Nonparametric inference from the M/G/1 workload

DEFF Research Database (Denmark)

Hansen, Martin Bøgsted; Pitts, Susan M.

2006-01-01

Consider an M/G/1 queue with unknown service-time distribution and unknown traffic intensity ρ. Given systematically sampled observations of the workload, we construct estimators of ρ and of the service-time distribution function, and we study asymptotoic properties of these estimators....

Nonparametric inference from the M/G/1 workload

DEFF Research Database (Denmark)

Hansen, Martin Bøgsted; Pitts, Susan M.

Consider an M/G/1 queue with unknown service-time distribution and unknown traffic intensity $\\rho$. Given systematically sampled observations of the workload, we construct estimators of $\\rho$ and of the service-time distribution function, and we study asymptotic properties of these estimators....

Ab initio study of 3C-SiC/M (M = Ti or Al) nano-hetero interfaces

International Nuclear Information System (INIS)

Tanaka, Shingo; Kohyama, Masanori

2003-01-01

Ab initio pseudopotential calculation of 3C-SiC(1 1 1)/Al nano-hetero interfaces have been performed and interface atom species dependence (IASD) and interface orientation dependence (IOD) of nano-hetero interfaces between 3C-SiC ((1 1 1) or (0 0 1) orientation) and metal (Ti or Al) have been studied systematically. Stable atomic configurations of the 3C-SiC(1 1 1)/Al interfaces are quite different from those of the 3C-SiC(1 1 1)/Ti interfaces. Two terminated, Si-terminated (Si-TERM) and C-terminated (C-TERM), 3C-SiC(1 1 1)/Al interfaces have covalent bonding nature. In 3C-SiC/M (M = Ti or Al) nano-hetero interfaces, the C-terminated interface has relative strong, covalent and ionic C-Ti or C-Al bonds as TiC or SiC while the Si-terminated interface has various type of bonding nature, relative weak Si-Ti or Si-Al bonds from metallic character at the (0 0 1) interface to covalent character at the (1 1 1) interface. Adhesive energy (AE) shows strong IASD and IOD. The AE of the C-terminated interface is larger than that of the Si-terminated one. In the C-terminated interface, the AE of the (1 1 1) interface is smaller than that of the (0 0 1) one while in the Si-terminated interface there exists opposite interrelation. Schottky barrier height (SBH) also shows strong IASD and IOD. The SBH of the C-terminated interface is smaller than that of the Si-terminated one. The C-terminated SiC/Al interfaces have extremely small SBHs. In comparison with some experimental SBH, the present result is reliable as the difference of SBH between the two terminated interfaces and qualitative properties

MiRNA-199a-3p Regulates C2C12 Myoblast Differentiation through IGF-1/AKT/mTOR Signal Pathway

Directory of Open Access Journals (Sweden)

Long Jia

2013-12-01

Full Text Available MicroRNAs constitute a class of ~22-nucleotide non-coding RNAs. They modulate gene expression by associating with the 3' untranslated regions (3' UTRs of messenger RNAs (mRNAs. Although multiple miRNAs are known to be regulated during myoblast differentiation, their individual roles in muscle development are still not fully understood. In this study, we showed that miR-199a-3p was highly expressed in skeletal muscle and was induced during C2C12 myoblasts differentiation. We also identified and confirmed several genes of the IGF-1/AKT/mTOR signal pathway, including IGF-1, mTOR, and RPS6KA6, as important cellular targets of miR-199a-3p in myoblasts. Overexpression of miR-199a-3p partially blocked C2C12 myoblast differentiation and the activation of AKT/mTOR signal pathway, while interference of miR-199a-3p by antisense oligonucleotides promoted C2C12 differentiation and myotube hypertrophy. Thus, our studies have established miR-199a-3p as a potential regulator of myogenesis through the suppression of IGF-1/AKT/mTOR signal pathway.

1.083 μm laser operation in Nd,Mg:LiTaO3 crystal

Science.gov (United States)

Hu, P. C.; Hang, Y.; Li, R.; Gong, J.; Yin, J. G.; Zhao, C. C.; He, X. M.; Yu, T.; Zhang, L. H.; Chen, W. B.; Zhu, Y. Y.

2011-10-01

Nd,Mg:LiTaO3 single crystal with high optical quality was grown by Czochralski technique. Absorption and fluorescence spectra were investigated. The peak absorption cross section at 806.5 nm and peak emission cross section at 1091 nm are 6.81×10-20 and 3.28×10-20 cm2, respectively. The fluorescence lifetime was measured to be 129 μs. With a laser-diode as the pump source, a maximum 375 mW continuous-wave laser output at 1083 nm has been obtained with a slope efficiency of 7.2% with respect to the pump power.

1.083 μm laser operation in Nd,Mg:LiTaO3 crystal

International Nuclear Information System (INIS)

Hu, P C; Hang, Y; Li, R; Gong, J; Yin, J G; Zhao, C C; He, X M; Yu, T; Zhang, L H; Chen, W B; Zhu, Y Y

2011-01-01

Nd,Mg:LiTaO 3 single crystal with high optical quality was grown by Czochralski technique. Absorption and fluorescence spectra were investigated. The peak absorption cross section at 806.5 nm and peak emission cross section at 1091 nm are 6.81×10 -20 and 3.28×10 -20 cm 2 , respectively. The fluorescence lifetime was measured to be 129 μs. With a laser-diode as the pump source, a maximum 375 mW continuous-wave laser output at 1083 nm has been obtained with a slope efficiency of 7.2% with respect to the pump power

The M/G/1 queue with permanent customers

NARCIS (Netherlands)

Boxma, O.J.; Cohen, J.W.

1991-01-01

The authors examine an M/G/1 FCFS (first come, first served) queue with two types of customers: ordinary customers, who arrive according to a Poisson process, and permanent customers, who immediately return to the end of the queue after having received a service. The influence of the permanent

Thermal, Spectral and Laser Properties of Er3+:Yb3+:GdMgB₅O10: A New Crystal for 1.5 μm Lasers.

Science.gov (United States)

Huang, Yisheng; Yuan, Feifei; Sun, Shijia; Lin, Zhoubin; Zhang, Lizhen

2017-12-25

A novel laser crystal of Er 3+ :Yb 3+ :GdMgB₅O 10 with dimension of 26 × 16 × 12 mm³ was grown successfully from K₂Mo₃O 10 flux by the top seeded solution growth method. The thermal diffusivity and specific heat capacity were measured to calculate the thermal conductivity of the crystal. The absorption and fluorescence properties of the crystal at room temperature were investigated in detail. The Judd-Ofelt method was used to analyze the polarized absorption spectra. The emission cross-section of the ⁴I 13/2 →⁴I 15/2 transition was calculated by the Füchtbauer-Ladenburg formula and the relevant gain cross-sections were estimated. Continuous-wave laser output of 140 mW at 1569 nm with the slope efficiency of 17.8% was demonstrated in a plano-concave resonator. The results reveal that Er 3+ :Yb 3+ :GdMgB₅O 10 crystal is a promising material for 1.5 μm lasers.

Micro-Raman study of the microheterogeneity in the MA-MC phase transition in 0.67PbMg1/3Nb2/3O3-0.33PbTiO3 single crystal

KAUST Repository

Yang, Y.

2011-04-20

Polarized Raman spectroscopy has been employed to investigate the evolution of the microstructure of 0.67PbMg1/3Nb2/3O3-0.33PbTiO3 (PMN-33%PT) single crystal in the temperature range from −195 to 300 °C. The M A-M C-cubic transition sequence was observed in the microareas with M A-type (space group Cm) and M C-type (space group Pm) monoclinic structures. Interestingly, the M A-M Cphase transition temperature exhibited remarkable microareal dependence due to the spatial inhomogeneity of polar nanoregions (PNRs). The M C-cubic phase transition took place at 155 °C in both microareas, which consisted well with previous reports. These results reveal that the phase transition in PMN-33%PT single crystal is closely related with the thermal dynamics of PNRs, which will be useful for understanding the microheterogeneity in this compound.

Investigations on FCAM-III (Ca2.38Mg2.09Fe3+10.61Fe2+1.59Al9.33O36): A new homologue of the aenigmatite structure-type in the system CaO-MgO-Fe2O3-Al2O3

Science.gov (United States)

Zöll, Klaus; Kahlenberg, Volker; Krüger, Hannes; Tropper, Peter

2018-02-01

In the course of a systematic study of a part of the quaternary system Fe2O3-CaO-Al2O3-MgO (FCAM) the previously unknown compound Ca2.38Mg2.09Fe3+10.61Fe2+1.59Al9.33O36 (FCAM-III) has been synthesized. By analogy with the so-called SFCA series [1-5], our investigation in the system of FCAM shows the existence of a stoichiometric homologous series M14+6nO20+8n, where M = Fe, Ca, Al, Mg and n = 1 or 2. In air, we can prove the formation of coexisting FCAM-III and FCAM-I solid solutions at 1400 °C. By increasing the temperature up to 1425 °C FCAM-I disappears completely and FCAM-III co-exists with magnesiumferrite and a variety of calcium iron oxides. At 1450 °C FCAM-III breaks down to a mixture of FCAM-I again as well as magnesioferrite and melt. Small single-crystals of FCAM-III up to 35 μm in size could be retrieved from the 1425 °C experiment and were subsequently characterized using electron microprobe analysis and synchroton X-ray single-crystal diffraction. Finally the Fe2+/Fetot ratio was calculated from the total iron content based on the crystal-chemical formula obtained from EMPA measurements and charge balance considerations. FCAM-III or Ca2.38Mg2.09Fe3+10.61Fe2+1.59Al9.33O36 has a triclinic crystal structure (space group P 1 ̅). The basic crystallographic data are: a = 10.223(22) Å, b = 10.316(21) Å, c = 14.203(15) Å, α = 93.473(50)°, β = 107.418(67)°, γ = 109.646(60)°, V = 1323.85(2) ų, Z = 1. Using Schreinemaker's technique to analyze the phase relations in the system Fe2O3-CaO-Al2O3-MgO it was possible to obtain the semi-quantitative stability relations between the participating phases and construct a topologically correct phase sequence as a function of T and fO2. The analysis shows that Ca2Al0.5Fe1.5O5 (C2A0.25F0.75) and CaAl1.5Fe2.5O7 (CA0.75F1.25) with higher calculated Fe2+ contents are preferably formed at lower oxygen fugacity and react to CaAl0.5Fe1.5O4 (CA0.25F0.75) by increasing fO2. Spinel-type magnesium

Luminescence and optical spectroscopy of charge transfer processes in solid solutions Ni{sub C}Mg{sub 1−C}O and Ni{sub x}Zn{sub 1−x}O

Energy Technology Data Exchange (ETDEWEB)

Sokolov, V.I., E-mail: visokolov@imp.uran.ru [Institute of Metal Physics, Russian Academy of Science, Ural Branch, S. Kovalevskaya Street 18, 620990 Yekaterinburg (Russian Federation); Pustovarov, V.A.; Churmanov, V.N. [Ural Federal University, Mira Street 19, 620002 Yekaterinburg (Russian Federation); Gruzdev, N.B.; Uimin, M.A.; Byzov, I.V.; Druzhinin, A.V. [Institute of Metal Physics, Russian Academy of Science, Ural Branch, S. Kovalevskaya Street 18, 620990 Yekaterinburg (Russian Federation); Mironova-Ulmane, N.A. [Institute of Solid State Physics, University of Latvia, Kengaraga Street 8, LV-1063 Riga (Latvia)

2016-01-15

In this work photoluminescence spectra for Ni{sub c}Mg{sub 1−c}O and Ni{sub x}Zn{sub 1−x}O solid solutions with the rock-salt crystal structure were obtained under synchrotron radiation excitation. Periodical peaks in the photoluminescence excitation spectrum of Ni{sub c}Mg{sub 1−c}O (c=0.008) have been discovered for a wide-gap oxide doped with 3d impurities for the first time. They can be considered as LO phonon repetitions of the narrow zero phonon line resulted from the optical transitions into the p–d charge transfer exciton [d{sup 9}h] state. A close coincidence in energy of different peculiarities in the optical absorption and photoluminescence excitation spectra for the Ni{sub c}Mg{sub 1−c}O and Ni{sub x}Zn{sub 1−x}O solid solutions is due to the practically equal interatomic distances Ni–O in the investigated materials. The bulk of new experimental results is the trustworthy evidence that only the p–d charge transfer transitions manifest themselves in the spectral region of 3.5–6.5 eV. - Highlights: • Emission of Ni{sub c}Mg{sub 1−c}O nanocystals excited by synchrotron radiation is obtained. • LO phonon repetitions have been observed in PLE spectra of Ni{sub c}Mg{sub 1−c}O firstly for wide gap oxide materials doped with 3d impurities. • The [d{sup 9}h] acceptor exciton state in Ni{sub c}Mg{sub 1−c}O (c=0.008) are indirectly revealed. • The begin of PLE spectra of Ni{sub x}Zn{sub 1−x}O are not virtually shifted with a change of composition x. • The near energy coincidence of absorption peaks for nanocrystals NiO and single crystal Ni{sub c}Mg{sub 1−c}O (c=0.0006) manifests itself.

Interface reactions in the Al-Si-SiC and Mg-Al-Al{sub 2}O{sub 3} composite systems

Energy Technology Data Exchange (ETDEWEB)

Johnson, P.K. [Commission of the European Communities, Petten (Netherlands). Inst. for Advanced Materials; Fazal-Ur-Rehman [Imperial Coll. of Science, Technology and Medicine, London (United Kingdom). Dept. of Materials; Fox, S. [Imperial Coll. of Science, Technology and Medicine, London (United Kingdom). Dept. of Materials; Flower, H.M. [Imperial Coll. of Science, Technology and Medicine, London (United Kingdom). Dept. of Materials; West, D.R.F.

1995-12-31

Structural and compositional observations are reported on the influence of the interfaces on the mechanisms and kinetics of liquid metal-ceramic reactions in Al-SiC, Al-Si-SiC, Mg-Al{sub 2}O{sub 3} and Mg-Al-Al{sub 2}O{sub 3} composites. The aluminium based materials contained up to 20 vol% SiC in particulate form, and were produced by a spray casting process; subsequently the interface reactions were studied in samples heated to temperatures up to 1100 C. The reaction product was Al{sub 4}C{sub 3} in both Al-SiC and Al-Si-SiC composites. The influence of the crystallography and topology of the SiC particle surfaces on the nucleation of the Al{sub 4}C{sub 3} has been demonstrated; surface asperities play an important role. Growth of nuclei proceeds to form continuous reaction product layers which control the subsequent kinetics. The magnesium based composites contained 5 vol% Al{sub 2}O{sub 3} fibres (3 {mu}m in diameter), and were produced by a liquid infiltration process. SD Safimax fibres with relatively low and high porosity, and also RF Saffil fibres, with a silica binder, were investigated. Fibre porosity plays a major role in accelerating the penetration of Mg into the fibres with reaction to form MgO. Silica binder on the fibre surface transforms to MgO. The reaction rate was reduced by the presence of aluminium in the matrix. The factors controlling the reactions in the aluminium and magnesium based composites are compared. (orig.)

The M/G/1 queue with quasi-restricted accessibility

NARCIS (Netherlands)

Boxma, O.J.; Perry, D.; Stadje, W.; Zacks, S.

2009-01-01

We consider single-server queues of the M/G/1 kind with a special kind of partial customer rejection called quasi-restricted accessibility (QRA). Under QRA, the actual service time assigned to an arriving customer depends on his service requirement, say x, the current workload, say w, and a

Structural, elastic and electronic properties of C14-type Al{sub 2}M (M=Mg, Ca, Sr and Ba) Laves phases

Energy Technology Data Exchange (ETDEWEB)

Lishi, Ma; Yonghua, Duan, E-mail: duanyh@kmust.edu.cn; Runyue, Li

2017-02-15

The structural and mechanical properties, Debye temperatures and anisotropic sound velocities of the Laves phases Al{sub 2}M (M=Mg, Ca, Sr and Ba) with C14-type structure were investigated using the first-principles corresponding calculations. The corresponding calculated structural parameters and formation enthalpies are in good agreement with the available theoretical values, and Al{sub 2}Ca has the best phase stability. The mechanical properties, including elastic constants, bulk modulus B, shear modulus G, Young’s modulus E, and Poisson ratio ν, were deduced within the Voigt-Reuss-Hill approximation. The brittleness and ductility were estimated by the values of Poisson ratio, B/G and Cauchy pressure. Moreover, the elastic anisotropy was investigated by calculating and discussing several anisotropy indexes. Finally, the electronic structures were used to illustrate the bonding characteristics of C14-Al{sub 2}M (M=Mg, Ca, Sr and Ba) phases.

Fatigue properties of piezoelectric-electrostrictive Pb(Mg1/3,Nb2/3)O3-PbTiO3 monolithic bilayer composites

Science.gov (United States)

Hall, A.; Akdogan, E. K.; Safari, A.

2006-11-01

The fatigue response of monolithic piezoelectric 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3-electrostrictive 0.90Pb(Mg1/3Nb2/3)O3-0.10PbTiO3 bilayer composites was investigated experimentally. The monomorph bilayers were cosintered at 1150°C, and the polarization hysteresis, relative permittivity, displacement, and cyclic fatigue (107cycles) were measured as a function of piezoelectric-electrostrictive volume fraction (PEVF) ratio. The highest tip displacement of bilayers was found in the 3:1 PEVF monolith, reaching 40μm at 5kV/cm applied field strength. By minimizing the electrostrictive layer thickness, tip displacement substantially increased, while maintaining a lower hysteresis than the purely piezoelectric counterpart. Fatigue measurements indicated a 31% decrease in displacement after 107cycles in 3:1 monoliths, whereas the 1:3 PEVF only showed a 12% decrease under the same conditions. There is a 30% increase in polarization after 107cycles for 1:1 PEVF bilayers, which is attributed to self-poling due to a diffuse transition layer in the vicinity of the interface. It was found that partial 90° domain switching occurred prior to poling because of the residual stresses in the composite, imposed by the electrostrictive layer and the spontaneous strain associated with the cubic-tetragonal transition in the ferroelectric layer. The results indicate that the electrostrictive layer, which is electrically in series with the piezoelectric one, enhances the fatigue resistance of the monolithic bilayer composites in addition to the increase in tip displacement.

Co-hydrothermal synthesis of LiMn{sub 23/24}Mg{sub 1/24}PO{sub 4}·LiAlO{sub 2}/C nano-hybrid cathode material with enhanced electrochemical performance for lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jun [School of Metallurgy, Northeastern University, Shenyang, 110004 (China); Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province, Qinhuangdao, 066004 (China); Luo, Shaohua, E-mail: tianyanglsh@163.com [School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao, 066004 (China); Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province, Qinhuangdao, 066004 (China); School of Materials Science and Engineering, Northeastern University, Shenyang, 110004 (China); Chang, Longjiao [School of New Energy, Bohai University, Jinzhou, 121013 (China); Hao, Aimin; Wang, Zhiyuan; Liu, Yanguo [School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao, 066004 (China); Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province, Qinhuangdao, 066004 (China); School of Materials Science and Engineering, Northeastern University, Shenyang, 110004 (China); Xu, Qian [School of Materials Science and Engineering, Shanghai University, Shanghai, 200072 (China); Wang, Qing; Zhang, Yahui [School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao, 066004 (China); Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province, Qinhuangdao, 066004 (China); School of Materials Science and Engineering, Northeastern University, Shenyang, 110004 (China)

2017-02-01

Highlights: • A co-hydrothermal approach to synthesize LiMn{sub 23/24}Mg{sub 1/24}PO{sub 4}·LiAlO{sub 2}/C composite material in water/PEG system is present. • The Mn{sub 1-x}Mg{sub x}PO{sub 4} precursor is prepared by precipitation reaction. • Co-modified with Mg{sup 2+} doping and LiAlO{sub 2} compositing strategies play an important role in improving the electronic conductivity and facilitating the diffusion of lithium ion. • LiMn{sub 23/24}Mg{sub 1/24}PO{sub 4}·LiAlO{sub 2}/C composite material exhibits a high specific discharge capacity of 151.8 mAh/g at 0.05C. - Abstract: LiMn{sub 23/24}Mg{sub 1/24}PO{sub 4}·LiAlO{sub 2}/C is synthesized by a co-hydrothermal method in water/PEG system using Li{sub 2}CO{sub 3}, AAO and Mn{sub 1-x}Mg{sub x}PO{sub 4} as raw material. The electronic structure and micromorphology of multi-component compound LiMn{sub 1-x}Mg{sub x}PO{sub 4}/C (x = 0, 1/24, 1/12, 1/6) and nano-hybrid LiMn{sub 23/24}Mg{sub 1/24}PO{sub 4}·LiAlO{sub 2}/C cathode materials are studied by first-principles calculation and experimental research including XRD, SEM, TEM. The calculated band gap of LiMn{sub 23/24}Mg{sub 1/24}PO{sub 4}/C is 2.296 eV, which is lower than other percentages Mg{sup 2+} doping samples. Electrochemical tests exhibit LiMn{sub 23/24}Mg{sub 1/24}PO{sub 4}/C has better cycling performance and rate capability than other contents Mg{sup 2+} doping samples with the discharge capacity of 143.5 mAh/g, 141.5 mAh/g, 139.2 mAh/g and 136.3 mAh/g at 0.05C, 0.1C, 0.5C and 1C in order. After compositing and preparation of LiMn{sub 23/24}Mg{sub 1/24}PO{sub 4}·LiAlO{sub 2}/C composite material by co-hydrothermal route, the initial discharge capacity reaches up to 151.8 mAh/g, which suggests that co-modified with Mg{sup 2+} doping and LiAlO{sub 2} compositing material can improve the electronic conductivity of LiMnPO{sub 4}/C by facilitating the lithium ion diffusion rate in the interior of the materials.

Legendre polynomial modeling for vibrations of guided Lamb waves modes in [001]c, [011]c and [111]c polarized (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (x = 0.29 and 0.33) piezoelectric plates: Physical phenomenon of multiple intertwining of An and Sn modes

Science.gov (United States)

Othmani, Cherif; Takali, Farid; Njeh, Anouar

2017-12-01

Guided wave devices have recently become one of the most important applications in the industry because such waves are directly related to applications in sensor technology, chemical sensing, agricultural science, fields of bio-sensing and surface acoustic wave (SAW) devices that are used in electronic filters and signal processing. On that account, this numerical investigation aims to study the propagation behavior of guided Lamb waves in a (1-x)Pb(Mg1/3Nb2/3)O3- x PbTiO3 [PMN- x PT] ( x=0.29 or 0.33) piezoelectric single crystal plate. In fact, the PMN- xPT ( x=0.29 or 0.33) piezoelectric crystals are being polarized along [001]c, [011]c and [111]c of the cubic reference directions so that the macroscopic symmetries are tetragonal 4 mm, orthogonal mm2 and rhombohedral 3 m, respectively. Both open- and short-circuit conditions are considered. Here, the Legendre polynomial method is proposed to solve the guided Lamb waves equations. The validity of the proposed method is illustrated by comparison with the ordinary differential equation (ODE). The convergence of this method is discussed. Consequently, the converged results are obtained with very low truncation order M . This constitutes a major advantage of the present method when compared with the other matrix methods. There is cross-crossings among multiple modes for both symmetric ( Sn) and the anti-symmetric ( An) guided Lamb waves propagation. A displacement field has been illustrated to judge whether Sn and An modes cross with each other. Moreover, electric displacement, stress field and electric potential for the open-circuit case were presented for both S0 and A0 Lamb modes.

Modelling M/G/1 queueing systems with server vacations using ...

African Journals Online (AJOL)

Simple numerical examples are also provided to illustrate the func- ... M/G/1/N queueing systems with server vacations under a limited service discipline ...... system contents in a discrete-time non-preemptive priority queue with general service.

Inefficient binding of IgM immune complexes to erythrocyte C3b-C4b receptors (CR1) and weak incorporation of C3b-iC3b into the complexes

DEFF Research Database (Denmark)

Kávai, M; Rasmussen, J M; Baatrup, G

1988-01-01

, but the binding was low (2-3%) when compared to the binding of the corresponding IgG-IC (50-60%). Solid phase IC were prepared by coating microwells with heat-aggregated bovine serum albumin (BSA) followed by incubation with rabbit IgM anti-BSA antibody. The IC were reacted with human serum at 37 degrees C....... The binding of C3b-iC3b was determined by use of biotinylated F(ab')2 antibodies to C3b-C3c and avidin-coupled alkaline phosphatase. The incorporation of C3b-iC3b into solid-phase IgM-IC increased when increasing amounts of IgM antibody were reacted with the antigen. The binding reaction was slow, reaching...

Stability of a1 mg/mL oral solution zidovudine

International Nuclear Information System (INIS)

Garcia Penna, Caridad Margarita; Morales Lacarrere, Ivan; Martinez Espinosa, Vivian

2011-01-01

The carrying out of a high-performance liquid chromatography analytical method was assessed; applicable to stability study of oral solution zidovudine (1 mg/mL) was made. The analytical method was linear, precise, specific and exact in the study concentrations. The stability study of oral solution zidovudine (1 mg/mL) was conducted determining expiring date. The shelf life study was conducted over 24 months at room temperature; whereas that of accelerated stability was conducted with the product under wet and temperature conditions; analysis was carried out over three months. Formula met quality specifications described in Pharmacopeia. Results from the shelf life study demonstrated that product keeps the parameters determining its quality during that time and in accelerated studies there was not significant product degradation. Under above mentioned conditions two years were established as expiring date

Hydrogen storage properties of LaMgNi3.6M0.4 (M = Ni, Co, Mn, Cu, Al) alloys

International Nuclear Information System (INIS)

Yang, Tai; Zhai, Tingting; Yuan, Zeming; Bu, Wengang; Xu, Sheng; Zhang, Yanghuan

2014-01-01

Highlights: • La–Mg–Ni system AB 2 -type alloys were prepared by induction melting. • Structures and lattice parameters were analysed by XRD. • Hydrogen absorption/desorption performances were studied. • Mechanisms of hydrogen absorption capacity fading were investigated. - Abstract: LaMgNi 3.6 M 0.4 (M = Ni, Co, Mn, Cu, Al) alloys were prepared through induction melting process. The phase compositions and crystal structures were characterised via X-ray diffraction (XRD). The hydrogen storage properties, including activation performance, hydrogen absorption capacity, cycle stability, alloy particle pulverisation and plateau pressure, were systemically investigated. Results show that Ni, Co, Mn and Cu substitution alloys exhibit multiphase structures comprising the main phase LaMgNi 4 and the secondary phase LaNi 5 . However, the secondary phase of the Al substitution alloy changes into LaAlNi 4 . The lattice parameters and cell volumes of the LaMgNi 4 phase follow the order Ni < Co < Al < Cu < Mn. Activation is simplified through partial substitution of Ni with Al, Cu and Co. The hydrogen absorption capacities of all of the alloys are approximately 1.7 wt.% at the first activation process; however, they rapidly decrease with increasing cycle number. In addition, the stabilities of hydriding and dehydriding cycles decrease in the order Al > Co > Ni > Cu > Mn. Hydriding processes result in numerous cracks and amorphisation of the LaMgNi 4 phase in the alloys. The p–c isotherms were determined by a Sieverts-type apparatus. Two plateaus were observed for the Ni, Co and Al substitution alloys, whereas only one plateau was found for Mn and Cu. This result was caused by the amorphisation of the LaMgNi 4 phase during the hydriding cycles. Reversible absorption and desorption of hydrogen are difficult to achieve. Substitutions of Ni with Co, Mn, Cu and Al significantly influence the reduction of hysteresis between hydriding and dehydriding

New Pb(Mg1/3Nb2/3)O3-Pb(In1/2Nb1/2)O3-PbZrO3-PbTiO3 Quaternary Ceramics: Morphotropic Phase Boundary Design and Electrical Properties.

Science.gov (United States)

Luo, Nengneng; Zhang, Shujun; Li, Qiang; Xu, Chao; Yang, Zhanlue; Yan, Qingfeng; Zhang, Yiling; Shrout, Thomas R

2016-06-22

Four series of Pb(Mg1/3Nb2/3)O3-Pb(In1/2Nb1/2)O3-PbZrO3-PbTiO3 (PMN-PIN-PZ-PT) quaternary ceramics with compositions located at the morphotropic phase boundary (MPB) regions were prepared. The MPBs of the multicomponent system were predicted using a linear combination rule and experimentally confirmed by X-ray powder diffraction and electrical measurement. The positions of MPBs in multicomponent systems were found in linear correlation with the tolerance factor and ionic radii of non-PT end-members. The phase structure, piezoelectric coefficient, electromechanical coupling coefficient, unipolar strains, and dielectric properties of as-prepared ceramics were systematically investigated. The largest d33s were obtained at S36.8, L37.4, M39.6, and N35.8, with the corresponding values of 580, 450, 420, and 530 pC/N, respectively, while the largest kps were found at S34.8, L37.4, M39.6, and N35.8, with the respective values of 0.54, 0.50, 0.47, and 0.53. The largest unipolar strain Smax and high-field piezoelectric strain coefficients d33* were also observed around the respective MPB regions. The rhombohedral-to-tetragonal phase transition temperature Trt increased with increasing PIN and PZ contents. Of particular importance is that high Trt of 140-197 °C was achieved in the M series with PZ and PIN contents being around 0.208 and 0.158, which will broaden the temperature usage range.

Multilevel processor-sharing algorithm for M/G/1 systems with priorities

Energy Technology Data Exchange (ETDEWEB)

Yassouridis, A.; Koller, R.

1983-01-01

The well-known multilevel processor-sharing algorithm for M/G/1 systems without priorities is extended to M/G/1 systems with priority classes. The average response time t/sub j/(x) and the average waiting time w/sub j/(x) for a j-class job, which requires a total service of x sec, are analytically calculated. Some figures demonstrate how the priority classes and the total number of different levels affect the behaviour of the functions t/sub j/(x) and w/sub j/(x). In addition, the foreground-background algorithm with priorities, which is not yet covered in the literature, is treated as a special case of the multilevel processor-sharing algorithm. 8 references.

PhaM is the physiological activator of poly(3-hydroxybutyrate) (PHB) synthase (PhaC1) in Ralstonia eutropha.

Science.gov (United States)

Pfeiffer, Daniel; Jendrossek, Dieter

2014-01-01

Poly(3-hydroxybutyrate) (PHB) synthase (PhaC1) is the key enzyme of PHB synthesis in Ralstonia eutropha and other PHB-accumulating bacteria and catalyzes the polymerization of 3-hydroxybutyryl-CoA to PHB. Activity assays of R. eutropha PHB synthase are characterized by the presence of lag phases and by low specific activity. It is assumed that the lag phase is caused by the time necessary to convert the inactive PhaC1 monomer into the active dimeric form by an unknown priming process. The lag phase can be reduced by addition of nonionic detergents such as hecameg [6-O-(N-heptyl-carbamoyl)-methyl-α-D-glucopyranoside], which apparently accelerates the formation of PhaC1 dimers. We identified the PHB granule-associated protein (PGAP) PhaM as the natural primer (activator) of PHB synthase activity. PhaM was recently discovered as a novel type of PGAP with multiple functions in PHB metabolism. Addition of PhaM to PHB synthase assays resulted in immediate polymerization of 3HB coenzyme A with high specific activity and without a significant lag phase. The effect of PhaM on (i) PhaC1 activity, (ii) oligomerization of PhaC1, (iii) complex formation with PhaC1, and (iv) PHB granule formation in vitro and in vivo was shown by cross-linking experiments of purified proteins (PhaM, PhaC1) with glutardialdehyde, by size exclusion chromatography, and by fluorescence microscopic detection of de novo-synthesized PHB granules.

Epitaxial Pb(Mg1/3Nb2/3)O3 thin films synthesized by metal-organic chemical vapor deposition

International Nuclear Information System (INIS)

Bai, G. R.; Streiffer, S. K.; Baumann, P. K.; Auciello, O.; Ghosh, K.; Stemmer, S.; Munkholm, A.; Thompson, Carol; Rao, R. A.; Eom, C. B.

2000-01-01

Metal-organic chemical vapor deposition was used to prepare Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) thin films on (001) SrTiO 3 and SrRuO 3 /SrTiO 3 substrates, using solid Mg β-diketonate as the Mg precursor. Parameters including the precursor ratio in the vapor phase, growth temperature, growth rate, and reaction pressure in the reactor chamber were varied in order to determine suitable growth conditions for producing phase-pure, epitaxial PMN films. A cube-on-cube orientation relationship between the thin film and the SrTiO 3 substrate was found, with a (001) rocking curve width of 0.1 degree sign , and in-plane rocking-curve width of 0.8 degree sign . The root-mean-square surface roughness of a 200-nm-thick film on SrTiO 3 was 2 to 3 nm as measured by scanning probe microscopy. The zero-bias dielectric constant and loss measured at room temperature and 10 kHz for a 200-nm-thick film on SrRuO 3 /SrTiO 3 were approximately 1100 and 2%, respectively. The remnant polarization for this film was 16 μC/cm 2 . (c) 2000 American Institute of Physics

Exposure-response analyses of liraglutide 3.0 mg for weight management.

Science.gov (United States)

Wilding, J P H; Overgaard, R V; Jacobsen, L V; Jensen, C B; le Roux, C W

2016-05-01

Liraglutide 3.0 mg, an acylated GLP-1 analogue approved for weight management, lowers body weight through decreased energy intake. We conducted exposure-response analyses to provide important information on individual responses to given drug doses, reflecting inter-individual variations in drug metabolism, absorption and excretion. We report efficacy and safety responses across a wide range of exposure levels, using data from one phase II (liraglutide doses 1.2, 1.8, 2.4 and 3.0 mg), and two phase IIIa [SCALE Obesity and Prediabetes (3.0 mg); SCALE Diabetes (1.8; 3.0 mg)] randomized, placebo-controlled trials (n = 4372). There was a clear exposure-weight loss response. Weight loss increased with greater exposure and appeared to level off at the highest exposures associated with liraglutide 3.0 mg in most individuals, but did not fully plateau in men. In individuals with overweight/obesity and comorbid type 2 diabetes, there was a clear exposure-glycated haemoglobin (HbA1c) relationship. HbA1c reduction increased with higher plasma liraglutide concentration (plateauing at ∼21 nM); however, for individuals with baseline HbA1c >8.5%, HbA1c reduction did not fully plateau. No exposure-response relationship was identified for any safety outcome, with the exception of gastrointestinal adverse events (AEs). Individuals with gallbladder AEs, acute pancreatitis or malignant/breast/benign colorectal neoplasms did not have higher liraglutide exposure compared with the overall population. These analyses support the use of liraglutide 3.0 mg for weight management in all subgroups investigated; weight loss increased with higher drug exposure, with no concomitant deterioration in safety/tolerability besides previously known gastrointestinal side effects. © 2016 John Wiley & Sons Ltd.

Exposure–response analyses of liraglutide 3.0 mg for weight management

Science.gov (United States)

Overgaard, R. V.; Jacobsen, L. V.; Jensen, C. B.; le Roux, C. W.

2016-01-01

Aims Liraglutide 3.0 mg, an acylated GLP‐1 analogue approved for weight management, lowers body weight through decreased energy intake. We conducted exposure‐response analyses to provide important information on individual responses to given drug doses, reflecting inter‐individual variations in drug metabolism, absorption and excretion. Methods We report efficacy and safety responses across a wide range of exposure levels, using data from one phase II (liraglutide doses 1.2, 1.8, 2.4 and 3.0 mg), and two phase IIIa [SCALE Obesity and Prediabetes (3.0 mg); SCALE Diabetes (1.8; 3.0 mg)] randomized, placebo‐controlled trials (n = 4372). Results There was a clear exposure–weight loss response. Weight loss increased with greater exposure and appeared to level off at the highest exposures associated with liraglutide 3.0 mg in most individuals, but did not fully plateau in men. In individuals with overweight/obesity and comorbid type 2 diabetes, there was a clear exposure–glycated haemoglobin (HbA1c) relationship. HbA1c reduction increased with higher plasma liraglutide concentration (plateauing at ∼21 nM); however, for individuals with baseline HbA1c >8.5%, HbA1c reduction did not fully plateau. No exposure–response relationship was identified for any safety outcome, with the exception of gastrointestinal adverse events (AEs). Individuals with gallbladder AEs, acute pancreatitis or malignant/breast/benign colorectal neoplasms did not have higher liraglutide exposure compared with the overall population. Conclusions These analyses support the use of liraglutide 3.0 mg for weight management in all subgroups investigated; weight loss increased with higher drug exposure, with no concomitant deterioration in safety/tolerability besides previously known gastrointestinal side effects. PMID:26833744

Dicty_cDB: Contig-U16449-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available pe... 48 2e-14 5 ( BC113336 ) Bos taurus Obg-like ATPase 1, mRNA (cDNA clone MG... 54 2e-14 4 ( FG283006 ) 1108383361067 New World... Screwworm Egg 9261 ESTs C... 70 2e-14 3 ( FG286073 ) 1108770713503 New World Screwwor...m Egg 9261 ESTs C... 70 2e-14 3 ( FG286027 ) 1108770713408 New World Screwworm Eg...g 9261 ESTs C... 70 3e-14 3 ( FG285996 ) 1108770710777 New World Screwworm Egg 9261 ESTs C... 70 3e-14 3 ( F...G283733 ) 1108770634630 New World Screwworm Egg 9261 ESTs C... 70 3e-14 3 ( EZ001364 ) TSA: Acropora millepo

One-Step Condensation and Hydrogenation of Furfural-Acetone Using Mixed and Single Catalyst Based on Ni/M-Oxide [M=Al; Mg

Science.gov (United States)

Ulfa, S. M.; Pramesti, I. N.; Mustafidah, H.

2018-01-01

Modification of furfural by condensation and hydrogenation reaction is a promising approach to produce higher alkane derivatives (C8-C13) as diesel fraction. This research investigated the catalytic activity of Ni/MgO as bifunctional catalyst compared with MgO-Ni/Al2O3 mixed catalyst for condensation-hydrogenation reaction. The Ni/MgO and Ni/Al2O3 with 20% Ni loading were prepared by wet impregnation methods using Ni(NO3)2.6H2O salt, calcined and reduced at 500°C. The catalyst performance was tested for one-step condensation-hydrogenation reaction using autoclave oil batch reactor. The reaction was conducted by reacting furfural and acetone in 1:1 ratio using water as solvent. Condensation reaction was performed at 100°C for 8 hours, followed by hydrogenation at 120°C during 7 hours. Analysis by gas chromatography showed that C=C double bond of furfurylidene acetone were successfully hydrogenated. Using Ni/MgO catalyst at 120°C, the products were identified as 1,5-bis-(2-furanyl)-1,4-penta-1-ene-3-one (2.68%) and 1,5-bis-(2-furanyl)-1,4-pentan-3-one (trace amount). On the other hand, reaction using mixed catalyst, MgO-Ni/Al2O3 showed better activity over bifunctional Ni/MgO at the same reaction temperature. The products were identified as 4-(2-furanyl)-3-butan-2-one (27.30%); 1,5-bis-(2-furanyl)-1,4-penta-1-ene-3-one (3.82%) and 1,5-bis-(2-furanyl)-1,4-pentan-3-one (1.11%). The impregnation of Ni on MgO decrease the physical properties of catalyst, confirmed by surface area analysis (SAA).

Toxicology and carcinogenesis studies of acrylamide (CASRN 79-06-1) in F344/N rats and B6C3F1 mice (feed and drinking water studies).

Science.gov (United States)

2012-07-01

Acrylamide, a water-soluble α,β-unsaturated amide, is a contaminant in baked and fried starchy foods, including french fries, potato chips, and bread, as a result of Maillard reactions involving asparagine and reducing sugars. Additional sources of acrylamide exposure include cigarettes, laboratory procedures involving polyacrylamide gels, and various occupations (e.g, monomer production and polymerization processes). Acrylamide is carcinogenic in experimental animals. To obtain data for developing quantitative risk assessments for dietary exposures to acrylamide, the Food and Drug Administration nominated acrylamide for an in-depth toxicological evaluation by the National Toxicology Program. As part of this evaluation, male and female B6C3F1/Nctr (C57BL/6N x C3H/HeN MTV-) mice and male and female F344/N Nctr rats were exposed to acrylamide (at least 99.4% pure) in drinking water for 2 years. 2-WEEK STUDY IN RATS: Groups of four male and four female F344/N rats were administered 0, 0.14, 0.35, 0.70, 1.41, 3.52, or 7.03 mM acrylamide in the drinking water (0, 10, 25, 50, 100, 250, or 500 ppm acrylamide) or 0.0, 7.4, 18.5, 37, 74, 185, or 370 mg acrylamide per kg diet for 14 days. One male rat administered 7.03 mM acrylamide in the drinking water died on day 14. Male and female rats receiving 7.03 mM acrylamide weighed 56% and 64% of controls, respectively. Male and female rats fed 370 mg acrylamide per kg diet weighed 74% and 83% of controls, respectively. Female rats receiving 3.52 mM acrylamide in drinking water and male rats fed 185 mg acrylamide per kg diet weighed 85% and 89% of controls, respectively. Rats receiving 7.03 mM acrylamide in drinking water or 370 mg acrylamide per kg diet exhibited hind-leg paralysis on day 14. Mild to moderate dilatation of the urinary bladder was observed in all rats given 370 mg acrylamide per kg diet, and in three of four male rats and all four female rats given 7.03 mM acrylamide in drinking water, and in one of four male

Low-Temperature Sintering Li3Mg1.8Ca0.2NbO6 Microwave Dielectric Ceramics with LMZBS Glass

Science.gov (United States)

Wang, Gang; Zhang, Huaiwu; Liu, Cheng; Su, Hua; Jia, Lijun; Li, Jie; Huang, Xin; Gan, Gongwen

2018-05-01

Li3Mg1.8Ca0.2NbO6 ceramics doped with Li2O-MgO-ZnO-B2O3-SiO2 glass (LMZBS) were prepared via a solid-state route. The LMZBS glass effectively reduced the sintering temperature of Li3Mg1.8Ca0.2NbO6 ceramics to 950°C. The effects of the LMZBS glass on the sintering behavior, microstructures and microwave dielectric properties of Li3Mg1.8Ca0.2NbO6 ceramics are discussed in detail. Among all the LMZBS doped Li3Mg1.8Ca0.2NbO6 ceramics, the sample with 1 wt.% of LMZBS glass sintered at 950°C for 4 h exhibited good dielectric properties: ɛ r = 16.7, Q × f = 31,000 GHz (9.92 GHz), τ f = - 1.3 ppm/°C. The Li3Mg1.8Ca0.2NbO6 ceramics possessed excellent chemical compatibility with Ag electrodes, and could be applied in low temperature co-fired ceramics (LTCC) applications.

Global and local asymptotics for the busy period of an M/G/1 queue

NARCIS (Netherlands)

Denisov, D.E.; Shneer, V.

2010-01-01

We consider an M/G/1 queue with subexponential service times. We give a simple derivation of the global and local asymptotics for the busy period. Our analysis relies on the explicit formula for the joint distribution for the number of customers and the length of the busy period of an M/G/1 queue.

Measured Hugoniot states of a two-element fluid, O2 + N2, near 2 Mg/m3

International Nuclear Information System (INIS)

Schott, G.L.

1983-01-01

Measured single-shock Hugoniot quantities are reported for a 1:1 atomic mixture of the elements oxygen and nitrogen in each of two liquid initial states. One of these is the inert equimolar solution O 2 + N 2 , at T approx. = 85K, v approx. = 1.06 m 3 /Mg; the other is the pure explosive compound nitric oxide, NO, at T approx. = 122K, v approx. = 0.79 m 3 /Mg. First-shock pressures are in the range 10 to 30 GPa. The two Hugoniots have common values of specific volumes and energies near 20 GPa; that is, they intersect. This permits a novel test of attainment of steady waves with equilibrium composition, such that a single equation of state may describe the shocked reactive fluid. 5 figures

Solid-state epitaxial effects in structurally diphasic xerogel of Pb(Mg1/3Nb2/3)O3

International Nuclear Information System (INIS)

Ravindranathan, P.; Komarneni, S.; Roy, R.

1990-01-01

Lead magnesium niobate (PMN), Pb(Mg 1/3 Nb 2/3 )O 3 , with perovskite structure has been prepared using structurally diphasic PMN gels. The diphasic gels were made using various concentrations of perovskite PMN seeds. The unseeded gel calcined at 775 degrees C for 2 h gave ∼ 98% of perovskite PMN phase. The use of 1% PMN perovskite seed not only led to a pure perovskite phase but also lowered the crystallization temperature of these gels by about 75 degrees C. These results show that isostructural seeding helps to lower the crystallization temperature of perovskite PMN phase

Isopiestic investigation of the osmotic coefficients of MgBr{sub 2}(aq) and study of bromide salts solubility in the (m{sub 1}KBr + m{sub 2}MgBr{sub 2})(aq) system at T = 323.15 K. Thermodynamic model of solution behaviour and (solid + liquid) equilibria in the MgBr{sub 2}(aq), and (m{sub 1}KBr + m{sub 2}MgBr{sub 2})(aq) systems to high concentration and temperature

Energy Technology Data Exchange (ETDEWEB)

Christov, Christomir, E-mail: christov@svr.igic.bas.b [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, ul. ' Acad. G. Bonchev' , bl. 11, 1113 Sofia (Bulgaria)

2011-03-15

The isopiestic method has been used to determine the osmotic coefficients of the binary solutions MgBr{sub 2}(aq) (from 0.4950 to 2.5197 mol {center_dot} kg{sup -1}) at the temperature T = 323.15 K. Sodium chloride solutions have been used as isopiestic reference standards. The solubility of the bromide minerals in the mixed system (m{sub 1}KBr + m{sub 2}MgBr{sub 2})(aq) has been investigated at T = 323.15 K by the physico-chemical analysis method. In addition to simple salts {l_brace}KBr(cr) and MgBr{sub 2} . 6H{sub 2}O(cr){r_brace}, equilibrium crystallization of the highly incongruent double salt with stoichiometric composition 1:1:6 {l_brace}bromcarnallite: KBr . MgBr{sub 2} . 6H{sub 2}O(cr){r_brace} was also established. The results obtained from the isopiestic and solubility measurements have been combined with all other experimental thermodynamic quantities available in the literature (osmotic coefficients, and solubility of the bromide mineral) to construct a chemical model that calculates solute and solvent activities and (solid + liquid) equilibria in the MgBr{sub 2}(aq) binary, and (m{sub 1}KBr + m{sub 2}MgBr{sub 2})(aq) mixed systems from dilute to high solution concentration within the (273.15 to 438.15) K temperature range. The solubility modelling approach based on fundamental Pitzer specific interaction equations is employed. It was found, that the standard for 2-1 type of electrolytes approach with three ({beta}{sup (0)}, {beta}{sup (1)}, and C{sup {phi}}) single electrolyte ion interaction parameters gives excellent agreement with osmotic coefficients from T = (298.15 to 373.45) K; up to saturation at 298.15 K, and up to m(MgBr{sub 2}) = 5.83 mol {center_dot} kg{sup -1} at 373.45 K, and with MgBr{sub 2} {center_dot} 6H{sub 2}O(cr) equilibrium pure water solubility data within the (273.15 to 438.15) K temperature range and up to {approx}8.5 mol {center_dot} kg{sup -1} used in parameterization. The model for the ternary system gives very good

Thermodynamic description of the C-Ge and C-Mg systems

Directory of Open Access Journals (Sweden)

Hu B.

2010-01-01

Full Text Available The thermodynamic modeling for the C-Ge and C-Mg systems is performed by the CALPHAD method. The enthalpy of formation for Mg2C3, the experimental value of which is not available in the literature, is obtained via first-principles calculation to refine the thermodynamic modeling of the C-Mg system. A comparison of the thermodynamic calculations with the available literature data shows that the presently obtained two sets of thermodynamic parameters for the C-Ge and C-Mg systems can well describe the these two systems.

Synthesis and performance of Li{sub 3}(V{sub 1-x}Mg{sub x}){sub 2}(PO{sub 4}){sub 3} cathode materials

Energy Technology Data Exchange (ETDEWEB)

Dai, Changsong; Chen, Zhenyu; Jin, Haizu; Hu, Xinguo [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China)

2010-09-01

In order to search for cathode materials with better performance, Li{sub 3}(V{sub 1-x}Mg{sub x}){sub 2}(PO{sub 4}){sub 3} (0, 0.04, 0.07, 0.10 and 0.13) is prepared via a carbothermal reduction (CTR) process with LiOH.H{sub 2}O, V{sub 2}O{sub 5}, Mg(CH{sub 3}COO){sub 2}.4H{sub 2}O, NH{sub 4}H{sub 2}PO{sub 4}, and sucrose as raw materials and investigated by X-ray diffraction (XRD), scanning electron microscopic (SEM) and electrochemical impedance spectrum (EIS). XRD shows that Li{sub 3}(V{sub 1-x}Mg{sub x}){sub 2}(PO{sub 4}){sub 3} (x = 0.04, 0.07, 0.10 and 0.13) has the same monoclinic structure as undoped Li{sub 3}V{sub 2}(PO{sub 4}){sub 3} while the particle size of Li{sub 3}(V{sub 1-x}Mg{sub x}){sub 2}(PO{sub 4}){sub 3} is smaller than that of Li{sub 3}V{sub 2}(PO{sub 4}){sub 3} according to SEM images. EIS reveals that the charge transfer resistance of as-prepared materials is reduced and its reversibility is enhanced proved by the cyclic votammograms. The Mg{sup 2+}-doped Li{sub 3}V{sub 2}(PO{sub 4}){sub 3} has a better high rate discharge performance. At a discharge rate of 20 C, the discharge capacity of Li{sub 3}(V{sub 0.9}Mg{sub 0.1}){sub 2}(PO{sub 4}){sub 3} is 107 mAh g{sup -1} and the capacity retention is 98% after 80 cycles. Li{sub 3}(V{sub 0.9}Mg{sub 0.1}){sub 2}(PO{sub 4}){sub 3}//graphite full cells (085580-type) have good discharge performance and the modified cathode material has very good compatibility with graphite. (author)

Electromechanical behavior of [001]-textured Pb(Mg1/3Nb2/3)O3-PbTiO3 ceramics

Science.gov (United States)

Yan, Yongke; Wang, Yu. U.; Priya, Shashank

2012-05-01

[001]-textured Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) ceramics were synthesized by using templated grain growth method. Significantly high [001] texture degree corresponding to 0.98 Lotgering factor was achieved at 1 vol. % BaTiO3 template. Electromechanical properties for [001]-textured PMN-PT ceramics with 1 vol. % BaTiO3 were found to be d33 = 1000 pC/N, d31 = 371 pC/N, ɛr = 2591, and tanδ = ˜0.6%. Elastoelectric composite based modeling results showed that higher volume fraction of template reduces the overall dielectric constant and thus has adverse effect on the piezoelectric response. Clamping effect was modeled by deriving the changes in free energy as a function of applied electric field and microstructural boundary condition.

Measurement of the figure of merit M for 1-C3F6/SF6 mixtures

DEFF Research Database (Denmark)

Christensen, Jørn Erik Berril; McAllister, Iain Wilson

1997-01-01

High precision measurements of the linear part of the Paschen curve are reported for 1-C3F6/SF6 mixtures. From these measurements, values for the pressure-reduced limiting electric field strength (E/p)lim and the associated figure of merit M are derived. These two parameters can be used to charac......High precision measurements of the linear part of the Paschen curve are reported for 1-C3F6/SF6 mixtures. From these measurements, values for the pressure-reduced limiting electric field strength (E/p)lim and the associated figure of merit M are derived. These two parameters can be used...

Synthesis and superstructure of La sub(2/3) (Mg sub(1/2)W sub(1/2))O/sub 3/

Energy Technology Data Exchange (ETDEWEB)

Torii, Y [Government Industrial Research Inst., Nagoya (Japan)

1979-10-01

A new perovskite La sub(2/3)(Mg sub(1/2)W sub(1/2))O/sub 3/ having an orthorhombic multiple-cell was synthesized. The lattice constants were a = 7.8157(5) A, b = 7.8344(6) A and c = 2 x 7.9067(6) A. The superstructure was found to be due to a NaCl-type ordering of B ions as well as an ordering of A-site vacancies.

The radioprotective effects of carboxy fullerene C3 on AHH-1 cell

International Nuclear Information System (INIS)

Shan, Husheng; Cai, Jianming; Huang, Yuecheng; Cui, Jianguo; Liu, Hanchen; Sun, Ding; Zhao, Fang; Dong, Junru; Li, Bailong

2008-01-01

Purpose: To investigate the radioprotective effects of carboxy fullerene C 3 on AHH-1 cell and it's prospective as a novel radioprotectant. Materials and Methods: Carboxy fullerene C 3 was prepared by chemical synthesis and trypan blue rejection test was performed to detect its cytotoxicity to AHH-1 cell. Then different concentration of C 3 was used to treat AHH-1 cells after radiated with 60 Coγ ray. Annexin-V/PI staining and flow cytometry assay were applied to assess the cell proliferation and apoptosis after irradiation. Results: C 3 showed little toxicity to AHH-1 cells with little change of trypan blue rejection rate during the drug concentration range 0-400 mg/L (P>0.05). We found in this study C 3 had good radioprotective effects to AHH-1 cell radiated with 1-8 Gy γ-ray. When the concentration was 10 mg/L, C 3 showed protection effects to AHH-1 cell irradiated with 4 Gy γ -ray, which was enhanced with increase of C 3 concentration. When the final concentration reached 200-400 mg/L, the cell survival rate after irradiation was similar to that of non-irradiated control cells(P >0.05). And the irradiation induced apoptosis and death rate were significantly lower than that of single radiation group cells(P 3 were time-dependant, and the best protection effects were observed when the C 3 was administered before irradiation (0-24 h). Conclusion: Carboxy fullerene C 3 has good radioprotective effects to AHH-1 cell, which is dose-dependent, and the higher concentration of C 3 is, the better protective effects it shows. In the effective drug concentration range of this study, C 3 do little harm on the survival rate of AHH-1 cell, which suggest that C 3 as a novel promising radioprotectant deserve to be further investigated. (author)

Neuroprotective activity of selective mGlu1 and mGlu5 antagonists in vitro and in vivo.

Science.gov (United States)

Szydlowska, Kinga; Kaminska, Bozena; Baude, Andrea; Parsons, Chris G; Danysz, Wojciech

2007-01-05

The neuroprotective potential of allosteric mGlu5 and mGlu1 antagonists such as 6-methyl-2-(phenylethynyl)-pyridin (MPEP)/[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP) and (3-ethyl-2-methyl-quinolin-6-yl)-(4-methoxy-cyclohexyl)-methanone methanesulfonate (EMQMCM), was tested in vitro in organotypic hippocampal cultures and in the middle cerebral artery occlusion model of stroke in vivo. Both classes of agent have high selectivity toward mGlu sub-types and are active in animal models of various diseases indicating satisfactory CNS penetration. In organotypic hippocampal cultures MPEP showed high neuroprotective potency against sub-chronic (12 days) insult produced by 3-NP with an IC50 of c.a. 70 nM. In contrast, although the mGlu1 antagonist EMQMCM was also protective, it seems to be weaker yielding an IC50 of c.a. 1 microM. Similarly, in the transient (90 min) middle cerebral artery occlusion model of ischaemia in rats, MTEP seems to be more effective than EMQMCM. MTEP, at 2.5 mg/kg and at 5 mg/kg provided 50 and 70% neuroprotection if injected 2 h after the onset of ischaemia. At a dose of 5 mg/kg, significant (50%) neuroprotection was also seen if the treatment was delayed by 4 h. EMQMCM was not protective at 5 mg/kg (given 2 h after occlusion) but at 10 mg/kg 50% of neuroprotection was observed. The present data support stronger neuroprotective potential of mGlu5 than mGlu1 antagonists.

Synthesis of [3-14C]- and [phenyl-U-14C] olaquindox

International Nuclear Information System (INIS)

Maul, W.; Scherling, D.; Seng, F.

1981-01-01

Olaquindox is a new feed additive. [ 14 C]Olaquindox, labelled in different positions, was needed for tracer-studies of pharmacokinetics, biotransformation and residues in several species of animals. 2-[N-(2-hydroxethyl)-carbamoyl]-3-methyl-[3- 14 C]quinoxaline-1,4-dioxide([3- 14 C]Olaquindox) was synthesized from barium[ 14 C]carbonate (22 mmoles; 1.15 Ci) via [1- 14 C]acetic acid, sodium[1- 14 C]acetate, [1- 14 C]acetylchloride, ethyl[3- 14 C]acetoacetate and 2-carbethoxy-3-methyl-[3- 14 C]quinoxaline-1,4-dioxide with an overall yield of 10%, based on barium[ 14 C]carbonate. The radiochemical purity was better than 98% (tlc). The specific activities of three preparations were 10.5, 8.4 and 5.45 μCi/mg respectively. [phenyl-U- 14 C]Olaquindox was synthesized starting from [U- 14 C]aniline (19.8 mmoles; 284.4 mCi). Intermediate products were N-acetyl[U- 14 C]aniline, 2-nitro-N-acetyl[U- 14 C]aniline, 2-nitro[U- 14 C]aniline and [U- 14 C]benzofurazanoxide. The total yield was 50% as calculated for [U- 14 C]aniline. At calibration samples of two preparations showed specific activities of 49.5 and 11.1 μCi/mg respectively. The radiochemical purity was checked by tlc and exceeded 98%. (author)

Instability of TiC and TiAl3 compounds in Al-10Mg and Al-5Cu alloys by addition of Al-Ti-C master alloy

Institute of Scientific and Technical Information of China (English)

无

2006-01-01

The performance of Al-Ti-C master alloy in refining Al-10Mg and A1-5Cu alloys was studied by using electron probe micro-analyzer (EPMA) and X-ray diffractometer (XRD) analysis.The results indicate that there are obvious fading phenomena in both Al-10Mg and Al-5Cu alloys with the addition of Al-5Ti-0.4C refiner which contains TiC and TiAl3 compounds.Mg element has no influence on the stability of TiC and TiAl3, while TiC particles in Al-10Mg alloy react with Al to form Al4C3 particles, resulting in the refinement fading.However, TiC particles are relatively stable in Al-5Cu alloy, while TiAl3 phase reacts with Al2Cu to produce a new phase Ti(Al, Cu)2, which is responsible for the refinement fading in Al-5Cu alloy.These indicate that the refinement fading will not occur only when both the TiC particles and TiAl3 compound of Al-Ti-C refiner are stable in Al alloys.

Far-infrared spectroscopy in ordered and disordered BaMg1/3Nb2/3O3 microwave ceramics

Science.gov (United States)

Dias, Anderson; Moreira, Roberto Luiz

2003-09-01

Ba(Mg1/3Nb2/3)O3 ceramics with suitable microwave dielectric properties for application in wireless communications and information access technologies were studied by far-infrared spectroscopy. Samples with different B-site ordering degrees, obtained by hydrothermal synthesis followed by sintering at various temperatures, were employed in this investigation. The sixteen infrared modes predicted by factor-group analysis were observed and adjusted according to a four-parameter semiquantum model. The dispersion parameters were determined in order to calculate the real part of the dielectric permittivity and the quality factors associated with the dielectric losses in the microwave region. The materials exhibited increasing ɛ0 and Q values up to 1100 °C, increasing more substantially when the temperature attained 1300 °C. The B-site ordering played an important role on this behavior along with the microstructural evolution above 1100 °C (grain growth), which also increased the phonon lifetime and contributed to the Q improvement. Kramers-Kronig analyses were carried out in all experimental data and the contributions of the main optical polar modes to the dielectric and microwave properties were carefully analyzed in order to identify and attribute the Ba-BO3 external mode, the inner modes related to the O-Mg-O and O-Nb-O bending vibrations, and the stretching modes of each MgO6 and NbO6 octahedron.

Age hardening in mechanically alloyed Al-Mg-Li-C-O

Energy Technology Data Exchange (ETDEWEB)

Papazian, J.M. (Corporate Research Center, Grumman Corporation, Bethpage, NY (USA)); Gilman, P. (Allied-Signal Inc., Morristown, NJ (USA))

1990-05-01

The age-hardening behavior of a series of mechanically alloyed Al-Mg-Li-C-O alloys containing 3.0-4.0 wt.% Mg and 1.3-1.75 wt.% Li was studied using hardness tests, differential scanning calorimetry (DSC) and transmission electron microscopy. The hardness tests showed an increased hardness after 100degC aging in all the alloys containing at least 1.5 at.% Li. Likewise, the calorimetry results showed the presence of pronounced precipitate dissolution peaks in these same alloys after 100degC aging. The volume fraction of precipitates formed (as measured by the dissolution enthalpies of the DSC peaks) increased systematically with increasing solute content. Transmission electron microscopy after 100 and 190degC aging showed images and diffraction spots similar to those of {delta}' (Al{sub 3}Li). Comparison of the DSC results with results from binary Al-Li and Al-Mg alloys indicated that the precipitates formed in the Al-Mg-Li-C-O alloys were similar to those formed in binary Al-Li alloys, and that the primary role of the magnesium was to lower the solid solubility of lithium. (orig.).

Behavior of 14C aflatoxin M1 during camembert cheese making.

Science.gov (United States)

Fremy, J M; Roiland, J C; Gaymard, A

1990-01-01

Camembert cheeses are made from raw milk spiked with aflatoxin M1. Three aflatoxin M1 levels (7.5 micrograms/L, 3 micrograms/L, and 0.3 micrograms/L) are used. In curds 35.6, 47.1, and 57.7% of aflatoxin M1, respectively, are recovered, and in wheys 64.4, 52.9, and 42.3%, respectively, are recovered. During the first 15 days of storage, the aflatoxin M1 content of different cheeses decreases 25, 55, and 75%, respectively. A similar experiment is made with milk contaminated with 14C labeled aflatoxin M1. The same results are obtained, except for the behavior of aflatoxin M1 in cheese; the same 14C activity is recovered during storage for 30 days.

Structural features of AgCaCdMg2(PO4)3 and AgCd2Mg2(PO4)3, two new compounds with the alluaudite-type structure, and their catalytic activity in butan-2-ol conversion

International Nuclear Information System (INIS)

Kacimi, Mohammed; Ziyad, Mahfoud; Hatert, Frederic

2005-01-01

AgCaCdMg 2 (PO 4 ) 3 and AgCd 2 Mg 2 (PO 4 ) 3 , two new compounds with the alluaudite-type structure, were synthesized by a solid state reaction in air at 750 deg. C. The X-ray powder diffraction pattern of AgCaCdMg 2 (PO 4 ) 3 indicates the presence of small amounts of (Ca, Mg) 3 (PO 4 ) 2 with the whitlockite structure, as impurity, whereas AgCd 2 Mg 2 (PO 4 ) 3 is constituted by pure alluaudite. The Rietveld refinements of the X-ray powder diffraction patterns indicate an ordered cationic distribution for AgCd 2 Mg 2 (PO 4 ) 3 , with Ag on A(2)', Cd on A(1) and M(1), and Mg on M(2), whereas a disordered distribution of Cd and Ca between the A(1) and M(1) sites is observed for AgCaCdMg 2 (PO 4 ) 3 . The catalytic properties of these compounds has been measured in reaction of butan-2-ol dehydrogenation. In the absence of oxygen, both samples exhibit poor dehydrogenation activity. All samples displayed no dehydration activity. Introduction of oxygen into the feed changed totally the catalytic behavior of the catalysts. The production of methyl ethyl ketone increases with time on stream and the reaction temperature. AgCaCdMg 2 (PO 4 ) 3 is more efficient than AgCd 2 Mg 2 (PO 4 ) 3

Stress corrosion cracking and corrosion fatigue characterisation of MgZn1Ca0.3 (ZX10) in a simulated physiological environment.

Science.gov (United States)

Jafari, Sajjad; Raman, R K Singh; Davies, Chris H J; Hofstetter, Joelle; Uggowitzer, Peter J; Löffler, Jörg F

2017-01-01

Magnesium (Mg) alloys have attracted great attention as potential materials for biodegradable implants. It is essential that an implant material possesses adequate resistance to cracking/fracture under the simultaneous actions of corrosion and mechanical stresses, i.e., stress corrosion cracking (SCC) and/or corrosion fatigue (CF). This study investigates the deformation behaviour of a newly developed high-strength low-alloy Mg alloy, MgZn1Ca0.3 (ZX10), processed at two different extrusion temperatures of 325 and 400°C (named E325 and E400, respectively), under slow strain tensile and cyclic tension-compression loadings in air and modified simulated body fluid (m-SBF). Extrusion resulted in a bimodal grain size distribution with recrystallised grain sizes of 1.2 μm ± 0.8 μm and 7 ± 5 μm for E325 and E400, respectively. E325 possessed superior tensile and fatigue properties to E400 when tested in air. This is mainly attributed to a grain-boundary strengthening mechanism. However, both E325 and E400 were found to be susceptible to SCC at a strain rate of 3.1×10 -7 s -1 in m-SBF. Moreover, both E325 and E400 showed similar fatigue strength when tested in m-SBF. This is explained on the basis of crack initiation from localised corrosion following tests in m-SBF. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Hydrogen storage properties of LaMgNi{sub 3.6}M{sub 0.4} (M = Ni, Co, Mn, Cu, Al) alloys

Energy Technology Data Exchange (ETDEWEB)

Yang, Tai [Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081 (China); Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010 (China); Zhai, Tingting; Yuan, Zeming; Bu, Wengang [Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081 (China); Xu, Sheng [Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010 (China); Zhang, Yanghuan, E-mail: zhangyh59@sina.com [Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081 (China); Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010 (China)

2014-12-25

Highlights: • La–Mg–Ni system AB{sub 2}-type alloys were prepared by induction melting. • Structures and lattice parameters were analysed by XRD. • Hydrogen absorption/desorption performances were studied. • Mechanisms of hydrogen absorption capacity fading were investigated. - Abstract: LaMgNi{sub 3.6}M{sub 0.4} (M = Ni, Co, Mn, Cu, Al) alloys were prepared through induction melting process. The phase compositions and crystal structures were characterised via X-ray diffraction (XRD). The hydrogen storage properties, including activation performance, hydrogen absorption capacity, cycle stability, alloy particle pulverisation and plateau pressure, were systemically investigated. Results show that Ni, Co, Mn and Cu substitution alloys exhibit multiphase structures comprising the main phase LaMgNi{sub 4} and the secondary phase LaNi{sub 5}. However, the secondary phase of the Al substitution alloy changes into LaAlNi{sub 4}. The lattice parameters and cell volumes of the LaMgNi{sub 4} phase follow the order Ni < Co < Al < Cu < Mn. Activation is simplified through partial substitution of Ni with Al, Cu and Co. The hydrogen absorption capacities of all of the alloys are approximately 1.7 wt.% at the first activation process; however, they rapidly decrease with increasing cycle number. In addition, the stabilities of hydriding and dehydriding cycles decrease in the order Al > Co > Ni > Cu > Mn. Hydriding processes result in numerous cracks and amorphisation of the LaMgNi{sub 4} phase in the alloys. The p–c isotherms were determined by a Sieverts-type apparatus. Two plateaus were observed for the Ni, Co and Al substitution alloys, whereas only one plateau was found for Mn and Cu. This result was caused by the amorphisation of the LaMgNi{sub 4} phase during the hydriding cycles. Reversible absorption and desorption of hydrogen are difficult to achieve. Substitutions of Ni with Co, Mn, Cu and Al significantly influence the reduction of hysteresis between

Structural and physical properties of Mg3-xZnxSb2 (x=0-1.34)

International Nuclear Information System (INIS)

Ahmadpour, Faraz; Kolodiazhnyi, Taras; Mozharivskyj, Yurij

2007-01-01

The Mg 3-x Zn x Sb 2 phases with x=0-1.34 were prepared by direct reactions of the elements in tantalum tubes. According to the X-ray single crystal and powder diffraction, the Mg 3-x Zn x Sb 2 phases crystallize in the same P3-bar m1 space group as the parent Mg 3 Sb 2 phase. The Mg 3-x Zn x Sb 2 structure is different from the other substituted structures of Mg 3 Sb 2 , such as (Ca, Sr, Ba) Mg 2 Sb 2 or Mg 5.23 Sm 0.77 Sb 4 , in a way that in Mg 3-x Zn x Sb 2 the Mg atoms on the tetrahedral sites are replaced, while in the other structures Mg on the octahedral sites is replaced. Thermoelectric performance for the two members of the series, Mg 3 Sb 2 and Mg 2.36 Zn 0.64 Sb 2 , was evaluated from low to room temperatures through resistivity, Seebeck coefficient and thermal conductivity measurements. In contrast to Mg 3 Sb 2 which is a semiconductor, Mg 2.36 Zn 0.64 Sb 2 is metallic and exhibits an 18-times larger dimensionless figure-of-merit, ZT, at room temperature. However, thermoelectric performance of Mg 2.36 Zn 0.64 Sb 2 is still poor and it is mostly due to its large electrical resistivity. - Graphical abstract: The Mg atoms in Mg 3 Sb 2 were successfully substituted with Zn, with Zn going exclusively into the tetrahedral sites. Zn substitution increases the electrical conductivity in Mg 2.36 Zn 0.64 Sb 2 by closing the band gap. This change combined with a decrease in the thermal conductivity improves the ZT value

Separation of {sup 195(m,g),197m}Hg from bulk gold target by liquid-liquid extraction using hydrophobic ionic liquids

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Kaustab; Lahiri, Susanta [Saha Institute of Nuclear Physics, Kolkata (India). Chemical Sciences Div.; Maiti, Moumita [Indian Institute of Technology Roorkee, Roorkee (India). Dept. of Physics

2017-07-01

The {sup 195(m,g),197m}Hg radionuclides were produced in accelerator when natural Au foil was irradiated with 23 MeV protons. The no-carrier-added (NCA) Hg radioisotopes were separated from the bulk Au target by liquid-liquid extraction (LLX) employing hydrophobic RTILs 1-butyl-3-methylimidazolium hexafluorophosphate([C{sub 4}mim][PF{sub 6}]) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide([bmim][Tf{sub 2}N]) as extractant with HNO{sub 3} and HCl. In each case, bulk Au was extracted into the RTIL phase leaving NCA Hg-radionuclides in the aqueous phase. The RTILs were recovered by washing with 1 M K{sub 2}S{sub 2}O{sub 5} and freshly prepared 1 M FeSO{sub 4}. The reported separation methods follow green chemistry approach as it does not involve any volatile reagents.

Nonparametric estimation of the stationary M/G/1 workload distribution function

DEFF Research Database (Denmark)

Hansen, Martin Bøgsted

2005-01-01

In this paper it is demonstrated how a nonparametric estimator of the stationary workload distribution function of the M/G/1-queue can be obtained by systematic sampling the workload process. Weak convergence results and bootstrap methods for empirical distribution functions for stationary associ...

Sojourn time asymptotics in the M/G/1 processor sharing queue

NARCIS (Netherlands)

A.P. Zwart (Bert); O.J. Boxma (Onno)

1998-01-01

textabstractWe show for the M/G/1 processor sharing queue that the service time distribution is regularly varying of index $-nu$, $nu$ non-integer, iff the sojourn time distribution is regularly varying of index $-nu $. This result is derived from a new expression for the Laplace-Stieltjes transform

The effect of pre-dose on thermally and optically stimulated luminescence from α-Al2O3:C,Mg and α-Al2O3:C.

Science.gov (United States)

Kalita, J M; Chithambo, M L

2018-06-15

We report the effect of pre-dose on the thermoluminescence (TL) and optically stimulated luminescence (OSL) dose response of α-Al 2 O 3 :C,Mg and α-Al 2 O 3 :C. Before any luminescence measurement, the samples were irradiated with different doses, namely 100, 500 and 1000 Gy to populate the deep electron traps. This is the pre-dose. The results from TL and OSL studies are compared with results from samples used without any pre-measurement dose. The TL glow curves and OSL decay curves of α-Al 2 O 3 :C,Mg recorded after pre-doses of 100, 500 and 1000 Gy are identical to those from a sample used without any pre-dose. Further, the TL and OSL dose response of all α-Al 2 O 3 :C,Mg samples are similar regardless of pre-dose. In comparison, the TL glow curves and OSL decay curves of α-Al 2 O 3 :C are influenced by pre-dose. We conclude that the differences in the TL and OSL dose response of various pre-dosed samples of α-Al 2 O 3 :C are due to the concentration of charge in the deep traps. On the other hand, owing to the lower concentration of such deep traps in α-Al 2 O 3 :C,Mg, the TL or OSL dose responses are not affected by pre-dose in this material. Copyright © 2018 Elsevier Ltd. All rights reserved.

Phospholipase C-independent effects of 3M3FBS in murine colon.

Science.gov (United States)

Dwyer, Laura; Kim, Hyun Jin; Koh, Byoung Ho; Koh, Sang Don

2010-02-25

The muscarinic receptor subtype M(3) is coupled to Gq/11 proteins. Muscarinic receptor agonists such as carbachol stimulate these receptors that result in activation of phospholipase C (PLC) which hydrolyzes phosphatidylinositol 4,5-bisphosphate into diacylglycerol and Ins(1,4,5)P(3). This pathway leads to excitation and smooth muscle contraction. In this study the PLC agonist, 2, 4, 6-trimethyl-N-(meta-3-trifluoromethyl-phenyl)-benezenesulfonamide (m-3M3FBS), was used to investigate whether direct PLC activation mimics carbachol-induced excitation. We examined the effects of m-3M3FBS and 2, 4, 6-trimethyl-N-(ortho-3-trifluoromethyl-phenyl)-benzenesulfonamide (o-3M3FBS), on murine colonic smooth muscle tissue and cells by performing conventional microelectrode recordings, isometric force measurements and patch clamp experiments. Application of m-3M3FBS decreased spontaneous contractility in murine colonic smooth muscle without affecting the resting membrane potential. Patch clamp studies revealed that delayed rectifier K(+) channels were reversibly inhibited by m-3M3FBS and o-3M3FBS. The PLC inhibitor, 1-(6-((17b-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122), did not prevent this inhibition by m-3M3FBS. Both m-3M3FBS and o-3M3FBS decreased two components of delayed rectifier K(+) currents in the presence of tetraethylammonium chloride or 4-aminopyridine. Ca(2+) currents were significantly suppressed by m-3M3FBS and o-3M3FBS with a simultaneous increase in intracellular Ca(2+). Pretreatment with U73122 did not prevent the decrease in Ca(2+) currents upon m-3M3FBS application. In conclusion, both m-3M3FBS and o-3M3FBS inhibit inward and outward currents via mechanisms independent of PLC acting in an antagonistic manner. In contrast, both compounds also caused an increase in [Ca(2+)](i) in an agonistic manner. Therefore caution must be employed when interpreting their effects at the tissue and cellular level.

The microstructure and mechanical properties of Mg-3Al-3RE alloys

International Nuclear Information System (INIS)

Tian, X.; Wang, L.M.; Wang, J.L.; Liu, Y.B.; An, J.; Cao, Z.Y.

2008-01-01

The Mg-3Al-3RE alloys (RE, the cerium-rich or the yttrium-rich misch metal) were smelted in a resistance furnace under the protective flux from the Mg-RE master alloys and pure magnesium ingots. The microstructure and mechanical properties of samples prepared by steel mould casting method were investigated. Results show that the main phases of the alloys are α-Mg, Mg 17 Al 12 and Al-RE compounds, and the grain size reduced with the increasing content of the cerium-rich misch metal. Mg-3Al-2Ymm-1Cemm (Ymm, the yttrium-rich misch metal; Cemm, the Cerium-rich misch metal) exhibited the highest mechanical properties, that is UTS = 201 MPa and YS = 75 MPa, and ε = 8.2% at room temperature; UTS = 146 MPa, and YS = 70 MPa, ε = 18.2% at the temperature of 150 deg. C, respectively. Fracture surface analysis revealed that the Mg-3Al-2Ymm-1Cemm alloy has a mixed fracture feature at room temperature but ductile fracture at elevated temperature (150 deg. C)

Beam-Mode Piezoelectric Properties of Ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 Single Crystals for Medical Linear Array Applications

Science.gov (United States)

Wang, Wei; Wang, Sheng; Zhang, Yaoyao; Zhao, Xiangyong; Luo, Haosu

2011-11-01

In this work, the dielectric and beam-mode piezoelectric properties of ternary 0.35Pb(In1/2Nb1/2)O3-0.35Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 (PIMNT35/35/30) piezoelectric single crystals were investigated. The Curie temperature ( T C) and rhombohedral-to-tetragonal phase-transition temperature ( T rt) are 187°C and 127°C, about 30°C higher than those of PMNT crystals. The beam-mode coupling coefficient k {33/ w } was found to be 90.3%. Furthermore, 3.5-MHz linear arrays based on PIMNT35/35/30 crystals and Pb(Zr1- x Ti x )O3 ceramic (PZT-5H) were simulated using PiezoCAD software. The results indicate that the sensitivity and -6 dB bandwidth of a PIMNT35/35/30 transducer would be approximately 4 dB and 20% higher, respectively, compared with a traditional PZT transducer.

Thermal conductivity of M-Si-N (M = Mg, Ca, Sr, Ba) compounds with varying M/Si ratio

NARCIS (Netherlands)

Hintzen, H.T.J.M.; Bruls, R.J.; Delsing, A.C.A.; Itatani, K.; Tanaka, S.; With, de G.; Metselaar, R.

2002-01-01

The thermal cond. of M-Si-N (M = Mg, Ca, Sr, Ba) compds. was examd. The emphasis is on MgSiN2 (a material which can be derived from AlN by replacing systematically 2Al3+ by Mg2+/Si4+), and Si3N4 (the well known b-modification as well as the recently discovered cubic modification with the spinel

Bluish-White Luminescence in Rare-Earth-Free Vanadate Garnet Phosphors: Structural Characterization of LiCa3MV3O12 (M = Zn and Mg).

Science.gov (United States)

Hasegawa, Takuya; Abe, Yusuke; Koizumi, Atsuya; Ueda, Tadaharu; Toda, Kenji; Sato, Mineo

2018-01-16

Extensive attention has been focused toward studies on inexpensive and rare-earth-free garnet-structure vanadate phosphors, which do not have a low optical absorption due to the luminescence color being easily controlled by its high composition flexibility. However, bluish emission phosphors with a high quantum efficiency have not been found until now. In this study, we successfully discovered bluish-white emitting, garnet structure-based LiCa 3 MV 3 O 12 (M = Zn and Mg) phosphors with a high quantum efficiency, and the detailed crystal structure was refined by the Rietveld analysis technique. These phosphors exhibit a broad-band emission spectra peak at 481 nm under near UV-light excitation at 341 nm, indicating no clear difference in the emission and excitation spectra. A very compact tetrahedral [VO 4 ] unit is observed in the LiCa 3 MV 3 O 12 (M = Zn and Mg) phosphors, which is not seen in other conventional garnet compounds, and generates a bluish-white emission. In addition, these phosphors exhibit high quantum efficiencies of 40.1% (M = Zn) and 44.0% (M = Mg), respectively. Therefore, these vanadate garnet phosphors can provide a new blue color source for LED devices.

The magnetic Curie temperature and exchange coupling between cations in tetragonal spinel oxide Mn{sub 2.5}M{sub 0.5}O{sub 4} (M = Co, Ni, Mn, Cr, and Mg) films

Energy Technology Data Exchange (ETDEWEB)

Kuo, K.; Cheng, C. W.; Chern, G. [Physics Department and SPIN Research Center, National Chung Cheng University, Chia-Yi, Taiwan, 621 (China)

2012-04-01

Mn{sub 3}O{sub 4} is a Jahn-Taller tetragonal ferrite that has a relatively low Curie temperature (T{sub c}) of {approx}43 K due to weak coupling between the canting spins. In this study, we fabricated a series of 100-nm-thick Mn{sub 2.5}M{sub 0.5}O{sub 4} (M = Co, Ni, Mn, Cr, and Mg) films via oxygen-plasma-assisted molecular beam epitaxy and measured the structural and magnetic properties of these films. These films show single phase quality, and the c-axis lattice parameter of pure Mn{sub 3}O{sub 4} is 0.944 nm, with a c/a ratio {approx}1.16, consistent with the bulk values. The replacement of Mn by M (M = Co, Ni, Cr, and Mg) changes the lattice parameters, and the c/a ratio varies between 1.16 and 1.06 depending upon the cation distribution of the films. The magnetic Curie temperatures of these films also vary in the range of 25-66 K in that Ni and Co enhance the T{sub c} whereas Mg reduces the T{sub c} (Cr shows no effect on the T{sub c}). These changes to the T{sub c} are related to both the element electronic state and the cation distributions in these compounds. As a non-collinear spin configuration can induce electrical polarization, the present study provides a systematic way to enhance the magnetic transition temperature in tetragonal spinel ferrites.

Diastereoselective synthesis of trans-2,3-dihydrofuro[3,2-c]coumarins by MgO nanoparticles under ultrasonic irradiation

Directory of Open Access Journals (Sweden)

Javad Safaei-Ghomi

2017-12-01

Full Text Available MgO nanoparticles have been used as an efficient catalyst for the diastereoselective preparation of trans-2-benzoyl-3-(aryl-2H-furo[3,2-c]chromen-4(3H-ones by the multi-component reaction of 2,4′-dibromoacetophenone, pyridine, benzaldehydes and 4-hydroxycoumarin under ultrasonic irradiation. This interesting result revealed that the pyridiniumylide assisted tandem three-component coupling reaction is highly diastereoselective. Atom economy, wide range of products, high catalytic activity, excellent yields in short reaction times, diastereoselective synthesis and environmental benignity are some of the important features of this protocol. Keywords: Furo[3,2-c]coumarins, Ultrasonic irradiation, MgO nanoparticles, Diastereoselective, One-pot syntheses

Effect Of SiC Particles On Sinterability Of Al-Zn-Mg-Cu P/M Alloy

Directory of Open Access Journals (Sweden)

Rudianto H.

2015-06-01

Full Text Available Premix Al-5.5Zn-2.5Mg-0.5Cu alloy powder was analyzed as matrix in this research. Gas atomized powder Al-9Si with 20% volume fraction of SiC particles was used as reinforcement and added into the alloy with varied concentration. Mix powders were compacted by dual action press with compaction pressure of 700 MPa. High volume fraction of SiC particles gave lower green density due to resistance of SiC particles to plastic deformation during compaction process and resulted voids between particles and this might reduce sinterability of this mix powder. Sintering was carried out under ultra high purity nitrogen gas from 565°-580°C for 1 hour. High content of premix Al-5.5Zn-2.5Mg-0.5Cu alloy powder gave better sintering density and reached up to 98% relative. Void between particles, oxide layer on aluminum powder and lower wettability between matrix and reinforcement particles lead to uncompleted liquid phase sintering, and resulted on lower sintering density and mechanical properties on powder with high content of SiC particles. Mix powder with wt90% of Alumix 431D and wt10% of Al-9Si-vf20SiC powder gave higher tensile strength compare to another mix powder for 270 MPa. From chemical compositions, sintering precipitates might form after sintering such as MgZn2, CuAl2 and Mg2Si. X-ray diffraction, DSC-TGA, and SEM were used to characterize these materials.

Structures and Spectroscopy Studies of Two M(II-Phosphonate Coordination Polymers Based on Alkaline Earth Metals (M = Ba, Mg

Directory of Open Access Journals (Sweden)

Kui-Rong Ma

2013-01-01

Full Text Available The two examples of alkaline-earth M(II-phosphonate coordination polymers, [Ba2(L(H2O9]·3H2O (1 and [Mg1.5(H2O9]·(L-H21.5·6H2O (2 (H4L = H2O3PCH2N(C4H8NCH2PO3H2, N,N′-piperazinebis(methylenephosphonic acid, (L-H2 = O3PH2CHN(C4H8NHCH2PO3 have been hydrothermally synthesized and characterized by elemental analysis, FT-IR, PXRD, TG-DSC, and single-crystal X-ray diffraction. Compound 1 possesses a 2D inorganic-organic alternate arrangement layer structure built from 1D inorganic chains through the piperazine bridge, in which the ligand L−4 shows two types of coordination modes reported rarely at the same time. In 1, both crystallographic distinct Ba(1 and Ba(2 ions adopt 8-coordination two caps and 9-coordination three caps triangular prism geometry structures, respectively. Compound 2 possesses a zero-dimensional mononuclear structure with two crystallographic distinct Mg(II ions. Free metal cations   [MgO6]n2+ and uncoordinated anions (L-H2n2- are joined together by static electric force. Results of photoluminescent measurement indicate three main emission bands centered at 300 nm, 378.5 nm, and 433 nm for 1 and 302 nm, 378 nm, and 434.5 nm for 2 (λex=235 nm, respectively. The high energy emissions could be derived from the intraligand π∗-n transition stations of H4L (310 nm and 382 nm, λex=235 nm, while the low energy emission (>400 nm of 1-2 may be due to the coordination effect with metal(II ions.

A randomized comparison of daunorubicin 90 mg/m2 vs 60 mg/m2 in AML induction

DEFF Research Database (Denmark)

Burnett, A. K.; Russell, N. H.; Hills, R. K.

2015-01-01

Modifying induction therapy in acute myeloid leukemia (AML) may improve the remission rate and reduce the risk of relapse, thereby improving survival. Escalation of the daunorubicin dose to 90 mg/m(2) has shown benefit for some patient subgroups when compared with a dose of 45 mg/m(2), and has been...... = .15). In an exploratory subgroup analysis, there was no subgroup that showed significant benefit, although there was a significant interaction by FLT3 ITD mutation. This trial is registered at http://www.isrctn.com as #ISRCTN55675535....

TL and OSL studies of carbon doped magnesium aluminate (MgAl2O4:C)

Science.gov (United States)

Raj, Sanu S.; Mishra, D. R.; Soni, Anuj; Grover, V.; Polymeris, G. S.; Muthe, K. P.; Jha, S. K.; Tyagi, A. K.

2016-10-01

The MgAl2O4:C has been synthesized by using two different methods by electron gun and vacuum assisted melting of MgAl2O4 in presence of graphite. The MgAl2O4:C phosphor thus developed by these two different methods have similar types of the TL/OSL defects with multiple overlapping TL glow peaks from 100 °C to 400 °C. The Computerized Curve De-convolution Analysis (CCDA) has been used to measure TL parameters such as thermal trap depth, frequency factor and order of kinetic associated with charge transfer process in TL phenomenon. The investigated TL/OSL results show that these two methods of incorporating carbon in MgAl2O4 have generated closely resemble the defects of similar types in MgAl2O4:C lattice. However, the MgAl2O4:C synthesized by electron gun shows relatively larger concentration of the TL/OSL defects as compared to MgAl2O4:C synthesized using vacuum assisted melting method. The photo-ionization cross-section (PIC) associated with fastest OSL component of MgAl2O4: C is found to be ∼ 0.5 times than that of fastest OSL component of commercially available dosimetric grade α-Al2O3:C. The MgAl2O4:C thus developed shows good dynamic OSL dose linearity from few mGy to 1 Gy. This work reveals that MgAl2O4:C could be developed as potential tissue equivalent OSL / TL material.

Structural and magnetic properties of Ni0.15Mg0.1Cu0.3Zn0.45Fe2O4 ferrite prepared by NaOH-precipitation method

International Nuclear Information System (INIS)

Hou, Wei-xiao; Wang, Zhi

2015-01-01

Highlights: • NiMgCuZn ferrites were successfully prepared by low-temperature sintering. • NiMgCuZn ferrites have the advantages of both NiCuZn and MgCuZn ferrites. • NiMgCuZn ferrites exhibit high Curie temperature & high stability of permeability. - Abstract: The Ni 0.15 Mg 0.1 Cu 0.3 Zn 0.45 Fe 2 O 4 ferrite powders have been prepared by NaOH co-precipitation method and characterized by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The XRD patterns confirm the single phase spinel structure of synthesized nanoparticles. The average crystallite size of the particles increases from 12 to 36 nm with calcining temperature (T a ) from 500 to 800 °C. The saturation magnetization (M s ) of the superparamagnetic particles was deduced by Langevin theory. Subsequently, the densification characteristics and magnetic properties of the low-temperature 950 °C-sintered ferrite bulk samples were also investigated. The magnetic measurement showed that the sintered bulk sample of T a = 600 °C has the highest initial permeability (μ i ), lowest coercivity (H c ), largest saturation magnetization (M s ) and satisfactory thermal stability of μ i . The microstructures of sintered samples were examined using field emission scanning electric microscope (FESEM). The T a has significant influence on the bulk density, initial permeability, saturation magnetization and coercivity of Ni 0.15 Mg 0.1 Cu 0.3 Zn 0.45 Fe 2 O 4 ferrite

The transient M/G/1/0 queue: some bounds and approximations for light traffic with application to reliability

Directory of Open Access Journals (Sweden)

J. Ben Atkinson

1995-01-01

Full Text Available We consider the transient analysis of the M/G/1/0 queue, for which Pn(t denotes the probability that there are no customers in the system at time t, given that there are n(n=0,1 customers in the system at time 0. The analysis, which is based upon coupling theory, leads to simple bounds on Pn(t for the M/G/1/0 and M/PH/1/0 queues and improved bounds for the special case M/Er/1/0. Numerical results are presented for various values of the mean arrival rate λ to demonstrate the increasing accuracy of approximations based upon the above bounds in light traffic, i.e., as λ→0. An important area of application for the M/G/1/0 queue is as a reliability model for a single repairable component. Since most practical reliability problems have λ values that are small relative to the mean service rate, the approximations are potentially useful in that context. A duality relation between the M/G/1/0 and GI/M/1/0 queues is also described.

Electric conductivity of solid solutions the Cs3-2xMxPO4 (M=Ba, Sr, Ca, Mg) systems

International Nuclear Information System (INIS)

Burmakin, E.I.; Stroev, S.S.; Shekhtman, G.Sh.; Antonov, B.D.

2003-01-01

The solid solutions in the Cs 3-2x M x PO 4 (M=Ba, Sr, Ca, Mg) system are synthesized and their thermal behavior and electric conductivity are studied. The introduction of the alkaline earth metal cations into cesium orthophosphates is accompanied by the shift of the phase transition occurring in the pure Cs 3 PO 4 at 450-620 Deg C into the low-temperature area as well as by increase in the cesium-cation conductivity at low temperatures. The electric conductivity in the area of existence of the Cs 3 PO 4 high-temperature modification slightly depends on the availability and concentration of the modifying additions, which make it possible to suppose the calcium sublattice structural disordering [ru

Temperature-dependent Raman spectra and electrical properties of 0.69Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.31PbTiO{sub 3} single crystals

Energy Technology Data Exchange (ETDEWEB)

Fang, Bijun [Changzhou University, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou (China); Liu, Xing [Changzhou University, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou (China); Chinese Academy of Sciences, Key Laboratory of Inorganic Function Material and Device, Shanghai (China); Li, Xiaobing; Zhao, Xiangyong; Luo, Haosu [Chinese Academy of Sciences, Key Laboratory of Inorganic Function Material and Device, Shanghai (China); Ding, Jianning [Changzhou University, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou (China); Jiangsu University, School of Material Science and Engineering, Zhenjiang (China)

2016-09-15

The temperature-dependent Raman spectra and electrical properties of the 0.69Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.31PbTiO{sub 3} (0.69PMN-0.31PT) single crystals were investigated. Based on the group theory, the poled 0.69PMN-0.31PT single crystals belong to the monoclinic crystal system, which was confirmed by the room-temperature Raman spectra. The 0.69PMN-0.31PT single crystals experience successive structural phase transitions, i.e., a monoclinic-tetragonal (FE{sub M}-FE{sub T}) phase transition at T{sub M-T} and a tetragonal-cubic (FE{sub T}-P{sub C}) phase transition at T{sub m} determined by the dielectric measurement. Due to the enhancement of long-range order, their FE{sub M}-FE{sub T} phase transition becomes more obvious after the poling process. The wavenumbers and line widths of the 271, 502, 575, 795 cm{sup -1} Raman modes, and the intensity ratios of I{sub 271cm}{sup {sub -}{sub 1}}/I{sub 795cm}{sup {sub -}{sub 1}} and I{sub 502cm}{sup {sub -}{sub 1}}/I{sub 575cm}{sup {sub -}{sub 1}} exhibit obvious anomalies around T{sub M-T} and T{sub m}, which are closely related to the FE{sub M}-FE{sub T} and FE{sub T}-P{sub C} phase transitions. The temperature and electric field (E)-induced phase transitions are observed in the unipolar strain-E (S-E) curves. The converse piezoelectric constant (d{sub 33}), maximum strain value (S{sub max}%) and longitudinal electrostrictive coefficient (Q) increase considerably around the ferroelectric phase transition temperature T{sub M-T}. (orig.)

Influence of elemental diffusion on low temperature formation of MgH2 in TiMn1.3T0.2-Mg (T = 3d-transition elements)

International Nuclear Information System (INIS)

Yamamoto, K.; Tanioka, S.; Tsushio, Y.; Shimizu, T.; Morishita, T.; Orimo, S.; Fujii, H.

1996-01-01

In order to examine the influence of the elemental diffusion from the host compound into the Mg region on low temperature formation of MgH 2 , we have investigated the hydriding properties and the microstructures of the composite materials TiMn 1.3 T 0.2 -Mg (T = V, Cr, Mn, Fe, Co, Ni and Cu). MgH 2 is formed at 353 K in all composite materials. Of all the substitutions, the amount of MgH 2 is the largest in the case of the Cu substitution, which originates from the existence of the Mg-Mg 2 Cu eutectic formed by Cu diffusion from the host compound TiMn 1.3 Cu 0.2 into the Mg region during the liquid phase sintering. In addition, the hydrogen capacity of TiMn 1.3 Cu 0.2 -Mg (that is TiMn 1.3 Cu 0.1 -(Mg+Mg 2 Cu) after the sintering) easily saturates in comparison with TiMn 1.5 -(Mg+Mg 2 Cu) without Cu diffusion. It is concluded that Cu diffusion promotes the mobility of hydrogen atoms at the complex interface between the host compound and the Mg region. (orig.)

Hydrogenation properties of Mg1-xM1xCu2 (M1=La and Nd) with larger interstitial sites than MgCu2

International Nuclear Information System (INIS)

Tsushio, Y.

1998-01-01

The hydrogenation properties of C15 compounds are controlled by crystal structure, the size of the interstitial hole being an especially important factor. Its effect on the hydrogenation properties of MgCu 2 substituted with rare earth elements of various radii is discussed and the limit in controlling the crystal structure by conventional substitution is explained. (orig.)

La0⋅ 9Sr0⋅ 1Ga0⋅ 8M0⋅ 2O3–δ (M= Mn, Co, Ni, Cu or Zn ...

Indian Academy of Sciences (India)

Perovskite oxides of the general formula, La0.9Sr0.1Ga0.8M0.2O3– for M = Mn, Co, Ni, Cu and Zn, have been prepared and investigated. All the oxides exhibit high electrical conductivities ( ∼ 10–2 S/cm at 800°C) comparable to that of the best perovskite oxide ion conductor, La0.9Sr0.1Ga0.8Mg0.2O2.85 (LSGM) ( ...

Nonlinear dielectric properties and tunability of 0.9Pb(Mg1/3,Nb2/3)O3-0.1 PbTiO3 and Ba(Ti0.85,Sn0.15)O3 paraelectrics

Science.gov (United States)

Akdogan, E. K.; Hall, A.; Simon, W. K.; Safari, A.

2007-01-01

We investigate the nonlinear dielectric properties of 0.9Pb(Mg1/3,Nb2/3)O3•0.1PbTiO3 (PMN-PT) and Ba[Ti0.85,Sn0.15]O3 (BTS) paraelectrics experimentally and theoretically. We measure the nonlinear dielectric response in the parallel plate capacitor configuration, whereby we obtain the low frequency linear permittivity (ε33), and the higher order permittivities (ε3333,ε333333) at 298K as ε33PMN-PT=2.1×10-7 and ε33BTS=4.1×10-8F /m, ε3333PMN-PT=-4.9×10-20 and ε3333BTS=-7.3×10-21F3m /C2, and ε333333PMN-PT=7.6×10-33 and ε333333BTS=9.85×10-34F5m3/C4. By using a self-consistent thermodynamic theory in conjunction with the experimental data, we compute the E3 dependence of electrostatic free energy ΔG, the field-induced polarization P3, and the thermodynamic tunability ∂2P3/∂E32, and prove that electrostatic free energy has to be expanded at least up to the sixth order in the electric field to define the critical field ∣E3*∣ at which maximum tunability is attained. We also show that ∣E3*∣ is a function on ∣ε3333∣/ε333333 only. Consequently, we find ∣E3*∣PMN-PT=8.0×105V /m and ∣E3*∣BTS=8.6×105V/m. We compute the engineering tunabilities as ΓPMN-PT=65% and ΓBTS=55%, and then define a normalized tunability ξ to take into account the ∣E3*∣ parameter. Thereof, we determine ∣ξ ∣PMT-PT=8.1×10-5%/Vm-1 and ∣ξ∣BTS=6.4×10-5%/Vm-1. Our results reveal that ∣E3*∣BTS>∣E3*∣PMN-PT although ΓBTS<ΓPMN-PT, unequivocally showing the need for defining a critical field parameter in evaluating the nonlinear dielectric response and tunability, in particular, and in nonlinear dielectrics in general. The results also indicate that the nonlinear dielectric properties of PMN-PT are an order of magnitude higher than that of BTS, which we discuss in the context of structure-property relations of relaxors.

A facile synthesis of Li_2Fe_1_/_3Mn_1_/_3Ni_1_/_3SiO_4/C composites as cathode materials for lithium-ion batteries

International Nuclear Information System (INIS)

Yang, Rong; Wang, Liqing; Deng, Kunfa; Lv, Mengni; Xu, Yunhua

2016-01-01

The novel Li_2Fe_1_/_3Mn_1_/_3Ni_1_/_3SiO_4/C has been successfully synthesized by a feasible solution process in ternary system. The spherical carbon-coated composites are obtained using a heat treatment in the presence of sucrose. X-ray diffraction (XRD) diffractogram displays that the Li_2Fe_1_/_3Mn_1_/_3Ni_1_/_3SiO_4/C crystallized in an orthorhombic structure with a space group of Pmn21. The energy-dispersive X-ray spectroscopy mappings indicate that Fe, Mn and Ni elements are distributed homogenously in Li_2Fe_1_/_3Mn_1_/_3Ni_1_/_3SiO_4/C nano-spherical particle with size less than 50 nm. The lithium storage capacity and cycling performance of the Li_2Fe_1_/_3Mn_1_/_3Ni_1_/_3SiO_4/C presents good results when tested as cathode materials in lithium cells at room temperature. It delivers an initial discharge capacity of 181.4 mAh g"−"1 and a discharge capacity of 172.9 mAh g"−"1 after 20 cycles at 0.1C in the voltage range of 1.5–4.6V. Furthermore, it also exhibits an excellent rate capability with a capacity under different current densities of about 144.0 mAh g"−"1 (0.2 C), 117.9 mAh g"−"1 (0.5 C), 106.1 mAh g"−"1 (1 C), respectively and a good capacity cycling maintenance of 153.7 mAh g"−"1 after 60 cycles. Above results indicate that the spherical Li_2Fe_1_/_3Mn_1_/_3Ni_1_/_3SiO_4/C becomes a very promising candidate for cathode material in lithium-ion batteries. - Highlights: • Li_2Fe_1_/_3Mn_1_/_3Ni_1_/_3SiO_4/C was obtained by solution process in a ternary system. • The material was pure phase ternary solid solution with tetrahedral morphology. • The spherical particle size was less than 50 nm with graphitized carbon coating. • The nanocomposite revealed high discharge capacity and excellent rate capability.

Piezoelectric properties and temperature stability of Mn-doped Pb(Mg1/3Nb2/3)-PbZrO3-PbTiO3 textured ceramics

OpenAIRE

Yan, Yongke; Cho, Kyung-Hoon; Priya, Shashank

2012-01-01

In this letter, we report the electromechanical properties of textured 0.4Pb(Mg1/3Nb2/3) O-3-0.25PbZrO(3)-0.35PbTiO(3) (PMN-PZT) composition which has relatively high rhombohedral to tetragonal (R-T) transition temperature (TR-T of 160 degrees C) and Curie temperature (T-C of 234 degrees C) and explore the effect of Mn-doping on this composition. It was found that MnO2-doped textured PMN-PZT ceramics with 5 vol.% BaTiO3 template (T-5BT) exhibited inferior temperature stability. The coupling f...

Validation of an analytical method applicable to study of 1 mg/mL oral Risperidone solution stability

International Nuclear Information System (INIS)

Abreu Alvarez, Maikel; Garcia Penna, Caridad Margarita; Martinez Miranda, Lissette

2010-01-01

A validated analytical method by high-performance liquid chromatography (HPLC) was applicable to study of 1 mg/mL Risperidone oral solution stability. The above method was linear, accurate, specific and exact. A stability study of the 1 mg/mL Risperidone oral solution was developed determining its expiry date. The shelf life study was conducted for 24 months at room temperature; whereas the accelerated stability study was conducted with product under influence of humidity and temperature; analysis was made during 3 months. Formula fulfilled the quality specifications described in Pharmacopeia. The results of stability according to shelf life after 24 months showed that the product maintains the parameters determining its quality during this time and in accelerated studies there was not significant degradation (p> 0.05) in the product. Under mentioned conditions expiry date was of 2 years

A new series of oxycarbonate superconductors (Cu{sub 0.5}C{sub 0.5}){sub m}Ba{sub m+1}Ca{sub n-1}Cu{sub n}O{sub 2}({sub m+n})+1

Energy Technology Data Exchange (ETDEWEB)

Takayama-Muromachi, E.; Kawashima, T.; Matsui, Y. [National Institute for Research in Inorganic Materials, Ibaraki (Japan)

1994-12-31

We found a new series of oxycarbonate superconductors in the Ba-Ca-Cu-C-O system under high pressure of 5 GPa. Their ideal formula is (Cu{sub 0.5}C{sub 0.5}){sub m}Ba{sub m+1}Ca{sub n-1}Cu{sub n}O{sub 2}({sub m+n})+1 ((Cu,C)-m(m+1)(n-1)n). Thus far, n=3, 4 members of the m=1 series, (Cu,C)-1223 and (Cu,C)-1234, have been prepared in bulk while n=4, 5 members, (Cu,C)-2334 and (Cu,C)-2345, have been prepared for the m=2 series. (Cu,C)-1223 shows superconductivity below 67 K while T{sub c}`s of other compounds are above 110 K. In particular, (Cu,C)=1234 has the highest T{sub c} of 117 K.

The MAP, M/G1,G2/1 queue with preemptive priority

Directory of Open Access Journals (Sweden)

Bong Dae Choi

1997-01-01

Full Text Available We consider the MAP, M/G1,G2/1 queue with preemptive resume priority, where low priority customers arrive to the system according to a Markovian arrival process (MAP and high priority customers according to a Poisson process. The service time density function of low (respectively: high priority customers is g1(x (respectively: g2(x. We use the supplementary variable method with Extended Laplace Transforms to obtain the joint transform of the number of customers in each priority queue, as well as the remaining service time for the customer in service in the steady state. We also derive the probability generating function for the number of customers of low (respectively, high priority in the system just after the service completion epochs for customers of low (respectively, high priority.

Effect of metal ion and ball milling on the electrochemical properties of M0.5TiOPO4 (M = Ni, Cu, Mg)

International Nuclear Information System (INIS)

Godbole, Vikram A.; Villevieille, Claire; Novák, Petr

2013-01-01

Various metal titanium oxyphosphates, M 0.5 TiOPO 4 (M = Ni, Cu, Mg) were synthesized via modified solution route synthesis. The as synthesized M 0.5 TiOPO 4 (M = Ni, Cu, Mg) were electrochemically tested using galvanostatic cycling, cyclic voltammetry, and rate performance measurements in order to investigate the effect of metal ion (M) on the electrochemical performance of this family of materials. All the studied materials reacted with 3 Li + during the 1st lithiation showing reaction plateaus at different potentials versus Lithium. Similar studies were performed on M 0.5 TiOPO 4 (M = Ni, Cu, Mg) samples with smaller particle size, obtained via ball milling, in order to understand the effect of particle size on the electrochemistry of the materials. The ball milled samples delivered higher specific charge during the 1st cycle showing reaction plateaus at different potentials, poorer capacity retention, and poorer rate capability as compared to the as synthesized ones. This was attributed to a change in morphology and particle size of the samples upon ball milling. Amongst all the tested materials, the as synthesized Cu 0.5 TiOPO 4 showed the best electrochemistry. The ball milled Mg 0.5 TiOPO 4 reacted with ∼5.5 Li + during 1st lithiation (as compared to 3 Li + expected from this family of compounds) and 3.3 Li + during the 1st delithiation (rather than the expected 2 Li + ). This suggests a reaction mechanism where Mg 0.5 TiOPO 4 undergoes a phase transformation forming Mg 0 , which reversibly alloys with 2.5 extra Li + . Thus the electrochemical cycling of Mg 0.5 TiOPO 4 gives insights into the reaction mechanism in this family of materials

Electronic transitions and band offsets in C60:SubPc and C60:MgPc on MoO3 studied by modulated surface photovoltage spectroscopy

International Nuclear Information System (INIS)

Fengler, S.; Dittrich, Th.; Rusu, M.

2015-01-01

Electronic transitions at interfaces between MoO 3 layers and organic layers of C 60 , SubPc, MgPc, and nano-composite layers of SubPc:C 60 and MgPc:C 60 have been studied by modulated surface photovoltage (SPV) spectroscopy. For all systems, time dependent and modulated SPV signals pointed to dissociation of excitons at the MoO 3 /organic layer interfaces with a separation of holes towards MoO 3 . The highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gaps (E HL ) of C 60 , SubPc, and MgPc and the effective E HL of SubPc:C 60 and MgPc:C 60 were measured. The offsets between the LUMO (ΔE L ) or HOMO (ΔE H ) bands were obtained with high precision and amounted to 0.33 or 0.73 eV for SubPc:C 60 , respectively, and to −0.33 or 0.67 eV for MgPc:C 60 , respectively. Exponential tails below E HL and most pronounced sub-bandgap transitions were characterized and ascribed to disorder and transitions from HOMO bands to unoccupied defect states

Photoluminescence of Mg-doped m-plane GaN grown by MOCVD on bulk GaN substrates

OpenAIRE

Monemar, Bo; Paskov, Plamen; Pozina, Galia; Hemmingsson, Carl; Bergman, Peder; Lindgren, David; Samuelson, Lars; Ni, Xianfeng; Morkoç, Hadis; Paskova, Tanya; Bi, Zhaoxia; Ohlsson, Jonas

2011-01-01

Photoluminescence (PL) properties are reported for a set of m-plane GaN films with Mg doping varied from mid 1018cm-3 to well above 1019 cm-3. The samples were grown with MOCVD at reduced pressure on low defect density m-plane bulk GaN templates. The sharp line near bandgap bound exciton (BE) spectra observed below 50 K, as well as the broader donor-acceptor pair (DAP) PL bands at 2.9 eV to 3.3 eV give evidence of several Mg related acceptors, similar to the case of c-plane GaN. The dependenc...

Effects of Bi(Zn2/3Nb1/3)O3 Modification on the Relaxor Behavior and Piezoelectricity of Pb(Mg1/3Nb2/3)O3-PbTiO3 Ceramics.

Science.gov (United States)

Liu, Zenghui; Wu, Hua; Paterson, Alisa; Ren, Wei; Ye, Zuo-Guang

2017-10-01

Relaxor lead magnesium niobate (PMN)-based materials exhibit complex structures and unusual properties that have been puzzling researchers for decades. In this paper, a new ternary solid solution of Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 -Bi(Zn 2/3 Nb 1/3 )O 3 (PMN-PT-BZN) is prepared in the form of ceramics, and the effects of the incorporation of BZN into the PMN-PT binary system are investigated. The crystal structure favors a pseudocubic symmetry and the relaxor properties are enhanced as the concentration of BZN increases. The relaxor behavior and the related phase transformations are studied by dielectric spectroscopy. A phase diagram mapping out the characteristic temperatures and various states is established. Interestingly, the piezoelectricity of the PMN-PT ceramics is significantly enhanced by the BZN substitution, with an optimal value of d 33 reaching 826 pC/N for 0.96[0.7Pb(Mg 1/3 Nb 2/3 )O 3 -0.3PbTiO 3 ]-0.04Bi(Zn 2/3 Nb 1/3 )O 3 . This paper provides a better understanding of the relaxor ferroelectric behavior, and unveils a new relaxor-based ternary system as piezoelectric materials potentially useful for electromechanical transducer applications.

The Chemical Composition Contrast between M3 and M13 Revisited: New Abundances for 28 Giant Stars in M3

Science.gov (United States)

Sneden, Christopher; Kraft, Robert P.; Guhathakurta, Puragra; Peterson, Ruth C.; Fulbright, Jon P.

2004-04-01

We report new chemical abundances of 23 bright red giant members of the globular cluster M3, based on high-resolution (R~45,000) spectra obtained with the Keck I telescope. The observations, which involve the use of multislits in the HIRES Keck I spectrograph, are described in detail. Combining these data with a previously reported small sample of M3 giants obtained with the Lick 3 m telescope, we compare metallicities and [X/Fe] ratios for 28 M3 giants with a 35-star sample in the similar-metallicity cluster M13, and with Galactic halo field stars having [Fe/H]=A(Si), we derive little difference in [X/Fe] ratios in the M3, M13, or halo field samples. All three groups exhibit C depletion with advancing evolutionary state beginning at the level of the red giant branch ``bump,'' but the overall depletion of about 0.7-0.9 dex seen in the clusters is larger than that associated with the field stars. The behaviors of O, Na, Mg, and Al are distinctively different among the three stellar samples. Field halo giants and subdwarfs have a positive correlation of Na with Mg, as predicted from explosive or hydrostatic carbon burning in Type II supernova sites. Both M3 and M13 show evidence of high-temperature proton-capture synthesis from the ON, NeNa, and MgAl cycles, while there is no evidence for such synthesis among halo field stars. But the degree of such extreme proton-capture synthesis in M3 is smaller than it is in M13: the M3 giants exhibit only modest deficiencies of O and corresponding enhancements of Na, less extreme overabundances of Al, fewer stars with low Mg and correspondingly high Na, and no indication that O depletions are a function of advancing evolutionary state, as has been claimed for M13. We have also considered NGC 6752, for which Mg isotopic abundances have been reported by Yong et al. Giants in NGC 6752 and M13 satisfy the same anticorrelation of O abundances with the ratio (25Mg+26Mg)/24Mg, which measures the relative contribution of rare to

Solid-solid interactions in Co3O4-MoO3/MgO system

International Nuclear Information System (INIS)

Radwan, Nagi R.E.; Ghozza, Ahmed M.; El-Shobaky, Gamil A.

2003-01-01

Cobalt/magnesium mixed oxide solids and cobalt-molybdenum/magnesium mixed oxide solids were prepared by thermal decomposition of basic magnesium carbonate pretreated with different proportions of cobalt nitrate and then with calculated amounts of ammonium molybdate. The proportions of cobalt expressed as Co 3 O 4 were 0.1, 0.2 and 0.3 mol while the concentrations of molybdenum expressed as mol% MoO 3 were 2.5 and 5.0. The prepared mixed solid specimens were calcined in air at 400-1000 deg. C. The solid-solid interactions in Co 3 O 4 -MoO 3 were investigated using DTA, TG and X-ray powder diffraction (XRD) techniques. The results obtained revealed that MgO dissolved cobalt oxide in its lattice forming CoO-MgO solid solution. The amount of cobalt dissolved increases by increasing the temperature in the range 800-1000 deg. C. This finding was confirmed by X-ray diffractograms in which all the diffraction lines of cobalt oxide disappeared at 1000 deg. C. MoO 3 present interacted readily with MgO and cobalt oxide by heat treatment at temperature starting from 400 deg. C producing MgMoO 4 and CoMoO 4 which remained stable by heating at 1000 deg. C. The impregnation of basic magnesium carbonate with cobalt nitrate much enhanced its thermal decomposition yielding MgO, which decomposed completely at 395.5 deg. C instead of 525 deg. C. The formation of magnesium cobaltite (MgCo 2 O 4 ) has been ruled out via XRD investigation at relatively high diffraction angles

Human alpha2-macroglobulin is composed of multiple domains, as predicted by homology with complement component C3.

Science.gov (United States)

Doan, Ninh; Gettins, Peter G W

2007-10-01

Human alpha2M (alpha2-macroglobulin) and the complement components C3 and C4 are thiol ester-containing proteins that evolved from the same ancestral gene. The recent structure determination of human C3 has allowed a detailed prediction of the location of domains within human alpha2M to be made. We describe here the expression and characterization of three alpha(2)M domains predicted to be involved in the stabilization of the thiol ester in native alpha2M and in its activation upon bait region proteolysis. The three newly expressed domains are MG2 (macroglobulin domain 2), TED (thiol ester-containing domain) and CUB (complement protein subcomponents C1r/C1s, urchin embryonic growth factor and bone morphogenetic protein 1) domain. Together with the previously characterized RBD (receptor-binding domain), they represent approx. 42% of the alpha2M polypeptide. Their expression as folded domains strongly supports the predicted domain organization of alpha2M. An X-ray crystal structure of MG2 shows it to have a fibronectin type-3 fold analogous to MG1-MG8 of C3. TED is, as predicted, an alpha-helical domain. CUB is a spliced domain composed of two stretches of polypeptide that flank TED in the primary structure. In intact C3 TED interacts with RBD, where it is in direct contact with the thiol ester, and with MG2 and CUB on opposite, flanking sides. In contrast, these alpha2M domains, as isolated species, show negligible interaction with one another, suggesting that the native conformation of alpha2M, and the consequent thiol ester-stabilizing domain-domain interactions, result from additional restraints imposed by the physical linkage of these domains or by additional domains in the protein.

Human α2-macroglobulin is composed of multiple domains, as predicted by homology with complement component C3

Science.gov (United States)

Doan, Ninh; Gettins, Peter G. W.

2007-01-01

Human α2M (α2-macroglobulin) and the complement components C3 and C4 are thiol ester-containing proteins that evolved from the same ancestral gene. The recent structure determination of human C3 has allowed a detailed prediction of the location of domains within human α2M to be made. We describe here the expression and characterization of three α2M domains predicted to be involved in the stabilization of the thiol ester in native α2M and in its activation upon bait region proteolysis. The three newly expressed domains are MG2 (macroglobulin domain 2), TED (thiol ester-containing domain) and CUB (complement protein subcomponents C1r/C1s, urchin embryonic growth factor and bone morphogenetic protein 1) domain. Together with the previously characterized RBD (receptor-binding domain), they represent approx. 42% of the α2M polypeptide. Their expression as folded domains strongly supports the predicted domain organization of α2M. An X-ray crystal structure of MG2 shows it to have a fibronectin type-3 fold analogous to MG1–MG8 of C3. TED is, as predicted, an α-helical domain. CUB is a spliced domain composed of two stretches of polypeptide that flank TED in the primary structure. In intact C3 TED interacts with RBD, where it is in direct contact with the thiol ester, and with MG2 and CUB on opposite, flanking sides. In contrast, these α2M domains, as isolated species, show negligible interaction with one another, suggesting that the native conformation of α2M, and the consequent thiol ester-stabilizing domain–domain interactions, result from additional restraints imposed by the physical linkage of these domains or by additional domains in the protein. PMID:17608619

Cryogenic milling for the fabrication of high J{sub c} MgB{sub 2} bulk superconductors

Energy Technology Data Exchange (ETDEWEB)

Kim, D. N.; Kang, M. O.; Park, H. W. [Korea University of Technology and Education, Cheonan (Korea, Republic of); Jun, B. H.; Kim, C. J. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2017-06-15

Cryogenic milling which is a combined process of low-temperature treatment and mechanical milling was applied to fabricate high critical current density (J{sub c}) MgB{sub 2} bulk superconductors. Liquid nitrogen was used as a coolant, and no solvent or lubricant was used. Spherical Mg (6-12 μm, 99.9 % purity) and plate-like B powder (⁓ 1 μm, 97 % purity) were milled simultaneously for various time periods (0, 2, 4, 6 h) at a rotating speed of 500 rpm using ZrO{sub 2} balls. The (Mg{sup +2B}) powders milled were pressed into pellets and heat-treated at 700°C for 1 h in flowing argon. The use of cryomilled powders as raw materials promoted the formation reaction of superconducting MgB{sub 2}, reduced the grain size of MgB{sub 2}, and suppressed the formation of impurity MgO. The superconducting critical temperature (T{sub c}) of MgB{sub 2} was not influenced as the milling time (t) increased up to 6 h. Meanwhile, the critical current density (J{sub c}) of MgB{sub 2} increased significantly when t increased to 4 h. When t increased further to 6 h, however, Jc decreased. The J{sub c} enhancement of MgB{sub 2} by cryogenic milling is attributed to the formation of the fine grain MgB{sub 2} and a suppression of the MgO formation.

Strategies for a centralized single product multiclass M/G/1 make-to-stock queue

OpenAIRE

Abouee-Mehrizi, Hossein; Balcıoğlu, Ahmet Barış; Balcioglu, Ahmet Baris; Baron, Opher

2012-01-01

Make-to-stock queues are typically investigated in the M/M/1 settings. For centralized single-item systems with backlogs, the multilevel rationing (MR) policy is established as optimal and the strict priority (SP) policy is a practical compromise, balancing cost and ease of implementation. However, the optimal policy is unknown when service time is general, i.e., for M/G/1 queues. Dynamic programming, the tool commonly used to investigate the MR policy in make-to-stock queues, is less practic...

Homoleptic diphosphacyclobutadiene complexes [M(η(4)-P2C2R2)2]x- (M = Fe, Co; x = 0, 1).

Science.gov (United States)

Wolf, Robert; Ehlers, Andreas W; Khusniyarov, Marat M; Hartl, František; de Bruin, Bas; Long, Gary J; Grandjean, Fernande; Schappacher, Falko M; Pöttgen, Rainer; Slootweg, J Chris; Lutz, Martin; Spek, Anthony L; Lammertsma, Koop

2010-12-27

The preparation and comprehensive characterization of a series of homoleptic sandwich complexes containing diphosphacyclobutadiene ligands are reported. Compounds [K([18]crown-6)(thf)(2)][Fe(η(4)-P(2)C(2)tBu(2))(2)] (K1), [K([18]crown-6)(thf)(2)][Co(η(4)-P(2)C(2)tBu(2))(2)] (K2), and [K([18]crown-6)(thf)(2)][Co(η(4)-P(2)C(2)Ad(2))(2)] (K3, Ad = adamantyl) were obtained from reactions of [K([18]crown-6)(thf)(2)][M(η(4)-C(14)H(10))(2)] (M = Fe, Co) with tBuC[triple bond]P (1, 2), or with AdC[triple bond]P (3). Neutral sandwiches [M(η(4)-P(2)C(2)tBu(2))(2)] (4: M = Fe 5: M = Co) were obtained by oxidizing 1 and 2 with [Cp(2)Fe]PF(6). Cyclic voltammetry and spectro-electrochemistry indicate that the two [M(η(4)-P(2)C(2)tBu(2))(2)](-)/[M(η(4)-P(2)C(2)tBu(2))(2)] moieties can be reversibly interconverted by one electron oxidation and reduction, respectively. Complexes 1-5 were characterized by multinuclear NMR, EPR (1 and 5), UV/Vis, and Mössbauer spectroscopies (1 and 4), mass spectrometry (4 and 5), and microanalysis (1-3). The molecular structures of 1-5 were determined by using X-ray crystallography. Essentially D(2d)-symmetric structures were found for all five complexes, which show the two 1,3-diphosphacyclobutadiene rings in a staggered orientation. Density functional theory calculations revealed the importance of covalent metal-ligand π bonding in 1-5. Possible oxidation state assignments for the metal ions are discussed.

HuR binds to a single site on the C/EBPβ mRNA of 3T3-L1 adipocytes

International Nuclear Information System (INIS)

Jones, Heath; Carver, Melinda; Pekala, Phillip H.

2007-01-01

HuR is a ligand for nuclear mRNAs containing adenylate-uridylate rich elements in the 3'-untranslated region. Once bound to the mRNA, HuR is recognized by adapter proteins which then facilitate nuclear export of the complex. In the cytosol HuR is thought to function to control stability and translation of its ligand message. In the 3T3-L1 cells HuR is constitutively expressed and localized predominantly to the nucleus in the preadipocytes. However within 30 min of exposure to the differentiation stimulus, the HuR content in the cytosol increases consistent with HuR regulating the availability of relevant mRNAs for translation. Using in vitro RNA gel shifts, we have demonstrated that the C/EBPβ message is a ligand for HuR and that the single binding site is an adenylate-uridylate rich element in the 3'-untranslated region

The light sensitivity of thermoluminescent materials: LiF:Mg,Cu,P, LiF:Mg,Ti and Al2O3:C

International Nuclear Information System (INIS)

Duggan, L.; Budzanowski, M.; Przegietka, K.; Reitsema, N.; Wong, J.; Kron, T.

2000-01-01

Many thermoluminescence dosimetry (TLD) materials exhibit a variation in read-out with light exposure (including both visible and UV radiation energy) which may cause problems in environmental dosimetry. The aim of the present study was to investigate this for three newer preparations of TLD material - LiF:Mg,Ti (GR-100, DML, China), LiF:Mg,Cu,P (MCP-N, TLD Niewiadomski and Co., Poland) and Al 2 O 3 :C (Stillwater Sciences, USA). TLDs irradiated to 1 or 10 Gy were exposed to light from a calibrated spectral lamp with three to four times higher UV component than sunlight. MCP-N proved to be approximately five times less light sensitive than GR-100. For both materials, the decay of the major glow peaks with increasing light exposure could be described by a single or dual exponential equation. Half lives for the major dosimetry peaks of GR-100, fit to a single exponential, were 1132 min (∼19 h) for peak 4 and 275 min (∼4((1)/(2)) h) for peak 5. The half lives for peak 4 of MCP-N, fit to a dual exponential, were 309 min (∼5 h) and 6627 min (∼4((1/2)) days). For MCP-N, this relates to approximately a loss of half the signal in 14 days of sun exposure (Polish summer). The readout of Al 2 O 3 :C increased with increasing light exposure and saturated after only 5 min at a level 26 times higher than the signal without light exposure

Synthesis of {sup 99m}Tc(CO){sub 3}-deoxyuridine derivatives as potential HSV1-tk gene expression imaging agents

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Young [Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of); Department of Chemistry, Hankuk University of Foreign Studies, Yongin 449-791 (Korea, Republic of); Oh, Seung Jun [Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of)], E-mail: sjoh@amc.seoul.kr; Ryu, Jin Sook [Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of); Choi, Seon-Joo [Division of Radioisotope Production and Application, Hanaro Center, Korea Atomic Energy Research Institute, Yusongku, Taejeon 305-600 (Korea, Republic of); Ha, Hyun-Joon [Department of Chemistry, Hankuk University of Foreign Studies, Yongin 449-791 (Korea, Republic of); Moon, Dae Hyuk [Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of)

2008-04-15

In this study, we synthesized {sup 99m}Tc(CO){sub 3}-2'-aminomethylpyridyl-2'-deoxyuridine ({sup 99m}Tc(CO){sub 3}-AMPDU) and {sup 99m}Tc(CO){sub 3}-aminoethylpyridyl-2'-deoxyuridine ({sup 99m}Tc(CO){sub 3}-AEPDU) as potential agents for imaging the expression of the non-invasive herpes simplex virus type-1 thymidine kinase. AMPDU and AEPDU were synthesized from uridine in five chemical steps and then labeled with [{sup 99m}Tc(CO){sub 3}(H{sub 2}O){sub 3}]{sup +} (370 MBq/0.5 mL) at 100 {sup o}C for 10 min. Under optimal conditions (0.5 and 1.0 mg for AMPDU and AEPDU and heating for 10 min), the labeling efficiency was 95.3{+-}2.8% for AMPDU and 94.2{+-}5.1% for AEPDU. To validate the chemical structure of {sup 99m}Tc(CO){sub 3}-labeled compounds, we also synthesized ReBr(CO){sub 3}-AMPDU and ReBr(CO){sub 3}-AEPDU by reacting [Et{sub 4}N][ReBr{sub 3}(CO){sub 3}] and AMPDU or AEPDU in methanol at 25 {sup o}C for 6 h. {sup 99m}Tc(CO){sub 3}-AMPDU and {sup 99m}Tc(CO){sub 3}-AEPDU had the same retention time on HPLC analysis as ReBr(CO){sub 3}-AMPDU and ReBr(CO){sub 3}-AEPDU. {sup 99m}Tc(CO){sub 3}-AMPDU and {sup 99m}Tc(CO){sub 3}-AEPDU had high radiochemical stabilities of 98.1{+-}1.5% and 98.0{+-}1.7% for 6 h, respectively.

Reevaluation of a twenty-four-month chronic toxicity/carcinogenicity study of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in the B6C3F1 hybrid mouse.

Science.gov (United States)

Parker, George A; Reddy, Gunda; Major, Michael A

2006-01-01

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) has been widely used as an explosive in U.S. army munitions formulations since World War II. Two-year carcinogenicity studies revealed RDX to be noncarcinogenic in two strains of rats, but a 2-year carcinogenicity study in B6C3F1 mice revealed an increased incidence of hepatocellular neoplasms in females. Based on results of the study in B6C3F1 mice, RDX has been classified as a possible carcinogen. The authors reevaluated the archived histological sections from the B6C3F1 mouse study, using current histopathologic diagnostic criteria and interpretations. The earlier evaluation showed a statistically significant increase in the incidence of hepatocellular adenoma/carcinoma in female mice from the three highest dose groups (7, 35, and 175/100 mg/kg/day). The revaluation yielded a slightly lower incidence at each of the dose levels in female mice. The reduced number of hepatocellular neoplasms was largely due to reclassification of hepatocellular adenomas as foci of cytoplasmic alteration, in compliance with current diagnostic criteria. The reevaluation was reviewed by a pathology working group (PWG), which arrived at a consensus classification of each lesion. Based on the consensus diagnoses of the PWG, only one female group (35 mg/kg/day) showed a significant increase when compared to controls. The incidence of hepatocellular neoplasms for all groups, including the 35 mg/kg/day group, was within the reported incidence range for spontaneous hepatocellular neoplasms in female B6C3F1 mice. The increased incidence of hepatocellular neoplasms in female mice given RDX at 35 mg/kg/day was interpreted as equivocal evidence of a carcinogenic effect.

Grain refinement of Ca addition in a twin-roll-cast Mg-3Al-1Zn alloy

Energy Technology Data Exchange (ETDEWEB)

Jiang Bin, E-mail: jiangbinrong@cqu.edu.cn [National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400030 (China); College of Materials Science and Engineering, Chongqing University, Chongqing 400030 (China); Liu Wenjun [College of Materials Science and Engineering, Chongqing University, Chongqing 400030 (China); Qiu Dong; Zhang Mingxing [Division of Materials, School of Mechanical and Mining Engineering, University of Queensland, St Lucia, QLD 4072 (Australia); Pan Fusheng [National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400030 (China)

2012-04-16

Highlights: Black-Right-Pointing-Pointer Grain refinement of Ca addition in a twin-roll-cast Mg-3Al-1Zn alloy was investigated. Black-Right-Pointing-Pointer Addition of 0.08 wt% Ca into Mg melts can significantly reduce the grain size to 30 {mu}m from 100 {mu}m. Black-Right-Pointing-Pointer Al{sub 2}Ca intermetallic particles have high potency to act as heterogeneous nucleation sites for {alpha}-Mg. - Abstract: Addition of 0.08 wt% Ca into AZ31 melts significantly reduces the average grain size of thin strips produced by twin-roll-cast to 30 {mu}m from 100 {mu}m. Like Zr, due to the high chemical activity, the Ca added into the melts reacts with Al and forms Al{sub 2}Ca intermetallic compound. X-ray diffraction result approves the existence of Al{sub 2}Ca in the thin strips, which formed in the melts. Crystallographic examination of relationship between Al{sub 2}Ca and Mg using the edge-to-edge matching model indicates that Al{sub 2}Ca particles are effective inoculants for heterogeneous nucleation of Mg. It is considered that Al{sub 2}Ca is a potential and effective grain refiner for Mg alloys and the grain refinement through addition of Ca in the AZ31 alloy is attributed to the inoculation effect of Al{sub 2}Ca particles formed in the melts.

Effect of Reduction in Thickness and Rolling Conditions on Mechanical Properties and Microstructure of Rolled Mg-8Al-1Zn-1Ca Alloy

Directory of Open Access Journals (Sweden)

Yuta Fukuda

2017-01-01

Full Text Available A cast Mg-8Al-1Zn-1Ca magnesium alloy was multipass hot rolled at different sample and roll temperatures. The effect of the rolling conditions and reduction in thickness on the microstructure and mechanical properties was investigated. The optimal combination of the ultimate tensile strength, 351 MPa, yield strength, 304 MPa, and ductility, 12.2%, was obtained with the 3 mm thick Mg-8Al-1Zn-1Ca rolled sheet, which was produced with a roll temperature of 80°C and sample temperature of 430°C. This rolling process resulted in the formation of a bimodal structure in the α-Mg matrix, which consequently led to good ductility and high strength, exclusively by the hot rolling process. The 3 mm thick rolled sheet exhibited fine (mean grain size of 2.7 μm and coarse grain regions (mean grain size of 13.6 μm with area fractions of 29% and 71%, respectively. In summary, the balance between the strength and ductility was enhanced by the grain refinement of the α-Mg matrix and by controlling the frequency and orientation of the grains.

Perovskites with noble metals of type Ba/sub 3/BM/sub 2/O/sub 9/; B = Mg, Fe, Co, Ni, Zn, Cd; M = Ru, Ir

Energy Technology Data Exchange (ETDEWEB)

Treiber, U; Kemmler-Sack, S; Ehmann, A [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1982-04-01

The perovskites Ba/sub 3/BM/sub 2/O/sub 9/ crystallize in a hexagonal BaTiO/sub 3/ structure and could be prepared for M = Ru; B = Mg, Fe, Co, Ni, Zn, Cd and M = Ir; B = Co, Ni. According to intensity calculations on powder data of Ba/sub 3/MgRu/sub 2/O/sub 9/ and Ba/sub 3/NiIr/sub 2/O/sub 9/ (refined intensity related R' value 6.7% (Ba/sub 3/MgRu/sub 2/O/sub 9/) and 6.9% (Ba/sub 3/NiIr/sub 2/O/sub 9/)) an 1:2 order is present and both lattices contain face connected M/sub 2/O/sub 9/ double octahedra linked by another via common corners through BO/sub 6/ single octahedra. The occurrence of this typ of cationic order results for B = Mg, Co, Ni, Zn, Cd from the analysis of the vibrational spectra. For B = Mg, Zn, Cd and presumable with B = Ni the charge distribution is B/sup 2 +// 2 M/sup 5 +/; for B = Co deviation can not be excluded. On the opposite in Ba/sub 3/FeRu/sub 2/O/sub 9/ an electron delocalisation is present.

Geometry and bonding in the ground and lowest triplet state of D{sub 6h} symmetric crenellated edged C{sub 6[3m(m-1)+1]}H{sub 6(2m-1)} (m = 2,..., 6) graphene hydrocarbon molecules

Energy Technology Data Exchange (ETDEWEB)

Philpott, Michael R., E-mail: philpott@imr.edu [Center for Computational Materials Science, Institute of Materials Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, 980-8577 Sendai (Japan); Kawazoe, Yoshiyuki [Center for Computational Materials Science, Institute of Materials Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, 980-8577 Sendai (Japan)

2009-03-30

Ab initio plane wave all valence electron based DFT calculations were used to explore the dichotomy of perimeter vs. interior in the electronic and geometric structure of the D{sub 6h} singlet ground state and D{sub 2h} lowest triplet state of planar graphene hydrocarbon molecules with crenellated (arm chair) edges and the general formula C{sub 6[3m(m-1)+1]} H{sub 6(2m-1)} where m = 2,...,6. The largest molecule C{sub 546}H{sub 66} was 4.78 nm across and contained 2250 valence electrons. These molecules are nominally 'fully benzenoid hydrocarbons'. However with increasing size, the core of central atoms abandoned any fully benzenoid geometry they had in small systems and organized into single layer graphite (graphene) structure. The perimeter atoms of the crenellation adopted a conjugated geometry with unequal bonds and between core and perimeter there were some C{sub 6} rings retaining remnants of aromatic sextet-type properties. Compared to a zigzag edge the crenellated edge conferred stability in all the systems studied as measured by the singlet homo-lumo level gap BG{sub 0} and the singlet-lowest triplet energy gap {Delta}E{sub ST}. For the largest crenellated system (m = 6) BG{sub 0} and {Delta}E{sub ST} were approximately 0.7 eV, larger in value than for similarly sized hexagonal graphenes with zigzag edges. Triplet states were identified for all the molecules in the series and in the case of the m = 2 molecule hexabenzocoronene C{sub 42}H{sub 18}, two conformations with D{sub 2h} symmetry were identified and compared to features on the triplet state potential energy surface of benzene.

Attenuation of insulin resistance in rats by agmatine: role of SREBP-1c, mTOR and GLUT-2.

Science.gov (United States)

Sharawy, Maha H; El-Awady, Mohammed S; Megahed, Nirmeen; Gameil, Nariman M

2016-01-01

Insulin resistance is a serious health condition worldwide; however, its exact mechanisms are still unclear. This study investigates agmatine (AGM; an endogenous metabolite of L-arginine) effects on insulin resistance induced by high fructose diet (HFD) in rats and the possible involved mechanisms. Sprague Dawley rats were fed 60% HFD for 12 weeks, and AGM (10 mg/kg/day, orally) was given from week 9 to 12. AGM significantly reduced HFD-induced elevation in fasting insulin level, homeostasis model assessment of insulin resistance (HOMA-IR) index and liver glycogen content from 3.44-, 3.62- and 2.07- to 2.59-, 2.78- and 1.3-fold, respectively, compared to the control group, while it increased HFD-induced reduction in glucose tolerance. Additionally, AGM significantly decreased HFD-induced elevation in serum triglycerides, low density lipoprotein cholesterol and very low density lipoprotein cholesterol levels from 3.18-, 2.97- and 4.75- to 1.25-, 1.25- and 1.07-fold, respectively, compared to control group. Conversely, AGM had no significant effect on HFD-induced changes in fasting glucose, glycosylated hemoglobin, insulin tolerance and high density lipoprotein cholesterol. Furthermore, AGM significantly reduced HFD-induced elevation in mRNA expression of glucose transporter type-2 (GLUT-2), mammalian target of rapamycin (mTOR) and sterol regulatory element-binding protein-1c (SREBP-1c) without affecting that of peroxisome proliferator-activated receptor-alpha (PPAR-α) in the liver. Additionally, AGM enhanced ACh-induced aortic relaxation and attenuated liver steatosis induced by HFD. In conclusion, AGM may have a therapeutic potential in insulin resistance through suppressing SREBP-1c, mTOR and GLUT-2 in liver.

Thermoelectric power of PrMg3

Science.gov (United States)

Isikawa, Yosikazu; Somiya, Kazuya; Koyanagi, Huruto; Mizushima, Toshio; Kuwai, Tomohiko; Tayama, Takashi

2010-01-01

PrMg3 is supposed to be one of the strongly correlated electron systems originated from the hybridization between the Pr 4f and conduction electrons, because the gigantic electronic specific heat coefficient C/T was observed at low temperatures. However, a typical behaviour of - ln T dependence was not observed in the temperature dependence of the electrical resistivity. The thermoelectric power S is a powerful tool to investigate the density of states at the Fermi energy. We measured carefully the thermoelectric power of PrMg3 in the temperature range between 2 and 300 K. S is extremely small, ranged within ±1 μV/K over the whole temperature. The value of S/T at low temperature limit was also significantly smaller than expected from the specific heat results. We therefore conclude that the density of state at the Fermi level is not enhanced in PrMg3.

Thermoelectric power of PrMg3

International Nuclear Information System (INIS)

Isikawa, Yosikazu; Somiya, Kazuya; Koyanagi, Huruto; Mizushima, Toshio; Kuwai, Tomohiko; Tayama, Takashi

2010-01-01

PrMg 3 is supposed to be one of the strongly correlated electron systems originated from the hybridization between the Pr 4f and conduction electrons, because the gigantic electronic specific heat coefficient C/T was observed at low temperatures. However, a typical behaviour of - ln T dependence was not observed in the temperature dependence of the electrical resistivity. The thermoelectric power S is a powerful tool to investigate the density of states at the Fermi energy. We measured carefully the thermoelectric power of PrMg 3 in the temperature range between 2 and 300 K. S is extremely small, ranged within ±1 μV/K over the whole temperature. The value of S/T at low temperature limit was also significantly smaller than expected from the specific heat results. We therefore conclude that the density of state at the Fermi level is not enhanced in PrMg 3 .

Transesterification of palm oil on K{sub y}Mg{sub 1} {sub -} {sub x}Zn{sub 1} {sub +} {sub x}O{sub 3} catalyst: Effect of Mg-Zn interaction

Energy Technology Data Exchange (ETDEWEB)

Olutoye, M.A.; Hameed, B.H. [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

2010-06-15

The Mg-Zn interaction effect of K{sub y}Mg{sub 1} {sub -} {sub x}Zn{sub 1} {sub +} {sub x}O{sub 3} heterogeneous type catalyst and its performance on transesterification of palm oil have been studied using the response surface methodology and the factorial design of experiments. The catalyst was synthesized using the co-precipitation method and the activity was assessed by transesterification of palm oil into fatty acid methyl esters. The ratio of the Mg/Zn metal interaction, temperature and time of calcination were found to have positive influence on the conversion of palm oil to fatty acid methyl ester (FAME) with the effect of metal to metal ratio and temperature of calcination being more significant. The catalytic activity was found to decrease at higher calcination temperature and the catalyst type K{sub 2}Mg{sub 0.34}Zn{sub 1.66}O{sub 3} with Mg/Zn ratio of 4.81 gave FAME content of 73% at a catalyst loading of 1.404 wt.% of oil with molar ratio of methanol to oil being 6:1 at temperature of 150 C in 6 h. A regression model was obtained to predict conversions to methyl esters as a function of metal interaction ratio, temperature of calcination and time. The observed activity of the synthesized catalyst was due to its synergetic structure and composition. (author)

Structural, morphological and interfacial characterization of Al-Mg/TiC composites

International Nuclear Information System (INIS)

Contreras, A.; Angeles-Chavez, C.; Flores, O.; Perez, R.

2007-01-01

Morphological and structural characterization of Al-Mg/TiC composites obtained by infiltration process and wetting by the sessile drop technique were studied. Focusing at the interface, wetting of TiC substrates by molten Al-Mg-alloys at 900 deg. C was investigated. Electron probe microanalysis (EPMA) indicated that aluminum carbide (Al 4 C 3 ) is formed at the interface and traces of TiAl 3 in the wetting assemblies were detected. Scanning Electron Microscopy (SEM) observations show that TiC particles do not appear to be uniformly attacked to produce a continuous layer of Al 4 C 3 at the interface. Molten Al-Mg-alloys were infiltrated into TiC preforms with flowing argon at a temperature of 900 deg. C. In the composites no reaction phase was observed by SEM. Quantification of the Al phase in the composite was carried out by X-ray diffraction (XRD) and Rietveld analysis. Chemical mapping analyzed by SEM shows that the Al-Mg alloy surrounds TiC particles. In the composites with 20 wt.% of Mg the Al-Mg-β phase was detected through XRD

A study on preparation and hydriding of β-Mg2Al3 and γ-Mg17Al12

International Nuclear Information System (INIS)

Hadi Suwarno

2009-01-01

The mechanism of the synthetic formation of β-Mg 2 Al 3 and γ-Mg 17 Al 12 has been studied. Mechanical alloying of Mg and Al powders with the atomic ratio of Mg:Al = 2:3 in toluene solution yields β-Mg 2 Al 3 compound after milling for 30 h. The γ-Mg 17 Al 12 can be formed by heating the β-Mg 2 Al 3 at 430°C under high vacuum. The measured hydrogen capacities of β-Mg 2 Al 3 and γ-Mg 17 Al 12 as hydride at 300°C are 3.2 and 4.9 wt%, respectively. Microstructure of the Mg-Al specimen shows that on hydriding at 300°C the polygonal shape of the γ-Mg 17 Al 12 changes into irregular shapes which are composed of γ-MgH 2 and Al. (author)

Production and characterization of a murine monoclonal IgM antibody to human C1q receptor (C1qR)

International Nuclear Information System (INIS)

Ghebrehiwet, B.

1986-01-01

A hybridoma cell line that produces a monoclonal antibody (MAb) to cell surface C1q receptor (C1qr) has been produced by fusion of the P3 x 63-Ag8.653 mouse myeloma cell line with the spleen cells of a CD-1 mouse that had been hyperimmunized with viable Raji cell suspensions (5 x 10 7 cells/inoculum). This MAb, designated II1/D1, is an IgM antibody with lambda-light chain specificity. Radiolabeled or unlabeled, highly purified II1/D1 was used to determine that: a) this antibody competes for C1q binding sites on C1qR-bearing cells; b) the molecule recognized by this MAb is the C1qR; and c) cells that are known to bind C1q also bind II1/D1 in a specific manner. Western blot analysis of solubilized Raji, or U937 cell membranes, showed that the 125 I-MAb detected a major protein band of approximately 85000 m.w. in its unreduced state, indicating that the C1qR is similar, if not identical, in both types of cells. Analyses of 125 I-II/D1 binding experiments revealed that the antibody bound to Raji cells or u937 cells in a specific manner. Uptake of the antibody was saturable, with equilibrium virtually attained within 35 min. Scatchard analysis of the binding data using the intact MAb suggests that the affinity constant K/sub D/ is 2.9 x 10 -10 M, and at apparent saturation, 24.6 ng of the antibody were bound per 2 x 10 6 cells, giving an estimated 7.8 x 10 3 antibody molecules bound per cell. That the II1/D1 antibody is specifically directed to the C1q was further evidenced by an ELISA in which the ability of C1qR-bearing cells to bind the MAb was abrogated by c-C1q in a specific dose-dependent manner

Note: High-power piezoelectric transformer fabricated with ternary relaxor ferroelectric Pb(Mg(1/3)Nb(2/3))O3-Pb(In(1/2)Nb(1/2))O3-PbTiO3 single crystal.

Science.gov (United States)

Wang, Qing; Ma, Chuanguo; Wang, Feifei; Liu, Bao; Chen, Jianwei; Luo, Haosu; Wang, Tao; Shi, Wangzhou

2016-03-01

A plate-shaped piezoelectric transformer was designed and fabricated using ternary relaxor ferroelectric single crystal Pb(Mg(1/3)Nb(2/3))O3-Pb(In(1/2)Nb(1/2))O3-PbTiO3. Both the input and output sections utilized the transverse-extensional vibration mode. The frequency and load dependences of the electrical properties for the proposed transformer were systematically studied. Results indicated that under a matching load resistance of 14.9 kΩ, a maximum output power of 2.56 W was obtained with the temperature rise less than 5 °C. The corresponding power density reached up to 50 W/cm(3). This ternary single-crystal transformer had potential applications in compact-size converters requiring high power density.

Prussian Blue Mg-Li Hybrid Batteries.

Science.gov (United States)

Sun, Xiaoqi; Duffort, Victor; Nazar, Linda F

2016-08-01

The major advantage of Mg batteries relies on their promise of employing an Mg metal negative electrode, which offers much higher energy density compared to graphitic carbon. However, the strong coulombic interaction of Mg 2+ ions with anions leads to their sluggish diffusion in the solid state, which along with a high desolvation energy, hinders the development of positive electrode materials. To circumvent this limitation, Mg metal negative electrodes can be used in hybrid systems by coupling an Li + insertion cathode through a dual salt electrolyte. Two "high voltage" Prussian blue analogues (average 2.3 V vs Mg/Mg 2+ ; 3.0 V vs Li/Li + ) are investigated as cathode materials and the influence of structural water is shown. Their electrochemical profiles, presenting two voltage plateaus, are explained based on the two unique Fe bonding environments. Structural water has a beneficial impact on the cell voltage. Capacities of 125 mAh g -1 are obtained at a current density of 10 mA g -1 (≈C/10), while stable performance up to 300 cycles is demonstrated at 200 mA g -1 (≈2C). The hybrid cell design is a step toward building a safe and high density energy storage system.

Mg2+ Doped into Electro-synthesized HKUST-1 and Their Initial Hydrogen Sorption Properties

Science.gov (United States)

Lestari, W. W.; Ni'maturrohmah, D.; Arrozi, U. S. F.; Suwarno, H.

2018-01-01

The hydrogen storage materials are essentially play important roles in supporting the utilization of hydrogen as a promising alternative energy. Several innovative materials have been proposed and intensively investigated in this regard, including Metal-Organic Framework (MOFs). MOFs type HKUST-1 [Cu3(BTC)2] (BTC = benzene-tri-carboxylate) is the most explored materials in hydrogen storage. In this research, HKUST-1 was electro-synthesized under 15 volt for 1.5 h. This material was ex-situ modified with magnesium(II) ion with variation: 3, 5 and 10 wt% to add attractive sites for hydrogen to form Mg2+@HKUST-1. The final materials were characterized by XRD, FTIR, SEM-EDX, and SAA. Hydrogen sorption measurement was conducted using Sievert system at 30 and 80 °C with pressure from 0.2 to 1.5 bar in 10 minutes for each condition. According to XRD analysis, the basic structure of Mg2+@HKUST-1 was remaining stable. In contrary, SEM analysis showed that HKUST-1 morphology was changed after modification with Mg2+. In addition, the surface area of materials significantly increased from 372.112 to 757.617m2/g, based on SAA analysis. The presence of Mg2+ in the HKUST-1 increased the hydrogen sorption capacity up to 0.475 wt% at 1.4 bar at 30 °C and 0.256 wt% at 80 °C (1.4 bar).

MgB2 and Mg1-xAlxB2 single crystals: high pressure growth and physical properties

International Nuclear Information System (INIS)

Karpinski, J.; Kazakov, S.M.; Jun, J.; Zhigadlo, N.D.; Angst, M.; Puzniak, R.; Wisniewski, A.

2004-01-01

Single crystals of MgB 2 have been grown with a high pressure cubic anvil technique. They grow via the peritectic decomposition of the MgNB 9 ternary nitride. The crystals are of a size up to 2 x 1 x 0.1 mm 3 with a weight up to 230 μg. Typically they have transition temperatures between 38 and 38.6 K with a width of 0.3-0.5 K. Investigations of the P-T phase diagram prove that the MgB 2 phase is stable at least up to 2190 deg. C at high hydrostatic pressure in the presence of Mg vapor under high pressure. Substitution of aluminum for magnesium in single crystals leads to stepwise decrease of T c . This indicates a possible appearance of superstructures or phases with different T c 's. The upper critical field decreases with Al doping

Dicty_cDB: Contig-U16487-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available 2 ( DW406563 ) EST000984 Trichophyton rubrum cDNA library Tricho... 72 1e-17 4 ( FL496835 ) Mg_Nor01_07E06 Nor01 Myti... stress library Fra... 101 6e-18 3 ( DB668091 ) Saccharomyces cerevisiae mRNA, clon...isia annua normalized leaf... 62 2e-15 4 ( DW680253 ) EST003734 Trichophyton rubrum cDNA library 0 Tric... 7...R946874 ) EST1138413 Aquilegia cDNA library Aquilegia formo... 66 5e-10 2 ( FC787763 ) CBGC17953.fwd CBGC Lotti...:VS... 293 9e-75 1 ( DT758323 ) EST1192172 Aquilegia cDNA library Aquilegia formo

Production of 9-thioxo-2,3,4,9-tetrahydro-pyrrolo[3,4-b]quinolin-1

African Journals Online (AJOL)

ated using SHELXTL and PLATON.10. Crystal data for 3a. C17H19N3OS, M = 313.41, monoclinic, space group C2/c (No. 15), a = 18.581(3), b = 13.760(2), c = 14.272(2) Å,. $ = 117.518(3)°, V = 3236.1(9) Å3, Z = 8, Dx = 1.287 Mg m–3,µ= 0.205 mm–1, T = 293(2) K, 10970 reflections collected for 1.93 <. 2 < 28.33° of which ...

Pharmacokinetic and tolerability of i.m. disodium clodronate 200 mg/lidocaine 1%, given twice monthly, in comparison with i.m. disodium clodronate 100 mg/lidocaine 1%, given weekly, in healthy postmenopausal female patients.

Science.gov (United States)

Radicioni, Milko; Cremonesi, Giovanni; Baraldi, Enrica; Leuratti, Chiara; Mariotti, Fabrizia

2013-04-01

Clodronate is a bisphosphonate effective in the prevention and treatment of osteoporosis in postmenopausal women. Non-adherence to bisphosphonates, however, is a major issue in clinical practice. Simplifying dose regimens may increase compliance. To assess bioequivalence between an intramuscular (i.m.) clodronate 200 mg/lidocaine 1% twice-a-month formulation and a clodronate 100 mg/lidocaine 1% weekly formulation in 32 postmenopausal women. In this double-blind, randomized, two-way crossover study, test and reference formulations were administered in single dose, with a 2-week wash-out between administrations. The primary endpoint was clodronic acid cumulative excretion in the first 24 hours after injection (Xu0-24h). Cumulative excretion in the 72 hours post-dose (Xu0-72h) and maximum excretion rate (Ratemax) were also evaluated. Bioequivalence was assumed if the 90% confidence intervals (CIs) of the geometric means ratios of the dose-normalized parameters were within the 80.00 - 125.00% range. Local tolerability was evaluated. Mean Xu0-24h values were 114.03 ±23.13 mg and 55.22 ±9.73 mg for clodronate 200 mg and 100 mg. The 90% CIs for dose-normalized Xu0-24h, Xu0-72h and Ratemax ere 95 -110%, 94 -107% and 95 - 113%. Local tolerability of both treatments was good. The differences in pain intensity between formulations were not sigificantly different at most assessment times. Headache was the only treatment-related adverse event. Bioequivalence of the two formulations was confirmed in terms of dose-normalized rate and amount of clodronic acid excretion. This result, together with the favorable tolerability of the novel 200 mg formulation, suggests the possibility of reducing the number of i.m. administrations from once-a-week to twice-a-month.

A comparison of the doppler-broadened positron annihilation spectra of neutron irradiated Al 2O 3 and MgAl 2O 3

Science.gov (United States)

Jones, P. L.; Schaffer, J. P.; Cocks, F. H.; Clinard, F. W.; Hurley, G. F.

1985-01-01

Radiation damage studies of oxides and ceramics have become of increasing importance due to the projected use of these materials in thermonuclear fusion reactors as electronic insulators and first wall materials. In addition these materials are important in RAD waste disposal. As part of a study of the defect structure in radiation damaged ceramics Doppler-broadened positron annihilation spectra have been obtained for a series of single crystal sapphire (α-Al 2O 3) and polycrystal (1:1) and (1:2) magnesium aluminate spinel (MgO·Al 2O 3 and MgO-2Al 2O 3) samples. These samples were irradiated in EBR-II to a fluence of 3 × 10 25 n/m 2 (E > 0.1 MeV) at 740°C, and 2 × 10 26 n/m 2 (E > 0.1 MeV) at ~ 550°C respectively. Positron annihilation spectra lineshapes for the irradiated, annealed, and as-received samples of both materials were compared using S parameter analysis. These calculations were made on deconvoluted gamma ray spectra that were free of any instrumental broadening effects. In this way, absolute S parameter changes could be calculated. The observed changes in the S parameter are consistent with independent volume swelling measurements for both the α-A1 2O 3 and the (1:2) MgAl 2O 4 samples. However, the change in S parameter measured for the (1:1) spinel is contrary to the measured volume change. This apparent anomaly indicates a predominence of interstitial as opposed to vacancy type defects in this material.

Microstructure and properties of hot extruded Mg-3Zn-Y-xCu (x = 0, 1, 3, 5) alloys

Energy Technology Data Exchange (ETDEWEB)

Liu, Bao-sheng; Kuang, Ya-fei; Fang, Da-qing; Chai, Yue-sheng [Taiyuan Univ. of Science and Technology (China). College of Materials Science and Engineering; Taiyuan Univ. of Science and Technology (China). Engineering Research Center for Magnesium Alloys of Shanxi Province; Zhang, Yue-zhong [Taiyuan Univ. of Science and Technology (China). Engineering Research Center for Magnesium Alloys of Shanxi Province; Taiyuan Univ. of Science and Technology (China). College of Chemical and Biological Engineering

2017-04-15

In petroleum drilling engineering, materials with high strength and rapid degradation are required for degradable fracturing ball applications. In this work, the microstructure, mechanical properties, and corrosion behavior of extruded Mg-3Zn-Y-xCu (x = 0, 1, 3, 5 weight percent) alloys are investigated using optical microscopy, scanning electronic microscopy equipped with energy dispersive X-ray spectroscopy, X-ray diffraction, transmission electronic microscopy, compression tests, electrochemical measurements, and hydrogen evolution tests, to explore their potential as excellent candidate alloys for degradable fracturing ball applications. It is found that the Mg-3Zn-Y alloy is mainly composed of α-Mg, Mg{sub 3}Zn{sub 3}Y{sub 2}, and Mg{sub 3}Zn{sub 6}Y phases. After Cu addition, a new MgZnCu phase is formed, while the Mg{sub 3}Zn{sub 3}Y{sub 2} phase disappears. The Mg-3Zn-Y-3Cu alloy shows the highest compressive strength (473 MPa) and yield strength (402 MPa), mainly attributed to the combined effect of the fine-grain and dispersed precipitation of Mg{sub 3}Zn{sub 6}Y and MgZnCu. The corrosion rate of Mg-3Zn-Y-3Cu reaches 0.41 mm day{sup -1} in 3.5 wt.% KCl solution. Consequently, Mg-3Zn-Y-3Cu alloy is a suitable degradable fracturing ball-seat material.

Hydrogen sorption properties of ball-milled Mg-C nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Spassov, Tony; Zlatanova, Zlatina; Spassova, Maya; Todorova, Stanislava [Faculty of Chemistry, University of Sofia ' ' St.Kl.Ohridski' ' , 1 James Bourchier str. 1164 Sofia (Bulgaria)

2010-10-15

MgH{sub 2} 75 at.%-C 25 at.% composites are synthesized by ball milling using different kinds of carbon additives: carbon black (CB), nanodiamonds (ND) and amorphous carbon soot (AC). X-ray diffraction analysis showed that the MgH{sub 2} phase in the as-obtained composite powders is nanocrystalline (80-100 nm). The SEM observations revealed that the samples consist of 5-15 {mu}m MgH{sub 2} particles, surrounded and in some cases coated by carbon flakes. The composite containing nanodiamonds revealed strong decrease of the MgH{sub 2} decomposition temperature with more than 100 C, compared to ball-milled pure MgH{sub 2}. Important issue of the present study is also the low temperature hydriding of the ball-milled Mg-C nanocomposites, investigated by high-pressure DSC. The process starts at about 200 C for all materials studied, but the hydriding mechanism looks different for the composites with different kinds of carbon additives. Whereas for Mg-carbon black it takes place in a relatively narrow temperature range, expressed by a single exothermic peak (200-300 C) for the other two composites the hydriding is a multi-step process, featured by two overlapped exothermic peaks for Mg-nanodiamonds and by two well separated exothermic effects (at about 300 C and 400 C) for Mg-amorphous carbon soot. The observed difference in the hydriding behavior of the Mg-C composites is attributed to the different kind of carbon component, which is supposed to play a catalytic role as well as protects magnesium from oxidation. The incorporation of carbon into the MgH{sub 2} particles results in the formation of high density of defects (dislocations and grain boundaries), which is supposed to be among the most possible reasons for the decreased hydride decomposition temperature. The Mg-C nanocomposites show reproducible hydriding/dehydriding behavior (thermodynamics and kinetics) during multiple cycling. Among the composites in the present study ''Mg-carbon black

Improved analysis of C4 and C3 photosynthesis via refined in vitro assays of their carbon fixation biochemistry

Science.gov (United States)

Sharwood, Robert E.; Sonawane, Balasaheb V.; Ghannoum, Oula; Whitney, Spencer M.

2016-01-01

Plants operating C3 and C4 photosynthetic pathways exhibit differences in leaf anatomy and photosynthetic carbon fixation biochemistry. Fully understanding this underpinning biochemical variation is requisite to identifying solutions for improving photosynthetic efficiency and growth. Here we refine assay methods for accurately measuring the carboxylase and decarboxylase activities in C3 and C4 plant soluble protein. We show that differences in plant extract preparation and assay conditions are required to measure NADP-malic enzyme and phosphoenolpyruvate carboxylase (pH 8, Mg2+, 22 °C) and phosphoenolpyruvate carboxykinase (pH 7, >2mM Mn2+, no Mg2+) maximal activities accurately. We validate how the omission of MgCl2 during leaf protein extraction, lengthy (>1min) centrifugation times, and the use of non-pure ribulose-1,5-bisphosphate (RuBP) significantly underestimate Rubisco activation status. We show how Rubisco activation status varies with leaf ontogeny and is generally lower in mature C4 monocot leaves (45–60% activation) relative to C3 monocots (55–90% activation). Consistent with their >3-fold lower Rubisco contents, full Rubisco activation in soluble protein from C4 leaves (<5min) was faster than in C3 plant samples (<10min), with addition of Rubisco activase not required for full activation. We conclude that Rubisco inactivation in illuminated leaves primarily stems from RuBP binding to non-carbamylated enzyme, a state readily reversible by dilution during cellular protein extraction. PMID:27122573

New quaternary carbide Mg1.52Li0.24Al0.24C0.86 as a disorder derivative of the family of hexagonal close-packed (hcp) structures and the effect of structure modification on the electrochemical behaviour of the electrode.

Science.gov (United States)

Pavlyuk, Volodymyr; Kulawik, Damian; Ciesielski, Wojciech; Pavlyuk, Nazar; Dmytriv, Grygoriy

2018-03-01

Magnesium alloys are the basis for the creation of light and ultra-light alloys. They have attracted attention as potential materials for the accumulation and storage of hydrogen, as well as electrode materials in metal-hydride and magnesium-ion batteries. The search for new metal hydrides has involved magnesium alloys with rare-earth transition metals and doped by p- or s-elements. The synthesis and characterization of a new quaternary carbide, namely dimagnesium lithium aluminium carbide, Mg 1.52 Li 0.24 Al 0.24 C 0.86 , belonging to the family of hexagonal close-packed (hcp) structures, are reported. The title compound crystallizes with hexagonal symmetry (space group P-6m2), where two sites with -6m2 symmetry and one site with 3m. symmetry are occupied by an Mg/Li statistical mixture (in Wyckoff position 1a), an Mg/Al statistical mixture (in position 1d) and C atoms (2i). The cuboctahedral coordination is typical for Mg/Li and Mg/Al, and the C atom is enclosed in an octahedron. Electronic structure calculations were used for elucidation of the ability of lithium or aluminium to substitute magnesium, and evaluation of the nature of the bonding between atoms. The presence of carbon in the carbide phase improves the corrosion resistance of the Mg 1.52 Li 0.24 Al 0.24 C 0.86 alloy compared to the ternary Mg 1.52 Li 0.24 Al 0.24 alloy and Mg.

An environment-friendly phosphate chemical conversion coating on novel Mg-9Li-7Al-1Sn and Mg-9Li-5Al-3Sn-1Zn alloys with remarkable corrosion protection

Science.gov (United States)

Maurya, Rita; Siddiqui, Abdul Rahim; Balani, Kantesh

2018-06-01

An environment-friendly phosphate chemical conversion (PCC) coating has been deposited on novel LAT971 (Mg-9 wt%Li-7 wt%Al-1 wt%Sn) and LATZ9531 (Mg-9 wt%Li-5 wt%Al-3 wt%Sn-1 wt%Zn) alloys for improving their corrosion resistance. A dense and homogeneous flower like morphology (∼30 μm thick) was observed on the PCC coated Mg-Li based alloys. The presence of calcium hydrogen phosphate hydrate, tricalcium phosphate and trimagnesium phosphate were confirmed from the X-ray diffraction and X-ray photoelectron spectroscopy analysis. A lower corrosion current density of 6.74 × 10-7 mA/cm2 and 5.39 × 10-7 mA/cm2 was obtained for PCC coated alloys in 3.5% NaCl aqueous solution than that of uncoated LAT971 (0.82 mA/cm2) and LATZ9531 (0.34 mA/cm2) alloys, respectively, which offers corrosion protection efficiency of >99%. Electrochemical impedance spectroscopy (EIS) has revealed that the inner PCC coating (at coating/substrate interface) delay the direct contact between electrolyte and substrate, which offered higher charge transfer resistance (>4 orders of magnitude) than that of uncoated alloys. Thus, the PCC coating provides an effective corrosion protection to the ultra-lightweight LAT971 and LATZ9531 alloys surface and may be helpful in proving good anchoring with the top organic coatings or paints.

Shared epitopes of glycoprotein A and protein 4.1 defined by antibody NaM10-3C10.

Science.gov (United States)

Rasamoelisolo, M; Czerwinski, M; Willem, C; Blanchard, D

1998-06-01

We have produced the murine monoclonal antibody (MAb) NaM70-3C10 (IgM) from splenocytes of mice immunized with human red blood cells (RBCs). The MAb agglutinated untreated as well as trypsin, chymotrypsin, neuraminidase, or ficin-treated RBCs from controls. In contrast, control RBCs treated with papaine or bromelaine were not agglutinated. On immunoblots, the MAb bound to glycophorin A (GPA) and to a 80 kDa protein identified as protein 4.1. Analysis by agglutination of variant RBCs carrying hybrid glycophorins made of the N-terminus (amino acids 1-58) of GPA and of the C-terminus (amino acids 27-72) of glycophorin B (GPB) and competition-inhibition test using purified GPA and a synthetic peptide corresponding to the amino acid sequence 48-58 of GPA demonstrated that the epitope is located within residues 48-58 of GPA. Epitope analysis with immobilized peptides showed that the MAb recognizes the sequence 53Pro-Pro-Glu-Glu-GIu58 of GPA. A homologous sequence is also present within amino acids 395 to 405 of protein 4.1. Finally, the MAb bound to 16 kDa chymotryptic peptide of protein 4.1, which carries the above amino acid sequence. In conclusion, it may be assumed that NaM70-3C10 specifically recognizes a common epitope on the extracellular domain of GPA and on the intracellular protein 4.1; this specificity explains the persistence of the 80 kDa band on blots when RBCs are treated with papain.

Growth and characterization of Pb(Lu{sub 1/2}Nb{sub 1/2})O{sub 3}-Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-PbTiO{sub 3} ternary piezo-/ferroelectric crystals

Energy Technology Data Exchange (ETDEWEB)

Liu, Ying [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); College of Physics and Energy, Fujian Normal University, Fuzhou, Fujian 350117 (China); He, Chao [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Yang, Xiaoming [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); College of Physics and Energy, Fujian Normal University, Fuzhou, Fujian 350117 (China); Li, Xiuzhi; Wang, Zujian [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Huang, Zhigao; Lai, Fachun [College of Physics and Energy, Fujian Normal University, Fuzhou, Fujian 350117 (China); Long, Xifa, E-mail: lxf@fjirsm.ac.cn [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

2016-08-05

Piezo-/ferroelectric crystals of Pb(Lu{sub 1/2}Nb{sub 1/2})O{sub 3}-Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-PbTiO{sub 3} ternary solid solution system with high Curie temperature, in the vicinity of morphotropic phase boundary (MPB) region, are grown by the top-seeded solution growth (TSSG) method for the first time. The compositions and structures of the crystals are analyzed, all the structures are found to have pure perovskite structure using X-ray diffraction analysis. Di-/piezo-/ferroelectric properties of the crystals are also characterized systematically. The Curie temperature T{sub c} and coercive field E{sub c}, increase gradually with increasing PbTiO{sub 3} content. In particular, the crystal with composition 0.34PLN-0.31PMN-0.35PT possesses excellent electric properties including the Curie temperature, the rhombohedral–tetragonal phase transition temperature, the piezoelectric coefficient, the remnant polarization and the coercive field, which are T{sub c} = 228 °C, T{sub RT} = 156 °C, d{sub 33} = 2092 pC N{sup −1}, Pr = 35.5 μC cm{sup −2} and E{sub c} = 8.1 kV cm{sup −1}, respectively, making it a promising material for transducers or detectors in a wide temperature range. - Highlights: • PLN-PMN-PT Piezo-/ferroelectric crystals are grown by TSSG method. • The Curie temperature and coercive field increase gradually with increasing PT. • The crystal of 0.34PLN-0.31PMN-0.35PT possesses excellent electric properties.

Microstructure, biocorrosion and cytotoxicity evaluations of rapid solidified Mg-3Ca alloy ribbons as a biodegradable material

International Nuclear Information System (INIS)

Gu, X N; Zhou, W R; Zheng, Y F; Li, X L; Cheng, Y

2010-01-01

Rapidly solidified (RS) Mg-3Ca alloy ribbons were prepared by the melt-spinning technique at different wheel rotating speeds (15 m s -1 , 30 m s -1 and 45 m s -1 ) with the as-cast Mg-3Ca alloy ingot as a raw material. The RS45 Mg-3Ca alloy ribbon showed a much more fine grain size feature (approximately 200-500 nm) in comparison to the coarse grain size (50-100 μm) of the original as-cast Mg-3Ca alloy ingot. The corrosion electrochemical tests in simulated body fluid indicated that the corrosion rate of the as-cast Mg-3Ca alloy was strongly reduced by the RS procedure and tended to be further decreased with increasing wheel rotating speeds (1.43 mm yr -1 for RS15, 0.94 mm yr -1 for RS30 and 0.36 mm yr -1 for RS45). The RS Mg-3Ca alloy ribbons showed more uniform corrosion morphology compared with the as-cast Mg-3Ca alloy after polarization. The cytotoxicity evaluation revealed that the three experimental as-spun Mg-3Ca alloy ribbon extracts did not induce toxicity to the L-929 cells, whereas the as-cast Mg-3Ca alloy ingot extract did. The L-929 cells showed more improved adhesion on the surfaces of the three as-spun Mg-3Ca alloy ribbons than that of the as-cast Mg-3Ca alloy ingot.

Thermoluminescent properties of Spinel-type oxides present in the Ternary system In2O3-TiO2-Mg O in air at 1350 degrees C

International Nuclear Information System (INIS)

Brown, F.; Hernandez P, T. C.; Alvarez M, V. E.; Cruz V, C.; Munoz, I. C.; Bernal, R.

2015-10-01

Full text: In the ternary system In 2 O 3 -TiO 2 -Mg O exists a solid solution Mg 2-x In 2x Ti 1-x O 4 (0≤ x ≤1) with spinel-type structure between MgIn 2 O 4 and Mg 2 TiO 4 (F. Brown et. al., 2000). In order to analyze their thermoluminescent (Tl) response, we obtained the spinel-type oxides with x= 0 (s1), 0.25 (s2), 0.5 (s3), 0.75 (s4), and 1 (s5) by a solid state reaction at 1350 degrees C in air. The X-ray patterns showed a spinel type structure for these compounds. The powders were exposed to beta particles from 90 Sr. The glow curve showed by s1 and s3 were hundreds of times more intense than s2, s4 and s5. At 50 Gy, s1 exhibits a main Tl maximum located at 200 degrees C, with two shoulders at 119 and 250 degrees C. The s3 oxide reveals a simple and wide glow curve at ≅195 degrees C with a Tl maximum located at 203 degrees C at 21.33 Gy. The peaks of the s1 and s3 oxide show a shift to lower temperatures and this increases its intensity as the irradiation dose increases. The lineal behavior observed for s1 and s3 were between 1.33-150 Gy and 10.66-341 Gy correspondingly, without evidence of saturation signal. After cycle 4, the s1 oxide has small variations in the relative sensitivity, with percentages below 1%. On the other hand, s3 reveals a relative sensitivity variation of 2.7%. Besides this, the standard deviation after ten consecutive irradiation-Tl readout cycles for s1 was 3.07 % and for s3 was 1%. The minimum detectable dose obtained were 0.5 Gy for s1 and 5.65 Gy for s3. These results suggest a possible application of Mg 1.5 InTi 0.5 O 4 in dosimetry. (Author)

Electrical properties of Sb and Cr-doped PbZrO3-PbTiO3-PbMg1/3Nb2/3O3 ceramics

OpenAIRE

Whatmore, Roger W.; Molter, O.; Shaw, Christopher P.

2003-01-01

The pyroelectric, dielectric and DC resistive properties of Sb and Cr-doped ceramics with a base composition of Pb(Mg1/3Nb2/3)0.025(Zr0.825Ti0.175)0.975O3 have been studied. Sb doping has been shown to produce a linear reduction in Curie temperature (TC=−22z+294 °C) with concentration (z) and to give an increase in pyroelectric coefficient from 250 to 310 μCm−2 K−1 for z increasing from 0 to 3 at.%. It also produces first a reduction and then an increase in both dielectric constant and loss, ...

Luminescence Properties of Self-Activated Mm(VO4)2 (M = Mg, Ca, Sr, and Ba) Phosphors Synthesized by Solid-State Reaction Method.

Science.gov (United States)

Min, Xin; Huang, Zhaohui; Fang, Minghao; Liu, Yan'gai; Tang, Chao; Wu, Xiaowen

2016-04-01

In this paper, M3(VO4)2 (M = Mg, Ca, Sr, and Ba) self-activated phosphors were prepared by a solid-state reaction method at 1,000 °C for 5 h. The phase formation and micrographs were analyzed by X-ray diffraction and scanning electron microscopy. The Ca3(VO4)2 phosphor does not show any emission peaks under excitation with ultraviolet (UV) light. However, the M3(VO4)2 (M = Mg, Sr, and Ba) samples are effectively excited by UV light chips ranging from 200 nm to 400 nm and exhibit broad emission bands due to the charge transfer from the oxygen 2p orbital to the vacant 3d orbital of the vanadium in the VO4. The color of these phosphors changes from yellow to light blue via blue-green with increasing ionic radius from Mg to Sr to Ba. The luminescence lifetimes and quantum yield decrease with the increasing unit cell volume and V-V distance, in the order of Mg3(VO4)2 to Sr3(VO4)2 to Ba3(VO4)2. The emission intensity decreases with the increase of temperatures, but presents no color shift. This confirms that these self-activated M3(VO4)2 phosphors can be suggested as candidates of the single-phase phosphors for light using UV light emitting diodes (LEDs).

Magnetic characteristics of M2FeV3O11 (M = Mg, Zn, Pb, Co, Ni) compounds

Science.gov (United States)

Groń, T.; Blonska-Tabero, A.; Filipek, E.; Stokłosa, Z.; Duda, H.; Sawicki, B.

2018-02-01

The unusual physical characteristics of the multicomponent oxide systems renewed the interest as the potential cathode materials in high-energy cells. Since the earlier magnetic characteristics were not entirely conclusive, we report the results of dc magnetic measurements including higher harmonics of ac magnetic susceptibility of the M2FeV3O11 (M = Mg, Zn, Pb, Co, Ni) compounds. Ferrimagnetic long-range and antiferromagnetic short-range interactions for all compounds under study at low temperatures as well as superparamagnetic-like behavior with the blocking temperature of 29 K and the freezing parameter of 0.013 were observed. These effects are discussed within the framework of superexchange and double exchange magnetic interactions as well as the mixed valence band of iron ions.

Quintinite-1 M from the Mariinsky Deposit, Ural Emerald Mines, Central Urals, Russia

Science.gov (United States)

Zhitova, E. S.; Popov, M. P.; Krivovichev, S. V.; Zaitsev, A. N.; Vlasenko, N. S.

2017-12-01

The paper describes the first finding of quintinite [Mg4Al2(OH)12][(CO3)(H2O)3] at the Mariinsky deposit in the Central Urals, Russia. The mineral occurs as white tabular crystals in cavities within altered gabbro in association with prehnite, calcite, and a chlorite-group mineral. Quintinite is the probable result of late hydrothermal alteration of primary mafic and ultramafic rocks hosting emerald-bearing glimmerite. According to electron microprobe data, the Mg: Al ratio is 2: 1. IR spectroscopy has revealed hydroxyl and carbonate groups and H2O molecules in the mineral. According to single crystal XRD data, quintinite is monoclinic, space group C2/ m, a =5.233(1), b = 9.051(2), c = 7.711(2) Å, β = 103.09(3)°, V = 355.7(2) Å3. Based on structure refinement, the polytype of quintinite should be denoted as 1M. This is the third approved occurrence of quintinite-1M in the world after the Kovdor complex and Bazhenovsky chrysotile-asbestos deposit.

The effects of Fe2O3 nanoparticles on MgB2 superconducting thin films

International Nuclear Information System (INIS)

Koparan, E.T.; Sidorenko, A.; Yanmaz, E.

2013-01-01

Full text: Since the discovery of superconductivity in binary MgB 2 compounds, extensive studies have been carried out because of its excellent properties for technological applications, such as high transition temperature (T c = 39 K), high upper critical field (H c2 ), high critical current density (J c ). Thin films are important for fundamental research as well as technological applications of any functional materials. Technological applications primarily depend on critical current density. The strong field dependence of J c for MgB 2 necessitates an enhancement in flux pinning performance in order to improve values in high magnetic fields. An effective way to improve the flux pinning is to introduce flux pinning centers into MgB 2 through a dopant having size comparable to the coherence length of MgB 2 . In this study, MgB 2 film with a thickness of about 600 nm was deposited on the MgO (100) single crystal substrate using a 'two-step' synthesis technique. Firstly, deposition of boron thin film was carried out by rf magnetron sputtering on MgO substrates and followed by a post deposition annealing at 850 degrees Celsius in magnesium vapour. In order to investigate the effect of Fe 2 O 3 nanoparticles on the structural and magnetic properties of films, MgB 2 films were coated with different concentrations of Fe 2 O 3 nanoparticles by a spin coating process. The effects of different concentrations of ferromagnetic Fe 2 O 3 nanoparticles on superconducting properties of obtained films were carried out by using structural (XRD, SEM, AFM), electrical (R-T) and magnetization (M-H, M-T and AC Susceptibility) measurements. It was calculated that anisotropic coefficient was about γ = 1.2 and coherence length of 5 nm for the uncoated film. As a result of coherence length, the appropriate diameters of Fe 2 O 3 nanoparticles were found to be 10 nm, indicating that these nanoparticles served as the pinning centers. Based on the data obtained from this study, it can be

Thermodynamic and kinetic properties of intrinsic defects and Mg transmutants in 3C–SiC determined by density functional theory

International Nuclear Information System (INIS)

Hu, Shenyang; Setyawan, Wahyu; Van Ginhoven, Renee M.; Jiang, Weilin; Henager, Charles H.; Kurtz, Richard J.

2014-01-01

Density functional theory (DFT) is used to calculate the thermodynamic and kinetic properties of transmutant Mg in 3C–SiC due to high-energy neutron irradiation associated with the fusion nuclear environment. The formation and binding energies of intrinsic defects, Mg-related defects, and clusters in 3C–SiC are systematically calculated. The minimum energy paths and activation energies during point defect migration and small cluster evolution are studied using a generalized solid-state nudged elastic band (G-SSNEB) method with DFT energy calculations. Stable defect structures and possible defect migration mechanisms are identified. The evolution of binding energies during Mg 2 Si formation demonstrates that the formation of Mg 2 Si needs to overcome a critical nucleus size and nucleation barrier. It is found that C vacancies promote the formation of the Mg 2 Si nucleus, and formation of which results in a compressive stress field around the nucleus. These data are important inputs in meso- and macro-scale modeling and experiments to understand and predict the impact of Mg on phase stability, microstructure evolution, and performance of SiC and SiC-based materials during long-term neutron exposures

Microstructure, biocorrosion and cytotoxicity evaluations of rapid solidified Mg-3Ca alloy ribbons as a biodegradable material

Energy Technology Data Exchange (ETDEWEB)

Gu, X N; Zhou, W R; Zheng, Y F [State Key Laboratory for Turbulence and Complex System and Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871 (China); Li, X L [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Cheng, Y, E-mail: yfzheng@pku.edu.c [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China)

2010-06-01

Rapidly solidified (RS) Mg-3Ca alloy ribbons were prepared by the melt-spinning technique at different wheel rotating speeds (15 m s{sup -1}, 30 m s{sup -1} and 45 m s{sup -1}) with the as-cast Mg-3Ca alloy ingot as a raw material. The RS45 Mg-3Ca alloy ribbon showed a much more fine grain size feature (approximately 200-500 nm) in comparison to the coarse grain size (50-100 {mu}m) of the original as-cast Mg-3Ca alloy ingot. The corrosion electrochemical tests in simulated body fluid indicated that the corrosion rate of the as-cast Mg-3Ca alloy was strongly reduced by the RS procedure and tended to be further decreased with increasing wheel rotating speeds (1.43 mm yr{sup -1} for RS15, 0.94 mm yr{sup -1} for RS30 and 0.36 mm yr{sup -1} for RS45). The RS Mg-3Ca alloy ribbons showed more uniform corrosion morphology compared with the as-cast Mg-3Ca alloy after polarization. The cytotoxicity evaluation revealed that the three experimental as-spun Mg-3Ca alloy ribbon extracts did not induce toxicity to the L-929 cells, whereas the as-cast Mg-3Ca alloy ingot extract did. The L-929 cells showed more improved adhesion on the surfaces of the three as-spun Mg-3Ca alloy ribbons than that of the as-cast Mg-3Ca alloy ingot.

Enhancement of Mechanical Properties of Extruded Mg-9Al-1Zn-1MM-0.7CaO-0.3Mn Alloy Through Pre-aging Treatment

Science.gov (United States)

Jeong, Seok Hoan; Kim, Yong Joo; Kong, Kyung Ho; Cho, Tae Hee; Kim, Young Kyun; Lim, Hyun Kyu; Kim, Won Tae; Kim, Do Hyang

2018-03-01

The effect of pre-aging treatment before extrusion has been investigated in Mg-9.0Al-1.0Zn-1MM-0.7CaO-0.3Mn alloy. The as-cast microstructure consists of α-Mg dendrite with secondary solidification phase particles, (Mg, Al)2Ca, β-Mg17Al12 and Al11RE3 at the inter-dendritic region. After extrusion, β-Mg17Al12 precipitates are present, but higher density and more homogeneous distribution in pre-aged alloy. In addition, μm-scale banded bulk β-Mg17Al12 particles are generated during extrusion. Al11RE3 particles are broken into small particles, and are aligned along the extrusion direction. (Mg, Al)2Ca particles are only slightly elongated along the extrusion direction, providing stronger particle stimulated nucleation (PSN) effect by severe deformation during extrusion. The mechanical properties can be significantly enhanced by introducing pre-aging treatment, i.e. β-Mg17Al12 precipitates provide grain refining and strengthening effects and (Mg, Al)2Ca particles provide PSN effect.

Microwave assisted synthesis of core–shell LiFe{sub 1/3}Mn{sub 1/3}Co{sub 1/3}PO{sub 4}/C nanocomposite cathode for high-performance lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Li, Huanhuan [Automotive Engineering Research Institute, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013 (China); Li, Yunxing [School of Material Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Chen, Long; Jiang, Haobin [Automotive Engineering Research Institute, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013 (China); Wei, Jinping [Institute of New Energy Material Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071 (China); Wang, Hongbo [China Aviation Lithium Battery Co. Ltd., Luoyang 471003 (China); Wang, Yaping, E-mail: wangyaping@ujs.edu.cn [School of Material Science and Engineering, Jiangsu University, Zhenjiang 212013 (China)

2014-12-25

Highlights: • We firstly report a fast microwave heating way to prepare LiFe{sub 1/3}Mn{sub 1/3}Co{sub 1/3}PO{sub 4}/C. • The reversible discharge capacity of LiFe{sub 1/3}Mn{sub 1/3}Co{sub 1/3}PO{sub 4}/C is about 169 mA h g{sup −1}. • LiFe{sub 1/3}Mn{sub 1/3}Co{sub 1/3}PO{sub 4}/C nanocomposite elucidates excellent cyclic stability. • LiFe{sub 1/3}Mn{sub 1/3}Co{sub 1/3}PO{sub 4}/C nanocomposite exhibits attractive rate capability. - Abstract: A microwave assisted method is developed for synthesizing pure LiFe{sub 1/3}Mn{sub 1/3}Co{sub 1/3}PO{sub 4} and LiFe{sub 1/3}Mn{sub 1/3}Co{sub 1/3}PO{sub 4}/C nanocomposite. Olivine LiFe{sub 1/3}Mn{sub 1/3}Co{sub 1/3}PO{sub 4} coated with uniform amorphous carbon film of ∼5 nm in thickness with an average size of ∼200 nm is successfully obtained. Compared with pure LiFe{sub 1/3}Mn{sub 1/3}Co{sub 1/3}PO{sub 4}, LiFe{sub 1/3}Mn{sub 1/3}Co{sub 1/3}PO{sub 4}/C composite presents enhanced electrochemical Li-ion intercalation performances. It exhibits a high discharge capacity of 169 mA h g{sup −1} at 0.1 C (theoretical capacity is 170 mA h g{sup −1}). The capacity retention is 99% after 30 cycles. Furthermore, the capacities are still retained 101 at 5 C and 76 mA h g{sup −1} and 20 C, respectively. Carbon coating can significantly improve the Li-ion diffusion, the reversibility of lithium extraction/insertion and electrical conductivity of LiCo{sub 1/3}Mn{sub 1/3}Fe{sub 1/3}PO{sub 4}.

Frequency metrology on the Mg 3s21S→3s4p 1P line for comparison with quasar data

International Nuclear Information System (INIS)

Hannemann, S.; Salumbides, E. J.; Witte, S.; Zinkstok, R. Th.; Duijn, E.-J. van; Eikema, K. S. E.; Ubachs, W.

2006-01-01

We report a frequency metrology study on the Mg 3s 2 1 S→3s4p 1 P transition near 202.5 nm. For this purpose, the fourth harmonic of the output from an injection-seeded Ti:sapphire pulsed laser is employed in a Mg atomic beam experiment with laser-induced fluorescence detection. Absolute frequency calibration with a frequency comb laser is performed on the cw seeding radiation, while the chirp-induced frequency shift between the pulsed output and the seed light is monitored on line. The resulting transition frequency for the main isotope 24 Mg is determined at 49 346.756 809(35) m -1 . This value is three orders of magnitude more precise than the best value in the literature. The line positions of the other isotopes 25 Mg and 26 Mg are also measured at comparable accuracy, giving rise to very exact values for the isotopic shifts. The achieved precision for the transition frequency at the 7x10 -10 level makes this second resonance line of Mg I an additional candidate for inclusion in many-multiplet methods, aimed at detecting a possible temporal variation of the fine-structure constant α from comparison with quasar spectra. The isotopic shifts obtained are also important to correct for possible systematic shifts due to evolution of isotopic abundances, which may mimic α-variation effects

Fisetin Suppresses Lipid Accumulation in Mouse Adipocytic 3T3-L1 Cells by Repressing GLUT4-Mediated Glucose Uptake through Inhibition of mTOR-C/EBPα Signaling.

Science.gov (United States)

Watanabe, Marina; Hisatake, Mitsuhiro; Fujimori, Ko

2015-05-27

3,7,3',4'-Tetrahydroxyflavone (fisetin) is a flavonoid found in vegetables and fruits having broad biological activities. Here the effects of fisetin on adipogenesis and its regulatory mechanism in mouse adipocytic 3T3-L1 cells are studied. Fisetin inhibited the accumulation of intracellular lipids and lowered the expression of adipogenic genes such as peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein (C/EBP) α and fatty acid-binding protein 4 (aP2) during adipogenesis. Moreover, the mRNA levels of genes such as acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase involved in the fatty acid biosynthesis (lipogenesis) were reduced by the treatment with fisetin. The expression level of the glucose transporter 4 (GLUT4) gene was also decreased by fisetin, resulting in down-regulation of glucose uptake. Furthermore, fisetin inhibited the phosphorylation of the mammalian target of rapamycin (mTOR) and that of p70 ribosomal S6 kinase, a target of the mTOR complex, the inhibition of which was followed by a decreased mRNA level of the C/EBPα gene. The results obtained from a chromatin immunoprecipitation assay demonstrated that the ability of C/EBPα to bind to the GLUT4 gene promoter was reduced by the treatment with fisetin, which agreed well with those obtained when 3T3-L1 cells were allowed to differentiate into adipocytes in medium in the presence of rapamycin, an inhibitor for mTOR. These results indicate that fisetin suppressed the accumulation of intracellular lipids by inhibiting GLUT4-mediated glucose uptake through inhibition of the mTOR-C/EBPα signaling in 3T3-L1 cells.

Design and syntheses of hybrid metal-organic materials based on K3[M(C2O4)3]·3H2O [M(III)=Fe, Al, Cr] metallotectons

Science.gov (United States)

Sun, Yayong; Zong, Yingxia; Ma, Haoran; Zhang, Ao; Liu, Kang; Wang, Debao; Wang, Wenqiang; Wang, Lei

2016-05-01

By using K3[M(C2O4)3]·3H2O [M(III)=Fe, Al, Cr] (C2O42-=oxalate) metallotectons as the starting material, we have synthesized eight novel complexes with formulas [{Fe(C2O4)2(H2O)2}2]·(H-L1)2·H2O 1, [Fe(C2O4)Cl2]·(H2-L2)0.5·(L2)0.5·H2O 2, [{Fe(C2O4)1.5Cl2}2]·(H-L3)43, [Fe2(C2O4)Cl8]·(H2-L4)2·2H2O 4, K[Al(C2O4)3]·(H2-L5)·2H2O 5, K[Al(C2O4)3]·(H-L6)2·2H2O 6, K[Cr(C2O4)3]·2H2O 7, Na[Fe(C2O4)3]·(H-L6)2·2H2O 8 (with L1=4-dimethylaminopyridine, L2=2,3,5,6-tetramethylpyrazine, L3=2-aminobenzimidazole, L4=1,4-bis-(1H-imidazol-1-yl)benzene, L5=1,4-bis((2-methylimidazol-1-yl)methyl)benzene, L6=2-methylbenzimidazole). Their structures have been determined by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra and thermogravimetric analyses. Compound 3 is a 2D H-bonded supramolecular architecture. Others are 3D supramolecular structures. Compound 1 shows a [Fe(C2O4)2(H2O)2]- unit and 3D antionic H-bonded framework. Compound 2 features a [Fe(C2O4)Cl2]- anion and 1D iron-oxalate-iron chain. Compound 3 features a [Fe2(C2O4)3Cl4]4- unit. Compound 4 features distinct [Fe2(C2O4)Cl8]4- units, which are mutual linked by water molecules to generated a 2D H-bonded network. Compound 5 features infinite ladder-like chains constructed by [Al(C2O4)3]3- units and K+ cations. The 1D chains are further extended into 3D antionic H-bonded framework through O-H···O H-bonds. Compounds 6-8 show 2D [KAl(C2O4)3]2- layer, [KCr(C2O4)3]2- layer and [NaFe(C2O4)3]2- layer, respectively.

Proton-oxygen conductivity in substituted perovskites ATi0.95Mo0.05O3-α (A = Ca, Sr, Ba; M = Sc, Mg) in the reducing hydrogen-containing atmospheres

International Nuclear Information System (INIS)

Gorelov, V.P.; Balakireva, V.B.; Sharova, N.V.

1999-01-01

Electric conductivity depending on temperature, oxygen partial pressure, as well as the number of t i ion transfer and transfer hydrogen numbers in the perovskites ATi 0.95 Mo 0.05 O 3-α (A = Ca, Sr, Ba; M = Sc, Mg) in reducing hydrogen-containing atmospheres in the temperature range of 450-850 deg C have been measured. With the temperature decrease t i increases reaching 1.0 at a temperature of 550 deg C for all compositions. Proton conductivity under conditions of assumed concomitant transfer of either O 2- or OH - has been ascertained [ru

Sojourn times in the M/G/1 FB queue with light-tailed service times

NARCIS (Netherlands)

M.R.H. Mandjes (Michel); M. Nuyens

2004-01-01

textabstractThe asymptotic decay rate of the sojourn time of a customer in the stationary M/G/1 queue under the Foreground-Background (FB) service discipline is studied. The FB discipline gives service to those customers that have received the least service so far. We prove that for light-tailed

Sojourn times in the M/G/1 FB queue with light-tailed service times.

NARCIS (Netherlands)

Mandjes, M.R.H.; Nuijens, M.F.M.

2005-01-01

ABSTRACT The asymptotic decay rate of the sojourn time of a customer in the stationary M/G/1 queue under the Foreground-Background (FB) service discipline is studied. The FB discipline gives service to those customers that have received the least service so far. We prove that for lighttailed service

Effects of TiC doping on the upper critical field of MgB2 superconductors

International Nuclear Information System (INIS)

Yan, S.C.; Zhou, L.; Yan, G.; Lu, Y.F.

2008-01-01

TiC doped MgB 2 bulks were fabricated by two-step reaction method. The sample with a nominal compositions of Mg(B 0.95 (TiC) 0.05 ) 4 was first sintered at 1000 deg. C for 0.5 h. An appropriate amount of Mg was added to reach the stoichiometry of Mg(B 0.95 (TiC) 0.05 ) 2 , which was sintered at 750 deg. C for 2 h. The H c2 for the micro-TiC doped MgB 2 reached 12 T at 20 K. And J c is 5.3 x 10 4 A/cm 2 at 20 K and 1 T. The results indicate that the two-step reaction method could effectively introduce the carbon in TiC into the MgB 2 crystalline lattice, and therefore improve the upper critical field

Mg doped Li2FeSiO4/C nanocomposites synthesized by the solvothermal method for lithium ion batteries.

Science.gov (United States)

Kumar, Ajay; Jayakumar, O D; Jagannath; Bashiri, Parisa; Nazri, G A; Naik, Vaman M; Naik, Ratna

2017-10-14

A series of porous Li 2 Fe 1-x Mg x SiO 4 /C (x = 0, 0.01, 0.02, 0.04) nanocomposites (LFS/C, 1Mg-LFS/C, 2Mg-LFS and 4Mg-LFS/C) have been synthesized via a solvo-thermal method using the Pluronic P123 polymer as an in situ carbon source. Rietveld refinement of the X-ray diffraction data of Li 2 Fe 1-x Mg x SiO 4 /C composites confirms the formation of the monoclinic P2 1 structure of Li 2 FeSiO 4 . The addition of Mg facilitates the growth of impurity-free Li 2 FeSiO 4 with increased crystallinity and particle size. Despite having the same percentage of carbon content (∼15 wt%) in all the samples, the 1Mg-LFS/C nanocomposite delivered the highest initial discharge capacity of 278 mA h g -1 (∼84% of the theoretical capacity) at the C/30 rate and also exhibited the best rate capability and cycle stability (94% retention after 100 charge-discharge cycles at 1C). This is attributed to its large surface area with a narrow pore size distribution and a lower charge transfer resistance with enhanced Li-ion diffusion coefficient compared to other nanocomposites.

The mGlu2/3 Receptor Agonists LY354740 and LY379268 Differentially Regulate Restraint-Stress-Induced Expression of c-Fos in Rat Cerebral Cortex

Directory of Open Access Journals (Sweden)

M. M. Menezes

2013-01-01

Full Text Available Metabotropic glutamate 2/3 (mGlu2/3 receptors have emerged as potential therapeutic targets due to the ability of mGlu2/3 receptor agonists to modulate excitatory transmission at specific synapses. LY354740 and LY379268 are selective and potent mGlu2/3 receptor agonists that show both anxiolytic- and antipsychotic-like effects in animal models. We compared the efficacy of LY354740 and LY379268 in attenuating restraint-stress-induced expression of the immediate early gene c-Fos in the rat prelimbic (PrL and infralimbic (IL cortex. LY354740 (10 and 30 mg/kg, i.p. showed statistically significant and dose-related attenuation of stress-induced increase in c-Fos expression, in the rat cortex. By contrast, LY379268 had no effect on restraint-stress-induced c-Fos upregulation (0.3–10 mg/kg, i.p.. Because both compounds inhibit serotonin 2A receptor (5-HT2AR-induced c-Fos expression, we hypothesize that LY354740 and LY379268 have different in vivo properties and that 5-HT2AR activation and restraint stress induce c-Fos through distinct mechanisms.

Self-association and domain rearrangements between complement C3 and C3u provide insight into the activation mechanism of C3.

Science.gov (United States)

Li, Keying; Gor, Jayesh; Perkins, Stephen J

2010-10-01

Component C3 is the central protein of the complement system. During complement activation, the thioester group in C3 is slowly hydrolysed to form C3u, then the presence of C3u enables the rapid conversion of C3 into functionally active C3b. C3u shows functional similarities to C3b. To clarify this mechanism, the self-association properties and solution structures of C3 and C3u were determined using analytical ultracentrifugation and X-ray scattering. Sedimentation coefficients identified two different dimerization events in both proteins. A fast dimerization was observed in 50 mM NaCl but not in 137 mM NaCl. Low amounts of a slow dimerization was observed for C3u and C3 in both buffers. The X-ray radius of gyration RG values were unchanged for both C3 and C3u in 137 mM NaCl, but depend on concentration in 50 mM NaCl. The C3 crystal structure gave good X-ray fits for C3 in 137 mM NaCl. By randomization of the TED (thioester-containing domain)/CUB (for complement protein subcomponents C1r/C1s, urchin embryonic growth factor and bone morphogenetic protein 1) domains in the C3b crystal structure, X-ray fits showed that the TED/CUB domains in C3u are extended and differ from the more compact arrangement of C3b. This TED/CUB conformation is intermediate between those of C3 and C3b. The greater exposure of the TED domain in C3u (which possesses the hydrolysed reactive thioester) accounts for the greater self-association of C3u in low-salt conditions. This conformational variability of the TED/CUB domains would facilitate their interactions with a broad range of antigenic surfaces. The second dimerization of C3 and C3u may correspond to a dimer observed in one of the crystal structures of C3b.

Diastereoselective synthesis of trans-2,3-dihydrofuro[3,2-c]coumarins by MgO nanoparticles under ultrasonic irradiation

OpenAIRE

Javad Safaei-Ghomi; Pouria Babaei; Hossein Shahbazi-Alavi; Safura Zahedi

2017-01-01

MgO nanoparticles have been used as an efficient catalyst for the diastereoselective preparation of trans-2-benzoyl-3-(aryl)-2H-furo[3,2-c]chromen-4(3H)-ones by the multi-component reaction of 2,4â²-dibromoacetophenone, pyridine, benzaldehydes and 4-hydroxycoumarin under ultrasonic irradiation. This interesting result revealed that the pyridiniumylide assisted tandem three-component coupling reaction is highly diastereoselective. Atom economy, wide range of products, high catalytic activity, ...

Search for C+ C clustering in Mg ground state

Indian Academy of Sciences (India)

2017-01-04

Jan 4, 2017 ... Finite-range knockout theory predictions were much larger for (12C,212C) reaction, indicating a very small 12C−12C clustering in 24Mg. (g.s.) . Our present results contradict most of the proposed heavy cluster (12C+12C) structure models for the ground state of 24Mg. Keywords. Direct nuclear reactions ...

The local structure of Ca-Na pyroxenes. 2-Xanes studies at the Mg and A1 K edges

International Nuclear Information System (INIS)

Mottana, A.; Cibin, G.; Paris, E.; Giuli, G.; Florence Univ., Florence

1999-01-01

X-ray absorption spectra at the Mg and A1 K edges have been recorded on synthetic endmember diopside (Di) and jadeite (Jd) and on a series of natural Fe-poor Ca-Na clinopyroxenes compositionally straddling the Jd-Di join. The spectra of C2/c members of the series (C-omphacites) are different from having P2/n symmetry (P-omphacites). Differences can be explained by theoretical spectra calculated via the multiple-scattering formalism on atomic clusters with at least 89 atoms, extending to a. 0.62 nm away from the Mg viz. A1 absorber: Xanes detects in these systems medium- rather than short-range order-disorder relationships. Near-edge features of C-omphacites reflect the single-type of octahedral arrangement of the back scattering nearest-neighbours (six O atoms) around the absorber (Mg resp. A1) at the centre of the cluster (site M1). Others arise again from medium-range order. P-omphacites show more complicated spectra than C-omphacites. Their additional features reflect the increased local disorder around the probed atom (Mg resp. A1) induced by the two alternative M1, M11 configurations of the six O atoms forming the first co-ordination spheres. Mg and A1 are confirmed to be preferentially partitioned in the M1 resp. M11 site of the P-omphacite crystal structure, however never exclusively, but in a ratio close to 85:15 (plus or minus 10%) that implies a certain degree of local disorder. Changes in the relative heights of some prominent features are more evident in the A1 than in the Mg K-edge spectra. They are diagnostic to qualitatively distinguish C-from P-omphacites

The local structure of Ca-Na pyroxenes. 2-Xanes studies at the Mg and A1 K edges

Energy Technology Data Exchange (ETDEWEB)

Mottana, A. [Rome Univ. Roma Tre, Rome (Italy). Dipt. di Scienze Geologiche; Murata, T. [Kyoto University of Education, Kyoto (Japan). Dept. of Physics; Marcelli, A. [Istituto Nazionale di Fisica Nucleare, Frascati, RM (Italy). Laboratori Nazionali di Frascati; Wu, Z.Y. [Istituto Nazionale di Fisica Nucleare, Frascati, RM (Italy). Laboratori Nazionali di Frascati]|[Laboratoire Piere Suee, Gif-sur Yvette Cedex, (France); Cibin, G. [Istituto Nazionale di Fisica Nucleare, Frascati, RM (Italy). Laboratori Nazionali di Frascati; Paris, E. [Camerino Univ., Camerino, MC (Italy). Dipt. di Scienze della Terra; Giuli, G. [Camerino Univ., Camerino, MC (Italy). Dipt. di Scienze della Terra]|[Florence Univ., Florence (Italy). Dipt. di Scienze della Terra

1999-07-01

X-ray absorption spectra at the Mg and A1 K edges have been recorded on synthetic end member diopside (Di) and jadeite (Jd) and on a series of natural Fe-poor Ca-Na clinopyroxenes compositionally straddling the Jd-Di join. The spectra of C2/c members of the series (C-omphacites) are different from having P2/n symmetry (P-omphacites). Differences can be explained by theoretical spectra calculated via the multiple-scattering formalism on atomic clusters with at least 89 atoms, extending to a. 0.62 nm away from the Mg viz. A1 absorber: Xanes detects in these systems medium- rather than short-range order-disorder relationships. Near-edge features of C-omphacites reflect the single-type of octahedral arrangement of the back scattering nearest-neighbours (six O atoms) around the absorber (Mg resp. A1) at the centre of the cluster (site M1). Others arise again from medium-range order. P-omphacites show more complicated spectra than C-omphacites. Their additional features reflect the increased local disorder around the probed atom (Mg resp. A1) induced by the two alternative M1, M11 configurations of the six O atoms forming the first co-ordination spheres. Mg and A1 are confirmed to be preferentially partitioned in the M1 resp. M11 site of the P-omphacite crystal structure, however never exclusively, but in a ratio close to 85:15 (plus or minus 10%) that implies a certain degree of local disorder. Changes in the relative heights of some prominent features are more evident in the A1 than in the Mg K-edge spectra. They are diagnostic to qualitatively distinguish C-from P-omphacites.

Structural disorder and electronic hybridization in Ni{sub c}Mg{sub 1-c}O solid solutions probed by XANES at the oxygen K edge

Energy Technology Data Exchange (ETDEWEB)

Chen Dongliang [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Zhong Jun [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chu Wangsheng [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wu Ziyu [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Kuzmin, Alexei [Institute of Solid State Physics, University of Latvia, Kengaraga 8, LV-1063 Riga (Latvia); Mironova-Ulmane, Nina [Institute of Solid State Physics, University of Latvia, Kengaraga 8, LV-1063 Riga (Latvia); Marcelli, Augusto [Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, PO Box 13, 00044 Frascati (Italy)

2007-09-05

A series of Ni{sub c}Mg{sub 1-c}O solid solutions has been studied for the first time looking at the structural disorder by means of x-ray absorption near-edge-structure (XANES) spectroscopy at the oxygen K edge. The experimental XANES signals were analysed within the full multiple scattering formalism and were interpreted taking into account clusters of up to 15 coordination shells around an absorbing oxygen atom. The substitution of nickel atoms by magnesium atoms results in a dramatic decrease of the empty density of states in the conduction band close to the Fermi level due to an exchange of the 3d(Ni)-2p(O) interaction with 3p(Mg)-2p(O). Besides, a simultaneous small decrease of the 3d(Ni)-2p(O) hybridization is also induced by the lattice expansion, determined by the difference in ionic radii between nickel and magnesium ions.

Mott transition in Ga-doped Mg{sub x}Zn{sub 1-x}O: A direct observation

Energy Technology Data Exchange (ETDEWEB)

Wei Wei; Nori, Sudhakar [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC (United States); Jin Chunming [Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Campus Box 7115, Raleigh, NC 27695-7115 (United States); Narayan, Jagdish [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC (United States); Narayan, Roger J., E-mail: roger_narayan@unc.edu [Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Campus Box 7115, Raleigh, NC 27695-7115 (United States); Ponarin, Dmtri; Smirnov, Alex [Department of Chemistry, North Carolina State University, Raleigh, NC (United States)

2010-07-25

This paper reports the direct evidence for Mott transition in Ga-doped Mg{sub x}Zn{sub 1-x}O thin films. Highly transparent Ga-doped Mg{sub x}Zn{sub 1-x}O thin films were grown on c-plane sapphire substrates using pulsed laser deposition. 0.1 at.%, 0.5 at.% and 1 at.% Ga-doped Mg{sub 0.1}Zn{sub 0.9}O films were selected for resistivity measurements in the temperature range from 250 K to 40 mK. The 0.1 at.% Ga-doped Mg{sub 0.1}Zn{sub 0.9}O thin film showed typical insulator-like behavior and the 1 at.% Ga-doped Mg{sub 0.1}Zn{sub 0.9}O thin film showed typical metal-like behavior. The 0.5 at.% Ga-doped Mg{sub 0.1}Zn{sub 0.9}O film showed increasing resistivity with decreasing temperature; resistivity was saturated with a value of 1.15 x 10{sup -2} {Omega} cm at 40 mK, which is characteristic of the metal-insulator transition region. Temperature-dependent conductivity {sigma}(T) in the low temperature range revealed that the electron-electron scattering is the dominant dephasing mechanism. The inelastic scattering time is found to vary as T{sup -3/2}.

The Remaining Service Time Upon Reaching a High Level in M/G/1 Queues

NARCIS (Netherlands)

de Boer, Pieter-Tjerk; Nicola, V.F.; van Ommeren, Jan C.W.

The distribution of the remaining service time upon reaching some target level in an M/G/1 queue is of theoretical as well as practical interest. In general, this distribution depends on the initial level as well as on the target level, say, B. Two initial levels are of particular interest, namely,

Novel ZnO/MgO/Fe2O3 composite optomagnetic nanoparticles

International Nuclear Information System (INIS)

Kamińska, I; Sikora, B; Fronc, K; Dziawa, P; Sobczak, K; Minikayev, R; Paszkowicz, W; Elbaum, D

2013-01-01

A facile sol–gel synthesis of novel ZnO/MgO/Fe 2 O 3 nanoparticles (NPs) is reported and their performance is compared to that of ZnO/MgO. Powder x-ray diffraction (XRD) patterns reveal the crystal structure of the prepared samples. The average particle size of the sample was found to be 4.8 nm. The optical properties were determined by UV–vis absorption and fluorescence measurements. The NPs are stable in biologically relevant solutions (phosphate buffered saline (PBS), 20 mM, pH = 7.0) contrary to ZnO/MgO NPs which degrade in the presence of inorganic phosphate. Superparamagnetic properties were determined with a superconducting quantum interference device (SQUID). Biocompatible and stable in PBS ZnO/MgO/Fe 2 O 3 core/shell composite nanocrystals show luminescent and magnetic properties confined to a single NP at room temperature (19–24 ° C), which may render the material to be potentially useful for biomedical applications. (paper)

Chemistry of the M (M=Fe, Ca, Ba-Se-H2O Systems at 25 °C

Directory of Open Access Journals (Sweden)

Fumihiko Hasegawa

2009-09-01

Full Text Available The chemistry of the M (M=Fe, Ca, Ba-Se-H2O systems at 25 °C is reviewed based on our previous papers. In this paper, the phase equilibria in the Fe(III-Se(IV-H2O, Ca-Se(IV,VI-H2O and Ba-Se(IV,VI-H2O systems at 25 °C are discussed. Then, the three-stage process for removal of selenium from industrial waste water [Se(IV,VI < 1,500 mg/L] containing sulfuric acid was introduced. This seems to be a promising process for selenium removal from acidic sulfate waste water containing high concentration levels of selenium to below 0.1 mg/L.

Stabilization of MgCr₂O₄ spinel in slags of the
SiO₂-CaO-MgO-Cr₂O₃ system

Directory of Open Access Journals (Sweden)

Arredondo-Torres, V.

2006-12-01

Full Text Available El objetivo de este estudio es analizar el efecto del contenido de MgO y la basicidad de la escoria sobre la estabilidad de las especies mineralógicas del sistema de escoria SiO₂-CaOMgO-
Cr₂O₃. Se realizaron ensayos al equilibrio a 1600 °C bajo condiciones reductoras (pO2=10^-9atm. El contenido de MgO fue de 0 a 12 % masa, el Cr₂O₃ de 10% y la basicidad de 1 y 1,5. También se realizó un análisis termodinámico para determinar las fases mineralógicas más estables en la escoria. Los resultados experimentales y calculados muestran que el Cr₂O₃ se encuentra principalmente ligado en una fase espinela MgCr₂O₄, incluso a bajos contenidos de MgO. Los resultados obtenidos por microscopia electrónica de barrido (MEB-EDS, muestran la evidencia de tres estructuras cristalinas: (A Octaedros, los cuales
corresponden a la espinela MgCr₂O₄, (B Cristales alargados que corresponden a la formación de silicatos cálcicos y (C Matriz de silicatos cálcicos con impurezas de Mg y Cr que no cristalizaron por completo.

El objetivo de este estudio es analizar el efecto del contenido de MgO y la basicidad de la escoria sobre la estabilidad de las especies mineralógicas del sistema de escoria SiO₂-CaOMgO-Cr₂O₃. Se realizaron ensayos al equilibrio a 1600 °C bajo condiciones reductoras (pO₂=10^-9atm. El contenido de MgO fue de 0 a 12 % masa, el Cr₂O₃ de 10% y la basicidad de 1 y 1,5. También se realizó un análisis termodinámico para determinar las fases mineralógicas más estables en la escoria. Los resultados experimentales y calculados muestran que el Cr₂O₃ se encuentra principalmente ligado en una fase espinela MgCr₂O₄, incluso a bajos contenidos de MgO. Los resultados obtenidos por

M3C (M: Fe, Co, Ni) Nanocrystals Encased in Graphene Nanoribbons: An Active and Stable Bifunctional Electrocatalyst for Oxygen Reduction and Hydrogen Evolution Reactions.

Science.gov (United States)

Fan, Xiujun; Peng, Zhiwei; Ye, Ruquan; Zhou, Haiqing; Guo, Xia

2015-07-28

Transition metal carbide nanocrystalline M3C (M: Fe, Co, Ni) encapsulated in graphitic shells supported with vertically aligned graphene nanoribbons (VA-GNRs) are synthesized through a hot filament chemical vapor deposition (HF-CVD) method. The process is based on the direct reaction between iron group metals (Fe, Co, Ni) and carbon source, which are facilely get high purity carbide nanocrystals (NCs) and avoid any other impurity at relatively low temperature. The M3C-GNRs exhibit superior enhanced electrocatalystic activity for oxygen reduction reaction (ORR), including low Tafel slope (39, 41, and 45 mV dec(-1) for Fe3C-GNRs, Co3C-GNRs, and Ni3C-GNRs, respectively), positive onset potential (∼0.8 V), high electron transfer number (∼4), and long-term stability (no obvious drop after 20 000 s test). The M3C-GNRs catalyst also exhibits remarkable hydrogen evolution reaction (HER) activity with a large cathodic current density of 166.6, 79.6, and 116.4 mA cm(-2) at an overpotential of 200 mV, low onset overpotential of 32, 41, and 35 mV, small Tafel slope of 46, 57, and 54 mV dec(-1) for Fe3C-GNRs, Co3C-GNRs, and Ni3C-GNRs, respectively, as well as an excellent stability in acidic media.

Grain refinement of AZ91D magnesium alloy by a new Mg–50%Al4C3 master alloy

International Nuclear Information System (INIS)

Liu, Shengfa; Chen, Yang; Han, Hui

2015-01-01

A novel and simple method for preparing Mg–50%Al 4 C 3 (hereafter in wt.%) master alloy has been developed by powder in-situ synthesis process under argon atmosphere. X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) results show the existence of Al 4 C 3 particles in this master alloy. After adding 1.8% Mg–50%Al 4 C 3 master alloy, the average grain size of α-Mg decreased from 360 μm to 154 μm. Based on the DTA test results and calculation of the planar disregistry between Al 4 C 3 and α-Mg, Al 4 C 3 particles located in the central regions of magnesium grains can act as the heterogeneous nucleus of primary α-Mg phase

Probing the central engine and environment of AGN using ARIES 1.3-m and 3.6-m telescopes

Science.gov (United States)

Chand, Hum; Rakshit, Suvendu; Jalan, Priyanka; Ojha, Vineet; Srianand, Raghunathan; Vivek, Mariappan; Mishra, Sapna; Omar, Amitesh; Kumar, Parveen; Joshi, Ravi; Gopal-Krishna; Kumar, Rathna

2018-04-01

We discuss three long term observational programmes to probe the central engine and environment of active galactic nuclei (AGN) using the recently installed ARIES 1.3-m and 3.6-m telescopes. The first programme is on the photometric reverberation mapping of low luminosity AGN by mainly using the ARIES 1.3-m telescope. The major impact of this programme other than to estimate the black hole mass will be to extend the broad line region (BLR) radius-luminosity (RBLR-LAGN) relation to the unexplored low luminosity regime, and to constrain the AGN broad line region geometry. The second programme is to use long slit spectroscopy on the ARIES 3.6-m telescope to discover new high redshift quasar pairs with angular separation less than 1-arcmin. Here, the background QSOs sight-line will be used to probe the environment of the foreground QSOs at kpc-Mpc scales. The major impact of this programme will be on the discovery of new pairs which have been missed in the SDSS survey due to fiber collision below 1-arcmin separation, and use them to understand about any excess overdensity around the QSO, any anisotropic emission of QSOs, and/or any episodic activity of QSOs. The third programme is related to spectral variability studies of the C IV broad absorption line (BAL) QSOs, based on low resolution spectroscopy using the ARIES 3.6-m telescope. Here, those most interesting cases will be monitored, where the BAL flow emerges afresh or disappears completely in the C IV trough of BAL QSOs sample as seen in SDSS multi-epoch observations. Continuous monitoring of such a sample will be important for our understanding of the nature and origin of the flow, along with their stability and dynamical evolution.

A determination of m_c(m_c) from HERA data using a matched heavy-flavor scheme

International Nuclear Information System (INIS)

Bertone, Valerio; Cooper-Sarkar, Amanda

2016-05-01

The charm quark mass is one of the fundamental parameters of the Standard Model Lagrangian. In this work we present a determination of the MS charm mass from a fit to the inclusive and charm HERA deep-inelastic structure function data. The analysis is performed within the xFitter framework, with structure functions computed in the FONLL general-mass scheme as implemented in APFEL. In the case of the FONLL-C scheme, we obtain m_c(m_c)=1.335±0.043(exp)"+"0"."0"1"9_-_0_._0_0_0(param)"+"0"."0"1"1_-_0_._0_0_8(mod)"+"0"."0"3"3_-_0_._0_0_8(th) GeV. We also perform an analogous determination in the fixed-flavor-number scheme at next-to-leading order, finding m_c(m_c)=1.318 ± 0.054(exp)"+"0"."0"1"1_-_0_._0_1_0(param)"+"0"."0"1"5_-_0_._0_1_9(mod)"+"0"."0"4 "5_-_0_._0_0_4(th) GeV, compatible with the FONLL-C value. Our results are consistent with previous determinations from DIS data as well as with the PDG world average.

Mecanismo de corrosión a refractarios de MgO-C y MgO-C-Al en horno eléctrico

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Guerrero Barranco, M.

2010-06-01

Full Text Available This article presents the results of a post-mortem study of various MgO-C and MgO-C-Al pieces that are used in the electric furnaces at the Acerinox factory in Cádiz. From the chemical, thermal, mineralogical and microstructural characterization of the materials prior to use and post-mortem it has been established that, in both types of refractories, the corrosion has lead to the formation of reaction layers with different chemical and mineralogical composition, as a function of temperature and oxygen partial pressure, ranging from the hot to the cold face and strongly depending on the zone of the electric furnace where the piece is situated. Changes in graphite content have been observed in both types of materials by X-ray diffraction. These changes have been quantified by Differential Thermal Analysis. In MgO-C-Al refractories it has been observed the formation of small amounts of C₃Al₄ inside the pieces and MgAl₂O₄ in the refractories’ hot face. Keeping in mind the obtained results and the phase equilibrium diagram of Mg-C-Al-O it has been established a corrosion mechanism for both types of materials. It cannot be established by the present results that additions of Al (≈ 2 % in weight improve the performance of MgO-C materials.

Se describen los resultados del estudio post-mortem de diversas piezas de MgO-C y MgO-C-Al utilizadas en los hornos eléctricos de la factoría de Acerinox en Cádiz. De la caracterización química, térmica, mineralógica y microestructural de los materiales sin usar y post-mortem se ha establecido que la corrosión ha dado lugar, en ambos tipos de refractarios, a la formación de capas de reacción con distinta composición química y mineralógica, en función de la temperatura y presión parcial de oxígeno en la pieza, que varían desde la cara caliente a la cara fría y dependen fuertemente de la zona del horno eléctrico en que está situada la pieza. En

Passivation kinetics of Mg-Nd-Gd-Zn-Zr (EV31A and Mg-Y-Nd-Gd-Zr (WE43C in NaOH solutions

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Jakraphan Ninlachart

2017-09-01

Full Text Available Passivation kinetics of two Mg-RE alloys, such as Mg-Nd-Gd-Zn-Zr (EV31A, and Mg-Y-Nd-Gd-Zr (WE43C were investigated in two different heat treated conditions (solution treated and overaged in 0.01 - 1.0 M NaOH solutions under potentiostatic conditions. Negative reaction order was observed in dilute NaOH which transitioned to positive values as the passivation time increased and in the 1 M NaOH as well. The passive layers showed platelet morphology and the size of the platelets decreased with increase in the NaOH concentration. The hydrogen evolution reaction (HER kinetics was not improved on the passive layer covered surface of the Mg-RE alloys in contrast to the improvements reported on the hydroxide covered pure magnesium. The electrochemical impedance increased with increase in the NaOH concentration in the solution treated condition of both Mg-RE alloys, whereas the overaged EV31A alloy showed a reverse trend. The passive layer of EV31A showed almost 100% higher charge carrier density than the film formed on the WE43C in the overaged condition. A better passivation behavior was observed in the solution treated condition than that in the overaged condition which could be attributed to the uniform distribution of the RE elements in the solution treated specimens. The WE43C alloy revealed better corrosion resistance in the alkaline solution than the EV31A alloy.

Microwave dielectric properties of La{sub (1-2x/3)}Ba{sub x}(Mg{sub 0.5}Sn{sub 0.5})O{sub 3} ceramics

Energy Technology Data Exchange (ETDEWEB)

Chen, Yih-Chien; Chen, Kuei-Chien; Hsu, Wei-Yu [Department of Electrical Engineering, Lunghwa University of Science and Technology, Gueishan Shiang, Taoyuan County (China)

2010-11-15

This study examined the potential applications of microwave dielectric properties of La{sub (1-2x/3)}Ba{sub x}(Mg{sub 0.5}Sn{sub 0.5})O{sub 3} ceramics in rectenna. The La{sub (1-2x/3)}Ba{sub x}(Mg{sub 0.5}Sn{sub 0.5})O{sub 3} ceramics were prepared by the conventional solid-state method with various sintering temperatures. An apparent density of 6.62 g/cm{sup 3}, a dielectric constant of 20.3, a quality factor of 51,700 GHz, and a temperature coefficient of resonant frequency of -78.2 ppm/K were obtained for La{sub 2.98/3}Ba{sub 0.01}(Mg{sub 0.5}Sn{sub 0.5})O{sub 3} ceramics that were sintered at 1550 C for 4 h. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Ropivacaine 7.5 mg/mL for Caesarean Section

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N. K. Nguyen

2010-01-01

Full Text Available Background. Pain after Caesarean delivery is partly related to Pfannenstiel incision, which can be infiltrated with local anaesthetic solutions. Methods. A double- blind randomized control trial was designed to assess the analgesic efficacy of 7.5 mg/mL ropivacaine solution compared to control group, in two groups of one hundred and forty four parturients for each group, who underwent Caesarean section under spinal anaesthesia: group R (ropivacaine group and group C (control group. All parturients also received spinal sufentanil (2.5 g. Results. Ropivacaine infiltration in the Pfannenstiel incision for Caesarean delivery before wound closure leads to a reduction of 30% in the overall consumption of analgesics (348 550 mg for group R versus 504 426 mg for group C with <.05, especially opioids in the first 24 hours, but also significantly increases the time interval until the first request for an analgesic (4 h 20 min ± 2 h 26 for group R versus 2 h 42 ± 1 h 30 for group C. The P values for the two groups were: <.0001 for paracetamol, <.0001 for ketoprofen and P for nalbuphine which was the most significant. There is no significant difference in the threshold of VAS in the two series. Conclusion. This technique can contribute towards a programme of early rehabilitation in sectioned mothers, with earlier discharge from the post-labour suite.

Microstructure of epitaxial SrRuO 3 thin films on MgO substrates

Science.gov (United States)

Ai, Wan Yong; Zhu, Jun; Zhang, Ying; Li, Yan Rong; Liu, Xing Zhao; Wei, Xian Hua; Li, Jin Long; Zheng, Liang; Qin, Wen Feng; Liang, Zhu

2006-09-01

SrRuO 3 thin films have been grown on singular (1 0 0) MgO substrates using pulsed laser deposition (PLD) in 30 Pa oxygen ambient and at a temperature of 400-700 °C. Ex situ reflection high-energy electron diffraction (RHEED) as well as X-ray diffraction (XRD) θ/2 θ scan indicated that the films deposited above 650 °C were well crystallized though they had a rough surface as shown by atom force microscopy (AFM). XRD Φ scans revealed that these films were composed of all three different types of orientation domains, which was further confirmed by the RHEED patterns. The heteroepitaxial relationship between SrRuO 3 and MgO was found to be [1 1 0] SRO//[1 0 0] MgO and 45°-rotated cube-on-cube [0 0 1] SRO//[1 0 0] MgO. These domain structures and surface morphology are similar to that of ever-reported SrRuO 3 thin films deposited on the (0 0 1) LaAlO 3 substrates, and different from those deposited on (0 0 1) SrTiO 3 substrates that have an atomically flat surface and are composed of only the [1 1 0]-type domains. The reason for this difference was ascribed to the effect of lattice mismatch across the film/substrate interface. The room temperature resistivity of SrRuO 3 films fabricated at 700 °C was 300 μΩ cm. Therefore, epitaxial SrRuO 3 films on MgO substrate could serve as a promising candidate of electrode materials for the fabrication of ferroelectric or dielectric films.

Homo sapiens natriuretic peptide precursor type C (NPPC) mRNA,partial cds and 3' UTR.

OpenAIRE

Landi, Stefano; Melaiu, Ombretta; Cabiati, Manuela; Landi, Debora; Caselli, Chiara; Prescimone, Tommaso; Giannessi, Daniela; Gemignani, Federica; Del Ry, Silvia

2010-01-01

LOCUS HQ419060 318 bp mRNA linear PRI 24-NOV-2010 DEFINITION Homo sapiens natriuretic peptide precursor type C (NPPC) mRNA, partial cds and 3' UTR. ACCESSION HQ419060 VERSION HQ419060.1 GI:312261407 KEYWORDS . SOURCE Homo sapiens (human) ORGANISM Homo sapiens Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo. REFERENCE 1 (bases 1 to 318) AUTHORS Landi,S., Melaiu,O., Cabiati,M., Landi,D., C...

Concurrent chemoradiotherapy for advanced pancreatic cancer. 1,000 mg/m{sup 2} gemcitabine can be administered using limited-field radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Yamazaki, Hideya [Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka (Japan). Dept. of Radiation Oncology; National Hospital Organization, Osaka National Hospital, Osaka (Japan). Dept. of Radiology; Nishiyama, Kinji; Koizumi, Masahiko; Tanaka, Eiichi [Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka (Japan). Dept. of Radiation Oncology; Ioka, Tatsuya; Uehara, Hiroyuki; Iishi, Hiroyasu; Nakaizumi, Akihiko [Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka (Japan). Dept. of Internal Medicine; Ohigashi, Hiroaki; Ishikawa, Osamu [Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka (Japan). Dept. of Surgery

2007-06-15

Purpose: To examine the feasibility of concurrent use of full-dose gemcitabine (GEM) and radiotherapy for advanced pancreatic cancer. Patient and Methods: 22 patients with advanced pancreatic cancer were subjected to concurrent chemoradiotherapy (GEM 1,000 mg/m2 weekly, three times during 4 weeks). They received limited-field irradiation by three-dimensional radiotherapy planning. Results: Of the 22 patients, 16 (72%) completed the treatment (50 Gy irradiation and at least three times concurrent administration of 1 g/m{sup 2} GEM). One patient with unresectable tail cancer showed peritonitis carcinomatosa and both chemotherapy and radiotherapy had to be stopped. Dose reduction or omission of GEM was necessary in another four patients. In addition, radiotherapy was discontinued in one patient for fatigue. Grade 3 hematologic toxicity was detected in eight patients (36%), and grade 3 nonhematologic toxicity (anorexia) in one patient (5%). In total, the response rate amounted to 32% (seven partial responses), and the median survival time (MST) was 16 months. Among the twelve patients who received preoperative chemoradiotherapy, nine underwent surgery and showed a survival rate of 78% at 1 year. Another 13 patients without surgery showed 14 months of MST. No regional lymph node failure has appeared so far. Conclusion: Limited-field radiotherapy enables the safe concurrent administration of 1,000 mg/m{sup 2} GEM.

A Revised Mechanism for the Activation of Complement C3 to C3b

Science.gov (United States)

Rodriguez, Elizabeth; Nan, Ruodan; Li, Keying; Gor, Jayesh; Perkins, Stephen J.

2015-01-01

The solution structure of complement C3b is crucial for the understanding of complement activation and regulation. C3b is generated by the removal of C3a from C3. Hydrolysis of the C3 thioester produces C3u, an analog of C3b. C3b cleavage results in C3c and C3d (thioester-containing domain; TED). To resolve functional questions in relation to C3b and C3u, analytical ultracentrifugation and x-ray and neutron scattering studies were used with C3, C3b, C3u, C3c, and C3d, using the wild-type allotype with Arg102. In 50 mm NaCl buffer, atomistic scattering modeling showed that both C3b and C3u adopted a compact structure, similar to the C3b crystal structure in which its TED and macroglobulin 1 (MG1) domains were connected through the Arg102–Glu1032 salt bridge. In physiological 137 mm NaCl, scattering modeling showed that C3b and C3u were both extended in structure, with the TED and MG1 domains now separated by up to 6 nm. The importance of the Arg102–Glu1032 salt bridge was determined using surface plasmon resonance to monitor the binding of wild-type C3d(E1032) and mutant C3d(A1032) to immobilized C3c. The mutant did not bind, whereas the wild-type form did. The high conformational variability of TED in C3b in physiological buffer showed that C3b is more reactive than previously thought. Because the Arg102-Glu1032 salt bridge is essential for the C3b-Factor H complex during the regulatory control of C3b, the known clinical associations of the major C3S (Arg102) and disease-linked C3F (Gly102) allotypes of C3b were experimentally explained for the first time. PMID:25488663

Effect of 3,3',5-triiodothyronine and 3,5-diiodothyronine on progesterone production, cAMP synthesis, and mRNA expression of STAR, CYP11A1, and HSD3B genes in granulosa layer of chicken preovulatory follicles.

Science.gov (United States)

Sechman, A; Pawlowska, K; Hrabia, A

2011-10-01

In vitro studies were performed to assess whether stimulatory effects of triiodothyronine (T3) on progesterone (P4) production in a granulosa layer (GL) of chicken preovulatory follicles are associated with 3',5'-cyclic adenosine monophosphate (cAMP) synthesis and mRNA expression of STAR protein, CYP11A1, and HSD3B. Effects of 3,5-diiodothyronine (3,5-T2) on steroidogenic function in these follicles were also investigated. The GL of F3 to F1 follicles was incubated in medium supplemented with T3 or 3,5-T2, LH, or forskolin (F), and a combination of each iodothyronine with LH or F. Levels of P4 and cAMP in culture media were determined by RIA. Expression of genes involved in P4 synthesis (ie, STAR protein, CYP11A1, and HSD3B) in the GL of F3 to F1 follicles incubated in medium with T3 or 3,5-T2 and their combination with LH was performed by real-time PCR. Triiodothyronine increased basal and LH- and F-stimulated P4 secretion by preovulatory follicles. The 3,5-T2 elevated P4 synthesis by F3, had no effect on F2 follicles, and diminished P4 production by the GL of F1 follicles. It had no effect on LH-stimulated P4 production; however, it augmented F-stimulated P4 production by F2 and F1 follicles. Although T3 did not affect basal and F-stimulated cAMP synthesis by the GL of preovulatory follicles, it increased LH-stimulated synthesis of this nucleotide. However, 3,5-T2 elevated F-stimulated cAMP synthesis in F3 and F2 follicles; it did not change basal and LH-stimulated cAMP production. Triiodothyronine decreased basal STAR and CYP11A1 mRNAs in F3 follicles, increased them in F1 follicles, and elevated HSD3B mRNA levels in F1 follicles. Triiodothyronine augmented LH-stimulated STAR, CYP11A1, and HSD3B mRNA levels in F2 and CYP11A1 in F1 follicles. However, T3 decreased LH-stimulated STAR and HSD3B mRNA levels in F1 follicles. The 3,5-T2 did not affect basal STAR and CYP11A1 mRNA expression in all investigated follicles; however, it decreased LH-stimulated STAR

Direct observation of the near-surface layer in Pb(Mg1/3Nb2/3)O3 using neutron diffraction

International Nuclear Information System (INIS)

Conlon, K.H.; Whan, T.; Fox, J.H.; Luo, H.; Viehland, D.; Li, J.F.; Stock, C.; Shirane, G.

2004-01-01

Spatially resolved neutron diffraction as a function of crystal depth in Pb(Mg 1/3 Nb 2/3 )O 3 reveals the presence of a distinct near-surface region where a strong distortion in the lattice exists. A dramatic change in both the lattice constant and the Bragg peak intensity as a function of crystal depth is observed to occur in this region over a length scale ∼100 μm. This confirms a previous assertion, based on a comparison between high-energy x rays and neutrons, that such a near surface region exists in the relaxors. Consequences to both single crystal and powder diffraction measurements and previous bulk neutron diffraction measurements on large single crystals are discussed

Adenosine A1 receptor mRNA expression and the effects of systemic theophylline administration on respiratory function 4 months after C2 hemisection.

Science.gov (United States)

Nantwi, Kwaku D; Basura, Gregory J; Goshgarian, Harry G

2003-01-01

Previous studies from our laboratory have demonstrated that in an animal model of acute cervical spinal cord injury (SCI), respiratory function can be restored by theophylline. We also have shown that respiratory recovery occurs spontaneously after prolonged postinjury survival periods when a hemidiaphragm is paralyzed by an ipsilateral upper cervical (C2) spinal cord hemisection. Theophylline mediates functional recovery by central nervous system adenosine A1 receptor antagonism; however, it is unclear whether adenosine receptors are altered after prolonged postinjury periods and whether theophylline can further enhance restored respiratory function that occurs spontaneously. To assess putative effects of systemic theophylline administration on further enhancing spontaneous respiratory muscle recovery 4 months after C2 hemisection in rats and to determine whether adenosine A1 receptor mRNA expression is altered in these animals. Electrophysiologic assessment of respiratory activity in the phrenic nerves was conducted in C2 hemisected rats 4 months after hemisection under standardized conditions. Immediately thereafter, rats were killed and the cervical spinal cords were prepared for adenosine A1 receptor mRNA expression by in situ hybridization. Spontaneous recovery of respiratory activity in the ipsilateral phrenic nerve was detected in a majority (15/20) of C2 hemisected animals and amounted to 44.06% +/- 2.38% when expressed as a percentage of activity in the homolateral phrenic nerve in noninjured animals. At the optimal dosage used in the acute studies, theophylline (15 mg/kg) did not enhance, but rather unexpectedly blocked, recovered respiratory activity in 4 out of 5 animals tested. At dosages of 5 mg/kg and 2.5 mg/kg, the drug blocked recovered respiratory activity in 3 out of 4 and 3 out of 5 animals tested, respectively. Quantitative analysis of adenosine A1 receptor mRNA expression did not reveal a significant difference between experimental animals

Alopecia in a viable phospholipase C delta 1 and phospholipase C delta 3 double mutant.

Directory of Open Access Journals (Sweden)

Fabian Runkel

Full Text Available BACKGROUND: Inositol 1,4,5trisphosphate (IP(3 and diacylglycerol (DAG are important intracellular signalling molecules in various tissues. They are generated by the phospholipase C family of enzymes, of which phospholipase C delta (PLCD forms one class. Studies with functional inactivation of Plcd isozyme encoding genes in mice have revealed that loss of both Plcd1 and Plcd3 causes early embryonic death. Inactivation of Plcd1 alone causes loss of hair (alopecia, whereas inactivation of Plcd3 alone has no apparent phenotypic effect. To investigate a possible synergy of Plcd1 and Plcd3 in postnatal mice, novel mutations of these genes compatible with life after birth need to be found. METHODOLOGY/PRINCIPAL FINDINGS: We characterise a novel mouse mutant with a spontaneously arisen mutation in Plcd3 (Plcd3(mNab that resulted from the insertion of an intracisternal A particle (IAP into intron 2 of the Plcd3 gene. This mutation leads to the predominant expression of a truncated PLCD3 protein lacking the N-terminal PH domain. C3H mice that carry one or two mutant Plcd3(mNab alleles are phenotypically normal. However, the presence of one Plcd3(mNab allele exacerbates the alopecia caused by the loss of functional Plcd1 in Del(9olt1Pas mutant mice with respect to the number of hair follicles affected and the body region involved. Mice double homozygous for both the Del(9olt1Pas and the Plcd3(mNab mutations survive for several weeks and exhibit total alopecia associated with fragile hair shafts showing altered expression of some structural genes and shortened phases of proliferation in hair follicle matrix cells. CONCLUSIONS/SIGNIFICANCE: The Plcd3(mNab mutation is a novel hypomorphic mutation of Plcd3. Our investigations suggest that Plcd1 and Plcd3 have synergistic effects on the murine hair follicle in specific regions of the body surface.

Dicty_cDB: Contig-U15201-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available 2e-04 2 ( EX698640 ) GF_AW109651c08 AW1 Schistosoma mansoni cDNA clone... 44 2e-04 2 ( CD147...-0107T-L395-E12-U.B MG1-0107 Schistosoma manso... 44 2e-04 2 ( CD147233 ) ML1-0002T-M131-E11-U.G ML1-0002 Sc

Magnetotransport properties of c-axis oriented La0.7Sr0.3MnO3 thin films on MgO-buffered SiO2/Si substrates

International Nuclear Information System (INIS)

Kang, Young-Min; Ulyanov, Alexander N.; Shin, Geo-Myung; Lee, Sung-Yun; Yoo, Dae-Gil; Yoo, Sang-Im

2009-01-01

c-axis oriented La 0.7 Sr 0.3 MnO 3 (LSMO) films on MgO-buffered SiO 2 /Si substrates were prepared, and their texture, microstructure, and magnetotransport properties were studied and compared to epitaxial LSMO/MgO (001) and polycrystalline LSMO/SiO 2 /Si films. c-axis oriented MgO buffer layers were obtained on amorphous SiO 2 layer through rf sputter deposition at low substrate temperature and consequent postannealing processes. In situ pulsed laser deposition-grown LSMO films, deposited on the MgO layer, show strong c-axis texture, but no in-plane texture. The c-axis oriented LSMO films which are magnetically softer than LSMO/SiO 2 /Si films exhibit relatively large low field magnetoresistance (LFMR) and sharper MR drop at lower field. The large LFMR is attributed to a spin-dependent scattering of transport current at the grain boundaries

Tuning structure in epitaxial Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} thin films by using miscut substrates

Energy Technology Data Exchange (ETDEWEB)

Mietschke, M., E-mail: m.mietschke@ifw-dresden.de [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Dresden University of Technology, Faculty of Mechanical Science and Engineering, D-01062 Dresden (Germany); Oswald, S.; Fähler, S. [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Schultz, L. [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Dresden University of Technology, Faculty of Mechanical Science and Engineering, D-01062 Dresden (Germany); Hühne, R. [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany)

2015-08-31

Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} (PMN–PT) is one of the most promising ferroelectric material for actuator, dielectric and electrocaloric applications. However, oriented and phase pure thin films are essential to use the outstanding properties of these compounds. In this work it is demonstrated that the use of miscut substrates influences the growth mechanism leading to a significantly broader deposition window to achieve the required film quality. Therefore, epitaxial 0.68Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–0.32PbTiO{sub 3} films were grown by pulsed laser deposition on (001)-oriented single crystalline SrTiO{sub 3} (STO) substrates with a miscut angle between 0 and 15° towards the [100] direction using a conducting La{sub 0.7}Sr{sub 0.3}CoO{sub 3} buffer layer. The influence of the vicinal angle on the PMN–PT structure was studied by high resolution X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. A nearly pure perovskite phase growth with a cube-on-cube epitaxial relationship was obtained on all miscut STO substrates, whereas a significant volume fraction of the pyrochlore phase was present on the standard substrate. Reciprocal space measurements revealed a peak split of the perovskite reflections indicating structural variants of PMN–PT with different c/a ratios. An additional tilting of the PMN–PT planes with respect to the buffer layer was observed on some samples, which might be explained with the incorporation of dislocations according to the Nagai model. Polarization loops were measured in a temperature range between room temperature and 150 °C showing a sharp drop of the remanent polarization above 65 °C on vicinal substrates. - Highlights: • Epitaxial growth of pure perovskite Pb (Mg{sub 1}/{sub 3}Nb{sub 2}/{sub 3})O{sub 3}–PbTiO{sub 3} on miscut SrTiO{sub 3}. • Significant broadening of the deposition window for pyrochlore-free films. • Dependence of the structural parameters

M/G/1/K system with push-out scheme under vacation policy

Directory of Open Access Journals (Sweden)

Shoji Kasahara

1996-01-01

Full Text Available We consider an M/G/1/K system with push-out scheme and multiple vacations. This model is particularly important in situations where it is essential to provide short waiting times to messages which are selected for service. We analyze the behavior of two types of messages: one that succeeds in transmission and the other that fails. We derive the Laplace-Stieltjes transform of the waiting time distribution for the message which is eventually served. Finally, we show some numerical results including the comparisons between the push-out and the ordinary blocking models.

Analysis of an M/G/1 queue with customer impatience and an adaptive arrival process

NARCIS (Netherlands)

Boxma, O.J.; Prabhu, B.J.

2009-01-01

We study an M/G/1 queue with impatience and an adaptive arrival process. The rate of the arrival process changes according to whether an incoming customer is accepted or rejected. We analyse two different models for impatience : (i) based on workload, and (ii) based on queue length. For the

Thermoluminescent properties of Spinel-type oxides present in the Ternary system In{sub 2}O{sub 3}-TiO{sub 2}-Mg O in air at 1350 degrees C

Energy Technology Data Exchange (ETDEWEB)

Brown, F.; Hernandez P, T. C.; Alvarez M, V. E.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Munoz, I. C. [Universidad de Sonora, Departamento de Ciencias Quimico-Biologicas, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R., E-mail: imunoz@polimeros.uson.mx [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83190 Hermosillo, Sonora (Mexico)

2015-10-15

Full text: In the ternary system In{sub 2}O{sub 3}-TiO{sub 2}-Mg O exists a solid solution Mg{sub 2-x}In{sub 2x}Ti{sub 1-x}O{sub 4} (0≤ x ≤1) with spinel-type structure between MgIn{sub 2}O{sub 4} and Mg{sub 2}TiO{sub 4} (F. Brown et. al., 2000). In order to analyze their thermoluminescent (Tl) response, we obtained the spinel-type oxides with x= 0 (s1), 0.25 (s2), 0.5 (s3), 0.75 (s4), and 1 (s5) by a solid state reaction at 1350 degrees C in air. The X-ray patterns showed a spinel type structure for these compounds. The powders were exposed to beta particles from {sup 90}Sr. The glow curve showed by s1 and s3 were hundreds of times more intense than s2, s4 and s5. At 50 Gy, s1 exhibits a main Tl maximum located at 200 degrees C, with two shoulders at 119 and 250 degrees C. The s3 oxide reveals a simple and wide glow curve at ≅195 degrees C with a Tl maximum located at 203 degrees C at 21.33 Gy. The peaks of the s1 and s3 oxide show a shift to lower temperatures and this increases its intensity as the irradiation dose increases. The lineal behavior observed for s1 and s3 were between 1.33-150 Gy and 10.66-341 Gy correspondingly, without evidence of saturation signal. After cycle 4, the s1 oxide has small variations in the relative sensitivity, with percentages below 1%. On the other hand, s3 reveals a relative sensitivity variation of 2.7%. Besides this, the standard deviation after ten consecutive irradiation-Tl readout cycles for s1 was 3.07 % and for s3 was 1%. The minimum detectable dose obtained were 0.5 Gy for s1 and 5.65 Gy for s3. These results suggest a possible application of Mg{sub 1.5}InTi{sub 0.5}O{sub 4} in dosimetry. (Author)

Excited states in 22Mg via the 12C(12C,2n)22Mg reaction

International Nuclear Information System (INIS)

Jewett, Cybele; Baktash, Cyrus; Bardayan, Daniel W.; Blackmon, Jeff C.; Chipps, K.; Galindo-Uribarri, Alfredo; Greife, U.; Gross, Carl J.; Jones, K. L.; Liang, Junjien; Livesay, Jake; Kozub, R. L.; Nesaraja, Caroline D; Radford, David C.; Sarazin, F.; Smith, Michael Scott; Thomas, J. S.; Yu, Chang-Hong

2007-01-01

The 12C(12C, 2n)22Mg reaction was measured with the CLARION array and the RMS separator at the Holifield Facility of Oak Ridge National Laboratory. This experiment was performed to gather more information on the excited states in 22Mg, which might be of relevance to recent radioactive ion beam measurements of the astrophysically important 21Na(p,γ)22Mg reaction. The results are compared to direct measurements, transfer experiments and a competing experiment performed with Gammasphere

Site-specific conjugation and labelling of prostate antibody 7E11C5.3 (CYT-351) with technetium-99m

International Nuclear Information System (INIS)

Stalteri, M.A.; Mather, S.J.; Belinka, B.A.; Coughlin, D.J.; Chengazi, V.U.; Britton, K.E.

1997-01-01

Attachment of chelating agents to the sugar residues of antibodies for subsequent radiolabelling is an attractive approach since it may have less effect on the immunoreactivity than attachment through lysine residues, which are distributed throughout the antibody and may be present near the antigen binding site. We have attached a new hydrazide-linked chelator CYT-395 (Cytogen Corp., Princeton, N.J.) to the sugar residues of the anti-prostate monoclonal antibody 7E11C5.3 and optimised the conditions for labelling the conjugate with technetium-99m in order to compare the conjugate to 7E11C5.3 antibody labelled directly with technetium using a mercaptoethanol reduction technique. Labelling yields of 70%-90% were obtained at specific activities up to 2000 MBq/mg antibody. The stability of the technetium-labelled conjugate in plasma or to a challenge with 0.1 or 1.0 mM cysteine was similar to that of direct-labelled antibody. In nine patients with prostate cancer, the plasma clearance of the labelled conjugate followed a two-compartment model, with an average β-phase half-life of 31.4±3.9 h. The average urinary clearance at 24 h was 15.3±5.0% of the injected dose. In this group of patients there was no significant difference between the blood and urine clearance of the labelled conjugate, and the clearances of the direct-labelled antibody. (orig.). With 5 figs

Effect of the La/Mg ratio on the structure and electrochemical properties of La xMg 3- xNi 9 ( x=1.6-2.2) hydrogen storage electrode alloys for nickel-metal hydride batteries

Science.gov (United States)

Liao, B.; Lei, Y. Q.; Chen, L. X.; Lu, G. L.; Pan, H. G.; Wang, Q. D.

Effect of La/Mg ratio on the structure and electrochemical properties of La xMg 3- xNi 9 ( x=1.6-2.2) ternary alloys was investigated. All alloys are consisted of a main phase with hexagonal PuNi 3-type structure and a few impurity phases (mainly LaNi 5 and MgNi 2). The increase of La/Mg ratio in the alloys leads to an increase in both the cell volume and the hydride stability. The discharge capacity of the alloys at 100 mA/g increases with the increase of La/Mg ratio and passes though a maximum of 397.5 mAh/g at x=2.0. As the La/Mg ratio increases, the high-rate dischargeability of the alloy electrodes at 1200 mA/g HRD 1200 decreases from 66.7% ( x=1.6) to 26.5% ( x=2.2). The slower decrease of HRD 1200 (from 66.7 to 52.7%) of the alloys with x=1.6-2.0 is mainly attributed to the decrease of electrocatalytic activity of the alloys for charge-transfer reaction, the more rapid decrease of HRD 1200 of the alloys with x>2.0 is mainly attributed to the lowering of the hydrogen diffusion rate in the bulk of alloy. The cycling capacity degradation of the alloys is rather fast for practical application due to the corrosion of La and Mg and the large VH in the hydride phase.

A two-state computational investigation of methane C--H and ethane C--C oxidative addition to [CpM(PH3)]n+ (M = Co, Rh, Ir; n = 0, 1).

Science.gov (United States)

Petit, Alban; Richard, Philippe; Cacelli, Ivo; Poli, Rinaldo

2006-01-11

Reductive elimination of methane from methyl hydride half-sandwich phosphane complexes of the Group 9 metals has been investigated by DFT calculations on the model system [CpM(PH(3))(CH(3))(H)] (M = Co, Rh, Ir). For each metal, the unsaturated product has a triplet ground state; thus, spin crossover occurs during the reaction. All relevant stationary points on the two potential energy surfaces (PES) and the minimum energy crossing point (MECP) were optimized. Spin crossover occurs very near the sigma-CH(4) complex local minimum for the Co system, whereas the heavier Rh and Ir systems remain in the singlet state until the CH(4) molecule is almost completely expelled from the metal coordination sphere. No local sigma-CH(4) minimum was found for the Ir system. The energetic profiles agree with the nonexistence of the Co(III) methyl hydride complex and with the greater thermal stability of the Ir complex relative to the Rh complex. Reductive elimination of methane from the related oxidized complexes [CpM(PH(3))(CH(3))(H)](+) (M = Rh, Ir) proceeds entirely on the spin doublet PES, because the 15-electron [CpM(PH(3))](+) products have a doublet ground state. This process is thermodynamically favored by about 25 kcal mol(-1) relative to the corresponding neutral system. It is essentially barrierless for the Rh system and has a relatively small barrier (ca. 7.5 kcal mol(-1)) for the Ir system. In both cases, the reaction involves a sigma-CH(4) intermediate. Reductive elimination of ethane from [CpM(PH(3))(CH(3))(2)](+) (M = Rh, Ir) shows a similar thermodynamic profile, but is kinetically quite different from methane elimination from [CpM(PH(3))(CH(3))(H)](+): the reductive elimination barrier is much greater and does not involve a sigma-complex intermediate. The large difference in the calculated activation barriers (ca. 12.0 and ca. 30.5 kcal mol(-1) for the Rh and Ir systems, respectively) agrees with the experimental observation, for related systems, of oxidatively

Probing the electronic properties of ternary A n M3n-1B2n (n = 1: A = Ca, Sr; M = Rh, Ir and n = 3: A = Ca, Sr; M = Rh) phases: observation of superconductivity.

Science.gov (United States)

Takeya, Hiroyuki; ElMassalami, Mohammed; Terrazos, Luis A; Rapp, Raul E; Capaz, Rodrigo B; Fujii, Hiroki; Takano, Yoshihiko; Doerr, Mathias; Granovsky, Sergey A

2013-06-01

We follow the evolution of the electronic properties of the titled homologous series when n as well as the atomic type of A and M are varied where for n = 1, A = Ca, Sr and M = Rh, Ir while for n = 3, A = Ca, Sr and M = Rh. The crystal structure of n = 1 members is known to be CaRh 2 B 2 -type ( Fddd ), while that of n = 3 is Ca 3 Rh 8 B 6 -type ( Fmmm ); the latter can be visualized as a stacking of structural fragments from AM 3 B 2 ( P 6/ mmm ) and AM 2 B 2 . The metallic properties of the n = 1 and 3 members are distinctly different: on the one hand, the n = 1 members are characterized by a linear coefficient of the electronic specific heat γ ≈ 3 mJ mol -1 K -2 , a Debye temperature θ D ≈ 300 K, a normal conductivity down to 2 K and a relatively strong linear magnetoresistivity for fields up to 150 kOe. The n = 3 family, on the other hand, exhibits γ ≈ 18 mJ mol -1 K -2 , θ D ≈ 330 K, a weak linear magnetoresistivity and an onset of superconductivity (for Ca 3 Rh 8 B 6 , T c = 4.0 K and H c2 = 14.5 kOe, while for Sr 3 Rh 8 B 6 , T c = 3.4 K and H c2 ≈ 4.0 kOe). These remarkable differences are consistent with the findings of the electronic band structures and density of state (DOS) calculations. In particular, satisfactory agreement between the measured and calculated γ was obtained. Furthermore, the Fermi level, E F , of Ca 3 Rh 8 B 6 lies at almost the top of a pronounced local DOS peak, while that of CaRh 2 B 2 lies at a local valley: this is the main reason behind the differences between the, e.g., superconducting properties. Finally, although all atoms contribute to the DOS at E F , the contribution of the Rh atoms is the strongest.

Structural and magnetic properties of Ni{sub 0.15}Mg{sub 0.1}Cu{sub 0.3}Zn{sub 0.45}Fe{sub 2}O{sub 4} ferrite prepared by NaOH-precipitation method

Energy Technology Data Exchange (ETDEWEB)

Hou, Wei-xiao; Wang, Zhi, E-mail: zhiwang@tju.edu.cn

2015-09-15

Highlights: • NiMgCuZn ferrites were successfully prepared by low-temperature sintering. • NiMgCuZn ferrites have the advantages of both NiCuZn and MgCuZn ferrites. • NiMgCuZn ferrites exhibit high Curie temperature & high stability of permeability. - Abstract: The Ni{sub 0.15}Mg{sub 0.1}Cu{sub 0.3}Zn{sub 0.45}Fe{sub 2}O{sub 4} ferrite powders have been prepared by NaOH co-precipitation method and characterized by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The XRD patterns confirm the single phase spinel structure of synthesized nanoparticles. The average crystallite size of the particles increases from 12 to 36 nm with calcining temperature (T{sub a}) from 500 to 800 °C. The saturation magnetization (M{sub s}) of the superparamagnetic particles was deduced by Langevin theory. Subsequently, the densification characteristics and magnetic properties of the low-temperature 950 °C-sintered ferrite bulk samples were also investigated. The magnetic measurement showed that the sintered bulk sample of T{sub a} = 600 °C has the highest initial permeability (μ{sub i}), lowest coercivity (H{sub c}), largest saturation magnetization (M{sub s}) and satisfactory thermal stability of μ{sub i}. The microstructures of sintered samples were examined using field emission scanning electric microscope (FESEM). The T{sub a} has significant influence on the bulk density, initial permeability, saturation magnetization and coercivity of Ni{sub 0.15}Mg{sub 0.1}Cu{sub 0.3}Zn{sub 0.45}Fe{sub 2}O{sub 4} ferrite.

Synthesis and characterization of "1"3C_3-tristearin

International Nuclear Information System (INIS)

Wu Hangyu; Lin Lin; Li Lei; Chen Dazhou

2011-01-01

A highly efficient synthesis of "1"3C_3 labeled triglycerides of stearic acids from "1"3C_3-glycerol and stearic acids, by immobilized lipase-catalyzed in solvent-free medium was described. The structure of the product were characterized by fourier transform infrared spectrum (FT-IR), nuclear magnetic resonance (NMR), mass spectra (MS). The results showed that triglycerides of stearic acids contained three "1"3C atoms. The isotope abundance of "1"3C_3-tristearin was more than 99% and the yield was 80% of "1"3C_3-tristearin through calculation. Chemical purity (> 98%) was obtained by differential scanning calorimetry (DSC). (authors)

Serum and Urine Markers of Collagen Type VI Formation (Pro-C6) and Type III Degradation (C3M) Reflect Renal Function in Type 1 Diabetes

DEFF Research Database (Denmark)

Hansen, Tine Wilum; Guldager, Daniel Kring Rasmussen; Pilemann-Lyberg, Sascha

). We applied unadjusted and adjusted linear regression analyses.Adjustment included age, sex, LDL cholesterol, smoking, HbA1c, systolic blood pressure, UAER (in analyses of eGFR) and eGFR (in analyses of UAER). To adjust for urine output levels, the urinary markers were normalized for urinary...... (unadjusted: plost after adjustment (p=0.43). Higher serum levels of C3M were associated with lower e...

Overexpression of the polycystin-1 (PC-1) C-tail enhances sensitivity of M-1 cells to ouabain

Science.gov (United States)

Jansson, Kyle; Magenheimer, Brenda S.; Maser, Robin L.; Calvet, James P.; Blanco, Gustavo

2014-01-01

Cells derived from renal cysts of patients with autosomal dominant polycystic kidney disease (ADPKD) are abnormally sensitive to ouabain, responding to physiological ouabain concentrations with enhanced proliferation and increased forskolin-induced transepithelial fluid secretion. This requires activation of the epidermal growth factor receptor (EGFR), Src kinase, and the extracellular regulated kinases MEK and ERK. Here, we have determined if the ADPKD phenotype obtained in mouse cortical collecting duct cells by stable overexpression of the C-terminal domain of polycystin-1 (PC-1 C-tail) also elicits the ADPKD-like response to ouabain in the cells. M-1 C20 cells expressing the PC-1 C-tail, and M-1 C17 cells, lacking expression of this construct, were treated with physiological concentrations of ouabain, and cell proliferation, activation of the EGFR-Src-MEK-ERK pathway, forskolin-induced transepithelial Cl− secretion, and the sensitivity of the Na,K-ATPase to ouabain were explored. M-1 C20 cells responded to ouabain with increased cell proliferation and ERK phosphorylation. Ouabain also augmented forskolin-induced and cystic fibrosis transmembrane conductance regulator (CFTR)-mediated apical secretion of Cl− in M-1 C20 cells. These effects required activation of EGFR, Src and MEK. In contrast, ouabain had no significant effects on M-1 C17 cells. Interestingly, approximately 20 % of the Na,K-ATPase from M-1 C20 cells presented an abnormally increased sensitivity to ouabain. Overexpression of PC-1 C-tail in M-1 C20 cells is associated with a ouabain sensitive phenotype and an increased ability of the cells to proliferate and secrete anions upon ouabain stimulation. This phenotype mimics the ouabain sensitivity of ADPKD cells and may help promote their cystogenic potential. PMID:23784065

Hydrogen storage of Mg1−xMxH2 (M = Ti, V, Fe) studied using first-principles calculations

International Nuclear Information System (INIS)

Bhihi, M.; Lakhal, M.; Benyoussef, A.; El Kenz, A.; Labrim, H.; Mounkachi, O.; Hlil, E.K.

2012-01-01

In this work, the hydrogen storage properties of the Mg-based hydrides, i.e., Mg 1−x M x H 2 (M = Ti, V, Fe, 0 ≤ x ≤ 0.1), are studied using the Korringa—Kohn—Rostoker (KKR) calculation with the coherent potential approximation (CPA). In particular, the nature and concentrations of the alloying elements and their effects are studied. Moreover, the material's stability and hydrogen storage thermodynamic properties are discussed. In particular, we find that the stability and the temperature of desorption decrease without significantly affecting the storage capacities

Synthesis of 1-13C-1-indanone and 2-13C-1,2,3,4-tetrahydroquinoline

International Nuclear Information System (INIS)

Pickering, R.E.; Wysocki, M.A.; Eisenbraun, E.J.

1985-01-01

The synthesis of 2- 13 C-1,2,3,4-tetrahydroquinoline (5) via 1- 13 C-3-phenylpropanoic acid (1), 1- 13 C-1-indanone (2), 1- 13 C-1-indanone hydrazone (3) and 2- 13 C-3,4-dihydro-2(1H)-quinolinone (4) proceeded in 78, 96, 95, 79, and 85% individual yields respectively for 1, 2, 3, 4, 5 and 61% overall yield of the latter from 1. (author)

Some observations on the synthesis and electrolytic properties of (Ba1-xCax (M0.9Y0.1O3, M = Ce, Zr-based samples modified with calcium

Directory of Open Access Journals (Sweden)

Dudek Magdalena

2016-03-01

Full Text Available In this paper, the impact of partial substitution of calcium for barium in (Ba1-xCax (M0.9Y0.1 O3, M = Ce, Zr on physicochemical properties of the powders and sintered samples was investigated. The powders, with various contents of calcium (x = 0, 0.02, 0.05, 0.1, were prepared by means of thermal decomposition of organometallic precursors containing EDTA. All of the BaCeO3-based powders synthesised at 1100 °C were monophasic with a rhombohedral structure, however, completely cubic BaZrO3-based solid solutions were obtained at 1200 °C. A study of the sinterability of BaZr0.9Y0.1O3 and BaCe0.9Y0.1O3-based pellets was performed under non-isothermal conditions within a temperature range of 25 to 1200 °C. The partial substitution of barium for calcium in the (Ba1-xCax (M0.9Y0.1 O3, M = Ce, Zr solid solution improved the sinterability of the samples in comparison to the initial BaCe0.9Y0.1O3 or BaZr0.9Y0.1O3. The relative density of calcium-modified BaCe0.9Y0.1O3-based samples reached approximately 95 to 97 % after sintering at 1500 °C for 2 h in air. The same level of relative density was achieved after sintering calcium-modified BaZr0.9Y0.1O3 at 1600 °C for 2 h. Analysis of the electrical conductivity from both series of investigated materials showed that the highest ionic conductivity, in air and wet 5 % H2 in Ar, was attained for the compositions of x = 0.02 to 0.05 (Ba1-xCax(M0.9Y0.1O3, M = Zr, Ce. The oxygen reduction reaction on the interface Pt│BaM0.9Y0.1O3, M = Ce, Zr was investigated using Pt microelectrodes. Selected samples of (Ba1-xCax (M0.9Y0.1O3, M = Zr, Ce were tested as ceramic electrolytes in hydrogen-oxygen solid oxide fuel cells operating at temperatures of 700 to 850 °C.

Cascade Pumping of 1.9–3.3 μm Type-I Quantum Well GaSb-Based Diode Lasers

International Nuclear Information System (INIS)

Shterengas, Leon; Kipshidze, Gela; Hosoda, Takashi; Liang, Rui; Feng, Tao

2017-01-01

Cascade pumping of type-I quantum well gain sections was utilized to increase output power and efficiency of GaSb-based diode lasers operating in spectral region from 1.9 to 3.3 μm. Coated devices with ~100-μm-wide aperture and 3-mm-long cavity demonstrated continuous wave (CW) output power of 1.96 W near 2 μm, 980 mW near 3 μm, 500 mW near 3.18 μm, and 360 mW near 3.25 μm at room temperature. The corresponding narrow ridge lasers with nearly diffraction limited beams operate in CW regime with tens of mW of output power up to 60 °C. Two step shallow/deep narrow/wide ridge waveguide devices showed lower threshold currents and higher slope efficiencies compared to single step narrow ridge lasers. Laterally coupled DFB lasers mounted epi-up generated above 10 mW of tunable single frequency CW power at 20 °C near 3.22 μm.

Design and syntheses of hybrid metal–organic materials based on K{sub 3}[M(C{sub 2}O{sub 4}){sub 3}]·3H{sub 2}O [M(III)=Fe, Al, Cr] metallotectons

Energy Technology Data Exchange (ETDEWEB)

Sun, Yayong; Zong, Yingxia; Ma, Haoran; Zhang, Ao; Liu, Kang; Wang, Debao, E-mail: dbwang@qust.edu.cn; Wang, Wenqiang; Wang, Lei, E-mail: inorchemwl@126.com

2016-05-15

By using K{sub 3}[M(C{sub 2}O{sub 4}){sub 3}]·3H{sub 2}O [M(III)=Fe, Al, Cr] (C{sub 2}O{sub 4}{sup 2−}=oxalate) metallotectons as the starting material, we have synthesized eight novel complexes with formulas [{Fe(C_2O_4)_2(H_2O)_2}{sub 2}]·(H–L{sub 1}){sub 2}·H{sub 2}O 1, [Fe(C{sub 2}O{sub 4})Cl{sub 2}]·(H{sub 2}–L{sub 2}){sub 0.5}·(L{sub 2}){sub 0.5}·H{sub 2}O 2, [{Fe(C_2O_4)_1_._5Cl_2}{sub 2}]·(H–L{sub 3}){sub 4}3, [Fe{sub 2}(C{sub 2}O{sub 4})Cl{sub 8}]·(H{sub 2}–L{sub 4}){sub 2}·2H{sub 2}O 4, K[Al(C{sub 2}O{sub 4}){sub 3}]·(H{sub 2}–L{sub 5})·2H{sub 2}O 5, K[Al(C{sub 2}O{sub 4}){sub 3}]·(H–L{sub 6}){sub 2}·2H{sub 2}O 6, K[Cr(C{sub 2}O{sub 4}){sub 3}]·2H{sub 2}O 7, Na[Fe(C{sub 2}O{sub 4}){sub 3}]·(H–L{sub 6}){sub 2}·2H{sub 2}O 8 (with L{sub 1}=4-dimethylaminopyridine, L{sub 2}=2,3,5,6-tetramethylpyrazine, L{sub 3}=2-aminobenzimidazole, L{sub 4}=1,4-bis-(1H-imidazol-1-yl)benzene, L{sub 5}=1,4-bis((2-methylimidazol-1-yl)methyl)benzene, L{sub 6}=2-methylbenzimidazole). Their structures have been determined by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra and thermogravimetric analyses. Compound 3 is a 2D H-bonded supramolecular architecture. Others are 3D supramolecular structures. Compound 1 shows a [Fe(C{sub 2}O{sub 4}){sub 2}(H{sub 2}O){sub 2}]{sup −} unit and 3D antionic H-bonded framework. Compound 2 features a [Fe(C{sub 2}O{sub 4})Cl{sub 2}]{sup -} anion and 1D iron-oxalate-iron chain. Compound 3 features a [Fe{sub 2}(C{sub 2}O{sub 4}){sub 3}Cl{sub 4}]{sup 4−} unit. Compound 4 features distinct [Fe{sub 2}(C{sub 2}O{sub 4})Cl{sub 8}]{sup 4−} units, which are mutual linked by water molecules to generated a 2D H-bonded network. Compound 5 features infinite ladder-like chains constructed by [Al(C{sub 2}O{sub 4}){sub 3}]{sup 3−} units and K{sup +} cations. The 1D chains are further extended into 3D antionic H-bonded framework through O–H···O H-bonds. Compounds 6–8 show 2D [KAl(C{sub 2}O

Modelling of NSTX hot vertical displacement events using M 3 D -C 1

Science.gov (United States)

Pfefferlé, D.; Ferraro, N.; Jardin, S. C.; Krebs, I.; Bhattacharjee, A.

2018-05-01

The main results of an intense vertical displacement event (VDE) modelling activity using the implicit 3D extended MHD code M3D-C1 are presented. A pair of nonlinear 3D simulations are performed using realistic transport coefficients based on the reconstruction of a so-called NSTX frozen VDE where the feedback control was purposely switched off to trigger a vertical instability. The vertical drift phase is solved assuming axisymmetry until the plasma contacts the first wall, at which point the intricate evolution of the plasma, decaying to large extent in force-balance with induced halo/wall currents, is carefully resolved via 3D nonlinear simulations. The faster 2D nonlinear runs allow to assess the sensitivity of the simulations to parameter changes. In the limit of perfectly conducting wall, the expected linear relation between vertical growth rate and wall resistivity is recovered. For intermediate wall resistivities, the halo region contributes to slowing the plasma down, and the characteristic VDE time depends on the choice of halo temperature. The evolution of the current quench and the onset of 3D halo/eddy currents are diagnosed in detail. The 3D simulations highlight a rich structure of toroidal modes, penetrating inwards from edge to core and cascading from high-n to low-n mode numbers. The break-up of flux-surfaces results in a progressive stochastisation of field-lines precipitating the thermalisation of the plasma with the wall. The plasma current then decays rapidly, inducing large currents in the halo region and the wall. Analysis of normal currents flowing in and out of the divertor plate reveals rich time-varying patterns.

The research on the effect of MgCO{sub 3} on the grain refinement in AZ31 magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Gao, S.Y.; Cui, J.Z.; Li, Q.C.; Zhang, Z.Q. [Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang (China)

2010-08-15

The effect of MgCO{sub 3} addition on the as-cast microstructure of AZ31 magnesium alloy has been widely investigated. The results show that the average grain size of the {alpha}-Mg grain in AZ31 magnesium alloy decreases from about 570 {mu}m to 100 {mu}m by the addition of 0.6 wt.% MgCO{sub 3} as gain refiner at 760 C. Based on the analysis of EDS, theoretical calculation of E{sub bind} and Gibbs free energy, we esteem that grain refiner mechanism is mainly attributed to the generation of Al{sub 4}C{sub 3}, which can be serviced as nucleation site and restrain grain boundary from growing and transferring. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Neuropsychiatric safety with liraglutide 3.0 mg for weight management

DEFF Research Database (Denmark)

O'Neil, Patrick M; Aroda, V R; Astrup, Arne

2017-01-01

with liraglutide 3.0 mg were evaluated post hoc. METHODS: Data from the liraglutide weight-management programme were pooled. Across trials, individuals with a body mass index ≥30 kg/m(2) or ≥27 kg/m(2) with weight-related comorbidities were randomized to once-daily subcutaneous liraglutide 3.0 mg (n = 3384......) or placebo (n = 1941), both with a 500 kcal/day deficit diet plus exercise. Adverse events related to neuropsychiatric safety were collected in all trials. Additionally, in the phase 3a trials, validated mental-health questionnaires were prospectively and systematically administered. RESULTS: In the pooled...... analysis of 5325 randomized and exposed individuals, rates of depression (2.1 versus 2.1 events/100 person-years) and anxiety (1.9 versus 1.7 events/100 person-years) through adverse event reporting were similarly low in the liraglutide group and the placebo group. Nine (0.3%) individuals on liraglutide...

[Comparison of 1 mg/body and 3 mg/body of intravenous granisetron for the prevention of chemotherapy-induced nausea and vomiting and adverse events in hematological malignancy patients].

Science.gov (United States)

Motohashi, Shinya; Hori, Katsuhito; Ono, Takaaki; Ohnishi, Kazunori; Kawakami, Junichi

2012-01-01

Granisetron is a selective 5-hydroxy tryptamine3 receptor antagonist and widely used for chemotherapy-induced nausea and vomiting (CINV). Recommended dose of intravenous granisetron in the USA and Europe has been set at 0.01 mg/kg (1 mg/body) in the antiemetic treatment guidelines established by the American Society of Clinical Oncology and National Comprehension Cancer Network. In contrast, the approved dose in Japan is 0.04 mg/kg (3 mg/body). Randomized controlled trials (RCTs) which compared 1 mg/body with 3 mg/body of intravenous granisetron for CINV had been reported in Japan. In these RCTs, however, hematological malignancy patients were excluded. We performed observational retrospective study to compare 1 mg/body with 3 mg/body of intravenous granisetron for the prevention of CINV and adverse events in hematological malignancy patients. Number of the patients and chemotherapy courses were 15 and 30 in the 1 mg/body group, and 15 and 27 in the 3 mg/body group, respectively. No nausea rates in the 1 and 3 mg/body group were 83% and 89% of courses, respectively. No vomiting rates in the 1 and 3 mg/body group were 97% and 100% of courses, respectively. The incidences of constipation in the 1 and 3 mg/body group were 34% and 45% of courses, respectively. Anaphylaxis and headache did not occur in both groups. Our findings suggested that 1 mg/body of intravenous granisetron can prevent from CINV in hematological malignancy patients, as well as 3 mg/body.

Disposition and metabolism of aniline in Fischer 344 rats and C57BL/6 X C3H F1 mice

International Nuclear Information System (INIS)

McCarthy, D.J.; Waud, W.R.; Struck, R.F.; Hill, D.L.

1985-01-01

We examined the metabolism and disposition of aniline, which induces spleen hemangiosarcomas in rats but no tumors in mice, in normal and predosed Fischer 344 rats, and C57BL/6 X C3H F1 mice administered low (50 and 100 mg/kg, respectively) or high (250 and 500 mg/kg, respectively) doses. Of 11 tissues examined, the highest levels of binding of [ 14 C]aniline to DNA were in the kidney, large intestine, and spleen of high-dose rats that had received prior dosing; these tissues had covalent binding indices of 14.2, 4.3, and 3.7 mumol/mol nucleotides/dose, respectively. Protein and RNA were the major macromolecular targets for binding of radioactivity from [ 14 C]aniline. Relative to controls, most tissues from predosed mice (low dose and high dose) showed less binding to protein and RNA; but for most tissues from predosed rats administered 50-mg/kg doses of [ 14 C]aniline, there was more extensive binding. Also relative to controls, binding of radioactivity in the spleen of predosed rats given [ 14 C]aniline (50 mg/kg) was 148% greater for protein and 302% greater for RNA. For rats administered 250 mg of [ 14 C]aniline per kg, however, there were no outstanding differences in binding to RNA and protein between normal and predosed animals. The profiles of urinary metabolites produced by rats and mice were not appreciably different in animals predosed with aniline. For rats, however, the profiles were different for the low and high doses, suggesting that the main metabolic pathway was saturated at the higher dose. p-Acetamidophenyl sulfate represented over 70% of the total radioactivity recovered from the urine of rats dosed with 50 mg of aniline per kg but only 30% in the urine of those dosed with 250 mg/kg. The urine of the high-dose rats contained greater percentages of p-aminophenyl sulfate, p-acetamidophenyl glucuronide, and unconjugated metabolites

Thickness dependence of J_c (0) in MgB_2 films

International Nuclear Information System (INIS)

Chen, Yiling; Yang, Can; Jia, Chunyan; Feng, Qingrong; Gan, Zizhao

2016-01-01

Highlights: • A serial of MgB_2 superconducting films from 10 nm to 8 µm have been prepared. • T_c and J_c (5 K, 0 T) of films are high. • J_c (5 K, 0 T) reaches its maximum 2.3 × 10"8 A cm"−"2 for 100 nm films. • The relationship between thickness and J_c has been discussed in detail. - Abstract: MgB_2 superconducting films, whose thicknesses range from 10 nm to 8 µm, have been fabricated on SiC substrates by hybrid physical–chemical vapor deposition (HPCVD) method. It is the first time that the T_c and the J_c of MgB_2 films are studied on such a large scale. It is found that with the increasing of thickness, T_c elevates first and then keeps roughly stable except for some slight fluctuations, while J_c (5 K, 0 T) experiences a sharp increase followed by a relatively slow fall. The maximum J_c (5 K, 0 T) = 2.3 × 10"8 A cm"−"2 is obtained for 100 nm films, which is the experimental evidence for preparing high-quality MgB_2 films by HPCVD method. Thus, this work may provide guidance on choosing the suitable thickness for applications. Meanwhile, the films prepared by us cover ultrathin films, thin films and thick films, so the study on them will bring a comprehensive understanding of MgB_2 films.

Piezoelectric properties and temperature stability of Mn-doped Pb(Mg1/3Nb2/3)-PbZrO3-PbTiO3 textured ceramics

Science.gov (United States)

Yan, Yongke; Cho, Kyung-Hoon; Priya, Shashank

2012-03-01

In this letter, we report the electromechanical properties of textured 0.4Pb(Mg1/3Nb2/3)O3-0.25PbZrO3-0.35PbTiO3 (PMN-PZT) composition which has relatively high rhombohedral to tetragonal (R-T) transition temperature (TR-T of 160 °C) and Curie temperature (TC of 234 °C) and explore the effect of Mn-doping on this composition. It was found that MnO2-doped textured PMN-PZT ceramics with 5 vol. % BaTiO3 template (T-5BT) exhibited inferior temperature stability. The coupling factor (k31) of T-5BT ceramic started to degrade from 75 °C while the random counterpart showed a very stable tendency up to 180 °C. This degradation was associated with the "interface region" formed in the vicinity of BT template. MnO2 doped PMN-PZT ceramics textured with 3 vol. % BT and subsequently poled at 140 °C (T-3BT140) exhibited very stable and high k31 (>0.53) in a wide temperature range from room temperature to 130 °C through reduction in the interface region volume. Further, the T-3BT140 ceramic exhibited excellent hard and soft combinatory piezoelectric properties of d33 = 720 pC/N, k31 = 0.53, Qm = 403, tan δ = 0.3% which are very promising for high power and magnetoelectric applications.

Ab initio study of the structure and stability of carbonates, silicates, nitrates, phosphates, borates and aluminates L2AO3 and MAO3 (L=Li, Na; M=Be, Mg; A=C, Si, N+, P+, B-, Al-)

International Nuclear Information System (INIS)

Charkin, D.O.; Makku, M.L.; Charkin, O.P

1998-01-01

Nonempiric calculations of potential energy surfaces of molecules and ions of lithium and sodium oxosalts of the L 2 AO 3 type and beryllium and magnesium salts of the MAO 3 type with 24 valent electrons (L=Li, Na; M=Be, Mg; A=C, Si, N + , P + , B - , Al - ) are accomplished within the frames of the MP2/6-31G * +ZPE(HF/6-31G * ) and MP4SDTQ/6-31+G * //MP2/6-31G * +ZPE(MP2/6-31G * )approximations. Equilibriumgeometrical parameters and relative energy of isomers and energy of their decomposition, IR-frequencies and intensities of normal oscillations are determined; trends in their change in various series of molecules and ions are analyzed. Deformation and polarization of the AO 3 trigonal oxoanions under the effect of alkali and alkaline-earth cations, ortho-meta-isomerism in negative ions of the MBO 3 - borates and MACO 3 - aluminates, as well as effect of electron correlation on calculation results are determined. The results are compared with the data of previous calculations of isoelectron lithium and sodium salts LAO 3

Modelling M/G/1 queueing systems with server vacations using stochastic Petri nets

Directory of Open Access Journals (Sweden)

K Ramanath

2006-12-01

Full Text Available The theory of non-Markovian stochastic Petri nets is employed in this paper to derive an alternative method for studying the steady state behaviour of the M/G/1 vacation queueing system with a limited service discipline. Three types of vacation schemes are considered, and sytems with both a finite population and those with an infinite population (but finite capacity are considered. Simple numerical examples are also provided to illustrate the functionality of the methods and some useful performance measures for the system are obtained.

Strong piezoelectric anisotropy d15/d33 in ⟨111⟩ textured Pb(Mg1/3Nb2/3)O3-Pb(Zr,Ti)O3 ceramics

Science.gov (United States)

Yan, Yongke; Priya, Shashank

2015-08-01

The shear mode piezoelectric properties of Pb(Mg1/3Nb2/3)O3-Pb(Zr,Ti)O3 (PMN-PZT) ceramic with 72% ⟨111⟩ texture were investigated. The piezoelectric anisotropic factor d15/d33 was as high as 8.5 in ⟨111⟩ textured ceramic as compared to 2.0 in random counterpart. The high d15/d33 indicates the "rotator" ferroelectric characteristics of PMN-PZT system and suggests that the large shear piezoelectric response contributes towards the high longitudinal piezoelectric response (d33) in non-polar direction (d33 = 1100 pC/N in ⟨001⟩ textured ceramic vs. d33 = 112 pC/N in ⟨111⟩ textured ceramic).

Formation, stability and structural characterization of ternary MgUO{sub 2}(CO{sub 3}){sub 3}{sup 2-} and Mg{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) complexes

Energy Technology Data Exchange (ETDEWEB)

Lee, Jun-Yeop; Yun, Jong-Il [KAIST, Daejeon (Korea, Republic of). Dept. of Nuclear and Quantum Engineering; Vespa, Marika; Gaona, Xavier; Dardenne, Kathy; Rothe, Joerg; Rabung, Thomas; Altmaier, Marcus [Karlsruhe Institute of Technology, Karlsruhe (Germany). Inst. for Nuclear Waste Disposal

2017-06-01

The formation of ternary Mg-UO{sub 2}-CO{sub 3} complexes under weakly alkaline pH conditions was investigated by time-resolved laser fluorescence spectroscopy (TRLFS) and extended X-ray absorption fine structure (EXAFS) and compared to Ca-UO{sub 2}-CO{sub 3} complexes. The presence of two different Mg-UO{sub 2}-C{sub 3} complexes was identified by means of two distinct fluorescence lifetimes of 17±2 ns and 51±2 ns derived from the multi-exponential decay of the fluorescence signal. Slope analysis in terms of fluorescence intensity coupled with fluorescence intensity factor as a function of log [Mg(II)] was conducted for the identification of the Mg-UO{sub 2}-CO{sub 3} complexes forming. For the first time, the formation of both MgUO{sub 2}(CO{sub 3}){sub 3}{sup 2-} and Mg{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) species was confirmed and the corresponding equilibrium constants were determined as log β {sub 113}=25.8±0.3 and β {sub 213}=27.1±0.6, respectively. Complementarily, fundamental structural information for both Ca-UO{sub 2}-CO{sub 3} and Mg-UO{sub 2}-CO{sub 3} complexes was gained by extended EXAFS revealing very similar structures between these two species, except for the clearly shorter U-Mg distance (3.83 Aa) compared with U-Ca distance (4.15 Aa). These results confirmed the inner-sphere character of the Ca/Mg-UO{sub 2}-CO{sub 3} complexes. The formation constants determined for MgUO{sub 2}(CO{sub 3}){sub 3}{sup 2-} and Mg{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) species indicate that ternary Mg-UO{sub 2}-CO{sub 3} complexes contribute to the relevant uranium species in carbonate saturated solutions under neutral to weakly alkaline pH conditions in the presence of Mg(II) ions, which will induce notable influences on the U(VI) chemical species under seawater conditions.

Synthesis and photoluminescence of Eu3+ and Mn2+ doped double phosphates KMLa(PO4)2 (M = Zn, Mg)

International Nuclear Information System (INIS)

Pan Yuexiao; Zhang Qinyuan; Jiang Zhonghong

2006-01-01

Two compounds, KMgLa(PO 4 ) 2 and KZnLa(PO 4 ) 2 doped with Eu 3+ and Mn 2+ ions, have been synthesized by a conventional solid-state method at 850 deg. C. Structures of KMgLa(PO 4 ) 2 and KZnLa(PO 4 ) 2 have been investigated and confirmed by X-ray diffraction and photoluminescence spectra. The results indicate that the compounds have remained the monoclinic structure of LaPO 4 with space group of C s when (K + , Mg 2+ ) or (K + , Zn 2+ ) could substitute half of the La 3+ ions. Under an ultraviolet source, KMgLa(PO 4 ) 2 :Mn 2+ has shown a bright red phosphorescent color, while KZnLa(PO 4 ) 2 :Mn 2+ has shown an orange-red emission which is assigned to the electronic transition of 4 T 1 ( 4 G)- 6 A 1 ( 6 S) of Mn 2+ in strong crystal field

Effect of M{sub 3}C on the precipitation behavior of M{sub 23}C{sub 6} phase during early stage of tempering in T91 ferritic steel

Energy Technology Data Exchange (ETDEWEB)

Liu, Chenxi; Liu, Yongchang; Zhang, Dantian; Ning, Baoqun; Yan, Zesheng [School of Material Science and Engineering, Tianjin Key Laboratory of Advanced Jointing Technology, Tianjin University, Tianjin (China)

2011-12-15

Tempered martensitic structure is the service condition of T91 ferritic steel after adopting the austenitizing followed by tempering. Needle-like M{sub 3}C particles are precipitated during air cooling after austenization, while the precipitation of M{sub 3}C is suppressed during the water cooling. The effect of existence of M{sub 3}C on the precipitation behaviors of M{sub 23}C{sub 6} during the early stage of tempering, as nucleation site, number density and size distribution, was investigated by means of TEM observation. The TEM results indicate that, upon the same tempering time, the size of M{sub 23}C{sub 6} is smaller and its number density is higher in the sample pre-existing M{sub 3}C than in the sample without M{sub 3}C. This can be explained that existence of M{sub 3}C results in more M{sub 23}C{sub 6} precipitates forming inside of grain, where a relatively low self-diffusion coefficient of alloy element leads to M{sub 23}C{sub 6} hardly coarsening. However, with the prolongation of tempering time, this effect becomes weaken. Microhardness results indicate that the existence of M{sub 3}C phase results in the increase of hardness after tempering due to the precipitation of finer and denser M{sub 23}C{sub 6} particles. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Immunomodulatory effects of black cohosh (Actaea racemosa) extract in female B6C3F1/N mice

International Nuclear Information System (INIS)

Smith, Matthew J.; Germolec, Dori R.; Frawley, Rachel P.; White, Kimber L.

2013-01-01

Black cohosh extracts (BCE; Actaea racemosa) are being used worldwide as an alternative to hormone replacement therapy for the management of menstrual and menopausal symptoms, yet the effects of BCE on the immune system are largely unknown. Female B 6 C 3 F 1 /N mice were treated daily with BCE (0, 62.5, 125, 250, 500, or 1000 mg/kg) for 28 days by oral gavage. Liver weights were significantly increased (26–32%) at the 1000 mg/kg dose. Dose-related increases in mean corpuscular volume and mean corpuscular hemoglobin were observed. Decreasing trends were observed in all thymic T cell populations, with the most notable dose-responsive effects on immature thymocytes. In the spleen, dose-related decreases were observed in all cell phenotypes evaluated, reaching the level of statistical significance at the 1000 mg/kg BCE dose. Splenic natural killer (NK) cell numbers were significantly decreased at all BCE doses, with the exception of absolute NK numbers at the 125 mg/kg dose. No effects were observed on T-dependent antibody responses of the humoral immune system, including the antibody-forming cell response to sheep erythrocytes (sRBC) and IgM antibody levels to both sRBC and keyhole limpet hemocyanin. Cytotoxic T cell (T CTL ) activity was increased, as was the mixed leukocyte response in one of two studies. Anti-CD3 mediated proliferation and the delayed-type hypersensitivity response were unaffected. No effects were observed on innate immunity or on bone marrow cellularity and colony-forming units. Overall, BCE exposure in B 6 C 3 F 1 /N mice for 28 days at doses up to 1000 mg/kg had minimal immune effects, with the exception of an increased T CTL response

Anodic behavior of Mg in acidic AlCl3–1-ethyl-3-methyl-imidazolium chloride ionic liquid

International Nuclear Information System (INIS)

Xu, Bajin; Qu, Rui; Ling, Guoping

2014-01-01

Highlights: • A viscous layer formed at Mg/ionic liquid interface after the dissolution of Mg. • As direct evidence, photo of viscous layer at the interface was presented. • Viscous layer was resulted from accumulation of dissolved Mg(II) at interface. • Formation of viscous layer resulted in a homogenous etched Mg surface. • Dissolution model of Mg and formation mechanism of viscous layer was discussed. - Abstract: In this paper, anodic behavior of Mg in acidic AlCl 3 –1-ethyl-3-methyl-imidazolium chloride (AlCl 3 –EMIC) ionic liquid was investigated by conducting linear sweep voltammetry, chronoamperometry and chonopotentiometry. The viscosity of Mg dissolved ionic liquid and the surface morphologies of Mg were characterized using an Ostwald viscometer and a scanning electron microscopy, respectively. The results showed that the oxide film on the surface of Mg had great effects on the anodic behavior. The dissolution of Mg under anodic polarization occurred after the breakdown of oxide film. A viscous layer was observed forming at the interface of Mg/ionic liquid during the dissolution process. The formation of viscous layer was attributed to the accumulation of Mg dissolved AlCl 3 –EMIC ionic liquid at the interface, which was of high viscosity. With a viscous layer formed in the anodic process, the etched surface of Mg anode was homogeneous and flat without any etching pits. Otherwise, the Mg showed a morphology of pitting on the surface

Structural disorder and electronic hybridization in NicMg1-cO solid solutions probed by XANES at the oxygen K edge

International Nuclear Information System (INIS)

Chen Dongliang; Zhong Jun; Chu Wangsheng; Wu Ziyu; Kuzmin, Alexei; Mironova-Ulmane, Nina; Marcelli, Augusto

2007-01-01

A series of Ni c Mg 1-c O solid solutions has been studied for the first time looking at the structural disorder by means of x-ray absorption near-edge-structure (XANES) spectroscopy at the oxygen K edge. The experimental XANES signals were analysed within the full multiple scattering formalism and were interpreted taking into account clusters of up to 15 coordination shells around an absorbing oxygen atom. The substitution of nickel atoms by magnesium atoms results in a dramatic decrease of the empty density of states in the conduction band close to the Fermi level due to an exchange of the 3d(Ni)-2p(O) interaction with 3p(Mg)-2p(O). Besides, a simultaneous small decrease of the 3d(Ni)-2p(O) hybridization is also induced by the lattice expansion, determined by the difference in ionic radii between nickel and magnesium ions

New Ti3C2 aerogel as promising negative electrode materials for asymmetric supercapacitors

Science.gov (United States)

Li, Lu; Zhang, Mingyi; Zhang, Xitian; Zhang, Zhiguo

2017-10-01

Novel 3D Ti3C2 aerogel has been first synthesized by a simple EDA-assisted self-assembly process. Its inside are channels and pores structure. The interconnected aerogel structure could efficiently restrain restacking of Ti3C2 flakes. Thus, it exhibits a large specific surface area as high as 176.3 m2 g-1. The electrochemical performances have been measured. The Ti3C2 aerogel achieves a quite high areal capacitance of 1012.5 mF cm-2 for the mass loading of 15 mg at a scan rate of 2 mV s-1 in 1 M KOH electrolyte. An asymmetric supercapacitor (ASC) has been assembled by using the Ti3C2 aerogel electrode as the negative electrode and electrospinning carbon nanofiber film as the positive electrode. The device can deliver a high energy density of 120.0 μWh cm-2 and a maximum power density of 26123 μW cm-2. A lamp panel with nineteen red light-emitting diodes has been powered by two ASCs in series.

Synthesis, crystal growth and structure of Mg containing β-rhombohedral boron: MgB17.4

International Nuclear Information System (INIS)

Adasch, Volker; Hess, Kai-Uwe; Ludwig, Thilo; Vojteer, Natascha; Hillebrecht, Harald

2006-01-01

For the first time, single crystals of Mg containing β-rhombohedral boron MgB 17.4 were synthesised from the elements in a Mg/Cu melt at 1600deg. C. The crystal structure determined by the refinement of single crystal data (space group R-3m, a=10.991(2)A, c=24.161(4)A, 890 reflections, 123 variables, R 1 (F)=0.049, wR 2 (I)=0.122) improves and modifies the former structure model derived from earlier investigations on powder samples. Mg is located on four different positions with partial occupation. While the occupation of the sites D (53.3%), E (91%) and F (7.2%) is already known from other boron-rich borides related to β-rhombohedral boron, the occupation of the fourth position (18h, 6.7%) is observed for the first time. Two boron positions show partial occupation. The summation reveals the composition MgB 17.4 and Mg 5.85 B 101.9 , respectively, confirmed by WDX measurements. The single crystals of MgB 17.4 show the highest Mg content ever found. Preliminary measurements indicate no superconductivity

En route to the conductivity bottleneck in p-type CuCr1-xMxO2-ySy (M = Li, Mg)

Science.gov (United States)

Mandal, P.; Mazumder, N.; Akhtar, A. J.; Roy, R.; Chattopadhyay, K. K.

2017-05-01

We extend our material design concept [P. Mandal et al. J. Phys. D: Appl. Phys. 49, 275109, (2016); N. Mazumder et al. J. Phys. Chem. Lett. 4, 3539, (2013)] further aiming to overcome the conductivity bottleneck (1 Scm-1) in p-type transparent conducting oxide (TCO). In this work, we execute the strategy of simultaneous cationic-anionic hole doping in the prototype p-TCO CuCrO2. CuCr1-xMxO2-ySy (M = Li, Mg) is prepared by solid state heating at 1150 °C. Using Rietveld analysis, the presence of Mgcr•, Licr • and SO×areconfirmed and quantified. The diffuse reflectance (DR) spectra are acquired to determine the dominant optical gap (˜ 3.5 eV) and found to be affected little upon site selective hole doping. From temperature dependence (80 - 300 K) of DC conductivity (σdc), (Licr •+SO×)dopingcan be identified to be the more plausible alternative to reach the bottleneck threshold compared to (Mgcr •+SO×) albeit of smaller σdc at 300 K.

Flux pinning behaviors of Ti and C co-doped MgB2 superconductors

International Nuclear Information System (INIS)

Yang, Y.; Zhao, D.; Shen, T.M.; Li, G.; Zhang, Y.; Feng, Y.; Cheng, C.H.; Zhang, Y.P.; Zhao, Y.

2008-01-01

Flux pinning behavior of carbon and titanium concurrently doped MgB 2 alloys has been studied by ac susceptibility and dc magnetization measurements. It is found that critical current density and irreversibility field of MgB 2 have been significantly improved by doping C and Ti concurrently, sharply contrasted to the situation of C-only-doped or Ti-only-doped MgB 2 samples. AC susceptibility measurement reveals that the dependence of the pinning potential on the dc applied field of Mg 0.95 Ti 0.05 B 1.95 C 0.05 has been determined to be U(B dc )∝B dc -1 compared to that of MgB 2 U(B dc )∝B dc -1.5 . As to the U(J) behavior, a relationship of U(J) ∝ J -0.17 is found fitting well for Mg 0.95 Ti 0.05 B 1.95 C 0.05 with respect to U(J) ∝ J -0.21 for MgB 2 . All the results reveal a strong enhancement of the high field pinning potential in C and Ti co-doped MgB 2

Electrical transport in low-lead (1-x)BaTiO3–xPbMg1/3Nb2/3O3 ceramics

Institute of Scientific and Technical Information of China (English)

J. SUCHANICZ; K. KONIECZNY; K. ŚWIERCZEK; M. LIPIŃSKI; M. KARPIERZ; D. SITKO; H. CZTERNASTEK; K. KLUCZEWSKA

2017-01-01

Low-lead (1-x)BaTiO3–xPbMg1/3Nb2/3O3 ceramics (x = 0, 0.025, 0.05, 0.075, 0.1, and 0.15) were prepared by the conventional oxide mixed sintering process, and their optical band gap, Seebeck coefficient, ac ( σac ) and dc ( σdc ) conductivities as a function of temperature were investigated for the first time. It was found that all samples have p-type conductivity. The low-frequency (20 Hz–2 MHz) ac conductivity obeys a power law σac ~ ωs , which is characteristic for disordered materials. The frequency exponent s is a decreasing function of temperature and tends to zero at high temperature. σac is proportional to ω0.07 – ω0.31 in the low-frequency region and to ω0.51 – ω0.98 in the high-temperature region. The temperature dependence of the dc conductivity showed a change in slope around the temperature at which the phase transition appeared. Both ac and dc conductivities showed a thermally activated character and possessed linear parts with different activation energies and some irregular changes. It was found that the hopping charge carriers dominate at low temperature and small polarons and oxygen vacancies dominate at higher temperature. (1-x)BaTiO3–xPbMg1/3Nb2/3O3 ceramics are expected to be promising new candidate for low-lead electronic materials.

Effects of carbon concentration and filament number on advanced internal Mg infiltration-processed MgB2 strands

International Nuclear Information System (INIS)

Li, G Z; Sumption, M D; Zwayer, J B; Susner, M A; Collings, E W; Rindfleisch, M A; Thong, C J; Tomsic, M J

2013-01-01

In this paper we show that an advanced internal Mg infiltration method (AIMI) is effective in producing superconducting wires containing dense MgB 2 layers with high critical current densities. The in-field critical current densities of a series of AIMI-fabricated MgB 2 strands were investigated in terms of C doping levels, heat treatment (HT) time and filament numbers. The highest layer J c for our monofilamentary AIMI strands was 1.5 × 10 5 A cm −2 at 10 T, 4.2 K, when the C concentration was 3 mol% and the strand was heat-treated at 675 ° C for 4 h. Transport critical currents were also measured at 4.2 K on short samples and 1 m segments of 18-filament C doped AIMI strands. The layer J c s reached 4.3 × 10 5 A cm −2 at 5 T and 7.1 × 10 4 A cm −2 at 10 T, twice as high as those of the best powder-in-tube strands. The analysis of these results indicates that the AIMI strands, possessing both high layer J c s and engineering J e s after further optimization, have strong potential for commercial applications. (paper)

Wetting of B4C, TiC and graphite substrates by molten Mg

International Nuclear Information System (INIS)

Zhang Dan; Shen Ping; Shi Laixin; Jiang Qichuan

2011-01-01

Highlights: → The wettability of TiC, B4C and C by molten Mg was determined using an improved sessile drop method. → A new method to evaluate the wetting behavior coupled with evaporation and reaction was proposed. → The bonding characteristics in the Mg/B4C, Mg/TiC and Mg/graphite systems were evaluated. - Abstract: The isotherm wetting of B 4 C, TiC and graphite substrates by molten Mg was studied in a flowing Ar atmosphere at 973-1173 K using an improved sessile drop method. The initial contact angles are in the ranges of 95-87 deg., 74-60 deg. and 142-124 deg., respectively, moderately depending on the temperature. All the systems are non-reactive in nature; however, the presence of impurity of free boron at the B 4 C surface gave rise to the chemical reaction with molten Mg and thus promoted the wettability to a certain degree. A new method was proposed to evaluate the wetting behavior coupled with evaporation and chemical reaction. Furthermore, based on the comparison of the work of adhesion and cohesion, the bonding in the Mg/B 4 C and Mg/TiC systems is presumably mainly chemical while that in the Mg/graphite system is physical.

Ethylbenzene dehydrogenation over Mg3Fe0.5−xCoxAl0.5 catalysts derived from hydrotalcites: Comparison with Mg3Fe0.5−yNiyAl0.5 catalysts

KAUST Repository

Atanda, Luqman A.

2011-04-01

A series of Mg3Fe0.5-xCoxAl0.5 (x = 0-0.5) catalysts were prepared from hydrotalcite precursors and their activities in the dehydrogenation of ethylbenzene were compared with those of a series of Mg3Fe0.5-yNiyAl0.5 (y = 0-0.5) catalysts also derived from hydrotalcite. The hydrotalcites prepared by co-precipitation were calcined at 550 °C to the mixed oxides with a high surface area of 150-240m2gcat-1; they were composed of Mg(Fe,Me,Al)O periclase and Mg(Me)(Fe,Al)2O4 spinel (Me = Co or Ni). Bimetallic Fe3+-Co2+ system showed a synergy, i.e., an increase in the activity, whereas Fe3+-Ni2+ bimetallic system showed no synergy. The high styrene yield was obtained on Mg 3Fe0.1Co0.4Al0.5; however, a large substitution of Fe3+ with Co2+ caused a decrease in styrene selectivity along with coking on the catalysts, due to an isolation of CoOx on the catalyst surface. The highest yield as well as the highest selectivity for styrene production was obtained at x = 0.25 at time on stream of 30 min. The coprecipitation at pH = 10.0 and the composition of Mg3Fe0.25Co0.25Al0.5 were the best for preparing the active catalyst. This is partly due to the formation of a good hydrotalcite structure. On this catalyst, the active Fe3+ species was reduced at a low temperature by the Fe3+-Co2+ bimetal formation, leading to a high activity. Simultaneously, the amount of reducible Fe3+ was the smallest, resulting in a high stability of the active Fe3+ species. It is likely that the dehydrogenation was catalyzed by the reduction-oxidation between Fe3+ and Fe2+ and that Co2+ assisted the reduction-oxidation by forming Fe 3+-Co2+ (1/1) bimetallic active species. © 2011 Elsevier B.V. All rights reserved.

17 CFR 270.3c-1 - Definition of beneficial ownership for certain 3(c)(1) funds.

Science.gov (United States)

2010-04-01

... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Definition of beneficial... AND EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.3c-1 Definition of beneficial ownership for certain 3(c)(1) funds. (a) As used in this section: (1) The term...

Effect of annealing on luminescence of Eu{sup 3+}- and Sm{sup 3+}-doped Mg{sub 2}TiO{sub 4} nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Medić, Mina; Antić, Željka; Đorđević, Vesna [University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia); Ahrenkiel, Phillip S. [South Dakota School of Mines & Technology, Rapid City, SD (United States); Marinović-Cincović, Milena [University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia); Dramićanin, Miroslav D., E-mail: dramican@vinca.rs [University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia)

2016-02-15

This work explores the influence of annealing temperature on the structure and luminescence of 2 at% Eu{sup 3+} and 1 at% Sm{sup 3+}-doped Mg{sub 2}TiO{sub 4} nanopowders produced via Pechini-type polymerized complex route. Mg{sub 2}TiO{sub 4} samples were annealed at 7 different temperatures (400 °C, 450 °C, 500 °C, 550 °C, 600 °C, 650 °C and 700 °C) to determine the temperature range in which cubic inverse spinel structure is stable and to follow the changes of material luminescence properties. X-ray diffraction revealed that crystallization of both Eu{sup 3+} and Sm{sup 3+}-doped Mg{sub 2}TiO{sub 4} nanopowders starts at 400 °C, and that Sm{sup 3+} doped Mg{sub 2}TiO{sub 4} starts to decompose at 650 °C, while Eu{sup 3+} doped Mg{sub 2}TiO{sub 4} starts to decompose at 700 °C. Samples annealed at higher temperatures show higher crystallinity and larger crystallite size. Mg{sub 2}TiO{sub 4} powder annealed at 600 °C is composed of ~5 nm size nanoparticles agglomerated in micron-size and dense chunks. The emission spectra of nanoparticles are composed of emissions from defects in Mg{sub 2}TiO{sub 4} host and characteristic emissions of Eu{sup 3+} ({sup 5}D{sub 0}→{sup 7}F{sub J}) and Sm{sup 3+} ({sup 4}G{sub 5/2}→{sup 6}H{sub J}) ions. The stronger emission and longer emission decays are observed with samples annealed at high temperatures. In the case of the Eu{sup 3+} ions emission intensity increased one order of magnitude between samples annealed at 400 °C and 650 °C. - Highlights: • Mg{sub 2}TiO{sub 4} nanoparticles of 5–10 nm in size are prepared by polymerized complex route. • Emission spectra and decays of Eu{sup 3+} and Sm{sup 3+} doped Mg{sub 2}TiO{sub 4} nanoparticles are shown. • Eu{sup 3+}(Sm{sup 3+}) doped Mg{sub 2}TiO{sub 4} can be annealed at temperatures <700 °C (650 °C). • Emission intensity of nanoparticles increases with increase of annealing temperature.

Electrical activation of nitrogen heavily implanted 3C-SiC(1 0 0)

Energy Technology Data Exchange (ETDEWEB)

Li, Fan, E-mail: f.li.1@warwick.ac.uk [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom); Sharma, Yogesh; Shah, Vishal; Jennings, Mike [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom); Pérez-Tomás, Amador [ICN2 – Institut Catala de Nanociència i Nanotecnologia, Campus UAB, 08193 Bellaterra, Barcelona (Spain); Myronov, Maksym [Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom); Fisher, Craig [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom); Leadley, David [Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom); Mawby, Phil [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom)

2015-10-30

Highlights: • Nitrogen is fully activated by 1175 °C annealing for 1.5 × 10{sup 19} cm{sup −3} doped 3C-SiC. • Free donor concentration is found to readily saturate in 3C-SiC at ∼7 × 10{sup 19} cm{sup −3}. • 3C-SiC is found to have complete donor thermal ionization above 150 K. • Donor in 1.5 × 10{sup 19} cm{sup −3} nitrogen implanted 3C-SiC has an energy level ∼15 meV. • The SiO{sub 2} cap is found to have a bigger influence on low and medium doped samples. - Abstract: A degenerated wide bandgap semiconductor is a rare system. In general, implant levels lie deeper in the band-gap and carrier freeze-out usually takes place at room temperature. Nevertheless, we have observed that heavily doped n-type degenerated 3C-SiC films are achieved by nitrogen implantation level of ∼6 × 10{sup 20} cm{sup −3} at 20 K. According to temperature dependent Hall measurements, nitrogen activation rates decrease with the doping level from almost 100% (1.5 × 10{sup 19} cm{sup −3}, donor level 15 meV) to ∼12% for 6 × 10{sup 20} cm{sup −3}. Free donors are found to saturate in 3C-SiC at ∼7 × 10{sup 19} cm{sup −3}. The implanted film electrical performances are characterized as a function of the dopant doses and post implantation annealing (PIA) conditions by fabricating Van der Pauw structures. A deposited SiO{sub 2} layer was used as the surface capping layer during the PIA process to study its effect on the resultant film properties. From the device design point of view, the lowest sheet resistivity (∼1.4 mΩ cm) has been observed for medium doped (4 × 10{sup 19} cm{sup −3}) sample with PIA 1375 °C 2 h without a SiO{sub 2} cap.

Excitation functions of inelastic and transfer channels in {sup 12} C+{sup 12} C around E{sub c.m.} = 32.5 MeV

Energy Technology Data Exchange (ETDEWEB)

Szilner, S.; Basrak, Z.; Freeman, R.M.; Haas, F.; Beck, C. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires]|[Strasbourg-1 Univ., 67 (France); Morsad, A. [Universite Hassan II, Casablanca (Morocco). Faculte des Sciences

1996-12-31

A prominent and wide resonance centered at E{sub c.m.} = 32.5 MeV has recently been found in the (0{sub 2}{sup +}, 0{sub 2}{sup +}) inelastic channel of the {sup 12}C+{sup 12}C reaction. It has been suggested that it corresponds to a 6{alpha}-particle-chain state in {sup 24}Mg. In the present work we study {sup 12}C+{sup 12}C excitation functions between center-of-mass energies of 30 and 35 MeV in steps of 250 keV for weakly populated outgoing channels. We present the inelastic channels to the states above the {alpha}-particle decay threshold, (0{sub 1}{sup +},0{sub 2}{sup +}), (0{sub 1}{sup +},3{sub 1}{sup -}), and (0{sub 1}{sup +},4{sub 1}{sup 4}), and the one- and two-nucleon transfer channels. In the inelastic and the transfer channels we observe correlated intermediate-width structures at E{sub c.m.} = 31, 32.5, and 33.5 MeV, whose widths are appreciably smaller than the width measured in the (0{sub 2}{sup +},0{sub 2}{sup +}) channel. Our E{sub c.m.} = 31, 32.5, and 33.5 MeV, whose widths are appreciably smaller than the width measured in the (0{sub 2}{sup +},0{sub 2}{sup +}) channel. Our E{sub c.m.} = 32.5 MeV angular distribution of the (0{sub 1}{sup +},0{sub 2}{sup +})channel exhibits oscillatory behavior and, unlike that of the (0{sup +}{sub 2}, 0{sup +}{sub 2}) channel, does not display enhancement around {Theta}{sub c.m.} = 90 deg. Data were collected via the kinematic coincidence technique. For data reduction we use a novel approach allowing for the extraction of results on non-binary channels. (authors). 39 refs.

Long-term Stability of Esomeprazole in 5% Dextrose Infusion Polyolefin Bags at 5 degrees C +/- 3 degrees C after Microwave Freeze-thaw Treatment.

Science.gov (United States)

Hecq, Jean-daniel; Rolin, Catherine; Godet, Marie; Gillet, Patricia; Jamart, Jacques; Galanti, Laurence M

2015-01-01

To improve quality assurance, security, time management, and cost saving of drug delivery, preparation in advance of intravenous solutions has been developed for several infusion solutions. The objective of this study was to investigate the stability of esomeprazole 0.4 mg/mL and 0.8 mg/mL in 5% dextrose polyolefin bags after freezing, long-term storage, and microwave thawing. The stability of five polyolefin bags containing approximately 0.4 mg/mL of esomeprazole and five other bags containing approximately 0.8 mg/mL in 5% dextrose prepared under aseptic conditions was studied after freezing for 1 month at -20 degrees C, thawing in a microwave oven with a validated cycle, and stored at 5 degrees C +/- 3 degrees C. Esomeprazole concentration was measured by high-pressure liquid chromatography using a reversed-phase column C8, a mobile phase consisting of 35% of acetonitrile and 65% of Na2HPO4 buffer at pH 7.59 with HPO4 (2 M) and NaOH (0.5 M), and detection with a diode array detector at 280 nm. Visual, microscopic, and spectrophotometric observation and pH measurements were also performed. No precipitation occurred in the preparations but little change of color was observed. No microaggregate was observed with optical microscopy or revealed by a change of absorbance at 350, 410, and 550 nm. Based on a shelf life of 90% residual potency, esomeprazole solutions (0.4 and 0.8 mg/mL) were stable for at least 20 or 29 days, respectively, after a freezing and microwave thawing period, where 95% one-side lower confidence limit of the concentration-time profile remained superior to 90% of the initial concentration. During this period, the pH values of drug solutions have been observed to decrease without affecting chromatographic parameters. Within these limits, esomeprazole (0.4 and 0.8 mg/mL) in 5% dextrose infusions may be prepared and frozen in advance by a centralized intravenous admixture service, thawed, and stored at least 20 days at 5 degrees C +/- 3 degrees C

Analysis of Two in Planta Expressed LysM Effector Homologs from the Fungus Mycosphaerella graminicola Reveals Novel Functional Properties and Varying Contributions to Virulence on Wheat1[W][OA

Science.gov (United States)

Marshall, Rosalind; Kombrink, Anja; Motteram, Juliet; Loza-Reyes, Elisa; Lucas, John; Hammond-Kosack, Kim E.; Thomma, Bart P.H.J.; Rudd, Jason J.

2011-01-01

Secreted effector proteins enable plant pathogenic fungi to manipulate host defenses for successful infection. Mycosphaerella graminicola causes Septoria tritici blotch disease of wheat (Triticum aestivum) leaves. Leaf infection involves a long (approximately 7 d) period of symptomless intercellular colonization prior to the appearance of necrotic disease lesions. Therefore, M. graminicola is considered as a hemibiotrophic (or necrotrophic) pathogen. Here, we describe the molecular and functional characterization of M. graminicola homologs of Ecp6 (for extracellular protein 6), the Lysin (LysM) domain-containing effector from the biotrophic tomato (Solanum lycopersicum) leaf mold fungus Cladosporium fulvum, which interferes with chitin-triggered immunity in plants. Three LysM effector homologs are present in the M. graminicola genome, referred to as Mg3LysM, Mg1LysM, and MgxLysM. Mg3LysM and Mg1LysM genes were strongly transcriptionally up-regulated specifically during symptomless leaf infection. Both proteins bind chitin; however, only Mg3LysM blocked the elicitation of chitin-induced plant defenses. In contrast to C. fulvum Ecp6, both Mg1LysM and Mg3LysM also protected fungal hyphae against plant-derived hydrolytic enzymes, and both genes show significantly more nucleotide polymorphism giving rise to nonsynonymous amino acid changes. While Mg1LysM deletion mutant strains of M. graminicola were fully pathogenic toward wheat leaves, Mg3LysM mutant strains were severely impaired in leaf colonization, did not trigger lesion formation, and were unable to undergo asexual sporulation. This virulence defect correlated with more rapid and pronounced expression of wheat defense genes during the symptomless phase of leaf colonization. These data highlight different functions for MgLysM effector homologs during plant infection, including novel activities that distinguish these proteins from C. fulvum Ecp6. PMID:21467214

Identification and characterization of luekotriene C4 and D4 receptors on a cultured smooth muscle cell line, BC3H-1

International Nuclear Information System (INIS)

Tamura, N.; Agrawal, D.K.; Townley, R.G.

1987-01-01

The authors studied the characteristics of the leukotriene (LT) C 4 and D 4 receptors on a cultured smooth muscle cell line, BC3H-1. Specific [ 3 H]LTC 4 binding to the cell membrane was greater than 80% of total binding and saturable at a density of 3.96 +/- 0.39 pmol/mg protein, with an apparent dissociation constant(Kd) of 14.3 +/- 2.0 nM (n=9). The association and dissociation of [ 3 H]LTC 4 binding were rapid and apparent equilibrium conditions were established within 5 min. Calculated Kd value of [ 3 H]LTC binding from the kinetic analysis was 9.9 nM. From the competition analysis, calculated Ki value of unlabeled LTC 4 to compete for the specific binding of [ 3 H]LTC 4 was 9.2 nM and was in good agreement with the Kd value obtained from the Scatchard plots or kinetic analysis. The maximum number of binding sites (Bmax) of [ 3 H]LTD 4 in the membrane of BC3H-1 cell line was about 11 times lower than that of the [ 3 H]LTC 4 . The calculated values of Kd and Bmax of [ 3 H]LTD 4 binding were 9.3 +/- 0.8 nM and 0.37 +/- 0.04 pmol/mg proteins, respectively (n=3). These findings demonstrate that BC3H-1 cell line possess both LTC 4 and LTD 4 receptors with a predominance of LTC 4 receptors. Thus, BC3H-1 cell line is a good model to study the regulation of LTC 4 and LTD 4 receptors. 34 references, 5 figures, 1 table

Electron paramagnetic resonance study of neutral Mg acceptors in β-Ga2O3 crystals

Science.gov (United States)

Kananen, B. E.; Halliburton, L. E.; Scherrer, E. M.; Stevens, K. T.; Foundos, G. K.; Chang, K. B.; Giles, N. C.

2017-08-01

Electron paramagnetic resonance (EPR) is used to directly observe and characterize neutral Mg acceptors ( M gGa0 ) in a β-Ga2O3 crystal. These acceptors, best considered as small polarons, are produced when the Mg-doped crystal is irradiated at or near 77 K with x rays. During the irradiation, neutral acceptors are formed when holes are trapped at singly ionized Mg acceptors ( M gGa- ). Unintentionally present Fe3+ (3d5) and Cr3+ (3d3) transition-metal ions serve as the corresponding electron traps. The hole is localized in a nonbonding p orbital on a threefold-coordinated oxygen ion adjacent to an Mg ion at a sixfold-coordinated Ga site. These M gGa0 acceptors (S = 1/2) have a slightly anisotropic g matrix (principal values are 2.0038, 2.0153, and 2.0371). There is also partially resolved 69Ga and 71Ga hyperfine structure resulting from unequal interactions with the two Ga ions adjacent to the hole. With the magnetic field along the a direction, hyperfine parameters are 2.61 and 1.18 mT for the 69Ga nuclei at the two inequivalent neighboring Ga sites. The M gGa0 acceptors thermally convert back to their nonparamagnetic M gGa- charge state when the temperature of the crystal is raised above approximately 250 K.

Single-Crystal X-Ray Diffraction Studies of Homologues in the Series nBa(Nb,Zr)O 3+3 mNbO with n=2, 3, 4, 5 and m=1

Science.gov (United States)

Nilsson, G.; Svensson, G.

2001-01-01

Single crystals of four homologues in the series nBa(Nb,Zr)O3+3mNbO, with n:m=2:1, 3:1, 4:1, and 5:1, were found in the reduced Ba-Nb-Zr-O system. Single-crystal X-ray diffraction data were collected for all the crystals. For all homologues the space group was found to be P4/mmm. The structures can be described as intergrowths of Ba(Nb,Zr)O3 perovskite and NbO slabs. The refined cell parameters and compositions of the 2:1, 3:1, and 4:1 homologues are a=4.1768(5) Å and c=12.269(2) Å for Ba2Nb4.5(1)Zr0.5(1)O9, a=4.1769(5) Å and c=16.493(3) Å for Ba3+δNb4.8(2)-δ Zr1.2(2)O12-δ (δ=0.098(4)), and a=4.1747(6) Å and c= 20.619(4) Å for Ba4+δNb5.1(4)-δZr1.9(4)O15-δ (δ=0.270(9)). The refined cell parameters of the 5:1 homologue are a=4.1727(3) Å and c=24.804(3) Å. Zr replaces Nb only in the NbO6 octahedra found in the perovskite slabs.

Development of doxorubicin-induced chronic cardiotoxicity in the B6C3F{sub 1} mouse model

Energy Technology Data Exchange (ETDEWEB)

Desai, Varsha G., E-mail: varsha.desai@fda.hhs.gov [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Herman, Eugene H. [Division of Drug Safety Research, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993 (United States); Moland, Carrie L.; Branham, William S. [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Lewis, Sherry M. [Office of Scientific Coordination, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Davis, Kelly J. [Toxicologic Pathology Associates, National Center for Toxicological Research, Jefferson, AR 72079 (United States); George, Nysia I. [Division Bioinformatics and Biostatistics, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Lee, Taewon [Department of Information and Mathematics, Korea University, Jochiwon, Chungnam 339-700 (Korea, Republic of); Kerr, Susan [Arkansas Heart Hospital, Little Rock, AR 72211 (United States); Fuscoe, James C. [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States)

2013-01-01

Serum levels of cardiac troponins serve as biomarkers of myocardial injury. However, troponins are released into the serum only after damage to cardiac tissue has occurred. Here, we report development of a mouse model of doxorubicin (DOX)-induced chronic cardiotoxicity to aid in the identification of predictive biomarkers of early events of cardiac tissue injury. Male B6C3F{sub 1} mice were administered intravenous DOX at 3 mg/kg body weight, or an equivalent volume of saline, once a week for 4, 6, 8, 10, 12, and 14 weeks, resulting in cumulative DOX doses of 12, 18, 24, 30, 36, and 42 mg/kg, respectively. Mice were sacrificed a week following the last dose. A significant reduction in body weight gain was observed in mice following exposure to a weekly DOX dose for 1 week and longer compared to saline-treated controls. DOX treatment also resulted in declines in red blood cell count, hemoglobin level, and hematocrit compared to saline-treated controls after the 2nd weekly dose until the 8th and 9th doses, followed by a modest recovery. All DOX-treated mice had significant elevations in cardiac troponin T concentrations in plasma compared to saline-treated controls, indicating cardiac tissue injury. Also, a dose-related increase in the severity of cardiac lesions was seen in mice exposed to 24 mg/kg DOX and higher cumulative doses. Mice treated with cumulative DOX doses of 30 mg/kg and higher showed a significant decline in heart rate, suggesting drug-induced cardiac dysfunction. Altogether, these findings demonstrate the development of DOX-induced chronic cardiotoxicity in B6C3F{sub 1} mice. -- Highlights: ► 24 mg/kg was a cumulative cardiotoxic dose of doxorubicin in male B6C3F{sub 1} mice. ► Doxorubicin-induced hematological toxicity was in association with splenomegaly. ► Doxorubicin induced severe testicular toxicity in B6C3F{sub 1} male mice.

Refractive Indices in Undoped and MgO-Doped Near-Stoichiometric LiTaO3 Crystals

Science.gov (United States)

Nakamura, Masaru; Higuchi, Shinji; Takekawa, Shunji; Terabe, Kazuya; Furukawa, Yasunori; Kitamura, Kenji

2002-04-01

Undoped and MgO (0.5 and 1.0-mol%)-doped near-stoichiometric LiTaO3 (SLT) crystals were grown from off-congruent Li-rich solutions (Li˜ 60 mol%) by the double-crucible Czochralski method using a continuous SLT ceramic grain charging system. Curie temperatures of the undoped and MgO (0.5 and 1.0-mol%)-doped SLT crystals are 688, 694 and 695°C, respectively. The ordinary and extraordinary refractive indices (no, ne) of these crystals were measured by the prism coupling technique in the wavelength range from 0.440 to 1.050 μm at room temperature, and the temperature-independent Sellmeier equations for each crystal were derived from the measured refractive index data. no of the SLT crystal was almost the same as that of a congruent-melt LiTaO3 (CLT) crystal, while ne of the SLT crystal was lower than that of the CLT crystal. ne was lower than no for the SLT crystal, similar to as in the case of the LiNbO3 crystal. The refractive indices of the SLT crystal, no and ne, were found to be almost independent of MgO concentration at the doping level of 0.5 and 1.0 mol%.

Peculiar temperature aging effects on the piezoelectric constant of Pb(Mg1sol3Nb2sol3)O3-PbTiO3 single crystal near the morphotropic phase boundary

International Nuclear Information System (INIS)

Xu Guisheng; Wang Xiaofeng; Yang Danfeng; Duan Ziqing; Feng Chude; Chen Kai

2005-01-01

After temperature aging, peculiar changes of the piezoelectric response of 0.67 Pb(Mg 1sol3 Nb 2sol3 )O 3- 0.33 PbTiO 3 crystals appeared. The piezoelectric constant d 33 of the (001)-cut crystals with T RT ∼35 deg. C abruptly rose more than 1000 pC/N in some regions after heat treatment at 65 deg. C for 12 h. For the (001)-cut crystals with T RT ∼74 deg. C, in spite of a fall of 40-100 pC/N after heat treatment at 65 deg. C for 12 h, the values of d 33 rose 50-100 pC/N unexpectedly after the subsequent heat treatment at 85 deg. C for 4 h. The structure adjustment caused by the internal stress relaxation during heat treatment at T>T RT accounted for the enhancement of d 33

Volatility study of [C1C1im][NTf2] and [C2C3im][NTf2] ionic liquids

International Nuclear Information System (INIS)

Rocha, Marisa A.A.; Ribeiro, Filipe M.S.; Schröder, Bernd; Coutinho, João A.P.; Santos, Luís M.N.B.F.

2014-01-01

Highlights: • Vapor pressures of [C 1 C 1 im][NTf 2 ] and [C 2 C 3 im][NTf 2 ] ionic liquids are reported. • [C 1 C 1 im][NTf 2 ] presents higher enthalpy and entropy of vaporization than expected. • The high volatility of [C 2 C 3 im][NTf 2 ] is a result from its asymmetric character. -- Abstract: Vapor pressures of 1,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, ([C 1 C 1 im][NTf 2 ]) and 1-ethyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, ([C 2 C 3 im][NTf 2 ]) ionic liquids were measured as a function of temperature using a Knudsen effusion apparatus combined with a quartz crystal microbalance. Enthalpies and entropies of vaporization were derived from the fitting of vapor pressure and temperature results to the Clarke and Glew equation. [C 1 C 1 im][NTf 2 ] presents a higher enthalpy and entropy of vaporization than the neighboring members of the series. The enthalpy of vaporization of [C 2 C 3 im][NTf 2 ] lies in between the asymmetric and symmetric ionic liquid series, reflecting a decrease in the electrostatic interactions due to a decrease of the charge accessibility between the ionic pairs when the methyl group is replaced by an ethyl group. The obtained higher volatility of [C 2 C 3 im][NTf 2 ] arises from its asymmetric character, leading to an higher entropic contribution that compensates the enthalpic penalty. The border conditions ([C 1 C 1 im][NTf 2 ], [C 2 C 1 im][NTf 2 ] and [C 2 C 2 im][NTf 2 ]), topology ([C 2 C 3 im][NTf 2 ]) and symmetry/asymmetry of the ILs effect were evaluated and rationalized based on a comparative analysis of the thermodynamic properties, enthalpies and entropies of vaporization