.6(PO4)3, was obtained using a flux method. Its crystal structure is related to that of NASICON-type compounds. The [(Mn/Fe)2(PO4)3] framework is built up from an (Mn/Fe)O6 octa­hedron (site symmetry 3.), with a mixed Mn/Fe occupancy, and a PO4 tetra­hedron (site symmetry .2). The Na+ cations are distributed over two partially occupied sites in the cavities of the framework. One Na+ cation (site symmetry -3.) is surrounded by six O atoms, whereas the other Na+ cation (site symmetry .2) is surrounded by eight O atoms. PMID:22807697

In situ carbon coated LiFePO4/C microrods with improved lithium intercalation behavior.

PubMed

Bhuvaneswari, D; Kalaiselvi, N

2014-01-28

LiFePO4/C microrods consisting of building blocks of interconnected nanoparticles surrounded by a thin and amorphous coating of carbon have been prepared by a customized hydrothermal method. Appreciable discharge capacity values of 168 mA h g(-1) at 0.1 C and 130 mA h g(-1) at 5 C rates have been exhibited by the currently synthesized LiFePO4/C cathode. The study enumerates the feasibility of exploiting the hydrothermal method to prepare an in situ carbon coated LiFePO4/C compound with tunable morphological properties and desirable electrochemical properties observed for up to 100 cycles at a 5 C rate.

Improved Electrochemical Performance of LiFePO4@N-Doped Carbon Nanocomposites Using Polybenzoxazine as Nitrogen and Carbon Sources.

PubMed