Toxicity, tissue distribution and excretion of 46ScCl3 and 46Sc-EDTA in mice

International Nuclear Information System (INIS)

Lachine, E.E.; Noujaim, A.A.; Ediss, C.; Wiebe, L.I.

1976-01-01

The acute toxicity, differential distribution in tissue, and elimination of ScCl 3 , 46 ScCl 3 , Sc-EDTA and 46 Sc-EDTA, in mice, has been investigated. The LD 50 sup(24hr) doses for ScCl 3 were 440 and 24 mg kg -1 respectively after intraperitioneal and intravenous injection, and 720 and 108 mg kg -1 respectively for Sc-EDTA. 46 ScCl 3 was extensively deposited in the liver and the spleen. 46 Sc-EDTA was rapidly taken up by the kidney with subsequent elimation via the urine. While-body desaturation kinetics for 46 Sc-EDTA were found to fit a three compartmental model. The fast elimination phase (T1/2 = 12.75 min; K = 0.05540 min -1 ) accounted for 74.6% of the dose; the intermediate phase (T1/2 = 40.2 min; K = 0.01722 min -1 ) for 21.8%, and the slow (T1/2 = 5351 min; K = 0.00013 min -1 ) for 3.6% of the dose. (author)

Discovery of human scFvs that cross-neutralize the toxic effects of B. jararacussu and C. d. terrificus venoms.

Science.gov (United States)

Silva, Luciano C; Pucca, Manuela B; Pessenda, Gabriela; Campos, Lucas B; Martinez, Edson Z; Cerni, Felipe A; Barbosa, José E

2018-01-01

Accidents involving venomous snakes are a public health problem worldwide, causing a large number of deaths per year. In Brazil, the majority of accidents are caused by the Bothrops and Crotalus genera, which are responsible for approximately 80% of severe envenoming cases. The cross-neutralization of snake venoms by antibodies is an important issue for development of more effective treatments. Our group has previously reported the construction of human monoclonal antibody fragments towards Bothrops jararacussu and Crotalus durissus terrificus' venoms. This study aimed to select human single-chain variable fragments (scFvs) that recognize both bothropic and crotalic crude venoms following venoms neutralizing capacity in vitro and in vivo. The cross-reactivity of Cro-Bothrumabs were demonstrated by ELISA and in vitro and in vivo experiments showed that a combination of scFvs neutralizes in vitro toxic activities (e.g. indirect hemolysis and plasma-clotting) of crotalic and bothropic venoms as well as prolonged survival time of envenomed animals. Our results may contribute to the development of the first human polyvalent antivenom against Bothrops jararacussu and Crotalus durissus terrificus venoms, overcoming some undesirable effects caused by conventional serotherapy. Copyright © 2017 Elsevier B.V. All rights reserved.

Crystal structure of Na3Sc2(PO4)3 at 60 deg C

International Nuclear Information System (INIS)

Lazoryak, B.I.; Kalinin, V.B.; Stefanovich, S.Yu.; Efremov, V.A.

1980-01-01

The structure of the ferroelectric phase of Na 3 Sc 2 (PO 4 ) 3 compound was studied. Na 3 Sc 2 (PO 4 ) 3 monocrystal heated by a jet of warm N 2 was investigated at 60 deg C. The rhombohedron modification was determined: a=8.927(3), c=22.34(4) A, Z=6, space group R anti 3c. Interatomic distances and inner angles of polyhedrons in Na 3 Sc 2 (PO 4 ) 3 structure were determined

α-ScVSe2O8, β-ScVSe2O8, and ScVTe2O8: new quaternary mixed metal oxides composed of only second-order Jahn-Teller distortive cations.

Science.gov (United States)

Kim, Yeong Hun; Lee, Dong Woo; Ok, Kang Min

2013-10-07

Three new quaternary scandium vanadium selenium/tellurium oxides, α-ScVSe2O8, β-ScVSe2O8, and ScVTe2O8 have been synthesized through hydrothermal and standard solid-state reactions. Although all three reported materials are stoichiometrically similar, they exhibit different crystal structures: α-ScVSe2O8 has a three-dimensional framework structure consisting of ScO6, VO6, and SeO3 groups. β-ScVSe2O8 reveals another three-dimensional framework composed of ScO7, VO5, and SeO3 polyhedra. ScVTe2O8 shows a layered structure with ScO6, VO4, and TeO4 polyhedra. Interestingly, the constituent cations, that is, Sc(3+), V(5+), Se(4+), and Te(4+) are all in a distorted coordination environment attributable to second-order Jahn-Teller (SOJT) effects. Complete characterizations including infrared spectroscopy, elemental analyses, thermal analyses, dipole moment calculation, and the magnitudes of out-of-center distortions for the compounds are reported. Transformation reactions suggest that α-ScVSe2O8 may change to β-ScVSe2O8, and then to Sc2(SeO3)3·H2O under hydrothermal conditions.

Binding of HIV-1 gp41-directed neutralizing and non-neutralizing fragment antibody binding domain (Fab and single chain variable fragment (ScFv antibodies to the ectodomain of gp41 in the pre-hairpin and six-helix bundle conformations.

Directory of Open Access Journals (Sweden)

John M Louis

Full Text Available We previously reported a series of antibodies, in fragment antigen binding domain (Fab formats, selected from a human non-immune phage library, directed against the internal trimeric coiled-coil of the N-heptad repeat (N-HR of HIV-1 gp41. Broadly neutralizing antibodies from that series bind to both the fully exposed N-HR trimer, representing the pre-hairpin intermediate state of gp41, and to partially-exposed N-HR helices within the context of the gp41 six-helix bundle. While the affinities of the Fabs for pre-hairpin intermediate mimetics vary by only 2 to 20-fold between neutralizing and non-neutralizing antibodies, differences in inhibition of viral entry exceed three orders of magnitude. Here we compare the binding of neutralizing (8066 and non-neutralizing (8062 antibodies, differing in only four positions within the CDR-H2 binding loop, in Fab and single chain variable fragment (ScFv formats, to several pre-hairpin intermediate and six-helix bundle constructs of gp41. Residues 56 and 58 of the mini-antibodies are shown to be crucial for neutralization activity. There is a large differential (≥ 150-fold in binding affinity between neutralizing and non-neutralizing antibodies to the six-helix bundle of gp41 and binding to the six-helix bundle does not involve displacement of the outer C-terminal helices of the bundle. The binding stoichiometry is one six-helix bundle to one Fab or three ScFvs. We postulate that neutralization by the 8066 antibody is achieved by binding to a continuum of states along the fusion pathway from the pre-hairpin intermediate all the way to the formation of the six-helix bundle, but prior to irreversible fusion between viral and cellular membranes.

Transmission electron microscope studies of phase transitions in single crystals and ceramics of ferroelectric Pb(Sc1/2Ta1/2)O3

International Nuclear Information System (INIS)

Baba-Kishi, K.Z.; Barber, D.J.

1990-01-01

An account is given of transmission electron microscope investigations of the phase transitions in single crystals and ceramics of the complex perovskite-structured ferroelectric 'relaxor' compound Pb(Sc 1/2 Ta 1/2 )O 3 . The crystal symmetries pertaining to both the non-polar paraelectric (PE) and polar ferroelectric (FE) states have been studied by the technique of convergent-beam electron diffraction. A new phase transition has been discovered in the temperature range for which the FE and PE states coexist. The new phase transition is interpreted as the creation of a modulated antiferroelectric state, and this is viewed as marking a departure from relaxor behaviour towards more 'normal' ferroelectric behaviour. (orig.)

PEMODELAN KONDUKTIVITAS ION DALAM STRUKTUR Li2Sc3(PO43 (Modeling Ionic Conductivity in Li2Sc3(PO43 Structure

Directory of Open Access Journals (Sweden)

Akram La Kilo

2011-11-01

Full Text Available ABSTRAK Fasa Li2Sc3(PO43 merupakan material konduktor superionik yang dapat diaplikasikan sebagai baterai yang dapat diisi ulang (rechargeable. Ion Li+ dalam struktur Li2Sc3(PO4 dapat mengalami migrasi dari posisi terisi ke posisi kosong. Penelitian ini telah memodelkan migrasi ion Li+ dalam struktur Li2Sc3(PO4 dengan menggunakan metode bond valence sum (BVS. Metode ini dapat memprediksi bilangan oksidasi suatu atom berdasarkan jarak dengan atom-atom tetangga. Source code berbasis BVS yang digunakan adalah JUMPITER yang mensimulasi efek gaya listrik eksternal yang bertindak pada ion litium sehingga nilai BVS litium dapat dipetakan terhadap jarak. Hasil simulasi menunjukkan bahwa konduksi ion Li+ dapat terjadi pada arah [010], [101], dan [120]. Namun, lintasan konduksi ion Li+ lebih mudah terjadi pada arah [120] atau bidang ab dengan nilai maksimum BVS adalah 0,982. ABSTRACT g-phase of Li2Sc3(PO43 is a lithium super ionic conductor which can be applied as a rechargeable lithium battery. Lithium ions of g-Li2Sc3(PO43 can migrate from occupied site to vacant site. In this research, simulation of Li+ ions migration in the structure of g-Li2Sc3(PO43 carried out using bond valence sum (BVS to predict the oxidation state of Li+ion based on the distance of the ion to neighboring atoms. BVS-based code used JUMPITER to simulate the effect of external electrical force acting on the lithium ions to produce the lithium BVS value which can be mapped to the distance. The simulation results shows that Li+ ion conduction can be occurred on [010], [101], and [120] directions. However, the Li ion conduction pathway occur more easily in the direction of [120] or ab plane with the BVS maximum value is 0.982.

Crystallographic information of intermediate phases in binary Mg–X (X=Sn, Y, Sc, Ag alloys

Directory of Open Access Journals (Sweden)

Dongyan Liu

2015-09-01

Full Text Available The compositions and structures of thermodynamically stable or metastable precipitations in binary Mg-X (X=Sn, Y, Sc, Ag alloys are predicted using ab-initio evolutionary algorithm. The geometry optimizations of the predicted intermetallic compounds are carried out in the framework of density functional theory (DFT [1]. A complete list of the optimized crystallographic information (in cif format of the predicted intermetallic phases is presented here. The data is related to “Predictions on the compositions, structures, and mechanical properties of intermediate phases in binary Mg–X (X=Sn, Y, Sc, Ag alloys” by Liu et al. [2].

Phase transformations, ionic conductivity and dipole ordering of NASICON-like double phosphates Na3M2(PO4)3 (M-Sc,Fe,Cr)

International Nuclear Information System (INIS)

Kalinin, V.B.

1990-01-01

Experimental data obtained using ceramic samples of Na 3 M 2 (PO 4 ) 3 and solid solutions on their basis have been analyzed and generalized. It is shown that isostoichiometry of Na 3 M 2 (PO 4 ) 3 compounds and different types of dipole ordering in their α-phases stimulate investigations of subsolidus regions in the systems Na 3 Sc 2 (PO 4 ) 3 -Na 3 Fe 2 (PO 4 ) 3 , Na 3 Sc 2 (PO 4 ) 3 -Na 3 Cr 2 (PO 4 ) 3 , Na 3 Fe 2 (PO 4 ) 3 -Na 3 Cr 2 (PO 4 ) 3 .It proved possible to detect changes of the properties in case of ferroelectric-antiferroelectric, antiferroelectric-antiferroelectric transitions

Isothermal cross-sections of Hf-Sc-Ga(800 deg C) and Hf-Ti-Ga (750 deg C) phase diagrams

International Nuclear Information System (INIS)

Markiv, V.Ya.; Belyavina, N.N.

1981-01-01

Isothermal cross sections of Hf-Sc-Ga (800 deg C) and Hf-Ti-Ga (750 deg C) state diagrams are plotted. The existence of two ternary Hfsub(0.1-0.8)Scsub(0.9)-sub(0.2)Ga and Hfsub(0.8)Scsub(0.2)Gasub(3) phases is stated in the Hf-Sc-Ga system. The crystal structure of these compounds investigated by the powder method belongs to the structural α-MoB and ZrAl 3 types respectively. Continuous rows of (Hf, Sc 5 Ga 5 , (Hf, Ti)Ga 3 and (Hf, Ti)Ga 2 solid solutions are formed in the investigated systems. Essential quantity of the third component dissolve binary Sc 5 Ga 4 , Sc 2 Ga 3 (15 and 30 at % Hf respectively), Hf 5 Ga 4 , HfGa 2 (20, 10 at. % Sc), Hf 5 Ga 4 , HfGa, Hf 5 Ga 3 , Hf 2 Ga 3 (48, 30, 46, 20 at. % Ti) gallides [ru

Fe-moment instability in Ti{sub 1-x}Sc{sub x}Fe{sub 2} Laves-phase compounds

Energy Technology Data Exchange (ETDEWEB)

Ouladdiaf, B. [Institut Laue-Langevin, BP 156, 38042 GRENOBLE Cedex 09 (France); Deportes, J. [Lab. Louis Neel, CNRS, BP 166, 38042 GRENOBLE Cedex 09 (France); Saoudi, M. [Centre Universitaire de Guelma, GUELMA 24 000 (Algeria)

2002-07-01

The magnetic properties of the pseudo-binary Laves-phase compounds Ti{sub 1-x}Sc{sub x}Fe{sub 2} were investigated by means of magnetisation and high-resolution powder neutron diffraction techniques. For x<0.2 a transition from an antiferromagnetic state to a canted one with a ferromagnetic component in the basal plane is observed, while for 0.22a site. (orig.)

Phase formation in the (1-y)BiFeO{sub 3}-yBiScO{sub 3} system under ambient and high pressure

Energy Technology Data Exchange (ETDEWEB)

Salak, A.N., E-mail: salak@ua.pt [Department of Materials and Ceramic Engineering and CICECO – Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro (Portugal); Khalyavin, D.D., E-mail: dmitry.khalyavin@stfc.ac.uk [ISIS Facility, Rutherford Appleton Laboratory, Chilton, OX11 0QX Didcot (United Kingdom); Pushkarev, A.V.; Radyush, Yu.V.; Olekhnovich, N.M. [Scientific-Practical Materials Research Centre of NAS of Belarus, P. Brovka Street, 19, 220072 Minsk (Belarus); Shilin, A.D.; Rubanik, V.V. [Institute of Technical Acoustics of NAS of Belarus, Lyudnikov Avenue, 13, 210023 Vitebsk (Belarus)

2017-03-15

Formation and thermal stability of perovskite phases in the BiFe{sub 1-y}Sc{sub y}O{sub 3} system (0≤y≤0.70) were studied. When the iron-to-scandium substitution rate does not exceed about 15 at%, the single-phase perovskite ceramics with the rhombohedral R3c symmetry (as that of the parent compound, BiFeO{sub 3}) can be prepared from the stoichiometric mixture of the respective oxides at ambient pressure. Thermal treatment of the oxide mixtures with a higher content of scandium results in formation of two main phases, namely a BiFeO{sub 3}-like R3c phase and a cubic (I23) sillenite-type phase based on γ-Bi{sub 2}O{sub 3}. Single-phase perovskite ceramics of the BiFe{sub 1-y}Sc{sub y}O{sub 3} composition were synthesized under high pressure from the thermally treated oxide mixtures. When y is between 0 and 0.25 the high-pressure prepared phase is the rhombohedral R3c with the √2a{sub p}×√2a{sub p}×2√3a{sub p} superstructure (a{sub p} ~ 4 Å is the pseudocubic perovskite unit-cell parameter). The orthorhombic Pnma phase (√2a{sub p}×4a{sub p}×2√2a{sub p}) was obtained in the range of 0.30≤y≤0.60, while the monoclinic C2/c phase (√6a{sub p}×√2a{sub p}×√6a{sub p}) is formed when y=0.70. The normalized unit-cell volume drops at the crossover from the rhombohedral to the orthorhombic composition range. The perovskite BiFe{sub 1-y}Sc{sub y}O{sub 3} phases prepared under high pressure are metastable regardless of their symmetry. At ambient pressure, the phases with the compositions in the ranges of 0.20≤y≤0.25, 0.30≤y<0.50 and 0.50≤y≤0.70 start to decompose above 970, 920 and 870 K, respectively. - Graphical abstract: Formation of perovskite phases in the BiFe{sub 1-y}Sc{sub y}O{sub 3} system when y≥0.15 requires application of pressure of several GPa. The phases formed under high pressure: R3c (0.20≤y≤0.25), Pnma (0.30≤y≤0.60) and C2/c (y≥0.70) are metastable. - Highlights: • Maximal Fe-to-Sc substitution rate in Bi

Ophiophagus hannah Venom: Proteome, Components Bound by Naja kaouthia Antivenin and Neutralization by N. kaouthia Neurotoxin-Specific Human ScFv

Directory of Open Access Journals (Sweden)

Witchuda Danpaiboon

2014-05-01

Full Text Available Venomous snakebites are an important health problem in tropical and subtropical countries. King cobra (Ophiophagus hannah is the largest venomous snake found in South and Southeast Asia. In this study, the O. hannah venom proteome and the venom components cross-reactive to N. kaouthia monospecific antivenin were studied. O. hannah venom consisted of 14 different protein families, including three finger toxins, phospholipases, cysteine-rich secretory proteins, cobra venom factor, muscarinic toxin, L-amino acid oxidase, hypothetical proteins, low cysteine protein, phosphodiesterase, proteases, vespryn toxin, Kunitz, growth factor activators and others (coagulation factor, endonuclease, 5’-nucleotidase. N. kaouthia antivenin recognized several functionally different O. hannah venom proteins and mediated paratherapeutic efficacy by rescuing the O. hannah envenomed mice from lethality. An engineered human ScFv specific to N. kaouthia long neurotoxin (NkLN-HuScFv cross-neutralized the O. hannah venom and extricated the O. hannah envenomed mice from death in a dose escalation manner. Homology modeling and molecular docking revealed that NkLN-HuScFv interacted with residues in loops 2 and 3 of the neurotoxins of both snake species, which are important for neuronal acetylcholine receptor binding. The data of this study are useful for snakebite treatment when and where the polyspecific antivenin is not available. Because the supply of horse-derived antivenin is limited and the preparation may cause some adverse effects in recipients, a cocktail of recombinant human ScFvs for various toxic venom components shared by different venomous snakes, exemplified by the in vitro produced NkLN-HuScFv in this study, should contribute to a possible future route for an improved alternative to the antivenins.

Ophiophagus hannah venom: proteome, components bound by Naja kaouthia antivenin and neutralization by N. kaouthia neurotoxin-specific human ScFv.

Science.gov (United States)

Danpaiboon, Witchuda; Reamtong, Onrapak; Sookrung, Nitat; Seesuay, Watee; Sakolvaree, Yuwaporn; Thanongsaksrikul, Jeeraphong; Dong-din-on, Fonthip; Srimanote, Potjanee; Thueng-in, Kanyarat; Chaicumpa, Wanpen

2014-05-13

Venomous snakebites are an important health problem in tropical and subtropical countries. King cobra (Ophiophagus hannah) is the largest venomous snake found in South and Southeast Asia. In this study, the O. hannah venom proteome and the venom components cross-reactive to N. kaouthia monospecific antivenin were studied. O. hannah venom consisted of 14 different protein families, including three finger toxins, phospholipases, cysteine-rich secretory proteins, cobra venom factor, muscarinic toxin, L-amino acid oxidase, hypothetical proteins, low cysteine protein, phosphodiesterase, proteases, vespryn toxin, Kunitz, growth factor activators and others (coagulation factor, endonuclease, 5'-nucleotidase). N. kaouthia antivenin recognized several functionally different O. hannah venom proteins and mediated paratherapeutic efficacy by rescuing the O. hannah envenomed mice from lethality. An engineered human ScFv specific to N. kaouthia long neurotoxin (NkLN-HuScFv) cross-neutralized the O. hannah venom and extricated the O. hannah envenomed mice from death in a dose escalation manner. Homology modeling and molecular docking revealed that NkLN-HuScFv interacted with residues in loops 2 and 3 of the neurotoxins of both snake species, which are important for neuronal acetylcholine receptor binding. The data of this study are useful for snakebite treatment when and where the polyspecific antivenin is not available. Because the supply of horse-derived antivenin is limited and the preparation may cause some adverse effects in recipients, a cocktail of recombinant human ScFvs for various toxic venom components shared by different venomous snakes, exemplified by the in vitro produced NkLN-HuScFv in this study, should contribute to a possible future route for an improved alternative to the antivenins.

Bulk viscosity in 2SC quark matter

International Nuclear Information System (INIS)

Alford, Mark G; Schmitt, Andreas

2007-01-01

The bulk viscosity of three-flavour colour-superconducting quark matter originating from the nonleptonic process u + s ↔ u + d is computed. It is assumed that up and down quarks form Cooper pairs while the strange quark remains unpaired (2SC phase). A general derivation of the rate of strangeness production is presented, involving contributions from a multitude of different subprocesses, including subprocesses that involve different numbers of gapped quarks as well as creation and annihilation of particles in the condensate. The rate is then used to compute the bulk viscosity as a function of the temperature, for an external oscillation frequency typical of a compact star r-mode. We find that, for temperatures far below the critical temperature T c for 2SC pairing, the bulk viscosity of colour-superconducting quark matter is suppressed relative to that of unpaired quark matter, but for T ∼> T c /30 the colour-superconducting quark matter has a higher bulk viscosity. This is potentially relevant for the suppression of r-mode instabilities early in the life of a compact star

Pressure-induced structural transformations in the molybdate Sc-2(MoO4)(3)

DEFF Research Database (Denmark)

Paraguassu, W.; Maczka, M.; Filho, A. G. Sonza

2004-01-01

High pressure Raman scattering and x-ray diffraction studies of the molybdate Sc-2(MoO4)(3) are presented. A sequence of changing symmetry effects is observed through two structural phase transitions ending up with an amorphous state. The observed two structural phase transformations are reversible...

Compensation of native donor doping in ScN: Carrier concentration control and p-type ScN

Science.gov (United States)

Saha, Bivas; Garbrecht, Magnus; Perez-Taborda, Jaime A.; Fawey, Mohammed H.; Koh, Yee Rui; Shakouri, Ali; Martin-Gonzalez, Marisol; Hultman, Lars; Sands, Timothy D.

2017-06-01

Scandium nitride (ScN) is an emerging indirect bandgap rocksalt semiconductor that has attracted significant attention in recent years for its potential applications in thermoelectric energy conversion devices, as a semiconducting component in epitaxial metal/semiconductor superlattices and as a substrate material for high quality GaN growth. Due to the presence of oxygen impurities and native defects such as nitrogen vacancies, sputter-deposited ScN thin-films are highly degenerate n-type semiconductors with carrier concentrations in the (1-6) × 1020 cm-3 range. In this letter, we show that magnesium nitride (MgxNy) acts as an efficient hole dopant in ScN and reduces the n-type carrier concentration, turning ScN into a p-type semiconductor at high doping levels. Employing a combination of high-resolution X-ray diffraction, transmission electron microscopy, and room temperature optical and temperature dependent electrical measurements, we demonstrate that p-type Sc1-xMgxN thin-film alloys (a) are substitutional solid solutions without MgxNy precipitation, phase segregation, or secondary phase formation within the studied compositional region, (b) exhibit a maximum hole-concentration of 2.2 × 1020 cm-3 and a hole mobility of 21 cm2/Vs, (c) do not show any defect states inside the direct gap of ScN, thus retaining their basic electronic structure, and (d) exhibit alloy scattering dominating hole conduction at high temperatures. These results demonstrate MgxNy doped p-type ScN and compare well with our previous reports on p-type ScN with manganese nitride (MnxNy) doping.

New indides Sc{sub 6}Co{sub 2.18}In{sub 0.82}, Sc{sub 10}Ni{sub 9}In{sub 19.44} and ScCu{sub 4}In-synthesis, structure, and crystal chemistry

Energy Technology Data Exchange (ETDEWEB)

Zaremba, R.I.; Rodewald, U. Ch.; Poettgen, R. [Inst. fuer Anorganische und Analytische Chemie, Westfaelische Wilhelms-Univ. Muenster (Germany); Kalychak, Y.M.; Zaremba, V.I. [Inorganic Chemistry Dept., Ivan Franko National Univ. of Lviv, Lviv (Ukraine)

2006-08-15

New indides Sc{sub 6}Co{sub 2.18}In{sub 0.82}, Sc{sub 10}Ni{sub 9}In{sub 19.44} and ScCu{sub 4}In have been synthesized from the elements by arc-melting. Single crystals were grown by special annealing modes. The thee indides were investigated via X-ray powder and single crystal diffraction: Ho{sub 6}Co{sub 2}Ga type, Immm, a = 886.7(3), b = 878.0(2), c = 932.1(3) pm, wR2 = 0.0517, 711 F{sup 2} values, 35 variables for Sc{sub 6}Co{sub 2.18}In{sub 0.82}, Ho{sub 10}Ni{sub 9}In{sub 20} type, P4/nmm, a = 1287.5(2), c = 884.7(1) pm, wR2 = 0.0642, 1221 F{sup 2} values, 63 variables for Sc{sub 10}Ni{sub 9}In{sub 19.44}, and MgCu{sub 4}Sn type, anti F 43m, a = 704.03(7) pm, wR2 = 0.0267, 101 F{sup 2} values, and 7 variables for ScCu{sub 4}In. The scandium rich indide Sc{sub 6}Co{sub 2.18}In{sub 0.82} contains two Co{sub 2} dumb-bells at Co-Co distances of 221 and 230 pm. Each cobalt atom within these dumb-bells has a tricapped trigonal prismatic coordination. The In1 site has a distorted cube-like coordination by scandium and shows a mixed occupancy (36%) with cobalt. The In2 atoms have distorted icosahedral scandium coordination. As a consequence of the small size of the scandium atoms, the In4 site in Sc{sub 10}Ni{sub 9}In{sub 19.44} shows defects and was furthermore refined with a split model leading to a new distorted variant within the family of Ho{sub 10}Ni{sub 9}In{sub 20} compounds. ScCu{sub 4}In is an ordered version of the cubic Laves phase with scandium and indium atoms in the CN16 voids of the copper substructure. The Cu-Cu distances within the three-dimensional network of corner-sharing tetrahedra are 248.6 and 249.2 pm. The crystal chemical peculiarities of these three indide structures are briefly discussed. (orig.)

Synthesis and Isolation of the Titanium-Scandium Endohedral Fullerenes-Sc2 TiC@Ih -C80 , Sc2 TiC@D5h -C80 and Sc2 TiC2 @Ih -C80 : Metal Size Tuning of the Ti(IV) /Ti(III) Redox Potentials.

Science.gov (United States)

Junghans, Katrin; Ghiassi, Kamran B; Samoylova, Nataliya A; Deng, Qingming; Rosenkranz, Marco; Olmstead, Marilyn M; Balch, Alan L; Popov, Alexey A

2016-09-05

The formation of endohedral metallofullerenes (EMFs) in an electric arc is reported for the mixed-metal Sc-Ti system utilizing methane as a reactive gas. Comparison of these results with those from the Sc/CH4 and Ti/CH4 systems as well as syntheses without methane revealed a strong mutual influence of all key components on the product distribution. Whereas a methane atmosphere alone suppresses the formation of empty cage fullerenes, the Ti/CH4 system forms mainly empty cage fullerenes. In contrast, the main fullerene products in the Sc/CH4 system are Sc4 C2 @C80 (the most abundant EMF from this synthesis), Sc3 C2 @C80 , isomers of Sc2 C2 @C82 , and the family Sc2 C2 n (2 n=74, 76, 82, 86, 90, etc.), as well as Sc3 CH@C80 . The Sc-Ti/CH4 system produces the mixed-metal Sc2 TiC@C2 n (2 n=68, 78, 80) and Sc2 TiC2 @C2 n (2 n=80) clusterfullerene families. The molecular structures of the new, transition-metal-containing endohedral fullerenes, Sc2 TiC@Ih -C80 , Sc2 TiC@D5h -C80 , and Sc2 TiC2 @Ih -C80 , were characterized by NMR spectroscopy. The structure of Sc2 TiC@Ih -C80 was also determined by single-crystal X-ray diffraction, which demonstrated the presence of a short Ti=C double bond. Both Sc2 TiC- and Sc2 TiC2 -containing clusterfullerenes have Ti-localized LUMOs. Encapsulation of the redox-active Ti ion inside the fullerene cage enables analysis of the cluster-cage strain in the endohedral fullerenes through electrochemical measurements. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Electrical Conductivity of 10 mol% Sc2O3-1 mol% M2O3-ZrO2 Ceramics

DEFF Research Database (Denmark)

Omar, Shobit; Bin Najib, Waqas; Chen, Weiwu

2012-01-01

follow similar conductivity trends with the maximum at 1In10ScSZ and 1Y10ScSZ, respectively. Around 475 degrees C, 1In10ScSZ but not other compositions exhibits an abrupt drop in the conductivity on cooling, due to the cubic to beta-phase transformation. At 600 degrees C, the activation energy...

Gas-phase salt bridge interactions between glutamic acid and arginine

NARCIS (Netherlands)

Jaeqx, S.; Oomens, J.; Rijs, A.M.

2013-01-01

The gas-phase side chain-side chain (SC-SC) interaction and possible proton transfer between glutamic acid (Glu) and arginine (Arg) residues are studied under low-temperature conditions in an overall neutral peptide. Conformation-specific IR spectra, obtained with the free electron laser FELIX, in

Enforced Electrical Neutrality of the Color-Flavor Locked Phase

International Nuclear Information System (INIS)

Rajagopal, Krishna; Wilczek, Frank

2001-01-01

We demonstrate that quark matter in the color-flavor locked phase of QCD is rigorously electrically neutral, despite the unequal quark masses, and even in the presence of an electron chemical potential. As long as the strange quark mass and the electron chemical potential do not preclude the color-flavor locked phase, quark matter is automatically neutral. No electrons are required and none are admitted

Lightweight hydrogen-storage material Mg0.65Sc0.35D2 studied with 2H and 2H–{45Sc} MAS NMR exchange spectroscopy

NARCIS (Netherlands)

Srinivasan, S.; Magusin, P.C.M.M.

2011-01-01

Using double-quantum 2H MAS NMR with 45Sc recoupling and Bloch–Siegert compensated 2H–{45Sc} TRAPDOR we have identified the overlapping NMR signals of deuterium with and without scandium neighbors in Mg0.65Sc0.35D2, a candidate lightweight material for hydrogen storage. At room temperature we also

Synthesis of anatase nanoparticles with extremely wide solid solution range and ScTiNbO6 with α-PbO2 structure

International Nuclear Information System (INIS)

Hirano, Masanori; Ito, Takaharu

2009-01-01

Anatase-type nanoparticles Sc X Ti 1-2X Nb X O 2 with wide solid solution range (X=0-0.35) were hydrothermally formed at 180 deg. C for 5 h. The lattice parameters a 0 and c 0 , and the optical band gap of anatase gradually and linearly increased with the increase of the content of niobium and scandium from X=0 to 0.35. Their photocatalytic activity and adsorptivity by the measurement of the concentration of methylene blue (MB) that remained in the solution in the dark or under UV-light irradiation were evaluated. The anatase phase existed stably up to 900 deg. C for the samples with X=0.25-0.30 and 750 deg. C for that with X=0.35 during heat treatment in air. The phase with α-PbO 2 structure and the rutile phases coexisted in the samples with X=0.25-0.30 after heated at temperatures above 900-950 deg. C. The α-PbO 2 structure having composition ScTiNbO 6 with possibly some cation order similar to that seen in wolframite existed as almost completely single phase after heat treatment at temperatures 900-1500 deg. C through phase transformation from anatase-type ScTiNbO 6 . - Graphical abstract: Anatase-type Sc X Ti 1-2X Nb X O 2 solid solutions with wide solid solution range (X=0-0.35) were hydrothermally formed as nanoparticles from the precursor solutions of Sc(NO 3 ) 3 , TiOSO 4 , NbCl 5 at 180 deg. C for 5 h using the hydrolysis of urea. Anatase-type ScTiNbO 6 was synthesized under hydrothermal condition. ScTiNbO 6 having α-PbO 2 structure with possibly some cation order similar to that seen in wolframite was formed through phase transformation above 900 deg. C.

Sc-Decorated WS_2 Nanoribbons as Hydrogen Storage Media

International Nuclear Information System (INIS)

Xu Bin; Wang Yu-Sheng; Zhang Jing; Song Na-Hong; Li Meng; Yi Lin

2016-01-01

The hydrogen storage behavior of Sc-decorated WS_2 monolayer and WS_2 nanoribbons is systematically studied by using first principles calculations based on the density functional theory. The present results indicate that an Sc-decorated WS_2 monolayer is not suitable for storing hydrogen due to the weak interaction between the monolayer WS_2 sheet and the Sc atoms. It is found that both the hybridization mechanism and the Coulomb attraction make the Sc atoms stably adsorb on the edges of WS_2 nanoribbons without clustering. The 2Sc/WS_2 NRs system can adsorb at most eight H_2 molecules with average adsorption energy of 0.20 eV/H_2. The results show that the desorption of H_2 is possible by lowering the pressure or by increasing the temperature. (paper)

Enhancement of Dielectric Breakdown Strength and Energy Conversion Efficiency of Niobate Glass-Ceramics by Sc2O3 Doping

Science.gov (United States)

Xiao, Shi; Xiu, Shaomei; Yang, Ke; Shen, Bo; Zhai, Jiwei

2018-01-01

Niobate glass-ceramics K2O-SrO-Nb2O5-B2O3-Al2O3-SiO2 (KSN-BAS) doped with different amounts of Sc2O3 have been prepared through a melt quenching/controlled crystallization method, and the influence of the Sc2O3 content on their phase composition, microstructure, dielectric performance, and charge-discharge properties investigated. X-ray powder diffraction results showed that the peak positions of the KSr2Nb5O15 phase shifted to higher angle and the glass-ceramic microstructures were significantly improved by Sc2O3 addition. Based on these results, 0.5 mol.% Sc2O3 doping was found to achieve remarkable enhancement in energy storage density, which reached 9.63 ± 0.39 J/cm3 at dielectric breakdown strength of 1450.38 ± 29.01 kV/cm with high conversion efficiency of ˜ 92.1%. For pulsed power applications, discharge speed of 17 ns and power density of 0.48 MW/cm3 were obtained in the glass-ceramic with 0.5 mol.% Sc2O3. These results could provide a new design strategy for high-performance dielectric capacitors.

Thermodynamic modeling of the Sc-Zn system coupled with first-principles calculation

Directory of Open Access Journals (Sweden)

Tang C.

2012-01-01

Full Text Available The Sc-Zn system has been critically reviewed and assessed by means of CALPHAD (CALculation of PHAse Diagram approach. By means of first-principles calculation, the enthalpies of formation at 0 K for the ScZn, ScZn2, Sc17Zn58, Sc3Zn17 and ScZn12 have been computed with the desire to assist thermodynamic modeling. A set of self-consistent thermodynamic parameters for the Sc-Zn system is then obtained. The calculated phase diagram and thermodynamic properties agree well with the experimental data and first-principles calculations, respectively.

Phase Transition Behavior in a Neutral Evolution Model

Science.gov (United States)

King, Dawn; Scott, Adam; Maric, Nevena; Bahar, Sonya

2014-03-01

The complexity of interactions among individuals and between individuals and the environment make agent based modeling ideal for studying emergent speciation. This is a dynamically complex problem that can be characterized via the critical behavior of a continuous phase transition. Concomitant with the main tenets of natural selection, we allow organisms to reproduce, mutate, and die within a neutral phenotype space. Previous work has shown phase transition behavior in an assortative mating model with variable fitness landscapes as the maximum mutation size (μ) was varied (Dees and Bahar, 2010). Similarly, this behavior was recently presented in the work of Scott et al. (2013), even on a completely neutral landscape, for bacterial-like fission as well as for assortative mating. Here we present another neutral model to investigate the `critical' phase transition behavior of three mating types - assortative, bacterial, and random - in a phenotype space as a function of the percentage of random death. Results show two types of phase transitions occurring for the parameters of the population size and the number of clusters (an analogue of species), indicating different evolutionary dynamics for system survival and clustering. This research was supported by funding from: University of Missouri Research Board and James S. McDonnell Foundation.

Thermoelastic properties of ScB2, TiB2, YB4 and HoB4

DEFF Research Database (Denmark)

Waskowska, A.; Gerward, L.; Staun Olsen, J.

2011-01-01

(4)GPa). No pressure-induced phase transformations are observed in any of the above borides up to about 20GPa. A continuous temperature-driven orthorhombic distortion is observed for HoB4 below 285K. Values of the thermal expansion coefficient are reported for ScB2 and HoB4 at 293, 200 and 100K...

Subsolidus Phase Relations of the CaO-REOx-CuO Systems (RE = Eu, Tb, Dy, Ho, Er, Lu and Sc) at 900 °C in Air

DEFF Research Database (Denmark)

Grivel, Jean-Claude

2016-01-01

The subsolidus phase relations of the CaO-REOx-CuO systems (RE = Eu, Tb, Dy, Ho, Er, Lu and Sc) were investigated in air at 900 °C. The pseudo-ternary sections with RE = Tb, Dy, Ho, Er and Lu have a similar structure. They have in common with the RE = Eu system a solid solution of Ca0.833−xRExCuO2......+y composition but the system with RE = Eu differs by the presence of an Eu2CuO4 phase instead of RE2Cu2O5 for RE = Tb, Dy, Ho, Er and Lu. In contrast, the CaO-ScO1.5-CuO section does not contain a Ca0.833−xScxCuO2+y solid solution and is dominated by the CaSc2O4 phase, which has no equivalent...... in the other systems at 900 °C in air....

Enforced neutrality and color-flavor unlocking in the three-flavor Polyakov-loop Nambu-Jona-Lasinio model

International Nuclear Information System (INIS)

Abuki, H.; Ciminale, M.; Nardulli, G.; Ruggieri, M.; Gatto, R.

2008-01-01

We study how the charge neutrality affects the phase structure of the three-flavor Polyakov-loop Nambu-Jona-Lasinio (PNJL) model. We point out that, within the conventional PNJL model at finite density, the color neutrality is missing because the Wilson line serves as an external colored field coupled to dynamical quarks. In this paper we heuristically assume that the model may still be applicable. To get color neutrality, one has then to allow nonvanishing color chemical potentials. We study how the quark matter phase diagram in (T,m s 2 /μ)-plane is affected by imposing neutrality and by including the Polyakov-loop dynamics. Although these two effects are correlated in a nonlinear way, the impact of the Polyakov loop turns out to be significant in the T direction, while imposing neutrality brings a remarkable effect in the m s 2 /μ direction. In particular, we find a novel unlocking transition, when the temperature is increased, even in the chiral SU(3) limit. We clarify how and why this is possible once the dynamics of the colored Polyakov loop is taken into account. Also we succeed in giving an analytic expression for T c for the transition from two-flavor pairing (2SC) to unpaired quark matter in the presence of the Polyakov loop.

Molecular and functional characterization of peptidoglycan-recognition protein SC2 (PGRP-SC2) from Nile tilapia (Oreochromis niloticus) involved in the immune response to Streptococcus agalactiae.

Science.gov (United States)

Gan, Zhen; Chen, Shannan; Hou, Jing; Huo, Huijun; Zhang, Xiaolin; Ruan, Baiye; Laghari, Zubair Ahmed; Li, Li; Lu, Yishan; Nie, Pin

2016-07-01

PGRP-SC2, the member of PGRP family, plays an important role in regulation of innate immune response. In this paper, a PGRP-SC2 gene of Nile tilapia, Oreochromis niloticus (designated as On-PGRP-SC2) was cloned and its expression pattern under the infection of Streptococcus agalactiae was investigated. Sequence analysis showed main structural features required for amidase activity were detected in the deduced amino acid sequence of On-PGRP-SC2. In healthy tilapia, the On-PGRP-SC2 transcripts could be detected in all the examined tissues, with the most abundant expression in the muscle. When infected with S. agalactiae, there was a clear time-dependent expression pattern of On-PGRP-SC2 in the spleen, head kidney and brain. The assays for the amidase activity suggested that recombinant On-PGRP-SC2 protein had a Zn(2+)-dependent PGN-degrading activity. Moreover, our works showed that recombinant On-PGRP-SC2 protein could significantly reduce bacterial load in target organs attacked by S. agalactiae. These findings indicated that On-PGRP-SC2 may play important roles in the immune response to S. agalactiae in Nile tilapia. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of the hyperfine magnetic field at Ta181 site in the Heusler Co2 Sc Sn, Co2 Sc Ga and Co2 Hf Sn alloys

International Nuclear Information System (INIS)

Attili, R.N.

1992-01-01

The hyperfine magnetic fields acting on 181 Ta nuclei at the Sc and Hf sites have been measured in Heusler alloys Co 2 Sc Sn and Co 2 Sc Ga and Co 2 Hf Sn using the Time Differential Perturbed γ-γ Angular Correlation (TDPAC) technique. The measurements were carried out using an automatic spectrometer consisting of two Ba F 2 detectors and the conventional electronics. The magnitude of hyperfine magnetic field at 181 Ta was measured for all the alloys. The signs of the were determined in the cases of Co 2 Sc Sn and Co 2 Hf Sn alloys by performing the Perturbed Angular Correlation measurements with an external polarizing magnetic field of ≅ 5 k Gauss. The hyperfine magnetic fields obtained are -187,6± 3,3 and 90,0 ± 2,1 kOe measured at 77 K for Co 2 Sc Sn and Co 2 Sc Ga alloys respectively, and -342,4 ± 10,1 kOe measured at the room temperature for Co 2 Hf Sn alloy. These results are discussed and compared with the hyperfine magnetic field systematics in Co-based Heusler alloy. (author)

Reactivity of dissolved- vs. supercritical-CO2 phase toward muscovite basal surfaces

Science.gov (United States)

Wan, J.; Tokunaga, T. K.; Kim, Y.; Wang, S.; Altoe, M. V. P.; Ashby, P. D.; DePaolo, D.

2015-12-01

The current understanding of geochemical reactions in reservoirs for geological carbon sequestration (GCS) is largely based on aqueous chemistry (CO2 dissolves in reservoir brine and brine reacts with rocks). However, only a portion of the injected supercritical (sc) CO2 dissolves before the buoyant plume contacts caprock, where it is expected to reside for a long time. Although numerous studies have addressed scCO2-mineral reactions occurring within adsorbed aqueous films, possible reactions resulting from direct CO2-rock contact remain less understood. Does CO2 as a supercritical phase react with reservoir rocks? Do mineral react differently with scCO2 than with dissolved CO2? We selected muscovite, one of the more stable and common rock-forming silicate minerals, to react with scCO2 phase (both water-saturated and water-free) and compared with CO2-saturated-brine. The reacted basal surfaces were analyzed using atomic force microscopy and X-ray photoelectron spectroscopy for examining the changes in surface morphology and chemistry. The results show that scCO2 (regardless of its water content) altered muscovite considerably more than CO2-saturated brine; suggest CO2 diffusion into mica interlayers and localized mica dissolution into scCO2 phase. The mechanisms underlying these observations and their implications for GCS need further exploration.

44Sc-DOTA-BN[2-14]NH2 in comparison to 68Ga-DOTA-BN[2-14]NH2 in pre-clinical investigation. Is 44Sc a potential radionuclide for PET?

International Nuclear Information System (INIS)

Koumarianou, E.; Loktionova, N.S.; Fellner, M.; Roesch, F.; Thews, O.; Pawlak, D.; Archimandritis, S.C.; Mikolajczak, R.

2012-01-01

Aim: In the present study we demonstrate the in vitro and in vivo comparison of the 44 Sc and 68 Ga labeled DOTA-BN[2-14]NH 2 . 44 Sc is a positron emitter with a half life of 3.92 h. Hence it could be used for PET imaging with ligands requiring longer observation time than in the case of 68 Ga. Methods: The binding affinity of nat Sc-DOTA-BN[2-14]NH 2 and nat Ga-DOTA-BN[2-14]NH 2 to GRP receptors was studied in competition to [ 125 I-Tyr 4 ]-Bombesin in the human prostate cancer cell line PC-3. A preliminary biodistribution in normal rats was performed, while first microPET images were assessed in male Copenhagen rats bearing the androgen-independent Dunning R-3327-AT-1 prostate cancer tumor. Results: The affinity to GRP receptors in the PC-3 cell line was higher for nat Ga-DOTA-BN[2-14]NH 2 (IC 50 (nM)=0.85±0.06) than that of nat Sc-DOTA-BN[2-14]NH 2 (IC 50 (nM)=6.49±0.13). The internalization rate of 68 Ga labeled DOTA-BN[2-14]NH 2 was slower than that of 44 Sc, but their final internalization percents were comparable. 68 Ga-DOTA-BN[2-14]NH 2 was externalized faster than 44 Sc-DOTA-BN[2-14]NH 2 . The biodistribution of 44 Sc-DOTA-BN[2-14]NH 2 and 68 Ga-DOTA-BN[2-14]NH 2 in normal rats revealed a higher uptake in target organs and tissues of the first one while both excreted mainly through urinary tract. In microPET images both tracers were accumulated in the tumor with similar uptake patterns. Conclusions: Despite the differences in the receptor affinity both the 68 Ga- and the 44 Sc-labeled DOTA-BN[2-14]NH 2 tracers showed comparable distribution and similar time constants of uptake and elimination. Moreover no differences in tumor accumulation (neither in the overall uptake nor in the dynamics) were observed from the microPet imaging. From that perspective the use of either 44 Sc or 68 Ga for detecting tumors with GRP receptors is equivalent. - Highlights: ► In vitro and in vivo evaluation of 44 Sc- and 68 Ga-DOTA-BN[2-14]NH 2 in reference to published

Microstructure evolution of the 1469 Al–Cu–Li–Sc alloy during homogenization

Energy Technology Data Exchange (ETDEWEB)

Jia, Min, E-mail: jm_lushan@163.com; Zheng, Ziqiao, E-mail: csu1469@163.com; Gong, Zhu, E-mail: start123gz@163.com

2014-11-25

Highlights: • The formation of the W phase (AlCuSc) was found in the 1469 Al-Cu–Li–Sc alloy. • The W phase formed during the homogenization process. • We model the formation process of the W phase. • The formation of the W phase consumes lots of Cu and Sc atoms. - Abstract: The present work aims to clarify the formation of the W phase (AlCuSc) and its formation time in the high Cu content alloy with Sc addition. The microstructure evolution during the two-step homogenization annealing process was investigated in the 1469 Al–Cu–Li–Sc alloy. No evidences of the Al{sub 3}Sc phase and the W phase were found in the solidification structure. The arrays of the W phases were found to form after homogenization. The AlCu phases with traces of Sc that formed during solidification suppose to be the precursor of the W phases, and then transform into the W phases by consuming the Sc atoms that fixed in the supersaturate solid solution. The formation of the W phase inhibits the precipitation of the Al{sub 3}Sc phase. A corresponding model of the W phase formation mechanism is proposed.

Properties of clusters in the gas phase: V. Complexes of neutral molecules onto negative ions

International Nuclear Information System (INIS)

Keesee, R.G.; Lee, N.; Castleman, A.W. Jr.

1980-01-01

Ion--molecules association reactions of the form A - (B)/sub n1/-+B=A - (B)/sub n/ were studied over a range of temperatures in the gas phase using high pressure mass spectrometry. Enthalpy and entropy changes were determined for the stepwise clustering reactions of (1) sulfur dioxide onto Cl - , I - , and NO 2 - with n ranging from one to three or four, and onto SO 2 - and SO 3 - with n equal to one; and (2) carbon dioxide onto Cl - , I - , NO 2 - , CO 3 - , and SO 3 - with n equal to one. From these data and earlier hydration results, the order of the magnitude of the enthalpy changes on the association of the first neutral for a series of negative ions was found to parallel the gas-phase basicity of those anions. For any given ion, the relative order of the addition enthalpies among the neutrals was found to be dependent on the polarizabilities of the neutrals and on the covalency in the ion-neutral bond. Dispersion of charge via covalent bonding was found to affect significantly the succeeding clustering steps

Predictive calculation of phase formation in Al-rich Al-Zn-Mg-Cu-Sc-Zr alloys using a thermodynamic Mg-alloy database

International Nuclear Information System (INIS)

Groebner, J.; Rokhlin, L.L.; Dobatkina, T.V.; Schmid-Fetzer, R.

2007-01-01

Three series of Al-rich alloys in the system Al-Zn-Mg-Cu-Sc-Zr and the subsystems Al-Zn-Mg-Cu-Sc and Al-Zn-Mg-Sc were studied by thermodynamic calculations. Phase formation was compared with experimental data obtained by DTA and microstructural analysis. Calculated phase diagrams, phase amount charts and enthalpy charts together with non-equilibrium calculations under Scheil conditions reveal significant details of the complex phase formation. This enables consistent and correct interpretation of thermal analysis data. Especially the interpretation of liquidus temperature and primary phase is prone to be wrong without using this tool of computational thermodynamics. All data are predictions from a thermodynamic database developed for Mg-alloys and not a specialized Al-alloy database. That provides support for a reasonable application of this database for advanced Mg-alloys beyond the conventional composition ranges

Predictive calculation of phase formation in Al-rich Al-Zn-Mg-Cu-Sc-Zr alloys using a thermodynamic Mg-alloy database

Energy Technology Data Exchange (ETDEWEB)

Groebner, J. [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch Strasse 42, D-38678 Clausthal-Zellerfeld (Germany); Rokhlin, L.L. [Baikov Institute of Metallurgy and Materials Science, Leninsky prosp. 49, 119991 GSP-1, Moscow (Russian Federation); Dobatkina, T.V. [Baikov Institute of Metallurgy and Materials Science, Leninsky prosp. 49, 119991 GSP-1, Moscow (Russian Federation); Schmid-Fetzer, R. [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch Strasse 42, D-38678 Clausthal-Zellerfeld (Germany)]. E-mail: schmid-fetzer@tu-clausthal.de

2007-05-16

Three series of Al-rich alloys in the system Al-Zn-Mg-Cu-Sc-Zr and the subsystems Al-Zn-Mg-Cu-Sc and Al-Zn-Mg-Sc were studied by thermodynamic calculations. Phase formation was compared with experimental data obtained by DTA and microstructural analysis. Calculated phase diagrams, phase amount charts and enthalpy charts together with non-equilibrium calculations under Scheil conditions reveal significant details of the complex phase formation. This enables consistent and correct interpretation of thermal analysis data. Especially the interpretation of liquidus temperature and primary phase is prone to be wrong without using this tool of computational thermodynamics. All data are predictions from a thermodynamic database developed for Mg-alloys and not a specialized Al-alloy database. That provides support for a reasonable application of this database for advanced Mg-alloys beyond the conventional composition ranges.

Saccharomyces cerevisiae Differential Functionalization of Presumed ScALT1 and ScALT2 Alanine Transaminases Has Been Driven by Diversification of Pyridoxal Phosphate Interactions

Directory of Open Access Journals (Sweden)

Erendira Rojas-Ortega

2018-05-01

Full Text Available Saccharomyces cerevisiae arose from an interspecies hybridization (allopolyploidiza-tion, followed by Whole Genome Duplication. Diversification analysis of ScAlt1/ScAlt2 indicated that while ScAlt1 is an alanine transaminase, ScAlt2 lost this activity, constituting an example in which one of the members of the gene pair lacks the apparent ancestral physiological role. This paper analyzes structural organization and pyridoxal phosphate (PLP binding properties of ScAlt1 and ScAlt2 indicating functional diversification could have determined loss of ScAlt2 alanine transaminase activity and thus its role in alanine metabolism. It was found that ScAlt1 and ScAlt2 are dimeric enzymes harboring 67% identity and intact conservation of the catalytic residues, with very similar structures. However, tertiary structure analysis indicated that ScAlt2 has a more open conformation than that of ScAlt1 so that under physiological conditions, while PLP interaction with ScAlt1 allows the formation of two tautomeric PLP isomers (enolimine and ketoenamine ScAlt2 preferentially forms the ketoenamine PLP tautomer, indicating a modified polarity of the active sites which affect the interaction of PLP with these proteins, that could result in lack of alanine transaminase activity in ScAlt2. The fact that ScAlt2 forms a catalytically active Schiff base with PLP and its position in an independent clade in “sensu strictu” yeasts suggests this protein has a yet undiscovered physiological function.

Saccharomyces cerevisiae Differential Functionalization of Presumed ScALT1 and ScALT2 Alanine Transaminases Has Been Driven by Diversification of Pyridoxal Phosphate Interactions

Science.gov (United States)

Rojas-Ortega, Erendira; Aguirre-López, Beatriz; Reyes-Vivas, Horacio; González-Andrade, Martín; Campero-Basaldúa, Jose C.; Pardo, Juan P.; González, Alicia

2018-01-01

Saccharomyces cerevisiae arose from an interspecies hybridization (allopolyploidiza-tion), followed by Whole Genome Duplication. Diversification analysis of ScAlt1/ScAlt2 indicated that while ScAlt1 is an alanine transaminase, ScAlt2 lost this activity, constituting an example in which one of the members of the gene pair lacks the apparent ancestral physiological role. This paper analyzes structural organization and pyridoxal phosphate (PLP) binding properties of ScAlt1 and ScAlt2 indicating functional diversification could have determined loss of ScAlt2 alanine transaminase activity and thus its role in alanine metabolism. It was found that ScAlt1 and ScAlt2 are dimeric enzymes harboring 67% identity and intact conservation of the catalytic residues, with very similar structures. However, tertiary structure analysis indicated that ScAlt2 has a more open conformation than that of ScAlt1 so that under physiological conditions, while PLP interaction with ScAlt1 allows the formation of two tautomeric PLP isomers (enolimine and ketoenamine) ScAlt2 preferentially forms the ketoenamine PLP tautomer, indicating a modified polarity of the active sites which affect the interaction of PLP with these proteins, that could result in lack of alanine transaminase activity in ScAlt2. The fact that ScAlt2 forms a catalytically active Schiff base with PLP and its position in an independent clade in “sensu strictu” yeasts suggests this protein has a yet undiscovered physiological function. PMID:29867852

Three-flavor color superconductivity

Energy Technology Data Exchange (ETDEWEB)

Malekzadeh, H.

2007-12-15

I investigate some of the inert phases in three-flavor, spin-zero color-superconducting quark matter: the CFL phase (the analogue of the B phase in superfluid {sup 3}He), the A and A{sup *} phases, and the 2SC and sSC phases. I compute the pressure of these phases with and without the neutrality condition. Without the neutrality condition, after the CFL phase the sSC phase is the dominant phase. However, including the neutrality condition, the CFL phase is again the energetically favored phase except for a small region of intermediate densities where the 2SC/A{sup *} phase is favored. It is shown that the 2SC phase is identical to the A{sup *} phase up to a color rotation. In addition, I calculate the self-energies and the spectral densities of longitudinal and transverse gluons at zero temperature in color-superconducting quark matter in the CFL phase. I find a collective excitation, a plasmon, at energies smaller than two times the gap parameter and momenta smaller than about eight times the gap. The dispersion relation of this mode exhibits a minimum at some nonzero value of momentum, indicating a van Hove singularity. (orig.)

Three-flavor color superconductivity

International Nuclear Information System (INIS)

Malekzadeh, H.

2007-12-01

I investigate some of the inert phases in three-flavor, spin-zero color-superconducting quark matter: the CFL phase (the analogue of the B phase in superfluid 3 He), the A and A * phases, and the 2SC and sSC phases. I compute the pressure of these phases with and without the neutrality condition. Without the neutrality condition, after the CFL phase the sSC phase is the dominant phase. However, including the neutrality condition, the CFL phase is again the energetically favored phase except for a small region of intermediate densities where the 2SC/A * phase is favored. It is shown that the 2SC phase is identical to the A * phase up to a color rotation. In addition, I calculate the self-energies and the spectral densities of longitudinal and transverse gluons at zero temperature in color-superconducting quark matter in the CFL phase. I find a collective excitation, a plasmon, at energies smaller than two times the gap parameter and momenta smaller than about eight times the gap. The dispersion relation of this mode exhibits a minimum at some nonzero value of momentum, indicating a van Hove singularity. (orig.)

Magnetic Compton scattering study of Laves phase ZrFe2 and Sc doped ZrFe2: Experiment and Green function based relativistic calculations

Science.gov (United States)

Bhatt, Samir; Mund, H. S.; Kumar, Kishor; Bapna, Komal; Dashora, Alpa; Itou, M.; Sakurai, Y.; Ahuja, B. L.

2018-05-01

Spin momentum densities of ferromagnetic ZrFe2 and Zr0.8Sc0.2Fe2 have been measured using magnetic Compton scattering with 182.65 keV circularly polarized synchrotron radiations. Site specific spin moments, which are responsible for the formation of total spin moment, have been deduced from Compton line shapes. At room temperature, the computed spin moment of ZrFe2 is found to be slightly higher than that of Sc doped ZrFe2 which is in consensus with the magnetization data. To compare the experimental data, we have also computed magnetic Compton profiles (MCPs), total and partial spin projected density of states (DOS) and the site specific spin moments using spin-polarized relativistic Korringa-Kohn-Rostoker method. It is observed that the spin moment at Fe site is aligned antiparallel to that of Zr site in both ZrFe2 and Zr0.8Sc0.2Fe2. The MCP results when compared with vibrating sample magnetometer based magnetization data, show a very small contribution of orbital moment in the formation of total magnetic moments in both the compounds. The DOS of ferromagnetic ground state of ZrFe2 and Zr0.8Sc0.2Fe2 are interpreted on the basis of a covalent magnetic model beyond the Stoner rigid band model. It appears that on alloying between a magnetic and a non-magnetic partner (with low valence), a polarization develops on the non-magnetic atom which is anti-parallel to that of the magnetic atom.

44Sc-DOTA-BN[2-14]NH2 in comparison to 68Ga-DOTA-BN[2-14]NH2 in pre-clinical investigation. Is 44Sc a potential radionuclide for PET?

Science.gov (United States)

Koumarianou, E; Loktionova, N S; Fellner, M; Roesch, F; Thews, O; Pawlak, D; Archimandritis, S C; Mikolajczak, R

2012-12-01

In the present study we demonstrate the in vitro and in vivo comparison of the (44)Sc and (68)Ga labeled DOTA-BN[2-14]NH(2). (44)Sc is a positron emitter with a half life of 3.92 h. Hence it could be used for PET imaging with ligands requiring longer observation time than in the case of (68)Ga. The binding affinity of (nat)Sc-DOTA-BN[2-14]NH(2) and (nat)Ga-DOTA-BN[2-14]NH(2) to GRP receptors was studied in competition to [(125)I-Tyr(4)]-Bombesin in the human prostate cancer cell line PC-3. A preliminary biodistribution in normal rats was performed, while first microPET images were assessed in male Copenhagen rats bearing the androgen-independent Dunning R-3327-AT-1 prostate cancer tumor. The affinity to GRP receptors in the PC-3 cell line was higher for (nat)Ga-DOTA-BN[2-14]NH(2) (IC(50)(nM)=0.85 ± 0.06) than that of (nat)Sc-DOTA-BN[2-14]NH(2) (IC(50) (nM)=6.49 ± 0.13). The internalization rate of (68)Ga labeled DOTA-BN[2-14]NH(2) was slower than that of (44)Sc, but their final internalization percents were comparable. (68)Ga-DOTA-BN[2-14]NH(2) was externalized faster than (44)Sc-DOTA-BN[2-14]NH(2). The biodistribution of (44)Sc-DOTA-BN[2-14]NH(2) and (68)Ga-DOTA-BN[2-14]NH(2) in normal rats revealed a higher uptake in target organs and tissues of the first one while both excreted mainly through urinary tract. In microPET images both tracers were accumulated in the tumor with similar uptake patterns. Despite the differences in the receptor affinity both the (68)Ga- and the (44)Sc-labeled DOTA-BN[2-14]NH(2) tracers showed comparable distribution and similar time constants of uptake and elimination. Moreover no differences in tumor accumulation (neither in the overall uptake nor in the dynamics) were observed from the microPet imaging. From that perspective the use of either (44)Sc or (68)Ga for detecting tumors with GRP receptors is equivalent. Copyright © 2012 Elsevier Ltd. All rights reserved.

Noninterferometric phase imaging of a neutral atomic beam

International Nuclear Information System (INIS)

Fox, P.J.; Mackin, T.R.; Turner, L.D.; Colton, I.; Nugent, K.A.; Scholten, R.E.

2002-01-01

We demonstrate quantitative phase imaging of a neutral atomic beam by using a noninterferometric technique. A collimated thermal atomic beam is phase shifted by an off-resonant traveling laser beam with both a Gaussian and a TEM 01 profile and with both red and blue detuning of as much as 50 GHz. Phase variations of more than 1000 rad were recovered from velocity-selective measurements of the propagation of the atomic beam and were found to be in quantitative agreement with theoretical predictions based on independently measured phase object intensity profiles and detunings

Solid solubility, phase transitions, thermal expansion, and compressibility in Sc{sub 1−x}Al{sub x}F{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Morelock, Cody R.; Gallington, Leighanne C. [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400 (United States); Wilkinson, Angus P., E-mail: angus.wilkinson@chemistry.gatech.edu [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400 (United States); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States)

2015-02-15

With the goal of thermal expansion control, the synthesis and properties of Sc{sub 1−x}Al{sub x}F{sub 3} were investigated. The solubility limit of AlF{sub 3} in ScF{sub 3} at ∼1340 K is ∼50%. Solid solutions (x≤0.50) were characterized by synchrotron powder diffraction at ambient pressure between 100 and 900 K and at pressures <0.414 GPa while heating from 298 to 523 K. A phase transition from cubic to rhombohedral is observed. The transition temperature increases smoothly with Al{sup 3+} content, approaching 500 K at the solid solubility limit, and also upon compression at fixed Al{sup 3+} content. The slope of the pressure–temperature phase boundary is ∼0.5 K MPa{sup −1}, which is steep relative to that for most symmetry-lowering phase transitions in perovskites. The volume coefficient of thermal expansion (CTE) for the rhombohedral phase is strongly positive, but the cubic-phase CTE varies from negative (x<0.15) to near-zero (x=0.15) to positive (x>0.20) between ∼600 and 800 K. The cubic solid solutions elastically stiffen on heating, while Al{sup 3+} substitution causes softening at a given temperature. - Graphical abstract: The cubic-phase coefficient of thermal expansion for Sc{sub 1−x}Al{sub x}F{sub 3}(solubility limit ∼50% at ∼1340 K) becomes more positive with increased Al{sup 3+} substitution, but the average isothermal bulk modulus decreases (elastic softening). - Highlights: • The solubility limit of AlF{sub 3} in ScF{sub 3} at ∼1340 K is ∼50%. • The phase transition temperature of Sc{sub 1−x}Al{sub x}F{sub 3} increases smoothly with x. • The cubic-phase volume CTE varies from negative to positive with increasing x. • The cubic solid solutions elastically stiffen on heating. • Al{sup 3+} substitution causes softening at a given temperature.

Clustering and phase transitions on a neutral landscape

Science.gov (United States)

Scott, Adam D.; King, Dawn M.; Marić, Nevena; Bahar, Sonya

2013-06-01

Recent computational studies have shown that speciation can occur under neutral conditions, i.e., when the simulated organisms all have identical fitness. These works bear comparison with mathematical studies of clustering on neutral landscapes in the context of branching and coalescing random walks. Here, we show that sympatric clustering/speciation can occur on a neutral landscape whose dimensions specify only the simulated organisms’ phenotypes. We demonstrate that clustering occurs not only in the case of assortative mating, but also in the case of asexual fission; it is not observed in the control case of random mating. We find that the population size and the number of clusters undergo a second-order non-equilibrium phase transition as the maximum mutation size is varied.

Some peculiarities of ScFe2 and ScNi2 interaction with ammonia in the presence of NH4Cl

International Nuclear Information System (INIS)

Shilkin, S.P.; Fokin, V.N.; Fokina, Eh.Eh.; Tarasov, B.P.; Korobkov, I.I.

2000-01-01

Interaction of ScFe 2 and ScNi 2 intermetallic compounds with ammonia in the presence of NH 4 Cl (10 mass % from intermetallide introduced in reaction) as an activator of the process in initial ammonia pressure 0.6-0.8 MPa is investigated. Possibility of preparation of crystalline intermetallide hydrides and amorphous products in highly dispersed state at different temperature are shown. It is established that intermetallides decompose in ammonia medium at ≥ 450 Deg C [ru

Rotary condenser for SC2

CERN Multimedia

1975-01-01

During 1975 the SC2 performance was improved among other things by redesigning some of the elements of the ROTCO (Annual Report 1975, p. 55). The photo shows an interior wiew of the housing of the rotary condenser and of the sixteen sets of shaped stator blades.

Functional characterization of two scFv-Fc antibodies from an HIV controller selected on soluble HIV-1 Env complexes: a neutralizing V3- and a trimer-specific gp41 antibody.

Directory of Open Access Journals (Sweden)

Maria Trott

Full Text Available HIV neutralizing antibodies (nAbs represent an important tool in view of prophylactic and therapeutic applications for HIV-1 infection. Patients chronically infected by HIV-1 represent a valuable source for nAbs. HIV controllers, including long-term non-progressors (LTNP and elite controllers (EC, represent an interesting subgroup in this regard, as here nAbs can develop over time in a rather healthy immune system and in the absence of any therapeutic selection pressure. In this study, we characterized two particular antibodies that were selected as scFv antibody fragments from a phage immune library generated from an LTNP with HIV neutralizing antibodies in his plasma. The phage library was screened on recombinant soluble gp140 envelope (Env proteins. Sequencing the selected peptide inserts revealed two major classes of antibody sequences. Binding analysis of the corresponding scFv-Fc derivatives to various trimeric and monomeric Env constructs as well as to peptide arrays showed that one class, represented by monoclonal antibody (mAb A2, specifically recognizes an epitope localized in the pocket binding domain of the C heptad repeat (CHR in the ectodomain of gp41, but only in the trimeric context. Thus, this antibody represents an interesting tool for trimer identification. MAb A7, representing the second class, binds to structural elements of the third variable loop V3 and neutralizes tier 1 and tier 2 HIV-1 isolates of different subtypes with matching critical amino acids in the linear epitope sequence. In conclusion, HIV controllers are a valuable source for the selection of functionally interesting antibodies that can be selected on soluble gp140 proteins with properties from the native envelope spike.

Reaction of intermetallic compounds of the ScT composition (T=Ag, Cu, Zn, Ni) with hydrogen

International Nuclear Information System (INIS)

Shilkin, S.P.; Volkova, L.S.; Tarasov, B.P.

1995-01-01

Reaction of intermetallic compounds of ScT composition (T=Ag, Cu, Zn, Ni), crystallized in CsCl structural type, with hydrogen at 0.2-10 MPa pressure and 293-673 K temperature is studied by chemical, x-ray phase and complex thermogravimetry analysis methods. It is shown that under such conditions hydrogen absorption by ScAg and ScCu is accompanied by the decay of their source matrices into scandium dihydride and metal silver and copper respectively. For ScZn a fine-dispersion mixture of scandium dihydride with zinc and hydride phase of a new zinc-containing intermetallic compound appears to be the finite reaction product. In case of ScNi a hydride phase of ScNiH 2.6 composition is produced, which is crystallized in a rhombic syngony with the lattice periods: a=0.5281±0.0007, b=0.7393±0.0009 and c=0.3327±0.0004 nm. 9 refs.; 2 tabs

Solubility and phase behaviors of DGA compounds in supercritical CO2

International Nuclear Information System (INIS)

Li Jia; Meng Qingyang

2010-01-01

Solubility and phase behaviors of DGA compounds in supercritical CO 2 (Sc-CO 2 ) was investigated. The results indicated: The dissolving ability of these six DGA compounds in Sc-CO 2 is TEDGA> TBDGA>THDGA>TODGA>TDDGA >TDdDGA; The solubility of DGA in Sc-CO 2 increase with increasing density of CO 2 , pressure and δ CO 2 ; The structure of DGA compounds is the mainly factor effected on solubility of DGA compounds in Sc-CO 2 , and the effect of hydrophobicity on solubility is much smaller than that of DGA's structure. In Sc-CO 2 , TDDGA and TDdDGA can't form the available extraction system; TEDGA and TBDGA are useful for extraction of solid powder; TODGA and THDGA are both useful for extraction of solid powder and solution contained some kind of actinide metal. (authors)

Syntheses, characterization and nonlinear optical properties of sodium-scandium carbonate Na5Sc(CO3)4·2H2O

Science.gov (United States)

Chen, Jie; Luo, Min; Ye, Ning

2014-10-01

A novel nonlinear optical (NLO) material Na5Sc(CO3)4·2H2O has been synthesized under a subcritical hydrothermal condition. The structure is determined by single-crystal X-ray diffraction and further characterized by TG analyses and UV-vis-NIR diffuse reflectance spectrum. It crystallizes in the tetragonal space group P-421c, with a = b = 7.4622(6) Å, C = 11.5928(15) Å. The Second-harmonic generation (SHG) on polycrystalline samples was measured using the Kurtz and Perry technique, which indicated that Na5Sc(CO3)4·2H2O was a phase-matchable material, and its measured SHG coefficient was about 1.8 times as large as that of d36 (KDP). The results from the UV-vis diffuse reflectance spectroscopy study of the powder samples indicated that the short-wavelength absorption edges of Na5Sc(CO3)4·2H2O is about 220 nm, suggesting that this crystal is a promising UV nonlinear optical (NLO) materials.

Synthesis, structure, and photoluminescence properties of novel KBaSc2 (PO4 )3 :Ce(3+) /Eu(2+) /Tb(3+) phosphors for white-light-emitting diodes.

Science.gov (United States)

Jiao, Mengmeng; Lü, Wei; Shao, Baiqi; Zhao, Lingfei; You, Hongpeng

2015-08-24

A series of novel KBaSc2 (PO4 )3 :Ce(3+) /Eu(2+) /Tb(3+) phosphors are prepared using a solid-state reaction. X-ray diffraction analysis and Rietveld structure refinement are used to check the phase purity and crystal structure of the prepared samples. Ce(3+) - and Eu(2+) -doped phosphors both have broad excitation and emission bands, owing to the spin- and orbital-allowed electron transition between the 4f and 5d energy levels. By co-doping the KBaSc2 (PO4 )3 :Eu(2+) and KBaSc2 (PO4 )3 :Ce(3+) phosphors with Tb(3+) ions, tunable colors from blue to green can be obtained. The critical distance between the Eu(2+) and Tb(3+) ions is calculated by a concentration quenching method and the energy-transfer mechanism for Eu(2+) →Tb(3+) is studied by utilizing the Inokuti-Hirayama model. In addition, the quantum efficiencies of the prepared samples are measured. The results indicate that KBaSc2 (PO4 )3 :Eu(2+) ,Tb(3+) and KBaSc2 (PO4 )3 :Ce(3+) ,Tb(3+) phosphors might have potential applications in UV-excited white-light-emitting diodes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermoelectric performance of functionalized Sc2C MXenes

KAUST Repository

Kumar, S.; Schwingenschlö gl, Udo

2016-01-01

Functionalization of the MXene Sc2C, which has the rare property to realize semiconducting states for various functionalizations including O, F, and OH, is studied with respect to the electronic and thermal behavior. The lowest lattice thermal conductivity is obtained for OH functionalization and an additional 30% decrease can be achieved by confining the phonon mean free path to 100 nm. Despite a relatively low Seebeck coefficient, Sc2C(OH)2 is a candidate for intermediate-temperature thermoelectric applications due to compensation by a high electrical conductivity and very low lattice thermal conductivity.

Thermoelectric performance of functionalized Sc2C MXenes

KAUST Repository

Kumar, S.

2016-07-05

Functionalization of the MXene Sc2C, which has the rare property to realize semiconducting states for various functionalizations including O, F, and OH, is studied with respect to the electronic and thermal behavior. The lowest lattice thermal conductivity is obtained for OH functionalization and an additional 30% decrease can be achieved by confining the phonon mean free path to 100 nm. Despite a relatively low Seebeck coefficient, Sc2C(OH)2 is a candidate for intermediate-temperature thermoelectric applications due to compensation by a high electrical conductivity and very low lattice thermal conductivity.

Observed travel times for Multiply-reflected ScS waves from a deep-focus earthquake

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A. F. ESPISOSA

1966-06-01

Full Text Available Tlie deep-focus Argentinean earthquake of December 8
1962, generated multiply reflected ScS phases which were recorded very
clearly at stations of the IGY and the TJSC&GS standardized worldwide
networks and at Canadian stations. The data gathered from this earthquake
for the multiply-reflected ScS and sScS were used to construct the
travel times and to extend them to shorter epicentral distances. These
new data brought to light an error in published travel times for the 2(ScS
phase.

Direct formation of new, phase-stable, and photoactive anatase-type Ti1-2XNbXScXO2 solid solution nanoparticles by hydrothermal method

International Nuclear Information System (INIS)

Hirano, Masanori; Ito, Takaharu

2008-01-01

A new anatase phase of photoactive Ti 1-2X Nb X Sc X O 2 (X = 0-0.2) solid solutions was directly formed as nanoparticles from precursor solutions of TiOSO 4 , NbCl 5 , and Sc(NO 3 ) 3 under mild hydrothermal conditions at 180 deg. C for 5 h using the hydrolysis of urea. With the increase of the content of niobium and scandium from X = 0 to 0.2, the lattice parameters a 0 and c 0 , the crystallite size, and the optical band gap of anatase gradually increased. Their photocatalytic activity and adsorptivity were evaluated separately by the measurement of the concentration of methylene blue (MB) remained in the solution in the dark or under UV-light irradiation. The anatase-type Ti 1-2X Nb X Sc X O 2 (X = 0.05) showed approximately two times and three times as high photocatalytic activity as those of the hydrothermal anatase-type pure TiO 2 and commercially available reference pure TiO 2 (ST-01), respectively. The anatase phase of Ti 1-2X Nb X Sc X O 2 (X = 0-0.2) existed stably up to 900 deg. C during heat treatment in air. New rutile-type Ti 1-2X Nb X Sc X O 2 solid solutions are formed through the phase transformation. The starting temperature of anatase-to-rutile phase transformation for Ti 1-2X Nb X Sc X O 2 (X = 0-0.2) solid solutions was delayed but its completing temperature was accelerated

Polymorphous GdScO3 as high permittivity dielectric

International Nuclear Information System (INIS)

Schäfer, A.; Rahmanizadeh, K.; Bihlmayer, G.; Luysberg, M.; Wendt, F.; Besmehn, A.; Fox, A.

2015-01-01

Four different polymorphs of GdScO 3 are assessed theoretically and experimentally with respect to their suitability as a dielectric. The calculations carried out by density functional theory reveal lattice constants, band gaps and the energies of formation of three crystal phases. Experimentally all three crystal phases and the amorphous phase can be realized as thin films by pulsed laser deposition using various growth templates. Their respective crystal structures are confirmed by X-ray diffraction and transmission electron microscopy reflecting the calculated lattice constants. X-ray photoelectron spectroscopy unveils the band gaps of the different polymorphs of GdScO 3 which are above 5 eV for all films demonstrating good insulating properties. From capacitance voltage measurements, high permittivities of up to 27 for hexagonal GdScO 3 are deduced. - Highlights: • Different epitaxial polymorph phases of GdScO 3 were grown by pulsed laser deposition. • The cubic phase of GdScO 3 is reported for the first time. • All phases are proven to be useful for the use in silicon based and III–V based microelectronic devices.

Effects of trace Be and Sc addition on the thermal stability of Al–7Si–0.6Mg alloys

Energy Technology Data Exchange (ETDEWEB)

Tzeng, Yu-Chih [Department of Mechanical Engineering, National Central University, Jhongli, Taiwan (China); Wu, Chih-Ting [Department of Vehicle Engineering, Army Academy R.O.C., Jhongli, Taiwan (China); Yang, Cheng-Hsien [Institute of Materials Science and Engineering, National Central University, Jhongli, Taiwan (China); Lee, Sheng-Long, E-mail: shenglon@cc.ncu.edu.tw [Department of Mechanical Engineering, National Central University, Jhongli, Taiwan (China)

2014-09-22

In the present study, the effects of trace amounts of beryllium (Be, 0.05 wt%) and scandium (Sc, 0.04 wt%) addition on the microstructures and thermal stability of Al–7Si–0.6Mg alloys were investigated. The results show that traces of Be and Sc significantly reduce the amount of the iron-bearing phase and the interdendritic shrinkage. Be transformed the acicular iron-bearing phases into the nodular Al–Fe–Si iron-bearing phase, which is less harmful to ductility. Moreover, the addition of Be increased the Mg content of the solid solution within the matrix, prompting greater precipitation of the metastable Mg{sub 2}Si phase after T6 heat treatment and effectively enhancing the mechanical properties of the alloy. However, during the following thermal exposure at 250 °C for 100 h, the metastable Mg{sub 2}Si phase grew into the coarse β-Mg{sub 2}Si equilibrium phase, resulting in a decrease in the mechanical strength of the alloy. Meanwhile, the addition of Sc had insignificant effect on the amount of metastable Mg{sub 2}Si phase that precipitated. However, here, the iron-bearing phase was a nodular Al{sub 12}Si{sub 6}Fe{sub 2}(Mg,Sc){sub 5} phase, which significantly enhanced the density of the castings. After the same thermal exposure procedure, it was remarkably found that the precipitation of fine Al{sub 3}Sc particles effectively inhibited grain growth and hindered the movement of dislocations. These factors led to the Sc-containing alloy having better mechanical properties (strength and ductility) than the alloys without Sc or with Be during the following thermal exposure at 250 °C.

X-ray spectra, chemical bonding, and electron structure of ScM2Si2 (M = Fe, Co, Ni)

International Nuclear Information System (INIS)

Shcherba, I.D.; Kotur, B.Ya.

1990-01-01

In a study of the interaction of the components in the ternary systems Sc-M-Si (where M is a 3d transition metal) it was established that there are compounds of the empirical formula ScM 2 Si 2 (M = Fe, Co, Ni). They crystallize in two structural types, HfFe 2 Si 2 (the compound ScFe 2 Si 2 ) and CeGa 2 Al 2 (ScCo 2 Si 2 and ScNi 2 Si 2 ) (ref. 1), leading to different coordination environment of the atoms in the structures of the compounds. With the aim of investigating the electron structure and the type ofin these compounds, they authors made a systematic x-ray spectral investigation with simultaneous analysis of the crystal structures of ScM 2 Si 2

Magnet measuring equipment of SC2

CERN Multimedia

CERN PhotoLab

1974-01-01

Checking the positioning of the magnet measuring equipment installed between the poles of SC2. The steel structure in front of the magnet is designed to house the rotary condenser and to shield it from the stray magnetic field of the accelerator.

Luminescent and scintillation properties of Sc3+and La3+doped Y2SiO5 powders and single crystalline films

International Nuclear Information System (INIS)

Zorenko, Yu.; Gorbenko, V.; Zorenko, T.; Voznyak, T.; Voloshynovskii, A.; Vistovskiy, V.; Paprocki, K.; Mosińska, L.; Bilski, P.; Twardak, A.; Fedorov, A.; Nikl, M.; Mares, J.A.

2016-01-01

The paper is dedicated to the investigation of the luminescence of Sc 3+ and La 3+ isoelectronic impurities in Y 2 SiO 5 (YSO) single crystalline films (SCF), grown by the liquid phase epitaxy (LPE) method, and in the powder analogs of these compounds prepared using the ceramic technology. The Sc 3+ and La 3+ dopants replacing the Y 3+ cations in Y1and Y2 positions of YSO host introduce the strong complex emission bands in the UV range peaked at 330 and 345 nm, respectively. The Sc 3+ and La 3+ dopant in YSO matrix yields also the strong TSL peaks at 400 and 405 K related to the ScY and ScLa centers formation, respectively. The luminescence and scintillation properties of YSO SCFs doped with Sc 3+ and La 3+ ions and co-doped with Ce 3+ ions on the trace impurity level have been also studied in our work. We have found that the light yield (LY) of these YSO:Sc and YSO:La SCFs can reach 50–65% of LY in reference YSO:Ce SCF due to strong quenching influence of Pb 2+ ions. Finally, the potential of Sc 3+ and La 3+ doped SCF of orthosilicates for creation of heavy scintillation screens, emitting in the UV range, is discussed.

Gadolinium scandium germanide, Gd2Sc3Ge4

Directory of Open Access Journals (Sweden)

Sumohan Misra

2009-04-01

Full Text Available Gd2Sc3Ge4 adopts the orthorhombic Pu5Rh4-type structure. The crystal structure contains six sites in the asymmetric unit: two sites are statistically occupied by rare-earth atoms with Gd:Sc ratios of 0.967 (4:0.033 (4 and 0.031 (3:0.969 (3, one site (.m. symmetry is occupied by Sc atoms, and three distinct sites (two of which with .m. symmetry are occupied by Ge atoms. The rare-earth atoms form two-dimensional slabs with Ge atoms occupying the trigonal-prismatic voids.

Characterizing Phase Transitions in a Model of Neutral Evolutionary Dynamics

Science.gov (United States)

Scott, Adam; King, Dawn; Bahar, Sonya

2013-03-01

An evolutionary model was recently introduced for sympatric, phenotypic evolution over a variable fitness landscape with assortative mating (Dees & Bahar 2010). Organisms in the model are described by coordinates in a two-dimensional phenotype space, born at random coordinates with limited variation from their parents as determined by a mutation parameter, mutability. The model has been extended to include both neutral evolution and asexual reproduction in Scott et al (submitted). It has been demonstrated that a second order, non-equilibrium phase transition occurs for the temporal dynamics as the mutability is varied, for both the original model and for neutral conditions. This transition likely belongs to the directed percolation universality class. In contrast, the spatial dynamics of the model shows characteristics of an ordinary percolation phase transition. Here, we characterize the phase transitions exhibited by this model by determining critical exponents for the relaxation times, characteristic lengths, and cluster (species) mass distributions. Missouri Research Board; J.S. McDonnell Foundation

SC*994C>T causes the Sc(null) phenotype in Pacific Islanders and successful transfusion of Sc3+ blood to a patient with anti-Sc3.

Science.gov (United States)

Reid, Marion E; Hue-Roye, Kim; Velliquette, Randall W; Larimore, Kathleen; Moscarelli, Sue; Ohswaldt, Nicolas; Lomas-Francis, Christine

2013-01-01

Antigens in the SC blood group system are expressed by the human erythrocyte membrane-associated protein (ERMAP).Two molecular bases have been reported for the Sc,un phenotype:SC*307del2 and SC*994C>T. We report our investigation of the molecular background of five Sc,n1 individuals from the Pacific Islands and describe the successful transfusion of Sc3+ blood to a patient with anti-Sc3 in her plasma. SC (ERMAP) exons 2,3, and 12 and their flanking intronic regions were analyzed. TheSC*994C>T change introduces a restriction enzyme cleavage site for Tsp45I, and polymerase chain reaction (PCR) products from exon 12 were subjected to this PCR-restriction fragment length polymorphism (RFLP) assay. The five samples had the variant SC*994T/T. One sample, from a first cousin of one Marshallese proband, was heterozygous for SC*1514C/T (in the 3' untranslated region); the other four samples were SC*1514C/C(consensus sequence). Samples from white donors (n = 100) and African American donors (n = 99) were tested using the Tsp45IPCR-RFLP assay; all gave a banding pattern that was consistent with the SC*994C/C consensus sequence. In all five samples,our analyses showed homozygosity for the nonsense nucleotide change SC*994C>Tin an allele carrying the nucleotide associated with SLd. Further investigation determined that one of the probands reported previously with the SC*994C>T change was from the Marshall Islands (which form part of the Micronesian Pacific Islands) and the other was from an unspecified location within the large collection of Pacific Islands. Taken together, the five known probands with the SC*994C>T silencing nucleotide change were from the Pacific Islands.

Use of antifungal Saponin SC-2 of Solanum chrysotrichum for the ...

African Journals Online (AJOL)

Fungistatic and fungicidal activity of saponin SC-2 on Candida albicans and other Candida species, fluconazole and ketoconazole resistaent strains was demostrated. SC-2-associated ultrastructural alterations in several Candida species were observed. An exploratory clinical, randomized, double-blind, and controlled ...

Tungsten phosphanylarylthiolato complexes [W{PhP(2-SC6H4)2-kappa3S,S',P} 2] and [W{P(2-SC6H4)3-kappa4S,S',S",P}2]: synthesis, structures and redox chemistry.

Science.gov (United States)

Hildebrand, Alexandra; Lönnecke, Peter; Silaghi-Dumitrescu, Luminita; Hey-Hawkins, Evamarie

2008-09-14

PhP(2-SHC6H4)2 (PS2H2) reacts with WCl6 with reduction of tungsten to give the air-sensitive tungsten(IV) complex [W{PhP(2-SC6H4)2-kappa(3)S,S',P}2] (1). 1 is oxidised in air to [WO{PhPO(2-SC6H4)2-kappa(3)S,S',O}{PhP(2-SC6H4)2-kappa(3)S,S',P}] (2). The attempted synthesis of 2 by reaction of 1 with iodosobenzene as oxidising agent was unsuccessful. [W{P(2-SC6H4)3-kappa(4)S,S',S",P}2] (3) was formed in the reaction of P(2-SHC6H4)3 (PS3H3) with WCl6. The W(VI) complex 3 contains two PS3(3-) ligands, each coordinated in a tetradentate fashion resulting in a tungsten coordination number of eight. The reaction of 3 with AgBF4 yields the dinuclear tungsten complex [W2{P(2-SC6H4)3-kappa(4)S,S',S",P}3]BF4 (4). Complexes 1-4 were characterised by spectral methods and X-ray structure determination.

Enrichment of Sc{sub 2}O{sub 3} and TiO{sub 2} from bauxite ore residues

Energy Technology Data Exchange (ETDEWEB)

Deng, Bona; Li, Guanghui, E-mail: liguangh@csu.edu.cn; Luo, Jun; Ye, Qing; Liu, Mingxia; Peng, Zhiwei; Jiang, Tao

2017-06-05

Highlights: • Sc{sub 2}O{sub 3} and TiO{sub 2} from bauxite ore residue were successfully enriched. • H{sub 3}PO{sub 4} and NaOH were efficient for enriching Sc{sub 2}O{sub 3} and TiO{sub 2} by removing SiO{sub 2}, Al{sub 2}O{sub 3}, and partial Fe{sub 2}O{sub 3} and CaO. • Enriching mechanism of Sc{sub 2}O{sub 3} and TiO{sub 2} was explicitly explained. - Abstract: As a major byproduct generated in the alumina industry, bauxite ore residue is an important reserve of scandium and titanium. In this study, the feasibility and mechanism of enriching Sc{sub 2}O{sub 3} and TiO{sub 2} from a non-magnetic material, which was obtained from carbothermal reductive roasting and magnetic separation of bauxite ore residue, were investigated based on a two-step (acidic and alkali) leaching process. It was revealed that approximately 78% SiO{sub 2} and 30–40% of CaO, FeO and Al{sub 2}O{sub 3} were removed from a non-magnetic material with 0.0134 wt.% Sc{sub 2}O{sub 3} and 7.64 wt.% TiO{sub 2} by phosphoric acidic leaching, while about 95% Al{sub 2}O{sub 3} and P{sub 2}O{sub 5} were further leached by subsequent sodium hydroxide leaching of the upper-stream leach residue. A Sc{sub 2}O{sub 3}-, TiO{sub 2}- rich material containing 0.044 wt.% Sc{sub 2}O{sub 3} and 25.5 wt.% TiO{sub 2} was obtained, the recovery and the enrichment factor of Sc{sub 2}O{sub 3} and TiO{sub 2} were about 85% and 5, respectively. The enrichment of Sc{sub 2}O{sub 3} was attributed to higher pH (>3.3) of phosphoric acid solution than its dissolution pH{sup 0}, and the enrichment of TiO{sub 2} was mainly associated with the insoluble perovskite (CaTiO{sub 3}) in the acidic solution at ambient temperature. As Sc{sub 2}O{sub 3} and TiO{sub 2} cannot be dissolved in the alkali solution, they were further enriched in the leach residue.

Solution Synthesis, Structure, and CO2 Reduction Reactivity of a Scandium(II) Complex, {Sc[N(SiMe3 )2 ]3 }.

Science.gov (United States)

Woen, David H; Chen, Guo P; Ziller, Joseph W; Boyle, Timothy J; Furche, Filipp; Evans, William J

2017-02-13

The first crystallographically characterizable complex of Sc 2+ , [Sc(NR 2 ) 3 ] - (R=SiMe 3 ), has been obtained by LnA 3 /M reactions (Ln=rare earth metal; A=anionic ligand; M=alkali metal) involving reduction of Sc(NR 2 ) 3 with K in the presence of 2.2.2-cryptand (crypt) and 18-crown-6 (18-c-6) and with Cs in the presence of crypt. Dark maroon [K(crypt)] + , [K(18-c-6)] + , and [Cs(crypt)] + salts of the [Sc(NR 2 ) 3 ] - anion are formed, respectively. The formation of this oxidation state of Sc is also indicated by the eight-line EPR spectra arising from the I=7/2 45 Sc nucleus. The Sc(NR 2 ) 3 reduction differs from Ln(NR 2 ) 3 reactions (Ln=Y and lanthanides) in that it occurs under N 2 without formation of isolable reduced dinitrogen species. [K(18-c-6)][Sc(NR 2 ) 3 ] reacts with CO 2 to produce an oxalate complex, {K 2 (18-c-6) 3 }{[(R 2 N) 3 Sc] 2 (μ-C 2 O 4 -κ 1 O:κ 1 O'')}, and a CO 2 - radical anion complex, [(R 2 N) 3 Sc(μ-OCO-κ 1 O:κ 1 O')K(18-c-6)] n . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Three Monoclonal Antibody Combination Potently Neutralizes Multiple Botulinum Neurotoxin Serotype E Subtypes

Directory of Open Access Journals (Sweden)

Consuelo Garcia-Rodriguez

2018-03-01

Full Text Available Human botulism is most commonly caused by botulinum neurotoxin (BoNT serotypes A, B, and E. For this work, we sought to develop a human monoclonal antibody (mAb-based antitoxin capable of binding and neutralizing multiple subtypes of BoNT/E. Libraries of yeast-displayed single chain Fv (scFv antibodies were created from the heavy and light chain variable region genes of humans immunized with pentavalent-toxoid- and BoNT/E-binding scFv isolated by Fluorescence-Activated Cell Sorting (FACS. A total of 10 scFv were isolated that bound one or more BoNT/E subtypes with nanomolar-level equilibrium dissociation constants (KD. By diversifying the V-regions of the lead mAbs and selecting for cross-reactivity, we generated three scFv that bound all four BoNT/E subtypes tested at three non-overlapping epitopes. The scFvs were converted to IgG that had KD values for the different BoNT/E subtypes ranging from 9.7 nM to 2.28 pM. An equimolar combination of the three mAbs was able to potently neutralize BoNT/E1, BoNT/E3, and BoNT/E4 in a mouse neutralization assay. The mAbs have potential utility as therapeutics and as diagnostics capable of recognizing multiple BoNT/E subtypes. A derivative of the three-antibody combination (NTM-1633 is in pre-clinical development with an investigational new drug (IND application filing expected in 2018.

A Three Monoclonal Antibody Combination Potently Neutralizes Multiple Botulinum Neurotoxin Serotype E Subtypes.

Science.gov (United States)

Garcia-Rodriguez, Consuelo; Razai, Ali; Geren, Isin N; Lou, Jianlong; Conrad, Fraser; Wen, Wei-Hua; Farr-Jones, Shauna; Smith, Theresa J; Brown, Jennifer L; Skerry, Janet C; Smith, Leonard A; Marks, James D

2018-03-01

Human botulism is most commonly caused by botulinum neurotoxin (BoNT) serotypes A, B, and E. For this work, we sought to develop a human monoclonal antibody (mAb)-based antitoxin capable of binding and neutralizing multiple subtypes of BoNT/E. Libraries of yeast-displayed single chain Fv (scFv) antibodies were created from the heavy and light chain variable region genes of humans immunized with pentavalent-toxoid- and BoNT/E-binding scFv isolated by Fluorescence-Activated Cell Sorting (FACS). A total of 10 scFv were isolated that bound one or more BoNT/E subtypes with nanomolar-level equilibrium dissociation constants (K D ). By diversifying the V-regions of the lead mAbs and selecting for cross-reactivity, we generated three scFv that bound all four BoNT/E subtypes tested at three non-overlapping epitopes. The scFvs were converted to IgG that had K D values for the different BoNT/E subtypes ranging from 9.7 nM to 2.28 pM. An equimolar combination of the three mAbs was able to potently neutralize BoNT/E1, BoNT/E3, and BoNT/E4 in a mouse neutralization assay. The mAbs have potential utility as therapeutics and as diagnostics capable of recognizing multiple BoNT/E subtypes. A derivative of the three-antibody combination (NTM-1633) is in pre-clinical development with an investigational new drug (IND) application filing expected in 2018.

Scandium doping brings speed improvement in Sb2Te alloy for phase change random access memory application.

Science.gov (United States)

Chen, Xin; Zheng, Yonghui; Zhu, Min; Ren, Kun; Wang, Yong; Li, Tao; Liu, Guangyu; Guo, Tianqi; Wu, Lei; Liu, Xianqiang; Cheng, Yan; Song, Zhitang

2018-05-01

Phase change random access memory (PCRAM) has gained much attention as a candidate for nonvolatile memory application. To develop PCRAM materials with better properties, especially to draw closer to dynamic random access memory (DRAM), the key challenge is to research new high-speed phase change materials. Here, Scandium (Sc) has been found it is helpful to get high-speed and good stability after doping in Sb 2 Te alloy. Sc 0.1 Sb 2 Te based PCRAM cell can achieve reversible switching by applying even 6 ns voltage pulse experimentally. And, Sc doping not only promotes amorphous stability but also improves the endurance ability comparing with pure Sb 2 Te alloy. Moreover, according to DFT calculations, strong Sc-Te bonds lead to the rigidity of Sc centered octahedrons, which may act as crystallization precursors in recrystallization process to boost the set speed.

Precipitation in cold-rolled Al-Sc-Zr and Al-Mn-Sc-Zr alloys prepared by powder metallurgy

KAUST Repository

Vlach, Martin

2013-12-01

The effects of cold-rolling on thermal, mechanical and electrical properties, microstructure and recrystallization behaviour of the AlScZr and AlMnScZr alloys prepared by powder metallurgy were studied. The powder was produced by atomising in argon with 1% oxygen and then consolidated by hot extrusion at 350 C. The electrical resistometry and microhardness together with differential scanning calorimetry measurements were compared with microstructure development observed by transmission and scanning electron microscopy, X-ray diffraction and electron backscatter diffraction. Fine (sub)grain structure developed and fine coherent Al3Sc and/or Al3(Sc,Zr) particles precipitated during extrusion at 350 C in the alloys studied. Additional precipitation of the Al3Sc and/or Al3(Sc,Zr) particles and/or their coarsening was slightly facilitated by the previous cold rolling. The presence of Sc,Zr-containing particles has a significant antirecrystallization effect that prevents recrystallization at temperatures minimally up to 420 C. The precipitation of the Al6Mn- and/or Al 6(Mn,Fe) particles of a size ~ 1.0 μm at subgrain boundaries has also an essential antirecrystallization effect and totally suppresses recrystallization during 32 h long annealing at 550 C. The texture development of the alloys seems to be affected by high solid solution strengthening by Mn. The precipitation of the Mn-containing alloy is highly enhanced by a cold rolling. The apparent activation energy of the Al3Sc particles formation and/or coarsening and that of the Al6Mn and/or Al 6(Mn,Fe) particle precipitation in the powder and in the compacted alloys were determined. The cold deformation has no effect on the apparent activation energy values of the Al3Sc-phase and the Al 6Mn-phase precipitation. © 2013 Elsevier Inc.

Precipitation in cold-rolled Al-Sc-Zr and Al-Mn-Sc-Zr alloys prepared by powder metallurgy

KAUST Repository

Vlach, Martin; Stulí ková , Ivana; Smola, Bohumil; Kekule, Tomá š; Kudrnová , Hana; Daniš, Stanislav; Gemma, Ryota; Očená šek, Vladivoj; Má lek, Jaroslav; Tanprayoon, Dhritti; Neubert, Volkmar

2013-01-01

The effects of cold-rolling on thermal, mechanical and electrical properties, microstructure and recrystallization behaviour of the AlScZr and AlMnScZr alloys prepared by powder metallurgy were studied. The powder was produced by atomising in argon with 1% oxygen and then consolidated by hot extrusion at 350 C. The electrical resistometry and microhardness together with differential scanning calorimetry measurements were compared with microstructure development observed by transmission and scanning electron microscopy, X-ray diffraction and electron backscatter diffraction. Fine (sub)grain structure developed and fine coherent Al3Sc and/or Al3(Sc,Zr) particles precipitated during extrusion at 350 C in the alloys studied. Additional precipitation of the Al3Sc and/or Al3(Sc,Zr) particles and/or their coarsening was slightly facilitated by the previous cold rolling. The presence of Sc,Zr-containing particles has a significant antirecrystallization effect that prevents recrystallization at temperatures minimally up to 420 C. The precipitation of the Al6Mn- and/or Al 6(Mn,Fe) particles of a size ~ 1.0 μm at subgrain boundaries has also an essential antirecrystallization effect and totally suppresses recrystallization during 32 h long annealing at 550 C. The texture development of the alloys seems to be affected by high solid solution strengthening by Mn. The precipitation of the Mn-containing alloy is highly enhanced by a cold rolling. The apparent activation energy of the Al3Sc particles formation and/or coarsening and that of the Al6Mn and/or Al 6(Mn,Fe) particle precipitation in the powder and in the compacted alloys were determined. The cold deformation has no effect on the apparent activation energy values of the Al3Sc-phase and the Al 6Mn-phase precipitation. © 2013 Elsevier Inc.

Impregnated cathode coated with tungsten thin film containing Sc2O3

International Nuclear Information System (INIS)

Yamamoto, S.; Taguchi, S.; Watanabe, I.; Kawase, S.

1987-01-01

An impregnated cathode of a novel structure is proposed, fabricated, and evaluated. A thin tungsten film 100--400 nm in thickness containing various amounts of Sc 2 O 3 is coated on a standard impregnated cathode composed of a porous tungsten body in which electron emissive materials are impregnated. The electron emission property measured with a diode configuration is found to be dependent on Sc 2 O 3 content and surface atom distribution. Surface atom distribution is depicted by means of Auger electron spectroscopy. For high electron emission enhancement it is necessary for Sc 2 O 3 content to be 2.5--6.5 wt. % and for a layer of the order of a monolayer in thickness composed of Ba, Sc, and O to develop on the cathode surface

Preparation and characterization of Sc doped MgB₂ wires

DEFF Research Database (Denmark)

Grivel, Jean-Claude; Burdusel, M.

2016-01-01

in the nominal composition, the formation of Sc–rich impurity phases was evidenced by SEM/EDS observations. The critical current density and accommodation field of the wires are weakly dependant on the Sc content. It is believed that these effects are related more to modifications of the thermal behaviour...

Magnet measuring equipment of SC2

CERN Multimedia

1974-01-01

Checking the positioning of the magnet measuring equipment installed between the poles of SC2. The steel structure in front of the magnet is designed to house the rotary condenser and to shield it from the stray magnetic field of the accelerator. On the left, Marinus van Gulik. (See Photo Archive 7402005 and Annual Report 1974, p. 44.)

Geometric phase for a neutral particle in rotating frames in a cosmic string spacetime

International Nuclear Information System (INIS)

Bakke, Knut; Furtado, Claudio

2009-01-01

We study of the appearance of geometric quantum phases in the dynamics of a neutral particle that possess a permanent magnetic dipole moment in rotating frames in a cosmic string spacetime. The relativistic dynamics of spin-1/2 particle in this frame is investigated and we obtain several contributions to relativistic geometric phase due rotation and topology of spacetime. We also study the geometric phase in the nonrelativistic limit. We obtain effects analogous to the Sagnac effect and Mashhoon effect in a rotating frame in the background of a cosmic string.

Effect of Sc addition and T6 aging treatment on the microstructure modification and mechanical properties of A356 alloy

Energy Technology Data Exchange (ETDEWEB)

Pramod, S.L. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Ravikirana [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Department of Physics and Nanotechnology, SRM University, Chennai 603203 (India); Rao, A.K. Prasada [College of Engineering and Design, Alliance University, Bengaluru 562106 (India); Murty, B.S., E-mail: murty@iitm.ac.in [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Bakshi, Srinivasa R., E-mail: sbakshi@iitm.ac.in [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India)

2016-09-30

Effect of Sc addition and T6 aging treatment on the secondary dendritic arm spacing (SDAS), modification of eutectic Si morphology, β-Al{sub 5}FeSiand π-Al{sub 8}Mg{sub 3}Si{sub 6}Fe{sub 1} phases and its effect on mechanical properties in A356 alloy has been investigated. Addition of 0.4 wt%Sc in A356 alloy resulted in a 50%reduction in the secondary dendritic arm spacing (SDAS). Sc addition changed the morphology of eutectic Si from plate like to fibrous and globular. The needle like morphology of β-Al{sub 5}FeSi phase in A356 alloy changed to Al{sub 5}Fe(Si,Sc) phase having smaller size and irregular morphology. Transmission electron microscopy (TEM) diffraction pattern and Energy dispersive spectroscopy (EDS) analysis revealed the presence of β-Al{sub 5}FeSiand π-Al{sub 8}Mg{sub 3}Si{sub 6}Fe{sub 1} phases in A356 alloy which changed to β-Al{sub 5}Fe(Si,Sc), π-Al{sub 8}Mg{sub 3}(Si,Sc){sub 6}Fe{sub 1} and additional V-AlSi{sub 2}Sc{sub 2}phase was observed in Sc containing alloys. Addition of 0.4 wt%Sc to A356 alloy improved its Vickers hardness, Ultimate tensile strength (UTS), Yield strength (YS) and ductility by 20%, 25%, 20% and 30% respectively. Artificial aging treatment resulted in significant improvement in the tensile properties for both A356 and Sc added A356 alloys.

Sc2C2@D3h(14246)-C74: A Missing Piece of the Clusterfullerene Puzzle.

Science.gov (United States)

Wang, Yaofeng; Tang, Qiangqiang; Feng, Lai; Chen, Ning

2017-02-20

Clusterfullerenes with variable carbon cages have been extensively studied in recent years. However, despite all these efforts, C 74 cage-based clusterfullerene remains a missing piece of the puzzle. Herein, we show that single-crystal X-ray crystallographic analysis unambiguously assigns the previously reported dimetallofullerene Sc 2 @C 76 to a novel carbide clusterfullerene, Sc 2 C 2 @D 3h (14246)-C 74 , the first experimentally proven clusterfullerene with a C 74 cage. In addition, Sc 2 C 2 @D 3h (14246)-C 74 was charaterized by mass spectrometry, ultraviolet-visible-near-infrared absorption spectroscopy, 45 Sc nuclear magnetic resonance, and cyclic voltammetry. Comparative studies of the motion of the carbide cluster in Sc 2 C 2 @D 3h (14246)-C 74 and Sc 2 C 2 @C 2n (n = 40-44) revealed that a combination of factors, involving both the shape and size of the cage, is crucial in dictating the cluster motion. Moreover, structural studies of D 3h (14246)-C 74 revealed that it can be easily converted to C s (10528)-C 72 and T d (19151)-C 76 cages via C 2 desertion/insertion and Stone-Wales transformation. This suggests that D 3h (14246)-C 74 might play an important role in the growth pathway of clusterfullerenes.

Characteristics of laser clad α-Ti/TiC+(Ti,W)C1-x/Ti2SC+TiS composite coatings on TA2 titanium alloy

Science.gov (United States)

Zhai, Yong-Jie; Liu, Xiu-Bo; Qiao, Shi-Jie; Wang, Ming-Di; Lu, Xiao-Long; Wang, Yong-Guang; Chen, Yao; Ying, Li-Xia

2017-03-01

TiC reinforced Ti matrix composite coating with Ti2SC/TiS lubricant phases in-situ synthesized were prepared on TA2 titanium alloy by laser cladding with different powder mixtures: 40%Ti-19.5%TiC-40.5%WS2, 40%Ti-25.2%TiC-34.8%WS2, 40%Ti-29.4%TiC-30.6%WS2 (wt%). The phase compositions, microstructure, microhardness and tribological behaviors and wear mechanisms of coatings were investigated systematically. Results indicate that the main phase compositions of three coatings are all continuous matrix α-Ti, reinforced phases of (Ti,W)C1-x and TiC, lubricant phases of Ti2SC and TiS. The microhardness of the three different coatings are 927.1 HV0.5, 1007.5 HV0.5 and 1052.3 HV0.5, respectively. Compared with the TA2 titanium alloy (approximately 180 HV0.5), the microhardness of coatings have been improved dramatically. The coefficients of friction and the wear rates of those coatings are 0.41 and 30.98×10-5 mm3 N-1 m-1, 0.30 and 18.92×10-5 mm3 N-1 m-1, 0.34 and 15.98×10-5 mm3 N-1 m-1, respectively. Comparatively speaking, the coating fabricated with the powder mixtures of 40%Ti-25.2%TiC-34.8%WS2 presents superior friction reduction and anti-wear properties and the main wear mechanisms of that are slight plastic deformation and adhesive wear.

Oxygen permeation flux through 10Sc1YSZ-MnCo2O4 asymmetric membranes prepared by two-step sintering

DEFF Research Database (Denmark)

Pirou, Stéven; Gurauskis, Jonas; Gil, Vanesa

2016-01-01

Asymmetric membranes based on a dual phase composite consisting of (Y2O3)0.01(Sc2O3)0.10(ZrO2)0.89 (10Sc1YSZ) as ionic conductor and MnCo2O4 as electronic conductor were prepared and characterized with respect to sinterability, microstructure and oxygen transport properties. The composite membranes...... were prepared by tape casting, lamination and fired in a two-step sintering process. Microstructural analysis showed that a gastight thin membrane layer with the desired ratio of ionic/electronic conducting phases could be fabricated. Oxygen permeation fluxes across the 10SclYSZ/MnCo2O4 (70/30 vol......%) composite membrane were measured from 750 to 940 degrees C using air or pure oxygen as feed gases and N2 or CO2 as sweep gases. Fluxes up to 2.3 mlN min-1 cm-2 were obtained for the 7 μm thick membrane. A degradation test over 1730 h showed an initial degradation of 21% during the first 1100 h after which...

Spinning cylinder experiments SC-I and SC-II: A review of results and analyses provided to the FALSIRE project

International Nuclear Information System (INIS)

Morland, E.; Sherry, A.H.

1993-01-01

A series of six large-scale experiments have been carried out at AEA Technology using the Spinning Cylinder test facility. Results from two of those experiments (SC-I and SC-II) have been provided to Project FALSIRE and are reviewed in this paper. The Spinning Cylinder tests were carried out using hollow cylinders of 1.4m outer diameter, 0.2m wall thickness and 1.3m length, containing full-length axial defects and fabricated from a modified A508 Class 3 steel. The first Spinning Cylinder test (SC-I) was an investigation of stable ductile growth induced via mechanical (primary) loading and under conditions of contained yielding. Mechanical loading was provided in the hoop direction by rotating the cylinder about its major axis within an enclosed oven. The second test (SC-II) investigated stable ductile growth under severe thermal shock (secondary) loading again under conditions of contained yielding. In this case thermal shock was produced by spraying cold water on the inside surface of the heated cylinder whilst it was rotating. For each experiment, results are presented in terms of a number of variables, eg. crack growth, temperature, stress, strain and applied K and J. In addition, an overview of the analyses of the FALSIRE Phase-1 report is also presented with respect to test SC-I and SC-II. 4 refs., 14 figs., 13 tabs

Investigating the local structure of B-site cations in (1-x)BaTiO3-xBiScO3 and (1-x)PbTiO3-xBiScO3 using X-ray absorption spectroscopy

Science.gov (United States)

Blanchard, Peter E. R.; Grosvenor, Andrew P.

2018-05-01

The structural properties of (1-x)BaTiO3-xBiScO3 and (1-x)PbTiO3-xBiScO3 were investigated using powder X-ray diffraction and X-ray absorption spectroscopy. Diffraction measurements confirmed that substituting small amounts of BiScO3 into BaTiO3 initially stabilizes a cubic phase at x = 0.2 before impurity phases begin to form at x = 0.5. BiScO3 substitution also resulted in noticeable changes in the local coordination environment of Ti4+. X-ray absorption near-edge spectroscopy (XANES) analysis showed that replacing Ti4+ with Sc3+ results in an increase in the off-centre displacement of Ti4+ cations. Surprisingly, BiScO3 substitution has no effect on the displacement of the Ti4+ cation in the (1-x)PbTiO3-xBiScO3 solid solution.

46 CFR 7.70 - Folly Island, SC to Hilton Head Island, SC.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Folly Island, SC to Hilton Head Island, SC. 7.70 Section... BOUNDARY LINES Atlantic Coast § 7.70 Folly Island, SC to Hilton Head Island, SC. (a) A line drawn from the...′ W. (Port Royal Sound Lighted Whistle Buoy “2PR”); thence to the easternmost extremity of Hilton Head...

Phonon and thermodynamical properties of CuSc: A DFT study

Science.gov (United States)

Jain, Ekta; Pagare, Gitanjali; Dubey, Shubha; Sanyal, S. P.

2018-05-01

A detailed systematic theoretical investigation of phonon and thermodynamical behavior of CuSc intermetallic compound has been carried out by uing first-principles density functional theory in B2-type (CsCl) crystal structure. Phonon dispersion curve and phonon density of states (PhDOS) are studied which confirm the stability of CuSc intermetallic compound in B2 phase. It is found that PhDOS at high frequencies mostly composed of Sc states. We have also presented some temperature dependent properties such as entropy, free energy, heat capacity, internal energy and thermal displacement, which are computed under PHONON code. The various features of these quantities are discussed in detail. From these results we demonstrate that the particular intermetallic have better ductility and larger thermal expansion.

Magnetic properties of Sc{sub x}Ti{sub 1-x}Fe{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Kessler, M. [Lab. de Cristallographie, CNRS, 38 - Grenoble (France); Deportes, J. [Lab. Louis Neel, CNRS, 38 - Grenoble (France); Ouladdiaf, B. [Institut Laue-Langevin, 38 - Grenoble (France); Sayetat, F. [Lab. de Cristallographie, CNRS, 38 - Grenoble (France)

1995-02-09

The magnetic properties and their thermal dependences of Sc{sub 0.1}Ti{sub 0.9}Fe{sub 1.96}, Sc{sub 0.1}Ti{sub 0.9}Fe{sub 2} and Sc{sub 0.1}Ti{sub 0.9}Fe{sub 2.04} are compared with those of TiFe{sub 2}. The substitution changes the iron-iron distances. Consequently, the Fe atoms on the 6h site show in addition to the antiferromagnetic component a small ferromagnetic one, and a weak magnetic moment appears on the 2a site. ((orig.)).

Martensitic Transformation in a β-Type Mg-Sc Alloy

Science.gov (United States)

Ogawa, Yukiko; Ando, Daisuke; Sutou, Yuji; Somekawa, Hidetoshi; Koike, Junichi

2018-03-01

Recently, we found that a Mg-Sc alloy with a bcc (β) phase exhibits superelasticity and a shape memory effect at low temperature. In this work, we examined the stress-induced and thermally induced martensitic transformation of the β-type Mg-Sc alloy and investigated the crystal structure of the thermally induced martensite phase based on in situ X-ray diffraction (XRD) measurements. The lattice constants of the martensite phase were calculated to be a = 0.3285 nm, b = 0.5544 nm, and c = 0.5223 nm when we assumed that the martensite phase has an orthorhombic structure (Cmcm). Based on the lattice correspondence between a bcc and an orthorhombic structures such as that in the case of β-Ti shape memory alloys, we estimated the transformation strain of the β Mg-Sc alloy. As a result, the transformation strains along the 001, 011, and 111 directions in the β phase were calculated to be + 5.7, + 8.8, and + 3.3%, respectively.

Martensitic Transformation in a β-Type Mg-Sc Alloy

Science.gov (United States)

Ogawa, Yukiko; Ando, Daisuke; Sutou, Yuji; Somekawa, Hidetoshi; Koike, Junichi

2017-12-01

Recently, we found that a Mg-Sc alloy with a bcc (β) phase exhibits superelasticity and a shape memory effect at low temperature. In this work, we examined the stress-induced and thermally induced martensitic transformation of the β-type Mg-Sc alloy and investigated the crystal structure of the thermally induced martensite phase based on in situ X-ray diffraction (XRD) measurements. The lattice constants of the martensite phase were calculated to be a = 0.3285 nm, b = 0.5544 nm, and c = 0.5223 nm when we assumed that the martensite phase has an orthorhombic structure (Cmcm). Based on the lattice correspondence between a bcc and an orthorhombic structures such as that in the case of β-Ti shape memory alloys, we estimated the transformation strain of the β Mg-Sc alloy. As a result, the transformation strains along the 001, 011, and 111 directions in the β phase were calculated to be + 5.7, + 8.8, and + 3.3%, respectively.

Existence of a critical point in the phase diagram of the ideal relativistic neutral Bose gas

International Nuclear Information System (INIS)

Park, Jeong-Hyuck; Kim, Sang-Woo

2011-01-01

We explore the phase transitions of the ideal relativistic neutral Bose gas confined in a cubic box, without assuming the thermodynamic limit nor continuous approximation. While the corresponding non-relativistic canonical partition function is essentially a one-variable function depending on a particular combination of temperature and volume, the relativistic canonical partition function is genuinely a two-variable function of them. Based on an exact expression for the canonical partition function, we performed numerical computations for up to 10 5 particles. We report that if the number of particles is equal to or greater than a critical value, which amounts to 7616, the ideal relativistic neutral Bose gas features a spinodal curve with a critical point. This enables us to depict the phase diagram of the ideal Bose gas. The consequent phase transition is first order below the critical pressure or second order at the critical pressure. The exponents corresponding to the singularities are 1/2 and 2/3, respectively. We also verify the recently observed 'Widom line' in the supercritical region.

Theoretical study of stability and superconductivity of ScHn (n =4 -8 ) at high pressure

Science.gov (United States)

Qian, Shifeng; Sheng, Xiaowei; Yan, Xiaozhen; Chen, Yangmei; Song, Bo

2017-09-01

The synthesis of hydrogen sulfides, with the potential of high-temperature superconductivity, was recently proposed at high Tc = 203 K. It motivated us to employ an ab initio approach for the predictions of crystal structures to find the stable scandium hydrides. In addition to the earlier predicted three stoichiometries of ScH, ScH2, and ScH3, we identify three other metallic stoichiometries of ScH4, ScH6, and ScH8, which show superconductivity at significantly higher temperatures. The phases of ScH4 and ScH6, whose stability does not require extremely high pressures (ZPE), are primarily ionic compounds containing exotic quasimolecular H2 arrangements. The present electron-phonon calculations revealed the superconductive potential of ScH4 and ScH6 with estimated Tc of 98 K and 129 K at 200 GPa and 130 GPa, respectively. The superconductivity of ScHn stems from the large electron-phonon coupling associated with the wagging, bending, and intermediate-frequency modes attributed mainly to the hydrogen atoms.

Anandan quantum phase for a neutral particle with Fermi-Walker reference frame in the cosmic string background

International Nuclear Information System (INIS)

Bakke, Knut; Furtado, C.

2010-01-01

We study geometric quantum phases in the relativistic and non-relativistic quantum dynamics of a neutral particle with a permanent magnetic dipole moment interacting with two distinct field configurations in a cosmic string spacetime. We consider the local reference frames of the observers are transported via Fermi-Walker transport and study the influence of the non-inertial effects on the phase shift of the wave function of the neutral particle due to the choice of this local frame. We show that the wave function of the neutral particle acquires non-dispersive relativistic and non-relativistic quantum geometric phases due to the topology of the spacetime, the interaction between the magnetic dipole moment with external fields and the spin-rotation coupling. However, due to the Fermi-Walker reference frame, no phase shift associated to the Sagnac effect appears in the quantum dynamics of a neutral particle. We show that in the absence of topological defect, the contribution to the quantum phase due to the spin-rotation coupling is equivalent to the Mashhoon effect in non-relativistic dynamics. (orig.)

Doped Sc2C(OH)2 MXene: new type s-pd band inversion topological insulator.

Science.gov (United States)

Balcı, Erdem; Akkuş, Ünal Özden; Berber, Savas

2018-04-18

The electronic structures of Si and Ge substitutionally doped Sc 2 C(OH) 2 MXene monolayers are investigated in density functional theory. The doped systems exhibit band inversion, and are found to be topological invariants in Z 2 theory. The inclusion of spin orbit coupling results in band gap openings. Our results point out that the Si and Ge doped Sc 2 C(OH) 2 MXene monolayers are topological insulators. The band inversion is observed to have a new mechanism that involves s and pd states.

Doped Sc2C(OH)2 MXene: new type s-pd band inversion topological insulator

Science.gov (United States)

Balcı, Erdem; Özden Akkuş, Ünal; Berber, Savas

2018-04-01

The electronic structures of Si and Ge substitutionally doped Sc2C(OH)2 MXene monolayers are investigated in density functional theory. The doped systems exhibit band inversion, and are found to be topological invariants in Z 2 theory. The inclusion of spin orbit coupling results in band gap openings. Our results point out that the Si and Ge doped Sc2C(OH)2 MXene monolayers are topological insulators. The band inversion is observed to have a new mechanism that involves s and pd states.

Solution synthesis, structure, and CO{sub 2} reduction reactivity of a Scandium(II) complex, {Sc[N(SiMe_3)_2]_3}{sup -}

Energy Technology Data Exchange (ETDEWEB)

Woen, David H.; Chen, Guo P.; Ziller, Joseph W.; Furche, Filipp; Evans, William J. [Department of Chemistry, University of California, Irvine, CA (United States); Boyle, Timothy J. [Sandia National Laboratories, Advanced Materials Laboratory, Albuquerque, NM (United States)

2017-02-13

The first crystallographically characterizable complex of Sc{sup 2+}, [Sc(NR{sub 2}){sub 3}]{sup -} (R=SiMe{sub 3}), has been obtained by LnA{sub 3}/M reactions (Ln=rare earth metal; A=anionic ligand; M=alkali metal) involving reduction of Sc(NR{sub 2}){sub 3} with K in the presence of 2.2.2-cryptand (crypt) and 18-crown-6 (18-c-6) and with Cs in the presence of crypt. Dark maroon [K(crypt)]{sup +}, [K(18-c-6)]{sup +}, and [Cs(crypt)]{sup +} salts of the [Sc(NR{sub 2}){sub 3}]{sup -} anion are formed, respectively. The formation of this oxidation state of Sc is also indicated by the eight-line EPR spectra arising from the I=7/2 {sup 45}Sc nucleus. The Sc(NR{sub 2}){sub 3} reduction differs from Ln(NR{sub 2}){sub 3} reactions (Ln=Y and lanthanides) in that it occurs under N{sub 2} without formation of isolable reduced dinitrogen species. [K(18-c-6)][Sc(NR{sub 2}){sub 3}] reacts with CO{sub 2} to produce an oxalate complex, {K_2(18-c-6)_3}{[(R_2N)_3Sc]_2(μ-C_2O_4-κ"1O:κ"1O'')}, and a CO{sub 2}{sup -} radical anion complex, [(R{sub 2}N){sub 3}Sc(μ-OCO-κ{sup 1}O:κ{sup 1}O')K(18-c-6)]{sub n}. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Chronic hypoxia suppresses the CO2 response of solitary complex (SC) neurons from rats.

Science.gov (United States)

Nichols, Nicole L; Wilkinson, Katherine A; Powell, Frank L; Dean, Jay B; Putnam, Robert W

2009-09-30

We studied the effect of chronic hypobaric hypoxia (CHx; 10-11% O(2)) on the response to hypercapnia (15% CO(2)) of individual solitary complex (SC) neurons from adult rats. We simultaneously measured the intracellular pH and firing rate responses to hypercapnia of SC neurons in superfused medullary slices from control and CHx-adapted adult rats using the blind whole cell patch clamp technique and fluorescence imaging microscopy. We found that CHx caused the percentage of SC neurons inhibited by hypercapnia to significantly increase from about 10% up to about 30%, but did not significantly alter the percentage of SC neurons activated by hypercapnia (50% in control vs. 35% in CHx). Further, the magnitudes of the responses of SC neurons from control rats (chemosensitivity index for activated neurons of 166+/-11% and for inhibited neurons of 45+/-15%) were the same in SC neurons from CHx-adapted rats. This plasticity induced in chemosensitive SC neurons by CHx appears to involve intrinsic changes in neuronal properties since they were the same in synaptic blockade medium.

Production of neutralizing antisera against viral hemorrhagic septicemia (VHS) virus by intravenous injections of rabbits

DEFF Research Database (Denmark)

Olesen, Niels Jørgen; Lorenzen, Niels; LaPatra, S.E.

1999-01-01

Rabbit antisera against viral hemorrhagic septicemia virus (VHSV) produced by two immunization procedures were compared for neutralization and immunochemical properties against homologous and heterologous strains. The VHSV isolate used as the immunogen was a member of a serogroup not neutralized...... by previously available antisera. The results from this study suggested that frequent intravenous (IV) injections of rabbits with viral antigens were superior to adjuvant-mediated, combined subcutaneous and intraperitoneal (SC/IP) injections for the production of neutralizing antisera. All IV injected rabbits...... produced high neutralization titers against the homologous VHSV isolate but not against an isolate from a different serogroup. The SC/IP injected rabbits had no significant neutralization titers against either the homologous VHSV strain or two isolates of a heterologous VHSV strain. Sera from all injected...

Investigation of phase stability in the scandia-zirconia

International Nuclear Information System (INIS)

Grosso, Robson Lopes

2016-01-01

In this work, the phase stability of scandia-zirconia (ScSZ) system was investigated by the thermodynamic study of nanoparticles, within the range of 0 to 20 mol% Sc 2 O 3 , and by codoping of ZrO 2 -10 mol% Sc 2 O 3 (10ScSZ) with Dy 2 O 3 and Nb 2 O 5 . The phase stability of ScSZ was evaluated based on thermodynamic data collected by water adsorption microcalorimetry and high temperature oxide melt solution. Nanostructured zirconia-scandia solid solutions were synthesized by coprecipitation method. Thermodynamic data were determined for ScSZ polymorph (monoclinic, tetragonal, cubic, rhombohedral β and γ) found by X-ray diffraction. This systemic work resulted in an unprecedented phase diagram at the nanoscale of particle size-composition. The effects of additives on 10ScSZ were investigated aiming to stabilize the cubic (c) structure at room temperature and to suppress the characteristic cubic-rhombohedral β phase transformation. Compositions were prepared by coprecipitation and solid state reaction. Materials were sintered by conventional and spark plasma sintering. Full stabilization of the cubic phase was attained by 1 mol% Dy 2 O 3 and 0.5 mol% Nb 2 O 5 additions. The smallest Nb 2 O 5 content required for cubic phase stabilization was attributed to liquid phase formation during sintering and to small ionic radius of Nb 5+ . Results of high temperature X-ray diffraction and thermal analysis show suppression of the c-β transformation. Samples containing 0.5 mol% Nb 2 O 5 show total ionic conductivity similar to 10ScSZ without additives within a broad temperature range with high stability during 170 h at 600 °C. (author)

Recombinant norovirus-specific scFv inhibit virus-like particle binding to cellular ligands

Directory of Open Access Journals (Sweden)

Hardy Michele E

2008-01-01

Full Text Available Abstract Background Noroviruses cause epidemic outbreaks of gastrointestinal illness in all age-groups. The rapid onset and ease of person-to-person transmission suggest that inhibitors of the initial steps of virus binding to susceptible cells have value in limiting spread and outbreak persistence. We previously generated a monoclonal antibody (mAb 54.6 that blocks binding of recombinant norovirus-like particles (VLP to Caco-2 intestinal cells and inhibits VLP-mediated hemagglutination. In this study, we engineered the antigen binding domains of mAb 54.6 into a single chain variable fragment (scFv and tested whether these scFv could function as cell binding inhibitors, similar to the parent mAb. Results The scFv54.6 construct was engineered to encode the light (VL and heavy (VH variable domains of mAb 54.6 separated by a flexible peptide linker, and this recombinant protein was expressed in Pichia pastoris. Purified scFv54.6 recognized native VLPs by immunoblot, inhibited VLP-mediated hemagglutination, and blocked VLP binding to H carbohydrate antigen expressed on the surface of a CHO cell line stably transfected to express α 1,2-fucosyltransferase. Conclusion scFv54.6 retained the functional properties of the parent mAb with respect to inhibiting norovirus particle interactions with cells. With further engineering into a form deliverable to the gut mucosa, norovirus neutralizing antibodies represent a prophylactic strategy that would be valuable in outbreak settings.

A single amino acid mutation in Spo0A results in sporulation deficiency of Paenibacillus polymyxa SC2.

Science.gov (United States)

Hou, Xiaoyang; Yu, Xiaoning; Du, Binghai; Liu, Kai; Yao, Liangtong; Zhang, Sicheng; Selin, C; Fernando, W G D; Wang, Chengqiang; Ding, Yanqin

2016-01-01

Sporulating bacteria such as Bacillus subtilis and Paenibacillus polymyxa exhibit sporulation deficiencies during their lifetime in a laboratory environment. In this study, spontaneous mutants SC2-M1 and SC2-M2, of P. polymyxa SC2 lost the ability to form endospores. A global genetic and transcriptomic analysis of wild-type SC2 and spontaneous mutants was carried out. Genome resequencing analysis revealed 14 variants in the genome of SC2-M1, including three insertions and deletions (indels), 10 single nucleotide variations (SNVs) and one intrachromosomal translocation (ITX). There were nine variants in the genome of SC2-M2, including two indels and seven SNVs. Transcriptomic analysis revealed that 266 and 272 genes showed significant differences in expression in SC2-M1 and SC2-M2, respectively, compared with the wild-type SC2. Besides sporulation-related genes, genes related to exopolysaccharide biosynthesis (eps), antibiotic (fusaricidin) synthesis, motility (flgB) and other functions were also affected in these mutants. In SC2-M2, reversion of spo0A resulted in the complete recovery of sporulation. This is the first global analysis of mutations related to sporulation deficiency in P. polymyxa. Our results demonstrate that a SNV within spo0A caused the sporulation deficiency of SC2-M2 and provide strong evidence that an arginine residue at position 211 is essential for the function of Spo0A. Copyright © 2016 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.

Performance and stability of (ZrO2)0.89(Y2O3)0.01(Sc2O3)0.10-LaCr0.85Cu0.10Ni0.05O3-δ oxygen transport membranes under conditions relevant for oxy-fuel combustion

DEFF Research Database (Denmark)

Pirou, Stéven; Bermudez, Jose M.; Tak Na, Beom

2018-01-01

Self-standing, planar dual-phase oxygen transport membranes consisting of 70 vol.% (ZrO2)0.89(Y2O3)0.01(Sc2O3)0.10 (10Sc1YSZ) and 30 vol.% LaCr0.85Cu0.10Ni0.05O3-δ (LCCN) were successfully developed and tested. The stability of the composite membrane was studied in simulated oxy-fuel power plant...

Determination of 46Sc in water

International Nuclear Information System (INIS)

Huo Bijun; Ji Zhaogang; Wang Juying

1985-01-01

Analytical procedures for the determination of 46 Sc in water is presented. 46 Sc in water is concentrated with Fe(OH) 3 ; Then 46 Sc is extracted with TBP and purified by precipitating it with Amygdalic Acid. Finally the precipitate is ignited into Sc 2 O 3 under 800 deg C and β-activity is counted. In this method chemical reeovery for Sc was (90.8 +- 2.8)% and radiochemical recovery for 46 Sc was (89.8 +- 3.8)%. Purification factors for some of the relevant Radionuclides ranged from 10 3 to 10 5

Negative thermal expansion in Sc2(WO4)3

International Nuclear Information System (INIS)

Evans, J.S.O.; Mary, T.A.; Sleight, A.W.

1998-01-01

Sc 2 (WO 4 ) 3 has been found to show the highly unusual property of negative thermal expansion over a temperature range of 10 to 1,073 K. Powder neutron diffraction data from 10 to 450 K shows an essentially linear decrease in cell volume as a function of temperature. The intrinsic linear coefficient of thermal expansion from this data is -2.2 x 10 -6 K -1 . The linear coefficient of thermal expansion measured on a ceramic bar of Sc 2 (WO 4 ) 3 can be as negative as -11 x 10 -6 K -1 due to microstructure changes as a function of temperature. Rietveld refinement as a function of temperature suggests that the intrinsic negative thermal expansion can be related to transverse vibrations of bridging oxygen atoms in the structure. The anharmonic nature of these vibrations leads to a coupled tilting of the quasi-rigid framework polyhedra. This tilting in turn causes the structure to become more dense with increasing temperature

Evaluation of the first 44Sc-labeled Affibody molecule for imaging of HER2-expressing tumors

International Nuclear Information System (INIS)

Honarvar, Hadis; Müller, Cristina; Cohrs, Susan; Haller, Stephanie; Westerlund, Kristina; Karlström, Amelie Eriksson; Meulen, Nicholas P. van der; Schibli, Roger; Tolmachev, Vladimir

2017-01-01

Introduction: Affibody molecules are small (58 amino acids) high-affinity proteins based on a tri-helix non-immunoglobulin scaffold. A clinical study has demonstrated that PET imaging using Affibody molecules labeled with 68 Ga (T ½ = 68 min) can visualize metastases of breast cancer expressing human epidermal growth factor receptor type 2 (HER2) and provide discrimination between tumors with high and low expression level. This may help to identify breast cancer patients benefiting from HER2-targeting therapies. The best discrimination was at 4 h post injection. Due to longer half-life, a positron-emitting radionuclide 44 Sc (T ½ = 4.04 h) might be a preferable label for Affibody molecules for imaging at several hours after injection. Methods: A synthetic second-generation anti-HER2 Affibody molecule Z HER2:2891 was labeled with 44 Sc via a DOTA-chelator conjugated to the N-terminal amino group. Binding specificity, affinity and cellular processing 44 Sc-DOTA-Z HER2:2891 and 68 Ga-DOTA-Z HER2:2891 were compared in vitro using HER2-expressing cells. Biodistribution and imaging properties of 44 Sc-DOTA-Z HER2:2891 and 68 Ga-DOTA-Z HER2:2891 were evaluated in Balb/c nude mice bearing HER2-expression xenografts. Results: The labeling yield of 98 ± 2% and specific activity of 7.8 GBq/μmol were obtained. The conjugate demonstrated specific binding to HER2-expressing SKOV3.ip cells in vitro and to SKOV3.ip xenografts in nude mice. The distribution of radioactivity at 3 h post injection was similar for 44 Sc-DOTA-Z HER2:2891 and 68 Ga-DOTA-Z HER2:2891 , but the blood clearance of the 44 Sc-labeled variant was slower and the tumor-to-blood ratio was reduced (15 ± 2 for 44 Sc-DOTA-Z HER2:2891 vs 46 ± 9 for 68 Ga-DOTA-Z HER2:2891 ). At 6 h after injection of 44 Sc-DOTA-Z HER2:2891 the tumor uptake was 8 ± 2% IA/g and the tumor-to-blood ratio was 51 ± 8. Imaging using small-animal PET/CT demonstrated that 44 Sc-DOTA-Z HER2:2891 provides specific and high

Conductivity ageing studies on 1M10ScSZ (M4+=Ce, Hf)

DEFF Research Database (Denmark)

Omar, Shobit; Bin Najib, Waqas; Bonanos, Nikolaos

2011-01-01

The long-term conductivity stability is tested on zirconia based electrolyte materials for solid oxide fuel cell applications. The ageing studies have been performed on the samples of ZrO2 co-doped with 10mol% of Sc2O3 and 1mol% MO2, where M = Ce or Hf (denoted respectively 1Ce10ScSZ and 1Hf10Sc......SZ) in oxidising and reducing atmospheres, at 600°C for 3000h. At 600°C, these compositions show initial conductivity of around 9–12mS∙cm−1 in air. After 3000h of ageing, no phase transitions are observed in any of the samples. For the first 1000h, the degradation rate is higher than in the subsequent 2000h......; thereafter, conductivity degrades linearly with time for all samples. In air, the loss in the conductivity is lower than in reducing conditions. The 1Ce10ScSZ shows the highest degradation rate of 3.8%/1000h in wet H2/N2 after the first 1000h of ageing. A colour change of the 1Ce10ScSZ sample from white...

Gaz Phase IR and UV Spectroscopy of Neutral Contact Ion Pairs

Science.gov (United States)

Habka, Sana; Brenner, Valerie; Mons, Michel; Gloaguen, Eric

2016-06-01

Cations and anions, in solution, tend to pair up forming ion pairs. They play a crucial role in many fundamental processes in ion-concentrated solutions and living organisms. Despite their importance and vast applications in physics, chemistry and biochemistry, they remain difficult to characterize namely because of the coexistence of several types of pairing in solution. However, an interesting alternative consists in applying highly selective gas phase spectroscopy which can offer new insights on these neutral ion pairs. Our study consists in characterizing contact ion pairs (CIPs) in isolated model systems (M+, Ph-(CH2)n-COO- with M=Li, Na, K, Rb, Cs, and n=1-3), to determine their spectral signatures and compare them to ion pairs in solution. We have used laser desorption to vaporize a solid tablet containing the desired salt. Structural information for each system was obtained by mass-selective, UV and IR laser spectroscopy combined with high level quantum chemistry calculations1. Evidence of the presence of neutral CIPs was found by scanning the π-π* transition of the phenyl ring using resonant two-photon ionization (R2PI). Then, conformational selective IR/UV double resonance spectra were recorded in the CO2- stretch region for each conformation detected. The good agreement between theoretical data obtained at the BSSE-corrected-fullCCSD(T)/dhf-TZVPP//B97-D3/dhf-TZVPP level and experimental IR spectra led us to assign the 3D structure for each ion pair formed. Spectral signatures of (M+, Ph-CH2-COO-) pairs, were assigned to a bidentate CIPs between the alkali cation and the carboxylate group. In the case of (Li+, Ph-(CH2)3-COO-) pairs, the presence of a flexible side chain promotes a cation-π interaction leading to a tridentate O-O-π structure with its unique IR and UV signatures. IR spectra obtained on isolated CIPs were found very much alike the ones published on lithium and sodium acetate in solution2. However, in the case of sodium acetate, solution

Differential dynamics of splicing factor SC35 during the cell cycle

Indian Academy of Sciences (India)

Srinivas

2.4 Immunofluorescence microscopy. HeLa cells were ... experiments were performed on an LSM510 inverted confocal ... a loss of signal of more than 10% during the imaging phase ... Recombinant GST-SC35 was expressed in E. coli.

Formation, structure and magnetism of the metastable defect fluorite phases AVO3.5+x (A=In, Sc)

International Nuclear Information System (INIS)

Shafi, Shahid P.; Lundgren, Rylan J.; Cranswick, Lachlan M.D.; Bieringer, Mario

2007-01-01

We report the preparation and stability of ScVO 3.5+x and the novel phase InVO 3.5+x . AVO 3.5+x (A=Sc, In) defect fluorite structures are formed as metastable intermediates during the topotactic oxidation of AVO 3 bixbyites. The oxidation pathway has been studied in detail by means of thermogravimetric/differential thermal analysis and in-situ powder X-ray diffraction. The oxidation of the bixbyite phase follows a topotactic pathway at temperatures between 300 and 400 deg. C in air/carbon dioxide. The range of accessible oxygen stoichiometries for the AVO 3.5+x structures following this pathway are 0.00≤x≤0.22. Rietveld refinements against powder X-ray and neutron data revealed that InVO 3.54 and ScVO 3.70 crystallize in the defect fluorite structure in space group Fm-3 m (227) with a=4.9863(5) and 4.9697(3)A, respectively with A 3+ /V 4+ disorder on the (4a) cation site. Powder neutron diffraction experiments indicate clustering of oxide defects in all samples. Bulk magnetic measurements showed the presence of V 4+ and the absence of magnetic ordering at low temperatures. Powder neutron diffraction experiments confirmed the absence of a long range ordered magnetic ground state. - Graphical abstract: Topotactic oxidation of AVO 3 bixbyite to AVO 3.5 defect fluorite structure followed by in-situ powder X-ray diffraction. The upper structural diagram shows a six coordinated (A/V)-O 6 fragment in bixbyite, the lower structure illustrates the same seven-fold coordinated (A/V)-O 7 cubic environment in the defect fluorite structure

Tunable band gap and optical properties of surface functionalized Sc2C monolayer

International Nuclear Information System (INIS)

Wang Shun; Du Yu-Lei; Liao Wen-He

2017-01-01

Using the density functional theory, we have investigated the electronic and optical properties of two-dimensional Sc 2 C monolayer with OH, F, or O chemical groups. The electronic structures reveal that the functionalized Sc 2 C monolayers are semiconductors with a band gap of 0.44–1.55 eV. The band gap dependent optical parameters, like dielectric function, absorption coefficients, reflectivity, loss function, and refraction index were also calculated for photon energy up to 20 eV. At the low-energy region, each optical parameter shifts to red, and the peak increases obviously with the increase of the energy gap. Consequently, Sc 2 C monolayer with a tunable band gap by changing the type of surface chemical groups is a promising 2D material for optoelectronic devices. (paper)

Coordination polymers of scandium sulfate. Crystal structures of (H2Bipy)[Sc(H2O)(SO4)2]2·2H2O and (H2Bipy)[HSO4]2

International Nuclear Information System (INIS)

Petrosyants, S.P.; Ilyukhin, A.B.

2005-01-01

Compounds with general formula Cat x [Sc(H 2 O) z (SO 4 ) y ]·nH 2 O (Cat=NH 4 , H 2 Bipy (Bipy - 4,4'-bipyridine), HEdp (Edp - ethylene dipyridine)) identified on element analysis data and IR spectra are synthesized. X-ray diffraction analysis of (H 2 Bipy)[Sc(H 2 O)(SO 4 ) 2 ] 2 ·2H 2 O shows that in structure of the compound chains of ScO 6 octahedron and SO 4 tetrahedrons are joined in bands by tridentate coordination of sulfate ions. Bands form skeleton in endless emptiness of which there are H 2 Bipy 2+ cations [ru

Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41.

Science.gov (United States)

Sabin, Charles; Corti, Davide; Buzon, Victor; Seaman, Mike S; Lutje Hulsik, David; Hinz, Andreas; Vanzetta, Fabrizia; Agatic, Gloria; Silacci, Chiara; Mainetti, Lara; Scarlatti, Gabriella; Sallusto, Federica; Weiss, Robin; Lanzavecchia, Antonio; Weissenhorn, Winfried

2010-11-18

The human monoclonal antibody (mAb) HK20 neutralizes a broad spectrum of primary HIV-1 isolates by targeting the highly conserved heptad repeat 1 (HR1) of gp41, which is transiently exposed during HIV-1 entry. Here we present the crystal structure of the HK20 Fab in complex with a gp41 mimetic 5-Helix at 2.3 Å resolution. HK20 employs its heavy chain CDR H2 and H3 loops to bind into a conserved hydrophobic HR1 pocket that is occupied by HR2 residues in the gp41 post fusion conformation. Compared to the previously described HR1-specific mAb D5, HK20 approaches its epitope with a different angle which might favor epitope access and thus contribute to its higher neutralization breadth and potency. Comparison of the neutralization activities of HK20 IgG, Fab and scFv employing both single cycle and multiple cycle neutralization assays revealed much higher potencies for the smaller Fab and scFv over IgG, implying that the target site is difficult to access for complete antibodies. Nevertheless, two thirds of sera from HIV-1 infected individuals contain significant titers of HK20-inhibiting antibodies. The breadth of neutralization of primary isolates across all clades, the higher potencies for C-clade viruses and the targeting of a distinct site as compared to the fusion inhibitor T-20 demonstrate the potential of HK20 scFv as a therapeutic tool.

Determination of Sc and Th in ScI3-NaI-ThI4 sample

International Nuclear Information System (INIS)

Yuan Hui; Yang Zhihong

1999-01-01

Determination of Sc and Th in ScI 3 -NaI-ThI 4 sample is studied by X-ray fluorescence and complexometry. The effect of working condition of Sc on X-ray fluorescence spectrometer and different sample-making method on the determination of Sc and Th are studied experimentally. The X-ray fluorescence analysis of determination of Sc and Th is developed by polyester film sample-making technique, the measuring precision of Sc and Th is better than 4%. The effect of acidity and temperature on the determining end point of titration is obvious. The results of different complexometric methods are compared. The precision of Sc and Th is less than 2% by comlexometry, it is fit for the routine analysis of ScI 3 -NaI-ThI 4 sample

The mediation effect of menstrual phase on negative emotion processing: evidence from N2.

Science.gov (United States)

Wu, Haiyan; Chen, Chunping; Cheng, Dazhi; Yang, Suyong; Huang, Ruiwang; Cacioppo, Stephanie; Luo, Yue-Jia

2014-01-01

Numerous studies have shown a 'negativity bias' in emotion processing and effect of menstrual phase on emotion processing. Most of these results, however, did not match the arousal of different types of stimuli. The present study examined the time course of negative emotion processing across different menstrual phases (e.g., late luteal/premenstrual phase and follicular phase) when the arousal level of negative and neutral stimuli was equal. Following previous studies, an oddball paradigm was utilized in present study. Participants viewed neutral and negative (highly (HN) and moderately negative (MN)) stimuli with matched arousal and were asked to make deviant vs. standard judgments. The behavioral results showed a higher accuracy for HN stimuli than neutral stimuli, and the other comparisons were not significant. The major event-related potential (ERP) finding was that N2 amplitude was larger for MN than neutral in the late luteal phase, whereas such difference was absent during the follicular phase. Moreover, The N2 for HN stimuli was larger in late luteal phase than in follicular phase. Therefore, female may be with higher sensitivity to MN stimuli during late luteal phase than during follicular phase when the arousal of stimuli was well controlled. These results provide additional insight to premenstrual affective syndrome and affective disorder.

Extended defects in epitaxial Sc2O3 films grown on (111) Si

International Nuclear Information System (INIS)

Klenov, Dmitri O.; Edge, Lisa F.; Schlom, Darrell G.; Stemmer, Susanne

2005-01-01

Epitaxial Sc 2 O 3 films with the cubic bixbyite structure were grown on (111) Si by reactive molecular beam epitaxy. High-resolution transmission electron microscopy (HRTEM) revealed an abrupt, reaction-layer free interface between Sc 2 O 3 and Si. The ∼10% lattice mismatch between Si and Sc 2 O 3 was relieved by the formation of a hexagonal misfit dislocation network with Burgers vectors of 1/2 Si and line directions parallel to Si . A high density of planar defects and threading dislocations was observed. Analysis of lattice shifts across the planar defects in HRTEM showed that these faults were likely antiphase boundaries (APBs). ABPs form when film islands coalesce during growth because films nucleate with no unique arrangement of the ordered oxygen vacancies in the bixbyite structure relative to the Si lattice

Nonionic Fluorinated Surfactant Removal from Mesoporous Film Using sc-CO2.

Science.gov (United States)

Chavez Panduro, Elvia A; Assaker, Karine; Beuvier, Thomas; Blin, Jean-Luc; Stébé, Marie-José; Konovalov, Oleg; Gibaud, Alain

2017-01-25

Surfactant templated silica thin films were self-assembled on solid substrates by dip-coating using a partially fluorinated surfactant R 8 F (EO) 9 as the liquid crystal template. The aim was 2-fold: first we checked which composition in the phase diagram was corresponding to a 2D rectangular highly ordered crystalline phase and second we exposed the films to sc-CO 2 to foster the removal of the surfactant. The films were characterized by in situ X-ray reflectivity (XRR) and grazing incidence small angle X-ray scattering (GISAXS) under CO 2 pressure from 0 to 100 bar at 34 °C. GISAXS patterns reveal the formation of a 2-D rectangular structure at a molar ratio R 8 F (EO) 9 /Si equal to 0.1. R 8 F (EO) 9 micelles have a cylindrical shape, which have a core/shell structure ordered in a hexagonal system. The core contains the R 8 F part and the shell is a mixture of (EO) 9 embedded in the silica matrix. We further evidence that the extraction of the template using supercritical carbon dioxide can be successfully achieved. This can be attributed to both the low solubility parameter of the surfactants and the fluorine and ethylene oxide CO 2 -philic groups. The initial 2D rectangular structure was well preserved after depressurization of the cell and removal of the surfactant. We attribute the very high stability of the rinsed film to the large value of the wall thickness relatively to the small pore size.

Basalt Reactivity Variability with Reservoir Depth in Supercritical CO2 and Aqueous Phases

Energy Technology Data Exchange (ETDEWEB)

Schaef, Herbert T.; McGrail, B. Peter; Owen, Antionette T.

2011-04-01

Long term storage of CO{sub 2} in geologic formations is currently considered the most attractive option to reduce greenhouse gas emissions while continuing to utilize fossil fuels for energy production. Injected CO{sub 2} is expected to reside as a buoyant water-saturated supercritical fluid in contact with reservoir rock, the caprock system, and related formation waters. As was reported for the first time at the GHGT-9 conference, experiments with basalts demonstrated surprisingly rapid carbonate mineral formation occurring with samples suspended in the scCO{sub 2} phase. Those experiments were limited to a few temperatures and CO{sub 2} pressures representing relatively shallow (1 km) reservoir depths. Because continental flood basalts can extend to depths of 5 km or more, in this paper we extend the earlier results across a pressure-temperature range representative of these greater depths. Different basalt samples, including well cuttings from the borehole used in a pilot-scale basalt sequestration project (Eastern Washington, U.S.) and core samples from the Central Atlantic Magmatic Province (CAMP), were exposed to aqueous solutions in equilibrium with scCO{sub 2} and water-rich scCO{sub 2} at six different pressures and temperatures for select periods of time (30 to 180 days). Conditions corresponding to a shallow injection of CO{sub 2} (7.4 MPa, 34 C) indicate limited reactivity with basalt; surface carbonate precipitates were not easily identified on post-reacted basalt grains. Basalts exposed under identical times appeared increasingly more reacted with simulated depths. Tests, conducted at higher pressures (12.0 MPa) and temperatures (55 C), reveal a wide variety of surface precipitates forming in both fluid phases. Under shallow conditions tiny clusters of aragonite needles began forming in the wet scCO{sub 2} fluid, whereas in the CO{sub 2} saturated water, cation substituted calcite developed thin radiating coatings. Although these types of coatings

Lanthanide-doped Na xScF 3+ x nanocrystals: Crystal structure evolution and multicolor tuning

KAUST Repository

Teng, Xue

2012-05-23

Rare-earth-based nanomaterials have recently drawn considerable attention because of their unique energy upconversion (UC) capabilities. However, studies of Sc 3+-based nanomaterials are still absent. Herein we report the synthesis and fine control of Na xScF 3+x nanocrystals by tuning of the ratio of oleic acid (OA, polar surfactant) to 1-octadecene (OD, nonpolar solvent). When the OA:OD ratio was increased from low (3:17) to high (3:7), the nanocrystals changed from pure monoclinic phase (Na 3ScF 6) to pure hexagonal phase (NaScF 4) via a transition stage at an intermediate OA:OD ratio (3:9) where a mixture of nanocrystals in monoclinic and hexagonal phases was obtained and the coexistence of the two phases inside individual nanocrystals was also observed. More significantly, because of the small radius of Sc 3+, Na xScF 3+x:Yb/Er nanocrystals show different UC emission from that of NaYF 4:Yb/Er nanocrystals, which broadens the applications of rare-earth-based nanomaterials ranging from optical communications to disease diagnosis. © 2012 American Chemical Society.

Magnetic moment of {sup 48}Sc

Energy Technology Data Exchange (ETDEWEB)

Ohtsubo, T., E-mail: tohtsubo@np.gs.niigata-u.ac.jp; Kawamura, Y.; Ohya, S. [Niigata University, Department of Physics (Japan); Izumikawa, T. [Niigata University, Radioisotope Center (Japan); Nishimura, K. [Toyama University, Faculty of Engineering (Japan); Muto, S. [Neutron Science Laboratory, KEK (Japan); Shinozuka, T. [Tohoku University, Cyclotron and Radioisotope Center (Japan)

2007-11-15

Nuclear magnetic resonances were measured for {sup 48}Sc and {sup 44m}Sc oriented at 8 mK in an Fe host metal. The magnetic hyperfine splitting frequencies at an external magnetic field of 0.2 T were determined to be 63.22(11) MHz and 64.81(1) MHz for {sup 48}Sc and {sup 44m}Sc, respectively. With the known magnetic moment of {mu}({sup 44m}Sc)=+3.88 (1) {mu}{sub N}, the magnetic moment of {sup 48}Sc is deduced as {mu}({sup 44}Sc)=+3.785(12) {mu}{sub N}. The measured magnetic moment of {sup 48}Sc is discussed in terms of the shell model using the effective interactions.

Hydrostatic pressing effect on some properties of Al2O3 and Sc2O3 base ceramics

International Nuclear Information System (INIS)

Artemova, K.K.; Rudenko, L.A.; Maslova, G.Ya.; Levkovich, N.A.; Orlova, L.A.

1981-01-01

Found is the effect of hydrostatic pressing pressure on some physico-mechanical properties of the ceramic on the Al 2 O 3 and Se 2 O 3 base. Mathematical models, describing dependences of the strength of materials made of Al 2 O 3 and Sc 2 O 3 on sintering conditions and on hydrostatic pressing pressure, are plotted. Production regimes on the Al 2 O 3 and Sc 2 O 3 base ceramics with improved properties are optimized [ru

Modification and application of the ATHLET-SC code to trans-critical simulations

International Nuclear Information System (INIS)

Fu, S.-W.; Zhou, C.; Xu, Z.-H.; Liu, X.-J.; Yang, Y.-H.; Cheng, H.

2011-01-01

In the simulation of trans-critical transients of Supercritical water cooled reactor (SCWR), calculation will terminate because of the sudden change in void fraction across the critical point. To solve this problem, a pseudo two-phase method is proposed with a virtual region of latent heat at pseudo-critical temperatures. A smooth variation of void fraction can be realized by using liquid-field conservation equations at temperatures lower than the pseudo-critical temperature, and vapor-field conservation equations at temperatures higher than the pseudo-critical temperature. Using this method, the system code ATHLET is modified to ATHLET-SC mod 2 on the basic of the previous modified version ATHLET-SC by Shanghai Jiao Tong University. The results of tests are verified that the calculation error with the pseudo two-phase method for supercritical fluid is acceptable, when the virtual region of latent heat is kept small. Moreover, the ATHLET-SC mod 2 code is used to simulate the pressurization and depressurization process of a single flow channel with the pressure transition as well as blowdown process. The results indicate a good applicability of the modified code. (author)

Quantum chemical study of the geometrical and electronic structures of ScSi{sub 3}{sup −/0} clusters and assignment of the anion photoelectron spectra

Energy Technology Data Exchange (ETDEWEB)

Tran, Quoc Tri; Tran, Van Tan, E-mail: tvtan@dthu.edu.vn [Theoretical and Physical Chemistry Division, Dong Thap University, 783-Pham Huu Lau, Cao Lanh City, Ward 6, Dong Thap (Viet Nam)

2016-06-07

The geometrical and electronic structures of ScSi{sub 3}{sup −/0} clusters have been studied with the B3LYP, CCSD(T), and CASPT2 methods. The ground state of the anionic cluster was evaluated to be the {sup 1}A{sub 1} of rhombic η{sup 2}-(Si{sub 3})Sc{sup −} isomer, whereas that of the neutral cluster was computed to be the {sup 2}A{sub 1} of the same isomer. All features in the 266 and 193 nm photoelectron spectra of ScSi{sub 3}{sup −} cluster were interpreted by the one- and two-electron detachments from the {sup 1}A{sub 1} of rhombic η{sup 2}-(Si{sub 3})Sc{sup −} isomer. The Franck-Condon factor simulation results show that the first broad band starting at 1.78 eV in the spectra comprises several vibrational progression peaks of two totally symmetric modes with the corresponding frequencies of 296 and 354 cm{sup −1}.

Retention at room temperature of the tetragonal t''-form in Sc{sub 2}O{sub 3}-doped ZrO{sub 2} nanopowders

Energy Technology Data Exchange (ETDEWEB)

Abdala, Paula M., E-mail: pabdala@citefa.gov.a [CINSO (Centro de Investigaciones en Solidos), CITEFA-CONICET, J.B. de La Salle 4397, 1603 Villa Martelli, Pcia. de Buenos Aires (Argentina); Lamas, Diego G. [CINSO (Centro de Investigaciones en Solidos), CITEFA-CONICET, J.B. de La Salle 4397, 1603 Villa Martelli, Pcia. de Buenos Aires (Argentina); Fantini, Marcia C.A.; Craievich, Aldo F. [Instituto de Fisica, FAP, USP, Travessa R da Rua do Matao, No. 187, Cidade Universitaria, 05508-900 Sao Paulo (Brazil)

2010-04-16

Synchrotron X-ray powder diffraction was applied to the study of the effect of crystallite size on the crystal structure of ZrO{sub 2}-10 mol% Sc{sub 2}O{sub 3} nanopowders synthesized by a nitrate-lysine gel-combustion route. Nanopowders with different average crystallite sizes were obtained by calcination at several temperatures, ranging from 650 to 1200 {sup o}C. The metastable t''-form of the tetragonal phase, exhibiting a cubic unit cell and tetragonal P4{sub 2}/nmc spatial symmetry, was retained at room temperature in fine nanocrystalline powders, completely avoiding the presence of the stable rhombohedral {beta} phase. Differently, this phase was identified in samples calcined at high temperatures and its content increased with increasing crystallite size. The critical maximum crystallite size for the retention of the mestastable t''-form resulted of about 35 nm.

SC: A NOVEL FUZZY CRITERION FOR SOLVING ENGINEERING AND CONSTRAINED OPTIMIZATION PROBLEMS

Directory of Open Access Journals (Sweden)

Sergio G. De los Cobos Silva

2017-04-01

Full Text Available In this paper a novel fuzzy convergence system (SC and its fundamentals are presented. The model was implemented on a monoobjetive PSO algorithm with three phases: 1 Stabilization, 2 generation and breadth-first search, and 3 generation and depth-first. The system SC-PSO-3P was tested with several benchmark engineering problems and with several CEC2006 problems. The computing experience and comparison with previously reported results is presented. In some cases the results reported in the literature are improved.

Implementation of LTE SC-FDMA on the USRP2 Software Defined Radio Platform

DEFF Research Database (Denmark)

Jørgensen, Peter Bjørn; Hansen, Thomas Lundgaard; Sørensen, Troels Bundgaard

2011-01-01

In this paper we discuss the implementation of a Single Carrier Frequency Division Multiple Access (SC-FDMA) transceiver running over the Universal Software Radio Peripheral 2 (USRP2). SC-FDMA is the air interface which has been selected for the uplink in the latest Long Term Evolution (LTE....../s. Experimental results on the Bit Error Rate (BER) versus Signal-to-Noise Ratio (SNR) are presented and compared to theoretical and simulated performance....

Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41.

Directory of Open Access Journals (Sweden)

Charles Sabin

Full Text Available The human monoclonal antibody (mAb HK20 neutralizes a broad spectrum of primary HIV-1 isolates by targeting the highly conserved heptad repeat 1 (HR1 of gp41, which is transiently exposed during HIV-1 entry. Here we present the crystal structure of the HK20 Fab in complex with a gp41 mimetic 5-Helix at 2.3 Å resolution. HK20 employs its heavy chain CDR H2 and H3 loops to bind into a conserved hydrophobic HR1 pocket that is occupied by HR2 residues in the gp41 post fusion conformation. Compared to the previously described HR1-specific mAb D5, HK20 approaches its epitope with a different angle which might favor epitope access and thus contribute to its higher neutralization breadth and potency. Comparison of the neutralization activities of HK20 IgG, Fab and scFv employing both single cycle and multiple cycle neutralization assays revealed much higher potencies for the smaller Fab and scFv over IgG, implying that the target site is difficult to access for complete antibodies. Nevertheless, two thirds of sera from HIV-1 infected individuals contain significant titers of HK20-inhibiting antibodies. The breadth of neutralization of primary isolates across all clades, the higher potencies for C-clade viruses and the targeting of a distinct site as compared to the fusion inhibitor T-20 demonstrate the potential of HK20 scFv as a therapeutic tool.

Measurement for commercial exposives with SC-DSC test. Sangyoyo bakuhayaku no SC-DSC sokutei

Energy Technology Data Exchange (ETDEWEB)

Yabashi, H.; Wada, Y.; Hwang, D.; Akutsu, Y.; Tamura, M.; Yoshida, T. (The University of Tokyo, Tokyo (Japan). Faculty of Engineering); Matsuzawa, T. (Nippon Kayaku Co. Ltd., Tokyo (Japan))

1991-08-30

The sealed cell differential scanning calorimetry (SC-DSC) was sintroduced of commercial blasting explosives. As a series of testing the commercial blasting explosives in performance, an SC-DSC test was made to compare the critical detonability line with that resulting therefrom. From the result of SC-DSC measurement, the critical dilution rate was estimated of commercial blasting explosives to become without detonating propagation. As a result, all the explosives with exception of ANFO one were assumed to have a possibility of detonating propagation so that the ANFO explosive was known to be material, unable to exactly evaluate the detonability by the SC-DSC test. The explosion heat, then calculated by the REITP2 in order to assume how the reaction proceeded in the DSC cell, was compared with the reaction heat measured by the SC-DSC test. As a result, the calculated value was known to be almost equal to or slightly larger than the measured one. 15 refs., 4 figs., 2 tabs.

Location of the major 2Psub(1/2) strength in 49Sc by forward angle heavy-ion j dependence

International Nuclear Information System (INIS)

Kemper, K.W.; Zeller, A.F.; Ophel, T.R.

1977-12-01

Foward angle 48 Ca( 7 Li, 6 He) data show the 4.49 MeV state in 49 Sc to be 2Psub(1/2) and not 2Psub(3/2) as reported in an earlier 48 Ca( 15 N, 14 C) work. The ( 3 He,d) spectroscopic factor of 0.55 indicates that this state has the major components of the 2psub(1/2) strength in 49 Sc. (Author)

A Study of Charge-Exchange Neutrals from a Rotating Plasma

DEFF Research Database (Denmark)

Jørgensen, L. W.; Sillesen, Alfred Hegaard

1980-01-01

Measurements of charge-exchange neutrals leaving a rotating plasma (a puffatron device) are reported. Neutrals are observed only during the breakdown phase (2-3 mu s) indicating that the created plasma is fully ionized. Several energy spectra of the neutrals for different plasma parameters are ob....... Neutral particle measurements at different distances from the puffatron midplane show ionization velocities parallel with the magnetic field of about 2*104 ms-1 and plasma expansion velocities of about 5-6*104 ms-1 corresponding to an electron temperature of about 25 eV.......Measurements of charge-exchange neutrals leaving a rotating plasma (a puffatron device) are reported. Neutrals are observed only during the breakdown phase (2-3 mu s) indicating that the created plasma is fully ionized. Several energy spectra of the neutrals for different plasma parameters...... are obtained. These spectra are grossly explained using a single-particle orbit model of the plasma ions. Assuming a Maxwellian distribution for the spread in the ion Larmor energy for the central part of the measured energy spectra, it is possible to determine the ion energy during the breakdown phase...

Intracellular scFvs against the viral E6 oncoprotein provoke apoptosis in human papillomavirus-positive cancer cells

International Nuclear Information System (INIS)

Lagrange, Magali; Boulade-Ladame, Charlotte; Mailly, Laurent; Weiss, Etienne; Orfanoudakis, Georges; Deryckere, Francois

2007-01-01

The E6 protein of human papillomavirus type 16 (16E6) is involved in the tumorigenesis of human cervical cells by targeting numerous cellular proteins. We have designed a strategy for neutralizing 16E6 based on the intracellular expression of single-chain Fv antibodies (scFvs) specific to 16E6. Recombinant adenovirus vectors were constructed to allow expression of two 16E6-binding scFvs and one 16E6-non-binding scFv in HPV16-positive and -negative cells. Expression of the scFvs provoked two types of effects: (i) inhibition of proliferation of all cell lines tested, this aspecific toxicity being likely due to the aggregation of unfolded scFvs; and (ii) apoptosis observed only in HPV16-positive cervical cancer cell lines after expression of 16E6-binding scFvs, this specific effect being proportional to the intracellular solubility of the scFvs. These data demonstrate the feasibility of intracellular immunization with anti-16E6 scFvs and highlight the importance of the solubility of the intracellular antibodies

Novel 2D or 3D alkaline-earth metal sulfonate-phosphonates based on [O 3S-C 2H 4-PO 3H] 2- ligand

Science.gov (United States)

Du, Zi-Yi; Wen, He-Rui; Xie, Yong-Rong

2008-11-01

Three novel alkaline-earth metal sulfonate-phosphonates based on [O 3S-C 2H 4-PO 3H] 2- ligand, namely, [Ca(O 3SC 2H 4PO 3H)(H 2O) 2] ( 1), [Sr(O 3SC 2H 4PO 3H)] ( 2) and [Ba 2(O 3SC 2H 4PO 3H) 2] ( 3), have been synthesized by hydrothermal reactions. They represent the first structurally characterized alkaline-earth metal complexes of phosphonic acid attached with a sulfonate group. The structure of compound 1 features a 2D layer based on 1D chains of [Ca 2(PO 3) 2] bridged by -CH 2-CH 2-SO 3- groups. Compounds 2 and 3 show pillar-layer architecture based on two different inorganic layers linked by -CH 2-CH 2- groups. The inorganic layer in compound 2 features a 1D chain of edge-sharing SrO 8 polyhedra whereas that in compound 3 features an edge-sharing Ba 2O 14 di-polyhedral unit which is further corner-shared with four neighboring ones. The [O 3S-C 2H 4-PO 3H] 2- ligand shows diverse coordination modes in the three alkaline-earth metal sulfonate-phosphonates.

Determination of the n-octanol/water partition coefficients of weakly ionizable basic compounds by reversed-phase high-performance liquid chromatography with neutral model compounds.

Science.gov (United States)

Liang, Chao; Han, Shu-ying; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin

2014-11-01

A strategy to utilize neutral model compounds for lipophilicity measurement of ionizable basic compounds by reversed-phase high-performance liquid chromatography is proposed in this paper. The applicability of the novel protocol was justified by theoretical derivation. Meanwhile, the linear relationships between logarithm of apparent n-octanol/water partition coefficients (logKow '') and logarithm of retention factors corresponding to the 100% aqueous fraction of mobile phase (logkw ) were established for a basic training set, a neutral training set and a mixed training set of these two. As proved in theory, the good linearity and external validation results indicated that the logKow ''-logkw relationships obtained from a neutral model training set were always reliable regardless of mobile phase pH. Afterwards, the above relationships were adopted to determine the logKow of harmaline, a weakly dissociable alkaloid. As far as we know, this is the first report on experimental logKow data for harmaline (logKow = 2.28 ± 0.08). Introducing neutral compounds into a basic model training set or using neutral model compounds alone is recommended to measure the lipophilicity of weakly ionizable basic compounds especially those with high hydrophobicity for the advantages of more suitable model compound choices and convenient mobile phase pH control. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Final Report: Molecular Mechanisms of Interfacial Reactivity in Near Surface and Extreme Geochemical Environments (DE-SC0009362)

Energy Technology Data Exchange (ETDEWEB)

Dixon, David A [Univ. of Alabama, Tuscaloosa, AL (United States)

2016-03-27

The prediction of the long-term stability and safety of geologic sequestration of greenhouse gases requires a detailed understanding of subsurface transport and chemical interactions between the disposed greenhouse gases and the geologic media. In this regard, mineral-fluid interactions are of prime importance since reactions that occur on or near the interface can assist in the long term sequestration of CO2 by trapping in mineral phases such as carbonates, as well as influencing the subsurface migration of the disposed fluids via creation or plugging of pores or fractures in the host rock strata. Previous research on mineral-fluid interaction for subsurface CO2 storage has focused almost entirely on the aqueous phase, i.e., reactivity with aqueous solutions or brines containing dissolved CO2. However, interactions with neat to water-saturated non-aqueous fluids are of equal if not greater importance since supercritical CO2 (scCO2) is less dense than the aqueous phase or oil which will create a buoyant scCO2 plume that ultimately will dominate the pore volume within the caprock, and the injected scCO2 will contain water soon after injection and this water can be highly reactive. Collectively, therefore, mineral interactions with water-saturated scCO2-dominated fluids are pivotal and could result in the stable sequestration of CO2 by trapping in mineral phases such as metal carbonates within otherwise permeable zones in the caprock. The primary objective is to unravel the molecular mechanisms governing the reactivity of mineral phases important in the geologic sequestration of CO2 with variably wet supercritical carbon dioxide as a function of T, P, and mineral structure using computational chemistry. This work is in close collaboration with the PNNL Geosciences effort. The focus of the work at The University of Alabama is computational studies of the formation of magnesium and calcium carbonates and oxides and their reactivity and providing computational support

Operational characteristics in the three-phase transformer-type SFCL with neutral line based on sequential reclosing process

International Nuclear Information System (INIS)

Cho, Y.S.; Choi, H.S.; Jung, B.I.

2011-01-01

The three-phase transformer-type SFCL with a neutral line can control the current limiting rates according to the turn's ratio between primary and secondary windings. The transformer-type SFCL with a neutral line can reliably conduct the fault current limiting operation according to the reclosing operation duty and fault types. The superconducting elements recovered their superconducting state within the opening cycle of the circuit breaker according to the reclosing operation duty. It is expected to improve the transient stability and supply reliability of the power network. In a transformer-type superconducting fault current limiter (SFCL) with a neutral line, which is connected between the superconducting elements and secondary windings, we verified that the SFCL has excellent characteristics that induce the perfect simultaneous quench of the superconducting elements in the previous study. The application of the SFCL to the power networks requires its coordination with the reclosing operation duty, which protects a circuit. In this study, the fault current limiting and recovery characteristics of superconducting elements in the three-phase transformer-type SFCL with the neutral line were analyzed. The limiting rate of the fault current in the transformer-type SFCL could increased by an iron core, which allows quenching of the superconducting elements in a sound phase as well as in a faulted phase. In addition, the simultaneous quench led to uniform burdens on superconducting elements, all of which recovered their superconducting state within an opening cycle of a circuit breaker. Thus, the transformer-type SFCL with the neutral line could reliably conduct the fault current limiting and recovery operations of superconducting elements according to the reclosing operation duty and fault types.

Toxic emissions and devaluated CO2-neutrality

DEFF Research Database (Denmark)

Czeskleba-Dupont, Rolf

Environmental, energy and climate policies need fresh reflections. In order to evaluate toxics reduction policies the Stockholm Convention on Persistent Organic Pollutants is mandatory. Denmark's function as lead country for dioxin research in the context of the OSPAR Convention is contrasted...... with a climate policy whose goals of CO2-reduction were made operational by green-wash. Arguments are given for the devaluation of CO2- neutrality in case of burning wood. Alternative practices as storing C in high quality wood products and/or leaving wood in the forest are recommended. A counter......-productive effect of dioxin formation in the cooling phase of wood burning appliances has been registered akin to de-novo-synthesis in municipal solid waste incinerators. Researchers, regulators and the public are, however, still preoccupied by notions of oven design and operation parameters, assuming that dioxin...

An EPR investigation of the dynamic Jahn-Teller effect in SrCl2:y(2 plus) and SrCl2:Sc(2 plus)

Science.gov (United States)

Herrington, J. R.; Estle, T. L.; Boatner, L. A.

1972-01-01

EPR spectra have been observed for SrCl2:Y(2+) and SrCl2:Sc(2+) at liquid helium temperatures. At 1.2 K the spectra were dominated by anisotropic hyperfine patterns whose lineshapes and angular dependences were explained using second order solutions of the effective Hamiltonian for an isolated 2Eg state split by large random internal strains. Pronounced asymmetries in some of the strin produced lineshapes for Srcl2:Sc(2+) are shown to result from second order terms in the solution of the effective Hamiltonian. Coexisting with the anisotropic hyperfine patterns are weak nearly isotropic hyperfine patterns with typical lineshapes. Variations in the apparent intensity of lines in these weak hyperfine patterns as functions of the applied magnetic field direction and temperature imply that these lines result from averaging by vibronic relaxation of a portion of the anisotropic pattern. The effective Hamiltonian parameters for SrCl2:La(2+), SrCl2:y(2+), and SrCl2:SC(2+) are analyzed in terms of crystal field theory modified to include a dynamic Jahn-Teller effect.

High precision measurements of hyperfine structure in Tm II, N2+ and Sc II

International Nuclear Information System (INIS)

Mansour, N.B.; Dinneen, T.P.; Young, L.

1988-01-01

We have applied the technique of collinear fast-ion-beam laser spectroscopy to measure the hyperfine structure (hfs) in Sc II, Tm II and N 2 + . Laser induced fluorescence was observed from a 50 keV ion beam which was superimposed with the output of an actively stabilized ring dye laser (rms bandwidth 2 and the excited 3d4p configuration of Sc II and in the 4f 13 6s and 4f 13 5d configurations of the Tm II. The fine and hyperfine structure of N 2 + has been observed in the (0,1) and (1,2) band of B 2 Σ/sub u/ + /minus/X 2 Σ/sub g/ + system. Higher resolution measurements of the metastable 3d 2 configuration in Sc II were also made by laser-rf double resonance. The experimental results will be compared with those obtained by multiconfiguration Hartree-Fock ab-initio calculations. 15 refs., 4 figs., 5 tabs

Effects of minor Zr and Sr on as-cast microstructure and mechanical properties of Mg-3Ce-1.2Mn-0.9Sc (wt.%) magnesium alloy

International Nuclear Information System (INIS)

Pan Fusheng; Yang Mingbo; Shen Jia; Wu Lu

2011-01-01

Research highlights: → Minor Zr and/or Sr additions can effectively refine the grains of the Mg-3Ce-1.2Mn-0.9Sc alloy. → Minor Zr and/or Sr additions can improve the tensile properties of the Mg-3Ce-1.2Mn-0.9Sc alloy. → Minor Zr and/or Sr additions can improve the creep properties of the Mg-3Ce-1.2Mn-0.9Sc alloy. - Abstract: The effects of minor Zr and Sr on the as-cast microstructure and mechanical properties of the Mg-3Ce-1.2Mn-0.9Sc (wt.%) alloy were investigated by using optical and electron microscopies, differential scanning calorimetry (DSC) analysis, and tensile and creep tests. The results indicate that adding minor Zr and/or Sr to the Mg-3Ce-1.2Mn-0.9Sc alloy does not cause an obvious change in the morphology and distribution of the Mg 12 Ce phase. However, the grains of the Zr and/or Sr-containing alloys are effectively refined. Among the Zr and/or Sr-containing alloys, the grains of the alloy with the addition of 0.5 wt.%Zr + 0.1 wt.%Sr are the finest, followed by the alloys with the additions of 0.5 wt.%Zr and 0.1 wt.%Sr, respectively. In addition, small additions of Zr and/or Sr can improve the tensile and creep properties of the Mg-3Ce-1.2Mn-0.9Sc alloy. Among the Zr and/or Sr-containing alloys, the alloy with the addition of 0.5 wt.%Zr + 0.1 wt.%Sr obtains the optimum tensile and creep properties.

Sc2[Se2O5]3: The First Rare-Earth Metal Oxoselenate(IV with Exclusively [Se2O5]2− Anions

Directory of Open Access Journals (Sweden)

Stefan Greiner

2018-04-01

Full Text Available The scandium oxodiselenate(IV Sc2[Se2O5]3 was synthesized via solid-state reactions between scandium sesquioxide (Sc2O3 and selenium dioxide (SeO2 with thallium(I chloride (TlCl as fluxing agent in molar ratios of 1:4:2. Evacuated fused silica ampoules were used as reactions vessels for annealing the mixtures for five days at 800 °C. The new scandium compound crystallizes in the triclinic space group P 1 ¯ with the lattice parameters a = 663.71(5 pm, b = 1024.32(7 pm, c = 1057.49(8 pm, α = 81.034(2°, β = 87.468(2°, γ = 89.237(2° and Z = 2. There are two distinct Sc3+ positions, which show six-fold coordination by oxygen atoms as [ScO6]9− octahedra (d(Sc–O = 205–212 pm. Three different [Se2O5]2− anions provide these oxygen atoms with their terminal ligands (Ot. Each of the six selenium(IV central atoms exhibit a stereochemically active lone pair of electrons, so that all [Se2O5]2− anions consist of two ψ1-tetrahedral [SeO3]2− subunits (d(Se–Ot = 164–167 pm, d(Se–Ob = 176–185 pm, ∢(O–Se–O = 93–104° sharing one bridging oxygen atom (Ob with ∢(Se–Ob–Se = 121–128°. The vibrational modes of the complex anionic [Se2O5]2− entities were characterized via single-crystal Raman spectroscopy.

Negative thermal expansion and broad band photoluminescence in a novel material of ZrScMo2VO12.

Science.gov (United States)

Ge, Xianghong; Mao, Yanchao; Liu, Xiansheng; Cheng, Yongguang; Yuan, Baohe; Chao, Mingju; Liang, Erjun

2016-04-21

In this paper, we present a novel material with the formula of ZrScMo2VO12 for the first time. It was demonstrated that this material exhibits not only excellent negative thermal expansion (NTE) property over a wide temperature range (at least from 150 to 823 K), but also very intense photoluminescence covering the entire visible region. Structure analysis shows that ZrScMo2VO12 has an orthorhombic structure with the space group Pbcn (No. 60) at room temperature. A phase transition from monoclinic to orthorhombic structure between 70 and 90 K is also revealed. The intense white light emission is tentatively attributed to the n- and p-type like co-doping effect which creates not only the donor- and acceptor-like states in the band gap, but also donor-acceptor pairs and even bound exciton complexes. The excellent NTE property integrated with the intense white-light emission implies a potential application of this material in light emitting diode and other photoelectric devices.

Band gaps of wurtzite Sc{sub x}Ga{sub 1−x}N alloys

Energy Technology Data Exchange (ETDEWEB)

Tsui, H. C. L.; Moram, M. A. [Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Goff, L. E. [Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Rhode, S. K. [Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Pereira, S. [CICECO and Dept. Physics, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Beere, H. E.; Farrer, I.; Nicoll, C. A.; Ritchie, D. A. [Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

2015-03-30

Optical transmittance measurements on epitaxial, phase-pure, wurtzite-structure Sc{sub x}Ga{sub 1−x}N films with 0 ≤ x ≤ 0.26 showed that their direct optical band gaps increased from 3.33 eV to 3.89 eV with increasing x, in agreement with theory. These films contained I{sub 1}- and I{sub 2}-type stacking faults. However, the direct optical band gaps decreased from 3.37 eV to 3.26 eV for Sc{sub x}Ga{sub 1−x}N films, which additionally contained nanoscale lamellar inclusions of the zinc-blende phase, as revealed by aberration-corrected scanning transmission electron microscopy. Therefore, we conclude that the apparent reduction in Sc{sub x}Ga{sub 1−x}N band gaps with increasing x is an artefact resulting from the presence of nanoscale zinc-blende inclusions.

Mapping the epitopes of a neutralizing antibody fragment directed against the lethal factor of Bacillus anthracis and cross-reacting with the homologous edema factor.

Directory of Open Access Journals (Sweden)

Philippe Thullier

Full Text Available The lethal toxin (LT of Bacillus anthracis, composed of the protective antigen (PA and the lethal factor (LF, plays an essential role in anthrax pathogenesis. PA also interacts with the edema factor (EF, 20% identity with LF to form the edema toxin (ET, which has a lesser role in anthrax pathogenesis. The first recombinant antibody fragment directed against LF was scFv 2LF; it neutralizes LT by blocking the interaction between PA and LF. Here, we report that scFv 2LF cross-reacts with EF and cross-neutralizes ET, and we present an in silico method taking advantage of this cross-reactivity to map the epitope of scFv 2LF on both LF and EF. This method identified five epitope candidates on LF, constituted of a total of 32 residues, which were tested experimentally by mutating the residues to alanine. This combined approach precisely identified the epitope of scFv 2LF on LF as five residues (H229, R230, Q234, L235 and Y236, of which three were missed by the consensus epitope candidate identified by pre-existing in silico methods. The homolog of this epitope on EF (H253, R254, E258, L259 and Y260 was experimentally confirmed to constitute the epitope of scFv 2LF on EF. Other inhibitors, including synthetic molecules, could be used to target these epitopes for therapeutic purposes. The in silico method presented here may be of more general interest.

Sc2O@Cs(126339)-C92: Di-scandium oxide cluster encapsulated into a large fullerene cage

Science.gov (United States)

Gu, Yong-Xin; Li, Qiao-Zhi; Li, De-Huai; Zhao, Rui-Sheng; Zhao, Xiang

2018-04-01

The geometric, electronic structure and thermodynamic stability of Sc2O@C92 has been characterized by using hybrid density functional theory calculations combined with statistical thermodynamic analyses. Results indicate that the isolated pentagon rule (IPR) isomers Sc2O@Cs(126339)-C92, Sc2O@C1(126367)-C92 and Sc2O@C1(126390)-C92 are favorable. Noteworthy, it is the first time to declare that fullerene isomer Cs(126339)-C92 could be considered as the suitable cage to encapsulate metallic cluster. The electronic properties of these three isomers were performed with frontier molecular orbital (HOMO and LUMO) analyses and bond order calculations. Finally, 13C NMR and UV-vis-NIR spectra were simulated to provide valuable information for future experiments.

Solid-State NMR Spectroscopy Proves the Presence of Penta-coordinated Sc Sites in MIL-100(Sc).

Science.gov (United States)

Giovine, Raynald; Volkringer, Christophe; Ashbrook, Sharon E; Trébosc, Julien; McKay, David; Loiseau, Thierry; Amoureux, Jean-Paul; Lafon, Olivier; Pourpoint, Frédérique

2017-07-18

Advanced solid-state NMR methods and first-principles calculations demonstrate for the first time the formation of penta-coordinated scandium sites. These coordinatively unsaturated sites were shown during the thermal activation of scandium-based metal-organic frameworks (MOFs). A 45 Sc NMR experiment allows their specific observation in activated Sc 3 BTB 2 (H 3 BTB=1,3,5-tris(4-carboxyphenyl)benzene) and MIL-100(Sc) MOFs. The assignment of the ScO 5 groups is supported by the DFT calculations of NMR parameters. The presence of ScO 5 Lewis acid sites in MIL-100(Sc) explains furthermore its catalytic activity. The first NMR experiment to probe 13 C- 45 Sc distances is also introduced. This advanced solid-state NMR pulse sequence allows the demonstration of the shrinkage of the MIL-100(Sc) network when the activation temperature is raised. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cross-sections of 45Sc(n,2n)44m,gSc reaction from the reaction threshold to 20 MeV

International Nuclear Information System (INIS)

Luo, J.; Peking Univ., Beijing; Liu, R.; Jiang, L.; Liu, Z.; Sun, G.; Ge, S.

2013-01-01

Cross sections of 45 Sc(n,2n) 44m,g Sc reactions and their isomeric cross section ratios σ m /σ g have been measured at three neutron energies between 13.5 and 14.8 MeV using the activation technique. The pure cross section of the groundstate was then obtained by utilizing the absolute cross section of the metastable state and analysis methods of residual nuclear decay. The monoenergetic neutron beam was produced via the 3 H(d, n) 4 He reaction. The cross sections were also estimated with the TALYS-1.2 nuclear model code using different level density options, at neutron energies varying from the reaction threshold to 20 MeV. Results are also discussed and compared with some corresponding values found in the literature. (orig.)

Electronic structure and physical properties of ScN in pressure: density-functional theory calculations

International Nuclear Information System (INIS)

Guan Pengfei; Wang Chongyu; Yu Tao

2008-01-01

Local density functional is investigated by using the full-potential linearized augmented plane wave (FP-LAPW) method for ScN in the hexagonal structure and the rocksalt structure and for hexagonal structures linking a layered hexagonal phase with wurtzite structure along a homogeneous strain transition path. It is found that the wurtzite ScN is unstable and the layered hexagonal phase, labelled as h o , in which atoms are approximately fivefold coordinated, is metastable, and the rocksalt ScN is stable. The electronic structure, the physical properties of the intermediate structures and the energy band structure along the transition are presented. It is found that the band gaps change from 4.0 to 1.0 eV continuously when c/a value varies from 1.68 to 1.26. It is noticeable that the study of ScN provides an opportunity to apply this kind of material (in wurtzite[h]-derived phase). (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Mouse in Vivo Neutralization of Escherichia coli Shiga Toxin 2 with Monoclonal Antibodies

Directory of Open Access Journals (Sweden)

Larry H. Stanker

2013-10-01

Full Text Available Shiga toxin-producing Escherichia coli (STEC food contaminations pose serious health concerns, and have been the subject of massive food recalls. STEC has been identified as the major cause of the life-threatening complication of hemolytic uremic syndrome (HUS. Besides supportive care, there currently are no therapeutics available. The use of antibiotics for combating pathogenic E. coli is not recommended because they have been shown to stimulate toxin production. Clearing Stx2 from the circulation could potentially lessen disease severity. In this study, we tested the in vivo neutralization of Stx2 in mice using monoclonal antibodies (mAbs. We measured the biologic half-life of Stx2 in mice and determined the distribution phase or t1/2 α to be 3 min and the clearance phase or t1/2 β to be 40 min. Neutralizing mAbs were capable of clearing Stx2 completely from intoxicated mouse blood within minutes. We also examined the persistence of these mAbs over time and showed that complete protection could be passively conferred to mice 4 weeks before exposure to Stx2. The advent of better diagnositic methods and the availability of a greater arsenal of therapeutic mAbs against Stx2 would greatly enhance treatment outcomes of life threatening E. coli infections.

Positive effect of Sc and Zr on globular microstructure formation in AA7075 thixoforming feedstock

International Nuclear Information System (INIS)

Rogal, L.; Dutkiewicz, J.; Litynska-Dobrzanska, L.; Olszowska-Sobieraj, B.; Modigell, M.

2011-01-01

One of methods of obtaining a fine globular microstructure in a semi-solid range, necessary for thixoforming process, is modifiers additions. For this purpose 0.5 weight percent of modifying elements-scandium and zirconium-was added to 7075 alloy. The microstructure of such alloy consisted of homogeneously distributed globular grains of solid solution with the following chemical composition: Mg - 1.9%, Al - 91.6%, Cu - 1.0%, Zn - 5.5%(all in wt.%). Quantitative metallographic analysis showed that the average grain size was 23.5 μm, much smaller than in the alloy without additions and 3.08% volume fraction of precipitates in the form of a layer between spherical α(Al) grains. X-ray phase analysis of the 7075 alloy with Sc and Zr additions confirmed the dominant presence of aluminum solid solution and the intermetallic hexagonal phase MgZn 2 . Electron diffraction pattern confirmed location of ηMgZn 2 phase at the grain boundaries. EDS chemical analysis of the ηMgZn 2 phase showed following content of elements: Mg - 17.2%, Al - 20.4%, Cu - 27.8%, Zn - 34.6%. The larger amount of Cu and Al indicated non-stoichiometry of the η phase, which can be presented with a formula [Mg(Zn,Al,Cu) 2 ]. Additionally, inside the aluminum solution, small, square-shaped precipitations enriched with Sc and Zr were observed. Electron diffraction pattern allowed identification of the precipitates as cubic Al 3 (Sc,Zr) phase. The average hardness of feedstock was 105 HV5. DSC analysis during heating of the alloy enabled the estimation of a solidus line, at temperature of 548 deg. C and a liquidus line at temperature: 656 deg. C. For cooling, the temperatures for solidus and liquidus were 545 deg. C and 636 deg. C respectively. Additionally, the relation of liquid phase as a function of temperature was determined. Measurements of rheological properties in the semi-solid range, using the Searl system indicated that an increase of a particle size leads to an observable decrease of

The effect of metal-rich growth conditions on the microstructure of Sc{sub x}Ga{sub 1-x}N films grown using molecular beam epitaxy

Energy Technology Data Exchange (ETDEWEB)

Tsui, H.C.L.; Moram, M.A. [Department of Materials, Imperial College London (United Kingdom); Goff, L.E. [Department of Materials, Imperial College London (United Kingdom); Department of Physics, University of Cambridge (United Kingdom); Barradas, N.P. [CTN - Centro de Ciencias e Tecnologias Nucleares, Instituto Superior Tecnico, Universidade de Lisboa, Bobadela LRS (Portugal); Alves, E. [IPFN - Instituto de Plasmas e Fusao Nuclear, Lisboa (Portugal); Laboratorio de Aceleradores e Tecnologias de Radiacao, Instituto Superior Tecnico, Universidade de Lisboa, Bobadela LRS (Portugal); Pereira, S. [CICECO and Department of Physics, Universidade de Aveiro (Portugal); Beere, H.E.; Farrer, I.; Nicoll, C.A.; Ritchie, D.A. [Department of Physics, University of Cambridge (United Kingdom)

2015-12-15

Epitaxial Sc{sub x}Ga{sub 1-x}N films with 0 ≤ x ≤ 0.50 were grown using molecular beam epitaxy under metal-rich conditions. The Sc{sub x}Ga{sub 1-x}N growth rate increased with increasing Sc flux despite the use of metal-rich growth conditions, which is attributed to the catalytic decomposition of N{sub 2} induced by the presence of Sc. Microstructural analysis showed that phase-pure wurtzite Sc{sub x}Ga{sub 1-x}N was achieved up to x = 0.26, which is significantly higher than that previously reported for nitrogen-rich conditions, indicating that the use of metal-rich conditions can help to stabilise wurtzite phase Sc{sub x}Ga{sub 1-x}N. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Inactivating mutations in ESCO2 cause SC phocomelia and Roberts syndrome: no phenotype-genotype correlation.

Science.gov (United States)

Schüle, Birgitt; Oviedo, Angelica; Johnston, Kathreen; Pai, Shashidhar; Francke, Uta

2005-12-01

The rare, autosomal recessive Roberts syndrome (RBS) is characterized by tetraphocomelia, profound growth deficiency of prenatal onset, craniofacial anomalies, microcephaly, and mental deficiency. SC phocomelia (SC) has a milder phenotype, with a lesser degree of limb reduction and with survival to adulthood. Since heterochromatin repulsion (HR) is characteristic for both disorders and is not complemented in somatic-cell hybrids, it has been hypothesized that the disorders are allelic. Recently, mutations in ESCO2 (establishment of cohesion 1 homolog 2) on 8p21.1 have been reported in RBS. To determine whether ESCO2 mutations are also responsible for SC, we studied three families with SC and two families in which variable degrees of limb and craniofacial abnormalities, detected by fetal ultrasound, led to pregnancy terminations. All cases were positive for HR. We identified seven novel mutations in exons 3-8 of ESCO2. In two families, affected individuals were homozygous--for a 5-nucleotide deletion in one family and a splice-site mutation in the other. In three nonconsanguineous families, probands were compound heterozygous for a single-nucleotide insertion or deletion, a nonsense mutation, or a splice-site mutation. Abnormal splice products were characterized at the RNA level. Since only protein-truncating mutations were identified, regardless of clinical severity, we conclude that genotype does not predict phenotype. Having established that RBS and SC are caused by mutations in the same gene, we delineated the clinical phenotype of the tetraphocomelia spectrum that is associated with HR and ESCO2 mutations and differentiated it from other types of phocomelia that are negative for HR.

Genome analysis coupled with physiological studies reveals a diverse nitrogen metabolism in Methylocystis sp. strain SC2.

Directory of Open Access Journals (Sweden)

Bomba Dam

Full Text Available BACKGROUND: Methylocystis sp. strain SC2 can adapt to a wide range of methane concentrations. This is due to the presence of two isozymes of particulate methane monooxygenase exhibiting different methane oxidation kinetics. To gain insight into the underlying genetic information, its genome was sequenced and found to comprise a 3.77 Mb chromosome and two large plasmids. PRINCIPAL FINDINGS: We report important features of the strain SC2 genome. Its sequence is compared with those of seven other methanotroph genomes, comprising members of the Alphaproteobacteria, Gammaproteobacteria, and Verrucomicrobia. While the pan-genome of all eight methanotroph genomes totals 19,358 CDS, only 154 CDS are shared. The number of core genes increased with phylogenetic relatedness: 328 CDS for proteobacterial methanotrophs and 1,853 CDS for the three alphaproteobacterial Methylocystaceae members, Methylocystis sp. strain SC2 and strain Rockwell, and Methylosinus trichosporium OB3b. The comparative study was coupled with physiological experiments to verify that strain SC2 has diverse nitrogen metabolism capabilities. In correspondence to a full complement of 34 genes involved in N2 fixation, strain SC2 was found to grow with atmospheric N2 as the sole nitrogen source, preferably at low oxygen concentrations. Denitrification-mediated accumulation of 0.7 nmol (30N2/hr/mg dry weight of cells under anoxic conditions was detected by tracer analysis. N2 production is related to the activities of plasmid-borne nitric oxide and nitrous oxide reductases. CONCLUSIONS/PERSPECTIVES: Presence of a complete denitrification pathway in strain SC2, including the plasmid-encoded nosRZDFYX operon, is unique among known methanotrophs. However, the exact ecophysiological role of this pathway still needs to be elucidated. Detoxification of toxic nitrogen compounds and energy conservation under oxygen-limiting conditions are among the possible roles. Relevant features that may stimulate

Final report of “A Detailed Study of the Physical Mechanisms Controlling CO2-Brine Capillary Trapping in the Subsurface” (University of Arizona, DE-SC0006696)

Energy Technology Data Exchange (ETDEWEB)

Schaap, Marcel G. [Univ. of Arizona, Tucson, AZ (United States)

2016-07-25

Carbon capture and storage (CCS) of carbon dioxide emissions generated by production or combustion of fossil fuels is a technologically viable means to reduce the build-up of CO2 in the atmosphere and oceans. Using advantages of scale and location, CCS is particularly suitable for large point sources near ubiquitous deep saline aquifers, depleted gas reservoirs, or at production reservoirs for enhanced oil recovery (EOR). In the BES-funded research project, Oregon State University (OSU) carried out capillary trapping experiments with proxy fluids that mimic the properties of the scCO2/brine system under ambient temperatures and pressures, and successfully developed a unique and novel x-ray compatible, high-pressure, elevated temperature setup to study the scCO2/brine system under challenging reservoir conditions. Both methodologies were applied to a variety of porous media, including synthetic (glass bead) and geologic (Bentheimer sandstone) materials. The University of Arizona (UA) developed pore-scale lattice Boltzmann (LB) models which are able to handle the experimental conditions for proxy fluids, as well as the scCO2/brine system, that are capable of simulating permeability in volumes of tens of millions of fluid elements. We reached the following summary findings (main institute indicated): 1. (OSU/UA) To understand capillary trapping in a multiphase fluid-porous medium system, the system must be analyzed from a pore-scale force balance perspective; trapping can be enhanced by manipulating wetting and nonwetting phase fluid properties. 2. (OSU) Pore-scale fluid connectivity and topology has a clear and direct effect on nonwetting phase capillary trapping efficiency. 3. (OSU) Rock type and flow regime also have a pronounced effects on capillary trapping. 4. (OSU/UA) There is a predictable relationship between NWP connectivity and NWP saturation, which allows for development of injection strategies that optimize trapping. The commonly used Land model (Land

Reactive diffusion in Sc/Si multilayer X-ray mirrors with CrB2 barrier layers

International Nuclear Information System (INIS)

Pershyn, Y.P.; Zubarev, E.N.; Kondratenko, V.V.; Sevryukova, V.A.; Kurbatova, S.V.

2011-01-01

Processes undergoing in Sc/Si multilayer X-ray mirrors (MXMs) with periods of ∝27 nm and barrier layers of CrB 2 0.3- and 0.7-nm thick within the temperature range of 420-780 K were studied by methods of small-angle X-ray reflectivity (λ=0.154 nm) and cross-sectional transmission electron microscopy. All layers with the exception of Sc ones are amorphous. Barrier layers are stable at least up to a temperature of 625 K and double the activation energy of diffusional intermixing at moderate temperatures. Introduction of barriers improves the thermal stability of Sc/Si MXMs at least by 80 degrees. Diffusion of Si atoms through barrier layers into Sc layers with formation of silicides was shown to be the main degradation mechanism of MXMs. A comparison of the stability for Sc/Si MXMs with different barriers published in the literature is conducted. The ways of further improvement of barrier properties are discussed. (orig.)

Supercritical SC-CO2 and Soxhlet n-Hexane Extract of Tunisian Opuntia ficus indica Seeds and Fatty Acids Analysis

Directory of Open Access Journals (Sweden)

Nizar Yeddes

2012-01-01

Full Text Available The fatty acids profiles of Tunisian Opuntia ficus indica seeds (spiny and thornless form were investigated. Results of supercritical carbon dioxide (SC-CO2 and soxhlet n-hexane extract were compared. Quantitatively, the better yield was obtained through soxhlet n-hexane: 10.32% (spiny and 8.91% (thornless against 3.4% (spiny and 1.94% (thornless by SC-CO2 extract (T = 40°C, P=180 bar, time = 135 mn, CO2 flow rate = 15 mL·s−1. Qualitatively, the main fatty acids components were the same for the two types of extraction. Linoleic acid was the major compound, SC-CO2: 57.60% (spiny, 59.98% (thornless, soxhlet n-hexane: 57.54% (spiny, 60.66% (thornless, followed by oleic acid, SC-CO2: 22.31% (spiny, 22.40% (thornless, soxhlet n-hexane: 25.28% (spiny, 20.58% (thornless and palmitic acid, SC-CO2: 14.3% (spiny, 12.92% (thornless, soxhlet n-hexane: 11.33% (spiny, 13.08% (thornless. The SC-CO2 profiles fatty acids showed a richness with other minority compounds such as C20:1, C20:2, and C22.The seeds oil was highly unsaturated (US = 4.44–5.25, and the rising temperatures donot affect the selectivity of fatty acids extract by SC-CO2: US = 4.44 (T = 40°C and 4.13 (T = 70°C.

Supercritical SC-CO2 and Soxhlet n-Hexane Extract of Tunisian Opuntia ficus indica Seeds and Fatty Acids Analysis

Science.gov (United States)

Yeddes, Nizar; Chérif, Jamila Kalthoum; Jrad, Amel; Barth, Danielle; Trabelsi-Ayadi, Malika

2012-01-01

The fatty acids profiles of Tunisian Opuntia ficus indica seeds (spiny and thornless form) were investigated. Results of supercritical carbon dioxide (SC-CO2) and soxhlet n-hexane extract were compared. Quantitatively, the better yield was obtained through soxhlet n-hexane: 10.32% (spiny) and 8.91% (thornless) against 3.4% (spiny) and 1.94% (thornless) by SC-CO2 extract (T = 40°C, P = 180 bar, time = 135 mn, CO2 flow rate = 15 mL·s−1). Qualitatively, the main fatty acids components were the same for the two types of extraction. Linoleic acid was the major compound, SC-CO2: 57.60% (spiny), 59.98% (thornless), soxhlet n-hexane: 57.54% (spiny), 60.66% (thornless), followed by oleic acid, SC-CO2: 22.31% (spiny), 22.40% (thornless), soxhlet n-hexane: 25.28% (spiny), 20.58% (thornless) and palmitic acid, SC-CO2: 14.3% (spiny), 12.92% (thornless), soxhlet n-hexane: 11.33% (spiny), 13.08% (thornless). The SC-CO2 profiles fatty acids showed a richness with other minority compounds such as C20:1, C20:2, and C22.The seeds oil was highly unsaturated (US = 4.44–5.25), and the rising temperatures donot affect the selectivity of fatty acids extract by SC-CO2: US = 4.44 (T = 40°C) and 4.13 (T = 70°C). PMID:22754699

Supercritical SC-CO(2) and Soxhlet n-Hexane Extract of Tunisian Opuntia ficus indica Seeds and Fatty Acids Analysis.

Science.gov (United States)

Yeddes, Nizar; Chérif, Jamila Kalthoum; Jrad, Amel; Barth, Danielle; Trabelsi-Ayadi, Malika

2012-01-01

The fatty acids profiles of Tunisian Opuntia ficus indica seeds (spiny and thornless form) were investigated. Results of supercritical carbon dioxide (SC-CO(2)) and soxhlet n-hexane extract were compared. Quantitatively, the better yield was obtained through soxhlet n-hexane: 10.32% (spiny) and 8.91% (thornless) against 3.4% (spiny) and 1.94% (thornless) by SC-CO(2) extract (T = 40°C, P = 180 bar, time = 135 mn, CO(2) flow rate = 15 mL·s(-1)). Qualitatively, the main fatty acids components were the same for the two types of extraction. Linoleic acid was the major compound, SC-CO(2): 57.60% (spiny), 59.98% (thornless), soxhlet n-hexane: 57.54% (spiny), 60.66% (thornless), followed by oleic acid, SC-CO(2): 22.31% (spiny), 22.40% (thornless), soxhlet n-hexane: 25.28% (spiny), 20.58% (thornless) and palmitic acid, SC-CO(2): 14.3% (spiny), 12.92% (thornless), soxhlet n-hexane: 11.33% (spiny), 13.08% (thornless). The SC-CO(2) profiles fatty acids showed a richness with other minority compounds such as C(20:1), C(20:2), and C(22).The seeds oil was highly unsaturated (US = 4.44-5.25), and the rising temperatures donot affect the selectivity of fatty acids extract by SC-CO2: US = 4.44 (T = 40°C) and 4.13 (T = 70°C).

Thermoluminescence response and glow curve structure of Sc2TiO5 ß-irradiated

International Nuclear Information System (INIS)

Muñoz, I.C.; Brown, F.; Durán-Muñoz, H.; Cruz-Zaragoza, E.; Durán-Torres, B.; Alvarez-Montaño, V.E.

2014-01-01

Discandium titanate (Sc 2 TiO 5 ) powder was synthesized in order to analyze its thermoluminescence (TL) response. The TL glow curve structure shows two peaks: at 453–433 K and at 590–553 K. The TL beta dose–response has a linear behavior over the dose range 50–500 Gy. The T stop preheat method shows five glow peaks that were taken into account to calculate the kinetic parameters using the CGCD procedure. TL results support the possible use of Sc 2 TiO 5 as a new phosphor in high ß-dose dosimetry. - Highlights: • Discandium titanate was synthesized, and its TL properties were analyzed. • The beta dose–response has a linear behavior on the dose range 50–500 Gy. • The kinetic parameters were obtained by the CGCD procedure. • Results support the possible use of Sc 2 TiO 5 as a new phosphor for ß-dose dosimetry

Isolation and characterization of ScGluD2, a new sugarcane beta-1,3-glucanase D family gene induced by Sporisorium scitamineum, ABA, H2O2, NaCl, and CdCl2 stresses

Directory of Open Access Journals (Sweden)

Yachun Su

2016-09-01

Full Text Available Beta-1,3-glucanases (EC 3.2.1.39, commonly known as pathogenesis-related (PR proteins, play an important role not only in plant defense against fungal pathogens but also in plant physiological and developmental processes. However, only a limited number of sugarcane beta-1,3-glucanase genes have been isolated. In the present study, we identified and characterized a new beta-1,3-glucanase gene ScGluD2 (GenBank Acc No. KF664181 from sugarcane. An X8 domain was present at the C terminal region of ScGluD2, suggesting beta-1,3-glucan-binding function. Phylogenetic analysis showed that the predicted ScGluD2 protein was classified into subfamily D beta-1,3-glucanase. Localization of the ScGluD2 protein in the plasma membrane was determined by tagging it with green fluorescent protein. The expression of ScGluD2 was more up-regulated in sugarcane smut-resistant cultivars in the early stage (1 d or 3 d than in the susceptible ones after being challenged by the smut pathogen, revealing that ScGluD2 may be involved in defense against the invasion of Sporisorium scitamineum. Transient overexpression of ScGluD2 in Nicotiana benthamiana leaves induced a defense response and exhibited antimicrobial action on the tobacco pathogens Pseudomonas solanacearum and Botrytis cinerea, further demonstrating that ScGluD2 was related to the resistance to plant pathogens. However, the transcripts of ScGluD2 partially increased (12 h under NaCl stress, and were steadily up-regulated from 6 h to 24 h upon ABA, H2O2, and CdCl2 treatments, suggesting that ABA may be a signal molecule regulating oxidative stress and play a role in the salt and heavy metal stress-induced stimulation of ScGluD2 transcripts. Taken together, ScGluD2, a novel member of subfamily D beta-1,3-glucanase, was a stress-related gene of sugarcane involved in plant defense against smut pathogen attack and salt and heavy metal stresses.

pPKCδ activates SC35 splicing factor during H9c2 myoblastic differentiation.

Science.gov (United States)

Zara, Susi; Falconi, Mirella; Rapino, Monica; Zago, Michela; Orsini, Giovanna; Mazzotti, Giovanni; Cataldi, Amelia; Teti, Gabriella

2011-01-01

Although Protein Kinase C (PKC) isoforms' role in the neonatal and adult cardiac tissue development and ageing has been widely described "in vivo", the interaction of such enzymes with specific nuclear substrates needs to be investigated. The aim of our research has been the study of the expression, localization and interaction with the splicing factor SC35 of PKC isoforms (α, δ, ε, ζ) and their potential role in modulating the transcription machinery. H9c2 cells induced to myoblast differentiation in the presence of 1% Horse Serum (HS) have represented our experimental model. The expression of PKC isoforms, their distribution and interaction with SC35 have been evaluated by western blotting, co-immunoprecipitation and double gold immunolabeling for transmission and scanning electron microscopy. Our results show PKCδ as the most expressed isoform in differentiated cells. Surprisingly, the distribution of PKCδ and SC35 does not show any significant modification between 10%FBS and 1%HS treated samples and no co-localization is observed. Moreover the interaction between the phosphorylated form of PKCδ (pPKCδ) and SC35 increases, is distributed and co-localizes within the nucleus of differentiated H9c2. These data represent reasonable evidence of pPKCδ mediated SC35 splicing factor activation, suggesting its direct effect on transcription via interaction with the transcription machinery. Furthermore, this co-localization represents a crucial event resulting in downstream changes in transcription of components which determine the morphological modifications related to cardiomyoblast differentiated phenotype.

The formation of urea in space. I. Ion-molecule, neutral-neutral, and radical gas-phase reactions

Science.gov (United States)

Brigiano, Flavio Siro; Jeanvoine, Yannick; Largo, Antonio; Spezia, Riccardo

2018-02-01

Context. Many organic molecules have been observed in the interstellar medium thanks to advances in radioastronomy, and very recently the presence of urea was also suggested. While those molecules were observed, it is not clear what the mechanisms responsible to their formation are. In fact, if gas-phase reactions are responsible, they should occur through barrierless mechanisms (or with very low barriers). In the past, mechanisms for the formation of different organic molecules were studied, providing only in a few cases energetic conditions favorable to a synthesis at very low temperature. A particularly intriguing class of such molecules are those containing one N-C-O peptide bond, which could be a building block for the formation of biological molecules. Urea is a particular case because two nitrogen atoms are linked to the C-O moiety. Thus, motivated also by the recent tentative observation of urea, we have considered the synthetic pathways responsible to its formation. Aims: We have studied the possibility of forming urea in the gas phase via different kinds of bi-molecular reactions: ion-molecule, neutral, and radical. In particular we have focused on the activation energy of these reactions in order to find possible reactants that could be responsible for to barrierless (or very low energy) pathways. Methods: We have used very accurate, highly correlated quantum chemistry calculations to locate and characterize the reaction pathways in terms of minima and transition states connecting reactants to products. Results: Most of the reactions considered have an activation energy that is too high; but the ion-molecule reaction between NH2OHNH2OH2+ and formamide is not too high. These reactants could be responsible not only for the formation of urea but also of isocyanic acid, which is an organic molecule also observed in the interstellar medium.

Morphologies and growth mechanisms of the eutectic particles in as-cast Al-Mg-Sc alloy; Morphologien und Wachstumsmechanismen eutektischer Partikel in Al-Mg-Sc-Legierung im Gusszustand

Energy Technology Data Exchange (ETDEWEB)

Pan, Dejiang; Zhou, Shi' ang; Li, Heng [Hefei Univ. of Technology (China); Zhang, Zhen; Wu, Yucheng [Laboratories of Nonferrous Metal Material and Processing Engineering of Anhui Province, Hefei (China); Li, Ming [Anhui Jianghuai Automobile Co., Ltd, Hefei (China)

2017-04-15

Primary particles with faceted cubic morphology were produced in as-cast Al-Mg alloy due to the addition of Sc. The cross-section of the particles revealed some eutectic structure composed of multilayer of 'Al{sub 3}Sc + α-Al + Al{sub 3}Sc..'. At the cooling rate of 200 - 300 K/s, Al{sub 3}Sc primary phase nucleated initially on oxides within the melt and developed to a cubic structure with a 'cellular-dendritic' mode of growth. The formation of α-Al structural shells was attributed as a reason for the segregation of Mg-rich lamellar dendrites at later stages. A growth mechanism for multilayer structure was proposed using the results presented.

Negative ion formation and neutralization processes, (2)

International Nuclear Information System (INIS)

Sugiura, Toshio

1982-09-01

This review is 2nd part of the report published at January 1982 (JAERI-M-9902). A compilation includes the survey of the data of the cross sections of H - and D - ion formations and the neutralization of these ions. This is also presented new information about the photosensitization by laser beam in dissociative-resonance electron capture of sulfur hexafluoride reported by Chen et al., for reference to enhancement of D - ions in discharge. For neutralization, the data of mutual neutralization and photodetachment are also presented. (author)

The SC gets ready for visitors

CERN Multimedia

Antonella Del Rosso

2012-01-01

Hall 300, which houses the Synchrocyclotron (SC), CERN’s first accelerator, is getting ready to host a brand-new exhibition. The site will be one of the stops on the new visit itineraries that will be inaugurated for the 2013 CERN Open Day.   The Synchrocyclotron through the years. Just as it did in the late 1950s, when the accelerator was first installed, the gigantic red structure of the Synchrocyclotron's magnet occupies a large part of the 300-square-metre hall. “We have completed the first phase of the project that will give the SC a new lease of life,” says Marco Silari, the project leader and a member of CERN’s Radiation Protection Group. “We have removed all the equipment that was not an integral part of the accelerator. The hall is now ready for the civil-engineering work that will precede the installation of the exhibition.” The SC was witness to a big part of the history of CERN. The accelerator produced ...

Investigation of phase stability in the scandia-zirconia; Investigacao da estabilidade de fases da zirconia-escandia

Energy Technology Data Exchange (ETDEWEB)

Grosso, Robson Lopes

2016-11-01

In this work, the phase stability of scandia-zirconia (ScSZ) system was investigated by the thermodynamic study of nanoparticles, within the range of 0 to 20 mol% Sc{sub 2}O{sub 3}, and by codoping of ZrO{sub 2}-10 mol% Sc{sub 2}O{sub 3} (10ScSZ) with Dy{sub 2}O{sub 3} and Nb{sub 2}O{sub 5}. The phase stability of ScSZ was evaluated based on thermodynamic data collected by water adsorption microcalorimetry and high temperature oxide melt solution. Nanostructured zirconia-scandia solid solutions were synthesized by coprecipitation method. Thermodynamic data were determined for ScSZ polymorph (monoclinic, tetragonal, cubic, rhombohedral β and γ) found by X-ray diffraction. This systemic work resulted in an unprecedented phase diagram at the nanoscale of particle size-composition. The effects of additives on 10ScSZ were investigated aiming to stabilize the cubic (c) structure at room temperature and to suppress the characteristic cubic-rhombohedral β phase transformation. Compositions were prepared by coprecipitation and solid state reaction. Materials were sintered by conventional and spark plasma sintering. Full stabilization of the cubic phase was attained by 1 mol% Dy{sub 2}O{sub 3} and 0.5 mol% Nb{sub 2}O{sub 5} additions. The smallest Nb{sub 2}O{sub 5} content required for cubic phase stabilization was attributed to liquid phase formation during sintering and to small ionic radius of Nb{sup 5+}. Results of high temperature X-ray diffraction and thermal analysis show suppression of the c-β transformation. Samples containing 0.5 mol% Nb{sub 2}O{sub 5} show total ionic conductivity similar to 10ScSZ without additives within a broad temperature range with high stability during 170 h at 600 °C. (author)

Structure and bonding of ScCN and ScNC: Ground and low-lying states

International Nuclear Information System (INIS)

Kalemos, Apostolos; Metropoulos, Aristophanes; Mavridis, Aristides

2012-01-01

Graphical abstract: The experimentally unknown systems ScCN and ScNC have been studied through single reference CISD and CCSD(T) methods. A total of 20 = 10 (ScCN) + 10 (ScNC) states were examined. All states are quite ionic whereas ScNC(X ∼3 Δ) is stabler than ScCN(X ∼3 Δ) by ∼5 kcal/mol. Display Omitted Highlights: ► We have studied through ab initio methods the polytopic system Sc[CN]. ► A series of low lying states for both isomeric forms have been examined. ► Around equilibrium the system displays a pronounced Sc + [CN] − ionic character. - Abstract: We have studied the experimentally unknown Sc[CN] molecular system in both its isomeric forms, scandium cyanide (ScCN) and isocyanide (ScNC), through ab initio computations. We report energetics, geometries, harmonic frequencies, and dipole moments for the first 20 Sc[CN] states correlating diabatically to Sc + ( 3 D, 1 D, 3 F) + CN − (X 1 Σ + ). Both isomers have a pronounced ionic character around equilibrium due to the high electron affinity of the CN group and the low ionization energy of the Sc atom. According to our calculations the ScNC isomer (X ∼3 Δ) is stabler than the ScCN(X ∼3 Δ) by ∼5 kcal/mol.

The phase transition of the incommensurate phases β-Ln(PO3)3(Ln=Y,Tb…Yb), crystal structures of α-Ln(PO3)3(Ln=Y,Tb…Yb) and Sc(PO3)3

Science.gov (United States)

Höppe, Hennig A.

2009-07-01

The incommensurately modulated room-temperature phases β-Ln(PO3)3(Ln=Y,Tb…Yb) undergo a topotactic phase transition monitored by vibrational spectroscopy below 180 K leading to α-Ln(PO3)3(Ln=Y,Dy…Yb), above 200 K the incommensurate phases are reobtained. The low-temperature phases exhibit a new structure type (α-Dy(PO3)3, P21/c, Z=12,a=14.1422(6), b=20.0793(9),c=10.1018(4) A˚, β=127.532(3)∘). α-Tb(PO3)3 is isotypic with Gd(PO3)3(α-Tb(PO3)3, I2/a,Z=16,a=25.875(6), b=13.460(3), c=10.044(2) A˚, β=119.13(3)∘). The symmetry relations between the involved phases of the phase transition are discussed. The crystal structure of Sc(PO3)3 is isotypic with that of Lu(PO3)3 and C-type phosphates. The polyphosphates consist of infinite zig-zag chains of corner-sharing PO4 tetrahedra, the cations are coordinated sixfold in an almost octahedral arrangement. To confirm the quality of the determined crystal structures the deviation of the phosphate tetrahedra from ideal symmetry was determined and discussed.

Sc-45 nuclear magnetic resonance analysis of precipitation in dilute Al-Sc alloys

NARCIS (Netherlands)

Celotto, S; Bastow, TJ

Nuclear magnetic resonance (NMR) with Sc-45 is used to determine the solid solubility of scandium in aluminium and to follow the precipitation of Al3Sc during the ageing of an Al-0.06 at.% Sc alloy via the two fully resolved peaks, corresponding to Sc in the solid solution Al matrix and to Sc in the

The phase transition of the incommensurate phases β-Ln(PO3)3(Ln=Y,Tb...Yb), crystal structures of α-Ln(PO3)3(Ln=Y,Tb...Yb) and Sc(PO3)3

International Nuclear Information System (INIS)

Hoeppe, Hennig A.

2009-01-01

The incommensurately modulated room-temperature phases β-Ln(PO 3 ) 3 (Ln=Y,Tb...Yb) undergo a topotactic phase transition monitored by vibrational spectroscopy below 180 K leading to α-Ln(PO 3 ) 3 (Ln=Y,Dy...Yb), above 200 K the incommensurate phases are reobtained. The low-temperature phases exhibit a new structure type (α-Dy(PO 3 ) 3 ,P2 1 /c,Z=12,a=14.1422(6),b=20.0793(9),c=10.1018(4)A, β=127.532(3) 0 ). α-Tb(PO 3 ) 3 is isotypic with Gd(PO 3 ) 3 (α-Tb(PO 3 ) 3 ,I2/a,Z=16,a=25.875(6),b=13.460(3),c=10.044(2)A, β=119.13(3) 0 ). The symmetry relations between the involved phases of the phase transition are discussed. The crystal structure of Sc(PO 3 ) 3 is isotypic with that of Lu(PO 3 ) 3 and C-type phosphates. The polyphosphates consist of infinite zig-zag chains of corner-sharing PO 4 tetrahedra, the cations are coordinated sixfold in an almost octahedral arrangement. To confirm the quality of the determined crystal structures the deviation of the phosphate tetrahedra from ideal symmetry was determined and discussed. - Abstract: Basic structure from which all crystal structures of the late lanthanoids' polyphosphates at room temperature and below can be derived.

Synthesis and structure of a new layered oxyfluoride Sr{sub 2}ScO{sub 3}F with photocatalytic property

Energy Technology Data Exchange (ETDEWEB)

Wang, Yongkun; Tang, Kaibin, E-mail: kbtang@ustc.edu.cn; Zhu, Baichuan; Wang, Dake; Hao, Qiaoyan; Wang, Yan

2015-05-15

Highlights: • A new oxyfluoride compound Sr{sub 2}ScO{sub 3}F was prepared by a solid state route. • The structure of this compound was determined by GSAS program based on XRD data. • The photocatalytic property was investigated under UV irradiation. - Abstract: A new Ruddlesden–Popper type scandium oxyfluoride, Sr{sub 2}ScO{sub 3}F, was synthesized by a conventional solid state reaction route. The detailed structure of Sr{sub 2}ScO{sub 3}F was investigated using X-ray diffraction (XRD) and selected area electron diffraction (SAED). The disorder distribution pattern of fluorine anions was determined by the {sup 19}F nuclear magnetic resonance (NMR) spectrum. The compound crystallizes in a K{sub 2}NiF{sub 4}-type tetragonal structure (space group I4/mmm) with O/F anions disordered over the apical sites of the perovskite-type Sc(O,F){sub 6} octahedron layers interleaved with strontium cations. Ultraviolet–visible (UV–vis) diffuse reflection spectrum of the prepared Sr{sub 2}ScO{sub 3}F indicates that it has an absorption in the UV–vis region. The photocatalytic activity of Sr{sub 2}ScO{sub 3}F was further investigated, showing an effective photodegradation of Rhodamine-B (RB) within 2 h under UV light irradiation.

A Further Study of the Products of Sc and Dioxygen Reactions

Science.gov (United States)

Bauschlicher, Charles W., Jr.; Zhou, Mingfei; Andrews, Lester; Johnson, J. R. Tobias; Panas, Itai; Snis, Anders; Roos, Bjoern O.; Arnold, James O. (Technical Monitor)

1999-01-01

The products of the reaction of Sc and dioxygen have been reinvestigated. By adding the electron-trapping molecule CC14, additional information about the IR spectra has been obtained, as well as the observation of new bands. New ab initio calculations are also performed on possible products of the Sc plus O2 reaction. The previously observed band at 722.5 per cm is assigned as the b2 mode of ScO2(-). Bands arising from ScO(+), Sc(O2)(+), and(O2)ScO are also assigned. We are still unable to assign any bands to OScO. The problems associated with the computational study of ScO2 are discussed.

Piezoelectric coefficients and spontaneous polarization of ScAlN

International Nuclear Information System (INIS)

Caro, Miguel A; Laurila, Tomi; Zhang, Siyuan; Moram, Michelle A; Riekkinen, Tommi; Ylilammi, Markku; Molarius, Jyrki; Lopez-Acevedo, Olga

2015-01-01

We present a computational study of spontaneous polarization and piezoelectricity in Sc x Al 1−x N alloys in the compositional range from x = 0 to x = 0.5, obtained in the context of density functional theory and the Berry-phase theory of electric polarization using large periodic supercells. We report composition-dependent values of piezoelectric coefficients e ij , piezoelectric moduli d ij and elastic constants C ij . The theoretical findings are complemented with experimental measurement of e 33 for a series of sputtered ScAlN films carried out with a piezoelectric resonator. The rapid increase with Sc content of the piezoelectric response reported in previous studies is confirmed for the available data. A detailed description of the full methodology required to calculate the piezoelectric properties of ScAlN, with application to other complex alloys, is presented. In particular, we find that the large amount of internal strain present in ScAlN and its intricate relation with electric polarization make configurational sampling and the use of large supercells at different compositions necessary in order to accurately derive the piezoelectric response of the material. (paper)

Study and Fabrication of Super Low-Cost Solar Cell (SLC-SC) Based on Counter Electrode from Animal’s Bone

Science.gov (United States)

Fadlilah, D. R.; Fajar, M. N.; Aini, A. N.; Haqqiqi, R. I.; Wirawan, P. R.; Endarko

2018-04-01

The synthesized carbon from bones of chicken, cow, and fish with the calcination temperature at 450 and 600°C have been successfully fabricated for counter electrode in the Super Low-Cost Solar Cell (SLC-LC) based the structure of Dye-Sensitized Solar Cells (DSSC). The main proposed study was to fabricate SLC-SC and investigate the influence of the synthesized carbon from animal’s bone for counter electrode towards to photovoltaic performance of SLC-SC. X-Ray Diffraction and UV-Vis was used to characterize the phase and the optical properties of TiO2 as photoanode in SLC-SC. Meanwhile, the morphology and particle size distribution of the synthesized carbon in counter electrodes were investigated by Scanning Electron Microscopy (SEM) and Particle Size Analyzer (PSA). The results showed that the TiO2 has anatase phase with the absorption wavelength of 300 to 550 nm. The calcination temperature for synthesizing of carbon could affect morphology and particle size distribution. The increasing temperature gave the effect more dense in morphology and increased the particle size of carbon in the counter electrode. Changes in morphology and particle size of carbon give effect to the performance of the SLC-SC where the increased morphology’s compact and particle size make decreased in the performance of the SLC-SC.

CO{sub 2} neutral steam production for the production of bioethanol; CO{sub 2}-neutrale Dampferzeugung fuer die Bioethanolproduktion

Energy Technology Data Exchange (ETDEWEB)

Wetter, Christof; Bruegging, Elmar; Baumkoetter, Daniel [Fachhochschule Muenster (Germany)

2011-10-15

Conventional plants for the production of bioethanol use fossil fuels such as heating oil or lignite for the supply of process energy. The authors of the contribution under consideration report on a tightly connection of an agricultural company with a biogas plant with a distillery by means an energy center consisting of two cogeneration plants and a steam generator. With this, a CO{sub 2} neutral fuel is produced from a CO{sub 2} neutral vapor.

Polar silica-based stationary phases. Part II- Neutral silica stationary phases with surface bound maltose and sorbitol for hydrophilic interaction liquid chromatography.

Science.gov (United States)

Rathnasekara, Renuka; El Rassi, Ziad

2017-07-28

Two neutral polyhydroxylated silica bonded stationary phases, namely maltose-silica (MALT-silica) and sorbitol-silica (SOR-silica), have been introduced and chromatographically characterized in hydrophilic interaction liquid chromatography (HILIC) for a wide range of polar compounds. The bonding of the maltose and sorbitol to the silica surface was brought about by first converting bare silica to an epoxy-activated silica surface via reaction with γ-glycidoxypropyltrimethoxysilane (GPTMS) followed by attaching maltose and sorbitol to the epoxy surface in the presence of the Lewis acid catalyst BF 3 .ethereate. Both silica based columns offered the expected retention characteristics usually encountered for neutral polar surface. The retention mechanism is majorly based on solute' differential partitioning between an organic rich hydro-organic mobile phase (e.g., ACN rich mobile phase) and an adsorbed water layer on the surface of the stationary phase although additional hydrogen bonding was also responsible in some cases for solute retention. The MALT-silica column proved to be more hydrophilic and offered higher retention, separation efficiency and resolution than the SOR-silica column among the tested polar solutes such as derivatized mono- and oligosaccharides, weak phenolic acids, cyclic nucleotide monophosphate and nucleotide-5'-monophosphates, and weak bases, e.g., nucleobases and nucleosides. Copyright © 2017 Elsevier B.V. All rights reserved.

Topological phase, electronic, magnetic and optical properties of ScPdBi compound with Gd, Np and Cm impurities

Energy Technology Data Exchange (ETDEWEB)

Narimani, Mitra; Nourbakhsh, Zahra, E-mail: z.nourbakhsh@sci.ui.ac.ir

2017-07-15

Highlights: • Gd, Np and Cm impurities induce the magnetic moment in ScPdBi compound. • ScPdBi compound with Gd, Np and Cm impurities has normal band order. • The ε(0) and R(0) increase by increasing the atomic number of X atom. - Abstract: The electronic, magnetic and optical properties of X-doped ScPdBi (X = Gd, Np, Cm) are investigated in the framework of density functional theory. The exchange-correlation potential is treated using generalized gradient approximation with Coulomb interaction parameter. The band order and energy band gap of X-doped ScPdBi are investigated by calculation of band structure. The effect of doping impurity on magnetic properties of ScPdBi compound is studied by calculation of total and partial magnetic moments of X-doped ScPdBi compound. Furthermore, the optical properties of X-doped ScPdBi are calculated and compared in the energy range of 0–25 eV.

Principle and Design of a Single-phase Inverter-Based Grounding System for Neutral-to-ground Voltage Compensation in Distribution Networks

DEFF Research Database (Denmark)

Wang, Wen; Yan, Lingjie; Zeng, Xiangjun

2017-01-01

Neutral-to-ground overvoltage may occur in non-effectively grounded power systems because of the distributed parameters asymmetry and resonance between Petersen coil and distributed capacitances. Thus, the constraint of neutral-to-ground voltage is critical for the safety of distribution networks....... In this paper, an active grounding system based on single-phase inverter and its control parameter design method is proposed to achieve this objective. Relationship between its output current and neutral-to-ground voltage is derived to explain the principle of neutral-to-ground voltage compensation. Then...

Contrasting pressure effects in Sr2VFeAsO3 and Sr2ScFePO3

International Nuclear Information System (INIS)

Kotegawa, Hisashi; Kawazoe, Takayuki; Tou, Hideki; Murata, Keizo; Ogino, Hiraku; Kishio, Kohji; Shimoyama, Jun-ichi

2009-01-01

We report the resistivity measurements under pressure of two Fe-based superconductors with a thick perovskite oxide layer, Sr 2 VFeAsO 3 and Sr 2 ScFePO 3 . The superconducting transition temperature T c of Sr 2 VFeAsO 3 markedly increases with increasing pressure. Its onset value, which was T c onset =36.4 K at ambient pressure, increases to T c onset =46.0 K at ∼4 GPa, ensuring the potential of the '21113' system as a high-T c material. However, the superconductivity of Sr 2 ScFePO 3 is strongly suppressed under pressure. The T c onset of ∼16 K decreases to ∼5 K at ∼4 GPa, and the zero-resistance state is almost lost. We discuss the factor that induces this contrasting pressure effect. (author)

Magnetic ground state of Ti{sub 1-x}Sc{sub x}Fe{sub 2} system

Energy Technology Data Exchange (ETDEWEB)

Saoudi, M.; Deportes, J.; Ouladdiaf, B. E-mail: ouladdiaf@ill.fr

2001-06-01

The magnetic ground states of the Laves phases Ti{sub 1-x}Sc{sub x}Fe{sub 2} system have been investigated by means of powder neutron diffraction and magnetisation techniques. For x=0.23, a transition is observed from a collinear ferromagnet along the c-axis to a canted one at T{sub f}=200 K. For x=0.27, 0.3, 0.33, an additional first-order transition is observed at T{sub t1}{approx}120 K accompanied by a large magnetovolume anomaly associated to a jump of the magnetic moment of the Fe atoms at the 2a site. The magnetic moment instability in a frustrated lattice should be considered to interpret this transition, although most of the other magnetic states can be discussed within Moriya's theory for itinerant electron systems with competing ferromagnetic and antiferromagnetic spin fluctuations.

Scandium doped Ge2Sb2Te5 for high-speed and low-power-consumption phase change memory

Science.gov (United States)

Wang, Yong; Zheng, Yonghui; Liu, Guangyu; Li, Tao; Guo, Tianqi; Cheng, Yan; Lv, Shilong; Song, Sannian; Ren, Kun; Song, Zhitang

2018-03-01

To bridge the gap of access time between memories and storage systems, the concept of storage class memory has been put forward based on emerging nonvolatile memory technologies. For all the nonvolatile memory candidates, the unpleasant tradeoff between operation speed and retention seems to be inevitable. To promote both the write speed and the retention of phase change memory (PCM), Sc doped Ge2Sb2Te5 (SGST) has been proposed as the storage medium. Octahedral Sc-Te motifs, acting as crystallization precursors to shorten the nucleation incubation period, are the possible reason for the high write speed of 6 ns in PCM cells, five-times faster than that of Ge2Sb2Te5 (GST) cells. Meanwhile, an enhanced 10-year data retention of 119 °C has been achieved. Benefiting from both the increased crystalline resistance and the inhibited formation of the hexagonal phase, the SGST cell has a 77% reduction in power consumption compared to the GST cell. Adhesion of the SGST/SiO2 interface has been strengthened, attributed to the reduced stress by forming smaller grains during crystallization, guaranteeing the reliability of the device. These improvements have made the SGST material a promising candidate for PCM application.

Neutral beam injection in 2XIIB

International Nuclear Information System (INIS)

Hibbs, S.M.

1975-01-01

Integrated into the operation of the 2XIIB controlled fusion experiment is a 600-A, 20-keV neutral injection system: the highest neutral-beam current capacity of any existing fusion machine. This paper outlines the requirements of the injection system and the design features to which they led. Both mechanical and electrical aspects are discussed. Also included is a brief description of some operational aspects of the system and some of the things we have learned along the way, as well as a short history of the most significant developments

Optical and electron transport properties of rock-salt Sc1-xAlxN

Science.gov (United States)

Deng, Ruopeng; Zheng, P. Y.; Gall, D.

2015-07-01

Epitaxial single-crystal Sc1-xAlxN ternary alloy layers deposited by magnetron co-sputtering on MgO(001) substrates at 950 °C exhibit a solid solution rock-salt phase for x = 0-0.2 without decomposition. Optical absorption indicates a linear increase in the optical gap from 2.51 eV for ScN to 3.05 eV for Sc0.8Al0.2N and, after correction due to the Moss-Burstein shift, a direct X point interband transition energy Eg(X) = 2.15 + 2.75 x (eV). Correspondingly, the direct transition at the zone center increases with Al concentration according to Eg(Γ) = 3.80 + 1.45 x (eV), as determined from a feature in the reflection spectra. All layers are degenerate n-type semiconductors with a room temperature mobility that decreases from 22 to 6.7 to 0.83 cm2/V s as x increases from 0 to 0.11 to 0.20. The corresponding carrier densities are 9.2 × 1020, 7.9 × 1020, and 0.95 × 1020 cm-3 as determined from Hall measurements and consistent with optical free carrier absorption below photon energies of 1 eV. Temperature dependent transport measurements indicate metallic conduction for ScN, but weak localization that leads to a resistivity minimum at 85 and 210 K for x = 0.051 and 0.15, respectively, and a negative temperature coefficient over the entire measured 4-300 K range for Sc0.8Al0.2N. The decreasing mobility is attributed to alloy scattering at randomly distributed Al atoms on cation sites, which also cause the weak localization. The carrier density is primarily due to unintentional F doping from the Sc target and decreases strongly for x > 0.15, which is attributed to trapping in defect states due to the deterioration of the crystalline quality, as evidenced by the x-ray diffraction peak width that exhibits a minimum of 0.14° for x = 0.11 but increases to 0.49° for x = 0.20. This is consistent with asymmetric x-ray diffraction analyses, indicating a relaxed lattice constant that decreases from 4.511 ± 0.005 to 4.411 ± 0.004 Å for x = 0-0.2, and a biaxial in

High-resolution clean-sc

NARCIS (Netherlands)

Sijtsma, P.; Snellen, M.

2016-01-01

In this paper a high-resolution extension of CLEAN-SC is proposed: HR-CLEAN-SC. Where CLEAN-SC uses peak sources in “dirty maps” to define so-called source components, HR-CLEAN-SC takes advantage of the fact that source components can likewise be derived from points at some distance from the peak,

Combustion synthesis of CaSc2O4:Ce3+ nano-phosphors in a closed system

International Nuclear Information System (INIS)

Peng Wenfang; Zou Shaoyu; Liu Guanxi; Xiao Quanlan; Zhang Rui; Xie Lijuan; Cao Liwei; Meng Jianxin; Liu Yingliang

2011-01-01

Highlights: → CaSc 2 O 4 :Ce 3+ nano-phosphors can be prepared by a single-step combustion method. → The ignition temperature is the lowest in the combustion synthesis of Ce 3+ /Eu 2+ doped phosphors. → The as-prepared nano-phosphors give a uniform particle size in the range of 15-20 nm and have highly dispersity and fluorescence intensity. → It is a convenient method for preparation of monodispersed oxide nano-phosphors, especially those being sensitive to air at high temperature. - Abstract: The CaSc 2 O 4 :Ce 3+ nano-phosphors were successfully prepared by a single-step combustion method at an ignition temperature as low as 200 deg. C in a closed autoclave using glycine as a fuel and PEG4000 as a dispersant. The samples were characterized by X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscope (TEM). The results revealed that CaSc 2 O 4 :Ce 3+ nano-phosphors can be conveniently prepared at an ignition temperature as low as 200 deg. C, which was much lower than that in the ordinary combustion methods. The optimized ignition temperature was 220 deg. C. The CaSc 2 O 4 :Ce 3+ nano-phosphors give a uniform particle size in the range of 15-20 nm. The low ignition temperature and the addition of PEG4000 dispersant play important roles in the formation of small sized nanoparticles. The as-prepared nano-phosphors were incompact aggregates, but highly dispersed nano-phosphors can be obtained after further ultrasonic treatment. The CaSc 2 O 4 :Ce 3+ nano-phosphors give satisfactory luminescence characteristic benefiting from the closed circumstance, in which cerium atoms can be isolated from the oxidizing atmosphere and non-fluorescent Ce 4+ ions can be ruled out. The present highly dispersed CaSc 2 O 4 :Ce 3+ nano-phosphors with efficient fluorescence are promising in the field of biological labeling, and the present low temperature combustion method is facile and convenient and can

The stability boundary of group-III transition metal diboride ScB 2 (0 0 0 1) surfaces

Science.gov (United States)

Zhao, Hui; Qin, Na

2012-01-01

Experimental observations and theoretical investigations exhibit that a group-IV(V) transition metal diboride (0 0 0 1) surface is terminated with a 1 × 1 TM(B) layer. As to a group-III transition metal diboride, we have investigated the stability boundary of ScB2 (0 0 0 1) surfaces using first principles total energy plane-wave pseudopotential method based on density functional theory. The Mulliken charge population analysis shows that Sc atoms in the second layer cannot provide B atoms in the first layer with sufficient electrons to form a complete graphene-like boron layer. We also found that the charge transfer between the first and the second layer for the B-terminated surface is more than that for Sc-terminated surface. It elucidates the reason that the outermost interlayer spacing contract more strongly in the B-terminated surface than in the Sc-terminated surface. The surface energies of both terminated ScB2 (0 0 0 1) surfaces as a function of the chemical potential of B are also calculated to check the relative stability of the two surface structures.

A novel strategy for efficient production of anti-V3 human scFvs against HIV-1 clade C

Directory of Open Access Journals (Sweden)

Kumar Rajesh

2012-11-01

Full Text Available Abstract Background Production of human monoclonal antibodies that exhibit broadly neutralizing activity is needed for preventing HIV-1 infection, however only a few such antibodies have been generated till date. Isolation of antibodies by the hybridoma technology is a cumbersome process with fewer yields. Further, the loss of unstable or slowly growing clones which may have unique binding specificities often occurs during cloning and propagation and the strongly positive clones are often lost. This has been avoided by the process described in this paper, wherein, by combining the strategy of EBV transformation and recombinant DNA technology, we constructed human single chain variable fragments (scFvs against the third variable region (V3 of the clade C HIV-1 envelope. Results An antigen specific phage library of 7000 clones was constructed from the enriched V3- positive antibody secreting EBV transformed cells. By ligation of the digested scFv DNA into phagemid vector and bio panning against the HIV-1 consensus C and B V3 peptides followed by random selection of 40 clones, we identified 15 clones that showed V3 reactivity in phage ELISA. DNA fingerprinting analysis and sequencing showed that 13 out of the 15 clones were distinct. Expression of the positive clones was tested by SDS-PAGE and Western blot. All the 13 anti-V3 scFvs showed cross-reactivity against both the clade C and B V3 peptides and did not show any reactivity against other unrelated peptides in ELISA. Preliminary neutralization assays indicated varying degrees of neutralization of clade C and B viruses. EBV transformation, followed by antigen selection of lines to identify specific binders, enabled the selection of phage from un-cloned lines for scFv generation, thus avoiding the problems of hybridoma technology. Moreover, as the clones were pretested for antigen binding, a comparatively small library sufficed for the selection of a considerable number of unique antigen binding

Cross-sections of {sup 45}Sc(n,2n){sup 44m,g}Sc reaction from the reaction threshold to 20 MeV

Energy Technology Data Exchange (ETDEWEB)

Luo, J. [Hexi Univ., Zhangye (China). School of Physics and Electromechanical Engineering; Peking Univ., Beijing (China). State Key Laboratory of Nuclear Physics and Technology; Liu, R.; Jiang, L. [Chinese Academy of Engineering Physics, Mianyang (China). Inst. of Nuclear Physics and Chemistry; Liu, Z.; Sun, G.; Ge, S. [Hexi Univ., Zhangye (China). School of Physics and Electromechanical Engineering

2013-07-01

Cross sections of {sup 45}Sc(n,2n){sup 44m,g}Sc reactions and their isomeric cross section ratios {sigma}{sub m}/{sigma}{sub g} have been measured at three neutron energies between 13.5 and 14.8 MeV using the activation technique. The pure cross section of the groundstate was then obtained by utilizing the absolute cross section of the metastable state and analysis methods of residual nuclear decay. The monoenergetic neutron beam was produced via the {sup 3}H(d, n){sup 4}He reaction. The cross sections were also estimated with the TALYS-1.2 nuclear model code using different level density options, at neutron energies varying from the reaction threshold to 20 MeV. Results are also discussed and compared with some corresponding values found in the literature. (orig.)

Theoretical study of phase stability and elastic properties of T0.75Y0.75B14 (T  =  Sc, Ti, V, Y, Zr, Nb, Si)

International Nuclear Information System (INIS)

Hunold, Oliver; Music, Denis; Schneider, Jochen M

2016-01-01

In this study the phase stability, elastic properties, and plastic behaviour of icosahedral transition metal borides T 0.75 Y 0.75 B 14 (T  =  Sc, Ti, V, Y, Zr, Nb, Si) have been investigated using density functional theory. Phase stability critically depends on the charge transferred by T and Y to the B icosahedra. For the metal sublattice occupancy investigated here, the minimum energy of formation is identified at an effective B icosahedra charge of  −1.8  ±  0.1. This charge corridor encompasses the highest phase stability among all the reported icosahedral transition metal boride systems so far. This data provides guidance for future experimental efforts: from a wear-resistance point of view, Sc 0.75 Y 0.75 B 14 , Ti 0.75 Y 0.75 B 14 , and Zr 0.75 Y 0.75 B 14 exhibit a rather unique and attractive combination of large Young’s modulus values ranging from 488 to 514 GPa with the highest phase stability for icosahedral transition metals borides reported so far. (paper)

Effects of hydroxyurea treatment for patients with hemoglobin SC disease.

Science.gov (United States)

Luchtman-Jones, Lori; Pressel, Sara; Hilliard, Lee; Brown, R Clark; Smith, Mary G; Thompson, Alexis A; Lee, Margaret T; Rothman, Jennifer; Rogers, Zora R; Owen, William; Imran, Hamayun; Thornburg, Courtney; Kwiatkowski, Janet L; Aygun, Banu; Nelson, Stephen; Roberts, Carla; Gauger, Cynthia; Piccone, Connie; Kalfa, Theodosia; Alvarez, Ofelia; Hassell, Kathryn; Davis, Barry R; Ware, Russell E

2016-02-01

Although hemoglobin SC (HbSC) disease is usually considered less severe than sickle cell anemia (SCA), which includes HbSS and HbS/β(0) -thalassemia genotypes, many patients with HbSC experience severe disease complications, including vaso-occlusive pain, acute chest syndrome, avascular necrosis, retinopathy, and poor quality of life. Fully 20 years after the clinical and laboratory efficacy of hydroxyurea was proven in adult SCA patients, the safety and utility of hydroxyurea treatment for HbSC patients remain unclear. Recent NHLBI evidence-based guidelines highlight this as a critical knowledge gap, noting HbSC accounts for ∼30% of sickle cell patients within the United States. To date, only 5 publications have reported short-term, incomplete, or conflicting laboratory and clinical outcomes of hydroxyurea treatment in a total of 71 adults and children with HbSC. We now report on a cohort of 133 adult and pediatric HbSC patients who received hydroxyurea, typically for recurrent vaso-occlusive pain. Hydroxyurea treatment was associated with a stable hemoglobin concentration; increased fetal hemoglobin (HbF) and mean corpuscular volume (MCV); and reduced white blood cell count (WBC), absolute neutrophil count (ANC), and absolute reticulocyte count (ARC). Reversible cytopenias occurred in 22% of patients, primarily neutropenia and thrombocytopenia. Painful events were reduced with hydroxyurea, more in patients >15 years old. These multicenter data support the safety and potentially salutary effects of hydroxyurea treatment for HbSC disease; however, a multicenter, placebo-controlled, Phase 3 clinical trial is needed to determine if hydroxyurea therapy has efficacy for patients with HbSC disease. © 2015 Wiley Periodicals, Inc.

On neutral plasma oscillations

International Nuclear Information System (INIS)

Shadwick, B.A.; Morrison, P.J.

1993-06-01

We examine the conditions for the existence of spectrally stable neutral modes in a Vlasov-Poisson plasma and show that for stable equilibria of systems that have unbounded spatial domain, the only possible neutral modes are those with phase velocities that correspond to stationary inflection points of the equilibrium distribution function. It is seen that these neutral modes can possess positive or negative free energy

On neutral plasma oscillations

International Nuclear Information System (INIS)

Shadwick, B.A.; Texas Univ., Austin; Morrison, P.J.; Texas Univ., Austin

1994-01-01

We examine the conditions for the existence of spectrally stable neutral modes in a Vlasov-Poisson plasma and show that for stable equilibria of systems that have unbounded spatial domain, the only possible neutral modes are those with phase velocities that correspond to stationary inflection points of the equilibrium distribution function. It is seen that these neutral modes can posses positive or negative free energy. (orig.)

Interface interaction and wetting of Sc2O3 exposed to Cu-Al and Cu-Ti melts

International Nuclear Information System (INIS)

Barzilai, S.; Nagar, H.; Froumin, N.; Frage, N.; Aizenshtein, M.

2009-01-01

Scandia is a thermodynamically stable oxide and could be used as a structural material for a crucible in order to avoid a melt contamination. In the present study wetting experiments of Cu-Al and Cu-Ti melts on Scandia substrate were preformed at 1423 K by a sessile drop method. It was established that Al and Ti additions lead to the improved wetting and that the final contact angle decreases with increasing the additives concentration. For Al containing melts, the contact angle changes gradually with time, and a relatively thick interaction layer, which consists of Al 2 O 3 , Sc 2 O 3 , and metallic channels, was formed at the Sc 2 O 3 /Cu-Al interface. For Ti containing melts, the final contact angle is achieved already during heating, and an extremely thin layer based on a Ti-Sc-O compound was detected by AES at the Sc 2 O 3 /Cu-Ti interface. The results of a thermodynamic analysis, which takes into account the formation free energy of the oxides, involved in the systems, and the thermodynamic properties of the liquid solutions are in a good agreement with the experimental observations. (orig.)

The colours of Hubble Sc galaxy nuclei

International Nuclear Information System (INIS)

Iskudaryan, S.G.

1975-01-01

The colorimetric data on the nuclei of the Sc galaxies are given. Comparison of the following parameters: color of a nucleus, integral color of a galaxy, Byurakan class, and spectral type of normal spirals gives the possibility to conclude: (1) The colors of the nuclei of the Sc galaxies have a high dispersion in its values. In all Byurakan classes the galaxies with intensely red and blue nuclei occur; (2) Some Sc galaxies exhibit a discrepancy between the spectral and morphological types. The results of colorimetry of nuclei indicate that almost all such Sc galaxies have intensely red nuclei which, naturally, provide for these late spectral types. It can be assumed that the intensely red color of the nuclei of such Sc galaxies is a result of a new type of activity of these nuclei; and (3) some Sc galaxies show the characteristics of the Markarian objects

Lifetime and g-factor measurements in 44Sc

International Nuclear Information System (INIS)

Chevallier, A.; Chavallier, J.; Gross, J.L.; Haas, B.; Schulz, N.; Styczen, J.; Toulemonde, M.

1975-01-01

The lifetimes of the 235 keV, 2 - state and 350 keV, 4 + state in 44 Sc have been measured via the 44 Ca(p, n) 44 Sc reaction with a pulsed proton beam. The time integral perturbed angular distribution technique with an external field was used to measure the precession angles of the 2 - and 4 + states populated by the 30 Si( 16 O, pnγ) 44 Sc reaction. The following values for the mean-lives and g-factors were obtained: π(2 - ) = 8.83(33) ns, g(2 - ) = 0.30(13) and π(4 + ) = 4.52(27)ns, g(4 + ) = 0.90(12). The results for the 2 - state support a rotational description of the negative parity states in 44 Sc. The magnetic moment of the 4 + state is compared to shell model predictions. (orig.) [de

Enhanced hardness in epitaxial TiAlScN alloy thin films and rocksalt TiN/(Al,Sc)N superlattices

Energy Technology Data Exchange (ETDEWEB)

Saha, Bivas [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Lawrence, Samantha K.; Bahr, David F. [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Schroeder, Jeremy L.; Birch, Jens [Thin Film Physics Division, Department of Physics, Chemistry, and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden); Sands, Timothy D. [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

2014-10-13

High hardness TiAlN alloys for wear-resistant coatings exhibit limited lifetimes at elevated temperatures due to a cubic-AlN to hexagonal-AlN phase transformation that leads to decreasing hardness. We enhance the hardness (up to 46 GPa) and maximum operating temperature (up to 1050 °C) of TiAlN-based coatings by alloying with scandium nitride to form both an epitaxial TiAlScN alloy film and epitaxial rocksalt TiN/(Al,Sc)N superlattices on MgO substrates. The superlattice hardness increases with decreasing period thickness, which is understood by the Orowan bowing mechanism of the confined layer slip model. These results make them worthy of additional research for industrial coating applications.

Regioselectivity of Sc2C2@C3v(8)-C82: Role of the Sumanene-Type Hexagon in Diels-Alder Reaction.

Science.gov (United States)

Zhao, Pei; Zhao, Xiang; Ehara, Masahiro

2016-09-16

Recently, several experiments have demonstrated high chemical reactivity of the sumanene-type hexagon in Sc2C2@C82. To further uncover its reactivity, the Diels-Alder reaction to all the nonequivalent C-C bonds of C82 and Sc2C2@C82 has been investigated by density functional theory calculations. For the free fullerene, the [5,6] bond 7 is the thermodynamically most favored, whereas the addition on the [6,6] bond 3 has the lowest activation energy. Diels-Alder reaction has no preference for addition sites in the sumanene-type hexagon. However, in the case of the endohedral fullerene, the [6,6] bond 19 in the special hexagon becomes the most reactive site according to both kinetic and thermodynamic considerations. Further analyses reveal that bond 19 in Sc2C2@C82 exhibits the shortest bond length and third largest π-orbital axis vector. In addition, the LUMOs of bond 19 are also symmetry-allowed to interact with butadiene.

Electronic structure of the [MNH2]+ (M = Sc-Cu) complexes.

Science.gov (United States)

Hendrickx, Marc F A; Clima, Sergiu

2006-11-23

B3LYP geometry optimizations for the [MNH2]+ complexes of the first-row transition metal cations (Sc+-Cu+) were performed. Without any exception the ground states of these unsaturated amide complexes were calculated to possess planar geometries. CASPT2 binding energies that were corrected for zero-point energies and including relativistic effects show a qualitative trend across the series that closely resembles the experimental observations. The electronic structures for the complexes of the early and middle transition metal cations (Sc+-Co+) differ from the electronic structures derived for the complexes of the late transition metal cations (Ni+ and Cu+). For the former complexes the relative higher position of the 3d orbitals above the singly occupied 2p(pi) HOMO of the uncoordinated NH2 induces an electron transfer from the 3d shell to 2p(pi). The stabilization of the 3d orbitals from the left to the right along the first-row transition metal series causes these orbitals to become situated below the HOMO of the NH2 ligand for Ni+ and Cu+, preventing a transfer from occurring in the [MNH2]+ complexes of these metal cations. Analysis of the low-lying states of the amide complexes revealed a rather unique characteristic of their electronic structures that was found across the entire series. Rather exceptionally for the whole of chemistry, pi-type interactions were calculated to be stronger than the corresponding sigma-type interactions. The origin of this extraordinary behavior can be ascribed to the low-lying sp2 lone pair orbital of the NH2 ligand with respect to the 3d level.

Three-phase-boundary dynamics at the Ni/ScYSZ interface

DEFF Research Database (Denmark)

Schmidt, Michael Stenbæk; Hansen, Karin Vels; Norrman, Kion

2009-01-01

Chronoamperometry using a three-electrode cell configuration was undertaken with a nickel point-electrode acting as the working electrode on a polished ScYSZ electrolyte in a hydrogen atmosphere at 750–850 °C. High anodic overpotentials resulted in the occurrence of distinct sawtooth oscillation...... of the current oscillations. A mechanism accounting for the observed phenomena and possible implications for solid oxide fuel cell operation are presented...

Reliability of Direct Behavior Ratings - Social Competence (DBR-SC) data: How many ratings are necessary?

Science.gov (United States)

Kilgus, Stephen P; Riley-Tillman, T Chris; Stichter, Janine P; Schoemann, Alexander M; Bellesheim, Katie

2016-09-01

The purpose of this investigation was to evaluate the reliability of Direct Behavior Ratings-Social Competence (DBR-SC) ratings. Participants included 60 students identified as possessing deficits in social competence, as well as their 23 classroom teachers. Teachers used DBR-SC to complete ratings of 5 student behaviors within the general education setting on a daily basis across approximately 5 months. During this time, each student was assigned to 1 of 2 intervention conditions, including the Social Competence Intervention-Adolescent (SCI-A) and a business-as-usual (BAU) intervention. Ratings were collected across 3 intervention phases, including pre-, mid-, and postintervention. Results suggested DBR-SC ratings were highly consistent across time within each student, with reliability coefficients predominantly falling in the .80 and .90 ranges. Findings further indicated such levels of reliability could be achieved with only a small number of ratings, with estimates varying between 2 and 10 data points. Group comparison analyses further suggested the reliability of DBR-SC ratings increased over time, such that student behavior became more consistent throughout the intervention period. Furthermore, analyses revealed that for 2 of the 5 DBR-SC behavior targets, the increase in reliability over time was moderated by intervention grouping, with students receiving SCI-A demonstrating greater increases in reliability relative to those in the BAU group. Limitations of the investigation as well as directions for future research are discussed herein. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Energy Levels, wavelengths and hyperfine structure measurements of Sc II

Science.gov (United States)

Hala, Fnu; Nave, Gillian

2018-01-01

Lines of singly ionized Scandium (Sc II) along with other Iron group elements have been observed [1] in the region surrounding the massive star Eta Carinae [2,3] called the strontium filament (SrF). The last extensive analysis of Sc II was the four-decade old work of Johansson & Litzen [4], using low-resolution grating spectroscopy. To update and extend the Sc II spectra, we have made observation of Sc/Ar, Sc/Ne and Sc/Ge/Ar hollow cathode emission spectrum on the NIST high resolution FT700 UV/Vis and 2 m UV/Vis/IR Fourier transform spectrometers (FTS). More than 850 Sc II lines have been measured in the wavelength range of 187 nm to 3.2 μm. connecting a total of 152 energy levels. The present work also focuses to resolve hyperfine structure (HFS) in Sc II lines. We aim to obtain accurate transition wavelengths, improved energy levels and HFS constants of Sc II. The latest results from work in progress will be presented.Reference[1] Hartman H, Gull T, Johansson S and Smith N 2004 Astron. Astrophys. 419 215[2] Smith N, Morse J A and Gull T R 2004 Astrophys. J. 605 405[3] Davidson K and Humphreys R M 1997 Annu. Rev. Astron. Astrophys. 35[4] Johansson S and Litzén U 1980 Phys. Scr. 22 49

Selection and characterization of a human neutralizing antibody to human fibroblast growth factor-2

International Nuclear Information System (INIS)

Tao, Jun; Xiang, Jun-Jian; Li, Dan; Deng, Ning; Wang, Hong; Gong, Yi-Ping

2010-01-01

Compelling evidences suggest that fibroblast growth factor-2 (FGF-2) plays important roles in tumor growth, angiogenesis and metastasis. Molecules blocking the FGF-2 signaling have been proposed as anticancer agents. Through screening of a human scFv phage display library, we have isolated several human single-chain Fv fragments (scFvs) that bind to human FGF-2. After expression and purification in bacteria, one scFv, named 1A2, binds to FGF-2 with a high affinity and specificity, and completes with FGF-2 binding to its receptor. This 1A2 scFv was then cloned into the pIgG1 vector and expressed in 293T cells. The purified hIgG1-1A2 antibody showed a high binding affinity of 8 x 10 -9 M to rhFGF-2. In a set of vitro assays, it inhibited various biological activities of FGF-2 such as the proliferation, migration and tube formation of human umbilical vein endothelial cells. More importantly, hIgG1-1A2 antibody also efficiently blocked the growth while inducing apoptosis of glioma cells. For the first time, we generated a human anti-FGF-2 antibody with proven in vitro anti-tumor activity. It may therefore present a new therapeutic candidate for the treatment of cancers that are dependent on FGF-2 signaling for growth and survival.

Method to Minimize the Low-Frequency Neutral-Point Voltage Oscillations With Time-Offset Injection for Neutral-Point-Clamped Inverters

DEFF Research Database (Denmark)

Choi, Ui-Min; Blaabjerg, Frede; Lee, Kyo-Beum

2015-01-01

time of small- and medium-voltage vectors. However, if the power factor is lower, there is a limitation to eliminate neutral-point oscillations. In this case, the proposed method can be improved by changing the switching sequence properly. Additionally, a method for neutral-point voltage balancing......This paper proposes a method to reduce the low-frequency neutral-point voltage oscillations. The neutral-point voltage oscillations are considerably reduced by adding a time offset to the three-phase turn-on times. The proper time offset is simply calculated considering the phase currents and dwell...

Heavy and light ion irradiation damage effects in δ-phase Sc{sub 4}Hf{sub 3}O{sub 12}

Energy Technology Data Exchange (ETDEWEB)

Wen, J. [School of Nuclear Science and Technology, Lanzhou University, Lanzhou, Gansu 730000 (China); Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Li, Y.H., E-mail: liyuhong@lzu.edu.cn [School of Nuclear Science and Technology, Lanzhou University, Lanzhou, Gansu 730000 (China); Tang, M.; Valdez, J.A.; Wang, Y.Q. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Patel, M.K.; Sickafus, K.E. [Department of Materials Science & Engineering, The University of Tennessee, Knoxville, TN 37996 (United States)

2015-12-15

Polycrystalline δ-phase Sc{sub 4}Hf{sub 3}O{sub 12} was irradiated with light and heavy ions to study the radiation stability of this compound. In order to explore the ion species spectrum effect, the irradiations were performed with 400 keV Ne{sup 2+} ions to fluences ranging from 1 × 10{sup 14} to 1 × 10{sup 15} ions/cm{sup 2}, 600 keV Kr{sup 3+} ions to fluences ranging from 5 × 10{sup 14} to 5 × 10{sup 15} ions/cm{sup 2}, and 6 MeV Xe{sup 26+} ions to fluences ranging from 2 × 10{sup 13} to 1 × 10{sup 15} ions/cm{sup 2}. Irradiated samples were characterized by various techniques including grazing incidence X-ray diffraction (GIXRD) and transmission electron microscopy (TEM). A complete phase transformation from ordered rhombohedral to disordered fluorite was observed by a fluence of 1 × 10{sup 15} ions/cm{sup 2} with 400 keV Ne{sup 2+} ions, equivalent to a peak ballistic damage dose of ∼0.33 displacements per atom (dpa). Meanwhile, the same transformation was also observed by 600 keV Kr{sup 3+} ions at the same fluence of 1 × 10{sup 15} ions/cm{sup 2}, which however corresponds to a peak ballistic damage dose of ∼2.2 dpa. Only a partial O-D transformation was observed for 6 MeV Xe{sup 26+} ions in the fluence range used. Experimental results indicated that the O-D transformation is observed under both electronic and nuclear stopping dominant irradiation regimes. It was also observed that light ions are more efficient than heavy ions in producing the retained defects that are presumably responsible for the O-D phase transformation. The O-D transformation mechanism is discussed in the context of anion oxygen Frenkel defects and cation antisite defects. We concluded that the irradiation induced O-D transformation is easier to occur in δ-phase compounds with partial order of cations than in that with fully disordered cation structures.

Elucidating the breathing of the metal-organic framework MIL-53(Sc) with ab initio molecular dynamics simulations and in situ X-ray powder diffraction experiments.

Science.gov (United States)

Chen, Linjiang; Mowat, John P S; Fairen-Jimenez, David; Morrison, Carole A; Thompson, Stephen P; Wright, Paul A; Düren, Tina

2013-10-23

Ab initio molecular dynamics (AIMD) simulations have been used to predict structural transitions of the breathing metal-organic framework (MOF) MIL-53(Sc) in response to changes in temperature over the range 100-623 K and adsorption of CO2 at 0-0.9 bar at 196 K. The method has for the first time been shown to predict successfully both temperature-dependent structural changes and the structural response to variable sorbate uptake of a flexible MOF. AIMD employing dispersion-corrected density functional theory accurately simulated the experimentally observed closure of MIL-53(Sc) upon solvent removal and the transition of the empty MOF from the closed-pore phase to the very-narrow-pore phase (symmetry change from P2(1)/c to C2/c) with increasing temperature, indicating that it can directly take into account entropic as well as enthalpic effects. We also used AIMD simulations to mimic the CO2 adsorption of MIL-53(Sc) in silico by allowing the MIL-53(Sc) framework to evolve freely in response to CO2 loadings corresponding to the two steps in the experimental adsorption isotherm. The resulting structures enabled the structure determination of the two CO2-containing intermediate and large-pore phases observed by experimental synchrotron X-ray diffraction studies with increasing CO2 pressure; this would not have been possible for the intermediate structure via conventional methods because of diffraction peak broadening. Furthermore, the strong and anisotropic peak broadening observed for the intermediate structure could be explained in terms of fluctuations of the framework predicted by the AIMD simulations. Fundamental insights from the molecular-level interactions further revealed the origin of the breathing of MIL-53(Sc) upon temperature variation and CO2 adsorption. These simulations illustrate the power of the AIMD method for the prediction and understanding of the behavior of flexible microporous solids.

Baculovirus display of single chain antibody (scFv using a novel signal peptide

Directory of Open Access Journals (Sweden)

Gonzalez Gaëlle

2010-11-01

Full Text Available Abstract Background Cells permissive to virus can become refractory to viral replication upon intracellular expression of single chain fragment variable (scFv antibodies directed towards viral structural or regulatory proteins, or virus-coded enzymes. For example, an intrabody derived from MH-SVM33, a monoclonal antibody against a conserved C-terminal epitope of the HIV-1 matrix protein (MAp17, was found to exert an inhibitory effect on HIV-1 replication. Results Two versions of MH-SVM33-derived scFv were constructed in recombinant baculoviruses (BVs and expressed in BV-infected Sf9 cells, N-myristoylation-competent scFvG2/p17 and N-myristoylation-incompetent scFvE2/p17 protein, both carrying a C-terminal HA tag. ScFvG2/p17 expression resulted in an insoluble, membrane-associated protein, whereas scFvE2/p17 was recovered in both soluble and membrane-incorporated forms. When coexpressed with the HIV-1 Pr55Gag precursor, scFvG2/p17 and scFvE2/p17 did not show any detectable negative effect on virus-like particle (VLP assembly and egress, and both failed to be encapsidated in VLP. However, soluble scFvE2/p17 isolated from Sf9 cell lysates was capable of binding to its specific antigen, in the form of a synthetic p17 peptide or as Gag polyprotein-embedded epitope. Significant amounts of scFvE2/p17 were released in the extracellular medium of BV-infected cells in high-molecular weight, pelletable form. This particulate form corresponded to BV particles displaying scFvE2/p17 molecules, inserted into the BV envelope via the scFv N-terminal region. The BV-displayed scFvE2/p17 molecules were found to be immunologically functional, as they reacted with the C-terminal epitope of MAp17. Fusion of the N-terminal 18 amino acid residues from the scFvE2/p17 sequence (N18E2 to another scFv recognizing CD147 (scFv-M6-1B9 conferred the property of BV-display to the resulting chimeric scFv-N18E2/M6. Conclusion Expression of scFvE2/p17 in insect cells using a BV

High performance control strategy for single-phase three-level neutral-point-clamped traction four-quadrant converters

DEFF Research Database (Denmark)

Kejian, Song; Konstantinou, Georgios; Jing, Li

2017-01-01

Operational data from Chinese railways indicate a number of challenges for traction four-quadrant converter (4QC) control including low-order voltage and current harmonics and reference tracking. A control strategy for a single-phase three-level neutral-point-clamped 4QC employed in the electric...

Laser photoelectron spectrometry of Sc- and Y-

International Nuclear Information System (INIS)

Feigerle, C.S.; Herman, Z.; Lineberger, W.C.

1981-01-01

The photoelectron spectra of Sc - and Y - have been obtained in a crossed ion- and laser-beam experiment. Analysis of the Sc - spectrum yields two bound terms of 3d4s 2 4p configuration ( 1 D 0 and 3 D 0 ), with EA(Sc) = 0.189 +- 0.020 eV and an excited-state binding energy of 0.042 +- 0.020 eV. Similarly, the (4d5s 2 5p) 1 D 0 ground state of Y - is bound by 0.308 +- 0.012 eV and a (4d5s 2 5p) 3 D 0 excited term is bound by 0.165 +- 0.025 eV. With the determination of the bound electronic configuration of Sc - as 3d4s 2 4p, the order of filling of electron shells of the first transition series negative ions is found to be 4s 2 ep, 3d4s 2 4p, the order of filling of electron shells of the first transition series negative ions is found to be 4s 2 4p, 3d4s 2 4p, followed by 3dsup(k) 4s 2 (k = 3, 4, ..., 10). (orig.)

Vecksler-Macmillan phase stability for neutral atoms accelerated by a laser beam

Science.gov (United States)

Mel'nikov, I. V.; Haus, J. W.; Kazansky, P. G.

2003-05-01

We use a Fokker-Planck equation to study the phenomenon of accelerating a neutral atom bunch by a chirped optical beam. This method enables us to obtain a semi-analytical solution to the problem in which a wide range of parameters can be studied. In addition it provides a simple physical interpretation where the problem is reduced to an analogous problem of charged particles accelerators, that is, the Vecksler-Macmillan principle of phase stability. A possible experimental scenario is suggested, which uses a photonic crystal fiber as the guiding medium.

Synthesis of Sc{sub 2}O{sub 3} powders for preparation of transparent ceramics; Synthese de poudres de Sc{sub 2}O{sub 3} destinees a l'elaboration d'une ceramique transparente

Energy Technology Data Exchange (ETDEWEB)

Bravo, A.C.; Longuet, L.; Autissier, D. [CEA Centre d' Etudes du Ripault, 37 - Tours (France); Baumard, J.F. [Laboratoire Science des Procedes Ceramiques et de Traitements de Surfaces, SPCTS, UMR CNRS 6638, 87 - Limoges (France)

2007-07-01

Different precursors have been prepared by precipitation from scandium nitrates salts using ammonium hydrogeno-carbonate as precipitating agent. The influence of the precipitation technique, of the preparation temperature and of the 'precipitating agent/Sc{sup 3+}' molar ratio on the characteristics (nature, grain size...) of the synthesized precursors has been observed. A heat treatment at 700 C of these precursors has allowed to obtain thin and homogeneous Sc{sub 2}O{sub 3} powders well adapted for transparent ceramics preparation. (O.M.)

Isolation of scFv antibody fragments against HER2 and CEA tumor antigens from combinatorial antibody libraries derived from cancer patients.

Science.gov (United States)

Ayat, Hoda; Burrone, Oscar R; Sadghizadeh, Majid; Jahanzad, Eissa; Rastgou, Nasrin; Moghadasi, Sarrira; Arbabi, Mehdi

2013-11-01

Tumor cells expressing HER-2/neu and CEA antigens are potentially ideal targets for antibody-targeted therapy. In this study, two large human combinatorial libraries have been generated from the lymph nodes of breast cancer patients that express HER2 and CEA antigens in their tumors. These 'immune' libraries have been constructed in two different formats of scFv, differing in the length of the peptide linker connecting the two variable VH and VL domains. Libraries derived from these patients may contain a larger pool of anti-tumor antigen antibodies and are useful repertoire for isolating scFvs against any tumor markers. The results of this study showed that we were successful in obtaining human scFvs against HER-2/neu and CEA. For HER-2, cell-panning strategy was performed and resulted in two scFv binders that detected the complete HER-2 receptor on the cell membrane and internalized to the cells. Also, preliminary ELISA data showed that several anti-CEA scFv binders were isolated by panning. Copyright © 2013 The International Alliance for Biological Standardization. All rights reserved.

Naked (C5Me5)(2)M cations (M = Sc, Ti, and V) and their fluoroarene complexes

NARCIS (Netherlands)

Bouwkamp, MW; Budzelaar, PHM; Gercama, J; Morales, ID; de Wolf, J; Meetsma, A; Troyanov, SI; Teuben, JH; Hessen, B; Budzelaar, Peter H.M.; Hierro Morales, Isabel Del; Troyanov, Sergei I.

2005-01-01

The ionic metallocene complexes [Cp*M-2][BPh4] (CP* = C5Me5) of the trivalent 3d metals Sc, Ti, and V were synthesized and structurally characterized. For M Sc, the anion interacts weakly with the metal center through one of the phenyl groups, but for M = Ti and V, the cations are naked. They each

Mixing in three-phase systems: Implications for enhanced oil recovery and unconventional gas extraction

Science.gov (United States)

Jimenez-Martinez, J.; Porter, M. L.; Hyman, J.; Carey, J. W.; Viswanathan, H. S.

2015-12-01

Although the mixing of fluids within a porous media is a common process in natural and industrial systems, how the degree of mixing depends on the miscibility of multiple phases is poorly characterized. Often, the direct consequence of miscible mixing is the modification of the resident fluid (brine and hydrocarbons) rheological properties. We investigate supercritical (sc)CO2 displacement and mixing processes in a three-phase system (scCO2, oil, and H2O) using a microfluidics experimental system that accommodates the high pressures and temperatures encountered in fossil fuel extraction operations. The miscibility of scCO2 with the resident fluids, low with aqueous solutions and high with hydrocarbons, impacts the mixing processes that control sweep efficiency in enhanced oil recovery (EOR) and the unlocking of the system in unconventional oil and gas extraction. Using standard volume-averaging techniques we upscale the aqueous phase saturation to the field-scale (i.e., Darcy scale) and interpret the results as a simpler two-phase system. This process allows us to perform a statistical analysis to quantify i) the degree of heterogeneity in the system resulting from the immiscible H2O and ii) how that heterogeneity impacts mixing between scCO2 and oil and their displacement. Our results show that when scCO2 is used for miscible displacement, the presence of an aqueous solution, which is common in secondary and tertiary EOR and unconventional oil and gas extraction, strongly impacts the mixing of scCO2 with the hydrocarbons due to low scCO2-H2O miscibility. H2O, which must be displaced advectively by the injected scCO2, introduces spatio-temporal variability into the system that acts as a barrier between the two miscibile fluids. This coupled with the effect of viscosity contrast, i.e., viscous fingering, has an impact on the mixing of the more miscible pair.

Analysis of various types of single-polypeptide-chain (sc) heterodimeric A{sub 2A}R/D{sub 2}R complexes and their allosteric receptor–receptor interactions

Energy Technology Data Exchange (ETDEWEB)

Kamiya, Toshio, E-mail: kamiya@z2.keio.jp [Department of Molecular Cell Signaling, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu, Tokyo 183-8526 (Japan); Department of Neurology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu, Tokyo 183-8526 (Japan); Cell Biology Laboratory, School of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502 (Japan); Yoshioka, Kazuaki; Nakata, Hiroyasu [Department of Molecular Cell Signaling, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu, Tokyo 183-8526 (Japan)

2015-01-09

Highlights: • Various scA{sub 2A}R/D{sub 2}R constructs, with spacers between the two receptors, were created. • Using whole cell binding assay, constructs were examined for their binding activity. • Although the apparent ratio of A{sub 2A}R to D{sub 2}R binding sites should be 1, neither was 1. • Counter agonist-independent binding cooperativity occurred in context of scA{sub 2A}R/D{sub 2}R. - Abstract: Adenosine A{sub 2A} receptor (A{sub 2A}R) heteromerizes with dopamine D{sub 2} receptor (D{sub 2}R). However, these class A G protein-coupled receptor (GPCR) dimers are not fully formed, but depend on the equilibrium between monomer and dimer. In order to stimulate the heteromerization, we have previously shown a successful design for a fusion receptor, single-polypeptide-chain (sc) heterodimeric A{sub 2A}R/D{sub 2}R complex. Here, using whole cell binding assay, six more different scA{sub 2A}R/D{sub 2}R constructs were examined. Not only in scA{sub 2A}R/D{sub 2}R ‘liberated’ with longer spacers between the two receptors, which confer the same configuration as the prototype, the A{sub 2A}R-odr4TM-D{sub 2L}R, but differ in size (Forms 1–3), but also in scA{sub 2A}R/D{sub 2L}R (Form 6) fused with a transmembrane (TM) of another type II TM protein, instead of odr4TM, neither of their fixed stoichiometry (the apparent ratios of A{sub 2A}R to D{sub 2}R binding sites) was 1, suggesting their compact folding. This suggests that type II TM, either odr4 or another, facilitates the equilibrial process of the dimer formation between A{sub 2A}R and D{sub 2L}R, resulting in the higher-order oligomer formation from monomer of scA{sub 2A}R/D{sub 2L}R itself. Also, in the reverse type scA{sub 2A}R/D{sub 2L}R, i.e., the D{sub 2L}R-odr4TM-A{sub 2A}R, counter agonist-independent binding cooperativity (cooperative folding) was found to occur (Forms 4 and 5). In this way, the scA{sub 2A}R/D{sub 2L}R system has unveiled the cellular phenomenon as a snapshot of the

Kampelite, Ba3Mg1.5Sc4(PO4)6(OH)3·4H2O, a new very complex Ba-Sc phosphate mineral from the Kovdor phoscorite-carbonatite complex (Kola Peninsula, Russia)

Science.gov (United States)

Yakovenchuk, Victor N.; Ivanyuk, Gregory Yu.; Pakhomovsky, Yakov A.; Panikorovskii, Taras L.; Britvin, Sergei N.; Krivovichev, Sergey V.; Shilovskikh, Vladimir V.; Bocharov, Vladimir N.

2018-02-01

Kampelite, Ba3Mg1.5Sc4(PO4)6(OH)3·4H2O, is a new Ba-Sc phosphate from the Kovdor phoscorite-carbonatite complex (Kola Peninsula, Russia). It is orthorhombic, Pnma, a = 11.256(1), b = 8.512(1), c = 27.707(4) Å, V = 2654.6(3) Å3 and Z = 4 (from powder diffraction data) or a = 11.2261(9), b = 8.5039(6), c = 27.699(2) Å, V = 2644.3(3) Å3 (from single-crystal diffraction data). The mineral was found in a void within the calcite-magnetite phoscorite (enriched in hydroxylapatite and Sc-rich baddeleyite) inside the axial zone of the Kovdor phoscorite-carbonatite pipe. Kampelite forms radiated aggregates (up to 1.5 mm in diameter) of platy crystals grown on the surfaces of crystals of quintinite-2 H in close association with pyrite, bobierrite and quintinite-3 R. Kampelite is colourless, with a pearly lustre and a white streak. The cleavage is perfect on {001}, the fracture is smooth. Mohs hardness is about 1. In transmitted light, the mineral is colourless without pleochroism or dispersion. Kampelite is biaxial + (pseudouniaxial), α ≈ β = 1.607(2), γ = 1.612(2) (589 nm), and 2 V calc = 0°. The calculated and measured densities are 3.28 and 3.07(3) g·cm-3, respectively. The mean chemical composition determined by electron microprobe is: MgO 4.79, Al2O3 0.45, P2O5 31.66, K2O 0.34, Sc2O3 16.17, Mn2O3 1.62, Fe2O3 1.38, SrO 3.44, and BaO 29.81 wt%. The H2O content estimated from the crystal-structure refinement is 7.12 wt%, giving a total of 96.51 wt%. The empirical formula calculated on the basis of P = 6 apfu (atoms per formula unit) is (Ba2.62Sr0.45K0.10Ca0.06)Σ3.23Mg1.60Mn0.28(Sc3.15Fe3+ 0.23Al0.12)Σ3.50(PO4)6(OH)2.61·4.01H2O. The simplified formula is Ba3Mg1.5Sc4(PO4)6(OH)3·4H2O. The mineral easily dissolves in 10% cold HCl. The strongest X-ray powder-diffraction lines [listed as d in Å ( I) ( hkl)] are as follows: 15.80(100)(001), 13.86(45)(002), 3.184(18)(223), 3.129(19)(026), 2.756(16)(402), 2.688(24)(10 10). The crystal structure of kampelite was

Characterization of iminothiosulfine-type ions [HNCS 2] rad +/ rad - and their neutral counterparts by mass spectrometry and computational chemistry

Science.gov (United States)

Vivekananda, S.; Raghunath, P.; Bhanuprakash, K.; Srinivas, R.; Trikoupis, Moschoula A.; Terlouw, Johan K.

2000-12-01

Electron ionization of rhodanine yields iminothiosulfine ions H- N C- S- Srad + , 1brad + , which readily communicate with the higher energy cyclic isomer H- N CS2rad + , 1arad + . CBS-QB3 and G AUSSIAN-2 model chemistries predict that one electron reduction reverses the stability order but that the (singlet) neutrals remain connected via a negligible energy barrier. Neutralization-reionization (NR) experiments demonstrate that singlet 1a and its heterocumulene isomer 1b are stable species in the gas-phase. However, the co-generated triplet species readily dissociate into 3S2rad + + HNC. Confirmatory experimental evidence comes from charge reversal (CR) and NR experiments on the cyclic anion H- N CS2rad - , 1arad - .

Maturation Pathways of Cross-Reactive HIV-1 Neutralizing Antibodies

Directory of Open Access Journals (Sweden)

Dimiter S. Dimitrov

2009-11-01

Full Text Available Several human monoclonal antibodies (hmAbs and antibody fragments, including the best characterized in terms of structure-function b12 and Fab X5, exhibit relatively potent and broad HIV-1 neutralizing activity. However, the elicitation of b12 or b12-like antibodies in vivo by vaccine immunogens based on the HIV-1 envelope glycoprotein (Env has not been successful. B12 is highly divergent from the closest corresponding germline antibody while X5 is less divergent. We have hypothesized that the relatively high degree of specific somatic hypermutations may preclude binding of the HIV-1 envelope glycoprotein (Env to closest germline antibodies, and that identifying antibodies that are intermediates in the pathways to maturation could help design novel vaccine immunogens to guide the immune system for their enhanced elicitation. In support of this hypothesis we have previously found that a germline-like b12 (monovalent and bivalent scFv as an Fc fusion protein or IgG lacks measurable binding to an Env as measured by ELISA with a sensitivity in the μM range [1]; here we present evidence confirming and expanding these findings for a panel of Envs. In contrast, a germline-like scFv X5 bound Env with high (nM affinity. To begin to explore the maturation pathways of these antibodies we identified several possible b12 intermediate antibodies and tested their neutralizing activity. These intermediate antibodies neutralized only some HIV-1 isolates and with relatively weak potency. In contrast, germline-like scFv X5 neutralized a subset of the tested HIV-1 isolates with comparable efficiencies to that of the mature X5. These results could help explain the relatively high immunogenicity of the coreceptor binding site on gp120 and the abundance of CD4-induced (CD4i antibodies in HIV-1-infected patients (X5 is a CD4i antibody as well as the maturation pathway of X5. They also can help identify antigens that can bind specifically to b12 germline and

Method to minimize the low-frequency neutral-point voltage oscillations with time-offset injection for neutral-point-clamped inverters

DEFF Research Database (Denmark)

Choi, Uimin; Lee, Kyo-Beum; Blaabjerg, Frede

2013-01-01

This paper proposes a method to reduce the low-frequency neutral-point voltage oscillations. The neutral-point voltage oscillations are considerably reduced by adding a time-offset to the three phase turn-on times. The proper time-offset is simply calculated considering the phase currents and dwell...

Neutralization of the edema-forming, defibrinating and coagulant effects of Bothrops asper venom by extracts of plants used by healers in Colombia

Directory of Open Access Journals (Sweden)

V. Núñez

2004-07-01

Full Text Available We determined the neutralizing activity of 12 ethanolic extracts of plants against the edema-forming, defibrinating and coagulant effects of Bothrops asper venom in Swiss Webster mice. The material used consisted of the leaves and branches of Bixa orellana (Bixaceae, Ficus nymphaeifolia (Moraceae, Struthanthus orbicularis (Loranthaceae and Gonzalagunia panamensis (Rubiaceae; the stem barks of Brownea rosademonte (Caesalpiniaceae and Tabebuia rosea (Bignoniaceae; the whole plant of Pleopeltis percussa (Polypodiaceae and Trichomanes elegans (Hymenophyllaceae; rhizomes of Renealmia alpinia (Zingiberaceae, Heliconia curtispatha (Heliconiaceae and Dracontium croatii (Araceae, and the ripe fruit of Citrus limon (Rutaceae. After preincubation of varying amounts of each extract with either 1.0 µg venom for the edema-forming effect or 2.0 µg venom for the defibrinating effect, the mixture was injected subcutaneously (sc into the right foot pad or intravenously into the tail, respectively, to groups of four mice (18-20 g. All extracts (6.2-200 µg/mouse partially neutralized the edema-forming activity of venom in a dose-dependent manner (58-76% inhibition, with B. orellana, S. orbicularis, G. panamensis, B. rosademonte, and D. croatii showing the highest effect. Ten extracts (3.9-2000 µg/mouse also showed 100% neutralizing ability against the defibrinating effect of venom, and nine prolonged the coagulation time induced by the venom. When the extracts were administered either before or after venom injection, the neutralization of the edema-forming effect was lower than 40% for all extracts, and none of them neutralized the defibrinating effect of venom. When they were administered in situ (sc at the same site 5 min after venom injection, the neutralization of edema increased for six extracts, reaching levels up to 64% for C. limon.

33 CFR 80.712 - Morris Island, SC to Hilton Head Island, SC.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Morris Island, SC to Hilton Head..., SC to Hilton Head Island, SC. (a) A line drawn from the easternmost tip of Folley Island to the... easternmost extremity of Hilton Head at latitude 32°13.0′ N. longitude 80°40.1′ W. [CGD 77-118a, 42 FR 35784...

Synergetic effects of Sc and Zr microalloying and heat treatment on mechanical properties and exfoliation corrosion behavior of Al-Mg-Mn alloys

International Nuclear Information System (INIS)

Peng, Yongyi; Li, Shu; Deng, Ying; Zhou, Hua; Xu, Guofu; Yin, Zhimin

2016-01-01

Mechanical properties, exfoliation corrosion behavior and microstructure of Al-5.98Mg-0.47Mn and Al-6.01Mg-0.45Mn-0.25Sc-0.10Zr (wt%) alloy sheets under various homogenizing and annealing processes were investigated comparatively by tensile tests, electrochemical measurements, X-ray diffraction technique and microscopy methods. The as-cast alloys mainly consist of Fe and Mn enriched impurity phases, Mg and Mn enriched non-equilibrium aluminides and Mg 3 Al 2 phases. During homogenization treatment, solvable intermetallics firstly precipitate and then dissolve into matrix. The optimized homogenization processes for removing micro-segregation and obtaining maximum precipitation strengthening of secondary Al 3 (Sc, Zr) particles are 440 °C×8 h and 300 °C×8 h, respectively. Sc and Zr additions can make the yield strength of Al-Mg-Mn alloy increase by 21 MPa (6.9%), 120 MPa (61.2%) and 127 MPa (68.3%), when annealed at 270 °C, 300 °C and 330 °C, respectively, indicating that Orowan precipitation strengthening caused by secondary Al 3 (Sc, Zr) nano-particles is much greater than grain boundary strengthening from primary Al 3 (Sc, Zr) micro-particles. Increasing homogenization and annealing degrees and adding Sc and Zr all can decrease corrosion current density and improve exfoliation corrosion resistance. The exfoliation corrosion behavior is dominant by anodic dissolution occurring at the interface between intermetallics and α(Al) matrix. After homogenizing at 440 °C for 8 h and annealing at 300 °C for 1 h, yield strength, ultimate strength, elongation to failure and exfoliation corrosion rank are 196 MPa, 360 MPa, 20.2% and PA (slight pitting corrosion) in Al-Mg-Mn alloy, and reach to 316 MPa, 440 MPa, 17.0% and PA in Al-Mg-Mn-Sc-Zr alloy, respectively, revealing that high strength, high ductility and admirable corrosion resistance of Al-Mg-Mn alloys can be achieved by the synergetic effects of Sc and Zr microalloying and heat treatment.

UPORABA SUPERKRITIČNEGA OGLIKOVEGA DIOKSIDA (SC CO 2 ) ZA IZOLACIJO ENCIMOV IN PROTEINOV IZ CELIC ČRNE KVASOVKE TRIMMATOSTROMA SALINUM

OpenAIRE

Bosilj, Monika

2012-01-01

Namen diplomske naloge je določiti vpliv superkritičnega ogljikovega dioksida (SC CO2) na preživetje črnih kvasovk Trimmatostroma salinum in izločanje proteinov in nukleinskih kislin iz celične suspenzije T. salinum. Suspenzijo s kulturo T. salinum smo v visokotlačnem šaržnem reaktorju izpostavili SC CO2 pri tlaku 100 bar in 35 °C. Rezultati so pokazali, da se je s podaljševanjem časa inkubacije v SC CO2 preživelost celic T. salinum zmanjševala. Merili smo tudi aktivnost encimov celulaze, α-a...

Dual-Emission SG7@MOF Sensor via SC-SC Transformation: Enhancing the Formation of Excimer Emission and the Range and Sensitivity of Detection.

Science.gov (United States)

Fu, Hong-Ru; Wu, Xiao-Xia; Ma, Lu-Fang; Wang, Fei; Zhang, Jian

2018-05-30

In this study, a water stable metal-organic framework FIR-53 is applied as a single-crystal container for anion exchange. The exceptional chemical stability and low crystallographic symmetry of FIR-53 makes it possible to determine anionic guests. Through ion exchange and single-crystal to single-crystal (SC-SC) transformation, 8-hydroxypyrene-1,3,6-trisulfonate (SG7, solvent green 7, ion form as SG7 3- ) is introduced into the pores of FIR-53 to obtain SG7@FIR-53. Because of the spatial confinement and partition effect, SG7@FIR-53 shows the bright exciter emission of SG7 ions. Interestingly, the composite SG7@FIR-53 exhibits a sensitive fluorescence quenching response against Cr 2 O 7 2- and MnO 4 - in aqueous solution. Especially, the detection limit toward MnO 4 - is as low as 0.12 ppb, which is the smallest value to date. Moreover, the prepared SG7@FIR-53 film also displays a broad response to nitro explosives in vapor/aqueous phase. Compared with the results of FIR-53, the range and sensitivity were greatly improved.

Impact of Neutral Point Current Control on Copper Loss Distribution of Five Phase PM Generators Used in Wind Power Plants

Directory of Open Access Journals (Sweden)

ARASHLOO, R. S.

2014-05-01

Full Text Available Efficiency improvement under faulty conditions is one of the main objectives of fault tolerant PM drives. This goal can be achieved by increasing the output power while reducing the losses. Stator copper loss not only directly affects the total efficiency, but also plays an important role in thermal stress generations of iron core. In this paper, the effect of having control on neutral point current is studied on the efficiency of five-phase permanent magnet machines. Open circuit fault is considered for both one and two phases, and the distribution of copper loss along the windings are evaluated in each case. It is shown that only by having access to neutral point, it is possible to generate less stator thermal stress and more mechanical power in five-phase permanent magnet generators. Wind power generation and their applications are kept in mind, and the results are verified via simulations and experimental tests on an outer-rotor type of five-phase PM machine.

The "innocent" role of Sc3+ on a non-heme Fe catalyst in an O2 environment

KAUST Repository

Poater, Albert; Chaitanya Vummaleti, Sai Vikrama; Cavallo, Luigi

2014-01-01

Density functional theory calculations have been used to investigate the reaction mechanism proposed for the formation of an oxoiron(iv) complex [Fe IV(TMC)O]2+ (P) (TMC = 1,4,8,11-tetramethylcyclam) starting from a non-heme reactant complex [FeII(TMC)]2+ (R) and O2 in the presence of acid H+ and reductant BPh4 -. We also addressed the possible role of redox-inactive Sc3+ as a replacement for H+ acid in this reaction to trigger the formation of P. Our computational results substantially confirm the proposed mechanism and, more importantly, support that Sc 3+ could trigger the O2 activation, mainly dictated by the availability of two electrons from BPh4 -, by forming a thermodynamically stable Sc3+-peroxo-Fe3+ core that facilitates O-O bond cleavage to generate P by reducing the energy barrier. These insights may pave the way to improve the catalytic reactivity of metal-oxo complexes in O2 activation at non-heme centers. This journal is © the Partner Organisations 2014.

Investigation of the Thermal Stability of Nd(x)Sc(y)Zr(1-x-y)O(2-δ) Materials Proposed for Inert Matrix Fuel Applications.

Science.gov (United States)

Hayes, John R; Grosvenor, Andrew P; Saoudi, Mouna

2016-02-01

Inert matrix fuels (IMF) consist of transuranic elements (i.e., Pu, Am, Np, Cm) embedded in a neutron transparent (inert) matrix and can be used to "burn up" (transmute) these elements in current or Generation IV nuclear reactors. Yttria-stabilized zirconia has been extensively studied for IMF applications, but the low thermal conductivity of this material limits its usefulness. Other elements can be used to stabilize the cubic zirconia structure, and the thermal conductivity of the fuel can be increased through the use of a lighter stabilizing element. To this end, a series of Nd(x)Sc(y)Zr(1-x-y)O(2-δ) materials has been synthesized via a co-precipitation reaction and characterized by multiple techniques (Nd was used as a surrogate for Am). The long-range and local structures of these materials were studied using powder X-ray diffraction, scanning electron microscopy, and X-ray absorption spectroscopy. Additionally, the stability of these materials over a range of temperatures has been studied by annealing the materials at 1100 and 1400 °C. It was shown that the Nd(x)Sc(y)Zr(1-x-y)O(2-δ) materials maintained a single cubic phase upon annealing at high temperatures only when both Nd and Sc were present with y ≥ 0.10 and x + y > 0.15.

44gSc production using a water target on a 13 MeV cyclotron

International Nuclear Information System (INIS)

Hoehr, Cornelia; Oehlke, Elisabeth; Benard, Francois; Lee, Chris Jaeil; Hou, Xinchi; Badesso, Brian; Ferguson, Simon; Miao, Qing; Yang, Hua; Buckley, Ken; Hanemaayer, Victoire; Zeisler, Stefan; Ruth, Thomas; Celler, Anna; Schaffer, Paul

2014-01-01

Introduction: Access to promising radiometals as isotopes for novel molecular imaging agents requires that they are routinely available and inexpensive to obtain. Proximity to a cyclotron center outfitted with solid target hardware, or to an isotope generator for the metal of interest is necessary, both of which can introduce significant hurdles in development of less common isotopes. Herein, we describe the production of 44 Sc (t 1/2 = 3.97 h, E avg,β + = 1.47 MeV, branching ratio = 94.27%) in a solution target and an automated loading system which allows a quick turn-around between different radiometallic isotopes and therefore greatly improves their availability for tracer development. Experimental yields are compared to theoretical calculations. Methods: Solutions containing a high concentration (1.44–1.55 g/mL) of natural-abundance calcium nitrate tetrahydrate (Ca(NO 3 ) 2 · 4 H 2 O) were irradiated on a 13 MeV proton-beam cyclotron using a standard liquid target. 44g Sc was produced via the 44 Ca(p,n) 44g Sc reaction. Results: 44g Sc was produced for the first time in a solution target with yields sufficient for early radiochemical studies. Saturation yields of up to 4.6 ± 0.3 MBq/μA were achieved using 7.6 ± 0.3 μA proton beams for 60.0 ± 0.2 minutes (number of runs n = 3). Experimental data and calculation results are in fair agreement. Scandium was isolated from the target mixture via solid-phase extraction with 88 ± 6% (n = 5) efficiency and successfully used for radiolabelling experiments. The demonstration of the production of 44 Sc in a liquid target greatly improves its availability for tracer development

Thermal shock behavior of W-ZrC/Sc2O3 composites under two different transient events by electron and laser irradiation

Science.gov (United States)

Chen, Hong-Yu; Luo, Lai-Ma; Zan, Xiang; Xu, Qiu; Tokunaga, Kazutoshi; Liu, Jia-Qin; Zhu, Xiao-Yong; Cheng, Ji-Gui; Wu, Yu-Cheng

2018-02-01

The transient thermal shock behaviors of W-ZrC/Sc2O3 composites with different ZrC contents were evaluated using transient thermal shock test by electron and laser beams. The effects of different ZrC doping contents on the surface morphology and thermal shock resistance of W-ZrC/Sc2O3 composites were then investigated. Similarity and difference between effects of electron and laser beam transient heat loading were also discussed in this study. Repeated heat loading resulted in thermal fatigue of the irradiated W-ZrC/Sc2O3 samples by thermal stress, leading to the rough surface morphologies with cracks. After different transient thermal tests, significant surface roughening, cracks, surface melting, and droplet ejection occurred. W-2vol.%Sc2O3 sample has superior thermal properties and greater resistance to surface modifications under transient thermal shock, and with the increasing ZrC content in W alloys, thermal shock resistance of W-Zr/Sc2O3 sample tends to be unsatisfied.

Effects of a Nano-Silica Additive on the Rock Erosion Characteristics of a SC-CO2 Jet under Various Operating Conditions

Directory of Open Access Journals (Sweden)

Man Huang

2017-02-01

Full Text Available In order to improve the erosion capacity of a supercritical carbon dioxide (SC-CO2 jet, the influence of a nano-silica additive on the rock erosion characteristics was experimentally investigated. By impinging the SC-CO2 jets with nano-silica mass fractions of 0 wt % (pure SC-CO2 jet, 3 wt %, 6 wt %, 9 wt %, 12 wt %, 15 wt %, and 18 wt % on specimens of red sandstone, the erosion volumes under various operating conditions were measured and analyzed. Results show that an appropriate amount of nano-silica additive can greatly enhance the erosion ability of a SC-CO2 jet. The effect on the erosion ability largely depends on the operating conditions. For instance, when the other conditions are fixed, 6 wt %, 9 wt %, 12 wt %, and 15 wt % were the optimum mass fractions, successively, with the inlet pressure increasing from 30 MPa to 60 MPa. With the increase in ambient pressure, the optimum mass fraction is unchanged under the constant inlet pressure, while it increases under the constant pressure drop. Additionally, the optimum mass fraction decreases when the fluid temperature increases. In addition, the optimal standoff distances are about five times the nozzle diameter of the nano-silica SC-CO2 jet, and three times for the pure jet. This research provides a new method for effectively enhancing the rock erosion performance of a SC-CO2 jet.

Suppressing flavor-changing neutral currents and CP-violating phases by extra dimensions

International Nuclear Information System (INIS)

Kubo, Jisuke; Terao, Haruhiko

2002-01-01

In extra dimensions the infrared attractive force of gauge interactions is amplified. We find that this force can align in the infrared limit the soft-supersymmetry breaking terms out of their anarchical disorder at a fundamental scale in such a way that flavor-changing neutral currents as well as dangerous CP-violating phases are sufficiently suppressed at the unification scale. The main assumption is that the matter and Higgs supermultiplets and the flavor-dependent interactions such as Yukawa interactions are stuck at the four-dimensional boundary. As a concrete example we consider the minimal model based on SU(5) in six dimensions

Effect of substrate temperatures on the optical properties of evaporated Sc2O3 thin films

International Nuclear Information System (INIS)

Liu Guanghui; Jin Yunxia; He Hongbo; Fan Zhengxiu

2010-01-01

Scandium oxide (Sc 2 O 3 ) films were deposited by electron beam evaporation with substrate temperatures varying from 50 to 350 o C. X-ray diffraction, scanning electron microscopy, spectrometer, and optical profilograph were employed to investigate the structural and optical properties of the films. The refractive index and extinction coefficient were calculated from the transmittance and reflectance spectra, and then the energy band gaps were deduced and discussed. Laser induced damage threshold of the films were also characterized. Optical and structural properties of Sc 2 O 3 films were found to be sensitive to substrate temperature.

Neutral insulin solutions physically stabilized by addition of Zn2+.

Science.gov (United States)

Brange, J; Havelund, S; Hommel, E; Sørensen, E; Kühl, C

1986-01-01

Commercial neutral insulin solutions, all of which contain 2-3 zinc atoms per hexameric unit of insulin, have a relatively limited physical stability when exposed to heat and movement, as for example in insulin infusion pumps. Physical stabilization of neutral insulin solutions has been obtained by addition of two extra Zn2+ per hexamer of insulin. This addition stabilizes porcine and human neutral solutions equally well and does not affect the chemical stability of the insulin. The stabilization is probably obtained by a further strengthening of the hexameric structure of insulin, so that the formation of insoluble insulin fibrils (via the dissociation into the insulin monomer or dimer) is impeded or prevented. The addition of an extra 2 Zn2+ has been shown to be without influence on the insulin immunogenicity in rabbits or on the rate of absorption after subcutaneous injection in diabetic patients. It is concluded that neutral insulin solution can be physically stabilized by addition of extra Zn2+ without affecting other qualities of the insulin preparation including chemical stability, immunogenicity, and duration of action after injection.

Modeling Secondary Neutral Helium in the Heliosphere

International Nuclear Information System (INIS)

Müller, Hans-Reinhard; Möbius, Eberhard; Wood, Brian E.

2016-01-01

An accurate, analytic heliospheric neutral test-particle code for helium atoms from the interstellar medium (ISM) is coupled to global heliospheric models dominated by hydrogen and protons from the solar wind and the ISM. This coupling enables the forward-calculation of secondary helium neutrals from first principles. Secondaries are produced predominantly in the outer heliosheath, upwind of the heliopause, by charge exchange of helium ions with neutral atoms. The forward model integrates the secondary production terms along neutral trajectories and calculates the combined neutral helium phase space density in the innermost heliosphere where it can be related to in-situ observations. The phase space density of the secondary component is lower than that of primary neutral helium, but its presence can change the analysis of primaries and the ISM, and can yield valuable insight into the characteristics of the plasma in the outer heliosheath. (paper)

CERN: SC-33

Energy Technology Data Exchange (ETDEWEB)

Anon.

1991-06-15

On 22 April a forward-looking CERN also looked back for a day, when the 'SC-33' event reviewed the achievements of CERN's first machine, the 600 MeV SynchroCyclotron (SC), which closed down on 17 December after 33 years of valiant service.

Characterization of gingerol analogues in supercritical carbon dioxide (SC CO2) extract of ginger (Zingiber officinale, R.,).

Science.gov (United States)

Swapna Sonale, R; Kadimi, Udaya Sankar

2014-11-01

Organically grown ginger rhizome (Zingiber officinale Roscoe) SC CO2 extract obtained at 280 bar and 40 °C and its column chromatographic fractions are characterised for its composition. The components in the extract and fractions are identified by HPLC and LC based MS and are used as standard for the estimation of gingerol analogues in the extract. HPLC and mass analysis of the extracts confirmed the various forms of gingerol constituents [4]-, [6]-, [10]-gingerols and [6]-, [8]-, [10]-shogaols in ginger extracts. SC CO2 extract of organic ginger was found to show 6-gingerol around 25.97 % of total extract. The estimation of [6]-gingerol, [6]-shogaols, [4]gingerol, [10]-gingerol and 6-gingediol content of the SC CO2 purified ginger extract was found to be 75.92 ± 1.14, 1.25 ± 0.04, 4.54 ± 0.04, 13.15 ± 0.30 and 0.37 ± 0.00 % respectively. Antioxidant activity was measured by 2, 2-diphenyl-1-pycryl-hydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) and the assay have shown 652 ± 0.37 mg TE/g and 3.68 ± 0.18 mg TE/100 g respectively, are significantly higher results with SC CO2 organic ginger extract. Paradol analogues are not detected in this study. Small quantities of [4]-, [10]gingediol and [6]-gingediacetate are also found in ginger extract.

Paracyclophane functionalized with Sc and Li for hydrogen storage

Science.gov (United States)

Sathe, Rohit Y.; Dhilip Kumar, T. J.

2018-01-01

Li and Sc metals functionalized on the delocalized π -electrons of benzene rings in [2,2]paracyclophane structure are studied for hydrogen storage efficiency by using the M06 DFT functional with 6-311G(d,p) basis set. It is found that Sc and Li functionalized [2,2]paracyclophane complexes can hold up to 10 H2 molecules and 8 H2 molecules by Kubas-Niu-Jena interaction and charge polarization mechanism with hydrogen weight percentage of 11.4 and 13.5, respectively. Molecular dynamics simulation at various temperatures showed appreciable thermal stability while the chemical potential calculation at room temperature reveals that Sc functionalized [2,2]paracyclophane system will be a promising hydrogen storage material.

The Roberts syndrome/SC phocomelia spectrum--a case report of an adult with review of the literature.

Science.gov (United States)

Goh, Elaine Suk-Ying; Li, Chumei; Horsburgh, Sheri; Kasai, Yumi; Kolomietz, Elena; Morel, Chantal France

2010-02-01

Roberts syndrome (RBS) (OMIM #268300) is a rare autosomal recessive disorder characterized by tetraphocomelia (symmetrical limb reduction), craniofacial anomalies, growth retardation, mental retardation, cardiac and renal abnormalities. The syndrome is caused by mutations in the ESCO2 (establishment of cohesion 1 homolog 2) (Entrez 609353) gene, which is located at 8p21.1, and encodes a protein essential in establishing sister chromatid cohesion during S phase. SC phocomelia (SC) (OMIM #269000), has less severe symmetric limb reduction, flexion contractures of various joints, minor facial anomalies, growth retardation and occasionally, mental retardation. These two syndromes can be considered part of a spectrum, with RBS at the most severe range in which severely affected infants may be stillborn or die in the post-natal period, while individuals with SC phocomelia represent the milder end of the spectrum and typically survive to adulthood. In both presentations, karyotype investigations characteristically reveal premature centromere separation (PCS), otherwise known as heterochromatin repulsion or puffing. There is little literature about the follow-up of adults with the spectrum of RBS/SC phocomelia or their recommended management. We report on an adult presentation of RBS/SC phocomelia spectrum disorder with a history of major cardiac malformation in childhood, normal limbs on physical examination, mild facial anomalies, mild learning difficulties, and PCS. Molecular studies of ESCO2 have confirmed the diagnosis. A literature review, focussing on adult manifestations of this condition and a discussion of follow-up guidelines are presented. Copyright 2010 Wiley-Liss, Inc.

Ternary scandium-rich indides Sc{sub 50}T{sub 13}In{sub 3} and Sc{sub 50}Rh{sub 13}In{sub 3}O{sub y} (T = Rh, Ir; y {approx} 8) - synthesis and crystal structure

Energy Technology Data Exchange (ETDEWEB)

Zaremba, R.; Poettgen, R. [Inst. fuer Anorganische und Analytische Chemie, Univ. Muenster (Germany)

2007-12-15

New intermetallic compounds Sc{sub 50}Rh{sub 13.3}In{sub 2.7} and Sc{sub 50}Ir{sub 13.6}In{sub 2.4} and the suboxides Sc{sub 49.2}Rh{sub 13}In{sub 3.8}O{sub 8.8} and Sc{sub 49.2}Rh{sub 13.7}In{sub 2.8}O{sub 8.0} were synthesized from the elements or with Sc{sub 2}O{sub 3} as an oxygen source, respectively, in sealed tantalum tubes in a water-cooled sample chamber of an induction furnace. They crystallize with a new cubic structure type, space group F m anti 3, a = 1772.5(6) pm, wR2 = 0.032, 1111 F{sup 2} values, 34 variables for Sc{sub 50}Rh{sub 13.3}In{sub 2.7}, a = 1766.5(6) pm, wR2 = 0.041, 745 F{sup 2} values, 34 variables for Sc{sub 50}Ir{sub 13.6}In{sub 2.4}, a = 1764.4(2) pm, wR2 = 0.044, 640 F{sup 2} values, 41 variables for Sc{sub 49.2}Rh{sub 13}In{sub 3.8}O{sub 8.8}, and a = 1761.5(6) pm, wR2 = 0.054, 740 F{sup 2} values, 42 variables for Sc{sub 49.2}Rh{sub 13.7}In{sub 2.8}O{sub 8.0}. The main structural motifs are rhodium-centered indium cubes in an fcc like arrangement in which the octahedral and tetrahedral voids are filled by In2Sc{sub 12} and In1Sc{sub 12} icosahedra, respectively, resembling a Li{sub 3}Bi-like structure. The Rh1 (Ir1) and Sc4 atoms lie between these polyhedral units. The oxygen atoms partially fill Sc{sub 6} octahedra in Sc{sub 49.2}Rh{sub 13}In{sub 3.8}O{sub 8.8} and Sc{sub 49.2}Rh{sub 13.7}In{sub 2.8}O{sub 8.0} with Sc-O distances of 214 - 230 pm. These octahedra are condensed via common edges and faces, encapsulating the In2Sc{sub 12} icosahedra. Due to the high scandium content one observes strong Sc-Sc bonding with Sc-Sc distances ranging from 303 to 362 pm in Sc{sub 49.2}Rh{sub 13}In{sub 3.8}O{sub 8.8}. The shortest distances occur for Sc-Rh (267 - 295 pm). The crystal chemical relationship with the Li{sub 3}Bi-related suboxide Ti{sub 12}Sn{sub 3}O{sub 10} is discussed. (orig.)

Upgrade of the TCV tokamak, first phase: Neutral beam heating system

Energy Technology Data Exchange (ETDEWEB)

Karpushov, Alexander N., E-mail: alexander.karpushov@epfl.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Alberti, Stefano; Chavan, René [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Davydenko, Vladimir I. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Duval, Basil P. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Ivanov, Alexander A. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Fasel, Damien; Fasoli, Ambrogio [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Gorbovsky, Aleksander I. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Goodman, Timothy [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Kolmogorov, Vyacheslav V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Martin, Yves; Sauter, Olivier [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Sorokin, Aleksey V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); and others

2015-10-15

Highlights: • Widening the parameter range of reactor relevant regimes on the TCV tokamak. • Installation of 1 MW, 30 keV neutral beam, direct ion heating, access to T{sub i}/T{sub e} ≥ 1. • ASTRA simulation of plasma response to NB and EC heating in different regimes. • Specific low divergency neutral beam injector with tunable beam power and energy. - Abstract: Experiments on TCV are designed to complement the work at large integrated tokamak facilities (such as JET) to provide a stepwise approach to extrapolation to ITER and DEMO in areas where medium-size tokamaks can often exploit their experimental capabilities and flexibility. Improving the understanding and control requirements of burning plasmas is a major scientific challenge, requiring access to plasma regimes and configurations with high normalized plasma pressure and a wide range of ion to electron temperature ratios, including T{sub e}/T{sub i} ∼ 1. These conditions will be explored by adding a 1 MW neutral heating beam to TCV's auxiliary for direct ion heating (2015) and increasing the ECH power injected in X-mode at the third harmonic (2 MW in 2015–2016). The manufacturing of the neutral beam injector was launched in 2014.

On new ternary equiatomic scandium transition metal aluminum compounds ScTAl with T = Cr, Ru, Ag, Re, Pt, and Au

Energy Technology Data Exchange (ETDEWEB)

Radzieowski, Mathis; Janka, Oliver [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Benndorf, Christopher [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Haverkamp, Sandra [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Eckert, Hellmut [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; University of Sao Paulo, Sao Carlos, SP (Brazil). Inst. of Physics

2016-08-01

The new equiatomic scandium transition metal aluminides ScTAl for T = Cr, Ru, Ag, Re, Pt, and Au were obtained by arc-melting of the elements followed by subsequent annealing for crystal growth. The samples were studied by powder and single crystal X-ray diffraction. The structures of three compounds were refined from single crystal X-ray diffractometer data: ScCrAl, MgZn{sub 2} type, P6{sub 3}/mmc, a = 525.77(3), c = 858.68(5) pm, R{sub 1} = 0.0188, wR{sub 2} = 0.0485, 204 F{sup 2} values, 13 variables, ScPtAl, TiNiSi type, Pnma, a = 642.83(4), b = 428.96(2), c = 754.54(5) pm, R{sub 1} = 0.0326, wR{sub 2} = 0.0458, 448 F{sup 2} values, 20 variables and ScAuAl, HfRhSn type, P anti 62c, a = 722.88(4), c = 724.15(4) pm, R{sub 1} = 0.0316, wR{sub 2} = 0.0653, 512 F{sup 2} values, 18 variables. Phase pure samples of all compounds were furthermore investigated by magnetic susceptibility measurements, and Pauli-paramagnetism but no superconductivity was observed down to 2.1 K for all of them. The local structural features and disordering phenomena have been characterized by {sup 27}Al and {sup 45}Sc magic angle spinning (MAS) and static NMR spectroscopic investigations.

Epitaxial growth of Sc{sub 2}O{sub 3} films on Gd{sub 2}O{sub 3}-buffered Si substrates by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Paulraj, Joseph; Wang, Rongping; Sellars, Matthew; Luther-Davies, Barry [Australian National University, Laser Physics Centre, Research School of Physics and Engineering, Acton, Canberra, ACT (Australia)

2016-04-15

We investigated the optimal conditions to prepare high-quality Sc{sub 2}O{sub 3} films on Gd{sub 2}O{sub 3}-buffered Si wafers using pulsed laser deposition technique with an aim at developing waveguide devices that can transform the performance of the gradient echo quantum memory based on bulk crystals. Under the optimal conditions, only oxide and Si (2 2 2) peaks appeared in the X-ray diffraction pattern. The Sc{sub 2}O{sub 3} (2 2 2) diffraction peak was located at 2θ=31.5 with a full width at half maxima (FWHM) of 0.16 , and its rocking curve had a FWHM of 0.10 . In-plane epitaxial relationship was confirmed by X-ray pole figure where Sc{sub 2}O{sub 3} (1 1 1) was parallel to Si (1 1 1). High-resolution TEM images indicated clear interfaces and perfect lattice images with sharp electron diffraction dots. All these results confirm that the oxide films on Si were single crystalline with high quality. (orig.)

Laboratory oscillator strengths of Sc i in the near-infrared region for astrophysical applications

Science.gov (United States)

Pehlivan, A.; Nilsson, H.; Hartman, H.

2015-10-01

Context. Atomic data is crucial for astrophysical investigations. To understand the formation and evolution of stars, we need to analyse their observed spectra. Analysing a spectrum of a star requires information about the properties of atomic lines, such as wavelengths and oscillator strengths. However, atomic data of some elements are scarce, particularly in the infrared region, and this paper is part of an effort to improve the situation on near-IR atomic data. Aims: This paper investigates the spectrum of neutral scandium, Sc I, from laboratory measurements and improves the atomic data of Sc I lines in the infrared region covering lines in R, I, J, and K bands. Especially, we focus on measuring oscillator strengths for Sc I lines connecting the levels with 4p and 4s configurations. Methods: We combined experimental branching fractions with radiative lifetimes from the literature to derive oscillator strengths (f-values). Intensity-calibrated spectra with high spectral resolution were recorded with Fourier transform spectrometer from a hollow cathode discharge lamp. The spectra were used to derive accurate oscillator strengths and wavelengths for Sc I lines, with emphasis on the infrared region. Results: This project provides the first set of experimental Sc I lines in the near-infrared region for accurate spectral analysis of astronomical objects. We derived 63 log(gf) values for the lines between 5300 Å and 24 300 Å. The uncertainties in the f-values vary from 5% to 20%. The small uncertainties in our values allow for an increased accuracy in astrophysical abundance determinations.

CERN: SC-33

International Nuclear Information System (INIS)

Anon.

1991-01-01

On 22 April a forward-looking CERN also looked back for a day, when the 'SC-33' event reviewed the achievements of CERN's first machine, the 600 MeV SynchroCyclotron (SC), which closed down on 17 December after 33 years of valiant service

S-C Mylonites

NARCIS (Netherlands)

Lister, G.S.; Snoke, A.W.

1984-01-01

Two types of foliations are commonly developed in mylonites and mylonitic rocks: (a) S-surfaces related to the accumulation of finite strain and (b) C-surfaces related to displacement discontinuities or zones of relatively high shear strain. There are two types of S-C mylonites. Type I S-C

Susceptibility of Granite Rock to scCO2/Water at 200 degrees C and 250 degrees C

Energy Technology Data Exchange (ETDEWEB)

Sugama, T.; Gill, S., Ecker, L., Butcher, T., Warren, J.

2011-01-01

Granite rock comprising anorthoclase-type albite and quartz as its major phases and biotite mica as the minor one was exposed to supercritical carbon dioxide (scCO{sub 2})/water at 250 C and 13.78 MPa pressure for 104 hours. For comparison purpose, four other rocks, albite, hornblende, diorite, and quartz, also were exposed. During the exposure of granite, ionic carbonic acid, known as the wet carbonation reactant, preferentially reacted with anorthoclase-type albite and biotite, rather than with quartz. The susceptibility of biotite to wet carbonation was higher than that of anorthoclase-type albite. All the carbonation by-products of anorthoclase-type albite were amorphous phases including Na- and K-carbonates, a kaolinite clay-like compound, and silicon dioxide, while wet carbonation converted biotite into potassium aluminum silicate, siderite, and magnesite in crystalline phases and hydrogen fluoride (HF). Three of these reaction by-products, Na- and K-carbonates and HF, were highly soluble in water. Correspondingly, the carbonated top surface layer, about 1.27 mm thick as carbonation depth, developed porous microstructure with numerous large voids, some of which have a size of {>=} 10 {mu}m, reflecting the erosion of granite by the leaching of these water-soluble reaction by-products. Comparing with this carbonation depth, its depth of other minerals was considerable lower, particularly, for hornblende and diorite with 0.07 and 0.02 mm, while no carbonate compound was detected in quartz. The major factor governing these low carbonation depths in these rocks was the formation of water-insensitive scale-like carbonate by-products such as calcite (CaCO{sub 3}), siderite (FeCO{sub 3}), and magnesite (MgCO{sub 3}). Their formation within the superficial layer of these minerals served as protective barrier layer that inhibits and retards further carbonation of fresh underlying minerals, even if the exposure time was extended. Thus, the coverage by this barrier layer

X-ray and electron diffraction studies of the structures of pseudo-perovskite compounds Pb2(Sc,Ta)O6 and Pb2(Mg,W)O6

International Nuclear Information System (INIS)

Baba-Kishi, K.Z.; Cernik, R.J.

1992-01-01

Electron diffraction patterns, X-ray precession patterns and synchrotron Rietveld powder diffraction profiles were used to study the crystal structure of the pseudo-perovskite compound Pb 2 (Sc, Ta)O 6 (PST). The results of a Rietveld refinement and single-crystal X-ray precession studies showed that PST has a lower symmetry than the cubic Fm3m in the paraelectric state. The remarkable similarities between the crystal structures of the antiferroelectric Pb 2 (Mg, W)O 6 (PMW) and ferroelectric PST are studied in detail by electron diffraction and it is suggested that PST is a weak or frustrated antiferroelectric oxide. The influence of the degree of structural long-range order on the existence of an antiferroelectric phase transition in PST and PMW is discussed. (orig.)

Ternary silicides ScIr{sub 4}Si{sub 2} and RERh{sub 4}Si{sub 2} (RE = Sc, Y, Tb-Lu) and quaternary derivatives RERh{sub 4}Si{sub 2-x}Sn{sub x} (RE = Y, Nd, Sm, Gd-Lu) - structure, chemical bonding, and solid state NMR spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Vosswinkel, Daniel; Benndorf, Christopher; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Eckert, Hellmut [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Sao Paulo Univ., Sao Carlos (Brazil). Inst. of Physics; Matar, Samir F. [Bordeaux Univ., CNRS, ICMCB, UPR 9048, Pessac (France)

2016-11-01

The silicides ScIr{sub 4}Si{sub 2} and RERh{sub 4}Si{sub 2} (RE = Sc, Y, Tb-Lu) and silicide stannides RERh{sub 4}Si{sub 2-x}Sn{sub x}(RE = Y, Nd, Sm, Gd-Lu) were synthesized from the elements by arc-melting and subsequent annealing. The new compounds crystallize with the orthorhombic YRh{sub 4}Ge{sub 2} type structure, space group Pnma. They were characterized by X-ray powder patterns and several structures were refined from single crystal X-ray diffractometer data. The main structural motifs of this series of silicides are tricapped trigonal prisms formed by the transition metal and rare earth atoms. One of the two crystallographically independent silicon sites allows for formation of solid solutions with tin, exemplarily studied for ErRh{sub 4}Si{sub 2-x}Sn{sub x}. Electronic structure calculations reveal strong covalent Rh-Si bonding as the main stability factor. Multinuclear ({sup 29}Si, {sup 45}Sc, and {sup 89}Y) magic-angle spinning (MAS) NMR spectra of the structure representatives with diamagnetic rare-earth elements (Sc, Y, Lu) are found to be consistent with the crystallographic data and specifically confirm the selective substitution of Sn in the Si2 sites in the quaternary compounds YRh{sub 4}SiSn and LuRh{sub 4}SiSn.

Numerical simulation on the screw pinch by 2-D MHD pinch code 'topics' including impurities and neutrals effects

International Nuclear Information System (INIS)

Nagata, A.; Ashida, H.; Okamoto, M.; Hirano, K.

1981-03-01

Two dimentional fluid simulation code ''TOPICS'' is developed for the STP-2, the shock heated screw pinch at Nagoya. It involves the effects of impurity ions and neutral atoms. In order to estimate the radiation losses, the impurity continuity equations with ionizations and recombinations are solved simultaneously with the plasma fluid equations. The results are compared with the coronal equilibrium model. It is found that the coronal equilibrium model underestimates the radiation losses from shock heated pinch plasmas in its initial dynamic phase. The present calculations including impurities and neutrals show the importance of the radiation losses from the plasma of the STP-2. Introducing the anomalous resistivity caused by the ion acoustic instability, the observed magnetic field penetration is explained fairly well. (author)

The effect of Sc additions on the microstructure and age hardening behaviour of as cast Al–Sc alloys

International Nuclear Information System (INIS)

Costa, S.; Puga, H.; Barbosa, J.; Pinto, A.M.P.

2012-01-01

Highlights: ► The Sc effect on the microstructure and ageing behaviour of Al–Sc alloys is studied. ► Cast into copper mould allows the elimination of solution heat treatment. ► Directly aged as cast alloys exhibits higher hardness and precipitation kinetics. ► Sc addition and optimised ageing result in an increase in Al–Sc mechanical properties. -- Abstract: The grain refinement effect and the ageing behaviour of Al–0.5 wt.% Sc, Al–0.7 wt.% Sc, and Al–1 wt.% Sc alloys are studied on the basis of optic microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) observations and hardness measurements. In Al–Sc alloys the higher grain refinement is observed for Sc contents greater than 0.5 wt.% accompanied by a notorious morphology modification, from coarse columnar grains to a fine perfect equiaxed structure. The as cast structures are characterised by a rich supersaturated solid solution in Sc, that promotes a great age hardening response at 250 °C and 300 °C. The age hardening curves also demonstrate a low overageing kinetics for all the alloys. Although the higher Sc content in solid solution for the alloys with 0.7 and 1 wt.% Sc, the age hardening response of all the Al–Sc alloys remains similar. The direct age hardening response of the as cast Al–0.5 wt.% Sc is shown to be greater than the solutionised and age hardened alloy.

Evidence for a modulation of neutral trehalase activity by Ca2+ and cAMP signaling pathways in Saccharomyces cerevisiae

Directory of Open Access Journals (Sweden)

Souza A.C.

2002-01-01

Full Text Available Saccharomyces cerevisiae neutral trehalase (encoded by NTH1 is regulated by cAMP-dependent protein kinase (PKA and by an endogenous modulator protein. A yeast strain with knockouts of CMK1 and CMK2 genes (cmk1cmk2 and its isogenic control (CMK1CMK2 were used to investigate the role of CaM kinase II in the in vitro activation of neutral trehalase during growth on glucose. In the exponential growth phase, cmk1cmk2 cells exhibited basal trehalase activity and an activation ratio by PKA very similar to that found in CMK1CMK2 cells. At diauxie, even though both cells presented comparable basal trehalase activities, cmk1cmk2 cells showed reduced activation by PKA and lower total trehalase activity when compared to CMK1CMK2 cells. To determine if CaM kinase II regulates NTH1 expression or is involved in post-translational modulation of neutral trehalase activity, NTH1 promoter activity was evaluated using an NTH1-lacZ reporter gene. Similar ß-galactosidase activities were found for CMK1CMK2 and cmk1cmk2 cells, ruling out the role of CaM kinase II in NTH1 expression. Thus, CaM kinase II should act in concert with PKA on the activation of the cryptic form of neutral trehalase. A model for trehalase regulation by CaM kinase II is proposed whereby the target protein for Ca2+/CaM-dependent kinase II phosphorylation is not the neutral trehalase itself. The possible identity of this target protein with the recently identified trehalase-associated protein YLR270Wp is discussed.

Synthesis and Characterization of Ferroelectric Liquid Crystalline Organosiloxanes Containing 4-(4-undecanyloxy bi-phenyl-1-carboxyloxyphenyl (2S,3S-2-chloro-3-methylvalerate and 4-(4-undecanyloxybenzoyloxybiphenyl (2S,3S-2-chloro-3-methylvalerate

Directory of Open Access Journals (Sweden)

Chih-Hung Lin

2013-10-01

Full Text Available A series of new organosiloxane ferroelectric liquid crystalline (FLC materials have been synthesized, and their mesomorphic and physical properties have been characterized. Four new disiloxanes and trisiloxanes, containing biphenyl 4-hydroxybenzoate and phenyl 4-hydroxybiphenylcarboxylate as mesogenic units and eleven methylene unit as spacers and (2S,3S-2-chloro-3-methylvalerate unit as chiral end groups. The molecule, using three phenyl ring as a mesogenic unit, formulates much wider liquid crystalline phase temperature ranges than that of a two phenyl ring unit. The phenyl arrangement differences of mesogenic unit result in the greater differences of the liquid crystal phase formation. The siloxane molecule induction is helpful to the more regular smectic phase formation and smectic phase stabilization, such as chiral SC (SC* and SB phases. The siloxane molecule is helpful to reduce the phase transition temperature and broaden the liquid crystal temperature range of the SC* phase and, simultaneously, it will not induce chain crystallization phenomenon and dilute the Ps value. The synthesis and characterization of the new FLCs materials, which exhibit a room temperature SC* phase and higher spontaneous polarization are presented.

Neutral and acidic oligosaccharides supplementation does not increase the vaccine antibody response in preterm infants in a randomized clinical trial.

Directory of Open Access Journals (Sweden)

Jolice P van den Berg

Full Text Available BACKGROUND: In preterm infants, a decreased immunological response and lower serological effectiveness are observed after immunizations due to ineffectiveness of both humoral and cellular immune mechanisms. OBJECTIVE: To determine the effect of 80% neutral oligosaccharides [small-chain galacto-oligosaccharides/long-chain fructo-oligosaccharides (scGOS/lcFOS] in combination with 20% pectin-derived acidic oligosaccharides (pAOS on antibody concentrations after DTaP-IPV-Hib immunization in preterm infants. DESIGN: In this randomized clinical trial, preterm infants with gestational age <32 weeks and/or birth weight <1500 g received enteral supplementation with scGOS/lcFOS/pAOS or placebo (maltodextrin between days 3 and 30 of life. Blood samples were collected at 5 and 12 months of age. RESULTS: In total, 113 infants were included. Baseline and nutritional characteristics were not different in both groups. Geometric mean titers were not different after prebiotic supplementation at 5 months, Ptx (37/44 EU/ml, FHA (78/96 EU/ml, Prn (78/80 EU/ml, Diphtheria (0.40/0.57 IU/ml, Tetanus (0.74/0.99 IU/ml and Hib (0.35/0.63 µg/ml, and at 12 months Ptx (55/66 EU/ml, FHA (122/119 EU/ml, Prn (116/106 Eu/ml, Diphtheria (0.88/1.11 IU/ml, Tetanus (1.64/1.79 IU/ml and Hib (2.91/2.55 µg/ml. CONCLUSIONS: Enteral supplementation of neutral (scGOS/lcFOS and acidic oligosaccharides (pAOS does not improve the immunization response in preterm infants. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN16211826 ISRCTN16211826.

Theoretical investigation of structure and stability of molecules of borohydrides B2H6, AlBH6 and ScBH6

International Nuclear Information System (INIS)

Musaev, D.G.; Zyubin, A.S.; Charkin, O.P.; Bonakkorsi, R.; Tomazi, Ya.

1988-01-01

Geometry of alternative structures of M 3+ BH 6 molecules are optimized on the two-exponent bases; their energies are refined with a fuller basis DEHD taking into account electron correlation within the frames of the MP3 method. The tendencies in the change of relative energies of the structures and their stability to decomposition are analyzed. It is noted that AlBH 6 and ScBH 6 molecules are not rigid to migration of M 3+ H 2 + ''cation'' round BH 4 - anion, as well ScBH 6 molecules are flexible to rotation of H 2 Sc group round the Sc-B axis. The data are compared with the results of previous similar calculations of borohydrides of elements in the first two groups (Li-Cu and Be-Zn)

Determination of a new structure type in the Sc-Fe-Ge-Sn system

Energy Technology Data Exchange (ETDEWEB)

Brgoch, Jakoah [Department of Chemistry, Iowa State University, Ames, IA 50011 (United States); Ran, Sheng [Ames Laboratory, US Department of Energy, Ames, IA 50011 (United States); Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Thimmaiah, Srinivasa [Department of Chemistry, Iowa State University, Ames, IA 50011 (United States); Ames Laboratory, US Department of Energy, Ames, IA 50011 (United States); Canfield, Paul C. [Ames Laboratory, US Department of Energy, Ames, IA 50011 (United States); Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Miller, Gordon J., E-mail: gmiller@iastate.edu [Department of Chemistry, Iowa State University, Ames, IA 50011 (United States); Ames Laboratory, US Department of Energy, Ames, IA 50011 (United States)

2013-01-05

Highlights: Black-Right-Pointing-Pointer A new structure type with the composition Sc{sub 4}Fe{sub 5}Ge{sub 6.10(3)}Sn{sub 1.47(2)}. Black-Right-Pointing-Pointer Crystallizes in the space group Immm (No. 71, oI144). Black-Right-Pointing-Pointer Sample obtained using a reactive Sn flux. Black-Right-Pointing-Pointer Electronic structure calculations indicate polar intermetallic bonding network. - Abstract: A new structure type has been discovered in the system Sc-Fe-Ge-Sn by employing Sn as a flux medium. According to single crystal X-ray diffraction, the new structure has a composition of Sc{sub 4}Fe{sub 5}Ge{sub 6.10(3)}Sn{sub 1.47(2)} and crystallizes in the space group Immm (No. 71, oI144) with lattice parameters of a = 5.230(1) A, b = 13.467(3) A, and c = 30.003(6) A. The structure is composed of square anti-prismatic clusters that are condensed into zig-zag chains along the [0 1 0] direction. These chains are further condensed through a split Sn/Ge position, forming a three-dimensional network. Magnetization measurements indicate an antiferromagnetic phase transition near 240 K. Electronic structure calculations identified the most favorable bonding network in this new system. Using crystal orbital Hamilton population (COHP) curves and their integrated values (ICOHP), a polar intermetallic bonding network involving Sc-Ge as well as Fe-Sn and Fe-Ge contacts can be assigned to this new structure type.

Canted ferrimagnetism in Ca2+Sc3+ substituted yttrium-iron-garnet

Science.gov (United States)

Pardavi-Horváth, M.; Thavendrarajah, A.; Wigen, P. E.; DeGasperis, P.

1988-11-01

The temperature dependence of the magnetization of Y3-y-zCayLuzFe5-xScxO12 (0.6≤x≤1.2, 0≤y≤0.3, 0≤z≤0.9) epitaxial garnet films was measured from 4.2 K up to the Curie temperature. For x=0.7 and T≥50 K, 4πMs is enhanced by about 10% compared to the magnetization of Sc0.7 YIG. At TJdd/Jad)/da =28 nm.-1 For x=1.2 and T<10 K the magnetization can be influenced by cooling through the Curie point in a magnetic field.

Creep properties and precipitate evolution in Al-Li alloys microalloyed with Sc and Yb

Energy Technology Data Exchange (ETDEWEB)

Krug, Matthew E. [Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208 (United States); Seidman, David N. [Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208 (United States); Northwestern Center for Atom Probe Tomography, Northwestern University, 2220 Campus Drive, Evanston, IL 60208 (United States); Dunand, David C., E-mail: dunand@northwestern.edu [Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208 (United States)

2012-07-30

Highlights: Black-Right-Pointing-Pointer We examine the creep behavior of Al-alloys with Li and rare earth element additions. Black-Right-Pointing-Pointer These alloys exhibit threshold stresses below which no measurable creep occurs. Black-Right-Pointing-Pointer Larger precipitate size and lattice parameter mismatch increase creep resistance. Black-Right-Pointing-Pointer A simple parameter describes the threshold stress behavior in ternary Al-Sc-X alloys. Black-Right-Pointing-Pointer The findings are explained by a recent model of dislocation-precipitate interactions. - Abstract: A dilute Al-Sc alloy (Al-0.12 Sc, at.%, Al-Sc), its counterpart with a Li addition (Al-2.9 Li-0.11 Sc, at.%, Al-Li-Sc), as well as a quaternary alloy (Al-5.53 Li-0.048 Sc-0.009 Yb, at.%, Al-Li-Sc-Yb) were isothermally aged at 325 Degree-Sign C, and in some cases isochronally aged to 450 Degree-Sign C. As the {alpha} Prime -Al{sub 3}(Li,Sc) and Al{sub 3}(Li,Sc,Yb) precipitates, with L1{sub 2} structure, coarsen in the two Li-containing alloys, their Li and Yb concentrations decrease and their Sc concentration increases. A significant interfacial excess of Li also segregates at the {alpha}-Al matrix/{alpha} Prime -Al{sub 3}Sc(Li,Sc,Yb) precipitate interface: 5.99 {+-} 0.05 atoms nm{sup -2} in Al-Li-Sc and 13.2 {+-} 0.4 atoms nm{sup -2} in Al-Li-Sc-Yb after aging isochronally to 450 Degree-Sign C. During compression creep at 300 Degree-Sign C, the aged alloys exhibit threshold stresses between 8 and 22 MPa. A recent threshold stress model based on elastic interactions between dislocations and precipitates predicts correctly that Li additions in the Al-Li-Sc alloy reduce the threshold stress, while Yb in the Al-Li-Sc-Yb alloy increases it. The model is also in agreement with the threshold stresses of all Al-Sc-X alloys published to date.

Modeling CO2 Storage in Fractured Reservoirs: Fracture-Matrix Interactions of Free-Phase and Dissolved CO2

Science.gov (United States)

Oldenburg, C. M.; Zhou, Q.; Birkholzer, J. T.

2017-12-01

The injection of supercritical CO2 (scCO2) in fractured reservoirs has been conducted at several storage sites. However, no site-specific dual-continuum modeling for fractured reservoirs has been reported and modeling studies have generally underestimated the fracture-matrix interactions. We developed a conceptual model for enhanced CO2 storage to take into account global scCO2 migration in the fracture continuum, local storage of scCO2 and dissolved CO2 (dsCO2) in the matrix continuum, and driving forces for scCO2 invasion and dsCO2 diffusion from fractures. High-resolution discrete fracture-matrix models were developed for a column of idealized matrix blocks bounded by vertical and horizontal fractures and for a km-scale fractured reservoir. The column-scale simulation results show that equilibrium storage efficiency strongly depends on matrix entry capillary pressure and matrix-matrix connectivity while the time scale to reach equilibrium is sensitive to fracture spacing and matrix flow properties. The reservoir-scale modeling results shows that the preferential migration of scCO2 through fractures is coupled with bulk storage in the rock matrix that in turn retards the fracture scCO2 plume. We also developed unified-form diffusive flux equations to account for dsCO2 storage in brine-filled matrix blocks and found solubility trapping is significant in fractured reservoirs with low-permeability matrix.

Toxicity of binary chemical munition destruction products: methylphosphonic acid, methylphosphinic acid, 2-diisopropylaminoethanol, DF neutralent, and QL neutralent.

Science.gov (United States)

Watson, Rebecca E; Hafez, Ahmed M; Kremsky, Jonathan N; Bizzigotti, George O

2007-01-01

This paper reports the toxicity and environmental impact of neutralents produced from the hydrolysis of binary chemical agent precursor chemicals DF (methylphosphonic difluoride) and QL (2-[bis(1-methylethyl)amino]ethyl ethyl methylphosphonite). Following a literature review of the neutralent mixtures and constituents, basic toxicity tests were conducted to fill data gaps, including acute oral and dermal median lethal dose assays, the Ames mutagenicity test, and ecotoxicity tests. For methylphosphonic acid (MPA), a major constituent of DF neutralent, the acute oral LD(50) in the Sprague-Dawley rat was measured at 1888 mg/kg, and the Ames test using typical tester strains of Salmonella typhimurium and Escherichia coli was negative. The 48-h LC(50) values for pH-adjusted DF neutralent with Daphnia magna and Cyprinodon variegatus were > 2500 mg/L and 1593 mg/L, respectively. The acute oral LD(50) values in the rat for QL neutralent constituents methylphosphinic acid (MP) and 2-diisopropylaminoethanol (KB) were both determined to be 940 mg/kg, and the Ames test was negative for both. Good Laboratory Practice (GLP)-compliant ecotoxicity tests for MP and KB gave 48-h D. magna EC(50) values of 6.8 mg/L and 83 mg/L, respectively. GLP-compliant 96-h C. variegatus assays on MP and KB gave LC(50) values of 73 and 252 mg/L, respectively, and NOEC values of 22 and 108 mg/L. QL neutralent LD(50) values for acute oral and dermal toxicity tests were both > 5000 mg/kg, and the 48-h LD(50) values for D. magna and C. variegatus were 249 and 2500 mg/L, respectively. Using these data, the overall toxicity of the neutralents was assessed.

Development of the self-learning machine for creating models of microprocessor of single-phase earth fault protection devices in networks with isolated neutral voltage above 1000 V

Science.gov (United States)

Utegulov, B. B.; Utegulov, A. B.; Meiramova, S.

2018-02-01

The paper proposes the development of a self-learning machine for creating models of microprocessor-based single-phase ground fault protection devices in networks with an isolated neutral voltage higher than 1000 V. Development of a self-learning machine for creating models of microprocessor-based single-phase earth fault protection devices in networks with an isolated neutral voltage higher than 1000 V. allows to effectively implement mathematical models of automatic change of protection settings. Single-phase earth fault protection devices.

Characterization of optical and microstructure properties of ultraviolet Sc2O3 thin films and their damage mechanism at high laser power

International Nuclear Information System (INIS)

Liu Guanghui; Xue Chunrong; Jin Yunxia; Zhang Weili; Fang Ming; He Hongbo; Fan Zhengxiu

2010-01-01

The electron beam evaporation deposition method was employed to prepare scandium oxide (Sc 2 O 3 ) films with substrate temperatures varying from 50 to 350 degree C. A spectrophotometer, a glancing incidence X-ray diffraction spectrometer and a WYKO optical profilograph were employed to investigate the optical, microstructure properties and surface roughness of the Sc 2 O 3 films. The refractive index and the extinction coefficient were calculated from the transmittance and reflectance spectra with the help of the Essential Macleod. The laser induced damage threshold (LIDT) of the Sc 2 O 3 films was characterized by a pulsed Nd: YAG laser system at 355 nm with a pulse duration of 8 ns. A maximum value of 2.6 J/cm 2 was derived, and the LIDT results were found to vary in the opposite direction to the extinction coefficient, surface root mean square roughness and optical loss of the Sc 2 O 3 films. An optical microscope and a scanning electron microscope were used to characterize the damage morphology of the samples, and the development of damage with increasing laser energy density was recorded and discussed. The relationship between the LIDT and the deposition parameters of the Sc 2 O 3 thin films was analyzed, and the damage mechanism of the films under 355 nm laser irradiation was discussed. (authors)

Single-Carrier Modulation for Neutral-Point-Clamped Inverters in Three-Phase Transformerless Photovoltaic Systems

DEFF Research Database (Denmark)

Guo, Xiaoqiang; Cavalcanti, Marcelo C.; Farias, Alexandre M.

2013-01-01

Modulation strategy is one of the most important issues for three-level neutral-point-clamped inverters in three-phase transformerless photovoltaic systems. A challenge for modulation is how to keep the common-mode voltages constant to reduce the leakage currents. A single-carrier modulation...... strategy is proposed. It has a very simple structure, and the common-mode voltages can be kept constant with no need of complex space-vector modulation or multicarrier pulsewidth modulation. Experimental results verify the theoretical analysis and the effectiveness of the presented method....

Thermodynamics and Phase Behavior of Miscible Polymer Blends in the Presence of Supercritical Carbon Dioxide

Science.gov (United States)

Young, Nicholas Philip

The design of environmentally-benign polymer processing techniques is an area of growing interest, motivated by the desire to reduce the emission of volatile organic compounds. Recently, supercritical carbon dioxide (scCO 2) has gained traction as a viable candidate to process polymers both as a solvent and diluent. The focus of this work was to elucidate the nature of the interactions between scCO2 and polymers in order to provide rational insight into the molecular interactions which result in the unexpected mixing thermodynamics in one such system. The work also provides insight into the nature of pairwise thermodynamic interactions in multicomponent polymer-polymer-diluent blends, and the effect of these interactions on the phase behavior of the mixture. In order to quantify the strength of interactions in the multicomponent system, the binary mixtures were characterized individually in addition to the ternary blend. Quantitative analysis of was made tractable through the use of a model miscible polymer blend containing styrene-acrylonitrile copolymer (SAN) and poly(methyl methacrylate) (dPMMA), a mixture which has been considered for a variety of practical applications. In the case of both individual polymers, scCO2 is known to behave as a diluent, wherein the extent of polymer swelling depends on both temperature and pressure. The solubility of scCO 2 in each polymer as a function of temperature and pressure was characterized elsewhere. The SAN-dPMMA blend clearly exhibited lower critical solution temperature behavior, forming homogeneous mixtures at low temperatures and phase separating at elevated temperature. These measurements allowed the determination of the Flory-Huggins interaction parameter chi23 for SAN (species 2) and dPMMA (species 3) as a function of temperature at ambient pressure, in the absence of scCO2 (species 1). Characterization of the phase behavior of the multicomponent (ternary) mixture was also carried out by SANS. An in situ SANS

Infectivity-associated PrP(Sc) and disease duration-associated PrP(Sc) of mouse BSE prions.

Science.gov (United States)

Miyazawa, Kohtaro; Okada, Hiroyuki; Masujin, Kentaro; Iwamaru, Yoshifumi; Yokoyama, Takashi

2015-01-01

Disease-related prion protein (PrP(Sc)), which is a structural isoform of the host-encoded cellular prion protein, is thought to be a causative agent of transmissible spongiform encephalopathies. However, the specific role of PrP(Sc) in prion pathogenesis and its relationship to infectivity remain controversial. A time-course study of prion-affected mice was conducted, which showed that the prion infectivity was not simply proportional to the amount of PrP(Sc) in the brain. Centrifugation (20,000 ×g) of the brain homogenate showed that most of the PrP(Sc) was precipitated into the pellet, and the supernatant contained only a slight amount of PrP(Sc). Interestingly, mice inoculated with the obtained supernatant showed incubation periods that were approximately 15 d longer than those of mice inoculated with the crude homogenate even though both inocula contained almost the same infectivity. Our results suggest that a small population of fine PrP(Sc) may be responsible for prion infectivity and that large, aggregated PrP(Sc) may contribute to determining prion disease duration.

L-Arginine ethylester enhances in vitro amplification of PrP(Sc) in macaques with atypical L-type bovine spongiform encephalopathy and enables presymptomatic detection of PrP(Sc) in the bodily fluids.

Science.gov (United States)

Murayama, Y; Ono, F; Shimozaki, N; Shibata, H

2016-02-12

Protease-resistant, misfolded isoforms (PrP(Sc)) of a normal cellular prion protein (PrP(C)) in the bodily fluids, including blood, urine, and saliva, are expected to be useful diagnostic markers of prion diseases, and nonhuman primate models are suited for performing valid diagnostic tests for human Creutzfeldt-Jakob disease (CJD). We developed an effective amplification method for PrP(Sc) derived from macaques infected with the atypical L-type bovine spongiform encephalopathy (L-BSE) prion by using mouse brain homogenate as a substrate in the presence of polyanions and L-arginine ethylester. This method was highly sensitive and detected PrP(Sc) in infected brain homogenate diluted up to 10(10) by sequential amplification. This method in combination with PrP(Sc) precipitation by sodium phosphotungstic acid is capable of amplifying very small amounts of PrP(Sc) contained in the cerebrospinal fluid (CSF), saliva, urine, and plasma of macaques that have been intracerebrally inoculated with the L-BSE prion. Furthermore, PrP(Sc) was detectable in the saliva or urine samples as well as CSF samples obtained at the preclinical phases of the disease. Thus, our novel method may be useful for furthering the understanding of bodily fluid leakage of PrP(Sc) in nonhuman primate models. Copyright © 2016 Elsevier Inc. All rights reserved.

SC tuning fork

CERN Document Server

The tuning fork used to modulate the radiofrequency system of the synchro cyclotron (SC) from 1957 to 1973. This piece is an unused spare part. The SC was the 1st accelerator built at CERN. It operated from August 1957 until it was closed down at the end of 1990. In the SC the magnetic field did not change with time, and the particles were accelerated in successive pulses by a radiofrequency voltage of some 20kV which varied in frequency as they spiraled outwards towards the extraction radius. The frequency varied from 30MHz to about 17Mz in each pulse. The tuning fork vibrated at 55MHz in vacuum in an enclosure which formed a variable capacitor in the tuning circuit of the RF system, allowing the RF to vary over the appropriate range to accelerate protons from the centre of the macine up to 600Mev at extraction radius. In operation the tips of the tuning fork blade had an amplitude of movement of over 1 cm. The SC accelerator underwent extensive improvements from 1973 to 1975, including the installation of a...

An approach for establishing the performance maps of the sc-CO_2 compressor: Development and qualification by means of CFD simulations

International Nuclear Information System (INIS)

Pham, H.S.; Alpy, N.; Ferrasse, J.H.; Boutin, O.; Tothill, M.; Quenaut, J.; Gastaldi, O.; Cadiou, T.; Saez, M.

2016-01-01

Highlights: • Ability of CFD to predict the performance of a sc-CO_2 test compressor is shown. • Risk of vapor pockets occurrence inside a scale 1:1 compressor is highlighted. • Limitation of previous performance maps approaches to model the real gas behavior is shown. • A performance maps approach for the sc-CO_2 compressor is proposed and validated. - Abstract: One of the challenges in the performance prediction of the supercritical CO_2 (sc-CO_2) compressor is the real gas behavior of the working fluid near the critical point. This study deals with the establishment of an approach that allows coping with this particularity by dressing compressor performance maps in adequate reduced coordinates (i.e., suitable dimensionless speed and flow parameters inputs and pressure ratio and enthalpy rise outputs), while using CFD for its validation. Two centrifugal compressor designs have been considered in this work. The first one corresponds to a 6 kW small scale component implemented in a test loop at Tokyo Institute of Technology. The second one corresponds to a 38 MW scale 1:1 design considered at an early stage of a project that investigates sc-CO_2 cycle for a Small Modular Reactor application. Numerical results on the former have been successfully confronted with the experimental data to qualify the ability of CFD to provide a performance database. Results on the latter have revealed a significant decrease in the static temperature and pressure during flow acceleration along the leading edge of the impeller blades. In this line, the increased risk of vapor pockets appearance inside a sc-CO_2 compressor has been highlighted and recommendations regarding the choice of the on-design inlet conditions and the compressor design have been given to overcome this concern. CFD results on the scale 1:1 compressor have then been used to evaluate the relevancy of some previous performance maps approaches for a sc-CO_2 compressor application. These include the conventional

Antioxidant Activity of Essential Oil Extracted by SC-CO2 from Seeds of Trachyspermum ammi

Directory of Open Access Journals (Sweden)

Aarti Singh

2017-07-01

Full Text Available Bcakground: Extracts obtained from natural sources such as plants are of immense importance for humans. Methods: Therefore this study was conducted to obtain essential oil from the seeds of T. ammi by conventional and non-conventional methods. Hydrodistillation (HD, Solvent Extraction (SE, Ultrasonication (US, and Supercritical Carbon-dioxide (SC-CO2 extraction techniques were used to extract essential oil from the powdered seeds of T. ammi. A quality control method for each extracted oil was developed using HPTLC, FTIR, and GC-MS. The optimization process was carried out using fractional factorial design (FFD under which three parameters were considered: pressure (150, 175, and 300 bar, temperature (25, 30, and 40 °C, and CO2 flow rate (5, 10, 15 g/min. Results: The yield of essential oil obtained from the HD, SE, US, and SC-CO2 methods were 1.20%, 1.82%, 2.30%, and 2.64% v/w, respectively. Antioxidant activity was determined by the DPPH and superoxide scavenging methods and the IC50 (Inhibition Concentration values of the T. ammi oil sample were found to be 36.41 and 20.55 µg mL−1, respectively. Conclusion: The present paper reported that different extraction methods lead to different yields of essential oils and the choice of a suitable method is extremely important to obtain more preferred compounds. The yield was higher in the SC-CO2 method and it is a sustainable and green extraction technique. Many important constituents were detected in analytical techniques. Antioxidant activities carried out showed that essential oil extracted from T. ammi seeds possess significant antioxidant activity.

Antioxidant Activity of Essential Oil Extracted by SC-CO2 from Seeds of Trachyspermum ammi

Science.gov (United States)

Singh, Aarti; Ahmad, Anees

2017-01-01

Bcakground: Extracts obtained from natural sources such as plants are of immense importance for humans. Methods: Therefore this study was conducted to obtain essential oil from the seeds of T. ammi by conventional and non-conventional methods. Hydrodistillation (HD), Solvent Extraction (SE), Ultrasonication (US), and Supercritical Carbon-dioxide (SC-CO2) extraction techniques were used to extract essential oil from the powdered seeds of T. ammi. A quality control method for each extracted oil was developed using HPTLC, FTIR, and GC-MS. The optimization process was carried out using fractional factorial design (FFD) under which three parameters were considered: pressure (150, 175, and 300 bar), temperature (25, 30, and 40 °C), and CO2 flow rate (5, 10, 15 g/min). Results: The yield of essential oil obtained from the HD, SE, US, and SC-CO2 methods were 1.20%, 1.82%, 2.30%, and 2.64% v/w, respectively. Antioxidant activity was determined by the DPPH and superoxide scavenging methods and the IC50 (Inhibition Concentration) values of the T. ammi oil sample were found to be 36.41 and 20.55 µg mL−1, respectively. Conclusion: The present paper reported that different extraction methods lead to different yields of essential oils and the choice of a suitable method is extremely important to obtain more preferred compounds. The yield was higher in the SC-CO2 method and it is a sustainable and green extraction technique. Many important constituents were detected in analytical techniques. Antioxidant activities carried out showed that essential oil extracted from T. ammi seeds possess significant antioxidant activity. PMID:28930268

XAFS Analysis of Local Structure around Ce in Ca3Sc2Si3O12:Ce Phosphor for White LEDs

International Nuclear Information System (INIS)

Akai, Toshio; Shigeiwa, Motoyuki; Okamoto, Kaoru; Shimomura, Yasuo; Kijima, Naoto; Honma, Tetsuo

2007-01-01

We have studied the local structure around Ce atom in Ca3Sc2Si3O12 host crystal, which has been developed as a new green phosphor for white light emitting diodes (LEDs). As the local structure and chemical environment of the dopant atom are very important to improve the performance of the phosphor, we have used XAFS to get chemical and structural information around the Ce dopant. The XANES spectrum of the Ce LIII-edge reveals that the Ce atom is trivalent in Ca3Sc2Si3O12. There are two kinds of possible Ce substitution sites, Ca site and Sc site, in garnet type Ca3Sc2Si3O12 crystal structure. The Ce atom is found to be at the Ca site in the host crystal by the comparison of the Fourier transform of Ce K-edge EXAFS spectrum with those of Ca and Sc K-edge EXAFS spectra. The theoretical analysis with FEFF also clarified the Ce substitution at the Ca site. Furthermore, the result of the analysis indicates the structural disorder around Ca and Si atoms at 3.75 A. It is possible that there are some defects around the Ca and Si atoms at 3.75 A to compensate the excess positive charge by introduced Ce3+ at the Ca2+ site

Neutral hydrogen in the stellar accociation Scorpius OB-2

Energy Technology Data Exchange (ETDEWEB)

Bystrova, N.V.

1979-01-01

The distribution of neutral hydrogen connected with the stellar association Scorpius OB-2 is more complex than the expanding semienvelope suggested earlier. The neutral gas is in connection with the nebulae S1, S7, S9 and with H/sub ..cap alpha../-filaments found in the association and giving it the appearence of a spiral galaxy. The HI-distribution is in disagreement with the model of a supernova remnant.

Characterization of semi-solid processing of aluminium alloy 7075 with Sc and Zr additions

Energy Technology Data Exchange (ETDEWEB)

Rogal, Ł., E-mail: l.rogal@imim.pl [Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); Dutkiewicz, J. [Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); Atkinson, H.V. [The University of Leicester, Department of Engineering University Road, Leicester, LE1 7RH (United Kingdom); Lityńska-Dobrzyńska, L.; Czeppe, T. [Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); Modigell, M. [RWTH Aachen—Department of Mechanical Process Engineering, 55 Templergraben St., Aachen (Germany)

2013-09-15

For thixoforming (semi-solid processing) it is necessary to have a fine globular microstructure in a semi-solid range. Here this has been obtained for 7075 aluminium alloy by addition of modifying agents: 0.5 weight % of scandium and zirconium. The thixoforming process was carried out at 632 °C which gave about 23 volume % of liquid phase. The microstructure of the thixo-formed part (a rotor) consisted of globular grains surrounded by precipitates of secondary phase. The average hardness of thixo-formed parts was 105 HV{sub 5} and the tensile strength 300 MPa. T6 heat treatments were performed with solutionisation at 450 °C for 30 min and 10 h. In both cases the ageing time was set as 18 h at 120 °C. The heat treatments led to an increase in average tensile strength up to 495 MPa. Transmission Electron Microscopy (TEM) analysis enabled the identification of precipitates of the metastable dispersoids of L1{sub 2}–Al{sub 3} (Zr, Sc) and η′ (MgZn{sub 2}) phases in the alloy after the thixoforming and T6 treatment. The measurements of rheological properties of 7075Al alloy with Sc and Zr additions in the semi-solid range indicated an increase of particle size and spheroidization leading to an observable decrease of viscosity during isothermal shearing. A shear rate jump experiment showed that with increasing shear rate the viscosity rapidly falls.

Phase diagram of (Li(1-x)Fe(x))OHFeSe: a bridge between iron selenide and arsenide superconductors.

Science.gov (United States)

Dong, Xiaoli; Zhou, Huaxue; Yang, Huaixin; Yuan, Jie; Jin, Kui; Zhou, Fang; Yuan, Dongna; Wei, Linlin; Li, Jianqi; Wang, Xinqiang; Zhang, Guangming; Zhao, Zhongxian

2015-01-14

Previous experimental results have shown important differences between iron selenide and arsenide superconductors which seem to suggest that the high-temperature superconductivity in these two subgroups of iron-based families may arise from different electronic ground states. Here we report the complete phase diagram of a newly synthesized superconducting (SC) system, (Li1-xFex)OHFeSe, with a structure similar to that of FeAs-based superconductors. In the non-SC samples, an antiferromagnetic (AFM) spin-density-wave (SDW) transition occurs at ∼127 K. This is the first example to demonstrate such an SDW phase in an FeSe-based superconductor system. Transmission electron microscopy shows that a well-known √5×√5 iron vacancy ordered state, resulting in an AFM order at ∼500 K in AyFe2-xSe2 (A = metal ions) superconductor systems, is absent in both non-SC and SC samples, but a unique superstructure with a modulation wave vector q = (1)/2(1,1,0), identical to that seen in the SC phase of KyFe2-xSe2, is dominant in the optimal SC sample (with an SC transition temperature Tc = 40 K). Hence, we conclude that the high-Tc superconductivity in (Li1-xFex)OHFeSe stems from the similarly weak AFM fluctuations as FeAs-based superconductors, suggesting a universal physical picture for both iron selenide and arsenide superconductors.

CO2-neutral fuels

Directory of Open Access Journals (Sweden)

Goede A. P. H.

2015-01-01

Full Text Available The need for storage of renewable energy (RE generated by photovoltaic, concentrated solar and wind arises from the fact that supply and demand are ill-matched both geographically and temporarily. This already causes problems of overcapacity and grid congestion in countries where the fraction of RE exceeds the 20% level. A system approach is needed, which focusses not only on the energy source, but includes conversion, storage, transport, distribution, use and, last but not least, the recycling of waste. Furthermore, there is a need for more flexibility in the energy system, rather than relying on electrification, integration with other energy systems, for example the gas network, would yield a system less vulnerable to failure and better adapted to requirements. For example, long-term large-scale storage of electrical energy is limited by capacity, yet needed to cover weekly to seasonal demand. This limitation can be overcome by coupling the electricity net to the gas system, considering the fact that the Dutch gas network alone has a storage capacity of 552 TWh, sufficient to cover the entire EU energy demand for over a month. This lecture explores energy storage in chemicals bonds. The focus is on chemicals other than hydrogen, taking advantage of the higher volumetric energy density of hydrocarbons, in this case methane, which has an approximate 3.5 times higher volumetric energy density. More importantly, it allows the ready use of existing gas infrastructure for energy storage, transport and distribution. Intermittent wind electricity generated is converted into synthetic methane, the Power to Gas (P2G scheme, by splitting feedstock CO2 and H2O into synthesis gas, a mixture of CO and H2. Syngas plays a central role in the synthesis of a range of hydrocarbon products, including methane, diesel and dimethyl ether. The splitting is accomplished by innovative means; plasmolysis and high-temperature solid oxygen electrolysis. A CO2-neutral fuel

Supercritical SC-CO2 and Soxhlet n-Hexane Extract of Tunisian Opuntia ficus indica Seeds and Fatty Acids Analysis

OpenAIRE

Nizar Yeddes; Jamila Kalthoum Chérif; Amel Jrad; Danielle Barth; Malika Trabelsi-Ayadi

2012-01-01

The fatty acids profiles of Tunisian Opuntia ficus indica seeds (spiny and thornless form) were investigated. Results of supercritical carbon dioxide (SC-CO2) and soxhlet n-hexane extract were compared. Quantitatively, the better yield was obtained through soxhlet n-hexane: 10.32% (spiny) and 8.91% (thornless) against 3.4% (spiny) and 1.94% (thornless) by SC-CO2 extract (T = 40°C, P=180 bar, time = 135 mn, CO2 flow rate = 15 mL·s−1). Qualitatively, the main fatty acids components were the sam...

Phase separation in Al-Zr-Sc alloys: from atomic jumps to ordered precipitates growth; Separation de phase dans les alliages Al-Zr-Sc: du saut des atomes a la croissance de precipites ordonnes

Energy Technology Data Exchange (ETDEWEB)

Clouet, E

2004-07-01

Zirconium and scandium addition to aluminium alloys leads to the formation of ordered precipitates. This study aims to a better understanding of precipitation kinetics thanks to an approach combining atomic and mesoscopic models. An experimental work has been undertaken too so as to characterize by transmission electron microscopy Al{sub 3}Zr kinetics of precipitation. We mainly focus on the nucleation stage and, in this purpose, an atomic model lying on a rigid lattice has been built for Al-Zr-Sc system allowing us to study precipitation with kinetic Monte Carlo simulations. While keeping the vacancy exchange mechanism for diffusion, we introduce multi-site interactions going thus beyond a simple pair interaction model, and test the influence of these interactions on kinetics of precipitation. The comparison between Monte Carlo simulations and classical nucleation theory shows that mesoscopic models can lead to a good description of the nucleation stage of Al{sub 3}Zr and Al{sub 3}Sc as long as the order tendency of the system has been taken into account to calculate input parameters of these models. For the ternary Al-Zr-Sc system, atomic simulations allow a better understanding of the precipitation kinetic path. It is then possible to extend the field of classical nucleation theory so as to model nucleation in a ternary alloy where the stoichiometry of the precipitates is unknown. (author)

Establishment and characterization of Roberts syndrome and SC phocomelia model medaka (Oryzias latipes).

Science.gov (United States)

Morita, Akihiro; Nakahira, Kumiko; Hasegawa, Taeko; Uchida, Kaoru; Taniguchi, Yoshihito; Takeda, Shunichi; Toyoda, Atsushi; Sakaki, Yoshiyuki; Shimada, Atsuko; Takeda, Hiroyuki; Yanagihara, Itaru

2012-06-01

Roberts syndrome and SC phocomelia (RBS/SC) are genetic autosomal recessive syndromes caused by establishment of cohesion 1 homolog 2 ( ESCO 2) mutation. RBS/SC appear to have a variety of clinical features, even with the same mutation of the ESCO2 gene. Here, we established and genetically characterized a medaka model of RBS/SC by reverse genetics. The RBS/SC model was screened from a mutant medaka library produced by the Targeting Induced Local Lesions in Genomes method. The medaka mutant carrying the homozygous mutation at R80S in the conserved region of ESCO2 exhibited clinical variety (i.e. developmental arrest with craniofacial and chromosomal abnormalities and embryonic lethality) as characterized in RBS/SC. Moreover, widespread apoptosis and downregulation of some gene expression, including notch1a, were detected in the R80S mutant. The R80S mutant is the animal model for RBS/SC and a valuable resource that provides the opportunity to extend knowledge of ESCO2. Downregulation of some gene expression in the R80S mutant is an important clue explaining non-correlation between genotype and phenotype in RBS/SC. © 2012 The Authors Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

LIAD-fs: A novel method for studies of ultrafast processes in gas phase neutral biomolecules

International Nuclear Information System (INIS)

Calvert, C R; Kelly, O; Duffy, M J; Belshaw, L; King, R B; Williams, I D; Greenwood, J B

2012-01-01

A new experimental technique for femtosecond (fs) pulse studies of gas phase biomolecules is reported. Using Laser-Induced Acoustic Desorption (LIAD) to produce a plume of neutral molecules, a time-delayed fs pulse is employed for ionisation/fragmentation, with subsequent products extracted and mass analysed electrostatically. By varying critical laser pulse parameters, this technique can be used to implement control over molecular fragmentation for a range of small biomolecules, with specific studies of amino acids demonstrated.

Possible indicators for low dimensional superconductivity in the quasi-1D carbide Sc{sub 3}CoC{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Scheidt, E-W; Hauf, C; Reiner, F; Eickerling, G; Scherer, W, E-mail: Ernst-Wilhelm.Scheidt@physik.uni-augsburg.de [CPM, Institut fuer Physik, Universitaet Augsburg, 86159 Augsburg (Germany)

2011-01-01

The transition metal carbide Sc{sub 3}CoC{sub 4} consists of a quasi-one-dimensional (1D) structure with [CoC{sub 4}]{sub {infinity}} polyanionic chains embedded in a scandium matrix. At ambient temperatures Sc{sub 3}CoC{sub 4} displays metallic behavior. At lower temperatures, however, charge density wave formation has been observed around 143 K which is followed by a structural phase transition at 72 K. Below T{sub c}{sup onset} = 4.5 K the polycrystalline sample becomes superconductive. From H{sub c1}(0) and H{sub c2}(0) values we could estimate the London penetration depth ({lambda}{sub L} {approx_equal} 9750 A) and the Ginsburg-Landau (GL) coherence length ({xi}{sub GL} {approx_equal} 187 A). The resulting GL-parameter ({kappa} {approx_equal} 52) classifies Sc{sub 3}CoC{sub 4} as a type II superconductor. Here we compare the puzzling superconducting features of Sc{sub 3}CoC{sub 4}, such as the unusual temperature dependence i) of the specific heat anomaly and ii) of the upper critical field H{sub c2}(T) at T{sub c}, and iii) the magnetic hysteresis curve, with various related low dimensional superconductors: e.g., the quasi-1D superconductor (SN){sub x} or the 2D transition-metal dichalcogenides. Our results identify Sc{sub 3}CoC{sub 4} as a new candidate for a quasi-1D superconductor.

Valence electron structure analysis of refining mecha-nism of Sc and Ti additions on aluminum

Institute of Scientific and Technical Information of China (English)

LI PieJie; YE YiCong; HE LiangJu

2009-01-01

The mechanism of the difference of refining effect between Sc and Ti adding to aluminum can not be explained substantially with traditional theory. Valence electron structures of AI-Ti and Al-Sc alloys have been studied by using the empirical electron theory of solids and molecules (EET). The covalent bond electron numbers and interfacial electron density differences are calculated. The conclusion is that, in the two alloys, different covalent bond electron numbers of nucleation particles, and different electron densities on the interface between the second phase particles and the matrix, fundamentally lead to the difference of refining effect between Sc and Ti adding to aluminum.

Gas-Phase Energetics of Actinide Oxides: An Assessment of Neutral and Cationic Monoxides and Dioxides from Thorium to Curium

Science.gov (United States)

Marçalo, Joaquim; Gibson, John K.

2009-09-01

An assessment of the gas-phase energetics of neutral and singly and doubly charged cationic actinide monoxides and dioxides of thorium, protactinium, uranium, neptunium, plutonium, americium, and curium is presented. A consistent set of metal-oxygen bond dissociation enthalpies, ionization energies, and enthalpies of formation, including new or revised values, is proposed, mainly based on recent experimental data and on correlations with the electronic energetics of the atoms or cations and with condensed-phase thermochemistry.

Compact Stars with Sequential QCD Phase Transitions

Science.gov (United States)

Alford, Mark; Sedrakian, Armen

2017-10-01

Compact stars may contain quark matter in their interiors at densities exceeding several times the nuclear saturation density. We explore models of such compact stars where there are two first-order phase transitions: the first from nuclear matter to a quark-matter phase, followed at a higher density by another first-order transition to a different quark-matter phase [e.g., from the two-flavor color-superconducting (2SC) to the color-flavor-locked (CFL) phase]. We show that this can give rise to two separate branches of hybrid stars, separated from each other and from the nuclear branch by instability regions, and, therefore, to a new family of compact stars, denser than the ordinary hybrid stars. In a range of parameters, one may obtain twin hybrid stars (hybrid stars with the same masses but different radii) and even triplets where three stars, with inner cores of nuclear matter, 2SC matter, and CFL matter, respectively, all have the same mass but different radii.

Compatibilities of YBa2Cu3O(9-delta) type phase in quintenary systems Y-Ba-Cu-O-X (impurity)

Science.gov (United States)

Karen, P.; Braaten, O.; Fjellvag, H.; Kjekshus, A.

1991-01-01

Isothermal phase diagrams at various oxygen pressures were studied by powder diffraction and chemical analytical methods. The components, Y, Ba, Cu, and O (specifically O2, O2-, and O2 sup 2-) are treated, together with C (specifically CO2 and CO2 sup 2-), alkaline metals, Mg, alkaline earths, Sc, 3-d and 4-f elements. Effects of the substitutions at the structural sites of YBa2Cu3O(9-delta) on T sub c are discussed with respect to changes in crystallochemical characteristics of the substituted phase and to the nature of the substituents.

Compatibilities of YBa2Cu3O(9-delta)-type phase in quintenary systems Y-Ba-Cu-O-X (impurity)

International Nuclear Information System (INIS)

Karen, P.; Braaten, O.; Fjellvag, H.; Kjekshus, A.

1991-01-01

Isothermal phase diagrams at various oxygen pressures were studied by powder diffraction and chemical analytical methods. The components, Y, Ba, Cu, and O (specifically O2, O2-, and O2 sup 2-) are treated, together with C (specifically CO2 and CO2 sup 2-), alkaline metals, Mg, alkaline earths, Sc, 3-d and 4-f elements. Effects of the substitutions at the structural sites of YBa2Cu3O(9-delta) on T sub c are discussed with respect to changes in crystallochemical characteristics of the substituted phase and to the nature of the substituents

Structural, electrical and magnetic properties of Sc{sup 3+} doped Mn-Zn ferrite nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Angadi, V. Jagdeesha [Department of Physics, Bangalore University, Bangalore 560056 (India); Choudhury, Leema [Department of Physics, K.G. Reddy College of Engineering & Technology, Moinabad, 501504 Ranga Reddy, Telangana (India); Sadhana, K. [Department of Physics, University College of Science, Osmania University, Saifabad, Hyderabad 500004 (India); Liu, Hsiang-Lin [Department of Physics, National Taiwan Normal University, Taipei 11677, Taiwan (China); Sandhya, R. [Department of Physics, University College of Science, Osmania University, Hyderabad 500007 (India); Matteppanavar, Shidaling; Rudraswamy, B.; Pattar, Vinayak; Anavekar, R.V. [Department of Physics, Bangalore University, Bangalore 560056 (India); Praveena, K., E-mail: praveenaou@gmail.com [Department of Physics, National Taiwan Normal University, Taipei 11677, Taiwan (China)

2017-02-15

Sc{sup 3+} doped Mn{sub 0.5}Zn{sub 0.5}Sc{sub y}Fe{sub 2−y}O{sub 4} (y=0.00, 0.01, 0.03 and 0.05) nanoparticles were synthesized by solution combustion method using mixture of fuels were reported for the first time. The mixture of fuels plays an important role in obtaining nano crystalline, single phase present without any heat treatment. X-ray diffraction (XRD) results confirm the formation of the single-phase ferrites which crystallize in cubic spinel structure. The Fourier transform infrared spectra (FTIR) exhibit two prominent bands around 360 cm{sup −1} and 540 cm{sup −1} which are characteristic feature of spinel ferrite. The transmission electron microscope (TEM) micrographs revealed the nanoparticles to be nearly spherical in shape and of fairly uniform size. The room temperature impedance spectra (IS) and vibrating sample magnetometry (VSM) measurements were carried out in order to study the effect of doping (Sc{sup 3+}) on the characteristic properties of Mn-Zn ferrites. Further, the frequency dependent dielectric constant and dielectric loss were found to decrease with increasing multiple Sc{sup 3+} concentration. Nyquist plot in the complex impedance spectra suggest the existence of multiple electrical responses. Magnetic measurements reveals that saturation magnetization (M{sub s}), remnant magnetization (M{sub r}), magnetic moment (η{sub B}) and magnetic particle size (D{sub m}) increase with Sc{sup 3+} ion concentration up to x=0.03 and then decrease. The values of spin canting angle (α{sub Y-K}) and the magnetic particle size (D{sub m}) are found to be in the range of 68–75° and 10–19 nm respectively with Sc{sup 3+} concentration. The room temperature Mössbauer spectra were fitted with two sextets corresponding to ions at tetrahedral (A-) and octahedral (B-) sites confirms the spinel lattice. The ferromagnetic resonance (FMR) spectra's has shown that high concentration of scandium doping leads to an increase in dipolar interaction

Ionic conductivity ageing behaviour of 10 mol.% Sc2O3–1 mol.% CeO2–ZrO2 ceramics

DEFF Research Database (Denmark)

Omar, Shobit; Bonanos, Nikolaos

2010-01-01

The long-term ionic conductivity behaviour of samples of zirconia co-doped with 10 mol.% of Sc2O3 and 1 mol.% CeO2 is evaluated in oxidizing and reducing atmospheres at 600 °C. After 3,000 h, the sample kept in reducing atmospheres exhibits 20% loss in the ionic conductivity, while the sample kep...

Combustion synthesis of CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors in a closed system

Energy Technology Data Exchange (ETDEWEB)

Peng Wenfang; Zou Shaoyu; Liu Guanxi; Xiao Quanlan; Zhang Rui; Xie Lijuan; Cao Liwei [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Meng Jianxin, E-mail: tmjx@jnu.edu.cn [Institute of Nano-Chemistry, Jinan University, Guangzhou 510632 (China); Liu Yingliang [Institute of Nano-Chemistry, Jinan University, Guangzhou 510632 (China)

2011-06-09

Highlights: > CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors can be prepared by a single-step combustion method. > The ignition temperature is the lowest in the combustion synthesis of Ce{sup 3+}/Eu{sup 2+} doped phosphors. > The as-prepared nano-phosphors give a uniform particle size in the range of 15-20 nm and have highly dispersity and fluorescence intensity. > It is a convenient method for preparation of monodispersed oxide nano-phosphors, especially those being sensitive to air at high temperature. - Abstract: The CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors were successfully prepared by a single-step combustion method at an ignition temperature as low as 200 deg. C in a closed autoclave using glycine as a fuel and PEG4000 as a dispersant. The samples were characterized by X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscope (TEM). The results revealed that CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors can be conveniently prepared at an ignition temperature as low as 200 deg. C, which was much lower than that in the ordinary combustion methods. The optimized ignition temperature was 220 deg. C. The CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors give a uniform particle size in the range of 15-20 nm. The low ignition temperature and the addition of PEG4000 dispersant play important roles in the formation of small sized nanoparticles. The as-prepared nano-phosphors were incompact aggregates, but highly dispersed nano-phosphors can be obtained after further ultrasonic treatment. The CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors give satisfactory luminescence characteristic benefiting from the closed circumstance, in which cerium atoms can be isolated from the oxidizing atmosphere and non-fluorescent Ce{sup 4+} ions can be ruled out. The present highly dispersed CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors with efficient fluorescence are promising in the field of biological labeling

Experimental and theoretical investigation of Cr_1-xSc_xN solid solutions for thermoelectrics

DEFF Research Database (Denmark)

Kerdsongpanya, Sit; Sun, Bo; Eriksson, Fredrik

2016-01-01

The ScN- and CrN-based transition-metal nitrides have recently emerged as a novel and unexpected class of materials for thermoelectrics. These materials constitute well-defined model systems for investigating mixing thermodynamics, phase stability, and band structure aiming for property tailoring......-factor improvement by Sc3d orbital delocalization on Cr3d electrons giving decreasing electrical resistivity, while localized Cr3d orbitals with a large DOS slope may yield an improved Seebeck coefficient. Sc-rich solid solutions show a large improvement in power factor compared to pure ScN, and all films have power...

Sc-Decorated Porous Graphene for High-Capacity Hydrogen Storage: First-Principles Calculations

Directory of Open Access Journals (Sweden)

Yuhong Chen

2017-08-01

Full Text Available The generalized gradient approximation (GGA function based on density functional theory is adopted to investigate the optimized geometrical structure, electron structure and hydrogen storage performance of Sc modified porous graphene (PG. It is found that the carbon ring center is the most stable adsorbed position for a single Sc atom on PG, and the maximum number of adsorbed H2 molecules is four with the average adsorption energy of −0.429 eV/H2. By adding a second Sc atom on the other side of the system, the hydrogen storage capacity of the system can be improved effectively. Two Sc atoms located on opposite sides of the PG carbon ring center hole is the most suitable hydrogen storage structure, and the hydrogen storage capacity reach a maximum 9.09 wt % at the average adsorption energy of −0.296 eV/H2. The adsorption of H2 molecules in the PG system is mainly attributed to orbital hybridization among H, Sc, and C atoms, and Coulomb attraction between negatively charged H2 molecules and positively charged Sc atoms.

Ab initio study of the EFG tensor at Cd impurities in Sc2O3 semiconductor

International Nuclear Information System (INIS)

Munoz, E.L.; Richard, D.; Errico, L.A.; Renteria, M.

2009-01-01

We present an ab initio study of diluted Cd impurities localized at both cation sites of the semiconductor Sc 2 O 3 . The electric-field-gradient (EFG) tensor at Cd impurities located at both cationic sites of the host structure was determined from the calculation of the electronic structure of the doped system. Calculations were performed with the full-potential augmented-plane wave plus local orbitals (APW+lo) method within the framework of the density functional theory. We studied the atomic structural relaxations and the perturbation of the electronic charge density induced by the impurities in the host system in a fully self-consistent way. We showed that the Cd impurity introduces an increase of 8% in the nearest oxygen neighbors bond-lengths, changing the EFG sign for probes located at the asymmetric cation site. The APW+lo predictions for the charged state of the Cd impurity were compared with EFG results existent in the literature, coming from time-differential γ-γ perturbed-angular-correlations experiments performed on 111 Cd-implanted Sc 2 O 3 powder samples. From the excellent agreement between theory and experiment, we can strongly suggest that the Cd acceptor impurities are ionized at room temperature. Finally, we showed that simple calculations like those performed within the point-charge model with antishielding factors do not correctly describe the problem of a Cd impurity in Sc 2 O 3 .

PET imaging of 64Cu-DOTA-scFv-anti-PSMA lipid nanoparticles (LNPs): Enhanced tumor targeting over anti-PSMA scFv or untargeted LNPs

International Nuclear Information System (INIS)

Wong, Patty; Li, Lin; Chea, Junie; Delgado, Melissa K.; Crow, Desiree; Poku, Erasmus; Szpikowska, Barbara; Bowles, Nicole; Channappa, Divya; Colcher, David; Wong, Jeffrey Y.C.; Shively, John E.; Yazaki, Paul J.

2017-01-01

Introduction: Single chain (scFv) antibodies are ideal targeting ligands due to their modular structure, high antigen specificity and affinity. These monovalent ligands display rapid tumor targeting but have limitations due to their fast urinary clearance. Methods: An anti-prostate membrane antigen (PSMA) scFv with a site-specific cysteine was expressed and evaluated in a prostate cancer xenograft model by Cu-64 PET imaging. To enhance tumor accumulation, the scFv-cys was conjugated to the co-polymer DSPE-PEG-maleimide that spontaneously assembled into a homogeneous multivalent lipid nanoparticle (LNP). Results: The targeted LNP exhibited a 2-fold increase in tumor uptake compared to the scFv alone using two different thiol ester chemistries. The anti-PSMA scFv-LNP exhibited a 1.6 fold increase in tumor targeting over the untargeted LNP. Conclusions: The targeted anti-PSMA scFv-LNP showed enhanced tumor accumulation over the scFv alone or the untargeted DOTA-micelle providing evidence for the development of this system for drug delivery. Advances in knowledge and implications for patient care: Anti-tumor scFv antibody fragments have not achieved their therapeutic potential due to their fast blood clearance. Conjugation to an LNP enables multivalency to the tumor antigen as well as increased molecular size for chemotherapy drug delivery.

A cancer specific cell-penetrating peptide, BR2, for the efficient delivery of an scFv into cancer cells.

Directory of Open Access Journals (Sweden)

Ki Jung Lim

Full Text Available Cell-penetrating peptides (CPPs have proven very effective as intracellular delivery vehicles for various therapeutics. However, there are some concerns about non-specific penetration and cytotoxicity of CPPs for effective cancer treatments. Herein, based on the cell-penetrating motif of an anticancer peptide, buforin IIb, we designed several CPP derivatives with cancer cell specificity. Among the derivatives, a 17-amino acid peptide (BR2 was found to have cancer-specificity without toxicity to normal cells. After specifically targeting cancer cells through interaction with gangliosides, BR2 entered cells via lipid-mediated macropinocytosis. Moreover, BR2 showed higher membrane translocation efficiency than the well-known CPP Tat (49-57. The capability of BR2 as a cancer-specific drug carrier was demonstrated by fusion of BR2 to a single-chain variable fragment (scFv directed toward a mutated K-ras (G12V. BR2-fused scFv induced a higher degree of apoptosis than Tat-fused scFv in K-ras mutated HCT116 cells. These results suggest that the novel cell-penetrating peptide BR2 has great potential as a useful drug delivery carrier with cancer cell specificity.

A cancer specific cell-penetrating peptide, BR2, for the efficient delivery of an scFv into cancer cells.

Science.gov (United States)

Lim, Ki Jung; Sung, Bong Hyun; Shin, Ju Ri; Lee, Young Woong; Kim, Da Jung; Yang, Kyung Seok; Kim, Sun Chang

2013-01-01

Cell-penetrating peptides (CPPs) have proven very effective as intracellular delivery vehicles for various therapeutics. However, there are some concerns about non-specific penetration and cytotoxicity of CPPs for effective cancer treatments. Herein, based on the cell-penetrating motif of an anticancer peptide, buforin IIb, we designed several CPP derivatives with cancer cell specificity. Among the derivatives, a 17-amino acid peptide (BR2) was found to have cancer-specificity without toxicity to normal cells. After specifically targeting cancer cells through interaction with gangliosides, BR2 entered cells via lipid-mediated macropinocytosis. Moreover, BR2 showed higher membrane translocation efficiency than the well-known CPP Tat (49-57). The capability of BR2 as a cancer-specific drug carrier was demonstrated by fusion of BR2 to a single-chain variable fragment (scFv) directed toward a mutated K-ras (G12V). BR2-fused scFv induced a higher degree of apoptosis than Tat-fused scFv in K-ras mutated HCT116 cells. These results suggest that the novel cell-penetrating peptide BR2 has great potential as a useful drug delivery carrier with cancer cell specificity.

The ground-state phase diagrams of the spin-3/2 Ising model

International Nuclear Information System (INIS)

Canko, Osman; Keskin, Mustafa

2003-01-01

The ground-state spin configurations are obtained for the spin-3/2 Ising model Hamiltonian with bilinear and biquadratic exchange interactions and a single-ion crystal field. The interactions are assumed to be only between nearest-neighbors. The calculated ground-state phase diagrams are presented on diatomic lattices, such as the square, honeycomb and sc lattices, and triangular lattice in the (Δ/z vertical bar J vertical bar ,K/ vertical bar J vertical bar) and (H/z vertical bar J vertical bar, K/ vertical bar J vertical bar) planes

A tetrapositive metal ion in the gas phase: Thorium(IV) coordinated by neutral tridentate ligands

International Nuclear Information System (INIS)

Gong, Yu; Tian, Guoxin; Rao, Linfeng; Gibson, John K.; Hu, Han-Shi; Li, Jun

2013-01-01

Sheltering thorium ions: A Th 4+ ion supported by three neutral tetramethyl-3-oxaglutaramide ligands (L=TMOGA) is produced in the gas phase by electrospray ionization. The thorium in chiral Th(L) 3 4+ is coordinated by nine oxygen atoms. Quantum chemical studies revealed a decrease in Th-O binding energies and bond orders and an increase in bond lengths, as the number of coordinating ligands increases. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A tetrapositive metal ion in the gas phase: Thorium(IV) coordinated by neutral tridentate ligands

Energy Technology Data Exchange (ETDEWEB)

Gong, Yu; Tian, Guoxin; Rao, Linfeng; Gibson, John K. [Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Hu, Han-Shi [Department of Chemistry and Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Tsinghua University (China); Li, Jun [Department of Chemistry and Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Tsinghua University (China); William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory (United States)

2013-07-01

Sheltering thorium ions: A Th{sup 4+} ion supported by three neutral tetramethyl-3-oxaglutaramide ligands (L=TMOGA) is produced in the gas phase by electrospray ionization. The thorium in chiral Th(L){sub 3}{sup 4+} is coordinated by nine oxygen atoms. Quantum chemical studies revealed a decrease in Th-O binding energies and bond orders and an increase in bond lengths, as the number of coordinating ligands increases. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Status Update on the NCRP Scientific Committee SC 5-1 Report: Decision Making for Late-Phase Recovery from Nuclear or Radiological Incidents - 13450

International Nuclear Information System (INIS)

Chen, S.Y.

2013-01-01

In August 2008, the U.S. Department of Homeland Security (DHS) issued its final Protective Action Guide (PAG) for radiological dispersal device (RDD) and improvised nuclear device (IND) incidents. This document specifies protective actions for public health during the early and intermediate phases and cleanup guidance for the late phase of RDD or IND incidents, and it discusses approaches to implementing the necessary actions. However, while the PAG provides specific guidance for the early and intermediate phases, it prescribes no equivalent guidance for the late-phase cleanup actions. Instead, the PAG offers a general description of a complex process using a site-specific optimization approach. This approach does not predetermine cleanup levels but approaches the problem from the factors that would bear on the final agreed-on cleanup levels. Based on this approach, the decision-making process involves multifaceted considerations including public health, the environment, and the economy, as well as socio-political factors. In an effort to fully define the process and approach to be used in optimizing late-phase recovery and site restoration following an RDD or IND incident, DHS has tasked the NCRP with preparing a comprehensive report addressing all aspects of the optimization process. Preparation of the NCRP report is a three-year (2010-2013) project assigned to a scientific committee, the Scientific Committee (SC) 5-1; the report was initially titled, Approach to Optimizing Decision Making for Late- Phase Recovery from Nuclear or Radiological Terrorism Incidents. Members of SC 5-1 represent a broad range of expertise, including homeland security, health physics, risk and decision analysis, economics, environmental remediation and radioactive waste management, and communication. In the wake of the Fukushima nuclear accident of 2011, and guided by a recent process led by the White House through a Principal Level Exercise (PLE), the optimization approach has since

Status Update on the NCRP Scientific Committee SC 5-1 Report: Decision Making for Late-Phase Recovery from Nuclear or Radiological Incidents - 13450

Energy Technology Data Exchange (ETDEWEB)

Chen, S.Y. [Environmental Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

2013-07-01

In August 2008, the U.S. Department of Homeland Security (DHS) issued its final Protective Action Guide (PAG) for radiological dispersal device (RDD) and improvised nuclear device (IND) incidents. This document specifies protective actions for public health during the early and intermediate phases and cleanup guidance for the late phase of RDD or IND incidents, and it discusses approaches to implementing the necessary actions. However, while the PAG provides specific guidance for the early and intermediate phases, it prescribes no equivalent guidance for the late-phase cleanup actions. Instead, the PAG offers a general description of a complex process using a site-specific optimization approach. This approach does not predetermine cleanup levels but approaches the problem from the factors that would bear on the final agreed-on cleanup levels. Based on this approach, the decision-making process involves multifaceted considerations including public health, the environment, and the economy, as well as socio-political factors. In an effort to fully define the process and approach to be used in optimizing late-phase recovery and site restoration following an RDD or IND incident, DHS has tasked the NCRP with preparing a comprehensive report addressing all aspects of the optimization process. Preparation of the NCRP report is a three-year (2010-2013) project assigned to a scientific committee, the Scientific Committee (SC) 5-1; the report was initially titled, Approach to Optimizing Decision Making for Late- Phase Recovery from Nuclear or Radiological Terrorism Incidents. Members of SC 5-1 represent a broad range of expertise, including homeland security, health physics, risk and decision analysis, economics, environmental remediation and radioactive waste management, and communication. In the wake of the Fukushima nuclear accident of 2011, and guided by a recent process led by the White House through a Principal Level Exercise (PLE), the optimization approach has since

One-Step Partially Purified Lipases (ScLipA and ScLipB from Schizophyllum commune UTARA1 Obtained via Solid State Fermentation and Their Applications

Directory of Open Access Journals (Sweden)

Yew Chee Kam

2017-12-01

Full Text Available Lipases with unique characteristics are of value in industrial applications, especially those targeting cost-effectiveness and less downstream processes. The aims of this research were to: (i optimize the fermentation parameters via solid state fermentation (SSF; and (ii study the performance in hydrolysis and esterification processes of the one-step partially purified Schizophyllum commune UTARA1 lipases. Lipase was produced by cultivating S. commune UTARA1 on sugarcane bagasse (SB with used cooking oil (UCO via SSF and its production was optimized using Design-Expert® 7.0.0. Fractions 30% (ScLipA and 70% (ScLipB which contained high lipase activity were obtained by stepwise (NH42SO4 precipitation. Crude fish oil, coconut oil and butter were used to investigate the lipase hydrolysis capabilities by a free glycerol assay. Results showed that ScLipA has affinities for long, medium and short chain triglycerides, as all the oils investigated were degraded, whereas ScLipB has affinities for long chain triglycerides as it only degrades crude fish oil. During esterification, ScLipA was able to synthesize trilaurin and triacetin. Conversely, ScLipB was specific towards the formation of 2-mono-olein and triacetin. From the results obtained, it was determined that ScLipA and ScLipB are sn-2 regioselective lipases. Hence, the one-step partial purification strategy proved to be feasible for partial purification of S. commune UTARA1 lipases that has potential use in industrial applications.

A novel variable antibody fragment dimerized by leucine zippers with enhanced neutralizing potency against rabies virus G protein compared to its corresponding single-chain variable antibody fragment.

Science.gov (United States)

Li, Zhuang; Cheng, Yue; Xi, Hualong; Gu, Tiejun; Yuan, Ruosen; Chen, Xiaoxu; Jiang, Chunlai; Kong, Wei; Wu, Yongge

2015-12-01

Fatal rabies can be prevented effectively by post-exposure prophylactic (PEP) with rabies immunoglobulin (RIG). Single-chain variable fragments (scFv), which are composed of a variable heavy chain (VH) and a variable light chain (VL) connected by a peptide linker, can potentially be used to replace RIG. However, in our previous study, a scFv (scFV57S) specific for the rabies virus (RV) G protein showed a lower neutralizing potency than that of its parent IgG due to lower stability and altered peptide assembly pattern. In monoclonal antibodies, the VH and VL interact non-covalently, while in scFvs the VH is connected covalently with the VL by the artificial linker. In this study, we constructed and expressed two peptides 57VL-JUN-HIS and 57VH-FOS-HA in Escherichia coli. The well-known Fos and Jun leucine zippers were utilized to dimerize VH and VL similarly to the IgG counterpart. The two peptides assembled to form zipFv57S in vitro. Due to the greater similarity in structure with IgG, the zipFv57S protein showed a higher binding ability and affinity resulting in notable improvement of in vitro neutralizing activity over its corresponding scFv. The zipFv57S protein was also found to be more stable and showed similar protective rate as RIG in mice challenged with a lethal dose of RV. Our results not only indicated zipFv57S as an ideal alternative for RIG in PEP but also offered a novel and efficient hetero-dimerization pattern of VH and VL leading to enhanced neutralizing potency. Copyright © 2015. Published by Elsevier Ltd.

Study of positive parity levels in 41Ca and 41Sc: electromagnetic deexcitation of the 3/2 isospin states

International Nuclear Information System (INIS)

Fortier, Simone.

1976-01-01

The γ-decay of T=3/2 states in 41 Ca has been investigated by means of the 42 Ca( 3 He,αγ) 41 Ca reaction. Angular correlation measurements have been performed for γ-rays in coincidence with α particles emitted near 0 deg, and branching ratios extracted. The lowest T=3/2 level in 41 Sc (E=5,94MeV) has been excited as a resonance in the 40 Ca(p,γ) 41 Sc reaction, and radiative widths of γ-transitions were measured. The γ decay of the first T=3/2 level in 41 Sc is found to be quite similar to the one measured for the analog level in 41 Ca (E=5,92MeV), as it could be expected from corresponding ΔT=1 transitions in mirror nuclei. The M1 strengths are also compared with the ft values of β + transitions from the 41 Ti ground state. The orbital momentum part of the M1 operator is found to be important for three couples of γ-transition in 41 Ca and 41 Sc. These results suggest that the antianalog configuration could be in the ) 72.01-2.10MeV{ levels whereas the core-excited configurations (2 particles in the f7/2 shell coupled to J=1 and T=0 in the 74.09-4.25MeV{ levels and 74.73-4.77MeV{ levels. Experimental results are finally compared with the predictions of a shell model calculation performed for positive parity levels in A=41 nuclei, with 2 or 4 particles in the 1f7/2 shell and 1 or 3 holes in the 1d3/2 and 2s1/2 shells. )] [fr

The influence of supercritical carbon dioxide (SC-CO2) processing conditions on drug loading and physicochemical properties.

Science.gov (United States)

Ahern, Robert J; Crean, Abina M; Ryan, Katie B

2012-12-15

Poor water solubility of drugs can complicate their commercialisation because of reduced drug oral bioavailability. Formulation strategies such as increasing the drug surface area are frequently employed in an attempt to increase dissolution rate and hence, improve oral bioavailability. Maximising the drug surface area exposed to the dissolution medium can be achieved by loading drug onto a high surface area carrier like mesoporous silica (SBA-15). The aim of this work was to investigate the impact of altering supercritical carbon dioxide (SC-CO(2)) processing conditions, in an attempt to enhance drug loading onto SBA-15 and increase the drug's dissolution rate. Other formulation variables such as the mass ratio of drug to SBA-15 and the procedure for combining the drug and SBA-15 were also investigated. A model drug with poor water solubility, fenofibrate, was selected for this study. High drug loading efficiencies were obtained using SC-CO(2), which were influenced by the processing conditions employed. Fenofibrate release rate was enhanced greatly after loading onto mesoporous silica. The results highlighted the potential of this SC-CO(2) drug loading approach to improve the oral bioavailability of poorly water soluble drugs. Copyright © 2012 Elsevier B.V. All rights reserved.

A Computational Model of the SC Multisensory Neurons: Integrative Capabilities, Maturation, and Plasticity

Directory of Open Access Journals (Sweden)

Cristiano Cuppini

2011-10-01

Full Text Available Different cortical and subcortical structures present neurons able to integrate stimuli of different sensory modalities. Among the others, one of the most investigated integrative regions is the Superior Colliculus (SC, a midbrain structure whose aim is to guide attentive behaviour and motor responses toward external events. Despite the large amount of experimental data in the literature, the neural mechanisms underlying the SC response are not completely understood. Moreover, recent data indicate that multisensory integration ability is the result of maturation after birth, depending on sensory experience. Mathematical models and computer simulations can be of value to investigate and clarify these phenomena. In the last few years, several models have been implemented to shed light on these mechanisms and to gain a deeper comprehension of the SC capabilities. Here, a neural network model (Cuppini et al., 2010 is extensively discussed. The model considers visual-auditory interaction, and is able to reproduce and explain the main physiological features of multisensory integration in SC neurons, and their acquisition during postnatal life. To reproduce a neonatal condition, the model assumes that during early life: 1 cortical-SC synapses are present but not active; 2 in this phase, responses are driven by non-cortical inputs with very large receptive fields (RFs and little spatial tuning; 3 a slight spatial preference for the visual inputs is present. Sensory experience is modeled by a “training phase” in which the network is repeatedly exposed to modality-specific and cross-modal stimuli at different locations. As results, Cortical-SC synapses are crafted during this period thanks to the Hebbian rules of potentiation and depression, RFs are reduced in size, and neurons exhibit integrative capabilities to cross-modal stimuli, such as multisensory enhancement, inverse effectiveness, and multisensory depression. The utility of the modelling

Investigation of Sc(3) state in nonaqueous solutions by the 45Sc NMR method of high permission

International Nuclear Information System (INIS)

Buslaev, Yu.A.; Kirakosyan, G.A.; Tarasov, V.P.

1980-01-01

The ScCl 3 + CH 3 CN and ScCl 3 + KNCS + CH 3 CN solutions have been studied by a high-resolution NMR 45 Sc method. It has been estimated that in acetonitrile solutions, with competing ligands of Cl - and NCS - being available, hexacoordination Sc(3) complexes of various compositions are formed, and solvent molecules also take part in formation of the coordination sphere of scandium. Chemical shifts in NMR 45 Sc signals depend linearly on the number of chlor- or NCS - ions bound to scandium(3). This made it possible to determine the value of chemical shifts in signals of all 28 potential complexes formed in a system with three competing ligands

A human scFv antibody that targets and neutralizes high molecular weight pathogenic amyloid-β oligomers.

Science.gov (United States)

Sebollela, Adriano; Cline, Erika N; Popova, Izolda; Luo, Kevin; Sun, Xiaoxia; Ahn, Jay; Barcelos, Milena A; Bezerra, Vanessa N; Lyra E Silva, Natalia M; Patel, Jason; Pinheiro, Nathalia R; Qin, Lei A; Kamel, Josette M; Weng, Anthea; DiNunno, Nadia; Bebenek, Adrian M; Velasco, Pauline T; Viola, Kirsten L; Lacor, Pascale N; Ferreira, Sergio T; Klein, William L

2017-07-03

Brain accumulation of soluble oligomers of the amyloid-β peptide (AβOs) is increasingly considered a key early event in the pathogenesis of Alzheimer's disease (AD). A variety of AβO species have been identified, both in vitro and in vivo, ranging from dimers to 24mers and higher order oligomers. However, there is no consensus in the literature regarding which AβO species are most germane to AD pathogenesis. Antibodies capable of specifically recognizing defined subpopulations of AβOs would be a valuable asset in the identification, isolation, and characterization of AD-relevant AβO species. Here, we report the characterization of a human single chain antibody fragment (scFv) denoted NUsc1, one of a number of scFvs we have identified that stringently distinguish AβOs from both monomeric and fibrillar Aβ. NUsc1 readily detected AβOs previously bound to dendrites in cultured hippocampal neurons. In addition, NUsc1 blocked AβO binding and reduced AβO-induced neuronal oxidative stress and tau hyperphosphorylation in cultured neurons. NUsc1 further distinguished brain extracts from AD-transgenic mice from wild type (WT) mice, and detected endogenous AβOs in fixed AD brain tissue and AD brain extracts. Biochemical analyses indicated that NUsc1 targets a subpopulation of AβOs with apparent molecular mass greater than 50 kDa. Results indicate that NUsc1 targets a particular AβO species relevant to AD pathogenesis, and suggest that NUsc1 may constitute an effective tool for AD diagnostics and therapeutics. © 2017 International Society for Neurochemistry.

Effect of Ti/Sc atom ratio on heterogeneous nuclei, microstructure and mechanical properties of A357-0.033Sr alloys

Energy Technology Data Exchange (ETDEWEB)

Shen, Xiaocen [School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University, Tianjin 300072 (China); Zhao, Naiqin, E-mail: nqzhao@tju.edu.cn [School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072 (China); Key Laboratory of Advanced Ceramics and Machining Technology, Ministry of Education, Tianjin University, Tianjin, 300072 (China); Li, Jiajun [School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University, Tianjin 300072 (China); He, Chunnian, E-mail: cnhe08@tju.edu.cn [School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072 (China); Key Laboratory of Advanced Ceramics and Machining Technology, Ministry of Education, Tianjin University, Tianjin, 300072 (China); Shi, Chunsheng [School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University, Tianjin 300072 (China); Liu, Enzuo [School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072 (China); He, Fang; Ma, Liying; Li, Qunying [School of Materials Science and Engineering and Tianjin Key Laboratory of Composites and Functional Materials, Tianjin University, Tianjin 300072 (China)

2016-08-01

A systematic study on heterogeneous nucleation, microstructure and mechanical properties of A357-0.033Sr alloys with different Ti/Sc atom ratio was carried out. According to the obtained results, a Ti/Sc atom ratio up to 1:1 did not show much change in the heterogeneous nuclei but at a higher atom ratio level, heterogeneous nuclei have a great change in chemical composition and morphology (from strip Ti-rich phase to the particle-like Ti-rich phase). In addition, compared to the other four alloys studied, the A357-0.033Sr-0.30Sc-0.35Ti alloy with 1:1 atom ratio has the smallest grain size (88 µm), optimum microstructure (morphology, size and distribution of eutectic Si), densest core-shell Al{sub 3}(Sc, Ti), all of which result in the best mechanical properties. Its tensile strength and elongation reach 287 MPa and 3.62% respectively, showing about 11% and 84% increases compared with A357-0.033Sr alloy.

PopSc: Computing Toolkit for Basic Statistics of Molecular Population Genetics Simultaneously Implemented in Web-Based Calculator, Python and R.

Science.gov (United States)

Chen, Shi-Yi; Deng, Feilong; Huang, Ying; Li, Cao; Liu, Linhai; Jia, Xianbo; Lai, Song-Jia

2016-01-01

Although various computer tools have been elaborately developed to calculate a series of statistics in molecular population genetics for both small- and large-scale DNA data, there is no efficient and easy-to-use toolkit available yet for exclusively focusing on the steps of mathematical calculation. Here, we present PopSc, a bioinformatic toolkit for calculating 45 basic statistics in molecular population genetics, which could be categorized into three classes, including (i) genetic diversity of DNA sequences, (ii) statistical tests for neutral evolution, and (iii) measures of genetic differentiation among populations. In contrast to the existing computer tools, PopSc was designed to directly accept the intermediate metadata, such as allele frequencies, rather than the raw DNA sequences or genotyping results. PopSc is first implemented as the web-based calculator with user-friendly interface, which greatly facilitates the teaching of population genetics in class and also promotes the convenient and straightforward calculation of statistics in research. Additionally, we also provide the Python library and R package of PopSc, which can be flexibly integrated into other advanced bioinformatic packages of population genetics analysis.

PopSc: Computing Toolkit for Basic Statistics of Molecular Population Genetics Simultaneously Implemented in Web-Based Calculator, Python and R.

Directory of Open Access Journals (Sweden)

Shi-Yi Chen

Full Text Available Although various computer tools have been elaborately developed to calculate a series of statistics in molecular population genetics for both small- and large-scale DNA data, there is no efficient and easy-to-use toolkit available yet for exclusively focusing on the steps of mathematical calculation. Here, we present PopSc, a bioinformatic toolkit for calculating 45 basic statistics in molecular population genetics, which could be categorized into three classes, including (i genetic diversity of DNA sequences, (ii statistical tests for neutral evolution, and (iii measures of genetic differentiation among populations. In contrast to the existing computer tools, PopSc was designed to directly accept the intermediate metadata, such as allele frequencies, rather than the raw DNA sequences or genotyping results. PopSc is first implemented as the web-based calculator with user-friendly interface, which greatly facilitates the teaching of population genetics in class and also promotes the convenient and straightforward calculation of statistics in research. Additionally, we also provide the Python library and R package of PopSc, which can be flexibly integrated into other advanced bioinformatic packages of population genetics analysis.

PET Imaging of 64Cu-DOTA-scFv-Anti-PSMA Lipid Nanoparticles (LNPs): Enhanced Tumor Targeting over Anti-PSMA scFv or Untargeted LNPs

Science.gov (United States)

Wong, Patty; Li, Lin; Chea, Junie; Delgado, Melissa K.; Crow, Desiree; Poku, Erasmus; Szpikowska, Barbara; Bowles, Nicole; Channappa, Divya; Colcher, David; Wong, Jeffrey Y.C.; Shively, John E.; Yazaki, Paul J.

2017-01-01

Introduction Single chain (scFv) antibodies are ideal targeting ligands due to their modular structure, high antigen specificity and affinity. These monovalent ligands display rapid tumor targeting but have limitations due to their fast urinary clearance. Methods An anti-prostate membrane antigen (PSMA) scFv with a site-specific cysteine was expressed and evaluated in a prostate cancer xenograft model by Cu-64 PET imaging. To enhance tumor accumulation, the scFv-cys was conjugated to the co-polymer DSPE-PEG-maleimide that spontaneously assembled into a homogeneous multivalent lipid nanoparticle (LNP). Results The targeted LNP exhibited a 2-fold increase in tumor uptake compared to the scFv alone using two different thiol ester chemistries. The anti-PSMA scFv-LNP exhibited a 1.6 fold increase in tumor targeting over the untargeted LNP. Conclusions The targeted anti-PSMA scFv-LNP showed enhanced tumor accumulation over the scFv alone or the untargeted DOTA-micelle providing evidence for the development of this system for drug delivery. Advances in Knowledge and implications for patient care Anti-tumor scFv antibody fragments have not achieved their therapeutic potential due to their fast blood clearance. Conjugation to a LNP enables multivalency to the tumor antigen as well as increased molecular size for chemotherapy drug delivery. PMID:28126683

Novel oxide buffer approach for GaN integration on Si(111) platform through Sc{sub 2}O{sub 3}/Y{sub 2}O{sub 3} bi-layer

Energy Technology Data Exchange (ETDEWEB)

Tarnawska, Lidia

2012-12-19

Motivation: Preparation of GaN virtual substrates on large-scale Si wafers is intensively pursued as a cost-effective approach for high power/high frequency electronics (HEMT's etc.) and optoelectronic applications (LED, LASER). However, the growth of high quality GaN layers on Si is hampered by several difficulties mainly related to a large lattice mismatch (-17%) and a huge difference in the thermal expansion coefficient (56%). As a consequence, GaN epitaxial layers grown on Si substrates show a high number of defects (threading dislocations etc.), which severely deteriorate the overall quality of the GaN films. Additionally, due to the different thermal expansion coefficients of the substrate and the film, um-thick GaN layers crack during post-growth cooling. To solve these integration problems, different semiconducting (e.g. AlN, GaAs, ZnO, HfN) and insulating (e.g. Al{sub 2}O{sub 3}, MgO, LiGaO{sub 2}) buffer layers, separating the Si substrate from the GaN film, are applied. Goal: In this thesis, a novel buffer approach for the integration of GaN on Si is proposed and investigated. The new approach employs Sc{sub 2}O{sub 3}/Y{sub 2}O{sub 3} bilayer templates as a step-graded buffer to reduce the lattice mismatch between GaN and the Si(111) substrate. According to the bulk crystal lattices, since the Y{sub 2}O{sub 3} has an in-plane lattice misfit of -2% to Si, Sc{sub 2}O{sub 3} -7% to Y{sub 2}O{sub 3}, the lattice misfit between GaN and the substrate can be theoretically reduced by about 50% from -17% (GaN/Si) to -8% (GaN/Sc{sub 2}O{sub 3}). Experimental: The GaN/Sc{sub 2}O{sub 3}/Y{sub 2}O{sub 3}/Si(111) heterostructures are prepared in a multichamber molecular beam epitaxy system on 4 inch Si(111) wafers. In order to obtain complete information on the structural quality of the oxide buffer as well as the GaN layer, synchrotron- and laboratory-based X-ray diffraction, transmission electron microscopy and photoluminescence measurements are performed. The

Radiolabeling of DOTATOC with the long-lived positron emitter {sup 44}Sc

Energy Technology Data Exchange (ETDEWEB)

Pruszynski, Marek; Majkowska-Pilip, Agnieszka [Centre of Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warszawa (Poland); Loktionova, Natalia S.; Eppard, Elisabeth [Institute of Nuclear Chemistry, Johannes Gutenberg-University of Mainz, Fritz-Strassmann-Weg 2, D-55128 Mainz (Germany); Roesch, Frank, E-mail: frank.roesch@uni-mainz.de [Institute of Nuclear Chemistry, Johannes Gutenberg-University of Mainz, Fritz-Strassmann-Weg 2, D-55128 Mainz (Germany)

2012-06-15

The positron-emitting radionuclide {sup 44}Sc with a half-life of 3.97 h and a {beta}{sup +} branching of 94.3% is of potential interest for clinical PET. As so far it is available from a {sup 44}Ti/{sup 44}Sc generator in Mainz, where long-lived {sup 44}Ti decays to no-carrier-added (nca) {sup 44}Sc. The {sup 44}Sc is a trivalent metal cation and should be suitable for complexation with many well established bifunctional chelators conjugated to peptides or other molecular targeting vectors. Thus, the aim of this work was to investigate the potential of {sup 44}Sc for labeling of DOTA-conjugated peptides. DOTA-D-Phe{sup 1}-Tyr{sup 3}-octreotide (DOTATOC) was used as a model molecule to study and optimize labeling procedure. Reaction parameters such as buffer conditions, concentration of peptide, pH range, reaction temperature and time were optimized. Addition of 21 nmol of DOTATOC to {sup 44}Sc in ammonium acetate buffer pH 4.0 provided labeling yields >98% within 25 min of heating in an oil-bath at 95 Degree-Sign C. This time can be reduced to 3 min only by applying microwave supported heating. {sup 44}Sc-DOTATOC was found to be stable in 0.9% NaCl, PBS pH 7.4, fetal calf and human serums, and also in the presence of competing metal cations (Fe{sup 3+}, Ca{sup 2+}, Cu{sup 2+}, Mg{sup 2+}), as well as other ligand competitors, like EDTA and DTPA, even after almost 25 h incubation at 37 Degree-Sign C. Present study shows that nca {sup 44}Sc forms stable complexes with the macrocyclic ligand DOTA and that {sup 44}Sc-DOTATOC and analog targeting vectors may be synthesized for further preclinical and clinical investigations. - Highlights: Black-Right-Pointing-Pointer Labeling of somatostatin analouges with positron emitter {sup 44}Sc was tested. Black-Right-Pointing-Pointer DOTATOC was labeled with {sup 44}Sc isotope. Black-Right-Pointing-Pointer Optimal conditions for {sup 44}Sc-DOTATOC synthesis were found. Black-Right-Pointing-Pointer Stability of {sup 44}Sc

Origin of CH+ in diffuse molecular clouds. Warm H2 and ion-neutral drift

Science.gov (United States)

Valdivia, Valeska; Godard, Benjamin; Hennebelle, Patrick; Gerin, Maryvonne; Lesaffre, Pierre; Le Bourlot, Jacques

2017-04-01

Context. Molecular clouds are known to be magnetised and to display a turbulent and complex structure where warm and cold phases are interwoven. The turbulent motions within molecular clouds transport molecules, and the presence of magnetic fields induces a relative velocity between neutrals and ions known as the ion-neutral drift (vd). These effects all together can influence the chemical evolution of the clouds. Aims: This paper assesses the roles of two physical phenomena which have previously been invoked to boost the production of CH+ under realistic physical conditions: the presence of warm H2 and the increased formation rate due to the ion-neutral drift. Methods: We performed ideal magnetohydrodynamical (MHD) simulations that include the heating and cooling of the multiphase interstellar medium (ISM), and where we treat dynamically the formation of the H2 molecule. In a post-processing step we compute the abundances of species at chemical equilibrium using a solver that we developed. The solver uses the physical conditions of the gas as input parameters, and can also prescribe the H2 fraction if needed. We validate our approach by showing that the H2 molecule generally has a much longer chemical evolution timescale compared to the other species. Results: We show that CH+ is efficiently formed at the edge of clumps, in regions where the H2 fraction is low (0.3-30%) but nevertheless higher than its equilibrium value, and where the gas temperature is high (≳ 300 K). We show that warm and out of equilibrium H2 increases the integrated column densities of CH+ by one order of magnitude up to values still 3-10 times lower than those observed in the diffuse ISM. We balance the Lorentz force with the ion-neutral drag to estimate the ion-drift velocities from our ideal MHD simulations. We find that the ion-neutral drift velocity distribution peaks around 0.04 km s-1, and that high drift velocities are too rare to have a significant statistical impact on the

Color superconductivity. Phase diagrams and Goldstone bosons in the color-flavor locked phase

Energy Technology Data Exchange (ETDEWEB)

Kleinhaus, Verena

2009-04-29

The phase diagram of strongly interacting matter is studied with great experimental and theoretical effort and is one of the most fascinating research areas in modern particle physics. It is believed that color superconducting phases, in which quarks form Cooper pairs, appear at very high densities and low temperatures. Such phases could appear in the cores of neutron stars. In this work color superconducting phases are studied within the Nambu-Jona-Lasinio model. First of all, the phase diagram of neutral matter in beta equilibrium is calculated for two different diquark couplings. To this end, we determine the dynamical quark masses self-consistently together with the order parameters of color superconductivity. The interplay between neutrality and quark masses results in an interesting phase structure, in particular for the smaller diquark coupling. In the following, we additionally include a conserved lepton number to map the situation in the first few seconds of the evolution of a protoneutron star when neutrinos are trapped. This has a huge influence on the phase structure and favors the 2SC phase compared to the CFL phase. In the second part of this work we concentrate on the CFL phase which is characterized by a special symmetry breaking pattern. The properties of the resulting nine pseudoscalar Goldstone bosons (GB) are studied by solving the Bethe-Salpeter equation for quark-quark scattering. The GB are the lowest-lying excitations in the CFL phase and therefore play an important role for the thermodynamics of the system. The properties of the GB can also be described by the low-energy effective theory (LEET) for the CFL phase. There the respective low-energy constants are derived for asymptotically high densities where the strong force is weak and can be treated perturbatively. Our aim is the comparison of our results with these predictions, on the one hand to check our model in the weak-coupling limit and on the other hand to derive information about

Color superconductivity: Phase diagrams and Goldstone bosons in the color-flavor locked phase

International Nuclear Information System (INIS)

Kleinhaus, Verena

2009-01-01

The phase diagram of strongly interacting matter is studied with great experimental and theoretical effort and is one of the most fascinating research areas in modern particle physics. It is believed that color superconducting phases, in which quarks form Cooper pairs, appear at very high densities and low temperatures. Such phases could appear in the cores of neutron stars. In this work color superconducting phases are studied within the Nambu-Jona-Lasinio model. First of all, the phase diagram of neutral matter in beta equilibrium is calculated for two different diquark couplings. To this end, we determine the dynamical quark masses self-consistently together with the order parameters of color superconductivity. The interplay between neutrality and quark masses results in an interesting phase structure, in particular for the smaller diquark coupling. In the following, we additionally include a conserved lepton number to map the situation in the first few seconds of the evolution of a protoneutron star when neutrinos are trapped. This has a huge influence on the phase structure and favors the 2SC phase compared to the CFL phase. In the second part of this work we concentrate on the CFL phase which is characterized by a special symmetry breaking pattern. The properties of the resulting nine pseudoscalar Goldstone bosons (GB) are studied by solving the Bethe-Salpeter equation for quark-quark scattering. The GB are the lowest-lying excitations in the CFL phase and therefore play an important role for the thermodynamics of the system. The properties of the GB can also be described by the low-energy effective theory (LEET) for the CFL phase. There the respective low-energy constants are derived for asymptotically high densities where the strong force is weak and can be treated perturbatively. Our aim is the comparison of our results with these predictions, on the one hand to check our model in the weak-coupling limit and on the other hand to derive information about

Optimization of reaction conditions for the radiolabeling of DOTA and DOTA-peptide with (44m/44)Sc and experimental evidence of the feasibility of an in vivo PET generator.

Science.gov (United States)

Huclier-Markai, S; Kerdjoudj, R; Alliot, C; Bonraisin, A C; Michel, N; Haddad, F; Barbet, J

2014-05-01

Among the number of generator systems providing radionuclides with decay parameters promising for imaging and treatment applications, there is the (44)Ti (T1/2=60 years)/(44)Sc (T1/2=3.97 h) generator. This generator provides a longer-lived daughter for extended PET/CT measurements compared to the chemically similar system (68)Ge/(68)Ga. Scandium also exists as (47)Sc, a potential therapeutic radionuclide. It is possible to produce (44)Sc in a cyclotron using, for example, the (44)Ca (d, n) (44)Sc nuclear reaction. In that case, the isomeric state (44 m)Sc (T1/2=58.6h) is co-produced and may be used as an in vivo(44 m)Sc/(44)Sc generator. The aim of this study is to evaluate the feasibility of this in vivo(44 m)Sc/(44)Sc generator and to demonstrate that the daughter radionuclide stays inside the chelator after decay of the parent radionuclide. Indeed, the physico-chemical process occurring after the primary radioactive decay (EC, IT, Auger electron …) has prevented in many cases the use of in-vivo generator, because of the post-effect as described in the literature. The DOTA macrocyclic ligand forms stable complexes with many cations and has been shown to be the most suitable chelating moiety for scandium. Initially, the radiolabeling of DOTA and a DOTA-peptide (DOTATATE) with Sc was performed and optimized as a function of time, pH, metal-to-ligand ratio and temperature. Next, the physico-chemical processes that could occur after the decay (post-effect) were studied. (44 m)Sc(III)-labeled DOTA-peptide was quantitatively adsorbed on a solid phase matrix through a hydrophobic interaction. Elutions were then performed at regular time intervals using a DTPA solution at various concentrations. Finally, the radiolabelled complex stability was studied in serum. Radiolabeling yields ranged from 90% to 99% for metal-to-ligand ratio ranging from 1:10 to 1:500 for DOTA or DOTATATE respectively. The optimum physico-chemical parameters were pH=4-6, t=20 min, T=70°C. Then

Evidence for neutral beam injected oxygen impurities in 2XIIB

International Nuclear Information System (INIS)

Drake, R.P.; Moos, H.W.

1978-01-01

A series of experiments indicates that the principal source of impurities in the 2XIIB mirror confinement plasma experiment at Lawrence Livermore Laboratory is oxygen in the neutral beams. The dependence of 0 II 539 A emissions on neutral beam current, spatial scans of oxygen emissions, impurity injection experiments, spectral scans of the 0 VI 1032 A line, and other experiments all support this conclusion

Stability of superfluid phases in the 2D spin-polarized attractive Hubbard model

Science.gov (United States)

Kujawa-Cichy, A.; Micnas, R.