WorldWideScience

Sample records for agentstva po atomnoj

  1. po_stack_movie

    DEFF Research Database (Denmark)

    2009-01-01

    po_stack® er et reolsystem, hvis enkle elementer giver stor flexibilitet, variation og skulpturel virkning. Elementerne stables og forskydes frit, så reolens rum kan vendes til begge sider, være åbne eller lukkede og farvekombineres ubegrænset. Reolen kan let ombygges, udvides eller opdeles, når ...

  2. Ostvarivanje solidarnosti po supsidijarnosti

    OpenAIRE

    Baloban, Stjepan

    2006-01-01

    Autor u ovom radu polazi od teoretske pretpostavke o povezanosti solidarnosti i supsidijarnosti i na osnovi toga pokazuje važnost supsidijarnosti za funkcioniranje solidarnosti, posebno društvene solidarnosti. U radu se koriste određena empirijska istraživanja, a posebno po prvi put empirijsko istraživanje unutar projekta Praćenje siromaštva u Hrvatskoj. U tom posljednjem spomenutom, istraživanju pokušao se dohvatiti i odnos prema supsidijarnosti u Hrvatskoj. U prvoj točki: Visoka razina o...

  3. Role of PO4 tetrahedron in LiFePO4 and FePO4 system.

    Science.gov (United States)

    Zeng, Yuewu

    2015-06-01

    Using high resolution transmission electron microscopy with image simulation and Fourier analysis, the Li1- x FePO4 (x LiFePO4 and FePO4 resulting from spinodal decomposition which promote Li ion easily getting into the particle due to uphill diffusion, (3) the particles of FePO4 formed in charging have heavily distorted lattice and contain some isolated LiFePO4 , (4) interface between LiFePO4 and FePO4 and between amorphous and crystal region provides the lattice distortion of small polarons. PMID:25846750

  4. LiHo(PO34

    Directory of Open Access Journals (Sweden)

    Mokhtar Férid

    2009-02-01

    Full Text Available Lithium holmium(III polyphosphate(V, LiHo(PO34, belongs to the type I of polyphosphates with general formula ALn(PO34, where A is a monovalent cation and Ln is a trivalent rare earth cation. In the crystal structure, the polyphosphate chains spread along the b-axis direction, with a repeat period of four tetrahedra and 21 internal symmetry. The Li and Ho atoms are both located on twofold rotation axes and are surrounded by four and eight O atoms, leading to a distorted tetrahedral and dodecahedral coordination, respectively. The HoO8 polyhedra are isolated from each other, the closest Ho...Ho distance being 5.570 (1 Å.

  5. Kinetics of neutralization of Po-218

    International Nuclear Information System (INIS)

    In a well-defined experimental system the neutralization of polonium-218 ions was investigated as a function of the physical and chemical properties of the controlled composition atmosphere. The mobilities of Po+ and PoO2+ are determined by combining experimental results with a computer model of the system. Three neutralization mechanisms were individually studied. The small ion recombination rate has been found to be proportional to the square root of radon concentration. The electron scavenging mechanism is responsible for the neutralization of Po+ in NO2 or H2O in nitrogen. When PoO2+ is formed, the electron transfer mechanism dominates the neutralization process. The electron is transferred to PoO2+ from molecules with lower ionization potentials. The ionization potential of PoO2+ is also determined to be 10.44 +/- 0.05 eV

  6. Profiliranje počinitelja ubojstava

    OpenAIRE

    Rašić, Helena; Kovačević, Dražen; Žarković Palijan, Tija

    2012-01-01

    Profiliranje počinitelja kaznenog djela ubojstva je jedan od najkontroverznijih dijelova moderne kriminologije, psihologije i psihijatrije koji je još uvijek u početnom stadiju ra-zvoja. U radu su prikazani neki od poznatijih modela profiliranja počinitelja ubojstava − modeli Holmesa i Holmesa, Keppel i Walterov te Turveyev model profiliranja. Prika-zana su i tri glavna smjera razvoja profiliranja počinitelja kriminalnih djela s pripada-jućim modelima: Model Douglasa i suradnika kao predstavn...

  7. The onset of collectivity in 196Po

    International Nuclear Information System (INIS)

    We have studied the in-beam γ-ray spectroscopy of 196Po, which is the first Po isotope to exhibit collective vibrational structure. The onset of collective motion occurs in this isotope because of the large overlap between valence protons in h9/2 and valence neutrons in i13/2 orbitals

  8. Metabolism of 210Po in rats: Volatile 210Po from faeces

    International Nuclear Information System (INIS)

    The metabolic formation of volatile 210Po species in a rat that was intravenously administered with 210Po-citrate was investigated in this study. A slurry of the faecal sample was prepared in water and was bubbled with nitrogen gas in a closed system. The discharged gas was passed through a trapping device filled with liquid scintillation cocktail in order to capture any volatile 210Po species. The amount of 210Po trapped in the scintillation cocktail was measured by a liquid scintillation analyser that provided evidence of the presence of volatile 210Po species in the faeces. The presence of volatile 210Po in the faeces indicates that the metabolic formation of volatile 210Po is likely to occur in the gut due to bacterial activity. The amount of volatile 210Po species was compared with the daily faecal excretion of 210Po. After 2 h of bubbling, the volatile 210Po collected from the faeces sample was found to be between 1.0 and 1.7 % of the daily faecal excretion for the 4 d following 210Po-citrate administration. (authors)

  9. Metabolism of 210Po in rats: Volatile 210Po in excreta

    International Nuclear Information System (INIS)

    Polonium-210 (210Po) is one of the most toxic radionuclides and was used as a poison in the Alexander Litvinenko case. In this study of the metabolism of 210Po in rats, volatile 210Po in excreta was measured, filling a knowledge gap of the previous studies. Five rats were intravenously administrated with 2 kBq and another five with 10 kBq of 210Po (citrate form). They were housed in a glass MetabowlR system for 4 d following the administration. Volatile 210Po from the excreta was collected in a trapping system filled with liquid scintillation cocktail and was measured by liquid scintillation counting. Results showed that the daily excretion of volatile 210Po by the rats is in a very small percentage (0.002-0.009%) of the administered amounts. However, if the administered amount is large, the excretion of volatile 210Po can be significant. (authors)

  10. Aspects on the analysis of 210Po.

    Science.gov (United States)

    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

  11. 210Po bioaccumulation by mushrooms from Poland.

    Science.gov (United States)

    Skwarzec, B; Jakusik, A

    2003-10-01

    The paper presents results on 210Po activity concentration measured in mushroom samples collected in northern Poland (Białogard and Elblag areas). Among 20 species of wild mushrooms, King Bolete (Boletus edulis), accumulated 210Po in the highest degree. Therefore this species of higher mushrooms is an excellent bioindicator for 210Po radioactivity in the land environment. Finally, the effective dose of polonium emission was calculated for a consumer of King Bolete. Wild mushroom consumption contributed up to 37 microSv to the effective dose in an individual consuming about 5 kg (fresh weight) of heavily contaminated Boletus edulis species per year. PMID:14587851

  12. Superconducting Coil of Po Dipole

    CERN Multimedia

    1983-01-01

    The Po superconducting dipole was built as a prototype beam transport magnet for the SPS extracted proton beam P0. Its main features were: coil aperture 72 mm, length 5 m, room-temperature yoke, NbTi cable conductor impregnated with solder, nominal field 4.2 T at 4.7 K (87% of critical field). It reached its nominal field without any quench.After this successful test up to its nominal field of 4.2 T, the power was not raised to reach a quench. The magnet was not installed in a beam and had no other further use. Nevertheless its construction provided knowledges and experience which became useful in the design and construction of the LHC magnets. The photo shows a detail of the inner layer winding before superposing the outer layer to form the complete coil of a pole. Worth noticing is the interleaved glass-epoxy sheet (white) with grooved channels for the flow of cooling helium. See also 8211532X.

  13. Investigation Of Water Assisted Phase Transformation Process From AlPO4-5 to AlPO4-tridymite

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Suochang; Zhao, Zhenchao; Hu, Mary Y.; Han, Xiuwen; Hu, Jian Z.; Bao, Xinhe

    2016-03-15

    Water assisted phase transformation process from crystalized AlPO4-5 to AlPO4-tridymite was studied by the combination of X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and in situ multinuclear MAS NMR. It is found that water first activates the residue amorphous aluminophosphate in crystalized AlPO4-5 sample through hydrolysis and condensation reactions. Then the activated aluminophosphate species reassemble into AlPO4-tridymite crystalline. Meanwhile, AlPO4-5 transforms into orthorhombic phase during heating process. With further crystallization of AlPO4-tridymite, the amorphous phase is gradually consumed, and mass transportation between AlPO4-5 and AlPO4-tridymite is established through gradually amorphization of AlPO4-5. Finally, most of the AlPO4-5 transforms into the thermodynamically stable dense phase AlPO4-tridymite.

  14. PO2 cycling reduces diaphragm fatigue by attenuating ROS formation.

    Directory of Open Access Journals (Sweden)

    Li Zuo

    Full Text Available 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.

  15. Radioactive {sup 210}Po in magnesium supplements

    Energy Technology Data Exchange (ETDEWEB)

    Struminska-Parulska, Dagmara Ida [Gdansk Univ. (Poland). Environmental Chemistry and Radiochemistry Chair

    2016-08-01

    The aim of this pioneer study was to determine polonium {sup 210}Po in the most popular magnesium supplements in Poland and estimate the possible related dose assessment to the consumers. The analyzed magnesium pharmaceutics contained organic or inorganic magnesium compounds; some from natural sources. The objectives of this research were to investigate the naturally occurring {sup 210}Po activity concentrations in magnesium supplements, find the correlations between {sup 210}Po concentration in medicament and magnesium chemical form, and calculate the effective radiation dose connected to analyzed magnesium supplement consumption. The highest {sup 210}Po activity concentrations were determined in mineral tablets made from sedimentary rocks, namely dolomite - 3.84 ± 0.15 mBq g{sup -1} (sample Mg17). The highest annual radiation dose from {sup 210}Po taken with 1 tablet of magnesium supplement per day or with 400 mg of pure Mg daily would come from sample Mg17 (dolomite) - 1.35 ± 0.5 and 8.44 ± 0.33 μSv year{sup -1} respectively.

  16. RbCuFe(PO42

    Directory of Open Access Journals (Sweden)

    Mongi Ben Amara

    2013-08-01

    Full Text Available A new iron phosphate, rubidium copper(II iron(III bis(phosphate, RbCuFe(PO42, has been synthesized as single crystals by the flux method. This compound is isostructural with KCuFe(PO42 [Badri et al. (2011, J. Solid State Chem. 184, 937–944]. Its structure is built up from Cu2O8 units of edge-sharing CuO5 polyhedra, interconnected by FeO6 octahedra through common corners to form undulating chains that extend infinitely along the [011] and [01-1] directions. The linkage of such chains is ensured by the PO4 tetraedra and the resulting three-dimensional framework forms quasi-elliptic tunnels parallel to the [101] direction in which the Rb+ cations are located.

  17. Poésie et musique

    OpenAIRE

    Taine-Cheikh, Catherine

    1995-01-01

    Dans la société maure, la poésie et la musique sont sans doute les arts les plus développés. De plus elles sont, comme dans beaucoup d'autres sociétés traditionnelles, souvent associées. Après avoir comparé la poésie en arabe classique (le šiˤr) et la poésie en dialecte ḥassāniyya (le ġnä), je présente les griots (les iggāwən) et décris l'organisation d'un concert traditionnel.

  18. The Po: Centuries of river training

    Science.gov (United States)

    Earchi, E.; Roth, G.; Siccardi, F.

    1995-12-01

    The Po river drains the largest morphological unit of the Italian territory. River training works started in the lower Po during the Roman Age and developed upstream, first as discontinuous systems, then connected to form two uninterrupted belts, which have reduced the overflow frequency but also the storage capacity of the river flood bed. The outcome is an increasing value of the flood peak with given probability in the lower Po, which is the reach with the higher flooding risk. On the other hand, the upstream catchment, in which the river is provided with partial embankments, recently experienced a flooding event and require some form of protection. A risk mitigation policy should perceive and take into account all the components of the river system and their connections. In this perspective the development of traditional structural protection along the Po river has reached a critical stage; a further expansion of the existing levee system increases the down-stream risk. From the viewpoint of non structural protection, the river morphology and the past experience suggest that, based on rainfall and discharge monitoring, early warnings of flood hazards can be provided to communities that could be affected by such occurrences. Finally, to reduce the flooding risk in the lower Po a reduction of the flood discharge entering this reach is needed. This can be obtained by diverting the higher part of the flood from the river immediately upstream of the lower Po, allowing the inundation and the temporary storage of the diverted water on pre-designed large agricultural areas. Implementing such a policy will require a reliable system of flood warning and, above all, a sound regulatory authority.

  19. β-K(VO22(PO4

    Directory of Open Access Journals (Sweden)

    Safa Ezzine Yahmed

    2013-01-01

    Full Text Available A new vanadium oxide, potassium bis(dioxovanadyl phosphate, β-K(VO22(PO4, has been synthesized by a solid-state reaction. In the title compound, the [V2PO8] framework is built up from infinite pyramidal [V2O8]∞ and [VPO7]∞ chains linked together by V—O—P bridges, leading to a three-dimensional framework which delimits two types of intersecting tunnels running along [100] and [010] in which the four unique K+ ions, showing coordination numbers of nine and ten, are located.

  20. BiPO4 photocatalyst employing synergistic action of Ag/Ag3PO4 nanostructure and graphene nanosheets

    Science.gov (United States)

    Mohaghegh, N.; Rahimi, E.

    2016-06-01

    Graphene-supported BiPO4/Ag/Ag3PO4 photocatalyst has been fabricated by simple hydrothermal and impregnation reaction. In BiPO4/Ag/Ag3PO4 based on Reduced Graphene Oxide (RGO), this network renders numerous pathways for rapid mass transport, strong adsorption and multireflection of incident light; meanwhile, the interface between BiPO4/Ag/Ag3PO4 and RGO increases the active sites and electron transfer rate. BiPO4/Ag/Ag3PO4 based on RGO noticeably exhibited high photocatalytic activity than that of BiPO4/Ag/Ag3PO4 and P25 under visible light irradiation for cationic dye (Rhodamine B), anionic dye (methyl orange) and 4-chlorophenol (4-CP) as a neutral pollutant, which are usually difficult to be degraded over the other catalysts. This enhanced photocatalytic activity of Graphene-supported BiPO4/Ag/Ag3PO4 for all pollutants could be mainly ascribed to the reinforced charge transfer from BiPO4/Ag/Ag3PO4 to RGO, which suppresses the recombination of electron/hole pairs. Besides that, this photocatalyst can be used repetitively with a high photocatalytic activity and no apparent loss of activity occurs. The results reveal that the RGO nanosheets work as a photocatalyst promoter during the photocatalytic reaction, leading to an improved photocatalytic activity.

  1. Sklenitev pogodbe s podajanjem izjav po e-pošti

    OpenAIRE

    Hrastovec, Uroš

    2012-01-01

    Sklepanje pogodb poteka preko podajanja ponudbe in istovetnega sprejema. Ti izjavi se lahko podata z različnimi komunikacijskimi sredstvi, pri čemer se danes najpogosteje uporabljajo elektronska komunikacijska sredstva. V to skupino se uvršča tudi komunikacija preko elektronske pošte. Ponudba, ki je podana po elektronski pošti učinkuje od trenutka, ko je naslovniku dostopna na njegovem elektronskem naslovu. Podobno je tudi pri sprejemu ponudbe, ki prav tako prične učinkovati z vstopom v p...

  2. Electronic Properties of LiFePO4 and Li doped LiFePO4

    International Nuclear Information System (INIS)

    The potential use of different iron phosphates as cathode materials in lithium-ion batteries has recently been investigated.1 One of the promising candidates is LiFePO4. This compound has several advantages in comparison to the state-of-the-art cathode material in commercial rechargeable lithium batteries. Firstly, it has a high theoretical capacity (170 mAh/g). Secondly, it occurs as mineral triphylite in nature and is inexpensive, thermally stable, non-toxic and non-hygroscopic. However, its low electronic conductivity (∼10-9 S/cm) results in low power capability. There has been intense worldwide research activity to find methods to increase the electronic conductivity of LiFePO4, including supervalent ion doping,2 introducing non-carbonaceous network conduction3 and carbon coating, and the optimization of the carbon coating on LiFePO4 particle surfaces.4 Recently, the Li doped LiFePO4 (Li1+xFe1-xPO4) synthesized at ARL has yield electronic conductivity increase up to 106.5 We studied electronic structure of LiFePO4 and Li doped LiFePO4 by synchrotron based soft X-ray emission (XES) and X-ray absorption (XAS) spectroscopies. XAS probes the unoccupied partial density of states, while XES the occupied partial density of states. By combining XAS and XES measurements, we obtained information on band gap and orbital character of both LiFePO4 and Li doped LiFePO4. The occupied and unoccupied oxygen partial density of states (DOS) of LiFePO4 and 5 percent Li doped LiFePO4 are presented in Fig. 1. Our experimental results clearly indicate that LiFePO4 has wideband gap (∼ 4 eV). This value is much larger than what is predicted by DFT calculation. For 5 percent Li doped LiFePO4, a new doping state was created closer to the Fermi level, imparting p-type conductivity, consistent with thermopower measurement. Such observation substantiates the suggestion that high electronic conductivity in Li1.05Fe0.95 PO4 is due to available number of charge carriers in the material

  3. Physical Oceanography Distributed Active Archive Center (PO.DAAC)

    Data.gov (United States)

    National Aeronautics and Space Administration — PO.DAAC is an element of the Earth Observing System Data Information System (EOSDIS). PO.DAAC's primary responsibility is to provide distribution and archive...

  4. Transient-diffusion measurements of radon. Fick's law confirmation and 218Po/214Po behavior determination

    International Nuclear Information System (INIS)

    Usually, radon diffusion coefficients in soils are measured based on the assumption that Fick's law holds true. But, unlike in a free volume, strictly speaking, there is no guarantee that Fick's law holds in soils. Transient-diffusion measurements of radon in soils are best employed in order to confirm Fick's law. Alpha-particles from 218Po/214Po and from 222Rn cannot be distinguished in the course of those measurements. Therefore, the relevant portions of the detector reading must be allocated to each of these nuclides. For that purpose, the behaviors of 218Po and 214Po in the detection volume were determined and their ratios of contribution to the detector reading were also determined by Monte Carlo calculations and a verification test. This information was used to confirm Fick's law for representative Japanese sand and loam samples through indicial transient-diffusion measurements and a theoretical interpretation of the measured data. (author)

  5. Poptávka po fitness centru

    OpenAIRE

    Šauerová, Petra

    2008-01-01

    Tato práce vykresluje celkový obraz poptávky po fitness centru. Co vede lidi k cvičení, podle čeho fitness centrum vybírají, které faktory nejvíce ovlivňují počet vstupů za měsíc. Lehký nástin pro podnikatele, jaké fitness centrum bude mít u lidí úspěch, kde by mělo být postaveno a co v něm považují lidé za důležité. Pomocí dotazování v pražských fitness centrech se tento cíl podařilo uskutečnit.

  6. Separation and electrodeposited of 210 Po

    International Nuclear Information System (INIS)

    Presently work it was determined the selective separation of the 210 Po that is in an uraniferous mineral, by means of acid leaching of the mineral and the purification was carried out by means of partition chromatography whose stationary phase is 2-ethylhexyl phosphoric acid (D2EHPA), it has been possible to isolate the 210 Po of the rest of the radioactive elements that conform the family 4 N+2, the optimal elutriation conditions of this element were settled down of manner of not dragging other radioelements. Another of the achievements presented in this communication has been the electrodeposition of this element has more than enough stainless steel discs with a superior yield to 95%. (Author)

  7. Blastomogenic effect of 210Po on rats

    International Nuclear Information System (INIS)

    A single intraperitoneal administration of 210Po (0.3-20.0 μ Ci/kg) to rats induced development of tumors of thyroid gland (25% of cumulative incidence of tumors), kidneys (11.7%), mammary gland (9.2%), hypophysis (9.2%), large intestine (8.3%), liver, adrenal glands, ovaries, parathyroid gland, prostate, subcutaneous connective tissue and leukosis (8.3%). With the dose increase from 0.3 to 2.4 μ Ci/kg, the incidence of tumors increases from 25 to 50% of total number of rats with a latency period of 580-425 days, respectively. It can be assumed that the ''virtually ineffective'' dose of 210Po, as determined by the criterion of tumor occurrence in rats, constitutes 0.006 μ Ci/kg

  8. Mohou bakterie počítat?

    Czech Academy of Sciences Publication Activity Database

    Wiedermann, Jiří

    Opava: Slezská univerzita, Filozoficko-přírodovědecká fakulta, 2010 - (Kelemen, J.; Kvasnička, V.), s. 415-422 ISBN 978-80-7248-589-5. [Kognice a umělý život /10./. Praha (CZ), 16.09.2010-17.09.2010] R&D Projects: GA ČR GAP202/10/1333 Institutional research plan: CEZ:AV0Z10300504 Keywords : nanovýpočty * molekulární komunikace * signální molekuly * univerzální výpočetní síla Subject RIV: IN - Informatics, Computer Science

  9. Eu2(PO3H)3

    International Nuclear Information System (INIS)

    The structure of dieuropium tris(hydrogen phosphite), Eu2(PO3H)3, contains three independent phosphite anions. One Eu3+ cation is eight-coordinate whereas the other is only seven-coordinate. One [EuO8] dodecahedron and one monocapped [EuO7] trigonal prism alternate so that, by sharing one vertex, infinite layers are formed parallel to the [101] direction. The layers are held together by Eu-O interlayer bonds. (orig.)

  10. Forenzika elektronske pošte

    Directory of Open Access Journals (Sweden)

    Milorad S. Markagić

    2013-10-01

    Full Text Available U najopštijem smislu digitalna forenzika može se definisati kao skup metoda za prikupljanje, analizu i prezentaciju digitalnih dokaza koji se mogu pronaći na računarima, serverima, u računarskim mrežama, bazama podataka, mobilnim uređajima i svim drugim elektronskim uređajima na kojima se čuvaju podaci. U ovom radu su opisane metode prikupljanja digitalnih dokaza u elektronskoj pošti i njihova analiza. Uvod Elektronska pošta se kao dokazni materijal pojavljuje u velikom broju kako građanskih tako i kriminalnih forenzičkih istraga. Elektronska pošta i elektronska pošta zasnovana na internet serverima  širi se veoma brzo, pa lako i brzo završi i na računaru korisnika kome nije namenjena. Prvu elektronsku poruku poslao je Ray Tomilson 1971. godine, a deset godina kasnije u kombinaciji sa personalnim računarima i internetom prerasta u globalni način komuniciranja i personalnog i poslovnog. Takođe se koristi i u svrhu zabave, načina razmene podataka, ali predstavlja i nezamenjiv izvor digitalnih dokaza, kada dodje do računarskog incidenta. Analiza elektronske pošte Svaka elektronska poruka sastoji se od dva dela: zaglavlja i teksta poruke. Iz zaglavlja je moguće saznati izvorišnu i odredišnu adresu, pošiljaoca i namenjenog primaoca, a telo poruke sadrži tekst poruke. Ekstenzije dokumenata elektronske pošte U slučajevima kada je potrebno otkriti samo dokumente potrebne za pregled elektronskih poruka, ili kopirati pojedinačni dokument sačuvan unutar elektronske pošte, moguće je koristiti sistem na istraživanom računaru ili specijalizovani softver kao što je Outlook Extract Pro ili Outlook Export. Mnogo ispravniji, sigurniji i jednostavniji način je korišćenje forenzičkih alata kao što su EnCase ili FTK, sa ugrađenim pregledačima koji omogućavaju pregled i snimanje sadržaja baze podataka kao i njihovo kopiranje na druge medije za dalju analizu. Forenzički alati automatizuju proces skidanja i kopiranja

  11. Half-life of 214Po and 212Po measured with CTF at LNGS

    International Nuclear Information System (INIS)

    Polonium isotopes 214Po and 212Po are part of the 238U and 232Th decay chains, respectively. There exist only a few measurements of these two mean lifetimes with precision better than one or two percent. Since we have been studying decay spectra of 214Bi and 212Bi with the purpose of experimentally constraining anti-neutrino spectral shape important for geoneutrino studies, we have a large statistics of decays of 214Po and 212Po collected with the Counting Test Facility (CTF), which was operational in the underground I.N.F.N. Gran Sasso National Laboratory. The apparatus consisted of an external cylindrical water tank (diameter ∼ 11 m, high ∼ 10 m; ∼ 1000 tons of water) serving as passive shielding for 4.8 m3 of liquid organic scintillator contained in an inner spherical vessel with a diameter of ∼ 2 m. The inner vessel was realized with a nylon membrane (∼ 500 ?m thick), with excellent optical clarity, which allowed the effective transmission of the scintillation light to the 100 phototubes (PMTs) forming the optical read-out, anchored on a 7 m diameter support structure inside the water tank. The high purity and low background in CTF allows a favourable signal to background ratio for these measurements. More specifically the ratio of signal to background of the present measurements is more than three orders of magnitude larger than the best existing measurements. We have studied the decays of 214Po into 210Pb and of 212Po into 208Pb tagged by the coincidence with the previously decays from 214Bi and 212Bi by using 222Rn, 232Th and 220Rn sources sealed inside quartz vials and inserted in the CTF

  12. Temporal changes of 210Po in temperate coastal waters

    International Nuclear Information System (INIS)

    The temporal variation of Polonium-210 (210Po) was examined in coastal sea water, the mussel Mytilus edulis, the winkle Littorina littorea and green algae 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

  13. 210Po in Mytilus edulis in the Irish marine environment

    International Nuclear Information System (INIS)

    210Po is available to the Irish marine environment as a result of natural and anthropogenic processes. As it constitutes a significant portion of the radiation exposure of the population through the consumption of seafood, it is of interest to identify a suitable bio-indicator to monitor fluctuations of 210Po concentrations in the marine environment. Mytilus edulis was examined to assess the geographical variation in 210Po concentrations around the coast of Ireland. Temporal variations and the effect of mussel size on their 210Po contents at two sites, Sutton and Carlingford, were also examined. Chemical techniques for the separation of 210Po from mussels, seawater and suspended particulate are described. These methods use 209Po as a chemical yield monitor, microwave systems and Teflon bomb procedures for sample digestion. The concentration of 210Po in mussels around the coast was found to vary between 80±9 Bq kg-1 (dry wt.) at Seapark near Belfast and 468±32 Bq kg-1 (dry wt.) at Sutton in Dublin. The two sites at Sutton and Carlingford, which displayed similarities in terms of mussel morphology and 210Po concentration in water, exhibited significant temporal variations in mussel concentration. Furthermore, relationships derived from both sites indicate a strong linear dependency between mean 210Po content and mean mussel dry weight with higher concentrations of 210Po found in smaller mussels at a given site. Concentration ratios for mussels and water are also presented. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  14. poCAMon personal online continuous airmonitor

    International Nuclear Information System (INIS)

    The poCAMon combines a very compact design with a high flow rate and long battery life. Its size and weight are still acceptable for carrying by one person. The unit measures long-lived aerosols as well as short-lived Radon/Thoron daughters by alpha spectroscopy and beta counting. The radioactive aerosols and particles are collected on the surface of a high resolution membrane filter. The alpha and beta decays on the filter are measured by a high-end semiconductor radiation detector (400 mm@). This allows a perfect separation of the different decay products. The increased pump rate (more than 3 l/ min) is suitable for lower detection limits. A sensor measures permanently the pressure drop on the filter in order to recognize an exhausted or perforated filter instantly. With the 3.8 Ah NiMH battery pack the poCAMon achieves an operation time of more than 30 hours. The quality control is a main issue of any radiation measurement. Therefore the poCAMon records a complete alpha spectrum for each measured value. This allows the monitoring of the device's perfect operation in each moment of the measurement. There are options for additional sensors for carbon monoxide and combustible gases as needed in underground mines. All measured data are stored in a 2GB memory card and can be accessed with a PC or laptop via a USB interface. Data transmission and device control can also be done via wireless ZigBee network or via a server for stationary operation with network access. A barometric pressure sensor and a GPS receiver are optional features of the device.

  15. Leaching of 210Po in human saliva from smokeless tobacco

    International Nuclear Information System (INIS)

    Use of smokeless tobacco (SLT) is associated with cancer of the oral cavity. 210Po, a known carcinogen present in SLT may leach into the saliva when the snuff is held in the mouth. Alpha emission from leached 210Po can cause oral tissue damage, especially in the presence of non healing ulcers seen frequently in snuff users' mouth. Leaching of 210Po from SLT in human saliva was determined for six popular US snuff brands. 210Po was leached into human saliva for 30 min, separated radiochemically and its activity was determined by α-counting. Approximately 2-10% of 210Po present in SLT was observed to leach. Annual exposure from leached 210Po, based on average daily consumption of 15 g of SLT, was calculated to range from 1.1 to 3.8 Bq year-1. (author)

  16. Acta Clinica Croatica: napredak korak po korak

    OpenAIRE

    Ramljak, Gordana

    2014-01-01

    Časopis Acta Clinica Croatica počeo je izlaziti 1962. godine na hrvatskom jeziku pod nazivom Anali Bolnice Dr. M. Stojanović. Godine 1995. naziv časopisa se mijenja u današnji, a svi radovi se objavljuju na engleskom jeziku. Godine 2000. objavljuje se i mrežna (online) verzija. U radu se prati razvoj časopisa od 1962. do 2012. godine temeljem analize vrste i broja radova, broja citata te broja domaćih i stranih autora u indeksnoj i citatnoj bazi SCOPUS (u tri razdoblja). Isti su parametri ana...

  17. A new polymorph of Lu(PO33

    Directory of Open Access Journals (Sweden)

    Anis Bejaoui

    2008-08-01

    Full Text Available A new polymorph of lutetium polyphosphate, Lu(PO33, was found to be isotypic with the trigonal form of Yb(PO33. Two of the three Lu atoms occupy special positions (Wyckoff positions 3a and 3b, site symmetry overline{3}. The atomic arrangement consists of infinite helical polyphosphate chains running along the c axis, with a repeat period of 12 PO4 tetrahedra, joined with LuO6 octahedra.

  18. A new polymorph of Lu(PO3)3

    OpenAIRE

    Anis Bejaoui; Karima Horchani-Naifer; Mokhtar Férid

    2008-01-01

    A new polymorph of lutetium polyphosphate, Lu(PO3)3, was found to be isotypic with the trigonal form of Yb(PO3)3. Two of the three Lu atoms occupy special positions (Wyckoff positions 3a and 3b, site symmetry overline{3}). The atomic arrangement consists of infinite helical polyphosphate chains running along the c axis, with a repeat period of 12 PO4 tetrahedra, joined with LuO6 octahedra.

  19. Cell volumes of LaPO4-CePO4 solid solutions

    International Nuclear Information System (INIS)

    Lattice constants have been determined for solid solutions of the form LaxCe1-xPO4. A plot of the cube root of the unit-cell volume as a function of χ shows that this system follows Vegard's law. (orig.)

  20. Sodium samarium tetrakis(polyphosphate, NaSm(PO34

    Directory of Open Access Journals (Sweden)

    Dan Zhao

    2010-07-01

    Full Text Available NaSm(PO34 has been prepared by solid state reactions. It belongs to type II of the structural family of MILnIII(PO34 compounds (MI = alkali metal and LnIII = rare earth metal and is composed of ∞(PO3n]n− polyphosphate chains with a repeating unit of four PO4 tetrahedra. The chains extend parallel to [100] and share O atoms with irregular SmO8 polyhedra, forming a three-dimensional framework which delimits tunnels occupied by Na+ cations in a distorted octahedral environment.

  1. Assessment of 210Po in foodstuffs consumed in Korea

    International Nuclear Information System (INIS)

    210Po in the daily diet in Korea was analyzed and the ingestion dose from an intake of 210Po was estimated by considering the dietary habit of a Korean person. The 210Po concentrations of a leafy vegetable (0.36 Bq x kg-1 for lettuce) in the terrestrial food were higher than those of grain, whereas Chinese cabbage had a lesser 210Po concentration (0.019 Bq x kg-1). The 210Po concentration of the animal product was similar to those detected in the grain and vegetable. The 210Po concentrations in the shell and crustaceous were high from 19.1 to 33.0 Bq x kg-1, however, its value fell in the overall range of the reported values. The effective dose from 210Po for an adult from the Korean population was about 269.4 μSv x y-1. Nearly 80% of the ingestion dose from the intake of 210Po was attributed to the consumption of seafood. It suggests that the marine food ingestion is a critical pathway for natural 210Po to the Korean population. (author)

  2. Studies of {sup 194,195,197}Po

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, M.P.; Ahmad, I.; Crowell, B. [and others

    1995-08-01

    The energy systematics of low-lying polonium states show sudden changes near N = 114. The observed drops in the low-lying levels of {sup 196,198}Po relative to the heavier isotopes indicate significant changes in the underlying structure of these nuclei. It is thought that this change is due to the onset of vibrational collectivity brought about by the quadrupole interaction between neutron and proton-pairs. In order to extend the Po systematics even further, we measured, for the first time, states in {sup 194,195,197}Po using the {sup 28}Si + {sup 170}Yb reaction at a beam energy of 142 MeV. The beam was supplied by ATLAS, and the data were taken with 10 Compton-suppressed Ge detectors placed at the target position of the Fragment Mass Analyzer. Preliminary level schemes were constructed for {sup 194,195,197}Po based on {gamma}-{gamma} and {gamma}-FMA coincidences. The results for {sup 194}Po show that the 2{sup +} - 0{sup +} transition energy decreased in energy by 140 keV relative to {sup 196}Po suggesting that this nucleus moved beyond the vibrational limit to more collective motion. An extrapolation of the systematics predicts that the 2{sup +} energy could drop another 140 keV between {sup 194}Po and {sup 192}Po which would indicate the onset of rotational motion. Currently, we have an approved experiment to investigate the decay of yrast isomers in {sup 194}Po which will allow us to (1) confirm our earlier level scheme of {sup 194}Po, and (2) assess the experimental conditions needed for a future study of {sup 192}Po.

  3. Effect of Phosphate Salts (Na3PO4, Na2HPO4, and NaH2PO4) on Ag3PO4 Morphology for Photocatalytic Dye Degradation under Visible Light and Toxicity of the Degraded Dye Products

    NARCIS (Netherlands)

    Amornpitoksuk, P; Intarasuwan, K; Suwanboon, S; Baltrusaitis, J.

    2013-01-01

    Ag3PO4 was synthesized by the precipitation method using three different types of phosphate salts (Na3PO4, Na2HPO4, and NaH2PO4) as a precipitating agent. Hydrolysis of each phosphate salt gave a specific pH that affected the purity and morphology of the prepared Ag3PO4. The Ag3PO4 prepared from Na2

  4. Volatilization of Po by microorganisms at laboratory culture experiments

    International Nuclear Information System (INIS)

    The previous experiments proved the volatility of polonium form culture medium in which microorganisms were propagated from seed of seawater, river water or pond water, therefore we did not know what kind of species are responsible to Po volatility. To search microorganisms, which concerned with Po emission we carried out culture experiments using known microorganisms. Three microorganisms were examined; Escherichia coli K-12, Bacillus subtilis and Chromobacterium violaceum. The microorganisms were pre-cultured in LB medium at 30 degree C and a small portion of the pre-cultured was transferred to a culture bottle in which LB medium and 208Po tracer were contained. The culture was done at 30 degree C with shaking the culture bottle and air passed through a filter was introduced. The Po volatilized was transferred into the trap vials in which scintillator for liquid scintillation counting (LSC) was contained. The Po activity was measured by LSC. All of the microorganisms examined volatilized Po but their ability was quite different each other. Highest ability was observed on Chromobacterium violaceum and then Escherichia coli K-12 followed by Bacillus subtilis, the relative magnitude of the ability was 102, 10, 1, respectively. Chromobacterium violaceum and Escherichia coli K-12 showed high volatility for the first 24 h but Escherichia coli K-12 showed a decrease thereafter. However high volatility was continued on Chromobacterium violaceum during the culture. The low culture temperature suppressed Po volatility, supporting biologically mediated Po emission from the culture.

  5. Synthesis of Nano FePO4 and Electrochemical Characterization of Composite Cathode Material LiFePO4/C

    Directory of Open Access Journals (Sweden)

    WU Yu-Ling, PU Wei-Hua, REN Jian-Guo, JIANG Chang-Yin, WAN Chun-Rong

    2012-04-01

    Full Text Available Nano FePO4·xH2O powders were synthesized by controlled crystallization method, using Fe(3) compound as the iron source. The nano FePO4·xH2O powders were pretreated at 500¡䟦or 4 h in air to obtain nano FePO4 precursor. Then the olivine nano LiFePO4/C composites were obtained through carbonthermal reduction process at different temperatures. The structure, morphology, physicochemical properties and electrochemical properties of the nano FePO4·xH2O powder, FePO4 precursor and LiFePO4/C composites synthesized at different temperatures were characterized in detail by thermogravimetric/differential scanning calorimeter (TG/DSC), X―ray diffraction (XRD), scanning?electron?microscope (SEM), Brunauer―Emmett―Teller (BET) surface area measurement and electrochemical measurement. The results show that the nano LiFePO4/C composite calcined at 700¡䟦or 10 h has fine particle sizes of about 40―100 nm .The BET test shows that the as―prepared nano LiFePO4/C composite has great specific surface area of 79.8 m2/g. The nano LiFePO4/C composite cathode material can deliver an initial discharge capacity of 156.5, 134.9, 105.8, 90.3 and 80.9 mAh/g in the voltage range of 2.5―4.2 V, at rate of 0.1C, 1C, 5C, 10C and 15C respectively, which exhibits good rate performance. The nano LiFePO4/C composite also demonstrates excellent cyclic performance.

  6. Estimation of 210Po in marine organisms at Mumbai, India

    International Nuclear Information System (INIS)

    210Po was estimated in the edible muscle of fifteen different marine species collected from Trans-Thane Creek area (Trombay) and Thane. Daily intake of 210Po and its radiation dose to human beings due to consumption of marine organisms collected from this particular area were assessed. Estimation of 210Po was carried out using radiochemical separation and alpha spectrometric technique. The concentration of 210Po was found to vary from 0.18 to 10.9 Bq kg-1wet wt in different biota species and maximum concentrations were observed in bivalves.The daily intake and individual dose of 210Po to human beings through biota consumption was calculated and found to be 31.89mBq d-1 and 19.44μSv yr-1 respectively. (author)

  7. K2Ho(PO4(WO4

    Directory of Open Access Journals (Sweden)

    Katherina V. Terebilenko

    2008-11-01

    Full Text Available 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.

  8. REVIEW: TALES OF KHA BA DKAR PO

    Directory of Open Access Journals (Sweden)

    Jundan (Jasmine Zhang

    2015-03-01

    Full Text Available Review of: Jing Guo . 2012. Xue shan zhi shu [Tales of Kha ba dkar po] [ཁ་བ་དཀར་པོ]. Kunming: Yunnan People's Press. My favorite color is to add a little white on the whiteness, as if there was a snow-white eagle landing on a snow-covered mountain rock. My favorite color is to add a bit green on the greenness, as if there was an emerald parrot flying in the wild walnut woods. Deqin xianzi lyrics. These lyrics evoke a space beyond a sense of realism. In his book, Tales of Kha ba dkar po (ToK, Guo mentions these lines three times, suggesting a transcendental experience one may encounter in Tibetan areas while, at the same time, humbled by the mindset of human nature relations enacted by Tibetan people. ToK is, in many ways, a valuable academic work. Guo's favorite lines of xianzi allude to a 'space-in-between' the secular and sacred, which provides a unique experience for a broad readership, and induces the readers to deeper reflections on topics such as 'nature/ culture', 'belief', 'rite', and 'life/ death'. ToK is one of nineteen contemporary anthropological and ethnological works conducted in Yunnan Province, Southwest China and published in the 'Anthropology and Ethnology series in Contemporary China'. In the preface for the series, Yin (2012 suggests that there are two primary reasons for the somewhat slow development of Chinese scholarship in the field of anthropology and ethnology. One is the historically Han-centered intellectual atmosphere, and the other is the ideological ambivalence that ethnic culture has faced since the establishment of the People's Republic of China. In this context, Guo's longitudinal academic and intellectual engagement with the Tibetan communities in northwest Yunnan is included in this series as part of the increasing recognition of the significance of understanding southwest China's complex ethnic and cultural diversity.

  9. Separation and electrodeposited of {sup 210} Po; Separacion y electrodeposito de {sup 210} Po

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez R, E.; Iturbe G, J.L

    1991-12-15

    Presently work it was determined the selective separation of the {sup 210} Po that is in an uraniferous mineral, by means of acid leaching of the mineral and the purification was carried out by means of partition chromatography whose stationary phase is 2-ethylhexyl phosphoric acid (D{sub 2}EHPA), it has been possible to isolate the {sup 210} Po of the rest of the radioactive elements that conform the family 4 N{sup +2}, the optimal elutriation conditions of this element were settled down of manner of not dragging other radioelements. Another of the achievements presented in this communication has been the electrodeposition of this element has more than enough stainless steel discs with a superior yield to 95%. (Author)

  10. Research Update: Retardation and acceleration of phase separation evaluated from observation of imbalance between structure and valence in LiFePO4/FePO4 electrode

    OpenAIRE

    Kazuya Tokuda; Tomoya Kawaguchi; Katsutoshi Fukuda; Tetsu Ichitsubo; Eiichiro Matsubara

    2014-01-01

    LiFePO4 is a potential positive electrode material for lithium ion batteries. We have experimentally observed an imbalance between the valence change of Fe ions and the structure change from the LiFePO4 phase to the FePO4 phase during delithiation by simultaneous in situ XRD and XANES measurements in an LiFePO4/FePO4 electrode. The ratio of structure change to valence change clearly indicates that the phase separation from LiFePO4 to FePO4 is suppressed at the beginning of delithiation, while...

  11. 210Pb and 210Po in tobacco - with a special focus on estimating the doses of 210Po to man

    International Nuclear Information System (INIS)

    Inhalation of tobacco smoke is ranked second to food as a source of 210Pb and 210Po exposure to man. assay of 210Pb and 210Po in commercially available tobacco collected from many countries have been carried out to assess the potential risk from 210Po present in tobacco. The range of 210Po contained in the tobacco grands varied from 10.08 to 15.0 mBq/tob or 13.0 to 20.1 mBq/g and the mean was 11.6 mBq/tob or 15.4 mBq/g. During the International Standard Smoking process about 50% of 210Po present in tobaccos was transferred into the smoke and the other 50% remained in the ash and butt. About 10% of the total 210Po of tobacco was inhaled by smoke through mainstream smoke. One pack-a-day smoker inhaled 24 mBq of 210Po per day through smoking and the annual inhalation was 8.8 Bq. The risk of mortality from lung cancer caused by 210Po in tobaccos was 18 per million persons for the above model. (author) 6 refs.; 1 fig.; 4 tabs

  12. Mechanical and thermal-expansion characteristics of Ca10(PO46(OH2-Ca3(PO42 composites

    Directory of Open Access Journals (Sweden)

    Ruseska G.

    2006-01-01

    Full Text Available Three types of composites consisting of Ca10(PO46(OH2 and Ca3(PO42 with composition: 75% (wt Ca10(PO46(OH2: 25%(wt Ca3(PO42; 50%(wt Ca10(PO46(OH2: 50%(wtCa3(PO42 and 25 %(wt Ca10(PO46(OH2: 75%(wt Ca3(PO42 were the subject of our investigation. Sintered compacts were in thermal equilibrium, which was proved by the absence of hysteresis effect of the dependence ΔL/L=f(T during heating /cooling in the temperature interval 20-1000-200C. Sintered compacts with the previously mentioned composition possess 26-50% higher values of the E-modulus, G-modulus and K-modulus indicating the presence of a synergism effect. Several proposed model equations for predicting the thermal expansion coefficient in dependence of the thermal and elastic properties of the constitutive phases and their volume fractions, given by: Turner, Kerner, Tummala and Friedberg, Thomas and Taya, were used for making correlations between mechanical and thermal-expansion characteristics of the Ca10(PO46(OH2 - Ca3(PO42 composites. Application of the previously mentioned model equations to all kinds of composites leads to the conclusion that the experimentally obtained results for the thermal expansion coefficient are in an excellent agreement with the theoretical calculated values on account of the volume fraction of each constitutive phase and with all applied model equations, with a coefficient of correlation from 98.16-99.86 %.

  13. Przestrzeń pożydowska

    Directory of Open Access Journals (Sweden)

    Konrad Matyjaszek

    2014-06-01

    Full Text Available The Post-Jewish SpaceThe paper offers a critical analysis of a prevalently used contemporary Polish design strategy of alteration and modification, practiced on the former Jewish districts in Poland. A majority of these districts’ urban substance consists of property once belonging to Polish Jews, and appropriated by non-Jewish Poles during the Holocaust and after 1945. Such property and its urban space are described in Polish language as a ‘post-Jewish’ ones (mienie pożydowskie.The article analyses two parallel cultural processes of contemporary adaptation of this urban space. First of these processes is focused on the concept of Jewish Space, a social idea proposed in 1999 by Diana Pinto. The Jewish Space, envisaged as a cultural and material space of an encounter between European Jews and non-Jews, in its Polish interpretation becomes free from any requirement of a Jewish presence. A social practice resulting from such interpretation differs radically from Pinto’s original idea.The second reviewed process concerns the physical construction of thus defined ‘space of encounter’. Its practice is analysed on an example of Oxygenator, an urban intervention by Joanna Rajkowska, installed in Warsaw in 2007. This work, one of first Polish attempts to create a physical space of encounter, despite of its altruistic principles could not fully go beyond the boundaries of the Polish discourse on the exclusivist ‘dialogue’. Consequently, a cultural vocabulary it allowed remains limited to meanings more likely to result with exclusion than with a possibility of participation. Przestrzeń pożydowskaArtykuł zawiera krytyczną analizę współczesnych strategii zmian oraz modyfikacji w pożydowskich dzielnicach w Polsce. Większość substancji miejskiej w tych rejonach składa się z nieruchomości wcześniej należących do polskich Żydów, a później przywłaszczonych przez Polaków nieżydowskiego pochodzenia podczas Holokaustu oraz

  14. 210Po/210Pb equilibrium ratios in Kaveri river ecosystem

    International Nuclear Information System (INIS)

    The behaviour of 210Po, the terminal radioactive member of the naturally occurring 238U series is reported to display markedly interesting movement and accumulation behaviour in the aquatic environment, from that of its parent 210Pb. A study was therefore carried out to investigate the status of 210Po/210Pb activity ratios in Kaveri river ecosystem extending from Karur to Grand Anicut (95 km). The paper presents the activity distribution of 210Po and 210Pb, and the observed 210Po/210Pb activity ratios in water, sediment and certain aquatic organisms (plankton, prawn, bivalve and fish) of the river. The aquatic organisms preferentially accumulated more 210Po than 210Pb. The results also demonstrate that while dissolved 210Po/210Pb ratios in river water are less than unity (0.52 - 0.71), there is a gradual enhancement of these ratios in river sediments (1.31 - 1.67) and plankton (5.2). Significantly higher ratios were recorded in higher species like crustacea, mollusca and fish, with a typical range observed from ∼10 to ∼102. The study thus illustrates the active uptake of 210Po than 210Pb by the biotic components of the river. (author). 11 refs., 1 fig., 3 tabs

  15. Quantitative determination of 210Po in geochemical samples

    International Nuclear Information System (INIS)

    To test the usefulness of 210Po in soils as a means of detecting buried U mineralization, methods for the determination of 210Po were investigated and adapted for routine production of 210Po data from geochemical samples. A number of conditions affecting autodeposition and detection of 210Po were investigated. The optimum area of deposition with a 450 mm2 solid state detector was found to be 300 mm2. Convenience dictated room temperature over-night deposition times, although increased temperature increased speed and efficiency of deposition. A clear inverse relationship was observed between volume of solution and deposition efficiency with stirring times of less than 2 hours. For routine analysis, soil and rock powders were dissolved by leaching 1 g samples in teflon beakers successively with conc. HNO3, HF, and HNO3-HClO4, evaporating the solution to dryness between leaches, and taking the residue up in 20 mL 0.5 M HCl. The 210Po was deposited on 19 mm diameter Ni discs and counted with an alpha spectrometer system employing 450 mm2 ruggedized surface barrier detectors. The method achieved 90 percent recovery of 210Po from solution and a detection efficiency of 30 percent. With a counting time of 3 hours, the method is capable of detecting 0.2 pCi of 210Po per gram of sample

  16. počtový model kotle KWH

    OpenAIRE

    Koiš, Jiří

    2014-01-01

    Tato diplomová práce se zabývá tepelným výpočtem stávající konstrukce kotle KWH. Na úvod je v této práci zařazena krátká rešerše, ve které je diskutováno spalované palivo a sledované zařízení. Pro realizaci výpočtu sdílení tepla jsou nejprve provedeny stechiometrické a bilanční výpočty zplyňovací komory ZKG. Bilanční rovnice vycházejí z výpočtů ztrát kotle, které jsou stanoveny na základě měřených dat. Za účelem ladění a manipulace s dílčími výpočty je celý výpočet zpracován v počítačovém pro...

  17. Accumulation of 210Po by benthic marine algae

    International Nuclear Information System (INIS)

    The accumulation of polonium 210Po by various species of benthic marine seaweeds collected from 4 different points on the coast of Rio de Janeiro, showed variations by species and algal groups. The highest value found was in red alga, Plocamium brasiliensis followed by other organisms of the same group. In the group of the brown alga, the specie Sargassum stenophylum was outstanding. The Chlorophyta presented the lowest content of 210Po. The algae collected in open sea, revealed greater concentration factors of 210Po than the same species living in bays. The siliceous residue remaining after mineralization of the algae did not interfere with the detection of polonium. (author)

  18. Biogeochemical factors affecting the presence of 210Po in groundwater

    Science.gov (United States)

    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

  19. Biogeochemical factors affecting the presence of 210Po in groundwater

    International Nuclear Information System (INIS)

    Research highlights: → 210Po activities in numerous domestic wells in Fallon NV exceed 500 mBq/L. → 210Po levels in sediment are not the primary determinant on levels in groundwater. → δ34S measurements indicate SO4 reduction occurred in all 210Po contaminated wells. → 210Po contaminated wells are anoxic, have high pH and low Ca. → Po mobilization probably involves an anaerobic S cycle in which H2S dissolves MnO2. - Abstract: 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

  20. poCAMon personal online continuous airmonitor; poCAMon online Personen Aerosolmonitor

    Energy Technology Data Exchange (ETDEWEB)

    Streil, T.; Oeser, V. [SARAD GmbH, Dresden (Germany)

    2015-07-01

    The poCAMon combines a very compact design with a high flow rate and long battery life. Its size and weight are still acceptable for carrying by one person. The unit measures long-lived aerosols as well as short-lived Radon/Thoron daughters by alpha spectroscopy and beta counting. The radioactive aerosols and particles are collected on the surface of a high resolution membrane filter. The alpha and beta decays on the filter are measured by a high-end semiconductor radiation detector (400 mm@). This allows a perfect separation of the different decay products. The increased pump rate (more than 3 l/ min) is suitable for lower detection limits. A sensor measures permanently the pressure drop on the filter in order to recognize an exhausted or perforated filter instantly. With the 3.8 Ah NiMH battery pack the poCAMon achieves an operation time of more than 30 hours. The quality control is a main issue of any radiation measurement. Therefore the poCAMon records a complete alpha spectrum for each measured value. This allows the monitoring of the device's perfect operation in each moment of the measurement. There are options for additional sensors for carbon monoxide and combustible gases as needed in underground mines. All measured data are stored in a 2GB memory card and can be accessed with a PC or laptop via a USB interface. Data transmission and device control can also be done via wireless ZigBee network or via a server for stationary operation with network access. A barometric pressure sensor and a GPS receiver are optional features of the device.

  1. Improving rate performance of LiFePO4 cathode materials by hybrid coating of nano-Li3PO4 and carbon

    International Nuclear Information System (INIS)

    Highlights: •This paper reports an improved solid-state method which leads to a uniform coating. The influence of Li3PO4 and carbon coating on the electrochemical performance of LiFePO4 was studied. •LiFePO4 coating with Li3PO4 and carbon shows a higher capacity than pure carbon coating sample. •Results indicate that the surface structure has an important influence on the electrochemical performance of LiFePO4. The addition of Li3PO4 can decrease the interfacial resistance of Li FePO4. -- Abstract: Li3PO4 coating on the surface of LiFePO4 particles was prepared by direct dispersing LiFePO4 precursor in starch slurry with nano-Li3PO4. The existence of nano-Li3PO4 was confirmed with X-ray powder diffraction (XRD). And the particle size and morphology were observed by scanning electron microscope (SEM) and transmission electron microscope analysis (TEM). The effects of the mixture coating on rate performance of LiFePO4 cathode vs Li anode at 25 °C was investigated. Li3PO4 and carbon mixing coated LiFePO4 cathode materials exhibited markedly improved rate capability relative to bare carbon-coated LiFePO4. Analyses on cell impedance showed that the Li3PO4 coating decreased the interfacial impedance. Transmission electron microscope analysis, electrochemical impedance spectroscopy (EIS) and cyclic voltammograms (CV) were carried out to explain the reason of better rate performance by Li3PO4 coating

  2. Improving rate performance of LiFePO{sub 4} cathode materials by hybrid coating of nano-Li{sub 3}PO{sub 4} and carbon

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shi-Xi, E-mail: zhaosx@sz.tsinghua.edu.cn [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Ding, Hao; Wang, Yan-Chao [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Li, Bao-Hua [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Nan, Ce-Wen [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2013-07-25

    Highlights: •This paper reports an improved solid-state method which leads to a uniform coating. The influence of Li{sub 3}PO{sub 4} and carbon coating on the electrochemical performance of LiFePO{sub 4} was studied. •LiFePO{sub 4} coating with Li{sub 3}PO{sub 4} and carbon shows a higher capacity than pure carbon coating sample. •Results indicate that the surface structure has an important influence on the electrochemical performance of LiFePO{sub 4}. The addition of Li{sub 3}PO{sub 4} can decrease the interfacial resistance of Li FePO{sub 4}. -- Abstract: Li{sub 3}PO{sub 4} coating on the surface of LiFePO{sub 4} particles was prepared by direct dispersing LiFePO{sub 4} precursor in starch slurry with nano-Li{sub 3}PO{sub 4}. The existence of nano-Li{sub 3}PO{sub 4} was confirmed with X-ray powder diffraction (XRD). And the particle size and morphology were observed by scanning electron microscope (SEM) and transmission electron microscope analysis (TEM). The effects of the mixture coating on rate performance of LiFePO{sub 4} cathode vs Li anode at 25 °C was investigated. Li{sub 3}PO{sub 4} and carbon mixing coated LiFePO{sub 4} cathode materials exhibited markedly improved rate capability relative to bare carbon-coated LiFePO{sub 4}. Analyses on cell impedance showed that the Li{sub 3}PO{sub 4} coating decreased the interfacial impedance. Transmission electron microscope analysis, electrochemical impedance spectroscopy (EIS) and cyclic voltammograms (CV) were carried out to explain the reason of better rate performance by Li{sub 3}PO{sub 4} coating.

  3. po_stack_movie:video, der viser funktionaliteten i systemet po_stack (design Anders Brix)

    OpenAIRE

    Brix, Anders

    2009-01-01

    po_stack® er et reolsystem, hvis enkle elementer giver stor flexibilitet, variation og skulpturel virkning. Elementerne stables og forskydes frit, så reolens rum kan vendes til begge sider, være åbne eller lukkede og farvekombineres ubegrænset.Reolen kan let ombygges, udvides eller opdeles, når nye behov opstår. Hylder og stablingselementer låser stabilt til hinanden, så selv store højder kan opbygges uden brug af værktøj eller samlinger. Et bredt udvalg af længder, dybder, højder og accessor...

  4. Electronic Properties of LiFePO4 and Li doped LiFePO4

    OpenAIRE

    Allen, J. L.; Zhuang, G.V.; P. N. ROSS; Guo, J.-H.; Jow, T.R.

    2006-01-01

    The potential use of different iron phosphates as cathode materials in lithium-ion batteries has recently been investigated.1 One of the promising candidates is LiFePO4. This compound has several advantages in comparison to the state-of-the-art cathode material in commercial rechargeable lithium batteries. Firstly, it has a high theoretical capacity (170 mAh/g). Secondly, it occurs as mineral triphylite in nature and is inexpensive, thermally stable, non-toxic and non-hygroscopic. Howeve...

  5. SPREMEMBE PRI POROČANJU PO ODSEKIH PO MSRP 8 V PRIMERJAVI Z NJEGOVIM PREDHODNIKOM MRS 14

    OpenAIRE

    Vrčkovnik, Matej

    2009-01-01

    S 1. 1. 2009 morajo podjetja, ki poročajo po MSRP, razkrivati informacije po odsekih po MSRP 8, ki je nadomestil MRS 14. MSRP 8 je standard, ki je skoraj kopija ameriškega standarda SFAS 131. Njegovo sprejetje je predvsem posledica zbliževanja MSRP in US GAAP. Z MSRP 8 se bistveno spremeni opredeljevanje odsekov. Medtem ko so bili pri MRS 14 odseki opredeljeni kot področni in območni, so pri MSRP 8 odseki, o katerih se poroča, opredeljeni na osnovi informacij, ki jih vodilna oseba za sprejema...

  6. Cs2Bi(PO4(WO4

    Directory of Open Access Journals (Sweden)

    Kateryna V. Terebilenko

    2009-09-01

    Full Text Available 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.

  7. Luminescence in LiCaPO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    More, S.D.; Meshram, M.N.; Wankhede, S.P. [Department of Physics, K.D.K. College of Engineering, Nagpur (India); Muthal, P.L.; Dhopte, S.M. [National Environmental Engineering Research Institute, Nehru Marg, Nagpur (India); Moharil, S.V., E-mail: svmoharil@yahoo.co [Department of Physics, Nagpur University, Nagpur 440010 (India)

    2011-03-01

    Phase pure LiCaPO{sub 4} was prepared by following a specific procedure involving several annealing steps, not exceeding the temperature 800 {sup o}C at any stage. Luminescence of Cu{sup +} and Eu{sup 2+} activators is studied. A single emission band is observed for both the activators in contrast to two bands reported in earlier literature. It is argued that in the earlier work the samples were contaminated by alpha Ca{sub 3}(PO{sub 4}){sub 2} phase, which could be responsible for these differences. Thermoluminescence of LiCaPO{sub 4}:Eu{sup 2+} was found to be four times more than the commercial phosphor LiF-TLD 100. Phase pure LiCaPO{sub 4} shows interesting luminescence properties different than those reported in the literature and hence it should prove fruitful to probe this material in future.

  8. Po-210 distribution in uranium-mill circuits

    International Nuclear Information System (INIS)

    Greater than 99% of all incoming Po-210 reports to the tailing piles for both the acid and the alkaline leach uranium circuits. Leached Po-210 may be carried along on small particles rather than dissolved in solution. There does not appear to be any radiologically significant buildup or accumulation in the acid leach circuit, but there are noteworthy amounts in the molybdenum recovery solution

  9. 210Po and Se speciation in Mytilus galloprovincialis

    International Nuclear Information System (INIS)

    Marine and freshwater microorganisms (algae, bacteria) as well as higher organisms such as mussels and fish metabolise polonium and selenium, and can accumulate them into cellular components. Selenium is a essential trace element for humans and animals, since it forms part of several enzymes, while 210Po is highly radiotoxic due to its high specific activity - 1.7 x 1014 Bq/g. Polonium has no known biological role and is involved in metal metabolism regarding its chemical-physical similarities with essential metals such as selenium. It follows the same biochemical pathways as selenium when considering the biochemistry of polonium. The aim of our study was to investigate distribution of 210Po and Se between soluble (supernatant) and insoluble (sediment) part of mussels from Slovenian market after enzymatic hydrolysis. 210Po and Se in supernatant are considered as bioavailable. We investigated the tissue of Mytilus galloprovincialis which lives attached on hard substrata, being filter feeders exposed to ambient seawater. These particular mussels are primarily used as food and also as indicators of environmental pollution, due to their ability to accumulate high levels of different contaminant (heavy metals, hydrocarbons and pesticides). The mussels were purchased on a local market as well as from a domestic producer. Samples were freeze dried and homogenized. After enzymatic hydrolysis of sample with Protease XIV, separation and determination of 210Po and Se in supernatant and sediment were performed. Measurements of 210Po were performed by alpha spectrometry while for Se measurements HG-AFS was used. The results obtained show that polonium in the soluble part of mussels tissue has similar pattern as selenium when Se increases also 210Po level increases, indicating the similar biochemistry of polonium and selenium. The soluble part of Se represented from 62 to 77 % of the total content, while soluble part of 210Po represented from 38 to 50 %. Extraction balance

  10. Study about excretion of 210 Po in urine

    International Nuclear Information System (INIS)

    The urine of mines's workers are analysed to detect the presence of 210 Po. The results was compared with the workers and with a control population. Cigarettes samples was analysed two and confirmed the 210 presence. The control population individuals were divided in smokers and non smokers and them urine was investigated the influence of the smoke in the 210 Po excretion. (L.M.J.)

  11. Po River channel (Italy): Recent modifications and connected problems

    International Nuclear Information System (INIS)

    For Italy's po River hydrological basin, artificial reservoirs have a great importance; water reserve is about 1600 million cubic meters for the hydroelectric reservoirs and about 76 million cubic meters of irrigation. In this paper, manmade and natural modifications which took place during last century in the Po River channel are examined; their prevailing causes are identified and open problems are pointed out, whose definition or solution is advisable within the framework of water-basin plan

  12. Principles of failure probability assessment (PoF)

    International Nuclear Information System (INIS)

    This abstract presents a method for computing Probability of Failure (PoF) namely the method integrating the so-called 'Bayesian approach'. PoF along with the assessment of the consequences of failure are required when it comes to assessing 'risks'. More and more frequently, in modern industries, the trend is to rely on the use of risk-based approaches for the scheduling of the inspection of static pressure vessels. Equipment PoF is the main driver for scheduling periodical inspections. Within the Bayesian approach, it is expected that the performance of inspection, provided effective techniques are used, increases the knowledge we have on the equipment condition and help us gain confidence in the planning of future inspections. The paper thus describes the theoretical principles yielding to the calculation of the PoF prior to conduct an inspection and after its performance. PoF calculation within a Risk-Based Inspection (RBI) planning is one of the aspects covered by the EU project called 'RIMAP' (Risk-Based Inspection and Maintenance Procedure). PoF calculation using Bayes theorem is the cornerstone of the RBI methodology described in American Petroleum Institute reference 'API 581'

  13. RAPID DETERMINATION OF {sup 210} PO IN WATER SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.

    2013-05-22

    A new rapid method for the determination of {sup 210}Po 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 {sup 210}Po in water samples have typically involved spontaneous auto-deposition of {sup 210}Po onto silver or other metal disks followed by counting by alpha 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 {sup 210}Po 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 {sup 210}Po 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 {sup 210} Po 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

  14. Les poèmes ragusains de Dejan Despic

    Directory of Open Access Journals (Sweden)

    Stefanović Ana

    2005-01-01

    Full Text Available (francuski Les œuvres de Dejan Despic (1930, inspirées par Dubrovnik: Jadranski soneti op. 17 (1951-1954, Dubrovacki divertimento op. 18 (1952 et Dubrovacki kanconijer op. 96 (1989, révèlent, outre leur thème commun, une parenté supplémentaire importante. Elles sont incitées et, d'une manière essentielle, médiatisées par la poésie: soit par les vers de Jovan Ducic (1871-1943, poète du Parnasse et symbolisme serbe, soit par la poésie pétrarquiste ragusaine. Or, ces compositions ne se montrent pas seulement en tant qu` issues de l`inspiration par la poésie sur Dubrovnik, mais aussi d'un conditionnement spirituel plus profond: de l`inspiration poétique du compositeur lui-même par Dubrovnik. C`est le sentiment poétique du monde, en tant que constante de la vision créatrice de Dejan Despic, qui provient de cette inspiration particulière. Ce monde ragusain du compositeur est le monde classique dans une signification universelle du concept, selon la nature même du milieu évoqué. Or, cela n implique pas une monochromie stylistique des compositions considérées. Au contraire, les perspectives musicales de l`impressionnisme, du néoclassicisme, voire, de la néorennaissance, varient ce cadre stylistique général, tout en marquant les traits distincts d'une poétique de composition très individualisée.

  15. Pressure-induced amorphization of antiferromagnetic FePO 4

    Science.gov (United States)

    Pasternak, M. P.; Rozenberg, G. Kh.; Milner, A. P.; Amanowicz, M.; Brister, K. E.; Taylor, R. D.

    1998-03-01

    In this paper we describe for the first time an unusual phenomenon, occurring in FePO 4 ( TN=25 K), where pressure drives the crystalline low-pressure phase (I) into two, coexisting antiferromagnetic states; one amorphous designated as IIa, the other crystalline (IIb) with an enhanced coordination number. This is unlike the case of berlinite (AlPO 4), which completely amorphizes above 15 GPa. Measurements were carried out with Mössbauer Spectroscopy (MS) and X-ray diffraction (XRD) at CHESS, over the pressure range 0-30 GPa. XRD shows that the double transformation starts at ˜2 GPa reaching saturation at 7 GPa. MS, however, show that the FePO 4-I phase coexists to the highest pressure, indicating possible formation of clusters with sizes undetected by XRD. The abundance of the FePO 4 IIa and IIb phases are about equal. Both XRD and the new TN (=60 K) value obtained by MS, show that the FePO 4-IIa phase is isostructural to CrVO 4. No change is observed in the relative abundance of the three phases at P>7 GPa in which the I-phase constitutes about 10% of the total. The TN value of the FePO 4-II phases increases with increasing pressure, from 50 K at 2.5 GPa to 65 at 25 GPa. The pressure transitions at room temperature are not reversible; after pressure release to ambient value, the FePO 4-I is completely restored only after heat treatment in air at T=700°C.

  16. Floodplain Management Strategies for Flood Attenuation in the River Po

    Science.gov (United States)

    Brath, A.; Castellarin, A.; di Baldassarre, G.

    2009-12-01

    This paper analyses the effects of different floodplain management policies on flood hazard using a 350km reach of the River Po (Italy) as a case study. The River Po is the longest Italian river, and the largest in terms of streamflow. The middle-lower Po flows East some 350km in the Pianura Padana (Po Valley), a very important agricultural region and industrial heart of Northern Italy. This portion of the river consists of a main channel (200-500m wide) and a floodplain (overall width from 200m to 5km) confined by two continuous artificial embankments. Floodplains are densely cultivated, and a significant portion of these areas is protected against frequent flooding by a system of minor dikes, which impacts significantly the hydraulic behaviour of the middle-lower Po during major flood events. This study aims at investigating the effects of the adoption of different floodplain management strategies (e.g., raising, lowering or removal of the minor dike system) on the hydrodynamics of the middle-lower Po and, in particular, on flood-risk mitigation. This is a crucial task for institutions and public bodies in charge of formulating robust flood risk management strategies for the Po River. Furthermore, the results of the study is of interest for other European water related public bodies managing large river basins, in the light of the recent Directive 2007/60/EC on the assessment and management of flood risks (European Parliament, 2007). The analysis is performed by means of a quasi-2D hydraulic model, which has been developed on the basis of a laser-scanning DTM and a large amount of calibration data recorded during the significant flood event of October 2000.

  17. Natural levels of {sup 210}Po in human urine

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Frances, I.; Manjon, G.; Mantero, J.; Diaz, J. [Departament of Applied Phisic II, University of Seville, P.O. Box 41012 Seville (Spain); Garcia-Tenorio, R. [Departament of Applied Phisic II, University of Seville, P.O. Box 41012 Seville (Spain); National Accelerator Centre, P.O. Box 41092 Seville (Spain)

    2014-07-01

    Since the secret agent Alexander Litvinenko was murdered in 2006 by a {sup 210}Po lethal dose, presumably ingested, there is renovated interest on the toxicity of this radionuclide in humans. {sup 210}Po is a radioactive isotope naturally found in nature, mainly incorporated by humans via food and water ingestion, as well as inhaled through its progenitor, the {sup 222}Rn. The total amount of natural {sup 210}Po in the human body can vary from person to person depending on their lifestyle: dietary habits, drinking water source, place of residence (associated with exposure to {sup 222}Rn), etc- and therefore in the concentrations of this element to be found in urine. To analyze the influence of dietary habits on the amount of {sup 210}Po excreted in urine, two volunteers in Seville had a well-defined and time-varying diet for a month, following a daily collection of their urine and determination of the concentrations therein of this radionuclide. The results obtained and the conclusions derived from them form the core of this communication. {sup 210}Po determinations were performed daily in 200 ml aliquots of urine using the technique of high resolution alpha spectrometry. This has involved the application of a single radiochemical method for the concentration and isolation {sup 210}Po, followed by its auto-deposition on copper planchets for proper measure. Daily {sup 210}Po activity concentrations in voluntary urine analyzed during the month of study show high variability with a difference of up to an order of magnitude between maximum and minimum values obtained, and a clear dependence on the diet type followed in the various stages of the experiment. The lowest concentrations obtained are associated with a diet rich in carbohydrates and proteins 'terrestrial' (pork, beef,...), while the highest concentrations were obtained in the final phase of the experiment when the diet was enriched with presence of marine products in fair correspondence with the

  18. Natural levels of 210Po in human urine

    International Nuclear Information System (INIS)

    Since the secret agent Alexander Litvinenko was murdered in 2006 by a 210Po lethal dose, presumably ingested, there is renovated interest on the toxicity of this radionuclide in humans. 210Po is a radioactive isotope naturally found in nature, mainly incorporated by humans via food and water ingestion, as well as inhaled through its progenitor, the 222Rn. The total amount of natural 210Po in the human body can vary from person to person depending on their lifestyle: dietary habits, drinking water source, place of residence (associated with exposure to 222Rn), etc- and therefore in the concentrations of this element to be found in urine. To analyze the influence of dietary habits on the amount of 210Po excreted in urine, two volunteers in Seville had a well-defined and time-varying diet for a month, following a daily collection of their urine and determination of the concentrations therein of this radionuclide. The results obtained and the conclusions derived from them form the core of this communication. 210Po determinations were performed daily in 200 ml aliquots of urine using the technique of high resolution alpha spectrometry. This has involved the application of a single radiochemical method for the concentration and isolation 210Po, followed by its auto-deposition on copper planchets for proper measure. Daily 210Po activity concentrations in voluntary urine analyzed during the month of study show high variability with a difference of up to an order of magnitude between maximum and minimum values obtained, and a clear dependence on the diet type followed in the various stages of the experiment. The lowest concentrations obtained are associated with a diet rich in carbohydrates and proteins 'terrestrial' (pork, beef,...), while the highest concentrations were obtained in the final phase of the experiment when the diet was enriched with presence of marine products in fair correspondence with the highest 210Po content in recent products. The use of urine to

  19. PoSSUM: Polar Suborbital Science in the Upper Mesosphere

    Science.gov (United States)

    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

  20. Electron-irradiation-induced nucleation and growth in amorphous LaPO4, ScPO4, and zircon

    International Nuclear Information System (INIS)

    Synthetic LaPO4, ScPO4, and crystalline natural zircon (ZrSiO4) from Mud Tanks, Australia were irradiated by 1.5 MeV Kr+ ions until complete amorphization occurred. The resulting amorphous materials were subsequently irradiated by an 80 to 300 keV electron beam in the transmission electron microscope at temperatures between 130 and 800 K, and the resulting microstructural changes were monitored in situ. Thermal anneals in the range of 500 to 600 K were also conducted to compare the thermally-induced microstructural development with that produced by the electron-irradiations. Amorphous LaPO4 and ScPO4 annealed to form a randomly oriented polycrystalline assemblage of the same composition as the original material, but zircon recrystallized to ZrO2 (zirconia)+amorphous SiO2 for all beam energies and temperatures investigated. The rate of crystallization increased in the order: zircon, ScPO4, LaPO4. Submicrometer tracks of crystallites having a width equal to that of the electron beam could be drawn on the amorphous substrate. In contrast, thermal annealing resulted in epitaxial recrystallization from the thick edges of the TEM samples. Electron-irradiation-induced nucleation and growth in these materials can be explained by a combination of radiation-enhanced diffusion as a result of ionization processes and a strong thermodynamic driving force for crystallization. The structure of the amorphous orthophosphates may be less rigid than that of their silicate analogues because of the lower coordination across the PO4 tetrahedron, and thus a lower energy is required for reorientation and recrystallization. The more highly constrained monazite structure-type recovers at a lower electron dose than the zircon structure-type, consistent with recent models used to predict the crystalline-to-amorphous transition as a result of ion irradiation. copyright 1997 Materials Research Society

  1. 210Pb and 210Po activities in French foodstuffs

    International Nuclear Information System (INIS)

    The data on 210Pb and 210Po activities in French foodstuffs acquired during the last 15 years are numerous enough to derive reference values which will be usable to assess the dose to the French population due to the intake of these two natural radionuclides. The means and ranges are close to those observed in various countries and are most often higher than the reference values proposed by UNSCEAR. Mussels and oysters exhibit the highest 210Po activities of all kinds of foodstuffs, with a mean value of 27 Bq.kg-1 fresh weight, followed by crustaceans and small fish species (anchovies, mullets, sardines, etc.) with 210Po activities in the order of 3 to 10 Bq.k-1 fresh weight; cephalopods and other fish species presenting activities around 1 to 3 Bq.kg-1 fresh, close to the UNSCEAR reference value. Below these highest 210Po activities are those of 210Po and 210Pb in terrestrial kinds of foodstuffs, by decreasing order: meats (around 1 Bq.kg-1 fresh), cereals (0.4 Bq.kg-1), leafy vegetables (0.3 Bq.kg-1), other vegetables and fruits (0.1 Bq.kg-1), and milk (from 0.03 to 0.1 Bq.L-1). (authors)

  2. 211 Po alpha decay level scheme

    International Nuclear Information System (INIS)

    deformations, so that their shapes in the ground state are represented by spheres. It is very interesting to note, that in the frame of this model, the linked level with 1s1/2 of the alpha particle is predicted to emerge from the orbital 1g9/2 of the spherical 211 Po parent, this level being deeply located in the potential well. Also, it is known that the ground state of the parent is 9/2+ emerging from 2g9/2 and the alpha decay exhibits a fine structure with 98.9% transitions to the ground state of the daughter with spin 1/2- (level 3p1/2), 0.55% transitions to the first single-particle excited state 5/2- (level 2f5/2) and 0.54% transitions to the second single-particle excited state 3/2- (level 3p3/2). In the frame of our formalism the fine structure can be understood by considering transitions between levels with the same quantum numbers in the avoided crossing regions, that means using the Landau-Zener effect. The system having only an axial symmetry, the good quantum number is the projection Ω of the nucleon spin. (author)

  3. Structural and Electrochemical Characterization of Pure LiFePO4 and Nanocomposite C-LiFePO4 Cathodes for Lithium Ion Rechargeable Batteries

    OpenAIRE

    Tomar, M. S.; Katiyar, R.S.; S. B. Majumder; N. K. Karan; J. J. Saavedra-Arias; Arun Kumar De; Thomas, R.; Singh, M K

    2009-01-01

    Pure lithium iron phosphate (LiFePO4) and carbon-coated LiFePO4 (C-LiFePO4) 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 LiFePO4 particles. Ex situ Raman spectrum of C-LiFePO4 at various stages of charging and discharging showed reversibility upon...

  4. Međufazna sinteza FePO4 različitih morfologija i utjecaj morfologije na elektrokemijska svojstva LiFePO4/C

    OpenAIRE

    Luo, Y.-H.; He, N.; Wang, Y.-C.; Cao, W.-G.; Feng, P.

    2015-01-01

    U ovom je radu korištena metoda međufazne sinteze za pripravu FePO4 različitih morfologija te je istraživan učinak morfologije na pripravu i elektrokemijska svojstva LiFePO4/C. Rezultati su pokazali da je FePO4 pri temperaturi obrade 30 °C amorfan, a pri 80 °C monoklinski. LiFePO4/C je pripravljen iz dvaju prekursora oblika polukružne šupljine s kristalnom strukturom olivina. LiFePO4/C proizveden iz monoklinski strukturiranog prekursora pokazao je sitniju morfologiju i bolja elektrokemijska s...

  5. Concentrations of 210Po in fish and shellfish from southern region of Japan and evaluation of 210Po intake from seafood for Japanese people

    International Nuclear Information System (INIS)

    Concentrations of 210Po in fish and shellfish, mostly collected from southern region of Japan were analyzed. Values ranged from 0.2 to 229 Bq/kg fresh weight and higher concentrations were observed in samples analyzed with viscera. Intake of 210Po through fish and shellfish was evaluated at different Japanese cities based on statistical consumption data. Phytoplankton, Heterosigma akashiwo was collected during a harmful algal bloom and 210Po was analyzed. The phytoplankton occupied only 4.4% of 210Po in seawater and a large fraction of 210Po was observed in the particulate form. (orig.)

  6. Concentrations of {sup 210}Po in fish and shellfish from southern region of Japan and evaluation of {sup 210}Po intake from seafood for Japanese people

    Energy Technology Data Exchange (ETDEWEB)

    Momoshima, N.; Sugihara, S. [Kyushu Univ., Fukuoka (Japan). Radioisotope Center; Nakao, H. [Kyushu Univ., Fukuoka (Japan). Graduate School of Sciences

    2012-07-01

    Concentrations of {sup 210}Po in fish and shellfish, mostly collected from southern region of Japan were analyzed. Values ranged from 0.2 to 229 Bq/kg fresh weight and higher concentrations were observed in samples analyzed with viscera. Intake of {sup 210}Po through fish and shellfish was evaluated at different Japanese cities based on statistical consumption data. Phytoplankton, Heterosigma akashiwo was collected during a harmful algal bloom and {sup 210}Po was analyzed. The phytoplankton occupied only 4.4% of {sup 210}Po in seawater and a large fraction of {sup 210}Po was observed in the particulate form. (orig.)

  7. Heinrich Heine. Poésie et histoire

    OpenAIRE

    BARBIER, Frédéric; Décultot, Élisabeth; Espagne, Michel; Hauschild, Jan-Christoph; Heine, Henri; Höhn, Gerhard; Kalinowski, Isabelle; Kortländer, Bernd; Lämke, Ortwin; Lefebvre, Jean-Pierre; Revel, Jacques; Trautmann-Waller, Céline; Werner, Michael

    2011-01-01

    Quiconque tente de définir l’originalité de la position littéraire de Heine a vite fait d’identifier la poésie et l’histoire comme deux registres essentiels de son activité créatrice. Les deux domaines étaient, en fait, rapportés d’emblée l’un à l’autre et vont se recomposer, en une interaction permanente, tout le long de sa vie d’écrivain. Le registre poétique vise la singularité: la voix du poète fait résonner une variété de destins individuels, son imagination met en scène des figures et d...

  8. {sup 210}Pb and {sup 210}Po in Finnish cereals

    Energy Technology Data Exchange (ETDEWEB)

    Turtiainen, Tuukka, E-mail: tuukka.turtiainen@stuk.f [STUK, Radiation and Nuclear Safety Authority, P.O. Box 14, 00881 Helsinki (Finland); Kostiainen, Eila, E-mail: eila.kostiainen@stuk.f [STUK, Radiation and Nuclear Safety Authority, P.O. Box 14, 00881 Helsinki (Finland); Hallikainen, Anja, E-mail: anja.hallikainen@evira.f [Finnish Food Safety Authority Evira, Mustialankatu 3, 00790 Helsinki (Finland)

    2011-05-15

    A survey was carried out on the activity concentrations of {sup 210}Pb and {sup 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 {sup 210}Pb/{sup 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{sup -1}, respectively. Combined with the consumption rates of the products, we assess that the mean effective doses from {sup 210}Pb and {sup 210}Po in cereal products for the adult male and female population are 22 and 17 {mu}Sv per year, respectively.

  9. Poëtica de l'instable

    OpenAIRE

    Torreilles, Claire

    2015-01-01

    Dins Une écriture en archipel F. Gardy destria dins la poësia d'oc contemporanèa doas tendéncias, l'una a l'epic e al cosmogonic, l'autra a l'expression brèva, concentrada, totas doas estent de biaisses de luchar contra lo silenci, l'angoissa de la lenga absenta, lo nonrés. De segur es dins la segonda mena que metriam F. Gardy poëta. A costat de Nelli, Max Roqueta, Joan Mouzat, Jòrgi Reboul e Sèrgi Bec. Son univèrs poëtic, lo sentissi coma essencialament movedís, cambiadís, un vertigi. Lo mon...

  10. Luminescence study of LaPO4: Eu, Tb phosphor

    International Nuclear Information System (INIS)

    The present paper reports the Photoluminescence (PL) of the LaPO4 phosphor doped with Eu and Tb rare-earth ions, keeping Eu concentration constant and varying Tb concentration as 0.1, 0.5 and 1.5% is described. The phosphors were synthesized using the standard solid state reaction technique and ground using mortar and pestle, fired at 1200 deg C for 1 hour in a muffle furnace. We have studied the effect of dopants on the Photo luminescent properties of the samples using Spectrofluorophotometer at room temperature. PL emission of undoped LaPO4 phosphor was observed at 470 nm. Under the excitation of 254 nm wavelength, PL emission of doped LaPO4 phosphor shows peaks at 589, 596, 614 and 622 nm with good intensity. As the Tb concentration increases the PL intensity also increases. (author)

  11. Po-210 and other radionuclides in terrestrial and freshwater environments

    Energy Technology Data Exchange (ETDEWEB)

    Gjelsvik, Runhild; Brown, Justin (eds.) (Norwegian Radiation Protection Authority (Norway)); Holm, Elis (Univ. of Lund (Sweden)); Roos, Per (Risoe DTU (Denmark)); Saxen, Ritva; Outola, Iisa (STUK - Radiation and Nuclear Safety Authority (Finland))

    2009-01-15

    This report provides new information on Po-210 (and where appropriate its grandparent Pb-210) behaviour in environmental systems including humans. This has primarily been achieved through measurements of Po-210 in aquatic and terrestrial environments that has led to the derivation of information on the levels of this radioisotope in plants, animals and the biotic components of their habitat (i.e. water, soil) providing basic information on transfer where practicable. For freshwater environments, Po-210 concentration ratios derived for freshwater benthic fish and bivalve mollusc were substantially different to values collated from earlier review work. For terrestrial environments, activity concentrations of Po-210 in small mammals (although of a preliminary nature because no correction was made for ingrowth from Pb-210) were considerably higher than values derived from earlier data compilations. It was envisaged that data on levels of naturally occurring radionuclides would render underpinning data sets more comprehensive and would thus allow more robust background dose calculations to be performed subsequently. By way of example, unweighted background dose-rates arising from internal distributions of Po-210 were calculated for small mammals in the terrestrial study. The biokinetics of polonium in humans has been studied following chronic and acute oral intakes of selected Po radioisotopes. This work has provided information on gastrointestinal absorption factors and biological retention times thus improving the database upon which committed effective doses to humans are derived. The information generated in the report, in its entirety, should be of direct relevance for both human and non-human impact assessments. (au)

  12. Po-210 and other radionuclides in terrestrial and freshwater environments

    International Nuclear Information System (INIS)

    This report provides new information on Po-210 (and where appropriate its grandparent Pb-210) behaviour in environmental systems including humans. This has primarily been achieved through measurements of Po-210 in aquatic and terrestrial environments that has led to the derivation of information on the levels of this radioisotope in plants, animals and the biotic components of their habitat (i.e. water, soil) providing basic information on transfer where practicable. For freshwater environments, Po-210 concentration ratios derived for freshwater benthic fish and bivalve mollusc were substantially different to values collated from earlier review work. For terrestrial environments, activity concentrations of Po-210 in small mammals (although of a preliminary nature because no correction was made for ingrowth from Pb-210) were considerably higher than values derived from earlier data compilations. It was envisaged that data on levels of naturally occurring radionuclides would render underpinning data sets more comprehensive and would thus allow more robust background dose calculations to be performed subsequently. By way of example, unweighted background dose-rates arising from internal distributions of Po-210 were calculated for small mammals in the terrestrial study. The biokinetics of polonium in humans has been studied following chronic and acute oral intakes of selected Po radioisotopes. This work has provided information on gastrointestinal absorption factors and biological retention times thus improving the database upon which committed effective doses to humans are derived. The information generated in the report, in its entirety, should be of direct relevance for both human and non-human impact assessments. (au)

  13. 210Po radiation dose due to cigarette smoking

    International Nuclear Information System (INIS)

    The level of 210Po in eight brands of cigarettes and four brands of bidis popular in and around Nagercoil town was determined to evaluate the annual effective dose. The 210Po activity in a full cigarette ranged from 32.8±3.6 to 68.4±5.9 mBq and from 34.3±3.5 to 62.9±5.8 mBq in a bidi. In tobacco, the highest 210Po content was recorded in the brand C4 (23.0±1.2 mBq) whereas for bidis it was the highest in the brand B2 (21.1±1.1 mBq). The activity in mainstream varied from 15.2±0.75 to 36.8±2.1 mBq in a cigarette and from 20.7±3.1 to 39.8±4.0 mBq in a bidi. With regard to 210Po activity concentration, not much specificity was noted with respect to the tobacco brand. The data showed a relatively wide range of activity concentration of 210Po in the different cigarette/bidi brands and even within the same brand. The bidis showed a higher activity when compared to cigarettes. The popular brands concentrated more activity than the fine brands. Smokers who smoke one pack (10 cigarettes/bidis) per day may inhale about 100-300 mBq d-1 (0.1-0.3 Bq d-1) of 210Po. In this study, radiation dose values in the range of 153.5-372.9 μSv Y-'1 from cigarettes and from 209.2 to 402.7 μSvY-1 from bidis was estimated for the whole body. (author)

  14. Structural and Electrochemical Characterization of Pure LiFePO4 and Nanocomposite C-LiFePO4 Cathodes for Lithium Ion Rechargeable Batteries

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2009-01-01

    Full Text Available Pure lithium iron phosphate (LiFePO4 and carbon-coated LiFePO4 (C-LiFePO4 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 LiFePO4 particles. Ex situ Raman spectrum of C-LiFePO4 at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of LiFePO4 and C-LiFePO4 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 LiFePO4 where as in case of C-LiFePO4 that were 163, 144, 118, and 70 mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pure LiFePO4 was 69% after 25 cycles where as that of C-LiFePO4 was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating.

  15. Research Update: Retardation and acceleration of phase separation evaluated from observation of imbalance between structure and valence in LiFePO4/FePO4 electrode

    Directory of Open Access Journals (Sweden)

    Kazuya Tokuda

    2014-07-01

    Full Text Available LiFePO4 is a potential positive electrode material for lithium ion batteries. We have experimentally observed an imbalance between the valence change of Fe ions and the structure change from the LiFePO4 phase to the FePO4 phase during delithiation by simultaneous in situ XRD and XANES measurements in an LiFePO4/FePO4 electrode. The ratio of structure change to valence change clearly indicates that the phase separation from LiFePO4 to FePO4 is suppressed at the beginning of delithiation, while it is accelerated at the latter stage, which is due to the coherent strain caused by the lattice misfit between the two phases.

  16. AKTIVNOSTI ZDRAVSTVENE NEGE PRI PACIENTKI PO CARSKEM REZU

    OpenAIRE

    Mikulič, Milka

    2009-01-01

    V diplomskem delu smo teoretično predstavili porodniško operacijo – carski rez, aktivnosti zdravstvene nege pri pacientki po carskem rezu in izvedli študijo primera pacientke po carskem rezu. Uvodoma je predstavljena zgodovina carskega reza ter definicija in indikacije za carski rez. Opisana je tudi razlika med elektivnim in nujnim carskim rezom, psihična in fizična priprava pacientke, anestezija za carski rez, prisotnost partnerja ter antibiotična zaščita med carskim rezom. V nadaljev...

  17. Poškodbe starostnikov v domskem varstvu

    OpenAIRE

    Šprager, Polona

    2012-01-01

    Pogostost padcev in posledično poškodb s starostjo narašča zaradi različnih vzrokov oz. spremljevalcev starosti, kot so starostno slabšanje vida, motenje ravnotežja, osteoporozne spremembe okostja, kronične bolezni, zdravila, pa tudi premajhna telesna dejavnost. Preprečevanje poškodb v starosti je preprečevanje padcev in njihovih posledic, ki bistveno poslabšajo kakovost življenja starejšega človeka. Zmanjša se funkcijska sposobnost, poveča se strah pred ponovnim padcem in zaradi tega omejeva...

  18. β-K(VO2)2(PO4).

    Science.gov (United States)

    Ezzine Yahmed, Safa; Ayed, Meriem; Zid, Mohamed Faouzi; Driss, Ahmed

    2013-01-01

    A new vanadium oxide, potassium bis-(dioxovanad-yl) phosphate, β-K(VO2)2(PO4), has been synthesized by a solid-state reaction. In the title compound, the [V2PO8] framework is built up from infinite pyramidal [V2O8]∞ and [VPO7]∞ chains linked together by V-O-P bridges, leading to a three-dimensional framework which delimits two types of inter-secting tunnels running along [100] and [010] in which the four unique K(+) ions, showing coordination numbers of nine and ten, are located. PMID:23476311

  19. β-K(VO2)2(PO4)

    OpenAIRE

    Safa Ezzine Yahmed; Meriem Ayed; Mohamed Faouzi Zid; Ahmed Driss

    2013-01-01

    A new vanadium oxide, potassium bis(dioxovanadyl) phosphate, β-K(VO2)2(PO4), has been synthesized by a solid-state reaction. In the title compound, the [V2PO8] framework is built up from infinite pyramidal [V2O8]∞ and [VPO7]∞ chains linked together by V—O—P bridges, leading to a three-dimensional framework which delimits two types of intersecting tunnels running along [100] and [010] in which the four unique K+ ions, showing coordination numbers of nine and ten, a...

  20. β-K(VO2)2(PO4)

    OpenAIRE

    Safa Ezzine Yahmed; Meriem Ayed; Mohamed Faouzi Zid; Ahmed Driss

    2013-01-01

    A new vanadium oxide, potassium bis(dioxovanadyl) phosphate, β-K(VO2)2(PO4), has been synthesized by a solid-state reaction. In the title compound, the [V2PO8] framework is built up from infinite pyramidal [V2O8]∞ and [VPO7]∞ chains linked together by V—O—P bridges, leading to a three-dimensional framework which delimits two types of intersecting tunnels running along [100] and [010] in which the four unique K+ ions, showing coordination number...

  1. SPLETNI PORTAL LIFERAY KOT INFORMACIJSKA TEHNOLOGIJA PO MERI UPORABNIKA

    OpenAIRE

    Pongračič, Aleš

    2016-01-01

    V diplomskem delu je predstavljen postopek, kako se lotiti izdelave in oblikovanja spletnega portala po meri vzorca uporabnikov. Naš cilj je bil predvideti in razumeti njihove potrebe in želje. V začetku je predstavljen primer raziskave trendov na globalnem nivoju. Kasneje pa smo zajeli tudi raziskavo uporabnikov po nekaterih regijah v Sloveniji. Obdelali smo tri večje sklope, in sicer izbiro kombinacije barv, postavitev objektov in načrtovanja pisave. Skozi različno literaturo in lastne razi...

  2. Po Superconducting Magnet:detail of the windings

    CERN Multimedia

    1982-01-01

    The Po superconducting dipole was built as a prototype beam transport magnet for the SPS extracted proton beam Po. Its main features were: coil aperture 72 mm, length 5 m, room-temperature yoke, NbTi cable conductor impregnated with solder, nominal field 4.2 T at 4.7 K (87% of critical field). It reached its nominal field without any quench. The photo shows a detail of the inner layer winding before superposing the outer layer to form the complete coil of a pole. Worth noticing is the interleaved glass-epoxy sheet (white) with grooved channels for the flow of cooling helium. See also 8307552X.

  3. Kardiotoksičnost požarnih plinova

    OpenAIRE

    Kovač, S.; Duraković, S.; Beritić, T

    1987-01-01

    Prikazani su direktni i indirektni uzroci hipoksije miokarda u požarima. Među prvima su zapreke u opskrbi kisikom, tj. hipoksija u samoj atmosferi požara i karboksihemoglobinemija, a među drugima su zapreke u korištenju kisika, tj. .teško fizičko i psihofizičko opterećenje, karboksimioglobin u miokardu i inhibicija citokromoksidaze cijanovodikom. Kao dodatna opasnost za miokard navedeni su klorirani ugljikovodici (gašenje) i njihovi pirolitički produkti (fozgen). Opširnije je opisana kardioto...

  4. POMEN ZDRAVSTVENE NEGE V REHABILITACIJSKEM POSTOPKU STAROSTNIKOV PO OPERACIJI KOLKA

    OpenAIRE

    Boltar, Katjuša

    2016-01-01

    Izhodišča: Pri starejših ljudeh postajajo poškodbe in s tem operacije vse pogostejše saj se prebivalstvo stara. Obraba kolka (artroza ) pomembno znižuje kakovost življenja in samostojnost v dnevnih aktivnostih, omejuje socialne stike in povečuje potreben obseg nadzora in pomoči s strani skrbnikov. Artroza kolka lahko nastane bodisi iz neznanega vzroka (idiopatska artroza) ali kot posledica predhodnega obolenja ali poškodbe. Vloge in naloge medicinske sestre pri izvajanju zdravstvene nege p...

  5. Neutron diffraction studies of the Na-ion battery electrode materials NaCoCr2(PO4)3, NaNiCr2(PO4)3, and Na2Ni2Cr(PO4)3

    Science.gov (United States)

    Yahia, H. Ben; Essehli, R.; Avdeev, M.; Park, J.-B.; Sun, Y.-K.; Al-Maadeed, M. A.; Belharouak, I.

    2016-06-01

    The new compounds NaCoCr2(PO4)3, NaNiCr2(PO4)3, and Na2Ni2Cr(PO4)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. NaCoCr2(PO4)3, NaNiCr2(PO4)3, and Na2Ni2Cr(PO4)3 crystallize with a stuffed α-CrPO4-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 structures of NaNiCr2(PO4)3, and Na2Ni2Cr(PO4)3 a statistical disorder Ni2+/Cr3+ was observed on both the 8g and 4a atomic positions, whereas in NaCoCr2(PO4)3 the statistical disorder Co2+/Cr3+ was only observed on the 8g atomic position. When tested as negative electrode materials, NaCoCr2(PO4)3, NaNiCr2(PO4)3, and Na2Ni2Cr(PO4)3 delivered specific capacities of 352, 385, and 368 mA h g-1, respectively, which attests to the electrochemical activity of sodium in these compounds.

  6. Poétique de l’invective dans les Poèmes aristophanesques de Laurent Tailhade

    Directory of Open Access Journals (Sweden)

    Laurent Robert

    2012-04-01

    Full Text Available Parmi l’abondant corpus traité par Marc Angenot dans La Parole pamphlétaire, les ouvrages de Laurent Tailhade Au Pays du mufle et À travers les Grouins [sic] constituent les seuls recueils poétiques. L’essayiste y voit une illustration du genre de la satire poétique, revivifié dès la fin du xviiie siècle avec les Iambes d’André Chénier, puis au xixe notamment par Auguste Barbier et Victor Hugo. Tailhade pourrait ainsi, superficiellement, être considéré comme le poète satiriste de la Troisième...

  7. Size-dependent magnetic ordering and spin-dynamics in DyPO4 and GdPO4 nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Evangelisti, Marco [Instituto de Ciencia de Materiales de Aragon (ICMA), Spain; Sorop, Tibi G [Leiden University; Bakharev, Oleg N [Leiden University; Visser, Dirk [ISIS Facility, Rutherford Appleton Laboratory; Hillier, Adrian D. [ISIS Facility, Rutherford Appleton Laboratory; Alonso, Juan [Universidad de Malaga, Spain; Haase, Markus [University of Osnabruck, Barbarastr Germany; Boatner, Lynn A [ORNL; De Jongh, L. Jos [Leiden University

    2011-01-01

    Low-temperature magnetic susceptibility and heat capacity measurements on nanoparticles (d 2.6 nm) of the antiferromagnetic compounds DyPO4 (TN = 3:4 K) and GdPO4 (TN = 0:77 K) provide clear demonstrations of finite-size effects, which limit the divergence of the magnetic correlation lengths, thereby suppressing the bulk long-range magnetic ordering transitions. Instead, the incomplete antiferromagnetic order inside the particles leads to the formation of net magnetic moments on the particles. For the nanoparticles of Ising-type DyPO4 superparamagnetic blocking is found in the ac-susceptibility at 1 K, those of the XY-type GdPO4 analogue show a dipolar spin-glass transition at 0:2 K. Monte Carlo simulations for the magnetic heat capacities of both bulk and nanoparticle samples are in agreement with the experimental data. Strong size effects are also apparent in the Dy3+ and Gd3+ spin-dynamics, which were studied by zero-field SR relaxation and high-field 31P-NMR nuclear relaxation measurements. The freezing transitions observed in the ac-susceptibility of the nanoparticles also appear as peaks in the temperature dependence of the zero-field SR rates, but at slightly higher temperatures - as to be expected from the higher frequency of the muon probe. For both bulk and nanoparticles of GdPO4, the muon and 31P-NMR rates are for T 5 K dominated by exchange-narrowed hyperfine broadening arising from the electron spin-spin interactions inside the particles. The dipolar hyperfine interactions acting on the muons and the 31P are, however, much reduced in the nanoparticles. For the DyPO4 analogues the high-temperature rates appear to be fully determined by electron spin-lattice relaxation processes.

  8. Poškodbe tal po strojni sečnji in spravilu lesa v redčenjih

    OpenAIRE

    Cerjak, Bojan

    2014-01-01

    Gozdno gospodarstvo Maribor je avgusta 2010 na raziskovalnih ploskvah na Pohorju in na Goričkem izvedlo prvo redčenje drogovnjakov s tehnologijo strojne sečnje. Na obeh objektih je bil uporabljen stroj za sečnjo Eco Log 580C in zgibni polprikoličar John Deere 1110. Namen diplomskega dela je bil preizkus metode snemanja sečnih poti, ugotoviti primernost uporabljenih strojevna izbranih objektih, ugotoviti razlike v globinah kolesnic po sečnji in po spravilu lesa ter vpliv sečnih ostankov na zma...

  9. PRIMERJAVA IZGRADNJE ŽELEZNIŠKE PROGE PO KLASIČNI METODI IN PO METODI TIRA NA TOGI PODLAGI

    OpenAIRE

    Pirš, Jurij

    2011-01-01

    Diplomska naloga obravnava primerjavo tehnologije gradnje železniške proge po klasični metodi in po metodi tira na togi podlagi. Predstavljene so osnovne zahteve za projektiranje železniške proge in kriteriji za izdelavo posameznih elementov spodnjega in zgornjega ustroja proge skupaj z opisom in uporabo gradbene mehanizacije. V nadaljevanju sledi predstavitev uporabe tehnologije tira na togi podlagi v predorih na odseku Košana – Gornje Ležeče. Prikazana je podrobna analiza togega tira s...

  10. Size effects on lithium storage and phase transition in LiFePO4/FePO4 system

    OpenAIRE

    Zhu, Changbao

    2013-01-01

    LiFePO4 is one of the most promising cathode materials, especially for its great potential to be applied in electric vehicles (EVs) and hybrid electric vehicles (HEVs), and has attracted great interest due to its appealing advantages, such as high theoretical capacity (170 mAhg-1), high safety, environmental benignity and low cost. Although a great improvement has already been reached in terms of electrochemical performance of LiFePO4 by doping, size-reduction, and network formation, several ...

  11. Proč počítáme a co počítáme?

    Czech Academy of Sciences Publication Activity Database

    Wiedermann, Jiří

    2014-01-01

    Roč. 59, č. 1 (2014), s. 33-43. ISSN 0032-2423 R&D Projects: GA ČR GAP202/10/1333 Institutional support: RVO:67985807 Keywords : výpočet * znalosti * výpočetní systémy * generování znalostí Subject RIV: IN - Informatics, Computer Science http://www. youtube .com/watch?v=Llot-KUbVRU http://hdl.handle.net/10338.dmlcz/143737

  12. Po kanalu TBTs pokazhut film o "Vaffen-SS"

    Index Scriptorium Estoniae

    2006-01-01

    Vene filmistuudio Treti Rim on tootnud lätivastase ajaloolise dokumentaali-propagandafilmi Teisest Maailmasõjast "Natslus Balti moodi" ("Natsizm po pribaltiski"). Filmi näitab täna Vene telekanal TVT, andes siiski võimaluse eetris esineda Läti Venemaa suursaadikule Andris Teikmanisele

  13. 211Po - Comments on Evaluation of Decay Data

    International Nuclear Information System (INIS)

    This evaluation was completed in August 2009. The literature available by December 31st, 2008 was included. Evaluation Procedures: The Limitation of Relative Statistical Weight (LWM) method was applied for averaging numbers throughout this evaluation; this method was implemented by using the computer code LWEIGHT, ver. 4 (designed for Excel, MS Office). The uncertainty assigned to an average value in this evaluation is never lower than the lowest uncertainty of any of the experimental input values. Decay Scheme; 211Po decays 100% by alpha particle emissions, mainly to the ground state of 207Pb. The most recent evaluations of the 211Po nuclear structure and decay data, published in Nuclear Data Sheets, were done by E. Browne (2004) and M.J. Martin (1993). In the present evaluation, the spin, parity and energy of the levels, together with the multipolarities and mixing ratios of the γ-ray transitions, have been adopted from the A=207 ENSDF mass-chain evaluation 1993Ma73.This data evaluation refers only to the decay of the 211Po ground state, and not to the decay of the 211Po metastable state at 1462 keV (with a half-life of 25.2 s)

  14. Volatility of 210Po in the gross alpha determination

    Czech Academy of Sciences Publication Activity Database

    Světlík, Ivo; Belanová, A.; Vršková, M.; Hanslík, E.; Ivanovova, D.; Marešová, J.; Tomášková, Lenka; Nováková, Tereza

    Roč. 286 , č. 2 ( 2010 ), s. 547-551. ISSN 0236-5731 R&D Projects: GA AV ČR IAAX00130801 Institutional research plan: CEZ:AV0Z10480505 Keywords : gross alpha * 210Po * polonium recovery Subject RIV: DL - Nuclear Waste, Radioactive Pollution ; Quality Impact factor: 0.777, year: 2010

  15. Structure for Storing Properties of Particles (PoP)

    International Nuclear Information System (INIS)

    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 (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

  16. Electron Phonon Superconductivity in LaNiPO

    Energy Technology Data Exchange (ETDEWEB)

    Subedi, Alaska P [ORNL; Singh, David J [ORNL; Du, Mao-Hua [ORNL

    2008-01-01

    We report first principles calculations of the electronic structure, phonon dispersions and electron phonon coupling of LaNiPO. These calculations show that this material can be explained as a conventional electron phonon superconductor in contrast to theFeAs based high temperature superconductors.

  17. Electron Phonon Superconductivity in LaNiPO

    International Nuclear Information System (INIS)

    We report first principles calculations of the electronic structure, phonon dispersions and electron phonon coupling of LaNiPO. These calculations show that this material can be explained as a conventional electron phonon superconductor in contrast to the FeAs based high temperature superconductors.

  18. Po-210 in the coastal waters at Kalpakkam

    International Nuclear Information System (INIS)

    The occurrence of patches of monazite in the beach sands at Kalpakkam is significant in the context of preoperational surveillance at site and the adjoining coastal marine environment. The paper gives data on Po-210 concentrations in the coastal marine environment - sea water, silt, pelagic and benthic fishes, intertidal biota (mollusca, crustacea and macrophytes) and discusses their relevance to population exposure

  19. SrMnII2MnIII(PO43

    Directory of Open Access Journals (Sweden)

    Ghaleb Alhakmi

    2013-09-01

    Full Text Available The title compound, strontium trimanganese tris(orthophosphate, was synthesized under hydrothermal conditions. Its structure is isotypic to that of the lead analogue PbMnII2MnIII(PO43. Two O atoms are in general positions, whereas all others atoms are in special positions. The Sr and one P atom exhibit mm2 symmetry, the MnII atom 2/m symmetry, the MnIII atom and the other P atom .2. symmetry and two O atoms are located on mirror planes. The three-dimensional network of the crystal structure is made up of two types of chains running parallel to [010]. One chain is linear and is composed of alternating MnIIIO6 octahedra and PO4 tetrahedra sharing vertices; the other chain has a zigzag arrangement and is built up from two edge-sharing MnIIO6 octahedra connected to PO4 tetrahedra by edges and vertices. The two types of chains are linked through PO4 tetrahedra, leading to the formation of channels parallel to [100] and [010] in which the SrII ions are located. They are surrounded by eight O atoms in the form of a slightly distorted bicapped trigonal prism.

  20. Adsorption gas chromatography with 150-ms 216Po

    International Nuclear Information System (INIS)

    A gas chromatography apparatus was developed, which allows experiments with volatile radionuclides having shorter half-lives than one second. This apparatus was tested with the 150-ms isotope 216Po. Experimental data were compared with a Monte Carlo model to determine the adsorption enthalpy ΔHa. (author) 2 figs., 2 refs

  1. Determination of 210Pb and 210Po in cigarette tobacco

    International Nuclear Information System (INIS)

    Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of 210Pb and 210Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The 210Pb was determined by counting the beta activity of the 210Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCr04. The 210Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 11,9 to 30,2 mBq per gram of dry tobacco for 210Pb and from 10,9 to 27,4 mBq per gram of dry tobacco for 210Po. (author)

  2. Environmental impact from inlet of radiocesium in the river Po

    International Nuclear Information System (INIS)

    In this report are reported the environmental parameters from which effective dose equivalent and collective effective dose equivalent, due to a letting of 370 GBq of radiocesium, spread uniformly over a period of a year, into the waters of river Po, are computed

  3. Development of a Portable Motor Learning Laboratory (PoMLab.

    Directory of Open Access Journals (Sweden)

    Ken Takiyama

    Full Text Available 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

  4. Development of a Portable Motor Learning Laboratory (PoMLab)

    Science.gov (United States)

    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

  5. A novel cesium hydroxygallophosphate with a layered structure built up of rutile ribbons: CsGa2(OH)2[(PO4)H(PO4)

    International Nuclear Information System (INIS)

    A new cesium gallophosphate, CsGa2(OH)2[(PO4)H(PO4)], with an original layer structure has been synthesized by hydrothermal route and characterized by single-crystal X-ray diffraction (R=0.0344, Rw=0.0319). Its structure crystallizes in the monoclinic space group P21/a with cell parameters a=16.079(6)A, b=5.9873(12)A, c=4.5033(15)A, β=93.36(4)o and Z=2. It consists of [Ga(OH)PO4]∼ layers built up of rutile ribbons interconnected through PO4 tetrahedra. The structure of CsGa2(OH)2[(PO4)H(PO4)] is closely related to those of (NH4)Ga(OH)PO4 and (en)Ga2(OH)2(PO4)2 (en=ethylenediamine [H3N(CH2)2NH3]2+). The three structures differ mainly from each other by the relative positions and the spacing of the successive layers, which are governed by different hydrogen bonding modes between [Ga(OH)PO4]∼ layers and the interleaved species. The title compound presents strong symmetric hydrogen bonds O-H-O which bridge two PO4 tetrahedra of two successive layers. As a consequence, the distance between the layers is significantly shorter than in the two other amine compounds

  6. Primjena zrakoplova pri gašenju požara

    OpenAIRE

    Rosavec, Roman; Španjol, Željko; Barčić, Damir; Palčić, Domagoj

    2014-01-01

    Svaki požar može se ugasiti kantom vode ako vatrogasac dovoljno brzo stigne do njega. Navedena tvrdnja upućuje na ključnu povezanost vremena reakcije na pojavu požara i utroška resursa za gašenje. U nastojanju smanjivanja broja početaka požara, uspješna služba zaštite od požara je ona koja ugasi sve požare dok još ne zahvate veliko područje. Požar ima kumulativno djelovanje, ne ponaša se i ne širi kao linearna funkcija, kako vremena tako i prostora. Požar nastaje kao posljedica zapaljivosti n...

  7. EPR studies of the defect centers in γ-irradiated KH2PO4, NH4H2PO4 and Ba(H2PO4)2 single crystals

    International Nuclear Information System (INIS)

    The CrO42- impurity has been found to be very effective in stabilizing a phosphorus oxyradical produced by γ-irradiation at room temperature in KH2PO4 and NH4H2PO4 crystals. A similar radical species can be observed in pure Ba(H2PO4)2 crystals γ-irradiated at room temperature. The observed principal values of the g-factor and the 31P hyperfine splitting indicate that this radical species could be the [PO5]2- or [O3POO]2-. (author)

  8. Preparation and Characterisation of LiFePO4/CNT Material for Li-Ion Batteries

    OpenAIRE

    Rushanah Mohamed; Shan Ji; Vladimir Linkov

    2011-01-01

    Li-ion battery cathode materials were synthesised via a mechanical activation and thermal treatment process and systematically studied. LiFePO4/CNT composite cathode materials were successfully prepared from LiFePO4 material. The synthesis technique involved growth of carbon nanotubes onto the LiFePO4 using a novel spray pyrolysis-modified CVD technique. The technique yielded LiFePO4/CNT composite cathode material displaying good electrochemical activity. The composite cathode exhibited excel...

  9. NASA's Planetary Science E/PO Forum: Reflections on Five Years of Effort to Support an E/PO Community

    Science.gov (United States)

    Shipp, S. S.; Shebby, S.; Buxner, S.; Boonstra, D.; Cobabe-Ammann, E. A.; Cobb, W. H.; Dalton, H.; Grier, J.; Klug Boonstra, S. L.; LaConte, K.; Ristvey, J.; Shupla, C. B.; Weeks, S.; Wessen, A. S.; Zimmerman-Brachman, R.

    2014-12-01

    Over the past decade, NASA's Science Mission Directorate (SMD) has funded four education and public outreach (E/PO) forums, aligned with each of its science divisions, including Astrophysics, Earth Science, Heliophysics, and Planetary Science. Together, these forums help organize individual division E/PO programs into a coordinated, effective, efficient, nationwide effort that shares the scientific discoveries of NASA across a broad array of audiences. In the past four-and-a-half years, the Planetary Science Division's Forum - in collaboration with the other three Forums - has worked to support its community of education professionals and scientists involved in E/PO to communicate, collaborate, and strengthen their efforts. The Forum's work encompasses identification of best practices based on educational research, increasing understanding of needs through audience-based working groups, the development of strategic collaborations and partnerships to increase programmatic reach, and the creation of strategic resources to support community members in their E/PO work (e.g., an online workspace for the community to communicate, collaborate, and share practices; recommendations to scientists for increasing impact in educational settings; a one-stop shop for NASA SMD classroom and informal education products, http://nasawavelength.org). Drawing on evaluation data, the presentation will explore what resources and support mechanisms are valued by the community, ways the community uses the available resources, and the outcomes of the effort to date.

  10. High-pressure phase relations of CsD2PO4

    International Nuclear Information System (INIS)

    The high-pressure phase diagram of CsD2PO4 to 4.5 GPa and temperatures between 0 and 4700C is reported. Comparisons are made with CsH2PO4 and correlated with the isotope effect on the high-temperature high-pressure phase relations of KH2PO4

  11. A Hybrid PO - Higher-Order Hierarchical MoM Formulation using Curvilinear Geometry Modeling

    DEFF Research Database (Denmark)

    Jørgensen, E.; Meincke, Peter; Breinbjerg, Olav

    2003-01-01

    A very efficient hybrid PO-MoM method has been presented. In contrast to existing methods, the present solution employs higher-order hierarchical basis functions to discretize the MoM and PO currents. This allows to reduce the number of basis functions in both the PO and MoM regions considerably...

  12. Morphological investigation of sub-micron FePO4 and LiFePO4 particles for rechargeable lithium batteries

    International Nuclear Information System (INIS)

    Microstructural variations of amorphous FePO4 and LiFePO4 (the latter obtained by chemical lithiation of the former) as a result of the annealing temperature have been studied by Thermogravimetric Analysis (TGA)/Differential Thermal Analysis (DTA), chemical analysis, Brunauer-Emmet-Taylor (BET) and Scanning Electron Microscopy (SEM) techniques. Round-shaped amorphous FePO4 particles 40-80 nm in size are obtained after heating (at 400 deg. C) amorphous FePO4·2H2O in air (previously prepared by a precipitation route). On further heating at 650 deg. C, in air, crystalline trigonal FePO4 of crystallite size 4 particles 40-80 nm in size crystallize by heating at 550 deg. C in Ar+5%H2 for 3 h. After thermal treatment, LiFePO4 particles are interconnected by necks, which resembled a sintering process. The particle size of LiFePO4 increases with an increase of temperature up to 750 deg. C, but an abnormal growth is evident at annealing temperatures above 650 deg. C. DTA analysis showed two exothermic peaks at 547 and 768 deg. C for FePO4 due to phase transitions, whereas for LiFePO4 two exothermic effects at 496 and 567 deg. C are shown

  13. Synthesis of FePO4.2H2O nanoplates and their usage for fabricating superior high-rate performance LiFePO4

    International Nuclear Information System (INIS)

    Research highlights: → Monoclinic phase FePO4.2H2O nanoplates are synthesized in waterbath. → The thickness of the FePO4.2H2O nanoplates can be easily tuned. → FePO4.2H2O nanoplates are lithiated to LiFePO4/C nanoparticles. → The LiFePO4/C nanoparticles have sizes ∼50 nm, with carbon coating layer ∼2 nm. → The nanoparticles show excellent high-rate performance and long-term cyclability. - Abstract: Monoclinic phase FePO4.2H2O nanoplates are synthesized very easily in a waterbath and are lithiated to LiFePO4/C nanoparticles by a simple rheological phase method. The thickness of the nanoplates can be tuned simply by changing the concentrations of the reactants. The LiFePO4/C nanoparticles lithiated from the thin FePO4.2H2O nanoplates, with the sizes about 50 nm and the carbon coating layer at the surface 1-2 nm, show excellent high-rate performance and long-term cyclability as the cathode for lithium ion batteries, delivering discharge capacities of more than 150, 120, 110, 100, and 75 mAh g-1 at rates of 5 C, 10 C, 15 C, 20 C and 30 C, respectively.

  14. Metodičke sastavnice početne nastave hrvatskoga jezika

    OpenAIRE

    Mendeš, Branimir

    2009-01-01

    U radu se donosi pregled metodičkih sastavnica početne nastave hrvatskoga jezika. Početna nastava hrvatskoga jezika, odnosno početna nastava čitanja i pisanja temeljno je nastavno područje kurikuluma hrvatskoga jezika u primarnom obrazovanju, a ujedno i temelj za svladavanje ostalih nastavnih premeta. U početnoj nastavi čitanja i pisanja mogu se identifi cirati sljedeće metodičke sastavnice: odnos i raspored početnog čitanja i pisanja, primjena posebnih metoda, izbor i raspored tiskanih i pis...

  15. New hybridization of PO, SBR, and MoM for scattering by large complex conducting objects

    Institute of Scientific and Technical Information of China (English)

    Dong Chunzhu; Geng Fangzhi; Yin Hongcheng; Wang Chao

    2007-01-01

    As a marked extension of the traditional MoM-PO (method of moment-physical optics) hybrid method,a new hybridization of PO, SBR, and MoM (MoM-SBR/PO) is presented to calculate the multi-reflection contribution in the PO region efficiently by introducing the method of SBR based on RDN notion, which avoids the time-consuming iterative procedure and the choice of proper Green's function. As compared with the traditional MoM-PO hybrid method, the calculation efficiency of the proposed method is greatly improved, and its validity is verified by numerical results.

  16. Study on preparation and performances of CDPVC/Ag3PO4 composite photocatalyst

    OpenAIRE

    Wang, Peng; Zhang, Shasha; Shaolei ZHANG; Desong WANG; Qingzhi LUO

    2016-01-01

    PVC/Ag3PO4 composites are prepared by solution-dipping method, and the as-prepared composites are heat-treated to release HCl from PVC molecules to obtain conjugated derivative of PVC/Ag3PO4(CDPVC/Ag3PO4) composites. The CDPVC/Ag3PO4 composites are characterized by XRD, SEM, UV-vis DRS, PL and XPS. The effects of preparation conditions on the visible-light photocatalytic performances of CDPVC/Ag3PO4 composites are investigated by evaluating the decomposition of methyl orange under visible lig...

  17. Preparation and electrochemical properties of LiFePO4/C nanocomposite using FePO4·2H2O nanoparticles by introduction of Fe3(PO4)2·8H2O at low cost

    International Nuclear Information System (INIS)

    A LiFePO4/C composite was synthesized by a simple solid-state reaction method using stearic acid as reductive agent and carbon source and nano-sized FePO4·2H2O as precursor which was prepared from intermediate Fe3(PO4)2·8H2O using industrial FeSO4·7H2O and industrial NH4H2PO4 at a low cost. The structure, morphology and electrochemical performance of LiFePO4/C were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), galvanostatic charge–discharge tests, cyclic voltammogram (CV) and electrochemical impedance spectroscopy (EIS). The results indicate that the LiFePO4/C has an olivine-type structure with nano-size and exhibits excellent electrochemical properties. The discharge capacities are 159 mAh g−1, 148 mAh g−1 and 113 mAh g−1 at 0.1 C, 1 C and 10 C, respectively. Furthermore, the capacity retention rate is higher than 99% after 100 cycles at 1 C and 10 C. The excellent electrochemical performances of LiFePO4/C composite should be attributed to spherical nanoparticles as well as less impurity in FePO4·2H2O precursor

  18. 210Po inhalation due to smoking. A dose estimation

    International Nuclear Information System (INIS)

    Smoking is the second reason for developing lung cancer. Our goal was to determine how the amount of 210Po in the tobacco is distributed among the cigarette parts and what percentage reaches the respiratory system, calculating the effective dose. 210Po from tobacco, filter and ash samples were measured from seven Romanian cigarette brands by alpha spectrometry. The obtained average results were 13.97 ± 1.75 mBq/cigarette in the tobacco; 1.61 ± 0.25 mBq/cigarette in the filter and 3.33 ± 0.29 mBq/cigarette in the ash. The dose originating from active smoking was estimated to have an average of 8.36 ± 0.91 μSv/year, while the passive smoking dose reaching the respiratory system was 5.92 ± 0.49 μSv. (author)

  19. D3PO - Denoising, Deconvolving, and Decomposing Photon Observations

    CERN Document Server

    Selig, Marco

    2013-01-01

    The analysis of astronomical images is a non-trivial task. The D3PO algorithm addresses the inference problem of denoising, deconvolving, and decomposing photon observations. The primary goal is the simultaneous reconstruction of the diffuse and point-like photon flux from a given photon count image. In order to discriminate between these morphologically different signal components, a probabilistic algorithm is derived in the language of information field theory based on a hierarchical Bayesian parameter model. The signal inference exploits prior information on the spatial correlation structure of the diffuse component and the brightness distribution of the spatially uncorrelated point-like sources. A maximum a posteriori solution and a solution minimizing the Gibbs free energy of the inference problem using variational Bayesian methods are discussed. Since the derivation of the solution does not dependent on the underlying position space, the implementation of the D3PO algorithm uses the NIFTY package to ens...

  20. Levels of 210Po in some beverages and in tobacco

    International Nuclear Information System (INIS)

    The objective of the present work is the estimation of the 210Po content in some beverages and in tobacco, in order to assess the corresponding collective doses to the population in Argentina. Yerba mate, tea leaves, their infusions and ground coffee were analyzed, as well as tobacco. Collective doses due to the annual consumption of the beverages described were found to be from 6 man.Sv to 1200 man.Sv. Results for 210Po in tobacco ranged from 10 Bq*kg-1 to 80 Bq*kg-1. Lung doses due to the use of tobacco vary from 75 μSv*y-1 to 600 μSv*y-1. (author) 14 refs.; 1 fig.; 5 tabs

  1. An emergency bioassay method for 210Po in urine

    International Nuclear Information System (INIS)

    A rapid method was developed to efficiently measure 210Po in urine samples in an emergency situation. Polonium-210 in small urine samples (10 mL) was spontaneously deposited on a stainless steel disc in 1 M HCl at room temperature for 4 h in a polyethylene bottle. The metallic disc was then counted for 4 h by alpha spectrometry. The developed method allowed the preparation of large sample batch in a short time. The method meets the requirements for an emergency bioassay procedure. - Highlights: • A new method was developed to rapidly measurement 210Po in urine. • The method is easy to perform and does not require highly qualified staffs. • Large sample batches can be simultaneously prepared. • The method meets the requirements for an emergency bioassay method

  2. La trayectoria poética de Adolfo Alonso Ares

    Directory of Open Access Journals (Sweden)

    Armando López Castro

    2010-03-01

    Full Text Available Los poemas de Adolfo Ares revelan una voz de lo natural, una resonancia de un mismo ritmo cósmico que articula tosa su escritura. Desde el punto de vista lingüístico, se puede decir que la cercanía del poeta a la lengua hablada, sin la cual no hay renovación posible, le permite crear un lenguaje dinámico, en continua transformación, con el cual cada experiencia poética adquiere un sentido nuevo. Tal ha sido la función del arte desde los tiempos más antiguos: integrar al hombre en el ritmo del universo, que a su vez ha de animar a la obra poética en su conjunto.

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

    Science.gov (United States)

    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. PMID:26413648

  4. Binary and ternary Po-containing molecules relevant for LBE cooled reactors at operating temperature

    Energy Technology Data Exchange (ETDEWEB)

    Van Yperen-De Deyne, Andy; Rijpstra, Kim; Waroquier, Michel; Van Speybroeck, Veronique [Center for Molecular Modeling (CMM), Ghent University, Technologiepark 903, BE-9052 Zwijnaarde (Belgium); Cottenier, Stefaan, E-mail: stefaan.cottenier@ugent.be [Center for Molecular Modeling (CMM), Ghent University, Technologiepark 903, BE-9052 Zwijnaarde (Belgium); Department of Materials Science and Engineering, Ghent University, Technologiepark 903, BE-9052 Zwijnaarde (Belgium)

    2015-03-15

    Highlights: • Ab initio methods assess the stability of Po-containing molecules above LBE. • 13 plausible binary and ternary Po-containing molecules are considered. • A fair compromise between accuracy and computational time is determined. - Abstract: Quantum-chemical calculations at several levels of theory were used to assess the stability at different temperatures of a set of 13 binary and ternary Po-containing molecules that could possibly be formed in an environment with lead, bismuth, oxygen and water. The conclusions are that especially PoPb, PbPoO and PoOH and to a lesser extent Po{sub 2} and PoO are stable. These small molecules are therefore likely to be found near the Lead-Bismuth eutectic (LBE) coolant at operational temperatures in a heavy liquid metal cooled fission reactor. In contrast, Po{sub 3} and PoBi are unlikely to be present under the assumed conditions. Several stability criteria, such as the dissociation into free atoms or into molecular fragments at realistic Po-concentrations or in the thermodynamic limit are discussed at different temperatures. The results obtained with a medium level of theory (Density Functional Theory, PBE0 with relativistic effective core potentials) show good qualitative correspondence with calculations performed at a much higher level of theory (Multi Reference Configuration Interaction, with spin–orbit coupling and scalar relativistic Hamiltonian)

  5. Binary and ternary Po-containing molecules relevant for LBE cooled reactors at operating temperature

    International Nuclear Information System (INIS)

    Highlights: • Ab initio methods assess the stability of Po-containing molecules above LBE. • 13 plausible binary and ternary Po-containing molecules are considered. • A fair compromise between accuracy and computational time is determined. - Abstract: Quantum-chemical calculations at several levels of theory were used to assess the stability at different temperatures of a set of 13 binary and ternary Po-containing molecules that could possibly be formed in an environment with lead, bismuth, oxygen and water. The conclusions are that especially PoPb, PbPoO and PoOH and to a lesser extent Po2 and PoO are stable. These small molecules are therefore likely to be found near the Lead-Bismuth eutectic (LBE) coolant at operational temperatures in a heavy liquid metal cooled fission reactor. In contrast, Po3 and PoBi are unlikely to be present under the assumed conditions. Several stability criteria, such as the dissociation into free atoms or into molecular fragments at realistic Po-concentrations or in the thermodynamic limit are discussed at different temperatures. The results obtained with a medium level of theory (Density Functional Theory, PBE0 with relativistic effective core potentials) show good qualitative correspondence with calculations performed at a much higher level of theory (Multi Reference Configuration Interaction, with spin–orbit coupling and scalar relativistic Hamiltonian)

  6. β-NbPO 5 and β-TaPO 5: Bronzoïds, second members of the monophosphate tungsten bronze series (PO 2) 4(WO 3) 2 m

    Science.gov (United States)

    Chahboun, H.; Groult, D.; Hervieu, M.; Raveau, B.

    1986-12-01

    The oxides β-NbPO 5 and β-TaPO 5 have been studied by X-ray diffraction and high resolution electron microscopy. They exhibit different supercells based on an orthorhombic subcell with the parameters a0 = 11.27 Å, b0 = 5.28 Å, c0 = 6.62 Å. It is shown that their framework corresponds to the member m = 2 of the series of monophosphate tungsten bronzes (PO 2) 4(WO 3) 2 m with pentagonal tunnels (MPTB P). The structure can thus be described as built up from ReO 3-type slabs which are two octahedra wide and connected through phosphate planes. The stability of these bronzoïds is discussed with respect to that of the MPTB P compounds. The relationships between the structures of the α and β forms of NbPO 5 and TaPO 5 are studied.

  7. Spectroscopy and measurement of electromagnetic moments in sup(198,200,210)Po

    International Nuclear Information System (INIS)

    The quadrupole coupling constants for the 210Po Isup(π)=8+, 11-, 13- isomers in Bi have been measured, and Q(11-)=82(2) fm2 and Q(13-)=90(2) fm2 normalized to Q(210Po8+)=57 fm2 are deduced. In beam γ-spectroscopy of sup(198,) 200Po showed the (πh2sub(9/2) 8+) π(hsub(9/2)isub(13/2) 11-) and (visub(13/2) 12+) isomers. The B(E2 8+->6+) and Q(8+) in 198Po to 210Po are discussed, a sudden drop is found for the B(E2) in 198Po. The B(E3, 11-->8+) rises very steeply in the light Po isotopes. (orig.)

  8. Visible light assisted degradation of organic dye using Ag3PO4

    International Nuclear Information System (INIS)

    The study of visible light photodegradation of organic dye Methylene Blue (MB) have been investigated using silver phosphate (Ag3PO4) as a photocatalyst which is good efficient material for photocatalytic reaction. The simple ion-exchange method is used to prepare Ag3PO4. The structure of the material have been confirmed using X-ray diffraction which shows cubic structure of Ag3PO4. The functional group of the Ag3PO4 has been verified by Fourier transform infrared spectroscopy. The bandgap of Ag3PO4 is calculated using kubelka-munk function from the ultra violet-visible diffuse reflectance spectroscopy, the absorption of Ag3PO4 starts from 470 nm. Under simulated visible light irradiation, Ag3PO4 catalyst exhibits good catalytic ability for degrading MB dye

  9. Hydrothermal synthesis of hierarchical LiFePO4 microspheres for lithium ion battery

    International Nuclear Information System (INIS)

    Highlights: ► Hierarchical LiFePO4 microspheres were prepared by simple hydrothermal process. ► Sucrose plays important role in formation of hierarchical LiFePO4 microspheres. ► Hierarchical LiFePO4 microspheres displayed improved electrochemical performance. -- Abstract: Hierarchical LiFePO4 microspheres were prepared by hydrothermal process in the sucrose solution. The microspheres showed a uniform size distribution of about 10 μm and were assembled by many rough sheets. Moreover, these sheets were consist of densely aggregated 300 nm particles. The presence of sucrose played an important role in the formation of hierarchical LiFePO4 microspheres. Compared with the spindle-like shape LiFePO4 particles obtained in deionized water, the hierarchical LiFePO4 microspheres displayed enhanced tap density, improved rate capability and cycling stability, which can be potential cathode material for lithium ion batteries

  10. Duas poéticas, dois olhares sobre o Barroco

    Directory of Open Access Journals (Sweden)

    Rogério Barbosa da Silva

    1998-12-01

    Full Text Available Resumo: Este ensaio pretende estudar relações existentes entre as poéticas de Affonso Ávila e Haroldo de Campos no contexto da poesia contemporânea, compreendendo o sentido que o Barroco adquiriu em suas produções criativas e críticas. Palavras-chave: experimentalismo, poesia concreta, Barroco, poesia crítica

  11. Comparison of LiFePO4 from different sources

    OpenAIRE

    Striebel, Kathryn; Shim, Joongpyo; Srinivasan, Venkat; Newman, John

    2004-01-01

    The lithium iron phosphate chemistry is plagued by the poor conductivity and slow lithium diffusion in the solid phase. In order to alleviate these problems, various research groups have adopted different strategies including decreasing the particle sizes, increasing the carbon content, and adding dopants. In this study we obtained LiFePO4 electrodes from six different sources and used a combined model-experimental approach to compare the performance. Samples ranged from one with no carb...

  12. Zaznavanje naravnih požarov s satelitskih posnetkov

    OpenAIRE

    Jaušovec, Aljaž

    2015-01-01

    V diplomski nalogi obravnavamo orodja in satelitske sisteme, namenjene spremljanju temperaturnih anomalij na površju Zemlje. Izbrali smo 5 požarov, na osnovi katerih predstavimo orodje MPEF FIRG (EUMETSAT) in orodje Nase, namenjeno podatkom senzorja MODIS. Predstavimo razlike med obema orodjema, ki imata skupni namen, vendar uporabljata povsem različen satelitski sistem. Rezultatom obeh globalnih orodij dodamo rezultate posameznih detajlnih analiz, izvedenih na osnovi podatkov geostacionarneg...

  13. 210Po activity concentrations in mussels at Aegean Turkish Coast

    International Nuclear Information System (INIS)

    In Turkey mussels (Mytilus galloprovincialis) are consumed in relatively large quantities. Therefore, analyses of mussel samples from different sampling sites in Aegean Sea were performed in order to evaluate the ingestion of 210Po and 210Pb by the Turkey population. Polonium analyses were performed with a complete dissolution of the sample in mineral acids. Polonium isotopes were plated onto a copper discs in 0.5 M HCl solution in the presence of ascorbic acid using a technique modified from Flynn (1968). The alpha activity measurements of polonium isotopes plated on copper discs were performed with ZnS(Ag) detector. The highest concentrations was found in Karaburun mussels as 254 Bq.kg-1 and the lowest one was at Inciralti as 18 Bq.kg-1. Based on these 210Po activity concentrations, annual dose equivalent rates delivered to biological tissues in mussels would vary widely, from 136 to 10 mSv.y-1. It is concluded that in mussels living in the Aegean Sea a wide range of internal radiation dose exists and it is essentially sustained by 210Po food-chain transfer. (author)

  14. A biokinetic study of {sup 209}Po in man

    Energy Technology Data Exchange (ETDEWEB)

    Henricsson, C.F.; Ranebo, Y. [Department of Medical Radiation Physics, Clinical Sciences in Lund, Lund University, Skane University Hospital in Lund (Sweden); Hansson, M. [Medical Radiation Physics, Department of Clinical Sciences in Malmoe, Lund University, Skane University Hospital in Malmoe (Sweden); Raeaef, C.L., E-mail: Christopher.Raaf@med.lu.se [Medical Radiation Physics, Department of Clinical Sciences in Malmoe, Lund University, Skane University Hospital in Malmoe (Sweden); Holm, E. [Norwegian Radiation Protection Authority, Osteras (Norway)

    2012-10-15

    Five adult volunteers participated in a biokinetic study of radioactive polonium. Portions of about 10 Bq of {sup 209}Po were orally administrated to four of the volunteers in a single ingestion. The fifth volunteer ingested a daily amount of 53 mBq of 209Po for 243 d to study the time to achieve equilibrium between intake and excretion for protracted intakes. For the subjects ingesting single intakes of {sup 209}Po complete sampling of urine and feces was subsequently collected the first few days upon the ingestion. The samples were processed with radiochemical extraction and analyzed with alpha spectrometry. In the study, the maximum daily excretion rates in feces were 18-50% of the ingested activity, observed within 3 d after intake. Regarding the urine excretion, the daily excretion peaked, on average, at 0.15-1% of the ingested activity within two days upon intake. These results indicate an average gastro-intestinal uptake fraction of 0.46 {+-} 0.08, which agrees well with earlier biokinetic studies of polonium in man. -- Highlights: Black-Right-Pointing-Pointer Human metabolism of an oral intake of polonium. Black-Right-Pointing-Pointer 4 individuals were administrated about 10 Bq polonium-209. Black-Right-Pointing-Pointer Gastro-intestinal uptake fraction, if orally administrated polonium-209 was investigated. Black-Right-Pointing-Pointer The biological half-time of polonium in human body was studied.

  15. Po River (Italy) channel water resource management: Dynamic processes

    International Nuclear Information System (INIS)

    For Italy's Po River hydrological basin, artificial reservoirs have a great importance; water reserve is about 1600 million cubic meters for the hydroelectric reservoirs and about 76 million cubic meters for irrigation. Historical analyses show that the Po River channel patterns and evolutionary trend remained practically unchanged for a period of 150 years until the 1960's with a progressive increase of channel length. Starting from 1960, this trend appears to have been reversed, essentially by human activities; the river bed was deepened by dredging, channelized, and its length reduced, with a decrease in sediment supply. Under the current morphologic conditions, the hydro-system response to very high flow rates is, as yet, undetermined, because in the last 40 years peak discharges have always been lower than any previous maximum floods. Between 1801 and 1951, the Po alluvial plain was flooded once every 10-12 years, with flood levels progressively rising (the highest having been recorded in 1951), as a result of the existing embankment system being continuously extended and strengthened

  16. Space matters: Li+ conduction versus strain effect at FePO4/LiFePO4 interface

    Science.gov (United States)

    Lv, Weiqiang; Niu, Yinghua; Jian, Xian; Zhang, Kelvin H. L.; Wang, Wei; Zhao, Jiyun; Wang, Zhiming; Yang, Weiqing; He, Weidong

    2016-02-01

    FePO4/LiFePO4 (FP/LFP) interfacial strain, giving rise to substantial variation in interfacial energy and lattice volume, is inevitable in the (de)lithiation process of LiFePO4, a prototype of Li ion battery cathodes. Extensive theoretical and experimental research has been focused on the effect of lattice strain energy on FP/LFP interface propagation orientation and cyclic stability of the electrode. However, the essential effect of strain induced lattice distortion on Li+ transport at the FP/LFP interface is typically overlooked. In this report, a coherent interface model is derived to evaluate quantitatively the correlation between FP/LFP lattice distortion and Li+ conduction. The results illustrate that the effect of lattice strain on Li+ conduction depends strongly on FP/LFP interface orientations. Lattice strain induces a 90% decrease of Li+ conductivity in ac-plane oriented (de)lithiation at room temperature. The opposite effect of lattice strain on delithiation and lithiation for ab- and bc-orientations is elucidated. In addition, the effect of lattice strain tends to be more pronounced at a lower working temperature. This study provides an efficient platform to comprehend and manipulate Li+ conduction in the charge and discharge of lithium ion batteries, the large-scale application of which is frequently challenged by limited in-cell ion conduction.

  17. Superconductivity in LnFePO (Ln= La, Pr and Nd) single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Baumbach, R E; Hamlin, J J; Shu, L; Zocco, D A; Crisosto, N M; Maple, M B [Department of Physics and Institute for Pure and Applied Physical Sciences, University of California, San Diego, La Jolla, CA 92093 (United States)], E-mail: mbmaple@ucsd.edu

    2009-02-15

    Single crystals of the compounds LaFePO, PrFePO and NdFePO have been prepared by means of a flux growth technique and studied by electrical resistivity, magnetic susceptibility and specific heat measurements. We have found that PrFePO and NdFePO display superconductivity with values of the superconducting critical temperature T{sub c} of 3.2 and 3.1 K, respectively. The effect of annealing on the properties of LaFePO, PrFePO and NdFePO is also reported. The LnFePO (Ln=lanthanide) compounds are isostructural with the LnFeAsO{sub 1-x}F{sub x} compounds that become superconducting with T{sub c} values as high as 55 K for Ln=Sm. A systematic comparison of the occurrence of superconductivity in the series LnFePO and LnFeAsO{sub 1-x}F{sub x} points to a possible difference in the origin of the superconductivity in these two series of compounds.

  18. Crystal structure and physical properties of uranium-copper oxyphosphide UCuPO

    International Nuclear Information System (INIS)

    Single crystals of uranium- and thorium-copper oxyphosphide, UCuPO and ThCuPO, have been grown by an iode-transport method. The crystallographic parameters for UCuPO and ThCuPO are determined at room temperature by single crystal X-ray diffraction. These materials crystallize in a tetragonal ZrCuSiAs-type structure. UCuPO is confirmed to be a semimetallic antiferromagnet with a Neel temperature of TN=220 K, while ThCuPO shows non-magnetic metallic behavior. The specific heat measurements at temperatures much lower than TN indicate that the density of states (DOS) for both compounds is quite low, and that the 5f component of DOS is fully gapped due to antiferromagnetic ordering in UCuPO. The magnetic susceptibility for a single crystal of UCuPO shows a large uniaxial anisotropy along the c axis in the paramagnetic state. The resistivity measurements for UCuPO under high pressures up to 2.45 GPa indicate a slight increase of the Neel temperature. When compared with the data for the reference material ThCuPO, the semimetallic conductivity may come mainly from Cu 4s-P 3p bands with low DOS, while the ordered and paramagnetic moments seem to be carried only by localized 5f electrons. (author)

  19. Kinetic study on selective extraction of HCl and H3PO4 in a microfluidic device☆

    Institute of Scientific and Technical Information of China (English)

    Fang Zhao; Yangcheng Lu; Kai Wang; Guangsheng Luo

    2016-01-01

    In the extraction method for preparing KH2PO4, one of the key processes is the selective extraction of HCl over H3PO4. In our work, extraction kinetic studies have been carried out in a microfluidic device with a coaxial microchannel, using the extractant of 33.3%(by volume) trioctylamine (TOA) dissolved in n-octanol, with differ-ent aqueous phases:the HCl solution, the H3PO4 solution, and H3PO4 and KCl solutions of different concentra-tions. The changes of the extraction efficiency of HCl and H3PO4 and the selectivity for HCl along with the residence time were investigated. We found that fast extraction kinetics could be realized in microfluidic devices, and that HCl could be extracted faster than H3PO4 due to smaller mass transfer resistance and much stronger re-action between HCl and TOA. For the extraction of H3PO4 and KCl solutions, the selectivity for HCl first increased and then decreased when TOA was in excess of H3PO4 in the initial feeds, and in contrast, always increased when H3PO4 was in excess of TOA in the initial feeds. The diverse changes of selectivity for HCl along with the residence time indicate that a dynamic control of selectivity in microfluidic devices may be important and accessible for im-proving the KH2PO4 conversion efficiency in extraction method.

  20. 210Po in Nevada groundwater and its relation to gross alpha radioactivity

    Science.gov (United States)

    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.

  1. Atmospheric depositions of 210Pb and 210Po in Lisbon, Portugal

    International Nuclear Information System (INIS)

    The long lived radon daughters 210Pb and 210Po were determined in samples of total surface deposition obtained with collectors continuously operated during 5 years, near Lisbon. The annual 210Pb flux was 66±12 Bqm-2, and the average annual 210Po flux was 8±3 Bq m-2, with an overall 210Po/210Pb activity ratio of 0.15±0.06. The deposition of 210Pb was positively correlated with seasonal rainfall, while 210Po was mainly originated in soil particles re-suspension throughout the year and also in seasonal forest fires. Unusually high 210Po/210Pb activity ratios, higher than unity, were occasionally recorded and the sources and causes are discussed. Long time-series of 210Pb and 210Po deposition fluxes, as presented herein, are rare although essential to test and constrain parameter of the atmospheric Global Circulation Models. (author)

  2. Investigations of the potential bioavailability of 210Po in some foodstuffs

    International Nuclear Information System (INIS)

    Extraction of 210Po from lamb's liver, pig's kidneys, mussel flesh and brown crabmeat with a series of solvent systems has been used to gain some insight into the uncertainty about the gastrointestinal absorption factor for Po incorporated into foodstuffs. By extracting the tissues with diethyldithiocarbamate dissolved in chloroform, and also in methanol, it has been shown that 210Po is more effectively extracted from lamb's liver and crabmeat than it is from each of the other tissues. A similar pattern of extractability is also evident for aqueous solutions of citric acid on crabmeat and mussel flesh. Of particular note is the low extractability by dimethylsulphoxide (3%) of 210Po in mussel flesh as opposed to 24% extractability of 210Po from crabmeat. 210Po-binding macromolecules of about 10 kDa have been released from crabmeat and mussel flesh by digestion with pepsin

  3. Distribution of Po-210 in two species of predatory marine fish from the Brazilian coast

    International Nuclear Information System (INIS)

    Polonium-210 (210Po) concentration was quantified in the muscle tissue and organs of two predatory marine fishes (Genypterus brasiliensis and Cynoscion microlepidotus) from Cabo Frio, Rio de Janeiro, Brazil. The species C. microlepidotus, a benthic carnivore, registered higher 210Po in its tissue. The organs associated with digestion displayed the maximum radionuclide compared with other organs. The average activity was 2 mBq kg−1 for G. brasiliensis and it was 6 mBq kg−1 for C. microlepidotus. The activity concentrations varied significantly between the species and among organs. -- Highlights: • We analyzed the distribution of 210Po in two species of predator marine fish. • 210Po tends to accumulate in some organs, which make this radionuclide radiotoxic. • The consumption of small quantities of fish can represent high potential of 210Po exposure. • Data about 210Po bioaccumulation in tropical predator marine fish are limited

  4. Arte, poética y educación

    OpenAIRE

    Belinche, Daniel

    2011-01-01

    Una línea poética e identitaria del arte es fácil de postular en el plano teórico. No así su concreción en un programa institucional. En los establecimientos cohabitan intereses personales, trayectorias apoyadas en legados históricos e incluso arengas ideológicas radicalizadas cuando defienden intereses corporativos que encubren posturas reaccionarias. Si las carreras artísticas no consiguen poner en discusión sus incumbencias será díficil sortear el alto desgranamiento y la frustración que p...

  5. Jak by mohly bakterie počítat

    Czech Academy of Sciences Publication Activity Database

    Wiedermann, Jiří

    Bratislava : Slovenská technická univerzita, 2011 - (Kvasnička, V.; Pospíchal, J.; Návrat, P.; Lacko, P.; Varga, Ľ.), s. 361-371 ISBN 978-80-227-3542-1 R&D Projects: GA ČR GAP202/10/1333 Institutional research plan: CEZ:AV0Z10300504 Keywords : quorum sensing * molekulární komunikace * nanomašinky * výpočetní universalita Subject RIV: IN - Informatics, Computer Science http://www2.fiit.stuba.sk/~kvasnicka/Free%20books/Umela_inteligencia_a_kognitivna_vedaI_III.pdf

  6. The poços de caldas project

    CERN Document Server

    Chapman, NA; Shea, ME; Smellie, JAT

    1993-01-01

    The safe disposal of radioactive wastes by burial in deep geological formations requires long-term predictions of the future behaviour of the wastes and their engineered repository. Such predictions can be tested by evaluating processes analogous to those which will occur in a repository, which have been long active in the natural geochemical environment. The Poços de Caldas Project is a comprehensive study of two ore deposits in Minas Gerais, Brazil, aimed at looking at uranium and thorium series radionuclide and rare-earth element mobility, the development and movement of redox fronts, and

  7. A poética de Edgar Allan Poe

    Directory of Open Access Journals (Sweden)

    Kiefer, Charles

    2009-01-01

    Full Text Available O estudo abrange o início da vida literária de Edgar Allan Poe como crítico do periódico Graham’s Magazine. Ao produzir resenhas sobre Nathanael Hawthorne, Poe elabora uma síntese de suas concepções a respeito do conto. Para o autor a vantagem do conto, como gênero, é que ele permite uma leitura totalizadora. O exame das resenhas de Poe torna possível uma aproximação entre a poética do autor norte-americado com a de Aristóteles.

  8. OBRAVNAVA BOLNIKOV PO ZDRAVLJENJU RAKA NA DEBELEM ČREVESU

    OpenAIRE

    Ljuljđuraj, Petar

    2013-01-01

    Diplomsko delo obravnava rak na debelem črevesu in nadaljnjo rehabilitacijo pacienta po odpustu iz bolnišnice. Pri izdelavi diplomskega dela smo uporabili deskriptivno metodo dela. V prvem delu diplomskega dela predstavimo debelo črevo, anatomijo, delovanje debelega črevesa in najpogostejše bolezni na debelem črevesu. Tu smo se predvsem osredotočili na rak debelega črevesa, ker je tretji najpogostejši rak na svetu in drugi najpogostejši v Evropi. Predstavili smo tudi način odkrivanja, pre...

  9. Projektiranje upravne stavbe CGP po evropskih standardih Evrokod

    OpenAIRE

    Pavlin, Rožle

    2015-01-01

    V diplomski nalogi analiziramo in projektiramo nosilno konstrukcijo upravne stavbe CGP po trenutno veljavnih standardih na področju gradbenih konstrukcij Evrokod. Nosilna konstrukcija stavbe je iz armiranega betona in je sestavljena iz dveh delov, ki sta medsebojno ločena z dilatacijo. Osredotočimo se na novejši del, ki je bil zgrajen leta 2007 in ima pet etaž, poleg kleti in pritličja še dve nadstropji ter podstrešje. Nosilno konstrukcijo sestavljajo monolitne armiranobetonske stropne plošče...

  10. Conductivity studies in SnO–NaPO3 glasses

    Indian Academy of Sciences (India)

    M Harish Bhat; Munia Ganguli; K J Rao

    2003-06-01

    Na+ ion conductivity has been studied in SnO.NaPO3 glasses, which have been prepared over a wide range of compositions using a microwave melting technique. D.c. activation barriers seem to reflect the structural changes in system. A.c. conductivity analysis has revealed that while the power law exponent, , seem to bear correlation to the structural changes, the exponent of the stretched exponential function describing the dielectric relaxation is largely insensitive to the structure. Possible importance of the correlation of transport property to the variation of available non-bridging oxygen (NBO) atoms in the structure is discussed.

  11. Reactive alumina–LaPO4 composite as machinable bioceramics

    Indian Academy of Sciences (India)

    Abhishek Badolia; Ritwik Sarkar; Sumit Kumar Pal

    2015-08-01

    Sintered Al2O3–LaPO4 composites were prepared using commercially available reactive alumina and phase pure lanthanum phosphate (LP), prepared by the reaction synthesis technique. LP content was varied between 10 and 50 wt% and sintering was carried out between 1400 and 1600°C. Sintered composites were characterized for phase analysis, densification, strength, machinability, microstructure and bioactivity (in SBF solution) and biocompatibility (MTT assay protocol) studies. Composite nature was confirmed by phase analysis and LP was found to reduce the densification and strength values but imparted machinability. Again positive bioactivity and biocompatibility character were observed for all the compositions.

  12. PoGOLite : The Polarised Gamma-ray Observer

    OpenAIRE

    Marini Bettolo, Cecilia

    2008-01-01

    PoGOLite is a balloon-borne experiment which will study polarised soft gamma-ray emission from astrophysical targets in the 25 keV – 80 keV energy range by applying well-type phoswich detector technology. Polarised gamma-rays are expected from a wide variety of sources including rotation-powered pulsars, accreting black holes and neutron stars, and jet-dominated active galaxies. Polarisation measurements provide a powerful probe of the gamma-ray emission mechanism and the distribution of magn...

  13. Poética de resistencia en Itxaro Borda

    OpenAIRE

    Escaja, Tina

    2013-01-01

    La actitud reivindicativa y visionaria de la pluralidad (del cuerpo, el lenguaje, la sexualidad, la cultura y la geografía) en la obra poética de Itxaro Borda es signo de celebración alternativa y de resistencia hacia los valores que impone una nacionalidad vasca unívoca, hipermasculina y fija que con frecuencia la autora vascofrancesa explícitamente denuncia. Su crítica al lenguaje/nación desde el lenguaje/nación que incorpora las diferencias, logra desarticular el discurso unívoco del poder...

  14. Alpha Decay Width of $^{212}$Po from a quartetting wave function approach

    CERN Document Server

    Xu, Chang; Röpke, G; Schuck, P; Funaki, Y; Horiuchi, H; Tohsaki, A; Yamada, T; Zhou, Bo

    2015-01-01

    A microscopic calculation of $\\alpha$-cluster preformation probability and $\\alpha$ decay width in the typical $\\alpha$ emitter $^{212}$Po is presented. Results are obtained by improving a recent approach to describe $\\alpha$ preformation in $^{212}$Po [Phys. Rev. C 90, 034304 (2014)] implementing four-nucleon correlations (quartetting). Using the actually measured density distribution of the $^{208}$ Pb core, the calculated alpha decay width of $^{212}$Po agrees fairly well with the measured one.

  15. Synthesis and Photocatalytic Activity of Ag3PO4 Triangular Prism

    OpenAIRE

    Pengyu Dong; Yan Hao; Peiyang Gao; Entian Cui; Qinfang Zhang

    2015-01-01

    Ag3PO4 triangular prism was synthesized by a facile chemical precipitation approach by simply adjusting external ultrasonic condition. The as-synthesized Ag3PO4 triangular prism was characterized by X-ray diffraction pattern (XRD), field emission scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectra, and ultraviolet-visible diffuse reflectance (UV-vis DRS) absorption spectra. The photocatalytic activity of Ag3PO4 triangular prism was evaluated by photodegradation of or...

  16. Po-210 and Pb-210 in water and fish from Taboshar uranium mining Pit Lake, Tajikistan

    International Nuclear Information System (INIS)

    Polonium-210 in water and 210Pb and 210Po in different fish organs from 3 different fish species in Taboshar Pit Lake (n = 13), located in the uranium mining area in Tajikistan, and in Kairakkum Reservoir (reference lake, n = 3), have been determined as part of a Joint project between Norway, Kazakhstan, Kyrgyzstan and Tajikistan. The average activity concentration of 210Pb and 210Po in liver, muscle and bone of Carassius auratus was higher than the concentration in similar tissues of C. carpio and Sander lucioperca from the reference site. The accumulation of 210Po was higher than for 210Pb, and the accumulation of 210Po was highest in the liver of C. auratus (3673 ± 434 Bq kg−1 ww). Although the average activity concentration of 210Pb in liver and bones of C. auratus from Pit Lake were fairly similar, a huge variation in the liver activity concentrations (25–327 Bq kg−1 ww) was found. The results confirm direct uptake of unsupported 210Po into the liver, and that the distributions of 210Po and 210Pb in fish organs were different. The BCF (L/kg) for 210Po in bone, liver and muscle clearly demonstrates high accumulation of 210Po in C. auratus, especially in the liver. The average BCFs of liver, bone and muscle were >1.4 × 105, >2.5 × 104 and >1.4 × 104, respectively. All fish in the Pit Lake were found to be in the same trophic level, however, a linear correlation between log 210Po in liver and δ15N could indicate biomagnification of 210Po in liver of C. auratus. In regards to the recommended Annual Limit of Intake (ALI) for 210Po, the concentration of 210Po in muscle tissues of C. auratus is alarming, as there is a high probability for the local population at risk to exceed the recommended ALI through consumption of fish from Taboshar Pit Lake

  17. A Hybrid PO - Higher-Order Hierarchical MoM Formulation using Curvilinear Geometry Modeling

    OpenAIRE

    Jørgensen, E; Meincke, Peter; Breinbjerg, Olav

    2003-01-01

    A very efficient hybrid PO-MoM method has been presented. In contrast to existing methods, the present solution employs higher-order hierarchical basis functions to discretize the MoM and PO currents. This allows to reduce the number of basis functions in both the PO and MoM regions considerably which implies a very modest memory requirement. Nevertheless, the hierarchical feature of the basis functions maintains the ability to treat small geometrical details efficiently. In addition, the sca...

  18. 210Po and 210Pb variations in fish species from the Aegean Sea and the contribution of 210Po to the radiation dose

    International Nuclear Information System (INIS)

    In recent years, there has been increasing interest in the significance of natural radionuclides, particularly 210Po, in the marine environment. 210Po, a naturally occurring alpha emitter, accumulates in marine organisms and reflects differences in their diets. In the literature, there is no data for 210Po and 210Pb 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 210Po and 210Pb content. The 210Po and 210Pb 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 210Po and 210Pb in fish samples between seasons (ANOVA, P > 0.05). The highest dose contribution of 210Po to humans was calculated to be 10,530 μSv year−1.

  19. Sodium samarium tetrakis(polyphosphate), NaSm(PO3)4

    OpenAIRE

    Dan Zhao; Lina Zhang; Feifei Li

    2010-01-01

    NaSm(PO3)4 has been prepared by solid state reactions. It belongs to type II of the structural family of MILnIII(PO3)4 compounds (MI = alkali metal and LnIII = rare earth metal) and is composed of ∞(PO3)n]n− polyphosphate chains with a repeating unit of four PO4 tetrahedra. The chains extend parallel to [100] and share O atoms with irregular SmO8 polyhedra, forming a three-dimensional framework which delimits tunnels occupied by Na+ cations in a distorted octahedral enviro...

  20. Research to improvement of the definition of 210 Po and 210 Pb in deposition

    International Nuclear Information System (INIS)

    Investigation to the improvement of the determination of 210Po and 210Pb in deposition. The results of the determination of 210Po and 210Pb in deposition in 1995 do not meet the criteria specified. The chemical recovery of the 208Po tracer added is by many analyses less than the required 50%. The cause of the poor chemical recovery is investigated. This report describes the execution of the investigation and the results. The investigation has led to the improvement of the determination of 210Po and 210Pb in deposition. 12 refs

  1. Performance degradation of LixFePO4 (x = 0, 1) induced by postannealing

    OpenAIRE

    Sun, Xiaofei; Xu, Youlong; Zheng, Xiaoyu; Meng, Xiangfei; Zhang, Rui

    2014-01-01

    Olivine LiFePO4 has been studied for more than a decade as a promising cathode material for rechargeable lithium batteries. However, the low electric conductivity and tap density still hinder its large-scale commercialization. Micro-sized LiFePO4 is prepared by an optimized hydrothermal method in this paper. The influence of postannealing on the physicochemical properties of LiFePO4 and FePO4 is investigated to understand the plausible mechanism for performance degradation. It is found ...

  2. Degradation Studies on LiFePO4 cathode

    DEFF Research Database (Denmark)

    Scipioni, Roberto; Jørgensen, Peter Stanley; Hjelm, Johan;

    2015-01-01

    In this paper we examine a laboratory LiFePO4 (LFP) cathode and propose a simple model that predicts the electrode capacity as function of C-rate, number of cycles and calendar time. Microcracks were found in Li1-xFePO4 particles in a degraded LFP electrode and low-acceleration voltage (1 kV) FIB....../SEM analysis allowed us to obtain phase contrast between FePO4 and LiFePO4. The evolution of micro-cracks is expected to increase the concentration of LFP particles which are not electronically accessible and thus cause a loss in capacity....

  3. Determination and distribution of 210Po in tobacco plants from Poland

    International Nuclear Information System (INIS)

    One of the most radiotoxic elements, 210Po in different parts of tobacco plant from Poland was determined. Investigation revealed that polonium is non-uniformly distributed within tobacco plant. Tobacco leaves constituting about 50% of the wet mass, contain 87.1% of the total burden of 210Po. Among the analyzed leaves about 66% of polonium is located in the oldest, over-ground part. It was indicated that 210Po is generally taken up by tobacco from the dry or wet deposition of the radioactive fall-out onto the plant. Moreover, 210Po concentration in tobacco leaves from Poland are higher than that in the other countries. (author)

  4. Decay/ingrowth uncertainty correction of 210Po/210Pb in seawater

    International Nuclear Information System (INIS)

    Due to increasing application of 210Po/210Pb in studying particle dynamics, a consistent procedure and calculation to derive accurate and precise result of 210Po and 210Pb in seawater should be proposed in the framework of intercalibration by GEOTRACES. The associated uncertainty of radioactivity, which is a significant component of data report, plays a vital role in intercomparison and should be well evaluated. Although measurement uncertainty of laboratory result was well defined in ISO standards and IAEA technical documents, the decay/ingrowth uncertainty correction from laboratory result to in-situ result was less studied. It was demonstrated that the relative uncertainty of in-situ 210Pb activity was independent of elapsed time and equal to relative uncertainty of laboratory measuring 210Po activity at second spontaneous deposition date. The relative uncertainty of in-situ 210Po activity decreases with in-situ activity ratio of 210Po to 210Pb and increases with elapsed time between sampling date and separation date, relative uncertainty of laboratory measuring 210Po activity at first spontaneous deposition date and relative uncertainty of in-situ 210Pb activity. It was more important to improve precision of 210Po at first spontaneous deposition date than that of 210Po at second spontaneous deposition date. To obtain a desirable relative uncertainty of in-situ 210Po activity, the maximum allowing elapsed time for 210Po, which was important for sampling strategy making and quality assurance, was calculated by in-situ activity ratio of 210Po to 210Pb and precision of analytical method for 210Po. The methodology of decay/ingrowth uncertainty correction could also be applied for other radionuclide pairs (234Th/238U, 90Y/90Sr, 210Bi/210Pb), sample matrixes (aerosols), and disciplines. - Highlights: • Uncertainty of 210Po/210Pb in seawater was comprehensively represented. • Decay/ingrowth uncertainty correction was well quantified and concisely expressed.

  5. Vitamins A, C, and E May Reduce Intestinal 210Po Levels after Ingestion.

    Science.gov (United States)

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

    2016-07-01

    Damage to the gut mucosa is a probable contributory cause of death from ingested Po. Therefore, medical products are needed that can prevent, mitigate, and/or repair gastrointestinal (GI) damage caused by high-LET radiation emitted by Po. 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 Po. Mice were gavaged with 0 or 18.5 kBq Po-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 Po on day 8 post-gavage. The concentration of Po in intestinal tissues was significantly (pvitamin ACE groups compared to control. There were borderline significant Po-induced reductions in intestinal absorption of D-fructose. The combination of vitamins A, C, and E may reduce Po incorporation in the intestines when given before, or enhance decorporation when provided after, Po gavage. PMID:27218295

  6. Komparace firemní kultury na příkladu České pošty a Slovenské pošty

    OpenAIRE

    Strolená, Jana

    2009-01-01

    This bachelor thesis is concentrated on the organizational culture in the companies Česká pošta, s.p. and Slovenská pošta, a.s. It is focused in the definitions of important concepts in the sphere of culture and in the subsequent description of particular elements of organizational culture, which are specified in descriptive cases of the post companies. This bachelor thesis has an aim to compare organizational culture in both companies and in case of Česká pošta also to find out the current s...

  7. Baseline concentration of {sup 210}Po in Sargassum from the Northern Gulf

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, S.; Bebhehani, M.; Talebi, L. [Kuwait Institute for Scientific Research (Kuwait)

    2014-07-01

    The concentration of the {sup 210}Po is of enormous interest because of its large contribution to the natural radiation dose received by marine organisms and human populations consuming seafood. In fact natural {sup 210}Po is responsible for higher radiation doses to humans consuming marine products than is plutonium and other man-made radionuclides. Many marine organisms are capable of concentrating {sup 210}Po in their tissues. {sup 210}Po is an alpha emitter in the {sup 238}U series, with 138-d half-life, that is supplied to seawater from atmospheric inputs and river runoff, however, the main source of {sup 210}Po in the environment is {sup 222}Rn exhalation from the ground. Assessing the impact of radionuclides in the environment requires the establishment of baseline levels in the environmental compartments. The objective of this study was to establish baseline levels in Sargassum. Two most common species of Sargassum found in the northern Gulf were analysed for {sup 210}Po. These macro-algae were collected from three different locations during January 2013. This study sets the baseline for {sup 210}Po concentration in northern Gulf, {sup 210}Po is absorbed from water and concentrated by Phytoplankton and macro-algae. This concentrated {sup 210}Po can then be passed along to the next trophic level of the marine food web. The {sup 210}Po concentration measured in Sargassum boveanum (4.405 - 4.952 BqKg{sup -1}) was significantly higher (p>0.084) than Sargassum oligocystum (3.838 - 4.358 BqKg{sup -1}). The {sup 210}Po concentration in these seaweeds from the Arabian/Persian Gulf were substantially lower than those found in various Phytoplankton and macro-algae species from other regions; this may be due to the lower background {sup 210}Po concentration in the Kuwait marine waters (0.282 - 0.382 mBq l{sup -1}). The {sup 210}Po concentrations in seawater measured at the 3 stations during January 2013 were less than those reported previously from the same region

  8. 210Po content in human urine of people living in south of Spain

    International Nuclear Information System (INIS)

    The death of the former secret service agent Alexander Livitnenko in 2006 due to a lethal intake of 210Po, presumably via ingestion, sparked renewed interest in the field of 210Po toxicity to humans. 210Po occurs widely in nature and is an important component of man' s natural radiation background. The main route of 210Po intake by the human body is the ingestion with foodstuffs, although ingestion with drinking water especially of underground origin represents another route of 210Po intakes. Inhalation of 222Rn released from the soil also contributes in 210Po body burden. However, the body burden of 210Po in normal human body may differ from one person to another depending upon the mode life including diet habits, origin of drinking water, residence place (radon exposure rate) and also smoking habits. Therefore, many factors may affect the 210Po intake and lead to variations in the body burden in different individuals, and consequently in their urine. To see the influence of the diet habits in the amount of 210Po excreted by urine, some volunteers in Seville (south of Spain) follow defined diets during approximately one month, with daily urine collection followed by 210Po determination by alpha-particle spectrometry. Depending on the type of diet ingested by the different volunteers, it was observed differences approaching even an order of magnitude in their levels of 210Po in urine. This fact difficult enormously the adoption of a predefined value of this nuclide in urine with natural origin with the consequence difficulties for screening through urine the possible anthropogenic intake of this element. (author)

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

    Science.gov (United States)

    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.

  10. Spatial and depth variation of 210Po and 210Pb in monazite sand along HBRA of coastal Kerala

    International Nuclear Information System (INIS)

    The samples collected from high background radiation area were analyzed for 210Po and 210Pb activities in order to understand their distribution, enrichment and depth profile in the beach sand. The 210Po and 210Pb activities vary from 1.85 to 31.27 Bq kg-1 and 9.77 to 132.30 Bq kg-1 respectively. The 210Po/210Pb indicate that the radionuclides 210Po and 210Pb are not in equilibrium and the accumulation of 210Pb in sand is greater than for 210Po. The spatial variations of 210Po and 210Pb activities were studied in detail. (author)

  11. Magnetic relaxation in Zn(PO3)2·Er(PO3)3 glass

    Science.gov (United States)

    Orendáč, M.; Tibenská, K.; Čižmár, E.; Tkáč, V.; Orendáčová, A.; Holubová, J.; Černošek, Z.; Černošková, E.

    2016-08-01

    The results of experimental studies of alternating (ac) magnetic susceptibility and specific heat of Zn(PO3)2·Er(PO3)3 glass are reported. Despite a high concentration of magnetic Er(III) ions the analysis of ac susceptibility ruled out the formation of a spin glass state in the used range of temperatures. Two relaxation processes were identified. The first one is thermally activated with a crossover in its temperature dependence observed at nominally 7 K. The relaxation at lower temperatures seems to be governed by a direct process with pronounced effect of phonon bottleneck. Striking deceleration of spin dynamics with increasing temperature found above 7 K is tentatively attributed to overcoming Ioffe - Regel crossover and strong scattering of acoustic phonons on local modes. Simplified prediction derived from a soft-mode-dynamics model confirms the presence of the boson peak observed in specific heat data and reasonably predicts the temperature of the crossover. The second process is consistent with a cross - tunneling relaxation. The obtained results suggest that magnetic doping of glasses and studying magnetic relaxation may represent an alternative tool for the investigation of lattice modes in glasses.

  12. Synthesis, crystal structure and optical properties of the catena-metaphosphates Ce(PO{sub 3}){sub 4} and U(PO{sub 3}){sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Hoeppe, Henning A.; Daub, Michi [Augsburg Univ. (Germany). Inst. fuer Physik

    2012-11-01

    The catena-metaphosphates of tetravalent cerium and tetravalent uranium were obtained as phase pure crystalline powders by reaction of the respective dioxides with phosphoric acid at 500 C. Ce(PO{sub 3}){sub 4} and U(PO{sub 3}){sub 4} crystallise in space group C2/c (Z = 16, a{sub Ce} = 13.7696(3) Aa, b{sub Ce} = 29.7120(7) Aa, c{sub Ce} = 8.9269(2) Aa, {beta}{sub Ce} = 90.00(1) Aa{sup 3} and a{sub U} = 13.786(3) Aa, b{sub U} = 29.843(6) Aa, c{sub U} = 8.9720(18) Aa, {beta}{sub U} = 90.01(3) Aa{sup 3}). The vibrational and optical spectra of pale yellow Ce(PO{sub 3}){sub 4} and emerald-greenish U(PO{sub 3}){sub 4} are also reported. (orig.)

  13. Chemical characterization of springtime submicrometer aerosol in Po Valley, Italy

    Directory of Open Access Journals (Sweden)

    S. Saarikoski

    2012-03-01

    Full Text Available The chemistry of submicron particles was investigated at San Pietro Capofiume (SPC measurement station in the Po Valley, Italy, in spring 2008. The measurements were performed by using both off-line and on-line instruments. Organic carbon (OC and elemental carbon, organic acids and biomass burning tracers were measured off-line by using a 24-h PM1 filter sampling. More detailed particle chemistry was achieved by using an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS and analyzing the data by positive matrix factorization (PMF. Oxalic acid had the highest concentrations of organic acids (campaign-average 97.4 ng m−3 followed by methane sulfonic, formic, malonic, and malic acids. Samples were also analyzed for glyoxylic, succinic, azelaic and maleic acids. In total, the nine acids composed 1.9 and 3.8% of OC and water-soluble OC, respectively (average, in terms of carbon atoms. Levoglucosan concentration varied from 17.7 to 495 ng m−3 with the concentration decreasing in the course of the campaign most likely due to the reduced use of domestic heating with wood. Six factors were found for organic aerosol (OA at SPC by PMF: hydrocarbon-like OA (HOA, biomass burning OA (BBOA, nitrogen-containing OA (N-OA and three different oxygenated OAs (OOA-a, OOA-b and OOA-c. Most of the OA mass was composed of OOA-a, HOA and OOA-c (26, 24 and 22%, respectively followed by OOA-b (13%, BBOA (8% and N-OA (7%. As expected, OOAs were the most oxygenated factors with organic matter:organic carbon (OM:OC ratios ranging from 1.9 to 2.2. The diurnal variability of the aerosol chemical composition was greatly affected by the boundary layer meteorology. Specifically, the effect of the nocturnal layer break-up in morning hours was most evident for nitrate and N-OA indicating that these compounds originated mainly from the local sources in the Po Valley. For sulfate and OOA-a the concentration did not

  14. Diurnal variations of 218Po, 214Pb, and 214Po and their effect on atmospheric electrical conductivity in the lower atmosphere at Mysore

    International Nuclear Information System (INIS)

    The short-lived radon daughters (218Po, 214Pb, 214Bi and 214Po) 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. Their behaviour is similar to that of aerosols with respect to their growth, transport, removal processes in the atmosphere. The electrical conductivity of the atmosphere is mainly due to the presence of highly mobile (small) ions. Hence the electrical conductivity of air at near the surface of the earth mainly due to 222Rn, 218Po, 214Pb, 214Bi and 214Po concentrations, and depends on aerosol concentrations and meteorological parameters. The individual radon progeny concentrations (218Po, 214Pb, and 214Po) are measured using Air Flow meter. The concentration of radon in the atmospheric air is measured using Low Level Radon Detection System. The total energy released due to both radon and its progeny is computed in energy units (eV cm-3s-1) and is converted into ion-pair production rate (No. cm-3 s-1), 32 eV being the energy producing one-ion pair. The atmospheric electrical conductivity (both positive and negative) is measured using a Gerdien's apparatus with two identical tubes. The average values of 218Po, 214Pb, and 214Po are respectively 13.70, 1.45 and 1.92 Bq m-3 respectively. The average value of positive and negative electrical conductivity are 5.08 x 10-14U-1 m-1 and 4.67 x 10-14 U-1 m-1. The concentrations of radon, its progeny, and positive and negative conductivity show a similar kind of diurnal variations with maximum in the early morning hours and a minimum during day time. The activity is higher in winter than in summer and rainy season. (author)

  15. Morphology-controlled synthesis of Ag3PO4 nano/microcrystals and their antibacterial properties

    International Nuclear Information System (INIS)

    Graphical abstract: The Ag3PO4 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 Ag3PO4 with three morphologies were controllable fabricated. • The Ag3PO4 as-prepared possess obvious antibacterial properties in the dark. • The antibacterial ability of Ag3PO4 could be greatly improved under the visible light irradiation. - Abstract: We reported the controllable fabrication of Ag3PO4 nano/microcrystals through a simple solution-based precipitation reaction. The samples were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and infrared spectroscopy. The results indicated that the Ag3PO4 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 Ag3PO4 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 Ag3PO4 could be greatly improved under the visible light irradiation, which are superior to that in the dark and commercial streptomycin

  16. 21 CFR 868.1200 - Indwelling blood oxygen partial pressure (PO2) analyzer.

    Science.gov (United States)

    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...

  17. 210Po and 210Pb activity concentration in the coral bands of Pulau Tuba, Langkawi

    International Nuclear Information System (INIS)

    We examined the concentrations of 210Po and 210Pb in each layers of coral banding of coral skeletons. Concentrations of 210Po and 210Pb in massive corals (i.e. Porites, Favites, Platygyra and Goniostrea) from Pulau Tuba, Langkawi were measured using the Alpha-Spectrometry. The concentrations of 210Po were higher than the concentrations of 210Pb. This may due to continuing source of 210Po from 210Pb. Highest concentration on 210Po in coral banding was 48.30 ± 28.53 Bq/ kg, meanwhile for 210Pb was 12.86 ± 5.80 Bq/ kg. The ratios of 210Po/ 210Pb were in the range of 2.21 to 5.49. The variation activity concentrations of 210Po and 210Pb in the coral bands are important to consider in using coral as retrospective study of environmental changes. The coral can represent the total of 210Po and 210Pb in the surrounding water for the past few years. (author)

  18. Concentration and distribution of 210Po in rats exposed to radon

    International Nuclear Information System (INIS)

    Objective: To study the concentration and distribution of 210Po in rats exposed to radon and its daughters. Methods: Fifteen male wistar rats were randomly divided into three groups, including one control group and two radon exposed groups with the cumulative doses of 100 WLM (low dose) and 200 WLM (high dose), respectively. Tissue samples containing 210Po were spontaneously deposited onto silvery discs with the diameter of 20 mm by means of wet ashing and electrodeposition. The concentration of 210Po in tissues were measured by α spectroscopy, and tissue burden were calculated. Results: The concentrations of 210Po were significantly different among the three dose groups in femur, liver, sex gland and hair (P210Po were different between the exposed groups and the control group in lung and soleus muscle (P210Po in lung, spleen and hair were higher than that in liver, bone and sex gland, the lowest was in intestine. The tissue burdens of liver, bone and sex gland were significantly different from those in other organs or tissues. Conclusions: 210Po was mainly distributed in lung, liver, spleen, femur and sex gland. The concentrations of 210Po in organs or tissues and the tissue burdens were correspondingly increased with the exposure dose of radon and its daughters. The results of this experiment provide a dosimetric basis for further studies on the carcinogenic effect of radon and its daughters. (authors)

  19. Synthesis and luminescent properties of LaPO4:Eu3+ microspheres

    International Nuclear Information System (INIS)

    Highlights: • LaPO4:Eu3+ microspheres with a monoclinic phase were synthesized. • CTAB plays an important role in the formation of LaPO4:Eu3+ microspheres. • The LaPO4:Eu3+ microspheres have an enhanced emission intensity. -- Abstract: LaPO4:Eu3+ microspheres were synthesized, using LaCl3, EuCl3 and (NH4)2HPO4 as starting materials. The morphology, formation mechanism, and luminescent property of samples were systemically studied. X-ray diffraction (XRD) and infrared spectroscopy (IR) show that LaPO4:Eu3+ microspheres have a pure monoclinic phase. Cetyltrimethyl ammonium bromide (CTAB) usually forms spherical micelles above a critical micelle concentration, which plays an important role in the formation of LaPO4:Eu3+ microspheres. The excitation spectrum of LaPO4:Eu3+ microspheres consists of several sharp lines due to the direct excitation of the Eu3+ cations from the ground state to higher levels of the 4f-manifold. The emission intensity of microspheres is higher than irregular particles because of the lowlier surface area. The lifetimes of Eu3+ ions in the LaPO4:Eu3+ microspheres are determined to be 2.41 ms

  20. A theoretical approach to the study of saturation phenomena of electrostatic collection efficiency of 218Po

    International Nuclear Information System (INIS)

    Radon monitors based on electrostatic collection have been widely used in different radon studies. Collection efficiency of this kind of instrument first depends on the cell geometry and electrostatic field intensity. In the process of new instrument development, some researchers found that electrostatic collection efficiency of 218Po was almost saturated when the voltage between the cylindrical vessel and the detector was higher than 1500 V. In this paper, we analyze the physical processes of the freshly positively charged 218Po formed from the α decay of 222Rn and the neutralization kinetics for positively charged 218Po cluster. The analytical expressions of the collection probability of any freshly positively charged 218Po cluster and the total collection efficiency in electrostatic collection cell are obtained. The ratio of the relative growth rate of the collection efficiency to the relative growth rate of the voltage is inversely proportional to the voltage. Such an approach is useful to understand the mechanism of the electrostatic collection of 218Po. - Highlights: • Expression for collection probability of positively charged 218Po has been obtained. • Expression for total collection efficiency of 218Po has been obtained. • The mechanism of electrostatic collection efficiency of 218Po has been explained

  1. PoD: dynamically create and use remote PROOF clusters. A thin client concept.

    CERN Document Server

    CERN. Geneva

    2012-01-01

    PoD’s newly developed “pod-remote” command made it possible for users to utilize a thin client concept. In order to create dynamic PROOF clusters, users are now able to select a remote computer, even behind a firewall, to control a PoD server on...

  2. Moderní počítačové viry

    OpenAIRE

    Malina, Lukáš

    2008-01-01

    Bakalářská práce Moderní počítačové viry se skládá ze dvou hlavních cílů (Analýza počítačových virů a návrh zabezpečení střední počítačové sítě) rozdělených na tři části: Analýza počítačových virů, Vlastní návrh zabezpečení osobního počítače koncového uživatele (Terminálu) a Vlastní návrh zabezpečení střední počítačové sítě. V první části jsou analyzovány metody šíření a infekce, specifické vlastnosti a dopady počítačových virů na osobní počítače. V druhé části je uvedeno řešení zabezpečení o...

  3. Synthesis and luminescence of CePO4 and CePO4:Tb hollow and core-shell microspheres composed of single-crystal nanorods

    International Nuclear Information System (INIS)

    Lanthanide phosphate microspheres composed of single-crystal CePO4 and CePO4:Tb nanorods were successfully synthesized, respectively, using the functionalized composite aggregate as a template, which is composed of P123, H6P4O13 and Ce3+, and also as a resource of reaction species with high chemical potential. The shape and the phase structure of the CePO4 nanocrystal can be easily controlled via adjusting reaction temperature, monomer concentration and annealing temperature. SEM images show the spherical superstructure composed of nanorods. HRTEM and SAED images reveal the single-crystalline nature of nanorod and TEM images show the hollow interiors of the superstructure. XRD patterns indicate that the crystal structure of the nanorods is hexagonal before and monoclinic after annealing. The formation mechanism was proposed. Strong UV and green luminescence were observed for the CePO4 and CePO4:Tb microspheres, respectively. The synthesis method can be extended to the fabrication of NRHS and core-shell microspheres of other rare-earth or doped LnPO4 materials for wide applications

  4. Multi-year Surface Deposition of {sup 210}Pb and {sup 210}Po at Lisbon - Atmospheric Depositions of {sup 210}Pb and {sup 210}Po in Lisbon, Portugal

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Fernando P.; Oliveira, Joao M.; Alberto, G. [Instituto Superior Tecnico/ Campus Tecnologico e Nuclear, Universidade Tecnica de Lisboa, E.N. 10, 2686-953 Sacavem (Portugal)

    2014-07-01

    The long lived radon daughters {sup 210}Pb and {sup 210}Po were determined in samples of total atmospheric depositions obtained with surface collectors continuously operated during 5 years, near Lisbon. The average annual {sup 210}Pb flux was 66±12 Bq m{sup -2}, and the average annual {sup 210}Po flux was 8±3 Bq m{sup -2}, with an overall {sup 210}Po/{sup 210}Pb activity ratio of 0.15±0.06. Direct determination of the {sup 210}Pb atmospheric flux was compared with the {sup 210}Pb excess determined in soil surface layers along with atmospheric depositions of {sup 137}Cs. The deposition of atmospheric {sup 210}Pb was positively correlated with seasonal rainfall, while {sup 210}Po was mainly originated in soil particles re-suspension throughout the year and also in seasonal forest fires. Unusually high {sup 210}Po/{sup 210}Pb activity ratios, higher than unity, were occasionally recorded in atmospheric depositions and the sources and causes are discussed. Long time-series of {sup 210}Pb and {sup 210}Po deposition fluxes, as presented herein are useful to test and constrain parameters of the atmospheric Global Circulation Models. (authors)

  5. Multi-year Surface Deposition of 210Pb and 210Po at Lisbon - Atmospheric Depositions of 210Pb and 210Po in Lisbon, Portugal

    International Nuclear Information System (INIS)

    The long lived radon daughters 210Pb and 210Po were determined in samples of total atmospheric depositions obtained with surface collectors continuously operated during 5 years, near Lisbon. The average annual 210Pb flux was 66±12 Bq m-2, and the average annual 210Po flux was 8±3 Bq m-2, with an overall 210Po/210Pb activity ratio of 0.15±0.06. Direct determination of the 210Pb atmospheric flux was compared with the 210Pb excess determined in soil surface layers along with atmospheric depositions of 137Cs. The deposition of atmospheric 210Pb was positively correlated with seasonal rainfall, while 210Po was mainly originated in soil particles re-suspension throughout the year and also in seasonal forest fires. Unusually high 210Po/210Pb activity ratios, higher than unity, were occasionally recorded in atmospheric depositions and the sources and causes are discussed. Long time-series of 210Pb and 210Po deposition fluxes, as presented herein are useful to test and constrain parameters of the atmospheric Global Circulation Models. (authors)

  6. Electrochemical performance of NiO-doped LiFePO4/C cathode materials prepared from amorphous FePO4 · xH2O

    Science.gov (United States)

    Mahmud, Iqbal; Kim, Dong-Seob; Ur, Soon-Chul

    2016-05-01

    LiFePO4/C composites are prepared from amorphous FePO4 · xH2O and are modified with NiO (0.0, 0.01, 0.02, 0.03, and 0.04 mol) by using a solid-state reaction process with a spex milling system. The crystalline structure and the morphology of synthesized powders have been characterized by using X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD patterns indicate a complete solid solution for all the NiO-doped LiFePO4/C composites. The SEM images show that the sizes of the particles produced are distributed in the range of 200 - 300 nm. The electrochemical performances have been evaluated by using an impedance measurement and a galvanostatic charge/discharge test. The initial properties and impedance measurement reveal different improvements for different amounts of NiO doping in LiFePO4/C. A maximum capacity of 158.8 mAh/g at 0.1 C has been achieved LiFePO4/C doped with NiO at 0.01 mol. The present work reveals that the newly processed composite of LiFePO4/C doped with a small amount of NiO may be a promising material for using in a lithium-ion battery.

  7. A Obra de Arte como Verdade Poética

    OpenAIRE

    Vilela, Maria Joana

    2014-01-01

    Tomando como referência o texto A Origem da Obra de Arte de Heidegger, o objectivo desta dissertação é a análise da questão da obra de arte como verdade poética. Considerando a experiência do conhecimento como a origem da criação, por via do que o mundo revela, e considerando tanto a produção artística como outras formas de produção pela mão do homem enquanto atitudes de apresentação da verdade encontrada, ela reflecte acerca daquilo que a obra de arte tem e que a distingue das...

  8. PO*WW*ER mobile treatment unit process hazards analysis

    Energy Technology Data Exchange (ETDEWEB)

    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 damage 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.

  9. OBLIKOVANJE NOTRANJIH PROSTOROV IN ELEMENTOV PO KITAJSKI METODI FENG SHUI

    OpenAIRE

    Tavčar, Romy

    2012-01-01

    Sodobni način življenja nam ne daje dovolj časa, da bi sproščeno živeli z naravo in ugotavljali vplive okolja na počutje in potek usode. Danes se soočamo z izjemnim tehnološkim napredkom in z vedno manj znanja o naravi. Bogastvo se meri s količino prostega časa, ki si ga lahko privoščimo. Zavedanje o tem, da tega ni možno kupiti ali nadomestiti z nobeno materialno vrednoto in da je to dosegljivo z višjo stopnjo zavedanja, nam odpira vrata v svobodo in brezčasnost. Ta raj je zunaj dosega našeg...

  10. Pour une poétique queer de Rimbaud

    OpenAIRE

    Kramer, Max

    2014-01-01

    La sexologie et les tabous sexuels ont eu une influence énorme sur la poésie de Rimbaud. Ce dernier a conçu plusieurs stratégies queer (particulièrement de métaphores queer) afin d’effectuer des commentaires obliques sur sa sexualité à une époque de plus en plus homophobe. Cet essai soutient que les études queer devraient faire plus attention, et de façon plus systématique, à ces stratégies et mettre fin à un malaise hétéronormatif de longue date caractéristique de la réception de l’œuvre de ...

  11. PO*WW*ER mobile treatment unit process hazards analysis

    International Nuclear Information System (INIS)

    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 damage 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

  12. Electrochemical performance of LiFePO4 cathode material for Li-ion battery

    Institute of Scientific and Technical Information of China (English)

    LI Shuzhong; LI Chao; FAN Yanliang; XU Jiaqiang; WANG Tao; YANG Shuting

    2006-01-01

    In the search for improved materials for rechargeable lithium batteries, LiFePO4 offers interesting possibilities because of its low raw materials cost, environmental friendliness and safety. The main drawback with using the material is its poor electronic conductivity and this limitation has to be overcome. Here Al-doped LiFePO4/C composite cathode materials were prepared by a polymer-network synthesis technique. Testing of X-ray diffraction, charge-discharge, and cyclic voltammetry were carried out for its performance. Results show that Al-doped LiFePO4/C composite cathode materials have a high initial capacity, good cycle stability and excellent low temperature performance. The electrical conductivity of LiFePO4 material can be obviously improved by doping Al. The better electrochemical performances of Al-doped LiFePO4/C composite cathode materials have a connection with its conductivity.

  13. Analysis of the crystal structure of a tetragonal RbD2PO4 single crystal

    International Nuclear Information System (INIS)

    Tetragonal RbD2PO4 single crystals, which are colorless and transparent, are synthesized from tetragonal RbH2PO4 crystals. A ferroelectric transition temperature was found to be 235 K from the temperature dependence of the structure factor F0 in neutron diffraction. Deuteriums in a paraelectric phase are in disordered array. Hydrogen bonds in the monoclinic structure form two-dimensional array in the bc plane, but in the tetragonal structure these display three-dimensional array. The distribution of deuterium was studied by Fourier analysis method. The crystal structure of tetragonal RbD2PO4 at a paraelectric phase was analyzed on the basis of neutron diffraction experiments, and the movement for PO4 tetrahedral was studied. The results for the tetragonal RbD2PO4 were compared with those for the monoclinic structure. (Y. Kazumata)

  14. Local structure of vanadium in doped LiFePO4

    International Nuclear Information System (INIS)

    LiFePO4 composites with 5 at.% vanadium doping are prepared by solid state reactions. X-ray absorption fine-structure spectroscopy is used as a novel technique to identify vanadium sites. Both experimental analyses and theoretical simulations show that vanadium does not enter into the LiFePO4 crystal lattice. When the vanadium concentration is lower then 1 at.%, the dopant remains insoluble. Thus, a single-phase vanadium-doped LiFePO4 cannot be formed and the improved electrochemical properties of vanadium doped LiFePO4 previously reported cannot be associated with crystal structure changes of the LiFePO4 via vanadium doping. (orig.)

  15. An evaluation of the exposure to 210Pb-210Po in italian population

    International Nuclear Information System (INIS)

    Following an introduction on the behaviour in the environment and in man of 210Pb-210Po, experimental data are reported on 210Pb-210Po exposure of the italian population. The analytical methods used to measure 210Pb-210Po activity in the many biological and environmental samples analyzed are also reported. The data collected refer to the intake, excretion, internal burden and metabolism both in a group of subjects representative of the general population and in other critical groups exposed to high internal contamination of 210Pb-210Po, as the radioactive spa wopkes and the miners. The absorbed dose due to 210Pb-210Po has also been evaluated, on the basis of data referring to the various population groups

  16. Ultrathin carbon nanopainting of LiFePO4 by oxidative surface polymerization of dopamine

    Science.gov (United States)

    Ding, Bo; Tang, Wei Chin; Ji, Ge; Ma, Yue; Xiao, Pengfei; Lu, Li; Lee, Jim Yang

    2014-11-01

    The common strategy to address the low electronic conductivity of LiFePO4 is to downsize LiFePO4 and to coat the nanocrystal with conductive carbon film. The major issues with existing carbon coating techniques are thickness and quality control. This paper reports a facile carbon coating method which can provide ultrathin, uniform and fully encapsulating carbon coating on LiFePO4. This coating method capitalizes on the redox chemistry of surface Fe3+ on solvothermally synthesized LiFePO4 nanocrystal, to deposit uniform thin films of polydopamine films. The polymer film is easily carbonized into ultrathin carbon film. The carbon coated LiFePO4 exhibits very high rate performance (143 mAh g-1 at current density of 1700 mA g-1) with excellent capacity retention.

  17. Estimation of 210Po in Cauvery river and ground water from south interior Karnataka state, India

    International Nuclear Information System (INIS)

    The study is carried out for the estimation of 210Po concentration in Cauvery River and Ground water from south interior Karnataka State region. 210Po is generated from Uranium decay series and is highly toxic element. The water samples were collected from Cauvery river belt of south interior Karnataka. These samples were processed using radiochemical analysis. As per WHO standards 210Po concentration in drinking water should not exceed 100 mBql-1. The concentration of 210Po ranges from 0.36 mBql-1 to 3.97 mBql-1 in river water samples and has a mean value of 1.98 mBql-1. In ground water samples the 210Po concentration ranges from 1.89 mBql-1 to 4.87 mBql-1 and mean value is 3.22 mBql-1. (author)

  18. Nucleation and growth of new particles in Po Valley, Italy

    Directory of Open Access Journals (Sweden)

    A. Hamed

    2007-01-01

    Full Text Available Aerosol number distribution measurements are reported at San Pietro Capofiume (SPC station (44°39' N, 11°37' E for the time period 2002–2005. The station is located in Po Valley, the largest industrial, trading and agricultural area in Italy with a high population density. New particle formation was studied based on observations of the particle size distribution, meteorological and gas phase parameters. The nucleation events were classified according to the event clarity based on the particle number concentrations, and the particle formation and growth rates. Out of a total of 769 operational days from 2002 to 2005 clear events were detected on 36% of the days whilst 33% are clearly non-event days. The event frequency was high during spring and summer months with maximum values in May and July, whereas lower frequency was observed in winter and autumn months. The average particle formation and growth rates were estimated as ~6 cm−3 s−1 and ~7 nm h−1, respectively. Such high growth and formation rates are typical for polluted areas. Temperature, wind speed, solar radiation, SO2 and O3 concentrations were on average higher on nucleation days than on non-event days, whereas relative and absolute humidity and NO2 concentration were lower; however, seasonal differences were observed. Backtrajectory analysis suggests that during majority of nucleation event days, the air masses originate from northern to eastern directions. We also study previously developed nucleation event correlations with environmental variables and show that they predict Po Valley nucleation events with variable success.

  19. Removal of lead from crude antimony by using NaPo3 as lead elimination reagent

    Directory of Open Access Journals (Sweden)

    Ye L.G.

    2015-01-01

    Full Text Available In order to solve the shortcomings when removing lead from crude antimony in the traditional antimony smelting, a new process was provided using NaPO3 as lead elimination reagent to yield phosphate slag, and it was removed by floating on the surface of the liquid antimony. Reaction mechanism was clarified by using the TG-DTA and XRD techniques and single factor experiments of removal lead from crude antimony were engaged. The results show that PbO and NaPO3 begin endothermic reaction at 863K (590°C, and the reaction mainly form NaPb4(PO43 and NaPbPO4 below 1123K (850°C and above 1123K (850°C, respectively. Sb2O3 and NaPO3 start the reaction at 773K (500°C and generate an antimonic salt compound. The reaction product of the mixture of PbO, Sb2O3 and NaPO3 show that NaPO3 reacted with PbO prior when NaPO3 was insufficient, amorphous antimony glass will be generated only when NaPO3 was adequate. Single factor experiments were taken with NaNO3 as oxidizing agent under argon, effect of reaction time, reaction temperature and dosage of NaPO3 and NaNO3 on smelting results. The average content of lead in refined antimony was 0.05340% and 98.85% of lead were removed under optimal conditions; the content of lead in antimony have meet the requirements of commercial antimony.

  20. Luminescence and energy transfer of Sm3+ and Eu3+ in Ca2PO4Cl

    International Nuclear Information System (INIS)

    Sm3+, Eu3+, and Sm3+–Eu3+ doped Ca2PO4Cl phosphors are synthesized by a solid-state method. Ca2PO4Cl:Sm3+ can produce red emission under the 400 nm radiation excitation, and the emission peak is located at 601 nm, which is assigned to the 4G5/2→6H7/2 transition of Sm3+. Ca2PO4Cl:Eu3+ can create red emission under the 392 nm radiation excitation, and the strongest peak is located at 620 nm, which is attributed to the 5D0→7F2 transition of Eu3+. The energy transfer from Sm3+ to Eu3+ in Ca2PO4Cl has been validated and the critical distance (Rc) of Sm3+ to Eu3+ in Ca2PO4Cl is calculated to be 1.14 nm. With increasing Eu3+ doping concentration, the energy transfer efficiency (Sm3+→Eu3+) gradually increases to 53.7%. The luminescence property of Ca2PO4Cl:Sm3+, Eu3+ can be tuned by properly tuning the relative ratio of Sm3+–Eu3+, and the emission intensity of Ca2PO4Cl:Eu3+ can be greatly enhanced by codoped Sm3+. - Highlights: • Ca2PO4Cl:Sm3+, Eu3+ can produce red emission under the 400 nm radiation excitation. • The energy transfer from Sm3+ to Eu3+ in Ca2PO4Cl has been validated. • The critical distance of Sm3+ to Eu3+ in Ca2PO4Cl is calculated to be 1.14 nm

  1. beta. -NbPO/sub 5/ and. beta. -TaPO/sub 5/: bronzoieds, second members of the monophosphate tungsten bronze series (PO/sub 2/)/sub 4/(WO/sub 3/)/sub 2m/

    Energy Technology Data Exchange (ETDEWEB)

    Chahboun, H.; Groult, D.; Hervieu, M.; Raveau, B.

    1986-12-01

    The oxides ..beta..-NbPO/sub 5/ and ..beta..-TaPO/sub 5/ have been studied by X-ray diffraction and high resolution electron microscopy. They exhibit different supercells based on an orthorhombic subcell with the parameters a/sub 0/ = 11.27 A, b/sub 0/ = 5.28 A, c/sub 0/ = 6.62 A. It is shown that their framework corresponds to the member m = 2 of the series of monophosphate tungsten bronzes (PO/sub 2/)/sub 4/(WO/sub 3/)/sub 2m/ with pentagonal tunnels (MPTB/sub P/). The structure can thus be described as built up from ReO/sub 3/-type slabs which are two octahedra wide and connected through phosphate planes. The stability of these bronzoieds is discussed with respect to that of the MPTB/sub P/ compounds. The relationships between the structures of the ..cap alpha.. and ..beta.. forms of NbPO/sub 5/ and TaPO/sub 5/ are studied.

  2. L’onomastique et la poétique de l’errance dans la poésie mohandienne

    OpenAIRE

    Yermeche, Ouerdia

    2012-01-01

    Si Mohand ou M’hand, figure emblématique de la culture et de la poésie kabyle de la fin du xixe siècle, symbolise l’écrivain qui, bien malgré lui, a su faire partager à ses concitoyenscette tension créatrice entre les vicissitudes de l’Histoire et la culture ancestrale qui intègre le sujet humain dans une mémoire collective. Agent involontaire d’une conjoncture particulière et d’une révolution sociétale tant brutale qu’inattendue, Si Mohand (ou M’hand) est un écrivain façonné par une expérien...

  3. In-beam spectroscopy of very neutron deficient polonium isotopes 190,191Po

    International Nuclear Information System (INIS)

    The phenomenon of shape coexistence is experimentally well established in even-even light Pb, Hg and Pt nuclei. The light Po isotopes are predicted to exhibit similar features. Due to the experimental difficulties when approaching the proton drip-line, the lightest Po isotope for which in-beam γ-ray data exists prior this work has been 192Po. Since shape coexistence should be most pronounced at the neutron mid-shell (N=104), information about the excited states in lighter Po isotopes would be valuable in verifying the existence and possibly understanding the origin of the phenomenon in these nuclei. In the present work the recoil decay tagging method has been used to study excited states in the neutron deficient isotopes 190,191Po. Prompt γ-rays were detected with the Jurosphere Ge detector array coupled to the gas- filled separator RITU. The 191Po nuclei were produced in the 142Nd(52Cr,3n)191Po reaction at a bombarding energy of 240MeV. The observed prompt γ-rays correlated with the α-decay of the 191mPo 13/2+ state were placed in two cascades. Similar sequences have been observed in 193,195Po and presumably correspond to favoured and unfavoured states in the vi13 band. The unfavoured states are lowered below the favoured ones, resulting in a strongly coupled scheme which suggests oblate deformation. In a separate experiment the 142Nd(52Cr,4n)190Po reaction was used at higher beam energy. The production cross-section was approximately 200nb. Four prompt α-transitions correlated with the 190Po α-decay were observed and intepreted to form a cascade of E2 transitions up to spin 8+. In comparison to the heavier even Po isotopes, a drop in 6+ and 8+ energies is observed. This suggest an onset of prolate deformation in light Po isotopes as predicted by Oros et al. The results will be discussed in the framework of intruder states (author)

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

    Science.gov (United States)

    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. PMID:26328435

  5. The preparation of conductive nano-LiFePO4/PAS and its electrochemical performance

    International Nuclear Information System (INIS)

    A simple and effective method has been developed to synthesize a nano-sized LiFePO4/PAS (polyacenic semiconductor) composite. The LiFePO4 particles coated and connected by PAS are uniformly distributed in the range of 50-80 nm. The electronic conductivity of this material is as high as 1.2 x 10-1 S/cm due to the conductive network of PAS. In comparison with the micro-LiFePO4/PAS, the nano-LiFePO4/PAS exhibits much better rate performance. At the 12-min charge-discharge rate, the power and energy densities of the nano-LiFePO4/PAS are shown as 2063 W/kg and 412 Wh/kg, which are much higher than those of the micro-LiFePO4/PAS (1600 W/kg and 320 Wh/kg). It is especially notable that the nano-LiFePO4/PAS cathode without adding Super P shows similar electrochemical behaviors with the cathode adding Super P at all C-rates. Thus, such cathode without adding Super P will enlarge both the volume energy density and weight energy density of batteries. In addition, this cathode exhibits an excellent long-term cyclability, retaining over 95.4% of its original discharge capacity beyond 500 cycles at 0.2C rate. These favorable electrochemical performances should be attributed to its nanometric particle size and the high electronic conductivity.

  6. On a framework for generating PoD curves assisted by numerical simulations

    Science.gov (United States)

    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.

  7. $^{206}$ Po sources for production and release studies relevant for high power spallation targets

    CERN Multimedia

    The knowledge of the evaporation behaviour of Po is of essential importance for several scientific and technological applications, like accelerator driven systems (ADS) or the LIEBE project at CERN-ISOLDE. Fundamental investigations on the experimental conditions for the formation of volatile Po species as well as on the chemical composition of the volatile compounds are necessary for a safe operation of such facilities. $^{206}$Po, a mainly $\\gamma$- ray-emitting Po isotope with a half-life of 8.8 d, is best suited for model studies, due to the lower radiation hazard compared to the longer-lived $\\alpha$-emitting isotopes $^{208-210}$Po as well as the easy-tomeasure $\\gamma$-ray emission. We propose the production of $^{206}$Po samples in several matrices via the implantation of its precursor $^{210}$Fr into selected metal foils at CERN-ISOLDE. Using these samples, experiments will be carried out at PSI studying the volatilization of Po from different matrices under varying chemical conditions.

  8. PO41, a snake venom metalloproteinase inhibitor isolated from Philander opossum serum.

    Science.gov (United States)

    Jurgilas, Patrícia B; Neves-Ferreira, Ana G C; Domont, Gilberto B; Perales, Jonas

    2003-11-01

    PO41 was isolated from Philander opossum serum by DEAE-Sephacel, Phenyl Superose and Superdex 200 chromatographies and showed a molecular mass of 41,330 Da by MALDI-TOF MS. Molecular masses of 81.5 and 84.5 kDa were obtained by size exclusion chromatography and dynamic laser light scattering, respectively, suggesting that PO41 is dimeric. Its isoelectric point was estimated to be lower than 3.5. PO41 presented similar amino terminal sequence to those of DM40 and DM43, two antihaemorrhagins previously isolated from Didelphis marsupialis serum and was recognized by polyclonal antibodies raised against D. marsupialis antibothropic fraction. To study the inhibitory properties of this protein, the metalloproteinases bothrolysin and jararhagin were isolated from Bothrops jararaca venom by chromatographies on Superdex 200 and Phenyl Superose. Jararhagin was further submitted to a Mono Q column. The proteolytic and haemorrhagic effects of these haemorrhagins were neutralized by PO41. Both snake venom metalloproteinases formed stable complexes with PO41. The stoichiometry of the complex PO41-jararhagin was one inhibitor subunit to one molecule of the enzyme. These results show that PO41 has physicochemical, structural, immunoreactive and biological properties similar to other metalloproteinase inhibitors belonging to the supergene family of immunoglobulins. PMID:14602117

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

    Science.gov (United States)

    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. PMID:26643716

  10. Unlocking the energy capabilities of micron-sized LiFePO4.

    Science.gov (United States)

    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

  11. Hollow GdPO4:Eu3+ microspheres: Luminescent properties and applications as drug carrier

    Science.gov (United States)

    Tang, Yanxia; Mei, Rui; Yang, Shaokun; Tang, Hongxia; Yin, Wenzhong; Xu, Yongchun; Gao, Yaping

    2016-04-01

    GdPO4:Eu3+ samples were synthesized by a hydrothermal process using melamine formaldehyde (MF) as template. The X-ray diffraction (XRD) patterns and the Fourier Transform Infrared (FTIR) spectrum suggested that GdPO4:Eu3+ has a hexagonal phase. The scanning electron microscope (SEM) and transmission electron microscope (TEM) images showed that the obtained GdPO4:Eu3+ are hollow microspheres with diameters in the range of 1-1.5 μm. Under the excitation at 245 nm, hexagonal GdPO4:Eu3+ hollow microspheres showed emission bands originating from the 5D0 → 7FJ (J = 1, 2, 3 and 4) transitions of Eu3+. The drug release properties of hexagonal GdPO4:Eu3+ hollow microspheres were exhibited by the doxorubicin hydrochloride (DOX) release test. The biocompatibility of hexagonal GdPO4:Eu3+ hollow microsphere was tested by the standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results indicated that hollow GdPO4:Eu3+ microspheres have potential applications in biomedicine fields.

  12. Alpha-spectroscopic determination of 210Pb and 210Po in snow samples

    International Nuclear Information System (INIS)

    The concentrations of 210Pb and 210Po in several snow samples were determined using α-spectrometry. After 5 l of snow-melt water was subjected to coprecipitation of both nuclides with AlPO4, the solvent extraction procedure with TBP (tri-butyl phosphate)-isopropyl ether was applied to purify the polonium fraction, followed by the spontaneous electro-deposition on a Ni-sheet. The α-spectrum was measured with a Si(Au)-semiconductor detector coupled with a multichannel pulse-height analyzer. After the first determination of 210Po, the concentration of 210Pb was estimated from second measurement of 210Po grown newly from the remaining Pb-fraction during the storage period of more than 3 months. In these analytical procedures, 212Pb and 208Po tracers were conveniently utilized for the determination of collection yield for 210Pb and of the final chemical yield of 210Po, respectively. The contents of 210Po and 210Pb in the fresh snow were 3 -- 30 mBq/l (81 -- 810 fCi/l) and 250 -- 720 mBq/l(6.8 -- 19.5 pCi/l), respectively, and the residence time of 210Pb was given to be 6 -- 12 days from the decay-growth relationships of both nuclides. (author)

  13. Evaluation of the 210Po method at the Midwest uranium deposit, northern Saskatchewan, Canada

    International Nuclear Information System (INIS)

    Vertical profiles of 210Po in soils near the Midwest uranium deposit and an associated surficial radioactive sandstone boulder train in northern Saskatchewan show a high 210Po background in air-dried forest litter (24 pCi/g) and Ah horizon soil (11 pCi/g) relative to lower soil horizons (210Po signal from the radioactive boulders in the near-surface soil horizons. Only in the Bf and C horizons can the existence of the radioactive boulders be inferred from 210Po determinations. For comparative purposes profiles for 226Ra, U, Ni, and other trace elements are also presented. Escape of most of the Rn from near surface soils into the atmosphere, homogenization and decay of Rn, and precipitation of decay products back onto surface soils satisfactorily explain the field observations discussed here. Compared to the highly anomalous 222Rn signal in soil gases over this boulder train the 210Po contrast is very weak and is of little use for prospecting for this type of boulder train. The relatively high 210Po background in surficial materials relative to lower soil horizons dictates that great care be taken with the 210Po method; the deepest possible horizons should be sampled. (orig.)

  14. 210Po and 210Pb in soils and vegetables in Kucuk Menderes basin of Turkey

    International Nuclear Information System (INIS)

    In this study concentrations of 210Po and 210Pb radionuclides in soils and vegetables collected from both cultivated and uncultivated agricultural lands of the Kucuk Menderes basin were determined. 210Po and 210Pb activity concentrations of vegetables collected from cultivated lands were found to be slightly higher than those collected from undisturbed lands. The activity concentrations in vegetables were detected between 0.15-9.40Bqkg-1 and 0.23-0.62Bqkg-1 for 210Po and 210Pb, respectively. In the bulk soil cores sampled from phosphate fertilizer-applied agricultural lands, the ranges for activity concentrations of 210Po and 210Pb are 30.10-47.15Bqkg-1 and 31.27-61.53Bqkg-1, respectively. 210Po and 210Pb activity concentrations in soil cores collected from uncultivated soils were also determined for comparison. The annual effective dose equivalents to man from 210Po and 210Pb due to consumption of leafy vegetables are calculated to be 30.51 and 22.73μSva-1, respectively. Likewise root vegetables give a dose equivalent of 22.89μSva-1 from 210Po and 44.77μSva-1 from 210Pb

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

    International Nuclear Information System (INIS)

    Highlights: ► The study reports baseline concentration of 210Po in commercial fish species of Kuwait. ► Radionuclide conc. in commercial fish is critical for food chain transfer. ► With nuclear plants coming-up in Gulf baseline is critical. - Abstract: This baseline study highlights the 210Po variation in whole fishes with different feeding habits. Whole-body 210Po concentrations were determined in ten important commercial fish species found in the northern Arabian Gulf to serve as baseline data. Primarily, 210Po 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 210Po 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 210Po in the marine food chain and the 210Po concentration factors in fish from the Arabian Gulf.

  16. Biogeochemical cycling of 210Po and 210Pb in the upper ocean

    International Nuclear Information System (INIS)

    The naturally occurring radionuclide 210Po is typically deficient relative to its parent 210Pb in the surface ocean due to preferential removal by biota, while in near equilibrium or excess below the surface mixed layer due to rapid regeneration from sinking organic matter. In general, larger deficit of 210Po is observed in the oligotrophic oceans interior, which seems to be due to efficient uptake of Po by cyanobacteria. The activities of 210Pb and 210Po were measured for the truly dissolved (< 10 kD), colloidal (10 kD - 0.45 mm), and particulate (> 0.45 mm) phases in the upper ocean (0-200 m) of the East/Japan Sea (EJS) in the summer of 2009. The total 210Pb and 210Po activities in the EJS were in the range of 6.3-23 and 3.3-10 dpm/100L, respectively. The proportions of the truly dissolved, colloidal, and particulate phases were 35±3, 48±7 and 17±8% for 210Pb and 19±2, 36±6, and 45±6% for 210Po, respectively, in the upper ocean. Using a net residence time model, which accounts for biological uptake and remineralization, the residence times of 210Po in the upper 100-m layer were calculated to be 92±41, 63±14, and 166±45 days for the truly dissolved, colloidal, an particulate phases, respectively. The residence time of colloidal 210Po was several-fold longer than typical turnover times (<10 days) of high-molecular-weight dissolved organic carbon and colloidal residence times of short-live 234Th in the surface water. This result suggests that 210Po turns over several times through the colloidal phase perhaps together with other bio-reactive elements, before settling down from the upper ocean. (author)

  17. 210Po accumulations in marine organisms from the Spanish East Coast

    International Nuclear Information System (INIS)

    One of the most radiotoxic natural radionuclides is 210Po. Its presence in the environment is mainly due to the 222Rn decay. The 222Rn is diffused, as a descendent of the natural Uranium chain, from the ground to the atmosphere and its daughters are deposited on the surface of the earth. Recent publications in the literature show anchovies (Engraulis encrasilocus) as the marine species with highest levels of 210Po. The aim of this work is the study of the 210Po concentrations in anchovies and other fish species from an area where radon contents is very high due to the influence of a coastal lagoon (measured radon contents in coastal lagoon water, by scintillation counter, shows 790 ±90 Bq m-3) that flows in the sea. The samples are being collected from different local markets and ports from March 2012. The fish samples were weighed and oven dry to a constant weigh at 70℃ and then thoroughly mixed. 208Po tracer was added to the samples which were digested using nitric and hydrochloric acid, after that samples were dissolved with hydrochloric acid and spontaneously plated onto a silver disc. 210Po is measured by á-particle spectrometry with a Si detector. The ratio between 210Po and 208Po peaks is used to determine the activity concentration of 210Po in the sample. First results of 210Po concentration in anchovies in the interesting area vary between 202 ± 22 Bq Kg-1 and 400 ± 49 Bq Kg-1 (d.w). (author)

  18. Crystal structure, energy band and optical properties of dysprosium monophosphate DyPO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Khadraoui, Z.; Bouzidi, C., E-mail: bouzidtc@yahoo.fr; Horchani-Naifer, K.; Ferid, M.

    2014-12-25

    Graphical abstract: The monophosphate DyPO{sub 4} has been synthesized by high temperature solid-state reaction method and was structurally characterized by single crystal X-ray diffraction. DyPO{sub 4} crystallizes in the tetragonal system (I4{sub 1}/Iamd). The energy-band structure, density of states and the chemical bonds have been investigated by density functional methods (DFT). - Highlights: • The DyPO{sub 4} has been synthesized by high temperature solid-state reaction method. • DFT was used to determine the electronic structure and optical properties of DyPO{sub 4}. • The monophosphate DyPO{sub 4} is an insulator with direct band gap (6.38 eV). - Abstract: A rare earth monophosphate crystal of DyPO{sub 4} has been synthesized by high temperature solid-state reaction method and was structurally characterized by single crystal X-ray diffraction. Atomic arrangement of DyPO{sub 4} structure is based on corner and edge sharing PO{sub 4} tetrahedra and DyO{sub 8} polyhedra. The FTIR, Raman, Scanning electron microscopy, diffuse reflectance and emission spectra of the compound have been investigated. Density functional calculation using a Generalized Gradient Approximation was used to determine the electronic structure and optical properties. The calculated total and partial densities of states indicate that the top of valance band is mainly built upon O-2p states with P-3p states via σ (P–O) interactions, and the low conduction bands mostly originates from Dy-5d. The results show that the monophosphate DyPO{sub 4} is an insulator with a calculated band gap (5.8 eV) closer to the experimental value (6.38 eV)

  19. Morphology and conductivity study of solid electrolyte Li3PO4

    International Nuclear Information System (INIS)

    The comparison between two different methods of synthesize of solid electrolyte Li3PO4 as precursor material for developing lithium ion battery, has been performed. The first method is to synthesize Li3PO4 prepared by wet chemical reaction from LiOH and H3PO4 which provide facile, abundant available resource, low cost, and low toxicity. The second method is solid state reaction prepared by Li2CO3 and NH4H2PO4. 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 of Li3PO4 powder products from two different reaction are characterized by SEM, EDS, and EIS. The Li3PO4 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 Li3PO4 prepared by wet chemical reaction is 2.238 gr/cm3, little bit lower than the sample prepared by solid state reaction which density is 2.3560 gr/cm3. The EIS measurement result shows that the conductivity of Li3PO4 is 1.7 x 10−9 S.cm−1 for wet chemical reaction and 1.8 x 10−10 S.cm−1 for solid state reaction. The conductivity of Li3PO4 is not quite different between those two samples even though they were prepared by different method of synthesize

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

    Energy Technology Data Exchange (ETDEWEB)

    Prayogi, Lugas Dwi, E-mail: ldprayodi@gmail.com; Faisal, Muhamad [Engineering Physics, Sepuluh Nopember Institute of Technology ITS Campus, Sukolilo, Surabaya 6011 (Indonesia); Kartini, Evvy, E-mail: kartini@batan.go.id; Honggowiranto, Wagiyo; Supardi [Center for Science and Technology of Advanced Materials, National Nuclear Energy Agency Kawasan Puspiptek Serpong, Tangerang Selatan15314, Banten (Indonesia)

    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 of 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.

  1. Behaviors of 210Pb and 210Po around hydrothermal vents in the Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    杨永亮; 日下部正志; 山本惠幸

    2002-01-01

    Vertical profiles for the uranium-series radioisotopes 210Pb and 210Po were obtained at the two hydrothermal vent sites, the Iheya Ridge and the Minami-Ensei Knoll, in the Mid-Okinawa Trough in 1993 and 1994, respectively. In 1995, both radioisotopes were measured at the Minami-Ensei Knoll again. At the Iheya Ridge, where the hydrothermal activity is not active as reflected by the CH4 and 222Rn data, both the total 210Pb and 210Po activities show deficiency relative to their parents, and the mean residence time of 210Pb and 210Po is approximately equal to 20 and 2~ 5 a, respectively. At the Minami-Ensei Knoll, which is characterized by black smokers, the total 210Pb(0.167 × 10-3 ~2.5 × 10-3 Bq/kg) around the plumes is deficient relative to 226Ra but the total 210Po activities ( 1.83 × 10- 3 ~ 2.83× 10-3 Bq/kg) are in excess relative to 210Pb. The 210Po activities are higher than those in the East China Sea and the Okinawa Trough and excess 210Po has been found. The 210Pb/226Ra and 210Po/210Pb activity ratios are 0.1~ 0.4 and 1.1 ~ 7.8, respectively. 210Pb is preferentially scavenged in the hydrothermal plumes. The possible mechanisms governing the concentration of 210Pb in the Minami-Ensei Knoll involve a lateral transport of 210Pb via diffusion. The high 210Po/210Pb activity ratios in the hydrothermal plumes suggest a depletion of 210Pb and addition of 210Po in the hydrothermal vent area.

  2. Pre-Flight Development of the PoGOLite Pathfinder

    International Nuclear Information System (INIS)

    The Polarized Gamma-ray Observer (PoGOLite) is a balloon-borne instrument that will measure gamma-ray polarization in the energy range 25-80 keV from astronomical sources such as pulsars, accretion discs and jets from active galactic nuclei. The two additional parameters provided by such observations, polarization angle and degree, will allow these objects to be studied in a new way, providing information about their emission mechanisms and geometries. The instrument measures azimuthal scattering angles of photons within a close packed array of phoswich detector cells (PDCs) based on coincident detection of Compton scattering and photoelectric absorption. Each PDC comprises three different scintillating components and combines photon detection, active collimation and bottom anticoincidence into one single unit. The three parts are viewed by a photomultiplier tube (PMT) and pulse shape discrimination is used to identify signals from dierent parts. Surrounding the detector array is a segmented side anticoincidence shield (SAS) made of BGO crystals. The detector elements of the instrument (PDCs, SAS units, PMTs) have been characterized, resulting in a placement scheme which details where within the detector array each element should be placed in order to maximize the instrument sensitivity and response uniformity. Suitable operating parameters for flight, such as threshold settings and PMT voltages, have also been dened. Geant4 Monte Carlo simulations have shown that a polyethylene shield is needed around the detector array in order to sufficiently reduce the background from atmospheric neutrons. To validate these simulations, a simple detector array with four plastic scintillators and three BGO crystals shielded with polyethylene was irradiated with 14 MeV neutrons. Measured results were accurately recreated in simulations, demonstrating that the treatment of neutron interactions in Geant4 is reliable. A Pathnder version of the PoGOLite instrument has been

  3. Interface Synthesis of FePO4 with Different Morphologies and Effect of Morphology on the Electrochemical Performance of LiFePO4/C

    Directory of Open Access Journals (Sweden)

    Luo Y.-H.

    2015-07-01

    Full Text Available In our work, interface synthesis method was put forward to prepare FePO4 with different morphologies, and the effect of morphology on the preparation and electrochemical performance of LiFePO4/C was investigated. The results showed that the morphology of FePO4 was amorphous and monoclinic at the treatment temperatures of 30 °C and 80 °C, respectively. LiFePO4/C prepared from two crystal precursors were both hemispherical hollow with an olivine crystal structure. LiFePO4/C produced from the monoclinic structured precursor exhibited smaller- sized morphology and better electrochemical performance, and its discharge capacities were 155.9 mA h g−1 and 141.8 mA h g−1 at the rates of 0.1 C and 1 C, respectively. After 150 cycles, its capacity retention was about 97.8 % and 95.1 % at 0.1 C and 1 C, respectively

  4. Isomorphism and phase diagram of Pb{sub 5}(PO{sub 4}){sub 3}F-Pb{sub 5}(PO{sub 4}){sub 3}Cl system

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, A.V., E-mail: knav@uic.nnov.ru [Nizhny Novgorod State University, Gagarin Prospekt 23/2, 603950 Nizhny Novgorod (Russian Federation); Chernorukov, N.G.; Bulanov, E.N. [Nizhny Novgorod State University, Gagarin Prospekt 23/2, 603950 Nizhny Novgorod (Russian Federation)

    2011-01-20

    Compounds of composition Pb{sub 5}(PO{sub 4}){sub 3}F{sub x}Cl{sub 1-x} (0 {<=} x {<=} 1), which are synthetic analogues of minerals pyromorphite, flourapatite, and endlichite, were synthesized for the first time by high-temperature solid phase reactions. X-ray diffraction and IR spectroscopy were used to determine the structure of the compounds and revealed complete miscibility in the solid phase of the Pb{sub 5}(PO{sub 4}){sub 3}F-Pb{sub 5}(PO{sub 4}){sub 3}Cl binary system. Adiabatic reaction calorimetry was used to measure standard enthalpies of mixing and formation and show that the regular solutions model is applicable to the Pb{sub 5}(PO{sub 4}){sub 3}F-Pb{sub 5}(PO{sub 4}){sub 3}Cl system. Differential thermal analysis in tandem with high-temperature X-ray diffraction were used to study the phase diagram and characterize phase transitions.

  5. LiFePO4电池电解液体系研究进展%Recent Development of Electrolytes for LiFePO4 Batteries

    Institute of Scientific and Technical Information of China (English)

    高军; 张焱; 施利勇; 史鹏飞; 庄大高; 张栋

    2011-01-01

    In this paper, the research progress of LiFePO4 battery electrolytes in recent years was summarized in the following four aspects, including: electrolyte salts and organic solvents; additives of organic electrolytes; polymer electrolytes; ionic liquid electrolytes. The research direction and application prospect of LiFePO4 battery electrolytes were discussed. It shows the research of LiFePO4 battery electrolytes still has more development space, and the new type electrolyte which is composed of all kinds of advantages of electrolyte is one of the most important direction in the future development.%综述了近年来LiFePO4电池电解液体系在电解质盐与有机溶剂体系、有机电解液添加剂、聚合物电解质、离子液体等4个方面的研究进展,讨论了LiFePO4电池电解液的研究方向和应用前景,认为LiFePO电池电解液的研究还有较大的发展空间,综合各类电解液体系的优势而组成新型电解液是未来发展的重要方向之一.

  6. α -decay width of 212Po from a quartetting wave function approach

    Science.gov (United States)

    Xu, Chang; Ren, Zhongzhou; Röpke, G.; Schuck, P.; Funaki, Y.; Horiuchi, H.; Tohsaki, A.; Yamada, T.; Zhou, Bo

    2016-01-01

    A microscopic calculation of α -cluster preformation probability and α -decay width in the typical α emitter 212Po is presented. Results are obtained by improving a recent approach to describe α preformation in 212Po [Phys. Rev. C 90, 034304 (2014), 10.1103/PhysRevC.90.034304] implementing four-nucleon correlations (quartetting). Using the actually measured density distribution of the 208Pb core, the calculated α -decay width of 212Po agrees fairly well with the measured one.

  7. Structure and performance of LiFePO4 cathode materials: A review

    Science.gov (United States)

    Zhang, Wei-Jun

    2011-03-01

    LiFePO4 has been considered a promising battery material in electric vehicles. However, there are still a number of technical challenges to overcome before its wide-spread applications. In this article, the structure and electrochemical performance of LiFePO4 are reviewed in light of the major technical requirements for EV batteries. The rate capability, capacity density, cyclic life and low-temperature performance of various LiFePO4 materials are described. The major factors affecting these properties are discussed, which include particle size, doping, carbon coating, conductive carbon loading and synthesis techniques. Important future research for science and engineering is suggested.

  8. COATING THE CONDUCTIVITY MATERIALS TO IMPROVING THE ELECTROCHEMICAL PROPERTIES OF LiFePO4

    OpenAIRE

    WAN LIN WANG; EN MEI JIN; HAL-BON GU

    2013-01-01

    LiFePO4 cathode materials were prepared by a solid-state method followed by one-step heat treatment. To improve the electrochemical properties of the LiFePO4, acetylene black (AB), citric acid (CA), and pyrene are added as carbon source, respectively. The cyclic voltammetry (CV), AC impedance and galvanostatic charge/discharge testing results showed that using the LiFePO4-C composite such as the AB carbon source exhibits higher discharge capacity and stability than the other composite. Synthe...

  9. Low-temperature synthesis of LiFePO4 nanocrystals by solvothermal route

    OpenAIRE

    Lim, Jinsub; Kang, Sung-Won; Moon, Jieh; Kim, Sungjin; Park, Hyosun; Baboo, Joseph Paul; Kim, Jaekook

    2012-01-01

    LiFePO4 nanocrystals were synthesized at a very low temperature of 170°C using carbon nanoparticles by a solvothermal process in a polyol medium, namely diethylene glycol without any heat treatment as a post procedure. The powder X-ray diffraction pattern of the LiFePO4 was indexed well to a pure orthorhombic system of olivine structure (space group: Pnma) with no undesirable impurities. The LiFePO4 nanocrystals synthesized at low temperature exhibited mono-dispersed and carbon-mixed plate-ty...

  10. [100]-Oriented LiFePO4 Nanoflakes toward High Rate Li-Ion Battery Cathode.

    Science.gov (United States)

    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. PMID:26694590

  11. Supervalent doping of LiFePO4 for enhanced electrochemical performance

    OpenAIRE

    Kosova, N. V.; Podgornova, O. A.

    2015-01-01

    Vanadium and titanium doped orthophosphates LiFe0.9M0.1PO4 with an olivinetype structure (space group Pnma) were prepared by mechanochemically assisted solid state synthesis using a high-energy AGO-2 planetary mill and post-annealing at 750 °C. It has been established that the V and Ti ions do not fully substitute for Fe2+ in the LiFePO4 structure. The other part of these ions participate in the formation of the secondary phases with the open Nasicon-type structures: monoclinic Li3V2(PO4)3...

  12. Electrochemical Kinetic Study of LiFePO4 Using Cavity Microelectrode

    OpenAIRE

    Come, Jérémy; Taberna, Pierre-Louis; Hamelet, Stéphane; Masquelier, Christian; Simon, Patrice

    2011-01-01

    Lithium cation insertion and extraction in LiFePO4 were electrochemically studied with a cavity microelectrode (CME). Cyclic voltammetry measurements were used to characterize the kinetics of the material. LiFePO4 was successfully cycled from 0.1 mV s-1 up to 1 V s-1 and is therefore a suitable material to be used in high power applications, such as asymmetric hybrid supercapacitors. Several kinetic behaviors were observed depending on the sweep rate. The LiFePO4 was found to follow different...

  13. Effect of conductive additives in LiFePO4 cathode for lithium-ion batteries

    OpenAIRE

    Shim, J; Guerfi, A.; Zaghib, K.; Striebel, K.A.

    2003-01-01

    The electrochemical properties of LiFePO4 cathodes with different carbon contents were studied to find out the role of carbon as conductive additive. LiFePO4 cathodes containing from 0 percent to 12 percent of conductive additive (carbon black or mixture of carbon black and graphite) were cycled at different C rates. The capacity of LiFePO4 cathode increased, as conductive additive content increased. Carbon increased the utilization of active material and the electrical conductivity of e...

  14. Formation and decay of neutron—deficient nuclei Po and Pb

    Institute of Scientific and Technical Information of China (English)

    ChenXue-Shi; AhmadI; 等

    1998-01-01

    A study of α-decay for &192,194Po and 188.190Pb was performed in the reaction of 36Ar on 160Dy at 176MeV,The formation cross sction was obtained to be 5.0±0.2μb for 192Po and 11.6±0.3ub for 194Po.The resulting reduced αwidth δ2 was 38(5)keV for 188Pb and 25(3)keV for 190Pb,which further confirmed the magic characteristics for neutron-deficient nuclei of Z=82.

  15. Role of lithium precursor in the structure and electrochemical performance of LiFePO4

    International Nuclear Information System (INIS)

    This study highlights the importance of precursor selection. Although a great understanding of the materials properties of LiFePO4 has been achieved, the role of the lithium precursor has been almost ignored. The lithium precursor used for synthesis of LiFePO4 influences the structure, particle size and electrochemical properties. A lithium precursor dependent structural change of LiFePO4 was observed from Rietveld refinement; using Li2CO3 instead of LiOH as lithium precursor resulted in a smaller crystal size and improved electrochemical properties

  16. Bulk Superconductivity and Disorder in Single Crystals of LaFePO

    Energy Technology Data Exchange (ETDEWEB)

    Analytis, James G.; Chu, Jiun-Haw; Erickson, Ann S.; Kucharczyk, Chris; /Stanford U., Appl. Phys. Dept.; Serafin, Alessandro; Carrington, Antony; /Bristol U.; Cox, Catherine; Kauzlarich, Susan M.; Hope, Hakon; /UC, Davis. Dept. Chem.

    2010-02-15

    We have studied the intrinsic normal and superconducting properties of the oxypnictide LaFePO. These samples exhibit bulk superconductivity and the evidence suggests that stoichiometric LaFePO is indeed superconducting, in contrast to other reports. We find that superconductivity is independent of the interplane residual resistivity {rho}{sub 0} and discuss the implications of this on the nature of the superconducting order parameter. Finally we find that, unlike T{sub c}, other properties in single-crystal LaFePO including the resistivity and magnetoresistance, can be very sensitive to disorder.

  17. Excellent Temperature Performance of Spherical LiFePO4/C Composites Modified with Composite Carbon and Metal Oxides

    OpenAIRE

    2014-01-01

    Nanosized spherical LiFePO4/C composite was synthesized from nanosized spherical FePO4 ·2H2O, Li2C2O4, aluminum oxide, titanium oxide, oxalic acid, and sucrose by binary sintering process. The phases and morphologies of LiFePO4/C were characterized using SEM, TEM, CV, EIS, EDS, and EDX as well as charging and discharging measurements. The results showed that the as-prepared LiFePO4/C composite with good conductive webs from nanosized spherical FePO4 ·2H2O exhibits excellent electrochemical pe...

  18. Superconductivity in single crystals of LaFePO

    Energy Technology Data Exchange (ETDEWEB)

    Hamlin, J J; Baumbach, R E; Zocco, D A; Sayles, T A; Maple, M B [Department of Physics and Institute for Pure and Applied Physical Sciences, University of California, San Diego, La Jolla, CA 92093 (United States)], E-mail: mbmaple@ucsd.edu

    2008-09-10

    Single crystals of the compound LaFePO were prepared using a flux growth technique at high temperatures. Electrical resistivity measurements reveal metallic behavior and a resistive transition to the superconducting state at a critical temperature T{sub c}{approx}6.6 K. Magnetization measurements also show the onset of superconductivity near 6 K. In contrast, specific heat measurements manifest no discontinuity at T{sub c}. These results lend support to the conclusion that the superconductivity is associated with oxygen vacancies that alter the carrier concentration in a small fraction of the sample, although superconductivity characterized by an unusually small gap value cannot be ruled out. Under applied magnetic fields, T{sub c} is suppressed anisotropically for fields perpendicular and parallel to the ab-plane, suggesting that the crystalline anisotropy strongly influences the superconducting state. Preliminary high pressure measurements show that T{sub c} passes through a maximum of nearly 14 K at {approx}110 kbar, demonstrating that significantly higher T{sub c} values may be achieved in the phosphorus-based oxypnictides.

  19. Perception of Blended Learning Inventory (PoBLi)

    DEFF Research Database (Denmark)

    Lassesen, Berit; Stenalt, Maria Hvid; Rossen, Dorte Sidelmann

    -to-face med online læring (Blended Learning). I et studie fandt Ellis og kolleger (2006), at undervisere, der overvejende havde opfattelsen af, at de studerende lærte ved, at han/hun formidlede viden til dem, havde en simpel, fragmenteret opfattelse af potentialet ved BL. Derimod syntes en mere......) underviseres oplevelse af undervisningsmiljøet Resultater: Spørgeskema og resultaterne af de foreløbige analyser vil blive præsenteret og diskuteret. Perspektiver: PoBLi-projektet vil bidrage til den eksisterende forskning vedrørende rationalet for inddragelse af blended learning-formatet i......En af de store udfordringer i udviklingen af undervisningsformater med brug af Educational IT omfatter identificering af rationaler for brug af teknologi i undervisningen, og hvordan disse påvirkes af institutionelle faktorer og måden, hvorpå undervisere forstår læring og undervisning. Det er...

  20. Radon distribution in groundwater of the Po sedimentary basin (Italy)

    International Nuclear Information System (INIS)

    222Rn in groundwaters from some areas of the Po sedimentary basin characterized by different hydrological conditions has been determined by alpha-ray activity. Aquifers of three different lithological domains have been considered: (a) an Apennine one, mainly sedimentary (Emilia); (b) an Alpine one, predominantly igneous acid-subacid (Lombardy); and (c) another Alpine one, mainly calcareous (Verona plain). In the first two areas, recent continental waters, waters with a long residence in the aquifers (paleowaters) and sodium chloride waters formed by squeezing of underlying marine sediments have been investigated. In the Verona area, thermal waters coming from deep fissured carbonate formations were analyzed. Rn content is significantly different in the various areas (averages: Lombardy plain, 392; Emilia upper plain, 291; Emilia lower plain, 142; sodium chloride waters, 160; paleowaters, 168 pCi/l). For the Verona thermal waters, the Rn values correlate with temperature and geothermal indicators (SiO2, etc). Hydrodynamic parameters within the aquifers seem to control the Rn distribution in groundwaters circulating in unconsolidated sediments. Factors governing the generation of 222Rn in the rock grains as well as parameters and processes contributing to its transport into the circulating fluids are discussed. Besides known parameters the effect of water molecules, bonded to solid-fluid interfaces on the Rn concentation in the fluids is considered. The release of Rn from these molecules into the circulating fluids is discussed in relation to fluid movement and temperature. (Auth.)

  1. Doppler radar wind field retrieval over the Po Valley

    Directory of Open Access Journals (Sweden)

    Y. K. Goh

    2006-01-01

    Full Text Available Although methods of using multiple Doppler radars to study wind fields have long been proposed, and many research studies have been made, very few operational radar operators adopt methods which require the use of specific scanning strategies to allow the extraction of wind information. Here we report a collaborative study on dual-Doppler radars based on two Doppler radars in the Po valley, Italy. Unusually, the radars are only about 90 km apart, though operated by the same authority. The wind field syntheses are carried out on a 30 km by 30 km region where the two radars have overlapping scan coverage. An iterative method based on the linear wind model and the equation of mass continuity is used to construct the wind fields. The methodology has been validated by two different methods. The first method is to reconstruct the radial wind observed by each radar, and the second method is calculating and comparing the along-track component with that derived from the observations. Both two comparisons show good agreement with the original data.

  2. Molecular cloning, structure and expressional profiles of two novel single-exon genes (PoCCR6A and PoCCR6B) in the Japanese flounder (Paralichthys olivaceus).

    Science.gov (United States)

    Wang, Lei; Zhang, Yong-zhen; Xu, Wen-teng; Jia, Xiao-dong; Chen, Song-lin

    2016-05-01

    CCR6 is an important binding receptor of CCL20 and beta-defensins, and has multiple functions in the innate and acquired immune responses. In this study, we cloned the PoCCR6A and PoCCR6B genes of the Japanese flounder and studied the gene structure and expression patterns of these two genes in bacterial infection. The full-length PoCCR6A cDNA is 1415 bp and the open reading frame (ORF) is 1113 bp, encoding a 370-amino-acid peptide. The full-length PoCCR6B cDNA is 2193 bp and the ORF is 1029 bp, encoding a 363-amino-acid peptide. The structures of PoCCR6A and PoCCR6B indicate that they are single-exon genes. The predicted proteins encoded by PoCCR6A and PoCCR6B have the typical G-protein-coupled receptor (GPCR) family signature of seven transmembrane domains and several conserved structural features. A tissue distribution analysis showed that PoCCR6A is predominately expressed in the intestine, gill, and blood, and PoCCR6B in the gill, spleen, and liver. The expression patterns of the two chemokine receptors were analyzed during bacterial infection. In spleen and kidney, the expression of PoCCR6A was significantly upregulated at 24 h after infection, whereas the expression of PoCCR6B was steady at these time points. While in intestine, both of them were upregulated at 6 h-12 h after infection, and in gill the expression levels of them were upregulated at 24 h. The patterns of expression suggested that PoCCR6A and PoCCR6B play an important role in the immune response of the Japanese flounder, especially in the mucosal tissues. PMID:26997201

  3. Une poésie pour tous les langages artistiques : poéticité et lecture numériques

    Directory of Open Access Journals (Sweden)

    Begoña Regueiro Salgado

    2011-02-01

    Full Text Available Ce travail examine les concepts de poéticité et de littérarité appliqués aux poètes numériques : il analyse de façon comparatiste les œuvres de Philippe Bootz, Belén Gache et Óscar Martín Centeno afin de distinguer les traits qui définissent la poésie numérique. L’article montre quels éléments de poéticité sont restés immuables, nous permettant de continuer à appeler poésie ces nouvelles formes numériques, et quels sont les traits qui ont fait avancer le concept de poéticité au point de nous obliger à redéfinir certaines des caractéristiques de ce que nous considérons traditionnellement comme littérature.This essay analyses the concepts of poeticity and literarity in digital poetry by meains of a comparative analysis of the works by Philippe Bootz, Belén Gache and Óscar Martín Centeno in order to isolate the features that define digital poetry. On the basis of this analysis, the essay then tries to demonstrate which elements of poeticity remain that allow us to continue to classify as poetry its new digital manifestations, and which elements have changed, so as to make us modify the idea of poeticity and to redefine what we have traditionally understood as literature.

  4. Surfactant Assisted Synthesis of LiFePO4 Nanostructures via Hydrothermal Processing

    Directory of Open Access Journals (Sweden)

    Zhang S.C.

    2013-09-01

    Full Text Available LiFePO4 is a potential cathode candidate for of secondary lithium batteries due to its low-cost, outstanding thermal stability and innocuity. In this paper, pure LiFePO4 obtained by hydrothermal method using cetyltrimethyl ammonium bromide (CTAB as surfactant. LiFePO4 particles produced without any surfactant showed typical morphologies of perfect octahedral with size of ~1μm. For products prepared with addition CTAB, the amount of surfactant controlled the growth of LiFePO4 crystals, with which different morphologies of plate, grains and flower-like structures were produced. Plate products displayed a capacity of 145.70 mAh·g-1 at 0.1C, which was superior to others. The results indicated the electrochemical performance depends crucially on the size and structure of active materials.

  5. Po-210 high levels in aquatic plants of the Carapebus sandbank, RJ, Brazil

    International Nuclear Information System (INIS)

    210 Po concentration have been determined in one green alga and in five freshwater plants grown in a pond of the Carapebus restinga (state of Rio de Janeiro). The alga Chara sp showed elevated concentration of 210 Po, similar to that observed in marine algae. All the other plants had the lowest concentration of 210 Po in the stems and the highest in the roots. Intermediate values were observed in the leaves. The unexpected high concentration of 210 Po in the roots, even superior to reported values for roots of plants from high radioactive background areas, must be due to the elevated levels of this radionuclide in associated soils that are known to be rich in humic organic material. There seem to have no translocation of this radionuclide from the roots to the other parts of the plants. (author)

  6. Sol-precipitation-hydrothermal synthesis and luminescence of GdPO4:Tb3+ submicron cubes

    Science.gov (United States)

    Cao, Yanyan; Sun, Peng; Liang, Yingmin; Wang, Rongrong; Zhang, Xiao

    2016-05-01

    GdPO4:Tb3+ submicron cubes were synthesized by a sol-precipitation-hydrothermal process. The XRD result indicated that GdPO4:Tb3+ submicron cubes have pure hexagonal phase. The SEM and TEM images confirmed the formation of cubic morphology. Under the excitation at 273 nm, GdPO4:Tb3+ submicron cubes show emission bands corresponding to Gd3+ and Tb3+. With the increasing Tb3+ concentration, the emission intensities originating from Gd3+ and 5D3 → 7Fj transition of Tb3+ decrease, but the emission intensities originating from 5D4 → 7Fj transition of Tb3+ increase. These results suggested energy transfer from Gd3+ to Tb3+ and the occurrence of cross-relaxation processes in GdPO4:Tb3+ submicron cubes.

  7. Magnetic structures, phase diagram and spin waves of magneto-electric LiNiPO4

    DEFF Research Database (Denmark)

    Jensen, Thomas Bagger Stibius

    2007-01-01

    LiNiPO4 is a magneto-electric material, having co-existing antiferromagnetic and ferroelectric phases when suitable magnetic fields are applied at low temperatures. Such systems have received growing interest in recent years, but the nature of the magneticelectric couplings is yet to be fully...... understand. Hopefully, studying LiNiPO4 will shed further light on the subject, especially since the crystal structure of LiNiPO4 is rather simple compared to most relevant multiferroic materials. Although the study of the magnetic-electric couplings is of main interest to the many scientists guiding me...... through the last three years, it is not the primary subject of this thesis. The objective of the phD project has been to provide groundwork that may be beneficiary to future studies of LiNiPO4. More specifically, we have mapped out the magnetic HT phase diagram with magnetic fields below 14.7 T applied...

  8. Probing the failure mechanism of nanoscale LiFePO4 for Li-ion batteries

    Science.gov (United States)

    Gu, Meng; Shi, Wei; Zheng, Jianming; Yan, Pengfei; Zhang, Ji-guang; Wang, Chongmin

    2015-05-01

    LiFePO4 is a high power rate cathode material for lithium ion battery and shows remarkable capacity retention, featuring a 91% capacity retention after 3300 cycles. In this work, we use high-resolution transmission electron microscopy and electron energy loss spectroscopy to study the gradual capacity fading mechanism of LiFePO4 materials. We found that upon prolonged electrochemical cycling of the battery, the LiFePO4 cathode shows surface amorphization and loss of oxygen species, which directly contribute to the gradual capacity fading of the battery. The finding can guide the design and improvement of LiFePO4 cathode for high-energy and high-power rechargeable battery for electric transportation.

  9. Searching for “LiCr{sup II}PO{sub 4}”

    Energy Technology Data Exchange (ETDEWEB)

    Mosymow, E. [Institut für Anorganische Chemie, Universität Bonn, Gerhard-Domagk-Straße 1, D-53121 Bonn (Germany); Glaum, R., E-mail: rglaum@uni-bonn.de [Institut für Anorganische Chemie, Universität Bonn, Gerhard-Domagk-Straße 1, D-53121 Bonn (Germany); Kremer, R.K. [Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569 Stuttgart (Germany)

    2014-10-15

    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 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} 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 Li{sub 5

  10. Determination of 210Po in Slovak mineral waters by sorption on ZnS(Ag)

    International Nuclear Information System (INIS)

    In determining of 210Po it was followed according to the Czech technical standard CSN 75 7626 Water quality - Determination of polonium-210. The aim of this work was to optimize the conditions for sorption of 210Po on ZnS (Ag) from acidic environment from the model solutions. The effect of pH of the sample, its volume and the presence of NaCl on the sorption of 210Po on ZnS (Ag) was studied. Three types of filters for filtering ZnS (Ag), Synpor, paper and glass fiber filters were tested. Bulk activity of 210Po was determined in the samples of Slovak mineral waters and healing waters as well as in water samples from antimony mine (mine Rufus) near the village Poproc (rural Kosice district). (author)

  11. Ekspert po SMI : Nuzhno tshotko ukazõvat na zakaznoi material / Ksenia Repson

    Index Scriptorium Estoniae

    Repson, Ksenia

    2007-01-01

    Telekanalis Pervõi Baltiiskii Kanal näidatud film Keskerakonna esimehest Edgar Savisaarest " Po prozvishtshu Nossorog" oli tehtud Keskerakonna tellimusel. Meediaeksperdi Tarmu Tammerki arvamus reklaamtelesaadete või -filmide nõuete kohta

  12. The Solar Terrestrial Relations Observatory (STEREO) Education and Outreach (E/PO) Program

    Science.gov (United States)

    Peticolas, L. M.; Craig, N.; Kucera, T.; Michels, D. J.; Gerulskis, J.; MacDowall, R. J.; Beisser, K.; Chrissotimos, C.; Luhmann, J. G.; Galvin, A. B.; Ratta, L.; Drobnes, E.; Méndez, B. J.; Hill, S.; Marren, K.; Howard, R.

    2008-04-01

    The STEREO mission’s Education and Outreach (E/PO) program began early enough its team benefited from many lessons learned as NASA’s E/PO profession matured. Originally made up of discrete programs, by launch the STEREO E/PO program had developed into a quality suite containing all the program elements now considered standard: education workshops, teacher/student guides, national and international collaboration, etc. The benefit of bringing so many unique programs together is the resulting diverse portfolio, with scientists, E/PO professionals, and their education partners all of whom can focus on excellent smaller programs. The drawback is a less cohesive program nearly impossible to evaluate in its entirety with the given funding. When individual components were evaluated, we found our programs mostly made positive impact. In this paper, we elaborate on the programs, hoping that others will effectively use or improve upon them. When possible, we indicate the programs’ effects on their target audiences.

  13. Hydrothermal Synthesis and Characterization of Nd Doped One-dimensional Hexagonal CePO_4 Nanowires

    Institute of Scientific and Technical Information of China (English)

    张新奇

    2012-01-01

    One-dimensional Nd doped CePO4 hexagonal nanowires have been synthesized for the first time at 140 ℃ for 24 hours via a hydrothermal method using P123 surfactant as the template.The products were characterized by X-ray diffraction,transmission electron microscopy,photoluminescence and high-resolution transmission electron microscopy.Compared with CePO4,one-dimensional nanomaterials we have synthesized,Nd doped CePO4 nanomaterials remain their hexagonal one-dimensional morphology and smooth surface.However,their photoluminescence emissions are greatly enhanced at the wavelength of 348 nm.With their novel fluorescence-emission property,the Nd doped CePO4 nanomaterials are potential in many fields such as optics and electronics.

  14. Inelastic neutron scattering and lattice dynamics of GaPO4

    Indian Academy of Sciences (India)

    R Mittal; S L Chaplot; A I Kolesnikov; C-K Loong; O D Jayakumar; S K Kulshreshtha

    2004-08-01

    We report here measurements of phonon spectrum and lattice dynamical calculations for GaPO4. The measurements in low-cristobalite phase of GaPO4 are carried out using high-resolution medium-energy chopper spectrometer at ANL, USA in the energy transfer range 0–160 meV. Semiempirical interatomic potential in GaPO4, previously determined using ab-initio calculations have been widely used in studying the phase transitions among various polymorphs. The calculated phonon spectrum using the available potential show fair agreement with the experimental data. However, the agreement between the two is improved by including the polarisability of the oxygen atoms in the framework of the shell model. The lattice dynamical models are also exploited for calculations of various thermodynamic properties of GaPO4.

  15. Dispersion, agglomeration, and gelation of LiFePO4 in water-based slurry

    Science.gov (United States)

    Tsai, Feng-Yen; Jhang, Jia-Hao; Hsieh, Han-Wei; Li, Chia-Chen

    2016-04-01

    The gelation of commercially available lithium iron phosphate (LiFePO4) in water-based slurry and its corresponding mechanism are studied. Based on surface chemistry analyses using zeta potential measurements and Fourier transform infrared spectroscopy, it is found that the key factor that causes LiFePO4 gelation in the aqueous slurry is the quality of the surface carbon coating on powder. When the surface carbon exhibits functional derivatives, such as carboxyl, hydroxyl, and carbonyl polar functional groups, LiFePO4 tends to form a three-dimensional, gel-like structure via hydrogen bonding. Moreover, the presence of the derivatives reduces the amount of conduction-favorable sp2-bonded carbon to LiFePO4, resulting in an electric resistance increase of the as-prepared electrode and the deterioration of the specific capacity of the as-constructed cell.

  16. Peroxidase-like catalytic activity of Ag3PO4 nanocrystals prepared by a colloidal route.

    Directory of Open Access Journals (Sweden)

    Yuanjun Liu

    Full Text Available Nearly monodispersed Ag3PO4 nanocrystals with size of 10 nm were prepared through a colloidal chemical route. It was proven that the synthesized Ag3PO4 nanoparticles have intrinsic peroxidase-like catalytic activity. They can quickly catalyze oxidation of the peroxidase substrate 3, 3, 5, 5-tetramethylbenzidine (TMB in the presence of H2O2, producing a blue color. The catalysis reaction follows Michaelis-Menten kinetics. The calculated kinetic parameters indicate a high catalytic activity and the strong affinity of Ag3PO4 nanocrystals to the substrate (TMB. These results suggest the potential applications of Ag3PO4 nanocrystals in fields such as biotechnology, environmental chemistry, and medicine.

  17. SHG Materials Based on the AlPO4-5 Single Crystals

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Large AlPO4-5 molecular sieve single crystals with high optical quality were synthesized hydrothermally by using TPA as template. As-synthesized crystals were calcined under O2 atmosphere to remove the organic templates in the channels. Disperse-Red-1 (DR1) and p-nitroaniline (pNA) molecules have been successfully incorporated into the one-dimensional channels of AlPO4-5 single crystals respectively by means of vapor phase diffusion. XRD patterns reveal that the loading of organic molecules has not destroyed the structures of AlPO4-5 crystals. Polarizing microscope and SHG results indicate that the DR1 and pNA molecules are well aligned in a preferred direction along the crystal channels. The different polarization-dependence SH intensity shows that different SHG processes occur in the DR1- and pNA-loaded AlPO4-5 crystals.

  18. Analiza požara in produkti gorenja v objektu lesnopredelovalne industrije

    OpenAIRE

    Mravlje, Anja

    2015-01-01

    Na področju industrije se je povečala uporaba materialov in snovi, ki ogrožajo človekovo zdravje in življenje, še posebej v primeru požara. Zaradi tega je postalo vse bolj pomembno, da so industrijski objekti pravilno projektirani in da v primeru požara ne ogrožajo človekovega zdravja in življenja ter okolja. Za ocenjevanje požarne varnosti se izvajajo tudi požarne simulacije z računalniškimi programi. V prvem delu diplomske naloge sem povzela osnove gorenja, produkte gorenja in značilnosti p...

  19. Probing the failure mechanism of nanoscale LiFePO4 for Li-ion batteries

    International Nuclear Information System (INIS)

    LiFePO4 is a high power rate cathode material for lithium ion battery and shows remarkable capacity retention, featuring a 91% capacity retention after 3300 cycles. In this work, we use high-resolution transmission electron microscopy and electron energy loss spectroscopy to study the gradual capacity fading mechanism of LiFePO4 materials. We found that upon prolonged electrochemical cycling of the battery, the LiFePO4 cathode shows surface amorphization and loss of oxygen species, which directly contribute to the gradual capacity fading of the battery. The finding can guide the design and improvement of LiFePO4 cathode for high-energy and high-power rechargeable battery for electric transportation

  20. Electronic structure and ground-state properties of Na2Po: A first-principles study

    International Nuclear Information System (INIS)

    Self-consistent scalar-relativistic band structure calculations have been performed to investigate the electronic structure and ground-state properties of Na2Po in cubic antifluorite (anti-CaF2-type) structure using the linear muffin-tin orbital in its tight-binding representation (TB-LMTO) method. Ground state properties such as equilibrium lattice constant and bulk modulus were calculated. The results of the electronic structure calculations show that Na2Po is direct bandgap semiconductor

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

    Science.gov (United States)

    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.

  2. Journal of Environmental Radioactivity special issue: International topical conference on Po and radioactive Pb isotopes

    OpenAIRE

    E Holm; García-Tenorio, R.

    2011-01-01

    An international conference on polonium (Po) and radioactive isotopes was held in Seville Spain, 26-28 October 2009 at the Centro Nacional de Aceleradores. It was attended by 138 participants from 38 different countries. The sessions covered all aspects on Po and lead (Pb) such as radiochemistry, terrestrial and marine radioecology, kinetics, sedimentation rates, atmospheric tracers, NORM industries and dose assessment. © 2010 Elsevier Ltd.

  3. Determination of (210)Po in calcium supplements and the possible related dose assessment to the consumers.

    Science.gov (United States)

    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). PMID:26318774

  4. Olivine Li(CO0.5)PO4 cathode for battery applications

    International Nuclear Information System (INIS)

    Lithium orthophosphates with general formula LiMPO4 (M = Fe, Mn, Co or Ni) adopt an ordered olivine structure and have been extensively explored as high- voltage cathode materials for lithium secondary batteries. In the current work, olivine-type lithium-containing mixed transition metal phosphate Li(Co0.5Ni0.5)PO4 was synthesized in a solid state reaction at 800°C in air. Infra-red spectroscopy, X-ray and neutron powder diffraction were used to characterize the as-prepared compound. Rietveld analysis was used to illustrate that the synthesized compound is isostructural with LiNiPO4 and Li1-x(CoPO4) with lattice parameters larger than the former and smaller than the latter. The Rietveld-refined Ni:Co ratio was found to be 0.498(4):0.502(4) and no evidence for long-range Ni:Co ordering or mixed Li/Ni/ Co cation sites was found. The charged electrode showed a mixture of two phases i.e. parent Li(Co0.5 Ni0.5)PO4 and lithium extracted Li1-x(Co0.5Ni0.5PO4 suggesting a delithiation process in aqueous electrolytes. Reversible Li transfer in an olivine Li(Co0.5Ni0.5)PO4 electrode was demonstrated using an aqueous LiOH electrolyte and detailed results will be presented at the conference. The synchrotron infrared radiation (SR-IR) as a source for IR spectroscopy pins down the differences in the chemical bonding for LiNiPO4 and Li(Co0.5Ni0.5)PO4 samples.

  5. Proton dynamics isomorphous TIH2PO4 and TIH2AsO4

    International Nuclear Information System (INIS)

    The proton dynamics in TIH2PO4 (TDP) and TIH2AsO4 (TDA) was studied by means of 1H nuclear magnetic resonance. In spite of their very similar crystal structures and phase transition sequences, these two isomorphous ferroelectrics showed distinct behaviors in proton motions through the ferroelastic phase transition temperature. Our results may be understood in terms of the coupled hydrogen-lattice model and are associated with distortion of the PO4- / AsO4- tetrahedra

  6. Suppression of Phase Separation in LiFePO4 Nanoparticles During Battery Discharge

    OpenAIRE

    Bai, Peng; Cogswell, Daniel A.; Bazant, Martin Z.

    2011-01-01

    Using a novel electrochemical phase-field model, we question the common belief that LixFePO4 nanoparticles separate into Li-rich and Li-poor phases during battery discharge. For small currents, spinodal decomposition or nucleation leads to moving phase boundaries. Above a critical current density (in the Tafel regime), the spinodal disappears, and particles fill homogeneously, which may explain the superior rate capability and long cycle life of nano-LiFePO4 cathodes.

  7. Columnar order in jammed LiFePO4 cathodes: ion transport catastrophe and its mitigation

    OpenAIRE

    Smith, Kyle C.; Mukherjee, Partha P.; Fisher, Timothy S.

    2012-01-01

    The high-rate, high-capacity potential of LiFePO4-based lithium-ion battery cathodes has motivated numerous experimental and theoretical studies aiming to realize such performance through nano-sizing, tailoring of particle shape through synthesis conditions, and doping. Here, a granular mechanics study of microstructures formed by dense jammed packings of experimentally and theoretically inspired LiFePO4 particle shapes is presented. A strong dependence of the resultant packing structures on ...

  8. Biocarbon-coated LiFePO4 nucleus nanoparticles enhancing electrochemical performances

    DEFF Research Database (Denmark)

    Zhang, X.G.; Zhang, X.D.; He, W.;

    2012-01-01

    We report a green biomimetic method to synthesize biocarbon-coated LiFePO4 nucleus nanoparticles using yeast cells as both a structural template and a biocarbon source for high-power lithium-ion batteries.......We report a green biomimetic method to synthesize biocarbon-coated LiFePO4 nucleus nanoparticles using yeast cells as both a structural template and a biocarbon source for high-power lithium-ion batteries....

  9. pO2 Fluctuation Pattern and Cycling Hypoxia in Human Cervical Carcinoma and Melanoma Xenografts

    International Nuclear Information System (INIS)

    Purpose: Blood perfusion in tumors is spatially and temporally heterogeneous, resulting in local fluctuations in tissue oxygen tension (pO2) and tissue regions showing cycling hypoxia. In this study, we investigated whether the pO2 fluctuation pattern and the extent of cycling hypoxia differ between tumor types showing high (e.g., cervical carcinoma xenograft) and low (e.g., melanoma xenograft) fractions of connective tissue-associated blood vessels. Methods and Materials: Two cervical carcinoma lines (CK-160 and TS-415) and two melanoma lines (A-07 and R-18) transplanted into BALB/c nu/nu mice were included in the study. Tissue pO2 was measured simultaneously in two positions in each tumor by using a two-channel OxyLite fiber-optic oxygen-sensing device. The extent of acute and chronic hypoxia was assessed by combining a radiobiological and a pimonidazole-based immunohistochemical assay of tumor hypoxia. Results: The proportion of tumor regions showing pO2 fluctuations, the pO2 fluctuation frequency in these regions, and the relative amplitude of the pO2 fluctuations were significantly higher in the melanoma xenografts than in the cervical carcinoma xenografts. Cervical carcinoma and melanoma xenografts did not differ significantly in the fraction of acutely hypoxic cells or the fraction of chronically hypoxic cells. However, the ratio between fraction of acutely hypoxic cells and fraction of chronically hypoxic cells was significantly higher in melanoma than in cervical carcinoma xenografts. Conclusions: Temporal heterogeneity in blood flow and tissue pO2 in tumors may depend on tumor histology. Connective tissue surrounding microvessels may stabilize blood flow and pO2 and, thus, protect tumor tissue from cycling hypoxia.

  10. Porosity evaluation of PoSi wafer using a nondestructive ultrasonic technic

    OpenAIRE

    BUSTILLO, Julien; Fortineau, Jérôme; Capelle, Marie; Vander Meulen, François; Haumesser, Lionel; Gautier, Gael; Lethiecq, Marc

    2012-01-01

    The manufacturing processes of porous silicon (PoSi) by electrochemical etching now allow samples with variable depths and variable degrees of porosity to be obtained. However, thickness and porosity measurement methods of PoSi are generally destructive. Therefore in this study a nondestructive ultrasonic method is investigated. For this, an immersion insertion-substitution technique has been used. Samples with different porosities and depths are studied. The thickness of the wafer (550 micro...

  11. Modeling Li-ion conductivity in LiLa(PO{sub 3}){sub 4} powder

    Energy Technology Data Exchange (ETDEWEB)

    Mounir, Ferhi, E-mail: ferhi.mounir@gmail.com [Laboratoire de Physicochimie des Materiaux Mineraux et leurs Applications, Centre National des Recherches en Sciences des Materiaux, BP No. 73, 8027 Soliman (Tunisia); Karima, Horchani-Naifer [Laboratoire de Physicochimie des Materiaux Mineraux et leurs Applications, Centre National des Recherches en Sciences des Materiaux, BP No. 73, 8027 Soliman (Tunisia); Khaled, Ben Saad [Laboratoire de Photovoltaieque, Centre des Recherches et des Technologies de l' Energie, Technopole Borj Cedria, BP No. 95, 2050 Hammam Lif (Tunisia); Mokhtar, Ferid [Laboratoire de Physicochimie des Materiaux Mineraux et leurs Applications, Centre National des Recherches en Sciences des Materiaux, BP No. 73, 8027 Soliman (Tunisia)

    2012-07-01

    Polycrystalline powder and single-crystal of LiLa(PO{sub 3}){sub 4} are synthesized by solid state reaction and flux technique, respectively. A morphological description of the obtained product was made based on scanning electron microscopy micrographs. The obtained powder was characterized by X-ray powder diffraction, FTIR and Raman spectroscopies. Ionic conductivity of the LiLa(PO{sub 3}){sub 4} powder was measured and evaluated over a temperature range from 553 to 913 K. Single crystals of LiLa(PO{sub 3}){sub 4} are characterized by single-crystal X-ray diffraction. The LiLa(PO{sub 3}){sub 4} structure was found to be isotypic with LiNd(PO{sub 3}){sub 4}. It crystallizes in the monoclinic system with space group C2/c and cell parameters: a=16.635(6) A, b=7.130(3) A, c=9.913(3) A, {beta}=126.37(4) Degree-Sign , V=946.72(6) A{sup 3} and Z=4. The LiLa(PO{sub 3}){sub 4} structure was described as an alternation between spiraling chains (PO{sub 3}){sub n} and (La{sup 3+}, Li{sup +}) cations along the b direction. The small Li{sup +} ions, coordinated to four oxygen atoms, were located in the large connected cavities created between the LaO{sub 8} polyhedra and the polyphosphate chains. The jumping of Li{sup +} through tunnels of the crystalline network was investigated using complex impedance spectroscopy. The close value of the activation energies calculated through the analysis of conductivity data and loss spectra indicate that the transport in the investigated system is through hopping mechanism. The correlation between ionic conductivity of LiLa(PO{sub 3}){sub 4} and its crystallographic structure was investigated and the most probably transport pathway model was determined.

  12. Analysis of the diffracted current basis functions used in the hybrid MoM-PO method

    Institute of Scientific and Technical Information of China (English)

    GONG Zhuqian; XIAO Boxun; ZHU Guoqiang; GUO Jianyan

    2007-01-01

    The combined moment method(MoM)-physical optics (PO)approach proposed by Bilow fails in some cases.Based on the theory of diffraction and the fundamental theory of electromagnetism,Bilow's diffracted current basis function was modified both within and outside the transition regions.The improved MoM-PO technique is validated by comparison with exact solutions for a right-angled perfectly conducting wedge at normal incidence.

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

    Science.gov (United States)

    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

  14. Synthesis and characterization of LaPO4 powder heat treated at various temperatures

    International Nuclear Information System (INIS)

    Lanthanum phosphate (LaPO4) powder has been synthesized by direct liquid-liquid reaction of La(NO3)3.6H2O and H3PO4. The as-received powder has been heat treated at various temperatures (100, 600, 800, 1000, or 1200 deg. C). The phase composition and microstructure of the powder have been characterized by XRD, SEM, HRTEM, and FFT. The anisotropic growth mechanism, phase transition from hexagonal to monoclinic structure, and shape evolution details of LaPO4 nanoparticles are discussed. The results show that the phase composition and microstructure of the powder depend on the heat treatment temperature. The hexagonal phase converts to a monoclinic structure around 600 deg. C. Another consequence of the heat treatment is a change in the shape of the LaPO4 as nanorods are converted into nanograins with increasing heat treatment temperature. Particularly, at 1000 oC, the nanorods begin a gradual transition to nanograins. When the temperature is increased to 1200 deg. C, all the LaPO4 nanorods have transformed into spherical LaPO4 nanoparticles with a diameter in the range of 300-500 nm.

  15. Phase dependent structural and electronic properties of lanthanum orthophosphate (LaPO4)

    Science.gov (United States)

    Neupane, M. R.; Garrett, G. A.; Rudin, S.; Andzelm, J. W.

    2016-05-01

    We study the phase-dependent structural and electronic properties of bulk LaPO4, using density functional theory (DFT). The applicability of conventional semi-local and hybrid functionals in predicting structural and electronic properties of monoclinic and hexagonal LaPO4 is evaluated by comparing results to available experimental data. The monoclinic LaPO4 was found to be more stable than the hexagonal phase in ambient conditions with a small energy difference, suggesting a possibility of a phase transition. Both the phases in the bulk form are found to be diamagnetic with indirect energy gaps. These results are consistent with available experimental results. In the monoclinic phase, the hybrid functionals predict indirect band gap at about 8 eV. Furthermore, the calculated indirect–direct transition energy offset (ΔE) in the hexagonal phase was three times lower than the monoclinic phase. Our calculations based on hybrid functionals also reveal that the states near the conduction band edge in the hexagonal LaPO4 are strongly hybridized between La and PO4 states. By analyzing the band dispersion around the band edges, we show that the hexagonal phase has lighter electron effective mass, as compared to the monoclinic phase. With a larger energy gap, smaller ΔE, and smaller electron effective mass, the hexagonal LaPO4 might be a promising candidate material as an n-type transparent oxide.

  16. Inhalation of 210Po and 210Pb from cigarette smoking in Poland

    International Nuclear Information System (INIS)

    The carcinogenic effect of 210Po and 210Pb with respect to lung cancer is an important problem in many countries with very high cigarette consumption. Poland has one of the highest consumptions of cigarettes in the world. The results of 210Po determination on the 14 most frequently smoked brands of cigarettes which constitute over 70% of the total cigarette consumption in Poland are presented and discussed. Moreover, the polonium content in cigarette smoke was estimated on the basis of its activity in fresh tobaccos, ash, fresh filters and post-smoking filters. The annual effective doses were calculated on the basis of 210Po and 210Pb inhalation with the cigarette smoke. The results of this work indicate that Polish smokers who smoke one pack (20 cigarettes) per day inhale from 20 to 215 mBq of 210Po and 210Pb each. The mean values of the annual effective dose for smokers were estimated to be 35 and 70 μSv from 210Po and 210Pb, respectively. For persons who smoke two packs of cigarettes with higher radionuclide concentrations, the effective dose is much higher (471 μSv yr-1) in comparison with the intake in diet. Therefore, cigarettes and the absorption through the respiratory system are the main sources and the principal pathway of 210Po and 210Pb intake of smokers in Poland

  17. PL and TSL investigations of lanthanide and uranium doped LiZnPO4 phosphor

    International Nuclear Information System (INIS)

    LiZnPO4:U, LiZnPO4:Eu and LiZnPO4:Dy phosphors were synthesized via solid-state route at 900 C in (Ar + 8% H2) atmosphere. PL studies revealed that the uranium is present in form of uranyl ion (UO22+). TSL emission studies supported the formation of uranyl ion at room temperature and indicated that uranyl ion (UO2 2+) acts as the luminescent centre. The emission spectra of LiZnPO4:Eu and LiZnPO4:Dy phosphors have showed the presence of Eu3+ and Dy3+ oxidation state respectively. The glow curves of gamma irradiated LiZnPO4:U sample has shown single peak at 441 K. The trap parameters were determined using different heating method. Considering the ionic radii of the hexavalent uranium and Li/Zn, it may be inferred that major component of uranium mainly occupies the lattice positions of Zinc site. (author)

  18. Levels of lead-210 (210Pb) and polonium 210 (210Po) in Cuban Tobacco products

    International Nuclear Information System (INIS)

    The release of 210Po in tobacco smoke and the radiation dose for man have been studied because of the high incidence of lung cancer among smoker. The electroplating of polonium at two different times onto copper disks and further measurement of alpha activity was the meted used for 210 Po determination in tobacco products. The Polonium daughter is used to determine both the 210Pb and 210Po using the Baseman equations for radioactive growth and decay. A cigarette contains between 10.6 and 14.7 mBq of 210Pb with an average activity of 13.0 mBq and between 8.5 and 12.3 mBq of 210Po with an average activity of 10.4 mBq for different Cuban cigarette brands. For a person smoking a pack of 20 cigarettes a day, the values of intakes estimated range from 32 to 44 mBq for 210Pb and from 34 to 49 mBq for 210 Po with an average daily intake of 39 mBq for 210 Pb and 42 mBq for 210Po. The annual effective dose estimated due to inhalation of these nuclides contained in cigarette smoke shows a value of 66[Sv and was in correspondence with world-wide range dose, 46 - 90 mSv.year 1 - for tobacco product consumption

  19. Effects of temperature variation on LixFePO4/C (0

    Institute of Scientific and Technical Information of China (English)

    肖政伟; 张英杰; 胡国荣

    2015-01-01

    LiFePO4/C was prepared via solid state reaction and characterized with X-ray powder diffraction and charge–discharge test. As-prepared LiFePO4/C has a triphylite structure and exhibits an excellent rate capability and capacity retention. Electrochemical impedance spectroscopy (EIS) was applied to investigate LixFePO4/C (0PO4/C is deeply delithiated at a relatively high temperature. EIS examination indicates that a temperature rise leads to a better reversibility, lower charge transfer resistance, higher exchange current densityJ0 and greater Li+ ion diffusion coefficient for the LixFePO4/C electrode process. The Li+ ion concentration in LixFePO4/C is potential to impact the Li+ ion diffusion coefficient, and a decrease in the former results in an increase in the latter.

  20. Effect of different carbon precursors on properties of LiFePO4/C

    Institute of Scientific and Technical Information of China (English)

    肖政伟; 张英杰; 胡国荣

    2015-01-01

    The anoxic decomposition and influence of carbon precursors on the properties of LiFePO4/C prepared by using Fe2O3 were investigated. X-ray powder diffractometry, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and carbon content and charge–discharge tests were applied to the characterization of the as-synthesized cathodes. Partial carbon is lost in the anaerobic decomposition of organic precursors and a high hydrogen content leads to a high residual carbon rate. Pyromellitic anhydride and citric acid participate in reactions before and in ball-milling. All the chosen carbon precursors are capable of producing LiFePO4 with high degree of crystallinity and purity. The carbon derived fromα-D-glucose, pyromellitic anhydride, soluble starch, citric acid and polyacrylamide has a loose and porous texture in LiFePO4/C which forms conduction on and between LiFePO4 particles. LiFePO4/C prepared by usingα-D-glucose, pyromellitic anhydride, citric acid and sucrose exhibits appreciable electrochemical performance. Graphite alone is able to enhance the electrochemical performance of LiFePO4 to a limited extent but incapable of preparing practical cathode.

  1. Fabrication and luminescence of BiPO4:Tb3+/Ce3+ nanofibers by electrospinning

    Science.gov (United States)

    Yang, Yuguo; Liu, Bing; Zhang, Yuanyuan; Lv, Xianshun; Wei, Lei; Wang, Xuping

    2016-02-01

    BiPO4:Tb3+/Ce3+ nanofibers are synthesized by a simple electrospinning process and followed by a calcination treatment. The nanofibers are characterized by TG-DSC, XRD, FT-IR, SEM, TEM, and spectrophotometer. The calcined BiPO4:Tb3+/Ce3+ nanofibers have a monoclinic phase and the diameters are in the range of 80-200 nm. The SEM and TEM images show that the nanofibers are mesoporous and composed of lots of linked nanoparticles. Under an excitation at 369 nm, BiPO4:Tb3+ and BiPO4:Tb3+/Ce3+ nanofibers show characteristic emission bands originating from the 5D4 → 7Fj (j = 6, 5, 4, and 3) transitions of Tb3+ ions. The luminescent properties of BiPO4:Tb3+ indicate that the quenching concentration for Tb3+ ions in BiPO4 host is about 15 mol%. The co-doped Ce3+ ions can improve the emission intensity through the energy transfer from Ce3+ to Tb3+ ions.

  2. Phase dependent structural and electronic properties of lanthanum orthophosphate (LaPO4).

    Science.gov (United States)

    Neupane, M R; Garrett, G A; Rudin, S; Andzelm, J W

    2016-05-25

    We study the phase-dependent structural and electronic properties of bulk LaPO4, using density functional theory (DFT). The applicability of conventional semi-local and hybrid functionals in predicting structural and electronic properties of monoclinic and hexagonal LaPO4 is evaluated by comparing results to available experimental data. The monoclinic LaPO4 was found to be more stable than the hexagonal phase in ambient conditions with a small energy difference, suggesting a possibility of a phase transition. Both the phases in the bulk form are found to be diamagnetic with indirect energy gaps. These results are consistent with available experimental results. In the monoclinic phase, the hybrid functionals predict indirect band gap at about 8 eV. Furthermore, the calculated indirect-direct transition energy offset (ΔE) in the hexagonal phase was three times lower than the monoclinic phase. Our calculations based on hybrid functionals also reveal that the states near the conduction band edge in the hexagonal LaPO4 are strongly hybridized between La and PO4 states. By analyzing the band dispersion around the band edges, we show that the hexagonal phase has lighter electron effective mass, as compared to the monoclinic phase. With a larger energy gap, smaller ΔE, and smaller electron effective mass, the hexagonal LaPO4 might be a promising candidate material as an n-type transparent oxide. PMID:27114454

  3. The nature of spin trimer in Ca3Cu2Ni(PO4)4

    International Nuclear Information System (INIS)

    The nature of spin trimer and 3d spin dynamics in Ca3Cu2Ni(PO4)4 was studied using 31P NMR measurements. This material is obtained replacing one of the Cu ions by a Ni ion in one dimensional spin trimer compound Ca3Cu3(PO4)4. NMR spectrum suggests the presence of two types of magnetically inequivalent phosphorous atoms as in the parent compound. This finding reveals the presence of only one type of trimer viz. Cu2-Cu1-Cu2 rather than three types viz., Cu2-Cu1-Cu2, Cu2-Cu1-Ni and Ni-Cu1-Ni as suggested from neutron scattering. Hence the ground state of Ca3Cu2Ni(PO4)4 appears to be a quintet. The present finding also explains the magnetic susceptibility behavior showing no indication of the reduction of net spin of a trimer in Ca3Cu2Ni(PO4)4, as expected for JNi-Cu = - 0.85 meV compared to JCu-Cu = - 4.74 meV, reported from neutron scattering. The spin lattice relaxation rate suggests that the three magnon mediated scattering process, dominant in Ca3Cu3(PO4)4, is reduced in Ca3Cu2Ni(PO4)4.

  4. Hydroxyapatite supported Ag3PO4 nanoparticles with higher visible light photocatalytic activity

    International Nuclear Information System (INIS)

    Hydroxyapatite supported Ag3PO4 nanocomposites have been synthesized by a wet impregnation process. UV-vis absorption spectra show a red shift of the absorption edges for the composite systems compared to pure hydroxyapatite support. The surface structure and morphology of the nanocomposites were characterized by Brunauer-Emmett-Teller (BET) apparatus, X-ray diffraction (XRD), transmission electron microscopy (TEM). The results suggest that Ag3PO4 nanoparticles (6-17 nm in diameter) are well dispersed on the hydroxyapatite support and Ag3PO4 nanoparticles density is larger for the higher Ag+ loading sample. The as-prepared nanocomposite photocatalysts showed a pronounced photocatalytic activity upon decomposition of methylene blue dye in aqueous solution under both visible light (wavelength > 400 nm) and UV-vis light irradiation. A synergic mechanism of inherent photocatalytic capability of Ag3PO4 and the accelerated electron/hole separation resulting from the photoinduced electrons captured by the slow-released Ag+ at the interface of Ag3PO4 and hydroxyapatite is proposed for the nanocomposites on the enhancement of photocatalytic performance in comparison to that of pure Ag3PO4 nanoparticles. The support of hydroxyapatite may also act as an absorbent which favors the mass transfer in heterogeneous photocatalysis reaction.

  5. Une poétique de la science :

    Directory of Open Access Journals (Sweden)

    Pierre Macherey

    2006-05-01

    Full Text Available L’article présente l’ouvrage de Fernand Hallyn, Les structures rhétoriques de la science de Kepler à Maxwell (éd. Seuil, 2004, où sont explorées les formes d’imaginaire théorique qui se développent à la limite entre pratiques littéraires et pratiques scientifiques. Sans prendre le risque d’en faire rentrer les vérités dans une perspective relativiste au point de vue de laquelle la science ne serait qu’une manière particulière de mettre le réel en récit, cette démarche apporte un précieux éclairage sur le processus de la science non déjà toute faite mais en train de se faire, où interviennent, entre autres, des modèles repris à la rhétorique et à la poétique. Ceci pris en compte, on est amené à renoncer à l’idée selon laquelle la connaissance scientifique parviendrait tout d’un coup à des vérités nues, dépouillées de tout revêtement textuel, et pouvant être appréhendées indépendamment du processus de leur production, sous forme d’énoncés autonomes, comme des phrases qui ne prendraient pas d’emblée place dans des textes, à l’intérieur desquels elles revêtent un sens qui, pour une part, déborde les limites objectives de leur énoncé, et s’offre à être restitué au point de vue, non seulement d’une épistémologie, mais aussi d’une poétique.The paper presents Fernand Hallyn’s Les Structures rhétoriques de la science de Kepler à Maxwell (Seuil, 2004, as an exploration of the theoretical imagination’s forms spreading between literary and scientific practices. This approach refuses any relativism about truth for science is not considered as a particular way to fictionalize reality. Fernand Hallyn throws so new light not on the achieved science, but on the science process, as modeled by rhetoric and poetic. Such analysis leads to abandon the idea that scientific knowledge gives nude, untextual truths, independent of their production process, like self

  6. La obra poética de Blas de Otero

    Directory of Open Access Journals (Sweden)

    Fernando Carratalá

    2006-12-01

    Full Text Available El escritor vasco Blas de Otero (Bilbao, 15-3-1916; Majadahonda –Madrid–, 29-6- 1979 es, en opinión de amplios sectores de la crítica, uno de los poetas líricos más relevantes en el panorama de la poesía contemporánea española. Fue Premio Boscán de Poesía 1950 (Redoble de conciencia y Premio de la Crítica 1959 y Premio Fastenrath 1961 (An- cia. Otero se mantuvo al margen de grupos literarios siguiendo un camino muy personal, aunque en él aparecen las tendencias en las que crecen y maduran los nuevos poetas de la posguerra: poesía de tono religioso; poesía de intención anticlasicista y antiformalista (poesía «desarraigada», en denominación de Dámaso Alonso, en respuesta al neogarcilasismo de José García Nieto y otros poetas de la llamada «Juventud Creadora» –años 1939–1944 aproximadamente–, e iniciada en 1944 con dos grandes libros: Sombra del paraíso, de Vicente Aleixandre, e Hijos de la ira, de Dámaso Alonso, libros que traen una poesía más humana y auténtica; y la que se ha llamado poesía «social». Blas de Otero que- da inmerso en estas tres tendencias, pero sin dependencia, sin ser en ninguna de ellas un mero seguidor de una moda poética.

  7. Eudragit RS PO nanoparticles for sustained release of pyridostigmine bromide

    International Nuclear Information System (INIS)

    Pyridostigmine bromide (PB) is an inhibitor of cholinesterase, which is used in the treatment of myasthenia gravis and administered for protection against exposure to toxic nerve agents. Tests were done to investigate prolonging the half-life of PB and improving its release behavior. PB was loaded in nanoparticles (NPs) of Eudragit RS PO (Eu-RS) prepared using the technique of quasi emulsion solvent diffusion. Variables of output power of the sonicator, bath temperature and mixing time, were chosen as the optimization factors to obtain the minimum sized NPs. In addition, emulsions were tested at different ratios of drug-to-polymer by dynamic light scattering to determine size and zeta potential of NPs. UV-spectroscopy was used to determine PB content of the NPs. Drug-loaded NPs were characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectra. Results determined that mixing time had a significant impact on the size of Eu-RS NPs, but power output of sonicator and bath temperature had no significant effect. The particle size obtained at the optimum condition (power output of 70 W, bath temperature of 33 °C, and mixing time of 7 min) was less than 200 nm (optimum sizes were 138.9 and 179.5 nm for Eu-RS and PB-loaded Eu-RS NPs, respectively). The optimum PB-loaded Eu-RS NPs at the PB to Eu-RS weight ratio of 1–4 and 20 % of loaded PB released from the nanocarriers within 100 h

  8. Eudragit RS PO nanoparticles for sustained release of pyridostigmine bromide

    Energy Technology Data Exchange (ETDEWEB)

    Hoobakht, Fatemeh; Ganji, Fariba, E-mail: fganji@modares.ac.ir; Vasheghani-Farahani, Ebrahim [Tarbiat Modares University, Biomedical Engineering Group, Chemical Engineering Department (Iran, Islamic Republic of); Mousavi, Seyyed Mohammad [Tarbiat Modares University, Biotechnology Group, Chemical Engineering Department (Iran, Islamic Republic of)

    2013-09-15

    Pyridostigmine bromide (PB) is an inhibitor of cholinesterase, which is used in the treatment of myasthenia gravis and administered for protection against exposure to toxic nerve agents. Tests were done to investigate prolonging the half-life of PB and improving its release behavior. PB was loaded in nanoparticles (NPs) of Eudragit RS PO (Eu-RS) prepared using the technique of quasi emulsion solvent diffusion. Variables of output power of the sonicator, bath temperature and mixing time, were chosen as the optimization factors to obtain the minimum sized NPs. In addition, emulsions were tested at different ratios of drug-to-polymer by dynamic light scattering to determine size and zeta potential of NPs. UV-spectroscopy was used to determine PB content of the NPs. Drug-loaded NPs were characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectra. Results determined that mixing time had a significant impact on the size of Eu-RS NPs, but power output of sonicator and bath temperature had no significant effect. The particle size obtained at the optimum condition (power output of 70 W, bath temperature of 33 Degree-Sign C, and mixing time of 7 min) was less than 200 nm (optimum sizes were 138.9 and 179.5 nm for Eu-RS and PB-loaded Eu-RS NPs, respectively). The optimum PB-loaded Eu-RS NPs at the PB to Eu-RS weight ratio of 1-4 and 20 % of loaded PB released from the nanocarriers within 100 h.

  9. Enhancement of electrochemical behavior of nanostructured LiFePO4/Carbon cathode material with excess Li

    Science.gov (United States)

    Bazzi, K.; Nazri, M.; Naik, V. M.; Garg, V. K.; Oliveira, A. C.; Vaishnava, P. P.; Nazri, G. A.; Naik, R.

    2016-02-01

    We have synthesized carbon coated LiFePO4 (C-LiFePO4) and C-Li1.05FePO4 with 5 mol% excess Li via sol-gel method using oleic acid as a source of carbon for enhancing electronic conductivity and reducing the average particle size. Although the phase purity of the crystalline samples was confirmed by x-ray diffraction (XRD), the 57Fe Mössbauer spectroscopy analyses show the presence of ferric impurity phases in both stoichiometric and non-stoichiometric C-LiFePO4 samples. Transmission electron microscopy measurements show nanosized C-LiFePO4 particles uniformly covered with carbon, with average particle size reduced from ∼100 nm to ∼50 nm when excess lithium is used. Electrochemical measurements indicate a lower charge transfer resistance and better electrochemical performance for C-Li1.05FePO4 compared to that of C-LiFePO4. The aim of this work is to systematically analyze the nature of impurities formed during synthesis of LiFePO4 cathode material, and their impact on electrochemical performance. The correlation between the morphology, charge transfer resistance, diffusion coefficient and electrochemical performance of C-LiFePO4 and C- Li1.05FePO4 cathode materials are discussed.

  10. One-dimensional ordering in ferroelectric CsD2PO4 and CsH2PO4 as studied with neutron scattering

    International Nuclear Information System (INIS)

    The triple-axis neutron technique has been used in a detailed study of the intensity distribution and temperature dependence of the diffuse quasielastic scattering associated with the ferroelectric transitions in monoclinic CsD2PO4 and CsH2PO4. The diffuse scattering differs greatly from that observed previously in tetragonal KD2PO4, in which case the intensity distribution clearly exhibits characteristics of three-dimensional dipolar interactions. In the present study, the nature and extent of the diffuse scattering can be explained quantitatively on the basis of chainlike ordering with temperature-dependent interchain correlations. The variation in intensity measured perpendicular to the chains (which are parallel to the ferroelectric b axis) is mostly due to variations in the dynamical structure factor of a hydrogen-bonded chain of phosphate groups, and approaches a purely-one-dimensional form at temperatures well above T/sub c/. The width of the scattering along the chain direction has been measured accurately for CsD2PO4 and yields an intrachain correlation of about 600 A near T/sub c/ (264 K), decreasing to about 140 A at 315 K. Near T/sub c/, the cross section develops short-range three-dimensional interchain correlations with no appreciable change in linewidth. Very near T/sub c/, the range of the latter is only about 30 A

  11. Irreversible phase transition between LiFePO4 and FePO4 during high-rate charge-discharge reaction by operando X-ray diffraction

    Science.gov (United States)

    Takahashi, Ikuma; Mori, Takuya; Yoshinari, Takahiro; Orikasa, Yuki; Koyama, Yukinori; Murayama, Haruno; Fukuda, Katsutoshi; Hatano, Masaharu; Arai, Hajime; Uchimoto, Yoshiharu; Terai, Takayuki

    2016-03-01

    LiFePO4 is a practically used cathode material for lithium-ion batteries due to a high theoretical capacity, high cycle capability and the high-rate performance. The metastable LixFePO4 (LxFP) phase with an intermediate composition appears in the non-equilibrium state at high-rate condition. However, the formation process of the metastable LxFP phase and its impact to the electrochemical property are still unclear. In order to elucidate these points, we directly observed the phase transition behavior by applying operando XRD during 10C charge-discharge. LxFP phase does not form in charge reaction but preferentially forms in discharge reaction. The phase transition from LxFP to Li-rich phase is less likely to proceed in the end of discharge reaction. The asymmetric phase transition between LiFePO4 and FePO4 results in decreasing the discharge capacity and increasing the irreversible capacity at high-rate conditions.

  12. Sr7U(PO4)6 and Ba7U(PO4)6 : structure and thermophysical properties

    International Nuclear Information System (INIS)

    Many crystalline ceramic matrices like Monazite, Hollandite, Kosnarite, NZP, Eulytine etc. have been proposed as a host material for nuclear Waste Immobilization (WI) due to their favourable stability against temperature, pressure and chemical reactivity. In Eulytine structure type, Sr7Th(PO4)6 was proposed with respect to WI, but no detailed report on the analogues U(IV) compounds and their thermo-physical properties are available in literature. Hence, we report here the preparation, structure and thermophysical properties of Sr7U(PO4)6 (1) and Ba7U(PO4)6 (2) compounds. The Compounds 1 and 2 were prepared by solid state reaction route (reaction is shown below) by mixing appropriate molar proportions of alkaline earth metal carbonates (Sr and Ba), UO2 and NH4H2PO4 (ADHP) and heated in high purity Ar atmosphere at 1373 K for 10 h with intermittent grinding. Powder XRD, TG-DTA, HT-XRD and DSC techniques were used for the characterization of phases, thermal stability, coefficients of thermal expansion and heat capacity (Cp) measurements, respectively

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

    Science.gov (United States)

    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.

  14. Determination of {sup 210}Pb and {sup 210}Po in cigarette tobacco; Determinacao de {sup 210}Pb e {sup 210}Po em tabaco de cigarros nacionais

    Energy Technology Data Exchange (ETDEWEB)

    Peres, Ana Claudia

    1999-07-01

    Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of {sup 210}Pb and {sup 210}Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The {sup 210}Pb was determined by counting the beta activity of the {sup 210}Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCr0{sub 4}. The {sup 210}Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 11,9 to 30,2 mBq per gram of dry tobacco for {sup 210}Pb and from 10,9 to 27,4 mBq per gram of dry tobacco for {sup 210}Po. (author)

  15. Natural Radioisotopes of Pb, Bi and Po in the Atmosphere of Coal Burning Area

    Directory of Open Access Journals (Sweden)

    Asnor Azrin Sabuti

    2011-07-01

    Full Text Available This paper is discussing the changes of natural radionuclides 210Pb, 210Bi and 210Po in atmospheric samples (rainwater and solid fallout caused by Sultan Salahuddin Abdul Aziz coal-fired Power Plant (SSAAPP operation. We also describe the seasonal changes of 210Pb, 210Bi and 210Po to the monsoon seasons in Peninsular Malaysia. Bulk atmospheric trap was used to collect atmospheric samples for five months (7 Feb 2007 to 27 July 2007 and placed within the SSAAPP area. The natural radionuclide activity levels in the atmosphere were affected by local meteorological conditions to impact their variance over time. As a result, the natural radionulides were increased from the ambient value in atmospheric particles (solid fallout, which related to coal combustion by-product releases into atmosphere. In contrast, this was giving relatively lower or in the same magnitude from most places of radionuclides in rainwater samples. Degree of changes between 210Pb, 210Bi and 210Po affected by high temperature combustions were found to be different for each nuclide due to their respective volatility. 210Po in rainwater and solid fallout were considerably low during early inter-monsoon period which mainly controlled by the rainfall pattern. On the other hand, 210Pb and 210Bi in solid fallout were recorded higher concentrations which associated to drier conditions and more particulate content in air column during southwest monsoon. The mean activity ratio of 210BiRW/210PbRW and 210PoRW/210PbRW are 0.47 ± 0.04 and 0.52 ± 0.17, respectively. Whereas for 210BiSF/210PbSF and 210PoSF/210PbSF are 0.52 ± 0.05 and 0.71 ± 0.13, respectively. Some results showed high activity ratios, reaching to 1.87 ± 0.08 for 210Bi/210Pb and 4.58 ± 0.55 for 210Po/210Pb, of which due to additional of 210Bi and 210Po excess. These ratios also indicating that 210Pb and 210Bi could potentially come from the same source, compared to 210Po which varied differently, showing evidence it came

  16. 超热水中快速连续制备LiFePO4/C纳米粒子%Rapid and Continuous Production of LiFePO4/C Nanoparticles in Super Heated Water

    Institute of Scientific and Technical Information of China (English)

    于文利; 赵亚平; 饶群力

    2009-01-01

    A rapid and continuous method for production of LiFePO4/C nanoparticles in super heated water is described, wherein soluble starch was used as carbon precursor. The effects of pH, flow rate, temperature, and pressure on the formation of LiFePO4/C particles were investigated. Results showed that the pH value was the key factor on the formation of phase pure LiFePO4, which only formed at pH = 7; the LiFePO4/C occurred as particles with about 70-200 nm size and LiFePO4 was covered by a thin carbon layer; higher flow rate, higher pressure, and lower temperature led to smaller particles of LiFePO4/C.

  17. Electronic structures and origin of intrinsic luminescence in Bi-containing oxide crystals BiPO4, K3Bi5(PO4)6, K2Bi(PO4)(MoO4), K2Bi(PO4)(WO4) and K5Bi(MoO4)4

    International Nuclear Information System (INIS)

    Highlights: • Main PL components of BiPO4, K3Bi5(PO4)6 and K2Bi(PO4)(MoO4) are bismuth-related. • Main PL components of K2Bi(PO4)(MoO4) and K5Bi(MoO4)4 are molybdate-related. • The red PL component of K2Bi(PO4)(WO4) originates from the molybdenum impurities. - Abstract: The origin of intrinsic photoluminescence (PL) in the set of Bi-containing phosphate, molybdate and tungstate crystals is analyzed in complex experimental and computational studies. The PL properties of polycrystalline powder samples of BiPO4, K3Bi5(PO4)6, K2Bi(PO4)(MoO4), K2Bi(PO4)(WO4) and K5Bi(MoO4)4 crystals synthesized by spontaneous crystallization method are studied under excitations in the VUV and UV region of photon energies (3.5–14 eV) at T = 8–300 K. The electronic band structures of the crystals are calculated by the Full-Potential Linear Augmented Plane Wave Method. The values of band gaps Eg of studied compounds are estimated from diffuse reflectance and PL excitation spectra. Calculations indicate that all studied crystals except K5Bi(MoO4)4 are indirect-gap materials. It is found that the Bi 6s and Bi 6p states contribute respectively at the tops of the Valence bands and the bottoms of the Conduction bands of all studied compounds. Each studied compound reveals several (at least two) PL emission components which undergo complete quenching below room temperature. Under nitrogen laser excitation with λex = 337.1 nm, all studied crystals reveal single-exponential decay of PL signal with decay constants τ in 3–35 μs range. It is assumed that the high-energy PL components of BiPO4, K3Bi5(PO4)6 and K2Bi(PO4)(MoO4) (peaking in the blue and violet regions) originate from 3P1 → 1S0 radiative transitions in Bi3+ ions. The red PL components of K2Bi(PO4)(MoO4) and K5Bi(MoO4)4 have the MoO42−-related origin. The red PL component of K2Bi(PO4)(WO4) presumably originates from the molybdenum impurities which form MoO42− emission centers in the phosphate–tungstate host

  18. Ingestion of 210Po by public residing in and around Kalpakkam through dietary source

    International Nuclear Information System (INIS)

    The distribution of naturally occurring radionuclide Polonium-210 (210Po) activity in dietary source of Kalpakkam, Nuclear Power Plant, Tamil Nadu and its nearby region was studied. The 210Po was analyzed in the food materials consumed by the male and female individuals (he/she) living in the study area of Kalpakkam (nuclear power plant) was done by 24-hr Duplicate Diet Study (DDS) and Market Basket Study (MBS). The MBS was done by collecting the food materials such as, cereals, fruits, nuts, leafy vegetables, other vegetables, fish, meat and milk collected from the study area. The DDS was done by collecting the food materials including the beverages consumed in 24 h from different age groups of male and female individuals living in surroundings of Kalpakkam. The intake and ingestion dose of the radionuclide 210Po was estimated. The mean concentration of 210Po in DDS (n= 33) was found to be 36 mBq.kg-1 of fresh weight. The MBS was collected based on food consumption representing more than 85-95% of annual supply, and were divided into 8 food groups. The mean concentration of 210Po in 8 food groups namely leafy vegetables was 288 mBq.kg-1 (n=4), vegetables 33 mBq.kg-1 (n=12), fish 7294 mBq.kg-1 (n=5) and cereal 34 (n=1) mBq.kg-1 of fresh weight respectively. The remaining food categories such as nuts (n=1), fruits (n= 4), meat food (n= 2) and milk (n= 2) are below detection limit of 30 mBq.kg-1 fresh weight. The annual intake and ingestion dose due to 210Po was estimated by DDS and MBS in adults, adolescents and children. Thereby, discussing the risk level of 210Po ingestion to the local inhabitants in Kalpakkam region. (author)

  19. Po 210 in the Turkish coast of the Aegean sea ecosystem

    International Nuclear Information System (INIS)

    Full text: Po 210 is a natural radionuclide which constitutes the major source of natural radiation received by humans through the consumption of food and contributes more to the total radiation dose than environmental levels of anthropogenic radionuclides, such as Cs 137 and Pu 239, 240. For Turkish Coast of Aegean Sea Ecosystem, although there some investigations presently available on some natural radionuclides and gross radioactivity concentrations, data on Po 210 in the sea water, bottom sediment and marine biota are very scarce. The aim of the present study is to improve our knowledge about the levels of radioactive polonium along Aegean Turkish Coastal zone and also assess its enhancement from the fosil fuel industry like coal-fired power plants (CPPs), oil industry and from phosphate industry, all located along the coast and also from the discharge of a number streams and rivers in the region. This paper introduces an extensive set of data and related results on Po 210 in surface sea water, bottom sediments, fishes and mussels (Mytilus galloprovincialis) obtained from 6 stations (Canakkale, Dikili, Foca, Ceshme, Didim and Bodrum) along the coast in the period of 2004-2005. In the bottom sediments, Po 210 concentration varies between 21±1 and 214±24 Bq kg-1 dry wt with an average value of 70±7 Bq kg-1. The concentrations in surface water of the sea during the sampling period are around 0.016±0.001 Bq l-1. Amongst the fishes, small pelagic plankton feding fish like anchovy (Engraulis encrasicolus) and sardine (Sardine plichardus) tend to accumulate more Po 210. The concentration of Po 210 in mussels (Mytilus galloprovincialis) varies between 55±5 and 2288±124 Bq kg-1 which is in general higher than those given in literature for other countries. The highest Po 210 concentration belongs to Didim mussels for winter time with a shell length of 4-6 cm

  20. Determination of 210Pb and 210Po in Brazilian cigarette tobacco

    International Nuclear Information System (INIS)

    Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of 210Pb and 210Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The 210 Pb was determined by counting the beta activity of the 210Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCrO4. The 210Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 15,8 to 30,2 mBq per gram of dry tobacco for 210Pb and from 18,8 to 27,4 mBq per gram of dry tobacco for 210Po. Taking in account the experimental error of the measurements, radioactive equilibrium between 210Pb and 210Po is observed for all analyzed samples. This result was expected, since the delayed time from the harvest of tobacco leaves to the introduction of cigarettes in the market is enough to reach that equilibrium. Assuming a 20 cigarettes per day consumption, and a 10% of Pb and 20% of Po being inhaled by the primary smokers, it is obtained a value of yearly intake of 11,3 Bq of 210Pb and 21,2 Bq of 210Po, due to cigarette consumption. These values lead to an increment to the committed effective dose of 0,025 mSv year-1 and an increment to the probability of getting cancer of 1 x 10-6 per year. (author)

  1. Removal of PO43- and Cu2+ Using Ferrihidrit-Chelex 100 Gel by Adsorption Coloumn

    Directory of Open Access Journals (Sweden)

    Risma Putri Disicahyani

    2013-12-01

    Full Text Available In the drinking water, there is a heavy metals and nutrient that is harmful to human health, such as phosphate and Cu2+ by product or waste material from sewage population, industry and agricultural. Government Regulation Number 82 at 2001 has said 0.2 mg PO43-/L and 2 mg Cu/L for maximum concentration in the drinking water. Resins chelex 100 and ferrihydrite could be used as a adsorbent for adsorption PO43- and Cu2+. Active sites of adsorbent chelex 100 was used as cation exchanger  because of its  negatively charged (-CH2COO-,  while ferrihydrite was used as anion exchanger  because of its positively charged (OH2+. Removal of Cu2+ are based on the formation of chelate compunds between iminodiacetic functional group and Cu2+, while ferrihydrite and PO43- was through the electrostatic interactions. Composition of ferrihydrite-chelex 100 used was 1:1. In this composition, could be removed PO43- and Cu2+ optimally at volume 7.5 mL with percentage of analyte were 97.66 % PO43- and 96.33% Cu2+. High desorption percentage of PO43- and Cu2+ could be achieved at 86.61% and 60.87% when H2SO4 0.3 M used. In the drinking water, ferrihydrite-chelex 100 gel could removed PO43- and Cu2+ from the refills water with removal percentage between 71 and 81% while from a tap water 84-98% at pH 5, respectivelly.

  2. Dynamic PROOF clusters with PoD: architecture and user experience

    International Nuclear Information System (INIS)

    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.

  3. Phase diagram of apatite system Ca{sub 10}(PO{sub 4}){sub 6}Cl{sub 2}-Pb{sub 10}(PO{sub 4}){sub 6}Cl{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, A.V., E-mail: knyazevav@gmail.com [Nizhny Novgorod State University, Gagarin Prospekt 23/2, 603950 Nizhny Novgorod (Russian Federation); Chernorukov, N.G.; Bulanov, E.N. [Nizhny Novgorod State University, Gagarin Prospekt 23/2, 603950 Nizhny Novgorod (Russian Federation)

    2011-11-10

    Highlights: Black-Right-Pointing-Pointer Compounds in Ca{sub 10}(PO{sub 4}){sub 6}Cl{sub 2}-Pb{sub 10}(PO{sub 4}){sub 6}Cl{sub 2} system were synthesized by solid state reaction. Black-Right-Pointing-Pointer In the investigated system there are two fields because of the formation a compound with formula Ca{sub 7}Pb{sub 3}(PO{sub 4}){sub 6}Cl{sub 2}. Black-Right-Pointing-Pointer The Pb{sub 10}(PO{sub 4}){sub 6}Cl{sub 2}-Ca{sub 7}Pb{sub 3}(PO{sub 4}){sub 6}Cl{sub 2} is characterized by unbounded mixing of components. Black-Right-Pointing-Pointer The Ca{sub 7}Pb{sub 3}(PO{sub 4}){sub 6}Cl{sub 2}-Ca{sub 10}(PO{sub 4}){sub 6}Cl{sub 2} area has complicated character due to presence of decomposition processes. - Abstract: Compounds in Ca{sub 10}(PO{sub 4}){sub 6}Cl{sub 2}-Pb{sub 10}(PO{sub 4}){sub 6}Cl{sub 2} system were synthesized by solid state reaction. It was ascertained using DTA and X-ray diffraction methods that in the investigated system there are two fields because of the formation a compound with formula Ca{sub 7}Pb{sub 3}(PO{sub 4}){sub 6}Cl{sub 2}. The first area is the Pb{sub 10}(PO{sub 4}){sub 6}Cl{sub 2}-Ca{sub 7}Pb{sub 3}(PO{sub 4}){sub 6}Cl{sub 2} which is characterized by unbounded mixing of components. The second Ca{sub 7}Pb{sub 3}(PO{sub 4}){sub 6}Cl{sub 2}-Ca{sub 10}(PO{sub 4}){sub 6}Cl{sub 2} area has complicated character due to presence of decomposition processes. In spite of the presence of the one nature polymorphic transitions of Ca{sub 10}(PO{sub 4}){sub 6}Cl{sub 2} and Pb{sub 10}(PO{sub 4}){sub 6}Cl{sub 2} the same effects on all solid solutions were not observed.

  4. Radiokinetic study on nucleation process of 65Zn(OH)2, 65Zn3(PO4)2 and 51CrPO4 crystals in gelatin and agar

    Science.gov (United States)

    Cecal, Al; Palamaru, M.; Chisca, S.; Balan, A.

    1999-01-01

    The nucleation process of 65Zn(OH)2, 65Zn3(PO4)2, and 51CrPO4 crystals in gelatin and agar was studied by using radioactive tracers. The diffusion rate, constants for 65Zn2+ and 51Cr3+ cations through gel, and the reaction rate constants of nucleation process as well as the beginning time of crystal appearance were established. It was found that the reaction rate constant of the low-soluble crystal is higher, and consequently, in a given colloidal medium this parameter varies as follows: k * Zn(PO4)2> k * Zn(OH) 2> k * CrPO 4

  5. Preparation and Characterization of Novel Ti-doped M-site Deficient Olivine LiFePO4

    Institute of Scientific and Technical Information of China (English)

    Yu Heng SUN; Xing Quan LIU

    2006-01-01

    A novel Ti-doped M-site deficient olivine LiFePO4, i.e. Li0.95Fe0.95Ti0.05PO4, was synthesized by a solid-state reaction method. XRD and FTIR were used to characterize the as-prepared samples. As a cathode material for lithium-ion batteries, Li0.95Fe0.95Ti0.05PO4 exhibited improved rate capability.

  6. Hierarchical LiFePO4 with a controllable growth of the (010) facet for lithium-ion batteries

    OpenAIRE

    Binbin Guo; Hongcheng Ruan; Cheng Zheng; Hailong Fei; Mingdeng Wei

    2013-01-01

    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 ...

  7. Synthesis of LiFePO4/Pani/C composite as a cathode material for lithium ion battery

    Science.gov (United States)

    Rahayu, Iman; Hidayat, Sahrul; Aryadi, Lutfi

    2016-02-01

    In recent years, LiFePO4 studied intensively as a cathode material for Li-ion batteries because of high theoretical capacity, stability, and environmental friendly. However, its low intrinsic electronic conductivity. One way to improve its conductivity is addition of conductive material. Polyaniline (PANI) is one of the conductive polymer materials that widely studied because its unique physical and chemical properties which can be an insulator and conductor by doping-dedoping processes and has large potential application. The purpose of this research is to improve the conductivity of LiFePO4 with conductive polymer PANI. The method is performed by the addition of LiFePO4 during the polymerization process to form LiFePO4 polyaniline then added to the C-PANI with the addition of mass percent variation of 5%, 10%, 15%, 20% form-LiFePO4 composite PANI-C. In LiFePO4 added during polymerization PANI provide a smooth surface profile after composited with the carbon to LiFePO4-PANI-C compared to LiFePO4-C. LiFePO4-PANI-C composite provided higher conductivity is 18.45×10-4 S/cm compared to LiFePO4-C is 10.48×10-4 S/cm at 20% addition of carbon. This is due to PANI in LiFePO4 is added to the polyaniline polymerization process can act as a conductive adhesive to glue between carbon and LiFePO4.

  8. Suitability of the Nanophosphate LiFePO4/C Battery Chemistry for the Fully Electric Vehicle

    DEFF Research Database (Denmark)

    Swierczynski, Maciej Jozef; Stroe, Daniel Ioan; Stan, Ana-Irina;

    2014-01-01

    intrinsic safety of the nanophosphate LiFePO4/C lithium ion chemistry make it possible to consider this chemistry for electric vehicle applications. This paper investigates the lifetime of the nanophosphate LiFePO4/C battery chemistry when it is used for full electrical vehicles. The investigation is...... is used to study the capacity and power capability degradation behaviour of the tested nanophosphate LiFePO4/C battery for two electric vehicle operational scenarios....

  9. Kinetic Behavior of LiFePO4/C Thin Film Cathode Material for Lithium-Ion Batteries

    OpenAIRE

    Kucinskis, G; Bajārs, G; Kleperis, J.; Smits, J.

    2010-01-01

    LiFePO4 was prepared in a solid state synthesis with various levels of carbon content. LiFePO4/C thin films were obtained via magnetron sputtering. The surface morphology and structure was examined. Electrochemical properties of LiFePO4/C were studied, by using cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy. Thin films acquired show a potential use as a cathode in lithium ion batteries, displaying charge capacity up to 34 mAh g-1.

  10. Luminescence properties of phosphate phosphor Ba3Y(PO4)3:Sm3+

    International Nuclear Information System (INIS)

    A series of reddish orange-emitting phosphate phosphors Ba3Y1−x(PO4)3:xSm3+(0.01≤x≤0.20) were synthesized by solid-state reaction. X-ray diffraction and photoluminescence spectra were utilized to characterize the structure and luminescence properties of as-synthesized phosphors. The optimized phosphors Ba3Y0.95(PO4)3:0.05Sm3+ present several excitation bands from 300 to 500 nm, and exhibit intense reddish orange-emitting properties. The energy transfer type between Sm3+ ions was confirmed as d–d interaction by using Van Uitert model. The chromatic properties of the typical sample Ba3Y(PO4)3:0.05Sm3+ phosphor have been found to have chromaticity coordinates of (0.583, 0.405), which are located in reddish orange region under the excitation of 401 nm. These results indicated that Ba3Y(PO4)3:Sm3+ phosphors have potential applications in the field of lighting and display due to their effective excitation in the near-ultraviolet range. - Graphical abstract: The color coordinates for 5 mol% Sm3+ doped Ba3Y(PO4)3 phosphor were calculated to be (0.583, 0.405), which are located in reddish orange region under the excitation of 401 nm. The peaks of Ba3Y0.95(PO4)3:0.05Sm3+ phosphor with the highest emission intensity at 600 nm are broader than those of Y2O3:Eu3+ and Y2O2S:Eu3+ phosphors. All these characteristics suggest that Ba3Y(PO4)3:Sm3+ phosphors are suitable for near-UV (370–410 nm) excitation and can be applicable to near UV-based WLEDs. ▪ - Highlights: • Different concentration Sm3+-doped Ba3Y(PO4)3 phosphors were fabricated by solid state method. • The optimized phosphors present the several excitation bands from 300 to 500 nm. • The Ba3Y(PO4)3:Sm3+ shows bright reddish orange emissions under 401 nm excitation

  11. Texte, métatexte et paratexte. La poétique du fragmentaire

    Directory of Open Access Journals (Sweden)

    Crina Zărnescu

    2009-03-01

    Full Text Available Essence du vol et de la mobilité, le martinet représente dans la mythorhétorique personnelle de René Char l’archétype de la liberté, de l’ « énergie disloquante » et antigravitationnelle. Le martinet trouve sa définition poétique dans la figure de la litote ; ce que c’est la litote au niveau stylistique le martinet l’est au niveau du signifiant poétique. Cet ouvrage se propose de faire l’analyse du poème « Le Martinet » de René Char par le biais de sa poétique gouvernée par les antinomies d’une existence fragmentée, par la hantise d’une unité originale-essentielle, récupérable par et dans la poésie et par ce désir indéfectible de liberté dont le symbole reste l’oiseau. L’analyse proprement dite s’occupe du décorticage du symbole central qui engage, en dépit de son apparente « transparence », plusieurs trajets sémantiques tels : le martinet – le cœur (enfant, le martinet – le moi poétique, le martinet - le texte poétique. Certaines collocations surprenantes, les suggestions visuelles qui font se dégager de l’horizontale de la page blanche le vol linéaire ou zigzagué du martinet, la juxtaposition des séquences poétiques transcrivant à la fois la rencontre des antinomiques ou de l’insolite et du surprenant dont le résultat est le choc de la perception originelle sont autant d’éléments qui font de ce petit poème l’image inédite d’une candeur solitaire.

  12. Determination of 210Pb e 210Po in marine samples and aerosols

    International Nuclear Information System (INIS)

    In this work the methodologies for 210Pb e 210Po analyses in marine samples, such as fish, seaweed, sediment, and aerosol samples are presented. The 210Pb levels in the samples were obtained by both210Bi and 210Po ingrowth. The 210Pb analysis via 210Bi presents the following steps: 210Pb leaching from samples with 8 M nitric acid and hydrogen peroxide; lead sulphate precipitation; conversion to carbonate; dissolution; lead sulphate precipitation; gravimetric analysis of lead; waiting of time to reach radioactive equilibrium and 210Bi beta counting by employing a Geiger-Mueller detector with a low background radiation. The 210Pb analysis via 210Po presents the following steps: 210Pb and 210Po leaching from samples with 8 M nitric acid and hydrogen peroxide; nitric acid elimination by heating and hydrochloric acid addition; spontaneous deposition onto silver disc and alpha counting of polonium in silicon surface-barrier detector. In order to determine 210Pb activity, the solution was percolated in the Dowex AG 1-X 8 anion exchange resin; preconditioned with 8 M nitric acid; the lead was eluted by 8 M hydrochloric acid; the solution was gently evaporated to dryness and diluted with 0.5 N hydrochloric acid. After 3-6 months a second 210Po spontaneous deposition onto silver disc was carried out. The methodology for 210Pb analysis via 210Bi showed lead recoveries from 63 to 100%. In the method via 210Po the polonium recoveries were varied from 39 to 63% under manual agitation, and from 60 to 100% under mechanical agitation. The radiochemical methods for 210Po and 210Pb analyses were applied in reference samples from International Atomic Energy Agency (IAEA) and the results obtained showed the good precision and accuracy of the established methods. The analysis of marine sediment samples of Antarctica presented 210Pb and Po levels from 8 to 60 Bq.kg-1, and fish samples from Sao Paulo Coast presented 210Po levels from 0.5 to 5.3 Bq.kg-1. These results for fish are

  13. Ingestion dose from 210Po due to the consumption of packaged drinking water

    International Nuclear Information System (INIS)

    Humans are chronically exposed to naturally occurring radionuclides from uranium and thorium series via inhalation and ingestion. With increased interest in radiological assessment a study was taken up for assessing natural radioactivity in drinking water. Drinking water is an important route of intake of naturally occurring 210Po. 210Po being a very important radionuclide from Uranium series with high specific activity causes significant internal dose. In our study 210Po in PDW was concentrated with calcium phosphate and spontaneously deposited onto silver planchette and subsequently measured by alpha spectrometry. The concentration of 210Po in the bottled water ranged from 0.11 mBq.l-1 to 2.9 mBq.l-1. The highest concentration was observed in that sample that was reportedly sourced from mountain regions. Based on the concentration of 210Po in each water sample, the annual intake rate (1.68L/d), and the Dose Coefficient (1.2 X 10-6 Vs./Bq) recommended by the International Commission on Radiological Protection (ICRP, 1996), the annual committed effective doses to the adult population was estimated. The annual effective doses ranged between 0.10-2.16 μSv/yr. (author)

  14. Intake of 226Ra, 210Pb and 210Po with food in Poland

    International Nuclear Information System (INIS)

    Intake with food and water of 226Ra, 210Pb and 210Po was determined for an adult population in regions of central, northern and northeastern Poland. The content of radionuclides was determined in the daily diet and, in the central region, also in foodstuffs and drinking water. The annual intake with foodstuffs was estimated on the basis of their average annual consumption. The 226Ra intake in northeastern Poland was approximately 17% higher than the overall average, correlating well with the higher concentration of this radionuclide in the soil. The 210Po/210Pb ratio was close to unity in the continental regions, whereas at the Baltic Sea coast it was approximately 1.5. The latter value can be ascribed to a larger consumption of fish for which the 210Po/210Pb ratio was found to be approximately 10. In central Poland the largest intake of 226Ra was with flour and vegetables (contribution approx. 60%), the largest intake of 210Pb was with flour and meat (approx. 50%) and the largest intake of 210Po was with fish (approx. 34%). From the intake and dose coefficient, annual effective doses were calculated. The dose from 210Pb and 210Po was approx. 54 μSv year-1, and the dose from 226Ra was approx. 4 μSv year-1

  15. Structure and luminescence properties of silver-doped NaY(PO3)4 crystal

    International Nuclear Information System (INIS)

    Single crystals of NaY(PO3)4 and Ag0.07Na0.93Y(PO3)4 have been synthesized by flux method. These new compounds turned out to be isostructural to NaLn(PO3)4, with Ln=La, Nd, Gd and Er [monoclinic, P21/n, a=7.1615(2) A, b=13.0077(1) A, c=9.7032 (3) A, β=90.55 (1)o, V=903.86(14) A3 and Z=4]. The structure is based upon long polyphosphate chains running along the shortest unit-cell direction and made up of PO4 tetrahedra sharing two corners, linked to yttrium and sodium polyhedra. Infrared and Raman spectra at room temperature confirms this atomic arrangement. The luminescence of silver ions was reported in metaphosphate of composition Ag0.07Na0.93Y(PO3)4. One luminescent centre was detected and assigned to single Ag+ ions. - Graphical abstract: The presence of only one Ag+ luminescence centre is the result from the perfect isolation (Ag+-Ag+=5.90 A) of each oxygenated silver site (AgO8 polyhedra) sharing two faces and one corner with three yttrium polyhedra

  16. Radionuclides behaviour in the Po river ecosystem (N. Italy) after the Chernobyl accident

    International Nuclear Information System (INIS)

    The Chernobyl accident gave the opportunity to carry on a radioecological experiment in a real situation concerning many compartments of the complex ecosystem of the Po basin. Concentrations of radionuclides in wet and dry deposition were determined and their accumulation in soil, concentrations in the Po river water and in the biotic riverine components were also determined. A temporal pattern for wet and dry deposition and the Po water are described. The investigations on the abiotic river components of ecological significance placed in evidence the primary role of the organic mineral debris of recent origin as an indicator of the presence of many radionuclides. The radiometric sediments analysis have allowed to evidence both the contamination dynamic of the different radionuclides and the influence of the littoral current to determine their distribution. The availability of information on concentrations in Po river water, on the rate of deposition on the ground and on the average and cumulative activity permitted both the formulation of a balance of the circulation of individual radionuclides in the Po valley and an estimate of the time required to return to the conditions pre-existing at the time of the accident. In particular it was observed that most of the radioactivity is retained by soil in relation to the different characteristics of each radionuclide and of the constituents of the soil (clay, organic matter, etc.). (author)

  17. Stability of Sunscreens Containing CePO4: Proposal for a New Inorganic UV Filter

    Directory of Open Access Journals (Sweden)

    Vitor C. Seixas

    2014-07-01

    Full Text Available 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.

  18. Solvothermal synthesis and electrochemical performance of hollow LiFePO{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Zhenmiao [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Pang, Wei Kong [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia); Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Tang, Xincun, E-mail: tangxincun@163.com [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Jia, Dianzeng; Huang, Yudai [Institute of Applied Chemistry, Xinjiang University, Urumqi 840046 (China); Guo, Zaiping [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia)

    2015-08-15

    Highlights: • Hollow LiFePO{sub 4} nanoparticles were successfully synthesized via solvothermal method. • The shorter b lattice parameter allows the shorter diffusion path of lithium ion. • Hollow LiFePO{sub 4} nanoparticles show better rate capability than solid LiFePO{sub 4}. - Abstract: Hollow LiFePO{sub 4} nanoparticles were synthesized via a solvothermal technique, using ammonium tartrate as additive and carbon source, and ethylene glycol/water as solvent. The as-prepared samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, scanning and transmission electron microscopies, and Brunauer–Emmett–Teller specific surface area measurements. The electrochemical properties of the LiFePO{sub 4} cathode were examined in coin-type cell configuration and the cathode exhibited excellent rate capability (i.e., discharge capacity of 120.9 mA h g{sup −1} at 10 C) and cycling performance (i.e., >98% of capacity retention rate after 50 cycles). It is believed that the enhanced performance is correlated to the hollow structure, small crystallite and particle sizes, and relatively shorter lattice parameter b.

  19. Rapid measurement of 210Po in seafood with large area grid ionization chamber α spectrometry

    Institute of Scientific and Technical Information of China (English)

    Li Yucheng; Yin Liangliang; Chen Fei; Shao Xianzhang; Shen Baoming; Kong Xiangyin; Ji Yanqin

    2015-01-01

    Objective To develop a rapid and reliable method for determination of 210Po using large-area grid ionization chamber α spectrometry.Methods Samples were digested using a microwave digestion system.After preparation of sample source,the concentration of 210Po in clam was detected by large-area grid ionization chamber (φ 25 cm).209Po tracer was used to obtain the recovery.Results Large-area grid ionization chamber could achieve better counting and α spectrum resolution when the optimized thickness was 250 μg/cm2.By spiking 209Po tracer in clam,the minimum detectable activity was 9.870 × 10 4 Bq and the recovery of 210Po was 98%.Conclusions Compared with the traditional method,the developed method can avoid separation process,using less quantity of sample (0.2-0.5 g dry) and simplify the measurement process.This method may be has broad application prospects.

  20. Synthesis, characterization, and structure determination of the orthorhombic U2(PO4)(P3O10)

    International Nuclear Information System (INIS)

    β-UP2O7 has been synthesized under hydrothermal conditions (θ=500 deg. C, P=200 MPa), using UO2 and H3PO4. β-UP2O7 crystallizes in the orthorhombic space group Pn21a, with a=11.526 (2) A, b=7.048 (2) A, c=12.807 (2) A and Z=4. Its structure has been determined through direct methods and difference Fourier synthesis and has been refined to R=0.0396. The structure is built on UO8 polyhedral chains along the b-axis. PO43- and P3O105- groups coexist in the structure and the latter groups form non-linear chains. Cohesion of the structure is made through the linkage of UO8 chains by PO4 and P3O10 groups leading to the formula U2(PO4)(P3O10) instead of β-UP2O7. Vibrational and optical spectra confirm the results obtained by X-ray diffraction. DTA-TGA measurements show that the transformation of U2(PO4)(P3O10) to the cubic α-UP2O7 occurs at θ=870 deg. C

  1. Microvascular and interstitial PO(2) measurements in rat skeletal muscle by phosphorescence quenching.

    Science.gov (United States)

    Shibata, M; Ichioka, S; Ando, J; Kamiya, A

    2001-07-01

    To clarify the transport of O(2) across the microvessels in skeletal muscle, we designed an intravital laser microscope that utilizes a phosphorescence quenching technique to determine both the microvascular and tissue PO(2). After we injected the phosphorescent probe into systemic blood, phosphorescence excited by a N(2)-dye pulse laser was detected with a photomultiplier over a 10 microm in diameter area. In vitro and in vivo calibrations confirmed that the present method is accurate for PO(2) measurements in the range of 7-90 Torr (r = 0.958) and has a rapid response time. This method was then used to measure the PO(2) of microvessels with different diameters (40-130 microm) and of interstitial spaces in rat cremaster muscle. These measurements showed a significant drop in PO(2) in the arterioles after branching (from 74.6 to 46.6 Torr) and the presence of a large PO(2) gradient at the blood-tissue interface of arterioles (15-20 Torr). These findings suggest that capillaries are not the sole source of oxygen supply to surrounding tissue. PMID:11408447

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

    Science.gov (United States)

    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.

  3. Intake of {sup 226}Ra, {sup 210}Pb and {sup 210}Po with food in Poland

    Energy Technology Data Exchange (ETDEWEB)

    Pietrzak-Flis, Z.; Chrzanowski, E.; Dembinska, S. [Department of Radiation Hygiene, Central Laboratory for Radiological Protection, Warsaw (Poland)

    1997-09-06

    Intake with food and water of {sup 226}Ra, {sup 210}Pb and {sup 210}Po was determined for an adult population in regions of central, northern and northeastern Poland. The content of radionuclides was determined in the daily diet and, in the central region, also in foodstuffs and drinking water. The annual intake with foodstuffs was estimated on the basis of their average annual consumption. The {sup 226}Ra intake in northeastern Poland was approximately 17% higher than the overall average, correlating well with the higher concentration of this radionuclide in the soil. The {sup 210}Po/{sup 210}Pb ratio was close to unity in the continental regions, whereas at the Baltic Sea coast it was approximately 1.5. The latter value can be ascribed to a larger consumption of fish for which the {sup 210}Po/{sup 210}Pb ratio was found to be approximately 10. In central Poland the largest intake of {sup 226}Ra was with flour and vegetables (contribution approx. 60%), the largest intake of {sup 210}Pb was with flour and meat (approx. 50%) and the largest intake of {sup 210}Po was with fish (approx. 34%). From the intake and dose coefficient, annual effective doses were calculated. The dose from {sup 210}Pb and {sup 210}Po was approx. 54 {mu}Sv year{sup -1}, and the dose from {sup 226}Ra was approx. 4 {mu}Sv year{sup -1}.

  4. 210Po in marine organisms: a wide range of natural radiation dose domains

    International Nuclear Information System (INIS)

    Marine biota is able to concentrate 210Po to high levels, as 103-105 relative to sea water concentration. 210Po concentrations in mixed zooplankton reaches 34-51 Bq.kg-1 (fresh wt), special groups such as copepods reaching even higher concentrations ∼ 90 Bq.kg-1, whereas gelatinous zooplankton display ∼ 1 Bq.kg-1. Epipelagic teleosts feeding on plankton displayed the highest concentrations found in fish muscle, 2-21 Bq.kg-1. Contrasting with this, demersal teleosts and elasmobranchs display lower 210Po concentrations, in the ranges 0.5-7 Bq.kg-1 and 0.2-1.7 Bq.kg-1, respectively. Much higher concentrations can, however, be measured in fish liver, gonad, bone and piloric caecca, and small mesopelagic fish can reach ∼ 800 Bq.kg-1 on a whole-body basis. Due to these 210Po activity concentrations, dose equivalent rates delivered to biological tissues in marine organisms can vary widely, from 0.4 mSv.y-1 in gelatinous plankton up to 5.6 x 103 mSv.y-1 in the gut wall of sardines. It is concluded that in organisms living in the same ocean layer a wide range of internal radiation doses exists and it is essentially sustained by 210Po food-chain transfer. (author)

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

    Science.gov (United States)

    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. PMID:27071463

  6. Facile preparation of porous LiFePO4/C composite granules by mechanical process

    International Nuclear Information System (INIS)

    Lithium iron phosphate (LiFePO4) which is a promising cathode material for lithium-ion batteries requires particle size reduction, carbon coating and granulation to improve its electrochemical performances and increase the energy densities. In addition, their composite granules desire a porous structure in order to assist the penetration of liquid electrolyte. Here, we report a facile preparation of porous LiFePO4/C composite granules by a mechanical method using an attrition-type mill. By the mechanical treatment of starting materials, LiFePO4/C composite granules with an average pore size of 20–30 nm were synthesized in one-step process without atmosphere control and external heating. This simple mechanical technique does not require additional pore forming agents. According to the cell tests, a favorable cycle performance was exhibited. - Highlights: • Porous LiFePO4/C composite granule was synthesized by one-pot mechanical process. • LiFePO4 was formed without atmosphere control and external heating. • Gases released from raw materials act as pore forming agents. • A favorable cycle performance was exhibited

  7. Improved optimum condition for recovery and measurement of 210Po in environmental samples

    International Nuclear Information System (INIS)

    An improved laboratory technique for measurement of polonium-210(210Po) in environmental samples has been developed in Radiochemistry and Environmental Laboratory (RAS), Malaysian Nuclear Agency. To further improve this technique, a study with the objectives to determine the optimum conditions for 210Po deposition and; evaluate the accuracy and precision results for the determination of 210Po in environmental samples was carried-out. Polonium-210 which is an alpha emitter obtained in acidic solution through total digestion and dissolution of samples has been efficiently plated onto one side of the silver disc in the spontaneous plating process for measurement of its alpha activity. The optimum conditions for deposition of 210Po were achieved using hydrochloric acid (HCl) media at acidity of 0.5 M with the presence of 1.0 gram hydroxyl ammonium chloride and the plating temperature at 90 degree Celsius. The plating was carried out in 80 ml HCl solution (0.5 M) for 4 hours. The recorded recoveries obtained using 209Po tracers in the CRM IAEA-385 and environmental samples were 85 % - 98% whereby the efficiency of the new technique is a distinct advantage over the existing techniques. Therefore, optimization of deposition parameters is a prime importance to achieve accuracy and precision results as well as economy and time saving. (author)

  8. PO2 in irradiated versus nonirradiated tumors of mice breathing oxygen at normal and elevated pressure

    International Nuclear Information System (INIS)

    Purpose: To determine if prior tumor irradiation influences tumor pO2 changes in mice breathing oxygen (100%) at normal and elevated pressure. Methods and Materials: Single-point pO2 measurements were performed in nonirradiated and previously irradiated (72 h) isotransplanted MCaIV tumors in C3H/Sed mice. Continuous recordings were performed at the same tumor locus under air breathing, followed by 100% oxygen and oxygen at three atmospheres pressure. Following decompression and induction of pentobarbital anesthesia, the procedure was repeated at the same locus. Six nonirradiated and five irradiated tumors were evaluated under the three gas breathing conditions ± anesthesia. Results: The mean, median, and range of pO2 values did not differ under air-breathing conditions in the nonirradiated vs. previously irradiated tumors. However, prior irradiation substantially enhanced the tumor pO2 increase when the inspired gas phase was switched from air to 100% oxygen at 1 or 3 atmospheres pressure. In four of six nonirradiated tumors, 100% oxygen breathing resulted in a pO2 increase of < 4 mmHg; in the irradiated tumors, the minimum increase was 16 mmHg. Pentobarbital anesthesia did not significantly influence the results obtained. Conclusion: These data indicate that the efficacy of oxygen breathing increases during tumor treatment, and suggests that oxygen breathing is a simple nontoxic method for reducing or eliminating radiobiologic hypoxia during therapy

  9. Crystal chemistry of MIIM′IV(PO4)2 double monophosphates

    International Nuclear Information System (INIS)

    MIIM′IV(PO4)2 compounds have been extensively studied for several decades for their potential applications in the field of several domains such as matrices for actinides conditioning, phosphors etc. In this paper, the relationships between composition and crystal structure of these compounds are established. A review of the various processes used for the synthesis of these compounds is also proposed, as well as their most reported properties. MIIM′IV(PO4)2 structures stem from two different archetypes: the cheralite and the yavapaiite structures, with some exceptions that are also described in this article. The ratio of the cations radii appears to be the most relevant parameter. The high ratio between the ionic radii of the divalent and tetravalent cations in yavapaiite derivates results in the ordering of these cations into well-differentiated polyhedra whereas cheralite is the only non-ordered structure encountered for MIIM′IV(PO4)2 compounds. - Graphical abstract: In this paper, the relationships between composition and crystal structure of MIIM′IV(PO4)2 compounds are established. A review of the various processes used for the synthesis of these compounds is also proposed, as well as their most reported properties. - Highlights: • Crystal structure–composition relationships of MIIM′IV(PO4)2 compounds. • Review of the various processes used for the synthesis of these compounds. • Their most reported properties are described and discussed

  10. Unusual 210Po/210Pb ratios in the surface water of the Gulf of Lions

    International Nuclear Information System (INIS)

    Concentrations of 210Po and 210Pb have been measured in sea water collected in the Grand Rhone Canyon. Concentrations of 210Pb are at similar levels to those found in other Mediterranean sea water samples, and are at the levels which would be expected in comparison with global sea water data. The same applies to the 210Po concentrations in samples from below 100 m depth. Surface samples from above 100 m have 210Po at levels rather higher than expected, and their 210Po/210Pb ratios are about 1 or more as compared with the usual open ocean ratio 0.5. These data can be interpreted as indicating another source of supply of 210Po to the surface layer in addition to the normal atmospheric input. We suggest that an episodic advective particulate input, probably originating in the output of the Rhone river and perhaps involving resuspension of fine particulates from the bottom sediments as a result of storm conditions, is he most likely candidate for this additional source. (authors)

  11. Solvothermal synthesis and electrochemical performance of hollow LiFePO4 nanoparticles

    International Nuclear Information System (INIS)

    Highlights: • Hollow LiFePO4 nanoparticles were successfully synthesized via solvothermal method. • The shorter b lattice parameter allows the shorter diffusion path of lithium ion. • Hollow LiFePO4 nanoparticles show better rate capability than solid LiFePO4. - Abstract: Hollow LiFePO4 nanoparticles were synthesized via a solvothermal technique, using ammonium tartrate as additive and carbon source, and ethylene glycol/water as solvent. The as-prepared samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, scanning and transmission electron microscopies, and Brunauer–Emmett–Teller specific surface area measurements. The electrochemical properties of the LiFePO4 cathode were examined in coin-type cell configuration and the cathode exhibited excellent rate capability (i.e., discharge capacity of 120.9 mA h g−1 at 10 C) and cycling performance (i.e., >98% of capacity retention rate after 50 cycles). It is believed that the enhanced performance is correlated to the hollow structure, small crystallite and particle sizes, and relatively shorter lattice parameter b

  12. Studies on proton conductivity of polyimide/H3PO4/imidazole blends

    International Nuclear Information System (INIS)

    A new anhydrous proton conducting material based on polyimide(PI)/H3PO4/imidazole(Imi) Blends was prepared. FTIR spectrum shows the existence of hydrogen bonds between protonated and unprotonated imidazole units. The addition of phosphoric acid can accelerate the degradation process of PIs, while the addition of imidazole in PI/H3PO4 blends can improve their chemical oxidation stability enormously. The proton conductivity of PI/H3PO4 blends increases significantly with increasing content of imidazole. Proton conductivity of PI/xH3PO4/yImi membranes increases with increasing temperature and content of phosphoric acid. The experimental results show that it is possible to significantly improve the operating temperature of PEM fuel cell system by replacing water with imidazole as proton solvent in the polymer membrane. Hydrogen bond seems to play an important role in the proton conductivity of this system. The decrease of proton conductivity of imidazolium phosphate shows in some degree that the interaction between imidazole and phosphoric acid is not the main reason for the conductivity increment of imidazole doped PI/H3PO4 system

  13. Advanced carbon materials/olivine LiFePO4 composites cathode for lithium ion batteries

    Science.gov (United States)

    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.

  14. Preparation and Characterisation of LiFePO4/CNT Material for Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Rushanah Mohamed

    2011-01-01

    Full Text Available Li-ion battery cathode materials were synthesised via a mechanical activation and thermal treatment process and systematically studied. LiFePO4/CNT composite cathode materials were successfully prepared from LiFePO4 material. The synthesis technique involved growth of carbon nanotubes onto the LiFePO4 using a novel spray pyrolysis-modified CVD technique. The technique yielded LiFePO4/CNT composite cathode material displaying good electrochemical activity. The composite cathode exhibited excellent electrochemical performances with 163 mAh/g discharge capacity with 94% cycle efficiency at a 0.1 C discharge rate in the first cycle, with a capacity fade of approximately 10% after 30 cycles. The results indicate that carbon nanotube addition can enable LiFePO4 to display a higher discharge capacity at a fast rate with high efficiency. The research is of potential interest for the application of carbon nanotubes as a new conducting additive in cathode preparation and for the development of high-power Li-ion batteries for hybrid electric vehicles.

  15. Organophosphonic acid as precursor to prepare LiFePO4/carbon nanocomposites for high-power lithium ion batteries

    International Nuclear Information System (INIS)

    Graphical abstract: LiFePO4/C nanocomposites were prepared by a quasi-sol–gel method with the use of organophosphonic acid, exhibiting improved electrochemical performance with excellent cycle stability. Display Omitted -- Highlights: •Amino tris(methylene phosphonic acid) is served as a novel precursor for LiFePO4/C. •Nano-sized and high-purity LiFePO4/C composites are obtained by a quasi-sol–gel route. •Core-shell structured LiFePO4/C nanocomposites are fabricated by further introducing sucrose. •Superior electrochemical performance is observed in the organophosphorus-synthesized LiFePO4/C. -- Abstract: Amino tris(methylene phosphonic acid) (ATMP) is selected as phosphorus and carbon co-source for the synthesis of uniformly nano-sized LiFePO4/C by a quasi-sol–gel method. This strategy using ATMP instead of conventional NH4H2PO4 supplies two advantages: firstly, ATMP in situ chelates Li+ onto its framework and subsequently binds with FeC2O4 in aqueous solution, forming a molecule-scale homogeneous precursor which can obviously improve the purity of LiFePO4. Secondly, the organic carbon contained in ATMP can form uniformly distributed conductive carbon networks among LiFePO4 particles after calcination, which improves the electrical conductivity. The resultant LiFePO4/C with 1.1 wt.% carbon achieves a higher discharge capacity than those of LiFePO4 and LiFePO4/C prepared with inorganic NH4H2PO4. Moreover, core-shell structured LiFePO4/C nanocomposites are also fabricated by further introducing sucrose into the synthesis system. The high-quality carbon shell effectively hinders the LiFePO4 particle growth and aggregation under high-temperature treatment, which further enhances the electrical conductivity and lithium-ion diffusion, resulting in the improved electrochemical performance with excellent cycle stability (the optimum discharge capacity of 158.6 mAh g−1 at 0.1 C and 138.4 mAh g−1 at 2 C). The high purity, nanosize and core-shell structure

  16. Comparing the Electrochemical Performance of LiFePO4/C Modified by Mg Doping and MgO Coating

    OpenAIRE

    Jianjun Song; Ying Zhang; Guangjie Shao

    2013-01-01

    Supervalent cation doping and metal oxide coating are the most efficacious and popular methods to optimize the property of LiFePO4 lithium battery material. Mg-doped and MgO-coated LiFePO4/C were synthesized to analyze their individual influence on the electrochemical performance of active material. The specific capacity and rate capability of LiFePO4/C are improved by both MgO coating and Mg doping, especially the Mg-doped sample—Li0.985Mg0.015FePO4/C, whose discharge capacity is up to 163 m...

  17. Electronic properties and structural properties of Li (1 - chi) FePO 4 (X = 0 , 0.5 ,1)

    OpenAIRE

    Kinyanjui, Michael Kiarie

    2010-01-01

    Lithium iron phosphate (LiFePO4) is currently applied as a cathode material for lithium ion batteries. However, its electronic properties and the mechanism by which lithium ions are extracted (delithiation) or inserted (lithiation) into the lattice are still not completely understood. In this thesis the electronic and structural properties of Li(1-x)FePO4 (LiFePO4 x = 0, FePO4 x = 1) have been investigated using valence and core loss electron energy loss spectroscopy (EELS) and high resolutio...

  18. Efficient PO-MOM Method for Analysis of the Radiation Characteristics of a Large Antenna-Radome System

    Institute of Scientific and Technical Information of China (English)

    HU Bing; XU Xiao-wen; HE Mang

    2008-01-01

    An efficient hybrid method based on the method of moments (MOM) and physical optics (PO) for the analysis of radiation characteristics of an electrically large antenna-radome system is presented. Specifically, MOM is first applied to the antenna to find the current on its surface, and then the equivalent PO currents produced by the antenna radiation are assumed on the radome wall. When the coupling of the PO currents and antenna current is considered, the coupling matrix is divided into a series of partial matrices, in order to deduce the memory requirement and accelerate the evaluation process. Numerical results indicate that the proposed hybrid PO-MOM method is accurate and efficient.

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

    International Nuclear Information System (INIS)

    Three vertical water profiles of 210Pb and 210Po have been measured in the East China and Philippine seas. All the profiles show a large 210Po deficiency of ∼ 8 dpm/cm2 relative to 210Pb in the top ∼ 1,000 m of the water column. Based on the 210Po deficiency, the steady state flux for 210Po removal from the surface water is estimated to be 14 dpm cm-2/yr. The 210Po/210Pb ratio of sinking particles will be too high unless an additional source of 210Pb into the surface is accounted for. Thus the large 210Po deficit is probably caused by the increased atmospheric input of 210Pb without any significant 210Po, which is focused in the Kuroshio region by isopycnal transport, and the preferential scavenging of 210Po relative to 210Pb by settling particles. The transient model calculations indicate that the model can account for the observed high excess 210Pb inventory and large 210Po deficiency in the water column if focusing of atmospherically derived 210Pb 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

  20. Possible unconventional superconductivity in iron-based layered compound LaFePO: Study of heat capacity

    OpenAIRE

    Kohama, Yoshimitsu; Kamihara, Yoichi; Kawaji, Hitoshi; Atake, Tooru; Hirano, Masahiro; Hosono, Hideo

    2008-01-01

    Heat capacity measurements were performed on recently discovered iron based layered superconductors, non doped LaFePO and fluorine doped LaFePO. A relatively large electronic heat capacity coefficient and a small normalized heat capacity jump at Tc = 3.3 K were observed in LaFePO. LaFePO0.94F0.06 had a smaller electronic heat capacity coefficient and a larger normalized heat capacity jump at Tc = 5.8 K. These values indicate that these compounds have strong electron electron correlation and m...

  1. Diurnal variations of 218Po, 214Pb, and 214Po and their effect on atmospheric electrical conductivity in the lower atmosphere at Mysore city, Karnataka State, India

    International Nuclear Information System (INIS)

    The short-lived radon daughters (218Po, 214Pb, 214Bi and 214Po) 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 222Rn, 218Po, 214Pb, 214Bi and 214Po, 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 222Rn, 218Po, 214Pb, and 214Po 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 respectively. The radon and

  2. 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.

    Science.gov (United States)

    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

  3. Farmacininkų požiūrio į GMO vertinimas

    OpenAIRE

    Našlėnė, Žilvinė

    2014-01-01

    Tyrimo tikslas – įvertinti vaistinių darbuotojų požiūrį į GMO. Tikslo įgyvendinimui iškelti 3 uždaviniai – įvertinti vaistinių darbuotojų žinias apie GMO, įvertinti vaistinių darbuotojų požiūrį į GMO riziką aplinkai ir žmonių sveikatai bei gautus rezultatus palyginti su 2009 m. ”Spinter“ visuomenės požiūrio į GMO tyrimais. Metodika. Atlikta anoniminė vaistinų darbuotojų anketinė apklausa. Apklausta 150 respondentų: 75 iš Vilniaus miesto ir 75 iš Ukmergės ir Šakių miestų. Duomenų statistinė an...

  4. (210)Po and (210)Pb in medicinal plants in the region of Karnataka, Southern India.

    Science.gov (United States)

    Chandrashekara, K; Somashekarappa, H M

    2016-08-01

    The activity concentrations of naturally occurring radionuclides (210)Po and (210)Pb were estimated in some selected medicinal plants and soil samples of coastal Karnataka in India. The mean activity concentrations of (210)Po and (210)Pb varied in the range of 4.7-42.9 Bq kg(-1) (dry weight) and 36.1-124 Bq kg(-1) (dry weight) in the soil samples, and 3.3-63.7 Bq kg(-1) (dry weight) and 12.0-406 Bq kg(-1) (dry weight), in the medicinal plant samples, respectively. The plants, Ocimum sanctum L. and Plectranthus amboinicus (Lour.) Spreng had significantly higher activity concentrations of (210)Po and (210)Pb than other species sampled. In spite of disequilibrium between them, these two radionuclides were well correlated in both soil and medicinal plants. PMID:27155527

  5. Les connotations expressives du verbe dans la poésie de G. Bacovia

    Directory of Open Access Journals (Sweden)

    Ina Alexandra CIODARU

    2009-11-01

    Full Text Available Dans la littérature roumaine, Bacovia est considéré comme l’initiateur du lyrisme moderne, par la richesse de son fond poétique, opinion soutenue d’ailleurs par de nombreux aspects de langage qui ont été analysés au niveau du lexique, de la construction de la phrase, des différentes figures: syntaxiques, stylistiques ou de la pensée, tout comme au niveau de la prosodie et des capacités mélodiques des vers. Tous ces aspects définitoires de l’esthétique bacovienne ont démontré la manière dont le poète a orienté les conceptions vers une révolution du langage poétique.

  6. Synthesis and characterization of LiFePO{sub 4} cathode preparation by low temperature method

    Energy Technology Data Exchange (ETDEWEB)

    Rajesh, Desapogu, E-mail: rajesh.desapogu@gmail.com; Srinivas Naik, V.; Sunandana, C.S., E-mail: sunandana@gmail.com

    2015-05-01

    We review in detail the physics and technology of the novel material LiFePO{sub 4}, a potential cathode material for Li-ion batteries. In the present work, nano crystalline LiFePO{sub 4} film has been synthesized in both powder and thin film forms from a non-aqueous sol–gel synthesis route based on oxalates of Li and Fe (II). Ferrous oxalate has been synthesized indigenously using a ferrous sulphate based chemical reaction and characterized. Nano powders and thin films of LiFePO{sub 4} have been fabricated and coated on stainless steel substrates with the aim of device development in future. The material has been characterized extensively by XRD for crystal structure, FESEM for microstructure, EDS for elemental analysis and FTIR for the internal modes of phosphate ion. Fe{sup 3+} impurity characterization has been done by using ESR.

  7. Heat-treatment-induced luminescence degradation in Tb3+-doped CePO4 nanorods

    International Nuclear Information System (INIS)

    CePO4:Tb nanorods were synthesized via a simple wet-chemical route. The as-synthesized CePO4:Tb nanorods present high photoluminescence efficiency due to an efficient energy transfer form Ce3+ to Tb3+. However, heat treatment at 150 deg. C in air leads to a significant decrease of photoluminescence. X-ray photoelectron spectroscopy and excitation spectra revealed the oxidation of Ce3+ to Ce4+ in the heat-treatment process, which should be responsible for significant photoluminescence degradation due to the breakage of Ce3+→Tb3+ energy transfer. This conclusion is further supported by atmosphere and size effects of photoluminescence of CePO4:Tb under the heat treatment.

  8. Impedance studies on Al3+ doped LiCoPO4

    International Nuclear Information System (INIS)

    LiCo1-0.03x/2Al0.01xPO4 (X=0, 5, 10, 15, 20) have been prepared by two step solid state reaction method using acetate based precursors. XRD analysis conforms the formation of the sample with orthorhombic structure. Impedance measurements have been carried out for prepared samples using Hioki LCR Hi-Tester 3532-30 over the frequency range of 42 Hz-1MHz at different temperatures. Doping of Al+3 causes modification in the conductivity of LiCoPO4. The calculated conductivity of LiCo0.925Al0.05PO4 is found to be 5.22 x 10-8 S cm-1 at 340℃ which is higher than the pristine one. Temperature dependent of conductivity follows the Arrhenius law of conduction. Modulus studies have also been discussed. (author)

  9. Design of a Flexible and Adaptable LMS Engine in Conformance with PoEML

    Directory of Open Access Journals (Sweden)

    Roberto Pérez-Rodríguez

    2009-03-01

    Full Text Available This paper describes the support of the Structural, Functional, Order and Temporal perspectives in PoEML. PoEML is a modeling language devoted to support a broad range of pedagogical approaches, from content-based, to collaborative and practical oriented. At this point, a main issue is to provide a good level of adaptability and flexibility. The final goal is to support changes in the educational process development, enabling the provision of different learning experiences depending on the learning goals, the learner needs and features, the previous results, etc. The introduced solution is based on the separation of concerns principle adopted in PoEML. Basically, the solution facilitates the use of a set of educational resources in different ways by separating the form in which such resources are organized (Structural perspective from the decisions of what has to be done (Functional perspective and when (Order and Temporal perspectives.

  10. Hydrogen reduction of vanadium in vanadium-doped LiMnPO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Kellerman, D.G., E-mail: kellerman@ihim.uran.ru [Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg (Russian Federation); Ural Federal University, 620002 Ekaterinburg (Russian Federation); Chukalkin, Yu.G. [Institute of Metal Physics, Ural Branch, Russian Academy of Sciences, 620990 Ekaterinburg (Russian Federation); Medvedeva, N.I.; Kuznetsov, M.V. [Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg (Russian Federation); Mukhina, N.A. [Eliont LLC, 620137 Ekaterinburg (Russian Federation); Semenova, A.S. [Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg (Russian Federation); Gorshkov, V.S. [Eliont LLC, 620137 Ekaterinburg (Russian Federation)

    2015-01-15

    The samples of vanadium-doped LiMnPO{sub 4} have been synthesized by the solid-state reaction technique. To reduce the oxidation state of vanadium from V{sup 5+} to V{sup 4+}, the samples have been additionally annealed under hydrogen atmosphere. The tetravalent state of vanadium was proved by analysis of V 2p X-ray photoelectron spectra. Raman spectroscopy, first-principle studies and magnetic measurements were used to determine the effect of V{sup 4+} on the Li–Mn phosphate properties. - Highlights: • The samples of LiMnPO{sub 4} doped with vanadium were prepared. • The samples were annealed under hydrogen atmosphere. • The V{sup 4+} presence was proved. • The ab initio calculations revealed the most favorable position for oxygen vacancy. • The presence of V{sup 4+} changes magnetic properties and Raman spectra of LiMnPO{sub 4}.

  11. Synthesis and luminescence properties of KSrPO4:Eu2+ phosphor for radiation dosimetry

    Science.gov (United States)

    Palan, C. B.; Bajaj, N. S.; Omanwar, S. K.

    2016-05-01

    The KSrPO4:Eu phosphor was synthesized via solid state method. The structural and morphological characterizations were done through XRD (X-ray diffraction) and SEM (Scanning Electronic Microscope). Additionally, the photoluminescence (PL), thermoluminescence (TL) and optically Stimulated luminescence (OSL) properties of powder KSrPO4:Eu were studied. The PL spectra show blue emission under near UV excitation. It was advocated that KSrPO4:Eu phosphor not only show OSL sensitivity (0.47 times) but also gives faster decay in OSL signals than that of Al2O3:C (BARC) phosphor. The TL glow curve consist of two shoulder peaks and the kinetics parameters such as activation energy and frequency factors were determined by using peak shape method and also photoionization cross-sections of prepared phosphor was calculated. The radiation dosimetry properties such as minimum detectable dose (MDD), dose response and reusability were reported.

  12. Ab initio study of pressure induced structural and electronic properties in TmPo

    Energy Technology Data Exchange (ETDEWEB)

    Makode, Chandrabhan, E-mail: cbmakode@gmail.com; Pataiya, Jagdish; Sanyal, Sankar P. [Department of Physics, Barkatullah University, Bhopal-462026 (India); Panwar, Y. S.; Aynyas, Mahendra [Department of Physics, C.S.A. Govt. P.G. College, Sehore-466001 (India)

    2015-06-24

    We report an ab initio calculation of pressure induced structural phase transition and electronic properties of Thulium Polonide (TmPo).The total energy as a function of volume is obtained by means of self-consistent tight binding linear muffin-tin-orbital (TB-LMTO) method within the local density approximation (LDA). It is found that TmPo is stable in NaCl-type (B{sub 1}-phase) structure to CsCl-type (B{sub 2}-phase) structure of this compound in the pressure range of 7.0 GPa. We also calculate the lattice parameter (a{sub 0}), bulk modulus (B{sub 0}), band structure and density of states. From energy diagram it is observed that TmPo exhibit metallic behavior. The calculated values of equilibrium lattice parameter and bulk modulus are in general good agreement.

  13. Analysis of 210Pb and 210Po in Brazilian foods and diets

    International Nuclear Information System (INIS)

    Radiochemical procedures for the analysis of 210Pb and 210Po in foods and diets are presented. Because of the low beta energy of 210Pb, its analysis was based on a separation of the daughter radionuclide 210Bi by precipitation of lead sulphate, 210Bi ingrowing and beta counting of this nuclide. 210Po analysis was based on wet dissolution of the sample, deposition onto silver disc and counting by alpha-spectrometry. Levels of these radionuclides in individual items and diets of selected university students were determined in order to evaluate the intakes of 210Pb and 210Po as well as the dose due to ingestion of foods and diets in Sao Paulo city. (author)

  14. Ab-initio multiplet calculations of Fe-L2,3 X-ray absorption spectra in LiFePO4 and FePO4

    International Nuclear Information System (INIS)

    Soft X-ray absorption near-edge structures (XANES) at the L2,3-edges of transition metal has been widely used for investigating the chemical reactions during charge-discharge cycles in the cathode materials of lithium ion batteries. In order to extract the information about the electronic structures from the experimental results, however, a theoretical tool that can deal with the strong electronic correlations between 2p and 3d electrons is necessary. In this study, the ab-initio multiplet method based on the relativistic configuration interaction (CI) method has been applied to the calculations of Fe-L2,3 XANES of LiFePO4 and FePO4. Experimental XANES spectra were quantitatively reproduced by this method. The effects of local symmetries around Fe ions to the spectral shapes were also discussed. (author)

  15. Improving the electrochemical properties of nanosized LiFePO4-based electrode by boron doping

    International Nuclear Information System (INIS)

    Highlights: • Thermal treatment of boron phosphate with LiFePO4 provides electrode materials with high performance in lithium half-cells: 160 mAh·g-1 (90% of theoretical capacity) under C/5 rate • The products are composites containing boron-modified LiFePO4, FePO4 and an amorphous phase with ionic diffusion properties • The boron treatment affects textural, conductive and lithium diffusivity of the electrode material leading to higher performance • A limited boron-doping of the phospholivine structure is observed - Abstract: Electrode materials with homogeneous distribution of boron were obtained by heating mixtures of nanosized carbon-coated lithium iron phosphate and BPO4 in 3-9% weight at 700 °C. The materials can be described as nanocomposites containing i) LiFePO4, possibly doped with a low amount of boron, ii) FePO4 and iii) an amorphous layer based on Li4P2O7-derived material that surrounds the phosphate particles. The thermal treatment with BPO4 also triggered changes in the carbon coating graphitic order. Galvanostatic and voltammetric studies in lithium half-cells showed smaller polarisation, higher capacity and better cycle life for the boron-doped composites. For instance, one of the solids, called B6-LiFePO4, provided close to 150 and 140 mAhg-1 (87% and 81% of theoretical capacity, respectively) under C/2.5 and C regimes after several cycles. Improved specific surface area, carbon graphitization, conductivity and lithium ion diffusivity in the boron-doped phospholivine network account for this excellent rate performance. The properties of an amorphous layer surrounding the phosphate particles also account for such higher performance

  16. Temperature effect on uranium retention onto Zr2O(PO4)2 surface

    International Nuclear Information System (INIS)

    Uranium sorption onto Zr2O(PO4)2 has been studied between 298 K and 363 K, in 0.1 M NaClO4 medium. Potentiometric titrations were realized to determine temperature dependency of the acid-base properties (pH(pcn), acidity constants). Classical batch experiments were performed at different temperatures. The sorption experiments revealed that the uranium sorption onto Zr2O(PO4)2 is favoured with the temperature. Structural characterization of the surface complexes was performed by both Time-Resolved Laser-Induced Fluorescence (TRLIF) and EXAFS spectroscopy. The TRLIF measurements vs. temperature revealed two uranyl surface complexes. No influence of the temperature onto the nature surface complex was observed. The EXAFS analysis showed a splitting of the equatorial oxygen atoms in two shells, corresponding to uranyl bidentate, inner-sphere complexes. The obtained structural uranyl surface complex information was used to simulate (using a constant capacitance model) the sorption edges. The proposed complexes equilibrium model consists of the following surface complexes: (ZrOH)2UO22+ and (PO)2UO2. Besides the stability constants for the surface complexes, the thermodynamic parameters ΔH0 and ΔS0 were determined using the van't Hoff equation. The enthalpy values associated to the U(VI) retention onto Zr2O(PO4)2, determined by the temperature dependence of the stability constants, testify that the formation of the complex (PO)2UO2 (55 kJ/mol) is endothermic, while no influence of the temperature was observed for the formation of the complex (ZrOH)2UO22+. The adsorption reaction of the last complex is then driven by entropy. In addition, calorimetric measurements of uranium sorption onto Zr2O(PO4)2 were carried out to directly quantify the enthalpy associated to the retention processes. (author)

  17. Enhanced apatite formation on Ti metal heated in PO2-controlled nitrogen atmosphere.

    Science.gov (United States)

    Hashimoto, Masami; Hayashi, Kazumi; Kitaoka, Satoshi

    2013-10-01

    The oxynitridation of biomedical titanium metal under a precisely regulated oxygen partial pressure (PO2) of 10(-14)Pa in nitrogen atmosphere at 973 K for 1 h strongly enhanced apatite formation compared with that on Ti heated in air. The factors governing the high apatite-forming ability are discussed from the viewpoint of the surface properties of Ti heated under a PO2 of 10(-14)Pa in nitrogen atmosphere determined from X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and zeta potential measurements. Nitrogen (N)-doped TiO2 (interstitial N) was formed on pure Ti heated under a PO2 of 10(-14)Pa in nitrogen atmosphere at 973 K. The XPS O1s main peak shifted toward a lower binding energy upon heating under a PO2 of 10(-14)Pa. This shift may be due to the formation of oxygen vacancies. This Ti surface had a positive zeta potential of approximately 20 mV. According to time-of-flight secondary ion mass spectroscopy results, PO4(3-) ions were predominantly adsorbed on Ti soaked in simulated body fluid (SBF) after heat treatment, followed by calcium ions. It was concluded that the apatite formation kinetics can be described using the Avrami-Erofeev equation with an Avrami index of n=2, which implies the instantaneous nucleation of apatite on the surface of Ti soaked in SBF after heat treatment at 973 K under a PO2 of 10(-14)Pa. PMID:23910327

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

    Science.gov (United States)

    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.

  19. Discharge of 210Po and 210Pb in coastal groundwater to the ocean

    International Nuclear Information System (INIS)

    The activities of 210Po and 210Pb were measured for the truly dissolved (<10 kDa) and colloidal (10 kDa - 0.45 ìm) phases in coastal ground water in 2010 and 2011. The sampling sites include the coast of a large tidal flat (Hampyeong Bay) and a volcanic island, Jeju, Korea, where submarine groundwater discharge (SGD) were reported to be higher than typical continental margins. The total dissolved fraction was separated into the colloidal and truly dissolved fractions using a tangential flow filtration (TFF) system (PLCGC Pellicon). The total 210Po and 210Pb activities in ground water were 1.0 - 18.2 dpm/100L (9.7±7.6 dpm/100L) an 2.9 - 29.1 dpm/100L (16.8±10.7 dpm/100L) in the Hampyeong Bay and Jeju Island samples, respectively. The total 210Po and 210Pb activities in groundwater were similar to or even slightly lower than those in the typical seawater. These lower activities seem to be due to the rapid adsorption of Po and Pb on to particles in the subterranean estuary. The proportions of the truly dissolved and colloidal phases were, respectively, 73±5% and 27±5% for 210Po, and 60±5% and 40±5% for 210Pb. This result is consistent with the earlier study that more than half of the some dissolved trace metals in coastal ground water are in the colloidal form. Thus, our result implies that the colloidal forms are important in controlling the behaviour of Po, Pb, and other trace metals in the subterranean estuary and SGD-associated fluxes to the ocean. (author)

  20. Retrospective assessment of indoor radon exposure by measurements of embedded 210Po activity in glass objects

    Science.gov (United States)

    Ramola, R. C.; Gusain, G. S.; Prasad, Ganesh

    In most of the epidemiological studies contemporary radon measurements have been used as surrogates for radon concentrations in past decades even though changes in radon levels and residence may have occurred. Short-lived radon progeny may deposit on available surfaces in dwellings thus giving rise over time to a build up of long-lived progeny. Airborne radon decay products can be deposited and implanted through alpha recoil into the glass surfaces. On glass surface, activities of 210Po may arise as a result of the decay of recoil implanted activity following the alpha decay of surface deposited 218Po or 214Po. Measurement of 210Po implanted on a household glass is a method that can be employed to retrospectively determine the historic level of radon in dwellings. This method is based on the assumption that levels of recoil implanted 210Po in the glass provide a measure of time integrated radon concentration in the environment in which the glass has been located. The surface deposited activity of the radon progenies, which then become implanted in the glass by alpha recoil, is believed to reflect past exposure to airborne activity. Such retrospective measurements on glass are valuable in estimating the human dose derived from radon during the time of exposure. In this paper an account is given of the principles and some field applications of a retrospective technique, using the alpha track detectors, CR-39 and LR-115, to measure 210Po implanted in glass surfaces (surface traps). By using this CR-LR difference technique, the cumulative radon exposure in a dwelling in past decades may be estimated. This method provides reliable radon exposure data as a support to epidemiological studies concerning the health effects of radon exposure in the living environment.

  1. Comparative studies on Ag3PO4/BiPO4–metal-organic framework–graphene-based nanocomposites for photocatalysis application

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Novel Ag3PO4/BiPO4 (AB)–graphene-based photocatalysts were reported. • Photocatalytic degradation mechanism of Atrazine herbicide was investigated. • It was divulged that the photodegradation is increased by AB supporting. • Enhanced photodegradation has been obtained by the AB/Cu(tpa).GR nanocomposite. • The unique heterojunction formed by coupling Cu(tpa) with GR caused high activity. - Abstract: For the first time, we report novel Ag3PO4/BiPO4 (AB)–graphene-based photocatalysts. The fabricated nanocomposites were characterized by various techniques. The photocatalytic properties of the prepared catalysts were evaluated by the photodegradation of Atrazine herbicide under both visible and UV light irradiation. Atrazine concentration was determined using the spectrophotometric method according to the Konig's reaction by monitoring the absorbance at 470 nm wavelength during the photodegradation process. Both degradation rate and efficiency using graphene (GR)-based nanocomposites are found to be much better than using pure AB. Atrazine photodegradation displayed that the AB supporting is an important point to become a great photocatalyst for this reaction. Enhanced photodegradation has been obtained by the AB/Cu(tpa).GR nanocomposite. The results showed that the novel synthesized AB/Cu(tpa).GR nanocomposite exhibits a dramatic separation of photogenerated electron/hole pairs. This was accounted for by the improved efficiency of an interfacial charge separation, thanks to the unique heterojunction formed by coupling Cu(tpa) with GR. Chemical oxygen demand of herbicide solution was measured and it posed a good idea about Atrazine herbicide degradation

  2. Comparative studies on Ag{sub 3}PO{sub 4}/BiPO{sub 4}–metal-organic framework–graphene-based nanocomposites for photocatalysis application

    Energy Technology Data Exchange (ETDEWEB)

    Mohaghegh, N. [Department of Chemistry, Sharif University of Technology, Azadi Avenue, Tehran (Iran, Islamic Republic of); Tasviri, M., E-mail: m_tasviri@sbu.ac.ir [Department of Chemistry, Shahid Beheshti University, Evin, P.O. Box 19839-63113, Tehran (Iran, Islamic Republic of); Rahimi, E. [Department of Mining Engineering, Islamic Azad University, South Tehran Branch, Tehran (Iran, Islamic Republic of); Gholami, M.R., E-mail: gholami@sharif.edu [Department of Chemistry, Sharif University of Technology, Azadi Avenue, Tehran (Iran, Islamic Republic of)

    2015-10-01

    Graphical abstract: - Highlights: • Novel Ag{sub 3}PO{sub 4}/BiPO{sub 4} (AB)–graphene-based photocatalysts were reported. • Photocatalytic degradation mechanism of Atrazine herbicide was investigated. • It was divulged that the photodegradation is increased by AB supporting. • Enhanced photodegradation has been obtained by the AB/Cu(tpa).GR nanocomposite. • The unique heterojunction formed by coupling Cu(tpa) with GR caused high activity. - Abstract: For the first time, we report novel Ag{sub 3}PO{sub 4}/BiPO{sub 4} (AB)–graphene-based photocatalysts. The fabricated nanocomposites were characterized by various techniques. The photocatalytic properties of the prepared catalysts were evaluated by the photodegradation of Atrazine herbicide under both visible and UV light irradiation. Atrazine concentration was determined using the spectrophotometric method according to the Konig's reaction by monitoring the absorbance at 470 nm wavelength during the photodegradation process. Both degradation rate and efficiency using graphene (GR)-based nanocomposites are found to be much better than using pure AB. Atrazine photodegradation displayed that the AB supporting is an important point to become a great photocatalyst for this reaction. Enhanced photodegradation has been obtained by the AB/Cu(tpa).GR nanocomposite. The results showed that the novel synthesized AB/Cu(tpa).GR nanocomposite exhibits a dramatic separation of photogenerated electron/hole pairs. This was accounted for by the improved efficiency of an interfacial charge separation, thanks to the unique heterojunction formed by coupling Cu(tpa) with GR. Chemical oxygen demand of herbicide solution was measured and it posed a good idea about Atrazine herbicide degradation.

  3. Variationas of 210Po Activity in Mussels (Perna viridis) of Samut Sakhon and Its Contribution to Dose Assessment

    International Nuclear Information System (INIS)

    Levels of 210Po and its effective dose in green mussel (Perna viridis) collected from mussel farming area at the Samut Sakhon province during the period of 2012-2013 are presented. Several parameters including maximum shell length and the physiological performance of mussels using condition index and physical properties of seawater (pH, salinity, conductivity, TDS, DO and cation-anion elements) were measured. Each individual mussel was measured on its maximum shell length which was adopted as size class. The activity concentration of 210Po was determined spectroscopically through its 5.30 MeV alpha particle emission, using 209Po as an internal tracer. The 210Po activity concentration in mussels was found to vary between 1.044 and 6.951 Bq.kg-1 wet weight. The 210Po concentration was higher in smaller sized classes (>35 mm) and lowest in larger ones (40-70 mm). This confirms that larger mussels have lower 210Po levels on a weight basis. The 210Po body burden (activity per mussel) ranged from 1.035 to 17.183 mBq. Contrary to the 210Po concentrations, results of the body burden revealed the lower activities in smaller sized mussels (>35 mm) and the higher in larger sized ones (40-70 mm). The type of fluctuations observed with 210Po concentrations are interpreted as a seasonal effect. Total annual effective 210Po dose due to mussel consumption was calculated to be in the range of 3.081 to 16.401 μSv. Based on the international guideline, the average dose calculated due to 210Po in mussels of Samut Sakhon would not pose any significant radiological impact on human health and the mussels are considered to be safe for intake.

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

    Science.gov (United States)

    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. PMID:26726564

  5. An assessment of 210Po in terrestrial environment around uranium deposit area, West Khasi Hills, Meghalaya, India

    International Nuclear Information System (INIS)

    The study aims to provide environmental data on 210Po in different type of food products grown around the proposed Uranium mining sites of Domiasiat, West Khasi Hills in the state of Meghalaya. 210Po occurs widely in nature and is an important compound of natural radiation background. Its presence in soil may be traced to the decay of radionuclides of the 238U chain in soil. This decay leads to the formation of 222Rn. Alpha counting of 208Po and 210Po was performed by using a silicon surface barrier detector. 210Po activity was corrected for recovery by comparison with the measured activity of 208Po yield tracer and for radioactive decay since the time of sampling. The mean concentration of 210Po in the soil was found to be 124.8±5.0 Bq kg-1 with a range of 123.97-132.72 Bq kg-1. The 210Po concentration in the vegetation observed lowest 20 mBq kg-1 in gobi to maximum 9690 mBq kg-1 in wild pitcher plant. The observed TR-Po was found lowest in cucumber 8.97 x 10-6 and highest in Shynrai Khlaw (leaves) 3.2 x 10-2 kg kg-1. In the present work the TR-Po value for rice is lower as compare to literature value of 3 x 10-2 kg kg-1. In the fresh water environment TR-Po in the fish was found in the range of 1.8 to 3.1 kg l-1 which was lower than the range in the published reported value of IAEA. (author)

  6. Louise Labé et les arts poétiques

    OpenAIRE

    Clement, Michèle

    2004-01-01

    Quels sont - d'après l'examen de ses oeuvres- les arts poétiques qu'a pu lire et suivre Louise Labé ? ceux relevant de l'esthétique naissante de la Pléiade ou des arts poétiques plus marotiques ? L'analyse des intertextes, les définitions génériques et l'analyse prosodique révèlent quelques choix nets.

  7. Izbor in vzpostavitev požarne pregrade v podjetju Zelinka d.o.o.

    OpenAIRE

    Barunčić, Mario

    2016-01-01

    Vse življenje se vsakodnevno in neprestano odločamo. V literaturi lahko zasledimo, da je odločanje mentalni proces, zavedni ali nezavedni, znotraj katerega izbiramo med več variantami. V proučevani organizaciji so se odločili za zamenjavo požarne pregrade. V okviru diplomske naloge smo zato izgradili odločitveni model, izbrali požarno pregrado ter jo vgradili v njihovo okolje. Za izgradnjo modela smo izbrali metodo ekspertnih sistemov na področju večkriterijskega odločanja z uporabo pro...

  8. Utrjevanje poškodovanih zidov s steklenimi vrvicami in epoksidnimi smolami

    OpenAIRE

    Božič, Luka

    2015-01-01

    V diplomski nalogi sem s pomočjo vrvice iz steklenih vlaken utrdil kamniti zid, ki je bil uporabljen že v predhodnih preiskavah in v le-teh tudi delno poškodovan. Imel je tipične strižne poškodbe, ki so bile sanirane z injektiranjem cementne mešanice. V prvem delu diplomske naloge sem na dveh vrstah kamna testiral sprijemno trdnost treh različnih vrst malt, pri čemer sem zasnoval postopek in način testiranja. Vsi testi so se izvajali v laboratoriju Fakultete za gradbeništvo in geodezijo v Lju...

  9. Synthetic LiFePO4/C without using inert gas

    Institute of Scientific and Technical Information of China (English)

    Guo Rong Hu; Xu Guang Gao; Zhong Dong Peng; Ke Du; Yan Jun Liu

    2007-01-01

    LiFePO4/C was synthesized by high temperature solid-state method with cheap Fe2O3, LiH2PO4 and glucose as raw materials in absence of inert gas. The sample had ordered olivine-type structure other impurities characterized by the test of X-ray diffraction(XRD). The charge-discharge test showed the sample could demonstrate 120.5 mAh/g at 0.2C rate with good cyclic capability. The powder microelectrode cyclic voltammetry test indicated that the redox process of the sample had good reversibility.

  10. On the vibrational properties of CsD2PO4 crystal

    International Nuclear Information System (INIS)

    Lattice dynamics simulation of CsD2PO4 crystal is performed in a quasiharmonic approximation using the atomistic potential involving Coulomb, short-range, covalent, van der Waals and hydrogen-bonded interactions. The phonon dispersion relations, partial density of states, velocities of ultrasonic waves and atomic displacement parameters are calculated both in the paraelectric and ferroelectric phases. The obtained data enable us to give a detailed description of the observed Raman and IR spectra and to determine the eventual local symmetry of the PO4 groups. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Neutron-scattering study of the ferroelectric phase transition in CsD2PO4

    International Nuclear Information System (INIS)

    A neutron-scattering study of the ferroelectric transition in CsD2PO4 has yielded quasi-elastic diffuse distributions of intensity typical of a one-dimensional system with chainlike ordering parallel to the ferroelectric b axis of this monoclinic crystal. Therefore, despite such suggestive similarities as the large isotope shift in T/sub c/, the transition is quite different from that of tetragonal KD2PO4 where the diffuse scattering clearly exhibits characteristics of three-dimensional dipolar interactions

  12. El grafofonema (fonoletra en el discurso poético: mensaje para descifrar

    Directory of Open Access Journals (Sweden)

    Goncharenko Serguéi

    2003-06-01

    Full Text Available

    El artículo data de la formación de las estructuras fónicas como mecanismos comunicativos en el discurso poético, para generar mensajes, proporcionando tanto información semántica como estética dentro del umbral de la información poética, la cual permite tanto pérdida como incremento semántico en la poesía.

  13. Removal of lead from crude antimony by using NaPo3 as lead elimination reagent

    OpenAIRE

    Ye L.G.; Tang C.B.; Yang S.H.; Chen Y.M.; Zhang W.H.

    2015-01-01

    In order to solve the shortcomings when removing lead from crude antimony in the traditional antimony smelting, a new process was provided using NaPO3 as lead elimination reagent to yield phosphate slag, and it was removed by floating on the surface of the liquid antimony. Reaction mechanism was clarified by using the TG-DTA and XRD techniques and single factor experiments of removal lead from crude antimony were engaged. The results show that PbO and NaPO3...

  14. Radionuclides of 210Po, 234U and 238U in drinking bottled mineral water in Poland

    International Nuclear Information System (INIS)

    A study of the radioactive content of drinking mineral bottled water in Poland was carried out. 210Po, 238U and 234U activity concentrations were determined by alpha-spectrometry with low-level-activity silicon detectors. The results revealed that the mean concentration of 210Po, 238U and 234U in analyzed water sample were 1.28, 0.80 and 0.80 mBq x dm-3, respectively. The effective doses due to the polonium and uranium emissions were calculated for bottled drinking water. (author)

  15. The Digital Universe Coalition: Building a Prototype NVO E/PO Portal

    Science.gov (United States)

    Mendez, B.; Craig, N.; Haisch, B.; Lindblom, J.; Hanisch, R.; Summers, F.; Abbott, B.

    2004-05-01

    The National Virtual Observatory (NVO) holds tremendous potential for Education and Public Outreach (E/PO) opportunities. The possibilities for E/PO with the NVO, which promises to make widely available the great majority of the world's astronomical data, are too numerous for any one E/PO effort to ever hope to develop. Therefore, it is critical that the NVO E/PO program develop an infrastructure and tools flexible enough that any E/PO program can make use of it. In response to the recommendations of the NVO science definition team, UC Berkeley's SEGway program conducted needs assessment surveys of potential non-traditional (i.e. non-scientist) NVO user communities. The SEGway team wished to use the results of these surveys to design a demonstration website that could show some of the potential capabilities of NVO E/PO. SEGway established an informal partnership with STScI, AMNH/Hayden Planetarium, and ManyOne Network to explore how to assemble the infrastructure and tools for NVO E/PO and to construct a demonstration portal that makes use of NVO resources. We called this partnership The Digital Universe Coalition. This prototype displays AMNH/Hayden's Digital Universe star catalog of approximately 100,000 stars, based largely on HIPPARCOS parallaxes, in a virtual three-dimensional space. Three types of user-interactive data display and/or navigation are possible: an Earth-based view of the sky with the option of displaying constellations; a spaceship-based view moving through space; and a "god's-eye" view of the local neighborhood from an external vantage point. One key feature of this demo is the linking of user-selectable locations in the sky to the online Digitized Sky Survey data sets. A second feature is a set of links for educational content on a handful of selected objects. Both of these capabilities will be extended further as we plan to begin development of a much more robust and complete E/PO portal for the NVO.

  16. Electrical conductivity studies of graphene wrapped nanocrystalline LiMnPO4 composite

    International Nuclear Information System (INIS)

    Nanocrystalline LiMnPO4 material was synthesized by template free sucrose assisted hydrothermal method. The material possesses the orthorhombic crystal structure with Pnma, space group having four formula units. The GO was prepared by the hummer’s method and it was reduced graphene oxide (rGO) with hydrazine hydrate in the presence of nitrogen atmosphere. LiMnPO4 material was wrapped by the rGO to increase its conductivity. The structural characterization was accomplished through X-ray diffraction, FT-IR and Raman spectroscopy. Morphology was identified by the SEM, Electrical characterization was done through impedance spectroscopy and the results were reported

  17. Extraction of Biomolecules Using Phosphonium-Based Ionic Liquids + K3PO4 Aqueous Biphasic Systems

    OpenAIRE

    Louros, Cláudia L. S.; Cláudio, Ana Filipa M.; Neves, Catarina M. S. S.; Freire, Mara G.; Marrucho, Isabel M.; Jérôme Pauly; Coutinho, João A. P.

    2010-01-01

    Aqueous biphasic systems (ABS) provide an alternative and efficient approach for the extraction, recovery and purification of biomolecules through their partitioning between two liquid aqueous phases. In this work, the ability of hydrophilic phosphonium-based ionic liquids (ILs) to form ABS with aqueous K3PO4 solutions was evaluated for the first time. Ternary phase diagrams, and respective tie-lines and tie-lines length, formed by distinct phosphonium-based ILs, water, and K3PO4 at 298 K, we...

  18. Measurement of the {sup 214}Po half-life by the DEVIS track setup

    Energy Technology Data Exchange (ETDEWEB)

    Belov, V. A.; Brakhman, E. V.; Zeldovich, O. Ya.; Karelin, A. K.; Kirichenko, V. V.; Kobyakin, A. S., E-mail: Alexander.Kobyakin@itep.ru; Kozodaeva, O. M.; Kuchenkov, A. V.; Tsvetkova, T. N. [Institute of Theoretical and Experimental Physics (Russian Federation)

    2013-04-15

    Measurement of the {sup 214}Po half-life with the DEVIS track setup at the Institute of Theoretical and Experimental Physics (ITEP, Moscow) by means of a procedure based on determining lifetimes of individual nuclei is described. The value obtained for the {sup 214}Po half-life is 163.8 {+-} 3.0 Micro-Sign s. The possibility of reaching the accuracy of the measurements that is required for testing the statement that the decay of some nuclei has a nonexponential character and the source intensity necessary for this are discussed.

  19. Unlocking the energy capabilities of micron-sized LiFePO4

    OpenAIRE

    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

    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. Spe...

  20. Optimization of LiFePO4 synthesis by hydrothermal method

    OpenAIRE

    MAZMAN, Muhsin; ÇUHADAR, Ömür; UZUN, Davut; Avci, Ercan

    2014-01-01

    Optimization of the LiFePO4 cathode active material synthesis process in the hydrothermal method consists of many factors, including pH, carbon coating, particle size optimization, sintering and hydrothermal synthesis temperature. The main goal of this study is to determine the effect of particle size, pH and carbon coating on capacity and cycle performance. In this study, LiFePO4 cathode active materials were prepared at different pH (6.5 and 8.5) and temperature (160 and 180 °C) leve...

  1. Finite-size effect of antiferromagnetic transition and electronic structure in LiFePO4

    OpenAIRE

    Shu, G. J.; Wu, M. W.; Chou, F. C.

    2012-01-01

    The finite-size effect on the antiferromagnetic (AF) transition and electronic configuration of iron has been observed in LiFePO4. Determination of the scaling behavior of the AF transition temperature (TN) versus the particle-size dimension (L) in the critical regime 1-TN(L)/TN(XTL)\\simL^-1 reveals that the activation nature of the AF ordering strongly depends on the surface energy. In addition, the effective magnetic moment that reflects the electronic configuration of iron in LiFePO4 is fo...

  2. Rising from the Dead: the Revival of the EUVE E/PO

    Science.gov (United States)

    Cullison, J. L.; Craig, N.; Stroozas, B. A.; Malina, R. F.

    2000-05-01

    NASA's Extreme Ultraviolet Explorer (EUVE) is dedicated to gathering data on our sky via instrumentation sensitive to the region of light between 76 and 760 angstroms. Since the all-sky survey was completed in 1993, astronomers have made studies of selected objects with EUVE to determine their physical properties and chemical compositions. Also, they have learned about the conditions that prevail and the processes at work in stars, planets, and other sources of EUV radiation. In its pre-launch and early prime mission, EUVE had a thriving education and public outreach (E/PO) program formed expressly to spread the word on recent EUVE findings, but due to budgetary restraints in its extended mission, the project has been unable in recent years to support extensive E/PO efforts. Now in it's eighth year of operation, the EUVE Project has revived its E/PO efforts without significantly impacting its shoe-string budget. Web sites are being reconstructed, including sophisticated interactive learning environments where elementary through college level students, teachers, and the general public can select from lesson plans including, for example, an introductory astronomical module on the relationship between spectra and object classification, download three-dimensional cutouts of the EUVE skymap, view a slide show on the history and instrumentation of the satellite, take a virtual tour of the EUVE observatory, find where EUVE is in its orbit, and catch up on EUVE's most recent news and events. EUVE's revived internet E/PO presence is supplemented with staff and technical support (up to 10% of each staff person's time) of hands-on elementary and community projects coordinated by the UC Berkeley Center for Science Education (the now independent offshoot of the original EUVE E/PO). All elements of the EUVE E/PO are supported without impacting the efficient and highly productive science goals of the small-staffed mission. Additional EUVE E/PO efforts in the works include

  3. We Need You! The Importance of Scientist Involvement in Education and Public Outreach (E/PO)

    Science.gov (United States)

    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

  4. Electrical conductivity studies of graphene wrapped nanocrystalline LiMnPO{sub 4} composite

    Energy Technology Data Exchange (ETDEWEB)

    Cheruku, Rajesh; D, Surya Bhaskaram; Govindaraj, G., E-mail: ggraj-7@yahoo.com [Department of Physics, School of Physical, Chemical and Applied Sciences, Pondicherry University, R.V. Nagar, Kalapet, Pondicherry -605 014 (India); Vijayan, Lakshmi [St. Aloysius’ College, Edathua, Alappuzha, Kerala 689 573 (India)

    2015-06-24

    Nanocrystalline LiMnPO{sub 4} material was synthesized by template free sucrose assisted hydrothermal method. The material possesses the orthorhombic crystal structure with Pnma, space group having four formula units. The GO was prepared by the hummer’s method and it was reduced graphene oxide (rGO) with hydrazine hydrate in the presence of nitrogen atmosphere. LiMnPO{sub 4} material was wrapped by the rGO to increase its conductivity. The structural characterization was accomplished through X-ray diffraction, FT-IR and Raman spectroscopy. Morphology was identified by the SEM, Electrical characterization was done through impedance spectroscopy and the results were reported.

  5. Zdravstvena nega bolnika s poškodbo hrbtenjače v ledvenem delu hrbtenice

    OpenAIRE

    Potočnik, Irena

    2011-01-01

    V diplomskem delu smo prikazali anatomijo, fiziologijo, patologijo, diagnostične metode in načine zdravljenja s poudarkom na zdravstveni negi bolnika s poškodbo hrbtenjače v ledvenem delu hrbtenice. Bolnik, ki je utrpel takšno poškodbo, potrebuje ob sebi negovalni in zdravstveni tim, ki mu bo stal ob strani, ko se bo soočal s svojo spremenjeno telesno podobo. Negovalni problemi so na področju vseh življenjskih aktivnosti, vendar jih zaradi možnosti zgodnje mobilizacije, kjer ima rehabilitacij...

  6. Vozni park Pošte Slovenije ter njegov vpliv na okolje

    OpenAIRE

    Tacer, Jerneja

    2013-01-01

    Pošta Slovenije je eno izmed podjetij, ki ima obsežen vozni park, posledično pa tudi velik vpliv na okolje. Z diplomskim delom smo želeli doprinesti k razumevanju problematike varstva okolja. Diplomsko delo je sestavljeno iz štirih delov. V teoretičnem delu smo na kratko opredelili promet oziroma transport, vpliv prometa na okolje ter vrste goriv, ki se lahko uporabljajo za pogon motornih vozil. V drugem delu smo naredili posnetek obstoječega stanja voznega parka Pošte Slovenije, opisali...

  7. TL-OSL study of Li{sub 3}PO{sub 4}: Mg, Cu phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Rahangdale, S. R., E-mail: sachin.rahangdale1@gmail.com; Wankhede, S. P. [Department of Physics, K.D.K.College of Engineering, Nagpur (India); Dhabekar, B. S. [RPAD, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Palikundwar, U. A.; Moharil, S. V. [Department of Physics, RTM Nagpur University, Nagpur, 440010 (India)

    2015-08-28

    In the present work, we report the thermoluminescence and optically stimulated luminescence properties of Mg and Cu doped Li{sub 3}PO{sub 4} phosphor. The phosphor was synthesized by precipitation method. The thermoluminescence dosimetric peak temperature for the phosphor varies with concentrations of Mg and Cu. Li{sub 3}PO{sub 4} 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.

  8. JPL Physical Oceanography Distributed Active Archive Center (PO.DAAC) data availability, version 1-94

    Science.gov (United States)

    1994-01-01

    The Physical Oceanography Distributed Active Archive Center (PO.DAAC) archive at the Jet Propulsion Laboratory (JPL) includes satellite data sets for the ocean sciences and global-change research to facilitate multidisciplinary use of satellite ocean data. Parameters include sea-surface height, surface-wind vector, sea-surface temperature, atmospheric liquid water, and integrated water vapor. The JPL PO.DAAC is an element of the Earth Observing System Data and Information System (EOSDIS) and is the United States distribution site for Ocean Topography Experiment (TOPEX)/POSEIDON data and metadata.

  9. TSL-EPR Correlation Study of LaPO4 : Ce, Tb

    OpenAIRE

    CHAKRABARTY, B. S.; Murthy, K. V. R.; JOSHI, T. R.

    2002-01-01

    Gamma irradiated TSL glow curves of laboratory made phosphor samples of LaPO4:Ce, Tb exhibited one intense peak around 408 K and two smaller peaks around 508 K and 613 K. The spectrum of the first glow peak gives spectral peaks around 480 nm and 540 nm, which can be attributed to the thermal destruction of F++ centres and PO42- radicals. The luminescense centre has been thought to be Cerium and Terbium ions. The glow peak around 413 K for UV irradiated samples has been attribute...

  10. Mitoituksen ja kaavojen luominen aloittavalle vaatetusalan yritykselle Case: PO&NY

    OpenAIRE

    Viitaniemi, Roosa

    2016-01-01

    Tämän opinnäytetyön tarkoituksena on luoda toimiva ja yhdenmukainen mitoitus aloittavalle suomalaiselle vaatetusalan yritykselle. Kiinteiden ja tuoteryhmäkohtaisten naisten sekä miesten mittataulukoiden lisäksi luon tuoteryhmäkohtaiset kaavat, joita yritys voi käyttää mallistojensa kuosittelun pohjana. Toimeksiantajayritykseni on vuonna 2015 toimintansa aloittanut PO&NY, joka on WWOOLLFF.CO:n aputoiminimi. PO&NY on Marianna Rahusen ja Jenna Vilkmanin perustama street-vaatteisiin keskitty...

  11. The influence of intruder states in even-even Po isotopes

    CERN Document Server

    Garcia-Ramos, J E

    2015-01-01

    We study the role of intruder states and shape coexistence in the even-even $^{190-206}$Po isotopes, through an interacting boson model with configuration mixing calculation. We analyzed the results in the light of known systematics on various observable in the Pb region, paying special attention to the unperturbed energy systematics and quadrupole deformation. We find that shape coexistence in the Po isotopes behaves in very much the same way as in the Pt isotopes, i.e., it is somehow hidden, contrary to the situation in the Pb and the Hg isotopes.

  12. Prirodna obnova u sastojinama alepskog bora (Pinus halepensis Mill.) nakon požara

    OpenAIRE

    Dubravac, Tomislav; Vrbek, Boris; Lalić, Zlatko

    2006-01-01

    U radu se istražuje problematika prirodne obnove opožarenih površina u sastojinama alepskog bora (Pinus halepensis Mill.) na tri trajne pokusne plohe. Rezultati se temelje na petogodišnjem sustavnom motrenju (2001.-2005.) u Šibeniku, trogodišnjem (2001.-2003.) u Splitu te dvogodišnjem (2002.-2003.) na Korčuli. Izmjerom je praćena prirodna obnova vegetacije po vrstama, brojnosti i visinskim klasama te učinci radova njege nakon požara. Istraživanja su obuhvatila pedološku obradu pokusnih plo...

  13. Analiza odziva tkiv na mehanska poškodovanja pri navadnem divjem kostanju s tridimenzionalnim magnetno resonančnim slikanjem

    OpenAIRE

    Lavk, Vanja

    2014-01-01

    Pri navadnem divjem kostanju (Aesculus hippocastanum L.) smo spremljali odziv tkiv na mehanska poškodovanja in vlažnostne spremembe. Vejice smo poškodovali tako, da smo skozi premer z baterijskim vrtalnikom zavrtali luknjo premera 3 mm. Vse vejice smo poškodovali 8. aprila 2010. Poškodovane segmente vejic smo preiskovali s pomočjo 3D MR slikanja, kar smo opravili v tedenskih intervalih. Takoj po mehanskem poškodovanju smo s 3D MR slikanjem opazili izsušitev tkiv v neposredni bližini rane. Med...

  14. Study of the solubility, viscosity and density in Na+, Zn2+/Cl− − H2O, Na+ − Zn2+ − (H2PO2)− − H2O, Na+, Cl−/(H2PO2)− − H2O, and Zn2+, Cl−/(H2PO2)− − H2O ternary systems, and in Na+, Zn2+/Cl−, (H2PO2)−//H2O reciprocal quaternary system at 273.15 K

    International Nuclear Information System (INIS)

    Highlights: • The physicochemical properties of ternary and one quaternary have been studied. • Reciprocal quaternary systems’ solubility and phase equilibrium have been studied. • In all systems the solid phases have been found. • It was found that Zn(H2PO2)2 salt contains 70% of the general crystallization field. - Abstract: The solubility and the physicochemical properties (density, viscosity) in the Na-Zn- Cl-H2O), (Na + Zn + H2PO2 + H2O), (Na + Cl + H2PO2 + H2O), and (Zn + Cl + H2PO2 + H2O) ternaries, and in Na+, Zn2+/Cl−, (H2PO2)−//H2O reciprocal quaternary systems at T = 273.15 K were investigated by using the isothermal method. The diagrams of ternary salts systems, (NaCl + ZnCl2 + H2O), (NaCl + NaH2PO2 + H2O), (NaH2PO2 + Zn(H2PO2)2 + H2O), (ZnCl2 + Zn(H2PO2)2 + H2O), are plotted in figures 1–4. However, whole ions of reciprocal quaternary salt systems are plotted in figure 5. Additionally, the density and viscosity values of ternary systems vs. their corresponding composition values in weight per cent are plotted in figures 6–10. At the (i) (ZnCl2 + Zn(H2PO2)2 + H2O), (ii) (NaCl + ZnCl2 + H2O), (iii) (NaCl + NaH2PO2 + H2O), (iv) (NaH2PO2 + Zn(H2PO2)2 + H2O) ternary systems the solid phase compositions have been determined as: (i) Zn(H2PO2)2 ⋅ H2O, Zn(H2PO2)2, ZnCl2 ⋅ 2H2O, (ii) NaCl, 2NaCl ⋅ ZnCl2 ⋅ 2H2O, and ZnCl2 ⋅ 2H2O, (iii) NaCl and NaH2PO2 ⋅ H2O, (iv) Zn(H2PO2)2 ⋅ H2O and NaH2PO2 ⋅ H2O, respectively. On the other hand reciprocal quaternary system was observed as: ZnCl2 ⋅ 2H2O, 2NaCl ⋅ ZnCl2 ⋅ 2H2O, Zn(H2PO2)2 ⋅ H2O, NaH2PO2 ⋅ H2O, NaCl. According to results, the least soluble salt was Zn(H2PO2)2. The crystallization field of this salt, being the largest in comparison with those of other salts, occupied 70% of the general crystallization field

  15. Evaluation of uncertainty and detection limits in {sup 210}Pb and {sup 210}Po measurement in water by alpha spectrometry using {sup 210}Po spontaneous deposition onto a silver disk

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Pedro L., E-mail: pedroluis.fernandez@unican.es [Department of Medical and Surgical Sciences (Medical Physics Section), Faculty of Medicine, University of Cantabria, 39011 Santander (Cantabria) (Spain); Gomez, Jose; Rodenas, Carmen [Department of Medical and Surgical Sciences (Medical Physics Section), Faculty of Medicine, University of Cantabria, 39011 Santander (Cantabria) (Spain)

    2012-04-15

    An easy and accurate method for the determination of {sup 210}Pb and {sup 210}Po in water using {sup 210}Po spontaneous deposition onto a silver disk is proposed and assessed for its detection capabilities according to the ISO Guide for the expression of uncertainty in measurement (GUM) and ISO Standard 11929-7 concerning the evaluation of the characteristic limits for ionizing radiation measurements. The method makes no assumption on the initial values of the activity concentrations of {sup 210}Pb, {sup 210}Bi and {sup 210}Po in the sample to be analyzed, and is based on the alpha spectrometric measurement of {sup 210}Po in two different aliquots: the first one measured five weeks after the sampling date to ensure radioactive equilibrium between {sup 210}Pb and {sup 210}Bi and the second after a sufficient time for the ingrowth of {sup 210}Po from {sup 210}Pb to be significant. As shown, for a recommended time interval of seven months between {sup 210}Po measurements, the applicability of the proposed method is limited to water samples with a {sup 226}Ra to {sup 210}Pb activity ratio C{sub Ra}/C{sub Pb}{<=}4, as usual in natural waters. Using sample and background counting times of 24 h and 240 h, respectively, the detection limit of the activity concentration of each radionuclide at the sampling time for a 1 L sample typically varies between 0.7 and 16 mBq L{sup -1} for {sup 210}Pb in water samples with an initial activity of {sup 210}Po in the range 0-200 mBq L{sup -1}, and between 0.6 and 8.5 mBq L{sup -1} for {sup 210}Po in water samples with an initial activity of {sup 210}Pb in the same range. - Highlights: Black-Right-Pointing-Pointer {sup 210}Pb and {sup 210}Po measurement in water by {sup 210}Po spontaneous deposition onto silver disks. Black-Right-Pointing-Pointer {sup 210}Pb and {sup 210}Po determination based on {sup 210}Po measurement in two different aliquots. Black-Right-Pointing-Pointer Evaluation of characteristic limits in radioactivity

  16. Removal of FePO{sub 4} and Fe{sub 3}(PO{sub 4}){sub 2} crystals on the surface of passive fillers in Fe{sup 0}/GAC reactor using the acclimated bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Bo, E-mail: laibo1981@163.com [Department of Environmental Science and Engineering, School of Architecture and Environment, Sichuan University, Chengdu 610065 (China); Research Center of Water Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Zhou, Yuexi [Research Center of Water Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Yang, Ping [Department of Environmental Science and Engineering, School of Architecture and Environment, Sichuan University, Chengdu 610065 (China); Wang, Juling [Research Center of Water Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Yang, Jinghui [China National Petroleum Corporation Research Institute of Safety and Environment Technology HSE Assessment Center, Beijing 100012 (China); Li, Huiqiang [Department of Environmental Science and Engineering, School of Architecture and Environment, Sichuan University, Chengdu 610065 (China)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer Fe{sub 3}(PO{sub 4}){sub 2} and FePO{sub 4} crystals would weaken treatment efficiency of Fe{sup 0}/GAC reactor. Black-Right-Pointing-Pointer Fe{sub 3}(PO{sub 4}){sub 2} and FePO{sub 4} crystals could be removed by the acclimated bacteria. Black-Right-Pointing-Pointer FeS and sulfur in the passive film would be removed by the sulfur-oxidizing bacteria. Black-Right-Pointing-Pointer Develop a cost-effective bio-regeneration technology for the passive fillers. - Abstract: As past studies presented, there is obvious defect that the fillers in the Fe{sup 0}/GAC reactor begin to be passive after about 60 d continuous running, although the complicated, toxic and refractory ABS resin wastewater can be pretreated efficiently by the Fe{sup 0}/GAC reactor. During the process, the Fe{sub 3}(PO{sub 4}){sub 2} and FePO{sub 4} crystals with high density in the passive film are formed by the reaction between PO{sub 4}{sup 3-} and Fe{sup 2+}/Fe{sup 3+}. Meanwhile, they obstruct the formation of macroscopic galvanic cells between Fe{sup 0} and GAC, which will lower the wastewater treatment efficiency of Fe{sup 0}/GAC reactor. In this study, in order to remove the Fe{sub 3}(PO{sub 4}){sub 2} and FePO{sub 4} crystals on the surface of the passive fillers, the bacteria were acclimated in the passive Fe{sup 0}/GAC reactor. According to the results, it can be concluded that the Fe{sub 3}(PO{sub 4}){sub 2} and FePO{sub 4} crystals with high density in the passive film could be decomposed or removed by the joint action between the typical propionic acid type fermentation bacteria and sulfate reducing bacteria (SRB), whereas the PO{sub 4}{sup 3-} ions from the decomposition of the Fe{sub 3}(PO{sub 4}){sub 2} and FePO{sub 4} crystals were released into aqueous solution which would be discharged from the passive Fe{sup 0}/GAC reactor. Furthermore, the remained FeS and sulfur (S) in the passive film also can be decomposed or removed easily by the

  17. {sup 210}Po and {sup 210}Pb in seals from the Baltic Sea and Lake Saimaa, Finland

    Energy Technology Data Exchange (ETDEWEB)

    Solatie, D.; Rissanen, K. [Radiation and Nuclear Safety Authority - STUK, Rovaniemi (Finland). Regional Laboratory in Northern Finland; Vesterbacka, P. [Radiation and Nuclear Safety Authority - STUK, Helsinki (Finland). Natural Radiation Laboratory

    2005-09-15

    {sup 210}Po and {sup 210}Pb are members of the {sup 238}U decay chain. {sup 210}Po is an {alpha}-emitter with a half-life of 138 days, while its grandmother, {sup 210}Pb is a {beta}-emitter with 22.3 year half-life. In the atmosphere {sup 222}Rn formats its decay products {sup 210}Po and {sup 210}Pb. These nuclides are deposited on to the surface of land and sea and thus enter the food chain. The naturally occurring radionuclides {sup 210}Po and {sup 210}Pb are important because their great contribution to radiation dose to human and other species. As top predators in the aquatic food chain, fish-eating seals are vulnerable to the accumulation of contaminants. In the Regional Laboratory in Northern Finland, measurements of {sup 210}Po and {sup 210}Pb activity concentrations in seals from the Baltic Sea and in ringed seals from Lake Saimaa have been performed. Concentrations of {sup 210}Po and {sup 210}Pb in seals were determined in muscle, liver, kidney and spleen. The results of {sup 210}Po and {sup 210}Pb activity concentrations and the ratio of {sup 210}Po / {sup 210}Pb in these samples are presented. (Summary-only contribution)

  18. An assessment of 210Pb and 210Po in terrestrial foodstuffs from regions of England and Wales

    International Nuclear Information System (INIS)

    Based on data for nationally available foodstuffs, naturally occurring 210Pb and 210Po contribute significantly to the UK radiation dose from dietary intake. To provide a more complete overview of radiological implications to the public, samples of offal, cereal, fruit, root and green vegetables were collected from 11 sites, including regions of potential 210Pb and 210Po enhancement. Considerable variability was evident in levels of 210Pb and 210Po from all sites and in all food types investigated. Higher concentrations were typically found in offal and cereals. Lowest concentrations were generally found in root vegetables. Between sites, the only evidence of elevated concentrations of 210Po occurred at Helston (210Po 3.0 Bq kg-1 in bovine liver, no other offal sample exceeding 0.8 Bq kg-1), and Holyhead 210Po 0.4 Bq kg-1 in blackberries, no other fruit sample exceeding 0.1 Bq kg-1). Other foodstuffs from these sites did not show similar enhanced levels of 210Po. The maximum dose arising from consumption of 210Pb and 210Po in foods surveyed in this study is estimated to be around 120 μSv year-1 to adults. This compares with an estimated UK average consumption dose from all nuclides and foodstuffs of 300 μSv year-1 (broad range 100-1000 μSv year-1). (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  19. Una aproximación al poema “Arte Poética” de Jorge Luis Borges

    Directory of Open Access Journals (Sweden)

    Lorena Chaves Salgado

    2013-01-01

    Full Text Available Este artículo presenta una lectura del poema 'Arte poética' de Jorge Luis Borges desarrollando aspectos teóricos relacionados con el análisis poético. El poema describe la labor del poeta y que significa escribir poesía, entendido para Borges como un acto y proceso creativo.

  20. Double Carbon Nano Coating of LiFePO4 Cathode Material for High Performance of Lithium Ion Batteries.

    Science.gov (United States)

    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. PMID:26682389

  1. Numerical Model and Analysis of Peak Temperature Reduction in LiFePO4 Battery Packs Using Phase Change Materials

    DEFF Research Database (Denmark)

    Coman, Paul Tiberiu; Veje, Christian

    2013-01-01

    Numerical model and analysis of peak temperature reduction in LiFePO4 battery packs using phase change materials......Numerical model and analysis of peak temperature reduction in LiFePO4 battery packs using phase change materials...

  2. Preparation and characterization of new cathodic materials for Li-ion battery based polypyrrole-FePO4

    International Nuclear Information System (INIS)

    To investigate the electrochemical properties and stability of our samples, we used cyclic voltammetry and electrochemical impedance spectroscopy. We found that PEG-PPy layer on the particles FePO4 considerably increased material conductivity in comparison with a layer of pure PPy. It also improved the incorporation of Li+ ions into FePO4 structure during charging and discharging. (Authors)

  3. Synthesis and tunable luminescence of RbCaGd(PO4)2:Ce3+, Mn2+ phosphors

    Science.gov (United States)

    Chen, Xue; Lv, Fengzhu; Li, Penggang; Zhang, Yihe

    2016-04-01

    RbCaGd(PO4)2 doped with Ce3+, Mn2+ was synthesized by the sol-gel method. The crystal structure and crystallographic location of Ce3+ in RbCaGd(PO4)2 were identified by Rietveld refinement. Powder X-ray diffraction (XRD) revealed that the structure of RbCaGd(PO4)2:Ce3+ compounds is hexagonal structure which is similar to that of hexagonal LnPO4 with the lattice constant of a = b = 7.005(57) Å, c = 6.352(05) Å, and V (cell volume) = 269.980 Å3. The photoluminescence behavior and emission mechanism were studied systematically by doping activators in the RbCaGd(PO4)2 host. The Mn2+ incorporated RbCaGd(PO4)2:Ce3+, Mn2+ compounds exhibited blue emission from the parity- and spin-allowed f-d transition of Ce3+ and orange-to-red emission from the forbidden 4T1 → 6A1 transition of Mn2+. The emission chromaticity coordinates of RbCaGd(PO4)2:0.10Ce3+, xMn2+ (x = 0.16, 0.25) are close to the white region due to an energy transfer process and the energy transfer mechanism from Ce3+ to Mn2+ in the RbCaGd(PO4)2 host was dominated by dipole-dipole interactions.

  4. Draft Genome Sequence of the Oleaginous Yeast Yarrowia lipolytica PO1f, a Commonly Used Metabolic Engineering Host

    OpenAIRE

    Liu, Leqian; Alper, Hal S

    2014-01-01

    The draft genome sequence of the oleaginous yeast Yarrowia lipolytica stain PO1f, a commonly used metabolic engineering host, is presented here. The approximately 20.3-Mb genome sequence of PO1f will greatly facilitate research efforts in metabolic engineering of Yarrowia lipolytica for value-added chemical production.

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

    Science.gov (United States)

    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.

  6. Improved battery performance using Pd nanoparticles synthesized on the surface of LiFePO4/C by ultrasound irradiation

    Science.gov (United States)

    Saliman, Muhammad Ali; Okawa, Hirokazu; Takai, Misaki; Ono, Yuki; Kato, Takahiro; Sugawara, Katsuyasu; Sato, Mineo

    2016-07-01

    LiFePO4 has been attracting interest as a cathode material for Li-ion batteries due to its high energy density, low cost, and eco-friendliness. The electrochemical performance of LiFePO4 is limited because it exhibits low Li-ion diffusivity and low electronic conductivity. Numerous solutions have been considered, such as carbon coating, which is widely known to improve the electronic conductivity of LiFePO4. The deposition of metal nanoparticles (NPs) on the surface of carbon-coated LiFePO4 further enhances the electronic conductivity. In this study, we deposited Pd NPs onto the surface of LiFePO4/C and investigated the resulting electrochemical performance. Sonochemical synthesis was used to prepare the metal NPs; the procedure did not require any surfactants and the reaction was rapid.

  7. Signes et traces dans l’œuvre poétique de Günter Eich

    Directory of Open Access Journals (Sweden)

    Sandie Attia

    2010-12-01

    Full Text Available Cette thèse porte sur les catégories « signe » (Zeichen et « trace » (Spur dans l’œuvre poétique et les déclarations poétologiques de Günter Eich (1907-1972. Signes naturels, linguistiques, traces biographiques et intertextuelles, relevé de stigmates historiques (Spurensicherung imprègnent l’œuvre de Eich tant sous la forme d’images poétiques que de concepts poétologiques. Complémentaires ou opposés, ils éclairent le parcours complexe du poète, du déchiffrement des signes naturels au souh...

  8. Signes et traces dans l’œuvre poétique de Günter Eich

    OpenAIRE

    Sandie Attia

    2010-01-01

    Cette thèse porte sur les catégories « signe » (Zeichen) et « trace » (Spur) dans l’œuvre poétique et les déclarations poétologiques de Günter Eich (1907-1972). Signes naturels, linguistiques, traces biographiques et intertextuelles, relevé de stigmates historiques (Spurensicherung) imprègnent l’œuvre de Eich tant sous la forme d’images poétiques que de concepts poétologiques. Complémentaires ou opposés, ils éclairent le parcours complexe du poète, du déchiffrement des signes naturels au souh...

  9. Glass implanted 210Po as a method of determination of long term exposure to radon: First experiments in Israel

    International Nuclear Information System (INIS)

    Radon gas (222Rn) is known to be the major contributor of the total exposure of the population to ionizing radiation. Retrospective assessment techniques have been developed to estimate long term exposures to (222Rn and its progeny in epidemiological studies. Measurements of implanted 210Po on glass panes surfaces characterize room radon concentration or habitant characterization.Various methods for retrospective radon measurement are described in the literature. The surface trap method is based on the 210Po implanted on glass or other vitreous objects, measured using solid-state nuclear track detectors (SSNTD). The volume trap method is based on measurements of 210Po in spongy, porous materials (210Po volume traps). Other approach is in-vivo measurements of 210Pb in the human skeleton. The present study uses the surface trap retrospective technique for the first time in Israel, coupled with an approach to estimate the 210Po concentration in glasses exposed to 222Rn using alpha spectrometry

  10. Electrochemical performance of C-La3+ codoped LiFePO4 synthesized by microwave heating

    Institute of Scientific and Technical Information of China (English)

    CUI Yan; WANG Miao; GUO Ruisong; XU Zhaohe

    2009-01-01

    La3+ was selected to elevate the lattice electronic conductivity of LiFePO4, and LiFePO4/(C+La3+) cathode powders were synthesized by microwave heating using a domestic microwave oven for 35 min. The microstructures and morphologies of the synthesized materials were investigated by XRD and SEM. The electrochemical performances were evaluated by galvanostatic charge-discharge. The electrochemical performance of LiFePO4 with different La3+ contents was studied. Results indicated that the initial specific discharge capacity of LiFePO4/(C+La3+) composites with 2% La3+(116.3 mAh/g) was better than that of LiFePO4/C (105.4 mAh/g). The addition of La3+ further improved the electrochemical properties. So the codoping is an effective method to improve the electrochemical performance.

  11. Structural and Electrical Properties of Lithium-Ion Rechargeable Battery Using the LiFePO4/Carbon Cathode Material.

    Science.gov (United States)

    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. PMID:26413683

  12. Tunable luminescence properties and efficient energy transfer in Eu2+, Tb3+ co-doped NaBaPO4

    Directory of Open Access Journals (Sweden)

    Qiuhong Zhang

    2014-01-01

    Full Text Available Eu2 + and Tb3+ singly doped and co-doped NaBaPO4 phosphors were synthesized by solid state reaction. The structure character, photoluminescence properties and the lifetime were investigated. The emission spectra of NaBaPO4:Eu2+, Tb3+, Na+ phosphor show both broad blue emission band and sharp green emission peaks. The energy transfer mechanism from Eu2+ to Tb3+ in NaBaPO4 host was discussed. The excitation spectra of NaBaPO4: Eu2+, Tb3+, Na+ phosphor show broad excitation band in the 250–400 nm range, which was in agreement with the near-ultraviolet (n-UV chip. The hue of the NaBaPO4: Eu2+, Tb3+, Na+ phosphors could be appropriately tuned by adjusting the contents of activators.

  13. Hypoxic Prostate/Muscle PO2 Ratio Predicts for Outcome in Patients With Localized Prostate Cancer: Long-Term Results

    International Nuclear Information System (INIS)

    Purpose: To correlate tumor oxygenation status with long-term biochemical outcome after prostate brachytherapy. Methods and Materials: Custom-made Eppendorf PO2 microelectrodes were used to obtain PO2 measurements from the prostate (P), focused on positive biopsy locations, and normal muscle tissue (M), as a control. A total of 11,516 measurements were obtained in 57 men with localized prostate cancer immediately before prostate brachytherapy was given. The Eppendorf histograms provided the median PO2, mean PO2, and % 2 ratio on BF. Results: With a median follow-up time of 8 years, 12 men had ASTRO BF and 8 had Phoenix BF. On multivariate analysis, P/M PO2 ratio 2 ratio 2 ratio) significantly predicts for poor long-term biochemical outcome, suggesting that novel hypoxic strategies should be investigated.

  14. A study on accumulation of 210Po in Ayurvedic medicinal plants in the environment of Mangalore, Southwest Coast of India

    International Nuclear Information System (INIS)

    Systematic studies on the accumulation of 210Po in twelve medicinal plants and activity concentration in associated soils have been carried out. The activity of 210Po was measured using ZnS (Ag) alpha counting system. The mean 210Po activity concentration was found to be 27.8 Bq kg-1 and 8.3 Bq kg-1 for plant and soil respectively. The plant to soil mean activity ratio of 210Po was found to be 3.8. A good correlation was observed between the activity concentration of 210Po in plant and soil. The absorbed gamma dose rates in the study are measured using portable scintillometer varies in the range 34.8 nGy h-1 - 52.2 nGy h-1 with a mean value of 43.5 nGy h-1. The results of these systematic investigations are presented and discussed. (author)

  15. Experimental and theoretical studies on the linear and nonlinear optical properties of lead phosphate crystals LiPbPO4.

    Science.gov (United States)

    Han, Guopeng; Liu, Qiong; Wang, Ying; Su, Xin; Yang, Zhihua; Pan, Shilie

    2016-07-28

    Phosphates with noncentrosymmetric (NCS) structures usually display short ultraviolet (UV) cut-off edges, but often exhibit weak powder second harmonic generation (SHG) intensities. Here we synthesized a NCS-phosphate, LiPbPO4, that achieves a desired balance between UV transparency, a cut-off edge of about 232 nm, and large SHG activity (about 3 × KDP). The three dimensional (3D) framework of LiPbPO4 consists of PO4 and LiO4 tetrahedra that are corner-shared, forming wide channels where lead cations reside. Local dipole moments for the PO4 and LiO4 tetrahedra as well as lead polyhedra in a unit cell were calculated. First-principles calculations have been performed for better understanding the structure-property relationships in LiPbPO4. In addition, to further explore spatial distribution of the electronic states dominating the NLO activity, the SHG density method was employed. PMID:27357234

  16. Three-dimensional seismo-tectonics in the Po Valley basin, Northern Italy

    NARCIS (Netherlands)

    Turrini, Claudio; Angeloni, Pamela; Lacombe, Olivier; Ponton, Maurizio; Roure, François

    2015-01-01

    The Po Valley (Northern Italy) is a composite foreland-foredeep basin caught in between the Southern Alps and Northern Apennine mountain belts. By integrating the 3D structural model of the region with the public earthquake dataset, the seismo-tectonics of the basin is shown at different scales of o

  17. Attracting applicants on the web: PO fit, industry culture stereotypes, and website design

    NARCIS (Netherlands)

    M.E.E. de Goede; A.E.M. van Vianen; U.-C. Klehe

    2011-01-01

    This study tested the extent to which industry culture stereotypes influence job-seekers' Person-Organization fit when job-seekers inspect organizations' websites. We proposed that PO fit would relate to Person-Industry (PI) fit, which is the fit between personal values and industry culture stereoty

  18. Specifika architektury hronovsko-poříčského zlomu

    Czech Academy of Sciences Publication Activity Database

    Prouza, V.; Coubal, Miroslav; Adamovič, Jiří

    2015-01-01

    Roč. 2014, č. 1 (2015), s. 13-18. ISSN 0514-8057 Institutional support: RVO:67985831 Keywords : fault architecture * fault core * damage zone * drag zone * Hronov-Poříčí Fault Subject RIV: DB - Geology ; Mineralogy

  19. The Aalborg University PO-PBL Model from a Socio-cultural Learning Perspective

    DEFF Research Database (Denmark)

    Hernández, Carola Hernández; Ravn, Ole; Valero, Paola

    2015-01-01

    Since the 1970’s, Aalborg University has been developing a new pedagogical model in higher education: The Project Oriented – Problem Based Learning (PO-PBL). In particular, the Faculty of Engineering and Science has developed a pedagogical proposal that introduces students to a different type of...

  20. The Aalborg University PO-PBL Model from a Socio-Cultural Learning Perspective

    Science.gov (United States)

    Hernandez, Carola; Ravn, Ole; Valero, Paola

    2015-01-01

    Since the 1970s, Aalborg University has been developing a new pedagogical model in higher education: The Project Oriented-Problem Based Learning (PO-PBL). In particular, the Faculty of Engineering and Science has developed a pedagogical proposal that introduces students to a different type of learning. One of the theoretical frameworks…

  1. 226Ra, 210Pb and 210Po in food and in population in Poland

    International Nuclear Information System (INIS)

    Content of 226Ra, 210Pb and 210Po was determined in daily diet, foodstuffs and drinking water in various regions in Poland. The annual intake of the radionuclides with foodstuffs for an adult population was estimated on the basis of the average annual consumption. The 226Ra intake was in all the places similar; variations between the samples from a locality were bigger than the differences between various localities. Slightly higher 226Ra intake was observed in Suwalki, evidently being associated with the higher concentration of this radionuclide in the soil. The average 210Po/210Pb ratios was below and close to unity in the daily diet of continental regions, whereas at the Baltic Sea coast it was about 1.5. The latter value can be ascribed to a larger consumption of fish for which the 210Po/210Pb ratio was close to 10. The calculated body burden for an adult man was 1.6 Bq for 226Ra, 6.8 Bq for210Pb and 6.8 Bq for 210Po. (author)

  2. Alpha-Decay of $^{211}Po$ on the 1633 keV $^{207}Pb$ level

    CERN Document Server

    Chumin, V G; Malikov, Sh R; Norseev, Yu V; Samatov, Z K; Fominykh, V I; Cherevatenko, A P; Yurkova, L V

    2000-01-01

    In investigations of gamma-spectrum of ^{211}At and daughter ^{211}Po and ^{207}Bi isotopes a new branch of the alpha-decay on the ^{207}Pb 1633 keV level is discovered. Its intensity is 8.1 cdot 10^{-4} %.

  3. Fluorescence spectra and energy levels of Terbium (4f8) in TbPO4

    International Nuclear Information System (INIS)

    The optical emission and excitation spectra of Tb3+ in TbPO4 at different temperatures lead to an energy level scheme for the Stark components of the 7F6, 7F5 and 5D4 manifolds. An antistokes radiation from 5D3 is observed which confirms the ground state splitting

  4. Kretanje Pb-210 i Po-210 u prehrambenom lancu krava-mlijeko-sir

    OpenAIRE

    Milošević, Zdravko; Horšić, Emilija; Kljaić, Ranko; Bauman, Alice

    1980-01-01

    Kretanje prirodnih radionuklida iz niza urana u prehrambenom lancu nedovoljno je ispitano uopće, a kod nas gotovo nije niti načeto. Ispitivanja su vršena na teritoriji BiH, kako bi se moglo predvidjeti kretanje Pb-210 i Po-210 u prehrambenom lancu na područjima s povišenim prirodnim fonom.

  5. Technologically enhanced 210Pb and 210Po in iron and steel industry

    International Nuclear Information System (INIS)

    Iron and steel manufacture has been ranked as the largest industrial source of environmental contamination in the USA; the wastes generated in their production processes contain heavy elements that can be a source of contamination, and natural radionuclides that can produce an occupational and/or public radiological impact. In this work the potential occupational effective dose rate (μSv/y) due to inhalation in four integrated steel-making factories from Egypt has been evaluated, by assuming a well defined scenario and with basis in the 210Pb and 210Po activity concentrations determined in ore and wastes collected in the aforementioned factories. Activity concentrations, in Bq/kg, of 210Pb and 210Po, and leachable Pb and Fe were measured using gamma-ray spectrometry based on HPGe detector, alpha particle spectrometry based on PIPS detector, and inductively coupled plasma-mass spectrometry (ICP-MS). Levels of 210Pb and 210Po in the range of 210Pb and 210Po radionuclides. → Both radionuclides are enriched through the thermal processes. → For radiation dose assessment inhalation would be the main route of exposure.

  6. Distribution of 210Pb and 210Po in boreal forest soil

    International Nuclear Information System (INIS)

    Vertical distribution and activity contents of 210Pb and 210Po were investigated in forest soils of Scots pine-dominated (Pinus sylvestris L.) stands from seven different locations in Finland. The mean total inventory in the soil profile, up to 20 cm, of 210Pb was 4.0 kBq m-2 (range 3.1-5.0 kBq m-2) and 210Po 5.5 kBq m-2 (range 4.0-7.4 kBq m-2), the organic soil layer containing 45% of the total inventory of both nuclides. In both the organic and the mineral layers the 210Po/210Pb ratio was close to unity indicating a radioactive equilibrium between them. In the litter layer there was, however, a clear excess of 210Po suggesting that polonium is recycled via root uptake from the root zone to the ground surface. The activity concentration (Bq kg-1) of 210Pb clearly correlated with organic matter and the Fe, Al and Mn concentrations in soil indicating that radioactive lead is associated both with humic substances and the oxides of iron, aluminium and manganese. Radioactive lead was also seen to follow the behavior of stable lead. No systematic correlation between polonium and soil properties was seen.

  7. Availability of Po-210 present in phosphogypsum used in agriculture: precision and accuracy of the methodology

    Energy Technology Data Exchange (ETDEWEB)

    Groppo, Guilherme H.; Mazzilli, Barbara P.; Saueia, Catia H.R., E-mail: g.groppo@ipen.br, E-mail: mazzilli@ipen.br, E-mail: chsaueia@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Phosphogypsum (PG) is a NORM residue of the phosphate fertilizer industry, and is stored in stacks at a rate of 5.5 x 10{sup 6} tons annually. In Brazil, PG has been used for many years as a soil conditioner. The Brazilian regulatory agency has established a limit of 1000 Bq kg{sup -1} for Ra-226 and Ra-228 and below this limit its use in agriculture is exempted of regulatory control. This study aims to determine the availability of the radionuclide Po-210 in the use of PG in agriculture as a soil conditioner. The Po-210 was purified and concentrated using a Sr-Spec resin. The final activity concentration was determined by spontaneous deposition of Po-210 in a silver disk and measurement by alpha spectrometry. The accuracy and precision of the methodology was checked by using a standard reference material provided by International Atomic Energy Agency, IAEA 385 - Irish Sea Sediment, and a Po-210 standard solution provided by Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ. The precision and accuracy achieved varied from 2.2% to 7.6% and from 1.5% to 17.5%, respectively. (author)

  8. Metabolic balances of 210Pb and 210Po at natural levels

    International Nuclear Information System (INIS)

    Metabolic balances of 210Po and 210Pb were determined under strictly controlled dietary conditions in adult males. The intakes of the two nuclides were due to the dietary contents of these radioisotopes, inhalation from the atmosphere, and smoking of cigarettes. No additional radioisotope was given. The mean dietary intake of 210Pb was 1.25 pCi/day and of 210Po, 1.63 pCi/day. The major pathway of excretion of both nuclides is via the gastrointestinal tract; the urinary excretion is much lower. The total excretions of 210Pb and 210Po were greater than the dietary intake and the overall balances were -0.28 and -0.16 pCi/day for the two nuclides, respectively, during a low calcium intake. The 210Pb balances did not change significantly when the calcium intake was increased 7- to 10-fold except for one patient in whom the balance became more negative. The 210Po balance was more negative during calcium intakes of 800 and 2200 mg than during a low calcium intake of 200 mg/day. The urinary and fecal excretions of the two radionuclides were not affected by the intake of sodium fluoride, while the diuretic compound, Hydrodiuril, appeared to decrease the fecal 210Pb excretion

  9. Controllable synthesis and photoluminescence of LaPO4:Eu3+ nanomaterials

    International Nuclear Information System (INIS)

    Hexagonal LaPO4.nH2O:Eu3+ nano-wires and dual-phase LaPO4:Eu3+ nano-wires with hexagonal and monoclinic structures were synthesized by hydrothermal reaction at 150 and 220 deg. C, respectively. The effects of high temperature treatment on the structure, morphology and photoluminescence of the specimens were also investigated with X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and fluorescence spectrophotometer (FL). The results indicated the phase transformation for LaPO4:Eu3+ from the hexagonal structure to the monoclinic structure occurred, after the specimens were calcined at 900 deg. C for 12 h in the air. The wire-like structures of LaPO4:Eu3+ were destroyed and transformed into particle-like structures at high temperature. The mechanism of transformation from nano-wires to particles was introduced briefly. The photoluminescence properties of as-prepared and annealed specimens were also discussed in detail.

  10. Preassembly-driven ratiometric sensing of H2PO4(-) anions in organic and aqueous environments.

    Science.gov (United States)

    Gong, Wei-tao; Na, Duo; Fang, Le; Mehdi, Hassan; Ning, Gui-ling

    2015-02-21

    Gemini surfactant-like receptor is designed and synthesized. The special preassembly phenomenon of in a nonpolar solvent facilitates the novel ratiometric fluorescence sensing of H2PO4(-)via an anion-induced reassembly process in organic solvents and an anion-induced disassembly process in water. PMID:25563510

  11. 210Po, 40K activity concentrations in bivalves collected along the Southern Coastal from Spain

    International Nuclear Information System (INIS)

    The levels of 210Po and 40K were determined in several species of bivalves growing along the coast of the region of Andalusia (southern Spain) during 2005. A network sampling of 30 points was designed and the 5 species more consumed were selected, in order to obtain the base line (background) of these species. Once the bivalve samples were lyophilized, the natural radionuclides were measured by both alpha-particle spectrometry (210Po) and gamma spectrometry (40K), being 40K the only one radionuclide detected by gamma spectrometry. Several variables like type of water (Atlantic Ocean vs Mediterranean Sea), bivalve specie, percentage of water (dry weight/wet weight relation), and the geographical distribution have been studied in relation to activity concentrations of natural radionuclides. The values of the activity concentrations between the different species and the origin of waters (atlantics or mediterranean) were not statistically significant. The activity concentrations of 210Po varied between 85 ± 4 Bq kg-1 (d.w., dry weight) and 648 ± 22 Bq kg-1 (d.w.) (Average = 250 ± 121 Bq kg-1), while 40K activity concentrations ranged from 357 ± 28 to 817 ± 48 Bq kg-1 (d.w.) (Average = 522 ± 114 Bq kg-1). On the other hand, and due to the high consume rates of bivalves in the coastal populations, the dosimetric implications of the 210Po activity concentrations found in the study have been also evaluated. (author)

  12. Dosimetry of 210Po in humans, caribou, and wolves in northern Canada

    International Nuclear Information System (INIS)

    Effective doses from 210Po 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 210Po 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 210Po. Baker Lake and Alaskan effective doses were similar at 0.4 mSv y-1 and slightly higher than Snowdrift doses (0.3 mSv y-1). Alaskan tissue activities indicated higher effective doses to liver, bone surfaces and red marrow and lower doses to spleen than the 210Po 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-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- from all sources. 51 refs., 2 figs., 9 tabs

  13. Anisotropy of ionic conductivity in Li3Fe2(PO4)3 single crystals

    International Nuclear Information System (INIS)

    Peculiarities of behaviour of σ conductivity in monocrystals of Li3Fe2(PO4)3 superionic conductor are considered. Anomalies of ionic electric conductivity are observed at different temperatures when measuring σ along different crystallographic directions. The maximal σ value is observed along b axis. Possible reasons of observed effects are discussed

  14. Types d'êtres discursifs dans la ScaPoLine

    DEFF Research Database (Denmark)

    Nølke, Henning

    2009-01-01

    Artiklen præsenterer en teoretisk og empirisk undersøgelse af diskursindividdernes  (DI) natur i et forsøg på bedre at forstå hvilken rolle de spiller i den konkrete tolkning af teksters polyfoni. DI er et centralt element i Den Skandinaviske Polyfoniteori (ScaPoLine). Først introduceres den...

  15. Temperature Dependence of Aliovalent-vanadium Doping in LiFePO4 Cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Katharine L [University of Texas at Austin; Bridges, Craig A [ORNL; Paranthaman, Mariappan Parans [ORNL; Idrobo Tapia, Juan C [ORNL; Manthiram, Arumugam [University of Texas at Austin; Goodenough, J. B. [University of Texas at Austin; Segre, C [Illinois Institute of Technology; Katsoudas, John [Illinois Institute of Technology; Maroni, V. A. [Argonne National Laboratory (ANL)

    2013-01-01

    Vanadium-doped olivine LiFePO4 cathode materials have been synthesized by a novel low-temperature microwave-assisted solvothermal (MW-ST) method at 300 oC. Based on chemical and powder neutron/X-ray diffraction analysis, the compositions of the synthesized materials were found to be LiFe1-3x/2Vx x/2PO4 (0 x 0.2) with the presence of a small number of lithium vacancies charge-compensated by V4+, not Fe3+, leading to an average oxidation state of ~ 3.2+ for vanadium. Heating the pristine 15 % V-doped sample in inert or reducing atmospheres led to a loss of vanadium from the olivine lattice with the concomitant formation of a Li3V2(PO4)3 impurity phase; after phase segregation, a partially V-doped olivine phase remained. For comparison, V-doped samples were also synthesized by conventional ball milling and heating, but only ~ 10 % V could be accommodated in the olivine lattice in agreement with previous studies. The higher degree of doping realized with the MW-ST samples demonstrates the temperature dependence of the aliovalent-vanadium doping in LiFePO4.

  16. Diffusion and possible freezing phases of Li-ions in LiFePO4

    Science.gov (United States)

    Yiu, Yuen; Toft-Petersen, Rasmus; Ehlers, Georg; Vaknin, David

    Elastic and inelastic neutron scattering studies of LiFePO4 single crystal reveal new Li-ion diffusion properties relevant to its function as Li-battery materials. In the past decade there has been broad interest in LiFePO4 and its related compounds, largely due to the applications of these materials as cathodes in Li- batteries. This is owing to these materials' high charge-discharge ability and conductivity, both of which are by virtue of the Li-ions' high mobility. In this talk, we present our findings on the temperature and directional dependence of Li-ions' diffusion in LiFePO4. LiFePO4 adopts the olivine structure at room temperature (Space group: Pnma), which contains channels along principal crystalline directions that allow Li-ion motion. Elastic neutron scattering reveals lowering of symmetry from the Pnma structure below room temperature, which can be interpreted as the freezing of Li-ions, and can be subsequently linked to the reported decrease in Li-ion conductivity. Inelastic neutron scattering, in the 35K to 720K temperature range, shows temperature dependence, as well as anisotropy (i.e. along 0K0 versus 00L) of Li-ion diffusion. Ames Laboratory is supported by U.S. DOE, BES, DMSE, under Contract #DE-AC02-07CH11358. Spallation Neutron Source of Oak Ridge National Laboratory is sponsored by U.S. DOE, BES, SUFD.

  17. LiFePO4/polymer/natural graphite: low cost Li-ion batteries

    International Nuclear Information System (INIS)

    The aging and performance of natural graphite/PEO-based gel electrolyte/LiFePO4 cells are reported. The gel polymer electrolytes were produced by electron-beam irradiation and then soaked in a liquid electrolyte. The natural graphite anode in gel electrolyte containing LiBF4-EC/GBL exhibited high reversible capacity (345 mAh/g) and high coulombic efficiency (91%). The LiFePO4 cathode in the same gel-polymer exhibited a reversible capacity of 160 mAh/g and 93% coulombic efficiency. Better performance was obtained at high-rate discharge with 6% carbon additive in the cathode, however the graphite anode performance suffers at high rate. The Li-ion gel polymer battery shows a capacity fade of 13% after 180 cycles and has poor performance at low temperature due to low diffusion of the lithium to the graphite in the GBL system. The LiFePO4/gel/Li system has an excellent rate capacity. LiFePO4 cathode material is suitable for HEV application

  18. Contamination problems from glass beaker inner surface in low level Po-210 analysis

    Czech Academy of Sciences Publication Activity Database

    Kameník, Jan; Hölgye, Z.

    2010-01-01

    Roč. 283, č. 2 (2010), s. 493-495. ISSN 0236-5731 Institutional research plan: CEZ:AV0Z10480505 Keywords : Po-210 * Low-level analysis * Contamination Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.777, year: 2010

  19. Molecular structure of (AgPO3)1-x (AgI)x glasses

    Science.gov (United States)

    Novita, D.

    2005-03-01

    Melt-quenched AgPO3 glasses were synthesized by dry ( Ag3PO4 + P2O5, prep. 1) and wet (NH4H2PO4 + AgNO3, prep. 2) routes. Glass transitions were examined in MDSC at a scan rate of 3^oC/min. Prep. 1 samples display bimodal glass transition temperatures, with Tg^low = 220^oC and Tg^high = 238^oC and with the Tg^low endotherm higher in strength than the Tg^high one. In contrast, prep. 2 samples show a single Tg = 203^oC that is significantly lower in temperature. These results are consistent with the notion that prep. 2 probably yields samples with bonded water while prep 1 gives pure AgPO3 glasses that are intrinsically phase separated. The nature of the two phases in the latter is less obvious at present, but we note that upon alloying AgI, the additive selectively bonds in the Tg^low phase at low x (0.20) a major structural reorganization occurs, and we observe the opening of a reversibility window in the 0.22 0.37 as floppy. A percolation threshold for electrical conduction occurs^1 near x ˜ 0.3 and falls in the reversibility window as expected. 1. M. Mangion and G.P. Johari, Phys. Rev. B36, 8845 (1987) Supported by NSF grant DMR 04-56472

  20. Floating Zone Growth of LiFePO_4 Single Crystals

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    During the past few years the search for cathode materials of rechargeable lithium batteries has been mainly focused on lithium metal oxides. Among them, lithium iron phosphate, LiFePO4, provides an attractive voltage of 3.5 V, high theoretical capacity

  1. Phosphorus-bearing molecules in solar-type star forming regions: First PO detection.

    Science.gov (United States)

    Lefloch, Bertrand; Vastel, C.; Viti, S.; Jimenez-Serra, I.; Codella, C.; Podio, L.; Ceccarelli, C.; Mendoza, E.; Lepine, J. R. D.; Bachiller, R.

    2016-08-01

    As part of the Large Program ASAI (Astrochemical Surveys At IRAM), we have used the IRAM 30m telescope to lead a systematic search for the emission of rotational transitions of P-bearing species between 80 and 350 GHz towards L1157-B1, a shock position in the solar-type star forming region L1157. We report the detection of several transitions of PN and, for the first time, of prebiotic molecule PO. None of these species are detected towards the driving protostar of the outflow L1157-mm. Analysis of the line profiles shows that PN arises from the outflow cavity, where SiO, a strong shock tracer, is produced. Radiative transfer analysis yields an abundance of 2.5 × 10-9 and 0.9 × 10-9 for PO and PN, respectively. These results imply a strong depletion (≈100) of Phosphorus in the quiescent cloud gas. Shock modelling shows that atomic N plays a major role in the chemistry of PO and PN. The relative abundance of PO and PN brings constraints both on the duration of the pre-shock phase, which has to be ˜ 106 yr, and on the shock parameters. The maximum temperature in the shock has to be larger than 4000 K, which implies a shock velocity of 40 km s-1.

  2. Phosphorus-bearing molecules in solar-type star forming regions: First PO detection

    CERN Document Server

    Lefloch, B; Viti, S; Jimenez-Serra, I; Codella, C; Podio, L; Ceccarelli, C; Mendoza, E; Lepine, J R D; Bachiller, R

    2016-01-01

    As part of the Large Program ASAI (Astrochemical Surveys At IRAM), we have used the IRAM 30m telescope to lead a systematic search for the emission of rotational transitions of P-bearing species between 80 and 350 GHz towards L1157-B1, a shock position in the solar-type star forming region L1157. We report the detection of several transitions of PN and, for the first time, of prebiotic molecule PO. None of these species are detected towards the driving protostar of the outflow L1157-mm. Analysis of the line profiles shows that PN arises from the outflow cavity, where SiO, a strong shock tracer, is produced. Radiative transfer analysis yields an abundance of 2.5e-9 and 0.9e-9 for PO and PN, respectively. These results imply a strong depletion (approx 100) of Phosphorus in the quiescent cloud gas. Shock modelling shows that atomic N plays a major role in the chemistry of PO and PN. The relative abundance of PO and PN brings constraints both on the duration of the pre-shock phase, which has to be about 1 Myr, an...

  3. Efektivní výpočet osvětlení

    OpenAIRE

    Kubovčík, Tomáš

    2014-01-01

    Tato práce se zabývá efektivním výpočtem osvětlení v grafických scénách s velkým počtem světel. Představeny budou základní techniky výpočtu osvětlení i pokročilé techniky, které jsou z nich odvozeny. Těžištěm práce je zejména technika tiled shading a její optimalizace popsané v teoretické i praktické části. Závěr práce se zaměřuje na experimenty prováděné na těchto technikách zachycující jejich přínos v efektivitě a rychlosti výpočtů osvětlení jakož i implementačním podrobnostem některých důl...

  4. Hair and feathers as indicator of internal contamination of 210Po and 210Pb

    International Nuclear Information System (INIS)

    The activities of the NKS-B HAIRPOL project is summarised in this report. The objective was to investigate if hair and feathers were suitable matrices for the estimation of the intake of 210Po. Human hair from people of different sex and age was analysed for 210Po showing concentrations between 0.4 to 11 Bq/kg dry weight. Samples from horses, mane, fur and tail showed concentration from 6 to 17 Bq/kg with no significant difference between the different sample types. Musk ox from Greenland showed much higher concentrations since the animal has to graze a large surface. In fur the concentration was 260 Bq/kg. A considerable fraction of the total 210Po in this animal is contained in the hair. Also different organs were analysed and the highest concentration was found in kidney, 2 700 Bq/kg. The 210Pb concentration in hair was estimated to about 20 Bq/kg. Three different seabirds from Svalbard were analysed. Feathers from all three seabird species show increasing activity concentrations of 210Po and 210Pb from the base to the tip of the feather, but it was difficult to relate feather concentrations to muscle concentrations due to a number of complicating factors. (author)

  5. Near-infrared Downconversion in LuPO4: Tm3+, Yb3+ Phosphors.

    Science.gov (United States)

    Li, Li; Wang, Yongjie; Shen, Jun; Chang, Wenxuan; Jin, Tianting; Wei, Xiantao; Tian, Ya

    2016-04-01

    Tm3+ and Yb3+ codoped LuPO4 phosphors were synthesized by the reverse-strike co-precipitation method. The obtained LuPO4:Tm3+,Yb3+ phosphors were characterized by X-ray diffraction (XRD), diffuse reflectance spectra, photoluminescence (PL) spectra, and decay lifetime to understand the observed near-infrared downconversion (DC) phenomena. The XRD results show that all the prepared phosphors can be readily indexed to the pure tetragonal phase of LuPO4 and exhibit good crystallinity. The experimental results showed that the strong visible emission around 649 nm from Tm3+(1G4 --> 3F4) and near-infrared (NIR) emission around 1003 nm from Yb3+(2F5/2 --> 2F7/2) of LuPO4:Tm3+,Yb3+ phosphors were observed under 468 nm excitation, respectively. The Yb3+ concentration dependence of luminescent properties and lifetimes of both the visible and NIR emissions have also been investigated. The quenching concentration of Yb3+ ions approaches 30 mol%. The DC mechanism is also discussed in detail. PMID:27451658

  6. Evaluation of 210Pb and 210Po in cigarette tobacco produced in Brazil

    International Nuclear Information System (INIS)

    Cigarette smoking is one of the pathways that might contribute significantly to the increase in the radiation dose reaching man, due to the relatively large concentrations of 210Pb and 210Po found in tobacco leaves. In the present study, the concentrations of these two radionuclides were determined in eight of the most frequently sold cigarette brands produced in Brazil. 210Pb was determined by counting the beta activity of 210Bi with a gas flow proportional detector after radiochemical separation and precipitation of PbCrO4. 210Po was determined by alpha spectrometry using a surface barrier detector after radiochemical separation and spontaneous deposition of Po on a copper disk. The results showed concentrations ranging from 11.9 to 30.2 mBq per gram of dry tobacco for 210Pb and from 10.9 to 27.4 mBq per gram of dry tobacco for 210Po. The collective committed effective dose resulting from the use of cigarettes produced in Brazil per year is estimated to be 1.5x104 man-Sv

  7. The effect of pressure on vibrational modes in Li3PO4

    International Nuclear Information System (INIS)

    We have studied the effect of pressure on the stretching and bending modes of (PO4)3- molecular groups in undoped Li3PO4 and (MnO4)3- groups in Mn5+-doped Li3PO4 using Raman spectroscopy and luminescence. The high-pressure Raman spectroscopy study confirmed an irreversible phase transition from the high-temperature phase to the low-temperature phase, observed in our previous high-pressure luminescence study (Riedener T, Shen Y R, Smith R J and Bray K L 2000 Chem. Phys. Lett. 321 445) and further characterized the rate and irreversibility of the phase transition. We observed and analysed vibronic transitions occurring in the 1E emission of Mn5+ in both phases. A stronger vibronic transition associated with the bending mode is interpreted in terms of an Exe Jahn-Teller coupling. Bulk and local compressibilities were predicted from variations of the energies of the (PO4)3- and (MnO4)3- stretching modes with pressure. (author)

  8. Confirmation of 20% error in the 209Po half-life

    International Nuclear Information System (INIS)

    First results of a half-life measurement of 209Po show 20% discrepancy with the formerly recommended value of 102 (5) years, which was based on a single experiment performed in 1956. After one year of measurement, a statistical uncertainty on T1/2 of 3.5% has been reached and effects of long-term instability are assumed to be less than 5%. The preliminary half-life value obtained in this work, 120 (6) years, supports the newly determined value of 125.2 (33) years by Collé et al. (2014). The 20% error in the half-life has an impact on numerous measurements in which aged 209Po solutions were used as a tracer. - Highlights: • Measured half-life of 209Po is 120 (6) a. • The formerly recommended value was in error by 20%. • Measurement results using 209Po as a tracer are affected. • The error persisted for half a century

  9. Paralelizace výpočtů pro zpracování obrazu

    OpenAIRE

    Fuksa, Tomáš

    2011-01-01

    Tato práce se zabývá problematikou paralelních výpočtů na moderních procesorech, ať už se jedná o vícejádrová CPU nebo grafické karty. Cílem práce je seznámit se s výpočetními prostředky vhodnými pro paralelizaci výpočtů na PC, definovat jejich výhody, nevýhody, otestovat jejich vlastnosti na příkladech a zvolit vhodné nástroje pro realizaci knihovny pro paralelní zpracování obrazu. Tato knihovna má urychlit výpočty potřebné k nalezení úběžníku v obraze cesty snímaném mobilním robotem....

  10. First detections of the key prebiotic molecule PO in star-forming regions

    CERN Document Server

    Rivilla, V M; Beltrán, M T; Vasyunin, A; Caselli, P; Martín-Pintado, J; Cesaroni, R

    2016-01-01

    Phosphorus is a crucial element in biochemistry, especially the P-O bond, which is key for the formation of the backbone of the deoxyribonucleic acid. So far, PO has only been detected towards the envelope of evolved stars, and never towards star-forming regions. We report the first detection of PO towards two massive star-forming regions, W51 e1/e2 and W3(OH), using data from the IRAM 30m telescope. PN has also been detected towards the two regions. The abundance ratio PO/PN is 1.8 and 3 for W51 and W3(OH), respectively. Our chemical model indicates that the two molecules are chemically related and are formed via gas-phase ion-molecule and neutral-neutral reactions during the cold collapse. The molecules freeze out onto grains at the end of the collapse and desorb during the warm-up phase once the temperature reaches 35 K. Similar abundances of the two species are expected during a period of 5x10^{4} yr at the early stages of the warm-up phase, when the temperature is in the range 35-90 K. The observed molec...

  11. The Cham's First Highland Sovereign: Po Romé (r. 1627-1651

    Directory of Open Access Journals (Sweden)

    William Noseworthy

    2013-12-01

    Full Text Available From 1627 to 1651, a member of the highland Austronesian Churu peoples, Po Romé, ruled over the lowland Austronesian Cham peoples' kingdom of Panduranga (now Khánh Hòa, Bình Thuận, andNinh Thuận provinces in Việt Nam. Po Romé has been referred to as the 'Charlemagne' of Cham studies (Bruckmayr, 2013, indicative of his importance in larger understandings of the Cham and their role in Southeast Asian history. The Cham have generally been understood as a lowland people who brought highland peoples into their cultural sphere through conquest and trade. Scott (2009 has recently critiqued such simplistic presentations of the 'civilizing' of the highlands, and argued for a more nuanced understanding of highland identity. However, one conspicuous absence in Scott's portrayal is an examination of highland-lowland relations through the biographies of figures such as Po Romé. I argue that an examination of Po Romé's life and its ethnographic and historiographic contexts deepens our understanding of upland peoples and Cham history.

  12. Characterization of PM10 accumulation periods in the Po valley by means of boundary layer profilers

    International Nuclear Information System (INIS)

    Low wind and stable atmospheric conditions cause frequent PM10 episodes in the Po Valley. Such weather conditions are well characterized by temperature and wind profiles. Thermal inversion strength, height and duration, as well as wind profiles are set in relation to daily PM10 increments, and guidelines for forecasting air quality (AQ) in said conditions are derived

  13. Hair and feathers as indicator of internal contamination of 210Po and 210Pb

    Energy Technology Data Exchange (ETDEWEB)

    Holm, E. (ed.); Gwynn, J.; Zaborska, A.; Gaefvert, T. (Norwegian Radiation Protection Authority (Norway)); Roos, P. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Henricsson, F. (Lund Univ., Lund (Sweden))

    2010-03-15

    The activities of the NKS-B HAIRPOL project is summarised in this report. The objective was to investigate if hair and feathers were suitable matrices for the estimation of the intake of 210Po. Human hair from people of different sex and age was analysed for 210Po showing concentrations between 0.4 to 11 Bq/kg dry weight. Samples from horses, mane, fur and tail showed concentration from 6 to 17 Bq/kg with no significant difference between the different sample types. Musk ox from Greenland showed much higher concentrations since the animal has to graze a large surface. In fur the concentration was 260 Bq/kg. A considerable fraction of the total 210Po in this animal is contained in the hair. Also different organs were analysed and the highest concentration was found in kidney, 2 700 Bq/kg. The 210Pb concentration in hair was estimated to about 20 Bq/kg. Three different seabirds from Svalbard were analysed. Feathers from all three seabird species show increasing activity concentrations of 210Po and 210Pb from the base to the tip of the feather, but it was difficult to relate feather concentrations to muscle concentrations due to a number of complicating factors. (author)

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

    DEFF Research Database (Denmark)

    Brown, J.E.; Gjelsvik, R.; Roos, Per;

    2011-01-01

    concentrations of the main dose forming radionuclides 210Po and 210Pb 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...

  15. Increase of {sup 210}Po levels in human semen fluid after mussel ingestion

    Energy Technology Data Exchange (ETDEWEB)

    Kelecom, Alphonse, E-mail: lararapls@hotmail.co [Laboratory of Radiobiology and Radiometry-LARARA-PLS, Universidade Federal Fluminense, P.O.Box 100.436, 24001-970 Niteroi, RJ (Brazil); Programs in Environmental Science and Marine Biology, Universidade Federal Fluminense, Niteroi, RJ (Brazil); Gouvea, Rita de Cassia dos Santos [Laboratory of Radiobiology and Radiometry-LARARA-PLS, Universidade Federal Fluminense, P.O.Box 100.436, 24001-970 Niteroi, RJ (Brazil)

    2011-05-15

    Polonium-210 ({sup 210}Po) radioactive concentrations were determined in human semen fluid of vasectomized non-smoker volunteers. The {sup 210}Po levels ranged from 0.10 to 0.39 mBq g{sup -1} (mean: 0.23 {+-} 0.08 mBq g{sup -1}). This value decreased to 0.10 {+-} 0.02 mBq g{sup -1} (range from 0.07 to 0.13 mBq g{sup -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 {sup 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 {sup 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.

  16. A vibrational spectral study of hydrated tantalum phosphate (TaPO sub 5 ) phases

    Energy Technology Data Exchange (ETDEWEB)

    Stranford, G.T.; Condrate, R.A. Sr. (Alfred Univ., NY (USA))

    1990-04-01

    Infrared and Raman spectra were measured for various hydrated tantalum phosphate (TaPO{sub 5}) materials after dehydration at various temperatures, and the spectral differences were interpreted on the basis of structure. The structural nature of water along with protonated phosphate and TaO{sub 6} groups in the amorphous hydrated materials was discussed.

  17. A vibrational spectral study of hydrated tantalum phosphate(TaPO 5) phases

    Science.gov (United States)

    Stranford, G. T.; Condrate, R. A.

    1990-04-01

    Infrared and Raman spectra were measured for various hydrated tantalum phosphate (TaPO 5) materialsafter dehydration at various temperatures, and the spectral differences were interpreted on the basis of structure. The structural nature of water along with protonated phosphate and TaO 6 groups in the amorphous hydrated materials was discussed.

  18. Função Poética e Televisão

    Directory of Open Access Journals (Sweden)

    Anna Maria Balogh

    1990-10-01

    Full Text Available Ao empreendermos uma rápida usca nos guardados da memória, verificamos a existência de conceitos arraigados no tocante ao que se considera artístico". Alguns dos conceitos de "artisticidade" revelam vinculações estreitas com as funções "estética" e "poética".

  19. Função Poética e Televisão

    OpenAIRE

    Anna Maria Balogh

    1990-01-01

    Ao empreendermos uma rápida usca nos guardados da memória, verificamos a existência de conceitos arraigados no tocante ao que se considera artístico". Alguns dos conceitos de "artisticidade" revelam vinculações estreitas com as funções "estética" e "poética".

  20. Non-isothermal kinetics study on synthesis of LiFePO4 via carbothermal reduction method

    International Nuclear Information System (INIS)

    Highlights: • Non-isothermal kinetics of LiFePO4 synthesis is studied. • LiFePO4 synthesis can be divided into dehydration and LiFePO4 formation stages. • Dehydration process is controlled by product layer diffusion. • LiFePO4 crystallization is controlled by random nucleation and subsequent growth. • Kinetic equations of dehydration and LiFePO4 formation are Avrami's A1.5 and A4. - Abstract: Non-isothermal kinetics of lithium ion phosphate synthesis via carbothermal reduction method with raw materials Li2CO3, FePO4·2H2O and C6H12O6·2H2O is studied by thermogravimetry-differential scanning calorimetry (TG–DSC) technology. The results indicate the synthesis process can be divided into two stages: dehydration and LiFePO4 formation. The apparent activation energy and natural logarithm frequency factor (ln A-value) for dehydration reaction is respectively 83.4 ± 4.7 kJ mol−1 and 22.1 ± 1.5 s−1, and that for LiFePO4 formation reaction is in turn 184.2 ± 10.4 kJ mol−1 and 28.3 ± 1.9 s−1. Additionally, the mechanism for dehydration and LiFePO4 formation stages is Avrami's A1.5 and A4, respectively. Furthermore, the dehydration process is diffusion controlled, and the crystallization of LiFePO4 formation is controlled by nuclei being formed randomly and growing in three-dimensions, and the kinetic equations for each stage are shown as follows: (table) where α is the fractional conversion, T the calcination temperature (K), t the calcination time (s), R the gas constant (8.314 J mol−1 K−1)

  1. Assessment of soil contamination by 210Po and 210Pb around heavy oil and natural gas fired power plants

    International Nuclear Information System (INIS)

    Soil contamination by 210Pb and 210Po around heavy oil and natural gas power plants has been investigated; fly and bottom ash containing enhanced levels of 210Pb and 210Po were found to be the main source of surface soil contamination. The results showed that 210Pb and 210Po in fly-ash (economizer, superheater) is highly enriched with 210Pb and 210Po, while bottom-ash (boiler) is depleted. The highest 210Pb and 210Po activity concentrations were found to be in economizer ash, whereas the lowest activity concentration was in the recirculator ash. On the other hand, 210Pb and 210Po activity concentrations in soil samples were found to be higher inside the plant site area than those samples collected from surrounding areas. The highest levels were found in the vicinity of Mhardeh and Tishreen power plants; both plants are operated by heavy oil and natural fuels, while the lowest values were found to be in those samples collected from Nasrieh power plant, which is only operated by one type of fuel, viz. natural gas. In addition, the levels of surface soil contamination have decreased as the distance from the power plant site center increased. - Highlights: • Fly ash containing 210Po and 210Pb is the main enhancement factor in surface soil. • 210Pb and 210Po in soil are higher inside the campus area than the surrounding areas. • 210Pb and 210Po in ash along the combustion path varied with compartment temperature. • Fly-ash contains 210Pb and 210Po much higher than bottom-ash

  2. Inflow of 210Po from the Odra River Catchment Area to the Baltic Sea

    International Nuclear Information System (INIS)

    In this study the activity of polonium 210Po in the Odra River water samples, collected from October 2003 to July 2004 has been was determined using alpha spectrometry. In autumn the highest concentration of 210Po was found in the Odra River water at Gozdowice (1.64 ± 0.08 Bq m-3) and in the Nysa Luzycka River (5.21 ± 0.19 Bq m-3). In contrary, the lowest concentrations were determined in water from the Barycz and the Bystrzyca Rivers (1.09 ± 0.07 and 1.09 ± 0.06 Bq m-3, respectively). During winter season, in turn, the highest concentration of 210Po was observed in the Odra River water collected at Chalupki (3.64 ± 0.03 Bq m-3) and Slubice (3.62 ± 0.03 Bq m-3), and the lowest in the Notec River (1.00 ± 0.06 Bq dm-3). In spring the highest concentration was in the Odra at Slubice (3.32 ± 0.04 Bq m-3) and in the Nysa Klodzka River (4.04 ± 0.03 Bq m-3), and the lowest in the Barycz River (1.10 ± 0.05 Bq m-3) and the Odra at Glogow (1.04 ± 0.06 Bq m-3). In summer the highest 210Po concentration was observed in Odra River at Widuchowa (1.79 ± 0.04 Bq m-3) and in the Nysa Klodzka River (2.00 ± 0.05 Bq m-3), and the lowest in the Odra at Gozdowice (1.10 ± 0.05 Bq m-3) and in the Barycz River (0.60 ± 0.09 Bq m-3). The highest quantity of polonium 210Po was transported to the Baltic Sea in spring, and the lowest in winter. It was calculated that the southern Baltic Sea, especially the Pomeranian Bay with the Szczecin Lagoon, receives 14.76 GBq 210Po annually. Among the Odra tributaries the highest surface runoff of 210Po was observed in autumn (up to 88 kBq km-2 quarter-1 for the Nysa Luzycka drainage area), and the lowest in summer (1 kBq km-2 quarter-1 for the Barycz drainage area). (authors)

  3. Adjustment and transformation strategies of ItalPoS Permanent GNSS Network

    Directory of Open Access Journals (Sweden)

    Alessandro Capra

    2009-06-01

    Full Text Available A private network of 133 Global Navigation Satellite Systems (GNSS permanent sites, named ItalPoS (Italian
    Positioning Service and uniformly covering the entire Italian territory, was established in April 2006 by the Italian
    Division of Leica Geosystems S.p.A. This network also involves several GPS stations of the INGV (Italian
    National Institute of Geophysics and Volcanology RING (Real-time Integrated National Gps network and GPS
    stations from other public and private bodies. Indeed Leica Geosystems contributed with its experience and its
    products to these networks which currently fulfil the national coverage where there are no ItalPoS stations. For
    instance, the purpose of the ItalPoS network is mainly GNSS data distribution in terms of real time corrections
    and RINEX files for the post-processing.
    In order to compute and distribute to private and scientific users a set of adjusted coordinates of the ItalPoS network
    in the IGS05 and ETRF89-2000 reference frames, a dataset of RINEX of about 120 GPS permanent sites
    was created and processed, using the distributed sessions approach, by means of Gamit/Globk 10.3 GPS data
    processor, also using some SOPAC (Scripps Orbits and Permanent Array Center and EUREF (European Permanent
    Network solutions to improve the reference frame definition and the internal constraints.
    This paper describes all the strategies adopted to estimate coordinates and velocities of the ItalPoS Network in
    IGS05 and in ETRF89-2000 reference frames in the whole Italian territory.

  4. The speciation and determination of 210Pb and 210Po in soil samples

    International Nuclear Information System (INIS)

    A method for speciation and determination of 210Pb and 210Po in soil samples was developed. The speciation was carried out by fractionating the soil samples into 5 fractions which are water soluble or exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and bound to residue. After mineralisation, 10% solution of each fraction was used to spontaneously deposit polonium on a silver disk at 85-90 degree C and pH 1.5 and 210Po was measured by α-spectrometry; the remain solution was used to separate lead by anion-exchange resin and purified by precipitation as PbS and PbSO4, and 210Pb was determined by a low background β-counter. IAEA-327 reference material (soil) has been studied for 210Pb and 210Po speciation. The results show that: (1) the average yields are 88.7±6.4% for 210Pb and 93.8±8.2% for 210Po; (2) if compared to the total 210Pb activity in the sample, 210Pb fractions are 0.95% in exchangeable form, 10.6% bound to carbonates, 14.3% bound to Fe-Mn oxides, 7.00% bound to organic matter, and 67.2% bound to residue or acid soluble, and the corresponding values for 210Po are 0.17%, 0.97%, 21.0%, 0.47% and 77.4%, respectively; and (3) the obtained 210Pb concentration is in good agreement with the recommended value given by IAEA.

  5. 137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, T F; Seagars, D J; Jokela, T; Layton, D

    2005-02-02

    The activity concentration of Cesium-137 ({sup 137}Cs) and naturally-occurring Polonium-210 ({sup 210}Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea. The mean {sup 137}Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg{sup -1} (N= 5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg{sup -1} (N=2, wet weight), respectively, in bearded seal. In general, {sup 137}Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, {sup 210}Po activity concentrations appear to be higher than those reported elsewhere but a larger variation. The mean {sup 210}Po concentration in the muscle tissue, liver and kidney of Pacific walrus (N=5, wet weight) were 28.7, 189, and 174 Bq kg{sup -1}, respectively. This compares with {sup 210}Po concentration values (N=2, wet weight) of 27, 207, and 68 Bq kg{sup -1} measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated bioaccumulation factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for {sup 210}Po that those of {sup 137}Cs. We conclude from radiological dose estimates that ingestion of {sup 137}Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessing health risks to Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic.

  6. Unveil the Chemistry of Olivine FePO4 as Magnesium Battery Cathode.

    Science.gov (United States)

    Zhang, Ruigang; Ling, Chen

    2016-07-20

    Despite growing interest in magnesium batteries, it is still a challenge to find a cathode that fulfills requirements such as high capacity and good cyclability. Because of their positions in the periodic table and the similar ionic sizes of lithium and magnesium, it was naturally postulated that a classical intercalation-type Li-ion battery cathode may also accommodate the intercalation of Mg. On the contrary, many Li-ion battery cathodes performed very poorly in Mg cells, although the mechanism behind such phenomena is still unclear. Here we provide first-hand evidence about the chemistry of olivine FePO4 as Mg battery cathode using a combined theoretical and experimental approach. Although LiFePO4 is a commercial cathode with extraordinary good performance in Li-ion batteries, the measured capacity of FePO4 in nonaqueous Mg cell was only ∼13 mAh/g. Density functional theory calculations predicted sufficient mobility of Mg(2+) in FePO4 lattice to support the insertion of Mg at a reasonable rate, suggesting the poor performance cannot be simply attributed to the limitation of Mg(2+) diffusion. Instead, the recorded low capacity was the result of surface amorphorization that prohibited the electrochemical reaction from penetrating deeply into the bulk phase. The amorphorization had a thermodynamic origin from the instability of intercalated product, which was predicted from DFT calculations and supported by the failure to synthesize magnesiated FePO4 in the solid state reaction route. These results highlighted the importance of a thermodynamically preferred intercalation in order to achieve successful Mg battery cathode. PMID:27355741

  7. The seasonal investigation of 210Po accumulation in Plankton samples in Izmir Bay

    International Nuclear Information System (INIS)

    Studies on natural radioactivity in marine ecosystem offer considerable scope for understanding the mechanism of radioactivity transfer to man through the marine food chain. Planktonic organisms are important in the dynamics and transport of radionuclides in the marine environment and also they can accumulate various radionuclides in elevated concentrations in their bodies, so this ability provides their use as bio monitors of radionuclides in water. In the present work, 210Po radionuclide concentrations in plankton samples collected with a plankton net (45210μm nylon mesh ) from Aegean Sea (Urla, Izmir) are determined monthly. After collecting, the samples were filtered through 120μm mesh and 0.45μm membrane filters and oven dried. After radiochemical processes 210Po were collected onto copper disks by means of electrochemical deposition and the alpha activities were measured. From the results obtained so far for spring and summer, it was observed that 210Po activity concentration increased as the size ranges of the plankton decreased. The maximum 210Po was measured as 91±9 Bq kg-1 (dry wt) in the range of 0.45-120μm and the minimum activity was found as 35±4 Bq kg-1 (dry wt) in the samples with size >120μm. The average concentrations in the ranges given above are 58.7 Bq kg1 (dry wt) and 54.4 Bq kg1 (dry wt) respectively. 210Po concentrations in the summer samples are observed to be higher then spring samples. The studies are going on for autumn and winter periods

  8. Atmospheric deposition of 210Po and 210Pb in Malaysian waters during haze events

    International Nuclear Information System (INIS)

    Biogenic burning as forest fire phenomena occurring from April to August each year in the Sumatra and Borneo islands are major sources of biogenic uranium–thorium decay series in marine systems. 30 samples were collected during the Ekspedisi Pelayaran Saintifik Perdana 2009 cruise (EPSP 2009 cruise) between 12th June and 1st August 2009 from the Straits of Malacca to the Sulu and Sulawesi Seas to study the effect of haze and the monsoon season on the deposition rate of 210Po and 210Pb in Malaysian waters. All samples were spiked with 1 ml of lead [Pb(NO3)2; 25 mg ml-1] and 0.05 ml of Polonium-209 tracer (26.08 dpm ml-1). 210Po activity was determined by auto plating onto silver foil and counting using an alpha spectrometry system (Canberra model Alpha Analyst with a silicon-surface barrier detector). Lead that was collected via electrodeposition, formed lead sulphate (PbSO4) precipitation. This precipitate was wrapped onto plastic discs and counted for 210Pb beta activity using a gross alpha-beta counting system (Tennelec model LB-5100 low background gas-flowing anti-coincidence alpha/beta counter) after 1 month to allow bismuth ingrowths. The range of 210Po activities varied between 51.08 ± 15.1 and 742.08 ± 220.34 Bq/kg, whereas the activity of 210Pb ranged from 31.10 ± 4.20 to 880.23 ± 123.86 Bq/kg and 210Po/210Pb ratio value varied between sampling stations from 0.19 to 13.77. The contents of 210Po were also statistically positively correlated with the amount of total suspended particulate especially those recorded during heavy haze period events. (author)

  9. Structural and spectroscopic properties of pure and doped LiCe(PO{sub 3}){sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Abdelhedi, M., E-mail: m_abdelhedi2002@yahoo.fr [Laboratoire de Chimie Inorganique, Université de Sfax, Faculté des Sciences de Sfax, BP 1171, 3000 Sfax (Tunisia); Horchani-Naifer, K. [Laboratoire de Physico-chimie des Matériaux Minéraux et leurs Applications, Centre National des Recherches en Sciences des Matériaux, Technopole de Borj Cedria, 6 BP 73, 8027 Soliman (Tunisia); Dammak, M. [Laboratoire de Chimie Inorganique, Université de Sfax, Faculté des Sciences de Sfax, BP 1171, 3000 Sfax (Tunisia); Ferid, M. [Laboratoire de Physico-chimie des Matériaux Minéraux et leurs Applications, Centre National des Recherches en Sciences des Matériaux, Technopole de Borj Cedria, 6 BP 73, 8027 Soliman (Tunisia)

    2015-10-15

    Graphical abstract: Emission and excitation and spectra of Eu{sup 3+} doped LiCe(PO{sub 3}){sub 4} host lattice with 1, 2, 3 and 4 mol%. - Highlights: • Europium–doped LiCe(PO{sub 3}){sub 4} were prepared by flux method. • It was analyzed by infrared and Raman spectroscopy, and luminescence spectroscopy. • LiCe(PO{sub 3}){sub 4} doped with Eu{sup 3+} ions as luminophore host materials to produce an intense red. - Abstract: Single crystals of LiCe(PO{sub 3}){sub 4} polyphosphate have been synthesized by the flux method and its structural and luminescence properties have been investigated. This compound crystallizes in the space group C2/c with unit cell dimensions a = 16.52(7) Å, b = 7.09(4) Å, c = 9.83 (4)Å, β = 126.29(4)°, Z = 8 and V = 927.84(3) Å{sup 3}. The obtained polytetraphosphate exhibits very small crystals and the dopant Eu{sup 3+} ions were successfully incorporated into the sites of Ce{sup 3+} ions of the host lattice. The spectroscopy properties confirm the potentiality of present LiCe(PO{sub 3}){sub 4} doped with Eu{sup 3+} ions as luminophore host materials to produce an intense red luminescence at 628 nm corresponding to {sup 5}D{sub 0} → {sup 7}F{sub 2} emission level and have significant importance in the development of emission optical systems.

  10. 137Cs and 210Po in Pacific walrus and bearded seal from St. Lawrence Island, Alaska

    International Nuclear Information System (INIS)

    The activity concentration of Cesium-137 (137Cs) and naturally-occurring Polonium-210 (210Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea during May 1996. The mean 137Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg-1 (n = 5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg-1 (n = 2, wet weight), respectively, in bearded seal. In general, 137Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, 210Po activity concentrations are more variable and appear to be higher level compared with mammal data from other regions. The mean 210Po concentration in the muscle tissue, liver and kidney of Pacific walrus (n = 5, wet weight) were 28.7, 189, and 174 Bq kg-1, respectively. This compares with 210Po concentration values (n = 2, wet weight) of 27, 207 and 68 Bq kg-1 measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated concentration factors-as defined by the radionuclide concentration ratio between the target tissue to that in sea water-were two to three orders of magnitude higher for 210Po that those of 137Cs. We conclude from radiological dose estimates that ingestion of 137Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessment of risks of Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic

  11. 137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska

    International Nuclear Information System (INIS)

    The activity concentration of Cesium-137 (137Cs) and naturally-occurring Polonium-210 (210Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea. The mean 137Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg-1 (N= 5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg-1 (N=2, wet weight), respectively, in bearded seal. In general, 137Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, 210Po activity concentrations appear to be higher than those reported elsewhere but a larger variation. The mean 210Po concentration in the muscle tissue, liver and kidney of Pacific walrus (N=5, wet weight) were 28.7, 189, and 174 Bq kg-1, respectively. This compares with 210Po concentration values (N=2, wet weight) of 27, 207, and 68 Bq kg-1 measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated bioaccumulation factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for 210Po that those of 137Cs. We conclude from radiological dose estimates that ingestion of 137Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessing health risks to Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic

  12. 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

    Science.gov (United States)

    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.

  13. Room temperature H2S gas sensing characteristics of platinum (Pt) coated porous alumina (PoAl) thick films

    International Nuclear Information System (INIS)

    The study reports H2S gas sensing characteristics of platinum (Pt) coated porous alumina (PoAl) films. The porous alumina (PoAl) thick layers were formed in the dark on aluminum substrates using an electrochemical anodization method. Thin semitransparent platinum (Pt) films were deposited on PoAl samples using chemical bath deposition (CBD) method. The films were characterized using energy dispersive X-ray analysis (EDAX) and scanning electron microscopy (SEM). The thicknesses of coated and bare films were measured using ellipsometry. The sensing properties such as sensitivity factor (S.F.), response time, recovery time and repeatability were measured using a static gas sensing system for H2S gas. The EDAX studies confirmed the purity of Pt–PoAl film and indicated the formation of pure platinum (Pt) phase. The ellipsometry studies revealed the thickness of PoAl layer of about 15–17 μm on aluminum substrates. The SEM studies demonstrated uniform distribution of spherical pores with a size between 0.250 and 0.500 μm for PoAl film and nearly spherical platinum particles with average particle size ∼100 nm for Pt–PoAl film. The gas-sensing properties of these samples were studied in a home-built static gas characterization system. The H2S gas sensing properties of Pt–PoAl at 1000 ppm of H2S gave maximum sensitivity factor (S.F.) = 1200. The response time and recovery time were found to be 2–3 min and ∼1 min respectively. Further, the measurement of H2S gas sensing properties clearly indicated the repeatability of gas sensing response of Pt–PoAl film. The present study indicated the significant potential of Pt coated PoAl films for H2S gas sensing applications in diverse areas. - Highlights: • Electrochemical anodization, cheap and effective method for fabrication of PoAl. • Chemical bath deposition, a simple and effective method for deposition of Pt on PoAl. • A nano-composite film sensor with high sensitivity (S.F. = 1200). • The study

  14. Evaluation of the amount of 210Po ingested by the Spanish population and its relation to their diet habit

    International Nuclear Information System (INIS)

    In this work, the contribution of 210Po to the committed effective dose via ingestion received by the Spanish population have been evaluated, by determining the 210Po activity concentrations in an ample set of samples which can be considered representatives of the diet consumed in Spain. The obtained results show a quit high variability, preventing the possibility to fix a representative value for the 210Po contribution to the ingestion doses received by the Spanish population, but in general these values, due exclusively to 210Po, are higher than the average value assigned by UNSCEAR to the annual committed effective dose received by the worldwide population due to the ingestion of natural and anthropogenic radionuclides. Knowing the diet habits of the Spanish population and the 210Po bioaccumulative behavior in the marine trophic chain, which implies enhanced concentration of 210Po in the sea food in comparison with the obtained ones in other components of the diet, the variable and generally higher ingestion doses due to 210Po received by the Spanish population can be associated to the variable and rich consumption of marine products. The Spanish population has the seafood as an essential component of his diet. Although the 210Po levels in the edible parts of a great variety of marine organisms can be found in the literature in general the great majority of these determinations corresponds to raw edible products. But little is known about the effects of cooking on the 210Po content of seafood which are normally cooked for human consumption. Then it is important to check if cooking can alter the 210Po content in the seafood in order to refine the dose estimates to human consumers. Trying to cover this gap, and at the same time trying to confirm the key role of the seafood in the 210Po ingestion doses received by the Spanish population, we have also analyzed the 210Po content in the edible parts of several seafood products bought in commercial markets of our town

  15. Synthesis of FePO{sub 4}.2H{sub 2}O nanoplates and their usage for fabricating superior high-rate performance LiFePO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Wang Meng; Xue Yinghui; Zhang Keli [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Zhang Youxiang, E-mail: yxzhang04@whu.edu.c [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

    2011-04-15

    Research highlights: {yields} Monoclinic phase FePO{sub 4}.2H{sub 2}O nanoplates are synthesized in waterbath. {yields} The thickness of the FePO{sub 4}.2H{sub 2}O nanoplates can be easily tuned. {yields} FePO{sub 4}.2H{sub 2}O nanoplates are lithiated to LiFePO{sub 4}/C nanoparticles. {yields} The LiFePO{sub 4}/C nanoparticles have sizes {approx}50 nm, with carbon coating layer {approx}2 nm. {yields} The nanoparticles show excellent high-rate performance and long-term cyclability. - Abstract: Monoclinic phase FePO{sub 4}.2H{sub 2}O nanoplates are synthesized very easily in a waterbath and are lithiated to LiFePO{sub 4}/C nanoparticles by a simple rheological phase method. The thickness of the nanoplates can be tuned simply by changing the concentrations of the reactants. The LiFePO{sub 4}/C nanoparticles lithiated from the thin FePO{sub 4}.2H{sub 2}O nanoplates, with the sizes about 50 nm and the carbon coating layer at the surface 1-2 nm, show excellent high-rate performance and long-term cyclability as the cathode for lithium ion batteries, delivering discharge capacities of more than 150, 120, 110, 100, and 75 mAh g{sup -1} at rates of 5 C, 10 C, 15 C, 20 C and 30 C, respectively.

  16. Determination of the Lamb-Moessbauer factors of LiFePO4 and FePO4 for electrochemical in situ and operando measurements in Li-ion batteries

    International Nuclear Information System (INIS)

    57Fe Moessbauer spectroscopy is a powerful tool to investigate redox reactions during in electrochemical lithium insertion/extraction processes. Electrochemical oxidation of LiFeIIPO4 (triphylite) in Li-ion batteries results in FeIIIPO4 (heterosite). LiFePO4 was synthesized by solid state reaction at 800 deg. C under Ar flow from Li2CO3, FeC2O4.2H2O and NH4H2PO4 precursors in stoichiometric composition. FePO4 was prepared from chemical oxidation of LiFePO4 using bromine as oxidative agent. For both materials a complete 57Fe Moessbauer study as a function of the temperature has been carried out. The Debye temperatures are found to be θM=336 K for LiFePO4 and θM=359 K for FePO4, leading to Lamb-Moessbauer factors f300K=0.73 and 0.77, respectively. These data will be useful for a precise estimation of the relative amounts of each species in a mixture. - Graphical abstract: Relative amount of FePO4 obtained by Moessbauer and electrochemical data. We have corrected Moessbauer spectral intensities with our f factor of both LiFePO4 and FePO4. Open (filled) squares correspond to values obtained during charging (discharging) process. The dashed line, given as a guideline for the eye, corresponds to the ideal case were amounts deduced from different experimental measurements are equal.

  17. Engaging Scientists in Meaningful E/PO: How the NASA SMD E/PO Community Addresses the Needs of the Higher Ed Community

    Science.gov (United States)

    Manning, James; Meinke, Bonnie K.; Schultz, Gregory R.; Smith, Denise A.; Lawton, Brandon L.; Gurton, Suzanne; NASA Astrophysics E/PO Community

    2015-01-01

    The NASA Astrophysics Science Education and Public Outreach Forum (SEPOF) coordinates the work of NASA Science Mission Directorate (SMD) Astrophysics EPO projects and their teams to bring cutting-edge discoveries of NASA missions to the introductory astronomy college classroom. The Astrophysics Forum assists scientist and educator involvement in SMD E/PO (uniquely poised to foster collaboration between scientists with content expertise and educators with pedagogy expertise) and makes SMD E/PO resources and expertise accessible to the science and education communities. We present three new opportunities for college instructors to bring the latest NASA discoveries in Astrophysics into their classrooms.To address the expressed needs of the higher education community, the Astrophysics Forum collaborated with the Astrophysics E/PO community, researchers, and Astronomy 101 instructors to place individual science discoveries and learning resources into context for higher education audiences. Among these resources are two Resource Guides on the topics of cosmology and exoplanets, each including a variety of accessible sources.The Astrophysics Forum also coordinates the development of the Astro 101 slide set series--5 to 7-slide presentations on new discoveries from NASA Astrophysics missions relevant to topics in introductory astronomy courses. These sets enable Astronomy 101 instructors to include new discoveries not yet in their textbooks into the broader context of the course: http://www.astrosociety.org/education/astronomy-resource-guides/.The Astrophysics Forum also coordinated the development of 12 monthly Universe Discovery Guides, each featuring a theme and a representative object well-placed for viewing, with an accompanying interpretive story, strategies for conveying the topics, and supporting NASA-approved education activities and background information from a spectrum of NASA missions and programs: http://nightsky.jpl.nasa.gov/news-display.cfm?News_ID=611

  18. Variations of 210Po and 210Pb in various marine organisms from Western English Channel: contribution of 210Po to the radiation dose

    International Nuclear Information System (INIS)

    Measurements of 210Po were carried out in various marine matrices (mussels, oysters, seaweed, fish, and abalones) and in seawater at several points along the French coast, over a period of 2 years (2003-2005). These measurements contribute to a better knowledge of this element, since few recent data exist for the French coast. Marked seasonal variations have been revealed in some species and there are differences according to the way of life of these species. Activities in mussels (Mytilus edulis) and oysters (Crassostrea gigas) are similar and varying between 90 and 600 Bq kg-1 (d.w.). Activities in macroalgae (Fucus serratus) are lowest, between 4 and 16 Bq kg-1 (d.w.). In oyster, abalone (Haliotis tuberculata) and fish (Solea solea, Sparus sp.), the strongest activities are measured in the digestive glands, the gills and the gonads. 210Po/210Pb ratios in all cases have values of more than one for all species. From a significant number of measurements, CFs were calculated for seaweed (between 4.6 x 103 and 5.0 x 103) and for molluscs, with highest CFs (>105) found for the digestive gland and gills of the oysters, the digestive gland of the abalones and the liver of fish. Finally, the activities measured have made it possible to estimate the internal dose from chronic exposure due to 210Po received by the marine organisms (0.05 μG h-1 for macroalgae, between 0.70 and 1.5 μG h-1 for mussels and oyster), and the contribution of seafood to the dose received by humans (46-129 μSv y-1)

  19. Variations of {sup 210}Po and {sup 210}Pb in various marine organisms from Western English Channel: contribution of {sup 210}Po to the radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Connan, O. [Institut de Radioprotection et de Surete Nucleaire, Laboratoire de Radioecologie de Cherbourg-Octeville, IRSN/DEI/SECRE/LRC, Rue Max Pol Fouchet, 50130 Cherbourg-Octeville (France)], E-mail: olivier.connan@irsn.fr; Germain, P.; Solier, L.; Gouret, G. [Institut de Radioprotection et de Surete Nucleaire, Laboratoire de Radioecologie de Cherbourg-Octeville, IRSN/DEI/SECRE/LRC, Rue Max Pol Fouchet, 50130 Cherbourg-Octeville (France)

    2007-10-15

    Measurements of {sup 210}Po were carried out in various marine matrices (mussels, oysters, seaweed, fish, and abalones) and in seawater at several points along the French coast, over a period of 2 years (2003-2005). These measurements contribute to a better knowledge of this element, since few recent data exist for the French coast. Marked seasonal variations have been revealed in some species and there are differences according to the way of life of these species. Activities in mussels (Mytilus edulis) and oysters (Crassostrea gigas) are similar and varying between 90 and 600 Bq kg{sup -1} (d.w.). Activities in macroalgae (Fucus serratus) are lowest, between 4 and 16 Bq kg{sup -1} (d.w.). In oyster, abalone (Haliotis tuberculata) and fish (Solea solea, Sparus sp.), the strongest activities are measured in the digestive glands, the gills and the gonads. {sup 210}Po/{sup 210}Pb ratios in all cases have values of more than one for all species. From a significant number of measurements, CFs were calculated for seaweed (between 4.6 x 10{sup 3} and 5.0 x 10{sup 3}) and for molluscs, with highest CFs (>10{sup 5}) found for the digestive gland and gills of the oysters, the digestive gland of the abalones and the liver of fish. Finally, the activities measured have made it possible to estimate the internal dose from chronic exposure due to {sup 210}Po received by the marine organisms (0.05 {mu}G h{sup -1} for macroalgae, between 0.70 and 1.5 {mu}G h{sup -1} for mussels and oyster), and the contribution of seafood to the dose received by humans (46-129 {mu}Sv y{sup -1})

  20. Literatura argentina e infancia: un caleidoscopio de poéticas : II Jornadas Poéticas de la Literatura Argentina para Niños

    OpenAIRE

    Blake, Cristina Elsa; Sardi, Valeria

    2010-01-01

    Nos hemos propuesto publicar las ponencias seleccionadas para ser leídas en las II Jornadas de Poéticas de la Literatura argentina para niños que tuvieron lugar en el Colegio Nacional “Rafael Henández” de la ciudad de La Plata, el 5 de noviembre de 2010 con el fin de poner en circulación la producción teórico-crítica de colegas argentinos interesados en el campo de la literatura infantil argentina. Cabe compartir con ustedes: ¿por qué nos interesa abordar la literatura argentina para niños...