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Sample records for ng m-2 mo-1

  1. One step hydrothermal synthesis of 3D CoS2@MoS2-NG for high performance supercapacitors.

    Science.gov (United States)

    Meng, Qi; Chen, Yizhi; Zhu, Wenkun; Zhang, Ling; Yang, Xiaoyong; Duan, Tao

    2018-05-03

    A three-dimensional (3D) MoS 2 coated CoS 2 -nitrogen doped graphene (NG) (CoS 2 @MoS 2 -NG) hybrid has been synthesized by a one step hydrothermal method as supercapacitor (SC) electrode material for the first time. Such a composite consists of NG embedded with stacked CoS 2 @MoS 2 sheets. With a 3D skeleton, it prevents the agglomeration of CoS 2 @MoS 2 nanoparticles, resulting in sound conductivity, rich porous structures and a large surface area. The results indicate that CoS 2 @MoS 2 -NG has higher specific capacitance (198 F g -1 at 1 A g -1 ), better rate performance (with about 56.57% from 1 to 16 A g -1 ) and an improved cycle stability (with about 96.97% after 1000 cycles). It is an ideal candidate for SC electrode materials.

  2. Phase relations in the M2MoO4 - Ag2MoO4 - Hf(MoO4)2 (M=Li, Na) systems

    International Nuclear Information System (INIS)

    Bazarova, Zh.G.; Bazarov, B.G.; Balsanova, L.V.

    2002-01-01

    The M 2 MoO 4 - Ag 2 MoO 4 - Hf(MoO 4 ) 2 (M=Li, Na) systems were studied by X-ray diffraction and differential thermal analyses in the subsolidus area (450 - 500 Deg C) for the first time. The formation of the binary compound with the variable composition Li 4-x Hf 1+0.2x (MoO 4 ) 4 (0 ≤ x ≤ 0.6) in the Li 2 MoO 4 - Hf(MoO 4 ) 2 system and the ternary molybdates Li 4 Ag 2 Hf(MoO 4 ) 5 (S 1 ) and Na 2 Ag 2 Hf(MoO 4 ) 4 (S 2 ) was established and the thermal characteristics of the prepared compounds were examined. The new binary molybdate Ag 2 Hf(MoO 4 ) 3 was prepared by the reaction between Ag 2 MoO 4 and Hf(MoO 4 ) 2 [ru

  3. Phase relations in the systems M2MoO4-Cr2(MoO4)3-Zr(MoO4)2 (M=Li, Na, or Rb)

    International Nuclear Information System (INIS)

    Bazarov, B.G.; Chimitova, O.D.; Bazarova, Ts.T.; Arkhincheeva, S.I.; Bazarova, Zh.G.

    2008-01-01

    Phase equilibria in the systems M 2 MoO 4 -Cr 2 (MoO 4 ) 3 -Zr(MoO 4 ) 2 (M=Li, Na, or Rb) were investigated by X-ray powder diffraction analysis, DTA, and IR spectroscopy. The subsolidus structure of the phase diagrams of the systems under study was established. Two phases are formed in the Rb 2 MoO 4 -Cr 2 (MoO 4 ) 3 -Zr(MoO 4 ) 2 system with the molar ratios of the starting components equal to 5:1:1 (S 2 ) and 1:1:1 (S 1 ). Proceeding from isostructural character of Rb 5 FeHf(MoO 4 ) 6 and S 2 , the unit cell parameters are determined for S 2 [ru

  4. Metal-metal bonding and aromaticity in [M2(NHCHNH)3]2 (μ-E)2 (E = O, S; M = Nb, Mo, Tc, Ru, Rh).

    Science.gov (United States)

    Yan, Xiuli; Meng, Lingpeng; Sun, Zheng; Li, Xiaoyan

    2016-02-01

    The nature of M-M bonding and aromaticity of [M2(NHCHNH)3]2(μ-E)2 (E = O, S; M = Nb, Mo, Tc, Ru, Rh) was investigated using atoms in molecules (AIM) theory, electron localization function (ELF), natural bond orbital (NBO) and molecular orbital analysis. These analyses led to the following main conclusions: in [M2(NHCHNH)3]2(μ-E)2 (E = O, S; M = Nb, Mo, Tc, Ru, Rh), the Nb-Nb, Ru-Ru, and Rh-Rh bonds belong to "metallic" bonds, whereas Mo-Mo and Tc-Tc drifted toward the "dative" side; all these bonds are partially covalent in character. The Nb-Nb, Mo-Mo, and Tc-Tc bonds are stronger than Ru-Ru and Rh-Rh bonds. The M-M bonds in [M2(NHCHNH)3]2(μ-S)2 are stronger than those in [M2(NHCHNH)3]2(μ-O)2 for M = Nb, Mo, Tc, and Ru. The NICS(1)ZZ values show that all of the studied molecules, except [Ru2(NHCHNH)3]2(μ-O)2, are aromaticity molecules. O-bridged compounds have more aromaticity than S-bridged compounds. Graphical Abstract Left Molecular graph, and right electron localization function (ELF) isosurface of [M2(NHCHNH)3]2(μ-E)2(E = O, S; M = Nb, Mo, Tc, Ru, Rh).

  5. Prostate health index significantly reduced unnecessary prostate biopsies in patients with PSA 2-10 ng/mL and PSA >10 ng/mL: Results from a Multicenter Study in China.

    Science.gov (United States)

    Na, Rong; Ye, Dingwei; Qi, Jun; Liu, Fang; Helfand, Brian T; Brendler, Charles B; Conran, Carly A; Packiam, Vignesh; Gong, Jian; Wu, Yishuo; Zheng, Siqun L; Mo, Zengnan; Ding, Qiang; Sun, Yinghao; Xu, Jianfeng

    2017-08-01

    The performance of prostate health index (phi) in predicting prostate biopsy outcomes has been well established for patients with prostate-specific antigen (PSA) values between 2 and 10 ng/mL. However, the performance of phi remains unknown in patients with PSA >10 ng/mL, the vast majority in Chinese biopsy patients. We aimed to assess the ability of phi to predict prostate cancer (PCa) and high-grade disease (Gleason Score ≥7) on biopsy in a Chinese population. This is a prospective, observational, multi-center study of consecutive patients who underwent a transrectal ultrasound guided prostate biopsy at four hospitals in Shanghai, China from August 2013 to December 2014. In the cohort of 1538 patients, the detection rate of PCa was 40.2%. phi had a significantly better predictive performance for PCa than total PSA (tPSA). The areas under the receiver operating characteristic curve (AUC) were 0.90 and 0.79 for phi and tPSA, respectively, P 10 ng/mL (N = 838, 54.5%). The detection rates of PCa were 35.9% and 57.7% in patients with tPSA 10.1-20 and 20.1-50 ng/mL, respectively. The AUCs of phi (0.79 and 0.89, for these two groups, respectively) were also significantly higher than tPSA (0.57 and 0.63, respectively), both P 10 ng/mL). © 2017 Wiley Periodicals, Inc.

  6. Successful labeling of 99mTc-MDP using 99mTc separated from 99Mo produced by 100Mo(n,2n)99Mo

    International Nuclear Information System (INIS)

    Nagai, Yasuki; Hatsukawa, Yuichi; Kin, Tadahiro; Hashimoto, Kazuyuki; Motoishi, Shoji; Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke; Sato, Yuichi; Sato, Norihito; Ohta, Akio; Yamabayashi, Hisamichi; Tanase, Masakazu; Fujisaki, Saburo; Kawauchi, Yukimasa; Teranaka, Tomoyuki; Takeuchi, Nobuhiro; Igarashi, Takashi

    2011-01-01

    We have for the first time succeeded in separating 99m Tc from a MoO 3 sample irradiated with accelerator neutrons free from any radioactive impurities and in formulating 99m Tc-methylene diphosphonate ( 99 mTc-MDP). 99 Mo, the mother nuclide of 99m Tc, was produced by the 100 Mo(n,2n) 99 Mo reaction using about 14 MeV neutrons provided by the 3 H(d,n) 4 He reaction at the Fusion Neutronics Source of Japan Atomic Energy Agency. The 99m Tc was separated from 99 Mo by sublimation and its radionuclide purity was confirmed to be higher than 99.99% by γ-spectroscopy. The labeling efficiency of 99m Tc-MDP was shown to be higher than 99% by thin-layer chromatography. These values exceed the United States Pharmacopeia requirements for a fission product, 99 Mo. Consequently, a 99m Tc radiopharmaceutical preparation formed by using the mentioned 99 Mo can be a promising substitute for the fission product 99 Mo, which is currently produced using a highly enriched uranium target in aging research reactors. A longstanding problem to ensure a reliable and constant supply of 99 Mo in Japan can be partially mitigated. (author)

  7. Spent 99Mo/99mTc generator as an economical source of 99Mo

    International Nuclear Information System (INIS)

    El-Kolaly, M.T.

    1990-01-01

    An improved method for utilization and purification of 99 Mo from spent 90 Mo/ 99m Tc generators has been described. After washing the generator with saline to remove the generated 99m Tc, followed by 2 mL 5 M NaOH containing a few drops of H 2 O 2 , the 99 Mo was quantitatively eluted from the generator with 5 mL 5 M NaOH. The alkaline eluate containing 99 Mo was contaminated with partially dissolved alumina. In the present method, an anion-exchange resin Dowex 1 x 8 column was used for purification of 99 Mo from the contaminating alumina. The resultant 99 Mo was of high purity and contained 3+ /mL 99 Mo solution, as estimated by atomic absorption. (author)

  8. Spatial organization of NG2 glial cells and astrocytes in rat hippocampal CA1 region.

    Science.gov (United States)

    Xu, Guangjin; Wang, Wei; Zhou, Min

    2014-04-01

    Similar to astrocytes, NG2 glial cells are uniformly distributed in the central nervous system (CNS). However, little is known about the interspatial relationship, nor the functional interactions between these two star-shaped glial subtypes. Confocal morphometric analysis showed that NG2 immunostained cells are spatially organized as domains in rat hippocampal CA1 region and that each NG2 glial domain occupies a spatial volume of ∼178, 364 μm(3) . The processes of NG2 glia and astrocytes overlap extensively; each NG2 glial domain interlaces with the processes deriving from 5.8 ± 0.4 neighboring astrocytes, while each astrocytic domain accommodates processes stemming from 4.5 ± 0.3 abutting NG2 glia. In CA1 stratum radiatum, the cell bodies of morphologically identified glial cells often appear to make direct somatic-somata contact, termed as doublets. We used dual patch recording and postrecording NG2/GFAP double staining to determine the glial identities of these doublets. We show that among 44 doublets, 50% were NG2 glia-astrocyte pairs, while another 38.6% and 11.4% were astrocyte-astrocyte and NG2 glia-NG2 glia pairs, respectively. In dual patch recording, neither electrical coupling nor intercellular biocytin transfer was detected in astrocyte-NG2 glia or NG2 glia-NG2 glia doublets. Altogether, although NG2 glia and astrocytes are not gap junction coupled, their cell bodies and processes are interwoven extensively. The anatomical and physiological relationships revealed in this study should facilitate future studies to understand the metabolic coupling and functional communication between NG2 glia and astrocytes. Copyright © 2013 Wiley Periodicals, Inc.

  9. FeS2-doped MoS2 nanoflower with the dominant 1T-MoS2 phase as an excellent electrocatalyst for high-performance hydrogen evolution

    International Nuclear Information System (INIS)

    Zhao, Xue; Ma, Xiao; Lu, Qingqing; Li, Qun; Han, Ce; Xing, Zhicai; Yang, Xiurong

    2017-01-01

    Well-established methods to improve the hydrogen evolution reaction (HER) performances include, but are not limited to, tailoring the morphology and electronic structure of transition metal dichalcogenides (TMDs), and doping of earth abundant chemicals such as iron pyrite FeS 2 into existing TMDs. In this work, MoS 2 nanoflowers with the majority being octahedral MoS 2 (1T-MoS 2 ) and doped with FeS 2 were prepared and applied to HER. The as-prepared catalysts were characterized by X-ray absorption fine structure at the K-edge of Mo, S, and Fe to probe the local electronic structures. The resulting nanomaterial was identified to be FeS 2 doped MoS 2 nanoflower (denoted as Fe-MoS 2 NF) with 66% 1T-MoS 2 which was the metallic phase and could drastically boost the HER properties. The Fe-MoS 2 NF exhibited high HER performance with a Tafel slope of 82 mV dec −1 and it needs 136 mV to achieve a current density of 10 mA cm −2 . The synthesis of Fe-MoS 2 NF with refined morphology and active electronic structure is expected to open a new era for improving the catalytic activity and stability of MoS 2 .

  10. Pressure Prediction of Electronic, Anisotropic Elastic, Optical, and Thermal Properties of Quaternary (M2/3Ti1/33AlC2 (M = Cr, Mo, and Ti

    Directory of Open Access Journals (Sweden)

    Liang Sun

    2016-01-01

    Full Text Available The electronic, mechanical, anisotropic elastic, optical, and thermal properties of quaternary (M2/3Ti1/33AlC2 (M = Cr, Mo, and Ti under different pressure are systematically investigated by first-principles calculations. The bonding characteristics of these compounds are the mixture of metallic and covalent bonds. With an increase of pressure, the heights of total density of states (TDOS for these compounds decrease at Fermi level. The highest volume compressibility among three compounds is Mo2TiAlC2 for its smallest relative volume decline. The relative bond lengths are decreasing when the pressure increases. The bulk and shear modulus of the one doped with Cr or Mo are larger than those of Ti3AlC2 with pressure increasing. With an increase of pressure, the anisotropy of these compounds also increases. Moreover, Mo2TiAlC2 has the biggest anisotropy among the three compounds. The results of optical functions indicate that the reflectivity of the three compounds is high in visible-ultraviolet region up to ~10.5 eV under ambient pressure and increasing constantly when under pressure. Mo2TiAlC2 has the highest loss function. The calculated sound velocity and Debye temperature show that they all increase with pressure. CV of the three compounds is also calculated.

  11. Phase diagrams for the M2MoO4–Ln2(MoO43–Hf(MoO42 systems, where M = Li–Cs, Tl and Ln = La–Lu

    Directory of Open Access Journals (Sweden)

    Zh. G. Bazarova

    2017-12-01

    Full Text Available In this paper, the results of systematic studies of complex molybdate systems M2MoO4–Ln2(MoO43–Hf(MoO42 (M = Li–Cs, Tl; Ln = La–Lu are presented. Subsolidus phase diagrams of ternary systems were constructed and new triple molybdates were obtained. The optimum synthesis conditions for poly- and monocrystalline form were determined. According to single-crystal data, the structure of one of the representatives of triple molybdates was determined.

  12. New metal-organic polygons involving MM quadruple bonds: M8(O2CtBu)4(mu-SC4H2-3,4-{CO2}2)6 (M=Mo, W).

    Science.gov (United States)

    Byrnes, Matthew J; Chisholm, Malcolm H; Patmore, Nathan J

    2005-12-12

    The reactions between M2(O2CtBu)4, where M=Mo or W, and thienyl-3,4-dicarboxylic acid (0.5-1.5 equiv) in toluene proceed via a series of detectable intermediates to the compounds M8(O2CtBu)4(mu-SC4H2-3,4-{CO2}2)6, which are isolated as air-sensitive yellow (M=Mo) or red (M=W) powders and show parent molecular ions in their mass spectra (MALDI). The structure of the molybdenum complex was determined by single-crystal X-ray crystallography and shown to contain an unusual M8 polygon involving four Mo2 quadruply bonded units linked via the agency of the six 3,4-thienylcarboxylate groups. The structure has crystallographically imposed S4 symmetry and may be described in terms of a highly distorted tetrahedron of Mo2 units or a bisphenoid in which two Mo2 units are linked by a thienyldicarboxylate such that intramolecular Mo2...O bonding is present, while the other thienylcarboxylate bridges merely serve to link these two [Mo2]...[Mo2] units together. The color of the compounds arises from intense M2 delta-to-thienyl pi transitions and, in THF, the complexes are redox-active and show four successive quasi-reversible oxidation waves. The [M8]+ radical cations, generated by one-electron oxidation with AgPF6, are shown to be valence-trapped (class II) by UV-vis-near-IR and electron paramagnetic resonance spectroscopy. These results are supported by the electronic structure calculations on model compounds M8(O2CH)4(mu-SC4H2-3,4-{CO}2)6 employing density functional theory that reveal only a small splitting of the M2 delta manifold via mixing with the 3,4-thienylcarboxylate pi system.

  13. Interference-free determination of sub ng kg-1 levels of long-lived 93Zr in the presence of high concentrations (μg kg-1) of 93Mo and 93Nb using ICP-MS/MS.

    Science.gov (United States)

    Petrov, Panayot; Russell, Ben; Douglas, David N; Goenaga-Infante, Heidi

    2018-01-01

    Long-lived high abundance radionuclides are of increasing interest with regard to decommissioning of nuclear sites and longer term nuclear waste storage and disposal. In many cases, no routine technique is available for their measurement in nuclear waste and low-level (ng kg -1 ) environmental samples. Recent advances in ICP-MS technology offer attractive features for the selective and sensitive determination of a wide range of long-lived radionuclides. In this work, inductively coupled plasma-tandem mass spectrometry (ICP-MS/MS)-based methodology, suitable for accurate routine determinations of 93 Zr at very low (ng kg -1 ) levels in the presence of high levels (μg kg -1 ) of the isobaric interferents 93 Nb and 93 Mo (often present in nuclear waste samples), is reported for the first time. Additionally, a novel and systematic strategy for method development based on the use of non-radioactive isotopes is proposed. It relies on gas-phase chemical reactions for different molecular ion formation to achieve isobaric interference removal. Using cell gas mixtures of NH 3 /He/H 2 or H 2 /O 2 , and suitable mass shifts, the signal from the 93 Nb and 93 Mo isobaric interferences on 93 Zr were suppressed by up to 5 orders of magnitude. The achieved limit of detection for 93 Zr was 1.3 × 10 -5  Bq g -1 (equivalent to 0.14 ng kg -1 ). The sample analysis time is 2 min, which represents a significant improvement in terms of sample throughput, compared to liquid scintillation counting methods. The method described here can be used for routine measurements of 93 Zr at environmentally relevant levels. It can also be combined with radiometric techniques for use towards the standardisation of 93 Zr measurements. Graphical abstract Interference-free determination of 93 Zr in the presence of high concentrations of isobaric 93 Mo and 93 Nb by ICP-MS/MS.

  14. Generator of 99m Tc with MnO2 as support of 99 Mo

    International Nuclear Information System (INIS)

    Granados C, F.; Serrano G, J.

    2002-01-01

    The generator of 99m Tc with MnO 2 as support of 99 Mo was studied. By mean of static experiments the retention of 99 Mo in MnO 2 in function of the stirring time and of the p H value of the solution of 99 Mo. It was found that the 99 Mo presents 100% of retention in MnO 2 in the rank of p H 3-11 and the balance was reached before of 10 minutes. In dynamic conditions the retention of 99 Mo in MnO 2 at p H=5 was also higher: 99.72%. The generated 99m Tc can be separated from 99 Mo, adsorbed in MnO 2 packed in the column, using distilled water at p H=5 or NaCl solution at 0.9%. With saline solution the elution yields were greater than 80% and only an aliquot of 5 ml was necessary for obtaining this yield. The better results were obtained when the column was packed with 1 g of MnO 2 . The water and the saline solution were passed through of the column with a flux of 1.25 ml/min. (Author)

  15. MoS2 @HKUST-1 Flower-Like Nanohybrids for Efficient Hydrogen Evolution Reactions.

    Science.gov (United States)

    Wang, Chengli; Su, Yingchun; Zhao, Xiaole; Tong, Shanshan; Han, Xiaojun

    2018-01-24

    A novel MoS 2 -based flower-like nanohybrid for hydrogen evolution was fabricated through coating the Cu-containing metal-organic framework (HKUST-1) onto MoS 2 nanosheets. It is the first time that MoS 2 @HKUST-1 nanohybrids have been reported for the enhanced electrochemical performance of HER. The morphologies and components of the MoS 2 @HKUST-1 flower-like nanohybrids were characterized by scanning electron microscopy, X-ray diffraction analysis and Fourier transform infrared spectroscopy. Compared with pure MoS 2 , the MoS 2 @HKUST-1 hybrids exhibit enhanced performance on hydrogen evolution reaction with an onset potential of -99 mV, a smaller Tafel slope of 69 mV dec -1 , and a Faradaic efficiency of nearly 100 %. The MoS 2 @HKUST-1 flower-like nanohybrids exhibit excellent stability in acidic media. This design opens new possibilities to effectively synthesize non-noble metal catalysts with high performance for the hydrogen evolution reaction (HER). © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Oxidation of cyclic amines by molybdenum(II and tungsten(II halocarbonyls, [M(CO4X2]2 (M = Mo, W; X = Cl, Br

    Directory of Open Access Journals (Sweden)

    H.M. Mbuvi

    2013-05-01

    Full Text Available The molybdenum(II and tungsten(II halocarbonyls, [M(CO4X2]2 (M = Mo, W; X = Cl, Br react with a large excess of the nitrogen bases, 1-methylpyrrolidine, 1-methylpiperidine, 1-ethylpiperidine and 2-ethylpiperidine to give aminecarbonyl complexes of the type M(CO3L3 (L= alkylamine. Excess piperidine reacts with the tungsten halocarbonyls, [W(CO4X2]2 (X = Cl, Br, to give the trans isomer of the complex, W(CO3(C5H11N3. The halogens were recovered as the amminium salts, amine, HX. The oxidized amine dimerized to form a yellow product which was recovered as an oily liquid but in very small amounts. However, in the reaction between Mo(CO4Br2 and 1-ethylpiperidine, a yellow crystalline solid, with a melting point of 224 oC was recovered in sufficient amounts for elemental analysis, melting point and spectral data. Its mass spectrum showed a molecular ion peak at m+/z = 222, a clear evidence that the oxidized amine dimerizes. The cyclic dibasic amine piperazine, C4H10N2 is not, however, oxidized by these halocarbonyls but rather it reacts by substituting some CO groups to form products of the type, M(CO3(C4H10N22X2 (M = Mo, W; X = Cl, Br. Products were characterized by elemental analysis, IR, UV, 1H NMR and mass spectrometry.

  17. Excitation energy transfer to luminescence centers in M{sup II}MoO{sub 4} (M{sup II}=Ca, Sr, Zn, Pb) and Li{sub 2}MoO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Spassky, D.A., E-mail: deris2002@mail.ru [Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Leninskie Gory 1, bld.2, 119991 Moscow (Russian Federation); National University of Science and Technology (MISiS), Leninsky Prospekt 4, 119049 Moscow (Russian Federation); Kozlova, N.S. [National University of Science and Technology (MISiS), Leninsky Prospekt 4, 119049 Moscow (Russian Federation); Nagirnyi, V. [Institute of Physics, University of Tartu, W. Ostwaldi 1, 50411 Tartu (Estonia); Savon, A.E. [Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Leninskie Gory 1, bld.2, 119991 Moscow (Russian Federation); Hizhnyi, Yu.A.; Nedilko, S.G. [Taras Shevchenko National University of Kyiv, Volodymyrska str. 64/13, 01601 Kyiv (Ukraine)

    2017-06-15

    Based on the results of spectroscopy studies and electronic band structure calculations, the analysis of excitation energy transformation into luminescence is performed for a set of molybdates M{sup II}MoO{sub 4} (M{sup II}=Ca, Sr, Zn, Pb) and Li{sub 2}MoO{sub 4}. The bandgap energies were determined from comparison of experimental and calculated reflectivity spectra as 3.3 eV for PbMoO{sub 4}, 4.3 eV for ZnMoO{sub 4}, 4.4 eV for CaMoO{sub 4}, 4.7 eV for SrMoO{sub 4}, and 4.9 eV for Li{sub 2}MoO{sub 4}. It is shown that photoluminescence excitation spectra of these materials reveal the specific features of their conduction bands. The threshold of separated charge carriers’ creation is shown to be by 1.3–1.9 eV higher than the bandgap energy in CaMoO{sub 4}, SrMoO{sub 4} and ZnMoO{sub 4}. The effect is explained by the peculiarities of conduction band structure, namely to the presence of gap between the subbands of the conduction band and to the low mobility of electrons in the lower sub-band of the conduction band.

  18. Generator of {sup 99m} Tc with MnO{sub 2} as support of {sup 99} Mo; Generador de {sup 99m} Tc con MnO{sub 2} como soporte del {sup 99}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Granados C, F.; Serrano G, J. [Departamento de Quimica, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    The generator of {sup 99m} Tc with MnO{sub 2} as support of {sup 99} Mo was studied. By mean of static experiments the retention of {sup 99} Mo in MnO{sub 2} in function of the stirring time and of the p H value of the solution of {sup 99} Mo. It was found that the {sup 99} Mo presents 100% of retention in MnO{sub 2} in the rank of p H 3-11 and the balance was reached before of 10 minutes. In dynamic conditions the retention of {sup 99} Mo in MnO{sub 2} at p H=5 was also higher: 99.72%. The generated {sup 99m} Tc can be separated from {sup 99} Mo, adsorbed in MnO{sub 2} packed in the column, using distilled water at p H=5 or NaCl solution at 0.9%. With saline solution the elution yields were greater than 80% and only an aliquot of 5 ml was necessary for obtaining this yield. The better results were obtained when the column was packed with 1 g of MnO{sub 2}. The water and the saline solution were passed through of the column with a flux of 1.25 ml/min. (Author)

  19. Structural chemistry of the cation-ordered perovskites Sr2CaMo1-xTexO6 (0=1)

    International Nuclear Information System (INIS)

    Prior, Timothy J.; Couper, Victoria J.; Battle, Peter D.

    2005-01-01

    The crystal structures of Sr 2 CaMoO 6 and Sr 2 CaTeO 6 have been determined at room temperature by neutron powder diffraction. Both compounds crystallize in the perovskite structure with a rock-salt ordered array of Ca 2+ and M 6+ cations (M=Mo, Te) on the six-coordinate sites (space group P2 1 /n (no. 14); for M=Mo, a=5.76228(7), b=5.84790(7), c=8.18707(9)A, β=90.194(1) o , for M=Te, a=5.79919(9), b=5.83756(8), c=8.2175(1)A, β=90.194(1) o ). Compositions in the solid solution Sr 2 CaMo 1-x Te x O 6 have been synthesized and shown by X-ray diffraction to adopt the same ordered structure. The results are used in a discussion of the cation oxidation states in Ca 2 FeMoO 6 and to establish the similarity between the structural chemistry of hexavalent Mo and Te

  20. Superconductivity in dense Mg1–xMxB2 (M= Zr, Nb, Mo; x= 0⋅ 05 ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 28; Issue 3. Superconductivity in dense Mg1–MB2 (M = Zr, Nb, Mo; = 0.05) materials sintered under pressure. S Kalavathi C Divakar. Superconductors Volume 28 Issue 3 June 2005 pp 249-252 ...

  1. Benchmark experiment for the cross section of the 100Mo(p,2n)99mTc and 100Mo(p,pn)99Mo reactions

    Science.gov (United States)

    Takács, S.; Ditrói, F.; Aikawa, M.; Haba, H.; Otuka, N.

    2016-05-01

    As nuclear medicine community has shown an increasing interest in accelerator produced 99mTc radionuclide, the possible alternative direct production routes for producing 99mTc were investigated intensively. One of these accelerator production routes is based on the 100Mo(p,2n)99mTc reaction. The cross section of this nuclear reaction was studied by several laboratories earlier but the available data-sets are not in good agreement. For large scale accelerator production of 99mTc based on the 100Mo(p,2n)99mTc reaction, a well-defined excitation function is required to optimise the production process effectively. One of our recent publications pointed out that most of the available experimental excitation functions for the 100Mo(p,2n)99mTc reaction have the same general shape while their amplitudes are different. To confirm the proper amplitude of the excitation function, results of three independent experiments were presented (Takács et al., 2015). In this work we present results of a thick target count rate measurement of the Eγ = 140.5 keV gamma-line from molybdenum irradiated by Ep = 17.9 MeV proton beam, as an integral benchmark experiment, to prove the cross section data reported for the 100Mo(p,2n)99mTc and 100Mo(p,pn)99Mo reactions in Takács et al. (2015).

  2. Electronic structures of B1 MoN, fcc Mo2N, and hexagonal MoN

    International Nuclear Information System (INIS)

    Ihara, H.; Kimura, Y.; Senzaki, K.; Kezuka, H.; Hirabayashi, M.

    1985-01-01

    The electronic structures of B1 MoN, fcc Mo 2 N, and hexagonal MoN were observed by photoelectron spectroscopic measurement. The B1-MoN phase has been predicted to be a high-T/sub c/ superconductor because of a large density of states at Fermi level. The observed electronic structure of the stoichiometric B1-MoN phase is different from that of the real B1-MoN type. The nitrogen excess B1-MoN/sub x/ (x> or =1.3) phase, however, shows the B1-type electronic structure. This is explained by the occurrence of a nitrogen vacancy in the apparent stoichiometric B1 phase and the occupation of the nitrogen vacancy in the nitrogen-excess B1 phase. This property is related to the previously reported low T/sub c/ of the B1-MoN crystals

  3. Optimal screening interval for men with low baseline prostate-specific antigen levels (≤1.0 ng/mL) in a prostate cancer screening program.

    Science.gov (United States)

    Urata, Satoko; Kitagawa, Yasuhide; Matsuyama, Satoko; Naito, Renato; Yasuda, Kenji; Mizokami, Atsushi; Namiki, Mikio

    2017-04-01

    To optimize the rescreening schedule for men with low baseline prostate-specific antigen (PSA) levels, we evaluated men with baseline PSA levels of ≤1.0 ng/mL in PSA-based population screening. We enrolled 8086 men aged 55-69 years with baseline PSA levels of ≤1.0 ng/mL, who were screened annually. The relationships of baseline PSA and age with the cumulative risks and clinicopathological features of screening-detected cancer were investigated. Among the 8086 participants, 28 (0.35 %) and 18 (0.22 %) were diagnosed with prostate cancer and cancer with a Gleason score (GS) of ≥7 during the observation period, respectively. The cumulative probabilities of prostate cancer at 12 years were 0.42, 1.0, 3.4, and 4.3 % in men with baseline PSA levels of 0.0-0.4, 0.5-0.6, 0.7-0.8, and 0.9-1.0 ng/mL, respectively. Those with GS of ≥7 had cumulative probabilities of 0.42, 0.73, 2.8, and 1.9 %, respectively. The cumulative probabilities of prostate cancer were significantly lower when baseline PSA levels were 0.0-0.6 ng/mL compared with 0.7-1.0 ng/mL. Prostate cancer with a GS of ≥7 was not detected during the first 10 years of screening when baseline PSA levels were 0.0-0.6 ng/mL and was not detected during the first 2 years when baseline PSA levels were 0.7-1.0 ng/mL. Our study demonstrated that men with baseline PSA levels of 0.0-0.6 ng/mL might benefit from longer screening intervals than those recommended in the guidelines of the Japanese Urological Association. Further investigation is needed to confirm the optimal screening interval for men with low baseline PSA levels.

  4. Residual stresses in 2 1/4Cr1Mo welds

    International Nuclear Information System (INIS)

    Fidler, R.; Jerram, K.

    1978-01-01

    Two separate investigations, initiated in an attempt to explain the large amount of residual stress scatter previously observed in the weld metal of eighteen nominally identical thick-section 2 1/4Cr1Mo butt welds, are described in this paper. The first examined the detailed surface residual stress distributions in 2 1/4Cr1Mo manual arc circumferential butt welds in 80mm and 100mm thick 1/2Cr1/2Mo1/4V steam pipe. High residual stresses were found in the regions of overlap between adjacent weld beads, with low values in virgin weld metal. The second utilised single pass manual metal arc bead-in-groove welds to investigate the effects of preheat and weld metal composition on weld metal residual stresses. In four weld metals, mild steel, 1/2Cr1/2Mo1/4V, 1Cr1/2Mo, and 2 1/4Cr1Mo, the residual stresses were very similar, becoming less tensile (or more compressive) with increase of preheat, while the residual stresses in the fifth weld metal (12Cr) were significantly different, being compressive and less affected by preheat. In both investigations the effects have been described in terms of the basic metallurgical phenomena occurring in the weld metal. (author)

  5. Structure re-determination and superconductivity observation of bulk 1T MoS{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yuqiang; He, Jianqiao; Bu, Kejun [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai (China); University of Chinese Academy of Sciences, Beijing (China); State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing (China); Pan, Jie; Wang, Dong; Che, Xiangli; Zhao, Wei; Lin, Tianquan [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai (China); Luo, Ruichun; Liu, Pan [State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai (China); Mu, Gang; Zhang, Hui [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai (China); Huang, Fuqiang [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai (China); State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing (China)

    2018-01-26

    2H MoS{sub 2} has been intensively studied because of its layer-dependent electronic structures and novel physical properties. Though the metastable 1T MoS{sub 2} with a [MoS{sub 6}] octahedron was observed over the microscopic area, the true crystal structure of 1T phase has not been strictly determined. Moreover, the true physical properties have not been demonstrated from experiments owing to the challenge for the preparation of pure 1T MoS{sub 2} crystals. 1T MoS{sub 2} single crystals were successfully synthesized and the crystal structure of 1T MoS{sub 2} re-determined from single-crystal X-ray diffraction. 1T MoS{sub 2} crystallizes in the space group P anti 3m1 with a cell of a=b=3.190(3) Aa and c=5.945(6) Aa. The individual MoS{sub 2} layer consists of MoS{sub 6} octahedra sharing edges with each other. More surprisingly, the bulk 1T MoS{sub 2} crystals undergo a superconducting transition of T{sub c}=4 K, which is the first observation of superconductivity in pure 1T MoS{sub 2} phase. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Diversification of 99Mo/99mTc separation: non–fission reactor production of 99Mo as a strategy for enhancing 99mTc availability.

    Science.gov (United States)

    Pillai, Maroor R A; Dash, Ashutosh; Knapp, Furn F Russ

    2015-01-01

    This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-specific-activity (99)Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of (99m)Tc separated from reactor-produced (99)Mo by (n,γ) activation of natural or enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of (99m)Tc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of (99m)Tc over a period of 2 wk, with 3 extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of (99)Mo once every 4 d can provide 1.48-3.33 TBq (40-90 Ci) of (99m)Tc daily. This model can use research reactors operating in the United States to supply current (99)Mo needs by applying natural (nat)Mo targets. (99)Mo production capacity can be enhanced by using (98)Mo-enriched targets. The proposed model reduces the loss of (99)Mo by decay and avoids proliferation as well as waste management issues associated with fission-produced (99)Mo.

  7. Holey Reduced Graphene Oxide Coupled with an Mo2 N-Mo2 C Heterojunction for Efficient Hydrogen Evolution.

    Science.gov (United States)

    Yan, Haijing; Xie, Ying; Jiao, Yanqing; Wu, Aiping; Tian, Chungui; Zhang, Xiaomeng; Wang, Lei; Fu, Honggang

    2018-01-01

    An in situ catalytic etching strategy is developed to fabricate holey reduced graphene oxide along with simultaneous coupling with a small-sized Mo 2 N-Mo 2 C heterojunction (Mo 2 N-Mo 2 C/HGr). The method includes the first immobilization of H 3 PMo 12 O 40 (PMo 12 ) clusters on graphite oxide (GO), followed by calcination in air and NH 3 to form Mo 2 N-Mo 2 C/HGr. PMo 12 not only acts as the Mo heterojunction source, but also provides the Mo species that can in situ catalyze the decomposition of adjacent reduced GO to form HGr, while the released gas (CO) and introduced NH 3 simultaneously react with the Mo species to form an Mo 2 N-Mo 2 C heterojunction on HGr. The hybrid exhibits superior activity towards the hydrogen evolution reaction with low onset potentials of 11 mV (0.5 m H 2 SO 4 ) and 18 mV (1 m KOH) as well as remarkable stability. The activity in alkaline media is also superior to Pt/C at large current densities (>88 mA cm -2 ). The good activity of Mo 2 N-Mo 2 C/HGr is ascribed to its small size, the heterojunction of Mo 2 N-Mo 2 C, and the good charge/mass-transfer ability of HGr, as supported by a series of experiments and theoretical calculations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Chemical disease-free survival in localized carcinoma of prostate treated with external beam irradiation: comparison of American Society of Therapeutic Radiology and Oncology Consensus or 1 ng/mL as endpoint

    International Nuclear Information System (INIS)

    Perez, Carlos A.; Michalski, Jeff M.; Lockett, Mary Ann

    2001-01-01

    Purpose: To compare postirradiation biochemical disease-free survival using the American Society of Therapeutic Radiology and Oncology (ASTRO) Consensus or elevation of postirradiation prostate-specific antigen (PSA) level beyond 1 ng/mL as an endpoint and correlate chemical failure with subsequent appearance of clinically detected local recurrence or distant metastasis. Methods and Materials: Records of 466 patients with histologically confirmed adenocarcinoma of the prostate treated with irradiation alone between January 1987 and December 1995 were analyzed; 339 patients were treated with bilateral 120 deg. arc rotation and, starting in 1992, 117 with three-dimensional conformal irradiation. Doses were 68-77 Gy in 1.8 to 2 Gy daily fractions. Minimum follow-up is 4 years (mean, 5.5 years; maximum, 9.6 years). A chemical failure was recorded using the ASTRO Consensus or when postirradiation PSA level exceeded 1 ng/mL at any time. Clinical failures were determined by rectal examination, radiographic studies, and, when clinically indicated, biopsy. Results: Six-year chemical disease-free survival rates using the ASTRO Consensus according to pretreatment PSA level for T1 tumors were: ≤4 ng/mL, 100%; 4.1-20 ng/mL, 80%; and >20 ng/mL, 50%. For T2 tumors the rates were: ≤4 ng/mL, 91%; 4.1-10 ng/mL, 81%; 10.1-20 ng/mL, 55%; 20.1-40 ng/mL, 63%; and >40 ng/mL, 46%. When postirradiation PSA levels higher than 1 ng/mL were used, the corresponding 6-year chemical disease-free survival rates for T1 tumors were 92% for pretreatment PSA levels of ≤4 ng/mL, 58-60% for levels of 4.1-20 ng/mL, and 30% for levels >20 ng/mL. For T2 tumors, the 6-year chemical disease-free survival rates were 78% in patients with pretreatment PSA levels of 4-10 ng/mL, 45% for 10.1-40 ng/mL, and 25% for >40 ng/mL. Of 167 patients with T1 tumors, 30 (18%) developed a chemical failure, 97% within 5 years from completion of radiation therapy; no patient has developed a local recurrence or distant

  9. Quaternary Pt{sub 2}Ru{sub 1}Fe{sub 1}M{sub 1}/C (M=Ni, Mo, or W) catalysts for methanol electro-oxidation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Min Ku; Lee, Ki Rak; Kang, Kweon Ho; Park, Geun Il [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Jeon, Hyung Joon [Kyoto University, Kyoto (Japan); McGinn, Paul J. [University of Notre Dame, Indiana (United States)

    2015-02-15

    Quaternary Pt{sub 2}Ru{sub 1}Fe{sub 1}M{sub 1}/C (M=Ni, Mo, or W) catalysts were investigated for the methanol electro-oxidation reaction (MOR). Electrocatalytic activities of the quaternary catalysts for CO electro-oxidation were studied via CO stripping experiments, and the Pt{sub 2}Ru{sub 1}Fe{sub 1}Ni{sub 1}/C and Pt{sub 2}Ru{sub 1}Fe{sub 1}W{sub 1}/C catalysts exhibited lowered on-set potential compared to that of a commercial PtRu/C catalyst. MOR activities of the quaternary catalysts were determined by linear sweep voltammetry (LSV) experiments, and the Pt{sub 2}Ru{sub 1}Fe{sub 1}W{sub 1}/C catalyst outperformed the commercial PtRu/C catalyst by 170 and 150% for the mass and specific activities, respectively. X-ray photoelectron spectroscopy (XPS) was employed to analyze surface oxidation states of constituent atoms, and it was identified that the structure of the synthesized catalysts are close to a nano-composite of Pt and constituent metal hydroxides and oxides. In addition, the XPS results suggested that the bi-functional mechanism accounts for the improved performance of the Pt{sub 2}Ru{sub 1}Fe{sub 1}Ni{sub 1}/C and Pt{sub 2}Ru{sub 1} Fe{sub 1}W{sub 1}/C catalysts.

  10. Efficient infrared (≈1.9-2.0 μm) laser operation in color-defect-free Tm:NaGd(MoO4)2 crystal

    Science.gov (United States)

    Han, X.; Rico, M.; Serrano, M. D.; Cascales, C.; Zaldo, C.

    2013-04-01

    Color-defect-free 5 at.% Tm:NaGd(MoO4)2 crystals have been grown in a Na2MoO4/Na2Mo2O7 flux. Using a hemispherical optical cavity and pumping at λ = 794.5 nm with a Ti-sapphire laser, up to 850 mW of output power at λ ≈ 1900 nm was obtained at 300 K with an output coupler transmission of 8%. In the cw regime, the slope efficiency versus absorbed power was η = 45% and the pump power laser threshold was ≈180 mW. The laser was tunable from 1875 to 1975 nm and the emission had a FWHM bandwidth ≈20 nm, indicating the potential for ultrashort laser pulse generation.

  11. Neuron-NG2 Cell Synapses: Novel Functions for Regulating NG2 Cell Proliferation and Differentiation

    Directory of Open Access Journals (Sweden)

    Qian-Kun Yang

    2013-01-01

    Full Text Available NG2 cells are a population of CNS cells that are distinct from neurons, mature oligodendrocytes, astrocytes, and microglia. These cells can be identified by their NG2 proteoglycan expression. NG2 cells have a highly branched morphology, with abundant processes radiating from the cell body, and express a complex set of voltage-gated channels, AMPA/kainate, and GABA receptors. Neurons notably form classical and nonclassical synapses with NG2 cells, which have varied characteristics and functions. Neuron-NG2 cell synapses could fine-tune NG2 cell activities, including the NG2 cell cycle, differentiation, migration, and myelination, and may be a novel potential therapeutic target for NG2 cell-related diseases, such as hypoxia-ischemia injury and periventricular leukomalacia. Furthermore, neuron-NG2 cell synapses may be correlated with the plasticity of CNS in adulthood with the synaptic contacts passing onto their progenies during proliferation, and synaptic contacts decrease rapidly upon NG2 cell differentiation. In this review, we highlight the characteristics of classical and nonclassical neuron-NG2 cell synapses, the potential functions, and the fate of synaptic contacts during proliferation and differentiation, with the emphasis on the regulation of the NG2 cell cycle by neuron-NG2 cell synapses and their potential underlying mechanisms.

  12. The structural phases and vibrational properties of Mo1-xWxTe2 alloys

    Science.gov (United States)

    Oliver, Sean M.; Beams, Ryan; Krylyuk, Sergiy; Kalish, Irina; Singh, Arunima K.; Bruma, Alina; Tavazza, Francesca; Joshi, Jaydeep; Stone, Iris R.; Stranick, Stephan J.; Davydov, Albert V.; Vora, Patrick M.

    2017-12-01

    The structural polymorphism in transition metal dichalcogenides (TMDs) provides exciting opportunities for developing advanced electronics. For example, MoTe2 crystallizes in the 2H semiconducting phase at ambient temperature and pressure, but transitions into the 1T‧ semimetallic phase at high temperatures. Alloying MoTe2 with WTe2 reduces the energy barrier between these two phases, while also allowing access to the T d Weyl semimetal phase. The \\text{M}{{\\text{o}}1-\\text{x}} WxTe2 alloy system is therefore promising for developing phase change memory technology. However, achieving this goal necessitates a detailed understanding of the phase composition in the MoTe2-WTe2 system. We combine polarization-resolved Raman spectroscopy with x-ray diffraction (XRD) and scanning transmission electron microscopy (STEM) to study bulk \\text{M}{{\\text{o}}1-\\text{x}} WxTe2 alloys over the full compositional range x from 0 to 1. We identify Raman and XRD signatures characteristic of the 2H, 1T‧, and T d structural phases that agree with density-functional theory (DFT) calculations, and use them to identify phase fields in the MoTe2-WTe2 system, including single-phase 2H, 1T‧, and T d regions, as well as a two-phase 1T‧  +  T d region. Disorder arising from compositional fluctuations in \\text{M}{{\\text{o}}1-\\text{x}} WxTe2 alloys breaks inversion and translational symmetry, leading to the activation of an infrared 1T‧-MoTe2 mode and the enhancement of a double-resonance Raman process in \\text{2H-M}{{\\text{o}}1-\\text{x}} WxTe2 alloys. Compositional fluctuations limit the phonon correlation length, which we estimate by fitting the observed asymmetric Raman lineshapes with a phonon confinement model. These observations reveal the important role of disorder in \\text{M}{{\\text{o}}1-\\text{x}} WxTe2 alloys, clarify the structural phase boundaries, and provide a foundation for future explorations of phase transitions and electronic phenomena in this

  13. Ternary alloying study of MoSi2

    International Nuclear Information System (INIS)

    Yi, D.; Li, C.; Akselsen, O.M.; Ulvensoen, J.H.

    1998-01-01

    Ternary alloying of MoSi 2 with adding a series of transition elements was investigated by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS). Iron, Co, Ni, Cr, V, Ti, and Nb were chosen as alloying elements according to the AB 2 structure map or the atomic size factor. The studied MoSi 2 base alloys were prepared by the arc melting process from high-purity metals. The EDS analysis showed that Fe, Co, and Ni have no solid solubility in as-cast MoSi 2 , while Cr, V, Ti, and Nb exhibit limited solid solubilities, which were determined to be 1.4 ± 0.7, 1.4 ± 0.4, 0.4 ± 0.1, and 0.8 ± 0.1. Microstructural characterization indicated that Mo-Si-M VIII (M VIII = Fe, Co, Ni) and Mo-Si-Cr alloys have a two-phase as-cast microstructure, i.e., MoSi 2 matrix and the second-phase FeSi 2 , CoSi, NiSi 2 , and CrSi 2 , respectively. In as-cast Mo-Si-V, Mo-Si-Ti, and Mo-Si-Nb alloys, besides MoSi 2 and C40 phases, the third phases were observed, which have been identified to be (Mo, V) 5 Si 3 , TiSi 2 , and (Mo, Nb) 5 Si 3

  14. Generation of 1.3 μm and 1.5 μm high-energy Raman radiations in α-BaTeMo2O9 crystals

    Science.gov (United States)

    Liu, Shande; Zhang, Junjie; Gao, Zeliang; Wei, Lei; Zhang, Shaojun; He, Jingliang; Tao, Xutang

    2014-02-01

    The generations of high energy 2nd- and 3rd-order stimulated Raman scattering lasers based on the α-BaTeMo2O9 crystal were demonstrated for the first time. The Raman gain coefficient has been compared with that of the YVO4 crystal. A maximum total Stokes radiation energy of 27.3 mJ was obtained, containing 20.1 mJ 2nd-order Stokes energy at 1318 nm, together with 7.2 mJ 3rd-order Stokes energy at 1497 nm, giving an overall conversion efficiency of 35.9% and a slope efficiency of 54.5%. With an optical coating design, a total 3rd- and 4th-order Stokes energy of 16.5 mJ was generated. The maximum energy for 4th-order Stokes radiation at 1731 nm was 2 mJ. The pulse durations for the 2nd-, 3rd-, and 4th-order Stokes shift were 10 ns, 8.6 ns, and 5.2 ns, respectively. Our experimental results show that the α-BTM crystal is a promising Raman crystal for the generations of eye-safe radiations.

  15. NG2 proteoglycan increases mesangial cell proliferation and extracellular matrix production

    International Nuclear Information System (INIS)

    Xiong Jing; Wang Yang; Zhu, Zhonghua; Liu Jianshe; Wang Yumei; Zhang Chun; Hammes, Hans-Peter; Lang, Florian; Feng Yuxi

    2007-01-01

    As a membrane-spanning protein, NG2 chondroitin sulfate proteoglycan interacts with molecules on both sides of plasma membrane. The present study explored the role of NG2 in the pathogenesis of diabetic nephropathy. In the normal kidneys, NG2 was observed predominantly in glomerular mesangium, Bowman's capsule and interstitial vessels. Both mRNA and protein expression in kidneys was significantly higher in strepozotocin-induced diabetic rats than that in normal rats. In the cultured rat mesangial cell line HBZY-1, overexpression of NG2 promoted mesangial cell proliferation and extracellular matrix (ECM) production, such as type VI collagen and laminin. Furthermore, target knockdown of NG2 resulted in decreased cell proliferation and ECM formation. The observations suggest that NG2 is up-regulated in diabetic nephropathy. It actively participates in the development and progression of glomerulosclerosis by stimulating proliferation of mesangial cells and deposition of ECM

  16. Mass spectrometric determination of stability of gaseous BaMoO2, Ba2MoO4, Ba2MoO5, Ba2Mo2O8 molecules

    International Nuclear Information System (INIS)

    Kudin, L.S.; Balduchchi, Dzh.; Dzhil'i, G.; Gvido, M.

    1982-01-01

    During the mass spectrometric investigation of BaCrO 4 evaporation Cr + , Ba + , BaO + main ions are recorded as well as BaMoO 4 + , BaMoO 3 + , BaMoO 2 + , BaMoO + , BaMoO 4 + , Ba 2 MoO 5 + , BaMo 2 O 8 + ions - the products of ionization of three-component (Ba, Mo, M) molecules, forming as a result of substance chemical interaction with the material of an effusion cell (Mo). Heats of formation of BaMoO 2 , Ba 2 MoO 4 , Ba 2 MoO 5 and Ba 2 Mo 2 O 8 molecules which constituted - 577+-70, -1343+-115, -1464+-70, -2393+-90 k J/mol respectively are determined on the base of the analysis of curves of ionisation efficiency and of reaction heats Ba 2 MoO 5 =BaO+BaMoO 4 , ΔH 0 0 =322+-60 kJ/mol Ba 2 Mo 2 O 8 =2BaMoO 4 , ΔH 0 0 =351+-80 kJ/mol calculated with the use of third low of thermodynamics [ru

  17. Synthesis, Structure, Bonding, and Reactivity of Metal Complexes Comprising Diborane(4) and Diborene(2): [{Cp*Mo(CO)2 }2 {μ-η22 -B2 H4 }] and [{Cp*M(CO)2 }2 B2 H2 M(CO)4 ], M=Mo,W.

    Science.gov (United States)

    Mondal, Bijan; Bag, Ranjit; Ghorai, Sagar; Bakthavachalam, K; Jemmis, Eluvathingal D; Ghosh, Sundargopal

    2018-04-26

    The reaction of [(Cp*Mo) 2 (μ-Cl) 2 B 2 H 6 ] (1) with CO at room temperature led to the formation of the highly fluxional species [{Cp*Mo(CO) 2 } 2 {μ-η 22 -B 2 H 4 }] (2). Compound 2, to the best of our knowledge, is the first example of a bimetallic diborane(4) conforming to a singly bridged C s structure. Theoretical studies show that 2 mimics the Cotton dimolybdenum-alkyne complex [{CpMo(CO) 2 } 2 C 2 H 2 ]. In an attempt to replace two hydrogen atoms of diborane(4) in 2 with a 2e [W(CO) 4 ] fragment, [{Cp*Mo(CO) 2 } 2 B 2 H 2 W(CO) 4 ] (3) was isolated upon treatment with [W(CO) 5 ⋅thf]. Compound 3 shows the intriguing presence of [B 2 H 2 ] with a short B-B length of 1.624(4) Å. We isolated the tungsten analogues of 3, [{Cp*W(CO) 2 } 2 B 2 H 2 W(CO) 4 ] (4) and [{Cp*W(CO) 2 } 2 B 2 H 2 Mo(CO) 4 ] (5), which provided direct proof of the existence of the tungsten analogue of 2. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Application of MoS{sub 2} modified screen-printed electrodes for highly sensitive detection of bovine serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Kukkar, Manil [Central Scientific Instruments Organisation (CSIR-CSIO), Sector 30-C, Chandigarh, 160030 (India); Academy of Scientific and Innovative Research, CSIR-CSIO, Sector 30-C, Chandigarh, 160030 (India); Sharma, Ashish [Central Scientific Instruments Organisation (CSIR-CSIO), Sector 30-C, Chandigarh, 160030 (India); UIET, Panjab University, Sector 14, Chandigarh, 160014 (India); Kumar, Parveen [Department of Biotechnology, Kurukshetra University, Kurukshetra, 136119 (India); Kim, Ki-Hyun, E-mail: kkim61@hanyang.ac.kr [Department of Civil & Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 04763 (Korea, Republic of); Deep, Akash, E-mail: dr.akashdeep@csio.res.in [Central Scientific Instruments Organisation (CSIR-CSIO), Sector 30-C, Chandigarh, 160030 (India); Academy of Scientific and Innovative Research, CSIR-CSIO, Sector 30-C, Chandigarh, 160030 (India)

    2016-10-05

    The present work reports the application of a new molybdenum disulphide (MoS{sub 2})-based electrochemical platform for highly sensitive quantitation of an iron-binding protein, bovine serum albumin (BSA). The gold screen-printed electrodes were modified with MoS{sub 2} nanoflakes, followed by bioconjugation with anti-BSA antibodies. Using the above bioelectrode, cyclic voltammetric analysis was carried out in the presence of a Fe{sup 3+}/Fe{sup 2+} redox probe which exhibited a linear response of peak current with varying concentrations of BSA up to 10 ng/mL (with a detection limit of 0.006 ng/mL). This study is novel in that it shows a considerable enhancement of signal during electrochemical sensing of a protein. - Highlights: • MoS{sub 2} nanoflakes have been used for an electrochemical immunosensor. • The sensor's response was proportional to the antigen concentration. • Highly sensitive and specific detection of iron-binding protein ‘BSA’ is achieved. • A wide linear range of detection of BSA is demonstrated.

  19. Photo-dynamics of the lyophilized photo-activated adenylate cyclase NgPAC2 from the amoeboflagellate Naegleria gruberi NEG-M strain

    Energy Technology Data Exchange (ETDEWEB)

    Penzkofer, A., E-mail: alfons.penzkofer@physik.uni-regensburg.de [Fakultät für Physik, Universität Regensburg, Universitätsstrasse 31, D-93053 Regensburg (Germany); Tanwar, M.; Veetil, S.K.; Kateriya, S. [Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021 (India); Stierl, M.; Hegemann, P. [Institut für Biologie/Experimentelle Biophysik, Humboldt Universität zu Berlin, Invalidenstrasse 42, D-10115 Berlin (Germany)

    2013-09-23

    Highlights: • Lyophilizing of NgPAC2 from Naegleria gruberi caused loss of BLUF domain activity. • Photo-induced tyrosine to flavin electron transfer in lyophilized NgPAC2. • Photo-induced Tyr–Tyr cross-linking to o,o′-dityrosine in lyophilized NgPAC2. • Photo-induced partial flavin cofactor reduction in lyophilized NgPAC2. • Two NgPAC2 conformations with fast and slow photo-induced electron transfer. - Abstract: The absorption and emission spectroscopic behavior of lyophilized photo-activated adenylate cyclase NgPAC2 from the amoeboflagellate Naegleria gruberi NEG-M strain consisting of a BLUF domain (BLUF = Blue Light sensor Using Flavin) and a cyclase homology domain was studied in the dark, during blue-light exposure and after blue-light exposure at a temperature of 4 °C. The BLUF domain photo-cycle dynamics observed for snap-frozen NgPAC2 was lost by lyophilization (no signaling state formation with flavin absorption red-shift). Instead, blue-light photo-excitation of lyophilized NgPAC2 caused sterically restricted Tyr–Tyr cross-linking (o,o′-ditysosine formation) and partial flavin cofactor reduction.

  20. Photo-dynamics of the lyophilized photo-activated adenylate cyclase NgPAC2 from the amoeboflagellate Naegleria gruberi NEG-M strain

    International Nuclear Information System (INIS)

    Penzkofer, A.; Tanwar, M.; Veetil, S.K.; Kateriya, S.; Stierl, M.; Hegemann, P.

    2013-01-01

    Highlights: • Lyophilizing of NgPAC2 from Naegleria gruberi caused loss of BLUF domain activity. • Photo-induced tyrosine to flavin electron transfer in lyophilized NgPAC2. • Photo-induced Tyr–Tyr cross-linking to o,o′-dityrosine in lyophilized NgPAC2. • Photo-induced partial flavin cofactor reduction in lyophilized NgPAC2. • Two NgPAC2 conformations with fast and slow photo-induced electron transfer. - Abstract: The absorption and emission spectroscopic behavior of lyophilized photo-activated adenylate cyclase NgPAC2 from the amoeboflagellate Naegleria gruberi NEG-M strain consisting of a BLUF domain (BLUF = Blue Light sensor Using Flavin) and a cyclase homology domain was studied in the dark, during blue-light exposure and after blue-light exposure at a temperature of 4 °C. The BLUF domain photo-cycle dynamics observed for snap-frozen NgPAC2 was lost by lyophilization (no signaling state formation with flavin absorption red-shift). Instead, blue-light photo-excitation of lyophilized NgPAC2 caused sterically restricted Tyr–Tyr cross-linking (o,o′-ditysosine formation) and partial flavin cofactor reduction

  1. Measurement of Mo-99 column activity in the evaluation of Mo-99/Tc-99m generator

    International Nuclear Information System (INIS)

    Kuster, Z.

    1994-01-01

    In order to calculate the real elution efficiency of Mo-99/Tc-99m generator the Mo-99 content on the column has to be previously determined. As found in this work, the external measurement of Mo-99-column activity by means of Geiger-Mueller counter is a simple, fast and reliable method. Generally, Mo-99-column is placed slightly out of the center of the generator; therefore the externally measured flux of photons (φ) is an angular-dependent function. If the thickness of the lead container is radially uniform, the flux measured at some distance from the generator (which is rotated in 2π/3 steps) is given by the equation φ = A (1 + Bcos (α-2π(i - 2)/3)) -1 , i=1,2 or 3 (Eq.1) where A is a numerical constant depending on the Mo-99-column activity, B is a numerical constant depending on the Mo-99- column position within the lead container, the angle α depends on the initial orientation of the generator. A total of 20 generator were studied. The measured Mo-99-column activities (Capintec dose calibrator) were in the range 13.1- 35.11 GBq. Contrary to the findings of Vinberg and Kristensen (Eur J Nucl Med 1/1976(219), values of A (Eq. 1) are in good correlation (r 2 =0.9794) with the measured Mo-99-column activities. (author)

  2. Magnesium-Molybate Compounds as Matrix for 99Mo/99mTc Generators

    Directory of Open Access Journals (Sweden)

    Fabiola Monroy-Guzman

    2011-01-01

    Full Text Available This work reports the preparation of a 99mTc generator based on conversion of 99Mo produced by neutron irradiation, into insoluble magnesium 99Mo-molybdates compounds as matrix. The effect of magnesium salt types and concentration, Mg:Mo molar ratios, pH of molybdate solutions, eluate volume as well as the addition order of molybdate and magnesium solutions’ influences on the final 99mTc were evaluated. Polymetalates and polymolybdates salts either crystallized or amorphous were obtained depending on the magnesium salt and Mg:Mo molar ratio used in matrix preparation. 99Mo/99mTc generator production based on magnesium-99Mo molybdate compounds allow reduction of preparation time and eliminates the use of specialized installations. The best generator performances were attained using matrices prepared from 0.1 mol/L MgCl2·6H2O solutions, ammonium molybdate solutions at pH 7 and at a Mg:Mo molar ratio of 1:1.

  3. A first principle Comparative study of electronic and optical properties of 1H –MoS2 and 2H –MoS2

    International Nuclear Information System (INIS)

    Kumar, Ashok; Ahluwalia, P.K.

    2012-01-01

    First principle calculations of electronic and optical properties of monolayer MoS 2 , so called 1H –MoS 2 , is performed which has emerged as a new direct band gap semiconductor. Before calculations of the properties of 1H –MoS 2 , we have calculated structural parameters, electronic properties (electronic band structure and electronic density of states) and frequency dependent optical response (real and imaginary part of dielectric function, energy loss function, absorption and reflectance spectra) of 2H –MoS 2 and compared with existing experimental results and found that our calculated results are in very good agreements with experimental results. To compare the dielectric functions of bulk (2H –MoS 2 ) and monolayer (1H –MoS 2 ) phases we have further extended these calculations to the single layer MoS 2 (1H –MoS 2 ) which is analogous to graphene. Structural parameters of 1H –MoS 2 are found very close to its bulk 2H –MoS 2 . We find direct electronic band gap at ‘K’ high symmetry point as compared to indirect band gap in its bulk 2H – MoS2. Our calculated dielectric function for 1H – MoS2 shows structure at nearly same energy positions as compared to 2H – MoS2 with additional structure at 3.8 eV. Also additional well defined energy loss peaks revealing the plasmonic resonances at 15.7 eV and 16.0 eV for E vector perpendicular and parallel to c axis respectively for 1H – MoS2 have been found, which are the signatures of surface plasmons at these energies. -- Highlights: ► Structural parameters of 2H-MoS2 and 1H-MoS2 are nearly identical. ► States around the Fermi energy are mainly due to the metal d states. ► Strong hybridization between Mo-d and S-p states below the Fermi energy has been found. ► Optical spectra of 2H-MoS2 finds very good agreements with experimental optical spectra. ► The band gap is found to be direct for 1H-MoS2 as compared to indirect for 2H-MoS2.

  4. 2D molybdenum disulphide (2D-MoS2) modified electrodes explored towards the oxygen reduction reaction

    Science.gov (United States)

    Rowley-Neale, Samuel J.; Fearn, Jamie M.; Brownson, Dale A. C.; Smith, Graham C.; Ji, Xiaobo; Banks, Craig E.

    2016-08-01

    Two-dimensional molybdenum disulphide nanosheets (2D-MoS2) have proven to be an effective electrocatalyst, with particular attention being focused on their use towards increasing the efficiency of the reactions associated with hydrogen fuel cells. Whilst the majority of research has focused on the Hydrogen Evolution Reaction (HER), herein we explore the use of 2D-MoS2 as a potential electrocatalyst for the much less researched Oxygen Reduction Reaction (ORR). We stray from literature conventions and perform experiments in 0.1 M H2SO4 acidic electrolyte for the first time, evaluating the electrochemical performance of the ORR with 2D-MoS2 electrically wired/immobilised upon several carbon based electrodes (namely; Boron Doped Diamond (BDD), Edge Plane Pyrolytic Graphite (EPPG), Glassy Carbon (GC) and Screen-Printed Electrodes (SPE)) whilst exploring a range of 2D-MoS2 coverages/masses. Consequently, the findings of this study are highly applicable to real world fuel cell applications. We show that significant improvements in ORR activity can be achieved through the careful selection of the underlying/supporting carbon materials that electrically wire the 2D-MoS2 and utilisation of an optimal mass of 2D-MoS2. The ORR onset is observed to be reduced to ca. +0.10 V for EPPG, GC and SPEs at 2D-MoS2 (1524 ng cm-2 modification), which is far closer to Pt at +0.46 V compared to bare/unmodified EPPG, GC and SPE counterparts. This report is the first to demonstrate such beneficial electrochemical responses in acidic conditions using a 2D-MoS2 based electrocatalyst material on a carbon-based substrate (SPEs in this case). Investigation of the beneficial reaction mechanism reveals the ORR to occur via a 4 electron process in specific conditions; elsewhere a 2 electron process is observed. This work offers valuable insights for those wishing to design, fabricate and/or electrochemically test 2D-nanosheet materials towards the ORR.Two-dimensional molybdenum disulphide nanosheets

  5. Preparation of clinical-scale 99Mo/99mTc column generator using neutron activated low specific activity 99Mo and nanocrystalline γ-Al2O3 as column matrix.

    Science.gov (United States)

    Chakravarty, Rubel; Ram, Ramu; Dash, Ashutosh; Pillai, M R A

    2012-10-01

    Preparation of clinical-scale (99)Mo/(99m)Tc generator using (n,γ) activated low specific activity (99)Mo and nanocrystalline γ-Al(2)O(3) as a high capacity sorbent matrix is attempted. Nanocrystalline γ-Al(2)O(3) was synthesized by 'solid state mechanochemical' reaction of aluminum nitrate with ammonium bicarbonate. Experimental parameters were optimized to effectively separate (99m)Tc from (99)Mo using this sorbent as the column matrix. The performance features of a 13 GBq (350 mCi) (99)Mo/(99m)Tc generator using this sorbent and (99)Mo produced by (n,γ) route having specific activity 12.9-18.5 GBq/g were evaluated for 10 days. The sorbent possessed the requisite selectivity for (99)Mo and demonstrated a maximum sorption capacity of 200 ± 5mg Mo/g, which is ~10 times higher than that of ordinary acidic alumina. The overall yield of (99m)Tc was >80%, with radionuclidic purity >99.99% and radiochemical purity >99%. The yield of (99m)Tc varied from 7.8 to 2.1 GBq in the eluate for the six days of operation of the generator. The radioactive concentration of (99m)Tc eluted was adequate for the formulation of radiopharmaceuticals. The performance of the generator remained consistent over an extended period of 10 days. The eluted (99m)Tc was suitable for the formulation of (99m)Tc-DMSA and (99m)Tc-EC resulting in high radiolabeling yields (>98%). The effectiveness of γ-Al(2)O(3) as a new generation sorbent in the development of clinically useful (99)Mo/(99m)Tc generator using low specific activity (99)Mo and yielding (99m)Tc with adequate radioactive concentration and high purity suitable for formulation of radiopharmaceuticals is demonstrated. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Salman Rushdie: "Troonide mäng" on rämps

    Index Scriptorium Estoniae

    2011-01-01

    Oma esimest telesarja "Järgmised inimesed" kirjutav Salman Rushdie ei hinda USA telekanali HBO seriaali "Troonide mäng" (George R. R. Martini "Jää ja tule laulu" sarja esimese raamatu "Troonide mäng" teleekraniseering)

  7. Radiative rates for E1, E2, M1, and M2 transitions in the Br-like ions Sr IV, Y V, Zr VI, Nb VII, and Mo VIII

    International Nuclear Information System (INIS)

    Aggarwal, Kanti M.; Keenan, Francis P.

    2015-01-01

    Energies and lifetimes are reported for the lowest 375 levels of five Br-like ions, namely Sr IV, Y V, Zr VI, Nb VII, and Mo VIII, mostly belonging to the 4s 2 4p 5 , 4s 2 4p 4 4ℓ, 4s4p 6 , 4s 2 4p 4 5ℓ, 4s 2 4p 3 4d 2 , 4s4p 5 4ℓ, and 4s4p 5 5ℓ configurations. Extensive configuration interaction has been included and the general-purpose relativistic atomic structure package (GRASP) has been adopted for the calculations. Additionally, radiative rates are listed among these levels for all E1, E2, M1, and M2 transitions. From a comparison with the measurements, the majority of our energy levels are assessed to be accurate to better than 2%, although discrepancies between theory and experiment for a few are up to 6%. An accuracy assessment of the calculated radiative rates (and lifetimes) is more difficult, because no prior results exist for these ions

  8. Evaluation of proton induced reactions on sup 1 sup 0 sup 0 Mo. New cross sections for production of sup 9 sup 9 sup m Tc and sup 9 sup 9 Mo

    CERN Document Server

    Takács, S; Tarkanyi, F; Hermanne, A; Sonck, M

    2003-01-01

    The use of the sup 9 sup 9 Mo -> sup 9 sup 9 sup m Tc generator in nuclear medicine is well established world wide. The production of the sup 9 sup 9 Mo (T sub 1 sub / sub 2 = 66 h) parent as a fission product of sup 2 sup 3 sup 5 U is largely based on the use of reactor technology. From the early 1990's accelerator based production methods to provide either direct produced sup 9 sup 9 sup m Tc or the parent sup 9 sup 9 Mo, were studied and suggested as potential alternatives to the reactor based production of sup 9 sup 9 Mo. A possible pathway for the charged particle production of sup 9 sup 9 sup m Tc and sup 9 sup 9 Mo is irradiation of molybdenum metal with protons via the reaction sup 1 sup 0 sup 0 Mo(p,2n) sup 9 sup 9 sup m Tc and sup 1 sup 0 sup 0 Mo(p,pn) sup 9 sup 9 Mo, respectively. The earlier published excitation functions show large differences in their maximum that result in large differences in the calculated yields. Study the excitation function for these proton-induced reactions was decided. ...

  9. "Troonide mäng" toob fantaasia usutavalt teleekraanile / Mari Rebane

    Index Scriptorium Estoniae

    Rebane, Mari

    2011-01-01

    USA telekanali HBO telesarjast "Troonide mäng", George R. R. Martini "Jää ja tule laulu" sarja esimese raamatu "Troonide mäng" teleekraniseeringust. Sarja esimene osa esilinastus USA-s 17. aprillil. Osades Sean Bean jt.

  10. Thermoelectric properties of M{sub 2}Mo{sub 6}Se{sub 6} (M =Tl,In)

    Energy Technology Data Exchange (ETDEWEB)

    Verebelyi, D T; Payne, J E; Tessema, G X; Mengistu, E

    1997-07-01

    The authors have measured the thermal conductivity of Tl{sub 2}Mo{sub 6}Se{sub 6}, a quasi-one dimensional conductor which belongs to the family of M{sub 2}Mo{sub 6}X{sub 6} linear chain compounds. Using these results and the measurements of the Seebeck coefficient and the electrical conductivity the authors estimate the dimensionless figure of merit to be of the order of 0.08. This result suggest that this compound and other related compounds are good potential TE.

  11. Enhanced Selectivity and Uptake Capacity of CO2 and Toluene Adsorption in Co0.5 M0.33 MoS4 (M= Sb or Y) Chalcogels by Impregnated Metal Salts

    KAUST Repository

    Adhiam, Fatima Abdullah Ahmed

    2017-11-17

    The synthesis of metal chalcogenide aerogels Co0.5M0.33MoS4 (M= Sb or Y) by the sol-gel method is reported. In this system, the building blocks [MoS4]2− chelated with Co2+ and (Sb3+) or (Y3+) salts in nonaqueous solvents forming amorphous networks with a gel property. The chalcogels obtained after supercritical drying have BET surface areas of 176 m2 g−1 (Co0.5Sb0.33MoS4) and 145 m2 g−1 (Co0.5Y0.33MoS4). Electron microscopy and physisorption studies reveal that the new materials are porous with wide pore size distribution and average pore width of 16 nm. These chalcogels show higher adsorption capacity of toluene vapor (Co0.5Sb0.33MoS4: 387 mg g−1) and (Co0.5Y0.33MoS4: 304 mg g−1) over cyclohexane vapor and high selectivity of CO2 over CH4 or H2, Co0.5Sb0.33MoS4 (CO2/H2: 80 and CO2/CH4: 21), Co0.5Y0.33MoS4 (CO2/H2: 27 and CO2/CH4: 15). We also demonstrated that the impregnation of various metal species like Li+, Mg2+, and Ni2+ significantly enhanced the uptake capacity and selectivity of toluene and CO2 adsorptions in the chacogels.

  12. Preparation of a gel of zirconium molybdate for use in the generators of 99 Mo - 99m Tc prepared with 99 Mo produced by the 98 Mo(n,γ)99 Mo reaction

    International Nuclear Information System (INIS)

    Osso Junior, Joao A.; Lima, Ana Lucia V.P.; Silva, Nestor C. da; Nieto, Renata C.; Velosa, Adriana C. de

    1998-01-01

    IPEN develops a project concerning the preparation of a gel of Zirconium Molybdate for use in the generators of 99 Mo- 99m Tc . 99m Tc is the most used radioisotope in nuclear medicine diagnosis procedures and nowadays the generators are being prepared with imported 99 Mo, produced by 235 U fission. The production of 99 Mo by the 98 Mo(n, γ) 99 Mo reaction is now possible because of the power upgrade of IPEN's IEA-R1 reactor, from 2 to 5 MW. This work describes the preparation method of Zirconium Molybdate gel that will be used in the 99 Mo- 99m Tc generators. The gel is prepared by the chemical reaction between Mo, in Mo O 3 form, and Zr, in Zr O Cl 2 .8H 2 O form. After the reaction, the gel is filtered, dried and cracked with saline solution. The product is then loaded into glass columns for use as 99m Tc generator. The results showed the good quality of the gel prepared at laboratory level and of the generators evaluated. (author)

  13. Thermodynamic stabilities of MO2+x(s) (M = U, Np, Pu and Am), pourbaix diagrams

    International Nuclear Information System (INIS)

    Vitorge, Pierre; Faure, Marie-Helene; Vercouter, Thomas; Capdevila, Helene; Maillard, Serge

    2002-01-01

    The experimental solubilities of the hydrated amorphous freshly precipitated M(OH) z (am) and MO 2 (OH) z (am) compounds are often used as an upper limit for the safety assessments of deep waste repositories, since these compounds slowly transform to less soluble ones, as typically M(OH) 4 (am) to MO 2 (cr). Solubility (vs. redox potential) at pH=8, and E-pH predominance diagrams are plotted in aqueous solutions at 25degC by using thermodynamic data recently selected by the NEA-TDB review, or estimated by using classical chemical analogies for the non-redox reactions. The solubilities and relative stabilities are also calculated for the MO 2+x (s) crystalline compounds of known stabilities: U 4 O 9 (s), U 3 O 7 (s), U 3 O 8 (s) and Np 2 O 5 (s) where 2+x = 2.25, 2.33, 2.67 and 2.5 respectively. The stabilities of the other MO 2+x (s) compounds are estimated by analogy: M 4 O 9 (s) (M=U, Np, Pu), M 3 O 7 (s) and M 3 O 8 (s) (M=U, Pu), and M 2 O 5 (s) (M=Np, Am) are predicted to be more stable (i.e. less soluble), than the amorphous hydroxides. However their precipitation have never been observed at room temperature possibly for kinetic reasons or difficulties in interpreting solubility experiments. (author)

  14. Thermal expansion of Cr2xFe2-2xMo3O12, Al2xFe2-2xMo3O12 and Al2xCr2-2xMo3O12 solid solutions

    International Nuclear Information System (INIS)

    Ari, M.; Jardim, P.M.; Marinkovic, B.A.; Rizzo, F.; Ferreira, F.F.

    2008-01-01

    The transition temperature from monoclinic to orthorhombic and the thermal expansion of the orthorhombic phase were investigated for three systems of the family A 2 M 3 O 12 : Cr 2x Fe 2-2x Mo 3 O 12 , Al 2x Fe 2-2x Mo 3 O 12 and Al 2x Cr 2-2x Mo 3 O 12 . It was possible to obtain a single-phase solid solution in all studied samples (x=0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1). A linear relationship between the transition temperature and the fraction of A 3+ cations (x) was observed for each system. In all orthorhombic solid solutions studied here the observed thermal expansion was anisotropic. These anisotropic thermal expansion properties of crystallographic axes a, b and c result in a low positive or near-zero overall linear coefficient of thermal expansion (α l =α V /3). The relationship between the size of A 3+ cations in A 2 M 3 O 12 and the coefficient of thermal expansion is discussed. Near-zero thermal expansion of Cr 2 Mo 3 O 12 is explained by the behavior of Cr-O and Mo-O bond distances, Cr-Mo non-bond distances and Cr-O-Mo bond angles with increasing temperature, estimated by Rietveld analysis of synchrotron X-ray powder diffraction data. - Graphical abstract: In this figure, all published overall linear coefficients of thermal expansion for orthorhombic A 2 M 3 O 12 family obtained through diffraction methods as a function of A 3+ cation radii size, together with dilatometric results, are plotted. Our results indicate that Cr 2 Mo 3 O 12 does not exactly follow the established relationship

  15. High-density expression of Ca2+-permeable ASIC1a channels in NG2 glia of rat hippocampus.

    Directory of Open Access Journals (Sweden)

    Yen-Chu Lin

    Full Text Available NG2 cells, a fourth type of glial cell in the mammalian CNS, undergo reactive changes in response to a wide variety of brain insults. Recent studies have demonstrated that neuronally expressed acid-sensing ion channels (ASICs are implicated in various neurological disorders including brain ischemia and seizures. Acidosis is a common feature of acute neurological conditions. It is postulated that a drop in pH may be the link between the pathological process and activation of NG2 cells. Such postulate immediately prompts the following questions: Do NG2 cells express ASICs? If so, what are their functional properties and subunit composition? Here, using a combination of electrophysiology, Ca2+ imaging and immunocytochemistry, we present evidence to demonstrate that NG2 cells of the rat hippocampus express high density of Ca2+-permeable ASIC1a channels compared with several types of hippocampal neurons. First, nucleated patch recordings from NG2 cells revealed high density of proton-activated currents. The magnitude of proton-activated current was pH dependent, with a pH for half-maximal activation of 6.3. Second, the current-voltage relationship showed a reversal close to the equilibrium potential for Na+. Third, psalmotoxin 1, a blocker specific for the ASIC1a channel, largely inhibited proton-activated currents. Fourth, Ca2+ imaging showed that activation of proton-activated channels led to an increase of [Ca2+]i. Finally, immunocytochemistry showed co-localization of ASIC1a and NG2 proteins in the hippocampus. Thus the acid chemosensor, the ASIC1a channel, may serve for inducing membrane depolarization and Ca2+ influx, thereby playing a crucial role in the NG2 cell response to injury following ischemia.

  16. Theoretical study for the reduction of N2O with CO Mediated by alkaline-earth metal oxide cations 2MO+(M=Ca, Sr, Ba)

    International Nuclear Information System (INIS)

    Zhang Jianhui; Leng Yanli; Wang Yongcheng

    2013-01-01

    The reaction mechanism of the reaction N 2 O( 0 Σ + ) + CO ( 1 Σ + )→N 2 ( 1 Σ g + ) + CO 2 ( 1 Σ g + ) mediated by alkaline-earth metal oxide cations 2 MO + (m=Ca, Sr, Ba) have been investigated by using the UB3LYP and CCSD (T) levels of theory. The O-atom affinities (OA) testified that only the 2 CaO + can capture O from N 2 O and transfer O to CO is thermodynamically allowed in three ions. The processes can be expressed as channels l and 2 for the reaction of N 2 O and CO mediated by 2 MO + (M=Ca, Sr, Ba). For the former, the main reaction processes in a two-step manner to products, the 2 MO + , as a catalyzer, transports an oxygen atom from N 2 O to CO. For the latter, firstly, the N 2 O interact with the 2 MO + to form IM1, then IM1 interact with the CO to form IM2', along the reaction pathway the intermediate species convert into products 2 1MO + , N 2 and CO 2 . From above results, the following conclusion was drawn. The channel 2 is kinetically and thermodynamically feasible. Our calculated results show the title reactions are accord with the experiment. (authors)

  17. Electronic properties of in-plane phase engineered 1T'/2H/1T' MoS2

    Science.gov (United States)

    Thakur, Rajesh; Sharma, Munish; Ahluwalia, P. K.; Sharma, Raman

    2018-04-01

    We present the first principles studies of semi-infinite phase engineered MoS2 along zigzag direction. The semiconducting (2H) and semi-metallic (1T') phases are known to be stable in thin-film MoS2. We described the electronic and structural properties of the infinite array of 1T'/2H/1T'. It has been found that 1T'phase induced semi-metallic character in 2H phase beyond interface but, only Mo atoms in 2H phase domain contribute to the semi-metallic nature and S atoms towards semiconducting state. 1T'/2H/1T' system can act as a typical n-p-n structure. Also high holes concentration at the interface of Mo layer provides further positive potential barriers.

  18. Using solution- and solid-state S K-edge X-ray absorption spectroscopy with density functional theory to evaluate M-S bonding for MS4(2-) (M = Cr, Mo, W) dianions.

    Science.gov (United States)

    Olson, Angela C; Keith, Jason M; Batista, Enrique R; Boland, Kevin S; Daly, Scott R; Kozimor, Stosh A; MacInnes, Molly M; Martin, Richard L; Scott, Brian L

    2014-12-14

    Herein, we have evaluated relative changes in M-S electronic structure and orbital mixing in Group 6 MS4(2-) dianions using solid- and solution-phase S K-edge X-ray absorption spectroscopy (XAS; M = Mo, W), as well as density functional theory (DFT; M = Cr, Mo, W) and time-dependent density functional theory (TDDFT) calculations. To facilitate comparison with solution measurements (conducted in acetonitrile), theoretical models included gas-phase calculations as well as those that incorporated an acetonitrile dielectric, the latter of which provided better agreement with experiment. Two pre-edge features arising from S 1s → e* and t electron excitations were observed in the S K-edge XAS spectra and were reasonably assigned as (1)A1 → (1)T2 transitions. For MoS4(2-), both solution-phase pre-edge peak intensities were consistent with results from the solid-state spectra. For WS4(2-), solution- and solid-state pre-edge peak intensities for transitions involving e* were equivalent, while transitions involving the t orbitals were less intense in solution. Experimental and computational results have been presented in comparison to recent analyses of MO4(2-) dianions, which allowed M-S and M-O orbital mixing to be evaluated as the principle quantum number (n) for the metal valence d orbitals increased (3d, 4d, 5d). Overall, the M-E (E = O, S) analyses revealed distinct trends in orbital mixing. For example, as the Group 6 triad was descended, e* (π*) orbital mixing remained constant in the M-S bonds, but increased appreciably for M-O interactions. For the t orbitals (σ* + π*), mixing decreased slightly for M-S bonding and increased only slightly for the M-O interactions. These results suggested that the metal and ligand valence orbital energies and radial extensions delicately influenced the orbital compositions for isoelectronic ME4(2-) (E = O, S) dianions.

  19. New intermetallic MIrP (M=Ti, Zr, Nb, Mo) and MgRuP compounds related with MoM'P (M'=Ni and Ru) superconductor

    Science.gov (United States)

    Kito, Hijiri; Iyo, Akira; Wada, Toshimi

    2011-01-01

    Using a cubic-anvil high-pressure apparatus, ternary iridium phosphides MIrP (M=Ti, Zr, Nb, Mo) and MgRuP have been prepared by reaction of stoichiometric amounts of each metal and phosphide powders at around 2 Gpa and above 1523 K for the first time. The structure of these compounds prepared at high-pressure has been characterized by X-ray powder diffraction. Diffraction lines of these compounds are assigned by the index of the Co2Si-type structure. The electrical resistivity and the d.c magnetic susceptibility of MIrP (M=Ti, Zr, Nb, Mo) have measured at low temperatures. Unfortunately, no superconducting transition for MIrP (M=Ti, Zr, Nb, Mo) and MgRuP are observed down to 2 K.

  20. New intermetallic MIrP (M=Ti, Zr, Nb, Mo) and MgRuP compounds related with MoM'P (M'=Ni and Ru) superconductor

    International Nuclear Information System (INIS)

    Kito, Hijiri; Iyo, Akira; Wada, Toshimi

    2011-01-01

    Using a cubic-anvil high-pressure apparatus, ternary iridium phosphides MIrP (M=Ti, Zr, Nb, Mo) and MgRuP have been prepared by reaction of stoichiometric amounts of each metal and phosphide powders at around 2 Gpa and above 1523 K for the first time. The structure of these compounds prepared at high-pressure has been characterized by X-ray powder diffraction. Diffraction lines of these compounds are assigned by the index of the Co 2 Si-type structure. The electrical resistivity and the d.c magnetic susceptibility of MIrP (M=Ti, Zr, Nb, Mo) have measured at low temperatures. Unfortunately, no superconducting transition for MIrP (M=Ti, Zr, Nb, Mo) and MgRuP are observed down to 2 K.

  1. Measurement of the molar heat capacities of MoO2 and MoO3 from 350 to 950 K

    International Nuclear Information System (INIS)

    Inaba, H.; Miyahara, K.; Naito, K.

    1984-01-01

    Molar heat capacities of MoO 2 and MoO 3 were measured in the range between 350 and 950 K by means of adiabatic scanning calorimetry. For MoO 2 , a sharp heat-capacity anomaly with a molar enthalpy change of (178 +- 24) J.mol -1 and a molar entropy change of (0.207 +- 0.028) J.K -1 .mol -1 was observed at 865 K, which had not been detected by drop calorimetry. For MoO 3 , two heat-capacity anomalies with molar enthalpy changes of (88 +- 21) and (60 +- 36) J.mol -1 were found at 808 K and 857 K, respectively; neither anomaly had been detected by the drop method. The lattice molar heat capacities of MoO 2 and MoO 3 are estimated as Csub(l,m)(MoO 2 ) = D(469 K/T) + E(578 K/T) + E(876 K/T) and Csub(l,m)(MoO 3 ) = D(208 K/T) + 2E(488 K/T) + E(1170 K/T), where D(x) and E(x) are the Debye and Einstein functions, respectively. The temperature coefficient of the electronic molar heat capacity of MoO 2 is estimated as (6.0 +- 0.5) mJ.K -2 .mol -1 . The excess heat capacity in MoO 3 found at higher temperatures is interpreted as being due to vacancy formation with a molar activation energy of (98 +-5) kJ.mol -1 . The origin of the heat-capacity anomalies is inferred as arising from the slight movement of distorted MoO 6 octahedra in the MoO 2 and MoO 3 structures. (author)

  2. Highly sensitive aptasensor based on synergetic catalysis activity of MoS2-Au-HE composite using cDNA-Au-GOD for signal amplification.

    Science.gov (United States)

    Song, Hai-Yan; Kang, Tian-Fang; Lu, Li-Ping; Cheng, Shui-Yuan

    2017-03-01

    Single or few-layer nanosheets of MoS 2 (MoS 2 nanosheets) and a composite composed of MoS 2 nanosheets, Au nanoparticles (AuNPs) and hemin (HE) (denoted as MoS 2 -Au-HE) were prepared. The composites possessed high synergetic catalysis activity towards the electroreduction of hydrogen peroxide. Furthermore, glucose oxidase (GOD) and AuNPs were used as marker of the complementary DNA (cDNA) strand of kanamycin aptamer to prepare a conjugate (reffered as cDNA-Au-GOD) that was designed as the signal probe. Both cDNA-Au-GOD and MoS 2 -Au-HE were applied to fabricate aptasensor for kanamycin. MoS 2 -Au-HE acted as solid platform for kanamycin aptamer and signal transmitters. AuNPs were employed as the supporter of cDNA and GOD which catalyze dissolved oxygen to produce hydrogen peroxide in the presence of glucose. Then cathodic peak current of H 2 O 2 was recorded by differential pulse voltammetry (DPV). The electrochemical reduction of H 2 O 2 was catalyzed by MoS 2 -Au-HE that was modified onto the surface of a glassy carbon electrode (GCE). The cathodic peak current of H 2 O 2 was highly linearly decreased with an increase of kanamycin concentrations from 1.0ng/L to 1.0×10 5 ng/L, with a detection limit of 0.8ng/L. This aptasensor can be used to detect kanamycin in milk with high specificity, sensitivity and selectivity. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Systems Tl2MoO4-E(MoO4)2, where E=Zr or Hf, and the crystal structure of Tl8Hf(MoO4)6

    International Nuclear Information System (INIS)

    Bazarov, B.G.; Bazarova, Ts.T.; Fedorov, K.N.; Bazarova, Zh.G.; Chimitova, O.D.; Klevtsova, R.F.; Glinskaya, L.A.

    2006-01-01

    Systems Tl 2 MoO 4 -E(MoO 4 ) 2 (E=Zr, Hf) were studied by X-ray diffraction, differential thermal analysis and IR spectroscopy. Formation of Tl 8 E(MoO 4 ) 6 and Tl 2 E(MoO 4 ) 2 compounds was established. Phase T-x diagrams of the Tl 2 MoO 4 -Zr(MoO 4 ) 2 system were constructed. Monocrystals were grown, and structure of Tl 8 Hf(MoO 4 ) 6 was studied. The compound is crystallized in monoclinic syngony with elementary cell parameters a=9.9688(6), b=18.830(1), c=7.8488(5) A, β=108.538(1) Deg, Z=2, sp. gr. C2/m. The isolated group [HfMo 6 O 24 ] 8- is responsible for fundamental fragment of the structure. Three varieties of crystallographically independent Tl-polyhedra fill space evenly between fragments [HfMo 6 O 24 ] 8- forming three-dimensional form [ru

  4. Enhanced field emission behavior of layered MoSe2

    International Nuclear Information System (INIS)

    Suryawanshi, Sachin R; Pawbake, Amit S; Jadkar, Sandesh R; More, Mahendra A; Pawar, Mahendra S; Late, Dattatray J

    2016-01-01

    Herein, we report one step facile chemical vapor deposition method for synthesis of single-layer MoSe 2 nanosheets with average lateral dimension ∼60 μm on 300 nm SiO 2 /Si and n-type silicon substrates and field emission investigation of MoSe 2 /Si at the base pressure of ∼1 × 10 −8 mbar. The morphological and structural analyses of the as-deposited single-layer MoSe 2 nanosheets were carried out using an optical microscopy, Raman spectroscopy and atomic force microscopy. Furthermore, the values of turn-on and threshold fields required to extract an emission current densities of 1 and 10 μA cm −2 , are found to be ∼1.9 and ∼2.3 V μm1 , respectively. Interestingly, the MoSe 2 nanosheet emitter delivers maximum field emission current density of ∼1.5 mA cm −2 at a relatively lower applied electric field of ∼3.9 V μm1 . The long term operational current stability recorded at the preset values of 35 μA over 3 hr duration and is found to be very good. The observed results demonstrates that the layered MoSe 2 nanosheet based field emitter can open up many opportunities for their potential application as an electron source in flat panel display, transmission electron microscope, and x-ray generation. Thus, the facile one step synthesis approach and robust nature of single-layer MoSe 2 nanosheets emitter can provide prospects for the future development of practical electron sources. (paper)

  5. Pharmaceutical grade sodium (99mTc) pertechnetate from 99Mo/99mTc-TCM-Autosolex generator

    International Nuclear Information System (INIS)

    Chattopadhyay, Sankha; Barua, Luna; Das, Sujata Saha

    2014-01-01

    Technetium-99m (T 1/2 = 6.02h; 140.51 keV (89%)) is the most useful radioisotope in diagnostic nuclear medicine. More than 80% of all diagnostic procedures done worldwide in nuclear medicine centre are performed with 99m Tc. Worldwide crisis of fission 99 Mo based generator in recent past had put the nuclear medicine fraternity in very harsh situation. In order to have an indigenous solution of this problem, we tried to develop a computer controlled semi automated 99 Mo/ 99m Tc generator using MEK solvent extraction technique, which utilizes abundantly available 99 Mo produced by (n,γ) reaction in BARC reactors. The aim of this work is to provide a more reliable, computer controlled module (TCM- AUTOSOLEX) for the recovery of pharmaceutical grade 99m Tc from low specific activity 99 Mo based on solvent extraction methodology

  6. Failure to Achieve a PSA Level ≤1 ng/mL After Neoadjuvant LHRHA Therapy Predicts for Lower Biochemical Control Rate and Overall Survival in Localized Prostate Cancer Treated With Radiotherapy

    International Nuclear Information System (INIS)

    Mitchell, Darren M.; McAleese, Jonathan; Park, Richard M.; Stewart, David P.; Stranex, Stephen; Eakin, Ruth L.; Houston, Russell F.; O'Sullivan, Joe M.

    2007-01-01

    Purpose: To investigate whether failure to suppress the prostate-specific antigen (PSA) level to ≤1 ng/mL after ≥2 months of neoadjuvant luteinizing hormone-releasing hormone agonist therapy in patients scheduled to undergo external beam radiotherapy for localized prostate carcinoma is associated with reduced biochemical failure-free survival. Methods and Materials: A retrospective case note review of consecutive patients with intermediate- or high-risk localized prostate cancer treated between January 2001 and December 2002 with neoadjuvant hormonal deprivation therapy, followed by concurrent hormonal therapy and radiotherapy was performed. Patient data were divided for analysis according to whether the PSA level in Week 1 of radiotherapy was ≤1.0 ng/mL. Biochemical failure was determined using the American Society for Therapeutic Radiology and Oncology (Phoenix) definition. Results: A total of 119 patients were identified. The PSA level after neoadjuvant hormonal deprivation therapy was ≤1 ng/mL in 67 patients and >1 ng/mL in 52. At a median follow-up of 49 months, the 4-year actuarial biochemical failure-free survival rate was 84% vs. 60% (p = 0.0016) in favor of the patients with a PSA level after neoadjuvant hormonal deprivation therapy of ≤1 ng/mL. The overall survival rate was 94% vs. 77.5% (p = 0.0045), and the disease-specific survival rate at 4 years was 98.5% vs. 82.5%. Conclusions: The results of our study have shown that patients with a PSA level >1 ng/mL at the beginning of external beam radiotherapy after ≥2 months of neoadjuvant luteinizing hormone-releasing hormone agonist therapy have a significantly greater rate of biochemical failure and lower survival rate compared with those with a PSA level of ≤1 ng/mL. Patients without adequate PSA suppression should be considered a higher risk group and considered for dose escalation or the use of novel treatments

  7. Ionic Liquid-Assisted Synthesis of Nanoscale (MoS2)x(SnO2)1-x on Reduced Graphene Oxide for the Electrocatalytic Hydrogen Evolution Reaction.

    Science.gov (United States)

    Ravula, Sudhir; Zhang, Chi; Essner, Jeremy B; Robertson, J David; Lin, Jian; Baker, Gary A

    2017-03-08

    Layered transition metal dichalcogenides (TMDs) have attracted increased attention due to their enhanced hydrogen evolution reaction (HER) performance. More specifically, ternary TMD nanohybrids, such as MoS 2(1-x) Se 2x or bimetallic sulfides, have arisen as promising electrocatalysts compared to MoS 2 and MoSe 2 due to their electronic, morphologic, and size tunabilities. Herein, we report the successful synthesis of few-layered MoS 2 /rGO, SnS 2 /rGO, and (MoS 2 ) x (SnO 2 ) 1-x /rGO nanohybrids anchored on reduced graphene oxide (rGO) through a facile hydrothermal reaction in the presence of ionic liquids as stabilizing, delayering agents. Spectroscopic and microscopic techniques (electron microscopy, X-ray diffraction, Raman spectroscopy, neutron activation analysis, and UV-vis spectrophotometry) are used to validate the hierarchical properties, phase identity, and the smooth compositional tunability of the (MoS 2 ) x (SnO 2 ) 1-x /rGO nanohybrids. Linear sweep voltammetry measurements reveal that incorporation of Sn into the ternary nanohybrids (as a discrete SnO 2 phase) greatly reduces the overpotential by 90-130 mV relative to the MoS 2 electrocatalyst. Significantly, the (MoS 2 ) 0.6 (SnO 2 ) 0.4 /rGO nanohybrid displays superior catalytic performance over MoS 2 alone, exhibiting a low overpotential (η 10 ) of 263 ± 5 mV and a small Tafel slope of 50.8 mV dec -1 . The hybrid catalyst shows high stability for the HER in acidic solutions, with negligible activity loss after 1000 cycles. The hierarchical structures and large surface areas possessing exposed, active edge sites make few-layered (MoS 2 ) x (SnO 2 ) 1-x /rGO nanohybrids promising nonprecious metal electrocatalysts for the HER.

  8. Measurement and Estimation of the 99Mo Production Yield by 100Mo(n,2n)99Mo

    Science.gov (United States)

    Minato, Futoshi; Tsukada, Kazuaki; Sato, Nozomi; Watanabe, Satoshi; Saeki, Hideya; Kawabata, Masako; Hashimoto, Shintaro; Nagai, Yasuki

    2017-11-01

    We, for the first time, measured the yield of 99Mo, the mother nuclide of 99mTc used in nuclear medicine diagnostic procedures, produced by the 100Mo(n,2n)99Mo reaction with accelerator neutrons. The neutrons with a continuous energy spectrum from the thermal energy up to about 40 MeV were provided by the C(d,n) reaction with 40 MeV deuteron beams. It was proved that the 99Mo yield agrees with that estimated by using the latest data on neutrons from the C(d,n) reaction and the evaluated cross section of the 100Mo(n,2n)99Mo reaction given in the Japanese Evaluated Nuclear Data Library. On the basis of the agreement, a systematic calculation was carried out to search for an optimum condition that enables us to produce as much 99Mo as possible with a good 99Mo/100Mo value from an economical point of view. The calculated 99Mo yield from a 150 g 100MoO3 sample indicated that about 30% of the demand for 99Mo in Japan can be met with a single accelerator capable of 40 MeV, 2 mA deuteron beams. Here, by referring to an existing 18F-fluorodeoxyglucose (FDG) distribution system we assumed that 99mTc radiopharmaceuticals formed after separating 99mTc from 99Mo can be delivered to hospitals from a radiopharmaceutical company within 6 h. The elution of 99mTc from 99Mo twice a day would meet about 50% of the demand for 99Mo.

  9. Heterometal cubane-type MFe(3)S(4) clusters (M = Mo, V) trigonally symmetrized with hydrotris(pyrazolyl)borate(1-) and tris(pyrazolyl)methanesulfonate(1-) capping ligands.

    Science.gov (United States)

    Fomitchev, Dmitry V; McLauchlan, Craig C; Holm, R H

    2002-02-25

    A series of heterometal cubane-type clusters containing [VFe(3)S(4)](2+) and [MoFe(3)S(4)](3+,2+) cores has been prepared. Ligand substitution of [(DMF)(3)VFe(3)S(4)Cl(3)](-) affords [(Tpms)VFe(3)S(4)L(3)](2)(-) (L = Cl(-) (8), EtS(-) (9), p-MeC(6)H(4)S(-), p-MeC(6)H(4)O(-)). A new procedure for the preparation of molybdenum single cubanes is introduced by the reaction of recently reported [(Tp)MoS(S(4))](-) with FeCl(2)/NaSEt to afford [(Tp)MoFe(3)S(4)Cl(3)](-) (1, 75% yield). This procedure is more efficient that the existing multistep synthesis of single cubanes, which generally affords clusters of mirror symmetry. Also prepared were [(Tp)MoFe(3)S(4)L(3)](-) (L = EtS(-) (2), p-MeC(6)H(4)S(-)). Reduction of 1 with borohydride gives [(Tp)MoFe(3)S(4)Cl(3)](2-) (5, 67%). Owing to the nature of the heterometal ligand, all clusters have idealized trigonal symmetry, reflected in their (1)H NMR spectra. Trigonal structures are demonstrated by crystallography of (Bu(4)N)[1,2], (Bu(4)N)(2)[5] x MeCN, and (Me(4)N)(2)[8,9]. The availability of 1 and 5 allows the first comparison of structures and (57)Fe isomer shifts of [MoFe(3)S(4)](3+,2+) in a constant ligand environment. Small increases in most bond distances indicate that an antibonding electron is added in the reduction of 1. Collective synthetic and electrochemical results from this and other studies demonstrate the existence of the series of oxidation states [VFe(3)S(4)](3+,2+,1+) and [MoFe(3)S(4)](4+,3+,2+) whose relative stabilities within a given series are strongly ligand dependent. Isomer shifts indicate that the reduction of 1 largely affects the Fe(3) subcluster and are consistent with the formal descriptions [MoFe(3+)(2)Fe(2+)S(4)](3+) (1) and [MoFe(3+)Fe(2+)(2)S(4)](2+) (5). Reaction of 1 with excess Li(2)S in acetonitrile affords the double cubane [[(Tp)MoFe(3)S(4)Cl(2)](2)(mu(2)(-)S)](2)(-), whose sulfide-bridged structure is supported by two sequential reductions separated by 290 mV, in analogy with

  10. Men presenting with prostate-specific antigen (PSA) values of over 100 ng/mL.

    Science.gov (United States)

    Ang, Mann; Rajcic, Branimir; Foreman, Darren; Moretti, Kim; O'Callaghan, Michael E

    2016-04-01

    To investigate overall survival and prostate cancer-specific mortality in men with prostate cancer presenting with a PSA level PSA level extracted from the South Australian Prostate Cancer Clinical Outcomes Collaborative (SA-PCCOC) database. Men included were diagnosed between January 1998 and August 2013. Patients were divided into groups according to diagnostic PSA level: 500 ng/mL. Outcomes measured include overall survival and prostate cancer-specific mortality. Clinical stage, Gleason score and the presence of bony metastasis was evaluated to determine if they were prognostic factors in patients with PSA over 100 at diagnosis. Cox proportional hazards and competing risks regression were used to model overall survival and prostate cancer-specific mortality outcomes respectively. Of this cohort, 241 patients (4.2%) had a diagnostic PSA level >100 ng/mL. Patients with PSA >100 ng/mL have a significant reduction in five (29.1% vs 62.5% vs 87%) and ten-year (18.2% vs 36.7% vs 70.7%) overall survival when compared to men with diagnostic PSA 20-100 and PSA level at diagnosis. Overall survival was associated with PSA level, Gleason score and age. There was a linear increase in risk (overall survival) as PSA increased until 200 and no association thereafter. Models of overall survival and prostate cancer-specific mortality incorporating a risk stratification developed by Izumi et al. predicted overall survival but not prostate cancer-specific mortality. The use of this stratification did not improve model accuracy. Only a small number of men (4.2%) with prostate cancer present with PSA >100 ng/mL at diagnosis. Overall survival at five and ten years was significantly poorer in patients with PSA >100 ng/mL. In this cohort of men presenting with PSA >100 at diagnosis, PSA level was not associated with prostate cancer-specific mortality. Gleason score and metastases are significant prognostic factors in this group of men. © 2016 The Authors BJU International © 2016

  11. Thermophysical properties of Na2Th (MoO4)3 (s) and Na4Th (MoO4)4 (s)

    International Nuclear Information System (INIS)

    Dash, Smruti; Rakshit, S.K.; Singh, Ziley; Keskar, Meera; Dahale, N.D.

    2009-01-01

    The heat capacity of Na 2 Th (MoO 4 ) 3 (s) and Na 4 Th (MoO 4 ) 4 (s) have been measured by differential scanning calorimeter in the temperature range 318 to 845 K. The corresponding values are: C p,m (Na 2 Th (MoO 4 ) 3 ,s,T) (JK-1 mol-1) 368.710+ 1.0 10-1 (T/K) - 4950267 (K/T)2 (318 ≤ T (K) ≤ 845). C p,m (Na 4 Th (MoO 4 ) 4 ,s,T) (JK-1 mol-1) = 638.761+ 5.12 10-3 (T/K) - 12691691 (K/T)-2 (318 ≤ T (K) ≤ 845). Experimental heat capacity values for Na 2 Th (MoO 4 ) 3 (s) match reasonably well with that of additive oxide values. But C p,m (T) values of Na 4 Th (MoO 4 ) 4 (s) deviates substantially from the additive oxide values above 700 K. The uncertainty of the measurements reported in this study is calculated to be within 1 to 3 % . (author)

  12. Spectroscopic analysis and efficient diode-pumped 1.9 μm Tm3+-doped β'-Gd2(MoO4)3 crystal laser.

    Science.gov (United States)

    Tang, Jianfeng; Chen, Yujin; Lin, Yanfu; Gong, Xinghong; Huang, Jianhua; Luo, Zundu; Huang, Yidong

    2011-07-04

    Tm3+-doped β'-Gd2(MoO4)3 single crystal was grown by the Czochralski method. Spectroscopic analysis was carried out along different polarizations. End-pumped by a quasi-cw diode laser at 795 nm in a plano-concave cavity, an average laser output power of 58 mW around 1.9 μm was achieved in a 0.93-mm-thick crystal when the output coupler transmission was 7.1%. The absorbed pump threshold was 8 mW and the slope efficiency of the laser was 57%. This crystal has smooth and broad gain curve around 1.9 μm, which shows that it is also a potential gain medium for tunable and short pulse lasers.

  13. Synthesis and electrochemical properties of tin-doped MoS{sub 2} (Sn/MoS{sub 2}) composites for lithium ion battery applications

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Lin; Min, Feixia; Luo, Zhaohui; Wang, Shiquan, E-mail: wsqhao@126.com [Hubei University, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules (China); Teng, Fei [Nanjing University of Information Science and Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School of Environmental Sciences and Engineering (China); Li, Guohua [Zhejiang University of Technology, School of Chemical Engineering and Materials Science (China); Feng, Chuanqi [Hubei University, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules (China)

    2016-12-15

    SnO{sub 2}-MoO{sub 3} composites were synthesized by using (NH{sub 4}){sub 6}Mo{sub 7}O{sub 24}·4H{sub 2}O and SnCl{sub 22H{sub 2}O as raw materials through a simple solvothermal method followed by pyrolysis. Tin-doped MoS{sub 2} (Sn/MoS{sub 2}) flowers have been synthesized by a solvothermal method followed with annealing in Ar(H{sub 2}) atmosphere, with SnO{sub 2}-MoO{sub 3}, thioacetamide (TAA), and urea as starting materials. The doping and the content of Sn-doping play crucial roles in the morphology and electrochemical performance of the MoS{sub 2}. As anode materials for lithium ion battery (LIB), all Sn/MoS{sub 2} composites exhibit both higher reversible capacity and better cycling performance at current density of 200 mA g{sup −1}, compared with MoS{sub 2} without Sn doping. The achieved discharge capacity for Sn/MoS{sub 2} composites is above 1000 mAh g{sup −1} after 100 cycles with nearly 100% coulombic efficiency. The doping of metal Sn in MoS{sub 2} can improve the conductivity of MoS{sub 2} and significantly enhance its electrochemical properties. The good electrochemical performance suggests that the Sn/MoS{sub 2} composite could be a promising candidate as a novel anode material for LIB application. Our present work provides a new approach to the fabrication of anode materials for LIB applications.

  14. Two-dimensional MoS2 electromechanical actuators

    Science.gov (United States)

    Hung, Nguyen T.; Nugraha, Ahmad R. T.; Saito, Riichiro

    2018-02-01

    We investigate the electromechanical properties of two-dimensional MoS2 monolayers with 1H, 1T, and 1T‧ structures as a function of charge doping by using density functional theory. We find isotropic elastic moduli in the 1H and 1T structures, while the 1T‧ structure exhibits an anisotropic elastic modulus. Moreover, the 1T structure is shown to have a negative Poisson’s ratio, while Poisson’s ratios of the 1H and 1T‧ are positive. By charge doping, the monolayer MoS2 shows a reversible strain and work density per cycle ranging from  -0.68% to 2.67% and from 4.4 to 36.9 MJ m-3, respectively, making them suitable for applications in electromechanical actuators. We also examine the stress generated in the MoS2 monolayers and we find that 1T and 1T‧ MoS2 monolayers have relatively better performance than 1H MoS2 monolayer. We argue that such excellent electromechanical performance originate from the electrical conductivity of the metallic 1T and semimetallic 1T‧ structures and also from their high Young’s modulus of about 150-200 GPa.

  15. Hybridized 1T/2H MoS2 Having Controlled 1T Concentrations and its use in Supercapacitors.

    Science.gov (United States)

    Thi Xuyen, Nguyen; Ting, Jyh-Ming

    2017-12-06

    Molybdenum disulfide (MoS 2 ) nanoflowers consisting of hybridized 1T/2H phases have been synthesized by using a microwave-assisted hydrothermal (MTH) method. The concentration of the 1T phase, ranging from 40 % to 73 %, is controlled by simply adjusting the ratio of the Mo and S precursors. By using the hybridized 1T/2H MoS 2 as an electrode material, it was demonstrated that the resulting supercapacitor performance is dominated by the 1T phase concentration. It was found that a supercapacitor with 73 % 1T phase exhibits excellent capacitance of 259 F g -1 and great cyclic stability after 1000 cycles. The formation mechanism of the MHT-synthesized hybridized 1T/2H MoS 2 is also reported. More importantly, the mechanism also explains the observed relationship between the 1T phase concentration and the ratio of the Mo and S precursors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Phase formation in Na2MoO4 - MgMoO4 - Cr2(MoO4)3 system

    International Nuclear Information System (INIS)

    Kotova, I.Yu.; Kozhevnikova, N.M.

    1998-01-01

    Interaction within Na 2 MoO 4 - MgMoO 4 - Cr 2 (MoO 4 ) 3 ternary system is studied by X ray phase and DTA methods. State diagram of NaCr(MoO 4 ) 2 - MgMoO 4 section is plotted. Production of ternary molybdates of Na 1-x Mg 1-x Cr 1+x (MoO 4 ) 3 , where 0 ≤ x ≤ 0.3, and NaMg 3 Cr(MoO 4 ) 5 composition is ascertained [ru

  17. Ab initio CASSCF study of the electronic structure of the transition-metal alkylidene-like complexes Mo-M[prime]H[sub 2] (M[prime] = C, Si, Ge, and Sn)

    Energy Technology Data Exchange (ETDEWEB)

    Marquez, A.; Sanz, J.F. (Universidad de Sevilla (Spain))

    1992-12-02

    Experimental and theoretical research on the electronic and geometric structure of transition-metal-carbenes and -alkylidenes is an active area in chemistry nowadays due to their potential activity in catalysis and in organic and organometallic synthesis. A theoretical investigation of the electronic structure of the high-valent, transition-metal, alkylidene-like complexes MoM[prime]H[sub 2] (M[prime] = C, Si, Ge, and Sn) is reported. Based on ab initio calculations carried out at the complete active space multiconfiguration self-consistent field (CASSCF) level, the molecular structure of the ground state and some low-lying excited states have been determined. For M[prime] = C, Si, and Ge, the ground state has C[sub 2v] symmetry (state [sup 5]B[sub 1]) and corresponds to pairing each electron of the M[prime]H[sub 2] triplet [sup 3]B[sub 1] with an electron of Mo ([sup 7]S). In the case of MoSnH[sub 2], the lowest state is bent (C[sub s] symmetry, state [sup 7]A[prime]), the out-of-plane angle being 68[degrees], and dissociates into SnH[sub 2] ([sup 1]A[sub 1]) + Mo ([sup 7]S). Dissociation energies, potential energy profiles for the dissociation, harmonic force constants in terms of internal symmetry coordinates, and vibrational frequencies are reported. The comparison of these properties with those of their pentacarbonylated homologous (CO)[sub 5]M[double bond]M[prime]H[sub 2] shows that the carbene-like (Fischer) type of complexation is stronger than the alkylidene-like one (Schrock). 28 refs., 4 figs., 6 tabs.

  18. On the coexistence of copper-molybdenum bronzes: CuxMoO3 (0.2 yMoO3-z (0.1 2-O quasi-ternary system

    International Nuclear Information System (INIS)

    Warner, T.E.; Skou, E.M.

    2010-01-01

    Two copper-molybdenum bronzes: Cu y MoO 3-z (0.1 x MoO 3 (0.2 3 at 600 o C under argon in Pt crucibles. Powder XRD showed that the material with global composition '0.1Cu.MoO 3 ' comprises ∼Cu 0.15 MoO 3 and MoO 3 ; whilst '0.2Cu.MoO 3 ' comprises ∼Cu 0.15 MoO 3 and ∼Cu 0.23 MoO 3 . DTA performed on '0.2Cu.MoO 3 ' reveals a reversible solid state phase transition ∼520 o C under argon. Reacting equimolar amounts of Cu 2 O and MoO 2 at 600 o C in a Cu crucible under argon yields: Cu 6 Mo 5 O 18 , Cu and MoO 2 . A tentative subsolidus Cu-MoO 2 -O isothermal (∼25 o C) phase diagram under argon is drawn from these data. Oxidation states of Cu and Mo within this system are discussed.

  19. Alloying as a Route to Monolayer Transition Metal Dichalcogenides with Improved Optoelectronic Performance: Mo(S1–xSex)2 and Mo1–yWyS2

    KAUST Repository

    Shi, Zhiming

    2018-04-26

    On the basis of first-principles and cluster expansion calculations, we propose an effective approach to realize monolayer transition metal dichalcogenides with sizable band gaps and improved optoelectronic performance. We show that monolayer Mo(S1–xSex)2 and Mo1–yWyS2 with x = 1/3, 2/3 and y = 1/3, 1/2, 2/3 are stable according to phonon calculations and realize 1T′ or 1T″ phases. The transition barriers from the 2H phase are lower than for monolayer MoS2, implying that the 1T′ or 1T″ phases can be achieved experimentally. Furthermore, it turns out that the 1T″ monolayer alloys with x = 1/3, 2/3 and y = 1/3, 2/3 are semiconductors with band gaps larger than 1 eV, due to trimerization. The visible light absorption and carrier mobility are strongly improved as compared to 2H monolayer MoS2, MoSe2, and WS2. Thus, the 1T″ monolayer alloys have the potential to expand the applications of transition metal dichalcogenides, for example, in solar cells.

  20. Ternary CoS{sub 2}/MoS{sub 2}/RGO electrocatalyst with CoMoS phase for efficient hydrogen evolution

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yan-Ru; Shang, Xiao [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Gao, Wen-Kun [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Dong, Bin, E-mail: dongbin@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Chi, Jing-Qi; Li, Xiao; Yan, Kai-Li; Chai, Yong-Ming [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Yun-Qi, E-mail: liuyq@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Chen-Guang [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China)

    2017-08-01

    Highlights: • Ternary CoS{sub 2}/MoS{sub 2}/RGO with CoMoS phase as electrocatalyst for HER was prepared. • CoMoS phase have the metallic nature and highly intrinsic activity for HER. • RGO support ensures good distribution of CoMoS phase and enhances the conductivity. • The introduction of CoMoS and RGO may be a novel strategy for efficient HER of MoS{sub 2}. - Abstract: CoMoS phase with metallic character plays crucial role on enhancing the activity of MoS{sub 2} electrocatalysts for hydrogen evolution reaction (HER). However, only Co atoms located in the edges of MoS{sub 2} can create CoMoS phase, so it is a challenge to obtain CoMoS phase with homogeneous distribution limited by the layered MoS{sub 2} and doping method of Co. Herein, we reported a simple one-pot hydrothermal method to prepare novel ternary CoS{sub 2}/MoS{sub 2}/RGO with CoMoS phase for HER using reduced graphene oxide (RGO) as support. XPS proves the formation of CoMoS phase, implying the enhanced activity for HER. RGO support ensures the well distribution of CoMoS phase and enhances the conductivity of CoS{sub 2}/MoS{sub 2}/RGO. Compared to CoS{sub 2}/RGO, MoS{sub 2}/RGO and CoS{sub 2}/MoS{sub 2}, the obtained CoS{sub 2}/MoS{sub 2}/RGO shows superior activity for HER with an onset overpotential of −80 mV (vs. RHE), small Tafel slope of 56 mV dec{sup −1}, high exchange current density of 11.4 μA cm{sup −2} and rigid electrochemical durability. The enhanced performances for HER may be ascribed to the formation of CoMoS phase with high activity and the existence of RGO support with good electrical conductivitys in ternary CoS{sub 2}/MoS{sub 2}/RGO. Therefore, the introduction of CoMoS phase and RGO into MoS{sub 2} could effectively enhance electrocatalytic properties for HER.

  1. Structural, magnetic and transport properties of Pb{sub 2}Cr{sub 1+x}Mo{sub 1−x}O{sub 6} (−1≤x≤1/3)

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, H.F. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); School of Mathematics and Physics, University of Science and Technology, Beijing 100083 (China); Cao, L.P. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Song, Y.J. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); School of Mathematics and Physics, University of Science and Technology, Beijing 100083 (China); Feng, S.M.; Shen, X. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Ni, X.D. [School of Mathematics and Physics, University of Science and Technology, Beijing 100083 (China); Yao, Y.; Wang, Y.G. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wang, R.M. [School of Mathematics and Physics, University of Science and Technology, Beijing 100083 (China); Jin, C.Q. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Yu, R.C., E-mail: rcyu@aphy.iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049 (China)

    2017-02-15

    Pb{sub 2}Cr{sub 1+x}Mo{sub 1-x}O{sub 6} (−1≤x≤1/3) samples were synthesized via a high pressure and high temperature route. X-ray diffraction results suggest the samples crystallize in a disordered double perovskite structure (Pm-3m). X-ray photoemission spectroscopy results confirm the presence of Mo{sup 4+} for x=−1 and Mo{sup 6+} for x=1/3. The measured magnetic and electrical properties exhibit systematic change with increasing x. - Highlights: • A series of Pb{sub 2}Cr{sub 1+x}Mo{sub 1−x}O{sub 6} samples were synthesized under high pressure. • Magnetic and electrical properties of the series samples were investigated. • Valence states of Cr and Mo were determined through the analyses of XRD and XPS results. • Ground state of PbMoO{sub 3} were determined through the transport study and first-principles calculations.

  2. 99Mo production by 100Mo(n,2n)99Mo using accelerator neutrons

    International Nuclear Information System (INIS)

    Sato, Nozomi; Kawabata, Masako; Nagai, Yasuki; Hashimoto, Kazuyuki; Hatsukawa, Yuichi; Saeki, Hideya; Motoishi, Shoji; Kin, Tadahiro; Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke; Minato, Futoshi; Iwamoto, Osamu; Iwamoto, Nobuyuki; Hashimoto, Shintaro

    2013-01-01

    We proposed a new route to produce a medical radioisotope 99 Mo by the 100 Mo(n,2n) 99 Mo reaction using accelerator neutrons. A high-quality 99 Mo with a minimum level of radioactive waste can be obtained by the proposed reaction. The decay product of 99 Mo, 99m Tc, is separated from 99 Mo by the sublimation method. The proposed route could bring a major breakthrough in the solution of ensuring a constant and reliable supply of 99 Mo. (author)

  3. MoS2 coated hollow carbon spheres for anodes of lithium ion batteries

    International Nuclear Information System (INIS)

    Zhang, Yufei; Wang, Ye; Shi, Wenhui; Yang, Huiying; Yang, Jun; Huang, Wei; Dong, Xiaochen

    2016-01-01

    With the assistance of resorcinol–formaldehyde, MoS 2 coated hollow carbon spheres (C@MoS 2 ) were synthesized through a facile hydrothermal route followed by heat and alkali treatments. The measurements indicate that the hollow carbon spheres with an average diameter of 300 nm and shell thickness of 20 nm. And the hollow core are uniformly covered by ultrathin MoS 2 nanosheets with a length increased to 400 nm. The unique hollow structure and the synergistic effect between carbon layer and MoS 2 nanosheets significantly enhance the rate capability and electrochemical stability of C@MoS 2 spheres as anode material of lithium-ion battery. The synthesized C@MoS 2 delivered a capacity of 750 mAh g −1 at a current density of 100 mA g −1 . More importantly, the C@MoS 2 maintained a reversible capacity of 533 mAh g −1 even at a high current density of 1000 mA g −1 . The study indicated that MoS 2 coated hollow carbon spheres can be promising anode material for next generation high-performance lithium-ion batteries. (paper)

  4. Lattice structures and electronic properties of MO/MoSe2 interface from first-principles calculations

    Science.gov (United States)

    Zhang, Yu; Tang, Fu-Ling; Xue, Hong-Tao; Lu, Wen-Jiang; Liu, Jiang-Fei; Huang, Min

    2015-02-01

    Using first-principles plane-wave calculations within density functional theory, we theoretically studied the atomic structure, bonding energy and electronic properties of the perfect Mo (110)/MoSe2 (100) interface with a lattice mismatch less than 4.2%. Compared with the perfect structure, the interface is somewhat relaxed, and its atomic positions and bond lengths change slightly. The calculated interface bonding energy is about -1.2 J/m2, indicating that this interface is very stable. The MoSe2 layer on the interface has some interface states near the Fermi level, the interface states are mainly caused by Mo 4d orbitals, while the Se atom almost have no contribution. On the interface, Mo-5s and Se-4p orbitals hybridize at about -6.5 to -5.0 eV, and Mo-4d and Se-4p orbitals hybridize at about -5.0 to -1.0 eV. These hybridizations greatly improve the bonding ability of Mo and Se atom in the interface. By Bader charge analysis, we find electron redistribution near the interface which promotes the bonding of the Mo and MoSe2 layer.

  5. Mo1-xWxSe2-Based Schottky Junction Photovoltaic Cells.

    Science.gov (United States)

    Yi, Sum-Gyun; Kim, Sung Hyun; Park, Sungjin; Oh, Donggun; Choi, Hwan Young; Lee, Nara; Choi, Young Jai; Yoo, Kyung-Hwa

    2016-12-14

    We developed Schottky junction photovoltaic cells based on multilayer Mo 1-x W x Se 2 with x = 0, 0.5, and 1. To generate built-in potentials, Pd and Al were used as the source and drain electrodes in a lateral structure, and Pd and graphene were used as the bottom and top electrodes in a vertical structure. These devices exhibited gate-tunable diode-like current rectification and photovoltaic responses. Mo 0.5 W 0.5 Se 2 Schottky diodes with Pd and Al electrodes exhibited higher photovoltaic efficiency than MoSe 2 and WSe 2 devices with Pd and Al electrodes, likely because of the greater adjusted band alignment in Mo 0.5 W 0.5 Se 2 devices. Furthermore, we showed that Mo 0.5 W 0.5 Se 2 -based vertical Schottky diodes yield a power conversion efficiency of ∼16% under 532 nm light and ∼13% under a standard air mass 1.5 spectrum, demonstrating their remarkable potential for photovoltaic applications.

  6. Effects of Coordinating a Hemilabile Ligand to 14e Cp*M(NO) Scaffolds (M = Mo, W).

    Science.gov (United States)

    Handford, Rex C; Patrick, Brian O; Legzdins, Peter

    2017-10-16

    This article describes the differing chemical properties imparted by the two ligands, hemilabile 2-[(diisopropylphosphino)methyl]-3-methylpyridine ( i Pr 2 PN) and the related 1,2-bis(dimethylphosphino)ethane (dmpe), when attached to the 14e Cp*M(NO) scaffolds (Cp* = η 5 -C 5 Me 5 ; M = W, Mo). For instance, the treatment of [Cp*W(NO)Cl 2 ] 2 with 2 or 1 equiv of dmpe in C 6 H 6 affords excellent yields of [Cp*W(NO)(κ 2 -dmpe)Cl]Cl (1) or [Cp*W(NO)Cl 2 ] 2 [μ-dmpe] (2). In contrast, the treatment of [Cp*W(NO)Cl 2 ] 2 with 1 equiv of i Pr 2 PN in C 6 H 6 does not produce the complex analogous to 1 but rather affords orange [Cp*W(NO)(κ 2 -P-N- i Pr 2 PN)Cl][Cp*W(NO)Cl 3 ] (3) in 90% yield. Furthermore, subsequent reduction of 1 or 2 with 2 or 4 equiv of Cp 2 Co in tetrahydrofuran (THF), respectively, results in the production of orange Cp*W(NO)(κ 2 -dmpe) (4) in good yields. However, a similar treatment of 3 with 1 equiv of Cp 2 Co in THF does not result in the production of Cp*W(NO)(κ 2 -P,N- i Pr 2 PN), the analogue of 4, but rather generates a 1:1 mixture of the novel complexes Cp*W(NO)(H)(κ 1 -P- i Pr 2 PN)Cl (5) and Cp*W(NO)(κ 2 -P,N- i Pr 2 PCH-2-(3-Me-C 5 H 3 N))Cl (6), which are separable by crystallization from pentane and diethyl ether solutions, respectively. The divergent reactivity imparted by the dmpe and i Pr 2 PN proligands is a unique demonstration of the unusual properties of a mixed-donor ligand. In the case of molybdenum, the reaction of [Cp*Mo(NO)Cl 2 ] 2 with 2 equiv of i Pr 2 PN in C 6 H 6 first forms Cp*Mo(NO)(κ 1 -P- i Pr 2 PN)Cl 2 , which then converts to [Cp*Mo(NO)(κ 2 -P,N- i Pr 2 PN)Cl][Cp*Mo(NO)Cl 3 ], the analogue of 3. Reduction of the Cp*Mo(NO)(κ 1 -P- i Pr 2 PN)Cl 2 intermediate complex with 2 equiv of Cp 2 Co affords dark-green Cp*Mo(NO)(κ 2 -P,N- i Pr 2 PN) (7). All new complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of most of them have

  7. Exfoliated MoS2 nanosheets as efficient catalysts for electrochemical hydrogen evolution

    International Nuclear Information System (INIS)

    Ji, Shanshan; Yang, Zhe; Zhang, Chao; Liu, Zhenyan; Tjiu, Weng Weei; Phang, In Yee; Zhang, Zheng; Pan, Jisheng; Liu, Tianxi

    2013-01-01

    Graphical abstract: An efficient electrocatalyst for hydrogen evolution has been developed based on exfoliation of bulk MoS 2 crystals via a direct dispersion and ultrasonication method. Drop-casting method is used to fabricate the exfoliated MoS 2 nanosheets modified glass carbon electrode (E-MoS 2 /GCE) with various loadings. The E-MoS 2 /GCE with electrode loading of 48 μg cm −1 exhibits high catalytic activity for hydrogen evolution with a low overpotential (−0.12 V) and a high current density (1.26 mA cm −2 , at η = 150 mV). -- Highlights: • Two-dimensional MoS 2 nanosheets have been obtained by exfoliation of bulk MoS 2 crystals. • Exfoliated MoS 2 nanosheets show high electrocatalytic activity for H 2 production. • This study provides a new approach for renewable and economic H 2 production. -- Abstract: An efficient electrocatalyst for hydrogen evolution has been developed based on liquid exfoliation of bulk MoS 2 via a direct dispersion and ultrasonication method. Transmission electron microscopy and atomic force microscopy measurements show that the exfoliated MoS 2 consists of two-dimensional nanosheets. The exfoliated MoS 2 nanosheets modified glass carbon electrode (E-MoS 2 /GCE) with various loadings is fabricated via a drop-casting method. The electrocatalytic activity of E-MoS 2 /GCE toward hydrogen evolution reaction is examined using linear sweep voltammetry. It is shown that the E-MoS 2 /GCE with an electrode loading of 48 μg cm −2 exhibits a high catalytic activity for hydrogen evolution with a low overpotential (−0.12 V) and a high current density (1.26 mA cm −2 , at η = 150 mV)

  8. Structure of restacked MoS{sub 2} and WS{sub 2} elucidated by electron crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Heising, J; Kanatzidis, M G

    1999-02-03

    There has been a lot of confusion about the nature of restacked MoS{sub 2} and WS{sub 2}. The structure has been proposed to be trigonal TiS{sub 2} type with octahedral M{sup 4} and called 1T-MoS{sub 2}. The presence of a distortion in the metal plane that gives rise to a superstructure has been suggested. Electron crystallographic studies on small (submicron) single crystal domains of restacked WS{sub 2} and MoS{sub 2} have been performed to solve their superstructure. It was shown that what initially seems to be a trigonal crystal is actually a triplet of three individual orthorhombic crystals. Using two-dimensional hk0 data from films for both triple and single crystals the authors calculated corresponding Patterson projections, which reveal a severe distortion in the Mo/W plane, forming infinite zigzag chains. The projection of the structure suggests M-M distances of 2.92 and 2.74 {angstrom} for MoS{sub 2} and Ws{sub 2}, respectively. Least-squares refinement from the single-crystal data gives R{sub 1} = 13.3% for WS{sub 2} and R{sub 1} = 15.3% for MoS{sub 2}. Therefore, it is proposed that restacked MoS{sub 2} and WS{sub 2} are not 1T form but rather WTe{sub 2} type.

  9. Rocking disc electro-deposition of copper films on Mo/MoSe{sub 2} substrates

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, Charles Y.; Frith, Paul E. [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Zoppi, Guillaume; Forbes, Ian [Northumbria Photovoltaics Applications Centre, Northumbria University, NE1 8ST (United Kingdom); Rogers, Keith D. [Cranfield Health, Cranfield University, Shrivenham Campus, Swindon, SN6 8LA (United Kingdom); Lane, David W. [Department of Applied Science, Security and Resilience, Cranfield University, Shrivenham, Swindon, SN6 8LA (United Kingdom); Marken, Frank, E-mail: F.Marken@bath.ac.uk [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

    2011-08-31

    A novel electro-deposition method based on a rocking disc system with {pi}/3 amplitude and variable frequency is introduced. Uniform copper films were deposited from a 0.1 M CuSO{sub 4}/3.0 M NaOH/0.2 M sorbitol bath directly onto 12.1 cm{sup 2} Mo/MoSe{sub 2} substrates with X-ray diffraction showing a thickness variation of {+-}5% over this area. Investigation of the mass transport conditions suggests (i) uniform diffusion over the sample, (ii) a rate of mass transport proportional to the square root of the rocking rate, and (iii) turbulent conditions, which are able to dislodge gas bubbles during electro-deposition.

  10. Vertical MoSe2-MoO x p-n heterojunction and its application in optoelectronics

    Science.gov (United States)

    Chen, Xiaoshuang; Liu, Guangbo; Hu, Yunxia; Cao, Wenwu; Hu, PingAn; Hu, Wenping

    2018-01-01

    The hybrid n-type 2D transition-metal dichalcogenide (TMD)/p-type oxide van der Waals (vdW) heterojunction nanosheets consist of 2D layered MoSe2 (the n-type 2D material) and MoO x (the p-type oxide) which are grown on SiO2/Si substrates for the first time via chemical vapor deposition technique, displaying the regular hexagon structures with the average length dimension of sides of ˜8 μm. Vertical MoSe2-MoO x p-n heterojunctions demonstrate obviously current-rectifying characteristic, and it can be tuned via gate voltage. What is more, the photodetector based on vertical MoSe2-MoO x heterojunctions displays optimal photoresponse behavior, generating the responsivity, detectivity, and external quantum efficiency to 3.4 A W-1, 0.85 × 108 Jones, and 1665.6%, respectively, at V ds = 5 V with the light wavelength of 254 nm under 0.29 mW cm-2. These results furnish a building block on investigating the flexible and transparent properties of vdW and further optimizing the structure of the devices for better optoelectronic and electronic performance.

  11. MoSe2 modified TiO2 nanotube arrays with superior photoelectrochemical performance

    Science.gov (United States)

    Zhang, Yaping; Zhu, Haifeng; Yu, Lianqing; He, Jiandong; Huang, Chengxing

    2018-04-01

    TiO2 nanotube arrays (TNTs) are first prepared by anodization Ti foils in ethylene glycol electrolyte. Then, MoSe2 deposites electrochemically on TNTs. The as-synthesized MoSe2/TiO2 composite has a much higher photocurrent density of 1.07 mA cm‑2 at 0 V than pure TNTs of 0.38 mA cm‑2, which suggests that the MoSe2/TiO2 composite film has optimum photoelectrocatalysis properties. The electron transport resistances of the MoSe2/TiO2 decreases to half of pure TiO2, at 295.6 ohm/cm2. Both photocurrent-time and Mott-Schottky plots indicate MoSe2 a p-type semiconductor characteristics. MoSe2/TiO2 composite can achieve a maximum 5 orders of magnitude enhancement in carrier density (4.650 × 1027 cm‑3) than that of pure TiO2 arrays. It can be attributed to p-n heterojunction formed between MoSe2 and TiO2, and the composite can be potentially applied in photoelectrochemical, photocatalysis fields.

  12. Facile synthesis of stable structured MoS{sub 2}-Mo-CNFs heteroarchitecture with enhanced hydrogen evolution

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Qionghua [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Faculty of Material and Energy, South West University, Chongqing 400700 (China); Yao, Yucen [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Liu, Bitao, E-mail: liubitao007@163.com [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Peng, Lingling; Yan, Hengqing; Hou, Zhupei; Wang, Jun [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Lin, Yue, E-mail: linyue@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Anhui 230026 (China)

    2017-06-01

    3D structured MoS{sub 2} are grown in-situ on Mo particles embedded carbon nanofibers (CNFs) via a hydrothermal method. Due to this special structure, the bonding and effective electron delivery between CNFs and MoS{sub 2} are both enhanced, and which will exhibits a better hydrogen evolution activity. The onset potential of this MoS{sub 2}-Mo-CNFs catalyst will decreased to 60 mV compared to the 90 mV for the MoS{sub 2}-CNFs. And its current density nearly no change with 5000 cycles which is better than the 32.3% decrease of MoS{sub 2}-CNFs at η = 300 mV (V vs RHE). - Highlights: • Newly structured MoS{sub 2}-Mo-CNFs with effectively connection between MoS{sub 2} and CNFs successfully synthesized. • This structure can enhance the charge transfer and significantly increase electrocatalytic efficiency. • Nearly no HER activity loss after 5000 CV cycles.

  13. Functionalization of liquid-exfoliated two-dimensional 2H-MoS2.

    Science.gov (United States)

    Backes, Claudia; Berner, Nina C; Chen, Xin; Lafargue, Paul; LaPlace, Pierre; Freeley, Mark; Duesberg, Georg S; Coleman, Jonathan N; McDonald, Aidan R

    2015-02-23

    Layered two-dimensional (2D) inorganic transition-metal dichalchogenides (TMDs) have attracted great interest as a result of their potential application in optoelectronics, catalysis, and medicine. However, methods to functionalize and process such 2D TMDs remain scarce. We have established a facile route towards functionalized layered MoS2 . We found that the reaction of liquid-exfoliated 2D MoS2 , with M(OAc)2 salts (M=Ni, Cu, Zn; OAc=acetate) yielded functionalized MoS2 -M(OAc)2 materials. Importantly, this method furnished the 2H-polytype of MoS2 which is a semiconductor. X-ray photoelectron spectroscopy (XPS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFT-IR), and thermogravimetric analysis (TGA) provide strong evidence for the coordination of MoS2 surface sulfur atoms to the M(OAc)2 salt. Interestingly, functionalization of 2H-MoS2 allows for its dispersion/processing in more conventional laboratory solvents. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Study of methodologies for quality control of 99Mo used in 99Mo/99mTc generators

    International Nuclear Information System (INIS)

    Said, Daphne de Souza

    2016-01-01

    99m Tc is the most used radionuclide in nuclear medicine. In Brazil, the 99 Mo/ 99m Tc generators are exclusively produced by Radiopharmacy Center at IPEN-CNEN/ SP, by importing 99 Mo from different suppliers. 99 Mo (t 1/2 = 66 h) is a fission product of 235 U and it can have radionuclidic impurities that are prejudicial for human health. For safe use of generators, it is necessary to perform the evaluation of 99 Mo by quality control tests in order to assess if 99 Mo complies with the specifications. The European Pharmacopoeia (EP) presents a monograph for evaluation of the quality of the [ 99 Mo] solution as sodium molybdate,that is used as raw material for 99 Mo/ 99m Tc generators production, including specification parameters (identification, radiochemical purity and radionuclidic purity), analysis methods and limits. However, it has been observed difficulties on the execution and implementation of these methods by the generators producers, with a few literature about this subject, probably due to complexity of the proposed methods. In this work, many quality control parameters of 99 Mo described in the EP monograph were evaluated. Separation methods for 99M o from its radionuclidic impurities by solid phase extraction (SPE) and TLC were studied. After SPE separation, the quantification of metals by ICP-OES to evaluate the percentage of retention of Mo and the percentage of recovery of Ru, Te and Sr using different types of cartridges were proposed, replacing radiotracers use. It was observed that the specific type of SPE cartridge recommended by the EP for separation of 99 Mo presented low recoveries for Ru, compared to other available anion exchange SPE cartridges. 99 Mo samples from different worldwide suppliers were analyzed. It was observed that quantification of 103 Ru in 99 Mo samples with decay time higher than 4 weeks is possible. An alternative method for separation of 131 I from 99 Mo showed promising results by TLC. The quantification of beta and

  15. Alloying as a Route to Monolayer Transition Metal Dichalcogenides with Improved Optoelectronic Performance: Mo(S1–xSex)2 and Mo1–yWyS2

    KAUST Repository

    Shi, Zhiming; Zhang, Qingyun; Schwingenschlö gl, Udo

    2018-01-01

    –xSex)2 and Mo1–yWyS2 with x = 1/3, 2/3 and y = 1/3, 1/2, 2/3 are stable according to phonon calculations and realize 1T′ or 1T″ phases. The transition barriers from the 2H phase are lower than for monolayer MoS2, implying that the 1T′ or 1T″ phases

  16. Creep Rupture Analysis and Life Estimation of 1.25Cr-0.5Mo, 2.25Cr-1Mo and Modified 9Cr-1Mo Steel: A Comparative Study

    Science.gov (United States)

    Roy, Prabir Kumar

    2018-04-01

    This paper highlights a comparative assessment of creep life of 1.25Cr-0.5Mo, 2.25Cr-1Mo and modified 9Cr-1Mo steels based on accelerated creep rupture tests. Creep rupture test data have been analysed and creep life of the above mentioned materials have been assessed using Larson Miller parameter at the stress levels of 60 and 42 MPa for different temperatures. Limiting steam temperatures for minimum design life of 105 h at 42 and 60 MPa for the above mentioned steels have also been calculated. Microstructural studies for the three above mentioned steels are also done.

  17. Na2MoO2As2O7

    Directory of Open Access Journals (Sweden)

    Raja Jouini

    2012-12-01

    Full Text Available Disodium molybdenum dioxide diarsenate, Na2MoO2As2O7, has been synthesized by a solid-state reaction. The structure is built up from MoAs2O12 linear units sharing corners to form a three-dimensional framework containing tunnels running along the a-axis direction in which the Na+ cations are located. In this framework, the AsV atoms are tetrahedrally coordinated and form an As2O7 group. The MoVI atom is displaced from the center of an octahedron of O atoms. Two Na+ cations are disordered about inversion centres. Structural relationships between different compounds: A2MoO2As2O7 (A = K, Rb, AMOP2O7 (A = Na, K, Rb; M = Mo, Nb and MoP2O7 are discussed.

  18. Synthesis, structure and optical properties of two isotypic crystals, Na3MO4Cl (M=W, Mo)

    International Nuclear Information System (INIS)

    Han, Shujuan; Bai, Chunyan; Zhang, Bingbing; Yang, Zhihua; Pan, Shilie

    2016-01-01

    Two isotypic compounds, Na 3 MO 4 Cl (M = W, Mo) have been obtained from the high temperature solution, and their structures were determined by single-crystal X-ray diffraction. Both of them crystallize in the space group P4/nmm of tetragonal system with the unit cells: a=7.5181(15), c=5.360(2) for Na 3 WO 4 Cl and a=7.4942(12), c=5.3409(18) for Na 3 MoO 4 Cl. The structure exhibits a 3D network built up by the ClNa 6 groups, and the MO 4 groups reside in the tunnels of the 3D network. The structural similarities and differences between Na 3 MO 4 Cl (M=W, Mo) and Sr 3 MO 4 F (M=Al, Ga) have been discussed. Meanwhile, detailed structure comparison analyses between Na 3 MO 4 Cl (M=W, Mo) and Na 3 MO 4 F (M=W, Mo) indicate that the different connection modes of ClNa 6 and FNa 6 make Na 3 MO 4 Cl and Na 3 MO 4 F crystallize in different structures. The IR spectra were used to verify the validity of the structure. The diffuse reflectance spectra show that the UV absorption edges are about 249 nm (4.99 eV) and 265 nm (4.69 eV) for Na 3 WO 4 Cl and Na 3 MoO 4 Cl, respectively. In addition, the first-principles theoretical studies are also carried out to aid the understanding of electronic structures and linear optical properties. - Graphical abstract: Two isotypic compounds, Na 3 MO 4 Cl (M=W, Mo) have been obtained from the high temperature solution. Both of them crystallize in the space group P4/nmm of tetragonal system. The structure exhibits a 3D network built up by the ClNa 6 groups, and the MO 4 groups reside in the tunnels of the 3D network. - Highlights: • Structure and properties of Na 3 MO 4 Cl (M=W, Mo) are reported for the first time. • They show a 3D network built by ClNa 6 , and WO 4 lies in the tunnels of the network. • IR spectra were used to verify the validity of the structure. • Band structures and density of states have been calculated.

  19. Magnetic MoS2 pizzas and sandwiches with Mnn (n = 1-4) cluster toppings and fillings: A first-principles investigation

    Science.gov (United States)

    Zhang, Meng; Huang, Zhongjia; Wang, Xiao; Zhang, Hongyu; Li, Taohai; Wu, Zhaolong; Luo, Youhua; Cao, Wei

    2016-01-01

    The inorganic layered crystal (ILC) MoS2 in low dimensions is considered as one of the most promising and efficient semiconductors. To enable the magnetism and keep intrinsic crystal structures, we carried out a first-principles study of the magnetic and semiconductive monolayer MoS2 adsorbed with the Mnn (n = 1-4) clusters, and bilayer MoS2 intercalated with the same clusters. Geometric optimizations of the Mnn@MoS2 systems show the complexes prefer to have Mnn@MoS2(M) pizza and Mnn@MoS2(B) sandwich forms in the mono- and bi-layered cases, respectively. Introductions of the clusters will enhance complex stabilities, while bonds and charge transfers are found between external Mn clusters and the S atoms in the hosts. The pizzas have medium magnetic moments of 3, 6, 9, 4 μB and sandwiches of 3, 2, 3, 2 μB following the manganese numbers. The pizzas and sandwiches are semiconductors, but with narrower bandgaps compared to their corresponding pristine hosts. Direct bandgaps were found in the Mnn@MoS2(M) (n = 1,4) pizzas, and excitingly in the Mn1@MoS2(B) sandwich. Combining functional clusters to the layered hosts, the present work shows a novel material manipulation strategy to boost semiconductive ILCs applications in magnetics.

  20. Structure of β-TlMo2P3O13

    International Nuclear Information System (INIS)

    Costentin, G.; Borel, M.M.; Grandin, A.; Leclaire, A.; Raveau, B.

    1991-01-01

    Thallium molybdenum triphosphate, TlMo 2 P 3 O 13 , M r =679.16, monoclinic, P2 1 /c, a=9.7536 (3), b=19.0640 (16), c=6.3945 (7) A, β=107.099 (7) 0 , V=1136 (2) A 3 , Z=4, D m not measured, D x =4.08 Mg m -3 , λ(MoKα)=0.71073 A, μ=16.90 mm -1 , F(000)=314, T=293 K, 951 reflections, R=0.047, ωR=0.047. The lattice is built up from MoO 6 , PO 4 and P 2 O 7 groups delimiting tunnels where the Tl + ions are located. The title compound is isotyopic with β-KMo 2 P 3 O 13 . (orig.)

  1. Regeneration of 98Mo enriched from waste 99mTc generators

    International Nuclear Information System (INIS)

    Khujaev, S.; Mirzaeva, N.A.; Ashrapov, U.T.; Berdieva, M.; Nushtaeva, L.B.

    2002-01-01

    Radioisotope generator of technetium-99m have found widespread application in nuclear medicine for production of sodium pertechnetate solution ( 99m Tc). In technology of radioisotope generator making, which developed in Institute of Nuclear Physics of Uzbekistan Academy of Science the parent radioisotopes of molybdenum-90 are produced with neutron capture reaction of the enriched isotope of molybdenum-98 in nuclear reactor of WWR-SM. The specific activity of 99 Mo is reached to 5.0 Ci/g after activation process of original material ( 98 Mo). The basic mass of the original materials ( 98 Mo) which took for the irradiation is remained inactive. The high cost of enriched 97 Mo to make up necessity of development of method of 98 Mo regeneration with end in view of its recurring in manufacture. In general, the chromatographic type generator are produced in manufacture with aluminium oxide as sorbent for the parent radionuclides. So we studied the description conditions of molybdenum from aluminium oxide phase, its purification from possible accompanying admixtures and production of molybdenum in goods state. The systems: sulphur acid, ammonium and ammonium with hydrogen peroxide have been considered for molybdenum desorption from aluminium oxide phase. The sulphur oxid solution is most optimal medium for molybdenum desorption with concentration 0.5 M and elution rate for this makes up 2.0-2.05 ml/min. The 98 Mo yield makes up not over 87 %. The subsequent purification of the desorption of molybdenum-98 from the possible admixture are realized by using column with tetra-phosphonium alkali. At first , 98 Mo sorption is realized by anion exchange resin, after that sorbate is washing and dispiriting by solution with composition: 1.0 M NH 4 NO 3 +8.0 % NH 4 OH+10 -2 % H 2 O 2 . The 98 Mo yield makes up under 80 %. Further from obtained solution is realized by precipitation of molybdenum-98 in acid medium and separation of sediments from liquid phase, drying if sediments and

  2. Ultra-broadband nonlinear saturable absorption of high-yield MoS2 nanosheets

    Science.gov (United States)

    Wei, Rongfei; Zhang, Hang; Hu, Zhongliang; Qiao, Tian; He, Xin; Guo, Qiangbing; Tian, Xiangling; Chen, Zhi; Qiu, Jianrong

    2016-07-01

    High-yield MoS2 nanosheets with strong nonlinear optical (NLO) responses in a broad near-infrared range were synthesized by a facile hydrothermal method. The observation of saturable absorption, which was excited by the light with photon energy smaller than the gap energy of MoS2, can be attributed to the enhancement of the hybridization between the Mo d-orbital and S p-orbital by the oxygen incorporation into MoS2. High-yield MoS2 nanosheets with high modulation depth and large saturable intensity generated a stable, passively Q-switched fiber laser pulse at 1.56 μm. The high output power of 1.08 mW can be attained under a very low pump power of 30.87 mW. Compared to recently reported passively Q-switched fiber lasers utilizing exfoliated MoS2 nanosheets, the efficiency of the laser for our passive Q-switching operation is larger and reaches 3.50%. This research may extend the understanding on the NLO properties of MoS2 and indicate the feasibility of the high-yield MoS2 nanosheets to passively Q-switched fiber laser effectively at low pump strengths.

  3. Enhancing photoresponsivity using MoTe2-graphene vertical heterostructures

    Science.gov (United States)

    Kuiri, Manabendra; Chakraborty, Biswanath; Paul, Arup; Das, Subhadip; Sood, A. K.; Das, Anindya

    2016-02-01

    MoTe2 with a narrow band-gap of ˜1.1 eV is a promising candidate for optoelectronic applications, especially for the near-infrared photo detection. However, the photo responsivity of few layers MoTe2 is very small (graphene vertical heterostructures have a much larger photo responsivity of ˜20 mA W-1. The trans-conductance measurements with back gate voltage show on-off ratio of the vertical transistor to be ˜(0.5-1) × 105. The rectification nature of the source-drain current with the back gate voltage reveals the presence of a stronger Schottky barrier at the MoTe2-metal contact as compared to the MoTe2-graphene interface. In order to quantify the barrier height, it is essential to measure the work function of a few layers MoTe2, not known so far. We demonstrate a method to determine the work function by measuring the photo-response of the vertical transistor as a function of the Schottky barrier height at the MoTe2-graphene interface tuned by electrolytic top gating.

  4. Alpha-fetoprotein level > 1000 ng/mL as an exclusion criterion for liver transplantation in patients with hepatocellular carcinoma meeting the Milan criteria.

    Science.gov (United States)

    Hameed, Bilal; Mehta, Neil; Sapisochin, Gonzalo; Roberts, John P; Yao, Francis Y

    2014-08-01

    Serum alpha-fetoprotein (AFP) has been increasingly recognized as a marker for a poor prognosis after liver transplantation (LT) for hepatocellular carcinoma (HCC). Many published reports, however, have included a large proportion of patients with HCC beyond the Milan criteria, and the effects of incorporating AFP as an exclusion criterion for LT remain unclear. We studied 211 consecutive patients undergoing LT for HCC within the Milan criteria according to imaging under the Model for End-Stage Liver Disease organ allocation system between June 2002 and January 2009. The majority (93.4%) had locoregional therapy before LT. The median follow-up was 4.5 years (minimum = 2 years). The Kaplan-Meier 1- and 5-year patient survival rates were 94.3% and 83.4%, respectively. In a univariate analysis, significant predictors of HCC recurrence included vascular invasion [hazard ratio (HR) = 10, 95% confidence interval (CI) = 3.9-26, P 1000 ng/mL (HR = 4.5, 95% CI = 1.3-15.3, P = 0.02), and an AFP level > 500 ng/mL (HR = 3.1, 95% CI = 1.04-9.4, P = 0.04). In a multivariate analysis, vascular invasion was the only significant predictor of tumor recurrence (HR = 5.6, 95% CI = 1.9-19, P = 0.02). An AFP level > 1000 ng/mL was the strongest pretransplant variable predicting vascular invasion (odds ratio = 6.8, 95% CI = 1.6-19.1, P = 0.006). The 1- and 5-year rates of survival without recurrence were 90% and 52.7%, respectively, for patients with an AFP level > 1000 ng/mL and 95% and 80.3%, respectively, for patients with an AFP level ≤ 1000 ng/mL (P = 0.026). Applying an AFP level > 1000 ng/mL as a cutoff would have resulted in the exclusion of 4.7% of the patients fr m LT and a 20% reduction in HCC recurrence. In conclusion, an AFP level > 1000 ng/mL may be a surrogate for vascular invasion and may be used to predict posttransplant HCC recurrence. Incorporating an AFP level > 1000 ng/mL as an exclusion criterion for LT within the Milan criteria may further improve posttransplant

  5. Effect of Mo/B atomic ratio on the properties of Mo2NiB2-based cermets

    International Nuclear Information System (INIS)

    Xie, Lang; Li, XiaoBo; Zhang, Dan; Yi, Li; Gao, XiaoQing; Xiangtan Univ.

    2015-01-01

    Using three elementary substances, Mo, Ni, and amorphous B as raw materials, four series of Mo 2 NiB 2 -based cermets with the Mo/B atomic ratio ranging from 0.9 to 1.2 were successfully prepared via reaction sintering. The effect of Mo/B atomic ratio on the microstructure and properties was studied for the cermets. The results indicate that there is a strong correlation between the Mo/B atomic ratio and properties. The transverse rupture strength of the cermets increases with an increase in Mo/B ratio and shows a maximum value of 1 872 MPa at an Mo/B atomic ratio of 1.1 and then decreases with increasing Mo/B atomic ratio. The hardness and the corrosion resistance of the cermets increase monotonically with an increase in Mo/B atomic ratio. In Mo-rich cermets with an atomic ratio of Mo/B above 1.1, a small amount Ni-Mo intermetallic compound is found precipitated at the interface of Mo 2 NiB 2 grains.

  6. Hydrothermal synthesis of flower-like MoS2 nanospheres for electrochemical supercapacitors.

    Science.gov (United States)

    Zhou, Xiaoping; Xu, Bin; Lin, Zhengfeng; Shu, Dong; Ma, Lin

    2014-09-01

    Flower-like MoS2 nanospheres were synthesized by a hydrothermal route. The structure and surface morphology of the as-prepared MoS2 was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The supercapacitive behavior of MoS2 in 1 M KCl electrolyte was studied by means of cyclic voltammetry (CV), constant current charge-discharge cycling (CD) and electrochemical impedance spectroscopy (EIS). The XRD results indicate that the as-prepared MoS2 has good crystallinity. SEM images show that the MoS2 nanospheres have uniform sizes with mean diameter about 300 nm. Many nanosheets growing on the surface make the MoS2 nanospheres to be a flower-like structure. The specific capacitance of MoS2 is 122 F x g(-1) at 1 A x g(-1) or 114 F x g(-1) at 2 mv s(-1). All the experimental results indicate that MoS2 is a promising electrode material for electrochemical supercapacitors.

  7. Thermodynamic evidence for phase transition in MoO2

    International Nuclear Information System (INIS)

    Jacob, K.T.; Saji, V.S.; Gopalakrishnan, J.; Waseda, Y.

    2007-01-01

    The standard Gibbs free energy of formation of MoO 2-δ , Δ f G 0 (MoO 2-δ ), has been measured over a wide temperature range (925 to 1925) K using an advanced version of bi-electrolyte solid-state electrochemical cell incorporating a buffer electrode: Pt vertical bar Mo + MoO 2-δ -parallel (Y 2 O 3 )ThO 2 -parallel (CaO)ZrO 2 -parallel O 2 (0.1 MPa) vertical bar Pt The Gibbs free energy of formation of MoO 2-δ , which is directly related to the measured cell e.m.f., can be represented by two linear segments: Δ f G 0 (MoO 2-δ )±570/(J.mol -1 )=-579,821+170.003(T/K), in the temperature range (925 to 1533) K, and Δ f G 0 (MoO 2-δ )±510/(J.mol -1 )=-564,634+160.096(T/K), in the temperature range (1533 to 1925) K. The change in slope at T = 1533 K is probably related to the phase transition of MoO 2 from monoclinic structure with space group P2 1 /c to tetragonal structure characteristic of rutile with space group P4 2 /mnm. The enthalpy and entropy change for the phase transition are: ΔH tr = (15.19 ± 2.1) kJ . mol -1 ; ΔS tr (9.91 ± 1.27) J . mol -1 . K -1 . The standard enthalpy of formation of MoO 2-δ at T = 298.15 K assessed by the third-law method is: Δ f H 0 (MoO 2-δ ) = (-592.28 ± 0.33) kJ . mol -1 . The new measurements refine thermodynamic data for MoO 2

  8. Phase formation in the Li2MoO4–K2MoO4–In2(MoO4)3 system and crystal structures of new compounds K3InMo4O15 and LiK2In(MoO4)3

    International Nuclear Information System (INIS)

    Khal’baeva, Klara M.; Solodovnikov, Sergey F.; Khaikina, Elena G.; Kadyrova, Yuliya M.; Solodovnikova, Zoya A.; Basovich, Olga M.

    2012-01-01

    XRD study of solid-phase interaction in the Li 2 MoO 4 –K 2 MoO 4 –In 2 (MoO 4 ) 3 system was performed. The boundary K 2 MoO 4 –In 2 (MoO 4 ) 3 system is an non-quasibinary join of the K 2 O–In 2 O 3 –MoO 3 system where a new polymolybdate K 3 InMo 4 O 15 isotypic to K 3 FeMo 4 O 15 was found. In the structure (a=33.2905(8), b=5.8610(1), c=15.8967(4) Å, β=90.725(1)°, sp. gr. C2/c, Z=8, R(F)=0.0407), InO 6 octahedra, Mo 2 O 7 diortho groups and MoO 4 tetrahedra form infinite ribbons {[In(MoO 4 ) 2 (Mo 2 O 7 )] 3− } ∞ along the b-axis. Between the chains, 8- to 10-coordinate potassium cations are located. A subsolidus phase diagram of the Li 2 MoO 4 –K 2 MoO 4 –In 2 (MoO 4 ) 3 system was constructed and a novel triple molybdate LiK 2 In(MoO 4 ) 3 was revealed. Its crystal structure (a=7.0087(2), b=9.2269(3), c=10.1289(3) Å, β=107.401(1)°, sp. gr. P2 1 , Z=2, R(F)=0.0280) contains an open framework of vertex-shared MoO 4 tetrahedra, InO 6 octahedra and LiO 5 tetragonal pyramids with nine- and seven-coordinate potassium ions in the framework channels. - Graphical abstract: Exploring the Li 2 MoO 4 –K 2 MoO 4 –In 2 (MoO 4 ) 3 system showed its partial non-quasibinarity and revealed new compounds K 3 InMo 4 O 15 (isotypic to K 3 FeMo 4 O 15 ) and LiK 2 In(MoO 4 ) 3 which were structurally studied. An open framework of the latter is formed by vertex-shared MoO 4 tetrahedra, InO 6 octahedra and LiO 5 tetragonal pyramids. Highlights: ► Subsolidus phase relations in the Li 2 MoO 4 –K 2 MoO 4 –In 2 (MoO 4 ) 3 system were explored. ► The K 2 MoO 4 –In 2 (MoO 4 ) 3 system is a non-quasibinary join of the K 2 O–In 2 O 3 –MoO 3 system. ► New compounds K 3 InMo 4 O 15 and LiK 2 In(MoO 4 ) 3 were obtained and structurally studied. ► K 3 InMo 4 O 15 is isotypic to K 3 FeMo 4 O 15 and carries bands of InO 6 , MoO 4 and Mo 2 O 7 units. ► An open framework of LiK 2 In(MoO 4 ) 3 is formed by polyhedra MoO 4 , InO 6 and LiO 5 .

  9. Magnetoresistance in Co/2D MoS2/Co and Ni/2D MoS2/Ni junctions.

    Science.gov (United States)

    Zhang, Han; Ye, Meng; Wang, Yangyang; Quhe, Ruge; Pan, Yuanyuan; Guo, Ying; Song, Zhigang; Yang, Jinbo; Guo, Wanlin; Lu, Jing

    2016-06-28

    Semiconducting single-layer (SL) and few-layer MoS2 have a flat surface, free of dangling bonds. Using density functional theory coupled with non-equilibrium Green's function method, we investigate the spin-polarized transport properties of Co/2D MoS2/Co and Ni/2D MoS2/Ni junctions with MoS2 layer numbers of N = 1, 3, and 5. Well-defined interfaces are formed between MoS2 and metal electrodes. The junctions with a SL MoS2 spacer are almost metallic owing to the strong coupling between MoS2 and the ferromagnets, while those are tunneling with a few layer MoS2 spacer. Both large magnetoresistance and tunneling magnetoresistance are found when fcc or hcp Co is used as an electrode. Therefore, flat single- and few-layer MoS2 can serve as an effective nonmagnetic spacer in a magnetoresistance or tunneling magnetoresistance device with a well-defined interface.

  10. Wear behavior of 2-1/4 Cr-1Mo tubing against alloy 718 tube-support material in sodium-cooled steam generators

    International Nuclear Information System (INIS)

    Wilson, W.L.

    1983-05-01

    A series of prototypic steam generator 2-1/4 Cr-1 Mo tube/alloy 718 tube support plate wear tests were conducted in direct support of the Westinghouse Nuclear Components Division -- Breeder Reactor Components Project Large Scale steam Generator design. The initial objective was to verify the acceptable wear behavior of softer, ''over-aged'' alloy 718 support plate material. For all interfaces under all test conditions, resultant wear damage was adhesive in nature with varying amounts of 2-1/4 Cr-1 Mo tube material being adhesively transferred to the alloy 718 tube supports. Maximum tube wear depths exceeded the initially established design allowable limit of 127 μm (.005 in.) at 17 of the 18 interfaces tested. A decrease in contact stresses produced acceptable tube wear depths below a readjusted maximum design allowable value of 381 μm (.015 in.). Additional conservatisms associated with the simulation of a 40-year lifetime of rubbing in a one-week laboratory test provided further confidence that the 381 μm maximum tube wear allowance would not be exceeded in service. Softer, ''over-aged'' alloy 718 material was found to produce slightly less wear damage on 2-1/4 Cr-1 Mo tubing than fully age hardened material. Also, air formed oxide films on the alloy 718 reduced initial tube wear and delayed the onset of adhesive surface damage. However, at high surface stress levels, these films were not sufficiently stable to provide adequate long term protection from adhesive wear. The results of the present work and those of previous test programs suggest that the successful in-sodium tribological performance of 2-1/4 Cr-1 Mo/alloy 718 rubbing couples is dependent upon the presence of lubricative surface films, such as oxides and/or surface reaction or deposition products. 11 refs., 13 figs., 4 tabs

  11. Hydrates of the alkali trioxidomonosulfidomolybdates and -tungstates. K{sub 2}[(Mo/W)O{sub 3}S] . 1.5 H{sub 2}O and (Rb/Cs){sub 2}[(Mo/W)O{sub 3}S] . H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Lehner, Anna J.; Braitsch, Milan; Roehr, Caroline [Freiburg Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

    2012-11-01

    The trioxidomonosulfidomolybdate and -tungstate anions [(Mo/W)O{sub 3}S]{sup 2-} are the first products formed when passing H{sub 2}S gas through a solution of the oxidometalates. Their potassium, rubidium and cesium salt hydrates form as crystalline precipitates from these solutions depending on pH, the polarity of the solvent, educt concentrations and temperature. The structures of the sesqui- (K) and mono- (Rb, Cs) hydrates have been determined by means of X-ray single crystal diffraction data. The potassium sesquihydrates K{sub 2}[(Mo/W)O{sub 3}S] . 1.5 H{sub 2}O are isotypic and crystallize with a new structure type (monoclinic, space group C2/c, M = Mo/W: a = 987.0(2)/993.13(11), b = 831.75(14)/831.10(11), c = 1868.9(4)/1865.2(2) pm, {beta} = 99.34(2)/99.153(8) , R1 = 0.0352/0.0390). In the crystal structure the [(Mo/W)O{sub 3}S]{sup 2-} anions are connected via hydrogen bonds to form columns along the c direction. Channels containing only water molecules run along the [101] direction. The dehydration process proceeds in a topotactic reaction between 60 to 95 C and yields crystals of the anhydrous salts K{sub 2}[(Mo/W)O{sub 3}S]. The two different K+ cations exhibit a 5 + 3 and 5 + 2 O/S coordination. The heavier alkali metal cations form the four monohydrates (Rb/Cs){sub 2}[(Mo/W)O{sub 3}S] . H{sub 2}O (trigonal rhombohedral, space group R anti 3m) with lattice parameters for the Rb/Cs molybdates of a = 621.17(6)/624.62(10), c = 3377.9(4)/3388.6(8) pm (R1 = 0.0505/0.0734) and the tungstates of a = 642.80(3)/643.3(4), c = 3532.8(3)/3566(4) pm (R1 = 0.0348/0.0660). In the structures the 3m symmetrical tetrahedra are arranged to form double layers in such a way, that the O{sub 3} bases of the tetrahedra are pointing towards each other in a staggered conformation. These double layers are stacked in the c direction in a rhombohedral sequence. In these hydrates, there are no distinct hydrogen bonds. Instead, partially disordered pairs of H{sub 2}O molecules are

  12. Performance of Tc-99m generator prepared with Mo adsorbent PZC and irradiated nature MoO3

    International Nuclear Information System (INIS)

    Liu Yishu

    2006-01-01

    This paper describes the technical process of Tc-99m generator prepared with reactor actived Mo-99 and PZC and the performance of the generator was also reported. Two generators were prepared with different batch of PZC and by different technical process. The results show that the adsorption rate was ∼65% and the adsorption efficiency of 99 Mo can be seriously affected by the adsorption process (the temperature, intensity and frequency of shaking and the PZC volume in solution etc.). The elution efficiency was 43-73%. The Mo breakthrough 1.2 - 16% without safe column and its can be decreased to be very low by connecting a hydrate zirconia (HZO) safe column. (author)

  13. 76 FR 27861 - Airworthiness Directives; Diamond Aircraft Industries GmbH Models DA 42, DA 42 NG, and DA 42 M-NG...

    Science.gov (United States)

    2011-05-13

    ... Airworthiness Directives; Diamond Aircraft Industries GmbH Models DA 42, DA 42 NG, and DA 42 M-NG Airplanes... on Diamond aeroplanes, the majority of which were DA 40. In additional, at least 18 doors have been... conditions) while the aeroplane was parked. All DA 40 and DA 42 aeroplanes have a system installed that...

  14. Magnetic Fe2MO4 (M:Fe, Mn) activated carbons: Fabrication, characterization and heterogeneous Fenton oxidation of methyl orange

    International Nuclear Information System (INIS)

    Nguyen, Thi Dung; Phan, Ngoc Hoa; Do, Manh Huy; Ngo, Kim Tham

    2011-01-01

    We present a simple and efficient method for the fabrication of magnetic Fe 2 MO 4 (M:Fe and Mn) activated carbons (Fe 2 MO 4 /AC-H, M:Fe and Mn) by impregnating the activated carbon with simultaneous magnetic precursor and carbon modifying agent followed by calcination. The obtained samples were characterized by nitrogen adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), and the catalytic activity in heterogeneous Fenton oxidation of methyl orange (MO) was evaluated. The resulting Fe 2 MnO 4 /AC-H showed higher catalytic activity in the methyl orange oxidation than Fe 3 O 4 /AC-H. The effect of operational parameters (pH, catalyst loading H 2 O 2 dosage and initial MO concentration) on degradation performance of the oxidation process was investigated. Stability and reusability of selected catalyst were also tested.

  15. Morphology-controlled synthesis of MoS2 nanostructures with different lithium storage properties

    International Nuclear Information System (INIS)

    Wang, Xiwen; Zhang, Zhian; Chen, Yaqiong; Qu, Yaohui; Lai, Yanqing; Li, Jie

    2014-01-01

    Highlights: • MoS 2 nanospheres, nanoribbons and nanoparticles were prepared by hydrothermal method. • The surfactant and temperature control the shape and crystal structure of MoS 2 . • MoS 2 nanospheres exhibit the excellent lithium storage property. - Abstract: A one-step hydrothermal process was employed to prepare a series of MoS 2 nanostructures via simply altering the surfactant as soft template and hydrothermal reaction temperature. Three kinds of MoS 2 nanostructures (three-dimensional (3D) hierarchical nanospheres, one-dimensional (1D) nanoribbons, and large aggregated nanoparticles) were successfully achieved and investigated well by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and Brunauer–Emmett–Teller analysis (BET). Electrochemical tests reveal that these MoS 2 samples could deliver high initial discharge capacities (higher than 1050.0 mA h g −1 ), but various cycling performances. The hierarchical MoS 2 nanospheres assembled by sheet-like subunits show the highest specific capacity of 1355.1 mA h g −1 , and 66.8% of which can be retained after 50 cycles. The good lithium storage property of hierarchical MoS 2 nanospheres can be attributed to the higher electrolyte/MoS 2 contact area and stable 3D layered structure

  16. Predictive value of [-2]propsa (p2psa and its derivatives for the prostate cancer detection in the 2.0 to 10.0ng/mL PSA range

    Directory of Open Access Journals (Sweden)

    I. Vukovic

    Full Text Available ABSTRACT Introduction To assess predictive value of new tumor markers, precursor of prostate specific antigen (p2PSA and its derivates-%p2PSA and prostate health index (PHI in detection of patients with indolent and aggressive prostate cancer (PC in a subcohort of man whose total PSA ranged from 2 to 10ng/mL. Materials and Methods This cross-sectional study included 129 consecutive male patients aged over 50 years, with no previous history of PC and with normal digital rectal examination findings, but with serum PSA in interval between 2 and 10ng/mL. All patients underwent standard transrectal ultrasonography guided prostate biopsy for the first time. For all patients, serum PSA, free PSA (fPSA and p2PSA were measured and PHI and %p2PSA were calculated. Results PHI and %p2PSA levels were significanlty higher in patients with PC compared to those without this malignancy. The same findings have been observed in group of patients with Gleason score ≥7 compared to those with Gleason score <7. ROC analysis reveled the highest area under the curve with these two markers. Multivariate logistic regression showed significant improvement in PC detection and its agressive form (assumed as Gleason score ≥7. Conclusions New markers, derivates of p2PSA (especially %p2PSA and PHI, represente potentially very important clinical tool for predicting presence of PC, and even more important, to discriminate patients with Gleason score <7 from those with Gleason score ≥7 with total PSA in range from 2 to 10ng/mL.

  17. Predictive value of [-2]propsa (p2psa) and its derivatives for the prostate cancer detection in the 2.0 to 10.0ng/mL PSA range.

    Science.gov (United States)

    Vukovic, I; Djordjevic, D; Bojanic, N; Babic, U; Soldatovic, I

    2017-01-01

    To assess predictive value of new tumor markers, precursor of prostate specific antigen (p2PSA) and its derivates-%p2PSA and prostate health index (PHI) in detection of patients with indolent and aggressive prostate cancer (PC) in a subcohort of man whose total PSA ranged from 2 to 10ng/mL. This cross-sectional study included 129 consecutive male patients aged over 50 years, with no previous history of PC and with normal digital rectal examination findings, but with serum PSA in interval between 2 and 10ng/mL. All patients underwent standard transrectal ultrasonography guided prostate biopsy for the first time. For all patients, serum PSA, free PSA (fPSA) and p2PSA were measured and PHI and %p2PSA were calculated. PHI and %p2PSA levels were significanlty higher in patients with PC compared to those without this malignancy. The same findings have been observed in group of patients with Gleason score ≥7 compared to those with Gleason score <7. ROC analysis reveled the highest area under the curve with these two markers. Multivariate logistic regression showed significant improvement in PC detection and its agressive form (assumed as Gleason score ≥7). New markers, derivates of p2PSA (especially %p2PSA and PHI), represente potentially very important clinical tool for predicting presence of PC, and even more important, to discriminate patients with Gleason score <7 from those with Gleason score ≥7 with total PSA in range from 2 to 10ng/mL. Copyright® by the International Brazilian Journal of Urology.

  18. Ultrathin 1T-phase MoS2 nanosheets decorated hollow carbon microspheres as highly efficient catalysts for solar energy harvesting and storage

    KAUST Repository

    Hsiao, Min-Chien

    2017-02-08

    The composite of MoS2 and hollow carbon sphere (MoS2@HCS) is prepared via a glucose-assisted one pot synthesis. The composite consists of hierarchical spheres with a diameter of 0.5–4 μm and these hollow spheres are decorated with a number of curled and interlaced MoS2 nanosheets. After the composite is subject to the lithium intercalation, the MoS2 is converted from 2H to 1T phase. In this current work, the activities of 1T-MoS2@HCS toward photocatalytic hydrogen evolution and the reduction of I3− in dye-sensitized solar cells (DSCs) are systemically investigated. When evaluated as the photocatalyst for hydrogen evolution, the amount of evolved hydrogen over 1T-MoS2@HCS can reach 143 μmol in 2 h, being 3.6 times higher than as-synthesized 2H-MoS2@HCS. Additionally, the 1T-MoS2@HCS can be employed as the counter electrode (CE) material in DSCs. The DSCs based on 1T-MoS2@HCS CE possesses the power conversion efficiency of 8.94%, being higher than that with 2H-MoS2@HCS CE (8.16%) and comparable to that with Pt CE (8.87%). Our study demonstrates that 1T-MoS2@HCS has a great potential as an inexpensive alternative to Pt catalysts.

  19. Ultrathin 1T-phase MoS2 nanosheets decorated hollow carbon microspheres as highly efficient catalysts for solar energy harvesting and storage

    KAUST Repository

    Hsiao, Min-Chien; Chang, Chin-Yu; Niu, Li-Juan; Bai, Feng; Li, Lain-Jong; Shen, Hsin-Hui; Lin, Jeng-Yu; Lin, Tsung-Wu

    2017-01-01

    The composite of MoS2 and hollow carbon sphere (MoS2@HCS) is prepared via a glucose-assisted one pot synthesis. The composite consists of hierarchical spheres with a diameter of 0.5–4 μm and these hollow spheres are decorated with a number of curled and interlaced MoS2 nanosheets. After the composite is subject to the lithium intercalation, the MoS2 is converted from 2H to 1T phase. In this current work, the activities of 1T-MoS2@HCS toward photocatalytic hydrogen evolution and the reduction of I3− in dye-sensitized solar cells (DSCs) are systemically investigated. When evaluated as the photocatalyst for hydrogen evolution, the amount of evolved hydrogen over 1T-MoS2@HCS can reach 143 μmol in 2 h, being 3.6 times higher than as-synthesized 2H-MoS2@HCS. Additionally, the 1T-MoS2@HCS can be employed as the counter electrode (CE) material in DSCs. The DSCs based on 1T-MoS2@HCS CE possesses the power conversion efficiency of 8.94%, being higher than that with 2H-MoS2@HCS CE (8.16%) and comparable to that with Pt CE (8.87%). Our study demonstrates that 1T-MoS2@HCS has a great potential as an inexpensive alternative to Pt catalysts.

  20. 99mTc gel generators based on zirconium molybdate-99Mo: III: Influence of preparatory conditions of zirconium molybdate-99Mo gel on generator performance

    International Nuclear Information System (INIS)

    Saraswathy, P.; Sarkar, S.K.; Arjun, G.; Ramamoorthy, N.; Nandy, S.K.

    2004-01-01

    The effect of subtle variations on zirconium molybdate- 99 Mo gel preparatory conditions, such as stoichiometry of reactants, pH of gel formation, conditioning of gel granules etc., prior to elution were investigated primarily to arrive at the conditions resulting in high 99m Tc release and minimal 99 Mo breakthrough upon elution with normal saline. Zirconium molybdate- 99 Mo gels were prepared by reacting solutions of Zr and Mo in mole ratios of 0.75-1.5. Both water and normal saline were used for gel disintegration, and the release of 99m Tc and 99 Mo from gel columns into eluates was compared. Sharper elution profile of 99m Tc, but with significantly higher 99 Mo breakthrough (5-8 times), was obtained when water alone was used for disintegration and elution, in comparison to when saline was used. Gels exhibiting optimum characteristics were found to be formed at a pH of 4-5 by reacting [Zr]: [Mo] in the mole ratio of 1.25: 1 and after drying, the product was dispersed into granules by disintegration with normal saline. 99m Tc elution efficiency was found to be ∝ 75% and 99 Mo breakthrough ∝ 0.05%. The elution profile was sharp when a 6 g gel column coupled to a 2 g acidic alumina column (to trap 99 Mo) was eluted with 6-9 ml normal saline. Generators containing upto 23 GBq 99 Mo were prepared, eluted extensively without changing the alumina column and found to provide pertechnetate of good quality, commensurate with hospital radiopharmacy requirements. (orig.)

  1. 76 FR 12627 - Airworthiness Directives; Diamond Aircraft Industries GmbH Models DA 42, DA 42 NG, and DA 42 M-NG...

    Science.gov (United States)

    2011-03-08

    ... Industries GmbH Models DA 42, DA 42 NG, and DA 42 M-NG Airplanes AGENCY: Federal Aviation Administration (FAA... on Diamond aeroplanes, the majority of which were DA 40. In additional, at least 18 doors have been... conditions) while the aeroplane was parked. All DA 40 and DA 42 aeroplanes have a system installed that...

  2. Chemistry of the oxophosphinidene ligand. 2. Reactivity of the anionic complexes [MCp{P(O)R*}(CO)(2)](-) (M = Mo, W; R* = 2,4,6-C(6)H(2)(t)Bu(3)) toward electrophiles based on elements different from carbon.

    Science.gov (United States)

    Alonso, María; Alvarez, M Angeles; García, M Esther; Ruiz, Miguel A; Hamidov, Hayrullo; Jeffery, John C

    2010-12-20

    The anionic oxophosphinidene complexes (H-DBU)[MCp{P(O)R*}(CO)(2)] (M = Mo, W; R* = 2,4,6-C(6)H(2)(t)Bu(3); Cp = η(5)-C(5)H(5), DBU = 1,8-diazabicyclo [5.4.0] undec-7-ene) displayed multisite reactivity when faced with different electrophilic reagents. The reactions with the group 14 organochloride compounds ER(4-x)Cl(x) (E = Si, Ge, Sn, Pb) led to either phosphide-like, oxophosphinidene-bridged derivatives [MCp{P(OE')R*}(CO)(2)] (E' = SiMe(3), SiPh(3), GePh(3), GeMe(2)Cl) or to terminal oxophosphinidene complexes [MCp{P(O)R*}(CO)(2)(E')] (E' = SnPh(3), SnPh(2)Cl, PbPh(3); Mo-Pb = 2.8845(4) Å for the MoPb compound). A particular situation was found in the reaction with SnMe(3)Cl, this giving a product existing in both tautomeric forms, with the phosphide-like complex [MCp{P(OSnMe(3))R*}(CO)(2)] prevailing at room temperature and the tautomer [MCp{P(O)R*}(CO)(2)(SnMe(3))] being the unique species present below 203 K in dichloromethane solution. The title anions also showed a multisite behavior when reacting with transition-metal based electrophiles. Thus, the reactions with the complexes [M'Cp(2)Cl(2)] (M' = Ti, Zr) gave phosphide-like derivatives [MCp{P(OM')R*}(CO)(2)] (M = Mo, M' = TiCp(2)Cl, ZrCp(2)Cl; M = W, M' = ZrCp(2)Cl), displaying a bridging κ(1),κ(1)-P,O- oxophosphinidene ligand connecting MCp(CO)(2) and M'Cp(2)Cl metal fragments (W-P = 2.233(1) Å, O-Zr = 2.016(4) Å for the WZr compound]. In contrast, the reactions with the complex [AuCl{P(p-tol)(3)}] gave the metal-metal bonded derivatives trans-[MCp{P(O)R*}(CO)(2){AuP(p-tol)(3)}] (M = Mo, W; Mo-Au = 2.7071(7) Å). From all the above results it was concluded that the terminal oxophosphinidene complexes are preferentially formed under conditions of orbital control, while charge-controlled reactions tend to give derivatives with the electrophilic fragment bound to the oxygen atom of the oxophosphinidene ligand (phosphide-like, oxophosphinidene-bridged derivatives).

  3. Determination of 99Mo contamination in 99mTc elute obtained from 99Mo/99mTc- generator

    International Nuclear Information System (INIS)

    Momennezhad, M.; Zakavi, S. R.; Sadeghi, R.

    2010-01-01

    99m Tc is a widely used radioisotope in nuclear medicine centers which is obtained by elution from Mo-99/Tc-99m generators. Usually the generators are either supplied by the Iran Atomic Energy Agency or by private companies from foreign countries. In this study we have measured 99 Mo contamination in 99m Tc elute from different generators in a period of one year. Materials and Methods: The radionuclide impurity of the 99m Tc elute were studied in two types of radionuclide generators (A: produced in Iran and B: Imported from other country). In-vitro measurements were performed using dose calibrator. Direct measurements were made, using a standard canister at the time of milking of the generators and also in Subsequent hours after milking. Results: The results showed a mean of 99 Mo impurity in generators A and B to be 0.00932±0.0043 and 0.0170±0.0127 respectively. Although the results showed that the 99 Mo contamination in 99 mTc elute was lesser than the maximum accepted activity limit of 0.015%, the difference in these two types may reflect different methods of productions of generator, as well as the quality control procedures. Conclusion: The mean of 99 Mo contamination in generators produced in Iran Atomic Energy Organization was lesser than generators imported from foreign origin.

  4. Hemilability of the 1,2-Bis(dimethylphosphino)ethane (dmpe) Ligand in Cp*Mo(NO)(κ2-dmpe).

    Science.gov (United States)

    Holmes, Aaron S; Patrick, Brian O; Levesque, Taleah M; Legzdins, Peter

    2017-09-18

    Reaction of Cp*Mo(NO)Cl 2 with 1 equiv of 1,2-bis(dimethylphosphino)ethane (dmpe) in THF at ambient temperature forms [Cp*Mo(NO)(Cl)(κ 2 -dmpe)]Cl (1), which is isolable as an analytically pure yellow powder in 65% yield. Further addition of 2 equiv of Cp 2 Co to 1 in CH 2 Cl 2 affords dark red Cp*Mo(NO)(κ 2 -dmpe) (2), which was isolated in 36% yield by recrystallization from Et 2 O at -30 °C. Reaction of a benzene solution of 2 with an equimolar amount of elemental sulfur results in the immediate production of dark blue (μ-S)[Cp*Mo(NO)(κ 1 -dmpeS)] 2 (3), which is a rare example of a bimetallic transition-metal complex bridged by only a single sulfur atom and involving Mo═S═Mo bonding. In contrast, reaction of 2 with an excess of sulfur in benzene results in the formation of Cp*Mo(NO)(η 2 -S 2 )(κ 1 -dmpeS) (4). Complex 4 can also be formed by the addition of elemental sulfur to 3, thereby indicating that 3 is a precursor to 4. Cp*Mo(NO)(κ 2 -dmpe) (2) also undergoes interesting transformations when treated with organic bromides. For instance, reaction of 2 with 5 equiv benzyl bromide in THF produces the bimetallic complex (μ-dmpe)[Cp*Mo(NO)Br 2 ] 2 (5) and bibenzyl after 4 d at 70 °C probably via radical intermediates. In contrast to its reaction with benzyl bromide, complex 2 forms [Mo(NO)Br 22 -dmpe)] 2 (6), olefin, alkane, and Cp*H when treated with 5 equiv of 1-bromopropane or 1-bromooctane in THF at 70 °C for 72 h. Interestingly, complex 2 does not display any reactivity with bromobenzene or 1-bromoadamantane even after being heated for several days at 70 °C. All new complexes were characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of most of them were established by single-crystal X-ray crystallographic analyses.

  5. Development of 99Mo/99mTc Generator System for Production of Medical Radionuclide 99mTc using a Neutron-activated 99Mo and Zirconium Based Material (ZBM as its Adsorbent

    Directory of Open Access Journals (Sweden)

    I. Saptiama

    2016-12-01

    Full Text Available Molybdenum produced from fission of U-235 is the most desirable precursor for 99Mo/99mTc generator system as it is non-carrier added and has high specific activity. However, in the last decade there has been short supply of 99Mo due to several constrains. Therefore, there have been many works performed for development of 99Mo/99mTc generator system using 99Mo which is not produced from either LEU or HEU. This report deals with development of 99Mo/99mTc generator system where zirconium-based material (ZBM is used as adsorbent of neutron-activated 99Mo. The system was prepared by firstly irradiating natural Mo in the G. A. Siwabessy reactor to produce neutron-activated 99Mo. The target was dissolved in NaOH 4N and then neutralized with 12 M HCl. The 99Mo solution was then mixed with a certain amount of ZBM followed by heating at 90°C for three hours to allow the 99Mo adsorbed on ZBM. The 99Mo-ZBM (9.36 GBq of 99Mo was Mo/ 4.2 g ZBM was packed on a fritz-glass column. This column was then fitted serially with an alumina column for trapping 99Mo breakthrough. The columns were then eluted daily with saline solution for up to one week. The yield of 99mTc was found to be between 53.7 – 74% (n= 5. All 99mTc eluates were clear solutions with pH of 5. Breakthrough of 99Mo in 99mTc eluates was found to be 0.031 ± 0.019 μCi 99Mo/ mCi 99mTc (n= 5 which was less than the maximum activity of 99Mo allowed in 99mTc solution ( 99%. Radiolabeling of this 99mTc towards methylene diphosphonate (MDP kit gave a radiolabelling efficiency of 99%. In summary, a new 99Mo/99mTc generator system that used neutron-activated 99Mo and ZBM as its adsorbent has been successfully prepared. The 99mTc produced from this new 99Mo/99mTc generator system attained the quality of 99mTc required for medical purposes.

  6. Effect of niobium on the embrittlement of 2.25 Cr and 2.25 Cr-1Mo steels by phosphous

    International Nuclear Information System (INIS)

    Antunes, J.L.B.

    1985-01-01

    The influence of niobium on the temper embrittlement of 2.25Cr and 2.25 Cr-1Mo steels doped with phosphorus is evaluated. The transition temperatures of the samples tempered at 650 0 C and aged at different temperatures for niobium steels. (M.J.C.) [pt

  7. Four-wave-mixing and nonlinear cavity dumping of 280 picosecond 2nd Stokes pulse at 1.3 μm from Nd:SrMoO4 self-Raman laser

    International Nuclear Information System (INIS)

    Smetanin, S N; Ivleva, L I; Jelínek, M Jr; Kubeček, V; Jelínková, H; Shurygin, A S

    2016-01-01

    The 280 picosecond 2nd Stokes Raman pulses at 1.3 μm were generated directly from the miniature diode-pumped Nd:SrMoO 4 self-Raman laser. Using the 90° phase matching insensitive to the angular mismatch, the self-Raman laser allowed for the achievement of the four-wave-mixing generation of the 2nd Stokes Raman pulse directly in the active Nd:SrMoO 4 crystal at stimulated Raman scattering (SRS) self-conversion of the laser radiation. The passive Cr:YAG Q-switching and nonlinear cavity dumping was used without any phase locking device. (letter)

  8. Direct elution of sup(99m)Tc complexes from neutron irradiation produced 99Mo incorporated in a MoCl2-MoBr2 mixture

    International Nuclear Information System (INIS)

    Ganzerli Valentini, M.T.; Stella, R.; Genova, N.

    1987-01-01

    A novel type of sup(99m)Tc generator, enabling radiopharmaceutical preparation without reductant addition, was prepared and tested. Neutron activated product 99 Mo, in the form of dichloride cluster, was incorporated into inactive molybdenum dichloride-dibromide mixture (MCB) that was left to settle over an activated alumina layer. Direct elution with aqueous ligands such as salicylate or iminodiacetate derivatives in the pH range 6.5-7.5 yielded chemically stable sup(99m)Tc complexes accompanied by small amounts of secondary products (mostly sup(99m)TcO - 4 ). Pentavalent oxidation state in the salicylate complex and tervalent in the iminodiacetate (IDA) and in the N-(2,6-dimethylphenylcarbamoylmethyl) iminodiacetate (HIDA) complexes were assigned to the element after comparison with reference complexes. The anion exchange version of reverse-phase HPLC was used to resolve the eluted product mixture. (author)

  9. Preperation and performance of {sup 99}Mo/{sup 99m}Tc chromatographic column generator based on zirconium molybdosilicate

    Energy Technology Data Exchange (ETDEWEB)

    Mostafa, M.; Saber, H.M.; El-Sadek, A.A. [Atomic Energy Authority, Cairo (Egypt). Hot Labs. Center; Nassar, M.Y. [Benha Univ. (Egypt). Chemistry Dept.

    2016-08-01

    Zirconium molybdosilicate (ZrMoSi) gel prepared using {sup 99}Mo radiotracer via peroxo route was used as a base material for {sup 99}Mo/{sup 99m}Tc column generator. The {sup 99m}Tc elution yield and {sup 99}Mo breakthrough in the eluate were studied as a function of the pH-value of gel precipitation, gel drying temperature and Zr: Mo: Si molar ratio. Precipitation pH-value of 2, drying temperature of 100 C and Zr: Mo: Si molar ratio of 0.5: 0.5: 1 were found to be the optimum conditions achieving {sup 99m}Tc elution yield of 82% and {sup 99}Mo breakthrough of 1.0 x 10{sup -3}%. The gel prepared with the optimum conditions was characterized by BET surface area and pore size analyzer, IR spectroscopy, thermal analysis (TGA and DTA), XRD, XRF and FESEM. Technetium-99m eluted from the optimum ZrMoSi {sup 99}Mo/{sup 99m}Tc generator was found to have a high radiochemical purity (98% as {sup 99m}TcO{sub 4}{sup -}) and chemical purity meeting criteria of clinical grade.

  10. Variations of force constants, M-O distances and bond order in solid solutions between Ba/sub 2/MgUO/sub 6/ and Ba/sub 2/MgWO/sub 6/

    Energy Technology Data Exchange (ETDEWEB)

    Kemmler-Sack, S; Fadini, A [Tuebingen Univ. (Germany, F.R.). Inst. fuer Chemie

    1977-12-01

    In solid solutions between the 1:1 ordered perovskites Ba/sub 2/MgUO/sub 6/ and Ba/sub 2/MgWO/sub 6/ (system Ba/sub 2/MgUsub(1-x)Wsub(x)O/sub 6/) the force constants of the UO/sub 6/ and WO/sub 6/ octahedras are variied. The valence force constants fsub(MO) tend to adjust for each x. The bond order and the M-O distances are reported as well.

  11. MoTe2 saturable absorber for passively Q-switched Ho,Pr:LiLuF4 laser at ∼3 μm

    Science.gov (United States)

    Yan, Zhengyu; Li, Tao; Zhao, Shengzhi; Yang, Kejian; Li, Dechun; Li, Guiqiu; Zhang, Shuaiyi; Gao, Zijing

    2018-03-01

    Multilayer molybdenum ditelluride (MoTe2) nanosheets were prepared by liquid-phase exfoliation (LPE) method. A YAG-based MoTe2 saturable absorption (SA) was consequently fabricated. The MoTe2-SA was employed in a passively Q-switched Ho,Pr:LiLuF4 laser at 2.95 μm. Under the absorbed pump power of 3.8 W, an average output power of 90 mW was achieved. The shortest pulse duration of 670 ns was generated with an output power of 73 mW and a repetition rate of 76.46 kHz, corresponding to a pulse energy of 0.95 μJ.

  12. Two-dimensional MoS2-graphene hybrid nanosheets for high gravimetric and volumetric lithium storage

    Science.gov (United States)

    Deng, Yakai; Ding, Lixin; Liu, Qixing; Zhan, Liang; Wang, Yanli; Yang, Shubin

    2018-04-01

    Two-dimensional (2D) MoS2-graphene (MoS2-G) hybrid is fabricated simultaneously and scalablely with an efficient electrochemical exfoliation approach from the combined bulk MoS2-graphite wafer. The as-prepared 2D MoS2-G hybrid is tightly covered with each other with lateral sizes of 600 nm to few micrometers and can be directly assembled to flexible films for lithium storage. When used as anode material for lithium ion battery, the resultant MoS2-G hybrid film exhibits both high gravimetric (750 mA h g-1 at 50 mA g-1) and volumetric capacities (1200 mA h cm-3 at 0.1 mA cm-2). Such excellent electrochemical performance should attributed to the unique 2D structure and good conductive graphene network, which not only facilitates the diffusion of lithium ions, but also improves the fast transfer of electrons, satisfying the kinetics requirements for rapid lithium storage.

  13. Impact of Reduced Graphene Oxide on MoS2 Grown by Sulfurization of Sputtered MoO3 and Mo Precursor Films (Postprint)

    Science.gov (United States)

    2016-05-26

    1,2 intercalation assisted exfoliation,8–11 physical vapor deposition (PVD),12,13 and a wet chemistry approach involving thermal decomposition of a... annealed MoO3, MoS2 films S1 (MoS2 using Mo precursor), S2 (MoS2 using MoO3 precursor), S1r (MoS2 using Mo pre- cursor and rGO), and S2r (MoS2 using...MoO3 precursor and rGO). The annealed MoO3 (a) shows Mo(IV) peaks which are indicative of MoO2, and Mo(VI) peaks that occur when MoO3 is present. Both

  14. An embedded system based computer controlled process automation for recovery and purification of 99mTc from (n,γ)99Mo

    International Nuclear Information System (INIS)

    De, Anirban; Pal, S.S.; Bhaskar, P.; Kumari, S.; Khare, V.K.; Duttaroy, A.; Garai, M.; Thakur, S.K.; Saha, S.; Chattopadhyay, Sankha; Barua, Luna; Das, Sujata Saha; Kumar, U.; Das, M.K.

    2012-01-01

    99 Mo produced 99 mTc (t 1/2 = 6 hr, 140 KeV γ-ray) is the most useful radioisotope for nuclear diagnostics. High specific activity 99 Mo is supplied globally mainly by five old reactors whose routine or unscheduled maintenance shutdown causes supply irregularities that adversely affects patient management in nuclear medicine centres. 99m Tc may also be produced via 98 Mo(n,γ) in a natural MoO 3 target in reactor or by 100 Mo(n,2n) 99 Mo or 100 Mo(p,2n) 99 mTc reaction in cyclotron. To meet the crisis proposals are there to produce 99 Mo by 100 Mo(n,2n) 99 Mo or 99m Tc directly by 100 Mo(p,2n) 99m Tc in a cyclotron. Of the several separation methods of 99 mTc from molybdenum, the most common are adsorption column chromatography, sublimation and liquid-liquid solvent extraction. The conventional methods besides being cumbersome are often hazardous, polluting, require skilled manpower and facilities like fume hood and so are not always practically feasible for hospitals. To address these, VECC and BRIT, Kolkata have collaborated to develop an embedded system based automated 99 Mo/ 99m Tc generator from low specific activity 99 Mo using solvent extraction technique, supervised by a PC based GUI. (author)

  15. Comparison of low-cycle fatigue data of 2 1/4%CrMo steels

    International Nuclear Information System (INIS)

    Sanderson, S.J.; Petrequin, P.; Nieuwland, H.C.D.

    Data files have been produced on international strain-controlled fatigue information available for 2 1/4%CrMo steels; data assessment from these files is treated in three categories viz: annealed and isothermally annealed 2 1/4%Cr1%Mo steel; normalised and tempered and quenched and tempered 2 1/4%Cr1%Mo steel; and 2 1/4%CrMo variants. The available data have been considered generally in terms of total strain range vs. cycles to failure (Nsub(f)), tensile stress at Nsub(f)/2 vs. cycles to failure and time to failure vs. cycles to failure. Where possible the continuous cycling data have been statistically analysed in terms of the elastic and plastic strain components and cycles to failure to yield best-fit equations over defined temperature (T) regimes viz: T <= 427 deg. C, 427 deg. C < T <= 550 deg. C. and 550 deg. C < T <= 600 deg. C. The behaviour of the steels within the various classifications is discussed. (author)

  16. A simple and sensitive separation technique of 99Mo and 99mTc from their equilibrium mixture

    International Nuclear Information System (INIS)

    Swadesh Mandal; Ajoy Mandal

    2014-01-01

    The present work describes a simple and inexpensive separation method of 99 Mo from the equilibrium mixture. The liquid-liquid extraction technique has been employed to separate 99 Mo and 99m Tc using triisooctylamine (TIOA). The 99 Mo and 99m Tc were quantitatively separated out in 2 M TIOA with tripled distilled water; 99m Tc was back extracted from TIOA organic phase to aqueous phase by 0.1 M DTPA. The species information or indirect speciation of molybdenum was also established by the extraction profile of the molybdenum. (author)

  17. Preparation of i.v. 99mTc radiopharmaceuticals from spent moly 99Mo

    International Nuclear Information System (INIS)

    Noronha, O.P.D.

    1998-01-01

    Full text: Expiry dating is an important quality assurance precept in (radio) pharmacy. There are occasions when for the sake of patient service one may be forced to continue using an over aged source of 99 Mo to generate 99m Tc beyond 7d, especially when there is short/no supply of 99 Mo, (In the early days the expiry date was 3 d or 3 extractions, whichever one was earlier). With the passage of time a few physico-chemical changes (apart from decay) do occur in the 99 Mo/ 99m Tc milieu. The cocktail also begins to contain traces of carried over MEK which is subjected to strong β-, γ irradiation. These impurity (in trace amounts) is soluble in MEK and even, to an extent, in aqueous media. Furthermore, the concentrated impurity tends to seemingly increase in the bulk 99m TcO 4 - since one is compelled to leach TcO 4 - in lower volume of saline. On many occasions we have been constrained to extend the use of 99 Mo beyond 7 - 14 d. Adequate activities were obtained by pooling the previous week's lot of 99 Mo with the current over aged lot. On a few occasions over the past 26 years we have used 99 Mo much beyond 14 d and 2 - 3 occasions for 26 - 28 d (i.e. >10 t 1 /2 of 99 Mo). On each of these occasions the purity of 99m TcO- 4 was ascertained by pharmacopoeial procedures. It was found that despite depleting activities, the purity was not compromised and the trace impurities, even if present, did not cause any interference. We have profitably utilised the bulk TcO- 4 to formulate a variety of i.v. dosage forms of 99m Tc radiodiagnostics. The following strategy was adopted for the patient services - the agents requiring larger activity levels/patients dose were made available in the earlier period, the other during the latter half. It is concluded that pure 99m TcO- 4 can be obtained over the entire useful life-period of 99 Mo, even > 10t l/2

  18. Luminescent phosphors, based on rare earth substituted oxyfluorides in the A(1)3-x A(2)xMO4F family with A(1)/A(2)=Sr, Ca, Ba and M=Al, Ga

    International Nuclear Information System (INIS)

    Park, Sangmoon; Vogt, Thomas

    2009-01-01

    A new family of UV-activated phosphors made by substituting rare-earth activators such as trivalent Eu, Tb, Tm and Er into A(1) 3-x A(2) x MO 4 F host lattices (A(1)/A(2)=Sr, Ca, Ba; M=Al, Ga) are introduced and their activation and emission spectra as well as their CIE values reported. The Tm-substituted system can be activated using light with a wavelength of 360 nm. Relative intensities of a family of Tb-substituted green phosphors activated at 254 nm and with emissions centered near 548 nm are discussed.

  19. Preparation and characterization of iron(III) 99Mo-molybdate(VI) gels for the assessment of 99mTc elution performance

    International Nuclear Information System (INIS)

    Amin, Mahmoud; Fasih, Tharwat W.; El-Absy, Mohamed A.

    2018-01-01

    New iron(III) 99 Mo-molybdate(VI) gels (Fe 99 Mo) of high Mo content were prepared by the precipitation/filtration method. 99 Mo-MoO 3 dissolved in NaOH was added to aqueous solutions of Fe(NO 3 ) 3 at Mo/Fe mole fractions ∝2.21 and 1.99 with continuous stirring at ambient room temperature. Two different Fe 99 Mo were precipitated from the mixed solutions adjusted at pH 2 and 4.7. The amount of water of hydration increased with the increasing the gel settling time and pH of the mixed solution. The matrices were characterized by radiometric, XRD, SEM, XRF, FT-IR, TGA, and DTA measurements. Small chromatographic columns of 2.0 g Fe 99 Mo containing ≥800 mg Mo tagged with 740 MBq 99 Mo were eluted with 5 mL saline solution. Highly reproducible 99m Tc elution indices suitable for preparation of 99 Mo/ 99m Tc generators were achieved from generator supported with 0.5 g Al 2 O 3 filter. Elution performance of 99m Tc radionuclide was highly dependent on the gel structural properties.

  20. Optimization of the {sup 99m} Tc generator with hydrotalcite as support of {sup 99} Mo; Optimizacion del generador de {sup 99m} Tc con hidrotalcita como soporte del {sup 99} Mo

    Energy Technology Data Exchange (ETDEWEB)

    Aranda O, N

    2004-07-01

    In the last years, in the laboratories of the National Institute of Nuclear Investigations (ININ) its have been investigating to the hydrotalcite like a material of support of the {sup 99} Mo with the purpose of developing a new technetium generator. During the development of the investigations it has been demonstrated that when putting in contact to the HTC with an aqueous solution that contains anions of any type, the HTC re hydrate and the structure is regenerated to laminate of the hydrotalcite. If the present anions in the solution are molybdate anions (MoO{sub 4}{sup 2-}), these anions passed to be part of the structure of the hydrotalcite (HT-MoO{sub 4}). These anions can contain, in turn, {sup 99} Mo in their composition ({sup 99}MoO{sub 4}{sup 2-}) and equally they can pass to be part of the structure of the hydrotalcite forming the HT-{sup 99}MoO{sub 4}. When the HT-{sup 99}MoO{sub 4} is packed in a column, the {sup 99m}Tc that it takes place when decaying the {sup 99}Mo radioactively can separate the column using aqueous solution of NaCl. This way, in previous studies (Serrano, 2000) it was found that the aqueous solution of NaCl to 0.5% it is the but appropriate for elutriate at the {sup 99m}Tc from the column the yield of the elution of the {sup 99m}Tc was since high (98%) in the first elution, and the radionuclide contamination caused by the presence of {sup 99}Mo in the eluate it was low (<0.01%). In this investigation it was also found that the HTC has a high capacity to retain molybdate ions (255.1 mg of ions MoO{sub 4}{sup 2-} for gram of HTC). These facts, standing out the high capacity of the HTC to retain molybdate ions, they drove from a direct way to investigate the optimization of the generator of {sup 99m}Tc, with hydrotalcite like support of the {sup 99}Mo, using {sup 99}Mo of low specific activity. This finishes radioactive material it can be obtained by the irradiation of the {sup 98}Mo (in the chemical form of MoO{sub 3} or (NH{sub 4

  1. Thermally fabricated MoS{sub 2}-graphene hybrids as high performance anode in lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, S.K., E-mail: sunil111954@yahoo.co.uk [Department of Chemistry, Indian Institute of Technology, Kharagpur, 721302 (India); Kartick, B. [Department of Chemistry, Indian Institute of Technology, Kharagpur, 721302 (India); Choudhury, S. [Department of Nanostructured Materials, Leibniz-Institut für Polymerforschung Dresden e.V. (IPF Dresden), Hohe Strasse 6, 01069, Dresden (Germany); Stamm, M. [Department of Nanostructured Materials, Leibniz-Institut für Polymerforschung Dresden e.V. (IPF Dresden), Hohe Strasse 6, 01069, Dresden (Germany); Technische Universität Dresden, Physical Chemistry of Polymer Materials, 01062, Dresden (Germany)

    2016-11-01

    MoS{sub 2}-reduced graphene oxide (MoS{sub 2}-rGO: where rGO = 0, 1, 3, 5, 7 and 10 wt%) hybrids have been fabricated using (NH{sub 4}){sub 2}MoS{sub 4} and graphite oxide as single source precursors of MoS{sub 2} and thermally exfoliated reduced graphene oxide respectively. These individual precursors were initially subjected to grinding for 30 min followed by heating at 1200 °C for 15 min and characterized. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) confirmed co-dispersion of MoS{sub 2} on thermally exfoliated graphite oxide. Electrochemical studies of these hybrids as anode materials showed that MoS{sub 2}-rGO (7 wt%) exhibited superior reversible capacity, cycling stability, enhanced rate performance (780 mAhg{sup −1}) and rate capability (880 mAhg{sup −1}) over pristine MoS{sub 2} and other hybrids. - Highlights: • MoS{sub 2}-graphene hybrids are synthesized by high temperature from individual precursors. • These hybrids have been used as anode material in LIB. • MoS{sub 2}-graphene (7 wt%) exhibited superior reversible capacity and cycling stability. • It showed high rate performance (780 mA h g{sup −1}) and rate capability (880 mA h g{sup −1}). • Enhanced performance at lower graphene makes it most attractive anode material in LIB.

  2. Synthesis of High-Quality Large-Area Homogenous 1T' MoTe2 from Chemical Vapor Deposition.

    Science.gov (United States)

    Zhou, Lin; Zubair, Ahmad; Wang, Ziqiang; Zhang, Xu; Ouyang, Fangping; Xu, Kai; Fang, Wenjing; Ueno, Keiji; Li, Ju; Palacios, Tomás; Kong, Jing; Dresselhaus, Mildred S

    2016-11-01

    High-quality large-area few-layer 1T' MoTe 2 films with high homogeneity are synthesized by the controlled tellurization of MoO 3 film. The Mo precursor plays a key role in determining the quality and morphology of the 1T' MoTe 2 . Furthermore, the amount of Te strongly influences the phase of the MoTe 2 . The growth method paves the way toward the scalable production of 1T' MoTe 2 -based applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Structural phase transition and magnetic properties of double perovskites Ba2CaMO6 (M=W, Re, Os)

    International Nuclear Information System (INIS)

    Yamamura, Kazuhiro; Wakeshima, Makoto; Hinatsu, Yukio

    2006-01-01

    Structures and magnetic properties for double perovskites Ba 2 CaMO 6 (M=W, Re, Os) were investigated. Both Ba 2 CaReO 6 and Ba 2 CaWO 6 show structural phase transitions at low temperatures. For Ba 2 CaReO 6 , the second order transition from cubic Fm3-bar m to tetragonal I4/m has been observed near 120K. For Ba 2 CaWO 6 , the space group of the crystal structure is I4/m at 295K and the transition to monoclinic I2/m has been observed between 220K. Magnetic susceptibility measurements show that Ba 2 CaReO 6 (S=1/2) and Ba 2 CaOsO 6 (S=1) transform to an antiferromagnetic state below 15.4 and 51K, respectively. Anomalies corresponding to their structural phase transition and magnetic transition have been also observed through specific heat measurements

  4. MoS{sub 2}/cotton-derived carbon fibers with enhanced cyclic performance for sodium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiang [School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 (China); Yang, Yan [School of Electrical Engineering, Southwest Jiaotong University, Chengdu, 610031 (China); Liu, Jiangwen; Ouyang, Liuzhang; Liu, Jun; Hu, Renzong [School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 (China); Yang, Lichun, E-mail: mslcyang@scut.edu.cn [School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 (China); Zhu, Min [School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 (China)

    2017-08-15

    Highlights: • MoS{sub 2} nanosheets vertically grow on cotton-derived carbon microfibers. • The carbon fibers facilitate charge transfer and structure stabilization. • The MoS{sub 2}/CDCFs exhibit enhanced cyclic performance for reversible Na{sup +} storage. - Abstract: Carbon fibers derived from bio-template are low cost and environmental benign, therefore have attracted much attention in energy storage materials. In this work, we successfully fabricated MoS{sub 2}/cotton-derived carbon fibers (MoS{sub 2}/CDCFs) via hydrothermal route followed by carbonization process. In the composite of MoS{sub 2}/CDCFs, MoS{sub 2} nanosheets vertically grow on the carbon fibers which offer fast ways for electron transfer and at the same time act as robust support to buffer the volume changes of MoS{sub 2} nanosheets during discharge/charge cycles. As anode materials for sodium-ion batteries, MoS{sub 2}/CDCFs exhibit good rate performance and markedly enhanced cyclic stability due to the conductive support of CDCFs. At a current density of 0.1 A g{sup −1}, the MoS{sub 2}/CDCFs-1 shows an initial reversible capacity of 504.9 mAh g{sup −1}, and maintains 444.5 mAh g{sup −1} after 50 cycles. Even when the current density increases to 0.5 A g{sup −1}, it maintains 323.1 mAh g{sup −1} after 150 cycles, which is much higher than the capacity retention of 149.6 mAh g{sup −1} for the bare MoS{sub 2} nanosheets. The improved electrochemical performance verifies the effective strategy of using cotton as carbon source to construct hierarchical composites for sodium-ion batteries.

  5. Microstructure and properties of MoSi2-MoB and MoSi2-Mo5Si3 molybdenum silicides

    International Nuclear Information System (INIS)

    Schneibel, J.H.; Sekhar, J.A.

    2003-01-01

    MoSi 2 -based intermetallics containing different volume fractions of MoB or Mo 5 Si 3 were fabricated by hot-pressing MoSi 2 , MoB, and Mo 5 Si 3 powders in vacuum. Both classes of alloys contained approximately 5 vol.% of dispersed silica phase. Additions of MoB or Mo 5 Si 3 caused the average grain size to decrease. The decrease in the grain size was typically accompanied by an increase in flexure strength, a decrease in the room temperature fracture toughness, and a decrease in the hot strength (compressive creep strength) measured around 1200 deg. C, except when the Mo 5 Si 3 effectively became the major phase. Oxidation measurements on the two classes of alloys were carried out in air. Both classes of alloys were protected from oxidation by an in-situ adherent scale that formed on exposure to high temperature. The scale, although not analyzed in detail, is commonly recognized in MoSi 2 containing materials as consisting mostly of SiO 2 . The MoB containing materials showed an increase in the scale thickness and the cyclic oxidation rate at 1400 deg. C when compared with pure MoSi 2 . However, in contrast with the pure MoSi 2 material, oxidation at 1400 deg. C began with a weight loss followed by a weight gain and the formation of the protective silica layer. The Mo 5 Si 3 containing materials experienced substantial initial weight losses followed by regions of small weight changes. Overall, the MoB and Mo 5 Si 3 additions to MoSi 2 tended to be detrimental for the mechanical and oxidative properties

  6. Clinical utility of serum folate measurement in tertiary care patients: Argument for revising reference range for serum folate from 3.0 ng/mL to 13.0 ng/mL

    Directory of Open Access Journals (Sweden)

    Gurmukh Singh

    2015-04-01

    Full Text Available Objective: Assess the need for folate testing, frequency of corrective action, and determine reference level for serum folate. Methods: Serum folate levels in 5313 samples from 4448 patients, and clinical data were reviewed for patient characteristics and for (a evidence of corrective action in patients with serum folate values 25.7 ng/mL. Results: The prevalence of serum folate levels, in patients, 25.7 ng/mL the sample was collected after supplementation with folic acid. Of the 128 patients with serum folate 60% of the patients. Since serum folate levels ≥13.0 ng/mL are needed for optimal prevention of neural tube defects in the embryo/fetus, we propose that normal serum folate level should be designated to be ≥13.0 ng/mL. Keywords: Serum folate, Prevalence of folate deficiency, Neural tube defects, Optimum serum folate level, Utility of folate testing

  7. MoS2 nanosheet functionalized with Cu nanoparticles and its application for glucose detection

    International Nuclear Information System (INIS)

    Huang, Jingwei; Dong, Zhengping; Li, Yanrong; Li, Jing; Tang, Weijie; Yang, Haidong; Wang, Jia; Bao, Yun; Jin, Jun; Li, Rong

    2013-01-01

    Graphical abstract: - Highlights: • First report on decorating MoS 2 nanosheet with Cu nanoparticles by chemical reduction. • Cu nanoparticles were uniformly decorated on MoS 2 nanosheet. • Glucose biosensor based on copper nanoparticles-MoS 2 nanosheet hybrid is fabricated. • The biosensor exhibits high sensitivity. - Abstract: For the first time, Cu nanoparticles were evenly decorated on MoS 2 nanosheet by chemical reduction. The as-prepared Cu-MoS 2 hybrid was characterized by atomic force microscope (AFM), Raman spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and then used to fabricate a non-enzymatic glucose sensor. The performance of our sensor was investigated by cyclic voltammetry and amperometric measurement in alkaline media. Electrochemical tests showed that Cu-MoS 2 hybrid exhibited synergistic electrocatalytic activity on the oxidation of glucose with a high sensitivity of 1055 μA mM1 cm −2 and a linear range up to 4 mM

  8. Spectral intensities: The emission spectra for the Cs2NaScCl6: MoCl63- system in the Fm3m space group

    International Nuclear Information System (INIS)

    Acevedo, R.; Meruane, T.; Navarro, G.

    2000-01-01

    Taking advantage of the data reported by Flint and Paulusz, we have undertaken a theoretical investigation of the intensity mechanism for the various emissions; Γ 8 ( 2 T 2g ) → Γ 8 ( 4 A 2g ), Γ 8 ( 2 E g ), Γ 8 ( 2 T 1g ), Γ 6 ( 2 T 1g ) for the Cs 2 NaScCl 6 :MoCl 6 3- system in the Fm3m-space group. The experimental data reported by these authors, refer to the visible and near infrared luminescence spectra of MoCl 3- 6 complex ion in different host, such as Cs 2 NaMCl 6 (M = Sc, Y, In), measured between 15,000 cm -1 and 3,000 cm -1 at liquid helium temperatures. At least, five luminescence transitions have been identified and assigned and each of them show extensive vibronic structure, which was analyzed to yield the vibrational frequencies of the MoX 3- 6 (X -1 = Cl -1 Br -1 ) ion in each excitation. A careful analysis of the experimental data reported shows that for the various observed electronic transitions, the vibration frequencies do change only slightly, and therefore there is no indication that the system undergoes a Jahn-Teller distortion (along an active coordinate) of some importance to be taken into account in the current work. There is, though clear evidence that for the chloro-elpasolites, there is a strong resonance interaction between ν 3 (τ 1u : stretching) of the MoX 6 3- , complex ion and that of the host when M = In, Y. Thus for M = Sc, the slighter higher host ν 3 , wavenumber is likely to minimizes the effect of this coupling. This experimental evidence, will allow us for the Cs 2 NaScCl 6 3- system to neglect to first order approximation, the coupling among the internal and the external vibrations and to proceed using a both a molecular model and the independent system model (ISM)

  9. Studies of techniques for the post-elution concentration of 99mTc obtained from gel type 99Mo/99mTc generators

    International Nuclear Information System (INIS)

    Suzuki, Katia Noriko

    2009-01-01

    On average 80% of the radiopharmaceuticals used in Nuclear Medicine are labeled with 99 mTc due to its physical properties and easy attainment through of 99 Mo/ 99 mTc generators. The Directory of Radiopharmacy (DIRF) of IPEN-CNEN/SP developed a gel type chromatographic generator of MoZr with 99 Mo produced by 98 Mo(n,γ) 99 Mo reaction that occurs at the IEA-R1 Nuclear Reactor. The gel is composed of zirconium molybdate with elution volume of 12 mL with an activity of 11100 MBq (300 mCi) producing a radioactive concentration of 925 MBq (25 mCi)/mL. The fission generator gives a higher radioactive concentration around 1850 MBq (50 mCi)/mL. The aim of this work is to study a system of post-elution concentration of 99 mTc for the attainment of a high enough radioactive concentration to meet the demands of the market, with a proved quality. Two types of systems of post-elution concentration were developed: the single and the tandem. The most appropriate system for the gel generator of 99 Mo/ 99 mTc, being at the same time sterile and vacuum automated, was the tandem system using Dionex 2.5 cc/QMA cartridges. The gel generator is eluted with 10 mL of solution of 0.1% NaCl and the pertechnetate anion is retained in the QMA cartridge and further eluted with 4 mL of saline. The process takes no more than 30 minutes. The elution efficiency of the system of concentration was 90 %. At the beginning of 2009 a global crisis in the supply of 99 Mo took place making it necessary the development of alternative technologies for the production of 99 Mo/ 99 mTc generators using fission produced 99 Mo and the development of an appropriate method to extend the useful life of this generator. The results of this study showed that the same system developed for the post- concentration of the gel generator can be employed for the fission generator, using the tandem system, giving a concentration factor of 3 for the elution of 99 mTc. (author)

  10. Preparation of 99Mo/99mTc generators based on 99Mo zirconium molybdates in the Gel Synthesis Device for Generators

    International Nuclear Information System (INIS)

    Lopez M, I. Z.; Monroy G, F.; Rivero G, T.; Rojas N, P.

    2008-01-01

    The 99m Tc is used for diagnosis and therapy. It is produced commercially from 99 Mo obtained from the fission of 235 U, which is retained in chromatographic columns filled with alumina whose maximum capacity is 0.2%. Given these constraints new methods of preparation 99 Mo/ 99m Tc generators have been developed using zirconium molybdates gels containing up to 30% of Mo, which is part of the generator matrix, and retaining quality and purity similar characteristics to those commercial generators. The present study aims to determine the flow of agitation, temperature and drying time optimal to prepare 99 Mo/ 99m Tc generators based on 99 Mo zirconium molybdates in the Gel Synthesis Device 99 Mo/ 99m Tc Generators designed and built by groups of the Radioactive Materials Research Laboratory and Automation and Instrumentation Department of the National Institute of Nuclear Research. (Author)

  11. Impact of PSA density of transition zone as a potential parameter in reducing the number of unnecessary prostate biopsies in patients with psa levels between 2.6 and 10.0 ng/mL.

    Science.gov (United States)

    Castro, Hugo A Socrates; Iared, Wagner; Santos, José Eduardo Mourão; Solha, Raphael Sandes; Shigueoka, David Carlos; Ajzen, Sergio Aron

    2018-04-10

    To assess the accuracy of prostate-specific antigen (PSA) adjusted for the transition zone volume (PSATZ) in predicting prostate cancer by comparing the ability of several PSA parameters in predicting prostate cancer in men with intermediate PSA levels of 2.6 - 10.0 ng/mL and its ability to reduce unnecessary biopsies. This study included 656 patients referred for prostate biopsy who had a serum PSA of 2.6 - 10.0 ng/mL. Total prostate and transition zone volumes were measured by transrectal ultrasound using the prolate ellipsoid method. The clinical values of PSA, free-to-total (F/T) ratio, PSA density (PSAD) and PSATZ for the detection of prostate cancer were calculated and statistical comparisons between biopsy-positive (cancer) and biopsy-negative (benign) were conducted. Cancer was detected in 172 patients (26.2%). Mean PSA, PSATZ, PSAD and F/T ratio were 7.5 ng/mL, 0.68 ng/mL/cc. 0.25 ng/mL/cc and 0.14 in patients with prostate cancer and 6.29 ng/mL, 0.30 ng/mL/cc, 0.16 ng/mL/cc and 0.22 in patients with benign biopsies, respectively. ROC curves analysis demonstrated that PSATZ had a higher area under curve (0,838) than F/T ratio (0,806) (PPSA. Compared to other PSA related parameters, it was better in differentiating between prostate cancer and benign prostatic enlargement. Also, PSATZ could reduce a significant number of unnecessary biopsies. Copyright® by the International Brazilian Journal of Urology.

  12. Preparation of MoB and MoB-MoSi2 composites by combustion synthesis in SHS mode

    International Nuclear Information System (INIS)

    Yeh, C.L.; Hsu, W.S.

    2007-01-01

    Combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS) was carried out in the Mo-B and Mo-B-Si systems for the preparation of molybdenum boride MoB and the composite of MoB-MoSi 2 from elemental powder compacts. Under a preheating temperature above 150 deg. C , the reaction of Mo with boron in the sample compact of Mo:B = 1:1 is characterized by a planar combustion front propagating in a self-sustaining and steady manner. As the preheating temperature or sample compaction density increased, combustion temperature was found to increase and the propagation rate of the combustion front was correspondingly enhanced. Moreover, the XRD analysis provides evidence of yielding nearly single-phase α-MoB from the Mo-B sample at equiatomic stoichiometry. In the synthesis of MoB-MoSi 2 composites, the starting stoichiometry of the Mo-B-Si powder compact was varied so as to produce the final composites containing 20-80 mol% MoB. It was also found the increase of flame-front velocity and combustion temperature with increasing MoB content formed in the composite. The composition analysis by XRD shows excellent conversion from the Mo-B-Si powder compact to the MoB-MoSi 2 composite through the SHS reaction; that is, in addition to a small amount of Mo 5 Si 3 , the as-synthesized composite is composed entirely of MoB and MoSi 2

  13. Morphology-controlled synthesis of MoS{sub 2} nanostructures with different lithium storage properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiwen; Zhang, Zhian, E-mail: zza75@163.com; Chen, Yaqiong; Qu, Yaohui; Lai, Yanqing; Li, Jie

    2014-07-05

    Highlights: • MoS{sub 2} nanospheres, nanoribbons and nanoparticles were prepared by hydrothermal method. • The surfactant and temperature control the shape and crystal structure of MoS{sub 2}. • MoS{sub 2} nanospheres exhibit the excellent lithium storage property. - Abstract: A one-step hydrothermal process was employed to prepare a series of MoS{sub 2} nanostructures via simply altering the surfactant as soft template and hydrothermal reaction temperature. Three kinds of MoS{sub 2} nanostructures (three-dimensional (3D) hierarchical nanospheres, one-dimensional (1D) nanoribbons, and large aggregated nanoparticles) were successfully achieved and investigated well by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and Brunauer–Emmett–Teller analysis (BET). Electrochemical tests reveal that these MoS{sub 2} samples could deliver high initial discharge capacities (higher than 1050.0 mA h g{sup −1}), but various cycling performances. The hierarchical MoS{sub 2} nanospheres assembled by sheet-like subunits show the highest specific capacity of 1355.1 mA h g{sup −1}, and 66.8% of which can be retained after 50 cycles. The good lithium storage property of hierarchical MoS{sub 2} nanospheres can be attributed to the higher electrolyte/MoS{sub 2} contact area and stable 3D layered structure.

  14. Infrared Spectra of Novel NgBeSO2 Complexes (Ng = Ne, Ar, Kr, Xe) in Low Temperature Matrixes.

    Science.gov (United States)

    Yu, Wenjie; Liu, Xing; Xu, Bing; Xing, Xiaopeng; Wang, Xuefeng

    2016-11-03

    The novel noble-gas complexes NgBeSO 2 (Ng = Ne, Ar, Kr, Xe) have been prepared in the laser-evaporated beryllium atom reactions with SO 2 in low-temperature matrixes. Doped with heavier noble gas, the guest (Ar, Kr, Xe) atom can substitute neon to form more stable complex. Infrared spectroscopy and theoretical calculations are used to confirm the band assignment. The dissociation energies are calculated at 0.9, 4.0, 4.7, and 6.0 kcal/mol for NeBeSO 2 , ArBeSO 2 , KrBeSO 2 , and XeBeSO 2 , respectively, at the CCSD(T) level. Quantum chemical calculations demonstrate that the Ng-Be bonds in NgBeSO 2 could be formed by the combination of electron-donation and ion-induced dipole interactions. The Wiberg bond index (WBI) values of Ng-Be bonds and LOL (localized orbital locator) profile indicate that the Ng-Be bond exhibits a gradual increase in covalent character along Ne to Xe.

  15. Phase formation in the Li2MoO4–Rb2MoO4–Fe2(MoO4)3 system and crystal structure of a novel triple molybdate LiRb2Fe(MoO4)3

    International Nuclear Information System (INIS)

    Khal'baeva, Klara M.; Solodovnikov, Sergey F.; Khaikina, Elena G.; Kadyrova, Yuliya M.; Solodovnikova, Zoya A.; Basovich, Olga M.

    2013-01-01

    X-ray investigation of solid state interaction of the components in the Li 2 MoO 4 –Rb 2 MoO 4 –Fe 2 (MoO 4 ) 3 system was carried out, and a subsolidus phase diagram of the said system was constructed. The subsystem Rb 2 MoO 4 –LiRbMoO 4 –RbFe(MoO 4 ) 2 was shown to be non-quasiternary. Formation of a novel triple molybdate LiRb 2 Fe(MoO 4 ) 3 was established, conditions of solid state synthesis and crystallization of the compound were found. Its crystal structure (orthorhombic, space group Pnma, Z=4, a=24.3956(6), b=5.8306(1), c=8.4368(2) Å) represents a new structure type and includes infinite two-row ribbons ([Fe(MoO 4 ) 3 ] 3− ) ∞ parallel to the b axis and composed of FeO 6 octahedra, terminal Mo(3)O 4 tetrahedra, and bridge Mo(1)O 4 and Mo(2)O 4 tetrahedra connecting two or three FeO 6 octahedra. The ribbons are connected to form 3D framework via corner-sharing LiO 4 tetrahedra. Rubidium cations are 11- and 13-coordinated and located in cavities of this heterogeneous polyhedral framework. - Graphical abstract: Exploring the Li 2 MoO 4 –Rb 2 MoO 4 –Fe 2 (MoO 4 ) 3 system showed its partial non-quasiternarity and revealed a new compound LiRb 2 Fe(MoO 4 ) 3 which was structurally studied. - Highlights: • The Li 2 MoO 4 –Rb 2 MoO 4 –Fe 2 (MoO 4 ) 3 system study revealed a new compound LiRb 2 Fe(MoO 4 ) 3 . • Its structure of a new type includes ribbons of FeO 6 octahedra and MoO 4 tetrahedra. • The ribbons are connected into a 3D framework via corner-sharing LiO 4 tetrahedra

  16. New Layered Oxide-Fluoride Perovskites: KNaNbOF5 and KNaMO2F4 (M = Mo6+, W6+

    Directory of Open Access Journals (Sweden)

    Rachelle Ann F. Pinlac

    2011-03-01

    Full Text Available KNaNbOF5 and KNaMO2F4 (M = Mo6+, W6+, three new layered oxide-fluoride perovskites with the general formula ABB’X6, form from the combination of a second-order Jahn-Teller d0 transition metal and an alkali metal (Na+ on the B-site. Alternating layers of cation vacancies and K+ cations on the A-site complete the structure. The K+ cations are found in the A-site layer where the fluoride ions are located. The A-site is vacant in the adjacent A-site layer where the axial oxides are located. This unusual layered arrangement of unoccupied A-sites and under bonded oxygen has not been observed previously although many perovskite-related structures are known.

  17. Hydrothermal synthesis of layer-controlled MoS_2/graphene composite aerogels for lithium-ion battery anode materials

    International Nuclear Information System (INIS)

    Zhao, Bing; Wang, Zhixuan; Gao, Yang; Chen, Lu; Lu, Mengna; Jiao, Zheng; Jiang, Yong; Ding, Yuanzhang; Cheng, Lingli

    2016-01-01

    Highlights: • Layer-controlled MoS_2/GA composites are synthesized by a facile hydrothermal route. • Few-layer (5–15 layers) MoS_2 nanosheets are decorated on the surface of GNS homogeneously and tightly. • The growth mechanism of the lay-controlled MoS_2/GA composites is proposed. • The composite delivers high specific capacity of 1085.0 mAh g"−"1 at 0.1 A g"−"1. - Abstract: Layer-controlled MoS_2/graphene aerogels (MoS_2/GA) composites are synthesized by a facile hydrothermal route, in which few-layer (5–15 layers) MoS_2 nanosheets with high crystalline are decorated on the surface of graphene nanosheets homogeneously and tightly. The number of the MoS_2 layers can be easily controlled through adjusting the amount of molybdenum source in the reaction system. Moreover, the growth mechanism of the lay-controlled MoS_2/GA composites is proposed. The three-dimensional MoS_2/GA with macroporous micro-structure not only shortens the transportation length of electrons and ions, but also restrains the re-stacking of MoS_2 effectively, stabilizing the electrode structure during repeated charging/discharging processes. Electrochemical tests demonstrate that this few-layer MoS_2/GA composite exhibits a high reversible capacity of 1085.0 mAh g"−"1 at current density of 100 mA g"−"1, as well as extraordinarily high cycling stability and rate capability.

  18. Comparative study of 99Mo/99mTc generators at base of synthesized gels starting from activation and fission 99Mo

    International Nuclear Information System (INIS)

    Lopez M, I.Z.; Monroy G, F.; Rivero G, T.; Rojas N, P.

    2007-01-01

    The 99m Tc is used for diagnostic and therapy. It is produced starting from 99 Mo, absorbed in chromatographic columns, loaded with alumina that absorb only 0.2% of 99 Mo with high specific activities of 99 Mo, obtained from the 235 U fission. Given these conditions and limitations, new preparation procedures of 99 Mo/ 99m Tc generators, its have been developed, using zirconium molybdates gels that incorporates until 30% of 99 Mo, conserve similar characteristics of quality and purity that the traditional generator. The radiochemical characteristics of the 99m Tc elution, depend strongly on the gel preparation conditions. In particular, the present work has by object to determine the influence of the 99 Mo used type, fission or activation product, during the gels synthesis, as well as the used air flow for the agitation in the gels preparation and its influence in the 99 Mo/ 99m Tc generators quality. When diminishing the flow of agitation air the efficiency it increases and in the radionuclide purity of the eluates and when using 99 Mo from fission for the gels production it increases in an important way the elutriation efficiency, the radiochemical and radionuclide purity of the 99m Tc eluates. (Author)

  19. Effects of Mo on microstructure of as-cast 28 wt.% Cr–2.6 wt.% C–(0–10) wt.% Mo irons

    Energy Technology Data Exchange (ETDEWEB)

    Imurai, S. [Department of Physics and Materials Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thanachayanont, C.; Pearce, J.T.H. [National Metal and Materials Technology Center, Pathumthani 12120 (Thailand); Tsuda, K. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Chairuangsri, T., E-mail: tchairuangsri@gmail.com [Department of Industrial Chemistry, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2014-04-01

    Microstructures of as-cast 28 wt.% Cr–2.6 wt.% C irons containing (0–10) wt.% Mo with the Cr/C ratio of about 10 were studied and related to hardness. The experimental irons were cast into dry sand molds. Microstructural investigation was performed by light microscopy, X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectrometry. It was found that the iron with about 10 wt.% Mo was eutectic/peritectic, whereas the others with less Mo content were hypoeutectic. The matrix in all irons was austenite, partly transformed to martensite during cooling. Mo addition promoted the formation of M{sub 23}C{sub 6} and M{sub 6}C. At 1 wt.% Mo, multiple eutectic carbides including M{sub 7}C{sub 3}, M{sub 23}C{sub 6} and M{sub 6}C were observed. M{sub 23}C{sub 6} existed as a transition zone between eutectic M{sub 7}C{sub 3} and M{sub 6}C, indicating a carbide transition as M{sub 7}C{sub 3}(M{sub 2.3}C) → M{sub 23}C{sub 6}(M{sub 3.8}C) → M{sub 6}C. At 6 wt.% Mo, multiple eutectic carbides including M{sub 7}C{sub 3} and M{sub 23}C{sub 6} were observed together with fine cellular/lamellar M{sub 6}C aggregates. In the iron with 10 wt.% Mo, only eutectic/peritectic M{sub 23}C{sub 6} and M{sub 6}C were found without M{sub 7}C{sub 3}. Mo distribution to all carbides has been determined to be increased from ca. 0.4 to 0.7 in mass fraction as the Mo content in the irons was increased. On the other hand, Cr distribution to all carbides is quite constant as ca. 0.6 in mass fraction. Mo addition increased Vickers macro-hardness of the irons from 495 up to 674 HV{sub 30}. High Mo content as solid-solution in the matrix and the formation of M{sub 6}C or M{sub 23}C{sub 6} aggregates were the main reasons for hardness increase, indicating potentially improved wear performance of the irons with Mo addition. - Highlights: • Mo promoted the formation of M{sub 23}C{sub 6} and M{sub 6}C in the irons with Cr/C ratio of about 10

  20. Polymer-Derived Ceramic Functionalized MoS2 Composite Paper as a Stable Lithium-Ion Battery Electrode

    Science.gov (United States)

    David, L.; Bhandavat, R.; Barrera, U.; Singh, G.

    2015-04-01

    A facile process is demonstrated for the synthesis of layered SiCN-MoS2 structure via pyrolysis of polysilazane functionalized MoS2 flakes. The layered morphology and polymer to ceramic transformation on MoS2 surfaces was confirmed by use of electron microscopy and spectroscopic techniques. Tested as thick film electrode in a Li-ion battery half-cell, SiCN-MoS2 showed the classical three-stage reaction with improved cycling stability and capacity retention than neat MoS2. Contribution of conversion reaction of Li/MoS2 system on overall capacity was marginally affected by the presence of SiCN while Li-irreversibility arising from electrolyte decomposition was greatly suppressed. This is understood as one of the reasons for decreased first cycle loss and increased capacity retention. SiCN-MoS2 in the form of self-supporting paper electrode (at 6 mg.cm-2) exhibited even better performance, regaining initial charge capacity of approximately 530 mAh.g-1 when the current density returned to 100 mA.g-1 after continuous cycling at 2400 mA.g-1 (192 mAh.g-1). MoS2 cycled electrode showed mud-cracks and film delamination whereas SiCN-MoS2 electrodes were intact and covered with a uniform solid electrolyte interphase coating. Taken together, our results suggest that molecular level interfacing with precursor-derived SiCN is an effective strategy for suppressing the metal-sulfide/electrolyte degradation reaction at low discharge potentials.

  1. Sorption of {sup 99}MoO{sub 4}{sup 2-} ions on commercial hydrotalcites

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, J.; Gonzalez, H.; Lopez, H.; Aranda, N.; Granados, F.; Bulbulian, S. [Delegacion Miguel Hidalgo, Mexico (Mexico). Instituto Nacional de Investigaciones Nucleares

    2005-07-01

    {sup 99}MoO{sub 4}{sup 2-} sorption behavior on 3 commercial hydrotalcites, produced by Sasol Chemie, was studied through batch experiments. Only one of them showed high sorption capacity. This product, the MG70 was identified by XRD diffraction analysis as hydrotalcite (Mg{sub 6}Al{sub 2}(OH){sub 16}CO{sub 3} x 4H{sub 2}O), while the other two, MG50 and MG30, were identified mainly as magnesium aluminum hydroxide hydrate, MgAl{sub 2}(OH){sub 14} x 3H{sub 2}O. Calcined MG70 (CMG70) was used to retain about 298.17{+-}8.3 mg of {sup 99}Mo-MoO{sub 4}{sup 2-} (MG70-{sup 99}MoO{sub 4}). When this material was packed in a glass column, the generated {sup 99m}Tc was eluted by using NaCl or HNO{sub 3} aqueous solutions. Saline solutions eluted {sup 99m}Tc with considerable amounts of {sup 99}Mo while 0.1 M HNO{sub 3} eluted {sup 99m}Tc together with a such small amount of {sup 99}Mo that the {sup 99}Mo {mu}Ci/{sup 99m}Tc mCi ratios are close to the value recommended by the American Pharmacopeia. (orig.)

  2. Tunneling in BP-MoS2 heterostructure

    Science.gov (United States)

    Liu, Xiaochi; Qu, Deshun; Kim, Changsik; Ahmed, Faisal; Yoo, Won Jong

    Tunnel field effect transistor (TFET) is considered to be a leading option for achieving SS mV/dec. In this work, black phosphorus (BP) and molybdenum disulfide (MoS2) heterojunction devices are fabricated. We find that thin BP flake and MoS2 form normal p-n junctions, tunneling phenomena can be observed when BP thickness increases to certain level. PEO:CsClO4 is applied on the surface of the device together with a side gate electrode patterned together with source and drain electrodes. The Fermi level of MoS2 on top of BP layer can be modulated by the side gating, and this enables to vary the MoS2-BP tunnel diode property from off-state to on-state. Since tunneling is the working mechanism of MoS2-BP junction, and PEO:CsClO4\\ possesses ultra high dielectric constant and small equivalent oxide thickness (EOT), a low SS of 55 mV/dec is obtained from MoS2-BP TFET. This work was supported by the Global Research Laboratory and Global Frontier R&D Programs at the Center for Hybrid Interface Materials, both funded by the Ministry of Science, ICT & Future Planning via the National Research Foundation of Korea (NRF).

  3. Transparent 1T-MoS2 nanofilm robustly anchored on substrate by layer-by-layer self-assembly and its ultra-high cycling stability as supercapacitors

    Science.gov (United States)

    Li, Danqin; Zhou, Weiqiang; Zhou, Qianjie; Ye, Guo; Wang, Tongzhou; Wu, Jing; Chang, Yanan; Xu, Jingkun

    2017-09-01

    Two-dimensional MoS2 materials have attracted more and more interest and been applied to the field of energy storage because of its unique physical, optical, electronic and electrochemical properties. However, there are no reports on high-stable transparent MoS2 nanofilms as supercapacitors electrode. Here, we describe a transparent 1T-MoS2 nanofilm electrode with super-long stability anchored on the indium tin oxide (ITO) glass by a simple alternate layer-by-layer (LBL) self-assembly of a highly charged cationic poly(diallyldimethylammonium chloride) (PDDA) and negative single-/few-layer 1T MoS2 nanosheets. The ITO/(PDDA/MoS2)20 electrode shows a transmittance of 51.6% at 550 nm and obviously exhibits excellent transparency by naked eye observation. Ultrasonic damage test validates that the (PDDA/MoS2)20 film with the average thickness about 50 nm is robustly anchored on ITO substrate. Additionally, the electrochemical results indicate that the ITO/(PDDA/MoS2)20 film shows areal capacitance of 1.1 mF cm-2 and volumetric capacitance of 220 F cm-3 at 0.04 mA cm-2, 130.6% retention of the original capacitance value after 5000 cycles. Further experiments indicate that the formation of transparent (PDDA/MoS2) x nanofilm by LBL self-assembly can be extended to other substrates, e.g., slide glass and flexible polyethylene terephthalate (PET). Thus, the easily available (PDDA/MoS2) x nanofilm electrode has great potential for application in transparent and/or flexible optoelectronic and electronics devices.

  4. Toughness of 2,25Cr-1Mo steel and weld metal

    Science.gov (United States)

    Acarer, Mustafa; Arici, Gökhan; Acar, Filiz Kumdali; Keskinkilic, Selcuk; Kabakci, Fikret

    2017-09-01

    2,25Cr-1Mo steel is extensively used at elevated temperature structural applications in fossil fire power plants for steam pipes, nozzle chambers and petrochemical industry for hydrocracking unit due to its excellent creep resistance and good redundant to oxidation. Also they should have acceptable weldability and toughness. The steels are supplied in quenched and tempered condition and their welded components are subjected to post-weld heat treatment (PWHT). Tempering process is carried out at 690-710°C to improve toughness properties. However they are sensitive to reheat cracking and temper embrittlement. To measure temper embrittlement of the steels and their weld metal, temper embrittlement factor and formula (J factor - Watanabe and X formula- Bruscato) are used. Step cooling heat treatment is also applied to determine temper embrittlement. In this study, toughness properties of Cr Mo (W) steels were reviewed. Also transition temperature curves of 2,25Cr-1Mo steel and its weld metal were constructed before and after step cool heat treatment as experimental study. While 2,25Cr-1Mo steel as base metal was supplied, all weld metal samples were produced in Gedik Welding Company. Hardness measurements and microstructure evaluation were also carried out.

  5. Ablation of NG2 proteoglycan leads to deficits in brown fat function and to adult onset obesity.

    Directory of Open Access Journals (Sweden)

    Yunchao Chang

    Full Text Available Obesity is a major health problem worldwide. We are studying the causes and effects of obesity in C57Bl/6 mice following genetic ablation of NG2, a chondroitin sulfate proteoglycan widely expressed in progenitor cells and also in adipocytes. Although global NG2 ablation delays early postnatal adipogenesis in mouse skin, adult NG2 null mice are paradoxically heavier than wild-type mice, exhibiting larger white fat deposits. This adult onset obesity is not due to NG2-dependent effects on CNS function, since specific ablation of NG2 in oligodendrocyte progenitors yields the opposite phenotype; i.e. abnormally lean mice. Metabolic analysis reveals that, while activity and food intake are unchanged in global NG2 null mice, O(2 consumption and CO(2 production are decreased, suggesting a decrease in energy expenditure. Since brown fat plays important roles in regulating energy expenditure, we have investigated brown fat function via cold challenge and high fat diet feeding, both of which induce the adaptive thermogenesis that normally occurs in brown fat. In both tests, body temperatures in NG2 null mice are reduced compared to wild-type mice, indicating a deficit in brown fat function in the absence of NG2. In addition, adipogenesis in NG2 null brown pre-adipocytes is dramatically impaired compared to wild-type counterparts. Moreover, mRNA levels for PR domain containing 16 (PRDM16 and peroxisome proliferator-activated receptor γ coactivator (PGC1-α, proteins important for brown adipocyte differentiation, are decreased in NG2 null brown fat deposits in vivo and NG2 null brown pre-adipocytes in vitro. Altogether, these results indicate that brown fat dysfunction in NG2 null mice results from deficits in the recruitment and/or development of brown pre-adipocytes. As a consequence, obesity in NG2 null mice may occur due to disruptions in brown fat-dependent energy homeostasis, with resulting effects on lipid storage in white adipocytes.

  6. In-situ fabrication of MoSi2/SiC–Mo2C gradient anti-oxidation coating on Mo substrate and the crucial effect of Mo2C barrier layer at high temperature

    International Nuclear Information System (INIS)

    Liu, Jun; Gong, Qianming; Shao, Yang; Zhuang, Daming; Liang, Ji

    2014-01-01

    MoSi 2 /SiC–Mo 2 C gradient coating on molybdenum was in situ prepared with pack cementation process by two steps: (1) carburizing with graphite powder to obtain a Mo 2 C layer on Mo substrate, and (2) siliconizing with Si powder to get a composite MoSi 2 /SiC layer on the upper part of Mo 2 C layer. The microstructure and elemental distribution in the coating were investigated with scanning electron microscopy (SEM), backscattered electron (BSE), energy dispersive spectroscopy (EDS), electron probe microanalysis (EPMA) and X-ray diffraction (XRD). Cyclic oxidation tests (at 500 °C, 1200 °C, 1400 °C and 1600 °C) demonstrated excellent oxidation resistance for the gradient composite coating and the mass loss was only 0.23% in 60 min at 1600 °C. XRD, EPMA, thermal dynamic and phase diagram analyses indicated that the Mo 2 C barrier layer played the key role in slowing down the diffusion of C and Si toward inner Mo substrate at high temperature and principally this contributed to the excellent anti-oxidation for Mo besides the outer MoSi 2 /SiC composite layer.

  7. Hydrothermal synthesis of 2D MoS 2 nanosheets for electrocatalytic hydrogen evolution reaction

    KAUST Repository

    Muralikrishna, S.

    2015-10-20

    Nanostructured molybdenum disulfide (MoS) is a very promising catalyst for producing molecular hydrogen by electrochemical methods. Herein, we have designed and synthesized highly electocatalytically active 2D MoS nanosheets (NS) from molybdenum trioxide (MoO) by a facile hydrothermal method and have compared their electrocatalytic activities for hydrogen evolution reaction (HER). The electrochemical characterization was performed using linear sweep voltammetry (LSV) in acidic medium. The MoS NS show a HER onset potential at about 80 mV vs. reversible hydrogen electrode (RHE) which is much lower than MoO (300 mV). The MoS NS and MoO show a current density of 25 mA cm and 0.3 mA cm, respectively at an overpotential of 280 mV vs. RHE. The MoS NS showed an 83 times higher current density when compared to MoO. The Tafel slopes of the MoS NS and MoO were about 90 mV per dec and 110 mV per dec respectively. This suggests that MoS NS are a better electrocatalyst when compared to MoO and follow the Volmer-Heyrovsky mechanism for HER.

  8. Hydrothermal synthesis of 2D MoS 2 nanosheets for electrocatalytic hydrogen evolution reaction

    KAUST Repository

    Muralikrishna, S.; Manjunath, K.; Samrat, D.; Reddy, Viswanath; Ramakrishnappa, T.; Nagaraju, Doddahalli H.

    2015-01-01

    Nanostructured molybdenum disulfide (MoS) is a very promising catalyst for producing molecular hydrogen by electrochemical methods. Herein, we have designed and synthesized highly electocatalytically active 2D MoS nanosheets (NS) from molybdenum trioxide (MoO) by a facile hydrothermal method and have compared their electrocatalytic activities for hydrogen evolution reaction (HER). The electrochemical characterization was performed using linear sweep voltammetry (LSV) in acidic medium. The MoS NS show a HER onset potential at about 80 mV vs. reversible hydrogen electrode (RHE) which is much lower than MoO (300 mV). The MoS NS and MoO show a current density of 25 mA cm and 0.3 mA cm, respectively at an overpotential of 280 mV vs. RHE. The MoS NS showed an 83 times higher current density when compared to MoO. The Tafel slopes of the MoS NS and MoO were about 90 mV per dec and 110 mV per dec respectively. This suggests that MoS NS are a better electrocatalyst when compared to MoO and follow the Volmer-Heyrovsky mechanism for HER.

  9. Thermal expansion studies on Th(MoO4)2, Na2Th(MoO4)3 and Na4Th(MoO4)4

    International Nuclear Information System (INIS)

    Keskar, Meera; Krishnan, K.; Dahale, N.D.

    2008-01-01

    Thermal expansion behavior of Th(MoO 4 ) 2 , Na 2 Th(MoO 4 ) 3 and Na 4 Th(MoO 4 ) 4 was studied under vacuum in the temperature range of 298-1123 K by high temperature X-ray diffractometer. Th(MoO 4 ) 2 was synthesized by reacting ThO 2 with 2 mol of MoO 3 , at 1073 K in air and Na 2 Th(MoO 4 ) 3 and Na 4 Th(MoO 4 ) 4 were prepared by reacting Th(MoO 4 ) 2 with 1 and 2 mol of Na 2 MoO 4 , respectively at 873 K in air. The XRD data of Th(MoO 4 ) 2 was indexed on orthorhombic system where as XRD data of Na 2 Th(MoO 4 ) 3 and Na 4 Th(MoO 4 ) 4 were indexed on tetragonal system. The lattice parameters and cell volume of all the three compounds, fit into polynomial expression with respect to temperature, showed positive thermal expansion (PTE) up to 1123 K. The average value of thermal expansion coefficients for Th(MoO 4 ) 2 , Na 2 Th(MoO 4 ) 3 and Na 4 Th(MoO 4 ) 4 were determined from the high temperature data

  10. Transition Metal Complexes of Cr, Mo, W and Mn Containing η1(S)-2,5-Dimethylthiophene, Benzothiophene and Dibenzothiophene Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, Michael [Iowa State Univ., Ames, IA (United States)

    2000-09-21

    The UV photolysis of hexanes solutions containing the complexes M(CO)6 (M=Cr, Mo, W) or CpMn(CO)3 (Cp=η5-C5H5) and excess thiophene (T*) (T*=2,5-dimethylthiophene (2,5-Me2T), benzothiophene (BT), and dibenzothiophene (DBT)) produces the η1(S)-T* complexes (CO)5M1(S)-T*) 1-8 or Cp(CO)2Mn(η1(S)-T*)9-11, respectively. However, when T*=DBT, and M=Mo, a mixture of two products result which includes the η1(S)-DBT complex (CO)5Mo1(S)-DBT) 4a and the unexpected π-complex (CO)3Mo(η{sup 6}-DBT) 4b as detected by 1H NMR. The liability of the η1(S)-T* ligands is illustrated by the rapid displacement of DBT in the complex (CO)5W(η1(S)-DBT) (1) by THF, and also in the complexes (CO)5Cr(η1(S)-DBT) (5) and CpMn(CO)21(S)-DBT) (9) by CO (1 atm) at room temperature. Complexes 1-11 have been characterized spectroscopically (1H NMR, IR) and when possible isolated as analytically pure solids (elemental analysis, EIMS). Single crystal, X-ray structural determinations are reported for (Cη)5W(η1(S)-DBT) and Cp(CO)2Mn(η1(S)-DBT).

  11. Highly Active 2D Layered MoS 2 -rGO Hybrids for Energy Conversion and Storage Applications.

    Science.gov (United States)

    Kamila, Swagatika; Mohanty, Bishnupad; Samantara, Aneeya K; Guha, Puspendu; Ghosh, Arnab; Jena, Bijayalaxmi; Satyam, Parlapalli V; Mishra, B K; Jena, Bikash Kumar

    2017-08-21

    The development of efficient materials for the generation and storage of renewable energy is now an urgent task for future energy demand. In this report, molybdenum disulphide hollow sphere (MoS 2 -HS) and its reduced graphene oxide hybrid (rGO/MoS 2 -S) have been synthesized and explored for energy generation and storage applications. The surface morphology, crystallinity and elemental composition of the as-synthesized materials have been thoroughly analysed. Inspired by the fascinating morphology of the MoS 2 -HS and rGO/MoS 2 -S materials, the electrochemical performance towards hydrogen evolution and supercapacitor has been demonstrated. The rGO/MoS 2 -S shows enhanced gravimetric capacitance values (318 ± 14 Fg -1 ) with higher specific energy/power outputs (44.1 ± 2.1 Whkg -1 and 159.16 ± 7.0 Wkg -1 ) and better cyclic performances (82 ± 0.95% even after 5000 cycles). Further, a prototype of the supercapacitor in a coin cell configuration has been fabricated and demonstrated towards powering a LED. The unique balance of exposed edge site and electrical conductivity of rGO/MoS 2 -S shows remarkably superior HER performances with lower onset over potential (0.16 ± 0.05 V), lower Tafel slope (75 ± 4 mVdec -1 ), higher exchange current density (0.072 ± 0.023 mAcm -2 ) and higher TOF (1.47 ± 0.085 s -1 ) values. The dual performance of the rGO/MoS 2 -S substantiates the promising application for hydrogen generation and supercapacitor application of interest.

  12. Radioactive study of Mo{sup 93} and Mo{sup 95} levels and research of subshell effects for the shell 2d 5/2; Etude, par radioactivite des niveaux de {sup 93}Mo et de {sup 95}Mo et essai de mise en evidence de la sous-couche 2d{sub 5/2}

    Energy Technology Data Exchange (ETDEWEB)

    Levi Lesueur, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-03-15

    We studied the decay schemes of Tc{sup 93} et Tc{sup 95} to determine the spins of Mo{sup 93} and M{sup 95} levels, and especially the position of the single-particle level 1g 7/2. We found a large spacing between the neutron shells 2d 5/2 and 1g 7/2 like that observed first in Mo{sup 97}. As the subshell 2d 5/2 is so far from its neighbours, we thought that subshell effects could perhaps be discovered in the systematics of separation energies and beta-decay energies. We found such effects. (author) [French] Par l'etude des schemas de desintegration de {sup 93}Tc et {sup 95}Tc, nous avons essaye de determiner les spins des niveaux de {sup 93}Mo et {sup 95}Mo et en particulier la position du niveau de particule 1g 7/2. Nous avons ainsi confirme l'ecart important entre les couches de neutrons 2d 5/2 et 1g 7/2 deja constate a propos de {sup 97}Mo. Nous avons pense que la sous-couche 2d 5/2 ainsi isolee des couches voisines pouvait, peut etre, etre mise en evidence par l'etude des systematiques d'energies de separation et d'energies de desintegration beta. Nous avons verifie qu'il en etait bien ainsi. (auteur)

  13. Heterometallic clusters arising from cubic Ni3M'O4 (M'=K and Na) entity: Solvothermal synthesis with/without the assistance of microwave

    International Nuclear Information System (INIS)

    Zhang Shuhua; Zhou Yanling; Sun Xiaojun; Wei, Lian-Qiang; Zeng Minghua; Liang Hong

    2009-01-01

    Solvothermal reaction assisted with microwave leads to the formation of two unique heterometallic cubic clusters [Ni 3 M'(L) 3 (OH)(CH 3 CN) 3 ] 2 .CH 3 CN (M'=K for 1 and M'=Na for 2, where L is an anion of 2-[(2-hydroxy-3-methoxy-benzylidene)-amino]-ethanesulfonate) with higher efficiency, yields and purity than those without it. The 6-metallacrown-3 [Ni 3 (OH)(L) 3 ] - groups exhibit interesting ion trapping and self-assembly of size-different Na + and K + through form recognition and coordination activity in 1 and 2. The magnetic studies for 1 and 2 suggest that the {Ni 3 M'O 4 } (M'=K and Na) cores both display dominant ferromagnetic interactions from the nature of the binding modes of μ 3 -O (oxidophenyl) and μ 3 -OH. - Graphical abstract: Solvothermal reaction assisted with microwave leads to two heterometallic cubic clusters with 6-metallacrown-3 structure [Ni 3 O 3 (OH)] - acting as a host for a K + or Na + ion. The {Ni 3 M'O 4 } (M'=K, Na) cores display dominant ferromagnetic interactions.

  14. A new molybdenum trioxide hydrate MoO3.1/3H2O and a new monoclinic form of MoO3

    International Nuclear Information System (INIS)

    Harb, F.; Gerand, B.; Nowogrocki, G.; Figlarz, M.

    1986-01-01

    A new hydrate of molybdenum trioxide MoO 3 .1/3H 2 O has been obtained by hydrothermal treatment at 110 0 C of either aqueous suspensions of MoO 3 .2H 2 O or aqueous molybdic acid solutions. The hydrate crystallizes in the orthorhombic system, lattice parameters are given; a structural model is proposed by comparison with the isostructural WO 3 .1/3H 2 O phase. The dehydration of MoO 3 .1/3H 2 O leads to a new anhydrous molybdenum trioxide, monoclinic, the structure of which is of ReO 3 type [fr

  15. Chemical vapor deposited monolayer MoS2 top-gate MOSFET with atomic-layer-deposited ZrO2 as gate dielectric

    Science.gov (United States)

    Hu, Yaoqiao; Jiang, Huaxing; Lau, Kei May; Li, Qiang

    2018-04-01

    For the first time, ZrO2 dielectric deposition on pristine monolayer MoS2 by atomic layer deposition (ALD) is demonstrated and ZrO2/MoS2 top-gate MOSFETs have been fabricated. ALD ZrO2 overcoat, like other high-k oxides such as HfO2 and Al2O3, was shown to enhance the MoS2 channel mobility. As a result, an on/off current ratio of over 107, a subthreshold slope of 276 mV dec-1, and a field-effect electron mobility of 12.1 cm2 V-1 s-1 have been achieved. The maximum drain current of the MOSFET with a top-gate length of 4 μm and a source/drain spacing of 9 μm is measured to be 1.4 μA μm-1 at V DS = 5 V. The gate leakage current is below 10-2 A cm-2 under a gate bias of 10 V. A high dielectric breakdown field of 4.9 MV cm-1 is obtained. Gate hysteresis and frequency-dependent capacitance-voltage measurements were also performed to characterize the ZrO2/MoS2 interface quality, which yielded an interface state density of ˜3 × 1012 cm-2 eV-1.

  16. Magnetic Fe{sub 2}MO{sub 4} (M:Fe, Mn) activated carbons: Fabrication, characterization and heterogeneous Fenton oxidation of methyl orange

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thi Dung [Institute of Chemical Technology, Vietnamese Academy of Science and Technology, 01 Mac Dinh Chi, District 1, Ho Chi Minh (Viet Nam); Phan, Ngoc Hoa [Department of Chemical Technology, Hochiminh University of Technology, 268 Ly Thuong Kiet, District 10, Ho Chi Minh (Viet Nam); Do, Manh Huy, E-mail: huydoma@vast-hcm.ac.vn [Institute of Chemical Technology, Vietnamese Academy of Science and Technology, 01 Mac Dinh Chi, District 1, Ho Chi Minh (Viet Nam); Ngo, Kim Tham [Institute of Chemical Technology, Vietnamese Academy of Science and Technology, 01 Mac Dinh Chi, District 1, Ho Chi Minh (Viet Nam); College of science, Can Tho University, 3/2, Can Tho (Viet Nam)

    2011-01-30

    We present a simple and efficient method for the fabrication of magnetic Fe{sub 2}MO{sub 4} (M:Fe and Mn) activated carbons (Fe{sub 2}MO{sub 4}/AC-H, M:Fe and Mn) by impregnating the activated carbon with simultaneous magnetic precursor and carbon modifying agent followed by calcination. The obtained samples were characterized by nitrogen adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), and the catalytic activity in heterogeneous Fenton oxidation of methyl orange (MO) was evaluated. The resulting Fe{sub 2}MnO{sub 4}/AC-H showed higher catalytic activity in the methyl orange oxidation than Fe{sub 3}O{sub 4}/AC-H. The effect of operational parameters (pH, catalyst loading H{sub 2}O{sub 2} dosage and initial MO concentration) on degradation performance of the oxidation process was investigated. Stability and reusability of selected catalyst were also tested.

  17. Functional roles of CSPG4/NG2 in chondrosarcoma.

    Science.gov (United States)

    Jamil, Nuor S M; Azfer, Asim; Worrell, Harrison; Salter, Donald M

    2016-04-01

    CSPG4/NG2 is a multifunctional transmembrane protein with limited distribution in adult tissues including articular cartilage. The purpose of this study was to investigate the possible roles of CSPG4/NG2 in chondrosarcomas and to establish whether this molecule may have potential for targeted therapy. Stable knock-down of CSPG4/NG2 in the JJ012 chondrosarcoma cell line by shRNA resulted in decreased cell proliferation and migration as well as a decrease in gene expression of the MMP (matrix metalloproteinase) 3 protease and ADAMTS4 (aggrecanase). Chondrosarcoma cells in which CSPG4/NG2 was knocked down were more sensitive to doxorubicin than wild-type cells. The results indicate that CSPG4/NG2 has roles in regulating chondrosarcoma cell function in relation to growth, spread and resistance to chemotherapy and that anti-CSPG4/NG2 therapies may have potential in the treatment of surgically unresectable chondrosarcoma. © 2016 The Authors. International Journal of Experimental Pathology © 2016 International Journal of Experimental Pathology.

  18. Anomalous Li Storage Capability in Atomically Thin Two-Dimensional Sheets of Nonlayered MoO2

    KAUST Repository

    Xia, Chuan

    2018-02-01

    Since the first exfoliation and identification of graphene in 2004, research on layered ultrathin two-dimensional (2D) nanomaterials has achieved remarkable progress. Realizing the special importance of 2D geometry, we demonstrate that the controlled synthesis of nonlayered nanomaterials in 2D geometry can yield some unique properties that otherwise cannot be achieved in these nonlayered systems. Herein, we report a systematic study involving theoretical and experimental approaches to evaluate the Li-ion storage capability in 2D atomic sheets of nonlayered molybdenum dioxide (MoO2). We develop a novel monomer-assisted reduction process to produce high quality 2D sheets of nonlayered MoO2. When used as lithium-ion battery (LIB) anodes, these ultrathin 2D-MoO2 electrodes demonstrate extraordinary reversible capacity, as high as 1516 mAh g–1 after 100 cycles at the current rate of 100 mA g–1 and 489 mAh g–1 after 1050 cycles at 1000 mA g–1. It is evident that these ultrathin 2D sheets did not follow the normal intercalation-cum-conversion mechanism when used as LIB anodes, which was observed for their bulk analogue. Our ex situ XPS and XRD studies reveal a Li-storage mechanism in these 2D-MoO2 sheets consisting of an intercalation reaction and the formation of metallic Li phase. In addition, the 2D-MoO2 based microsupercapacitors exhibit high areal capacitance (63.1 mF cm–2 at 0.1 mA cm–2), good rate performance (81% retention from 0.1 to 2 mA cm–2), and superior cycle stability (86% retention after 10,000 cycles). We believe that our work identifies a new pathway to make 2D nanostructures from nonlayered compounds, which results in an extremely enhanced energy storage capability.

  19. Quality control studies of 99Mo used in 99Mo/99mTc generators produced at IPEN/CNEN-SP, Brazil

    International Nuclear Information System (INIS)

    Said, Daphne S.; Brambilla, Tania P.; Matsuda, Margareth M.N.; Osso Junior, Joao A.

    2015-01-01

    99m Tc is the most used radionuclide in nuclear medicine. In Brazil, the 99 Mo/ 99m Tc generators are produced exclusively by the Center of Radiopharmacy at IPEN-CNEN/SP, by importing 99 Mo from different suppliers. 99 Mo (t 1/2 = 66 h) is a fission product of 235 U, therefore, it can be accompanied by several radioisotopes that are highly prejudicial for human health, demanding a strict quality control of this product for generators safe use. The European Pharmacopoeia established some parameters and limits that evaluate the quality of the solution of sodium [ 99 Mo]molybdate, that is used as raw material for generator's production. The European Pharmacopoeia also recommends some analytical methods to perform these evaluations, however, it has been observed difficulties on the implementation of these methods by the generator's producers. These difficulties are probably related to the lack of practicability of the proposed methods and the extensive list of utilized reagents. In this work some procedures of the European Pharmacopoeia's quality control method for 99 Mo were evaluated. Different types of solid phase exchanger cartridges were tested for retention of 99 Mo in 3 different conditions. Cartridges that presented percentages of retention higher than 90% were also tested for separation of 99 Mo from possible contaminants (Ru e Te). The results shown that solid phase exchanger cartridges that presented percentages of retention of Mo higher than 90% also presented significant percentages of retention of Ru and Te. An alternative method for separation of 99 Mo from 131 I (other contaminant) are also proposed. (author)

  20. Development of 99mTc extraction techniques from 99Mo by (n,γ) reaction

    International Nuclear Information System (INIS)

    Kimura, Akihiro; Hori, Naohiko; Tsuchiya, Kunihiko; Ishihara, Masahiro; Yamabayashi, Hisamichi; Tanase, Masakazu; Fujisaki, Saburo; Sato, Yuichi

    2010-11-01

    Investigation of production method of 99 Mo by (n, γ) reaction, where the processing is relatively simple and generating less amount of radioactive waste, is conducted in the Neutron Irradiation and Testing Reactor Center. The 99 Mo is adsorbed to highly efficient adsorbent PZC after neutron irradiation and 99m Tc is eluted. However, radioactivity concentration of the 99m Tc solution obtained from PZC column loaded with 99 Mo derived by (n, γ) method is lower than that obtained from alumina column with 99 Mo by (n, f) method due to extremely low specific activity of (n, f) 99 Mo. Therefore, it is necessary to develop technique for increasing the amount of 99 Mo and the 99m Tc solution of high radioactivity concentration (minimum: 1Ci/ cm 3 ). In this study, the preliminary fabrication tests using high density MoO 3 pellets were carried out to increase the production of 99 Mo. The method of concentrating 99m Tc solution through solvent extraction with MEK was investigated and a device for this concentration process was also developed. In the preliminary tests of the MoO 3 pellets, the pellets having high density were successfully fabricated by the SPS method. Additionally, it was ascertained that the pellets can be dissolved with 6M-NaOH solution completely. The test for 99 Mo adsorption followed by 99m Tc elution using PZC was carried out. As the result, amount of Mo adsorbed to 1g-PZC was about 250mg, and 99m Tc yield was about 80%. In the concentration test using Re solution instead of 99m Tc solution, it was ascertained that the concentration efficiency is higher than 80% of the theoretical value. A concentration device for 99m Tc solution could be realized based on the method employed in the present experiments. The outcomes of development of 99m Tc extraction techniques from 99 Mo by (n,γ) reaction was reviewed in this paper, and the contents were presented in the 3rd International Symposium on Material Test Reactors. (author)

  1. PSA Nadir of <0.5 ng/mL Following Brachytherapy for Early-Stage Prostate Adenocarcinoma is Associated With Freedom From Prostate-Specific Antigen Failure

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Eric C. [Department of Radiation Oncology, Mount Sinai Medical Center, New York, NY (United States); Stone, Nelson N. [Department of Radiation Oncology, Mount Sinai Medical Center, New York, NY (United States); Department of Urology, Mount Sinai Medical Center, New York, NY (United States); Stock, Richard G., E-mail: Richard.Stock@mountsinai.org [Department of Radiation Oncology, Mount Sinai Medical Center, New York, NY (United States)

    2012-06-01

    Purpose: Because limited information exists regarding whether the rate or magnitude of PSA decline following brachytherapy predicts long-term clinical outcomes, we evaluated whether achieving a prostate-specific antigen (PSA) nadir (nPSA) <0.5 ng/mL following brachytherapy is associated with decreased PSA failure and/or distant metastasis. Methods and Materials: We retrospectively analyzed our database of early-stage prostate adenocarcinoma patients who underwent brachytherapy, excluding those receiving androgen-deprivation therapy and those with <2 years follow-up. Median and mean pretreatment PSA were 6 ng/mL and 7.16 ng/mL, respectively. By clinical stage, 775 were low risk ({<=}T2a), 126 were intermediate risk (T2b), and 20 were high risk (>T2b). By Gleason score, 840 were low risk ({<=}6), 71 were intermediate risk (7), and 10 were high risk (>7). Patients were treated with brachytherapy only (I-125, n = 779, or Pd-103, n = 47), or brachytherapy + external-beam radiation therapy (n = 95). Median follow-up was 6.3 years. We noted whether nPSA <0.5 ng/mL was achieved and the time to achieve this nadir and tested for associations with pretreatment risk factors. We also determined whether this PSA endpoint was associated with decreased PSA failure or distant metastasis. Results: Absence of high-risk factors in clinical stage ({<=}T2b), Gleason score ({<=}7), and pretreatment PSA ({<=}20 ng/mL) was significantly associated with achieving nPSA <0.5 ng/mL. By Kaplan-Meier analysis, patients achieving nPSA <0.5 ng/mL had significantly higher long-term freedom from biochemical failure (FFBF) than nonresponders (5-year FFBF: 95.2 {+-} 0.8% vs. 71.5 {+-} 6.7%; p < 0.0005). Among responders, those who achieved nPSA <0.5 ng/mL in {<=}5 years had higher FFBF than those requiring >5 years (5-year FFBF: 96.7 {+-} 0.7% vs. 80.8 {+-} 4.6%; p < 0.0005). On multivariate analysis, patients who achieved nPSA <0.5 ng/mL in {<=}5 years had significantly higher FFBF than other

  2. Full article: The Reaction between MoO3 and Molten K2S2O7 forming K2MoO2(SO4)2

    DEFF Research Database (Denmark)

    Nørbygaard, Thomas; Berg, Rolf W.; Nielsen, Kurt

    1998-01-01

    .4540(4), c = 8.8874(3) Å, beta = 112.194(1)o, wR2 = 0.0897 for 3491 independent reflections. The compound, K2MoO2(SO4)2, contains (Mo02)2+ core ions in distorted octahedral coordination, with two short (ca. 1.69 Å) terminal bonds in cis-configuration (the O-Mo-O angle is 103.1(2)o), and with two long (ca. 2...

  3. Mo-doped Gray Anatase TiO2: Lattice Expansion for Enhanced Sodium Storage

    International Nuclear Information System (INIS)

    Liao, Hanxiao; Xie, Lingling; Zhang, Yan; Qiu, Xiaoqing; Li, Simin; Huang, Zhaodong; Hou, Hongshuai; Ji, Xiaobo

    2016-01-01

    Gray-colored Mo 6+ -doped anatase TiO 2 is prepared uniformly with particle size of 10–20 nm, and is firstly employed as anode material in sodium-ion batteries (SIBs), presenting excellent electrochemical performances. It delivered reversible specific capacities of 231.8 mAh g −1 at 0.1 C (33.5 mA g −1 ) after 100 cycles and 108.3 mAh g −1 at 5 C (1.68 A g −1 ), comparing to 170.5 mAh g −1 at 0.1 C and only 41.7 mAh g −1 at 5C for the bare TiO 2 . The improved electrochemical performances might be beneficial from the doping of Mo 6+ , which can effectively enhance the conductivity of TiO 2 resulting from induced conduction band electrons, interstitial oxygen defects and vacancies. In addition, the doping can also lead to the lattice expansion, which can facilitate the diffusion of Na + . In combination with natural abundance and environmental benignity, Mo 6+ -doped TiO 2 can be expected to be utilized as an anode material for enhanced sodium storage.

  4. Development on UO3-K2O and MoO3-K2O binary systems and study of UO2MoO4-MoO3 domain within UO3-MoO3-K2O ternary system

    International Nuclear Information System (INIS)

    Dion, C.; Noel, A.

    1983-01-01

    This paper confirms the previous study on the MoO 3 -K 2 O system, and constitutes a clarity of the UO 3 -K 2 O system. Four distinct uranates VI with alkaline metal/uranium ratio's 2, 1, 0,5 and 0,285 exist. Preparation conditions and powder diffraction spectra of these compounds are given. Additional informations relative to K 2 MoO 4 allotropic transformations are provided. Study of UO 2 MoO 4 -K 2 MoO 4 diagram has brought three new phases into prominence: (B) K 6 UMo 4 O 18 incongruently melting point, (E) K 2 UMo 2 O 10 congruently melting and (F) K 2 U 3 Mo 4 O 22 incongruently melting point. Within MoO 3 -K 2 MoO 4 -UO 2 MoO 4 ternary system, no new phase is found. The general appearance of ternary liquidus and crystallization fields of several compounds are given. These three new compounds become identified with these of UO 2 MoO 4 -Na 2 MoO 4 binary system [fr

  5. Enhanced Selectivity and Uptake Capacity of CO2 and Toluene Adsorption in Co0.5 M0.33 MoS4 (M= Sb or Y) Chalcogels by Impregnated Metal Salts

    KAUST Repository

    Edhaim, Fatimah A.; Rothenberger, Alexander

    2017-01-01

    The synthesis of metal chalcogenide aerogels Co0.5M0.33MoS4 (M= Sb or Y) by the sol-gel method is reported. In this system, the building blocks [MoS4]2− chelated with Co2+ and (Sb3+) or (Y3+) salts in nonaqueous solvents forming amorphous networks

  6. Effects of sodium environment on the mechanical properties of Fe-2 1/4Cr-1Mo steel

    International Nuclear Information System (INIS)

    Chopra, O.K.

    1983-09-01

    Mechanical property data on isothermally annealed, thermally aged, and sodium-exposed Fe-2 1/4Cr-1Mo steel are analyzed to evaluate the influence of the sodium environment as well as the effects of the microstructural and compositional changes that occur in the steel during long-term exposure to sodium. Correlations are developed to predict the environmental effects on tensile, creep, fatigue, and creep-fatigue properties of Fe-2 1/4Cr-1Mo steel in sodium. The results indicate that at temperatures 0 C), degradation of mechanical properties is essentially due to thermal aging. Loss of carbon from the steel reduces both the tensile and creep-rupture strength, but has little or no effect on the fatigue properties. The cyclic properties of Fe-2 1/4Cr-1Mo steel in sodium are superior to those in air. The creep-fatigue behavior in sodium is significantly different from that in an air environment. The creep-fatigue data are analyzed using the interactive damage rate equations to predict the time-dependent fatigue behavior of isothermally annealed Fe-2 1/4Cr-1Mo steel in sodium. 15 references, 7 figures, 1 table

  7. Accelerator production of 99mTc with proton beams and enriched 100Mo targets

    International Nuclear Information System (INIS)

    Lagunas-Solar, M.C.

    1999-01-01

    The direct production of 99m Tc has been developed based upon the use of the 100 Mo(p,2n) 99m Tc reaction (Q= -7.9 MeV), using enriched 100 Mo targets and accelerated protons of 99m Tc yields measured in this work reached 851 ± 77 MBq/μA/h (23.0 ± 3.0 mCi/μA/h) at end-of-bombardment (EOB) in the 22-12 MeV energy region, with 96 Tc (4.35 d) as the only detectable impurity at - accelerators, and by extracting multiple H + beams to bombard a single or an array of enriched 100 Mo targets, this method could provide nearly 851 GBq (23 Ci) of 99m Tc in 1-h bombardments. Because of this large-batch potential, this new method appears to be an effective alternative to the production and distribution of 99 Mo → 99m Tc generator systems, although it may be limited to daily, regional/local distribution and use. 99m Tc produced in this fashion has high radionuclidic and radiochemical purity, although its specific activity has not been determined. The accelerator-made 99m Tc has been shown to have similar physical and chemical characteristics than 99m Tc eluted from commercial fission-produced 99 Mo → 99m Tc generators. Technical and logistical factors need further study and analysis but the potential and the expected impact of this new method are clear in the context of the operation of large radionuclide distribution centers as well as for small programs in developing regions. (author)

  8. Three-Dimensional Heterostructures of MoS 2 Nanosheets on Conducting MoO 2 as an Efficient Electrocatalyst To Enhance Hydrogen Evolution Reaction

    KAUST Repository

    Nikam, Revannath Dnyandeo

    2015-10-05

    Molybdenum disulfide (MoS) is a promising catalyst for hydrogen evolution reaction (HER) because of its unique nature to supply active sites in the reaction. However, the low density of active sites and their poor electrical conductivity have limited the performance of MoS in HER. In this work, we synthesized MoS nanosheets on three-dimensional (3D) conductive MoO via a two-step chemical vapor deposition (CVD) reaction. The 3D MoO structure can create structural disorders in MoS nanosheets (referred to as 3D MoS/MoO), which are responsible for providing the superior HER activity by exposing tremendous active sites of terminal disulfur of S2 (in MoS) as well as the backbone conductive oxide layer (of MoO) to facilitate an interfacial charge transport for the proton reduction. In addition, the MoS nanosheets could protect the inner MoO core from the acidic electrolyte in the HER. The high activity of the as-synthesized 3D MoS/MoO hybrid material in HER is attributed to the small onset overpotential of 142 mV, a largest cathodic current density of 85 mA cm, a low Tafel slope of 35.6 mV dec, and robust electrochemical durability.

  9. Three-Dimensional Heterostructures of MoS 2 Nanosheets on Conducting MoO 2 as an Efficient Electrocatalyst To Enhance Hydrogen Evolution Reaction

    KAUST Repository

    Nikam, Revannath Dnyandeo; Lu, Ang-Yu; Sonawane, Poonam Ashok; Kumar, U. Rajesh; Yadav, Kanchan; Li, Lain-Jong; Chen, Yit Tsong

    2015-01-01

    Molybdenum disulfide (MoS) is a promising catalyst for hydrogen evolution reaction (HER) because of its unique nature to supply active sites in the reaction. However, the low density of active sites and their poor electrical conductivity have limited the performance of MoS in HER. In this work, we synthesized MoS nanosheets on three-dimensional (3D) conductive MoO via a two-step chemical vapor deposition (CVD) reaction. The 3D MoO structure can create structural disorders in MoS nanosheets (referred to as 3D MoS/MoO), which are responsible for providing the superior HER activity by exposing tremendous active sites of terminal disulfur of S2 (in MoS) as well as the backbone conductive oxide layer (of MoO) to facilitate an interfacial charge transport for the proton reduction. In addition, the MoS nanosheets could protect the inner MoO core from the acidic electrolyte in the HER. The high activity of the as-synthesized 3D MoS/MoO hybrid material in HER is attributed to the small onset overpotential of 142 mV, a largest cathodic current density of 85 mA cm, a low Tafel slope of 35.6 mV dec, and robust electrochemical durability.

  10. Effects of sodium environment on the mechanical properties of Fe-2 1/4Cr-1Mo steel

    International Nuclear Information System (INIS)

    Chopra, O.K.

    Mechanical property data on isothermally annealed, thermally aged, and sodium-exposed Fe-2 1/4Cr-1Mo steel are analyzed to evaluate the influence of the sodium environment as well as the effects of the microstructural and compositional changes that occur in the steel during long-term exposure to sodium. Correlations are developed to predict the environmental effects on tensile, creep, fatigue, and creep-fatigue properties of Fe-2 1/4Cr-1Mo steel in sodium. The results indicate that at temperatures <823 K (550 deg. C), degradation of mechanical properties is essentially due to thermal aging. Loss of carbon from the steel reduces both the tensile and creep-rupture strength, but has little or no effect on the fatigue properties. The cyclic properties of Fe-2 1/4Cr-1Mo steel in sodium are superior to those in air. The creep-fatigue behaviour in sodium is significantly different from that in an air environment. The creep-fatigue data are analyzed using the interactive damage rate equations to predict the time-dependent fatigue bahaviour of isothermally annealed Fe-2 1/4Cr-1Mo steel in sodium. (author)

  11. Direct elution of sup(99m)Tc complexes from neutron irradiation produced /sup 99/Mo incorporated in a MoCl/sub 2/-MoBr/sub 2/ mixture

    Energy Technology Data Exchange (ETDEWEB)

    Ganzerli Valentini, M.T.; Stella, R.; Genova, N.

    1987-01-01

    A novel type of sup(99m)Tc generator, enabling radiopharmaceutical preparation without reductant addition, was prepared and tested. Neutron activated product /sup 99/Mo, in the form of dichloride cluster, was incorporated into inactive molybdenum dichloride-dibromide mixture (MCB) that was left to settle over an activated alumina layer. Direct elution with aqueous ligands such as salicylate or iminodiacetate derivatives in the pH range 6.5-7.5 yielded chemically stable sup(99m)Tc complexes accompanied by small amounts of secondary products (mostly sup(99m)TcO/sup -//sub 4/). Pentavalent oxidation state in the salicylate complex and tervalent in the iminodiacetate (IDA) and in the N-(2,6-dimethylphenylcarbamoylmethyl) iminodiacetate (HIDA) complexes were assigned to the element after comparison with reference complexes. The anion exchange version of reverse-phase HPLC was used to resolve the eluted product mixture.

  12. An investigation of the thermal conductivity of Cs2MoO4

    International Nuclear Information System (INIS)

    Ishii, T.; Mizuno, T.

    1997-01-01

    The thermal diffusivity of 82.6% TD and 89.3% TD Cs 2 MoO 4 was measured by the laser flash method and the thermal conductivity was calculated. The thermal conductivity of these Cs 2 MoO 4 ranged from 0.3 to 0.5 W m -1 K -1 . The density dependence of the thermal conductivity was correlated based on the experimental values of these two densities and on the 94.3% TD specimen from the preceding study. The correlation of the thermal conductivity of Cs 2 MoO 4 is k=(1.0-1.848 x P)/(1.0-1.848 x P ref ) x k ref , where k ref =132.56/T+0.03+3.2 x 10 -10 x T 3 , P ref =1.0-0.943=0.057 and k and k ref are the thermal conductivities (Wm -1 K -1 ) of Cs 2 MoO 4 with the porosities P and P ref , respectively, where P ref is the porosity for the 94.3% TD Cs 2 MoO 4 . T is the temperature (K). This correlation is applicable for 82.6 to 94.3% TD Cs 2 MoO 4 from 873 to 1023 K. (orig.)

  13. Optimization of the 99m Tc generator with hydrotalcite as support of 99 Mo

    International Nuclear Information System (INIS)

    Aranda O, N.

    2004-01-01

    In the last years, in the laboratories of the National Institute of Nuclear Investigations (ININ) its have been investigating to the hydrotalcite like a material of support of the 99 Mo with the purpose of developing a new technetium generator. During the development of the investigations it has been demonstrated that when putting in contact to the HTC with an aqueous solution that contains anions of any type, the HTC re hydrate and the structure is regenerated to laminate of the hydrotalcite. If the present anions in the solution are molybdate anions (MoO 4 2- ), these anions passed to be part of the structure of the hydrotalcite (HT-MoO 4 ). These anions can contain, in turn, 99 Mo in their composition ( 99 MoO 4 2- ) and equally they can pass to be part of the structure of the hydrotalcite forming the HT- 99 MoO 4 . When the HT- 99 MoO 4 is packed in a column, the 99m Tc that it takes place when decaying the 99 Mo radioactively can separate the column using aqueous solution of NaCl. This way, in previous studies (Serrano, 2000) it was found that the aqueous solution of NaCl to 0.5% it is the but appropriate for elutriate at the 99m Tc from the column the yield of the elution of the 99m Tc was since high (98%) in the first elution, and the radionuclide contamination caused by the presence of 99 Mo in the eluate it was low ( 4 2- for gram of HTC). These facts, standing out the high capacity of the HTC to retain molybdate ions, they drove from a direct way to investigate the optimization of the generator of 99m Tc, with hydrotalcite like support of the 99 Mo, using 99 Mo of low specific activity. This finishes radioactive material it can be obtained by the irradiation of the 98 Mo (in the chemical form of MoO 3 or (NH 4 ) 2 MoO 4 ), with a flow of thermal neutrons in the nuclear reactor TRIGA Mark lll that one has in the Nuclear Center N abor Carrillo Flores . The technetium generators with alumina like support of the 99 Mo use 99 Mo of high specific activity

  14. Physicochemical investigation of Bi2MoO6 solid-phase interaction with Sm2MoO6

    International Nuclear Information System (INIS)

    Khajkina, E.G.; Kovba, L.M.; Bazarova, Zh.G.; Khal'baeva, K.M.; Khakhinov, V.V.; Mokhosoev, M.V.

    1986-01-01

    Bi 2 MoO 6 -Sm 2 MoO 6 interaction in the temperature range of 700-1000 deg C is studied using X-ray phase analysis and vibrational spectroscopy. Formation of monoclinic solid solutions based on γ'-Bi 2 MoO 6 and B 2-x Sm x MoO 6 varied composition phase with α-Ln 2 MoO 6 structure which homogeneity region extent at 1000 deg C constitutes ∼ 50 mol % (0.7≤x≤1.7) is stated. Crystallographic characteristics of the synthesized phases are determined

  15. Interstitial Mo-Assisted Photovoltaic Effect in Multilayer MoSe2 Phototransistors.

    Science.gov (United States)

    Kim, Sunkook; Maassen, Jesse; Lee, Jiyoul; Kim, Seung Min; Han, Gyuchull; Kwon, Junyeon; Hong, Seongin; Park, Jozeph; Liu, Na; Park, Yun Chang; Omkaram, Inturu; Rhyee, Jong-Soo; Hong, Young Ki; Yoon, Youngki

    2018-03-01

    Thin-film transistors (TFTs) based on multilayer molybdenum diselenide (MoSe 2 ) synthesized by modified atmospheric pressure chemical vapor deposition (APCVD) exhibit outstanding photoresponsivity (103.1 A W -1 ), while it is generally believed that optical response of multilayer transition metal dichalcogenides (TMDs) is significantly limited due to their indirect bandgap and inefficient photoexcitation process. Here, the fundamental origin of such a high photoresponsivity in the synthesized multilayer MoSe 2 TFTs is sought. A unique structural characteristic of the APCVD-grown MoSe 2 is observed, in which interstitial Mo atoms exist between basal planes, unlike usual 2H phase TMDs. Density functional theory calculations and photoinduced transfer characteristics reveal that such interstitial Mo atoms form photoreactive electronic states in the bandgap. Models indicate that huge photoamplification is attributed to trapped holes in subgap states, resulting in a significant photovoltaic effect. In this study, the fundamental origin of high responsivity with synthetic MoSe 2 phototransistors is identified, suggesting a novel route to high-performance, multifunctional 2D material devices for future wearable sensor applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Minimizing Molybdenum 99 contamination in Technetium 99m Pertechnetate from the elution of 99Mo/ 99m Tc Generator

    International Nuclear Information System (INIS)

    Zakaria Ibrahim; Zulkifli Hashim; Bohari Yaacob

    2011-01-01

    Radioisotope Tc-99m is widely used for variety of nuclear medicine diagnostic procedures. For many commercial applications, it is prepared in a portable type generator. Nuclear Malaysia has been producing a dry type alumina chromatographic column generator utilizing fission Mo-99. This injectable Tc-99m must meet the British Pharmacopeia [1] product specification prior to be apply on patient. This paper provides a method to minimize the up to acceptable level Mo-99 in the final product. Purposely made pertechnetate contaminated with Mo-99 and re-eluate by using old generator. Excellent removal of Mo-99 impurity was achieved and more than 80 % of Tc-99m total activity was recovered. (author)

  17. Cold cathode emission studies on topographically modified few layer and single layer MoS2 films

    Science.gov (United States)

    Gaur, Anand P. S.; Sahoo, Satyaprakash; Mendoza, Frank; Rivera, Adriana M.; Kumar, Mohit; Dash, Saroj P.; Morell, Gerardo; Katiyar, Ram S.

    2016-01-01

    Nanostructured materials, such as carbon nanotubes, are excellent cold cathode emitters. Here, we report comparative field emission (FE) studies on topographically tailored few layer MoS2 films consisting of ⟨0001⟩ plane perpendicular (⊥) to c-axis (i.e., edge terminated vertically aligned) along with planar few layer and monolayer (1L) MoS2 films. FE measurements exhibited lower turn-on field Eto (defined as required applied electric field to emit current density of 10 μA/cm2) ˜4.5 V/μm and higher current density ˜1 mA/cm2, for edge terminated vertically aligned (ETVA) MoS2 films. However, Eto magnitude for planar few layer and 1L MoS2 films increased further to 5.7 and 11 V/μm, respectively, with one order decrease in emission current density. The observed differences in emission behavior, particularly for ETVA MoS2 is attributed to the high value of geometrical field enhancement factor (β), found to be ˜1064, resulting from the large confinement of localized electric field at edge exposed nanograins. Emission behavior of planar few layers and 1L MoS2 films are explained under a two step emission mechanism. Our studies suggest that with further tailoring the microstructure of ultra thin ETVA MoS2 films would result in elegant FE properties.

  18. Synthesis, characterization and electrochemical performance of graphene decorated with 1D NiMoO4.nH2O nanorods

    Science.gov (United States)

    Ghosh, Debasis; Giri, Soumen; Das, Chapal Kumar

    2013-10-01

    One-dimensional NiMoO4.nH2O nanorods and their graphene based hybrid composite with good electrochemical properties have been synthesized by a cost effective hydrothermal procedure. The formation of the mixed metal oxide and the composite was confirmed by XRD, XPS and Raman analyses. The morphological characterizations were carried out using FESEM and TEM analyses. The materials were subjected to electrochemical characterization through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) studies with 6 M KOH as the supporting electrolyte. For NiMoO4.nH2O, a maximum specific capacitance of 161 F g-1 was obtained at 5 A g-1 current density, accompanied with an energy density of 4.53 W h kg-1 at a steady power delivery rate of 1125 W kg-1. The high utility of the pseudocapacitive NiMoO4.nH2O was achieved in its graphene based composite, which exhibited a high specific capacitance of 367 F g-1 at 5 A g-1 current density and a high energy density of 10.32 W h kg-1 at a power density of 1125 W kg-1 accompanied with long term cyclic stability.One-dimensional NiMoO4.nH2O nanorods and their graphene based hybrid composite with good electrochemical properties have been synthesized by a cost effective hydrothermal procedure. The formation of the mixed metal oxide and the composite was confirmed by XRD, XPS and Raman analyses. The morphological characterizations were carried out using FESEM and TEM analyses. The materials were subjected to electrochemical characterization through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) studies with 6 M KOH as the supporting electrolyte. For NiMoO4.nH2O, a maximum specific capacitance of 161 F g-1 was obtained at 5 A g-1 current density, accompanied with an energy density of 4.53 W h kg-1 at a steady power delivery rate of 1125 W kg-1. The high utility of the pseudocapacitive NiMoO4.nH2O was achieved in its graphene

  19. Hydrothermal synthesis of layer-controlled MoS{sub 2}/graphene composite aerogels for lithium-ion battery anode materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Bing; Wang, Zhixuan [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Gao, Yang; Chen, Lu [Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China); Lu, Mengna [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Jiao, Zheng [Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China); Jiang, Yong, E-mail: jiangyong@shu.edu.cn [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Ding, Yuanzhang [Jiangsu Aoxin New Energy Automobile Ltd., Jiangsu 224007 (China); Cheng, Lingli, E-mail: chenglingli@shu.edu.cn [Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China)

    2016-12-30

    Highlights: • Layer-controlled MoS{sub 2}/GA composites are synthesized by a facile hydrothermal route. • Few-layer (5–15 layers) MoS{sub 2} nanosheets are decorated on the surface of GNS homogeneously and tightly. • The growth mechanism of the lay-controlled MoS{sub 2}/GA composites is proposed. • The composite delivers high specific capacity of 1085.0 mAh g{sup −1} at 0.1 A g{sup −1}. - Abstract: Layer-controlled MoS{sub 2}/graphene aerogels (MoS{sub 2}/GA) composites are synthesized by a facile hydrothermal route, in which few-layer (5–15 layers) MoS{sub 2} nanosheets with high crystalline are decorated on the surface of graphene nanosheets homogeneously and tightly. The number of the MoS{sub 2} layers can be easily controlled through adjusting the amount of molybdenum source in the reaction system. Moreover, the growth mechanism of the lay-controlled MoS{sub 2}/GA composites is proposed. The three-dimensional MoS{sub 2}/GA with macroporous micro-structure not only shortens the transportation length of electrons and ions, but also restrains the re-stacking of MoS{sub 2} effectively, stabilizing the electrode structure during repeated charging/discharging processes. Electrochemical tests demonstrate that this few-layer MoS{sub 2}/GA composite exhibits a high reversible capacity of 1085.0 mAh g{sup −1} at current density of 100 mA g{sup −1}, as well as extraordinarily high cycling stability and rate capability.

  20. Nanostructured metal oxides: promise opportunity and challenge to develop clinically useful 99Mo/99mTc generators using (n, gamma)99Mo

    International Nuclear Information System (INIS)

    Dash, Ashutosh

    2014-01-01

    The role of 99m Tc diagnostic nuclear medicine needs hardly to be reiterated. Today, it is the most widely used radionuclide for single photon emission computed tomography (SPECT) imaging procedures. The current strategy of availing 99m Tc is ensured from column chromatographic 99 Mo/ 99m Tc generators using a bed of acidic alumina. While the column chromatographic 99 Mo/ 99m Tc generator constitute a successful exemplar of availing 99m Tc, the limited capacity of alumina (2-20 mg Mo per g of alumina) for taking up molybdate ions necessitates the use of 99 Mo of the highest specific activity available, as can be found in fission produced 99 Mo (F 99 Mo). In order to reduce dependence of F 99 Mo, the scope of using low specific activity (n,γ) 99 Mo along with high capacity adsorbent is an interesting prospect. In this context, the scope of using nanomaterials as a viable adsorbent seemed attractive by virtue of their huge surface to volume ratios, altered physical properties, tailored surface chemistry, favorable adsorption characteristics, and enhanced surface reactivity resulting from the nanoscale dimensions. This emerging class of adsorbent represents an innovative paradigm and is expected to play an important role in the development of 99 Mo/ 99m Tc generators adaptable to the existing and foreseeable demands. This talk outlines a critical assessment on the role of nanostructured metal oxides, recent developments, the contemporary status, and key challenges and apertures to the near future. (author)

  1. Mechanistic Insight into the Stability of HfO2-Coated MoS2 Nanosheet Anodes for Sodium Ion Batteries

    KAUST Repository

    Ahmed, Bilal; Anjum, Dalaver H.; Hedhili, Mohamed N.; Alshareef, Husam N.

    2015-01-01

    It is demonstrated for the first time that surface passivation of 2D nanosheets of MoS2 by an ultrathin and uniform layer of HfO2 can significantly improve the cyclic performance of sodium ion batteries. After 50 charge/discharge cycles, bare MoS2 and HfO2 coated MoS2 electrodes deliver the specific capacity of 435 and 636 mAh g-1, respectively, at current density of 100 mA g-1. These results imply that batteries using HfO2 coated MoS2 anodes retain 91% of the initial capacity; in contrast, bare MoS2 anodes retain only 63%. Also, HfO2 coated MoS2 anodes show one of the highest reported capacity values for MoS2. Cyclic voltammetry and X-ray photoelectron spectroscopy results suggest that HfO2 does not take part in electrochemical reaction. The mechanism of capacity retention with HfO2 coating is explained by ex situ transmission electron microscope imaging and electrical impedance spectroscopy. It is illustrated that HfO2 acts as a passivation layer at the anode/electrolyte interface and prevents structural degradation during charge/discharge process. Moreover, the amorphous nature of HfO2 allows facile diffusion of Na ions. These results clearly show the potential of HfO2 coated MoS2 anodes, which performance is significantly higher than previous reports where bulk MoS2 or composites of MoS2 with carbonaceous materials are used. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Mechanistic Insight into the Stability of HfO2-Coated MoS2 Nanosheet Anodes for Sodium Ion Batteries

    KAUST Repository

    Ahmed, Bilal

    2015-06-01

    It is demonstrated for the first time that surface passivation of 2D nanosheets of MoS2 by an ultrathin and uniform layer of HfO2 can significantly improve the cyclic performance of sodium ion batteries. After 50 charge/discharge cycles, bare MoS2 and HfO2 coated MoS2 electrodes deliver the specific capacity of 435 and 636 mAh g-1, respectively, at current density of 100 mA g-1. These results imply that batteries using HfO2 coated MoS2 anodes retain 91% of the initial capacity; in contrast, bare MoS2 anodes retain only 63%. Also, HfO2 coated MoS2 anodes show one of the highest reported capacity values for MoS2. Cyclic voltammetry and X-ray photoelectron spectroscopy results suggest that HfO2 does not take part in electrochemical reaction. The mechanism of capacity retention with HfO2 coating is explained by ex situ transmission electron microscope imaging and electrical impedance spectroscopy. It is illustrated that HfO2 acts as a passivation layer at the anode/electrolyte interface and prevents structural degradation during charge/discharge process. Moreover, the amorphous nature of HfO2 allows facile diffusion of Na ions. These results clearly show the potential of HfO2 coated MoS2 anodes, which performance is significantly higher than previous reports where bulk MoS2 or composites of MoS2 with carbonaceous materials are used. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Preparation and characterization of iron(III) {sup 99}Mo-molybdate(VI) gels for the assessment of {sup 99m}Tc elution performance

    Energy Technology Data Exchange (ETDEWEB)

    Amin, Mahmoud; Fasih, Tharwat W.; El-Absy, Mohamed A. [Egyptian Atomic Energy Authority, Cairo (Egypt)

    2018-04-01

    New iron(III) {sup 99}Mo-molybdate(VI) gels (Fe{sup 99}Mo) of high Mo content were prepared by the precipitation/filtration method. {sup 99}Mo-MoO{sub 3} dissolved in NaOH was added to aqueous solutions of Fe(NO{sub 3}){sub 3} at Mo/Fe mole fractions ∝2.21 and 1.99 with continuous stirring at ambient room temperature. Two different Fe{sup 99}Mo were precipitated from the mixed solutions adjusted at pH 2 and 4.7. The amount of water of hydration increased with the increasing the gel settling time and pH of the mixed solution. The matrices were characterized by radiometric, XRD, SEM, XRF, FT-IR, TGA, and DTA measurements. Small chromatographic columns of 2.0 g Fe{sup 99}Mo containing ≥800 mg Mo tagged with 740 MBq {sup 99}Mo were eluted with 5 mL saline solution. Highly reproducible {sup 99m}Tc elution indices suitable for preparation of {sup 99}Mo/{sup 99m}Tc generators were achieved from generator supported with 0.5 g Al{sub 2}O{sub 3} filter. Elution performance of {sup 99m}Tc radionuclide was highly dependent on the gel structural properties.

  4. Luminescent phosphors, based on rare earth substituted oxyfluorides in the A(1){sub 3-x} A(2){sub x}MO{sub 4}F family with A(1)/A(2)=Sr, Ca, Ba and M=Al, Ga

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sangmoon, E-mail: spark@silla.ac.k [Department of Engineering in Energy and Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Vogt, Thomas [NanoCenter and Department of Chemistry and Biochemistry, University of South Carolina, Columbia 29208, SC (United States)

    2009-09-15

    A new family of UV-activated phosphors made by substituting rare-earth activators such as trivalent Eu, Tb, Tm and Er into A(1){sub 3-x}A(2){sub x}MO{sub 4}F host lattices (A(1)/A(2)=Sr, Ca, Ba; M=Al, Ga) are introduced and their activation and emission spectra as well as their CIE values reported. The Tm-substituted system can be activated using light with a wavelength of 360 nm. Relative intensities of a family of Tb-substituted green phosphors activated at 254 nm and with emissions centered near 548 nm are discussed.

  5. Pathophysiology of NG2-glia:a ‘Chicken and Egg’ scenario of altered neurotransmission and disruption of NG2-glial cell function

    OpenAIRE

    Rivera, Andrea Domenico; De La Rocha, Irene Chacon; Neville, Rebekah; Butt, Arthur Morgan

    2016-01-01

    Classically, the central nervous system (CNS) was considered to contain neurons and three main types of glial cells - astrocytes, oligodendrocytes, and microglia. Now, it has been clearly established that NG2-glia are a fourth glial cell type that are defined by their expression of the NG2 chondroitin sulfate proteoglycan (Cspg4). NG2-glia are also known as oligodendrocyte precursor cells (OPCs) and express the alpha receptor for platelet-derived growth factor (Pdgfra) as well as other oligod...

  6. High-Performance Photovoltaic Detector Based on MoTe2 /MoS2 Van der Waals Heterostructure.

    Science.gov (United States)

    Chen, Yan; Wang, Xudong; Wu, Guangjian; Wang, Zhen; Fang, Hehai; Lin, Tie; Sun, Shuo; Shen, Hong; Hu, Weida; Wang, Jianlu; Sun, Jinglan; Meng, Xiangjian; Chu, Junhao

    2018-03-01

    Van der Waals heterostructures based on 2D layered materials have received wide attention for their multiple applications in optoelectronic devices, such as solar cells, light-emitting devices, and photodiodes. In this work, high-performance photovoltaic photodetectors based on MoTe 2 /MoS 2 vertical heterojunctions are demonstrated by exfoliating-restacking approach. The fundamental electric properties and band structures of the junction are revealed and analyzed. It is shown that this kind of photodetectors can operate under zero bias with high on/off ratio (>10 5 ) and ultralow dark current (≈3 pA). Moreover, a fast response time of 60 µs and high photoresponsivity of 46 mA W -1 are also attained at room temperature. The junctions based on 2D materials are expected to constitute the ultimate functional elements of nanoscale electronic and optoelectronic applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Coupling Mo2C@C core-shell nanocrystals on 3D graphene hybrid aerogel for high-performance lithium ion battery

    Science.gov (United States)

    Xin, Hailin; Hai, Yang; Li, Dongzhi; Qiu, Zhaozheng; Lin, Yemao; Yang, Bo; Fan, Haosen; Zhu, Caizhen

    2018-05-01

    Hybrid aerogel by dispersing Mo2C@C core-shell nanocrystals into three-dimensional (3D) graphene (Mo2C@C-GA) has been successfully prepared through two-step methods. Firstly, carbon-coated MoO2 nanocrystals uniformly anchor on 3D graphene aerogel (MoO2@C-GA) via hydrothermal reaction. Then the MoO2@C-GA precursor is transformed into Mo2C@C-GA after the following carbonization process. Furthermore, the freeze-drying step plays an important role in the resulting pore size distribution of the porous networks. Moreover, graphene aerogels exhibit extremely low densities and superior electrical properties. When evaluated as anode material for lithium ion battery, Mo2C@C-GA delivers excellent rate capability and stable cycle performance when compared with C-GA and Mo2C nanoparticles. Mo2C@C-GA exhibits the initial discharge capacity of 1461.4 mA h g-1 at the current density of 0.1 A g-1, and retains a reversible capacity of 1089.8 mA h g-1 after 100 cycles at a current density of 0.1 A g-1. Even at high current density of 5 A g-1, a discharge capacity of 623.5 mA h g-1 can be still achieved. The excellent performance of Mo2C@C-GA could be attributed to the synergistic effect of Mo2C@C nanocrystals and the 3D graphene conductive network.

  8. In-situ fabrication of MoSi{sub 2}/SiC–Mo{sub 2}C gradient anti-oxidation coating on Mo substrate and the crucial effect of Mo{sub 2}C barrier layer at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jun [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084 (China); Gong, Qianming, E-mail: gongqianming@mail.tsinghua.edu.cn [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084 (China); Shao, Yang; Zhuang, Daming [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084 (China); Liang, Ji [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China)

    2014-07-01

    MoSi{sub 2}/SiC–Mo{sub 2}C gradient coating on molybdenum was in situ prepared with pack cementation process by two steps: (1) carburizing with graphite powder to obtain a Mo{sub 2}C layer on Mo substrate, and (2) siliconizing with Si powder to get a composite MoSi{sub 2}/SiC layer on the upper part of Mo{sub 2}C layer. The microstructure and elemental distribution in the coating were investigated with scanning electron microscopy (SEM), backscattered electron (BSE), energy dispersive spectroscopy (EDS), electron probe microanalysis (EPMA) and X-ray diffraction (XRD). Cyclic oxidation tests (at 500 °C, 1200 °C, 1400 °C and 1600 °C) demonstrated excellent oxidation resistance for the gradient composite coating and the mass loss was only 0.23% in 60 min at 1600 °C. XRD, EPMA, thermal dynamic and phase diagram analyses indicated that the Mo{sub 2}C barrier layer played the key role in slowing down the diffusion of C and Si toward inner Mo substrate at high temperature and principally this contributed to the excellent anti-oxidation for Mo besides the outer MoSi{sub 2}/SiC composite layer.

  9. Low-frequency 1/f noise in MoS2 transistors: Relative contributions of the channel and contacts

    Science.gov (United States)

    Renteria, J.; Samnakay, R.; Rumyantsev, S. L.; Jiang, C.; Goli, P.; Shur, M. S.; Balandin, A. A.

    2014-04-01

    We report on the results of the low-frequency (1/f, where f is frequency) noise measurements in MoS2 field-effect transistors revealing the relative contributions of the MoS2 channel and Ti/Au contacts to the overall noise level. The investigation of the 1/f noise was performed for both as fabricated and aged transistors. It was established that the McWhorter model of the carrier number fluctuations describes well the 1/f noise in MoS2 transistors, in contrast to what is observed in graphene devices. The trap densities extracted from the 1/f noise data for MoS2 transistors, are 2 × 1019 eV-1cm-3 and 2.5 × 1020 eV-1cm-3 for the as fabricated and aged devices, respectively. It was found that the increase in the noise level of the aged MoS2 transistors is due to the channel rather than the contact degradation. The obtained results are important for the proposed electronic applications of MoS2 and other van der Waals materials.

  10. Structures and magnetic properties of rare earth double perovskites containing antimony or bismuth Ba{sub 2}LnMO{sub 6} (Ln=rare earths; M=Sb, Bi)

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Shumpei, E-mail: m-nis-s-o@ec.hokudai.ac.jp; Hinatsu, Yukio

    2015-07-15

    A series of double perovskite-type oxides Ba{sub 2}LnMO{sub 6} (Ln=lanthanides; M=Sb, Bi) were synthesized and their structures were studied. The Ln and M are structurally ordered in the rock-salt type at the B-site of the perovskite ABO{sub 3}. For Ba{sub 2}PrBiO{sub 6} and Ba{sub 2}TbBiO{sub 6}, it has been found that the disordering between Ln ion and Bi ion occurs at the B-site of the double perovskite and both the Pr (Tb) and Bi exist in two oxidation state in the same compound from the analysis of the X-ray diffraction and magnetic susceptibility data. Magnetic susceptibility measurements show that all these compounds are paramagnetic and have no magnetic ordering down to 1.8 K. - Graphical abstract: Tolerance factor for Ba{sub 2}LnMO{sub 6} (M=Sb, Bi) plotted against the ionic radius of Ln{sup 3+}. We have found that there is a clear relation between crystal structures and tolerance factors. - Highlights: • The Ln and M ions are structurally ordered in the rock-salt type at the B-site. • The disordering between Pr (Tb) ion and Bi ion occurs at the B-site. • Ba{sub 2}LnMO{sub 6} (M=Sb, Bi) have no magnetic ordering down to 1.8 K.

  11. Stage T1-2 prostate cancer with pretreatment PSA 10 ng/ml or less: radiotherapy or surgery?

    International Nuclear Information System (INIS)

    Keyser, Douglas; Kupelian, Patrick; Zippe, Craig; Klein, Eric

    1996-01-01

    Purpose: Presently, patients with pretreatment PSA levels ≤10 ng/ml constitute the majority of cases presenting for definitive treatment. Our aim was to determine whether the type of treatment (radiotherapy versus surgery) affected biochemical failure rates in this group of patients. This study is based on 389 patients treated at a single institution. Material and Methods: The charts of all patients treated with either radiotherapy or prostatectomy alone between 1987 and 1993 were reviewed (n=811). Patients with clinical stage T1 or T2 disease, and a pretreatment PSA level (iPSA) of 10.0 or less were analyzed (n=389). Two hundred forty nine (64%) received radical prostatectomy and 140 (36%) received radiotherapy (median dose 66.6 Gy). Pretreatment patient characteristics including clinical stage, biopsy Gleason score (GS) and iPSA level were not significantly different between the radiation and surgery groups (Table 1). The patients treated with radiation were significantly older (median age 70 years vs. 64 years, p<0.05). A total of 37% of the prostatectomy patients had a positive margin. The median follow-up time was 33 months; 1458 follow-up PSA levels were available for analysis. Biochemical failure was defined as a rise in PSA level of 1.0 ng/ml above the nadir PSA level in radiotherapy cases, or any value above 0.2 ng/ml in the prostatectomy cases. Results: The overall 5 year actuarial biochemical relapse free survival (bRFS) rate was 70%. The 5-year bRFS rates for prostatectomy and radiotherapy were identical (70%) (Fig.1). The significant factors affecting bRFS rates were iPSA level (≤4 vs. 4-10 ng/ml) and Gleason score (≤6 vs. ≥7) (Table 2). The 5-year bRFS rates of patients with iPSA ≤4 vs. iPSA 4-10 ng/ml were 92% vs. 61% respectively, p<0.01. The 5-year clinical relapse free survival was 93%. All clinical failures were preceded by biochemical failure. Patients with positive surgical margins did significantly worse than those with negative

  12. Scalable Patterning of MoS2 Nanoribbons by Micromolding in Capillaries.

    Science.gov (United States)

    Hung, Yu-Han; Lu, Ang-Yu; Chang, Yung-Huang; Huang, Jing-Kai; Chang, Jeng-Kuei; Li, Lain-Jong; Su, Ching-Yuan

    2016-08-17

    In this study, we report a facile approach to prepare dense arrays of MoS2 nanoribbons by combining procedures of micromolding in capillaries (MIMIC) and thermolysis of thiosalts ((NH4)2MoS4) as the printing ink. The obtained MoS2 nanoribbons had a thickness reaching as low as 3.9 nm, a width ranging from 157 to 465 nm, and a length up to 2 cm. MoS2 nanoribbons with an extremely high aspect ratio (length/width) of ∼7.4 × 10(8) were achieved. The MoS2 pattern can be printed on versatile substrates, such as SiO2/Si, sapphire, Au film, FTO/glass, and graphene-coated glass. The degree of crystallinity of the as-prepared MoS2 was discovered to be adjustable by varying the temperature through postannealing. The high-temperature thermolysis (1000 °C) results in high-quality conductive samples, and field-effect transistors based on the patterned MoS2 nanoribbons were demonstrated and characterized, where the carrier mobility was comparable to that of thin-film MoS2. In contrast, the low-temperature-treated samples (170 °C) result in a unique nanocrystalline MoSx structure (x ≈ 2.5), where the abundant and exposed edge sites were obtained from highly dense arrays of nanoribbon structures by this MIMIC patterning method. The patterned MoSx was revealed to have superior electrocatalytic efficiency (an overpotential of ∼211 mV at 10 mA/cm(2) and a Tafel slope of 43 mV/dec) in the hydrogen evolution reaction (HER) when compared to the thin-film MoS2. The report introduces a new concept for rapidly fabricating cost-effective and high-density MoS2/MoSx nanostructures on versatile substrates, which may pave the way for potential applications in nanoelectronics/optoelectronics and frontier energy materials.

  13. High temperature corrosion behavior of different grain size specimens of 2.25 Cr-1 Mo steel in SO2+O2 environment

    International Nuclear Information System (INIS)

    Ghosh, D.; Mitra, S.K.

    2011-01-01

    The investigation is primarily aimed at the high temperature corrosion behavior of different grain sizes of 2.25 Cr-1 Mo steel at SO 2 +O 2 (mixed oxidation and sulfidation). The various grain sizes (18 μm,26 μm, 48 μm, and 72 μm) are obtained by different annealing treatment. Isothermal corrosion studies are carried out in different grain size specimens at 973K for 8 hours. The corrosion growth rate and the reaction kinetics are studied by weight gain method. The external scales of the post corroded specimen are studied in Scanning Electron Microscope (SEM) to examine the corrosion products morphology on the scale. X-ray mapping analysis of the different elements (Fe, O, Cr and S) is carried out by Energy Dispersive Spectroscopy (EDS) attached with SEM. The X-ray Diffraction Analysis (XRD) is also carried out to identify the corrosion products in the external scale. Finally, it is concluded that that the corrosion rate of 2.25 Cr-1 Mo steel strongly depend on grain sizes of the specimens. The corrosion rate increases with the decreases of grain size. The finer grain (18 μm) show higher corrosion rate than the coarse grains (72 μm). The weight gain kinetics follows the parabolic growth rate which further indicates that the corrosion process is diffusion controlled. The scale analysis shows the thicker scale and extensive scale cracking and spallations in case of finer grain size specimen (18 μm), whereas the coarse grain specimen (72 μm) shows compact and adherent layer. The XRD analysis shows that the corrosion products consist of mixtures of iron oxides( Fe 3 O 4 and Fe 2 O 3 ) and iron sulfides (FeS). The details mechanism of the corrosion is discussed to explain the difference in corrosion rate for different grain sizes. (author)

  14. Comparative study of {sup 99}Mo/{sup 99m}Tc generators at base of synthesized gels starting from activation and fission {sup 99}Mo; Estudio comparativo de generadores {sup 99}Mo/{sup 99m}Tc a base de geles sintetizados a partir de {sup 99}Mo de activacion y de fision

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, I Z [UAEM, Paseo Colon esq. Paseo Tollocan, 50120 Toluca, Estado de Mexico (Mexico); Monroy G, F; Rivero G, T; Rojas N, P [ININ, Carretera Mexico -Toluca S/N, 52045 La Marquesa Ocoyoacac, Estado de Mexico (Mexico)

    2007-07-01

    The {sup 99m}Tc is used for diagnostic and therapy. It is produced starting from {sup 99}Mo, absorbed in chromatographic columns, loaded with alumina that absorb only 0.2% of {sup 99}Mo with high specific activities of {sup 99}Mo, obtained from the {sup 235}U fission. Given these conditions and limitations, new preparation procedures of {sup 99}Mo/{sup 99m}Tc generators, its have been developed, using zirconium molybdates gels that incorporates until 30% of {sup 99}Mo, conserve similar characteristics of quality and purity that the traditional generator. The radiochemical characteristics of the {sup 99m}Tc elution, depend strongly on the gel preparation conditions. In particular, the present work has by object to determine the influence of the {sup 99}Mo used type, fission or activation product, during the gels synthesis, as well as the used air flow for the agitation in the gels preparation and its influence in the {sup 99}Mo/{sup 99m}Tc generators quality. When diminishing the flow of agitation air the efficiency it increases and in the radionuclide purity of the eluates and when using {sup 99}Mo from fission for the gels production it increases in an important way the elutriation efficiency, the radiochemical and radionuclide purity of the {sup 99m}Tc eluates. (Author)

  15. Incorporation of Co into MoS2/graphene nanocomposites: One effective way to enhance the cycling stability of Li/Na storage

    Science.gov (United States)

    Li, Xiaomin; Feng, Zhenxing; Zai, Jiantao; Ma, Zi-Feng; Qian, Xuefeng

    2018-01-01

    Layered transition metal dichalcogenides are promising as lithium and/or sodium storage materials for lithium and sodium (Li/Na) ion batteries. However they always exhibit limited rate capability and long-term cycling stability, due to the fact that their 2D structures are easily restacking and agglomeration during cycling process and further result poor electrochemical reversibility. Herein, hierarchical Co1/3Mo2/3S2/graphene nanocomposites without CoSx and MoS2 impurities have been synthesized via one-pot solvothermal process. The incorporation of Co into MoS2 at atomic level can not only give rise to thinner and smaller nanosheets in the nanocomposites than MoS2/graphene nanocomposites, but also significantly decrease the size of in-situ formed MoS2/CoSx nanoparticles during electrochemical conversion process, which can greatly promoting the ion diffusion and suppressing the aggregation of active materials. Furthermore, the conductivity of Co1/3Mo2/3S2/graphene nanocomposites can be enhanced from 0.46 S m-1 (MoS2/graphene) to 1.39 S m-1via changing the semiconducting MoS2 to metallic Co1/3Mo2/3S2. The simultaneously optimized electron conductivity and ions diffusion dynamics of Co1/3Mo2/3S2/graphene nanocomposites can effectively improve the reversibility of electrochemical conversion reactions. A capacity of 940 mAh g-1 and 529 mAh g-1 can be maintained at 3200th cycle (2 A g-1) in lithium-ion batteries and 200th cycle (1 A g-1) in sodium-ion batteries, respectively.

  16. Evaluation of the influence of pH in the efficiency of the {sup 99}Mo-{sup 99m}Tc at basis of zirconium molybdate; Evaluacion de la influencia de pH en la eficiencia del generador {sup 99}Mo-{sup 99m}Tc a base de molibdato de zirconio

    Energy Technology Data Exchange (ETDEWEB)

    Diaz A, L V

    2003-07-01

    of these generators. The obtained results show that to p H average (3.8 and 4.5), the obtained efficiencies they are the biggest (- 80%). To high concentrations of the zirconil used in the synthesis of those gels (0.5 M), the efficiencies are low and with contained first floor of {sup 99} Mo in the eluates; while that, to low concentrations of ZrOCl{sub 2} * 8H{sub 2}0 (0.045M), the efficiencies increase, but also the quantity of {sup 99} Mo present in the eluates. At the using solutions of ZrOCl{sub 2} * 8H{sub 2}O prepared one day before the synthesis of the gel, bigger efficiency is obtained. The suitable p H of this solution this in the interval of 0.7 at 1.5. The relation Zr:Mo but convenient for to synthesize the gel is 1:1, because to this relation Zr:Mo the efficiency of the generator is bigger than the 80 %. Therefore, the choice of each one of the parameters studied in this work, it should be then a commitment among: high efficiency of the generator {sup 99} Mo- {sup 99m}Tc and contained first floor of {sup 99} Mo in the eluates. (Author)

  17. Theoretical prediction of high electron mobility in multilayer MoS2 heterostructured with MoSe2

    Science.gov (United States)

    Ji, Liping; Shi, Juan; Zhang, Z. Y.; Wang, Jun; Zhang, Jiachi; Tao, Chunlan; Cao, Haining

    2018-01-01

    Two-dimensional (2D) MoS2 has been considered to be one of the most promising semiconducting materials with the potential to be used in novel nanoelectronic devices. High carrier mobility in the semiconductor is necessary to guarantee a low power dissipation and a high switch speed of the corresponding electronic device. Strain engineering in 2D materials acts as an important approach to tailor and design their electronic and carrier transport properties. In this work, strain is introduced to MoS2 through perpendicularly building van der Waals heterostructures MoSe2-MoS2. Our first-principles calculations demonstrate that acoustic-phonon-limited electron mobility can be significantly enhanced in the heterostructures compared with that in pure multilayer MoS2. It is found that the effective electron mass and the deformation potential constant are relatively smaller in the heterostructures, which is responsible for the enhancement in the electron mobility. Overall, the electron mobility in the heterostructures is about 1.5 times or more of that in pure multilayer MoS2 with the same number of layers for the studied structures. These results indicate that MoSe2 is an excellent material to be heterostructured with multilayer MoS2 to improve the charge transport property.

  18. V1.42In1.83Mo15Se19

    Directory of Open Access Journals (Sweden)

    Michel Potel

    2010-10-01

    Full Text Available The structure of the title compound, vanadium indium pentadecamolybdenum nonadecaselenide, V1.42In1.83Mo15Se19, is isotypic with In2.9Mo15Se19 [Grüttner et al. (1979. Acta Cryst. B35, 285–292]. It is characterized by two cluster units Mo6Sei8Sea6 and Mo9Sei11Sea6 (where i represents inner and a apical atoms that are present in a 1:1 ratio. The cluster units are centered at Wyckoff positions 2b and 2c and have point-group symmetry overline{3} and overline{6}, respectively. The clusters are interconnected through additional Mo—Se bonds. In the title compound, the V3+ cations replace the trivalent indium atoms present in In2.9Mo15Se19, and a deficiency is observed on the monovalent indium site. One Mo, one Se and the V atom are situated on mirror planes, and two other Se atoms and the In atom are situated on threefold rotation axes.

  19. Phase formation in the Rb2MoO4-Li2MoO4-Hf(MoO4)2 system and the crystal structure of Rb5(Li1/3Hf5/3)(MoO4)6

    International Nuclear Information System (INIS)

    Solodovnikov, S.F.; Zolotova, E.S.; Balsanova, L.V.; Bazarov, B.G.; Bazarova, Zh.G.

    2003-01-01

    Phase formation in the Rb 2 MoO 4 -Li 2 MoO 4 -Hf(MoO 4 ) 2 system is studied in subsolidus region in air by the method of crossing sections. Three ternary molybdates are detected in the system. Compositions of two of them are corroborated by selection of isostructural analogues [ru

  20. Printable Transfer-Free and Wafer-Size MoS2/Graphene van der Waals Heterostructures for High-Performance Photodetection.

    Science.gov (United States)

    Liu, Qingfeng; Cook, Brent; Gong, Maogang; Gong, Youpin; Ewing, Dan; Casper, Matthew; Stramel, Alex; Wu, Judy

    2017-04-12

    Two-dimensional (2D) MoS 2 /graphene van der Waals heterostructures integrate the superior light-solid interaction in MoS 2 and charge mobility in graphene for high-performance optoelectronic devices. Key to the device performance lies in a clean MoS 2 /graphene interface to facilitate efficient transfer of photogenerated charges. Here, we report a printable and transfer-free process for fabrication of wafer-size MoS 2 /graphene van der Waals heterostructures obtained using a metal-free-grown graphene, followed by low-temperature growth of MoS 2 from the printed thin film of ammonium thiomolybdate on graphene. The photodetectors based on the transfer-free MoS 2 /graphene heterostructures exhibit extraordinary short photoresponse rise/decay times of 20/30 ms, which are significantly faster than those of the previously reported MoS 2 /transferred-graphene photodetectors (0.28-1.5 s). In addition, a high photoresponsivity of up to 835 mA/W was observed in the visible spectrum on such transfer-free MoS 2 /graphene heterostructures, which is much higher than that of the reported photodetectors based on the exfoliated layered MoS 2 (0.42 mA/W), the graphene (6.1 mA/W), and transfer-free MoS 2 /graphene/SiC heterostructures (∼40 mA/W). The enhanced performance is attributed to the clean interface on the transfer-free MoS 2 /graphene heterostructures. This printable and transfer-free process paves the way for large-scale commercial applications of the emerging 2D heterostructures in optoelectronics and sensors.

  1. Preparation of 2D MoSe2/PEDOT:PSS composite and its thermoelectric properties

    Science.gov (United States)

    Li, Xia; Liu, Congcong; Wang, Tongzhou; Wang, Wenfang; Wang, Xiaodong; Jiang, Qinglin; Jiang, Fengxing; Xu, Jingkun

    2017-11-01

    Nowadays, inorganic/polymer composites have attracted significant interest in thermoelectric field, since the composite materials usually achieve their respective advantages complementary to each other. In this work, molybdenum diselenide (MoSe2) was synthesized by a facile hydrothermal method. Solution processible two-dimensional (2D) MoSe2 nanosheets (NSs) were successfully obtained using dimethylsulfoxide (DMSO) solvent or lithium intercalation procedure. Combined with Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), MoSe2/PEDOT:PSS composite thin films were fabricated by direct vacuum-filtration method. Thermoelectric properties of composite thin films were investigated systematically and found that 2D MoSe2 NSs and PEDOT:PSS have the synergistic effect on improving thermoelectric properties. The maximum power factor was calculated to be 48.6 µW m-1 K-2 with 5 wt% 2D MoSe2 NSs embedding into PEDOT:PSS matrix, which is almost 69% higher than that of pure PEDOT:PSS. These results demonstrate that 2D inorganic/polymer composite method is one of promising strategies to get high-performance polymer-based thermoelectric composites.

  2. Sensitive Phonon-Based Probe for Structure Identification of 1T' MoTe2.

    Science.gov (United States)

    Zhou, Lin; Huang, Shengxi; Tatsumi, Yuki; Wu, Lijun; Guo, Huaihong; Bie, Ya-Qing; Ueno, Keiji; Yang, Teng; Zhu, Yimei; Kong, Jing; Saito, Riichiro; Dresselhaus, Mildred

    2017-06-28

    In this work, by combining transmission electron microscopy and polarized Raman spectroscopy for the 1T' MoTe 2 flakes with different thicknesses, we found that the polarization dependence of Raman intensity is given as a function of excitation laser wavelength, phonon symmetry, and phonon frequency, but has weak dependence on the flake thickness from few-layer to multilayer. In addition, the frequency of Raman peaks and the relative Raman intensity are sensitive to flake thickness, which manifests Raman spectroscopy as an effective probe for thickness of 1T' MoTe 2 . Our work demonstrates that polarized Raman spectroscopy is a powerful and nondestructive method to quickly identify the crystal structure and thickness of 1T' MoTe 2 simultaneously, which opens up opportunities for the in situ probe of anisotropic properties and broad applications of this novel material.

  3. Strain-Gated Field Effect Transistor of a MoS2-ZnO 2D-1D Hybrid Structure.

    Science.gov (United States)

    Chen, Libo; Xue, Fei; Li, Xiaohui; Huang, Xin; Wang, Longfei; Kou, Jinzong; Wang, Zhong Lin

    2016-01-26

    Two-dimensional (2D) molybdenum disulfide (MoS2) is an exciting material due to its unique electrical, optical, and piezoelectric properties. Owing to an intrinsic band gap of 1.2-1.9 eV, monolayer or a-few-layer MoS2 is used for fabricating field effect transistors (FETs) with high electron mobility and on/off ratio. However, the traditional FETs are controlled by an externally supplied gate voltage, which may not be sensitive enough to directly interface with a mechanical stimulus for applications in electronic skin. Here we report a type of top-pressure/force-gated field effect transistors (PGFETs) based on a hybrid structure of a 2D MoS2 flake and 1D ZnO nanowire (NW) array. Once an external pressure is applied, the piezoelectric polarization charges created at the tips of ZnO NWs grown on MoS2 act as a gate voltage to tune/control the source-drain transport property in MoS2. At a 6.25 MPa applied stimulus on a packaged device, the source-drain current can be tuned for ∼25%, equivalent to the results of applying an extra -5 V back gate voltage. Another type of PGFET with a dielectric layer (Al2O3) sandwiched between MoS2 and ZnO also shows consistent results. A theoretical model is proposed to interpret the received data. This study sets the foundation for applying the 2D material-based FETs in the field of artificial intelligence.

  4. Transfer matrix approach to electron transport in monolayer MoS2/MoO x heterostructures

    Science.gov (United States)

    Li, Gen

    2018-05-01

    Oxygen plasma treatment can introduce oxidation into monolayer MoS2 to transfer MoS2 into MoO x , causing the formation of MoS2/MoO x heterostructures. We find the MoS2/MoO x heterostructures have the similar geometry compared with GaAs/Ga1‑x Al x As semiconductor superlattice. Thus, We employ the established transfer matrix method to analyse the electron transport in the MoS2/MoO x heterostructures with double-well and step-well geometries. We also considere the coupling between transverse and longitudinal kinetic energy because the electron effective mass changes spatially in the MoS2/MoO x heterostructures. We find the resonant peaks show red shift with the increasing of transverse momentum, which is similar to the previous work studying the transverse-momentum-dependent transmission in GaAs/Ga1‑x Al x As double-barrier structure. We find electric field can enhance the magnitude of peaks and intensify the coupling between longitudinal and transverse momentums. Moreover, higher bias is applied to optimize resonant tunnelling condition to show negative differential effect can be observed in the MoS2/MoO x system.

  5. Point defects in the 1 T' and 2 H phases of single-layer MoS2: A comparative first-principles study

    Science.gov (United States)

    Pizzochero, Michele; Yazyev, Oleg V.

    2017-12-01

    The metastable 1 T' phase of layered transition metal dichalcogenides has recently attracted considerable interest due to electronic properties, possible topological phases, and catalytic activity. We report a comprehensive theoretical investigation of intrinsic point defects in the 1 T' crystalline phase of single-layer molybdenum disulfide (1 T'-MoS2 ) and provide comparison to the well-studied semiconducting 2 H phase. Based on density functional theory calculations, we explore a large number of configurations of vacancy, adatom, and antisite defects and analyze their atomic structure, thermodynamic stability, and electronic and magnetic properties. The emerging picture suggests that, under thermodynamic equilibrium, 1 T'-MoS2 is more prone to hosting lattice imperfections than the 2 H phase. More specifically, our findings reveal that the S atoms that are closer to the Mo atomic plane are the most reactive sites. Similarly to the 2 H phase, S vacancies and adatoms in 1 T'-MoS2 are very likely to occur while Mo adatoms and antisites induce local magnetic moments. Contrary to the 2 H phase, Mo vacancies in 1 T'-MoS2 are expected to be an abundant defect due to the structural relaxation that plays a major role in lowering the defect formation energy. Overall, our study predicts that the realization of high-quality flakes of 1 T'-MoS2 should be carried out under very careful laboratory conditions but at the same time the facile defects introduction can be exploited to tailor physical and chemical properties of this polymorph.

  6. Cation non-stoichiometry in pulsed laser deposited Sr{sub 2+y}Fe{sub 1+x}Mo{sub 1-x}O₆ epitaxial films

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, T. L.; Woodward, P. M., E-mail: woodward.55@osu.edu [Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210-1117 (United States); Dixit, M.; Williams, R. E. A.; Susner, M. A.; Fraser, H. L.; McComb, D. W.; Sumption, M. D. [Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210-1117 (United States); Lemberger, T. R. [Department of Physics, The Ohio State University, Columbus, Ohio 43210-1117 (United States)

    2014-07-07

    Sr₂FeMoO₆ (SFMO) films were grown on SrTiO₃ (100)- and (111)-oriented substrates via pulsed laser deposition (PLD). In order to study the fundamental characteristics of deposition, films were grown in two different PLD chambers. In chamber I, the best films were grown with a relatively long substrate-to-target distance (89 mm), high substrate temperature (850 °C), and low pressure (50 mTorr) in a 95% Ar/5% H₂ atmosphere. Although X-ray diffraction (XRD) measurements indicate these films are single phase, Rutherford Backscattering (RBS) measurements reveal considerable non-stoichiometry, corresponding to a Sr₂Fe{sub 1–x}Mo{sub 1+x}O₆ composition with x≅0.2–0.3. This level of non-stoichiometry results in inferior magnetic properties. In chamber II, the best films were grown with a much shorter substrate-to-target distance (38 mm), lower temperature (680 °C), and higher pressure (225 mTorr). XRD measurements show that the films are single phase, and RBS measurements indicate that they are nearly stoichiometric. The degree of ordering between Fe and Mo was dependent on both the temperature and pressure used during deposition, reaching a maximum order parameter of 85%. The saturation magnetization increases as the Fe/Mo ordering increases, reaching a maximum of 2.4 μB/f.u. Based on prior studies of bulk samples, one would expect a higher saturation magnetization for this degree of Fe/Mo order. The presence of extra strontium oxide layers in the form of Ruddlesden-Popper intergrowths appears to be responsible for the lower than expected saturation magnetization of these films.

  7. Understanding the NG2 glial scar after spinal cord injury

    Directory of Open Access Journals (Sweden)

    Amber R Hackett

    2016-11-01

    Full Text Available NG2 cells, also known as oligodendrocyte progenitor cells, are located throughout the central nervous system and serve as a pool of progenitors to differentiate into oligodendrocytes. In response to spinal cord injury, NG2 cells increase their proliferation and differentiation into remyelinating oligodendrocytes. While astrocytes are typically associated with being the major cell type in the glial scar, many NG2 cells also accumulate within the glial scar but their function remains poorly understood. Similar to astrocytes, these cells hypertrophy, upregulate expression of chondroitin sulfate proteoglycans, inhibit axon regeneration, contribute to the glial-fibrotic scar border, and some even differentiate into astrocytes. Whether NG2 cells also have a role in other astrocyte functions, such as preventing the spread of infiltrating leukocytes and expression of inflammatory cytokines, is not yet known. Thus, NG2 cells are not only important for remyelination after spinal cord injury, but are also a major component of the glial scar with functions that overlap with astrocytes in this region. In this review, we describe the signaling pathways important for the proliferation and differentiation of NG2 cells, as well as the role of NG2 cells in scar formation and tissue repair.

  8. Facile one-pot synthesis of CoS_2-MoS_2/CNTs as efficient electrocatalyst for hydrogen evolution reaction

    International Nuclear Information System (INIS)

    Liu, Yan-Ru; Hu, Wen-Hui; Li, Xiao; Dong, Bin; Shang, Xiao; Han, Guan-Qun; Chai, Yong-Ming; Liu, Yun-Qi; Liu, Chen-Guang

    2016-01-01

    Highlights: • Ternary hybrid CoS_2-MoS_2/CNTs electrocatalysts have been prepared. • CNTs as support may provide good conductivity and low the agglomeration of MoS_2. • CoS_2 with intrinsic metallic conductivity may enhance the activity for HER. • Ternary CoS_2-MoS_2/CNTs have the better activity and stability for HER. - Abstract: Ternary hybrid cobalt disulfide-molybdenum disulfides supported on carbon nanotubes (CoS_2-MoS_2/CNTs) electrocatalysts have been prepared via a simple hydrothermal method. CNTs as support may provide good conductivity and low the agglomeration of layered MoS_2 structure. CoS_2 with intrinsic metallic conductivity may enhance the activity of the ternary hybrid electrocatalysts for hydrogen evolution reaction (HER). X-ray diffraction (XRD) data confirm the formation of ternary hybrid nanocomposites composed of CNTs, CoS_2 and amorphous MoS_2. Scanning electron microscopy (SEM) images show that strong combination between MoS_2, CNTs and regular orthohexagonal CoS_2 has been obtained. The dispersion of each component is good and no obvious agglomeration can be observed. It is found that compared with CoS_2/CNTs and MoS_2/CNTs, the ternary CoS_2-MoS_2/CNTs have the better activity for HER with a low onset potential of 70 mV (vs. RHE) and a small Talel slope of 67 mV dec"−"1, and are extremely stable after 1000 cycles. In addition, the optimal doping ratio of Co to Mo is 2:1, which have better HER activity. It is proved that the introduction of carbon materials and Co atoms could improve the performances of MoS_2-based electrocatalysts for HER.

  9. Phase stability and fracture toughness of t' ZrO2 stabilised with MO1.5 (M=Yb and Gd) for thermal barrier application

    International Nuclear Information System (INIS)

    Loganathan, Archana; Gandhi, Ashutosh S.

    2010-01-01

    Thermal Barrier coatings (TBC's) protect the gas turbine blades at high temperature exposure. The t' phase is metastable and slowly transforms to the high-temperature equilibrium state consisting of tetragonal (t) and cubic (c) during high temperature exposure. Nanometric grain size also influences the fracture toughness and t' stability. A comparative study of the phase stability and fracture toughness evolution of Yb and Gd stabilized zirconia with composition 8 mol%MO 1.5 . The t' ZrO 2 -8mol% MO 1.5 (M = Yb and Gd) were prepared by co-precipitation method with crystallite size ∼ 20nm. Spark plasma sintering at 1250 deg C for 10 min was carried out to produce compacts with ∼ 96% relative density for fracture toughness measurements. The dense compacts were heat treated at 1250 deg C upto 192h. XRD studies revealed the partitioning of t' to t+c. No spontaneous monoclinic phase formed during cooling, except after 192h exposure. The fracture toughness of the sintered pellets with various time intervals of thermal exposure was measured. The results were analysed in terms of the effect of phase constitution on fracture toughness. The role of ferroelastic toughening in these materials was explored. (author)

  10. P-MoS2 / n-CdS thin film heterojunction

    International Nuclear Information System (INIS)

    El Maliki, H.; Gourmelon, E.; Bernede, J.C.; Pouzet, J.; Mebarki, M.; Khelil, A.; Zoaeter, M.

    1999-01-01

    Full text.Layered transition metal dichacolgenides such as MoS 2 are semiconductors that can be good candidates for solar energy conversion. Photo-electrochemical cells based on single crystals have achieved and efficiency of 17% (1). However, up to day, no solid rectifying contact has been put in evidence in the case of MoS 2 thin films.. Recently we have shown that such high crystalline quality MoS 2 films can be obtained onto textured tungsten slides. This allowed to try to grow sandwich rectifying structures. The bottom electrode will be W, MoS 2 being p-type, the n type film used was CdS and the upper electrode was indium. W foils textured along the (h00) direction were used as substrate and bottom electrode. The use of a W (textured) substrate induces the texturation of the MoS 2 films along the (001) direction when after evaporation of the constituents the films were annealed at T=1073 K for half an hour under argon atmosphere. Upon the MoS 2 a CdS thin film was deposited by chemical bath deposition (CBD). CdS thin films were prepared classically from a solution of cadmium sulfate, thiourea in hydrazine and ammonia. Ammonia was used adjust the solution pH to a value between 9 and 10. Bath temperature has been held constant at 343 K. Thin deposit films of CdS were yellow colored. They were constituted of an homogenous and adherent layer with a thickness of about 100 nm. It has been shown by x-ray diffraction the they were crystallized in their hexagonal structure. At least an indium film was deposited in order to achieve the structure M/MoS 2 p/CdSn/M. In order to check the equality of the W/MoS 2 contact, W/MoS 2 /W samples were also carried out by sputtering deposition of the tungsten upper electrode (300 nm thick). The thickness of the MoS 2 layers was about 500 nm. The J-V characteristics of a W/MoS 2 /W sample are ohmic. Moreover the resistance deduced from the slope ΔV/ΔI increases when the temperature decreases, which shows that there is not any

  11. Comparative study of 99Mo/99mTc generators at base of synthesized gels starting from 99Mo of activation and of fission

    International Nuclear Information System (INIS)

    Lopez M, I.Z.; Monroy G, F.; Rivero G, T.; Rojas N, P.

    2007-01-01

    At the present time the more used and diffused radionuclide in nuclear medicine it is the Technetium 99 metastable ( 99 mTc) it is used for diagnostic and therapy. It is produced starting from molybdenum 99 ( 99 Mo), which is absorbed in chromatographic columns, loaded with alumina that absorb only 0.2% of 99 Mo situation that forces to use high specific activities of 99 Mo that it is obtained starting from the fission of the 235 U. Given these conditions and limitations, new preparation procedures of 99 Mo/ 99m Tc generators, of low or medium specific activity, its have been developed, using gels of zirconium molybdates that incorporates until 30% in weight of 99 Mo in the gel, and also conserve similar characteristics of quality and purity that those obtained by the traditional generator; reducing by this way the cost of production of the 99m Tc, when using 99 Mo of low specific activity, in the preparation of 99 Mo/ 99m Tc generators. The radiochemical characteristics of the elution of 99m Tc, depends strongly on the gel preparation conditions. In particular, the present work has for object to determine the influence of the used type of 99 Mo, fission or activation product, during the gels synthesis, as well as the used air flow for the agitation in the gels preparation and its influence in the quality of the 99 Mo/ 99m Tc generators. When diminishing the agitation air flow the efficiency it increases and in the radionuclide purity of the eluates and when using 99 Mo of fission for the gels production it increases in an important way the elution efficiency, the radiochemical purity and radionuclide of the eluates of 99m Tc. (Author)

  12. Evaluation of the influence of pH in the efficiency of the 99Mo-99mTc at basis of zirconium molybdate

    International Nuclear Information System (INIS)

    Diaz A, L.V.

    2003-01-01

    (- 80%). To high concentrations of the zirconil used in the synthesis of those gels (0.5 M), the efficiencies are low and with contained first floor of 99 Mo in the eluates; while that, to low concentrations of ZrOCl 2 * 8H 2 0 (0.045M), the efficiencies increase, but also the quantity of 99 Mo present in the eluates. At the using solutions of ZrOCl 2 * 8H 2 O prepared one day before the synthesis of the gel, bigger efficiency is obtained. The suitable p H of this solution this in the interval of 0.7 at 1.5. The relation Zr:Mo but convenient for to synthesize the gel is 1:1, because to this relation Zr:Mo the efficiency of the generator is bigger than the 80 %. Therefore, the choice of each one of the parameters studied in this work, it should be then a commitment among: high efficiency of the generator 99 Mo- 99m Tc and contained first floor of 99 Mo in the eluates. (Author)

  13. Spontaneous polarization and pyroelectric effect in improper ferroelectrics-ferroelastics Gd2(MoO4)3 and Tb2(MoO4)3 at low temperature

    International Nuclear Information System (INIS)

    Matyjasik, S; Shaldin, Yu.V.

    2013-01-01

    Experimental dependencies for spontaneous polarization ΔP s (T) and pyroelectric coefficient γ s (T)for Gd 2 (MoO 4 ) 3 (GMO) and Tb 2 (MoO 4 ) 3 (TMO) reported here differs from those for intrinsic ferroelectrics. We found fundamental distinction in GMO and TMO samples behavior at their repolarization at the fixed temperatures 300 and 4.2 K. In TMO monodomainization temperature does not affect experimental data, while in GMO monodomainization at 4.2 K results in increase of ΔP s (T) by order of magnitude at 85 K and γ s (T) dependence shows well-defined anomalies, reaching a record magnitude of 3 centre dot 10 -4 C/(m 2 centre dot K) at T = 25 K. At T = 200 K the pyroelectric coefficients values are -1.45 centre dot 10 -6 C/(m 2 centre dot K) and-1.8 centre dot 10 -6 C/(m 2 centre dot K). Taking into account our data, results related to transformation of structure in (001) plane and symmetry reasons we suggested crystallographic model of GMO type improper ferroelectric. It is formed by four meso-tetrahedrons constructed of three coordination tetrahedrons MO 4 (a, b and c types). In the framework of this model we discuss the physical meaning of pseudodeviator Q 12 *, coefficient, that initiate the phase transition at T > 433 K from noncentrosymmetric phase (mm2) to another one (4-bar2m).

  14. Spectroscopic analysis and laser performance of Tm3+ : NaGd(MoO4)2 crystal

    International Nuclear Information System (INIS)

    Guo Weijie; Chen Yujin; Lin Yanfu; Gong Xinghong; Luo Zundu; Huang Yidong

    2008-01-01

    Detailed polarized spectral properties of Tm 3+ : NaGd(MoO 4 ) 2 crystal have been investigated. The room temperature absorption and fluorescence spectra were recorded. The fluorescence decay mechanisms of the 1 G 4 and 3 H 4 multiplets in Tm 3+ : NaGd(MoO 4 ) 2 crystal were discussed. Room temperature quasi-cw 1.9 μm laser emission from the Ti : sapphire laser pumped Tm 3+ : NaGd(MoO 4 ) 2 crystal has been demonstrated. The maximum output power of 170 mW has been achieved with a slope efficiency of 25%

  15. Study of phase equilibria in LiIn(MoO4)2 - MeIn(MoO4)2 (Me - K, Rb) systems

    International Nuclear Information System (INIS)

    Smirnyagina, N.N.; Kozhevnikova, N.M.; Alekseev, F.P.; Mokhosoev, M.V.

    1983-01-01

    To determine the possibilities of formation of ternary molybdates, containing two different alkali cations and a cation of trivalent element, the qUasibinary LiIn(MoO 4 ) 2 -MeIn(MoO 4 ) 2 cross-sections of quaternary Li 2 O-Me 2 O-In 2 O 3 -MoO 3 , (Me-K, Rb) systems have been studied. Methods of X-ray phase-, differential thermal- and crystal optical analyses were used. The studied systems are eutectics with segregation; ternary compounds are not formed in theM

  16. Low-frequency 1/f noise in MoS2 transistors: Relative contributions of the channel and contacts

    International Nuclear Information System (INIS)

    Renteria, J.; Jiang, C.; Samnakay, R.; Rumyantsev, S. L.; Goli, P.; Balandin, A. A.; Shur, M. S.

    2014-01-01

    We report on the results of the low-frequency (1/f, where f is frequency) noise measurements in MoS 2 field-effect transistors revealing the relative contributions of the MoS 2 channel and Ti/Au contacts to the overall noise level. The investigation of the 1/f noise was performed for both as fabricated and aged transistors. It was established that the McWhorter model of the carrier number fluctuations describes well the 1/f noise in MoS 2 transistors, in contrast to what is observed in graphene devices. The trap densities extracted from the 1/f noise data for MoS 2 transistors, are 2 × 10 19  eV −1 cm −3 and 2.5 × 10 20  eV −1 cm −3 for the as fabricated and aged devices, respectively. It was found that the increase in the noise level of the aged MoS 2 transistors is due to the channel rather than the contact degradation. The obtained results are important for the proposed electronic applications of MoS 2 and other van der Waals materials

  17. Ordering in rapidly solidified Ni/sub 2/Mo

    International Nuclear Information System (INIS)

    Kulkarni, U.D.; Dey, G.K.; Banerjee, S.

    1988-01-01

    Ordering processes in the Ni-Mo system have been a subject of several investigations. Although the ordering behaviour of the Ni/sub 4/Mo and the Ni/sub 3/Mo has been examined in detail, no such study has been reported in the case of the Ni/sub 2/Mo alloy. The lack of experimental work on ordering transformations in Ni/sub 2/Mo is presumably due to the difficulty in obtaining a single phase fcc alloy of this composition. Enhanced solid solubility of Mo in Ni, which accompanies rapid solidification processing (RSP) makes the formation of such a phase possible. The ordering processes in Ni-Mo based alloys show several remarkable features. Firstly, the alloy (15 - 28 at % Mo) quenched from the α -phase filed exhibit a short range order (SRO) characterized by the presence of intensity maxima at /1 1/2 0/ fcc positions of the reciprocal space. This state of SRO has been attributed to the occurrence of 1 1/2 O spinodal ordering in the system. Secondly, the transformation from the state of SRO to the equilibrium/metastable coherent long range ordered (LRO) structures appears to take place in a continuous manner at relatively low temperatures of aging. Three different coherent LRO structures, namely: the equilibrium Ni/sub 4/Mo (prototype structure D1/sub a/) and the metastable Ni/sub 3/Mo (DO/sub 22/) and Ni/sub 2/Mo (Pt/sub 2/Mo) structures have reported to evolve from the SRO alloy, depending upon the aging treatment and the composition of the alloy

  18. High-Risk Prostate Cancer With Gleason Score 8–10 and PSA Level ≤15 ng/ mL Treated With Permanent Interstitial Brachytherapy

    International Nuclear Information System (INIS)

    Fang, L. Christine; Merrick, Gregory S.; Butler, Wayne M.; Galbreath, Robert W.; Murray, Brian C.; Reed, Joshua L.; Adamovich, Edward; Wallner, Kent E.

    2011-01-01

    Purpose: With widespread prostate-specific antigen (PSA) screening, there has been an increase in men diagnosed with high-risk prostate cancer defined by a Gleason score (GS) ≥8 coupled with a relatively low PSA level. The optimal management of these patients has not been defined. Cause-specific survival (CSS), biochemical progression-free survival (bPFS), and overall survival (OS) were evaluated in brachytherapy patients with a GS ≥8 and a PSA level ≤15 ng/mL with or without androgen-deprivation therapy (ADT). Methods and Materials: From April 1995 to October 2005, 174 patients with GS ≥8 and a PSA level ≤15 ng/mL underwent permanent interstitial brachytherapy. Of the patients, 159 (91%) received supplemental external beam radiation, and 113 (64.9%) received ADT. The median follow-up was 6.6 years. The median postimplant Day 0 minimum percentage of the dose covering 90% of the target volume was 121.1% of prescription dose. Biochemical control was defined as a PSA level ≤0.40 ng/mL after nadir. Multiple parameters were evaluated for impact on survival. Results: Ten-year outcomes for patients without and with ADT were 95.2% and 92.5%, respectively, for CSS (p = 0.562); 86.5% and 92.6%, respectively, for bPFS (p = 0.204); and 75.2% and 66.0%, respectively, for OS (p = 0.179). The median post-treatment PSA level for biochemically controlled patients was <0.02 ng/mL. Multivariate analysis failed to identify any predictors for CSS, whereas bPFS and OS were most closely related to patient age. Conclusions: Patients with GS ≥8 and PSA level ≤15 ng/mL have excellent bPFS and CSS after brachytherapy with supplemental external beam radiotherapy. The use of ADT did not significantly impact bPFS, CSS, or OS.

  19. Review of time-dependent fatigue behavior and life prediction for 2 1/4 Cr-1 Mo steel

    International Nuclear Information System (INIS)

    Booker, M.K.; Majumdar, S.

    1982-01-01

    Available data on creep-fatigue life and fracture behavior of 2 1/4 Cr-1 Mo steel are reviewed. Whereas creep-fatigue interaction is important for Type 304 stainless steel, oxidation effects appear to dominate the time-dependent fatigue behavior of 2 1/4 Cr-1 Mo steel. Four of the currently available predictive methods - the Linear Damage Rule, Frequency Separation Equation, Strain Range Partitioning Equation, and Damage Rate Equation - are evaluated for their predictive capability. Variations in the parameters for the various predictive methods with temperature, heat of material, heat treatment, and environment are investigated. Relative trends in the lives predicted by the various methods as functions of test duration, waveshape, etc., are discussed. The predictive methods will need modification in order to account for oxidation and aging effects in the 2 1/4 Cr-1 Mo steel. Future tests that will emphasize the difference between the various predictive methods are proposed

  20. Synthesis of Li2MO3 (M = Ti or Zr) by the combustion method

    International Nuclear Information System (INIS)

    Cruza, D.; Bulbuliana, S.; Cruza, D.; Pfeifferc, H.

    2006-01-01

    The advantages and disadvantages of the combustion method to prepare Li 2 TiO 3 and Li 2 ZrO 3 ceramics were studied. Firstly, the ceramic powders were prepared by the combustion process using LiOH, MO 2 (where M=Ti or Zr) and urea in different molar ratios (from 2:1:3 to 3:1:3) at different temperatures for 5 minutes. Li 2 TiO 3 and Li 2 ZrO 3 were also obtained by the solid-state method, and the results were compared with those obtained by the combustion process. The powders were characterized by X-ray diffraction and scanning electron microscopy. It was found that the combustion process reduces the synthesis time of Li 2 TiO 3 (1 minute at 750 C), but it does not have any advantage on producing Li 2 ZrO 3 , due to thermodynamic factors. On the other hand, the combustion process produces carbon contaminants in the solids. It was necessary to add excess of lithium hydroxide, in order to compensate the quantity of Li sublimated during the production of the ceramics. Finally, it seems that both reactions follow the same mechanism, which is determined by the lithium diffusion into the metal oxides. (authors)

  1. Electronic structure of structural open derivatives of the [Mo6X14]2- cluster: [Mo5Cl13]2- and [Mo4I11]2-

    International Nuclear Information System (INIS)

    Miessner, H.; Korol'kov, D.V.

    1983-01-01

    The electronic structure of structural open derivatives of the [Mo 6 X 14 ] 2 - -cluster [Mo 5 Cl 13 ] 2 - and [Mo 4 I 11 ] 2 - has been studied by the EHMO method. In [Mo 5 Cl 13 ] 2 - 9 occupied MO's with dominant Mo4d character are responsible for the formation of the 8 metal-metal bonds. In [Mo 4 I 11 ] 2 - the stronger covalent character of the Mo-I bonds affects the localization and the energy of molecular orbitals and also the charge distribution. The metal-metal bonds are formed by 8 MO's containing considerable participation of halogen AO's contrary to the chloride cluster. There is no bonding between the Mo atoms at the wing tips of the Mo 4 butterfly and the reason for decreasing the dihedral angle between the Mo 3 planes in [Mo 4 I 11 ] 2 - compared with the octahedral angle is apparently the stabilization of the whole system (Mo-Mo and Mo-I bonds). The unpaired electron occupies in both clusters a slightly antibonding (with regard to the Mo-Mo bonds) orbital. (author)

  2. On the coexistence of copper-molybdenum bronzes: CuxMoO3 (0.2 < x < 0.25; typically x = 0.23) and CuyMoO3-z (0.1 < y < 0.2; typically y = 0.15) in the Cu-MoO2-O quasi-ternary system

    DEFF Research Database (Denmark)

    Warner, Terence Edwin; Skou, Eivind Morten

    2010-01-01

    Two copper-molybdenum bronzes: CuyMoO3-z (0.1black polycrystalline materials by the solid state reaction of Cu and MoO3 at 600 C under argon in Pt crucibles. Powder XRD showed that the material...... with global composition ‘0.1Cu.MoO3’ comprises ~Cu0.15MoO3 and MoO3; whilst ‘0.2Cu.MoO3’ comprises ~Cu0.15MoO3 and ~Cu0.23MoO3. DTA performed on ‘0.2Cu.MoO3’ reveals a reversible solid state phase transition = 520 C under argon. Reacting equimolar amounts of Cu2O and MoO2 at 600 C in a Cu crucible under argon...

  3. Scalable Patterning of MoS2Nanoribbons by Micromolding in Capillaries

    KAUST Repository

    Hung, Yu-Han

    2016-07-27

    In this study, we report a facile approach to prepare dense arrays of MoS2 nanoribbons by combining procedures of micromolding in capillaries (MIMIC) and thermolysis of thiosalts ((NH4)2MoS4) as the printing ink. The obtained MoS2 nanoribbons had a thickness reaching as low as 3.9 nm, a width ranging from 157 to 465 nm, and a length up to 2 cm. MoS2 nanoribbons with an extremely high aspect ratio (length/width) of ∼7.4 × 108 were achieved. The MoS2 pattern can be printed on versatile substrates, such as SiO2/Si, sapphire, Au film, FTO/glass, and graphene-coated glass. The degree of crystallinity of the as-prepared MoS2 was discovered to be adjustable by varying the temperature through postannealing. The high-temperature thermolysis (1000 °C) results in high-quality conductive samples, and field-effect transistors based on the patterned MoS2 nanoribbons were demonstrated and characterized, where the carrier mobility was comparable to that of thin-film MoS2. In contrast, the low-temperature-treated samples (170 °C) result in a unique nanocrystalline MoSx structure (x ≈ 2.5), where the abundant and exposed edge sites were obtained from highly dense arrays of nanoribbon structures by this MIMIC patterning method. The patterned MoSx was revealed to have superior electrocatalytic efficiency (an overpotential of ∼211 mV at 10 mA/cm2 and a Tafel slope of 43 mV/dec) in the hydrogen evolution reaction (HER) when compared to the thin-film MoS2. The report introduces a new concept for rapidly fabricating cost-effective and high-density MoS2/MoSx nanostructures on versatile substrates, which may pave the way for potential applications in nanoelectronics/optoelectronics and frontier energy materials. © 2016 American Chemical Society.

  4. Magnetic MoS2 on multiwalled carbon nanotubes for sulfide sensing.

    Science.gov (United States)

    Li, Chunxiang; Zhang, Dan; Wang, Jiankang; Hu, Pingan; Jiang, Zhaohua

    2017-07-04

    A novel hybrid metallic cobalt insided in multiwalled carbon nanotubles/molybdenum disulfide (Co@CNT/MoS 2 ) modified glass carbon electrode (GCE) was fabricated with a adhesive of Nafion suspension and used as chemical sensors for sulfide detection. Single-layered MoS 2 was coated on CNTs through magnetic traction force between paramagnetic monolayer MoS 2 and Co particles in CNTs. Co particles faciliated the collection of paramagnetic monolayer MoS 2 exfoliated from bulk MoS 2 in solution. Amperometric analysis, cycle voltammetry, cathodic stripping analysis and linear sweep voltammetry results showed the Co@CNT/MoS 2 modified GCE exhibited excellent electrochemical activity to sulfide in buffer solutions, but amperometric analysis was found to be more sensitive than the other methods. The amperometric response result indicated the Co@CNT/MoS 2 -modified GCE electrode was an excellent electrochemical sensor for detecting S 2- with a detection limit of 7.6 nM and sensitivity of 0.23 mA/μM. The proposed electrode was used for the determination of sulfide levels in hydrogen sulfide-pretreated fruits, and the method was also verified with recovery studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Preparation of Zr(Mo,W)2O8 with a larger negative thermal expansion by controlling the thermal decomposition of Zr(Mo,W)2(OH,Cl)22H2O.

    Science.gov (United States)

    Petrushina, Mariya Yu; Dedova, Elena S; Filatov, Eugeny Yu; Plyusnin, Pavel E; Korenev, Sergei V; Kulkov, Sergei N; Derevyannikova, Elizaveta A; Sharafutdinov, Marat R; Gubanov, Alexander I

    2018-03-28

    Solid solutions of Zr(Mo,W) 2 O 7 (OH,Cl) 22H 2 O with a preset ratio of components were prepared by a hydrothermal method. The chemical composition of the solutions was determined by energy dispersive X-ray spectroscopy (EDX). For all the samples of ZrMo x W 2-x O 7 (OH,Cl) 22H 2 O (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0), TGA and in situ powder X-ray diffraction (PXRD) studies (300-1100 K) were conducted. For each case, the boundaries of the transformations were determined: Zr(Mo,W) 2 O 7 (OH,Cl) 22H 2 O → orthorhombic-ZrMo x W 2-x O 8 (425-525 K), orthorhombic-ZrMo x W 2-x O 8  → cubic-ZrMo x W 2-x O 8 (700-850 K), cubic-ZrMo x W 2-x O 8  → trigonal-ZrMo x W 2-x O 8 (800-1050 K for x > 1) and cubic-ZrMo x W 2-x O 8  → oxides (1000-1075 K for x ≤ 1). The cell parameters of the disordered cubic-ZrMo x W 2-x O 8 (space group Pa-3) were measured within 300-900 K, and the thermal expansion coefficients were calculated: -3.5∙10 -6  - -4.5∙10 -6  K -1 . For the ordered ZrMo 1.8 W 0.2 O 8 (space group P2 1 3), a negative thermal expansion (NTE) coefficient -9.6∙10 -6  K -1 (300-400 K) was calculated. Orthorhombic-ZrW2O 8 is formed upon the decomposition of ZrW 2 O 7 (OH,Cl) 22H 2 O within 500-800 K.

  6. Large-area few-layer MoS 2 deposited by sputtering

    KAUST Repository

    Huang, Jyun-Hong

    2016-06-06

    Direct magnetron sputtering of transition metal dichalcogenide targets is proposed as a new approach for depositing large-area two-dimensional layered materials. Bilayer to few-layer MoS2 deposited by magnetron sputtering followed by post-deposition annealing shows superior area scalability over 20 cm(2) and layer-by-layer controllability. High crystallinity of layered MoS2 was confirmed by Raman, photo-luminescence, and transmission electron microscopy analysis. The sputtering temperature and annealing ambience were found to play an important role in the film quality. The top-gate field-effect transistor by using the layered MoS2 channel shows typical n-type characteristics with a current on/off ratio of approximately 10(4). The relatively low mobility is attributed to the small grain size of 0.1-1 mu m with a trap charge density in grain boundaries of the order of 10(13) cm(-2).

  7. Generation of MoS{sub 2} quantum dots by laser ablation of MoS{sub 2} particles in suspension and their photocatalytic activity for H{sub 2} generation

    Energy Technology Data Exchange (ETDEWEB)

    Baldoví, Herme G.; Latorre-Sánchez, Marcos; Esteve-Adell, Iván [Universitat Politècnica de València, Instituto Universitario de Tecnología Química CSIC-UPV and Departamento de Química (Spain); Khan, Anish; Asiri, Abdullah M. [King Abdulaziz University, Center of Excellence for Advanced Materials Research (Saudi Arabia); Kosa, Samia A. [King Abdulaziz University, Chemistry Department, Faculty of Science (Saudi Arabia); Garcia, Hermenegildo, E-mail: hgarcia@qim.upv.es [Universitat Politècnica de València, Instituto Universitario de Tecnología Química CSIC-UPV and Departamento de Química (Spain)

    2016-08-15

    MoS{sub 2} quantum dots (QDs) have been obtained in colloidal suspensions by 532 nm laser ablation (7 ns fwhp/pulse, 50 mJ/pulse) of commercial MoS{sub 2} particles in acetonitrile. High-resolution transmission electron microscopy images show a lateral size distribution from 5 to 20 nm, but a more homogeneous particle size of 20 nm can be obtained by silica gel chromatography purification in acetonitrile. MoS{sub 2} QDs obtained by laser ablation are constituted by 3–6 MoS{sub 2} layers (1.8–4 nm thickness) and exhibit photoluminescence whose λ{sub PL} varies from 430 to 530 nm depending on the excitation wavelength. As predicted by theory, the confinement effect and the larger periphery in MoS{sub 2} QDs increasing the bandgap and having catalytically active edges are reflected in an enhancement of the photocatalytic activity for H{sub 2} generation upon UV–Vis irradiation using CH{sub 3}OH as sacrificial electron donor due to the increase in the reduction potential of conduction band electrons and the electron transfer kinetics.

  8. Few-layered MoSe2 nanosheets as an advanced electrode material for supercapacitors.

    Science.gov (United States)

    Balasingam, Suresh Kannan; Lee, Jae Sung; Jun, Yongseok

    2015-09-21

    We report the synthesis of few-layered MoSe2 nanosheets using a facile hydrothermal method and their electrochemical charge storage behavior. A systematic study of the structure and morphology of the as-synthesized MoSe2 nanosheets was performed. The downward peak shift in the Raman spectrum and the high-resolution transmission electron microscopy images confirmed the formation of few-layered nanosheets. The electrochemical energy-storage behavior of MoSe2 nanosheets was also investigated for supercapacitor applications in a symmetric cell configuration. The MoSe2 nanosheet electrode exhibited a maximum specific capacitance of 198.9 F g(-1) and the symmetric device showed 49.7 F g(-1) at a scan rate of 2 mV s(-1). A capacitance retention of approximately 75% was observed even after 10 000 cycles at a high charge-discharge current density of 5 A g(-1). The two-dimensional MoSe2 nanosheets exhibited a high specific capacitance and good cyclic stability, which makes it a promising electrode material for supercapacitor applications.

  9. Phase formation in the Li2MoO4-Rb2MoO4-Ln2(MoO4)3 systems and the properties of LiRbLn2(MoO4)4

    International Nuclear Information System (INIS)

    Basovich, O.M.; Khajkina, E.G.; Vasil'ev, E.V.; Frolov, A.M.

    1995-01-01

    Phase equilibria within subsolidus range of ternary salt systems Li 2 MoO 4 -Rb 2 MoO 4 -Ln 2 (MoO 4 ) 4 (Ln - Nd, Er) are analyzed. Formation of ternary molybdate LiRbNd 2 (MoO 4 ) 4 is proved along LiNd(MoO 4 ) 2 -RbNd(MoO 4 )-2 cross-section. Phase diagram of this cross-section is plotted. Similar compounds are synthesized for Ln = La-Eu. The parameters of their monoclinic elementary cells are determined. Luminescent properties of LiRbLa 2 (MoO 4 ) 4 -Nd 3+ are studied. 17 refs., 4 figs., 2 tabs

  10. Corrosion critique of the 2 1/4 Cr--1 Mo steel for LMFBR steam generation system applications

    International Nuclear Information System (INIS)

    Zima, G.E.

    1977-07-01

    The unstabilized ferritic steel of nominal composition, 2 1 / 4 Cr-1Mo, has been proposed for critical structural assignments in LMFBR powerplants, specifically: the tubing, tubesheet and shell of the evaporator and superheater components. The interest in this steel has been based on a presumably favorable general corrosion property spectrum, acceptable mechanical properties and fabricability, and certain economies associated with the low alloy content. This report is an attempt at a general corrosion assessment for the 2 1 / 4 Cr-1Mo steel and an identification of corrosion problem areas potential to this steel from the sodium and water/steam systems of the proposed working environment. There is a considerable area of uncertainty in the sodium-side response of 2 1 / 4 Cr-1Mo steel, centered in the loss and redisposition of carbon during long-term exposure to sodium of various impurity backgrounds. It is submitted that present evidence relating to the water/steam-side corrosion behavior of the 2 1 / 4 Cr-1Mo steel, under nominal and conceivable perturbed environmental conditions, constitutes the principal concern for the proposed LMFBR powerplant applications of this steel. It is suggested that this unfavorable corrosion aspect represents an inherent limitation of the low alloy content of this steel, probably largely independent of melting and processing recourses, and it is a sufficient basis to question the incentive for a continuation of the collateral studies of this steel for the proposed LMFBR steam generation system assignments

  11. Normal and grazing incidence pulsed laser deposition of nanostructured MoSx hydrogen evolution catalysts from a MoS2 target

    Science.gov (United States)

    Fominski, V. Yu.; Romanov, R. I.; Fominski, D. V.; Dzhumaev, P. S.; Troyan, I. A.

    2018-06-01

    Pulsed laser ablation of a MoS2 target causes enhanced splashing of the material. So, for MoSx films obtained by pulsed laser deposition (PLD) in the conventional normal incidence (NI) configuration, their typical morphology is characterized by an underlying granular structure with an overlayer of widely dispersed spherical Mo and MoSx particles possessing micro-, sub-micro- and nanometer sizes. We investigated the possibility of using high surface roughness, which occurs due to particle deposition, as a support with a large exposed surface area for thin MoSx catalytic layers for the hydrogen evolution reaction (HER). For comparison, the HER performance of MoSx layers formed by grazing incidence (GI) PLD was studied. During GI-PLD, a substrate was placed along the direction of laser plume transport and few large particles loaded the substrate. The local structure and composition of thin MoSx layers formed by the deposition of the vapor component of the laser plume were varied by changing the pressure of the buffer gas (argon, Ar). In the case of NI-PLD, an increase in Ar pressure caused the formation of quasi-amorphous MoSx (x ≥ 2) films that possessed highly active catalytic sites on the edges of the layered MoS2 nanophase. At the same time, a decrease in the deposition rate of the MoSx film appeared due to the scattering of the vapor flux by Ar molecules during flux transport from the target to the substrate. This effect prevented uniform deposition of the MoSx catalytic film on the surface of most particles, whose deposition rate was independent of Ar pressure. The scattered vapor flux containing Mo and S atoms was a dominant source for MoSx film growth during GI-PLD. The thickness and composition distribution of the MoSx film on the substrate depended on both the pressure of the buffer gas and the distance from the target. For 1.0-2.5 cm from the target, the deposition rate was quite sufficient to form S-enriched quasi-amorphous MoSx (2.5 < x < 6) catalytic

  12. Quadruple metal-metal bonds with strong donor ligands. Ultraviolet photoelectron spectroscopy of M{sub 2}(form){sub 4} (M = Cr, Mo, W; form = N,N{prime}-diphenylformamidinate)

    Energy Technology Data Exchange (ETDEWEB)

    Lichtenberger, D.L.; Lynn, M.A.; Chisholm, M.H.

    1999-12-29

    The He I photoelectron spectra of M{sub 2}(form){sub 4}(M = Cr, Mo, W; form - N,N{prime}-diphenylformamidinate) and Mo{sub 2}(cyform){sub 4} (cyform = N,N{prime}-dicyclohexylformamidinate) are presented. For comparison, the Ne I, He I, and He II photoelectron spectra of Mo{sub 2}(p-CH{sub 3}-form){sub 4} have also been obtained. The valence ionization features of these molecules are interpreted based on (1) the changes that occur with the metal and ligand substitutions, (2) the changes in photoelectron cross sections with excitation source, and (3) the changes from previously studied dimetal complexes. These photoelectron spectra are useful for revealing the effects that better electron donor ligands have on the valence electronic structure of M{sub 2}(L-L){sub 4} systems. Comparison with the He I spectra of the isoelectronic M{sub 2}(O{sub 2}CCH{sub 3}){sub 4} compounds is particularly revealing. Unlike with the more electron-withdrawing acetate ligand, several formamidinate-based ionizations derived from the nitrogen p{sub {pi}} orbitals occur among the metal-metal {sigma}, {pi}, and {delta} ionization bands. Although these formamidinate-based levels are close in energy to the occupied metal-metal bonds, they have little direct mixing interaction with them. The shift of the metal-metal bond ionizations to lower ionization energies for the formamidinate systems is primarily a consequence of the lower electronegativity of the ligand and the better {pi} donation into empty metal levels. The metal-metal {delta} orbital experiences some additional net bonding interaction with ligand orbitals of the same symmetry. Also, an additional bonding interaction from ligand-to-metal electron donation to the {delta}* orbital is identified. These spectra suggest a greater degree of metal-ligand covalency than in the related M{sub 2}(O{sub 2}CCH{sub 3}){sub 4} systems. Fenske-Hall molecular orbital and density functional (ADF) calculations agree with the assignment and

  13. First-Principles Study on the Structural Stability and Segregation Behavior of γ-Fe/Cr2N Interface with Alloying Additives M (M = Mn, V, Ti, Mo, and Ni

    Directory of Open Access Journals (Sweden)

    Hui Huang

    2016-07-01

    Full Text Available This study investigated the structural stability and electrochemical properties of alloying additives M (M = Mn, V, Ti, Mo, or Ni at the γ-Fe(111/Cr2N(0001 interface by the first-principles method. Results indicated that V and Ti were easily segregated at the γ-Fe(111/Cr2N(0001 interface and enhanced interfacial adhesive strength. By contrast, Ni and Mo were difficult to segregate at the γ-Fe(111/Cr2N(0001 interface. Moreover, the results of the work function demonstrated that alloying additives Mn reduced local electrochemical corrosion behavior of the γ-Fe(111/Cr2N(0001 interface by cutting down Volta potential difference (VPD between clean γ-Fe(111 and Cr2N(0001, while alloying additives V, Ti, Mo, and Ni at the γ-Fe(111/Cr2N(0001 interface magnified VPD between clean γ-Fe(111 and Cr2N(0001, which were low-potential sites that usually serve as local attack initiation points.

  14. Exfoliated thin Bi{sub 2}MoO{sub 6} nanosheets supported on WO{sub 3} electrode for enhanced photoelectrochemical water splitting

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ying; Jia, Yulong; Wang, Lina [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, CAS, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Yang, Min [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, CAS, Lanzhou 730000 (China); Bi, Yingpu, E-mail: yingpubi@licp.cas.cn [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, CAS, Lanzhou 730000 (China); Qi, Yanxing, E-mail: qiyx@licp.cas.cn [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, CAS, Lanzhou 730000 (China)

    2016-12-30

    Highlights: • Thin Bi{sub 2}MoO{sub 6} nanosheets were prepared by microwave assisted ultrasonic separation. • The thin Bi{sub 2}MoO{sub 6} nanosheets could be more favorable to charge shift and separation. • The WO{sub 3}/thin Bi{sub 2}MoO{sub 6} exhibits superior photoelectric activity than WO{sub 3}/Bi{sub 2}MoO{sub 6} film. • The efficient photoelectric property results from facilitated charge separation. - Abstract: Thin Bi{sub 2}MoO{sub 6} nanosheets are obtained by a microwave-assisted ultrasonic separation process. After exfoliation, the thinner and uniform nanosheets with a thickness of about 10 nm were obtained. The exfoliated nanosheets would provide many amazing functionalities such as high electron mobility and quantum Hall effects. Therefore, thin Bi{sub 2}MoO{sub 6} supported on WO{sub 3} electrode (WO{sub 3}/thin Bi{sub 2}MoO{sub 6}) exhibits facilitated charge separation than pure WO{sub 3} film and the un-exfoliated Bi{sub 2}MoO{sub 6} nanosheets supported on WO{sub 3} electrode (WO{sub 3}/Bi{sub 2}MoO{sub 6}). As a result, WO{sub 3}/thin Bi{sub 2}MoO{sub 6} shows remarkably stable photocurrent density of 2.2 mA/cm{sup 2} at 0.8 V{sub SCE} in 0.1 M Na{sub 2}SO{sub 4} which is higher than that of that of WO{sub 3} (1.1 mA/cm{sup 2}) and WO{sub 3}/Bi{sub 2}MoO{sub 6} (1.5 mA/cm{sup 2}).

  15. Dye sensitized photoelectrochemical immunosensor for the tumor marker CEA by using a flower-like 3D architecture prepared from graphene oxide and MoS2.

    Science.gov (United States)

    Song, Kaijing; Ding, Chuanmin; Zhang, Bing; Chang, Honghong; Zhao, Zhihuan; Wei, Wenlong; Wang, Junwen

    2018-06-01

    The authors describe a dye-sensitized photoelectrochemical immunoassay for the tumor marker carcinoembryonic antigen (CEA). The method employs the rhodamine dye Rh123 with red color and absorption maximum at 500 nm for spectral sensitization, and a 3D nanocomposite prepared from graphene oxide and MoS 2 acting as the photoelectric conversion layer. The nanocomposite with flower-like 3D architectures was characterized by transmission electron microscopy, scanning electron microscopy, X-ray powder diffraction, and UV-vis diffuse reflectometry. A photoelectrochemical sandwich immunoassay was developed that is based on the use of the nanocomposite and based on the specific binding of antibody and antigen, and by using a secondary antibody labeled with Rh123 and CdS (Ab 2 -Rh123@CdS). Under optimal conditions and at a typical working voltage of 0 V (vs. Hg/HgCl 2 ), the photocurrent increases linearly 10 pg mL -1 to 80 ng mL -1 CEA concentration range, with a 3.2 pg mL -1 detection limit. Graphical abstract Flower-like GO-MoS 2 complex with high efficiency of electron transport was synthesized to construct photoelectrochemical platform. The sandwich-type immunoassay was built on this platform based on specific binding of antigen and antibody. Carcinoembryonic antigen in sample was detected sensitively by using sensitization of rhodamine dye Rh123 as signal amplification strategy.

  16. Phase formation in the K2MoO4-Lu2(MoO4)3-Hf(MoO4)2 system and the structural study of triple molybdate K5LuHf(MoO4)6

    International Nuclear Information System (INIS)

    Romanova, E.Yu.; Bazarov, B.G.; Tushinova, Yu.L.; Fedorov, K.N.; Bazarova, Zh.G.; Klevtsova, R.F.; Glinskaya, L.A.

    2007-01-01

    Interactions in the ternary system K 2 MoO 4 -Lu 2 (MoO 4 ) 3 -Hf(MoO 4 ) 2 have been studied by X-ray powder diffraction and differential thermal analysis. A new triple (potassium lutetium hafnium) molybdate with the 5 : 1 : 2 stoichiometry has been found. Monocrystals of this molybdate have been grown. Its X-ray diffraction structure has been refined (an X8 APEX automated diffractometer, MoK α radiation, 1960 F(hkl), R = 0.0166). The trigonal unit cell has the following parameters: a = 10.6536(1) A, c = 37.8434(8) A, V=3719.75(9) A, Z = 6, space group R3-bar c. The mixed 3D framework of the structure is built of Mo tetrahedra sharing corners with two independent (Lu,Hf)O 6 octahedra. Two sorts of potassium atoms occupy large framework voids [ru

  17. Probing the Optical Properties and Strain-Tuning of Ultrathin Mo1- xW xTe2.

    Science.gov (United States)

    Aslan, Ozgur Burak; Datye, Isha M; Mleczko, Michal J; Sze Cheung, Karen; Krylyuk, Sergiy; Bruma, Alina; Kalish, Irina; Davydov, Albert V; Pop, Eric; Heinz, Tony F

    2018-04-11

    Ultrathin transition metal dichalcogenides (TMDCs) have recently been extensively investigated to understand their electronic and optical properties. Here we study ultrathin Mo 0.91 W 0.09 Te 2 , a semiconducting alloy of MoTe 2 , using Raman, photoluminescence (PL), and optical absorption spectroscopy. Mo 0.91 W 0.09 Te 2 transitions from an indirect to a direct optical band gap in the limit of monolayer thickness, exhibiting an optical gap of 1.10 eV, very close to its MoTe 2 counterpart. We apply tensile strain, for the first time, to monolayer MoTe 2 and Mo 0.91 W 0.09 Te 2 to tune the band structure of these materials; we observe that their optical band gaps decrease by 70 meV at 2.3% uniaxial strain. The spectral widths of the PL peaks decrease with increasing strain, which we attribute to weaker exciton-phonon intervalley scattering. Strained MoTe 2 and Mo 0.91 W 0.09 Te 2 extend the range of band gaps of TMDC monolayers further into the near-infrared, an important attribute for potential applications in optoelectronics.

  18. Neutron flux stabilization in the NG-150 neutron generators

    International Nuclear Information System (INIS)

    Kuz'min, L.E.; Makarov, S.A.; Pronman, I.M.

    1986-01-01

    Problem of metal tritium target lifetime increase and neutron flux stabilization in the NG-150 neutron generators is studied. Possibility on neutron flux stabilization using the mass analyzer for low-angle (4 deg and 41 deg) mass separation of a beam in thre components, which fall on a target simultaneously, is confirmed experimentally. Basic generator parameters are: accelerating voltage of 150 kV, total beam current on a target of 1.5 mA, beam current density of 0.3-1.6 mA/cm 2 , beam diameter of 8 mm. The initial neutron flux on the targets of 0.73 mg/cm 2 thick constituted 1.1x10 11 ssup(-1). The neutron flux monitoring was accomplished from recoil proton recording by a plastic scintillator. Flux decrease by more than 5% served as a signel for measuring mass analyzer magnetic field providing beam displacement on a target and restoration of the given flux. The NG-150 generator neutron flux stabilization was attained during 2h

  19. The influence of heating rate on reheat-cracking in a commercial 2 1/4Cr1Mo steel

    International Nuclear Information System (INIS)

    Hippsley, C.A.

    1983-03-01

    The effects of elevated heating rate on stress-relief cracking in a commercial 2 1/4 Cr1Mo steel have been investigated. A SEN bend-specimen stress-relaxation test was used to assess reheat cracking susceptibility and fracture mechanisms for an initial post-weld heating rate of 1000 Kh - 1 . Two factors controlling the influence of heating rate on the final severity of cracking were identified, i.e. the rate of stress-relaxation with respect to temperature, and the time available for crack-growth. The factors were found to counteract each other, but in the case of commercial 2 1/4 Cr1Mo steel, the crack-growth factor outweighed the relaxation factor, resulting in a reduction in the propensity to stress-relief cracking at the elevated heating rate. However, by reference to the results of a separate investigation concerning A508/2 MnMoNiCr steel it was demonstrated that the balance between these two factors may be reversed in other alloy systems, with the consequence that reheat cracking is exacerbated by increasing the initial heating rate. A computer model was addressed to the stress-relaxation test conditions using data from the commercial 2 1/4 Cr1Mo steel. The model predictions exhibited reasonable agreement with experimental test results for both 100 Kh - 1 and 1000 Kh - 1 heating rates. (author)

  20. Ultrathin MoS{sub 2} sheets supported on N-rich carbon nitride nanospheres with enhanced lithium storage properties

    Energy Technology Data Exchange (ETDEWEB)

    Chenrayan, Senthil; Chandra, Kishore S.; Manickam, Sasidharan, E-mail: sasidharan.m@res.srmuniv.ac.in

    2017-07-15

    Graphical abstract: We report the construction of N-rich C{sub 3}N{sub 4}/MoS{sub 2} nanospheres from 2D layered materials that serve as potential anode materials for lithium-ion battery delivering a reversible capacity of 857 mAh g{sup −1} at 0.1 C rate and superior rate performance of 383 mAh g{sup −1} at 10 C rate. - Highlights: • 3D N-rich C{sub 3}N{sub 4}@MoS{sub 2} nanospheres scaffolds reported from 2D layered g–C{sub 3}N{sub 4}. • TEM confirmed N-rich spheres coated by MoS{sub 2} sheets forming an interconnected architecture. • N-rich C{sub 3}N{sub 4}@MoS{sub 2} scaffolds were explored as potential anode material for lithium ion batteries. • The electrode exhibited a high reversible discharge capacity of 857 mAh g{sup −1} after 50 repeated cycles. • At 10 C, the electrodes deliver capacity of 383 mAh {sup g−1}, which is superior to the pristine graphite anode. - Abstract: Deciphering the structural and volume changes occurring during electrode reactions in lithium-ion batteries is perhaps a boon for high energy density batteries. Here, we report the synthesis of 3D network of dichalcogenide molybdenum disulfide (MoS{sub 2}) encapsulated over nitrogen rich graphitic carbon nitride nanosphere (g-C{sub 3}N{sub 4}) forming an interconnected and uniform g-C{sub 3}N{sub 4}/MoS{sub 2} scaffolds. The crystallinity, phase purity, morphological features and elemental composition were evaluated through XRD, FESEM, TEM, HRTEM, BET and XPS analyses. The electrochemical properties of N-rich g-C{sub 3}N{sub 4}/MoS{sub 2} scaffolds were investigated as potential anode materials for lithium-ion batteries. Electrochemical testing of the g-C{sub 3}N{sub 4}/MoS{sub 2} constructured electrode delivered reversible capacity of 857 mAh g{sup −1}at 0.1 C rate after fifty cycles and exhibited a high rate performance with reversible capacity of 383 mAh g{sup −1} at 10 C rate (higher than theoretical capacity of graphite, 372 mAh g{sup −1}). The superior

  1. Silica-gel modified with zirconium oxide as a novel 99Mo adsorbent 99mTc generators

    International Nuclear Information System (INIS)

    Salehi, H.; Mollarazi, E.; Abbasi, H.

    2010-01-01

    A new 99 Mo adsorbent has been prepared with modified silica gel with zirconium oxide (SiO 2 /ZrO 2 :Na 2 MoO 4 ) and used in technetium-99m generator. The adsorption behaviors of 99 Mo in the form of molybdate and 99m Tc in the form of pertechnetate on the new adsorbent was investigated showed that the adsorption capacity of molybdate on this generator was considerably higher than the usual generator with alumina column. Coating zirconium oxide on the surface of silica gel resulted in higher 99 Mo adsorption of this compound. 99m Tc is eluted with 0.9% NaCl, and the radionuclidic, radiochemical and chemical purities of the eluate were checked. This generator has a great potential as compared to the traditional alumina generators.

  2. Carbon and Mo transformations during the synthesis of mesoporous Mo2C/carbon catalysts by carbothermal hydrogen reduction

    Science.gov (United States)

    Wang, Haiyan; Liu, Shida; Liu, Bing; Montes, Vicente; Hill, Josephine M.; Smith, Kevin J.

    2018-02-01

    The synthesis of mesoporous Mo2C/carbon catalysts by carbothermal hydrogen reduction is reported. Petroleum coke (petcoke) was activated with KOH at 800 °C to obtain high surface area microporous activated petcoke (APC; 2000 m2/g). The APC was wet impregnated with ammonium heptamolybdate (AHM: 10 wt% Mo), dried and reduced in H2 at temperatures from 400 to 800 °C, to yield Mo2C/APC catalysts. Increased reduction temperature increased the Mo2C yield and the mesoporous volume of the Mo2C/APC. At a reduction temperature of 750 °C the mesopore volume of the catalyst doubled compared to the APC support and accounted for 37% of the total pore volume. Maintaining the final CHR temperature for 90 min further increased the Mo2C yield and mesoporosity of the catalyst. The role of Mo2C in the catalytic hydrogenation of the APC and mesopore generation is demonstrated. The activity of the Mo2C/carbon catalysts in the hydrodeoxygenation of 4-methyl phenol increased with increased CHR temperature and catalyst mesoporosity.

  3. Effect of milking efficiency on Tc-99 content of Tc-99m derived from Tc-99m generators

    International Nuclear Information System (INIS)

    Bonnyman, J.

    1983-01-01

    Tc-99m obtained by separation from its parent Mo-99 always contains Tc-99 produced by decay of Tc-99m and Mo-99. Factors effecting the Tc-99/Tc-99m ratios are discussed. An HPLC method has been developed to measure the 99 TcO 4- content of sodium pertechnetate from generators with a detection limit of 0.9 ng Tc-99 for a 500 μl/ aliquot of TcO 4- -99m. First eluates of 10 chromatograph-ic generators gave Tc-99/Tc-99m ratios ranging from 3.5-46 ng Tc/mCi Tc-99m measured at the time of milking. The measurements indicate that Tc-99/Tc-99m ratios high enough to cause adverse labelling effects could be found in 'instant pertechnetate' and in the first eluate from Tc-99m generators for the activities normally used in radiopharmaceutical production

  4. Theoretical investigation of lithium adsorption, diffusion and coverage on MX2 (M = Mo, W; X = O, S, Se, Te) monolayers

    Science.gov (United States)

    Ersan, F.; Ozaydin, H. D.; Gökoğlu, G.; Aktürk, E.

    2017-12-01

    It is important to improve the high-efficient anode materials for Li batteries, which require the large capacity, high stability and mobility. In this work, we present the adsorption and diffusion properties of lithium atom on MX2 (M = Mo, W; X = O, S, Se, Te) transition metal dichalcogenide structures using first principles calculations within density functional theory. All the MX2 systems considered are semiconductor in bare state with band gaps between 0.93 eV (MoO2) and 1.79 eV (WS2). They turn into metal upon single Li adsorption. Li atom is adsorbed on MoO2 and WO2 rather stronger than other systems. The energy barrier for diffusion of single Li on MX2 varies between 0.15 eV and 0.28 eV which are lower or comparable to that of graphene or silicene. Two Li atoms are preferably adsorbed on MX2 monolayer symmetrically at opposite sides with high adsorption energy. The increasing number of Li atoms does not remarkably affect the adsorption energy per Li atom. This can be attributed to that Li atoms do not accumulate on certain regions of the surface. The systems under investigation provide insights into exploring electronic properties which are rather adequate for possible applications in Li-ion batteries.

  5. Phase equilibria in the Tl2MoO4–R2(MoO43–Zr(MoO42 (R = Al, Cr systems: synthesis, structure and properties of new triple molybdates Tl5RZr(MoO46 and TlRZr0.5(MoO43

    Directory of Open Access Journals (Sweden)

    V. G. Grossman

    2017-12-01

    Full Text Available The Tl2MoO4–R2(MoO43–Zr(MoO42 (R = Al, Cr systems were studied in the subsolidus region using X-ray powder diffraction and differential scanning calorimetric (DSC analysis. Quasi-binary joins were revealed, and triangulation was carried out. New ternary molybdates: Tl5RZr(MoO46 (5:1:2 and TlRZr0.5(MoO43 (1:1:1 (R = Al, Cr were prepared. The unit cell parameters for the new compounds were calculated.

  6. Coaxial MoS2@Carbon Hybrid Fibers: A Low-Cost Anode Material for High-Performance Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Rui Zhou

    2017-02-01

    Full Text Available A low-cost bio-mass-derived carbon substrate has been employed to synthesize MoS2@carbon composites through a hydrothermal method. Carbon fibers derived from natural cotton provide a three-dimensional and open framework for the uniform growth of MoS2 nanosheets, thus hierarchically constructing coaxial architecture. The unique structure could synergistically benefit fast Li-ion and electron transport from the conductive carbon scaffold and porous MoS2 nanostructures. As a result, the MoS2@carbon composites—when serving as anodes for Li-ion batteries—exhibit a high reversible specific capacity of 820 mAh·g−1, high-rate capability (457 mAh·g−1 at 2 A·g−1, and excellent cycling stability. The use of bio-mass-derived carbon makes the MoS2@carbon composites low-cost and promising anode materials for high-performance Li-ion batteries.

  7. Oxidation of atomically thin MoS2 on SiO2

    Science.gov (United States)

    Yamamoto, Mahito; Cullen, William; Einstein, Theodore; Fuhrer, Michael

    2013-03-01

    Surface oxidation of MoS2 markedly affects its electronic, optical, and tribological properties. However, oxidative reactivity of atomically thin MoS2 has yet to be addressed. Here, we investigate oxidation of atomic layers of MoS2 using atomic force microscopy and Raman spectroscopy. MoS2 is mechanically exfoliated onto SiO2 and oxidized in Ar/O2 or Ar/O3 (ozone) at 100-450 °C. MoS2 is much more reactive to O2 than an analogous atomic membrane of graphene and monolayer MoS2 is completely etched very rapidly upon O2 treatment above 300 °C. Thicker MoS2 (> 15 nm) transforms into MoO3 after oxidation at 400 °C, which is confirmed by a Raman peak at 820 cm-1. However, few-layer MoS2 oxidized below 400 °C exhibits no MoO3 Raman mode but etch pits are formed, similar to graphene. We find atomic layers of MoS2 shows larger reactivity to O3 than to O2 and monolayer MoS2 transforms chemically upon O3 treatment even below 100 °C. Work supported by the U. of Maryland NSF-MRSEC under Grant No. DMR 05-20741.

  8. Impact of reduced graphene oxide on MoS{sub 2} grown by sulfurization of sputtered MoO{sub 3} and Mo precursor films

    Energy Technology Data Exchange (ETDEWEB)

    Pacley, Shanee, E-mail: shanee.pacley@us.af.mil; Brausch, Jacob; Beck-Millerton, Emory [U.S. Air Force Research Laboratory (AFRL)/Wright Patterson Air Force Base, Wright Patterson, Ohio 45433-7707 (United States); Hu, Jianjun; Jespersen, Michael [University of Dayton Research Institute, 300 College Park, Dayton, Ohio 45469 (United States); Hilton, Al [Wyle Laboratories, 4200 Colonel Glenn Hwy, Beavercreek, Ohio 45431 (United States); Waite, Adam [University Technology Corporation, 1270 N Fairfield Rd., Beavercreek, Ohio 45432 (United States); Voevodin, Andrey A. [Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle, Denton, Texas 76203 (United States)

    2016-07-15

    Monolayer molybdenum disulfide (MoS{sub 2}), a two dimensional semiconducting dichalcogenide material with a bandgap of 1.8–1.9 eV, has demonstrated promise for future use in field effect transistors and optoelectronics. Various approaches have been used for MoS{sub 2} processing, the most common being chemical vapor deposition. During chemical vapor deposition, precursors such as Mo, MoO{sub 3}, and MoCl{sub 5} have been used to form a vapor reaction with sulfur, resulting in thin films of MoS{sub 2}. Currently, MoO{sub 3} ribbons and powder, and MoCl{sub 5} powder have been used. However, the use of ribbons and powder makes it difficult to grow large area-continuous films. Sputtering of Mo is an approach that has demonstrated continuous MoS{sub 2} film growth. In this paper, the authors compare the structural properties of MoS{sub 2} grown by sulfurization of pulse vapor deposited MoO{sub 3} and Mo precursor films. In addition, they have studied the effects that reduced graphene oxide (rGO) has on MoS{sub 2} structure. Reports show that rGO increases MoS{sub 2} grain growth during powder vaporization. Herein, the authors report a grain size increase for MoS{sub 2} when rGO was used during sulfurization of both sputtered Mo and MoO{sub 3} precursors. In addition, our transmission electron microscopy results show a more uniform and continuous film growth for the MoS{sub 2} films produced from Mo when compared to the films produced from MoO{sub 3}. Atomic force microscopy images further confirm this uniform and continuous film growth when Mo precursor was used. Finally, x-ray photoelectron spectroscopy results show that the MoS{sub 2} films produced using both precursors were stoichiometric and had about 7–8 layers in thickness, and that there was a slight improvement in stoichiometry when rGO was used.

  9. Solid lubricant behavior of MoS2 and WSe2-based nanocomposite coatings

    Science.gov (United States)

    Domínguez-Meister, Santiago; Rojas, Teresa Cristina; Brizuela, Marta; Sánchez-López, Juan Carlos

    2017-12-01

    Tribological coatings made of MoS2 and WSe2 phases and their corresponding combinations with tungsten carbide (WC) were prepared by non-reactive magnetron sputtering of individual targets of similar composition. A comparative tribological analysis of these multiphase coatings was done in both ambient air (30-40% relative humidity, RH) and dry nitrogen (RHgoverns the tribological behavior for each type of environment. This allowed conclusions to be made about the influence of the coating microstructure and composition on the tribological response. The best performance obtained with a WSex film (specific wear rate of 2 × 10-8 mm3 N-1m-1 and a friction coefficient of 0.03-0.05) was compared with that of the well-established MoS2 lubricant material.

  10. Facile one-pot synthesis of CoS{sub 2}-MoS{sub 2}/CNTs as efficient electrocatalyst for hydrogen evolution reaction

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yan-Ru; Hu, Wen-Hui; Li, Xiao [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Dong, Bin, E-mail: dongbin@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Shang, Xiao [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Han, Guan-Qun [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Chai, Yong-Ming [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Yun-Qi, E-mail: liuyq@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Chen-Guang [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China)

    2016-10-30

    Highlights: • Ternary hybrid CoS{sub 2}-MoS{sub 2}/CNTs electrocatalysts have been prepared. • CNTs as support may provide good conductivity and low the agglomeration of MoS{sub 2}. • CoS{sub 2} with intrinsic metallic conductivity may enhance the activity for HER. • Ternary CoS{sub 2}-MoS{sub 2}/CNTs have the better activity and stability for HER. - Abstract: Ternary hybrid cobalt disulfide-molybdenum disulfides supported on carbon nanotubes (CoS{sub 2}-MoS{sub 2}/CNTs) electrocatalysts have been prepared via a simple hydrothermal method. CNTs as support may provide good conductivity and low the agglomeration of layered MoS{sub 2} structure. CoS{sub 2} with intrinsic metallic conductivity may enhance the activity of the ternary hybrid electrocatalysts for hydrogen evolution reaction (HER). X-ray diffraction (XRD) data confirm the formation of ternary hybrid nanocomposites composed of CNTs, CoS{sub 2} and amorphous MoS{sub 2}. Scanning electron microscopy (SEM) images show that strong combination between MoS{sub 2}, CNTs and regular orthohexagonal CoS{sub 2} has been obtained. The dispersion of each component is good and no obvious agglomeration can be observed. It is found that compared with CoS{sub 2}/CNTs and MoS{sub 2}/CNTs, the ternary CoS{sub 2}-MoS{sub 2}/CNTs have the better activity for HER with a low onset potential of 70 mV (vs. RHE) and a small Talel slope of 67 mV dec{sup −1}, and are extremely stable after 1000 cycles. In addition, the optimal doping ratio of Co to Mo is 2:1, which have better HER activity. It is proved that the introduction of carbon materials and Co atoms could improve the performances of MoS{sub 2}-based electrocatalysts for HER.

  11. MoS2 Nanosheets Vertically Grown on Carbonized Corn Stalks as Lithium-Ion Battery Anode.

    Science.gov (United States)

    Ma, Luxiang; Zhao, Binglu; Wang, Xusheng; Yang, Junfeng; Zhang, Xinxiang; Zhou, Yuan; Chen, Jitao

    2018-06-25

    In this study, MoS 2 nanosheets are vertically grown on the inside and outside surfaces of the carbonized corn stalks (CCS) by a simple hydrothermal reaction. The vertically grown structure can not only improve the transmission rate of Li + and electrons but also avoid the agglomeration of the nanosheets. Meanwhile, a new approach of biomass source application is presented. We use CCS instead of graphite powders, which can not only avoid the exploitation of graphite resources, but also be used as a matrix for MoS 2 growth to prevent the electrode from being further decomposed during long cycles and at high current densities. Meanwhile, lithium-ion batteries show remarkable electrochemical performance. They demonstrate a high specific capacity of 1409.5 mA g -1 at 100 mA g -1 in the initial cycle. After 250 cycles, the discharge capacity is still as high as 1230.9 mAh g -1 . Even at 4000 mA g -1 , they show a high specific capacity of 777.7 mAh g -1 . Furthermore, the MoS 2 /CCS electrodes show long cycle life, and the specific capacity is still up to ∼500 mAh g -1 at 5000 mA g -1 after 1000 cycles.

  12. Study of the viability of hydroxyapatite as matrix of the generator 99 Mo/99m Tc

    International Nuclear Information System (INIS)

    Aguilar D, I.C.; Badillo A, V.E.; Monroy G, F.

    2004-01-01

    The generator more used in the nuclear medicine it is the generator 99 Mo / 99 Tc. The separation of 99 Mo and 99m Tc in the commercial generator is carried out on a column that contains alumina (Al 2 0 3 ). The adsorbent proposed in this investigation work, the hydroxyapatite, is an insoluble solid considered within of the fixers of anions more important. To evaluate the efficiency of the hydroxyapatite in the separation of the Mo and the Tc they were carried out preliminary tests to know the likeness of the one been accustomed to by the molybdate ions (MoO 4 -2 ) and the pertechnetate ions (Tc0 4 - ) in function of the value of the p H, in a solution of CaCI 2 0.01 M. For the study of the retention of the molybdate ion, it was used the radioisotope Mo-99 fission product, and for the pertechnetate ion it was used the Tc- 99 m radionuclide son of the Mo-99. The obtained results in a solution of CaCl 2 0.01 M to different values of p H of the solution, show that the fixation of the pertechnetate ions (TcO 4 - ) and the fixation of the molybdate ions (MoO 4 -2 ), they present very different behaviors in the hydroxyapatite. The results indicate that the synthetic hydroxyapatite BIO-RAD retains to the molybdate ion to values of lightly acid p H (5-6), being the retention of the pertechnetate practically worthless. (Author)

  13. Evaluation of '99Mo presence in eluates of 99mTc used in nuclear medicine

    International Nuclear Information System (INIS)

    Ribeiro, Bianca da Silva

    2010-01-01

    Tc-99m is used for diagnostic imaging in nuclear medicine through SPECT technique. It is obtained by the elution of 99 Mo/ 99m Tc generators. During the elution process 99 Mo can be extracted becoming a radionuclidic impurity. One of the quality parameters of the eluate is the radionuclidic purity, MBT (molybdenum break through), defined as the ratio between 99 Mo and 99m Tc activities in the eluate. The North-American and European pharmacopoeias restrict the 99 Mo content, respectively, in 0.015 e 0.1% and, according to the International Atomic Energy Agency (IAEA), the activity ratio at the moment of administration of the radiopharmaceutical to the patient, should not exceed 0.015%. In Brazil, the control of such parameter is not obliged in official regulations. Thus, the objective of this work is to evaluate the occurrence of 99 Mo in 99m Tc eluates. It was initially optimized a methodology to determine the activity of 99 Mo in eluate samples. Efficiency curves were obtained for a NaI (Tl) 8'' x 4'' scintillation detector installed at the In Vivo Monitoring Laboratory (LABMIV-IRD). The methodology has been validated through the measurement of a 99 Mo standard liquid source calibrated at the National Metrology Laboratory for Ionizing Radiation (LNMRI-IRD). The samples analyzed in this work were gently supplied by 5 Nuclear Medicine Clinics located in the city of Rio de Janeiro. The activities of 99 mTc and 99 Mo in those samples have been measured respectively at the clinics and at the LABMIV. By applying a standardized methodology, the ration between the activities were calculated. The results show that 147 out of 174 samples presented 99 Mo activities above the minimum detectable activity of the technique. On the other hand, only 2 out of 147 samples surpassed the MBT limit suggested by the IAEA and have been detected in samples eluted from generators of 750 mCi. In one of the samples, eluted from a generator of 1000 mCi, the calculated MBT value was very close

  14. Morphology-dependent electrocatalytic performance of Fe2(MoO43 for electro-oxidation of methanol in alkaline medium

    Directory of Open Access Journals (Sweden)

    Daoming Zhang

    2017-06-01

    Full Text Available Electrochemically synthesized nanosphere, nanorod and nanotube Fe2(MoO43 at optimized temperature and current density are characterized with XRD, SEM, TEM, XPS. Crystal lattices of the three types Fe2(MoO43 detected by HRTEM are well matched with the simulation analysis results from Materials Studio 6.0 based on the inorganic crystal structure database (ICSD data and the modified XRD lattice parameters. The ratios of Fe/Mo on the surface resulted from XPS analysis are 1.47, 1.63 and 2.22 respectively for nanosphere, nanorod and nanotube. The mixture of Fe2(MoO43 with polytetrafluoroethylene dispersion are coated on glass carbon substrate as electrode for electrocatalytic performance test by cyclic voltammetries in 0.1 mol/L KOH and 1 mol/L methanol electrolyte. Methanol oxidation peak current density of the Nanotube- Fe2(MoO43/GCEs electrode is 3.27 mA/cm2 higher than 2.8 mA/cm2 of platinum foil electrode, which shows enhanced catalytic activity of Nanotube-Fe2(MoO43/GCEs. The cyclic stability in terms of peak current retention are 91%, 92% and 88% respectively for Nanosphere-Fe2(MoO43/GCE, Nanorod-Fe2(MoO43/GCE and Nanotube-Fe2(MoO43/GCE electrode after 220 cycles. It is concluded that nanosized Fe2(MoO43 could be promising alternative non-noble electro-catalysts for electro-oxidation of methanol in alkaline medium.

  15. Tm-doped fiber laser mode-locking with MoS2-polyvinyl alcohol saturable absorber

    Science.gov (United States)

    Cao, Liming; Li, Xing; Zhang, Rui; Wu, Duanduan; Dai, Shixun; Peng, Jian; Weng, Jian; Nie, Qiuhua

    2018-03-01

    We have designed an all-fiber passive mode-locking thulium-doped fiber laser that uses molybdenum disulfide (MoS2) as a saturable absorber (SA) material. A free-standing few-layer MoS2-polyvinyl alcohol (PVA) film is fabricated by liquid phase exfoliation (LPE) and is then transferred onto the end face of a fiber connector. The excellent saturable absorption of the fabricated MoS2-based SA allows the laser to output soliton pulses at a pump power of 500 mW. Fundamental frequency mode-locking is realized at a repetition frequency of 13.9 MHz. The central wavelength is 1926 nm, the 3 dB spectral bandwidth is 2.86 nm and the pulse duration is 1.51 ps. Additionally, third-order harmonic mode-locking of the laser is also achieved. The pulse duration is 1.33 ps, which is slightly narrower than the fundamental frequency mode-locking bandwidth. The experimental results demonstrate that the few-layer MoS2-PVA SA is promising for use in 2 μm laser systems.

  16. Influence of the electrolyte in the fixation of {sup 99} Mo in hydroxyapatite as matrix of the {sup 99} Mo/ {sup 99m} Tc generator; Influencia del electrolito en la fijacion de {sup 99} Mo en hidroxiapatita coma matriz del generador {sup 99} Mo/ {sup 99m} Tc

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez G, S.; Badillo A, V.E. [UAZ, Zacatecas (Mexico); Monroy G, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: s_vazgro@hotmail.com

    2005-07-01

    The more used isotope at the moment in the services of nuclear medicine in the world is the technetium-99m. The {sup 99m} Tc emitts gamma rays of 141 keV and it semi disintegration period is of six hours, given it short half life, to produce it is necessary to order generators that are systems that allow to separate periodically at the {sup 99m}Tc of the {sup 99} Mo by means of chromatographic techniques. In this work it is sought to evaluate the use of the hydroxyapatite, to separate molybdates {sup 99} MoO{sub 4}{sup 2} of pertechnetates {sup 99m}TcO{sub 4}{sup -} and to be able to determine if it is feasible their use for to build generators of {sup 99m} Tc. With this purpose preliminary tests to know the likeness of the hydroxyapatite for the molybdates in function of the pH value, in different solutions were carried out: one of NaCl 0.9%, NaCl 2% and CaCl{sub 2} 0.01 M. The obtained results in a NaCl 0.9% solution and at to 2% to different pH values of the solution, shows that the fixation of the molybdate ions (MoO{sub 4}{sup -2}) it is worthless to basic pH values of (9-11), as long as in solution of CaCI{sub 2} 0.01 M show a considerable retention of molybdate ions. (Author)

  17. Structural and electrochemical properties of single crystalline MoV 2O8 nanowires for energy storage devices

    KAUST Repository

    Shahid, Muhammad; Liu, Jingling; Ali, Zahid; Shakir, Imran; Warsi, Muhammad Farooq

    2013-01-01

    We report the synthesis of MoV2O8 nanowires of high quality using spin coating followed by the thermal annealing process. Transmission electron microscopy (TEM) reveals the average diameter of synthesized nanowire about 100 nm, and average length ranges from 1 to 5 μm. The TEM analysis further confirms the <001> growth direction of MoV 2O8 nanowires. The electrochemical properties of synthesized nanowires using cyclic voltammetry show the specific capacitance 56 Fg-1 at the scan rate of 5 mV s-1 that remains 24 Fg -1 at 100 mV s-1. The electrochemical measurements suggest that the MoV2O8 nanowires can be used as a material for the future electrochemical capacitors (energy storage devices). © 2012 Published by Elsevier Inc. All rights reserved.

  18. Structural and electrochemical properties of single crystalline MoV 2O8 nanowires for energy storage devices

    KAUST Repository

    Shahid, Muhammad

    2013-05-01

    We report the synthesis of MoV2O8 nanowires of high quality using spin coating followed by the thermal annealing process. Transmission electron microscopy (TEM) reveals the average diameter of synthesized nanowire about 100 nm, and average length ranges from 1 to 5 μm. The TEM analysis further confirms the <001> growth direction of MoV 2O8 nanowires. The electrochemical properties of synthesized nanowires using cyclic voltammetry show the specific capacitance 56 Fg-1 at the scan rate of 5 mV s-1 that remains 24 Fg -1 at 100 mV s-1. The electrochemical measurements suggest that the MoV2O8 nanowires can be used as a material for the future electrochemical capacitors (energy storage devices). © 2012 Published by Elsevier Inc. All rights reserved.

  19. Design of a type - a transport package for 99Mo-99mTc Coltech generator

    International Nuclear Information System (INIS)

    Kothalkar, Chetan; Suryanarayana, G.V.; Dey, A.C.; Sachdev, S.S.; Choughule, N.; Murali, S.

    2012-01-01

    BRIT is launching a new product called 99 Mo- 99m Tc Coltech generator. The Coltech generator is a devise designed for the transport of 99 Mo radioisotope adsorbed on the acidic alumina in a sealed glass column (max dimensions: 13 mm diameter, 70 mm height) as the primary containment. At hospital end, 99m Tc, the daughter product of 99 Mo, can be eluted out from the generator using saline. The active column is fitted with a leak proof network of stainless steel needles. The glass column carrying 99 Mo is housed inside a lead shielding having minimum thickness of 50 mm all around, which serves as secondary containment. The shielding is housed inside the ABS shell which acts as tertiary containment, also provides protection to the needles, filters etc. Total weight of the generator is 16 kg. Based on the AERB code SC/TR-1 (being revised), 99 Mo- 99m Tc Coltech generator will be transported in a Type-A transport container. A transport package has been designed by following the code SC/TR-1. Principle design of the package is based on the package for transportation of the similar generator produced by POLATOM, Poland and the package is approved by the Polish regulatory authority. Components are manufactured locally taking care of lndian conditions. The package comprised of a MS drum (HOBBOCK) with tamper proof lockable MS lid and a handle to assist in lifting. For absorbing the shock during transportation, the generator assembly is packed inside the two pieces EPS top and bottom support. The package has been designed for transportation by all modes of transport. Since radioactive material is solid in form and sealed a glass column, it has been designed to sustain a free drop test of 1.2 m, in addition to other tests specified in SC/TR-1. During trial batches upto ∼ 1 Ci of 99 Mo generators were produced, packed in the same Type-A package and supplied to local nuclear medicine center RMC, Mumbai in BRIT vehicle in consultation with AERB. The radiometry of the packages

  20. Large-area snow-like MoSe2 monolayers: synthesis, growth mechanism, and efficient electrocatalyst application.

    Science.gov (United States)

    Huang, Jingwen; Liu, Huiqiang; Jin, Bo; Liu, Min; Zhang, Qingchun; Luo, Liqiong; Chu, Shijin; Chu, Sheng; Peng, Rufang

    2017-07-07

    This study explores the large-area synthesis of controllable morphology, uniform, and high-quality monolayer. MoSe 2 is essential for its potential application in optoelectronics, photocatalysis, and renewable energy sources. In this study, we successfully synthesized snow-like MoSe 2 monolayers using a simple chemical vapor deposition method. Results reveal that snow-like MoSe 2 is a single crystal with a hexagonal structure, a thickness of ∼0.9 nm, and a lateral dimension of up to 20 μm. The peak position of the photoluminescence spectra is ∼1.52 eV corresponding to MoSe 2 monolayer. The growth mechanism of the snow-like MoSe 2 monolayer was investigated and comprised a four-step process during growth. Finally, we demonstrate that the snow-like MoSe 2 monolayers are ideal electrocatalysts for hydrogen evolution reactions (HERs), reflected by a low Tafel slope of ∼68 mV/decade. Compared with the triangular-shaped MoSe 2 monolayer, the hexangular snow-like shape with plentiful edges is superior for perfect electrocatalysts for HERs or transmission devices of optoelectronic signals.

  1. M(4-PridinkarboksialdehidNi(CN4.nG Hofmann Tipi Konak-Konuk Bileşiklerinin Kırmızıaltı Spektroskopik Özelliklerinin İncelenmesi (M = Ni, Cd ve G = 1,4-Dioksan

    Directory of Open Access Journals (Sweden)

    Zeki KARTAL

    2014-12-01

    M(4-PyridinecarboxaldehydeNi(CN4.nG Hofmann Type Clathrates (M = Ni, Cd and G = 1,4-Dioxane Abstract: In this study, clathrate of 4-pyridinecarboxaldehyde tetracyanonickel-dioxane, given by the formula M(4-PyridinecarboxaldehydeNi(CN4 nG (m = Ni, Cd and G = 1,4-dioxane, is obtained for the first time through chemical methods. The FT-IR spectroscopic data in the region of (3000–400 cm-1 was recorded and the IR vibrational modes frequencies were given and explained in detail. The spectral analyzes results of the newly synthesized clathrate of 4-pyridinecarboxaldehyde tetracyanonickel- dioxane suggests that these clathrates are new examples of the Hofmann-type dioxane clathrates. In our study, the Hofmann-type dioxane clathrates formed by bounding electrons of nitrogen-donor atom of pyridine ring and electrons of oxygen-donor atom of aldehyde group (-CH=O of 4-pyridinecarboxaldehyde ligand molecule to transition metal atoms consist of the corrugated |M–Ni(CN4|ï‚¥ polymeric layers which are held in parallel through the chain of (–M–4PCA–M–. Key words: Infrared Spectroscopy, Hofmann Types Clathrates, Tetracyanonickelate, 4-pyridinecarboxaldehyde, 1,4-dioxane

  2. Quality control studies of {sup 99}Mo used in {sup 99}Mo/{sup 99m}Tc generators produced at IPEN/CNEN-SP, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Said, Daphne S.; Brambilla, Tania P.; Matsuda, Margareth M.N.; Osso Junior, Joao A., E-mail: daphnesaid@usp.br, E-mail: taniabrambilla@yahoo.com.br, E-mail: mmatsuda@ipen.br, E-mail: jaosso@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    {sup 99m}Tc is the most used radionuclide in nuclear medicine. In Brazil, the {sup 99}Mo/{sup 99m}Tc generators are produced exclusively by the Center of Radiopharmacy at IPEN-CNEN/SP, by importing {sup 99}Mo from different suppliers. {sup 99}Mo (t{sub 1/2} = 66 h) is a fission product of {sup 235}U, therefore, it can be accompanied by several radioisotopes that are highly prejudicial for human health, demanding a strict quality control of this product for generators safe use. The European Pharmacopoeia established some parameters and limits that evaluate the quality of the solution of sodium [{sup 99}Mo]molybdate, that is used as raw material for generator's production. The European Pharmacopoeia also recommends some analytical methods to perform these evaluations, however, it has been observed difficulties on the implementation of these methods by the generator's producers. These difficulties are probably related to the lack of practicability of the proposed methods and the extensive list of utilized reagents. In this work some procedures of the European Pharmacopoeia's quality control method for {sup 99}Mo were evaluated. Different types of solid phase exchanger cartridges were tested for retention of {sup 99}Mo in 3 different conditions. Cartridges that presented percentages of retention higher than 90% were also tested for separation of {sup 99}Mo from possible contaminants (Ru e Te). The results shown that solid phase exchanger cartridges that presented percentages of retention of Mo higher than 90% also presented significant percentages of retention of Ru and Te. An alternative method for separation of {sup 99}Mo from {sup 131}I (other contaminant) are also proposed. (author)

  3. Study of the viability of hydroxyapatite as matrix of the generator {sup 99} Mo/{sup 99m} Tc; Estudio de la viabilidad de la hidroxiapatita como matriz del generador {sup 99} Mo/{sup 99m} Tc

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar D, I.C.; Badillo A, V.E. [UAZ, Unidad Academica de Ciencias Quimicas, 98600 Guadalupe, Zacatecas (Mexico); Monroy G, F. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail: itzelaguilar@hotmail.com

    2004-07-01

    The generator more used in the nuclear medicine it is the generator {sup 99} Mo / {sup 99} Tc. The separation of {sup 99}Mo and {sup 99m}Tc in the commercial generator is carried out on a column that contains alumina (Al{sub 2}0{sub 3}). The adsorbent proposed in this investigation work, the hydroxyapatite, is an insoluble solid considered within of the fixers of anions more important. To evaluate the efficiency of the hydroxyapatite in the separation of the Mo and the Tc they were carried out preliminary tests to know the likeness of the one been accustomed to by the molybdate ions (MoO{sub 4}{sup -2}) and the pertechnetate ions (Tc0{sub 4}{sup -}) in function of the value of the p H, in a solution of CaCI{sub 2} 0.01 M. For the study of the retention of the molybdate ion, it was used the radioisotope Mo-99 fission product, and for the pertechnetate ion it was used the Tc- 99 m radionuclide son of the Mo-99. The obtained results in a solution of CaCl{sub 2} 0.01 M to different values of p H of the solution, show that the fixation of the pertechnetate ions (TcO{sub 4}{sup -}) and the fixation of the molybdate ions (MoO{sub 4}{sup -2}), they present very different behaviors in the hydroxyapatite. The results indicate that the synthetic hydroxyapatite BIO-RAD retains to the molybdate ion to values of lightly acid p H (5-6), being the retention of the pertechnetate practically worthless. (Author)

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

    Science.gov (United States)

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

    2018-05-01

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

  5. 99Mo-99mTc production development by (n, γ) reaction

    International Nuclear Information System (INIS)

    Izumo, Hironobu; Nishikata, Kaori; Kimura, Akihiro; Tanimoto, Masataka; Tsuchiya, Kunihiko; Ishihara, Masahiro; Kaminaga, Masanori

    2012-01-01

    The renewed JMTR will be started from the later half of JFY2012, and it is expected to various fields. Supply of 99 Mo in Japan depends only on imports from foreign countries. JAEA has a plan to produce 99 Mo, a parent nuclide of 99m Tc. JMTR will contribute to produce 99 Mo by (n, r) method as one of effective uses of the JMTR. In this paper, outline of the technical study items for production method of 99 Mo- 99m Tc in JMTR will be described. (author)

  6. Low-frequency 1/f noise in MoS{sub 2} transistors: Relative contributions of the channel and contacts

    Energy Technology Data Exchange (ETDEWEB)

    Renteria, J.; Jiang, C. [Nano-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California – Riverside, Riverside, California 92521 (United States); Samnakay, R. [Materials Science and Engineering Program, Bourns College of Engineering, University of California – Riverside, Riverside, California 92521 (United States); Rumyantsev, S. L. [Department of Electrical, Computer, and Systems Engineering, Center for Integrated Electronics, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Ioffe Physical-Technical Institute, St. Petersburg 194021 (Russian Federation); Goli, P.; Balandin, A. A., E-mail: balandin@ee.ucr.edu [Nano-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California – Riverside, Riverside, California 92521 (United States); Materials Science and Engineering Program, Bourns College of Engineering, University of California – Riverside, Riverside, California 92521 (United States); Shur, M. S. [Department of Electrical, Computer, and Systems Engineering, Center for Integrated Electronics, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2014-04-14

    We report on the results of the low-frequency (1/f, where f is frequency) noise measurements in MoS{sub 2} field-effect transistors revealing the relative contributions of the MoS{sub 2} channel and Ti/Au contacts to the overall noise level. The investigation of the 1/f noise was performed for both as fabricated and aged transistors. It was established that the McWhorter model of the carrier number fluctuations describes well the 1/f noise in MoS{sub 2} transistors, in contrast to what is observed in graphene devices. The trap densities extracted from the 1/f noise data for MoS{sub 2} transistors, are 2 × 10{sup 19} eV{sup −1}cm{sup −3} and 2.5 × 10{sup 20} eV{sup −1}cm{sup −3} for the as fabricated and aged devices, respectively. It was found that the increase in the noise level of the aged MoS{sub 2} transistors is due to the channel rather than the contact degradation. The obtained results are important for the proposed electronic applications of MoS{sub 2} and other van der Waals materials.

  7. Radionuclidic contamination of 99Mo, 131I and 103Ru in the eluate of 99Mo-99mTc chromatographic generator: comparision on fission produced 99Mo from RPC, Nordio and ARI

    International Nuclear Information System (INIS)

    Soenarjo, Sunarhadijoso; Gunawan, Adang Hardi

    1996-01-01

    The 99 Mo- 99m Tc Chromatographic generators is the most popular system to provide 99m Tc medical radioisotope. Radioisotope Production Centre (RPC)- BATAN has routinely produced the generator loaded with 99 Mo prepared by 235 U fission. By using fission produced 99 Mo, the resulting 99m Tc is potentially contaminated by other fission products which are difficult to eliminate completely. In order to study the characteristic of the generator and radionuclidic impurity pattern of the 99m Tc eluates, an evaluation of gamma spectrometric determination has been carried out. The bulk solutions of 99 Mo produced by RPC BATAN (Indonesia), Nordion (Canada) and ARI (Australia) were loaded to generators manufactured between July 1993 to May 1994. The saline-eluate 99m Tc, in a total volume of 10 ml each, was subjected to gamma spectrometric determination. The radiation of 99m Tc was eliminated by lead shield of 0.6913 cm thickness. The 99m Tc yield fluctuation from 28 generators indicated that the characteristics of the generator columns were very good. The 99m Tc eluates were consistently contaminated by 99 Mo, 131 I and 103 Ru, although the contamination level in all cases did not exceed the maximum permissible levels. The fluctuation of radionuclidic impurities were probably caused by variation in the irradiation parameter or by variation in the 99 Mo separation methods. (author), 23 refs, 1 tab, 3 figs

  8. Edge-rich MoS_2 Naonosheets Rooting into Polyaniline Nanofibers as Effective Catalyst for Electrochemical Hydrogen Evolution

    International Nuclear Information System (INIS)

    Zhang, Nan; Ma, Weiguang; Wu, Tongshun; Wang, Haoyu; Han, Dongxue; Niu, Li

    2015-01-01

    Graphical abstract: For the first time polyaniline (PANI) was employed as an admirable substrate to construct the hierarchical integrative hybrid with MoS_2 (MoS_2/PANI) for hydrogen evolution reaction (HER), which achieved great active edges exposure and excellent HER performance. - Highlights: • PANI is first applied as the support of MoS_2 for enhanced HER performance. • Great active edges exposure of the hybrid significantly benefits the HER activity. • Superior HER activity and excellent stability of MoS_2/PANI have been achieved. - Abstract: Conductive polymer polyaniline (PANI) with abundant protonated sites which are beneficial to hydrogen evolution reaction (HER), was applied as the support of MoS_2 for enhanced HER performance for the first time. The novel three dimensional (3D) HER catalyst (MoS_2/PANI) was constructed with two dimensional (2D) MoS_2 building blocks rooting into the integrative nanowires. PANI nanofibers acted as excellent substrates for the uniform, dense and approximate vertical growth of MoS_2 nanosheets exposing abundant active edges. Consequently, excellent HER performance has been achieved with a low onset overpotential of 100 mV and a small Tafel slope of 45 mV dec"−"1. Most importantly, it only needed 200 and 247 mV overpotential to reach the current density of 30 and 100 mA/cm"2 respectively. Additionally, MoS_2/PANI has achieved superior stability over other MoS_2-polymer-based HER electrocatalyst. In general, for the first time, employing PANI for the construction of the edge-rich integrative hybrid has successfully achieved an outstanding HER performance.

  9. Influence of the electrolyte in the fixation of 99 Mo in hydroxyapatite as matrix of the 99 Mo/ 99m Tc generator

    International Nuclear Information System (INIS)

    Vazquez G, S.; Badillo A, V.E.; Monroy G, F.

    2005-01-01

    The more used isotope at the moment in the services of nuclear medicine in the world is the technetium-99m. The 99m Tc emitts gamma rays of 141 keV and it semi disintegration period is of six hours, given it short half life, to produce it is necessary to order generators that are systems that allow to separate periodically at the 99m Tc of the 99 Mo by means of chromatographic techniques. In this work it is sought to evaluate the use of the hydroxyapatite, to separate molybdates 99 MoO 4 2 of pertechnetates 99m TcO 4 - and to be able to determine if it is feasible their use for to build generators of 99m Tc. With this purpose preliminary tests to know the likeness of the hydroxyapatite for the molybdates in function of the pH value, in different solutions were carried out: one of NaCl 0.9%, NaCl 2% and CaCl 2 0.01 M. The obtained results in a NaCl 0.9% solution and at to 2% to different pH values of the solution, shows that the fixation of the molybdate ions (MoO 4 -2 ) it is worthless to basic pH values of (9-11), as long as in solution of CaCI 2 0.01 M show a considerable retention of molybdate ions. (Author)

  10. Supercapacitive properties of hydrothermally synthesized sphere like MoS2 nanostructures

    International Nuclear Information System (INIS)

    Krishnamoorthy, Karthikeyan; Veerasubramani, Ganesh Kumar; Radhakrishnan, Sivaprakasam; Kim, Sang Jae

    2014-01-01

    Highlights: • MoS 2 nanostructures were synthesized by hydrothermal method. • Randomly stacked MoS 2 was obtained. • FE-SEM studies show the sphere like morphology of MoS 2 . • Specific capacitance of 92.85 F/g was achieved using charge–discharge analysis. • MoS 2 electrode shows capacitance retention of about 93.8% after 1000 cycles. - Abstract: In this communication, we have investigated the supercapacitive behaviour of MoS 2 nanostructures prepared by a facile one-pot hydrothermal approach using ammonium heptamolybdate and thiourea as starting materials. The X-ray diffraction study revealed the formation of randomly stacked layers of MoS 2 . The field-emission scanning electron microscope studies suggested the formation of sphere like MoS 2 nanostructures and a plausible mechanism for the formation of the obtained structure is discussed. The cyclic voltammetry study shows the typical rectangular shaped curves with a specific capacitance of 106 F/g at a scan rate of 5 mV/s. Galvanostatic charge–discharge measurements suggested the maximum specific capacitance of about 92.85 F/g at discharge current density of 0.5 mA/cm 2 . Cyclic stability tests revealed the capacitance retention of about 93.8% after 1000 cycles suggesting a good cyclic capacity of the prepared MoS 2 . The electrochemical impedance spectroscopic results such as Nyquist and Bode phase angle plots suggested that the hydrothermally synthesized MoS 2 nanostructures will be a suitable candidate for electrochemical supercapacitor applications

  11. Edge Epitaxy of Two-dimensional MoSe2 and MoS2 Nanosheets on One-dimensional Nanowires

    KAUST Repository

    Chen, Junze

    2017-06-05

    Rational design and synthesis of heterostructures based on transition metal dichalcogenides (TMDs) have attracted increasing interests because of their promising applications in electronics, catalysis, etc. However, the construction of epitaxial heterostructures with interface at the edges of TMD nanosheets (NSs) still remains great challenge. Here, we report a strategy for controlled synthesis of a new type of heterostructures in which TMD NSs, including MoS2 and MoSe2, vertically grow along the longitudinal direction of one-dimensional (1D) Cu2-xS nanowires (NWs) in an epitaxial manner. The obtained Cu2-xS-TMD heterostructures with tunable loading amount and lateral size of TMD NSs are achieved by the consecutive growth of TMD NSs on Cu2-xS NWs through the gradually injection of chalcogen precursors. After cation exchange of Cu in Cu2-xS-TMD heterostructures with Cd, the obtained CdS-MoS2 heterostructures remained their original architectures. Compared to the pure CdS NWs, the CdS-MoS2 heterostructures with 7.7 wt% loading of MoS2 NSs exhibit the best performance in the photocatalytic hydrogen evolution reaction with the H2 production rate up to 4,647 μmol·h-1·g-1, about 58 times that catalyzed with pure CdS NWs. Our synthetic strategy opens up a new way for the controlled synthesis of TMD-based heterostructures which could have various promising applications.

  12. K0.78Na0.22MoO2AsO4

    Directory of Open Access Journals (Sweden)

    Ahmed Driss

    2013-08-01

    Full Text Available The title compound, potassium sodium dioxidomolybdenum(VI arsenate, K0.78Na0.22MoO2AsO4, was synthesized by a solid-state reaction route. The structure is built up from corner-sharing MoO6 octahedra and AsO4 tetrahedra, creating infinite [MoAsO8]∞ chains running along the b-axis direction. As, Mo and all but one O atom are on special positions (4c with m symmetry and K (occupancy 0.78 is on a position (4a of -1 in the tunnels. The possible motion of the alkali cations has been investigated by means of the bond-valance sum (BVS model. The simulation shows that the Na+ motion appears to be easier mainly along the b-axis direction. Structural relationships between the different compounds of the AMoO2AsO4 (A = Ag, Li, Na, K, Rb series and MXO8 (M = V; X = P, As chains are discussed.

  13. Susceptibility of 2 1/4 Cr-1Mo steel to liquid metal induced embrittlement by lithium-lead solutions

    International Nuclear Information System (INIS)

    Eberhard, B.A.; Edwards, G.R.

    1984-08-01

    An investigation has been conducted on the liquid metal induced embrittlement susceptibility of 2 1/4Cr-1Mo steel exposed to lithium and 1a/o lead-lithium at temperatures between 190 0 C and 525 0 C. This research was part of an ongoing effort to evaluate the compatibility of liquid lithium solutions with potential fusion reactor containment materials. Of particular interest was the microstructure present in a weld heat-affected zone, a microstructure known to be highly susceptible to corrosive attack by liquid lead-lithium solutions. Embrittlement susceptibility was determined by conducting tension tests on 2 1/4Cr-1Mo steel exposed to an inert environment as well as to a lead-lithium liquid and observing the change in tensile behavior. The 2 1/4Cr-1Mo steel was also given a base plate heat treatment to observe its embrittlement susceptibility to 1a/o lead-lithium. The base plate microstructure was severely embrittled at temperatures less than 500 0 C. Tempering the base plate was effective in restoring adequate ductility to the steel

  14. Carbon transfer between 2 1/4 Cr 1 Mo alloy and austenitic steels (experiments in anisothermal loops)

    International Nuclear Information System (INIS)

    Baque, P.; Besson, M.; Champeix, L.; Donati, J.R.; Oberlin, C.; Saint-Paul, P.

    1976-01-01

    Studies on carbon transfer between the ferritic steel 2 1/4 Cr 1 Mo and the austenitic steels 316L and 321H have shown that there is not any measurable carbon transfer in the operating conditions of the secondary circuit of PHENIX (475 deg C was the maximal temperature of the 2 1/4 Cr 1 Mo steel). A significant carbon transfer has been observed between the ferritic steel and the 316L steel when the 321H was replaced by the 2 1/4 Cr 1 Mo steel in the same thermohydraulic conditions (the ferritic steel was then used up to 545 deg C). This experiment has demonstrated the importance of the temperature and the initial carbon content of the ferritic steel as parameters in the decarburization process. It appears that decarburization may not be sensitive to the thermohydraulic conditions at least in the range investigated in those experiments. In the other hand the 316L steel is observed to have been carburized, the degree of carburization remaining appreciably constant and independent on the temperature between 400 deg C and 550 deg C [fr

  15. Production of 95mTc with proton bombardment of 95Mo

    International Nuclear Information System (INIS)

    Izumo, M.; Matsuoka, H.; Sorita, T.; Nagame, Y.; Sekine, T.; Hata, K.; Baba, S.

    1991-01-01

    Formation cross sections of 95m Tc and 95g Tc via the 95 Mo (p,n) reaction have been measured to evaluate the production yield of 95m Tc which is expected to be a useful radiotracer of technetium isotopes. It was found from the cross section data that for incident proton energies above 15 MeV, the thick-target yield of 95m Tc was more than 20 μCi/μAh at the end of bombardment and the 95g Tc contamination was less than 1% after 12 d cooling. To examine the separation and purification of 95m Tc from target, we have carried out a test production of 95m Tc using a thick 95 Mo-enriched target. Other reactions of producing 95m Tc are compared and discussed in terms of the production yield and amounts of contaminants. (author)

  16. Puuduv lugu, ainult kangelane : Zidane ja kunsti mäng / Zoe Stillpass

    Index Scriptorium Estoniae

    Stillpass, Zoe

    2010-01-01

    Režissööride Philippe Parreno ja Douglas Gordoni film prantsuse jalgpallurist Zinedine Zidanest. Film on 23. aprillil 2005 peetud mäng Real Madridi ja Villareali vahel Madridis, mida filmiti 17 kaameraga, mis kõik olid fokusseeritud Zidane'ile. Helitaust pärineb šoti alternatiivroki bändilt Mogwai

  17. Ternary system of Na2MoO4-Cs2MoO4-MoO3

    International Nuclear Information System (INIS)

    Zueva, V.P.; Shabanova, A.N.; Drobasheva, T.I.

    1982-01-01

    Using the methods of thermal analysis interaction of components in ternary system Na 2 MoO 4 -Cs 2 MoO 4 -MoO 3 has been studied. Crystallization surface consists of nine fields belonging to initial components and compounds of lateral sides. Triangulation of the system is carried out and the character of nonvariant points is clarified, the temperature of 360 deg C corresponds to low-melting eutectics

  18. Status of Tc-99m and 99Mo/99mTc generator production in Bangladesh

    International Nuclear Information System (INIS)

    Abedin, Md. Zainul; Haque, Md. Azizul; Ali, Md. Ramjan; Hossain, Md. Anwar; Razzaque, Md. Abdur; Yasmin, Lyzu; Waheed, M. Fatima; Akhter, Rabeya; Mondal, Rafiuddin

    2007-01-01

    Radioisotope Production Division (RIPD) produced instant technetium-99m by solvent extraction method for several years. On R and D basis, the division produced portable sterile Tc-99m sublimation generator by irradiating titanium molybdate in the reactor. The division produced (4/batch) from imported fission Mo-99 till June 2005. Since August 2005, as per demand of the government hospitals, the division have been producing 12-14 pieces of 15 GBq chromatographic 99m Tc-generators weekly by using the new generator production plant installed last year having online Mo-99 loading system with the of producing 50 generator per batch. Development of PZC and (n,γ) 99 Mo based generator holds potential in Bangladesh. (author)

  19. First-principle study of hydrogenation on monolayer MoS2

    International Nuclear Information System (INIS)

    Xu, Yong; Li, Yin; Chen, Xi; Zhang, Ru; Zhang, Chunfang; Lu, Pengfei

    2016-01-01

    The structural and electronic properties of hydrogenation on 1H-MoS 2 and 1T-MoS 2 have been systematically explored by using density functional theory (DFT) calculations. Our calculated results indicate an energetically favorable chemical interaction between H and MoS 2 monolayer for H adsorption when increasing concentration of H atoms. For 1H-MoS 2 , single H atom adsorption creates midgap approaching the Fermi level which increases the n-type carrier concentration effectively. As a consequence, its electrical conductivity is expected to increase significantly. For 1T-MoS 2 , H atoms adsorption can lead to the opening of a direct gap of 0.13 eV compared to the metallic pristine 1T-MoS 2 .

  20. The Magnaporthe oryzae Alt A 1-like protein MoHrip1 binds to the plant plasma membrane.

    Science.gov (United States)

    Zhang, Yi; Liang, Yingbo; Dong, Yijie; Gao, Yuhan; Yang, Xiufen; Yuan, Jingjing; Qiu, Dewen

    2017-10-07

    MoHrip1, a protein isolated from Magnaporthe oryzae, belongs to the Alt A 1 (AA1) family. mohrip1 mRNA levels showed inducible expression throughout the infection process in rice. To determine the location of MoHrip1 in M. oryzae, a mohrip1-gfp mutant was generated. Fluorescence microscopy observations and western blotting analysis showed that MoHrip1 was both present in the secretome and abundant in the fungal cell wall. To obtain MoHrip1 protein, we carried out high-yield expression of MoHrip1 in Pichia pastoris. Treatment of tobacco plants with MoHrip1 induced the formation of necrosis, accumulation of reactive oxygen species and expression of several defense-related genes, as well as conferred disease resistance. By fusion to green fluorescent protein, we showed that MoHrip1 was able to bind to the tobacco and rice plant plasma membrane, causing rapid morphological changes at the cellular level, such as cell shrinkage and chloroplast disorganization. These findings indicate that MoHrip1 is a microbe-associated molecular pattern that is perceived by the plant immune system. This is the first study on an AA1 family protein that can bind to the plant plasma membrane. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Carbon-based coating containing ultrafine MoO2 nanoparticles as an integrated anode for high-performance lithium-ion batteries

    Science.gov (United States)

    Li, Quanyi; Yang, Qi; Zhao, Yanhong; Wan, Bin

    2017-10-01

    Copper-supported MoO2-C composite as an integrated anode with excellent battery performance was synthesized by a facile knife coating technique followed by heat treatment in a vacuum. The obtained samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermal analysis, nitrogen adsorption and desorption analysis, field emission scanning microscopy (FESEM), and transmission electron microscopy (TEM). The results show the MoO2-C composite coating is comprised of a porous carbon matrix with a pore size of 1-3 nm and ultrafine MoO2 nanoparticles with a size of 5-10 nm encapsulated inside, the coating is tightly attached on the surface of copper foil, and the interface between them is free of cracks. Stable PAN-DMF-H2O system containing ammonium molybdate suitable for knife coating technique and the MoO2-C composite with ultrafine MoO2 nanoparticles encapsulated in the carbon matrix can be prepared through controlling amount of added ammonium molybdate solution. The copper-supported MoO2-C composite coating can be directly utilized as the integrated anode for lithium-ion batteries (LIBs). It delivers a capacity of 814 mA h g-1 at a current density of 100 mA g-1 after 100 cycles without apparent capacity fading. Furthermore, with increase of current densities to 200, 500, 1000, 2000, and 5000 mA g-1, it exhibits average capacities of 809, 697, 568, 383, and 188 mA h g-1. Its outstanding electrochemical performance is attributed to combined merits of integrated anode and structure with ultrafine MoO2 nanoparticles embedded in the porous carbon matrix.

  2. Development of the Mo loading apparatus for adsorbing high level 99Mo to PZC and packing in 99mTc generator column

    International Nuclear Information System (INIS)

    Hishinuma, Yukio; Ohmori, Hiroyuki; Noguchi, Tuneyuki; Tatenuma, Katsuyoshi; Genka, Tsuguo; Machi, Sueo

    2006-01-01

    For developing the automatic system to produce the PZC- 99m Tc generator column based on (n, gamma) method, we developed and fabricated the proto-type apparatus for semi hot test to prepare and pack PZC adsorbed 99 Mo produced by (n, gamma) method into the generator column; PZC is Mo adsorbent with practical performance for (n, gamma) 99m Tc generator with high 99 Mo adsorption and high 99m Tc elution. For conducting the constant supply and delivery of 99m Tc generator, it is necessary to establish the technology of (n, gamma) method 99m Tc generator using PZC and to develop the fabrication system for 99 Mo loading to PZC and packing the 99m Tc generator column. By the reason, we are developing the Mo loading apparatus. In order to automatically conduct the process of 99 Mo adsorption to PZC and PZC- 99 Mo packing into the generator column, based on one channel system developed by JAERI-KAKEN at 3 years ago, an advanced automatic loading system functioned with 8 channels was developed as FNCA project proceeded by the core with Kaken Co. and JAIF for realizing a mass production of 99m Tc generators, and moreover the Japanese patent regarding the PZC- 99m Tc generator including the automatic loading system of 99 Mo to PZC and making 99m Tc generator columns has already been applied with joint applicants of BATAN and Kaken Co. Regarding the multi-type Mo loading apparatus mentioned above, we set it up in a hot of BATAN at December 2003 year. In this report, we will introduce mainly about the multi-channel automatic loading system of 99 Mo. (author)

  3. Piezoelectricity enhancement and bandstructure modification of atomic defect-mediated MoS2 monolayer.

    Science.gov (United States)

    Yu, Sheng; Rice, Quinton; Neupane, Tikaram; Tabibi, Bagher; Li, Qiliang; Seo, Felix Jaetae

    2017-09-13

    Piezoelectricity appears in the inversion asymmetric crystal that converts mechanical deformation to electricity. Two-dimensional transition metal dichalcolgenide (TMDC) monolayers exhibit the piezoelectric effect due to inversion asymmetry. The intrinsic piezoelectric coefficient (e 11 ) of MoS 2 is ∼298 pC m -1 . For the single atomic shift of Mo of 20% along the armchair direction, the piezoelectric coefficient (e 11 ) of MoS 2 with 5 × 5 unit cells was enhanced up to 18%, and significantly modified the band structure. The single atomic shift in the MoS 2 monolayer also induced new energy levels inside the forbidden bandgap. The defect-induced energy levels for a Mo atom shift along the armchair direction are relatively deeper than that for a S atom shift along the same direction. This indicates that the piezoelectricity and band structure of MoS 2 can be engineered by a single atomic shift in the monolayer with multi unit cells for piezo- and opto-electric applications.

  4. Preparation of LiMO2(M=Co,Ni) cathode materials for intermediate temperature fuel cells by sol-gel processes

    DEFF Research Database (Denmark)

    Tao, S.W.; Wu, Q.Y.; Zhan, Z.L.

    1999-01-01

    LiMO2 (M = Co, Ni) was prepared by complexing sol-gel processes. The phase and thermal stability were characterized by XRD and TG analyses. LiCoO2 and LiNiO2 phases are formed around 400 degrees C and 700 degrees C respectively in our synthesis process. LiNiO2 exhibit higher electrical conductivity...

  5. Enhanced performance of lithium-sulfur batteries with an ultrathin and lightweight MoS2/carbon nanotube interlayer

    Science.gov (United States)

    Yan, Lingjia; Luo, Nannan; Kong, Weibang; Luo, Shu; Wu, Hengcai; Jiang, Kaili; Li, Qunqing; Fan, Shoushan; Duan, Wenhui; Wang, Jiaping

    2018-06-01

    Ultrathin and lightweight MoS2/carbon nanotube (CNT) interlayers are developed to effectively trap polysulfides in high-performance lithium-sulfur (Li-S) batteries. The MoS2/CNT interlayer is constructed by loading MoS2 nanosheets onto a cross-stacked CNT film. The CNT film with excellent conductivity and superior mechanical properties provides the Li-S batteries with a uniform conductive network, a supporting skeleton for the MoS2 nanosheets, as well as a physical barrier for the polysulfides. Moreover, chemical interactions and bonding between the MoS2 nanosheets and the polysulfides are evident. The electrode with the MoS2/CNT interlayer delivers an attractive specific capacity of 784 mA h g-1 at a high capacity rate of 10 C. In addition, the electrode demonstrates a high initial capacity of 1237 mA h g-1 and a capacity fade as low as -0.061% per cycle over 500 charge/discharge cycles at 0.2 C. The problem of self-discharge can also be suppressed with the introduction of the MoS2/CNT interlayer. The simple fabrication procedure, which is suitable for commercialization, and the outstanding electrochemical performance of the cells with the MoS2/CNT interlayer demonstrate a great potential for the development of high-performance Li-S batteries.

  6. Labelling of MoAb with 153SmH1ETA: Preliminary results

    International Nuclear Information System (INIS)

    Ferro-Flores, G.; De, F.; Ramirez, M.; Pedraza-Lopez, M.; Tendilla, J.I.; Melendez-Alafort, L.; Murphy, C.A.

    2001-01-01

    A method to label MoAb with Sm-153 using 1,5,9,13-tetraazacyclohexadecane N,N',N'',N''' tetraacetic acid (H 4 ETA) as a bifunctional chelator was developed. H 4 ETA and SmH 1 ETA were synthesized in our laboratory and characterized by IR spectroscopy, TGA (thermogravimetric analysis), SEM (Scattering Electronic Microscopy), EDAX (Elemental Dispersion Analysis by X-rays) and EPR (Electron Paramagnetic Resonance) at 6 K. The 153 SmH 1 ETAMoAb was prepared by a simple incubation of the MoAb ior cea1, and the 153 SmH 1 ETA complex at neutral pH and at room temperature for 24 h. The specific activity of the labelled antibody was 111 MBq/mg (3 mCi/mg). Sm-153(III) is commercially available with specific activities up to 318.2 GBq/mg. Therefore, under the conditions described above 153 SmH 1 ETA labelled MoAb could be obtained with specific activity up to 1.14 GBq/mg (30.7 mCi/mg). (author)

  7. The modulation of Schottky barriers of metal-MoS2 contacts via BN-MoS2 heterostructures.

    Science.gov (United States)

    Su, Jie; Feng, Liping; Zhang, Yan; Liu, Zhengtang

    2016-06-22

    Using first-principles calculations within density functional theory, we systematically studied the effect of BN-MoS2 heterostructure on the Schottky barriers of metal-MoS2 contacts. Two types of FETs are designed according to the area of the BN-MoS2 heterostructure. Results show that the vertical and lateral Schottky barriers in all the studied contacts, irrespective of the work function of the metal, are significantly reduced or even vanish when the BN-MoS2 heterostructure substitutes the monolayer MoS2. Only the n-type lateral Schottky barrier of Au/BN-MoS2 contact relates to the area of the BN-MoS2 heterostructure. Notably, the Pt-MoS2 contact with n-type character is transformed into a p-type contact upon substituting the monolayer MoS2 by a BN-MoS2 heterostructure. These changes of the contact natures are ascribed to the variation of Fermi level pinning, work function and charge distribution. Analysis demonstrates that the Fermi level pinning effects are significantly weakened for metal/BN-MoS2 contacts because no gap states dominated by MoS2 are formed, in contrast to those of metal-MoS2 contacts. Although additional BN layers reduce the interlayer interaction and the work function of the metal, the Schottky barriers of metal/BN-MoS2 contacts still do not obey the Schottky-Mott rule. Moreover, different from metal-MoS2 contacts, the charges transfer from electrodes to the monolayer MoS2, resulting in an increment of the work function of these metals in metal/BN-MoS2 contacts. These findings may prove to be instrumental in the future design of new MoS2-based FETs with ohmic contact or p-type character.

  8. Evaluation of ferritic alloy Fe-2 1/4Cr-1Mo after neutron irradiation: Microstructural development

    International Nuclear Information System (INIS)

    Gelles, D.S.

    1986-10-01

    As part of a program to provide a data base on the bainitic alloy Fe-2-1/4-1Mo for fusion energy applications, microstructural examinations are reported for nine specimen conditions for 2-1/4Cr-1Mo steel which had been irradiated by fast neutrons over the temperature range 390 to 510 0 C. Void swelling is found following irradiation at 400 0 C to 480 0 C. Concurrently dislocation structure and precipitation developed. Peak void swelling, void density, dislocation density and precipitate number density formed at the lowest temperature, approximately 400 0 C, whereas mean void size, and mean precipitate size increased with increasing irradiation temperature. The examination results are used to provide interpretation of in-reactor creep, density change and post irradiation tensile behavior

  9. Influence of the Ti concentration and of the Ti:Mo molar ratio, in the efficiency of the {sup 99} Mo - {sup 99m} Tc generator, at basis of gels of titanium molybdates; Influencia de la concentracion de Ti y de la relacion molar Ti:Mo, en la eficiencia del generador {sup 99} Mo - {sup 99m} Tc a base de geles de molibdatos de titanio

    Energy Technology Data Exchange (ETDEWEB)

    Cortes R, O.; Monroy G, F.; Martinez C, T. [Facultad de Quimica, UNAM, 04510 Mexico D.F. (Mexico)]. e-mail: ocielcr@hotmail.com

    2003-07-01

    The {sup 99m} Tc, continues being the radionuclide more used in nuclear medicine to world scale. The production of this radioisotope, is carried out by means of generators {sup 99} Mo/{sup 99m} Tc that get ready commercially with {sup 99} Mo of high specific activity, adsorbed in alumina (2 mg {sup 99} Mo/g alumina) and that they are elutriated every 23 hours. In an alternative way, it is intended to use gels of titanium molybdates, as matrices of this generators. The gels are synthesized starting from solutions of ammonium molybdates and of titanium tetrachloride in aqueous media. These gels allow to incorporate until 25% of molybdenum in their structure, being been able to use {sup 99} Mo of low specific activity that can be obtained starting from the reaction {sup 98} Mo (n, {gamma}) {sup 99} Mo. With the object of producing generators of medium activity, with the base of gels of titanium molybdates, intends in this work, to study the influence of two synthesis parameters of these gels: the concentration of the titanium solutions and the molar ratio Ti: Mo. The decrease of the concentration of the titanium solution, used during the synthesis of the gels, is converted in an efficiency decrease and radionuclide purity of the generators, as well as an increment so much of the volume of elutriation, as of the pH of the elutriates. The gels that contain an major number of titanium moles, regarding the molybdenum moles, present a greater radionuclide purity, but they diminish their efficiency. The best characteristics for the gels synthesis of titanium molybdates are: a molar ratio 1:1 for Ti and Mo, and to use solutions of titanium whose concentration is near at 1 M. (Author)

  10. Synthesis and Characterization of Mixed Chalcogen Triangular Complexes with New Mo-3(mu(3)-S)(mu(2)-Se-2)(3)(4+) and M-3(mu(3)-S)mu(2)-Se)(3)(4+) (M = Mo, W) Cluster Cores

    DEFF Research Database (Denmark)

    Gushchin, Artem; Ooi, Bee Lean; Harris, Pernille

    2009-01-01

    In our pursuit of mixed chalcogen-bridged cluster complexes, solids of the compositions Mo3SSe6Br4 and W3SSe6Br4 were prepared using high-temperature synthesis from the elements. Treatment of Mo3SSe6Br4 with Bu4NBr in a vibration mill yielded (Bu4N)(3)([Mo-3(mu(3)-S)(mu(2)-Se-2)(3)Br-6]Br} (I). Its......), was isolated and its structure determined using X-ray crystallography. W3SSe6Br4 upon reaction with H3PO2 gave a mixture of all of the [W3SxSe4-x(H2O)(9)](4+) species. After repeated chromatography, crystals of {[W-3(mu(3)-S)(mu(2)-Se)(3)(H2O)(7)Cl--(2)](2)CB[6]}Cl-4 center dot 12H(2)O (IV) were crystallized...

  11. Modulated Structures of Homologous Compounds In MO 3(ZnO) m( M=In, Ga; m=Integer) Described by Four-Dimensional Superspace Group

    Science.gov (United States)

    Li, Chunfei; Bando, Yoshio; Nakamura, Masaki; Onoda, Mitsuko; Kimizuka, Noboru

    1998-09-01

    The modulated structures appearing in the homologous compounds InMO3(ZnO)m(M=In, Ga;m=integer) were observed by using a high-resoultion transmission electron microscope and are described based on a four-dimensional superspace group. The electron diffraction patterns for compounds withmlarger than 6 reveal extra spots, indicating the formation of a modulated structure. The subcell structures form=odd and even numbers are assigned to be either monoclinic or orthorhombic, respectively. On the other hand, extra spots can be indexed by one-dimensional modulated structure. The possible space groups for the subcell structure areCm,C2, andC2/mform=odd numbers, while those form=even numbers areCcm21andCcmm, respectively. Then, corresponding possible superspace groups are assigned to bePC2s,PCmoverline1, andPC2/msoverline1for oddmnumbers andPCcm211overline1overline1andPCcmm1overline11for evenmnumbers. Based on the superspace group determination, a structure model for a one-dimensional modulated structure is proposed.

  12. Quality assurance of Mo-99/Tc-99m radionuclide generators

    Science.gov (United States)

    Uzunov, Nikolay; Yordanova, Galina; Salim, Seniha; Stancheva, Natalya; Mineva, Vanya; Meléndez-Alafort, Laura; Rosato, Antonio

    2018-03-01

    Gamma-ray spectrometry analyses of the radionuclide content of eluate from two Mo-99/Tc-99m radionuclide generators POLTECHNET have been performed. The relative activities of 99Mo 103Ru and 131I radioisotopes with respect to the activity of 99mTc at different time intervals after the primary pertechnetate elution of the generators have been analyzed. The relative activities of the isotopes were determined and compared to the radionuclidic purity requirements for 99mTc.

  13. Observation of Vacancies, Faults, and Superstructures in Ln5Mo2O12 (Ln = La, Y, and Lu) Compounds with Direct Mo-Mo Bonding.

    Science.gov (United States)

    Colabello, Diane M; Sobalvarro, Elizabeth M; Sheckelton, John P; Neuefeind, Joerg C; McQueen, Tyrel M; Khalifah, Peter G

    2017-11-06

    Among oxide compounds with direct metal-metal bonding, the Y 5 Mo 2 O 12 (A 5 B 2 O 12 ) structural family of compounds has a particularly intriguing low-dimensional structure due to the presence of bioctahedral B 2 O 10 dimers arranged in one-dimensional edge-sharing chains along the direction of the metal-metal bonds. Furthermore, these compounds can have a local magnetic moment due to the noninteger oxidation state (+4.5) of the transition metal, in contrast to the conspicuous lack of a local moment that is commonly observed when oxide compounds with direct metal-metal bonding have integer oxidation states resulting from the lifting of orbital degeneracy typically induced by the metal-metal bonding. Although a monoclinic C2/m structure has been previously proposed for Ln 5 Mo 2 O 12 (Ln = La-Lu and Y) members of this family based on prior single crystal diffraction data, it is found that this structural model misses many important structural features. On the basis of synchrotron powder diffraction data, it is shown that the C2/m monoclinic unit cell represents a superstructure relative to a previously unrecognized orthorhombic Immm subcell and that the superstructure derives from the ordering of interchangeable Mo 2 O 10 and LaO 6 building blocks. The superstructure for this reason is typically highly faulted, as evidenced by the increased breadth of superstructure diffraction peaks associated with a coherence length of 1-2 nm in the c* direction. Finally, it is shown that oxygen vacancies can occur when Ln = La, producing an oxygen deficient stoichiometry of La 5 Mo 2 O 11.55 and an approximately 10-fold reduction in the number of unpaired electrons due to the reduction of the average Mo valence from +4.5 to +4.05, a result confirmed by magnetic susceptibility measurements. This represents the first observation of oxygen vacancies in this family of compounds and provides an important means of continuously tuning the magnetic interactions within the one

  14. Disposable MoS2-Arrayed MALDI MS Chip for High-Throughput and Rapid Quantification of Sulfonamides in Multiple Real Samples.

    Science.gov (United States)

    Zhao, Yaju; Tang, Minmin; Liao, Qiaobo; Li, Zhoumin; Li, Hui; Xi, Kai; Tan, Li; Zhang, Mei; Xu, Danke; Chen, Hong-Yuan

    2018-04-27

    In this work, we demonstrate, for the first time, the development of a disposable MoS 2 -arrayed matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) chip combined with an immunoaffinity enrichment method for high-throughput, rapid, and simultaneous quantitation of multiple sulfonamides (SAs). The disposable MALDI MS chip was designed and fabricated by MoS 2 array formation on a commercial indium tin oxide (ITO) glass slide. A series of SAs were analyzed, and clear deprotonated signals were obtained in negative-ion mode. Compared with MoS 2 -arrayed commercial steel plate, the prepared MALDI MS chip exhibited comparable LDI efficiency, providing a good alternative and disposable substrate for MALDI MS analysis. Furthermore, internal standard (IS) was previously deposited onto the MoS 2 array to simplify the experimental process for MALDI MS quantitation. 96 sample spots could be analyzed within 10 min in one single chip to perform quantitative analysis, recovery studies, and real foodstuff detection. Upon targeted extraction and enrichment by antibody conjugated magnetic beads, five SAs were quantitatively determined by the IS-first method with the linear range of 0.5-10 ng/mL ( R 2 > 0.990). Good recoveries and repeatability were obtained for spiked pork, egg, and milk samples. SAs in several real foodstuffs were successfully identified and quantified. The developed method may provide a promising tool for the routine analysis of antibiotic residues in real samples.

  15. Diode-pumped orthogonally polarized dual-wavelength Nd3+:LaBO2MoO4 laser

    Science.gov (United States)

    Chen, Y. J.; Gong, X. H.; Lin, Y. F.; Huang, J. H.; Luo, Z. D.; Huang, Y. D.

    2013-08-01

    Polarized spectroscopic properties related to 1.07 μm laser operation of a 1.8 at.% Nd3+:LaBO2MoO4 crystal grown by the Czochralski method were investigated at room temperature. Using a 2.2-mm-thick, Z-cut Nd3+:LaBO2MoO4 crystal as gain medium, orthogonally polarized dual-wavelength laser at 1,068 and 1,074 nm was first realized in a plano-concave resonator end-pumped by a quasi-continuous-wave 795 nm diode laser. A total output peak power of 1.2 W with slope efficiency of 26 % around 1.07 μm was obtained. The influences of resonator length and pump power on output laser wavelength were also investigated.

  16. Influence of the Ti concentration and of the Ti:Mo molar ratio, in the efficiency of the 99 Mo - 99m Tc generator, at basis of gels of titanium molybdates

    International Nuclear Information System (INIS)

    Cortes R, O.; Monroy G, F.; Martinez C, T.

    2003-01-01

    The 99m Tc, continues being the radionuclide more used in nuclear medicine to world scale. The production of this radioisotope, is carried out by means of generators 99 Mo/ 99m Tc that get ready commercially with 99 Mo of high specific activity, adsorbed in alumina (2 mg 99 Mo/g alumina) and that they are elutriated every 23 hours. In an alternative way, it is intended to use gels of titanium molybdates, as matrices of this generators. The gels are synthesized starting from solutions of ammonium molybdates and of titanium tetrachloride in aqueous media. These gels allow to incorporate until 25% of molybdenum in their structure, being been able to use 99 Mo of low specific activity that can be obtained starting from the reaction 98 Mo (n, γ) 99 Mo. With the object of producing generators of medium activity, with the base of gels of titanium molybdates, intends in this work, to study the influence of two synthesis parameters of these gels: the concentration of the titanium solutions and the molar ratio Ti: Mo. The decrease of the concentration of the titanium solution, used during the synthesis of the gels, is converted in an efficiency decrease and radionuclide purity of the generators, as well as an increment so much of the volume of elutriation, as of the pH of the elutriates. The gels that contain an major number of titanium moles, regarding the molybdenum moles, present a greater radionuclide purity, but they diminish their efficiency. The best characteristics for the gels synthesis of titanium molybdates are: a molar ratio 1:1 for Ti and Mo, and to use solutions of titanium whose concentration is near at 1 M. (Author)

  17. Production optimization of {sup 99}Mo/{sup 99m}Tc zirconium molybate gel generators at semi-automatic device: DISIGEG

    Energy Technology Data Exchange (ETDEWEB)

    Monroy-Guzman, F., E-mail: fabiola.monroy@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, 52750, Estado de Mexico (Mexico); Rivero Gutierrez, T., E-mail: tonatiuh.rivero@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, 52750, Estado de Mexico (Mexico); Lopez Malpica, I.Z.; Hernandez Cortes, S.; Rojas Nava, P.; Vazquez Maldonado, J.C. [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, 52750, Estado de Mexico (Mexico); Vazquez, A. [Instituto Mexicano del Petroleo, Eje Central Norte Lazaro Cardenas 152, Col. San Bartolo Atepehuacan, 07730, Mexico D.F. (Mexico)

    2012-01-15

    DISIGEG is a synthesis installation of zirconium {sup 99}Mo-molybdate gels for {sup 99}Mo/{sup 99m}Tc generator production, which has been designed, built and installed at the ININ. The device consists of a synthesis reactor and five systems controlled via keyboard: (1) raw material access, (2) chemical air stirring, (3) gel dried by air and infrared heating, (4) moisture removal and (5) gel extraction. DISIGEG operation is described and dried condition effects of zirconium {sup 99}Mo- molybdate gels on {sup 99}Mo/{sup 99m}Tc generator performance were evaluated as well as some physical-chemical properties of these gels. The results reveal that temperature, time and air flow applied during the drying process directly affects zirconium {sup 99}Mo-molybdate gel generator performance. All gels prepared have a similar chemical structure probably constituted by three-dimensional network, based on zirconium pentagonal bipyramids and molybdenum octahedral. Basic structural variations cause a change in gel porosity and permeability, favouring or inhibiting {sup 99m}TcO{sub 4}{sup -} diffusion into the matrix. The {sup 99m}TcO{sub 4}{sup -} eluates produced by {sup 99}Mo/{sup 99m}Tc zirconium {sup 99}Mo-molybdate gel generators prepared in DISIGEG, air dried at 80 Degree-Sign C for 5 h and using an air flow of 90 mm, satisfied all the Pharmacopoeias regulations: {sup 99m}Tc yield between 70-75%, {sup 99}Mo breakthrough less than 3 Multiplication-Sign 10{sup -3}%, radiochemical purities about 97% sterile and pyrogen-free eluates with a pH of 6. - Highlights: Black-Right-Pointing-Pointer {sup 99}Mo/{sup 99m}Tc generators based on {sup 99}Mo-molybdate gels were synthesized at a semi-automatic device. Black-Right-Pointing-Pointer Generator performances depend on synthesis conditions of the zirconium {sup 99}Mo-molybdate gel. Black-Right-Pointing-Pointer {sup 99m}TcO{sub 4}{sup -} diffusion and yield into generator depends on gel porosity and permeability. Black

  18. Mo-doped V2O5 hierarchical nanorod/nanoparticle core/shell porous microspheres with improved performance for cathode of lithium-ion battery

    Science.gov (United States)

    Yu, Haolin; Zeng, Jianyun; Hao, Wen; Zhou, Peng; Wen, Xiaogang

    2018-05-01

    Mo-doped V2O5 hierarchical nanorod/nanoparticle core/shell porous microspheres (MVHPMs) were prepared via a simple hydrothermal approach using ammonium metavanadate and ammonium molybdate as precursors followed by a thermal annealing process. The samples were characterized by XRD, SEM, TEM, EDS, and XPS carefully; it confirmed that porous microspheres with uniform Mo doping in the V2O5 matrix were obtained, and it contains an inner core self-assembled with 1D nanorods and outer shell consisting of nanoparticles. A plausible growth mechanism of Mo-doped V2O5 (Mo-V2O5) porous microspheres is suggested. The unique microstructure made the Mo-V2O5 hierarchical microspheres a good cathode material for Li-ion battery. The results indicate the synthesized Mo-V2O5 hierarchical microspheres exhibit well-improved electrochemical performance compared to the undoped samples. It delivers a high initial reversible capacity of 282 mAh g-1 at 0.2 C, 208 mAh g-1 at 2 C, and 111 mAh g-1 at 10 C, and it also exhibits good cycling stabilities; a capacity of 144 mAh g-1 is obtained after 200 cycles at 6 C with a capacity retention of > 82%, which is much high than that of pure V2O5 (95 mAh g-1 with a capacity retention of 72%). [Figure not available: see fulltext.

  19. Electronic and magnetic properties of infinite 1D chains of paddlewheel carboxylates M2(COOR)4 (M = Mo, W, Ru, Rh, Ir, Cu)

    KAUST Repository

    Peskov, Maxim

    2013-03-14

    Dinuclear complexes of transition metals bridged by four carboxylate-groups are examples of stable atomic configurations serving as fundamental building blocks of catalysts and prototypical molecular electronic devices. The electronic structure and magnetic properties of many molecular tetracarboxylate complexes were meticulously studied; however, the properties of the one-dimensional (1D) polymeric chain of associated tetracarboxylates have so far evaded much attention. Using periodic density-functional theory calculations, we analyze the electronic structure of condensed tetracarboxylates Mo(II), W(II), Ru(II), Rh(II), Ir(II), and Cu(II). The relationship between crystal structure of the polymerized tetracarboxylates and the electronic properties of the metal-metal bond in the M24+ core is studied. The electronic effects emanating from the association of dinuclear transition metal tetracarboxylates are important for designing molecular electronic devices. In this study, its influence on both direct and indirect metal-metal interactions, and the electronic structure, in particular transport properties, is discussed. © 2013 American Chemical Society.

  20. Fabrication of multilayered-sandwich MoS2/c architectures with advanced lithium storage properties

    International Nuclear Information System (INIS)

    Du, Jinlong; Yang, Zhanxu; Wang, Xiaorong; Qi, Chengyuan; Li, Yue; Mao, Wei; Qiao, Haiyan; Yu, ZongBao; Ren, Tieqiang; Qiao, Qingdong

    2017-01-01

    MoS 2 /C nanocomposite with a multilayered sandwich structure based on few-layered MoS 2 and carbon layers in an alternating sequence, was successfully synthesized through a one-step synchronized carbonization and sulfuration method. The hybrids were characterized by X-ray diffraction, High-resolution transmission electron microscopy, Atomic force microscope, Raman and X-ray photoelectron spectroscopic methods. The as-obtained MoS 2 /C nanocomposite applied as lithium-ion batteries anode materials, showed a high initial discharge and charge capacities of 1678.5 and 1386.0 mAh g −1 , respectively. High specific reversible capacity is maintained at fast C rates, e.g., 1390, 1223, 1017, 566, and 450 mAh g −1 at 0.1C, 0.6C, 3C, 10C and 20C, respectively. The good performance of the composite is mainly attributed to the unique few layered composite architectures, which can improve ion/electron transportation and prevent aggregation and restacking during the lithiation/delithiation process.

  1. Molecules based on M(v) (M=Mo, W) and Ni(II) ions: a new class of trigonal bipyramidal cluster and confirmation of SMM behavior for the pentadecanuclear molecule {NiII[NiII(tmphen)(MeOH)]6[Ni(H2O)3]2[micro-CN]30[WV(CN)3]6}.

    Science.gov (United States)

    Hilfiger, Matthew G; Zhao, Hanhua; Prosvirin, Andrey; Wernsdorfer, Wolfgang; Dunbar, Kim R

    2009-07-14

    The preparation, single crystal X-ray crystallography, and magnetic properties are reported for four new clusters based on [M'V(CN)8]3- octacyanometallates (M'=Mo, W). Reactions of [M'V(CN)8]3- with mononuclear NiII ions in the presence of the tmphen blocking ligand (tmphen=3,4,7,8-tetramethyl-1,10-phenanthroline) in a 2:3:6 ratio, respectively, lead to the formation of the trigonal bipyramidal clusters [NiII(tmphen)2]3[M'V(CN)8]2. Analogous reactions with the same starting materials performed in a 2:3:2 ratio, respectively, produce pentadecanuclear clusters of the type {NiII[NiII(tmphen)(MeOH)]6[Ni(H2O)3]2[micro-CN]30[WV(CN)3]6}. The W2Ni3 (1) and Mo2Ni3(2) pentanuclear clusters and the W6Ni9 (3) and Mo6Ni9 (4) pentadecanuclear molecules are isostructural to each other and crystallize in the space groups P2(1)/c and R3 respectively. Magnetic measurements indicate that the ground states for the trigonal bipyamidal clusters are S=4 as a consequence of ferromagnetic coupling with JW-Ni=9.5 cm(-1), JMo-Ni=10 cm(-1). The pentadecanuclear clusters exhibit ferromagnetic coupling as well, which leads to S=12 ground states (JW-Ni=12 cm(-1), JMo-Ni=12.2 cm(-1)). Reduced magnetization studies on the W-Ni analogues support the conclusion that they exhibit a negative axial anisotropy term; the fits give D values of -0.24 cm(-1) for the W2Ni3 cluster and D=-0.04 cm(-1)for the W6Ni9 cluster. AC susceptibility measurements indicate the beginning of an out-of-phase signal for the W2Ni3 and the W6Ni9 compounds, but detailed low temperature studies on small crystals by the microSQUID technique indicate that only the pentadecanuclear cluster exhibits hysteresis in accord with SMM behavior. Neither Mo cluster reveals any evidence for slow paramagnetic relaxation at low temperatures.

  2. Performance study of molybdenum gels with titanium for preparation of 99Mo-99mTc generators

    International Nuclear Information System (INIS)

    Moraes, Vanessa; Osso Junior, Joao Alberto

    2005-01-01

    99m Tc is the most used radioisotope in Nuclear Medicine, due to nuclear characteristics. It is obtained by the radioactive decay of 99 Mo, generator of radioisotope system. When 99 Mo is produced by the activation in reactor, the most used technique for the preparation of the generators is the gel type generator, which incorporates 99 Mo to the gel that is insoluble, chemically inert to the solutions and with properties of ion exchange. Several countries had already studied this methodology, as is the case of Vietnam, India, China, Australian. This work has the objective of studying the performance and characterization of molybdenum gels with titanium. Four variables in the preparation of the gel were studied: mass ratio between Mo and Ti (1.80 and 2.25), concentration of NaOH (2 and 4 mol/L), final temperature (25 and 50 deg C) and pH (3.5 and 4.5). The prepared gels were analyzed with relation to the size of its particles, identification of its structure, amount of molybdenum, amount of titanium, profile of elution, pH of the elution, determination of the radioisotopes in the eluate and final radiochemical purity. The final result is a formularization of the gel with the best characteristics for posterior preparation of the generator of 99m Tc- 99 Mo. (author)

  3. Atomic oxygen-MoS sub 2 chemical interactions

    Energy Technology Data Exchange (ETDEWEB)

    Cross, J.B.; Martin, J.A. (Los Alamos National Lab., NM (USA)); Pope, L.E. (Sandia National Labs., Albuquerque, NM (USA)); Koontz, S.L. (National Aeronautics and Space Administration, Johnson Space Center, Houston, TX (USA))

    1990-10-01

    The present study shows that an O-atom translation energy of 1.5 eV, SO{sub 2} is generated and outgases from an anhydrous MoS{sub 2} surface with an initial reactivity nearly 50% that of kapton. The reaction of atomic oxygen with MoS{sub 2} has little or no translational energy barrier, i.e. thermally generated atomic oxygen reacts as readily as that having 1.5 eV of translational energy. For MoS{sub 2} films sputter-deposited at 50-70deg C, friction measurements showed a high initial friction coefficient (up to 0.25) for MoS{sub 2} surfaces exposed to atomic oxygen, which dropped to the normal low values after several cycles of operation in air and ultrahigh vacuum. For MoS{sub 2} films deposited at 200deg C, the friction coefficient was not affected by the O-atom exposure. (orig.).

  4. Measurement of target and double-spin asymmetries for the e<mo>→>p<mo>→eπ+(n)> reaction in the nucleon resonance region at low Q2

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, X.; Adhikari, K. P.; Bosted, P.; Deur, A.; Drozdov, V.; El Fassi, L.; Kang, Hyekoo; Kovacs, K.; Kuhn, S.; Long, E.; Phillips, S. K.; Ripani, M.; Slifer, K.; Smith, L. C.; Adikaram, D.; Akbar, Z.; Amaryan, M. J.; Anefalos Pereira, S.; Asryan, G.; Avakian, H.; Badui, R. A.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Briscoe, W. J.; Bültmann, S.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Chen, J. -P.; Chetry, T.; Choi, Seonho; Ciullo, G.; Clark, L.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Crede, V.; D' Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Djalali, C.; Dodge, G. E.; Dupre, R.; Egiyan, H.; El Alaoui, A.; Elouadrhiri, L.; Eugenio, P.; Fanchini, E.; Fedotov, G.; Fersch, R.; Filippi, A.; Fleming, J. A.; Gevorgyan, N.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Gleason, C.; Golovach, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guler, N.; Guo, L.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jenkins, D.; Jiang, H.; Jo, H. S.; Joosten, S.; Keller, D.; Khachatryan, G.; Khandaker, M.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, V.; Lanza, L.; Lenisa, P.; Livingston, K.; MacGregor, I. J. D.; Markov, N.; McKinnon, B.; Mirazita, M.; Mokeev, V.; Movsisyan, A.; Munevar, E.; Munoz Camacho, C.; Murdoch, G.; Nadel-Turonski, P.; Net, L. A.; Ni, A.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Paremuzyan, R.; Park, K.; Pasyuk, E.; Peng, P.; Pisano, S.; Pogorelko, O.; Price, J. W.; Puckett, A. J. R.; Raue, B. A.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schumacher, R. A.; Sharabian, Y. G.; Skorodumina, Iu.; Smith, G. D.; Sokhan, D.; Sparveris, N.; Stankovic, I.; Strakovsky, I. I.; Strauch, S.; Taiuti, M.; Tian, Ye; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zhang, J.; Zonta, I.

    2016-10-01

    We report measurements of target- and double-spin asymmetries for the exclusive channel e<mo>→>p<mo>→eπ+(n)> in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH3 target and a longitudinally polarized electron beam with energies 1.1, 1.3, 2.0, 2.3, and 3.0 GeV. The new results are consistent with previous CLAS publications but are extended to a low Q2 range from 0.0065 to 0.35 (GeV/c)2. The Q2 access was made possible by a custom-built Cherenkov detector that allowed the detection of electrons for scattering angles as low as 6 degrees. These results are compared with the unitary isobar models JANR and MAID, the partial-wave analysis prediction from SAID, and the dynamic model DMT. In many kinematic regions our results, in particular results on the target asymmetry, help to constrain the polarization-dependent components of these models.

  5. Synthesis of Monolayer MoS2 by Chemical Vapor Deposition

    Science.gov (United States)

    Withanage, Sajeevi; Lopez, Mike; Dumas, Kenneth; Jung, Yeonwoong; Khondaker, Saiful

    Finite and layer-tunable band gap of transition metal dichalcogenides (TMDs) including molybdenum disulfide (MoS2) are highlighted over the zero band gap graphene in various semiconductor applications. Weak interlayer Van der Waal bonding of bulk MoS2 allows to cleave few to single layer MoS2 using top-down methods such as mechanical and chemical exfoliation, however few micron size of these flakes limit MoS2 applications to fundamental research. Bottom-up approaches including the sulfurization of molybdenum (Mo) thin films and co-evaporation of Mo and sulfur precursors received the attention due to their potential to synthesize large area. We synthesized monolayer MoS2 on Si/SiO2 substrates by atmospheric pressure Chemical Vapor Deposition (CVD) methods using sulfur and molybdenum trioxide (MoO3) as precursors. Several growth conditions were tested including precursor amounts, growth temperature, growth time and flow rate. Raman, photoluminescence (PL) and atomic force microscopy (AFM) confirmed monolayer islands merging to create large area were observed with grain sizes up to 70 μm without using any seeds or seeding promoters. These studies provide in-depth knowledge to synthesize high quality large area MoS2 for prospective electronics applications.

  6. Rational synthesis of high nuclearity Mo/Fe/S clusters: the reductive coupling approach in the convenient synthesis of (Cl(4)-cat)(2)Mo(2)Fe(6)S(8)(PR(3))(6) [R = Et, (n)Pr, (n)Bu] and the new [(Cl(4)-cat)(2)Mo(2)Fe(2)S(3)O(PEt(3))(3)Cl]-1/2(Fe(PEt(3))(2)(MeCN)(4)) and (Cl(4)-cat)(2)Mo(2)Fe(3)S(5)(PEt(3))(5) clusters.

    Science.gov (United States)

    Han, J; Koutmos, M; Ahmad, S A; Coucouvanis, D

    2001-11-05

    A general method for the synthesis of high nuclearity Mo/Fe/S clusters is presented and involves the reductive coupling of the (Et(4)N)(2)[(Cl(4)-cat)MoOFeS(2)Cl(2)] (I) and (Et(4)N)(2)[Fe(2)S(2)Cl(4)] (II) clusters. The reaction of I and II with Fe(PR(3))(2)Cl(2) or sodium salts of noncoordinating anions such as NaPF(6) or NaBPh(4) in the presence of PR(3) (R = Et, (n)Pr, or (n)Bu) affords (Cl(4)-cat)(2)Mo(2)Fe(6)S(8)(PR(3))(6) [R = Et (IIIa), (n)Pr (IIIb), (n)Bu (IIIc)], Fe(6)S(6)(PEt(3))(4)Cl(2) (IV) and (PF(6))[Fe(6)S(8)(P(n)Pr(3))(6)] (V) as byproducts. The isolation of (Et(4)N)[Fe(PEt(3))Cl(3)] (VI), NaCl, and SPEt(3) supports a reductive coupling mechanism. Cluster IV and V also have been synthesized by the reductive self-coupling of compound II. The reductive coupling reaction between I and II by PEt(3) and NaPF(6) in a 1:1 ratio produces the (Et(4)N)(2)[(Cl(4)-cat)Mo(L)Fe(3)S(4)Cl(3)] clusters [L = MeCN (VIIa), THF (VIIb)]. The hitherto unknown [(Cl(4)-cat)(2)Mo(2)Fe(2)S(3)O(PEt(3))(3)Cl](+) cluster (VIII) has been isolated as the 2:1 salt of the (Fe(PEt(3))(2)(MeCN)(4))(2+) cation after the reductive self-coupling reaction of I in the presence of Fe(PEt(3))(2)Cl(2). Cluster VIII crystallizes in the monoclinic space group P2(1)/c with a = 11.098(3) A, b = 22.827(6) A, c = 25.855(6) A, beta = 91.680(4) degrees, and Z = 4. The formal oxidation states of metal atoms in VIII have been assigned as Mo(III), Mo(IV), Fe(II), and Fe(III) on the basis of zero-field Mössbauer spectra. The Fe(PEt(3))(2)(MeCN)(4) cation of VIII is also synthesized independently, isolated as the BPh(4)(-) salt (IX), and has been structurally characterized. The reductive coupling of compound I also affords in low yield the new (Cl(4)-cat)(2)Mo(2)Fe(3)S(5)(PEt(3))(5) cluster (X) as a byproduct. Cluster X crystallizes in the monoclinic space group P2(1)/n with a = 14.811(3) A, b = 22.188(4) A, c = 21.864(4) A, beta = 100.124(3) degrees, and Z = 4 and the structure shows very short Mo

  7. The effect of lithium adsorption on the formation of 1T-MoS2 phase based on first-principles calculation

    International Nuclear Information System (INIS)

    Zheng, Yuanliao; Huang, Yan; Shu, Haibo; Zhou, Xiaohao; Ding, Jiayi; Chen, Xiaoshuang; Lu, Wei

    2016-01-01

    The effect of lithium adsorption on the phase transition from 1H-MoS 2 to 1T-MoS 2 is studied by first-principles computations. The results indicate the possibilities of the phase transition for the lithium adsorption. Based on the results of charge density difference and charge-transfer of molybdenum disulfide with lithium adsorption, we elucidated that the mechanism of the changes of electronic property accompanying the phase transition is attributed to the electron transfer of different atoms. According to the result of transition state, it can be found that the phase-transition barrier is related to the coverage of lithium atoms on MoS 2 surface. It may be helpful to obtaining experimentally the stable 1T-MoS 2 structure. - Highlights: • The transformation of MoS 2 from semiconducting to metallic phases is elucidated on the essence of the electron transfer. • The relationship between Li coverage and phase transition barrier is obtained. • The decomposing of Lithiated 1T-MoS 2 at a high concentration of Li adsorption is explained. • The results can be helpful to obtaining experimentally the stable 1T-MoS 2 structure.

  8. Structural stability of coplanar 1T-2H superlattice MoS2 under high energy electron beam

    Science.gov (United States)

    Reshmi, S.; Akshaya, M. V.; Satpati, Biswarup; Basu, Palash Kumar; Bhattacharjee, K.

    2018-05-01

    Coplanar heterojunctions composed of van der Waals layered materials with different structural polymorphs have drawn immense interest recently due to low contact resistance and high carrier injection rate owing to low Schottky barrier height. Present research has largely focused on efficient exfoliation of these layered materials and their restacking to achieve better performances. We present here a microwave assisted easy, fast and efficient route to induce high concentration of metallic 1T phase in the original 2H matrix of exfoliated MoS2 layers and thus facilitating the formation of a 1T-2H coplanar superlattice phase. High resolution transmission electron microscopy (HRTEM) investigations reveal formation of highly crystalline 1T-2H hybridized structure with sharp interface and disclose the evidence of surface ripplocations within the same exfoliated layer of MoS2. In this work, the structural stability of 1T-2H superlattice phase during HRTEM measurements under an electron beam of energy 300 keV is reported. This structural stability could be either associated to the change in electronic configuration due to induction of the restacked hybridized phase with 1T- and 2H-regions or to the formation of the surface ripplocations. Surface ripplocations can act as an additional source of scattering centers to the electron beam and also it is possible that a pulse train of propagating ripplocations can sweep out the defects via interaction from specific areas of MoS2 sheets.

  9. The Use of Sodium Hypochlorite Solution for (n,γ99Mo/99mTc Generator Based on Zirconium-Based Material (ZBM

    Directory of Open Access Journals (Sweden)

    I. Saptiama

    2015-08-01

    Full Text Available The many problems in preparing fission product 99Mo led into this work to develop 99Mo/99mTc generator using neutron-irradiated natural MoO3 targets and, more specifically, to develop a zirconium-based material (ZBM for chromatography columns that have an adsorption capacity of more than 100 mg Mo/g ZBM. This paper reports our recent experiments in the use of sodium hypochlorite solution of various concentrations to improve the yield of 99mTc in performance of (n,γ99Mo/99mTc generators based on the ZBM. The synthesized ZBM was coated with tetraethyl orthosilicate for improving the hardness of the material. The adsorption of [99Mo]molybdate into ZBM was carried out by reacting ZBM into [99Mo]molybdate solution at 90°C to form ZBM-[99Mo] molybdate. ZBM-[99Mo]molybdate was then packed into generator column, then eluted with 10 × 1 mL of saline followed by 1 × 5 mL of NaOCl solution. The NaOCl solution concentrations used were 0.5%; 1%; 3%; and 5% for each column, respectively. This study resulted in a ZBM which has a 99Mo adsorption capacity of 167.5 ± 3.4 mgMo/g ZBM, as well as in a yield eluate of 99mTc of up to 70%, and the find that the optimum NaOCl concentration was 3%. The use of sodium hypochlorite solution affected 99Mo breakthrough. The higher sodium hypochlorite concentration used, the more 99Mo breaktrough exist on 99mTc eluate.

  10. MoO2-ordered mesoporous carbon nanocomposite as an anode material for lithium-ion batteries.

    Science.gov (United States)

    Zeng, Lingxing; Zheng, Cheng; Deng, Cuilin; Ding, Xiaokun; Wei, Mingdeng

    2013-03-01

    In the present work, the nanocomposite of MoO2-ordered mesoporous carbon (MoO2-OMC) was synthesized for the first time using a carbon thermal reduction route and the mesoporous carbon as the nanoreactor. The synthesized nanocomposite was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), N2 adsorption-desorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) measurements. Furthermore, this nanocomposite was used as an anode material for Li-ion intercalation and exhibited large reversible capacity, high rate performance, and good cycling stability. For instance, a high reversible capacity of 689 mAh g(-1) can remain after 50 cycles at a current density of 50 mA g(-1). It is worth mentioning that the MoO2-OMC nanocomposite electrode can attain a high reversible capacity of 401 mAh g(-1) at a current density as high as 2 A g(-1). These results might be due to the intrinsic characteristics of nanocomposite, which offered a better accommodation of the strain and volume changes and a shorter path for Li-ion and electron transport, leading to the improved capacity and enhanced rate capability.

  11. Thermodynamic calculation and an experimental study of the combustion synthesis of (Mo{sub 1−x}Nb{sub x})Si{sub 2} (0 ⩽ x ⩽ 1)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaohong, E-mail: matinbow@163.com; Lu, Qiong; Wu, Guangzhi; Shi, Jialing; Sun, Zhi

    2015-08-25

    Highlights: • (Mo{sub 1−x}Nb{sub x})Si{sub 2} alloys were synthesized by a simple and energy-saving process of SHS. • Theoretical adiabatic temperature of (Mo{sub 1−x}Nb{sub x})Si{sub 2} was calculated for the first time. • The variation of the actual temperature is consistent with theoretical temperature. - Abstract: The theoretical adiabatic temperature of (Mo{sub 1−x}Nb{sub x})Si{sub 2} (0 ⩽ x ⩽ 1) is calculated. The results indicate that the theoretical adiabatic temperature of (Mo{sub 1−x}Nb{sub x})Si{sub 2} increases with an increasing Nb content when (Mo{sub 1−x}Nb{sub x})Si{sub 2} is of a single-phase structure, but decreases with an increasing Nb content when (Mo{sub 1−x}Nb{sub x})Si{sub 2} is of a double-phase structure. All of the temperatures are higher than 1800 K, indicating that (Mo{sub 1−x}Nb{sub x})Si{sub 2} (0 ⩽ x ⩽ 1) can be prepared by the combustion synthesis method. In this work, (Mo{sub 1−x}Nb{sub x})Si{sub 2} (0 ⩽ x ⩽ 1) alloys are successfully synthesized by the combustion synthesis process from elemental powders of Mo, Nb, and Si. The highest combustion temperature and combustion product structure are studied. The results confirm that the variation of the experimental maximum combustion temperature of (Mo{sub 1−x}Nb{sub x})Si{sub 2} is consistent with that of the theoretical adiabatic temperature. The combustion products are non-equilibrium species, and a supersaturated solid solution of C11{sub b} type (Mo{sub 1−x}Nb{sub x})Si{sub 2} forms during combustion synthesis.

  12. Structure of glasses of the TeO2-MoO3 system

    International Nuclear Information System (INIS)

    Dimitriev, Y.; Dimitrov, V.; Bart, J.C.J.

    1981-01-01

    Structural models for glasses of the TeO 2 -MoO 3 system are suggested. On the basis of X-ray and infrared spectral investigations, by comparing with known crystalline structures of TeO 2 , MoO 3 and Te 2 MoO 7 9t 2 M, it is shown that the glasses from TeO 2 to Te 2 MoO 7 possess [TeO 4 ] and [MoO 5 ] groups as basic structural units. The latter are connected to form [Mo 2 O 8 ] complexes. The glasses in the MoO 3 -rich compositional range are built up of [TeO 3 ] and [MoO 6 ] polyhedra. The glass-formation tendency is discussed in relation to the role of the free electron pair and the disruption of secondary and weak primary bonds in the crystals. (author)

  13. Facile fabrication of CNTs@C@MoSe2@Se hybrids with amorphous structure for high performance anode in lithium-ion batteries.

    Science.gov (United States)

    Jin, Rencheng; Cui, Yuming; Wang, Qingyao; Li, Guihua

    2017-12-15

    Amorphous MoSe 2 and Se anchored on amorphous carbon coated multiwalled carbon nanotubes (CNTs@C@MoSe 2 @Se) have been synthesized by a facile solvothermal strategy. The one dimensional CNTs@C@MoSe 2 @Se can effectively buffer the volume variation, prohibit the aggregation and facilitate electron and ion transport throughout the electrode. Furthermore, the combination of MoSe 2 and Se also provides buffer spaces for the volumetric change during cycling. Thus, the obtained CNTs@C@MoSe 2 @Se hybrids display the enhanced cycle stability and excellent high rate capacity. The reversible capacity of 1010mAhg -1 can be achieved after 100 cycles at the current density of 0.1Ag -1 . Even after 500 cycles, a reversible capacity of 508mAhg -1 is still retained at 5Ag -1 . Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Synaptic communication between neurons and NG2+ cells.

    Science.gov (United States)

    Paukert, Martin; Bergles, Dwight E

    2006-10-01

    Chemical synaptic transmission provides the basis for much of the rapid signaling that occurs within neuronal networks. However, recent studies have provided compelling evidence that synapses are not used exclusively for communication between neurons. Physiological and anatomical studies indicate that a distinct class of glia known as NG2(+) cells also forms direct synaptic junctions with both glutamatergic and GABAergic neurons. Glutamatergic signaling can influence intracellular Ca(2+) levels in NG2(+) cells by activating Ca(2+) permeable AMPA receptors, and these inputs can be potentiated through high frequency stimulation. Although the significance of this highly differentiated form of communication remains to be established, these neuro-glia synapses might enable neurons to influence rapidly the behavior of this ubiquitous class of glial progenitors.

  15. Measurement of formation cross-section of 99Mo from the 98Mo(n,γ) and 100Mo(n,2n) reactions.

    Science.gov (United States)

    Badwar, Sylvia; Ghosh, Reetuparna; Lawriniang, Bioletty M; Vansola, Vibha; Sheela, Y S; Naik, Haladhara; Naik, Yeshwant; Suryanarayana, Saraswatula V; Jyrwa, Betylda; Ganesan, Srinivasan

    2017-11-01

    The formation cross-section of medical isotope 99 Mo from the 98 Mo(n,γ) reaction at the neutron energy of 0.025eV and from the 100 Mo(n,2n) reaction at the neutron energies of 11.9 and 15.75MeV have been determined by using activation and off-line γ-ray spectrometric technique. The thermal neutron energy of 0.025eV was used from the reactor critical facility at BARC, Mumbai, whereas the average neutron energies of 11.9 and 15.75MeV were generated using 7 Li(p,n) reaction in the Pelletron facility at TIFR, Mumbai. The experimentally determined cross-sections were compared with the evaluated nuclear data libraries of ENDF/B-VII.1, CENDL-3.1, JENDL-4.0 and JEFF-3.2 and are found to be in close agreement. The 100 Mo(n,2n) 99 Mo reaction cross-sections were also calculated theoretically by using TALYS-1.8 and EMPIRE-3.2 computer codes and compared with the experimental data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. On-stack two-dimensional conversion of MoS2 into MoO3

    Science.gov (United States)

    Yeoung Ko, Taeg; Jeong, Areum; Kim, Wontaek; Lee, Jinhwan; Kim, Youngchan; Lee, Jung Eun; Ryu, Gyeong Hee; Park, Kwanghee; Kim, Dogyeong; Lee, Zonghoon; Lee, Min Hyung; Lee, Changgu; Ryu, Sunmin

    2017-03-01

    Chemical transformation of existing two-dimensional (2D) materials can be crucial in further expanding the 2D crystal palette required to realize various functional heterostructures. In this work, we demonstrate a 2D ‘on-stack’ chemical conversion of single-layer crystalline MoS2 into MoO3 with a precise layer control that enables truly 2D MoO3 and MoO3/MoS2 heterostructures. To minimize perturbation of the 2D morphology, a nonthermal oxidation using O2 plasma was employed. The early stage of the reaction was characterized by a defect-induced Raman peak, drastic quenching of photoluminescence (PL) signals and sub-nm protrusions in atomic force microscopy images. As the reaction proceeded from the uppermost layer to the buried layers, PL and optical second harmonic generation signals showed characteristic modulations revealing a layer-by-layer conversion. The plasma-generated 2D oxides, confirmed as MoO3 by x-ray photoelectron spectroscopy, were found to be amorphous but extremely flat with a surface roughness of 0.18 nm, comparable to that of 1L MoS2. The rate of oxidation quantified by Raman spectroscopy decreased very rapidly for buried sulfide layers due to protection by the surface 2D oxides, exhibiting a pseudo-self-limiting behavior. As exemplified in this work, various on-stack chemical transformations can be applied to other 2D materials in forming otherwise unobtainable materials and complex heterostructures, thus expanding the palette of 2D material building blocks.

  17. Adsorption of DNA/RNA nucleobases onto single-layer MoS2 and Li-Doped MoS2: A dispersion-corrected DFT study

    Science.gov (United States)

    Sadeghi, Meisam; Jahanshahi, Mohsen; Ghorbanzadeh, Morteza; Najafpour, Ghasem

    2018-03-01

    The kind of sensing platform in nano biosensor plays an important role in nucleic acid sequence detection. It has been demonstrated that graphene does not have an intrinsic band gap; therefore, transition metal dichalcogenides (TMDs) are desirable materials for electronic base detection. In the present work, a comparative study of the adsorption of the DNA/RNA nucleobases [Adenine (A), Cytosine (C) Guanine (G), Thymine (T) and Uracil (U)] onto the single-layer molybdenum disulfide (MoS2) and Li-doped MoS2 (Li-MoS2) as a sensing surfaces was investigated by using Dispersion-corrected Density Functional Theory (D-DFT) calculations and different measure of equilibrium distances, charge transfers and binding energies for the various nucleobases were calculated. The results revealed that the interactions between the nucleobases and the MoS2 can be strongly enhanced by introducing metal atom, due to significant charge transfer from the Li atom to the MoS2 when Lithium is placed on top of the MoS2. Furthermore, the binding energies of the five nucleobases were in the range of -0.734 to -0.816 eV for MoS2 and -1.47 to -1.80 eV for the Li-MoS2. Also, nucleobases were adsorbed onto MoS2 sheets via the van der Waals (vdW) force. This high affinity and the renewable properties of the biosensing platform demonstrated that Li-MoS2 nanosheet is biocompatible and suitable for nucleic acid analysis.

  18. Characterizing and improving the toughness of thick-sectioned 2 1/4 Cr-1 Mo electroslag weldments

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, G.R.; Frost, R.H.

    1980-09-01

    Efforts to improve the toughness of electroslag weldments consisted of four endeavors: process control, changes caused in 2 1/4 Cr-1 Mo steel by electroslag welding and post-weld heat treatment, electrochemical reactions during the electroslag welding, and toughness testing.

  19. MoEDAL expands

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    The MoEDAL collaboration deployed a test array of 18 plastic Nuclear Track Etch Detector (NTD) stacks – covering an area of 1 m2 – in the MoEDAL/VELO cavern at Point 8 of the LHC ring in November 2009. This small array was supplemented by a further 110 stacks this past January. The MoEDAL test array, which now covers an area of 8 m2, will reveal its secrets early in 2013. The full MoEDAL detector will be installed in the next long shutdown of the LHC in 2013.   View of the MoEDAL detectors installed at Point 8 of the LHC ring in January 2011. MoEDAL (Monopole and Exotics Detector At the LHC), the seventh LHC experiment, was approved by the CERN Research Board at the end of 2009. Its goal is to search for very specific exotics such as highly ionising massive stable (or pseudo-stable) particles with conventional electrical charge and magnetic monopoles. “The main LHC experiments are designed to detect conventionally charged particles, with conventional ionisation patte...

  20. Influence of some metal substitutions on the superconducting behaviour of molybdenum borocarbide. [Mo/sub 2-x/M/sub x/BC; M = Zr, Nb, Rh, Hf, Ta, or W

    Energy Technology Data Exchange (ETDEWEB)

    Lejay, P.; Chevalier, B.; Etourneau, J.; Hagenmuller, P. [Bordeaux-1 Univ., 33 - Talence (France)

    1981-11-15

    The superconducting properties of the Mosub(2-x)Msub(x)BC borocarbides (M equivalent to Zr, Nb, Rh, Hf, Ta, W) are reported. They have an Mo/sub 2/BC-type structure with orthorhombic symmetry and the space group Cmcm. Stoichiometric powder samples were prepared by arc melting. A large single crystal of Mo/sub 2/BC was obtained by a Czochralski-type method. The upper limit of x depends mainly on the size of the M atoms. A study of the magnetization as a function of field at different temperatures shows that all borocarbides are type II superconductors. Resistivity measurements give generally a critical temperature Tsub(cr) above 4.2 K. Tsub(cr) and the critical fields Hsub(c2) increase for rhodium substitution but decrease in other cases. For comparison the superconducting properties are discussed in terms of the valence electron concentration and the molar volume.

  1. The theoretical investigations of the core structure and the Peierls stress of the 1/2{1 1 0} edge dislocation in Mo

    International Nuclear Information System (INIS)

    Liu Ruiping; Wang Shaofeng; Wang Rui; Jiao Jian

    2010-01-01

    By using the modified Peierls-Nabarro (P-N) model in which the lattice discrete effect is taken into account, the core structure and the Peierls stress of the 1/2 {1 1 0} edge dislocation in molybdenum (Mo) have been investigated in the anisotropic elasticity approximation. The coefficient of the lattice discrete correction and the energy coefficient are all calculated in the anisotropic elasticity approximation. By considering the lattice discrete effect, the core width obtained from the modified P-N model is much wider than the results obtained from the P-N model. Because the Peierls stress of the 1/2 {1 1 0} edge dislocation in Mo moving with the rigid mechanism is smaller than that with the kink mechanism, therefore, through investigating the Peierls stress of the edge dislocation we obtained with the atomistic simulations, it can be indicated that when the external stress is loaded on the 1/2 {1 1 0} edge dislocation in Mo, the dislocation may move with the rigid mechanism rather than the kink mechanism or other mechanisms.

  2. Development of improved HP/IP rotor material 2% CrMoNiWV (23 CrMoNiWV 88)

    International Nuclear Information System (INIS)

    Wiemann, W.

    1989-01-01

    The new 2% CrMoNiWV steel has a sufficient strength level, a very good creep (rupture) behaviour and an excellent toughness behaviour for a creep resistant steel. Even after long time high temperature exposure the toughness degradation is so small that it is still better than this of best 1% CrMo(Ni)V steels. The fatigue behaviour is well comparable to this of 1% CrMo(Ni)V. The 2% CrMoNiWV steel has the capability to substitute the traditional 1% CrMo(Ni)V. (orig.) With 26 annexes

  3. The fracture toughness and DBTT of MoB particle-reinforced MoSi2 composites

    International Nuclear Information System (INIS)

    Xiong Zhi; Wang Gang; Jiang Wan

    2005-01-01

    The room temperature fracture toughness and the high temperature DBTT of MoB particle-reinforced MoSi 2 composites were investigated using Vickers indentation technique and MSP testing method, respectively. Modified small punch (MSP) test is a method for evaluation of mechanical properties using very small specimens, and it's appropriate for the determination of strength and DBTT. It was found that the approximate fracture toughness of the composite is 1.3 times that of monolithic MoSi 2 , and its DBTT is 100 C higher than that of monolithic MoSi 2 materials. Cracks deflection is a probable mechanism responsible for this behavior. (orig.)

  4. Influence of phosphorous addition on Bi3Mo2Fe1 oxide catalysts for the oxidative dehydrogenation of 1-butene

    KAUST Repository

    Park, Jung-Hyun

    2016-01-22

    Bi3Mo2Fe1Px oxide catalysts were prepared by a co-precipitation method and the influence of phosphorous content on the catalytic performance in the oxidative dehydrogenation of 1-butene was investigated. The addition of phosphorous up to 0.4mole ratio to Bi3Mo2Fe1 oxide catalyst led to an increase in the catalytic performance; however, a higher phosphorous content (above P=0.4) led to a decrease of conversion. Of the tested catalysts, Bi3Mo2Fe1P0.4 oxide catalyst exhibited the highest catalytic performance. Characterization results showed that the catalytic performance was related to the quantity of a π-allylic intermediate, facile desorption behavior of adsorbed intermediates and ability for re-oxidation of catalysts. © 2015 Korean Institute of Chemical Engineers, Seoul, Korea

  5. Influence of phosphorous addition on Bi3Mo2Fe1 oxide catalysts for the oxidative dehydrogenation of 1-butene

    KAUST Repository

    Park, Jung-Hyun; Shin, Chae-Ho

    2016-01-01

    Bi3Mo2Fe1Px oxide catalysts were prepared by a co-precipitation method and the influence of phosphorous content on the catalytic performance in the oxidative dehydrogenation of 1-butene was investigated. The addition of phosphorous up to 0.4mole ratio to Bi3Mo2Fe1 oxide catalyst led to an increase in the catalytic performance; however, a higher phosphorous content (above P=0.4) led to a decrease of conversion. Of the tested catalysts, Bi3Mo2Fe1P0.4 oxide catalyst exhibited the highest catalytic performance. Characterization results showed that the catalytic performance was related to the quantity of a π-allylic intermediate, facile desorption behavior of adsorbed intermediates and ability for re-oxidation of catalysts. © 2015 Korean Institute of Chemical Engineers, Seoul, Korea

  6. Problems in clinical practice of domestic supply of 99Mo/99mTc. Considerations on the domestic production of 99Mo/99mTc

    International Nuclear Information System (INIS)

    Yamabayashi, Hisamichi

    2012-01-01

    At present, a bulky import product, 99 Mo supplied in Japan is produced by a nuclear fission method which enables to produce a generator system with no need of commercially preparing 99m Tc-labeled radiopharmaceuticals due to its high specific activity. However its usage of enriched uranium target leads to avoiding the fission method from the option of domestic production. In order to secure the domestic supply of 99 Mo/ 99m Tc, the neutron activation method, aiming to meet about 20% of domestic demand, is under development along with the re-start program of JMTR. Development of various production methods using accelerators are also in progress. In those non-fission methods with reactors or accelerators, rapid and effective procedures for concentration and refinement of 99m Tc solution eluted from 99 Mo of low specific activity are the subjects to be considered for attaining the stable labeling performances. (author)

  7. Dual-Native Vacancy Activated Basal Plane and Conductivity of MoSe2 with High-Efficiency Hydrogen Evolution Reaction.

    Science.gov (United States)

    Gao, Daqiang; Xia, Baorui; Wang, Yanyan; Xiao, Wen; Xi, Pinxian; Xue, Desheng; Ding, Jun

    2018-04-01

    Although transition metal dichalcogenide MoSe 2 is recognized as one of the low-cost and efficient electrocatalysts for the hydrogen evolution reaction (HER), its thermodynamically stable basal plane and semiconducting property still hamper the electrocatalytic activity. Here, it is demonstrated that the basal plane and edges of 2H-MoSe 2 toward HER can be activated by introducing dual-native vacancy. The first-principle calculations indicate that both the Se and Mo vacancies together activate the electrocatalytic sites in the basal plane and edges of MoSe 2 with the optimal hydrogen adsorption free energy (ΔG H* ) of 0 eV. Experimentally, 2D MoSe 2 nanosheet arrays with a large amount of dual-native vacancies are fabricated as a catalytic working electrode, which possesses an overpotential of 126 mV at a current density of 100 mV cm -2 , a Tafel slope of 38 mV dec -1 , and an excellent long-term durability. The findings pave a rational pathway to trigger the activity of inert MoSe 2 toward HER and also can be extended to other layered dichalcogenide. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Studies of the effect of irradiation in a nuclear reactor, of targets containing Mo used for the preparation of 99Mo gel, material that constitutes the 99Mo - 99mTc generators

    International Nuclear Information System (INIS)

    Nieto, Renata Correa

    2004-01-01

    The most used radioisotope in Nuclear Medicine is 99m Tc, obtained in the 99 Mo - 99m Tc generator form. 99 Mo can be produced by several nuclear reactions in Cyclotron and Reactor. The production in Cyclotron is not technically and commercially feasible. The production in Nuclear Reactor can be made in two ways: 235 U fission and 99 Mo (n,γ) 99 Mo reaction. A project aiming the production of 99 Mo by activation of Mo is under way at IPEN, producing a gel type MoZr generator. There are two ways of preparing the gel and the generators: by irradiating MoO 3 and preparing the gel or by the preparation of the gel and further irradiation. This work consists in the study of the irradiation effects in several targets containing Mo for the production of 99 Mo by the 98 Mo (n,γ) 99 Mo reaction and further preparation of the gel for use as a gel type 99 Mo - 99m Tc generator. Three rinds of gel were studied: zirconium, titanium and cerium molybdate, and their morphology, infrared structure and elution yield of 99m Tc were analysed. The best results were achieved with the generators prepared with MoZr post formed gel, with amorphous structure and better elution yields. The pre formed gel induced crystallinity and worst performance of the generators. (author)

  9. Results of regular study on radionuclidic purity of sup(99m)Tc obtained from 99Mo-sup(99m)Tc generators

    International Nuclear Information System (INIS)

    Vlcek, J.; Rohacek, J.; Husak, V.

    1979-01-01

    A total of 39 sup(99m)Tc eluates obtained from 9 99 Mo-sup(99m)Tc generators delivered by The Radiochemical Centre Amersham during one year was studied with regard to their radionuclide purity. Using a Ge(Li) spectrometer the contaminants 60 Co, 103 Ru, 131 I, 134 Cs, 140 La and 188 Re were found in sup(99m)Tc-eluates with average levels ranging from 2.9 x 10 -3 to 2.8 x 10 -1 per cent of sup(99m)Tc activity. The additional total body absorbed dose caused by these contaminants, as calculated from their average content in sup(99m)Tc eluates, was less than 1% of the dose due to sup(99m)Tc pertechnetate. (orig.) 891 MG/orig. 892 CS [de

  10. MoS2 anchored free-standing three dimensional vertical graphene foam based binder-free electrodes for enhanced lithium-ion storage

    International Nuclear Information System (INIS)

    Ouyang, Bo; Wang, Ying; Zhang, Zheng; Rawat, R.S.

    2016-01-01

    The vertical graphene with hierarchical three-dimensional network architecture is a promising substrate for high energy and power density Li-ion battery due to its large surface area, inherent three-dimensional network and excellent ion transport property. Three dimensional vertical graphene (3DVG) is synthesized via plasma enhanced chemical vapor deposition (PECVD) using cost-effective and environment-friendly natural oil of M. alternifolia as precursor. The MoS 2 nanosheets are then anchored on free-standing 3DVG by hydrothermal method to make the binder free MoS 2 @3DVG anode of a Li-ion battery. The MoS 2 @3DVG electrodes deliver an enhanced capacity of 670 mAh g −1 with the capacity retention of 99% after 30 cycles at 100 mA g −1 , much better than that of the reference sample of MoS 2 @3DG (550 mAh g −1 at 100 mA g −1 ) which uses 3D planar graphene. Superior performance of the vertical graphene based electrode is attributed to the unique hierarchical structure and densely packed reactive edges of the as-synthesized 3DVG. The versatility of plasma-assisted natural precursor based vertical graphene as functional nano-structured substrate for MoS 2 , as active material, for advanced energy storage devices is demonstrated.

  11. Transistor properties of exfoliated single crystals of 2 H -Mo (Se1-xT ex ) 2(0 ≤x ≤1 )

    Science.gov (United States)

    Uesugi, Eri; Miao, Xiao; Ota, Hiromi; Goto, Hidenori; Kubozono, Yoshihiro

    2017-06-01

    Field-effect transistors (FETs) were fabricated using exfoliated single crystals of Mo (Se1-xT ex) 2 with an x range of 0 to 1, and the transistor properties fully investigated at 295 K in four-terminal measurement mode. The chemical composition and crystal structure of exfoliated single crystals were identified by energy-dispersive x-ray spectroscopy (EDX), single-crystal x-ray diffraction, and Raman scattering, suggesting the 2 H - structure in all Mo (Se1-xT ex) 2 . The lattice constants of a and c increase monotonically with increasing x , indicating the substitution of Se by Te. When x 0.4 . In contrast, the polarity of a thick single-crystal Mo (Se1-xT ex) 2 FET did not change despite an increase in x . The change of polarity in a thin single-crystal FET was well explained by the variation of electronic structure. The absence of such change in the thick single-crystal FET can be reasonably interpreted based on the large bulk conduction due to naturally accumulated electrons. The μ value in the thin single-crystal FET showed a parabolic variation, with a minimum μ at around x =0.4 , which probably originates from the disorder of the single crystal caused by the partial replacement of Se by Te, i.e., a disorder that may be due to ionic size difference of Se and Te.

  12. Hydrothermal Synthesis of MoO2 and Supported MoO2 Cata-lysts for Oxidative Desulfurization of Dibenzothiophene

    Institute of Scientific and Technical Information of China (English)

    Wang Danhong; Zhang Jianyong; Liu Ni; Zhao Xin; Zhang Minghui

    2014-01-01

    A novel method for obtaining spherical MoO2 nanoparticles and SiO2-Al2O3 supported MoO2 by hydrothermal reduction of Mo (VI) species was studied. The obtained MoO2 catalysts show very high catalytic activity in the oxidative desulfurization (ODS) process. The effect of hydrothermal temperature and crystallization temperature on ODS activity was investigated. The ODS activity of supported MoO2 catalysts with various MoO2 contents were also investigated. The mecha-nism for formation of MoO2 involving oxalic acid was proposed.

  13. Fabrication of blue luminescent MoS{sub 2} quantum dots by wet grinding assisted co-solvent sonication

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Junaid; Siddiqui, Ghayas Uddin [Department of Mechatronics Engineering, Jeju National University, Jeju (Korea, Republic of); Choi, Kyung Hyun, E-mail: amm@jejunu.ac.kr [Department of Mechatronics Engineering, Jeju National University, Jeju (Korea, Republic of); Jang, Yunseok [Department of Printed Electronics, Korea Institute of Machinery & Materials, Daejeon, Republic of Korea (Korea, Republic of); Lee, Kangtaek [Department of Chemical and Biomolecular Engineering, Yonsei University (Korea, Republic of)

    2016-01-15

    Molybdenum disulfide (MoS{sub 2}) belongs to transition-metal dichalcogenides (TMDs) family and has vital position among 2D materials. Here, an efficient strategy for the synthesis of zero-dimensional MoS{sub 2} quantum dots (QDs) has been represented. This strategy consists of wet grinding of pristine MoS{sub 2} in N-methyl-2-pyrrolidone (NMP) followed by sonication in NMP and 1,2-dichlorobenzene (o-DCB). The efficacy of this approach to synthesize MoS{sub 2} QDs has been reported by analyzing the as synthesized MoS{sub 2} QDs by different characterization techniques such as high resolution transmission electron microscopy, energy dispersive x-ray spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, Fourier transform infrared spectroscopy and UV–vis spectroscopy. The concentration (yield) of as synthesized MoS{sub 2} QDs was found to be 7 mg mL{sup −1}. Most of the MoS{sub 2} QDs were measured around 2–5 nm in size. The as synthesized MoS{sub 2} QDs showed distinct blue luminescence upon UV excitation. - Highlights: • Synthesis of MoS{sub 2} quantum dots. • Wet grinding of MoS{sub 2} flakes for 6 h in NMP. • Ultrasonication of MoS{sub 2} in NMP and DCB. • Particle size 2–5 nm and concentration 7 mg/ml. • MoS{sub 2} QDs showed blue luminescence.

  14. First-principle study of hydrogenation on monolayer MoS{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yong; Li, Yin [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); School of science, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Chen, Xi; Zhang, Ru [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); School of Ethnic Minority Education, Beijing University of Posts and Telecommunications, Beijing 102209 (China); Zhang, Chunfang [Beijing Computational Science Research Center, Beijing 100094 (China); Lu, Pengfei, E-mail: photon.bupt@gmail.com [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China)

    2016-07-15

    The structural and electronic properties of hydrogenation on 1H-MoS{sub 2} and 1T-MoS{sub 2} have been systematically explored by using density functional theory (DFT) calculations. Our calculated results indicate an energetically favorable chemical interaction between H and MoS{sub 2} monolayer for H adsorption when increasing concentration of H atoms. For 1H-MoS{sub 2}, single H atom adsorption creates midgap approaching the Fermi level which increases the n-type carrier concentration effectively. As a consequence, its electrical conductivity is expected to increase significantly. For 1T-MoS{sub 2}, H atoms adsorption can lead to the opening of a direct gap of 0.13 eV compared to the metallic pristine 1T-MoS{sub 2}.

  15. Ganoderma-Like MoS2 /NiS2 with Single Platinum Atoms Doping as an Efficient and Stable Hydrogen Evolution Reaction Catalyst.

    Science.gov (United States)

    Guan, Yongxin; Feng, Yangyang; Wan, Jing; Yang, Xiaohui; Fang, Ling; Gu, Xiao; Liu, Ruirui; Huang, Zhengyong; Li, Jian; Luo, Jun; Li, Changming; Wang, Yu

    2018-05-27

    Herein, a unique ganoderma-like MoS 2 /NiS 2 hetero-nanostructure with isolated Pt atoms anchored is reported. This novel ganoderma-like heterostructure can not only efficiently disperse and confine the few-layer MoS 2 nanosheets to fully expose the edge sites of MoS 2 , and provide more opportunity to capture the Pt atoms, but also tune the electronic structure to modify the catalytic activity. Because of the favorable dispersibility and exposed large specific surface area, single Pt atoms can be easily anchored on MoS 2 nanosheets with ultrahigh loading of 1.8 at% (the highest is 1.3 at% to date). Owing to the ganoderma-like structure and platinum atoms doping, this catalyst shows Pt-like catalytic activity for the hydrogen evolution reaction with an ultralow overpotential of 34 mV and excellent durability of only 2% increase in overpotential for 72 h under the constant current density of 10 mA cm -2 . © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Evaluation of '9{sup 9}Mo presence in eluates of {sup 99}mTc used in nuclear medicine; Avaliacao da presenca de {sup 99}Mo em eluatos de {sup 99m}Tc utilizados em medicina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Bianca da Silva

    2010-07-01

    Tc-99m is used for diagnostic imaging in nuclear medicine through SPECT technique. It is obtained by the elution of {sup 99}Mo/{sup 99m}Tc generators. During the elution process {sup 99}Mo can be extracted becoming a radionuclidic impurity. One of the quality parameters of the eluate is the radionuclidic purity, MBT (molybdenum break through), defined as the ratio between {sup 99}Mo and {sup 99m}Tc activities in the eluate. The North-American and European pharmacopoeias restrict the {sup 99}Mo content, respectively, in 0.015 e 0.1% and, according to the International Atomic Energy Agency (IAEA), the activity ratio at the moment of administration of the radiopharmaceutical to the patient, should not exceed 0.015%. In Brazil, the control of such parameter is not obliged in official regulations. Thus, the objective of this work is to evaluate the occurrence of {sup 99}Mo in {sup 99m}Tc eluates. It was initially optimized a methodology to determine the activity of {sup 99}Mo in eluate samples. Efficiency curves were obtained for a NaI (Tl) 8'' x 4'' scintillation detector installed at the In Vivo Monitoring Laboratory (LABMIV-IRD). The methodology has been validated through the measurement of a {sup 99}Mo standard liquid source calibrated at the National Metrology Laboratory for Ionizing Radiation (LNMRI-IRD). The samples analyzed in this work were gently supplied by 5 Nuclear Medicine Clinics located in the city of Rio de Janeiro. The activities of {sup 99}mTc and {sup 99}Mo in those samples have been measured respectively at the clinics and at the LABMIV. By applying a standardized methodology, the ration between the activities were calculated. The results show that 147 out of 174 samples presented {sup 99}Mo activities above the minimum detectable activity of the technique. On the other hand, only 2 out of 147 samples surpassed the MBT limit suggested by the IAEA and have been detected in samples eluted from generators of 750 mCi. In one of the

  17. Synthesis of MoS2 and MoO2 for their applications in H2 generation and lithium ion batteries: a review

    International Nuclear Information System (INIS)

    Zhao Yufei; Zhang Yuxia; Yang Zhiyu; Yan Yiming; Sun Kening

    2013-01-01

    Scientists increasingly witness the applications of MoS 2 and MoO 2 in the field of energy conversion and energy storage. On the one hand, MoS 2 and MoO 2 have been widely utilized as promising catalysts for electrocatalytic or photocatalytic hydrogen evolution in aqueous solution. On the other hand, MoS 2 and MoO 2 have also been verified as efficient electrode material for lithium ion batteries. In this review, the synthesis, structure and properties of MoS 2 and MoO 2 are briefly summarized according to their applications for H 2 generation and lithium ion batteries. Firstly, we overview the recent advancements in the morphology control of MoS 2 and MoO 2 and their applications as electrocatalysts for hydrogen evolution reactions. Secondly, we focus on the photo-induced water splitting for H 2 generation, in which MoS 2 acts as an important co-catalyst when combined with other semiconductor catalysts. The newly reported research results of the significant functions of MoS 2 nanocomposites in photo-induced water splitting are presented. Thirdly, we introduce the advantages of MoS 2 and MoO 2 for their enhanced cyclic performance and high capacity as electrode materials of lithium ion batteries. Recent key achievements in MoS 2 - and MoO 2 -based lithium ion batteries are highlighted. Finally, we discuss the future scope and the important challenges emerging from these fascinating materials. (review)

  18. Local structure of Th1-xMO2 solid solutions (M = U, Pu)

    International Nuclear Information System (INIS)

    Hubert, S.; Heisbourg, G.; Moisy, Ph.; Dacheux, N.; Purans, J.E.

    2004-01-01

    X-ray absorption spectroscopy of Th 1-x U x O 2 and Th 1-x Pu x O 2 solid solutions was carried out on the Th, U L 3 -edges, and Pu L 3 edge to study the local structure environment of actinide mixed oxides. Various compositions of Th 1-x M x O 2 solid solutions have been prepared through the coprecipitation of the mixed oxalates from chloride or nitrate solutions: x = 0.11, 0.24, 0.37, 0.53, 0.67, 0.81, 0.91 and 1 for Th 1-x U x O 2 , and x = 0.13, 0.32, 0.66 and 1 for Th 1-x Pu x O 2 . They were characterized using X- ray diffraction. XRD analysis allowed to confirm that the variation of the lattice parameters varies linearly with the composition between the end members, suggesting that the atomic volume was conserved regardless of the details of the local distortions of the lattice, following the Vegard's law. Extending X-ray absorption fine structure (EXAFS) provides a direct characterization of the local distortions present in solid solutions. We found that opposite to the lattice parameter obtained by XRD, the interatomic distances given by EXAFS do not follow completely to neither the Vegard's law nor the virtual crystal approximation (VCA). However, the average lattice parameter obtained from EXAFS data for the first and the second shells agrees well with the one calculated from XRD data. (authors)

  19. Nanoparticles of superconducting γ-Mo2N and δ-MoN

    International Nuclear Information System (INIS)

    Gomathi, A.; Sundaresan, A.; Rao, C.N.R.

    2007-01-01

    We have been able to prepare nanoparticles (∼4 nm diameter) of cubic γ-Mo 2 N by a simple procedure involving the reaction of MoCl 5 with urea at 873 K. The nanoparticles show a superconducting transition around 6.5 K. The γ-Mo 2 N nanoparticles are readily transformed to nanoparticles of δ-MoN with a slightly larger diameter on heating in a NH 3 atmosphere at 573 K. Phase-pure δ-MoN obtained by this means shows a superconducting transition around 5 K. - Graphical abstract: TEM image of the γ-Mo 2 N particles with the inset showing the resistivity of the sample as a function of temperature

  20. MoDnm1 Dynamin Mediating Peroxisomal and Mitochondrial Fission in Complex with MoFis1 and MoMdv1 Is Important for Development of Functional Appressorium in Magnaporthe oryzae.

    Directory of Open Access Journals (Sweden)

    Kaili Zhong

    2016-08-01

    Full Text Available Dynamins are large superfamily GTPase proteins that are involved in various cellular processes including budding of transport vesicles, division of organelles, cytokinesis, and pathogen resistance. Here, we characterized several dynamin-related proteins from the rice blast fungus Magnaporthe oryzae and found that MoDnm1 is required for normal functions, including vegetative growth, conidiogenesis, and full pathogenicity. In addition, we found that MoDnm1 co-localizes with peroxisomes and mitochondria, which is consistent with the conserved role of dynamin proteins. Importantly, MoDnm1-dependent peroxisomal and mitochondrial fission involves functions of mitochondrial fission protein MoFis1 and WD-40 repeat protein MoMdv1. These two proteins display similar cellular functions and subcellular localizations as MoDnm1, and are also required for full pathogenicity. Further studies showed that MoDnm1, MoFis1 and MoMdv1 are in complex to regulate not only peroxisomal and mitochondrial fission, pexophagy and mitophagy progression, but also appressorium function and host penetration. In summary, our studies provide new insights into how MoDnm1 interacts with its partner proteins to mediate peroxisomal and mitochondrial functions and how such regulatory events may link to differentiation and pathogenicity in the rice blast fungus.

  1. Synthesis of Au NP@MoS2 Quantum Dots Core@Shell Nanocomposites for SERS Bio-Analysis and Label-Free Bio-Imaging

    Directory of Open Access Journals (Sweden)

    Xixi Fei

    2017-06-01

    Full Text Available In this work, we report a facile method using MoS2 quantum dots (QDs as reducers to directly react with HAuCl4 for the synthesis of Au nanoparticle@MoS2 quantum dots (Au NP@MoS2 QDs core@shell nanocomposites with an ultrathin shell of ca. 1 nm. The prepared Au NP@MoS2 QDs reveal high surface enhanced Raman scattering (SERS performance regarding sensitivity as well as the satisfactory SERS reproducibility and stability. The limit of detection of the hybrids for crystal violet can reach 0.5 nM with a reasonable linear response range from 0.5 μM to 0.5 nM (R2 ≈ 0.974. Furthermore, the near-infrared SERS detection based on Au NP@MoS2 QDs in living cells is achieved with distinct Raman signals which are clearly assigned to the various cellular components. Meanwhile, the distinguishable SERS images are acquired from the 4T1 cells with the incubation of Au NP@MoS2 QDs. Consequently, the straightforward strategy of using Au NP@MoS2 QDs exhibits great potential as a superior SERS substrate for chemical and biological detection as well as bio-imaging.

  2. Controllable growth of MoS{sub 2}/C flower-like microspheres with enhanced electrochemical performance for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Q.Q., E-mail: zjxqq@hdu.edu.cn; Ji, Z.G.

    2016-07-15

    Tailored design/fabrication of hierarchical porous advanced electrodes is of great importance for developing high-performance power sources. Herein, we report a facile solvothermal method for fabrication of hierarchical porous MoS{sub 2}/C flower-like microspheres. Interestingly, the obtained MoS{sub 2}/C microspheres are composed of interconnected secondary thin nanoflakes and an amorphous carbon layer. As an anode material for lithium ion batteries, the resultant MoS{sub 2}/C flower-like microspheres electrode delivers a high specific capacity of 1125.9 mAh g{sup −1} and good cycle capability (916.6 mAh g{sup −1} at 200 mA g{sup −1} up to 400 cycles), as well as enhanced rate performance. The excellent electrochemical performance is attributed to the unique porous composite architecture with fast transportation of ion/electron and good strain accommodation during the lithiation/delithiation reaction. Our research may pave the way for construction of other high-performance metal sulfides electrodes for electrochemical energy storage. - Graphical abstract: We report a facile solvothermal method for fabrication of hierarchical porous MoS{sub 2}/C flower-like microspheres composed of interconnected thin nanoflakes and an amorphous carbon layer. As an anode material for LIBs, MoS{sub 2}/C flower-like microspheres electrode delivers enhanced electrochemical performance. - Highlights: • We prepared MoS{sub 2}/C flower-like microspheres via a facile solvothermal method. • The microsphere consists of interconnected nanoflake and an amorphous carbon layer. • The MoS{sub 2}/C microspheres show high capacity and good rate performance.

  3. Interactions among magnetic moments in the double perovskites Sr2Fe1+xMo1−xO6

    International Nuclear Information System (INIS)

    Pilo, J.; Carvajal, E.; Oviedo-Roa, R.; Cruz-Irisson, M.; Navarro, O.

    2014-01-01

    It is well known that every double perovskite shows a characteristic magnetic behavior, as a consequence of the interactions among the magnetic moments associated with the atoms in their cells; at the same time, the electric and magnetic properties of the bulk double perovskite Sr 2 FeMoO 6 are well characterized. In this work we studied the iron rich compounds Sr 2 Fe 1+x Mo 1−x O 6 , using a supercell to model such concentrations that made Fe richer perovskites by ±66.6% and ±200%. Starting from the stoichiometric double perovskite, and modifying the Fe/Mo ratio in the compound, the study of these materials were based on the calculation of the magnetic moment at each atom, as well as the partial density of states

  4. Hydrogen induced plastic damage in pressure vessel steel of 2.25Cr-1Mo

    International Nuclear Information System (INIS)

    Han, G.W.; Song, Y.J.

    1995-01-01

    2.25Cr-1Mo steel is generally employed as a hydrogenation reaction vessel material used at elevated temperature and in a hydrogen containing environment. During service of the reaction vessel, a large number of hydrogen atoms would enter its wall. When the reaction vessel is shutdown and the temperature reduces to about ambient temperature, the hydrogen atoms remaining in the wall would induce plastic damage in the steel. The mechanism of hydrogen induced plastic damage is different for various materials with different microstructures. Investigations have demonstrated that the hydrogen induced plastic damage in carbide annealed carbon steels is caused by hydrogen accelerating the initiating and growing of microvoids from the carbide particles. However, SEM examination on the fracture surface of hydrogen charged tensile specimen of 2.25Cr-1Mo steel show that a large number of fisheyes appear on the fracture surface. This indicates that hydrogen induced plastic damage in 2.25Cr-1Mo steel is related to the occurrence of fisheye cracks during plastic deformation. By means of micro-fracture mechanics to analyze fisheye crack occurrence from the first generation microvoid, the mechanism of hydrogen induced plastic damage in the pressure vessel steel is investigated

  5. In2Mo3O12: A low negative thermal expansion compound

    International Nuclear Information System (INIS)

    Marinkovic, Bojan A.; Ari, Monica; Jardim, Paula Mendes; Avillez, Roberto R. de; Rizzo, Fernando; Ferreira, Fabio Furlan

    2010-01-01

    Orthorhombic In 2 Mo 3 O 12 has low negative linear coefficient of thermal expansion (α l = -1.85 x 10 -6 o C -1 ) as evaluated by X-ray powder diffraction using a synchrotron facility. The linear coefficient of thermal expansion for orthorhombic In 2 Mo 3 O 12 is directly dependent on the inherent volume distortion parameter (υ) of InO 6 . This finding strongly corroborates the recently proposed relationship between the linear coefficient of thermal expansion in A 2 M 3 O 12 compounds (α l ) and the distortion level of AO 6 polyhedra. With the increase of inherent distortion parameter (υ) of AO 6 polyhedra, the linear coefficient of thermal expansion becomes more negative. Another important feature of AO 6 polyhedra, including InO 6 , is that their distortion increases as a function of temperature. Orthorhombic In 2 Mo 3 O 12 is stable in the studied temperature range, 370-760 o C.

  6. Performance study of molybdenum gels with titanium for preparation of {sup 99}Mo-{sup 99m}Tc generators; Estudo do desempenho de geis de molibdenio com titanio no preparo de geradores de {sup 99}Mo-{sup 99m}Tc

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Vanessa; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: vmoraes@ipen.br

    2005-07-01

    {sup 99m}Tc is the most used radioisotope in Nuclear Medicine, due to nuclear characteristics. It is obtained by the radioactive decay of {sup 99}Mo, generator of radioisotope system. When {sup 99}Mo is produced by the activation in reactor, the most used technique for the preparation of the generators is the gel type generator, which incorporates {sup 99}Mo to the gel that is insoluble, chemically inert to the solutions and with properties of ion exchange. Several countries had already studied this methodology, as is the case of Vietnam, India, China, Australian. This work has the objective of studying the performance and characterization of molybdenum gels with titanium. Four variables in the preparation of the gel were studied: mass ratio between Mo and Ti (1.80 and 2.25), concentration of NaOH (2 and 4 mol/L), final temperature (25 and 50 deg C) and pH (3.5 and 4.5). The prepared gels were analyzed with relation to the size of its particles, identification of its structure, amount of molybdenum, amount of titanium, profile of elution, pH of the elution, determination of the radioisotopes in the eluate and final radiochemical purity. The final result is a formularization of the gel with the best characteristics for posterior preparation of the generator of {sup 99m}Tc-{sup 99}Mo. (author)

  7. M1 and M2 Monocytes in Rheumatoid Arthritis: A Contribution of Imbalance of M1/M2 Monocytes to Osteoclastogenesis

    Directory of Open Access Journals (Sweden)

    Shoichi Fukui

    2018-01-01

    Full Text Available ObjectivesWe investigated the relationships among M1 monocytes, M2 monocytes, osteoclast (OC differentiation ability, and clinical characteristics in patients with rheumatoid arthritis (RA.MethodsPeripheral blood mononuclear cells (PBMCs were isolated from RA patients and healthy donors, and we then investigated the number of M1 monocytes or M2 monocytes by fluorescence-activated cell sorting. We also obtained and cultured CD14-positive cells from PBMCs from RA patients and healthy donors to investigate OC differentiation in vitro.ResultsForty RA patients and 20 healthy donors were included. Twenty-two patients (55% were anticitrullinated protein antibody (ACPA positive. The median M1/M2 ratio was 0.59 (0.31–1.11, interquartile range. There were no significant differences between the RA patients and healthy donors. There was a positive correlation between the M1/M2 ratio and the differentiated OC number in vitro in RA patients (ρ = 0.81, p < 0.001. The ACPA-positive patients had significantly higher M1/M2 ratios in vivo (p = 0.028 and significantly greater numbers of OCs in vitro (p = 0.005 than the ACPA-negative patients. Multivariable regression analysis revealed that the M1/M2 ratio was the sole significant contribution factor to in vitro osteoclastogenesis. RA patients with M1/M2 ratios >1 (having relatively more M1 monocytes had higher C-reactive protein and erythrocyte sedimentation rates than RA patients with M1/M2 ratios ≤1. M1-dominant monocytes in vitro produced higher concentrations of interleukin-6 upon stimulation with lipopolysaccharide than M2 monocytes.ConclusionM1/M2 monocytes imbalance strongly contributes to osteoclastogenesis of RA patients. Our findings cast M1 and M2 monocyte subsets in a new light as a new target of treatments for RA to prevent progression of osteoclastic bone destruction.

  8. Altered [99mTc]Tc-MDP biodistribution from neutron activation sourced 99Mo.

    Science.gov (United States)

    Demeter, Sandor; Szweda, Roman; Patterson, Judy; Grigoryan, Marine

    2018-01-01

    Given potential worldwide shortages of fission sourced 99 Mo/ 99m Tc medical isotopes there is increasing interest in alternate production strategies. A neutron activated 99 Mo source was utilized in a single center phase III open label study comparing 99m Tc, as 99m Tc Methylene Diphosphonate ([ 99m Tc]Tc-MDP), obtained from solvent generator separation of neutron activation produced 99 Mo, versus nuclear reactor produced 99 Mo (e.g., fission sourced) in oncology patients for which an [ 99m Tc]Tc-MDP bone scan would normally have been indicated. Despite the investigational [ 99m Tc]Tc-MDP passing all standard, and above standard of care, quality assurance tests, which would normally be sufficient to allow human administration, there was altered biodistribution which could lead to erroneous clinical interpretation. The cause of the altered biodistribution remains unknown and requires further research.

  9. Carbide Precipitation in 2.25 Cr-1 Mo Bainitic Steel: Effect of Heating and Isothermal Tempering Conditions

    Science.gov (United States)

    Dépinoy, Sylvain; Toffolon-Masclet, Caroline; Urvoy, Stéphane; Roubaud, Justine; Marini, Bernard; Roch, François; Kozeschnik, Ernst; Gourgues-Lorenzon, Anne-Françoise

    2017-05-01

    The effect of the tempering heat treatment, including heating prior to the isothermal step, on carbide precipitation has been determined in a 2.25 Cr-1 Mo bainitic steel for thick-walled applications. The carbides were identified using their amount of metallic elements, morphology, nucleation sites, and diffraction patterns. The evolution of carbide phase fraction, morphology, and composition was investigated using transmission electron microscopy, X-ray diffraction, as well as thermodynamic calculations. Upon heating, retained austenite into the as-quenched material decomposes into ferrite and cementite. M7C3 carbides then nucleate at the interface between the cementite and the matrix, triggering the dissolution of cementite. M2C carbides precipitate separately within the bainitic laths during slow heating. M23C6 carbides precipitate at the interfaces (lath boundaries or prior austenite grain boundaries) and grow by attracting nearby chromium atoms, which results in the dissolution of M7C3 and, depending on the temperature, coarsening, or dissolution of M2C carbides, respectively.

  10. High pressure effect on MoS2 and MoSe2 single crystals grown by ...

    Indian Academy of Sciences (India)

    Unknown

    tetrahedral anvil apparatus up to 5 GPa. In this paper we report room temperature resistance mea- surements as a function of pressure on MoS2 and MoSe2 single crystals. In each case the resistance decreases un- der pressure due to an increase in the carrier concentration. 2. Experimental. Single crystals of MoS2 and ...

  11. Comparative study on cubic and tetragonal CexZr1-xO2 supported MoO3-catalysts for sulfur-resistant methanation

    Science.gov (United States)

    Liu, Zhaopeng; Xu, Yan; Cheng, Jiaming; Wang, Weihan; Wang, Baowei; Li, Zhenhua; Ma, Xinbin

    2018-03-01

    In this paper, two kinds of CexZr1-xO2 solid solution carriers with different Ce/Zr ratio were prepared by one-step co-precipitation method: the cubic Ce0.8Zr0.2O2 and the tetragonal Ce0.2Zr0.8O2 support. The MoO3/Ce0.8Zr0.2O2 and MoO3/Ce0.2Zr0.8O2 catalysts were prepared by incipient wetness impregnation method for comparative study on sulfur-resistant methanation reaction. The N2 adsorption/desorption, X-ray diffraction (XRD), Raman spectroscopy (RS), X-ray photoelectron (XPS), transmission electron microscopy (TEM), temperature-programmed reduction by hydrogen (H2-TPR) were undertaken to characterize the physico-chemical properties of the samples. The results indicated that the prepared MoO3/CexZr1-xO2 catalysts have a mesoporous structure with high surface area and uniform pore size distribution, achieving good MoO3 dispersion on CexZr1-xO2 supports. As for the catalytic performance of sulfur-resistant methanation, the cubic MoO3/Ce0.8Zr0.2O2 exhibited better than the tetragonal MoO3/Ce0.2Zr0.8O2 catalyst at reaction temperature 400 °C and 450 °C. CO conversion on the cubic MoO3/Ce0.8Zr0.2O2 catalyst was 50.1% at 400 °C and 75.5% at 450 °C, which is respectively 7% and 20% higher than that on the tetragonal MoO3/Ce0.2Zr0.8O2 catalyst. These were mainly attributed to higher content of active MoS2 on the surface of catalyst, the enhanced oxygen mobility, increased Mo-species dispersion as well as the excellent reducibility resulted from the increased amount of the reducible Ce3+ on the cubic MoO3/Ce0.8Zr0.2O2 catalyst.

  12. Determination of 99Mo in 99mTc eluates used in nuclear medicine centers in Rio de Janeiro

    International Nuclear Information System (INIS)

    Ribeiro, Bianca da S.; Souza, Raphael S.S.; Lucena, Eder A.; Dantas, Ana Leticia A.; Dantas, Bernardo M.

    2009-01-01

    99m Tc is used in nuclear medicine for image diagnoses with SPECT. It is obtained from the elution of molybdenum-99/technetium-99m ( 99 Mo/ 99m Tc) generators. During the elution, 99 Mo can detach from the column, passing through the filter and mixing in the solution of pertechnetate eluate and becoming a radionuclidic impurity. The presence of molybdenum in the radiopharmaceutical solution imparts an unnecessary radiation dose to the patient, since its half-life is relatively long (66 hours) and it emits beta particles and high-energy photons of (740 keV). A parameter that indicates the quality of the eluates is the radionuclidic purity, the MBT (molybdenum break through), defined as the ratio between 99 Mo and 99m Tc activities in the eluate. The American and the European Pharmacopoeias restrict 99 Mo content to respectively 0.015% and 0.1% activity ratio 99 Mo/ 99m Tc at the time of the administration to the patient. In Brazil, this parameter is not controlled by official regulations. The objective of this work is to determine the presence of 99 Mo in the eluates used in nuclear medicine centers (NMC). The activity measurements of 99 Mo were performed with a NaI(Tl)8''x4'' scintillation detector installed in the IRD whole body counter. The activity of 99m Tc was measured in the NMC where the eluates were collected and, using the established calculations, it was determined the activity ratio 99 Mo/ 99m Tc. The eluate samples were kindly supplied by the participating NMC of Rio de Janeiro. All measurements indicated the presence of 99 Mo. It is concluded that the technique is sensitive to detect 99 Mo in 99m Tc eluates and permits to verify the quality of the generators used in NMC evaluated in this study. (author)

  13. Comparitive study of fluorescence lifetime quenching of rhodamine 6G by MoS2 and Au-MoS2

    Science.gov (United States)

    Shakya, Jyoti; Kasana, Parath; Mohanty, T.

    2018-04-01

    Time resolved fluorescence study of Rhodamine 6G (R6G) in the presence of Molybdenum disulfide (MoS2) nanosheets and gold doped MoS2 (Au-MoS2) have been carried out and discussed. We have analyzed the fluorescence decay curves of R6G and it is observed that Au-MoS2 is a better fluorescence lifetime quencher as compare to MoS2 nanosheets. Also, the energy transfer efficiency and energy transfer rate from R6G to MoS2 and Au-MoS2 has been calculated and found higher for Au-MoS2.

  14. Improvements in the susceptibility to hydrogen attack and stress-relief cracking of 2 1/4Cr-1Mo steels

    International Nuclear Information System (INIS)

    Imanaka, T.; Sato, S.; Shimomura, J.; Aso, K.

    1985-01-01

    The influence of sulphur content at extremely low level on the susceptibility to hydrogen attack and stress-relief cracking in 2 1/4Cr-1Mo steels was studied. The reduction of sulphur content and/or the addition of REM (rare earth metal) or Ca in accordance with sulphur content remarkably improve the resistivity against hydrogen attack and stress-relief cracking. Micro-structural examination has showed that there exist Mn-REM-S-Al-O complex particles in the REM-added steels. It is concluded that the effect of REM on hydrogen attack and stress-relief cracking is to reduce ''the free sulphur'' in 2 1/4Cr-1Mo steels

  15. Evaluation of environmental effect on creep-fatigue of 2 1/4Cr-1Mo steel

    International Nuclear Information System (INIS)

    Yang Beinan; Ishikawa, Akiyoshi; Asada, Yasuhide.

    1991-01-01

    In the present study, a trial evaluation was made to evaluate the environmental effect of air separately from the behavior of material origin. Data with 2 1/4Cr-1Mo steel at 550degC in air were subjected to the evaluation based on data of the steel in high vacuum with a newly developed procedure using the overstress concept. An empirical expression was proposed to describe the environmental effect of air on the creep-fatigue behavior. Following conclusions were obtained in the present study on a separation of the environmental effect of air on a creep-fatigue behavior of 2 1/4Cr-1Mo steel at 550degC. 1) The environmental effect of air reduces a fatigue life, that is, it increases the time-independent damage component of the creep-fatigue. 2) The environmental effect of air brings on the frequency effect which is mainly dependent upon a strain rate or time in a compression going stroke. Other environmental effect on F-S or compression hold-time cycles depends upon the strain rate in compression. 3) The rate-time dependent damage component, that is, the creep damage is reduced by the environmental effect of air. That means a creep-fatigue life recovers in air environment. (author)

  16. Thermal fatigue strength estimation of 2.25Cr-1Mo steel under creep-fatigue interaction

    International Nuclear Information System (INIS)

    Kuwahara, Kazuo; Nitta, Akihito; Kitamura, Takayuki

    1980-01-01

    A 2-1/4Cr-1Mo steel is one of principal materials for high temperature equipments in nuclear and thermal power plants. The authors experimentally analyzed the high temperature fatigue strength and creep strength of a 2-1/4 Cr-1Mo steel main steam pipe which had been used in a thermal plant for operation up to 130,000 hours, and pointed out that the strain-range vs. life curves crossed each other due to the difference of temperature-strain phase in thermal fatigue. This suggests that it is difficult to estimate thermal fatigue life of steel materials having been subjected to different temperature-strain phase on the basis of isothermal low-cycle fatigue life at the upper limit temperature of thermal fatigue, and that it is urgently required to establish an appropriate method of evaluating thermal fatigue life. The authors attempted to prove that the strain range partitioning method used for the evaluation of thermal fatigue life in SUS 304 steels is applicable to this 2-1/4Cr-1Mo steel. Consequently, it was found that the thermal fatigue life could be estimated within a factor of 2.5 by the application of this method. (author)

  17. Shape-selective synthesis of Sn(MoO4)2 nanomaterials for catalysis and supercapacitor applications.

    Science.gov (United States)

    Sakthikumar, K; Ede, Sivasankara Rao; Mishra, Soumyaranjan; Kundu, Subrata

    2016-06-07

    Size and shape-selective Sn(MoO4)2 nanomaterials have been synthesized for the first time using a simple hydrothermal route by the reaction of Sn(ii) chloride salt with sodium molybdate in CTAB micellar media under stirring at 60 °C temperature for about three hours. Needle-like and flake-like Sn(MoO4)2 nanomaterials were synthesized by optimizing the CTAB to metal salt molar ratio and by controlling other reaction parameters. The eventual diameter and length of the nanoneedles are ∼100 ± 10 nm and ∼850 ± 100 nm respectively. The average diameter of the flakes is ∼250 ± 50 nm. The synthesized Sn(MoO4)2 nanomaterials can be used in two potential applications, namely, catalytic reduction of nitroarenes and as an anodic material in electrochemical supercapacitors. From the catalysis study, it was observed that the Sn(MoO4)2 nanomaterials could act as a potential catalyst for the successful photochemical reduction of nitroarenes into their respective aminoarenes within a short reaction time. From the supercapacitor study, it was observed that the Sn(MoO4)2 nanomaterials of different shapes show different specific capacitance (Cs) values and the highest Cs value was observed for Sn(MoO4)2 nanomaterials having a flake-like morphology. The highest Cs value observed was 109 F g(-1) at a scan rate of 5 mV s(-1) for the flake-like Sn(MoO4)2 nanomaterials. The capacitor shows an excellent long cycle life along with 70% retention of the Cs value, even after 4000 consecutive cycles at a current density of 8 mA cm(-2). Other than the applications in catalysis and supercapacitors, the synthesized nanomaterials can find further applications in photoluminescence, sensor and other energy-related devices.

  18. Measurement of Aflatoxin M1 in Raw and Pasteurized Cow Milk Samples by HPLC

    Directory of Open Access Journals (Sweden)

    afshin Nazari

    2007-10-01

    Full Text Available Nazari A1, Noroozi H2, Movahedi M3, Khaksarian M1 1. Instructor, Department of Physiology, Faculty of Medicine, Lorestan University of Medical Sciences 2. Assistant Professor, Department of Mycology, Faculty of Medicine, Iran University of Medical Sciences 3. Assistant Professor, Department of Genetic Epidemiology, Faculty of Medicine, Lorestan University of Medical Sciences Abstract Background: Aflatoxin M1 is a hydroxylated form of aflatoxin B1 which is produced by Aspergillus flavus. This toxin is produced when cows or other ruminants eat foods contaminated with these mycotoxins and then excrete them in the milk. The toxin is a potent liver and kidney carcinogenetic agent. Materials and methods: Forty two raw cows milk samples from local sources of milk collection and forty samples of commercial pasteurized market milk from Khorramabad, Lorestan, Iran were collected in summer and winter season of 2005. Twenty-one cow milk samples and 20 pasteurized milk samples in each season were analyzed for the presence of aflatoxin M1 (AFM1 by HPLC immunoaffinity columns. Results: Four of 21 raw milk samples in summer showed AFM1 levels between 0.017-0.046 ng/ml and all samples (100% in winter showed the presence of AFM1 levels between 0.003-0.041ng/ ml. AFM1 was detected in 55% of market pasteurized cow milk samples ranging from 0.017 to 0.533 ng/ml in summer and 100% ranging from 0.005-0.0054 ng/ml in winter.,Only one of all milk samples of pasteurized milk in summer had toxin level (0.533 ng/ml more than the maximum permissive limit (0.5 ng/ml. No significant difference was observed among mean contamination level of raw and pasteurized cow milk in two seasons. Key words: Aflatoxin M1, raw milk, pasteurized milk, Khoramabad, HPLC

  19. Effect of zirconia morphology on sulfur-resistant methanation performance of MoO3/ZrO2 catalyst

    Science.gov (United States)

    Liu, Chen; Wang, Weihan; Xu, Yan; Li, Zhenhua; Wang, Baowei; Ma, Xinbin

    2018-05-01

    Two kinds of ZrO2 support with different morphologies were prepared by facile solvothermal method in different solvents. The obtained two supports showed monoclinic zirconia (m-ZrO2) and tetragonal zirconia (t-ZrO2) phase with similar crystalline size. Their supported Mo-based catalysts were prepared by impregnation method and the effect of zirconia morphology on the performance of sulfur-resistant methanation was examined. The results indicated that the MoO3/m-ZrO2 has higher CO conversion than the MoO3/t-ZrO2 catalyst. Characterizations by XRD, Raman, H2-TPR and IR confirmed that the m-ZrO2 is superior to t-ZrO2 for dispersing molybdenum species. In addition, the MoO3/m-ZrO2 catalyst has weaker interaction between support and active Mo speices than the MoO3/t-ZrO2 catalyst, which facilitates to forming active species of nanocrystalline MoS2 layers for sulfur-resistant methanation. The weaker interaction of molybdenum species with m-ZrO2 is related with the more covalent character of the Zrsbnd O bond and more oxygen defective structure of m-ZrO2. A larger number of Lewis acid centers appear on the surface of m-ZrO2, which verified the substantial vacancies on m-ZrO2 exposing coordinately unsaturated Zr3+ and Zr4+ cations. Meanwhile, the less Lewis acid of t-ZrO2 result in stronger interaction between support and molybdenum species and trigger crystalline phase MoO3 and Mosbnd Osbnd Zr linkages.

  20. Non-stoichiometry of MoS2 phase prepared by sputtering

    International Nuclear Information System (INIS)

    Ito, T.; Nakajima, K.

    1978-01-01

    The lattice parameters and S/Mo atomic ratio in sputtered MoS 2 films have been examined as a function of sputtering conditions, especially the vacuum pressure in the chamber. It was found that the deposited films had a defect MoS 2 structure ranging from 1.6 to 2 in S/Mo ratio, depending on the pressure. (author)

  1. Species dependent studies of no-carrier-added 93mMo: A green method

    International Nuclear Information System (INIS)

    Mandal, Swadesh; Nayak, Dalia

    2010-01-01

    The present paper reports a combination of radioanalytical and green methodology for the ultra-trace scale speciation of molybdenum. The differential attitude of iron-doped calcium alginate (Fe-CA) and chitosan biopolymers towards no-carrier-added 93m Mo radionuclide was studied to develop environmentally sustainable speciation methodology in ultra-trace scale. The affinity of 93m Mo towards the Fe-CA beads is greater than that of chitosan. Species information was obtained by comparing the adsorption profile of 93m Mo on Fe-CA and chitosan biopolymer with the software code CHEAQS PRO program. From the experimental results it is concluded that no-carrier-added 93m Mo radionuclide form mononuclear species instead of polynuclear species in aqueous solution. Use of biodegradable, non-toxic biopolymer makes this method a step forward towards green chemistry.

  2. Potential Ways to Address Shortage Situations of 99Mo/99mTc.

    Science.gov (United States)

    Filzen, Leah M; Ellingson, Lacey R; Paulsen, Andrew M; Hung, Joseph C

    2017-03-01

    99m Tc, the most common radioisotope used in nuclear medicine, is produced in a nuclear reactor from the decay of 99 Mo. There are only a few aging nuclear reactors around the world that produce 99 Mo, and one of the major contributors, the National Research Universal (Canada), ceased production on October 31, 2016. The National Research Universal produced approximately 40% of the world's 99 Mo supply, so with its shut down, shortages of 99 Mo/ 99m Tc are expected. Methods: Nuclear pharmacies and nuclear medicine departments throughout the United States were contacted and asked to provide their strategies for coping with a shortage of 99 Mo/ 99m Tc. Each of these strategies was evaluated on the basis of its effectiveness for conserving 99m Tc while still meeting the needs of the patients. Results: From the responses, the following 6 categories of strategies, in order of importance, were compiled: contractual agreements with commercial nuclear pharmacies, alternative imaging protocols, changes in imaging schedules, software use, generator management, and reduction of ordered doses or elimination of backup doses. Conclusion: The supply chain of 99 Mo/ 99m Tc is quite fragile; therefore, being aware of the most appropriate coping strategies is crucial. It is essential to build a strong collaboration between the nuclear pharmacy and nuclear medicine department during a shortage situation. With both nuclear medicine departments and nuclear pharmacies implementing viable strategies, such as the ones proposed, the amount of 99m Tc available during a shortage situation can be maximized. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  3. Metallic 1T-LixMoS2 Cocatalyst Significantly Enhanced the Photocatalytic H2 Evolution over Cd0.5Zn0.5S Nanocrystals under Visible Light Irradiation.

    Science.gov (United States)

    Du, Hong; Guo, Hong-Li; Liu, Ya-Nan; Xie, Xiao; Liang, Kuang; Zhou, Xiao; Wang, Xin; Xu, An-Wu

    2016-02-17

    In the present work, metallic 1T-LixMoS2 is utilized as a novel cocatalyst for Cd0.5Zn0.5S photocatalyst. The obtained LixMoS2/Cd0.5Zn0.5S hybrids show excellent photocatalytic performance for H2 generation from aqueous solution containing Na2S and Na2SO3 under splitting visible light illumination (λ ≥ 420 nm) without precious metal cocatalysts. It turns out that a certain amount of intercalating Li(+) ions ultimately drives the transition of MoS2 crystal from semiconductor triagonal phase (2H phase) to metallic phase (1T phase). The distinct properties of 1T-LixMoS2 promote the efficient separation of photoexcited electrons and holes when used as cocatalyst for Cd0.5Zn0.5S photocatalyst. As compared to 2H-MoS2 nanosheets only having edge active sites, photoinduced electrons not only transfer to the edge sites of 1T-LixMoS2, but also to the plane active sites of 1T-LixMoS2 nanosheets. The content of LixMoS2 in hybrid photocatalysts influences the photocatalytic activity. The optimal 1T-LixMoS2 (1.0 wt %)/Cd0.5Zn0.5S nanojunctions display the best activity for hydrogen production, achieving a hydrogen evolution rate of 769.9 μmol h(-1), with no use of noble metal loading, which is about 3.5 times higher than that of sole Cd0.5Zn0.5S, and 2 times higher than that of 2H-MoS2 (1.0 wt %)/Cd0.5Zn0.5S samples. Our results demonstrate that Li(+)-intercalated MoS2 nanosheets with high conductivity, high densities of active sites, low cost, and environmental friendliness are a prominent H2 evolution cocatalyst that might substitute for noble metal for potential hydrogen energy applications.

  4. Evolution of MoTeO x/SiO 2 and MoBiTeO x/SiO 2 catalysts in the partial oxidation of propane to acrolein

    Science.gov (United States)

    He, Yiming; Wu, Ying

    2010-04-01

    A thorough investigation of the catalysts Mo 1Te 1O x/SiO 2 and Mo 1Bi 0.05Te 1O x/SiO 2 in the partial oxidation of propane is presented in this paper, in order to elucidate the nature and behavior of the active surface. The catalysts' structures and redox properties were investigated by means of X-ray powder diffraction, Raman spectroscopy, in situ Raman spectroscopy, X-ray photoelectron spectroscopy, and H 2-TPR techniques. The results indicate that Te-polymolybdate is the main active phase on fresh catalysts. During reaction, the catalysts underwent a progressive reduction, resulting in the reconstruction of the active surface and the formation of a MoO 3 phase. The synergistic effect between Te-polymolybdate and MoO 3 was assumed to promote catalytic performance. The different stabilities of Mo 1Te 1O x/SiO 2 and Mo 1Bi 0.05Te 1O x/SiO 2 catalysts are also discussed.

  5. Low percentage of free prostate-specific antigen (PSA) is a strong predictor of later detection of prostate cancer among Japanese men with serum levels of total PSA of 4.0 ng/mL or less.

    Science.gov (United States)

    Sasaki, Mitsuharu; Ishidoya, Shigeto; Ito, Akihiro; Saito, Hideo; Yamada, Shigeyuki; Mitsuzuka, Koji; Kaiho, Yasuhiro; Shibuya, Daisuke; Yamaguchi, Takuhiro; Arai, Yoichi

    2014-11-01

    To investigate the effect of the percentage of free prostate-specific antigen (%fPSA) on future prostate cancer risk. We examined serum total PSA (tPSA) and %fPSA annually in a prostate cancer-screening cohort between July 2001 and June 2011. Men with tPSA >4.0 ng/mL or tPSA of 2.0-4.0 ng/mL with %fPSA ≤12% were screened as positive and were recommended to undergo a biopsy. The study population consisted of 6368 men, aged 40-79 years, who had tPSA ≤4.0 ng/mL at initial screening and who subsequently underwent 1 or more screenings. We calculated the cumulative risk and hazard ratio of prostate cancer stratified by the initial %fPSA groups as quartiles of prostate cancer patients. During a median follow-up of 36 months, 119 men were diagnosed with prostate cancer. The lowest quartile of %fPSA (22.2%). For the subset with an initial tPSA ≤1.0 ng/mL, all men diagnosed with cancer had an initial %fPSA ≤33.3% (median). For the subset with tPSA >1.0 ng/mL, men with %fPSA ≤23.0% (median) had significantly higher risk for cancer than those with %fPSA >23.0% (P men with prostate cancer in whom pathologic findings were available, 79 (69.3%) had a Gleason score ≥3 + 4 = 7. A low %fPSA is a strong predictor of a subsequent diagnosis of prostate cancer among men with tPSA levels ≤4.0 ng/mL. Measurement of %fPSA might enhance the detection of high-grade cancer that warrants aggressive treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Type IIIa cracking at 2CrMo welds in 1/2CrMoV pipework

    Energy Technology Data Exchange (ETDEWEB)

    Brett, S J; Smith, P A [National Power plc, Swindon (United Kingdom)

    1999-12-31

    The most common form of in-service defect found today on the welds of National Power`s 1/2CrMoV pipework systems is Type IV cracking which occurs in intercritically transformed material at the edge of the heat affected zone. However an alternate form of cracking, termed IIIa, which occurs close to the weld fusion line in fully grain refined heat affected zones, has also been observed. The incidence of Type IIIa cracking has increased in recent years and these defects now constitute a significant part of the total recorded crack population. This presentation describes Type IIIa cracking and compares and contrasts it with the better documented Type IV cracking. Particular reference is made to the role of carbon diffusion at the weld fusion line in promoting Type IIIa damage in preference to Type IV. (orig.) 5 refs.

  7. Type IIIa cracking at 2CrMo welds in 1/2CrMoV pipework

    Energy Technology Data Exchange (ETDEWEB)

    Brett, S.J.; Smith, P.A. [National Power plc, Swindon (United Kingdom)

    1998-12-31

    The most common form of in-service defect found today on the welds of National Power`s 1/2CrMoV pipework systems is Type IV cracking which occurs in intercritically transformed material at the edge of the heat affected zone. However an alternate form of cracking, termed IIIa, which occurs close to the weld fusion line in fully grain refined heat affected zones, has also been observed. The incidence of Type IIIa cracking has increased in recent years and these defects now constitute a significant part of the total recorded crack population. This presentation describes Type IIIa cracking and compares and contrasts it with the better documented Type IV cracking. Particular reference is made to the role of carbon diffusion at the weld fusion line in promoting Type IIIa damage in preference to Type IV. (orig.) 5 refs.

  8. Top-Down and Bottom-Up Approaches in Engineering 1 T Phase Molybdenum Disulfide (MoS2 ): Towards Highly Catalytically Active Materials.

    Science.gov (United States)

    Chua, Chun Kiang; Loo, Adeline Huiling; Pumera, Martin

    2016-09-26

    The metallic 1 T phase of MoS2 has been widely identified to be responsible for the improved performances of MoS2 in applications including hydrogen evolution reactions and electrochemical supercapacitors. To this aim, various synthetic methods have been reported to obtain 1 T phase-rich MoS2 . Here, the aim is to evaluate the efficiencies of the bottom-up (hydrothermal reaction) and top-down (chemical exfoliation) approaches in producing 1 T phase MoS2 . It is established in this study that the 1 T phase MoS2 produced through the bottom-up approach contains a high proportion of 1 T phase and demonstrates excellent electrochemical and electrical properties. Its performance in the hydrogen evolution reaction and electrochemical supercapacitors also surpassed that of 1 T phase MoS2 produced through a top-down approach. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Effect of MoSi2 addition and particle size of SiC on pressureless sintering behavior and mechanical properties of ZrB2–SiC–MoSi2 composites

    Directory of Open Access Journals (Sweden)

    Mehri Mashhadi

    2016-07-01

    Full Text Available In the present paper, ZrB2–SiC–MoSi2 composites were prepared by pressureless sintering at temperatures of 2050, 2100 and 2150 °C for 1 h under argon atmosphere. In order to prepare composite samples, ZrB2 powder was milled for 2 h, then the reinforcing particles including of micron and nano-sized SiC powder were added. MoSi2 was added to ZrB2 from 0 to 5 wt.% as sintering aid. The mixtures were formed and, after the pyrolysis, they were sintered. Densification, microstructure and mechanical properties of ZrB2–SiC composites were investigated. The shrinkage of samples was measured, and the microstructure of samples was examined using scanning electron microscopy (SEM, equipped with EDS spectroscopy. In order to examine the oxidation behavior, the samples were heat treated at 1500 °C in air and then their weight changes were measured. Room temperature mechanical properties were examined. Mass fraction of MoSi2, particle size of SiC powder and sintering temperature have a great effect on relative density, porosity, shrinkage, hardness, fracture toughness, oxidation resistance and microstructure of these composites. The highest relative density, hardness, fracture toughness and weight changes of 98.7%, 16.17 GPa, 3 MPa m1/2 and 0.28%, respectively, were obtained in ZrB2–10 wt.%SiCnano–4 wt.%MoSi2 composites sintered at 2150 °C.

  10. Mild hydrothermal synthesis, crystal structure, spectroscopic and magnetic properties of the [MxIIM2.5-xIII(H2O)2(HPIIIO3)y(PVO4)2-yF] [M=Fe, x=2.08, y=1.58; M=Co, Ni, x=2.5, y=2] compounds

    International Nuclear Information System (INIS)

    Orive, Joseba; Mesa, Jose L.; Legarra, Estibaliz; Plazaola, Fernando; Arriortua, Maria I.; Rojo, Teofilo

    2009-01-01

    The [M x II M 2.5-x III (H 2 O) 2 (HP III O 3 ) y (P V O 4 ) 2-y F] [M=Fe (1), x=2.08, y=1.58; M=Co (2), x=2.5, y=2; Ni (3), x=2.5, y=2] compounds have been synthesized using mild hydrothermal conditions at 170 deg. C during five days. Single-crystals of (1) and (2), and polycrystalline sample of (3) were obtained. These isostructural compounds crystallize in the orthorhombic system, space group Aba2, with a=9.9598(2), b=18.8149(4) and c=8.5751(2) A for (1), a=9.9142(7), b=18.570(1) and c=8.4920(5) A for (2) and a=9.8038(2), b=18.2453(2) and c=8.4106(1) A for (3), with Z=8 in the three phases. An X-ray diffraction study reveals that the crystal structure is composed of a three-dimensional skeleton formed by [MO 5 F] and [MO 4 F 2 ] (M=Fe, Co and Ni) octahedra and [HPO 3 ] tetrahedra, partially substituted by [PO 4 ] tetrahedra in phase (1). The IR spectra show the vibrational modes of the water molecules and those of the (HPO 3 ) 2- tetrahedral oxoanions. The thermal study indicates that the limit of thermal stability of these phases is 195 deg. C for (1) and 315 deg. C for (2) and (3). The electronic absorption spectroscopy shows the characteristic bands of the Fe(II), Co(II) and Ni(II) high-spin cations in slightly distorted octahedral geometry. Magnetic measurements indicate the existence of global antiferromagnetic interactions between the metallic centers with a ferromagnetic transition in the three compounds at 28, 14 and 21 K for (1), (2) and (3), respectively. Compound (1) exhibits a hysteresis loop with remnant magnetization and coercive field values of 0.72 emu/mol and 880 Oe, respectively. - Abstract: Polyhedral view of the crystal structure of the [M x II M 2.5-x III (H 2 O) 2 (HP III O 3 ) y (P IV O 4 ) 2-y F] [M=Fe, x=2.08, y=1.58; M=Co, Ni, x=2.5, y=2] compounds showing the sheets along the [001] direction.

  11. A calorimetric and thermodynamic investigation of A2[(UO2)2(MoO4)O2] compounds with A = K and Rb and calculated phase relations in the system (K2MoO4 + UO3 + H2O)

    International Nuclear Information System (INIS)

    Lelet, Maxim I.; Suleimanov, Evgeny V.; Golubev, Aleksey V.; Geiger, Charles A.; Bosbach, Dirk; Alekseev, Evgeny V.

    2015-01-01

    Highlights: • We determined the low temperature heat capacity of A 2 [(UO 2 ) 2 (MoO 4 )O 2 ] compounds with A = K and Rb. • We determined enthalpy of formation of K 2 [(UO 2 ) 2 (MoO 4 )O 2 ] by HF solution calorimetry. • We calculated Δ f G° (T = 298 K) of all phases from studied series. • Using obtained data we performed a thermodynamic modelling in the system (K 2 MoO 4 + UO 3 + H 2 O). - Abstract: A calorimetric and thermodynamic investigation of two alkali-metal uranyl molybdates with general composition A 2 [(UO 2 ) 2 (MoO 4 )O 2 ], where A = K and Rb, was performed. Both phases were synthesized by solid-state sintering of a mixture of potassium or rubidium nitrate, molybdenum (VI) oxide and gamma-uranium (VI) oxide at high temperatures. The synthetic products were characterised by X-ray powder diffraction and X-ray fluorescence methods. The enthalpy of formation of K 2 [(UO 2 ) 2 (MoO 4 )O 2 ] was determined using HF-solution calorimetry giving Δ f H° (T = 298 K, K 2 [(UO 2 ) 2 (MoO 4 )O 2 ], cr) = −(4018 ± 8) kJ · mol −1 . The low-temperature heat capacity, C p °, was measured using adiabatic calorimetry from T = (7 to 335) K for K 2 [(UO 2 ) 2 (MoO 4 )O 2 ] and from T = (7 to 326) K for Rb 2 [(UO 2 ) 2 (MoO 4 )O 2 ]. Using these C p ° values, the third law entropy at T = 298.15 K, S°, is calculated as (374 ± 1) J · K −1 · mol −1 for K 2 [(UO 2 ) 2 (MoO 4 )O 2 ] and (390 ± 1) J · K −1 · mol −1 for Rb 2 [(UO 2 ) 2 (MoO 4 )O 2 ]. These new experimental results, together with literature data, are used to calculate the Gibbs energy of formation, Δ f G°, for both phases giving: Δ f G° (T = 298 K, K 2 [(UO 2 ) 2 (MoO 4 )O 2 ], cr) = (−3747 ± 8) kJ · mol −1 and Δ f G° (T = 298 K, Rb 2 [(UO 2 ) 2 (MoO 4 )], cr) = −3736 ± 5 kJ · mol −1 . Smoothed C p °(T) values between 0 K and 320 K are presented, along with values for S° and the functions [H°(T) − H°(0)] and [G°(T) − H°(0)], for both phases. The

  12. Syntheses, structures, and properties of Ag4(Mo2O5)(SeO4)2(SeO3) and Ag2(MoO3)3SeO3

    International Nuclear Information System (INIS)

    Ling Jie; Albrecht-Schmitt, Thomas E.

    2007-01-01

    Ag 4 (Mo 2 O 5 )(SeO 4 ) 2 (SeO 3 ) has been synthesized by reacting AgNO 3 , MoO 3 , and selenic acid under mild hydrothermal conditions. The structure of this compound consists of cis-MoO 2 2+ molybdenyl units that are bridged to neighboring molybdenyl moieties by selenate anions and by a bridging oxo anion. These dimeric units are joined by selenite anions to yield zigzag one-dimensional chains that extended down the c-axis. Individual chains are polar with the C 2 distortion of the Mo(VI) octahedra aligning on one side of each chain. However, the overall structure is centrosymmetric because neighboring chains have opposite alignment of the C 2 distortion. Upon heating Ag 4 (Mo 2 O 5 )(SeO 4 ) 2 (SeO 3 ) looses SeO 2 in two distinct steps to yield Ag 2 MoO 4 . Crystallographic data: (193 K; MoKα, λ=0.71073 A): orthorhombic, space group Pbcm, a=5.6557(3), b=15.8904(7), c=15.7938(7) A, V=1419.41(12), Z=4, R(F)=2.72% for 121 parameters with 1829 reflections with I>2σ(I). Ag 2 (MoO 3 ) 3 SeO 3 was synthesized by reacting AgNO 3 with MoO 3 , SeO 2 , and HF under hydrothermal conditions. The structure of Ag 2 (MoO 3 ) 3 SeO 3 consists of three crystallographically unique Mo(VI) centers that are in 2+2+2 coordination environments with two long, two intermediate, and two short bonds. These MoO 6 units are connected to form a molybdenyl ribbon that extends along the c-axis. These ribbons are further connected together through tridentate selenite anions to form two-dimensional layers in the [bc] plane. Crystallographic data: (193 K; MoKα, λ=0.71073 A): monoclinic, space group P2 1 /n, a=7.7034(5), b=11.1485(8), c=12.7500(9) A, β=105.018(1) V=1002.7(2), Z=4, R(F)=3.45% for 164 parameters with 2454 reflections with I>2σ(I). Ag 2 (MoO 3 ) 3 SeO 3 decomposes to Ag 2 Mo 3 O 10 on heating above 550 deg. C. - Graphical abstract: A view of the one-dimensional [(Mo 2 O 5 )(SeO 4 ) 2 (SeO 3 )] 4- chains that extend down the c-axis in the structure of Ag 4 (Mo 2 O 5 )(SeO 4

  13. '99Mo/99mTc Generator Based on High Radionuclidic Pure Zirconium Molybdate Gel

    International Nuclear Information System (INIS)

    Amin, M.; Mostafa, M.; El-Amir, M.A.; El-Absy, M.A.; Mohamed, O.I.; Farag, A.B.

    2014-01-01

    99 Mo / 99 mTc radioisotope generator was prepared using in-situ precipitated zirconium molybdate chromatographic column. Zirconium molybdate gel matrix was synthesized by precipitation of neutron activation molybdenum-99 from its solution after variety purification processes to prevent contamination of the 99m Tc eluate with cross-contaminants. Greeter than 82.7 ± 0.4 % of the generated 99m Tc was immediately and reproducible eluted by passing 10 ml 0.9 % NaCl solution through the 1 g zirconium molybdate- 99 Mo column matrix at a flow rate of 0.5 ml / min and room temperature with high chemical, radionuclide ( ≥ 99.9 % 99m Tc) and radiochemical purity ( ≥ 97.7 % % as 99 mTcO 4 - ) with ph value suitable for medical uses.

  14. Plasmons on the edge of MoS2 nanostructures

    DEFF Research Database (Denmark)

    Andersen, Kirsten; Jacobsen, Karsten Wedel; Thygesen, Kristian Sommer

    2014-01-01

    Using ab initio calculations we predict the existence of one-dimensional (1D), atomically confined plasmons at the edges of a zigzag MoS2 nanoribbon. The strongest plasmon originates from a metallic edge state localized on the sulfur dimers decorating the Mo edge of the ribbon. A detailed analysis...... of the dielectric function reveals that the observed deviations from the ideal 1D plasmon behavior result from single-particle transitions between the metallic edge state and the valence and conduction bands of the MoS2 sheet. The Mo and S edges of the ribbon are clearly distinguishable in calculated spatially...... resolved electron energy loss spectrum owing to the different plasmonic properties of the two edges. The edge plasmons could potentially be utilized for tuning the photocatalytic activity of MoS2 nanoparticles....

  15. Intercalation of Si between MoS2 layers

    Directory of Open Access Journals (Sweden)

    Rik van Bremen

    2017-09-01

    Full Text Available We report a combined experimental and theoretical study of the growth of sub-monolayer amounts of silicon (Si on molybdenum disulfide (MoS2. At room temperature and low deposition rates we have found compelling evidence that the deposited Si atoms intercalate between the MoS2 layers. Our evidence relies on several experimental observations: (1 Upon the deposition of Si on pristine MoS2 the morphology of the surface transforms from a smooth surface to a hill-and-valley surface. The lattice constant of the hill-and-valley structure amounts to 3.16 Å, which is exactly the lattice constant of pristine MoS2. (2 The transitions from hills to valleys are not abrupt, as one would expect for epitaxial islands growing on-top of a substrate, but very gradual. (3 I(V scanning tunneling spectroscopy spectra recorded at the hills and valleys reveal no noteworthy differences. (4 Spatial maps of dI/dz reveal that the surface exhibits a uniform work function and a lattice constant of 3.16 Å. (5 X-ray photo-electron spectroscopy measurements reveal that sputtering of the MoS2/Si substrate does not lead to a decrease, but an increase of the relative Si signal. Based on these experimental observations we have to conclude that deposited Si atoms do not reside on the MoS2 surface, but rather intercalate between the MoS2 layers. Our conclusion that Si intercalates upon the deposition on MoS2 is at variance with the interpretation by Chiappe et al. (Adv. Mater. 2014, 26, 2096–2101 that silicon forms a highly strained epitaxial layer on MoS2. Finally, density functional theory calculations indicate that silicene clusters encapsulated by MoS2 are stable.

  16. Application of 2-1/4 Cr-1 Mo as a structural material in saturated steam cycle LMFBR systems. Final report

    International Nuclear Information System (INIS)

    Licina, G.J.; Busboom, H.J.; Ring, P.J.; Roy, P.; Schmidt, C.G.; Spalaris, C.N.

    1982-02-01

    The suitability and incentives were examined for using 2-1/4Cr-1Mo steel as a structural material for the entire primary and secondary sodium systems in a 1000 MWe pool-type Liquid Metal Fast Breeder Reactor. The critical properties, advantages and disadvantages of 2-1/4Cr-1Mo, and data needed for design were described for each major component in the reactor. The relative importance of alloy properties to the successful use of ferritics in LMFBR was identified. Licensing issues, likely to surface if ferritic alloys were to be used for critical reactor components, were discussed

  17. First-principles analysis of MoS2/Ti2C and MoS2/Ti2CY2 (Y=F and OH) all-2D semiconductor/metal contacts

    KAUST Repository

    Gan, Liyong

    2013-06-13

    First-principles calculations are used to explore the geometry, bonding, and electronic properties of MoS2/Ti2C and MoS2/Ti2CY2 (Y = F and OH) semiconductor/metal contacts. The structure of the interfaces is determined. Strong chemical bonds formed at the MoS2/Ti2C interface result in additional states next to the Fermi level, which extend over the three atomic layers of MoS2 and induce a metallic character. The interaction in MoS2/Ti2CY2, on the other hand, is weak and not sensitive to the specific geometry, and the semiconducting nature thus is preserved. The energy level alignment implies weak and strong n-type doping of MoS2 in MoS2/Ti2CF2 and MoS2/Ti2C(OH)2, respectively. The corresponding n-type Schottky barrier heights are 0.85 and 0.26 eV. We show that the MoS2/Ti2CF2 interface is close to the Schottky limit. At the MoS2/Ti2C(OH)2 interface, we find that a strong dipole due to charge rearrangement induces the Schottky barrier. The present interfaces are well suited for application in all-two-dimensional devices.

  18. First-principles analysis of MoS2/Ti2C and MoS2/Ti2CY2 (Y=F and OH) all-2D semiconductor/metal contacts

    KAUST Repository

    Gan, Liyong; Huang, Dan; Schwingenschlö gl, Udo; Zhao, Yu-Jun

    2013-01-01

    First-principles calculations are used to explore the geometry, bonding, and electronic properties of MoS2/Ti2C and MoS2/Ti2CY2 (Y = F and OH) semiconductor/metal contacts. The structure of the interfaces is determined. Strong chemical bonds formed at the MoS2/Ti2C interface result in additional states next to the Fermi level, which extend over the three atomic layers of MoS2 and induce a metallic character. The interaction in MoS2/Ti2CY2, on the other hand, is weak and not sensitive to the specific geometry, and the semiconducting nature thus is preserved. The energy level alignment implies weak and strong n-type doping of MoS2 in MoS2/Ti2CF2 and MoS2/Ti2C(OH)2, respectively. The corresponding n-type Schottky barrier heights are 0.85 and 0.26 eV. We show that the MoS2/Ti2CF2 interface is close to the Schottky limit. At the MoS2/Ti2C(OH)2 interface, we find that a strong dipole due to charge rearrangement induces the Schottky barrier. The present interfaces are well suited for application in all-two-dimensional devices.

  19. Electrical characteristics of multilayer MoS2 FET's with MoS2/graphene heterojunction contacts.

    Science.gov (United States)

    Kwak, Joon Young; Hwang, Jeonghyun; Calderon, Brian; Alsalman, Hussain; Munoz, Nini; Schutter, Brian; Spencer, Michael G

    2014-08-13

    The electrical properties of multilayer MoS2/graphene heterojunction transistors are investigated. Temperature-dependent I-V measurements indicate the concentration of unintentional donors in exfoliated MoS2 to be 3.57 × 10(11) cm(-2), while the ionized donor concentration is determined as 3.61 × 10(10) cm(-2). The temperature-dependent measurements also reveal two dominant donor levels, one at 0.27 eV below the conduction band and another located at 0.05 eV below the conduction band. The I-V characteristics are asymmetric with drain bias voltage and dependent on the junction used for the source or drain contact. I-V characteristics of the device are consistent with a long channel one-dimensional field-effect transistor model with Schottky contact. Utilizing devices, which have both graphene/MoS2 and Ti/MoS2 contacts, the Schottky barrier heights of both interfaces are measured. The charge transport mechanism in both junctions was determined to be either thermionic-field emission or field emission depending on bias voltage and temperature. On the basis of a thermionic field emission model, the barrier height at the graphene/MoS2 interface was determined to be 0.23 eV, while the barrier height at the Ti/MoS2 interface was 0.40 eV. The value of Ti/MoS2 barrier is higher than previously reported values, which did not include the effects of thermionic field emission.

  20. Recent Developments in Synthesis of xLi2MnO3 · (1 − x)LiMO2 (M = Ni, Co, Mn) Cathode Powders for High-Energy Lithium Rechargeable Batteries

    International Nuclear Information System (INIS)

    Doan, The Nam Long; Yoo, Kimoon; Hoang, Tuan K. A.; Chen, P.

    2014-01-01

    Lithium-rich layered powders, Li 2 MnO 3 -stabilized LiMO 2 (M = Ni, Co, Mn), are attractive cathode candidates for the next generations of high-energy lithium-ion batteries. However, most of the state-of-the-art preparation procedures are complicated and require multiple energy-intensive reaction steps. Thus, elucidating a low-cost synthetic protocol is important for the application of these materials in future lithium-ion batteries. Recent developments in the synthesis procedures of lithium-rich layered powders are discussed and future directions are pointed out in this review.

  1. Spin pumping in ion-beam sputtered C o2FeAl /Mo bilayers: Interfacial Gilbert damping

    Science.gov (United States)

    Husain, Sajid; Kumar, Ankit; Barwal, Vineet; Behera, Nilamani; Akansel, Serkan; Svedlindh, Peter; Chaudhary, Sujeet

    2018-02-01

    The spin-pumping mechanism and associated interfacial Gilbert damping are demonstrated in ion-beam sputtered C o2FeAl (CFA)/Mo bilayer thin films employing ferromagnetic resonance spectroscopy. The dependence of the net spin-current transportation on Mo layer thickness, 0 to 10 nm, and the enhancement of the net effective Gilbert damping are reported. The experimental data have been analyzed using spin-pumping theory in terms of spin current pumped through the ferromagnet/nonmagnetic metal interface to deduce the real spin-mixing conductance and the spin-diffusion length, which are estimated to be 1.56 (±0.30 ) ×1019m-2 and 2.61 (±0.15 )nm , respectively. The damping constant is found to be 8.8 (±0.2 ) ×10-3 in the Mo(3.5 nm)-capped CFA(8 nm) sample corresponding to an ˜69 % enhancement of the original Gilbert damping 5.2 (±0.6 ) ×10-3 in the Al-capped CFA thin film. This is further confirmed by inserting the Cu dusting layer which reduces the spin transport across the CFA/Mo interface. The Mo layer thickness-dependent net spin-current density is found to lie in the range of 1 -4 MA m-2 , which also provides additional quantitative evidence of spin pumping in this bilayer thin-film system.

  2. Analysis of Scattering by Inhomogeneous Dielectric Objects Using Higher-Order Hierarchical MoM

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Jørgensen, Erik; Meincke, Peter

    2003-01-01

    An efficient technique for the analysis of electromagnetic scattering by arbitrary shaped inhomogeneous dielectric objects is presented. The technique is based on a higher-order method of moments (MoM) solution of the volume integral equation. This higher-order MoM solution comprises recently...... that the condition number of the resulting MoM matrix is reduced by several orders of magnitude in comparison to existing higher-order hierarchical basis functions and, consequently, an iterative solver can be applied even for high expansion orders. Numerical results demonstrate excellent agreement...

  3. Effect of alloying Mo on mechanical strength and corrosion resistance of Zr-1% Sn-1% Nb-1% Fe alloy

    International Nuclear Information System (INIS)

    Sugondo

    2011-01-01

    It had been done research on Zr-1%Sn-1%Nb-1%Fe-(x)%Mo alloy. The ingot was prepared by means of electrical electrode technique. The chemical analysis was identified by XRF, the metallography examination was perform by an optical microscope, the hardness test was done by Vickers microhardness, and the corrosion test was done in autoclave. The objective of this research were making Zr-1%Sn-1%Nb-1%Fe-(x)%Mo alloy with Mo concentration; comparing effect of Mo concentration to metal characteristics of Zr-1%Sn-1%Nb-1%Fe which covered microstructure; composition homogeneity, mechanical strength; and corrosion resistance in steam, and determining the optimal Mo concentration in Zr-1%Sn-1%Nb-1%Fe-(x)% Mo alloy for nuclear fuel cladding which had corrosion resistance and high hardness. The results were as follow: The alloying Mo refined grains at concentration in between 0,1%-0,3% and the concentration more than that could coarsened grains. The hardness of the Zr-1%Sn-1%Nb-1%Fe-(x)%Mo alloy was controlled either by the flaw or the dislocation, the intersection of the harder alloying element, the solid solution of the alloying element and the second phase formation of ZrMo 2 . The corrosion rate of the Zr-1%Sn-1%Nb-1%Fe-(x)%Mo alloy was controlled by the second phase of ZrMo 2 . The 0.3% Mo concentration in Zr-1%Sn-1%Nb-1%Fe-(x)%Mo alloy was the best for second phase formation. The Mo concentration in between 0,3-0,5% in Zr-1%Sn-1%Nb-1%Fe-(x)%Mo alloy was good for the second phase formation and the solid solution. (author)

  4. Sign system choice influence on the substance formation forecast in A2MoO4-B2(MoO4)3 and A2MoO4-CMoO4 systems

    International Nuclear Information System (INIS)

    Manzanov, Yu.E.; Lutsik, V.I.; Mokhosoev, M.V.

    1987-01-01

    Three sign spaces were used for forecasting compound formation in A 2 MoO 4 -B 2 (MoO 4 ) 3 (5:1 ratio, where A-Li, Na, K, Rb, Cs; B-Al, In, Ga, Sc, Cr, Fe, Bi, La, Nd, Sm-Lu, Y) and A 2 MoO 4 -CMoO 4 (1:2 ratio, where A-Li, Na, K, RB, Cs, Tl; C-Mg, Ca, Sr, Ba, Cu, Zn, Cd, Pd, Mn, Co, Ni) systems: 1-electron distribution on energy shells of cations and their valency; 2-the type of incomplete electron shell, charge of cations, three first ionization potentials, standard heat capacity, ionic radius of cations; 3-standard formation enthalpy and standard entropy, oxide melting points and ionic radius of cations. It is shown that sign space, related with thermodynamic properties of oxides contains data, necessary for forecasting interaction in molybdate systems. This enables to improve reliability of forecasting

  5. Crystal structure and thermal stability of AgIn(MoO4)2

    International Nuclear Information System (INIS)

    Klevtsov, P.V.; Solodovnikov, S.F.; Perepelitsa, A.P.; Klevtsova, R.F.

    1984-01-01

    Tetragonal crystals of double molybdate AgIn(MoO 4 ) 2 are prepared bi crystallization from solution in Ag 2 Mo 2 O 7 melt (a=4.998, c=36.725 A, space group I4 1 , Z=6). Its crystal structure is determined (autodaffractometer ''Syntex P2 1 '', MoKsub(α)-radiation, 876 reflections, R=0.054) in which along with Mo-tetrahedrons Mo-octahedrons are present. By mutual edges latter are united into bands forming fragments of wolframite structure alonside with (In, Ag) octahedrons. In the direction of c axis wolframite fragments alternate with scheelite fragments consisting of Mo-tetrahedrons and Ag-octavertices. The crystallochemical formula of the compound is Ag(Insub(0.75)Agsub(0.25))sub(2)Mosub(2)Osub(8) [MoO 4 ]. At a temperature of about 600 deq C AgIn-molybdate transforms into modification with NaIn(MoO 4 ) 2 structure NaIn(MoO 4 ) 2 and melts at 650 deg C decomposing into In 2 (MoO 4 ) 3 solid phase and Ag 2 MoO 4 melt

  6. Achieving tunable doping of MoSe2 based devices using GO@MoSe2 heterostructure

    Science.gov (United States)

    Maji, Tuhin Kumar; Tiwary, Krishna Kanhaiya; Karmakar, Debjani

    2017-05-01

    Doping nature of MoSe2, one of th