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Sample records for rh based heusler

  1. Noncollinear magnetism in Mn{sub 2}RhSn Heusler compound

    Energy Technology Data Exchange (ETDEWEB)

    Meshcheriakova, Olga

    2014-09-15

    Heusler compounds is a large class of materials, which exhibits diverse fundamental phenomena, together with the possibility of their specific tailoring for various engineering demands. Present work discusses the magnetic noncollinearity in the family of noncentrosymmetric ferrimagnetic Mn{sub 2}-based Heusler compounds. Based on the obtained experimental and theoretical results, Mn{sub 2}YZ Heusler family is suspected to provide promising candidates for the formation of the skyrmion lattice. The work is focused on Mn{sub 2}RhSn bulk polycrystalline sample, which serves as a prototype. It crystallizes in the tetragonal noncentrosymmetric structure (No. 119, I anti 4m2), which enables the anisotropic Dzyaloshinskii-Moriya (DM) exchange coupling. Additional short-range modulation, induced by the competing nearest and next-nearest interplanes Heisenberg exchange, is suppressed above the 80 K. This allows to develop the long-range modulations in the ideal ferrimagnetic structure within the ab crystallographic planes, and thus, favors to the occurrence of the skyrmion lattice within the temperature range of (80≤T≤ 270) K. The studies of Mn{sub 2}RhSn were expanded to the broad composition range and continued on thin film samples.

  2. Standard enthalpies of formation of selected Rh2YZ Heusler compounds

    International Nuclear Information System (INIS)

    Yin, Ming; Nash, Philip

    2015-01-01

    The standard enthalpies of formation (Δ f H°) of selected ternary Rh-based Rh 2 YZ (Y = Cu, Fe, Mn, Ni, Ru, Ti, V; Z = Al, Ga, In, Si, Ge, Sn) compounds were measured using high temperature direct reaction calorimetry. The measured standard enthalpies of formation (in kJ/mol of atoms) are, for the Heusler compound Rh 2 MnSn (−40.1 ± 3.6), for the B2-structured compounds: Rh 2 FeAl (−48.5 ± 2.9); Rh 2 MnAl (−72.4 ± 2.7); Rh 2 MnGa (−55.3 ± 2.0); Rh 2 MnIn (−35.3 ± 1.9), for the tetragonal compounds: Rh 2 FeSn (−28.9 ± 1.3); Rh 2 TiAl (−97.6 ± 2.2); Rh 2 TiGa (−79.0 ± 1.8); Rh 2 TiSn (−74.7 ± 3.1). Values are compared with those from first principles calculations in published papers and the Open Quantum Materials Database (OQMD). Lattice parameters of these compounds are determined using X-ray diffraction analysis (XRD). Microstructures were characterized using scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). - Highlights: • Standard enthalpies of formation of Rh 2 YZ were measured using a drop calorimeter. • Measured enthalpies agree with first principles data in general. • Lattice parameters and related phase relationships were consistent with literature data. • Rh 2 TiSn of tI8 structure were reported for the first time.

  3. Standard enthalpies of formation of selected Rh{sub 2}YZ Heusler compounds

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    Yin, Ming, E-mail: myin1@hawk.iit.edu; Nash, Philip

    2015-11-25

    The standard enthalpies of formation (Δ{sub f}H°) of selected ternary Rh-based Rh{sub 2}YZ (Y = Cu, Fe, Mn, Ni, Ru, Ti, V; Z = Al, Ga, In, Si, Ge, Sn) compounds were measured using high temperature direct reaction calorimetry. The measured standard enthalpies of formation (in kJ/mol of atoms) are, for the Heusler compound Rh{sub 2}MnSn (−40.1 ± 3.6), for the B2-structured compounds: Rh{sub 2}FeAl (−48.5 ± 2.9); Rh{sub 2}MnAl (−72.4 ± 2.7); Rh{sub 2}MnGa (−55.3 ± 2.0); Rh{sub 2}MnIn (−35.3 ± 1.9), for the tetragonal compounds: Rh{sub 2}FeSn (−28.9 ± 1.3); Rh{sub 2}TiAl (−97.6 ± 2.2); Rh{sub 2}TiGa (−79.0 ± 1.8); Rh{sub 2}TiSn (−74.7 ± 3.1). Values are compared with those from first principles calculations in published papers and the Open Quantum Materials Database (OQMD). Lattice parameters of these compounds are determined using X-ray diffraction analysis (XRD). Microstructures were characterized using scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). - Highlights: • Standard enthalpies of formation of Rh{sub 2}YZ were measured using a drop calorimeter. • Measured enthalpies agree with first principles data in general. • Lattice parameters and related phase relationships were consistent with literature data. • Rh{sub 2}TiSn of tI8 structure were reported for the first time.

  4. Systematic study of hyperfine fields in Rh2 Y Z type Heusler alloys with 119 Sn impurity using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Ramos, S.M.M.

    1985-01-01

    The magnetic hyperfine fields in the Heusler alloys Rh 2 Mn .98 Ge Sn 02 , Rh 2 Mn Ge .98 Sn .02 , Rh 2 Mn Pb .98 Sn .02 and Rh 2 Mn Sn has been studied by 119 Sn Moessbauer spectroscopy at 293 K, 77 K, 4.2 K and 293 K with applied external magnetic field. The results show that when one compare the magnetic hyperfine fields systematic with the Heusler alloys X 2 Mn Z (X = Co, Ni, Cu, Pd, and Z = s p metal), this systematic is similar to the Co alloys, although can not explained by the currents models for the Heusler alloys. (author)

  5. Electronic structure and magnetic properties of quaternary Heusler alloys CoRhMnZ (Z = Al, Ga, Ge and Si) via first-principle calculations

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    Benkabou, M. [Laboratoire des Matériaux Magnétiques, Faculté des Sciences, Université DjillaliLiabès de Sidi Bel-Abbès, Sidi Bel-Abbès 22000 (Algeria); Rached, H. [Laboratoire des Matériaux Magnétiques, Faculté des Sciences, Université DjillaliLiabès de Sidi Bel-Abbès, Sidi Bel-Abbès 22000 (Algeria); Département de Physique, Faculté des Sciences, Université Hassiba Benbouali, Chlef 02000 (Algeria); Abdellaoui, A. [Laboratoire des Matériaux Magnétiques, Faculté des Sciences, Université DjillaliLiabès de Sidi Bel-Abbès, Sidi Bel-Abbès 22000 (Algeria); Rached, D., E-mail: rachdj@yahoo.fr [Laboratoire des Matériaux Magnétiques, Faculté des Sciences, Université DjillaliLiabès de Sidi Bel-Abbès, Sidi Bel-Abbès 22000 (Algeria); Khenata, R. [Laboratoire de Physique Quantique et de Modélisation Mathématique de la Matière, (LPQ3M), Université de Mascara, Mascara 29000 (Algeria); and others

    2015-10-25

    First-principle calculations are performed to predict the electronic structure and elastic and magnetic properties of CoRhMnZ (Z = Al, Ga, Ge and Si) Heusler alloys. The calculations employ the full-potential linearized augmented plane wave. The exchange-correlations are treated within the generalized gradient approximation of Perdew–Burke and Ernzerhof (GGA-PBE). The electronic structure calculations show that these compounds exhibit a gap in the minority states band and are clearly half-metallic ferromagnets, with the exception of the CoRhMnAl and CoRhMnGa, which are simple ferromagnets that are nearly half metallic in nature. The CoRhMnGe and CoRhMnSi compounds and their magnetic moments are in reasonable agreement with the Slater-Pauling rule, which indicates the half metallicity and high spin polarization for these compounds. At the pressure transitions, these compounds undergo a structural phase transition from the Y-type I → Y-type II phase. We have determined the elastic constants C{sub 11}, C{sub 12} and C{sub 44} and their pressure dependence, which have not previously been established experimentally or theoretically. - Highlights: • Based on DFT calculations, CoRhMnZ (Z = Al, Ga, Ge and Si) Heusler alloys were investigated. • The magnetic phase stability was determined from the total energy calculations. • The mechanical properties were investigated.

  6. Phase stability, magnetic, electronic, half-metallic and mechanical properties of a new equiatomic quaternary Heusler compound ZrRhTiIn: A first-principles investigation

    Science.gov (United States)

    Wang, Jia-Xing; Chen, Z. B.; Gao, Y. C.

    2018-05-01

    In this manuscript, we have studied the electronic, magnetic, half-metallic and mechanical properties of a new Zr-based equiatomic quaternary Heusler (EQH) compound, ZrRhTiIn using first-principles calculations. The generalized gradient approximation (GGA) calculation results imply that at its equilibrium lattice constant of 6.70 Å, ZrRhTiIn is a half-metallic material (HMM) with a considerable band gap (Ebg) of 0.530 eV and a spin-filter/half-metallic band-gap (EHM) of 0.080 eV in the minority-spin channel. For ZrRhTiIn, the formation energy of -2.738 eV and the cohesive energy of 21.38 eV indicate that it is a thermodynamically stable material according to theory. The minority-spin EHM arises from the hybridization among Zr-4d, Ti-3d and Rh-4d electrons. The calculated total magnetic moment of ZrRhTiIn is 2 μB, meeting the well-known Slater-Pauling rule Mt = Zt -18. Furthermore, uniform strain and tetragonal strain were applied in this work to examine the magneto-electronic and half-metallic behaviors of the ZrRhTiIn system. Finally, we show that ZrRhTiIn is mechanically stable, ductile and anisotropic.

  7. Gallium-containing Heusler phases ScRh{sub 2}Ga, ScPd{sub 2}Ga, TmRh{sub 2}Ga and LuRh{sub 2}Ga. Magnetic and solid state NMR-spectroscopic characterization

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    Heletta, Lukas; Seidel, Stefan; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Benndorf, Christopher [Leipzig Univ. (Germany). Inst. fuer Mineralogie, Kristallographie und Materialwissenschaften; Eckert, Hellmut [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Sao Paulo Univ., Sao Carlos (Brazil). Inst. of Physics

    2017-10-01

    The gallium-containing Heusler phases ScRh{sub 2}Ga, ScPd{sub 2}Ga, TmRh{sub 2}Ga and LuRh{sub 2}Ga have been synthesized by arc-melting of the elements followed by different annealing sequences to improve phase purity. The samples have been studied by powder X-ray diffraction. The structures of Lu{sub 0.97}Rh{sub 2}Ga{sub 1.03} (Fm3m, a=632.94(5) pm, wR2=0.0590, 46 F{sup 2} values, seven variables) and Sc{sub 0.88}Rh{sub 2}Ga{sub 1.12} (a=618.91(4) pm, wR2=0.0284, 44 F{sup 2} values, six variables) have been refined from single crystal X-ray diffractometer data. Both gallides show structural disorder through Lu/Ga and Sc/Ga mixing. Temperature dependent magnetic susceptibility measurements showed Pauli paramagnetism for ScRh{sub 2}Ga, ScPd{sub 2}Ga, and LuRh{sub 2}Ga and Curie-Weiss paramagnetism for TmRh{sub 2}Ga. {sup 45}Sc and {sup 71}Ga solid state MAS NMR spectroscopic investigations of the Sc containing compounds confirmed the site mixing effects typically observed for Heusler phases. The data indicate that the effect of mixed Sc/Ga occupancy is significantly stronger in ScRh{sub 2}Ga than in ScPd{sub 2}Ga.

  8. First-principles study of new quaternary Heusler compounds without 3d transition metal elements: ZrRhHfZ (Z = Al, Ga, In)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaotian [School of Material Sciences and Engineering, Hebei University of Technology, Tianjin 300130 (China); Institute for Superconducting & Electronic Materials (ISEM), University of Wollongong, Wollongong 2500 (Australia); Cheng, Zhenxiang, E-mail: cheng@uow.edu.au [Institute for Superconducting & Electronic Materials (ISEM), University of Wollongong, Wollongong 2500 (Australia); Guo, Ruikang [School of Material Sciences and Engineering, Hebei University of Technology, Tianjin 300130 (China); Wang, Jianli [Institute for Superconducting & Electronic Materials (ISEM), University of Wollongong, Wollongong 2500 (Australia); Rozale, Habib [Condensed Matter and Sustainable Development Laboratory, Physics Department, University of Sidi-Bel-Abbès, 22000 Sidi-Bel-Abbès (Algeria); Wang, Liying [Department of Physics, Tianjin University, Tianjin 300350 (China); Yu, Zheyin [Institute for Superconducting & Electronic Materials (ISEM), University of Wollongong, Wollongong 2500 (Australia); Liu, Guodong, E-mail: gdliu1978@126.com [School of Material Sciences and Engineering, Hebei University of Technology, Tianjin 300130 (China)

    2017-06-01

    Plane-wave pseudo-potential methods based on density functional theory are employed to investigate the electronic structures, and the magnetic and half-metallic properties of the newly designed quaternary Heusler compounds ZrRhHfZ (Z = Al, Ga, In) without 3d transition metal elements. The calculated results show that ZrRhHfZ (Z = Al, Ga, In) compounds are half-metallic, with 100% spin polarization around the Fermi level. The structural stability of these compounds has been tested from the aspects of their cohesion energy and formation. The spin-flip/half-metallic gaps of ZrRhHfZ (Z = Al, Ga, In) compounds are quite large, with values of 0.2548 eV, 0.3483 eV, and 0.2866 eV, respectively. These compounds show Slater-Pauling behavior, and the total spin magnetic moment per unit cell (M{sub t}) scales with the total number of valence electrons (Z{sub t}) following the rule: M{sub t} = Z{sub t} - 18. The magnetization of ZrRhHfZ (Z = Al, Ga, In) compounds mainly comes from the 4d electrons of the Zr atoms and the 5d electrons of the Hf atoms. Furthermore, the effects of uniform strain and tetragonal deformation on the half metallicity has been investigated in detail, which is important for practical application. Finally, we reveal that the half-metallicity can be maintained when the Coulomb interactions are considered. - Highlights: • New quaternary compounds without 3d transition metal elements have been designed. • The electronic structures and magnetism of the ZrRhHfZ compounds have been studied. • The effect of strain on the half-metallic behavior has been tested. • The effect of the Coulomb interactions on the half-metallicity has been investigated.

  9. Magnetic interactions in martensitic Ni-Mn based Heusler systems

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    Aksoy, Seda

    2010-04-22

    In this work, magnetic, magnetocaloric and structural properties are investigated in Ni-Mn-based martensitic Heusler alloys with the aim to tailor these properties as well as to understand in detail the magnetic interactions in the various crystallographic states of these alloys. We choose Ni{sub 50}Mn{sub 34}In{sub 16} as a prototype which undergoes a martensitic transformation and exhibits field-induced strain and the inverse magnetocaloric effect. Using the structural phase diagram of martensitic Ni-Mn-based Heusler alloys, we substitute gallium and tin for indium to carry these effects systematically closer to room temperature by shifting the martensitic transformation. A magneto-calorimeter is designed and built to measure adiabatically the magnetocaloric effect in these alloys. The temperature dependence of strain under an external magnetic field is studied in Ni{sub 50}Mn{sub 50-x}Z{sub x} (Z: Ga, Sn, In and Sb) and Ni{sub 50}Mn{sub 34}In{sub 16-x}Z{sub x} (Z: Ga and Sn). An argument based on the effect of the applied magnetic field on martensite nucleation is adopted to extract information on the direction of the magnetization easy axis in the martensitic unit cell in Heusler alloys. Parallel to these studies, the structure in the presence of an external field is also studied by powder neutron diffraction. It is demonstrated that martensite nucleation is influenced by cooling the sample under a magnetic field such that the austenite phase is arrested within the martensitic state. The magnetic interactions in Ni{sub 50}Mn{sub 37}Sn{sub 13} and Ni{sub 50}Mn{sub 40}Sb{sub 10} are characterized by using neutron polarization analysis. Below the martensitic transformation temperature, M{sub s}, an antiferromagnetically correlated state is found. Ferromagnetic resonance experiments are carried out on Ni{sub 50}Mn{sub 37}Sn{sub 13} and Ni{sub 50}Mn{sub 34}In{sub 16} to gain more detailed information on the nature of the magnetic interactions. The experimental

  10. Effects of Rh on the thermoelectric performance of the p-type Zr0.5Hf0.5Co1-xRhxSb0.99Sn0.01 half-Heusler alloys

    International Nuclear Information System (INIS)

    Maji, Pramathesh; Takas, Nathan J.; Misra, Dinesh K.; Gabrisch, Heike; Stokes, Kevin; Poudeu, Pierre F.P.

    2010-01-01

    We show that Rh substitution at the Co site in Zr 0.5 Hf 0.5 Co 1-x Rh x Sb 0.99 Sn 0.01 (0≤x≤1) half-Heusler alloys strongly reduces the thermal conductivity with a simultaneous, significant improvement of the power factor of the materials. Thermoelectric properties of hot-pressed pellets of several compositions with various Rh concentrations were investigated in the temperature range from 300 to 775 K. The Rh 'free' composition shows n-type conduction, while Rh substitution at the Co site drives the system to p-type semiconducting behavior. The lattice thermal conductivity of Zr 0.5 Hf 0.5 Co 1-x Rh x Sb 0.99 Sn 0.01 alloys rapidly decreased with increasing Rh concentration and lattice thermal conductivity as low as 3.7 W/m*K was obtained at 300 K for Zr 0.5 Hf 0.5 RhSb 0.99 Sn 0.01 . The drastic reduction of the lattice thermal conductivity is attributed to mass fluctuation induced by the Rh substitution at the Co site, as well as enhanced phonon scattering at grain boundaries due to the small grain size of the synthesized materials. - Graphical abstract: Significant reduction of the lattice thermal conductivity with increasing Rh concentration in the p-type Zr 0.5 Hf 0.5 Co 1-x Rh x Sb 0.99 Sn 0.01 half-Heusler materials prepared by solid state reaction at 1173 K.

  11. Growth and transport properties of thin Co-based Heusler films; Wachstum und Transporteigenschaften duenner Co-basierter Heusler-Filme

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Horst

    2010-07-01

    During this work, thin films of Co-based Heusler compounds were deposited under optimized conditions, and their structural, magnetic, and transport properties were investigated. The growth of the thin film samples was accomplished by two different methods. At first Co{sub 2}Cr{sub 0.6}Fe{sub 0.4}Al and Co{sub 2}FeSi were deposited by sputter deposition from stoichiometric targets. This is considered the standard technique for the preparation of thin Heusler films. Also for the compounds investigated here it resulted in samples with a high degree of L2{sub 1} ordering. An excess of Fe atoms on Si sites was discovered by a detailed X-ray analysis in conjunction with NMR spectroscopy. The choice of different substrates allowed the adjustment of the growth direction. On the other hand, bulk magnetometry revealed that these sputter deposited films exhibit only a reduced magnetic moment, which is an indication of a reduced spin asymmetry at the Fermi level. One source of this problem seems to be a high residual gas pressure, which leads to an increased sample contamination. To improve this situation, a pulsed laser deposition system was constructed and put into operation. The resulting film growth under ultra-high vacuum conditions led to a further improvement of the short-range crystallographic ordering and a clear enhancement of the magnetic properties. The additional use of a metallic buffer layer resulted in samples with a smooth surface. This opens the door for a number of further analytical experiments, such as tunneling spectroscopy or Brillouin light scattering. After this successful demonstration of this growth technique, an additional method for the flexible variation of the film stoichiometry was implemented. In this work, this method was successfully applied in the deposition of Co{sub 2}Mn{sub 1-x}Fe{sub x}Si films. All samples in this series show a high degree of atomic ordering. Their magnetization values are compatible with the Slater-Pauling rule for

  12. Electronic structure of Rh-based CuRh0.9Mg0.1O2 oxide thermoelectrics

    Science.gov (United States)

    Vilmercati, P.; Martin, E.; Cheney, C. Parks; Bondino, F.; Magnano, E.; Parmigiani, F.; Sasagawa, T.; Mannella, N.

    2013-03-01

    The electronic structure of the Rh-based CuRh0.9Mg0.1O2 oxide thermoelectric compound has been studied with a multitechnique approach consisting of photoemission, x-ray absorption, and x-ray emission spectroscopies. The data indicate that the region of the valence band in the proximity of the Fermi level is dominated by Rh-derived states. These findings outline the importance of the electronic structure of the Rh ions for the large thermoelectric power in CuRh0.9Mg0.1O2 at high temperature.

  13. (V,Nb)-doped half Heusler alloys based on {Ti,Zr,Hf}NiSn with high ZT

    International Nuclear Information System (INIS)

    Rogl, G.; Sauerschnig, P.; Rykavets, Z.; Romaka, V.V.; Heinrich, P.; Hinterleitner, B.; Grytsiv, A.; Bauer, E.; Rogl, P.

    2017-01-01

    Half Heusler alloys are among the most promising materials for thermoelectric generators as they can be used in a wide temperature range and their starting materials are abundant and cheap, the latter as long as no hafnium is involved. For Sb-doped Ti 0.5 Zr 0.25 Hf 0.25 NiSn Sakurada and Shutoh in 2008 have published ZT max  = 1.5 at 690 K, a value that hitherto was never reproduced independently. In this paper we successfully prepared Ti 0.5 Zr 0.25 Hf 0.25 NiSn with ZT max  = 1.5, however, at higher temperature (825 K). As the main goal is to produce hafnium – free half Heusler alloys, we investigated the influence of niobium or vanadium dopants on Ti x Zr 1−x NiSn 0.98 Sb 0.02 , reaching ZTs > 1.2 and thermal-electric conversion efficiencies up to 13.1%. For Hf-free n-type TiNiSn-based half Heusler alloys these values are unsurpassed. In order to further improve our thermoelectric materials our study is completed by electrical resistivity and thermal conductivity data in the low temperature range but also by mechanical properties (elastic moduli, hardness) at room temperature. The electrical properties have been discussed in comparison with DFT calculations.

  14. Structure and properties of quarternary and tetragonal Heusler compounds for spintronics and spin transver torque applications

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    Zamani, Vajiheh Alijani

    2012-03-07

    This work is divided into two parts: part 1 is focused on the prediction of half-metallicity in quaternary Heusler compounds and their potential for spintronic applications and part 2 on the structural properties of Mn{sub 2}-based Heusler alloys and tuning the magnetism of them from soft to hard-magnetic for spin-transfer torque applications. In part 1, three different series of quaternary Heusler compounds are investigated, XX'MnGa (X=Cu, Ni and X'=Fe,Co), CoFeMnZ (Z=Al,Ga,Si,Ge), and Co{sub 2-x}Rh{sub x}MnZ (Z=Ga,Sn,Sb). All of these quaternary compounds except CuCoMnGa are predicted to be half-metallic ferromagnets by ab-initio electronic structure calculations. In the XX'MnGa class of compounds, NiFeMnGa has a low Curie temperature for technological applications but NiCoMnGa with a high spin polarization, magnetic moment, and Curie temperature is an interesting new material for spintronics applications. All CoFeMnZ compounds exhibit a cubic Heusler structur and their magnetic moments are in fair agreement with the Slater-Pauling rule indicating the halfmetallicity and high spin polarization required for spintronics applications. Their high Curie temperatures make them suitable for utilization at room temperature and above. The structural investigation revealed that the crystal structure of all Co{sub 2-x}Rh{sub x}MnZ compounds aside from CoRhMnSn exhibit different types of anti-site disorder. The magnetic moments of the disordered compounds deviate from the Slater-Pauling rule indicating that 100% spin polarization are not realized in CoRhMnGa, CoRhMnSb, and Co{sub 0.5}Rh{sub 1.5}MnSb. Exchange of one Co in Co{sub 2}MnSn by Rh results in the stable, well-ordered compound CoRhMnSn. This exchange of one of the magnetic Co atoms by a non-magnetic Rh atom keeps the magnetic properties and half-metallicity intact. In part 2, two series of Mn{sub 2}-based Heusler alloys are investigated, Mn{sub 3-x}Co{sub x}Ga and Mn{sub 2-x}Rh{sub 1+x}Sn. It has been

  15. Designing magnetic compensated states in tetragonal Mn{sub 3}Ge-based Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    You, Yurong; Xu, Guizhou, E-mail: gzxu@njust.edu.cn; Hu, Fang; Gong, Yuanyuan; Liu, Er; Peng, Guo; Xu, Feng, E-mail: xufeng@njust.edu.cn

    2017-05-01

    Magnetic compensated materials attracted much interests due to the observed large exchange bias and large coercivity, and also their potential applications in the antiferromagnetic spintronics with merit of no stray field. In this work, by using ab-initio studies, we designed several Ni (Pd, Pt) doped Mn{sub 3}Ge-based D0{sub 22}-type tetragonal Heusler alloys with fully compensated states. Theoretically, we find the total moment change is asymmetric across the compensation point (at ~x=0.3) in Mn{sub 3-x}Y{sub x}Ge (Y=Ni, Pd, Pt). In addition, an uncommon discontinuous jump is observed across the critical zero-moment point, indicating that some non-trivial properties may emerge at this point. Further electronic analyses of these compensated alloys reveal high spin polarizations at the Fermi level, which is advantageous for spin transfer torque applications. - Highlights: • Several new fully compensated magnetic states are identified in Mn{sub 3}Ge-based tetragonal alloys. • The magnetic moment changes are asymmetric upon Ni, Pd and Pt substitution. • Discontinuous jumps exist across the compensated points. • The three compensated alloys possess large spin polarizations.

  16. Simulation of stress-modulated magnetization precession frequency in Heusler-based spin torque oscillator

    International Nuclear Information System (INIS)

    Huang, Houbing; Zhao, Congpeng; Ma, Xingqiao

    2017-01-01

    We investigated stress-modulated magnetization precession frequency in Heusler-based spin transfer torque oscillator by combining micromagnetic simulations with phase field microelasticity theory, by encapsulating the magnetic tunnel junction into multilayers structures. We proposed a novel method of using an external stress to control the magnetization precession in spin torque oscillator instead of an external magnetic field. The stress-modulated magnetization precession frequency can be linearly modulated by externally applied uniaxial in-plane stress, with a tunable range 4.4–7.0 GHz under the stress of 10 MPa. By comparison, the out-of-plane stress imposes negligible influence on the precession frequency due to the large out-of-plane demagnetization field. The results offer new inspiration to the design of spin torque oscillator devices that simultaneously process high frequency, narrow output band, and tunable over a wide range of frequencies via external stress. - Highlights: • We proposed stress-modulated magnetization precession in spin torque oscillator. • The magnetization precession frequency can be linearly modulated by in-plane stress. • The stress also can widen the magnetization frequency range 4.4–7.0 GHz. • The stress-modulated oscillation frequency can simplify STO devices.

  17. Simulation of stress-modulated magnetization precession frequency in Heusler-based spin torque oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Houbing, E-mail: hbhuang@ustb.edu.cn; Zhao, Congpeng; Ma, Xingqiao, E-mail: xqma@sas.ustb.edu.cn

    2017-03-15

    We investigated stress-modulated magnetization precession frequency in Heusler-based spin transfer torque oscillator by combining micromagnetic simulations with phase field microelasticity theory, by encapsulating the magnetic tunnel junction into multilayers structures. We proposed a novel method of using an external stress to control the magnetization precession in spin torque oscillator instead of an external magnetic field. The stress-modulated magnetization precession frequency can be linearly modulated by externally applied uniaxial in-plane stress, with a tunable range 4.4–7.0 GHz under the stress of 10 MPa. By comparison, the out-of-plane stress imposes negligible influence on the precession frequency due to the large out-of-plane demagnetization field. The results offer new inspiration to the design of spin torque oscillator devices that simultaneously process high frequency, narrow output band, and tunable over a wide range of frequencies via external stress. - Highlights: • We proposed stress-modulated magnetization precession in spin torque oscillator. • The magnetization precession frequency can be linearly modulated by in-plane stress. • The stress also can widen the magnetization frequency range 4.4–7.0 GHz. • The stress-modulated oscillation frequency can simplify STO devices.

  18. Structural and magnetic characterization of Fe2CrSi Heusler alloy nanoparticles as spin injectors and spin based sensors

    Science.gov (United States)

    Saravanan, G.; Asvini, V.; Kalaiezhily, R. K.; Parveen, I. Mubeena; Ravichandran, K.

    2018-05-01

    Half-metallic ferromagnetic [HMF] nanoparticles are of considerable interest in spintronics applications due to their potential use as a highly spin polarized current source. HMF exhibits a semiconductor in one spin band at the Fermi level Ef and at the other spin band they poses strong metallic nature which shows 100 % spin polarization at Ef. Fe based full Heusler alloys are primary interest due to high Curie temperature. Fe2CrSi Heusler alloys are synthesized using metallic powders of Fe, Cr and Si by mechanical alloying method. X-Ray diffractions studies were performed to analyze the structural details of Fe2CrSi nanoparticles with High resolution scanning electron microscope (HRSEM) studies for the morphological details of nanoparticles and magnetic properties were studied using Vibrating sample magnetometer (VSM). XRD Data analysis conforms the Heusler alloy phase showing the existence of L21 structure. Magnetic properties are measured for synthesized samples exhibiting a soft magnetic property possessing low coercivity (HC = 60.5 Oe) and saturation magnetic moment of Fe2CrSi is 3.16 µB, which is significantly higher than the ideal value of 2 µB from the Slater-Pauling rule due to room temperature measurement. The change in magnetic properties are half-metallic nature of Fe2CrSi is due to the shift of the Fermi level with respect to the gap were can be used as spin sensors and spin injectors in magnetic random access memories and other spin dependent devices.

  19. Spin disordered resistivity of the Heusler Ni.sub.2./sub.MnGa-based alloys

    Czech Academy of Sciences Publication Activity Database

    Kamarád, Jiří; Kaštil, Jiří; Albertini, F.; Fabbrici, S.; Arnold, Zdeněk

    2017-01-01

    Roč. 131, č. 4 (2017), s. 1072-1074 ISSN 0587-4246 R&D Projects: GA ČR GAP204/12/0692 Institutional support: RVO:68378271 Keywords : spin disordered resistivity * magnetoresistance * Heusler alloys * Ni 2 MnGa Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 0.469, year: 2016

  20. Structural, electronic, magnetic and optical properties of Ni,Ti/Al-based Heusler alloys. A first-principles approach

    Energy Technology Data Exchange (ETDEWEB)

    Adebambo, Paul O. [Univ. of Agriculture. Abeokuta (Nigeria). Dept. of Physics; McPherson Univ., Abeokuta (Nigeria). Dept. of Physical and Computer Sciences; Adetunji, Bamidele I. [Univ. of Agriculture. Abeokuta (Nigeria). Dept. of Physics; Bells Univ. of Technology, Oto (Nigeria). Dept. of Mathematics; Olowofela, Joseph A. [Univ. of Agriculture. Abeokuta (Nigeria). Dept. of Physics; Oguntuase, James A. [Univ. of Agriculture. Abeokuta (Nigeria). Dept. of Mathematics; Adebayo, Gboyega A. [Univ. of Agriculture. Abeokuta (Nigeria). Dept. of Physics; Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)

    2016-05-01

    In this work, detailed first-principles calculations within the generalised gradient approximation (GGA) of electronic, structural, magnetic, and optical properties of Ni,Ti, and Al-based Heusler alloys are presented. The lattice parameter of C1{sub b} with space group F anti 43m (216) NiTiAl alloys is predicted and that of Ni{sub 2}TiAl is in close agreement with available results. The band dispersion along the high symmetry points W→L→Γ→X→W→K in Ni{sub 2}TiAl and NiTiAl Heusler alloys are also reported. NiTiAl alloy has a direct band gap of 1.60 eV at Γ point as a result of strong hybridization between the d state of the lower and higher valence of both the Ti and Ni atoms. The calculated real part of the dielectric function confirmed the band gap of 1.60 eV in NiTiAl alloys. The present calculations revealed the paramagnetic state of NiTiAl. From the band structure calculations, Ni{sub 2}TiAl with higher Fermi level exhibits metallic properties as in the case of both NiAl and Ni{sub 3}Al binary systems.

  1. Ab initio study of effect of Co substitution on the magnetic properties of Ni and Pt-based Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Tufan, E-mail: tufanroyburdwan@gmail.com [Theory and Simulations Lab, HRDS, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094 (India); Chakrabarti, Aparna [Theory and Simulations Lab, HRDS, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094 (India)

    2017-04-25

    Using density functional theory based calculations, we have carried out in-depth studies of effect of Co substitution on the magnetic properties of Ni and Pt-based shape memory alloys. We show the systematic variation of the total magnetic moment, as a function of Co doping. A detailed analysis of evolution of Heisenberg exchange coupling parameters as a function of Co doping has been presented here. The strength of RKKY type of exchange interaction is found to decay with the increase of Co doping. We calculate and show the trend, how the Curie temperature of the systems vary with the Co doping. - Highlights: • We discuss the effects of Co doping on magnetic properties of Ni/Pt based Heusler alloys. • Indirect RKKY interaction is maximum for shape memory alloy like systems. • We predict Pt{sub 2}MnSn as a probable ferromagnetic shape memory alloy.

  2. Growth and Electronic Structure of Heusler Compounds for Use in Electron Spin Based Devices

    Science.gov (United States)

    2015-06-01

    this procedure seemed to succeed, with the successful growth of PtLuSb films on GdSb. However, upon examination of x-ray diffrac- 55 tion data, it was...0.33, 0.66, and 1 were all grown as a series, in immediate succession without changing the Co or Si source temperatures so as to eliminate any...39(1):1–50, May 2011. doi:10.1016/j.progsolidstchem.2011.02.001. [3] F. Heusler, W. Starck, and E. Haupt. Uber magnetische manganlegierun- gen

  3. Magnetocaloric effect and multifunctional properties of Ni-Mn-based Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dubenko, Igor, E-mail: igor_doubenko@yahoo.com [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Samanta, Tapas; Kumar Pathak, Arjun [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Kazakov, Alexandr; Prudnikov, Valerii [Faculty of Physics, Moscow State University, Vorob' evy Gory, 11999I Moscow (Russian Federation); Stadler, Shane [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Granovsky, Alexander [Faculty of Physics, Moscow State University, Vorob' evy Gory, 11999I Moscow (Russian Federation); IKERBASQUE, The Basque Foundation for Science, 48011 Bilbao (Spain); Departamento de Fisica de Materiales, Facultad de Quimica, Universidad del Pais Vasco, Paseo M. de Lardizabal 3, 20018 Donostia - San Sebastian (Spain); Zhukov, Arcady [IKERBASQUE, The Basque Foundation for Science, 48011 Bilbao (Spain); Departamento de Fisica de Materiales, Facultad de Quimica, Universidad del Pais Vasco, Paseo M. de Lardizabal 3, 20018 Donostia - San Sebastian (Spain); Ali, Naushad [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States)

    2012-10-15

    The studies of magnetocaloric properties, phase transitions, and phenomena related to magnetic heterogeneity in the vicinity of the martensitic transition (MT) in Ni-Mn-In and Ni-Mn-Ga off-stoichiometric Heusler alloys are summarized. The crystal structure, magnetocaloric effect (MCE), and magnetotransport properties were studied for the following alloys: Ni{sub 50}Mn{sub 50-x}In{sub x}, Ni{sub 50-x}Co{sub x}Mn{sub 35}In{sub 15}, Ni{sub 50}Mn{sub 35-x}Co{sub x}In{sub 15}, Ni{sub 50}Mn{sub 35}In{sub 14}Z (Z=Al, Ge), Ni{sub 50}Mn{sub 35}In{sub 15-x}Si{sub x}, Ni{sub 50-x}Co{sub x}Mn{sub 25+y}Ga{sub 25-y}, and Ni{sub 50-x}Co{sub x}Mn{sub 32-y}FeyGa{sub 18}. It was found that the magnetic entropy change, {Delta}S, associated with the inverse MCE in the vicinity of the temperature of the magneto-structural transition, TM, persists in a range of (125-5) J/(kg K) for a magnetic field change {Delta}H=5 T. The corresponding temperature varies with composition from 143 to 400 K. The MT in Ni{sub 50}Mn{sub 50-x}In{sub x} (x=13.5) results in a transition between two paramagnetic states. Associated with the paramagnetic austenite-paramagnetic martensite transition {Delta}S=24 J/(kg K) was detected for {Delta}H=5 T at T=350 K. The variation in composition of Ni{sub 2}MnGa can drastically change the magnetic state of the martensitic phase below and in the vicinity of TM. The presence of the martensitic phase with magnetic moment much smaller than that in the austenitic phase above TM leads to the large inverse MCE in the Ni{sub 42}Co{sub 8}Mn{sub 32-y}FeyGa{sub 18} system. The adiabatic change of temperature ({Delta}T{sub ad}) in the vicinity of TC and TM of Ni{sub 50}Mn{sub 35}In{sub 15} and Ni{sub 50}Mn{sub 35}In{sub 14}Z (Z=Al, Ge) was found to be {Delta}T{sub ad}=-2 K and 2 K for {Delta}H=1.8 T, respectively. It was observed that |{Delta}T{sub ad}| Almost-Equal-To 1 K for {Delta}H=1 T for both types of transitions. The results on resistivity, magnetoresistance, Hall

  4. L2₁ and XA Ordering Competition in Hafnium-Based Full-Heusler Alloys Hf₂VZ (Z = Al, Ga, In, Tl, Si, Ge, Sn, Pb).

    Science.gov (United States)

    Wang, Xiaotian; Cheng, Zhenxiang; Wang, Wenhong

    2017-10-20

    For theoretical designing of full-Heusler based spintroinc materials, people have long believed in the so-called Site Preference Rule (SPR). Very recently, according to the SPR, there are several studies on XA-type Hafnium-based Heusler alloys X₂YZ, i.e., Hf₂VAl, Hf₂CoZ (Z = Ga, In) and Hf₂CrZ (Z = Al, Ga, In). In this work, a series of Hf₂-based Heusler alloys, Hf₂VZ (Z = Al, Ga, In, Tl, Si, Ge, Sn, Pb), were selected as targets to study the site preferences of their atoms by first-principle calculations. It has been found that all of them are likely to exhibit the L2₁-type structure instead of the XA one. Furthermore, we reveal that the high values of spin-polarization of XA-type Hf₂VZ (Z = Al, Ga, In, Tl, Si, Ge, Sn, Pb) alloys have dropped dramatically when they form the L2₁-type structure. Also, we prove that the electronic, magnetic, and physics nature of these alloys are quite different, depending on the L2₁-type or XA-type structures.

  5. High performance p-type half-Heusler thermoelectric materials

    Science.gov (United States)

    Yu, Junjie; Xia, Kaiyang; Zhao, Xinbing; Zhu, Tiejun

    2018-03-01

    Half-Heusler compounds, which possess robust mechanical strength, good high temperature thermal stability and multifaceted physical properties, have been verified as a class of promising thermoelectric materials. During the last two decades, great progress has been made in half-Heusler thermoelectrics. In this review, we summarize some representative work of p-type half-Heusler materials, the thermoelectric performance of which has been remarkably enhanced in recent years. We introduce the features of the crystal and electronic structures of half-Heusler compounds, and successful strategies for optimizing electrical and thermal transport in the p-type RFeSb (R  =  V, Nb, Ta) and MCoSb (M  =  Ti, Zr, Hf) based systems, including band engineering, the formation of solid solutions and hierarchical phonon scattering. The outlook for future research directions of half-Heusler thermoelectrics is also presented.

  6. Thermoelectric and Structural Properties of Zr-/Hf-Based Half-Heusler Compounds Produced at a Large Scale

    Science.gov (United States)

    Zillmann, D.; Waag, A.; Peiner, E.; Feyand, M.-H.; Wolyniec, A.

    2018-02-01

    The half-Heusler (HH) systems are promising candidates for thermoelectric (TE) applications since they have shown high figures of merit ( zT) of ˜ 1, which are directly related to the energy conversion efficiency. To use HH compounds for TE devices, the materials must be phase-stable at operating temperatures up to 600°C. Currently, only a few HH compositions are available in large quantities. Hence, we focus on the TE and structural properties of three commercially available Zr-/Hf-based HH compounds in this publication. In particular, we evaluate the thermal conductivities and the figures of merit and critically discuss uncertainties and propagation error in the measurements. We find thermal conductivities of less than 6.0 W K^{-1}m^{-1} for all investigated materials and notably high figures of merit of 0.93 and 0.60 for n- and p-type compounds, respectively, at 600°C. Additionally, our investigations reveal that the grain structures of all materials also contain secondary phases like HfO2, Sn-Ni and Ti-Zr-Sn rich phases while an additional SnO_2 phase was found following several hours of harsh heat treatment at 800°C.

  7. Temperature dependence of differential conductance in Co-based Heusler alloy Co2TiSn and superconductor Pb junctions

    Science.gov (United States)

    Ooka, Ryutaro; Shigeta, Iduru; Umetsu, Rie Y.; Nomura, Akiko; Yubuta, Kunio; Yamauchi, Touru; Kanomata, Takeshi; Hiroi, Masahiko

    2018-05-01

    We investigated temperature dependence of differential conductance G (V) in planar junctions consisting of Co-based Heusler alloy Co2TiSn and superconductor Pb. Ferromagnetic Co2TiSn was predicted to be half-metal by first-principles band calculations. The spin polarization P of Co2TiSn was deduced to be 60.0% at 1.4 K by the Andreev reflection spectroscopy. The G (V) spectral shape was smeared gradually with increasing temperature and its structure was disappeared above the superconducting transition temperature Tc. Theoretical model analysis revealed that the superconducting energy gap Δ was 1.06 meV at 1.4 K and the Tc was 6.8 K , indicating that both values were suppressed from bulk values. However, the temperature dependent Δ (T) behavior was in good agreement with that of the Bardeen-Cooper-Schrieffer (BCS) theory. The experimental results exhibit that the superconductivity of Pb attached to half-metallic Co2TiSn was kept the conventional BCS mechanism characterized strong-coupling superconductors while its superconductivity was slightly suppressed by the superconducting proximity effect at the Co2TiSn/Pb interface.

  8. Spin injection and magnetoresistance in MoS2-based tunnel junctions using Fe3Si Heusler alloy electrodes.

    Science.gov (United States)

    Rotjanapittayakul, Worasak; Pijitrojana, Wanchai; Archer, Thomas; Sanvito, Stefano; Prasongkit, Jariyanee

    2018-03-19

    Recently magnetic tunnel junctions using two-dimensional MoS 2 as nonmagnetic spacer have been fabricated, although their magnetoresistance has been reported to be quite low. This may be attributed to the use of permalloy electrodes, injecting current with a relatively small spin polarization. Here we evaluate the performance of MoS 2 -based tunnel junctions using Fe 3 Si Heusler alloy electrodes. Density functional theory and the non-equilibrium Green's function method are used to investigate the spin injection efficiency (SIE) and the magnetoresistance (MR) ratio as a function of the MoS 2 thickness. We find a maximum MR of ~300% with a SIE of about 80% for spacers comprising between 3 and 5 MoS 2 monolayers. Most importantly, both the SIE and the MR remain robust at finite bias, namely MR > 100% and SIE > 50% at 0.7 V. Our proposed materials stack thus demonstrates the possibility of developing a new generation of performing magnetic tunnel junctions with layered two-dimensional compounds as spacers.

  9. Mechanistic Investigation of the Reduction of NOx over Pt- and Rh-Based LNT Catalysts

    Directory of Open Access Journals (Sweden)

    Lukasz Kubiak

    2016-03-01

    Full Text Available The influence of the noble metals (Pt vs. Rh on the NOx storage reduction performances of lean NOx trap catalysts is here investigated by transient micro-reactor flow experiments. The study indicates a different behavior during the storage in that the Rh-based catalyst showed higher storage capacity at high temperature as compared to the Pt-containing sample, while the opposite is seen at low temperatures. It is suggested that the higher storage capacity of the Rh-containing sample at high temperature is related to the higher dispersion of Rh as compared to Pt, while the lower storage capacity of Rh-Ba/Al2O3 at low temperature is related to its poor oxidizing properties. The noble metals also affect the catalyst behavior upon reduction of the stored NOx, by decreasing the threshold temperature for the reduction of the stored NOx. The Pt-based catalyst promotes the reduction of the adsorbed NOx at lower temperatures if compared to the Rh-containing sample, due to its superior reducibility. However, Rh-based material shows higher reactivity in the NH3 decomposition significantly enhancing N2 selectivity. Moreover, formation of small amounts of N2O is observed on both Pt- and Rh-based catalyst samples only during the reduction of highly reactive NOx stored at 150 °C, where NOx is likely in the form of nitrites.

  10. Design of Fatigue Resistant Heusler-strengthened PdTi-based Shape Memory Alloys for Biomedical Applications

    Science.gov (United States)

    Frankel, Dana J.

    The development of non-surgical transcatheter aortic valve implantation (TAVI) techniques, which utilize collapsible artificial heart valves with shape memory alloy (SMA)-based frames, pushes performance requirements for biomedical SMAs beyond those for well-established vascular stent applications. Fatigue life for these devices must extend into the ultra-high cycle fatigue (UHCF) regime (>600M cycles) with zero probability of failure predicted at applied strain levels. High rates of Ni-hypersensitivity raise biocompatibility concerns, driving the development of low-Ni and Ni-free SMAs. This work focuses on the development of biocompatible, precipitation-strengthened, fatigue-resistant PdTi-based SMAs for biomedical applications. Functional and structural fatigue are both manifestations of cyclic instability resulting in accumulation of slip and eventual structural damage. While functional fatigue is easily experimentally evaluated, structural fatigue is more difficult to measure without the proper equipment. Therefore, in this work a theoretical approach using a model well validated in steels is utilized to investigate structural fatigue behavior in NiTi in the UHCF regime, while low cycle functional fatigue is evaluated in order to monitor the core phenomena of the cyclic instability. Results from fatigue simulations modeling crack nucleation at non-metallic inclusions in commercial NiTi underscore the importance of increasing yield strength for UHCF performance. Controlled precipitation of nanoscale, low-misfit, L21 Heusler aluminides can provide effective strengthening. Phase relations, precipitation kinetics, transformation temperature, transformation strain, cyclic stability, and mechanical properties are characterized in both Ni-free (Pd,Fe)(Ti,Al) and low-Ni high-strength "hybrid" (Pd,Ni)(Ti,Zr,Al) systems. Atom probe tomography is employed to measure phase compositions and particle sizes used to calibrate LSW models for coarsening kinetics and Gibbs

  11. Engineering half-Heusler thermoelectric materials using Zintl chemistry

    Science.gov (United States)

    Zeier, Wolfgang G.; Schmitt, Jennifer; Hautier, Geoffroy; Aydemir, Umut; Gibbs, Zachary M.; Felser, Claudia; Snyder, G. Jeffrey

    2016-06-01

    Half-Heusler compounds based on XNiSn and XCoSb (X = Ti, Zr or Hf) have rapidly become important thermoelectric materials for converting waste heat into electricity. In this Review, we provide an overview on the electronic properties of half-Heusler compounds in an attempt to understand their basic structural chemistry and physical properties, and to guide their further development. Half-Heusler compounds can exhibit semiconducting transport behaviour even though they are described as ‘intermetallic’ compounds. Therefore, it is most useful to consider these systems as rigid-band semiconductors within the framework of Zintl (or valence-precise) compounds. These considerations aid our understanding of their properties, such as the bandgap and low hole mobility because of interstitial Ni defects in XNiSn. Understanding the structural and bonding characteristics, including the presence of defects, will help to develop different strategies to improve and design better half-Heusler thermoelectric materials.

  12. Rare earth-based quaternary Heusler compounds MCoVZ (M = Lu, Y; Z = Si, Ge with tunable band characteristics for potential spintronic applications

    Directory of Open Access Journals (Sweden)

    Xiaotian Wang

    2017-11-01

    Full Text Available Magnetic Heusler compounds (MHCs have recently attracted great attention since these types of material provide novel functionalities in spintronic and magneto-electronic devices. Among the MHCs, some compounds have been predicted to be spin-filter semiconductors [also called magnetic semiconductors (MSs], spin-gapless semiconductors (SGSs or half-metals (HMs. In this work, by means of first-principles calculations, it is demonstrated that rare earth-based equiatomic quaternary Heusler (EQH compounds with the formula MCoVZ (M = Lu, Y; Z = Si, Ge are new spin-filter semiconductors with total magnetic moments of 3 µB. Furthermore, under uniform strain, there are physical transitions from spin-filter semiconductor (MS → SGS → HM for EQH compounds with the formula LuCoVZ, and from HM → SGS → MS → SGS → HM for EQH compounds with the formula YCoVZ. Remarkably, for YCoVZ EQH compounds there are not only diverse physical transitions, but also different types of spin-gapless feature that can be observed with changing lattice constants. The structural stability of these four EQH compounds is also examined from the points of view of formation energy, cohesive energy and mechanical behaviour. This work is likely to inspire consideration of rare earth-based EQH compounds for application in future spintronic and magneto-electronic devices.

  13. Synthesis, structural, magnetic and optical properties of Sr2CoSn based inverse Heusler alloy nanoparticles

    Science.gov (United States)

    Asvini, V.; Saravanan, G.; Kalaiezhily, R. K.; Ravichandran, K.

    2018-05-01

    The peculiar ternary full Heusler alloy Sr2CoSn nanoparticles are synthesized by co-precipitation method. X- ray diffraction pattern confirms the formation of XA or Xα structure of Sr2CoSn. Using Williamson-Hall plot (W-H plot), we are able to use the uniform deformation model and get low value of strain induced broadening. UV-Visible absorption spectrum shows sharp absorption peak at 210 nm and the estimated band gap energy of Sr2CoSn Heusler alloy nanoparticles is Eg = 4.6 eV (from Tauc plot). The presence of Sr2CoSn with the particle size of approximately 90 nm was observed using high resolution scanning electron microscopy. The magnetization measurements were carried out using VSM and studied M verses H hysteresis studies.

  14. Tuning the magnetocaloric response in half-Heusler/Heusler MnNi1 +xSb solid solutions

    Science.gov (United States)

    Levin, Emily E.; Bocarsly, Joshua D.; Wyckoff, Kira E.; Pollock, Tresa M.; Seshadri, Ram

    2017-12-01

    Materials with a large magnetocaloric response are associated with a temperature change upon the application of a magnetic field and are of interest for applications in magnetic refrigeration and thermomagnetic power generation. The usual metric of this response is the gravimetric isothermal entropy change Δ SM . The use of a simple proxy for the Δ SM that is based on density functional theory (DFT) calculations of the magnetic electronic structure suggests that half-Heusler MnNiSb should be a better magnetocaloric than the corresponding Heusler compound MnNi2Sb . Guided by this observation, we present a study of MnNi1 +xSb (x =0 , 0.25, 0.5, 0.75, and 1.0) to evaluate relevant structural and magnetic properties. DFT stability calculations suggest that the addition of Ni takes place at a symmetrically distinct Ni site in the half-Heusler structure and support the observation using synchrotron x-ray diffraction of a homogeneous solid solution between the half-Heusler and Heusler end members. There is a maximum in the saturation magnetization at x =0.5 and the Curie temperature systematically decreases with increasing x . Δ SM for a maximum magnetic field change of Δ H =5 T monotonically decreases in magnitude from -2.93 J kg-1K-1 in the half-Heusler to -1.35 J kg-1K-1 in the Heusler compound. The concurrent broadening of the magnetic transition results in a maximum in the refrigerant capacity at x =0.75 . The Curie temperature of this system is highly tunable between 350 K and 750 K, making it ideal for low grade waste heat recovery via thermomagnetic power generation. The increase in Δ SM with decreasing x may be extendable to other MnNi2Z Heusler systems that are currently under investigation for use in magnetocaloric refrigeration applications.

  15. Production of polarizing Heusler crystals

    Energy Technology Data Exchange (ETDEWEB)

    Courtois, P. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1999-11-01

    Heusler crystals simultaneously produce monochromatized and polarized neutrons. However, in the past, it was difficult to produce these crystals. In collaboration with the neutron scattering group of CEA Grenoble and LLB Saclay, the production of high quality Heusler crystals has been established at ILL. (author) 3 refs., 2 figs., 1 tab.

  16. Local moments and electronic correlations in Fe-based Heusler alloys: Kα x-ray emission spectra measurements

    International Nuclear Information System (INIS)

    Svyazhin, Artem; Kurmaev, Ernst; Shreder, Elena; Shamin, Sergey; Sahle, Christoph J.

    2016-01-01

    Heusler alloys are a property-rich class of materials, intensively investigated today from both theoretical and real-world application points of view. In this paper, we attempt to shed light on the role of electronic correlations in the Fe_2MeAl group (where Me represents all 3d elements from Ti to Ni) of Heusler alloys. For this purpose, we have investigated the local moments of iron by means of the x-ray emission spectroscopy technique. To obtain numerical values of local moments, the Kα-FWHM method has been employed for the first time. In every compound of the group, the presence of a local moment on the Fe atom was detected. As has been revealed, the values of these moments are temperature-independent, pointing to an insufficiency of a pure itinerant approach to magnetism in these alloys. We also comprehensively compare the usage of Kβ main lines and Kα spectra as tools for the probing of local moments and point out the significant advantages of the latter. - Highlights: • Local spin moments of iron in Fe_2MeAl (Me = Ti … Ni) Heusler alloys were investigated by means of x-ray emission spectroscopy. • Independence of the local moments from temperature confirms their localized nature. • A local moment value of iron in Fe_2MeAl raises with the atomic number of element Me. • The applicability of the Kα x-ray emission line for extracting local moment values of 3d elements was established.

  17. Simulation study of ballistic spin-MOSFET devices with ferromagnetic channels based on some Heusler and oxide compounds

    Science.gov (United States)

    Graziosi, Patrizio; Neophytou, Neophytos

    2018-02-01

    Newly emerged materials from the family of Heuslers and complex oxides exhibit finite bandgaps and ferromagnetic behavior with Curie temperatures much higher than even room temperature. In this work, using the semiclassical top-of-the-barrier FET model, we explore the operation of a spin-MOSFET that utilizes such ferromagnetic semiconductors as channel materials, in addition to ferromagnetic source/drain contacts. Such a device could retain the spin polarization of injected electrons in the channel, the loss of which limits the operation of traditional spin transistors with non-ferromagnetic channels. We examine the operation of four material systems that are currently considered some of the most prominent known ferromagnetic semiconductors: three Heusler-type alloys (Mn2CoAl, CrVZrAl, and CoVZrAl) and one from the oxide family (NiFe2O4). We describe their band structures by using data from DFT (Density Functional Theory) calculations. We investigate under which conditions high spin polarization and significant ION/IOFF ratio, two essential requirements for the spin-MOSFET operation, are both achieved. We show that these particular Heusler channels, in their bulk form, do not have adequate bandgap to provide high ION/IOFF ratios and have small magnetoconductance compared to state-of-the-art devices. However, with confinement into ultra-narrow sizes down to a few nanometers, and by engineering their spin dependent contact resistances, they could prove promising channel materials for the realization of spin-MOSFET transistor devices that offer combined logic and memory functionalities. Although the main compounds of interest in this paper are Mn2CoAl, CrVZrAl, CoVZrAl, and NiFe2O4 alone, we expect that the insight we provide is relevant to other classes of such materials as well.

  18. Rh Incompatibility

    Science.gov (United States)

    ... type is called Rh. Rh factor is a protein on red blood cells. Most people are Rh-positive; they have Rh factor. Rh-negative people don't have it. Rh factor is inherited though genes. When you're pregnant, blood from your baby can cross into your ...

  19. Rice husk (RH) as additive in fly ash based geopolymer mortar

    Science.gov (United States)

    Yahya, Zarina; Razak, Rafiza Abd; Abdullah, Mohd Mustafa Al Bakri; Rahim, Mohd Azrin Adzhar; Nasri, Armia

    2017-09-01

    In recent year, the Ordinary Portland Cement (OPC) concrete is vastly used as main binder in construction industry which lead to depletion of natural resources in order to manufacture large amount of OPC. Nevertheless, with the introduction of geopolymer as an alternative binder which is more environmental friendly due to less emission of carbon dioxide (CO2) and utilized waste materials can overcome the problems. Rice husk (RH) is an agricultural residue which can be found easily in large quantity due to production of paddy in Malaysia and it's usually disposed in landfill. This paper investigated the effect of rice husk (RH) content on the strength development of fly ash based geopolymer mortar. The fly ash is replaced with RH by 0%, 5%, 10%, 15% and 20% where the sodium silicate and sodium hydroxide was used as alkaline activator. A total of 45 cubes were casted and their compressive strength, density and water absorption were evaluated at 1, 3, and 7 days. The result showed compressive strength decreased when the percentage of RH increased. At 5% replacement of RH, the maximum strength of 17.1MPa was recorded at day 7. The geopolymer has lowest rate of water absorption (1.69%) at 20% replacement of RH. The density of the sample can be classified as lightweight geopolymer concrete.

  20. Coupled Simulation of Thermomagnetic Energy Generation Based on NiMnGa Heusler Alloy Films

    Science.gov (United States)

    Kohl, Manfred; Gueltig, Marcel; Wendler, Frank

    2018-03-01

    This paper presents a simulation model for the coupled dynamic properties of thermomagnetic generators based on magnetic shape memory alloy (MSMA) films. MSMA thermomagnetic generators exploit the large abrupt temperature-induced change of magnetization at the first- or second-order magnetic transition as well as the short heat transfer times due to the large surface-to-volume ratio of films. These properties allow for resonant self-actuation of freely movable MSMA cantilever devices showing thermomagnetic duty cycles in the order of 10 ms duration, which matches with the period of oscillatory motion. We present a numerical analysis of the energy conversion processes to understand the effect of design parameters on efficiency and power output. A lumped element model is chosen to describe the time dependence of MSMA cantilever deflection and of temperature profiles as well as the magnitude and phase dependency of magnetization change. The simulation model quantitatively describes experimentally observed oscillatory motion and resulting power output in the order of 100 mW cm-3. Furthermore, it predicts a power output of 490 mW cm-3 for advanced film materials with temperature-dependent change of magnetization Δ M/Δ T of 4 A m2 (kg K)-1, which challenges state-of-the-art thermoelectric devices.

  1. Structural, electronic, magnetic, elastic, and thermal properties of Co-based equiatomic quaternary Heusler alloys

    Science.gov (United States)

    Paudel, Ramesh; Zhu, Jingchuan

    2018-05-01

    In this research work, we have predicted the physical properties of CoFeZrGe and CoFeZrSb for the first time by utilizing first principle calculations based on density functional theory. The exchange-correlation potentials are treated within the generalized-gradient approximation of Perdew-Burke and Ernzerhof (GGA-PBE). The investigated equilibrium lattice parameters of CoFeCrSi are in agreement with available theoretical data and for CoFeZrZ(Z = Ge,Sb) are 6.0013 and 6.2546 Å respectively. The calculated magnetic moments are 1.01μB /fu , 2μB /fu and 1μB /fu for CoFeZrZ(Z = Ge, Sb and Si) respectively, and agree with the Slater-Pauling rule, Mt =Zt - 24 . The CoFeZrGe, CoFeZrSb and CoFeZrSi composites showed half-metallic behaviour with 100 % spin polarization at equilibrium lattice parameters with band gap of 0.43, 0.70 and 0.59 eV for GGA and an improved band gap of 0.86, 1.01 and 1.08 for GGA + U respectively. Elastic properties are also discussed in this paper and it is found that all the materials are mechanically stable and ductile in nature. The CoFeZrSi alloy is found to be stiffer than CoFeZrZ(Z = Ge and Sb) alloys. The Debye temperatures are predicted by using calculated elastic constants. Moreover, the volume heat capacities (Cv) are investigated by utilizing the quasi-harmonic Debye model.

  2. The pressure dependence of structural, electronic, mechanical, vibrational, and thermodynamic properties of palladium-based Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Coban, Cansu [Balikesir Univ. (Turkey). Dept. of Physics

    2017-07-01

    The pressure dependent behaviour of the structural, electronic, mechanical, vibrational, and thermodynamic properties of Pd{sub 2}TiX (X=Ga, In) Heusler alloys was investigated by ab initio calculations. The lattice constant, the bulk modulus and its first pressure derivative, the electronic band structure and the density of states (DOS), mechanical properties such as elastic constants, anisotropy factor, Young's modulus, etc., the phonon dispersion curves and phonon DOS, entropy, heat capacity, and free energy were obtained under pressure. It was determined that the calculated lattice parameters are in good agreement with the literature, the elastic constants obey the stability criterion, and the phonon dispersion curves have no negative frequency which shows that the compounds are stable. The band structures at 0, 50, and 70 GPa showed valence instability at the L point which explains the superconductivity in Pd{sub 2}TiX (X=Ga, In).

  3. Half-Heusler Alloys as Promising Thermoelectric Materials

    Science.gov (United States)

    Page, Alexander A.

    This thesis describes Ph.D. research on the half-Heusler class of thermoelectric materials. Half-Heusler alloys are a versatile class of materials that have been studied for use in photovoltaics, phase change memory, and thermoelectric power generation. With respect to thermoelectric power generation, new approaches were recently developed in order to improve the thermoelectric figure of merit, ZT, of half-Heusler alloys. Two of the strategies discussed in this work are adding excess Ni within MNiSn (M = Ti, Zr, or Hf) compounds to form full-Heusler nanostructures and using isoelectronic substitution of Ti, Zr, and Hf in MNiSn compounds to create microscale grain boundaries. This work uses computational simulations based on density functional theory, combined with the cluster expansion method, to predict the stable phases of pseudo-binary and pseudo-ternary composition systems. Statistical mechanics methods were used to calculate temperature-composition phase diagrams that relate the equilibrium phases. It is shown that full-Heusler nanostructures are predicted to remain stable even at high temperatures, and the microscale grain boundaries observed in (Ti,Zr,Hf)NiSn materials are found to be thermodynamically unstable at equilibrium. A new strategy of combining MNiSn materials with ZrNiPb has also recently emerged, and theoretical and experimental work show that a solid solution of the two materials is stable.

  4. Computer predictions on Rh-based double perovskites with unusual electronic and magnetic properties

    Science.gov (United States)

    Halder, Anita; Nafday, Dhani; Sanyal, Prabuddha; Saha-Dasgupta, Tanusri

    2018-03-01

    In search for new magnetic materials, we make computer prediction of structural, electronic and magnetic properties of yet-to-be synthesized Rh-based double perovskite compounds, Sr(Ca)2BRhO6 (B=Cr, Mn, Fe). We use combination of evolutionary algorithm, density functional theory, and statistical-mechanical tool for this purpose. We find that the unusual valence of Rh5+ may be stabilized in these compounds through formation of oxygen ligand hole. Interestingly, while the Cr-Rh and Mn-Rh compounds are predicted to be ferromagnetic half-metals, the Fe-Rh compounds are found to be rare examples of antiferromagnetic and metallic transition-metal oxide with three-dimensional electronic structure. The computed magnetic transition temperatures of the predicted compounds, obtained from finite temperature Monte Carlo study of the first principles-derived model Hamiltonian, are found to be reasonably high. The prediction of favorable growth condition of the compounds, reported in our study, obtained through extensive thermodynamic analysis should be useful for future synthesize of this interesting class of materials with intriguing properties.

  5. Rh-Based Mixed Alcohol Synthesis Catalysts: Characterization and Computational Report

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, Karl O.; Glezakou, Vassiliki Alexandra; Rousseau, Roger J.; Engelhard, Mark H.; Varga, Tamas; Colby, Robert J.; Jaffe, John E.; Li, Xiaohong S.; Mei, Donghai; Windisch, Charles F.; Kathmann, Shawn M.; Lemmon, Teresa L.; Gray, Michel J.; Hart, Todd R.; Thompson, Becky L.; Gerber, Mark A.

    2013-08-01

    The U.S. Department of Energy is conducting a program focused on developing a process for the conversion of biomass to bio-based fuels and co-products. Biomass-derived syngas is converted thermochemically within a temperature range of 240 to 330°C and at elevated pressure (e.g., 1200 psig) over a catalyst. Ethanol is the desired reaction product, although other side compounds are produced, including C3 to C5 alcohols; higher (i.e., greater than C1) oxygenates such as methyl acetate, ethyl acetate, acetic acid and acetaldehyde; and higher hydrocarbon gases such as methane, ethane/ethene, propane/propene, etc. Saturated hydrocarbon gases (especially methane) are undesirable because they represent a diminished yield of carbon to the desired ethanol product and represent compounds that must be steam reformed at high energy cost to reproduce CO and H2. Ethanol produced by the thermochemical reaction of syngas could be separated and blended directly with gasoline to produce a liquid transportation fuel. Additionally, higher oxygenates and unsaturated hydrocarbon side products such as olefins also could be further processed to liquid fuels. The goal of the current project is the development of a Rh-based catalyst with high activity and selectivity to C2+ oxygenates. This report chronicles an effort to characterize numerous supports and catalysts to identify particular traits that could be correlated with the most active and/or selective catalysts. Carbon and silica supports and catalysts were analyzed. Generally, analyses provided guidance in the selection of acceptable catalyst supports. For example, supports with high surface areas due to a high number of micropores were generally found to be poor at producing oxygenates, possibly because of mass transfer limitations of the products formed out of the micropores. To probe fundamental aspects of the complicated reaction network of CO with H2, a computational/ theoretical investigation using quantum mechanical and ab

  6. Structural, electronic and magnetic properties of Fe{sub 2}-based full Heusler alloys: A first principle study

    Energy Technology Data Exchange (ETDEWEB)

    Dahmane, F., E-mail: fethallah05@gmail.com [Département de SM, Institue des sciences et des technologies, Centre universitaire de Tissemsilt, 38000, Tissemsilt (Algeria); Modelling and Simulation in Materials Science Laboratory, Physics Department, University of Sidi Bel-Abbes, 22000 Sidi Bel-Abbes (Algeria); Mogulkoc, Y. [Department of Engineering Physics, Ankara University, Ankara (Turkey); Doumi, B.; Tadjer, A. [Modelling and Simulation in Materials Science Laboratory, Physics Department, University of Sidi Bel-Abbes, 22000 Sidi Bel-Abbes (Algeria); Khenata, R. [Laboratoire de Physique Quantique de la Matière et de Modélisation Mathématique (LPQ3M), Université de Mascara, 29000 Mascara (Algeria); Bin Omran, S. [Department of Physics and Astronomy, College of Science, King Saud University, P.O Box 2455, Riyadh 11451 (Saudi Arabia); Rai, D.P. [Department of Physics, Pachhunga University College, Aizawl-796001 (India); Murtaza, G. [Materials Modeling Lab, Department of Physics, Islamia College University, Peshawar (Pakistan); Varshney, Dinesh [Materials Science Laboratory, School of Physics, Vigyan Bhavan, Devi Ahilya University, Khandwa Road Campus, Indore 452001 (India)

    2016-06-01

    Using the first-principles density functional calculations, the structural, electronic and magnetic properties of the Fe{sub 2}XAl (X=Cr, Mn, Ni) compounds in both the Hg{sub 2}CuTi and Cu{sub 2}MnAl-type structures were studied by the full-potential linearized augmented plane waves (FP-LAPW) method. The exchange and correlation potential is treated by the generalized-gradient approximation (GGA) where the results show that the Cu{sub 2}MnAl-type structure is energetically more stable than the Hg{sub 2}CuTi-type structure for the Fe{sub 2}CrAl and Fe{sub 2}MnAl compounds at the equilibrium volume. The full Heusler compounds Fe{sub 2}XAl (X=Cr, Mn) are half-metallic in the Cu{sub 2}MnAl-type structure. Fe{sub 2}NiAl has a metallic character in both CuHg{sub 2}Ti and AlCu{sub 2}Mn-type structures. The total magnetic moments of the Fe{sub 2}CrAl and Fe{sub 2}MnAl compounds are 1.0 and 2.0 μ{sub B}, respectively, which are in agreement with the Slater–Pauling rule M{sub tot}=Z{sub tot}− 24.

  7. Effects of p-substituents on electrochemical CO oxidation by Rh porphyrin-based catalysts.

    Science.gov (United States)

    Yamazaki, Shin-ichi; Yamada, Yusuke; Takeda, Sahori; Goto, Midori; Ioroi, Tsutomu; Siroma, Zyun; Yasuda, Kazuaki

    2010-08-21

    Electrochemical CO oxidation by several carbon-supported rhodium tetraphenylporphyrins with systematically varied meso-substituents was investigated. A quantitative analysis revealed that the p-substituents on the meso-phenyl groups significantly affected CO oxidation activity. The electrocatalytic reaction was characterized in detail based on the spectroscopic and X-ray structural results as well as electrochemical analyses. The difference in the activity among Rh porphyrins is discussed in terms of the properties of p-substituents along with a proposed reaction mechanism. Rhodium tetrakis(4-carboxyphenyl)porphyrin (Rh(TCPP)), which exhibited the highest activity among the porphyrins tested, oxidized CO at a high rate at much lower potentials (means that CO is electrochemically oxidized by this catalyst when a slight overpotential is applied during the operation of a proton exchange membrane fuel cell. This catalyst exhibited little H(2) oxidation activity, in contrast to Pt-based catalysts.

  8. Special Heusler compounds for spintronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Balke, B.

    2007-07-01

    This work emphasizes the potential of Heusler compounds in a wide range of spintronic applications. Using electronic structure calculations it is possible to design compounds for specific applications. Examples for GMR and TMR applications, for spin injection into semiconductors, and for spin torque transfer applications will be shown. After a detailed introduction about spintronics and related materials chapter 5 reports about the investigation of new half-metallic compounds where the Fermi energy is tuned in the middle of the gap to result in more stable compounds for GMR and TMR applications. The bulk properties of the quaternary Heusler alloy Co{sub 2}Mn{sub 1-x}Fe{sub x}Si with the Fe concentration ranging from x=0 to 1 are reported and the results suggest that the best candidate for applications may be found at an iron concentration of about 50%. Due to the effect that in the Co{sub 2}Mn{sub 1-x}Fe{sub x}Si series the transition metal carrying the localized moment is exchanged and this might lead to unexpected effects on the magnetic properties if the samples are not completely homogeneous chapter 6 reports about the optimization of the Heusler compounds for GMR and TMR applications. The structural and magnetic properties of the quaternary Heusler alloy Co{sub 2}FeAl{sub 1-x}Si{sub x} with varying Si concentration are reported. From the combination of experimental (better order for high Si content) and theoretical findings (robust gap at x=0.5) it is concluded that a compound with an intermediate Si concentration close to x=0.5-0.7 would be best suited for spintronic applications, especially for GMR and TMR applications. In chapter 7 the detailed investigation of compounds for spin injection into semiconductors is reported. It is shown that the diluted magnetic semiconductors based on CoTiSb with a very low lattice mismatch among each other are interesting materials for spintronics applications like Spin-LEDs or other spin injection devices. Chapter 8 refers

  9. Electron transport in all-Heusler Co2CrSi/Cu2CrAl/Co2CrSi device, based on ab-initio NEGF calculations

    Science.gov (United States)

    Mikaeilzadeh, L.; Pirgholi, M.; Tavana, A.

    2018-05-01

    Based on the ab-initio non-equilibrium Green's function (NEGF) formalism based on the density functional theory (DFT), we have studied the electron transport in the all-Heusler device Co2CrSi/Cu2CrAl/Co2CrSi. Results show that the calculated transmission spectra is very sensitive to the structural parameters and the interface. Also, we obtain a range for the thickness of the spacer layer for which the MR effect is optimum. Calculations also show a perfect GMR effect in this device.

  10. Structure and catalytic reactivity of Rh oxides

    DEFF Research Database (Denmark)

    Gustafson, J.; Westerström, R.; Resta, A.

    2009-01-01

    Using a combination of experimental and theoretical techniques, we show that a thin RhO2 surface oxide film forms prior to the bulk Rh2O3 corundum oxide on all close-packed single crystal Rh surfaces. Based on previous reports, we argue that the RhO2 surface oxide also forms on vicinal Rh surface...

  11. Liposome-based delivery systems for ginsenoside Rh2: in vitro and in vivo comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Linqiang [China Pharmaceutical University, Department of Pharmaceutics, State Key Laboratory of Natural Medicines (China); Yu, Hua [University of Macao, Institute of Chinese Medical Sciences (China); Yin, Shaoping; Zhang, Ruixia; Zhou, Yudan; Li, Juan, E-mail: lijuancpu@163.com [China Pharmaceutical University, Department of Pharmaceutics, State Key Laboratory of Natural Medicines (China)

    2015-10-15

    The Ginsenoside Rh2 (Rh2) has been shown to possess anti-cancer properties both in vitro and in vivo. However, the poor bioavailability and fast plasma elimination limit the further clinical applications of Rh2 for cancer treatments. In the present study, three types of Rh2-loaded liposomes including Rh2-loaded normal liposome (Rh2-LP), Rh2-loaded cationic liposome (Rh2-CLP), and Rh2-loaded Methoxy poly(ethylene glycol)-poly(lactide) (mPEG-PLA) liposome (Rh2-PLP) have been optimized and prepared with mean particle size of 80–125 nm. Compared to Rh2-LP, surface modifications with mPEG or octadecylamine significantly improve the physicochemical and biological properties both in vitro and in vivo. Moreover, PLP presented better tumor accumulation of the fluorescent cyanine dye, 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindotricarbocyanine iodide (DiR) in HepG2-xenografted nude mice than CLP (1.3-fold) or LP (1.6-fold) and prolong the resident time of DiR in tumor and organs (more than 24 h). The in vivo anti-cancer efficacy assessments indicate that Rh2-PLP presents the most activity on suppressing tumor growth in HepG2-xenografted mice than Rh2-LP and Rh2-CLP and without any significant toxicity. Our results indicate that mPEG-PLA modified liposome should be a potential and promising strategy to enhance the therapeutic index for anti-cancer agents.

  12. Structure and magnetoresistive properties of current-perpendicular-to-plane pseudo-spin valves using polycrystalline Co2Fe-based Heusler alloy films

    International Nuclear Information System (INIS)

    Nakatani, T.M.; Du, Ye; Takahashi, Y.K.; Furubayashi, T.; Hono, K.

    2013-01-01

    We report current-perpendicular-to-plane giant magnetoresistance (CPP–GMR) of pseudo-spin valves (PSVs) with polycrystalline Co 2 Fe(Al 0.5 Si 0.5 ) (CFAS) and Co 2 Fe(Ga 0.5 Ge 0.5 ) (CFGG) Heusler alloy films. Strongly [0 1 1] textured polycrystalline Heusler alloy films grew on the Ta/Ru/Ag underlayer. Relatively large CPP–GMR values of ΔRA up to 4 mΩ μm 2 and ΔR/R up to 10% were obtained with 5 nm thick Heusler alloy films and Ag spacer layer by annealing CFAS PSV at 450 °C and CFGG PSV at 350 °C. Transmission electron microscopy revealed a flat and sharp interface between the [0 1 1] textured CFAS layers and the [1 1 1] textured Ag spacer layer. Annealing above an optimal temperature for each PSV led to reductions in MR values as a result of the thickening of the spacer layer induced by the Ag diffusion from the outer Ag layers

  13. Effect of an interface Mg insertion layer on the reliability of a magnetic tunnel junction based on a Co{sub 2}FeAl full-Heusler alloy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jungmin; Kil, Gyuhyun; Lee, Gaehun; Choi, Chulmin; Song, Yunheub [Hanyang University, Seoul (Korea, Republic of); Sukegawa, Hiroaki; Mitani, Seiji [National Institute for Materials Science, Ibaraki (Japan)

    2014-04-15

    The reliability of a magnetic tunnel junction (MTJ) based on a Co{sub 2}FeAl (CFA) full-Heusler alloy with a MgO tunnel barrier was evaluated. In particular, the effect of a Mg insertion layer under the MgO was investigated in view of resistance drift by using various voltage stress tests. We compared the resistance change during constant voltage stress (CVS) and confirmed a trap/detrap phenomenon during the interval stress test for samples with and without a Mg insertion layer. The MTJ with a Mg insertion layer showed a relatively small resistance change for the CVS test and a reduced trap/detrap phenomenon for the interval stress test compared to the sample without a Mg insertion layer. This is understood to be caused by the improved crystallinity at the bottom of the CFA/MgO interface due to the Mg insertion layer, which provides a smaller number of trap site during the stress test. As a result, the interface condition of the MgO layer is very important for the reliability of a MTJ using a full-Heusler alloy, and the the insert of a Mg layer at the MgO interface is expected to be an effective method for enhancing the reliability of a MTJ.

  14. Characteristics of Mammalian Rh Glycoproteins (SLC42 transporters) and Their Role in Acid-Base Transport

    Science.gov (United States)

    Nakhoul, Nazih L.; Hamm, L. Lee

    2012-01-01

    The mammalian Rh glycoproteins belong to the solute transporter family SLC42 and include RhAG, present in red blood cells, and two non-erythroid members RhBG and RhCG that are expressed in various tissues, including kidney, liver, skin and the GI tract. The Rh proteins in the red blood cell form an “Rh complex” made up of one D-subunit, one CE-subunit and two RhAG subunits. The Rh complex has a well-known antigenic effect but also contributes to the stability of the red cell membrane. RhBG and RhCG are related to the NH4+ transporters of the yeast and bacteria but their exact function is yet to be determined. This review describes the expression and molecular properties of these membrane proteins and their potential role as NH3/NH4+ and CO2 transporters. The likelihood that these proteins transport gases such as CO2 or NH3 is novel and significant. The review also describes the physiological importance of these proteins and their relevance to human disease. PMID:23506896

  15. Effect of Rh-based additives on NO and CO formed during regeneration of spent FCC catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Iliopoulou, E.F.; Efthimiadis, E.A.; Vasalos, I.A. [Aristotle University of Thessaloniki and Center for Research and Technology Hellas, Chemical Process Engineering Research Institute, Department of Chemical Engineering, P.O. Box 1517, 54006 University City, Thessaloniki (Greece); Barth, J.-O.; Lercher, J.A. [Institut fur Technische Chemie, Technische Universitat Munchen, Lichtenbergstrasse 4, D-85748 Garching (Germany)

    2004-02-10

    Regeneration studies of spent FCC catalyst were performed in a bench-scale unit under reaction conditions that sufficiently simulate those in the regenerator of the fluid catalytic cracking (FCC) unit. The effect of a conventional Pt-based CO promoter (CP-3) on the composition of flue gases was examined. As expected addition of CP-3 in the catalytic inventory decreased CO emissions by one order of magnitude, but tripled the NO emissions independently of the concentration of CO promoter used. Addition of a series of Rh-based catalysts modified the composition of flue gases emitted during regeneration. The parameters under study were the catalytic support, the Rh loading on the additive, and the amount of additive used during regeneration. Both a stoichiometric spinel MgO{center_dot}Al{sub 2}O{sub 3} of high crystallinity and a commercial alumina were competent supports. Promotion of the alumina support with Ce or performing regeneration introducing CO did not affect the additive performance significantly. A combined performance of CO oxidation and NO reduction was achieved minimizing both the Rh loading in the additive (0.1wt.%) and the concentration of additive used during regeneration (1wt.%). IR studies suggest that NO reduction by CO over Rh/alumina additives proceeds via the dissociative adsorption of NO, the formation of NCO species on Rh and their migration to the alumina support to finally yield N{sub 2} and CO{sub 2}.

  16. EDITORIAL: Cluster issue on Heusler compounds and devices Cluster issue on Heusler compounds and devices

    Science.gov (United States)

    Felser, Claudia; Hillebrands, Burkard

    2009-04-01

    of the spin-Hall effect, spin-torque investigations and CPP GMR (current perpendicular plane giant magnetoresistance). Schneider et al have studied the Hall effect of laser ablated Co2(MnFe)Si thin films. Recently Inomata's group has reported on a high CPP GMR effect based on CFSA [19]. In this issue a theoretical study by Dai et al reports on the interfaces between CCFA and very thin chromium layers. Here the interface stays half-metallic which is a promising result regarding the realization of potential GMR devices. For spin-torque applications special requirements concerning the materials are necessary. Low damping constants, low magnetic moments and a perpendicular anisotropy are favourable properties. Ferrimagnetic Heusler compounds are candidates for low magnetic moments despite a high spin polarization and a high Curie temperature [20, 21]. Mn3Ga shows additionally a tetragonal distortion, which is favourable for perpendicular anisotropy [21]. The stability of Heusler compounds versus structural distortion is a well known phenomenon in shape memory alloys [22]. We hope this cluster of papers will inspire many researchers in the field of spintronics and motivate some of them to use these advanced materials for new devices. References [1] Heusler F 1903 Verh. Dtsch. Phys. Ges. 12 219 [2] de Groot R A, Müller F M, van Engen P G and Buschow K H J 1983 Phys. Rev. Lett. 50 2024 [3] Kübler J, Williams A R, Sommers C B 1983 Phys. Rev. B 28 1745 [4] Block T, Felser C and Jakob G 2003 J. Solid State Chem. 176 646 [5] Galanakis I, Mavropoulos Ph and Dederichs P H 2006 J. Phys. D: Appl. Phys. 39 765 [6] Kandpal H C, Fecher G H and Felser C 2007 J. Phys. D: Appl. Phys. 40 1507 [7] Wurmehl S, Fecher G H, Kandpal H C, Ksenofontov V, Felser C and Lin H J 2006 Appl. Phys. Lett. 86 032503 [8] Kämmerer S, Thomas A, Hütten A and Reiss G 2004 Appl. Phys. Lett. 85 79 [9] Yamato M, Marukame T, Ishikawa T, Matsuda K, Uemura T and Arita M 2006 J. Phys. D: Appl. Phys. 39 824 [10

  17. Performance analysis of STT-RAM with cross shaped free layer using Heusler alloys

    Science.gov (United States)

    Bharat Kumary, Tangudu; Ghosh, Bahniman; Awadhiya, Bhaskar; Verma, Ankit Kumar

    2016-01-01

    We have investigated the performance of a spin transfer torque random access memory (STT-RAM) cell with a cross shaped Heusler compound based free layer using micromagnetic simulations. We have designed a free layer using a Cobalt based Heusler compound. Simulation results clearly show that the switching time from one state to the other state has been reduced, also it has been found that the critical switching current density (to switch the magnetization of the free layer of the STT RAM cell) is reduced.

  18. Quantitative determination of charge transfer parameters of photorefractive BaTiO3:Rh from EPR-based defect studies

    International Nuclear Information System (INIS)

    Veber, C; Meyer, M; Schirmer, O F; Kaczmarek, M

    2003-01-01

    Optical absorption bands can be used as fingerprints of defects and their charge states in insulators and semiconductors. On the basis of the photochromicity usually shown by such materials, a method is introduced by which the optical bands are assigned to the defects and their charge states. It is based on simultaneous measurements of the light-induced changes of the optical absorption and of the corresponding EPR signals. Moreover, indirectly optical bands of EPR-silent defects can also be labelled in this way, strongly widening the scope of EPR based defect studies. We apply this method to the infrared-sensitive photorefractive system BaTiO 3 :Rh, where illumination leads to recharging among the valence states Rh 5+ , Rh 4+ and Rh 3+ . The values of all parameters governing the charge transfers responsible are inferred from the magnitude of the absorption bands, the absolute determination of their absorption cross-sections and the kinetics of the absorption changes under illumination. In contrast to previous investigations, these parameters are deduced independently of photorefractive measurements

  19. Chitosan-based DNA delivery vector targeted to gonadotropin-releasing hormone (GnRH) receptor.

    Science.gov (United States)

    Boonthum, Chatwalee; Namdee, Katawut; Boonrungsiman, Suwimon; Chatdarong, Kaywalee; Saengkrit, Nattika; Sajomsang, Warayuth; Ponglowhapan, Suppawiwat; Yata, Teerapong

    2017-02-10

    The main purpose of this study was to investigate the application of modified chitosan as a potential vector for gene delivery to gonadotropin-releasing hormone receptor (GnRHR)-expressing cells. Such design of gene carrier could be useful in particular for gene therapy for cancers related to the reproductive system, gene disorders of sexual development, and contraception and fertility control. In this study, a decapeptide GnRH was successfully conjugated to chitosan (CS) as confirmed by proton nuclear magnetic resonance spectroscopy ( 1 H NMR) and Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The synthesized GnRH-conjugated chitosan (GnRH-CS) was able to condense DNA to form positively charged nanoparticles and specifically deliver plasmid DNA to targeted cells in both two-dimensional (2D) and three-dimensional (3D) cell cultures systems. Importantly, GnRH-CS exhibited higher transfection activity compared to unmodified CS. In conclusion, GnRH-conjugated chitosan can be a promising carrier for targeted DNA delivery to GnRHR-expressing cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Thin film Heusler compounds manganese nickel gallium

    Science.gov (United States)

    Jenkins, Catherine Ann

    Multiferroic Heusler compounds Mn3--xNi xGa (x=0,1,2) have a tetragonal unit cell that can variously be used for magneto-mechanically coupled shape memory ( x=1,2) and spin-mechanical applications (x=0). The first fabrication of fully epitaxial thin films of these and electronically related compounds by sputtering is discussed. Traditional and custom lab characterization of the magnetic and temperature driven multiferroic behavior is augmented by more detailed synchrotron-based high energy photoemission spectroscopic techniques to describe the atomic and electronic structure. Integration of the MnNi2Ga magnetic shape memory compound in microwave patch antennas and active free-standing structures represents a fraction of the available and promising applications for these compounds. Prototype magnetic tunnel junctions are demonstrated by Mn3Ga electrodes with perpendicular anisotropy for spin torque transfer memory structures. The main body of the work concentrates on the definition and exploration of the material series Mn3--xNi xGa (x=0,1,2) and the relevant multiferroic phenomena exhibited as a function of preparation and external stimuli. Engineering results on each x=0,1,2 are presented with device prototypes where relevant. In the appendices the process of the materials design undertaken with the goal of developing new ternary intermetallics with enhanced properties is presented with a full exploration of the road from band structure calculations to device implementation. Cobalt based compounds in single crystal and nanoparticle form are fabricated with an eye to developing the production methods for new cobalt- and iron-based magnetic shape memory compounds for device applications in different forms. Mn2CoSn, a compound isolectronic and with similar atomic ordering to Mn2NiGa is experimentally determined to be a nearly half-metallic ferromagnet in contrast to the metallic ferrimagnetism in the parent compound. High energy photoemission spectroscopy is shown to

  1. Stability and ordering properties of fcc alloys based on Rh, Ir, Pd, and Pt

    Czech Academy of Sciences Publication Activity Database

    Turchi, P. E. A.; Drchal, Václav; Kudrnovský, Josef

    2006-01-01

    Roč. 74, č. 6 (2006), 064202/1-064202/12 ISSN 1098-0121 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z1010914 Keywords : alloy phase stability * ordering in alloys * fcc alloys of Rh, Ir, Pd, Pt Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.107, year: 2006

  2. Rational design of a carboxylic esterase RhEst1 based on computational analysis of substrate binding.

    Science.gov (United States)

    Chen, Qi; Luan, Zheng-Jiao; Yu, Hui-Lei; Cheng, Xiaolin; Xu, Jian-He

    2015-11-01

    A new carboxylic esterase RhEst1 which catalyzes the hydrolysis of (S)-(+)-2,2-dimethylcyclopropanecarboxylate (S-DmCpCe), the key chiral building block of cilastatin, was identified and subsequently crystallized in our previous work. Mutant RhEst1A147I/V148F/G254A was found to show a 5-fold increase in the catalytic activity. In this work, molecular dynamic simulations were performed to elucidate the molecular determinant of the enzyme activity. Our simulations show that the substrate binds much more strongly in the A147I/V148F/G254A mutant than in wild type, with more hydrogen bonds formed between the substrate and the catalytic triad and the oxyanion hole. The OH group of the catalytic residue Ser101 in the mutant is better positioned to initiate the nucleophilic attack on S-DmCpCe. Interestingly, the "170-179" loop which is involved in shaping the catalytic sites and facilitating the product release shows remarkable dynamic differences in the two systems. Based on the simulation results, six residues were identified as potential "hot-spots" for further experimental testing. Consequently, the G126S and R133L mutants show higher catalytic efficiency as compared with the wild type. This work provides molecular-level insights into the substrate binding mechanism of carboxylic esterase RhEst1, facilitating future experimental efforts toward developing more efficient RhEst1 variants for industrial applications. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. A novel paper-based assay for the simultaneous determination of Rh typing and forward and reverse ABO blood groups.

    Science.gov (United States)

    Noiphung, Julaluk; Talalak, Kwanrutai; Hongwarittorrn, Irin; Pupinyo, Naricha; Thirabowonkitphithan, Pannawich; Laiwattanapaisal, Wanida

    2015-05-15

    We propose a new, paper-based analytical device (PAD) for blood typing that allows for the simultaneous determination of ABO and Rh blood groups on the same device. The device was successfully fabricated by using a combination of wax printing and wax dipping methods. A 1:2 blood dilution was used for forward grouping, whereas whole blood could be used for reverse grouping. A 30% cell suspension of A-cells or B-cells was used for haemagglutination on the reverse grouping side. The total assay time was 10 min. The ratio between the distance of red blood cell movement and plasma separation is the criterion for agglutination and indicates the presence of the corresponding antigen or antibody. The proposed PAD has excellent reproducibility in that the same blood groups, namely A, AB, and O, were reported by using different PADs that were fabricated on the same day (n=10). The accuracy for detecting blood group A (n=12), B (n=13), AB (n=9), O (n=14), and Rh (n=48) typing were 92%, 85%, 89%, 93%, and 96%, respectively, in comparison with the conventional slide test method. The haematocrit of the sample affects the accuracy of the results, and appropriate dilution is suggested before typing. In conclusion, this study proposes a novel method that is straightforward, time-saving, and inexpensive for the simultaneous determination of ABO and Rh blood groups, which is promising for use in developing countries. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. RH-TRU Waste Content Codes (RH-TRUCON)

    International Nuclear Information System (INIS)

    2007-01-01

    The Remote-Handled Transuranic (RH-TRU) Content Codes (RH-TRUCON) document describes the inventory of RH-TRU waste within the transportation parameters specified by the Remote-Handled Transuranic Waste Authorized Methods for Payload Control (RH-TRAMPAC).1 The RH-TRAMPAC defines the allowable payload for the RH-TRU 72-B. This document is a catalog of RH-TRU 72-B authorized contents by site. A content code is defined by the following components: A two-letter site abbreviation that designates the physical location of the generated/stored waste (e.g., ID for Idaho National Laboratory [INL]). The site-specific letter designations for each of the sites are provided in Table 1. A three-digit code that designates the physical and chemical form of the waste (e.g., content code 317 denotes TRU Metal Waste). For RH-TRU waste to be transported in the RH-TRU 72-B, the first number of this three-digit code is '3.' The second and third numbers of the three-digit code describe the physical and chemical form of the waste. Table 2 provides a brief description of each generic code. Content codes are further defined as subcodes by an alpha trailer after the three-digit code to allow segregation of wastes that differ in one or more parameter(s). For example, the alpha trailers of the subcodes ID 322A and ID 322B may be used to differentiate between waste packaging configurations. As detailed in the RH-TRAMPAC, compliance with flammable gas limits may be demonstrated through the evaluation of compliance with either a decay heat limit or flammable gas generation rate (FGGR) limit per container specified in approved content codes. As applicable, if a container meets the watt*year criteria specified by the RH-TRAMPAC, the decay heat limits based on the dose-dependent G value may be used as specified in an approved content code. If a site implements the administrative controls outlined in the RH-TRAMPAC and Appendix 2.4 of the RH-TRU Payload Appendices, the decay heat or FGGR limits based

  5. RH-TRU Waste Content Codes (RH-TRUCON)

    Energy Technology Data Exchange (ETDEWEB)

    Washington TRU Solutions LLC

    2007-08-01

    The Remote-Handled Transuranic (RH-TRU) Content Codes (RH-TRUCON) document describes the inventory of RH-TRU waste within the transportation parameters specified by the Remote-Handled Transuranic Waste Authorized Methods for Payload Control (RH-TRAMPAC).1 The RH-TRAMPAC defines the allowable payload for the RH-TRU 72-B. This document is a catalog of RH-TRU 72-B authorized contents by site. A content code is defined by the following components: • A two-letter site abbreviation that designates the physical location of the generated/stored waste (e.g., ID for Idaho National Laboratory [INL]). The site-specific letter designations for each of the sites are provided in Table 1. • A three-digit code that designates the physical and chemical form of the waste (e.g., content code 317 denotes TRU Metal Waste). For RH-TRU waste to be transported in the RH-TRU 72-B, the first number of this three-digit code is “3.” The second and third numbers of the three-digit code describe the physical and chemical form of the waste. Table 2 provides a brief description of each generic code. Content codes are further defined as subcodes by an alpha trailer after the three-digit code to allow segregation of wastes that differ in one or more parameter(s). For example, the alpha trailers of the subcodes ID 322A and ID 322B may be used to differentiate between waste packaging configurations. As detailed in the RH-TRAMPAC, compliance with flammable gas limits may be demonstrated through the evaluation of compliance with either a decay heat limit or flammable gas generation rate (FGGR) limit per container specified in approved content codes. As applicable, if a container meets the watt*year criteria specified by the RH-TRAMPAC, the decay heat limits based on the dose-dependent G value may be used as specified in an approved content code. If a site implements the administrative controls outlined in the RH-TRAMPAC and Appendix 2.4 of the RH-TRU Payload Appendices, the decay heat or FGGR

  6. RH-TRU Waste Content Codes (RH-TRUCON)

    Energy Technology Data Exchange (ETDEWEB)

    Washington TRU Solutions

    2007-05-30

    The Remote-Handled Transuranic (RH-TRU) Content Codes (RH-TRUCON) document describes the inventory of RH-TRU waste within the transportation parameters specified by the Remote-Handled Transuranic Waste Authorized Methods for Payload Control (RH-TRAMPAC).1 The RH-TRAMPAC defines the allowable payload for the RH-TRU 72-B. This document is a catalog of RH-TRU 72-B authorized contents by site. A content code is defined by the following components: • A two-letter site abbreviation that designates the physical location of the generated/stored waste (e.g., ID for Idaho National Laboratory [INL]). The site-specific letter designations for each of the sites are provided in Table 1. • A three-digit code that designates the physical and chemical form of the waste (e.g., content code 317 denotes TRU Metal Waste). For RH-TRU waste to be transported in the RH-TRU 72-B, the first number of this three-digit code is “3.” The second and third numbers of the three-digit code describe the physical and chemical form of the waste. Table 2 provides a brief description of each generic code. Content codes are further defined as subcodes by an alpha trailer after the three-digit code to allow segregation of wastes that differ in one or more parameter(s). For example, the alpha trailers of the subcodes ID 322A and ID 322B may be used to differentiate between waste packaging configurations. As detailed in the RH-TRAMPAC, compliance with flammable gas limits may be demonstrated through the evaluation of compliance with either a decay heat limit or flammable gas generation rate (FGGR) limit per container specified in approved content codes. As applicable, if a container meets the watt*year criteria specified by the RH-TRAMPAC, the decay heat limits based on the dose-dependent G value may be used as specified in an approved content code. If a site implements the administrative controls outlined in the RH-TRAMPAC and Appendix 2.4 of the RH-TRU Payload Appendices, the decay heat or FGGR

  7. RH-TRU Waste Content Codes (RH-Trucon)

    International Nuclear Information System (INIS)

    2007-01-01

    The Remote-Handled Transuranic (RH-TRU) Content Codes (RH-TRUCON) document describes the inventory of RH-TRU waste within the transportation parameters specified by the Remote-Handled Transuranic Waste Authorized Methods for Payload Control (RH-TRAMPAC).1 The RH-TRAMPAC defines the allowable payload for the RH-TRU 72-B. This document is a catalog of RH-TRU 72-B authorized contents by site. A content code is defined by the following components: A two-letter site abbreviation that designates the physical location of the generated/stored waste (e.g., ID for Idaho National Laboratory [INL]). The site-specific letter designations for each of the sites are provided in Table 1. A three-digit code that designates the physical and chemical form of the waste (e.g., content code 317 denotes TRU Metal Waste). For RH-TRU waste to be transported in the RH-TRU 72-B, the first number of this three-digit code is '3.' The second and third numbers of the three-digit code describe the physical and chemical form of the waste. Table 2 provides a brief description of each generic code. Content codes are further defined as subcodes by an alpha trailer after the three-digit code to allow segregation of wastes that differ in one or more parameter(s). For example, the alpha trailers of the subcodes ID 322A and ID 322B may be used to differentiate between waste packaging configurations. As detailed in the RH-TRAMPAC, compliance with flammable gas limits may be demonstrated through the evaluation of compliance with either a decay heat limit or flammable gas generation rate (FGGR) limit per container specified in approved content codes. As applicable, if a container meets the watt*year criteria specified by the RH-TRAMPAC, the decay heat limits based on the dose-dependent G value may be used as specified in an approved content code. If a site implements the administrative controls outlined in the RH-TRAMPAC and Appendix 2.4 of the RH-TRU Payload Appendices, the decay heat or FGGR limits based

  8. Rh Incompatibility (For Parents)

    Science.gov (United States)

    ... work to destroy, foreign substances) against the Rh proteins. Other ways Rh-negative pregnant women can be exposed to the Rh protein that might cause antibody production include blood transfusions ...

  9. ABO and RhD blood groups and gestational hypertensive disorders: a population-based cohort study.

    Science.gov (United States)

    Lee, B K; Zhang, Z; Wikman, A; Lindqvist, P G; Reilly, M

    2012-09-01

    To examine the association between ABO and RhD blood groups and gestational hypertensive disorders in a large population-based cohort. Cohort study. Risks of gestational hypertensive disorders, pre-eclampsia, and severe pre-eclampsia, estimated by odds ratios for maternal ABO blood group and RhD status. National health registers of Sweden. All singleton deliveries in Sweden born to first-time mothers during the period 1987-2002 [total n = 641 926; any gestational hypertensive disorders, n = 39 011 (6.1%); pre-eclampsia cases, n = 29 337 (4.6%); severe pre-eclampsia cases, n = 8477 (1.3%)]. Using blood group O as a reference, odds ratios of gestational hypertensive disorders, pre-eclampsia, and severe pre-eclampsia were obtained from logistic regression models adjusted for potential confounding factors. Gestational hypertensive disorders, pre-eclampsia, and severe pre-eclampsia. Compared with blood group O, all non-O blood groups had modest but statistically significantly higher odds of pre-eclampsia. Blood group AB had the highest risk for pre-eclampsia (OR = 1.10, 95% CI 1.04-1.16) and severe pre-eclampsia (OR = 1.18, 95% CI 1.07-1.30). RhD-positive mothers had a small increased risk for pre-eclampsia (OR = 1.07, 95% CI 1.03-1.10). In the largest study on this topic to date, women with AB blood group have the highest risks of gestational hypertensive disorders, pre-eclampsia, and severe pre-eclampsia, whereas women with O blood group have the lowest risks of developing these disorders. Although the magnitude of increased risk is small, this finding may help improve our understanding of the etiology of pre-eclampsia. © 2012 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2012 RCOG.

  10. RH-TRU Waste Content Codes (RH TRUCON)

    International Nuclear Information System (INIS)

    2007-01-01

    The Remote-Handled Transuranic (RH-TRU) Content Codes (RH-TRUCON) document describes the inventory of RH-TRU waste within the transportation parameters specified by the Remote-Handled Transuranic Waste Authorized Methods for Payload Control (RH-TRAMPAC).1 The RH-TRAMPAC defines the allowable payload for the RH-TRU 72-B. This document is a catalog of RH-TRU 72-B authorized contents by site. A content code is defined by the following components: (1) A two-letter site abbreviation that designates the physical location of the generated/stored waste (e.g., ID for Idaho National Laboratory [INL]). The site-specific letter designations for each of the sites are provided in Table 1. (2) A three-digit code that designates the physical and chemical form of the waste (e.g., content code 317 denotes TRU Metal Waste). For RH-TRU waste to be transported in the RH-TRU 72-B, the first number of this three-digit code is ''3''. The second and third numbers of the three-digit code describe the physical and chemical form of the waste. Table 2 provides a brief description of each generic code. Content codes are further defined as subcodes by an alpha trailer after the three-digit code to allow segregation of wastes that differ in one or more parameter(s). For example, the alpha trailers of the subcodes ID 322A and ID 322B may be used to differentiate between waste packaging configurations. As detailed in the RH-TRAMPAC, compliance with flammable gas limits may be demonstrated through the evaluation of compliance with either a decay heat limit or flammable gas generation rate (FGGR) limit per container specified in approved content codes. As applicable, if a container meets the watt*year criteria specified by the RH-TRAMPAC, the decay heat limits based on the dose-dependent G value may be used as specified in an approved content code. If a site implements the administrative controls outlined in the RH-TRAMPAC and Appendix 2.4 of the RH-TRU Payload Appendices, the decay heat or FGGR

  11. RH-TRU Waste Content Codes (RH TRUCON)

    Energy Technology Data Exchange (ETDEWEB)

    Washington TRU Solutions

    2007-05-01

    The Remote-Handled Transuranic (RH-TRU) Content Codes (RH-TRUCON) document describes the inventory of RH-TRU waste within the transportation parameters specified by the Remote-Handled Transuranic Waste Authorized Methods for Payload Control (RH-TRAMPAC).1 The RH-TRAMPAC defines the allowable payload for the RH-TRU 72-B. This document is a catalog of RH-TRU 72-B authorized contents by site. A content code is defined by the following components: • A two-letter site abbreviation that designates the physical location of the generated/stored waste (e.g., ID for Idaho National Laboratory [INL]). The site-specific letter designations for each of the sites are provided in Table 1. • A three-digit code that designates the physical and chemical form of the waste (e.g., content code 317 denotes TRU Metal Waste). For RH-TRU waste to be transported in the RH-TRU 72-B, the first number of this three-digit code is “3.” The second and third numbers of the three-digit code describe the physical and chemical form of the waste. Table 2 provides a brief description of each generic code. Content codes are further defined as subcodes by an alpha trailer after the three-digit code to allow segregation of wastes that differ in one or more parameter(s). For example, the alpha trailers of the subcodes ID 322A and ID 322B may be used to differentiate between waste packaging configurations. As detailed in the RH-TRAMPAC, compliance with flammable gas limits may be demonstrated through the evaluation of compliance with either a decay heat limit or flammable gas generation rate (FGGR) limit per container specified in approved content codes. As applicable, if a container meets the watt*year criteria specified by the RH-TRAMPAC, the decay heat limits based on the dose-dependent G value may be used as specified in an approved content code. If a site implements the administrative controls outlined in the RH-TRAMPAC and Appendix 2.4 of the RH-TRU Payload Appendices, the decay heat or FGGR

  12. GnRH and prostaglandin-based synchronization protocols as alternatives to progestogen-based treatments in sheep.

    Science.gov (United States)

    Rekik, M; Haile, A; Abebe, A; Muluneh, D; Goshme, S; Ben Salem, I; Hilali, M El-Dine; Lassoued, N; Chanyalew, Y; Rischkowsky, B

    2016-12-01

    The study investigated, for cycling sheep, synchronizing protocols simultaneously to the standard "P" protocol using progestogens priming with intravaginal devices and gonadotropin. In November 2014, 90 adult Menz ewes were assigned to either the "P" protocol, "PGF" treatment where oestrus and ovulation were synchronized using two injections of prostaglandin 11 days apart or a "GnRH" treatment where the ewes had their oestrus and ovulation synchronized with GnRH (day 0)-prostaglandin (day 6)-GnRH (day 9) sequence. The ewes were naturally mated at the induced oestrus and the following 36 days. Plasma progesterone revealed that 92% of the ewes were ovulating before synchronization and all, except one, ovulated in response to the applied treatments. All "P" ewes exhibited oestrus during the 96-hr period after the end of the treatments in comparison with only 79.3% and 73.3% for "PGF" and "GnRH" ewes, respectively (p sheep after the rainy season when most animals are spontaneously cycling. © 2016 Blackwell Verlag GmbH.

  13. Ferromagnetic resonance study of the half-Heusler alloy NiMnSb. The benefit of using NiMnSb as a ferromagnetic layer in pseudo-spin-valve based spin-torque oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Riegler, Andreas

    2011-11-25

    Since the discovery of spin torque in 1996, independently by Berger and Slonczewski, and given its potential impact on information storage and communication technologies, (e.g. through the possibility of switching the magnetic configuration of a bit by current instead of a magnetic field, or the realization of high frequency spin torque oscillators (STO)), this effect has been an important field of spintronics research. One aspect of this research focuses on ferromagnets with low damping. The lower the damping in a ferromagnet, the lower the critical current that is needed to induce switching of a spin valve or induce precession of its magnetization. In this thesis ferromagnetic resonance (FMR) studies of NiMnSb layers are presented along with experimental studies on various spin-torque (ST) devices using NiMnSb. NiMnSb, when crystallized in the half-Heusler structure, is a half-metal which is predicted to have 100% spin polarization, a consideration which further increases its potential as a candidate for memory devices based on the giant magnetoresistance (GMR) effect. The FMR measurements show an outstandingly low damping factor for NiMnSb, in low 10{sup -3} range. This is about a factor of two lower than permalloy and well comparable to lowest damping for iron grown by molecular beam epitaxy (MBE). According to theory the 100% spin polarization properties of the bulk disappear at interfaces where the break in translational symmetry causes the gap in the minority spin band to collapse but can remain in other crystal symmetries such as (111). Consequently NiMnSb layers on (111)(In,Ga)As buffer are characterized in respect of anisotropies and damping. The FMR measurements on these samples indicates a higher damping that for the 001 samples, and a thickness dependent uniaxial in-plane anisotropy. Investigations of the material for device use is pursued by considering sub-micrometer sized elements of NiMnSb on 001 substrates, which were fabricated by electron

  14. Frequencies and ethnic distribution of ABO and RhD blood groups in China: a population-based cross-sectional study.

    Science.gov (United States)

    Liu, Jue; Zhang, Shikun; Wang, Qiaomei; Shen, Haiping; Zhang, Yiping; Liu, Min

    2017-12-03

    ABO and RhD blood groups are key factors affecting blood transfusion safety. The distribution of ABO and RhD blood groups varies globally, but limited data exist for ethnic distributions of these blood groups in Asian populations. We aimed to evaluate the distribution of ABO and RhD blood groups among Chinese ethnic groups. A population-based cross-sectional study. Data on ABO groups and ethnicities were obtained from the National Free Preconception Health Examination Project (NFPHEP) with participants from 220 counties of 31 provinces in China PARTICIPANTS: There were 3 832 034 participants aged 21-49 years who took part in the NFPHEP from January 2010 to December 2012 and were included in this study. The proportion of ABO and RhD blood groups among different ethnic groups was calculated. ABO and RhD blood distribution was significantly different among nine ethnic groups (Pgroups, the Yi group had more A phenotypes (34.0%), and the Manchu (33.7%) and Mongolian (33.3%) ethnic groups had more B phenotypes. The Zhuang group had the greatest proportion of O phenotypes (41.8%), followed by the Miao group (37.7%). AB phenotypes were more frequent in the Uygur ethnic group (10.6%) but lower in the Zhuang group (5.5%). Meanwhile, RhD negativity (RhD-) was greater in the Uygur group (3.3%) than in the Mongolian (0.3%) and Manchu ethnic groups (0.4%). O RhD- blood groups were more frequent in the Uygur group (0.8%) than in the other ethnic groups (0.1%-0.4%, Pblood phenotypes vary across different ethnic groups in China. The diversity in the distribution of the ABO and RhD blood groups in different ethnic groups should be considered when developing rational and evidence-based strategies for blood collection and management. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  15. Electrochemical Sensor Based on Rh(III) Ion-Imprinted Polymer as a New Modifying Agent for Rhodium Determination.

    Science.gov (United States)

    Bai, Huiping; Xiong, Caiyun; Wang, Chunqiong; Liu, Peng; Dong, Su; Cao, Qiue

    2018-05-01

    A rhodium (III) ion carbon paste electrode (CPE) based on an ion imprinted polymer (IIP) as a new modifying agent has been prepared and studied. Rh(III) ion imprinted polymer was synthesized by copolymerization of acrylamide-Rh(III) complex and ethylene glycol dimethacrylate according to the precipitation polymerization. Acrylamide acted as both functional monomer and complexing agent to create selective coordination sites in a cross-linked polymer. The ion imprinted carbon paste electrode (IIP-CPE) was prepared by mixing rhodium IIP-nanoparticles and graphite powder in n-eicosane as an adhesive and then embedding them in a Teflon tube. Amperometric i-t curve method was applied as the determination technique. Several parameters, including the functional monomer, molar ratio of template, monomer and cross-linking agent, the amounts of IIP, the applied potential, the buffer solution and pH have been studied. According to the results, IIP-CPE showed a considerably higher response in comparison with the electrode embedded with non-imprinted polymer (NIP), indicating the formation of suitable recognition sites in the IIP structure during the polymerization stage. The introduced electrode showed a linear range of 1.00×10-8~3.0×10-5 mol·L-1 and detection limit of 6.0 nmol L-1 (S/N = 3). The IIP-CPE was successfully applied for the trace rhodium determination in catalyst and plant samples with RSD of less than 3.3% (n = 5) and recoveries in the range of 95.5~102.5%.

  16. Phase separation and antisite defects in the thermoelectric TiNiSn half-Heusler alloys

    International Nuclear Information System (INIS)

    Kirievsky, K.; Gelbstein, Y.; Fuks, D.

    2013-01-01

    The half-Heusler TiNiSn alloys have recently gained an attention as promising candidates for thermoelectric applications. Improvement of these alloys for such applications can be obtained by both electronic and compositional optimizations. The latter can result in a miscibility gap, allowing a phase separation in the nano-scale and consequently a thermal conductivity reduction. Combination of ab initio calculations and statistical thermodynamics was applied for studying the relative stability of a number of superstructures in TiNiSn based alloys. The quasi-binary phase diagram beyond T=0 K for TiNiSn–TiNi 2 Sn solid solutions was calculated using energy parameters extracted from the total energy calculations for ordered structures in the Ni sublattice. We demonstrated that a decomposition of the off-stoichiometric Ni-rich half-Heusler alloy into the stoichiometric TiNiSn phase and into Ni deficient Heusler TiNi 2 Sn phase occurs at elevated temperatures—an effect which recently had been observed experimentally. Furthermore, favorable energetic conditions for antisite defects formation were deduced, based on calculations of the energy of formation, an effect which was explained as a cooperative process of partial disordering on the Ni sublattice. The influence of these two effects on improvement of the thermoelectric performance of TiNiSn based half Heusler compounds is discussed. - Graphical abstract: Phase separation and antisite defects in the thermoelectric TiNiSn alloy, are covered as methods for nanostructuring and thereby enhancement of the thermoelectric potential. - Highlights: • Ab initio calculations/statistical thermodynamics was applied for studying the TiNiSn system. • The phase diagram for TiNiSn–TiNi 2 Sn solid solutions was calculated. • Decomposition of the Ni-rich HH into TiNiSn and Ni deficient TiNi 2 Sn phases was observed. • Favorable energetic conditions for antisite defects formation were deduced

  17. Improvement of thermoelectric properties for half-Heusler TiNiSn by interstitial Ni defects

    International Nuclear Information System (INIS)

    Hazama, Hirofumi; Matsubara, Masato; Asahi, Ryoji; Takeuchi, Tsunehiro

    2011-01-01

    We have synthesized off-stoichiometric Ti-Ni-Sn half-Heusler thermoelectrics in order to investigate the relation between randomly distributed defects and thermoelectric properties. A small change in the composition of Ti-Ni-Sn causes a remarkable change in the thermal conductivity. An excess content of Ni realizes a low thermal conductivity of 2.93 W/mK at room temperature while keeping a high power factor. The low thermal conductivity originates in the defects generated by an excess content of Ni. To investigate the detailed defect structure, we have performed first-principles calculations and compared with x ray photoemission spectroscopy measurement. Based on these analyses, we conclude that the excess Ni atoms randomly occupy the vacant sites in the half-Heusler structure, which play as phonon scattering centers, resulting in significant improvement of the figure of merit without any substitutions of expensive heavy elements, such as Zr and Hf.

  18. A retrospective study: ABO and Rh phenotype blood group distribution among blood donors in H.N.B. Base Hospital, Srinagar, Uttarakhand, India

    Directory of Open Access Journals (Sweden)

    Satish Kumar

    2018-01-01

    Full Text Available Objective: To determine the prevalence of ABO and Rh blood groups based on the antigenic presence on the surface of red blood cells with respect to gender and calculate allele frequency of the blood groups. Globally, approximately 700 type red cell antigens have been identified till now. ABO and Rh blood groups play an important role in the process of blood transfusion, resolving certain medicolegal issues, parental testing, and various genetic studies. Methods: This study was conducted in H.N.B. Base Hospital, Srinagar, Uttarakhand, from January 2012 to December 2016. Relevant data of blood donors were collected from blood bank department of the hospital. Blood grouping was conducted using commercially available standard monoclonal antisera applying test tube and column agglutination techniques. Results: Out of 9883 individuals, 9333 (92.4% were males and 750 (7.6% were female individuals. The most common blood group found was B (31.68% and least common being AB (11.70%. The prevalence of Rhesus positive and negative distribution in the present studied population was found as 93.51% and 6.49%, respectively. Overall, male ABO group pattern found was shown by formula B > A > O > AB which was similar among Rh-positive male individuals while Rh-negative males' pattern was found as A > B = O > AB. In females, ABO group pattern was B > O > A > AB which was similar to Rh-positive female pattern while differs in Rh negative. The estimated allele frequencies were found as 0.2403, 0.2475, and 0.5122 for IA (p, IB (q, and IO (r, respectively. Conclusion: The most common blood group found among the Gharwali donors was B positive while the least common was AB negative, which plays an important contribution for making government policies to develop National Health Program.

  19. Thermodynamic properties of Heusler Fe2VSi

    Science.gov (United States)

    Ito, Masakazu; Kai, Keita; Furuta, Tatsuya; Manaka, Hirotaka; Terada, Norio; Hiroi, Masahiko; Kondo, Akihiro; Kindo, Koichi

    2018-05-01

    We investigated temperature, T, dependence of magnetization, M(T), electrical resistivity, ρ(T), and specific heat, Cp(T), for the Heusler compound Fe2VSi. M(T) shows anomalies at TN1 ˜ 115 K and at TN2 ˜ 35 K. The anomaly at TN1 is caused by the magnetic transition with a crystal structural change. On the other hand, ρ(T) and Cp(T) show only anomaly at TN1, and no trace of anomaly at TN2 is observed. Because of the irreversibility of M(T), which is the characteristic of spin-glass freezing, appears below TN2, a spin-glass freezing may occur at TN2. From the analogy of the Heusler compound (Fe1-xVx ) 3Si with the cubic D03 crystal structure, (0 ≤ x ≤ 0.2), we suggested that the atomic disorder of V site by the Fe atoms gives rise to the magnetic frustration. This could be cause for the spin-glass freezing. By the Clausius-Clapeyron relation, pressure, P, derivative of TN1, (d/TN 1 d P ), is estimated to be ˜-10 K/Gpa.

  20. EDITORIAL: New materials with high spin polarization: half-metallic Heusler compounds

    Science.gov (United States)

    Felser, Claudia; Hillebrands, Burkard

    2007-03-01

    The development of magnetic Heusler compounds, specifically designed as materials for spintronic applications, has made tremendous progress in the very recent past [1-21]. Heusler compounds can be made as half-metals, showing a high spin polarization of the conduction electrons of up to 100% [1]. These materials are exceptionally well suited for applications in magnetic tunnel junctions acting, for example, as sensors for magnetic fields. The tunnelling magneto-resistance (TMR) effect is the relative change in the electrical resistance upon application of a small magnetic field. Tunnel junctions with a TMR effect of 580% at 4 K were reported by the group of Miyazaki and Ando [1], consisting of two Co2MnSi Heusler electrodes. High Curie temperatures were found in Co2 Heusler compounds with values up to 1120 K in Co2FeSi [2]. The latest results are for a TMR device made from the Co2FeAl0.5Si0.5 Heusler compound and working at room temperature with a TMR effect of 174% [3]. The first significant magneto-resistance effect was discovered in Co2Cr0.6Fe0.4Al (CCFA) in Mainz [4]. With the classical Heusler compound CCFA as one electrode, the record TMR effect at 4 K is 240% [5]. Positive and negative TMR values at room temperature utilizing magnetic tunnel junctions with one Heusler compound electrode render magnetic logic possible [6]. Research efforts exist, in particular, in Japan and in Germany. The status of research as of winter 2005 was compiled in a recent special volume of Journal of Physics D: Applied Physics [7-20]. Since then specific progress has been made on the issues of (i) new advanced Heusler materials, (ii) advanced characterization, and (iii) advanced devices using the new materials. In Germany, the Mainz and Kaiserslautern based Research Unit 559 `New Materials with High Spin Polarization', funded since 2004 by the Deutsche Forschungsgemeinschaft, is a basic science approach to Heusler compounds, and it addresses the first two topics in particular

  1. Genetic admixture of eight Mexican indigenous populations: based on five polymarker, HLA-DQA1, ABO, and RH loci.

    Science.gov (United States)

    Buentello-Malo, Leonora; Peñaloza-Espinosa, Rosenda I; Salamanca-Gómez, Fabio; Cerda-Flores, Ricardo M

    2008-01-01

    This study explores the genetic admixture of eight Mexican indigenous populations (Otomi-Ixmiquilpan, Otomi-Actopan, Tzeltales, Nahua-Milpa-Alta, Nahua-Xochimilco, Nahua-Zitlala, Nahua-Ixhuatlancillo, and Nahua-Coyolillo) on the basis of five PCR-based polymorphic DNA loci (LDLR, GYPA, HBGG, D7S8, GC), HLA_DQA1, and the blood groups ABO and Rh (CcDEe). Among the indigenous populations, the highest gene frequencies for O and D were 0.9703 and 1.000 for Zitlala (State of Guerrero) and 0.9955 and 0.9414 for Tzeltales (State of Chiapas), respectively. Maximum likelihood estimates of admixture components yield a trihybrid model with Amerindian (assuming that Nahua-Zitlala is the most representative indigenous population), Spanish, and African ancestry with the admixture proportions: 93.03, 6.03, and 0.94 for Tzeltales, and 28.99, 44.03, and 26.98 for Coyolillo. A contribution of the ancestral populations of Ixhuatlancillo, Actopan, Ixmiquilpan, Milpa-Alta, and Xochimilco were found with the following average of admixture proportions: 75.84, 22.50, and 1.66. The findings herein demonstrate that the genetic admixture of the Mexican indigenous populations who at present speak the same Amer-Indian language can be differentiated and that the majority of them have less ancestral indigenous contribution than those considered as Mestizo populations.

  2. Modeling of full-Heusler alloys within tight-binding approximation: Case study of Fe2MnAl

    Science.gov (United States)

    Azhar, A.; Majidi, M. A.; Nanto, D.

    2017-07-01

    Heusler alloys have been known for about a century, and predictions of magnetic moment values using Slater-Pauling rule have been successful for many such materials. However, such a simple counting rule has been found not to always work for all Heusler alloys. For instance, Fe2CuAl has been found to have magnetic moment of 3.30 µB per formula unit although the Slater-Pauling rule suggests the value of 2 µB. On the other hand, a recent experiment shows that a non-stoichiometric Heusler compound Fe2Mn0.5Cu0.5Al possesses magnetic moment of 4 µB, closer to the Slater-Pauling prediction for the stoichiometric compound. Such discrepancies signify that the theory to predict the magnetic moment of Heusler alloys in general is still far from being complete. Motivated by this issue, we propose to do a theoretical study on a full-Heusler alloy Fe2MnAl to understand the formation of magnetic moment microscopically. We model the system by constructing a density-functional-theory-based tight-binding Hamiltonian and incorporating Hubbard repulsive as well as spin-spin interactions for the electrons occupying the d-orbitals. Then, we solve the model using Green's function approach, and treat the interaction terms within the mean-field approximation. At this stage, we aim to formulate the computational algorithm for the overall calculation process. Our final goal is to compute the total magnetic moment per unit cell of this system and compare it with the experimental data.

  3. Structure and magnetic properties of Heusler alloy Co{sub 2}RuSi melt-spun ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Yuepeng; Ma, Yuexing; Hao, Hongyue [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Luo, Hongzhi, E-mail: luo_hongzhi@163.com [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Meng, Fanbin; Liu, Heyan [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Liu, Enke; Wu, Guangheng [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2017-08-01

    Highlights: • New Heusler alloy Co{sub 2}RuSi has been prepared by melt-spinning successfully. • Magnetic and electronic properties of Co{sub 2}RuSi were investigated. • Ru has a strong site preference for A, C sites in the lattice of Co{sub 2}RuSi. • Site preference of Ru cannot be determined by “number of valence electrons”. - Abstract: Heusler alloy Co{sub 2}RuSi has been synthesized by melt-spinning technology successfully. Co{sub 2}RuSi bulk sample after annealing is composed of an HCP Co-rich phase and a BCC Ru-Si phase, but melt-spinning can suppress the precipitation of the HCP phase and produce a single Co{sub 2}RuSi Heusler phase. In the XRD pattern, it is found that Ru has a strong preference for the (A, C) sites, though it has fewer valence electrons compared with Co. This site preference is different from the case in Heusler alloys containing only 3d elements and is supported further by first-principles calculations. Melt-spun Co{sub 2}RuSi has a M{sub s} of 2.67 μ{sub B}/f.u. at 5 K and a Tc of 491 K. An exothermic peak is observed at 871 K in the DTA curve, corresponding to the decomposition of the Heusler phase. Finally, the site preference and magnetic properties of Co{sub 2}RuSi were discussed based on electronic structure calculation and charge density difference.

  4. 2-(2′-Pyridyl)-4,6-diphenylphosphinine versus 2-(2′-Pyridyl)-4,6-diphenylpyridine: Synthesis, Characterization, and Reactivity of Cationic RhIII and IrIII Complexes Based on Aromatic Phosphorus Heterocycles

    NARCIS (Netherlands)

    de Krom, I.; Broeckx, L.E.E.; Lutz, M.; Müller, Christian

    2013-01-01

    The bidentate P,N hybrid ligand 1 allows access for the first time to novel cationic phosphinine-based RhIII and IrIII complexes, broadening significantly the scope of low-coordinate aromatic phosphorus heterocycles for potential applications. The coordination chemistry of 1 towards RhIII and IrIII

  5. Copper-based alloys, crystallographic and crystallochemical parameters of alloys in binary systems Cu-Me (Me=Co, Rh, Ir, Cu, Ag, Au, Ni, Pd, Pt)

    Energy Technology Data Exchange (ETDEWEB)

    Porobova, Svetlana, E-mail: porobova.sveta@yandex.ru; Loskutov, Oleg, E-mail: lom58@mail.ru [Tomsk State University of Architecture and Building, Russia, Tomsk, 2 Solyanaya sq, Tomsk, 634003 (Russian Federation); Markova, Tat’jana, E-mail: patriot-rf@mail.ru [Siberian State Industrial University. 42 Kirov St., Novokuznetsk, 654007 (Russian Federation); Klopotov, Vladimir, E-mail: vdklopotov@mail.ru [Research Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation); Klopotov, Anatoliy, E-mail: klopotovaa@tsuab.ru [Tomsk State University of Architecture and Building, Russia, Tomsk, 2 Solyanaya sq, Tomsk, 634003 (Russian Federation); National Research Tomsk State University, 36, Lenin Ave., Tomsk, 634050 (Russian Federation); Vlasov, Viktor, E-mail: vik@tsuab.ru [Tomsk State University of Architecture and Building, Russia, Tomsk, 2 Solyanaya sq, Tomsk, 634003 (Russian Federation); Research Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation)

    2016-01-15

    The article presents the results of the analysis of phase equilibrium of ordered phases in binary systems based on copper Cu- Me (where Me - Co, Rh, Ir, Ag, Au, Ni, Pd, Pt) to find correlations of crystallochemical and crystallographic factors. It is established that the packing index in disordered solid solutions in binary systems based on copper is close to the value of 0.74 against the background of an insignificant deviation of atomic volumes from the Zen’s law.

  6. Random laser based on Rhodamine 6G (Rh6G doped poly(methyl methacrylate (PMMA films coating on ZnO nanorods synthesized by hydrothermal oxidation

    Directory of Open Access Journals (Sweden)

    Hua Zhang

    Full Text Available Random laser based on Rh6G doped PMMA thin films coating on ZnO nanorods synthesized by a simple hydrothermal oxidation method has been demonstrated. This kind of random laser medium is based on waveguide structure consisting of ZnO nanorods, Rh6G doped PMMA film and air. By controlling the time of hydrothermal oxidation reaction, wheat-like and hexagonal prism ZnO nanorods have been successfully fabricated. The emission spectra of these gain mediums based on different ZnO nanorods are different. The one based on wheat-like ZnO nanorods mainly exhibits amplified spontaneous emission, and the other one based on hexagonal prism ZnO nanorods shows random laser emission. The threshold of the random laser medium is about 73.8 μJ/pulse, and the full width at half maximum (FWHM is around 2.1 nm. The emission spectra measured at different detecting angles reveal that the output direction is strongly confined in ±30° by the waveguide effect. Our experiments demonstrate a promising method to achieve organic random laser medium. Keywords: Random laser, ZnO nanorods, Hydrothermal oxidation, Rhodamine 6G (Rh6G, Poly(methyl methacrylate (PMMA

  7. Rh-catalyzed linear hydroformylation of styrene

    NARCIS (Netherlands)

    Boymans, E.H.; Janssen, M.C.C.; Mueller, C.; Lutz, M.; Vogt, D.

    2012-01-01

    Usually the Rh-catalyzed hydroformylation of styrene predominantly yields the branched, chiral aldehyde. An inversion of regioselectivity can be achieved using strong p-acceptor ligands. Binaphthol-based diphosphite and bis(dipyrrolyl-phosphorodiamidite) ligands were applied in the Rh-catalyzed

  8. Evaluation of a Novel HA/ZrO2-Based Porous Bioceramic Artificial Vertebral Body Combined with a rhBMP-2/Chitosan Slow-Release Hydrogel.

    Directory of Open Access Journals (Sweden)

    Yihui Shi

    Full Text Available A new HA/ZrO2-based porous bioceramic artificial vertebral body (AVB, carried a recombinant human bone morphogenetic protein-2 (rhBMP-2/chitosan slow-release hydrogel was prepared to repair vertebral bone defect in beagles. An ionic cross-linking was used to prepare the chitosan hydrogel (CS gel as the rhBMP-2 slow-release carrier. The vertebral body defects were implanted with the rhBMP-2-loaded AVB in group A, or a non-drug-loaded AVB in group B, or autologous iliac in group C. The encapsulation rate of rhBMP-2 in rhBMP-2-loaded CS gel was 91.88±1.53%, with a drug load of 39.84±2.34 ng/mg. At 6, 12, 24 weeks postoperatively, radiography showed that the bone calluses gradually increased with time in group A, where the artificial vertebral body had completely fused with host-bone at 24 weeks after surgery. In group C, an apparent bone remodeling was occurred in the early stages, and the graft-bone and host-bone had also fused completely at 24 weeks postoperatively. In group B, fusion occurred less than in groups A and C. At 24 weeks after surgery, micro-computed tomography (Micro-CT revealed that the volume of newly-formed bone in group A was significantly more than in group B (p<0.05. At 24 weeks after surgery, ultra-compressive strengths of the operated segments were 14.03±1.66 MPa in group A, 8.62±1.24 MPa in group B, and 13.78±1.43 MPa in group C. Groups A and C were both significantly higher than group B (p < 0.05. At 24 weeks postoperatively, the hard tissue sections showed that the AVB of group A had tightly fused with host bone, and that pores of the AVB had been filled with abundant nearly mature bone, and that the new bone structured similarly to a trabecular framework, which was similar to that in group C. In contrast, implant fusion of the AVB in group B was not as apparent as group A. In conclusion, the novel HA/ZrO2-based porous bioceramic AVB carried the rhBMP-2-loaded CS gel can promote the repair of bony defect, and induce

  9. RH-TRU Waste Content Codes

    Energy Technology Data Exchange (ETDEWEB)

    Washington TRU Solutions

    2007-07-01

    The Remote-Handled Transuranic (RH-TRU) Content Codes (RH-TRUCON) document describes the inventory of RH-TRU waste within the transportation parameters specified by the Remote-Handled Transuranic Waste Authorized Methods for Payload Control (RH-TRAMPAC).1 The RH-TRAMPAC defines the allowable payload for the RH-TRU 72-B. This document is a catalog of RH-TRU 72-B authorized contents by site. A content code is defined by the following components: • A two-letter site abbreviation that designates the physical location of the generated/stored waste (e.g., ID for Idaho National Laboratory [INL]). The site-specific letter designations for each of the sites are provided in Table 1. • A three-digit code that designates the physical and chemical form of the waste (e.g., content code 317 denotes TRU Metal Waste). For RH-TRU waste to be transported in the RH-TRU 72-B, the first number of this three-digit code is “3.” The second and third numbers of the three-digit code describe the physical and chemical form of the waste. Table 2 provides a brief description of each generic code. Content codes are further defined as subcodes by an alpha trailer after the three-digit code to allow segregation of wastes that differ in one or more parameter(s). For example, the alpha trailers of the subcodes ID 322A and ID 322B may be used to differentiate between waste packaging configurations. As detailed in the RH-TRAMPAC, compliance with flammable gas limits may be demonstrated through the evaluation of compliance with either a decay heat limit or flammable gas generation rate (FGGR) limit per container specified in approved content codes. As applicable, if a container meets the watt*year criteria specified by the RH-TRAMPAC, the decay heat limits based on the dose-dependent G value may be used as specified in an approved content code. If a site implements the administrative controls outlined in the RH-TRAMPAC and Appendix 2.4 of the RH-TRU Payload Appendices, the decay heat or FGGR

  10. Noise Reduction Based on an Fe -Rh Interlayer in Exchange-Coupled Heat-Assisted Recording Media

    Science.gov (United States)

    Vogler, Christoph; Abert, Claas; Bruckner, Florian; Suess, Dieter

    2017-11-01

    High storage density and high data rate are two of the most desired properties of modern hard disk drives. Heat-assisted magnetic recording (HAMR) is believed to achieve both. Recording media, consisting of exchange-coupled grains with a high and a low TC part, were shown to have low dc noise—but increased ac noise—compared to hard magnetic single-phase grains like FePt. We extensively investigate the influence of an Fe -Rh interlayer on the magnetic noise in exchange-coupled grains. We find an optimal grain design that reduces the jitter in the down-track direction by up to 30% and in the off-track direction by up to 50%, depending on the head velocity, compared to the same structures without FeRh. Furthermore, the mechanisms causing this jitter reduction are demonstrated. Additionally, we show that, for short heat pulses and low write temperatures, the switching-time distribution of the analyzed grain structure is reduced by a factor of 4 compared to the same structure without an Fe -Rh layer. This feature could be interesting for HAMR use with a pulsed laser spot and could encourage discussion of this HAMR technique.

  11. Large magnetoresistance in Heusler-alloy-based epitaxial magnetic junctions with semiconducting Cu(In{sub 0.8}Ga{sub 0.2})Se{sub 2} spacer

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, S. [Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Center for Emergent Matter Science, RIKEN, 2-1 Hirosawa, Wako 351-0198 (Japan); Takahashi, Y. K.; Ohkubo, T. [Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Cheng, P.-H.; Ikhtiar,; Mitani, S.; Hono, K. [Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577 (Japan); Kondou, K. [Center for Emergent Matter Science, RIKEN, 2-1 Hirosawa, Wako 351-0198 (Japan); Otani, Y. [Center for Emergent Matter Science, RIKEN, 2-1 Hirosawa, Wako 351-0198 (Japan); Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8581 (Japan)

    2016-07-18

    We investigated the structure and magneto-transport properties of magnetic junctions using a Co{sub 2}Fe(Ga{sub 0.5}Ge{sub 0.5}) Heusler alloy as ferromagnetic electrodes and a Cu(In{sub 0.8}Ga{sub 0.2})Se{sub 2} (CIGS) semiconductor as spacers. Owing to the semiconducting nature of the CIGS spacer, large magnetoresistance (MR) ratios of 40% at room temperature and 100% at 8 K were obtained for low resistance-area product (RA) values between 0.3 and 3 Ω μm{sup 2}. Transmission electron microscopy observations confirmed the fully epitaxial growth of the chalcopyrite CIGS layer, and the temperature dependence of RA indicated that the large MR was due to spin dependent tunneling.

  12. Large linear magnetoresistance and shubnikov-de hass oscillations in single crystals of YPdBi heusler topological insulators

    KAUST Repository

    Wang, Wenhong

    2013-07-12

    We report the observation of a large linear magnetoresistance (MR) and Shubnikov-de Hass (SdH) quantum oscillations in single crystals of YPdBi Heusler topological insulators. Owning to the successfully obtained the high-quality YPdBi single crystals, large non-saturating linear MR of as high as 350% at 5K and over 120% at 300K under a moderate magnetic field of 7T is observed. In addition to the large, field-linear MR, the samples exhibit pronounced SdH quantum oscillations at low temperature. Analysis of the SdH data manifests that the high-mobility bulk electron carriers dominate the magnetotransport and are responsible for the observed large linear MR in YPdBi crystals. These findings imply that the Heusler-based topological insulators have superiorities for investigating the novel quantum transport properties and developing the potential applications.

  13. Large linear magnetoresistance and shubnikov-de hass oscillations in single crystals of YPdBi heusler topological insulators

    KAUST Repository

    Wang, Wenhong; Du, Yin; Xu, Guizhou; Zhang, Xiaoming; Liu, Enke; Liu, Zhongyuan; Shi, Youguo; Chen, Jinglan; Wu, Guangheng; Zhang, Xixiang

    2013-01-01

    We report the observation of a large linear magnetoresistance (MR) and Shubnikov-de Hass (SdH) quantum oscillations in single crystals of YPdBi Heusler topological insulators. Owning to the successfully obtained the high-quality YPdBi single crystals, large non-saturating linear MR of as high as 350% at 5K and over 120% at 300K under a moderate magnetic field of 7T is observed. In addition to the large, field-linear MR, the samples exhibit pronounced SdH quantum oscillations at low temperature. Analysis of the SdH data manifests that the high-mobility bulk electron carriers dominate the magnetotransport and are responsible for the observed large linear MR in YPdBi crystals. These findings imply that the Heusler-based topological insulators have superiorities for investigating the novel quantum transport properties and developing the potential applications.

  14. Rh Factor Blood Test

    Science.gov (United States)

    ... Also, talk with your health care provider about scheduling an Rh immune globulin injection during your pregnancy ... of Privacy Practices Notice of Nondiscrimination Manage Cookies Advertising Mayo Clinic is a not-for-profit organization ...

  15. RH Packaging Operations Manual

    International Nuclear Information System (INIS)

    Washington TRU Solutions LLC

    2003-01-01

    This procedure provides operating instructions for the RH-TRU 72-B Road Cask, Waste Shipping Package. In this document, ''Packaging'' refers to the assembly of components necessary to ensure compliance with the packaging requirements (not loaded with a payload). ''Package'' refers to a Type B packaging that, with its radioactive contents, is designed to retain the integrity of its containment and shielding when subject to the normal conditions of transport and hypothetical accident test conditions set forth in 10 CFR Part 71. Loading of the RH 72-B cask can be done two ways, on the RH cask trailer in the vertical position or by removing the cask from the trailer and loading it in a facility designed for remote-handling (RH). Before loading the 72-B cask, loading procedures and changes to the loading procedures for the 72-B cask must be sent to CBFO at sitedocuments at wipp.ws for approval

  16. Predicting the effect of gonadotropin-releasing hormone (GnRH) analogue treatment on uterine leiomyomas based on MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsuno, Y.; Yamashita, Y.; Takahashi, M. [Dept. of Radiology, Kumamoto Univ. School of Medicine, Kumamoto (Japan); Katabuchi, H.; Okamura, H. [Dept. of Gynecology and Obstetrics, Kumamoto Univ. School of Medicine, Kumamoto (Japan); Kitano, Y.; Shimamura, T. [Dept. of Gynecology and Obstetrics, Amakusa Chuou General Hospital, Hondo (Japan)

    1999-11-01

    Purpose: To test the hypothesis that the simple assessment of signal intensity on T2-weighted MR images is predictive of the effect of hormonal treatment with gonadotropin-releasing hormone (GnRH) analogue. Material and methods: The correlation between T2-weighted MR imaging of uterine leiomyomas and histologic findings was evaluated using 85 leiomyomas from 62 females who underwent myomectomy or hysterectomy. We also correlated the pretreatment MR images features obtained in 110 women with 143 leiomyomas with the effect of GnRH analogue treatment. The size (length x width x depth) of the leiomyoma was evaluated before and at 6 months after treatment by ultrasound. Results: The proportion of leiomyoma cell fascicles and that of extracellular matrix affected signal intensities of uterine leiomyomas on T2-weighted MR images. The amount of extracellular matrix was predominant in hypointense leiomyomas on T2-weighted images, while diffuse intermediate signal leiomyomas were predominantly composed of leiomyoma cell fascicles. Marked degenerative changes were noted in leiomyomas with heterogenous hyperintensity. The homogeneously intermediate signal intensity leiomyomas showed significant size reduction after treatment (size ratio; posttreatment volume/pretreatment volume 0.29{+-}0.11). The size ratio for the hypointense tumors was 0.82{+-}0.14, and 0.82{+-}0.18 for the heterogeneously hyperintense tumors. There was a significant difference in the response to treatment between the homogeneously intermediate signal intensity leiomyomas and the hypointense or heterogeneously hyperintense leiomyomas (both p<0.01). Conclusion: Signal intensity on T2-weighted MR images depends on the amount of leiomyoma cell fascicles and extracellular matrix. Simple assessment of the MR signal intensity is useful in predicting the effect of GnRH analogue on uterine leiomyomas. (orig.)

  17. Predicting the effect of gonadotropin-releasing hormone (GnRH) analogue treatment on uterine leiomyomas based on MR imaging

    International Nuclear Information System (INIS)

    Matsuno, Y.; Yamashita, Y.; Takahashi, M.; Katabuchi, H.; Okamura, H.; Kitano, Y.; Shimamura, T.

    1999-01-01

    Purpose: To test the hypothesis that the simple assessment of signal intensity on T2-weighted MR images is predictive of the effect of hormonal treatment with gonadotropin-releasing hormone (GnRH) analogue. Material and methods: The correlation between T2-weighted MR imaging of uterine leiomyomas and histologic findings was evaluated using 85 leiomyomas from 62 females who underwent myomectomy or hysterectomy. We also correlated the pretreatment MR images features obtained in 110 women with 143 leiomyomas with the effect of GnRH analogue treatment. The size (length x width x depth) of the leiomyoma was evaluated before and at 6 months after treatment by ultrasound. Results: The proportion of leiomyoma cell fascicles and that of extracellular matrix affected signal intensities of uterine leiomyomas on T2-weighted MR images. The amount of extracellular matrix was predominant in hypointense leiomyomas on T2-weighted images, while diffuse intermediate signal leiomyomas were predominantly composed of leiomyoma cell fascicles. Marked degenerative changes were noted in leiomyomas with heterogenous hyperintensity. The homogeneously intermediate signal intensity leiomyomas showed significant size reduction after treatment (size ratio; posttreatment volume/pretreatment volume 0.29±0.11). The size ratio for the hypointense tumors was 0.82±0.14, and 0.82±0.18 for the heterogeneously hyperintense tumors. There was a significant difference in the response to treatment between the homogeneously intermediate signal intensity leiomyomas and the hypointense or heterogeneously hyperintense leiomyomas (both p<0.01). Conclusion: Signal intensity on T2-weighted MR images depends on the amount of leiomyoma cell fascicles and extracellular matrix. Simple assessment of the MR signal intensity is useful in predicting the effect of GnRH analogue on uterine leiomyomas. (orig.)

  18. Scattering of fast neutrons from 103Rh

    International Nuclear Information System (INIS)

    Barnard, E.; Reitmann, D.

    1978-01-01

    The scattering of fast neutrons from 103 Rh was studied by means of (n, n), (n, n') and (n, n'γ) measurements at neutron energies up to 2 MeV. More than fifty unknown γ-transitions were identified and a level scheme established which includes fifteen unreported excited states. Branching ratios, spins and parities for these levels were deduced, as well as the effective activation cross sections for the 103 Rh(n, n')sup(103m)Rh reaction. The results are compared with existing data and with calculations based on the optical and statistical models. (Auth.)

  19. Disorder dependent half-metallicity in Mn2CoSi inverse Heusler alloy

    International Nuclear Information System (INIS)

    Singh, Mukhtiyar; Saini, Hardev S.; Thakur, Jyoti; Reshak, Ali H.; Kashyap, Manish K.

    2013-01-01

    Heusler alloys based thin-films often exhibit a degree of atomic disorder which leads to the lowering of spin polarization in spintronic devices. We present ab-initio calculations of atomic disorder effects on spin polarization and half-metallicity of Mn 2 CoSi inverse Heusler alloy. The five types of disorder in Mn 2 CoSi have been proposed and investigated in detail. The A2 a -type and B2-type disorders destroy the half-metallicity whereas it sustains for all disorders concentrations in DO 3a - and A2 b -type disorder and for smallest disorder concentration studied in DO 3b -type disorder. Lower formation energy/atom for A2 b -type disorder than other four disorders in Mn 2 CoSi advocates the stability of this disorder. The total magnetic moment shows a strong dependence on the disorder and the change in chemical environment. The 100% spin polarization even in the presence of disorders explicitly supports that these disorders shall not hinder the use of Mn 2 CoSi inverse Heusler alloy in device applications. - Graphical abstract: Minority-spin gap (E g↓ ) and HM gap (E sf ) as a function of concentrations of various possible disorder in Mn 2 CoSi inverse Heusler alloy. The squares with solid line (black color)/dotted line (blue color)/dashed line (red color) reperesents E g↓ for DO 3a -/DO 3b -/A2 b -type disorder in Mn 2 CoSi and the spheres with solid line (black color)/dottedline (blue color)/dashed line (red color) represents E sf for DO 3a -/DO 3b -/A2 b -type disorder in Mn 2 CoSi. - Highlights: • The DO 3 - and A2-type disorders do not affect the half-metallicity in Mn 2 CoSi. • The B2-type disorder solely destroys half-metallicity in Mn 2 CoSi. • The A2-type disorder most probable to occur out of all three types. • The total spin magnetic moment strongly depends on the disorder concentrations

  20. Band structure of Heusler compounds studied by photoemission and tunneling spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Arbelo Jorge, Elena

    2011-07-01

    Heusler compounds are key materials for spintronic applications. They have attracted a lot of interest due to their half-metallic properties predicted by band structure calculations. The aim of this work is to evaluate experimentally the validity of the predictions of half metallicity by band structure calculations for two specific Heusler compounds, Co{sub 2}FeAl{sub 0.3}Si{sub 0.7} and Co{sub 2}MnGa. Two different spectroscopy methods for the analysis of the electronic properties were used: Angular Resolved Ultraviolet Photoemission Spectroscopy (ARUPS) and Tunneling Spectroscopy. Heusler compounds are prepared as thin films by RF-sputtering in an ultra high vacuum system. For the characterization of the samples, bulk and surface crystallographic and magnetic properties of Co{sub 2}FeAl{sub 0.3}Si{sub 0.7} and Co{sub 2}MnGa are studied. X-ray and electron diffraction reveal a bulk and surface crossover between two different types of sublattice order (from B2 to L2{sub 1}) with increasing annealing temperature. X-ray magnetic circular dichroism results show that the magnetic properties in the surface and bulk are identical, although the magnetic moments obtained are 5 % below from the theoretically predicted. By ARUPS evidence for the validity of the predicted total bulk density of states (DOS) was demonstrated for both Heusler compounds. Additional ARUPS intensity contributions close to the Fermi energy indicates the presence of a specific surface DOS. Moreover, it is demonstrated that the crystallographic order, controlled by annealing, plays an important role on broadening effects of DOS features. Improving order resulted in better defined ARUPS features. Tunneling magnetoresistance measurements of Co{sub 2}FeAl{sub 0.3}Si{sub 0.7} and Co{sub 2}MnGa based MTJ's result in a Co{sub 2}FeAl{sub 0.3}Si{sub 0.7} spin polarization of 44 %, which is the highest experimentally obtained value for this compound, although it is lower than the 100 % predicted. For Co

  1. Vacancy induced half-metallicity in half-Heusler semiconductors

    KAUST Repository

    Zhu, Zhiyong; Cheng, Yingchun; Schwingenschlö gl, Udo

    2011-01-01

    First-principles calculations are performed to investigate the effect of vacancies on the electronic structure and magnetic properties of the two prototypical half-Heusler semiconductors NiTiSn and CoTiSb. The spin degeneracy of the host materials

  2. Achieving perpendicular anisotropy in half-metallic Heusler alloys for spin device applications

    Science.gov (United States)

    Munira, Kamaram; Romero, Jonathon; Butler, William H.

    2014-05-01

    Various full Heusler alloys are interfaced with MgO and the magnetic properties of the Heusler-MgO junctions are studied. Next to MgO, the cubic Heusler system distorts to a tetragonal one, thereby inducing an anisotropy. The half-metallicity and nature of anisotropy (in-plane or perpendicular) in the Heusler-MgO system is governed mostly by the interface Heusler layers. There is a trend that Mn-O bonding near the MgO-Heusler junction results in perpendicular anisotropy. The ability to remain half-metallic and have perpendicular anisotropy makes some of these alloys potential candidates as free-layers in Spin Transfer Torque Random Access Memory (STT-RAM) devices, particularly, Cr2MnAs-MgO system with MnAs interface layers and Co2MnSi-MgO system with Mn2 interface layers.

  3. Multifunctional properties related to magnetostructural transitions in ternary and quaternary Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dubenko, Igor, E-mail: igor_doubenko@yahoo.com [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Quetz, Abdiel; Pandey, Sudip; Aryal, Anil; Eubank, Michael [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Rodionov, Igor; Prudnikov, Valerii; Granovsky, Alexander [Faculty of Physics, Moscow State University, Vorob' evy Gory, 11999I Moscow (Russian Federation); Lahderanta, Erkki [Lappeenranta University of Technology, 53851 (Finland); Samanta, Tapas; Saleheen, Ahmad; Stadler, Shane [Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Ali, Naushad [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States)

    2015-06-01

    In this report, the results of a study on the effects of compositional variations induced by the small changes in concentrations of the parent components and/or by the substitution of Ni, Mn, or In by an extra element Z, on the phase transitions, and phenomena related to the magnetostructural transitions in off-stoichiometric Ni–Mn–In based Heusler alloys are summarized. The crystal structures, phase transitions temperatures, and magnetic and magnetocaloric properties were analyzed for representative samples of the following systems (all near 15 at% indium concentration): Ni–Mn–In, Ni–Mn–In–Si, Ni–Mn–In–B, Ni–Mn–In–Cu, Ni–Mn–In–Cu–B, Ni–Mn–In–Fe, Ni–Mn–In–Ag, and Ni–Mn–In–Al. - Highlights: • The experimental results on phase transitions temperatures, adiabatic temperature changes, magnetoresistance and heat flow for the ternary and quaternary Heusler alloys based on Ni{sub 50}Mn{sub 35}In{sub 15} demonstrate high sensitivity of magnetic properties to the small changes in concentrations of the parent components and/or by the substitution of Ni, Mn, or In by an additional element Z. • The phenomena related to the magnetostructural transitions strongly depend on the weighted average radius of constituent ions.

  4. Unconventional superconductivity and surface pairing symmetry in half-Heusler compounds

    Science.gov (United States)

    Wang, Qing-Ze; Yu, Jiabin; Liu, Chao-Xing

    2018-06-01

    Signatures of nodal line/point superconductivity [Kim et al., Sci. Adv. 4, eaao4513 (2018), 10.1126/sciadv.aao4513; Brydon et al., Phys. Rev. Lett. 116, 177001 (2016), 10.1103/PhysRevLett.116.177001] have been observed in half-Heusler compounds, such as LnPtBi (Ln = Y, Lu). Topologically nontrivial band structures, as well as topological surface states, have also been confirmed by angular-resolved photoemission spectroscopy in these compounds [Liu et al., Nat. Commun. 7, 12924 (2016), 10.1038/ncomms12924]. In this paper, we present a systematical classification of possible gap functions of bulk states and surface states in half-Heusler compounds and the corresponding topological properties based on the representations of crystalline symmetry group. Different from all the previous studies based on the four band Luttinger model, our study starts with the six-band Kane model, which involves both four p-orbital type of Γ8 bands and two s-orbital type of Γ6 bands. Although the Γ6 bands are away from the Fermi energy, our results reveal the importance of topological surface states, which originate from the band inversion between Γ6 and Γ8 bands, in determining surface properties of these compounds in the superconducting regime by combining topological bulk state picture and nontrivial surface state picture.

  5. High thermoelectric figure of merit by resonant dopant in half-Heusler alloys

    Science.gov (United States)

    Chen, Long; Liu, Yamei; He, Jian; Tritt, Terry M.; Poon, S. Joseph

    2017-06-01

    Half-Heusler alloys have been one of the benchmark high temperature thermoelectric materials owing to their thermal stability and promising figure of merit ZT. Simonson et al. early showed that small amounts of vanadium doped in Hf0.75Zr0.25NiSn enhanced the Seebeck coefficient and correlated the change with the increased density of states near the Fermi level. We herein report a systematic study on the role of vanadium (V), niobium (Nb), and tantalum (Ta) as prospective resonant dopants in enhancing the ZT of n-type half-Heusler alloys based on Hf0.6Zr0.4NiSn0.995Sb0.005. The V doping was found to increase the Seebeck coefficient in the temperature range 300-1000 K, consistent with a resonant doping scheme. In contrast, Nb and Ta act as normal n-type dopants, as evident by the systematic decrease in electrical resistivity and Seebeck coefficient. The combination of enhanced Seebeck coefficient due to the presence of V resonant states and the reduced thermal conductivity has led to a state-of-the-art ZT of 1.3 near 850 K in n-type (Hf0.6Zr0.4)0.99V0.01NiSn0.995Sb0.005 alloys.

  6. Systematic ab initio study of half-Heusler materials for optoelectronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Gruhn, Thomas; Felser, Claudia [Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg University, Mainz (Germany)

    2010-07-01

    The development of new, optimized optoelectronic devices depends crucially on the availability of semiconductors with taylored electronic and structural properties. At the moment, the majority of applications is based on a rather small set of semiconducting materials, while many more semiconductors exist in the huge class of ternary compounds. Especially, the class of 8-electron half-Heusler materials comprises a large number semiconducters with various properties. With the help of ab initio density functional theory we have studied essentially all 8-electron half-Heusler compounds that are of technological relevance. For more than 650 compounds we have determined the optimum configuration by varying the lattice constant and permuting the elements over the sublattices. Within this exceptionally large data set we have studied the band structure and the lattice constants as a function of the electronegativities of the elements, the arrangement of the atoms, and the atomic radii. The results are used to select suitable materials for the buffer layer in thin-film solar cells with a Cu(In,Ga)Se{sub 2} (CIGS) absorber layer. Considering the bandgap and the geometrical matching with the CIGS film, we have obtained a set of 29 compounds that are promissing materials for cadmium-free CIGS buffer layer.

  7. Neutron irradiation effects on magnetic properties of some Heusler alloys

    International Nuclear Information System (INIS)

    Onodera, Hideya; Shinohara, Takeshi; Yamamoto, Hisao; Watanabe, Hiroshi

    1975-01-01

    The neutron irradiation effects were studied with measurements of temperature dependence of magnetization in ordered and disordered Heusler alloys. The irradiation was carried out in JMTR with a total flux of fast neutrons of 10 20 nvt. Fully ordered Cu 2 MnIn, partially ordered Cu 2 MnAl and completely disordered Cu 2 MnSn were prepared with various temperature treatments. The magnetization-temperature curves of each specimen were measured before and after irradiation. In the irradiated Cu 2 MnIn, the disordering by the irradiation gave rise to a decrease of magnetization, and the temperature dependence of magnetization showed that the disordered region contained various regions with different degrees of disorder. For the distribution of the disordered region, the calculation based on the theory of temperature spike by Seitz and Koekler gave a feasible result that a disordered region comprised a central core with a radius of 5.4 A which was completely disordered and a periphery of 3.3 A thickness which was partially disordered. From the magnetization-temperature curves of Cu 2 MnAl, it was considered that the disordered regions induced by the irradiation had different properties from those induced by the heat treatment. The former were the localized and comprised regions corresponding to various degrees of disorder, while the latter spread spatially in a wide range with a certain degree of disorder. The ordering by enhanced diffusion occurred simultaneously to an extent comparable to the disordering, and so it played an important role in the magnetization in the partially disordered Cu 2 MnAl. In the disordered Cu 2 MnSn, however, the ordering effect was very small. It is supposed to be difficult for the A2 structure to transform into the L2 1 structure by the enhanced diffusion. (auth.)

  8. Steam reforming of methane over Pt/Rh based wire mesh catalyst in single channel reformer for small scale syngas production

    DEFF Research Database (Denmark)

    Sigurdsson, Haftor Örn; Kær, Søren Knudsen

    2012-01-01

    of a catalytic parallel plate type heat exchanger (CPHE) reformer stack, where coated Pt/Rh based wire mesh is used as a catalyst. Heat is supplied to the endothermic reaction with infrared electric heaters. All the experiments were performed under atmospheric pressure and at stable operating conditions......The purpose of this study is to investigate a small scale steam methane reformer for syngas production for a micro combined heat and power (mCPH) unit under different operational conditions. The study presents an experimental analysis of the performance of a specially built single channel...... to evaluate the effect of flow maldistribution in a CPHE reformer stack on the CH4 conversion and H2 yield....

  9. Hyperfine field at 111Cd nuclei in Heusler alloys

    International Nuclear Information System (INIS)

    Styczen, B.; Walus, W.; Szytula, A.

    1978-01-01

    The magnitudes and signs of the hyperfine fields in the ordered ferromagnetic Heusler Alloys X 2 MnZ and XMnZ (where X is Cu, Ni, Pd while Z is In, Sn and Sb) have been investigated at liquid nitrogen and room temperatures using TDPAC method. Their signs have been found to be negative. The results have been compared with the predictions of Caroll-Blandin and Cambell-Blandin models and RKKY theory. (Auth)

  10. Transport measurements on superconducting iron pnictides and Heusler compounds; Transportmessungen an Supraleitenden Eisenpniktiden und Heusler-Verbindungen

    Energy Technology Data Exchange (ETDEWEB)

    Bombor, Dirk

    2014-09-05

    In this work, results of electronic transport measurements are discussed for superconducting iron pnictides as well as for ferromagnetic Heusler compounds. The iron pnictides are a recently discovered class of high temperature superconductors where magnetism might play a crucial role. While the 122-pnictides show antiferromagnetism and migrate to the superconducting state upon doping, ferromagnetism has been observed in doped LiFeAs. On the other hand, in the undoped state this material shows interesting superconducting properties. Among other properties, Heusler compounds are well known due to their ferromagnetism. Co{sub 2}FeSi, which was investigated in this work, is one of the strongest ferromagnets. Beside this, one predicts this compound to be a half-metallic ferromagnet with completely spin polarized electronic transport where all conducting electrons have the same spin. The here addressed properties can well be investigated with the method of electronic transport measurements, whose results on single crystals are discussed in this work.

  11. CoFeRh alloys

    Energy Technology Data Exchange (ETDEWEB)

    Tabakovic, Ibro [Seagate Technology, Research and Development, Bloomington, MN 55435 (United States)], E-mail: ibro.m.tabakovic@seagate.com; Qiu Jiaoming; Riemer, Steve; Sun Ming; Vas' ko, Vlad; Kief, Mark [Seagate Technology, Research and Development, Bloomington, MN 55435 (United States)

    2008-01-01

    The electrochemical behavior of Rh(III) species in CoFe solution containing RhCl{sub 3}, NH{sub 4}Cl, H{sub 3}BO{sub 3}, CoSO{sub 4}, FeSO{sub 4}, saccharin, and NaLS (Na lauryl sulfate) has been investigated. The electrochemistry of Rh(III) species is influenced by each of the compounds present in CoFe plating solution, but especially by addition of saccharin and H{sub 3}BO{sub 3} to the RhCl{sub 3}-NH{sub 4}Cl solution. The nucleation and growth of Rh on GC (glassy carbon), Ru, and Cu electrodes from NH{sub 4}Cl solution was studied using the potentiostatic current-transient methods. The results support a predominantly progressive nucleation of Rh on all three-electrode surfaces. The nucleation kinetic parameters ANo (steady state nucleation rate) and Ns (saturation nuclear number density) were found to vary with potential and are electrode-dependent in order: GC > Ru{approx}Cu. The electrodeposited Rh films obtained from NH{sub 4}Cl solution and nonmagnetic CoFeRh film obtained from CoFe solution were characterized in terms of the following properties: morphology, surface roughness, crystal structure and chemical composition. The origin of light elements found in Rh and CoFeRh films (O, Cl, S, C, N) was discussed.

  12. CoFeRh alloys

    International Nuclear Information System (INIS)

    Tabakovic, Ibro; Qiu Jiaoming; Riemer, Steve; Sun Ming; Vas'ko, Vlad; Kief, Mark

    2008-01-01

    The electrochemical behavior of Rh(III) species in CoFe solution containing RhCl 3 , NH 4 Cl, H 3 BO 3 , CoSO 4 , FeSO 4 , saccharin, and NaLS (Na lauryl sulfate) has been investigated. The electrochemistry of Rh(III) species is influenced by each of the compounds present in CoFe plating solution, but especially by addition of saccharin and H 3 BO 3 to the RhCl 3 -NH 4 Cl solution. The nucleation and growth of Rh on GC (glassy carbon), Ru, and Cu electrodes from NH 4 Cl solution was studied using the potentiostatic current-transient methods. The results support a predominantly progressive nucleation of Rh on all three-electrode surfaces. The nucleation kinetic parameters ANo (steady state nucleation rate) and Ns (saturation nuclear number density) were found to vary with potential and are electrode-dependent in order: GC > Ru∼Cu. The electrodeposited Rh films obtained from NH 4 Cl solution and nonmagnetic CoFeRh film obtained from CoFe solution were characterized in terms of the following properties: morphology, surface roughness, crystal structure and chemical composition. The origin of light elements found in Rh and CoFeRh films (O, Cl, S, C, N) was discussed

  13. RH Packaging Program Guidance

    International Nuclear Information System (INIS)

    2008-01-01

    The purpose of this program guidance document is to provide the technical requirements for use, operation, inspection, and maintenance of the RH-TRU 72-B Waste Shipping Package (also known as the 'RH-TRU 72-B cask') and directly related components. This document complies with the requirements as specified in the RH-TRU 72-B Safety Analysis Report for Packaging (SARP), and Nuclear Regulatory Commission (NRC) Certificate of Compliance (C of C) 9212. If there is a conflict between this document and the SARP and/or C of C, the C of C shall govern. The C of C states: 'each package must be prepared for shipment and operated in accordance with the procedures described in Chapter 7.0, Operating Procedures, of the application.' It further states: 'each package must be tested and maintained in accordance with the procedures described in Chapter 8.0, Acceptance Tests and Maintenance Program of the Application.' Chapter 9.0 of the SARP tasks the Waste Isolation Pilot Plant (WIPP) Management and Operating (M and O) Contractor with assuring the packaging is used in accordance with the requirements of the C of C. Because the packaging is NRC-approved, users need to be familiar with Title 10 Code of Federal Regulations (CFR) 71.8, 'Deliberate Misconduct.' Any time a user suspects or has indications that the conditions of approval in the C of C were not met, the U.S. Department of Energy (DOE) Carlsbad Field Office (CBFO) shall be notified immediately. The CBFO will evaluate the issue and notify the NRC if required.In accordance with 10 CFR Part 71, 'Packaging and Transportation of Radioactive Material,' certificate holders, packaging users, and contractors or subcontractors who use, design, fabricate, test, maintain, or modify the packaging shall post copies of (1) 10 CFR Part 21, 'Reporting of Defects and Noncompliance,' regulations, (2) Section 206 of the Energy Reorganization Act of 1974, and (3) NRC Form 3, Notice to Employees. These documents must be posted in a conspicuous

  14. Electronic, phonon and superconducting properties of LaPtBi half-Heusler compound

    Science.gov (United States)

    Shrivastava, Deepika; Sanyal, Sankar P.

    2018-05-01

    In the framework of density functional theory based on plane wave pseudopotential method and linear response technique, we have studied the electronic, phonon and superconducting properties of LaPtBi half-Heusler compound. The electronic band structure and density of states show that it is gapless semiconductor which is consistent with previous results. The positive phonon frequencies confirm the stability of this compound in cubic MgAgAs phase. Superconductivity is studied in terms of Eliashberg spectral function (α2F(ω)), electron-phonon coupling constants (λ). The value of electron-phonon coupling parameter is found to be 0.41 and the superconducting transition temperature is calculated to be 0.76 K, in excellent agreement with the experimentally reported values.

  15. Heat capacities of several Co{sub 2}YZ Heusler compounds

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Ming, E-mail: myin1@hawk.iit.edu; Nash, Philip; Chen, Song

    2013-12-20

    Highlights: • Heat contents from 600 K to 1500 K of selected Co{sub 2}YZ were measured by drop calorimeters. • Heat capacities were obtained by taking derivatives of heats contents which were fitted with second order polynomial with respect to temperature. • Melting points determined by DSC were consistent with literature data. • Heats of fusion determined by DSC were comparable with those obtained by extrapolation of heat contents. - Abstract: Heat contents of several Co{sub 2}-based Heusler compounds Co{sub 2}YZ (Y = Fe, Mn, Ti; Z = Al, Ga, Si, Ge, Sn) were measured from 500 K to 1500 K using a Setaram MTHC 96 drop calorimeter. Second order polynomials were adopted to fit the data and heat capacities were obtained by taking the derivatives with respect to temperature. Melting points were determined by differential scanning calorimetry (DSC) and measured heats of fusion were compared with those obtained from extrapolation of heat contents.

  16. A potential role of substrate as a base for deprotonation pathway in Rh-catalysed C-H amination of heteroArenes: DFT insights

    KAUST Repository

    Ajitha, Manjaly John

    2016-03-29

    The possibility of direct introduction of a new functionality through C–H bond activation is an attractive strategy in covalent synthesis. Here, we investigated the mechanism of Rh-catalysed C-H amination of the hetero-aryl substrate (2-phenylpyridine) using phenyl azide as nitrogen source by density functional theory (DFT). For the deprotocyclometallation and protodecyclometallation processes of the title reaction, we propose a stepwise base-assisted mechanism (pathway I) instead of previously reported concerted mechanism (pathway II). In the new mechanism proposed here, 2-phenylpyridine acts as a base in the initial deprotonation step (C-H bond cleavage) and transports the proton towards the final protonation step. In fact, the N-H bond of the strong conjugate acid (formed during initial C-H bond cleavage) considered in pathway I (via TS4) is more acidic than the C-H bond of the neutral substrate considered in pathway II (via TS5). The higher activation barrier of TS5 mainly originates from the ring strain of the four membered cyclic transition state. The vital role of base, as disclosed here, can potentially have broader mechanistic implications for the development of reaction conditions of transition metal catalysed reactions.

  17. Study of structural, electronic and magnetic properties of CoFeIn and Co2FeIn Heusler alloys

    International Nuclear Information System (INIS)

    El Amine Monir, M.; Khenata, R.; Baltache, H.; Murtaza, G.; Abu-Jafar, M.S.; Bouhemadou, A.; Bin Omran, S.

    2015-01-01

    The structural, electronic and magnetic properties of half-Heusler CoFeIn and full-Heusler Co 2 FeIn alloys have been investigated by using the state of the art full-potential linearized augmented plane wave (FP-LAPW) method. The exchange-correlation potential was treated with the generalized gradient approximation (PBE-GGA) for the calculation of the structural properties, whereas the PBE-GGA+U approximation (where U is the Hubbard Coulomb energy term) is applied for the computation of the electronic and magnetic properties in order to treat the “d” electrons. The structural properties have been calculated in the paramagnetic and ferromagnetic phases where we have found that both the CoFeIn and Co 2 FeIn alloys have a stable ferromagnetic phase. The obtained results of the spin-polarized band structure and the density of states show that the CoFeIn alloy is a metal and the Co 2 FeIn alloy has a complete half-metallic nature. Through the obtained values of the total spin magnetic moment, we conclude that in general, the Co 2 FeIn alloy is half-metallic ferromagnet material whereas the CoFeIn alloy has a metallic nature. - Highlights: • Based on DFT calculations, CoFeIn and Co2FeIn Heusler alloys were investigated. • The magnetic phase stability was determined from the total energy calculations. • Electronic properties reveal the metallic (half-metallic) nature for CoFeIn (Co2FeIn)

  18. Equiatomic quaternary Heusler alloys: A material perspective for spintronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Bainsla, Lakhan, E-mail: lakhanbainsla@gmail.com, E-mail: suresh@phy.iitb.ac.in; Suresh, K. G., E-mail: lakhanbainsla@gmail.com, E-mail: suresh@phy.iitb.ac.in [Magnetic Materials Lab, Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India)

    2016-09-15

    Half-metallic ferromagnetic (HMF) materials show high spin polarization and are therefore interesting to researchers due to their possible applications in spintronic devices. In these materials, while one spin sub band has a finite density of states at the Fermi level, the other sub band has a gap. Because of their high Curie temperature (T{sub C}) and tunable electronic structure, HMF Heusler alloys have a special importance among the HMF materials. Full Heusler alloys with the stoichiometric composition X{sub 2}YZ (where X and Y are the transition metals and Z is a sp element) have the cubic L2{sub 1} structure with four interpenetrating fcc sublattices. When each of these four fcc sublattices is occupied by different atoms (XX′YZ), a quaternary Heusler structure with different structural symmetries (space group F-43m, #216) is obtained. Recently, these equiatomic quaternary Heusler alloys (EQHAs) with 1:1:1:1 stoichiometry have attracted a lot of attention due to their superior magnetic and transport properties. A special class of HMF materials identified recently is known as spin gapless semiconductors (SGS). The difference in this case, compared with HMFs, is that the density of states for one spin band is just zero at the Fermi level, while the other has a gap as in the case of HMFs. Some of the reported SGS materials belong to EQHAs family. This review is dedicated to almost all reported materials belonging to EQHAs family. The electronic structure and hence the physical properties of Heusler alloys strongly depend on the degree of structural order and distribution of the atoms in the crystal lattice. A variety of experimental techniques has been used to probe the structural parameters and degree of order in these alloys. Their magnetic properties have been investigated using the conventional methods, while the spin polarization has been probed by point contact Andreev reflection technique. The experimentally obtained values of saturation magnetization are

  19. Spin-filter and spin-gapless semiconductors: The case of Heusler compounds

    International Nuclear Information System (INIS)

    Galanakis, I.; Özdoğan, K.; Şaşıoğlu, E.

    2016-01-01

    We review our recent first-principles results on the inverse Heusler compounds and the ordered quaternary (also known as LiMgPdSn-type) Heusler compounds. Among these two subfamilies of the full-Heusler compounds, several have been shown to be magnetic semiconductors. Such material can find versatile applications, e.g. as spin-filter materials in magnetic tunnel junctions. Finally, a special case are the spin-gapless semiconductors, where the energy gap at the Fermi level for the one spin-direction is almost vanishing, offering novel functionalities in spintronic/magnetoelectronic devices.

  20. RH Packaging Program Guidance

    International Nuclear Information System (INIS)

    2006-01-01

    The purpose of this program guidance document is to provide the technical requirements for use, operation, inspection, and maintenance of the RH-TRU 72-B Waste Shipping Package and directly related components. This document complies with the requirements as specified in the RH-TRU 72-B Safety Analysis Report for Packaging (SARP), and Nuclear Regulatory Commission (NRC) Certificate of Compliance (C of C) 9212. If there is a conflict between this document and the SARP and/or C of C, the C of C shall govern. The C of C states: 'each package must be prepared for shipment and operated in accordance with the procedures described in Chapter 7.0, Operating Procedures, of the application.' It further states: 'each package must be tested and maintained in accordance with the procedures described in Chapter 8.0, Acceptance Tests and Maintenance Program of the Application.' Chapter 9.0 of the SARP tasks the Waste Isolation Pilot Plant (WIPP) Management and Operating (M and O) Contractor with assuring the packaging is used in accordance with the requirements of the C of C. Because the packaging is NRC-approved, users need to be familiar with 10 Code of Federal Regulations (CFR) 1.8, 'Deliberate Misconduct.' Any time a user suspects or has indications that the conditions of approval in the C of C were not met, the U.S. Department of Energy (DOE) Carlsbad Field Office (CBFO) shall be notified immediately. CBFO will evaluate the issue and notify the NRC if required. In accordance with 10 CFR Part 71, 'Packaging and Transportation of Radioactive Material,' certificate holders, packaging users, and contractors or subcontractors who use, design, fabricate, test, maintain, or modify the packaging shall post copies of (1) 10 CFR Part 21, 'Reporting of Defects and Noncompliance,' regulations, (2) Section 206 of the Energy Reorganization Act of 1974, and (3) NRC Form 3, Notice to Employees. These documents must be posted in a conspicuous location where the activities subject to these

  1. Magnetocaloric effect in Heusler shape-memory alloys

    International Nuclear Information System (INIS)

    Planes, A.; Manosa, Ll.; Moya, X.; Krenke, T.; Acet, M.; Wassermann, E.F.

    2007-01-01

    We present a comparative study of the magnetocaloric properties of Ni-Mn-X Heusler shape-memory alloys with X=Ga, Sn and In. In these materials, the magnetocaloric effect is a consequence of the magnetostructural coupling that enables the magnetic shape-memory properties. We show that inverse magnetocaloric effects can occur in these materials. The origin of this anomalous behavior is different in stoichiometric Ni 2 MnGa and in Ni-Mn-Sn/In. In the former case it is related to the strong uniaxial magnetic anisotropy of the martensitic phase, while in the later it is an intrinsic effect associated with an incipient antiferromagnetism

  2. Hyperfine magnetic fields at 111Cd in Heusler alloys

    International Nuclear Information System (INIS)

    Styczen, B.; Szytula, A.; Walus, W.

    1977-01-01

    The magnitudes and signs of the hyperfine magnetic field on 111 Cd nuclei at Z sites in the ordered ferromagnetic Heusler alloys X 2 MnZ and XMnZ (where X is Cu, Ni, Pd while Z is In, Sn and Sb) have been investigated at liquid nitrogen and room temperatures using TDPAC method. Their signs have been found to be negative. The results have been compared with the predictions of Caroli-Blandin and Campbell-Blandin models and RKKY theory. (author)

  3. RH Packaging Program Guidance

    International Nuclear Information System (INIS)

    Washington TRU Solutions, LLC

    2003-01-01

    The purpose of this program guidance document is to provide technical requirements for use, operation, inspection, and maintenance of the RH-TRU 72-B Waste Shipping Package and directly related components. This document complies with the requirements as specified in the RH-TRU 72-B Safety Analysis Report for Packaging (SARP), and Nuclear Regulatory Commission (NRC) Certificate of Compliance (C of C) 9212. If there is a conflict between this document and the SARP and/or C of C, the SARP and/or C of C shall govern. The C of C states: ''...each package must be prepared for shipment and operated in accordance with the procedures described in Chapter 7.0, ''Operating Procedures,'' of the application.'' It further states: ''...each package must be tested and maintained in accordance with the procedures described in Chapter 8.0, ''Acceptance Tests and Maintenance Program of the Application.'' Chapter 9.0 of the SARP tasks the Waste Isolation Pilot Plant (WIPP) Management and Operating (M and O) contractor with assuring the packaging is used in accordance with the requirements of the C of C. Because the packaging is NRC approved, users need to be familiar with 10 CFR (section) 71.11, ''Deliberate Misconduct.'' Any time a user suspects or has indications that the conditions of approval in the C of C were not met, the Carlsbad Field Office (CBFO) shall be notified immediately. CBFO will evaluate the issue and notify the NRC if required. This document details the instructions to be followed to operate, maintain, and test the RH-TRU 72-B packaging. This Program Guidance standardizes instructions for all users. Users shall follow these instructions. Following these instructions assures that operations are safe and meet the requirements of the SARP. This document is available on the Internet at: ttp://www.ws/library/t2omi/t2omi.htm. Users are responsible for ensuring they are using the current revision and change notices. Sites may prepare their own document using the word

  4. Structural stability, electronic and magnetic behaviour of spin-polarized YCoVZ (Z = Si, Ge) and YCoTiZ (Z = Si, Ge) Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Rasool, Muhammad Nasir, E-mail: nasir4iub@gmail.com [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur, 63100 (Pakistan); Hussain, Altaf, E-mail: altafiub@yahoo.com [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur, 63100 (Pakistan); Javed, Athar [Department of Physics, University of the Punjab, Lahore, 54590 (Pakistan); Khan, Muhammad Azhar; Iqbal, F. [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur, 63100 (Pakistan)

    2016-11-01

    The structural stability, electronic and magnetic behaviour of YCoVZ (Z = Si, Ge) and YCoTiZ (Z = Si, Ge) Heusler alloys have been studied by first principle approach. Generalized gradient approximation (GGA) based on density functional theory (DFT) has been applied to investigate the properties of quaternary Heusler alloys. The YCoVSi, YCoVGe, YCoTiSi and YCoTiGe Heusler alloys of Type-3 structure are found to be stable in spin-polarized/magnetic phase. The YCoVSi and YCoVGe alloys exhibit nearly spin gapless semiconductor (SGS) behaviour while YCoTiSi and YCoTiGe alloys show half-metallic ferromagnetic (HMF) behaviour. For YCoVSi, YCoVGe, YCoTiSi and YCoTiGe alloys, the calculated energy band gaps in spin down (↓) channel are 0.60, 0.54, 0.68 and 0.44 eV, respectively. The YCoVZ and YCoTiZ alloys are found to have integral value of total magnetic moment (M{sub T}), thus obeying the Slater-Pauling rule, M{sub T} = (N{sub v}–18)μ{sub B}. - Highlights: • Four Heusler alloys i.e. YCoVZ (Z = Si, Ge) and YCoTiZ (Z = Si, Ge) are studied. • Type-3 crystal structure of all four alloys is stable in magnetic phase. • The compressibility (S) follows the order: S{sub YCoVSi} > S{sub YCoTiSi} > S{sub YCoVGe} > S{sub YCoTiGe}. • Half metallic ferromagnetic behaviour is observed in all four alloys. • All four alloys obey the Slater-Pauling rule, M{sub T} = (N{sub v} – 18)μ{sub B}.

  5. Mapping of monoclonal antibody- and receptor-binding domains on human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) using a surface plasmon resonance-based biosensor.

    Science.gov (United States)

    Laricchia-Robbio, L; Liedberg, B; Platou-Vikinge, T; Rovero, P; Beffy, P; Revoltella, R P

    1996-10-01

    An automated surface plasmon resonance (SPR)-based biosensor system has been used for mapping antibody and receptor-binding regions on the recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) molecule. A rabbit antimouse IgG1-Fc antibody (RAM.Fc) was coupled to an extended carboxymethylated-hydrogel matrix attached to a gold surface in order to capture an anti-rhGM-CSF monoclonal antibody (MAb) injected over the sensing layer. rhGM-CSF was subsequently injected and allowed to bind to this antibody. Multisite binding assays were then performed, by flowing sequentially other antibodies and peptides over the surface, and the capacity of the latter to interact with the entrapped rhGM-CSF in a multimolecular complex was monitored in real time with SPR. Eleven MAb (all IgG1K), were analyzed: respectively, four antipeptide MAb raised against three distinct epitopes of the cytokine (two clones against residues 14-24, that includes part of the first alpha-helix toward the N-terminal region; one clone against peptide 30-41, an intrahelical loop; and one clone against residues 79-91, including part of the third alpha-helix) and seven antiprotein MAbs raised against the entire rhGM-CSF, whose target native epitopes are still undetermined. In addition, the binding capacity to rhGM-CSF of a synthetic peptide, corresponding to residues 238-254 of the extracellular human GM-CSF receptor alpha-chain, endowed with rhGM-CSF binding activity, was tested. The results from experiments performed with the biosensor were compared with those obtained by a sandwich enzyme-linked immunosorbent assay (ELISA), using the same reagents. The features of the biosensor technology (fully automated, measure in real time, sharpened yes/no response, less background disturbances, no need for washing step or labeling of the reagent) offered several advantages in these studies of MAb immunoreactivity and epitope mapping, giving a much better resolution and enabling more distinct

  6. Half-metallic ferromagnetism in (Z B, Al, Ga, and In) Heusler alloys ...

    Indian Academy of Sciences (India)

    K H SADEGHI

    2018-01-03

    11], and zincblende (ZB) transition-metal pnictides and chalcogenides [12–17]. Among HM ferromagnets, Heusler alloys are attractive because of their technical applications (in spin-injection devices [18], spin-filters [19], ...

  7. Moving from Classical Ru-NHC to Neutral or Charged Rh-NHC Based Catalysts in Olefin Metathesis

    Directory of Open Access Journals (Sweden)

    Albert Poater

    2016-01-01

    Full Text Available Considering the versatility of oxidation states of rhodium together with the successful background of ruthenium-N-heterocyclic carbene based catalysts in olefin metathesis, it is envisaged the exchange of the ruthenium of the latter catalysts by rhodium, bearing an open-shell neutral rhodium center, or a +1 charged one. In the framework of in silico experiments, density functional theory (DFT calculations have been used to plot the first catalytic cycle that as a first step includes the release of the phosphine. DFT is, in this case, the tool that allows the discovery of the less endergonic reaction profile from the precatalytic species for the neutral catalyst with respect to the corresponding ruthenium one; increasing the endergonic character when dealing with the charged system.

  8. High performance p-type segmented leg of misfit-layered cobaltite and half-Heusler alloy

    International Nuclear Information System (INIS)

    Hung, Le Thanh; Van Nong, Ngo; Snyder, G. Jeffrey; Viet, Man Hoang; Balke, Benjamin; Han, Li; Stamate, Eugen; Linderoth, Søren; Pryds, Nini

    2015-01-01

    Highlights: • p-type segmented leg of oxide and half-Heusler was for the first time demonstrated. • The maximum conversion efficiency reached a value of about 5%. • The results are among the highest reported values so far for oxide-based legs. • Oxide-based segmented leg is very promising for generating electricity. - Abstract: In this study, a segmented p-type leg of doped misfit-layered cobaltite Ca 2.8 Lu 0.15 Ag 0.05 Co 4 O 9+δ and half-Heusler Ti 0.3 Zr 0.35 Hf 0.35 CoSb 0.8 Sn 0.2 alloy was fabricated and characterized. The thermoelectric properties of single components, segmented leg, and the electrical contact resistance of the joint part were measured as a function of temperature. The output power generation characteristics of segmented legs were characterized in air under various temperature gradients, ΔT, with the hot side temperature up to 1153 K. At ΔT ≈ 756 K, the maximum conversion efficiency reached a value of ∼5%, which is about 65% of that expected from the materials without parasitic losses. The long-term stability investigation for two weeks at the hot and cold side temperatures of 1153/397 K shows that the segmented leg has good durability as a result of stable and low electrical resistance contacts

  9. Experimental study of the electric resistivity in Heusler alloys

    International Nuclear Information System (INIS)

    Kunzler, J.V.

    1980-01-01

    Electrical resistivity measurements have been performed in the Cu 2 Mn (A1sub(1-x) Snsub(x)) Heusler alloys, where x = 0, 0.05, 0.10 and 0.15, in the temperature range from 4.2 to 800 0 K. Measurements have also been made on the Ni 2 MnX Heusler asloys, with X = In, Sn or Sb, in the range from 4.2 to 300 0 K. The experimental curves clearly show the importance of the ferromagnetic character for the alloys resistivity. The results obtained for the copper alloys, as well as for the Ni 2 MnSn alloy, are in agreement with an interpretation in terms of Bloch-Gruneisen and spin-disorder models, and fail to provide evidences of s-d scattering for the conduction electrons. This is not the case for the Ni 2 MnIn and Ni 2 MnSb alloys, in which the presence of (s-d) interband electronic scattering process, via phonon, was detected. Specially for the two last alloys specific heat and electronic photo-emissivity experiments are suggested. (Author) [pt

  10. Hybrid Spintronic Structures With Magnetic Oxides and Heusler Alloys

    DEFF Research Database (Denmark)

    Xu, Y. B.; Hassan, S. S. A.; Wong, P. K. J.

    2008-01-01

    Hybrid spintronic structures, integrating half-metallic magnetic oxides and Heusler alloys with their predicted high spin polarization, are important for the development of second-generation spintronics with high-efficient spin injection. We have synthesized epitaxial magnetic oxide Fe3O4 on Ga......As(100) and the unit cell of the Fe3O4 was found to be rotated by 45 degrees to match the gallium arsenide GaAs. The films were found to have a bulk-like moment down to 3-4 nm and a low coercivity indicating a high-quality magnetic interface. The magnetization hysteresis loops of the ultrathin films...... are controlled by uniaxial magnetic anisotropy. The dynamic response of the sample shows a heavily damped precessional response to the applied field pulses. In the Heusler alloy system of Co-2 MnGa on GaAs, we found that the magnetic moment was reduced for thicknesses down to 10 nm, which may account...

  11. Observation of Dirac state in half-Heusler material YPtBi

    OpenAIRE

    Hosen, M. Mofazzel; Dhakal, Gyanendra; Dimitri, Klauss; Choi, Hongchul; Kabir, Firoza; Sims, Christopher; Pavlosiuk, Orest; Wisniewski, Piotr; Durakiewicz, Tomasz; Zhu, Jian-Xin; Kaczorowski, Dariusz; Neupane, Madhab

    2018-01-01

    The prediction of non-trivial topological electronic states hosted by half-Heusler compounds makes them prime candidates for discovering new physics and devices as they harbor a variety of electronic ground states including superconductivity, magnetism, and heavy fermion behavior. Here we report normal state electronic properties of a superconducting half-Heusler compound YPtBi using angle-resolved photoemission spectroscopy (ARPES). Our data reveal the presence of a Dirac state at the zone c...

  12. On the Phase Separation in n-Type Thermoelectric Half-Heusler Materials

    Directory of Open Access Journals (Sweden)

    Michael Schwall

    2018-04-01

    Full Text Available Half-Heusler compounds have been in focus as potential materials for thermoelectric energy conversion in the mid-temperature range, e.g., as in automotive or industrial waste heat recovery, for more than ten years now. Because of their mechanical and thermal stability, these compounds are advantageous for common thermoelectric materials such as Bi 2 Te 3 , SiGe, clathrates or filled skutterudites. A further advantage lies in the tunability of Heusler compounds, allowing one to avoid expensive and toxic elements. Half-Heusler compounds usually exhibit a high electrical conductivity σ , resulting in high power factors. The main drawback of half-Heusler compounds is their high lattice thermal conductivity. Here, we present a detailed study of the phase separation in an n-type Heusler materials system, showing that the Ti x Zr y Hf z NiSn system is not a solid solution. We also show that this phase separation is key to the thermoelectric high efficiency of n-type Heusler materials. These results strongly underline the importance of phase separation as a powerful tool for designing highly efficient materials for thermoelectric applications that fulfill the industrial demands of a thermoelectric converter.

  13. Perpendicular Magnetic Anisotropy in Heusler Alloy Films and Their Magnetoresistive Junctions

    Directory of Open Access Journals (Sweden)

    Atsufumi Hirohata

    2018-01-01

    Full Text Available For the sustainable development of spintronic devices, a half-metallic ferromagnetic film needs to be developed as a spin source with exhibiting 100% spin polarisation at its Fermi level at room temperature. One of the most promising candidates for such a film is a Heusler-alloy film, which has already been proven to achieve the half-metallicity in the bulk region of the film. The Heusler alloys have predominantly cubic crystalline structures with small magnetocrystalline anisotropy. In order to use these alloys in perpendicularly magnetised devices, which are advantageous over in-plane devices due to their scalability, lattice distortion is required by introducing atomic substitution and interfacial lattice mismatch. In this review, recent development in perpendicularly-magnetised Heusler-alloy films is overviewed and their magnetoresistive junctions are discussed. Especially, focus is given to binary Heusler alloys by replacing the second element in the ternary Heusler alloys with the third one, e.g., MnGa and MnGe, and to interfacially-induced anisotropy by attaching oxides and metals with different lattice constants to the Heusler alloys. These alloys can improve the performance of spintronic devices with higher recording capacity.

  14. GnRH agonist ovulation trigger and hCG-based, progesterone-free luteal support: a proof of concept study

    DEFF Research Database (Denmark)

    Kol, Shahar; Humaidan, Peter; Itskovitz-Eldor, Joseph

    2011-01-01

    in normal responder IVF patients. We here present a novel approach for luteal support after a GnRHa trigger. METHODS Normal responder patients who failed at least one previous IVF attempt, during which a conventional hCG trigger was used, were consecutively enrolled in the study. A GnRH antagonist...

  15. A potential role of substrate as a base for deprotonation pathway in Rh-catalysed C-H amination of heteroArenes: DFT insights

    KAUST Repository

    Ajitha, Manjaly John; Huang, Kuo-Wei; Kwak, Jaesung; Kim, Hyun Jin; Chang, Sukbok; Jung, Yousung

    2016-01-01

    The possibility of direct introduction of a new functionality through C–H bond activation is an attractive strategy in covalent synthesis. Here, we investigated the mechanism of Rh-catalysed C-H amination of the hetero-aryl substrate (2

  16. Concept design on RH maintenance of CFETR Tokamak reactor

    International Nuclear Information System (INIS)

    Song, Yuntao; Wu, Songtao; Wan, Yuanxi; Li, Jiangang; Ye, Minyou; Zheng, Jinxing; Cheng, Yong; Zhao, Wenlong; Wei, Jianghua

    2014-01-01

    Highlights: •We discussed the concept design of the RH maintenance system based on the main design work of the key components for CFETR. •The main design work for RH maintenance in this paper was carried out including the divertor RH system, the blanket RH system and the transfer cask system. •The technical problems encountered in the design process were discussed. •The present concept design of remote maintenance system in this paper can meet the physical and engineering requirement of CFETR. -- Abstract: CFETR which stands for Chinese Fusion Engineering Testing Reactor is a superconducting Tokamak device. The concept design on RH maintenance of CFETR has been done in the past year. It is known that, the RH maintenance is one of the most important parts for Tokamak reactor. The fusion power was designed as 50–200 MW and its duty cycle time (or burning time) was estimated as 30–50%. The center magnetic field strength on the TF magnet is 5.0 T, the maximum capacity of the volt seconds provided by center solenoid winding will be about 160 VS. The plasma current will be 10 MA and its major radius and minor radius is 5.7 m and 1.6 m respectively. All the components of CFETR which provide their basic functions must be maintained and inspected during the reactor lifetime. Thus, the remote handling (RH) maintenance system should be a key component, which must be detailedly designed during the concept design processing of CFETR, for the operation of reactor. The main design work for RH maintenance in this paper was carried out including the divertor RH system, the blanket RH system and the transfer cask system. What is more, the technical problems encountered in the design process will also be discussed

  17. Synthesis, Molecular Structure and Cytotoxicity of Molecular Materials Based on Water Soluble Half-Sandwich Rh(III) and Ir(III) Tetranuclear Metalla-Cycles

    Science.gov (United States)

    Gupta, Gajendra; Murray, Benjamin S.; Dyson, Paul J.; Therrien, Bruno

    2013-01-01

    The neutral dinuclear complexes [(η5-C5Me5)2Rh2(μ-dhnq)Cl2] (1) and [(η5-C5Me5)2Ir2(μ-dhnq)Cl2] (2) (dhnqH2 = 5,8-dihydroxy-1,4-naphthoquinone) were obtained from the reaction of [(η5-C5Me5)M(μ-Cl)Cl]2 (M = Rh, Ir) with dhnqH2 in the presence of CH3COONa. Treatment of 1 or 2 in methanol with linear ditopic ligands L (L = pyrazine, 4,4′-bipyridine or 1,2-bis(4-pyridyl)ethylene), in the presence of AgCF3SO3, affords the corresponding tetranuclear metalla-rectangles [(η5-C5Me5)4M4(μ-dhnq)2(μ-L)2]4+ (L = pyrazine, M = Rh, 3; M = Ir, 4; L = 4,4′-bipyridine, M = Rh, 5; M = Ir, 6; L = 1,2-bis(4-pyridyl)ethylene, M = Rh, 7; M = Ir, 8). All complexes were isolated as their triflate salts and were fully characterized by infrared, 1H and 13C NMR spectroscopy, and some representative complexes by single-crystal X-ray structure analysis. The X-ray structures of 3, 5 and 6 confirm the formation of the tetranuclear metalla-cycles, and suggest that complexes 5 and 6 possess a cavity of sufficient size to encapsulate small guest molecules. In addition, the antiproliferative activity of the metalla-cycles 3–8 was evaluated against the human ovarian A2780 (cisplatin sensitive) and A2780cisR (cisplatin resistant) cancer cell lines and on non-tumorigenic human embryonic kidney HEK293 cells. All cationic tetranuclear metalla-rectangles were found to be highly cytotoxic, with IC50 values in the low micromolar range. PMID:28788394

  18. Synthesis, Molecular Structure and Cytotoxicity of Molecular Materials Based on Water Soluble Half-Sandwich Rh(III and Ir(III Tetranuclear Metalla-Cycles

    Directory of Open Access Journals (Sweden)

    Gajendra Gupta

    2013-11-01

    Full Text Available The neutral dinuclear complexes [(η5-C5Me52Rh2(μ-dhnqCl2] (1 and [(η5-C5Me52Ir2(μ-dhnqCl2] (2 (dhnqH2 = 5,8-dihydroxy-1,4-naphthoquinone were obtained from the reaction of [(η5-C5Me5M(μ-ClCl]2 (M = Rh, Ir with dhnqH2 in the presence of CH3COONa. Treatment of 1 or 2 in methanol with linear ditopic ligands L (L = pyrazine, 4,4′-bipyridine or 1,2-bis(4-pyridylethylene, in the presence of AgCF3SO3, affords the corresponding tetranuclear metalla-rectangles [(η5-C5Me54M4(μ-dhnq2(μ-L2]4+ (L = pyrazine, M = Rh, 3; M = Ir, 4; L = 4,4′-bipyridine, M = Rh, 5; M = Ir, 6; L = 1,2-bis(4-pyridylethylene, M = Rh, 7; M = Ir, 8. All complexes were isolated as their triflate salts and were fully characterized by infrared, 1H and 13C NMR spectroscopy, and some representative complexes by single-crystal X-ray structure analysis. The X-ray structures of 3, 5 and 6 confirm the formation of the tetranuclear metalla-cycles, and suggest that complexes 5 and 6 possess a cavity of sufficient size to encapsulate small guest molecules. In addition, the antiproliferative activity of the metalla-cycles 3–8 was evaluated against the human ovarian A2780 (cisplatin sensitive and A2780cisR (cisplatin resistant cancer cell lines and on non-tumorigenic human embryonic kidney HEK293 cells. All cationic tetranuclear metalla-rectangles were found to be highly cytotoxic, with IC50 values in the low micromolar range.

  19. Remote-Handled Transuranic Waste Content Codes (RH-Trucon)

    International Nuclear Information System (INIS)

    2006-01-01

    The Remote-Handled Transuranic (RH-TRU) Content Codes (RH-TRUCON) document describes the inventory of RH-TRU waste within the transportation parameters specified by the Remote-Handled Transuranic Waste Authorized Methods for Payload Control (RH-TRAMPAC). The RH-TRAMPAC defines the allowable payload for the RH-TRU 72-B. This document is a catalog of RH-TRU 72-B authorized contents by site. A content code is defined by the following components: (1) A two-letter site abbreviation that designates the physical location of the generated/stored waste (e.g., ID for Idaho National Laboratory [INL]). The site-specific letter designations for each of the sites are provided in Table 1. (2) A three-digit code that designates the physical and chemical form of the waste (e.g., content code 317 denotes TRU Metal Waste). For RH-TRU waste to be transported in the RH-TRU 72-B, the first number of this three-digit code is ''3''. The second and third numbers of the three-digit code describe the physical and chemical form of the waste. Table 2 provides a brief description of each generic code. Content codes are further defined as subcodes by an alpha trailer after the three-digit code to allow segregation of wastes that differ in one or more parameter(s). For example, the alpha trailers of the subcodes ID 322A and ID 322B may be used to differentiate between waste packaging configurations. As detailed in the RH-TRAMPAC, compliance with flammable gas limits may be demonstrated through the evaluation of compliance with either a decay heat limit or flammable gas generation rate (FGGR) limit per container specified in approved content codes. As applicable, if a container meets the watt*year criteria specified by the RH-TRAMPAC, the decay heat limits based on the dose-dependent G value may be used as specified in an approved content code. If a site implements the administrative controls outlined in the RH-TRAMPAC and Appendix 2.4 of the RH-TRU Payload Appendices, the decay heat or FGGR

  20. Vacancy induced half-metallicity in half-Heusler semiconductors

    KAUST Repository

    Zhu, Zhiyong

    2011-09-28

    First-principles calculations are performed to investigate the effect of vacancies on the electronic structure and magnetic properties of the two prototypical half-Heusler semiconductors NiTiSn and CoTiSb. The spin degeneracy of the host materials is broken for all types of isolated vacancies under consideration, except for Ni-deficient NiTiSn. A half-metallic character is identified in Sn-deficient NiTiSn and Co/Ti/Sb-deficient CoTiSb. We can explain our findings by introducing an extending Slater-Pauling rule for systems with defects. A ferromagnetic ordering of the local moments due to double exchange appears to be likely.

  1. Selective interactions among Rh, ABO, and sex ratio of newborns.

    Science.gov (United States)

    Valenzuela, C Y; Walton, R

    1985-01-01

    The hypothesis that the Rh and ABO blood systems behave like the HLA system in relation to mother-conception tolerance-rejection mechanisms was tested in 25,501 mother-infant pairs. According to this hypothesis, heterozygotes carrying a paternal gene that is not present in their mothers should be better tolerated than homozygotes. Significantly more BO infants born to AO mothers. AO infants born to BO mothers, Rh(+) heterozygotes born to Rh(-) mothers, and less significantly AO infants born to OO mothers confirm the hypothesis. Fewer homozygotes occurred in Rh(-) infants born to Rh(+) mothers and in O infants born to non-O mothers. Deviations from the Hardy-Weinberg equilibrium found in the ABO system were modified by the Rh and sex of the infant. These data strongly support the hypothesis that at least two feto-maternal systems influence the destiny of pregnancies: the classical known incompatibility system which operates late in pregnancy and a new one which is based on the induction of maternal tolerance early in pregnancy: maternal tolerance seems to be better elicited by heterozygous eggs or embryos carrying a gene not present in the mother. The data also support the hypothesis that the sex ratio is influenced by feto-maternal tolerance-rejection mechanisms associated with the ABO and Rh systems.

  2. Practice Bulletin No. 181 Summary: Prevention of Rh D Alloimmunization.

    Science.gov (United States)

    2017-08-01

    Advances in the prevention and treatment of Rh D alloimmunization have been one of the great success stories of modern obstetrics. There is wide variation in prevalence rates of Rh D-negative individuals between regions, for example from 5% in India to 15% in North America (1). However, high birth rates in low prevalence areas means Rh hemolytic disease of the newborn is still an important cause of morbidity and mortality in countries without prophylaxis programs (1). In such countries, 14% of affected fetuses are stillborn and one half of live born infants suffer neonatal death or brain injury (1). The routine use of Rh D immune globulin is responsible for the reduced rate of red cell alloimmunization in more economically developed countries. First introduced in the 1970s, the postpartum administration of Rh D immune globulin reduced the rate of alloimmunization in at-risk pregnancies from approximately 13-16% to approximately 0.5-1.8% (2, 3). The risk was further reduced to 0.14-0.2% with the addition of routine antepartum administration (2, 3). Despite considerable proof of efficacy, there are still a large number of cases of Rh D alloimmunization because of failure to follow established protocols. In addition, there are new data to help guide management, especially with regard to weak D phenotype women. The purpose of this document is to provide evidence-based guidance for the management of patients at risk of Rh D alloimmunization.

  3. Practice Bulletin No. 181: Prevention of Rh D Alloimmunization.

    Science.gov (United States)

    2017-08-01

    Advances in the prevention and treatment of Rh D alloimmunization have been one of the great success stories of modern obstetrics. There is wide variation in prevalence rates of Rh D-negative individuals between regions, for example from 5% in India to 15% in North America (1). However, high birth rates in low prevalence areas means Rh hemolytic disease of the newborn is still an important cause of morbidity and mortality in countries without prophylaxis programs (1). In such countries, 14% of affected fetuses are stillborn and one half of live born infants suffer neonatal death or brain injury (1). The routine use of Rh D immune globulin is responsible for the reduced rate of red cell alloimmunization in more economically developed countries. First introduced in the 1970s, the postpartum administration of Rh D immune globulin reduced the rate of alloimmunization in at-risk pregnancies from approximately 13-16% to approximately 0.5-1.8% (2, 3). The risk was further reduced to 0.14-0.2% with the addition of routine antepartum administration (2, 3). Despite considerable proof of efficacy, there are still a large number of cases of Rh D alloimmunization because of failure to follow established protocols. In addition, there are new data to help guide management, especially with regard to weak D phenotype women. The purpose of this document is to provide evidence-based guidance for the management of patients at risk of Rh D alloimmunization.

  4. Performance of the digene LQ, RH and PS HPVs genotyping systems on clinical samples and comparison with HC2 and PCR-based Linear Array.

    Science.gov (United States)

    Godínez, Jose M; Tous, Sara; Baixeras, Nuria; Moreno-Crespi, Judith; Alejo, María; Lejeune, Marylène; Bravo, Ignacio G; Bosch, F Xavier; de Sanjosé, Silvia

    2011-11-18

    Certain Human Papillomaviruses (HPVs) are the infectious agents involved in cervical cancer development. Detection of HPVs DNA is part of the cervical cancer screening protocols and HPVs genotyping has been proposed for its inclusion in these preventive programs. The aim of this study was to evaluate three novel genotyping tests, namely Qiagen LQ, RH and PS, in clinical samples with and without abnormalities. For this, 305 cervical samples were processed and the results of the evaluated techniques were compared with those obtained in the HPVs diagnostic process in our lab, by using HC2 and Linear Array (LA) technologies. The concordances and kappa statistics (k) for each technique compared with HC2 were 98.69% (k = 0.94) for LQ, 98.03% (k = 0.91) for RH and 91.80% (k = 0.82) for PS. There was a very good agreement in HPVs type-specific concordance for the most prevalent types HPV16 (kappa range = 0.83-0.90), HPV18 (k.r.= 0.74-0.80) and HPV45 (k.r.= 0.82-0.90). The three tests showed an overall good concordance for HPVs detection when compared with HR-HC2 system. LQ and RH rendered lower detection rate for multiple infections than LA genotyping. However, our understanding of the clinical significance of multiple HPVs infections is still incomplete and therefore the relevance of the lower ability to detect multiple infections needs to be evaluated.

  5. Methanol electro-oxidation and direct methanol fuel cell using Pt/Rh and Pt/Ru/Rh alloy catalysts

    International Nuclear Information System (INIS)

    Choi, Jong-Ho; Park, Kyung-Won; Park, In-Su; Nam, Woo-Hyun; Sung, Yung-Eun

    2004-01-01

    Pt-based binary or ternary catalysts containing Rh for use as anodes in direct methanol fuel cells (DMFC) were synthesized by borohydride reduction method combined with freeze-drying. The resulting catalysts had a specific surface area of approximately 65-75 m 2 /g. X-ray diffraction (XRD) patterns indicated that the catalysts were well alloyed and the average size of alloy catalysts was confirmed by transmission electron microscopy (TEM). The Pt/Rh (2:1) and Pt/Ru/Rh (5:4:1) alloy catalysts showed better catalytic activities for methanol electro-oxidation than Pt or Pt/Ru (1:1), respectively

  6. Standard enthalpies of formation of selected Ru{sub 2}YZ Heusler compounds

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Ming, E-mail: myin1@hawk.iit.edu; Nash, Philip

    2015-06-15

    Highlights: • Standard enthalpies of formation of Ru{sub 2}YZ were measured using a drop calorimeter. • Result of L2{sub 1} structured compounds agrees with first principles data. • Lattice parameters and related phase relationships were consistent with literature data. • Ru{sub 2}HfSn, Ru{sub 2}TiSn, Ru{sub 2}VGa, Ru{sub 2}VSi, Ru{sub 2}VSn of L2{sub 1} structure were reported for the first time. - Abstract: The standard enthalpies of formation of selected ternary Ru-based Heusler compounds Ru{sub 2}YZ (Y = Fe, Hf, Mn, Ti, V; Z = Al, Ga, In, Si, Ge, Sn) were measured using high temperature direct reaction calorimetry. The measured enthalpies of formation (in kJ/mole of atoms) of the Heusler compounds are, Ru{sub 2}FeGe (−19.7 ± 3.3); Ru{sub 2}HfSn (−24.9 ± 3.6); Ru{sub 2}MnSi (−46.0 ± 2.6); Ru{sub 2}MnGe (−29.7 ± 1.0); Ru{sub 2}MnSn (−20.6 ± 2.4); Ru{sub 2}TiSi (−94.9 ± 4.0); Ru{sub 2}TiGe (−79.1 ± 3.2); Ru{sub 2}TiSn (−60.6 ± 1.8); Ru{sub 2}VSi (−55.9 ± 1.7);for the B2-structured compounds, Ru{sub 2}FeSi (−28.5 ± 0.8); Ru{sub 2}HfAl (−70.8 ± 1.9); Ru{sub 2}MnAl (−32.3 ± 1.9); Ru{sub 2}MnGa (−25.3 ± 3.0); Ru{sub 2}TiAl (−62.7 ± 3.5); Ru{sub 2}VAl (−30.9 ± 1.6); Ru{sub 2}ZrAl (−64.5 ± 1.5). Values were compared with those from published first principles calculations and the OQMD (Open Quantum Materials Database). Lattice parameters of these compounds were determined using X-ray diffraction analysis (XRD). Microstructures were identified using scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS)

  7. Structural and physical properties of new uranium and transition element ternary stannides (Fe, Co, Ni, Ru, Rh, Pd, Ir, Pt); Proprietes structurales et physiques de nouveaux stannures ternaires a base d'uranium et d'element de transition (Fe, Co, Ni, Rh, Pd, Ir, Pt)

    Energy Technology Data Exchange (ETDEWEB)

    Mirambet, F

    1993-12-15

    This work is dedicated to the study of ternary stannides based on uranium. The author reviews the structural, magnetic and electric properties of different families of stannides. The study of the U{sub 2}M{sub 2}Sn family where M stands for Fe, Co, Ni, Ru, Rh, Pd, Ir and Pt shows that the magnetic behaviour of uranium in these compounds is strongly influenced by the transition element M, which is explained by the hybridization force 5f(U) - nd(M) that depends on the number of electrons on the d shell of the M element. For instance, for the elements whose d shell is low filled (Fe, Ru), the U{sub 2}M{sub 2}Sn stannides show no magnetic order. On the other hand, when the number of d-electrons increases, a magnetic order appears progressively.

  8. Performance of the digene LQ, RH and PS HPVs genotyping systems on clinical samples and comparison with HC2 and PCR-based Linear Array

    Directory of Open Access Journals (Sweden)

    Godínez Jose M

    2011-11-01

    Full Text Available Abstract Background Certain Human Papillomaviruses (HPVs are the infectious agents involved in cervical cancer development. Detection of HPVs DNA is part of the cervical cancer screening protocols and HPVs genotyping has been proposed for its inclusion in these preventive programs. The aim of this study was to evaluate three novel genotyping tests, namely Qiagen LQ, RH and PS, in clinical samples with and without abnormalities. For this, 305 cervical samples were processed and the results of the evaluated techniques were compared with those obtained in the HPVs diagnostic process in our lab, by using HC2 and Linear Array (LA technologies. Results The concordances and kappa statistics (k for each technique compared with HC2 were 98.69% (k = 0.94 for LQ, 98.03% (k = 0.91 for RH and 91.80% (k = 0.82 for PS. There was a very good agreement in HPVs type-specific concordance for the most prevalent types HPV16 (kappa range = 0.83-0.90, HPV18 (k.r.= 0.74-0.80 and HPV45 (k.r.= 0.82-0.90. Conclusions The three tests showed an overall good concordance for HPVs detection when compared with HR-HC2 system. LQ and RH rendered lower detection rate for multiple infections than LA genotyping. However, our understanding of the clinical significance of multiple HPVs infections is still incomplete and therefore the relevance of the lower ability to detect multiple infections needs to be evaluated.

  9. Quality of Heusler single crystals examined by depth-dependent positron annihilation techniques

    Science.gov (United States)

    Hugenschmidt, C.; Bauer, A.; Böni, P.; Ceeh, H.; Eijt, S. W. H.; Gigl, T.; Pfleiderer, C.; Piochacz, C.; Neubauer, A.; Reiner, M.; Schut, H.; Weber, J.

    2015-06-01

    Heusler compounds exhibit a wide range of different electronic ground states and are hence expected to be applicable as functional materials in novel electronic and spintronic devices. Since the growth of large and defect-free Heusler crystals is still challenging, single crystals of Fe2TiSn and Cu2MnAl were grown by the optical floating zone technique. Two positron annihilation techniques—angular correlation of annihilation radiation and Doppler broadening spectroscopy (DBS)—were applied in order to study both the electronic structure and lattice defects. Recently, we succeeded to observe clearly the anisotropy of the Fermi surface of Cu2MnAl, whereas the spectra of Fe2TiSn were disturbed by foreign phases. In order to estimate the defect concentration in different samples of Heusler compounds, the positron diffusion length was determined by DBS using a monoenergetic positron beam.

  10. Magnetic microstructure of candidates for epitaxial dual Heusler magnetic tunnel junctions

    International Nuclear Information System (INIS)

    Kaiser, A.; Banerjee, D.; Rata, A.D.; Wiemann, C.; Cramm, S.; Schneider, C.M.

    2009-01-01

    Heusler alloys are considered as interesting ferromagnetic electrode materials for magnetic tunnel junctions, because of their high spin polarization. We, therefore, investigated the micromagnetic properties in a prototypical thin film system comprising two different Heusler phases Co 2 MnSi (CMS) and Co 2 FeSi (CFS) separated by a MgO barrier. The magnetic microstructure was investigated by X-ray photoemission electron microscopy (XPEEM). We find a strong influence of the Heusler phase formation process on the magnetic domain patterns. SiO 2 /V/CMS/MgO/CFS and SiO 2 /V/CFS/MgO/CMS trilayer structures exhibit a strikingly different magnetic behavior, which is due to pinhole coupling through the MgO barrier and a strong thickness dependence of the magnetic ordering in Co 2 MnSi

  11. Lattice dynamics of Ru2FeX (X = Si, Ge) Full Heusler alloys

    Science.gov (United States)

    Rizwan, M.; Afaq, A.; Aneeza, A.

    2018-05-01

    In present work, the lattice dynamics of Ru2FeX (X = Si, Ge) full Heusler alloys are investigated using density functional theory (DFT) within generalized gradient approximation (GGA) in a plane wave basis, with norm-conserving pseudopotentials. Phonon dispersion curves and phonon density of states are obtained using first-principles linear response approach of density functional perturbation theory (DFPT) as implemented in Quantum ESPRESSO code. Phonon dispersion curves indicates for both Heusler alloys that there is no imaginary phonon in whole Brillouin zone, confirming dynamical stability of these alloys in L21 type structure. There is a considerable overlapping between acoustic and optical phonon modes predicting no phonon band gap exists in dispersion curves of alloys. The same result is shown by phonon density of states curves for both Heusler alloys. Reststrahlen band for Ru2FeSi is found smaller than Ru2FeGe.

  12. A first-principles study of the possible magnetism of Rh in the Cu/Rh/Cu(001) system

    CERN Document Server

    Jang, Y R; Chang, C S; Cho, L H; Lee, J I

    1999-01-01

    Possible 4d magnetism of a Rh monolayer in a Cu/Rh/Cu(001) system is investigated using the full-potential linearized augmented-plane-wave (FLAPW) energy band method based on the local-spin-density approximation (LSDA). We have calculated the total energy of the Cu/Rh/Cu(001) system and have found that the Rh monolayer is ferromagnetic (FM) with a tiny magnetic moment. However, the total energy difference between the ferromagnetic and the paramagnetic states is found to be very small, and thus which state can be realized at room temperature is uncertain. The calculated charge densities and layer-projected density of states (LDOS) are presented and discussed in relation to the magnetic properties.

  13. Thickness dependencies of structural and magnetic properties of cubic and tetragonal Heusler alloy bilayer films

    Science.gov (United States)

    Ranjbar, R.; Suzuki, K. Z.; Sugihara, A.; Ando, Y.; Miyazaki, T.; Mizukami, S.

    2017-07-01

    The thickness dependencies of the structural and magnetic properties for bilayers of cubic Co-based Heusler alloys (CCHAs: Co2FeAl (CFA), Co2FeSi (CFS), Co2MnAl (CMA), and Co2MnSi (CMS)) and D022-MnGa were investigated. Epitaxy of the B2 structure of CCHAs on a MnGa film was achieved; the smallest thickness with the B2 structure was found for 3-nm-thick CMS and CFS. The interfacial exchange coupling (Jex) was antiferromagnetic (AFM) for all of the CCHAs/MnGa bilayers except for unannealed CFA/MnGa samples. A critical thickness (tcrit) at which perpendicular magnetization appears of approximately 4-10 nm for the CMA/MnGa and CMS/MnGa bilayers was observed, whereas this thickness was 1-3 nm for the CFA/MnGa and CFS/MnGa films. The critical thickness for different CCHAs materials is discussed in terms of saturation magnetization (Ms) and the Jex .

  14. Electronic structure, magnetic and transport properties of the Heusler shape memory alloy Mn{sub 2}NiGa

    Energy Technology Data Exchange (ETDEWEB)

    Blum, C.G.F. [Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg - University, Mainz (Germany); Institute of Solid State Research, IFW Dresden, D-01171 Dresden (Germany); Ouardi, S.; Fecher, G.H.; Balke, B.; Felser, C. [Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg - University, Mainz (Germany); Wurmehl, S.; Buechner, B. [Institute of Solid State Research, IFW Dresden, D-01171 Dresden (Germany); Ueda, S.; Kobayashi, K. [NIMS Beamline Station, National Institute for Materials Science, Hyogo 679-5148, Japan. (Germany)

    2011-07-01

    Magnetic shape memory based on Heusler compounds have received increasing interest, due their potential use for actuator and sensor applications. The single crystals Mn{sub 2}NiGa were grown by the optical floating zone method using a image furnace with vertical setup under a purified argon atmosphere. The both cubic (austenite) and tetragonal (martensite) phases of the sample were determined using temperature dependence powder x-ray diffraction XRD. The effect of martensitic transitions on the magnetic and transport properties of the compound was investigated by measuring the saturation magnetization, electrical resistivity {rho}(T), the Seebeck coefficient S(T) and magnetoresistance R{sub M}. All measurements detect clear signatures of the martensitic transition around room temperature with a thermal hysteresis up to 30 K. The electronic structures of the martensitic as well the austenitic phase were investigated using bulk-sensitive hard X-ray photoelectron spectroscopy (HAXPES).

  15. Optimized thermoelectric performance of the n-type half-Heusler material TiNiSn by substitution and addition of Mn

    Directory of Open Access Journals (Sweden)

    Enkhtaivan Lkhagvasuren

    2017-04-01

    Full Text Available Alloys based on the half-Heusler compound TiNiSn with the addition of Mn or with a substitution of Ti by Mn are investigated as high-temperature thermoelectric materials. In both materials an intrinsic phase separation is observed, similar to TiNiSn where Ti has been partially substituted by Hf, with increasing Mn concentration the phase separation drastically reduces the lattice thermal conductivity while the power factor is increased. The thermoelectric performance of the n-type conducting alloy can be optimized both by substitution of Ti by Mn as well as the addition of Mn.

  16. The effect of disorder on electronic and magnetic properties of quaternary Heusler alloy CoFeMnSi with LiMgPbSb-type structure

    International Nuclear Information System (INIS)

    Feng, Yu; Chen, Hong; Yuan, Hongkuan; Zhou, Ying; Chen, Xiaorui

    2015-01-01

    Thin films based on Heusler alloy often lost their theoretical predicted ultra-high spin polarization owing to the appearance of disorder. Using the first-principles calculations within density functional theory (DFT), we investigate the effect of disorder including antisite and swap on electronic and magnetic properties of quaternary Heusler alloy CoFeMnSi with LiMgPbSb-type structure. Twelve kinds of antisites and six kinds of swap disorders are proposed and studied comprehensively. In our calculations, Co(Fe)-, Mn(Fe)-, Si(Mn)-antisite and Co–Fe swap disorders are most favorable due to their lowest formation energies. Moreover, the positive binding energies of Co–Fe, Co–Si, Fe–Si and Mn–Si swap disorders with respect to their corresponding antisite disorders indicate that these complex swap disorders are more stable compared with their corresponding isolated antisite disorders. The investigations on density of states (DOS) show that the spin down energy gap of disordered structures suffers contraction and their DOS entirely move towards lower zone. Besides, the 100% spin polarization is maintained in all structures with antisite and swap disorders except for those with Co(Mn)-, Co(Si)-antisite and Co–Mn, Co–Si swap disorders. Therefore, the half-metallicity of quaternary Heusler alloy CoFeMnSi is quite robust against interfering effects such as Si(Mn), Co(Fe) and Co–Fe disorders most possibly formed in the growth. - Highlights: • CoFeMnSi with LiMgPbSb-type structure is found to be a half-metallic ferromagnet. • Si(Mn), Co(Fe), Mn(Fe) antisites and Co–Fe swap disorders are most likely to form. • The half-metallicity of CoFeMnSi is robust against the most possible disorders. • The magnetic moments of the most possible disorders follow the Pauli-Slater rule

  17. Study of structural, electronic and magnetic properties of CoFeIn and Co{sub 2}FeIn Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    El Amine Monir, M. [Laboratoire de Physique Quantique de la Matière et de la Modélisation Mathématique (LPQ3M), Faculté des Sciences, Université de Mascara, Mascara 29000 (Algeria); Khenata, R., E-mail: khenata_rabah@yahoo.fr [Laboratoire de Physique Quantique de la Matière et de la Modélisation Mathématique (LPQ3M), Faculté des Sciences, Université de Mascara, Mascara 29000 (Algeria); Baltache, H. [Laboratoire de Physique Quantique de la Matière et de la Modélisation Mathématique (LPQ3M), Faculté des Sciences, Université de Mascara, Mascara 29000 (Algeria); Murtaza, G., E-mail: murtaza@icp.edu.pk [Materials Modeling Lab, Department of Physics, Islamia College University, Peshawar (Pakistan); Abu-Jafar, M.S., E-mail: mabujafar@najah.edu [Dipartimento di Fisica Universita di Roma ' La Sapienza' , Roma (Italy); Department of Physics, An-Najah N. University, Nablus, Palestine (Country Unknown); Bouhemadou, A. [Laboratory for Developing New Materials and their Characterization, Department of Physics, Faculty of Science, University of Setif, 19000 Setif (Algeria); Bin Omran, S. [Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); and others

    2015-11-15

    The structural, electronic and magnetic properties of half-Heusler CoFeIn and full-Heusler Co{sub 2}FeIn alloys have been investigated by using the state of the art full-potential linearized augmented plane wave (FP-LAPW) method. The exchange-correlation potential was treated with the generalized gradient approximation (PBE-GGA) for the calculation of the structural properties, whereas the PBE-GGA+U approximation (where U is the Hubbard Coulomb energy term) is applied for the computation of the electronic and magnetic properties in order to treat the “d” electrons. The structural properties have been calculated in the paramagnetic and ferromagnetic phases where we have found that both the CoFeIn and Co{sub 2}FeIn alloys have a stable ferromagnetic phase. The obtained results of the spin-polarized band structure and the density of states show that the CoFeIn alloy is a metal and the Co{sub 2}FeIn alloy has a complete half-metallic nature. Through the obtained values of the total spin magnetic moment, we conclude that in general, the Co{sub 2}FeIn alloy is half-metallic ferromagnet material whereas the CoFeIn alloy has a metallic nature. - Highlights: • Based on DFT calculations, CoFeIn and Co2FeIn Heusler alloys were investigated. • The magnetic phase stability was determined from the total energy calculations. • Electronic properties reveal the metallic (half-metallic) nature for CoFeIn (Co2FeIn)

  18. Use of HPLC/UPLC-spectrophotometry for detection of formazan in in vitro Reconstructed human Tissue (RhT)-based test methods employing the MTT-reduction assay to expand their applicability to strongly coloured test chemicals.

    Science.gov (United States)

    Alépée, N; Barroso, J; De Smedt, A; De Wever, B; Hibatallah, J; Klaric, M; Mewes, K R; Millet, M; Pfannenbecker, U; Tailhardat, M; Templier, M; McNamee, P

    2015-06-01

    A number of in vitro test methods using Reconstructed human Tissues (RhT) are regulatory accepted for evaluation of skin corrosion/irritation. In such methods, test chemical corrosion/irritation potential is determined by measuring tissue viability using the photometric MTT-reduction assay. A known limitation of this assay is possible interference of strongly coloured test chemicals with measurement of formazan by absorbance (OD). To address this, Cosmetics Europe evaluated use of HPLC/UPLC-spectrophotometry as an alternative formazan measurement system. Using the approach recommended by the FDA guidance for validation of bio-analytical methods, three independent laboratories established and qualified their HPLC/UPLC-spectrophotometry systems to reproducibly measure formazan from tissue extracts. Up to 26 chemicals were then tested in RhT test systems for eye/skin irritation and skin corrosion. Results support that: (1) HPLC/UPLC-spectrophotometry formazan measurement is highly reproducible; (2) formazan measurement by HPLC/UPLC-spectrophotometry and OD gave almost identical tissue viabilities for test chemicals not exhibiting colour interference nor direct MTT reduction; (3) independent of the test system used, HPLC/UPLC-spectrophotometry can measure formazan for strongly coloured test chemicals when this is not possible by absorbance only. It is therefore recommended that HPLC/UPLC-spectrophotometry to measure formazan be included in the procedures of in vitro RhT-based test methods, irrespective of the test system used and the toxicity endpoint evaluated to extend the applicability of these test methods to strongly coloured chemicals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. The IVF Outcome Counseling Based on the Model Combining DHEAS and Age in Patients with Low AMH Prior to the First Cycle of GnRH Antagonist Protocol of Ovarian Stimulation

    Directory of Open Access Journals (Sweden)

    Miro Šimun Alebić

    2013-01-01

    Full Text Available Objective. To investigate the endocrine and/or clinical characteristics of women with low anti-Müllerian hormone (AMH that could improve the accuracy of IVF outcome prediction based on the female age alone prior to the first GnRH antagonist IVF cycle. Methods. Medical records of 129 patients with low AMH level (<6.5 pmol/L who underwent their first GnRH antagonist ovarian stimulation protocol for IVF/ICSI were retrospectively analyzed. The main outcome measure was the area under the ROC curve (AUC-ROC for the models combining age and other potential predictive factors for the clinical pregnancy. Results. Clinical pregnancy rate (CPR per initiated cycles was 11.6%. For the prediction of clinical pregnancy, DHEAS and age showed AUC-ROC of 0.726 (95%CI 0.641–0.801 and 0.662 (95%CI 0.573–0.743, respectively (. The predictive accuracy of the model combining age and DHEAS (AUC-ROC 0.796; 95%CI 0.716–0.862 was significantly higher compared to that of age alone (. In patients <37.5 years with DHEAS  pmol/L, 60% (9/15 of all pregnancies were achieved with CPR of 37.5%. Conclusions. DHEAS appears to be predictive for clinical pregnancy in younger women (<37.5 years with low AMH after the first GnRH antagonist IVF cycle. Therefore, DHEAS-age model could refine the pretreatment counseling on pregnancy prospects following IVF.

  20. Optimization of smart Heusler alloys from first principles

    Energy Technology Data Exchange (ETDEWEB)

    Entel, Peter, E-mail: entel@thp.uni-duisburg.de [Faculty of Physics and Center for Nanointegration, CeNIDE, University of Duisburg-Essen, 47048 Duisburg (Germany); Siewert, Mario; Gruner, Markus E. [Faculty of Physics and Center for Nanointegration, CeNIDE, University of Duisburg-Essen, 47048 Duisburg (Germany); Chakrabarti, Aparna [Faculty of Physics and Center for Nanointegration, CeNIDE, University of Duisburg-Essen, 47048 Duisburg (Germany); Raja Ramanna Centre for Advanced Technology, Indore 452013, Madhya Pradesh (India); Barman, Sudipta R. [UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore 452001, Madhya Pradesh (India); Sokolovskiy, Vladimir V.; Buchelnikov, Vasiliy D. [Condensed Matter Physics Department, Chelyabinsk State University, 454001, Chelyabinsk (Russian Federation)

    2013-11-15

    Highlights: ► We investigate the tensile deformation of single crystalline Ni–Mn–Ga stripes by DIC. ► Mechanical constraints (fixation, bending) determine the type of twin boundary formed during training in a magnetic field. ► Orientation of strain bands (45° or 84° inclination) depends on the type of twin boundary. ► The twinning stress is lower for twin boundaries inclined by 84° compared to the case of 45°. -- Abstract: The strong magnetoelastic interaction in ternary X{sub 2}YZ Heusler alloys is reponsible for the appearance of magnetostructural phase transitions and related functional properties such as the magnetocaloric and magnetic shape-memory effects. Here, X and Y are transition metal elements and Z is usually an element from the III–V group. In order to discuss possibilities to optimize the multifunctional effects, we use density functional theory calculations from which the martensitic driving forces of the magnetic materials can be derived. We find that the electronic contribution arising from the band Jahn–Teller effect is one of the major driving forces. The ab initio calculations also give a hint of how to design new intermetallics with higher martensitic transformation temperatures compared to the prototype alloy system Ni–Mn–Ga. As an example, we discuss quarternary Pt{sub x}Ni{sub 2−x}MnGa alloys which have properties very similar to Ni–Mn–Ga but exhibit a higher maximal eigenstrain of 14%.

  1. Thermoelectric Properties of the XCoSb (X: Ti,Zr,Hf) Half-Heusler Alloys

    KAUST Repository

    Gandi, Appala; Schwingenschlö gl, Udo

    2017-01-01

    We investigate the thermoelectric properties of the half-Heusler alloys XCoSb (X: Ti,Zr,Hf) by solving Boltzmann transport equations and discuss them in terms of the electronic band structure. The rigid band approximation is employed to address

  2. Pressure dependence of Curie temperature and resisitvity in complex Heusler alloys

    Czech Academy of Sciences Publication Activity Database

    Bose, S. K.; Kudrnovský, Josef; Drchal, Václav; Turek, I.

    2011-01-01

    Roč. 84, č. 17 (2011), 174422/1-174422/8 ISSN 1098-0121 R&D Projects: GA ČR GA202/09/0775 Institutional research plan: CEZ:AV0Z10100520 Keywords : Curie temperature * resistivity * Heusler alloys * hydrostatic pressure * first-principles Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.691, year: 2011

  3. Superconductivity and magnetic order in the noncentrosymmetric half-Heusler compound ErPdBi

    NARCIS (Netherlands)

    Pan, Y.; Nikitin, A.M.; Bay, T.V.; Huang, Y.K.; Paulsen, C.; Yan, B.H.; de Visser, A.

    2013-01-01

    We report superconductivity at Tc = 1.22 K and magnetic order at TN = 1.06\\ K in the semimetallic noncentrosymmetric half-Heusler compound ErPdBi. The upper critical field, Bc2, has an unusual quasi-linear temperature variation and reaches a value of 1.6 T for T - 0 . Magnetic order is found below

  4. Fabrication and Magnetic Properties of Co₂MnAl Heusler Alloys by Mechanical Alloying.

    Science.gov (United States)

    Lee, Chung-Hyo

    2018-02-01

    We have applied mechanical alloying (MA) to produce nanocrystalline Co2MnAl Heusler alloys using a mixture of elemental Co50Mn25Al25 powders. An optimal milling and heat treatment conditions to obtain a Co2MnAl Heusler phase with fine microstructure were investigated by X-ray diffraction, differential scanning calorimeter and vibrating sample magnetometer measurements. α-(Co, Mn, Al) FCC phases coupled with amorphous phase are obtained after 3 hours of MA without any evidence for the formation of Co2MnAl alloys. On the other hand, a Co2MnAl Heusler alloys can be obtained by the heat treatment of all MA samples up to 650 °C. X-ray diffraction result shows that the average grain size of Co2MnAl Heusler alloys prepared by MA for 5 h and heat treatment is in the range of 95 nm. The saturation magnetization of MA powders decreases with MA time due to the magnetic dilution by alloying with nonmagnetic Mn and Al elements. The magnetic hardening due to the reduction of the grain size with ball milling is also observed. However, the saturation magnetization of MA powders after heat treatment increases with MA time and reaches to a maximum value of 105 emu/g after 5 h of MA. It can be also seen that the coercivity of 5 h MA sample annealed at 650 °C is fairly low value of 25 Oe.

  5. The kidneys play a central role in the clearance of rhGH in rats

    DEFF Research Database (Denmark)

    Vestergaard, Bill; Thygesen, Peter; Kreilgaard, Mads

    2016-01-01

    at treatment of patients with growth hormone disorders. The purpose of this study was to investigate the relative importance of the kidneys in the clearance of rhGH. The study employed a newly validated nephrectomy rat model and a population based pharmacokinetic approach to assess renal clearance of rh...... that renal clearance plays a pivotal role in the elimination of rhGH in rats....

  6. Corrosion protection of zirconium surface based on Heusler alloy

    Czech Academy of Sciences Publication Activity Database

    Horáková, Kateřina; Cichoň, Stanislav; Lančok, Ján; Kratochvílová, Irena; Fekete, Ladislav; Sajdl, P.; Krausová, A.; Macák, J.; Cháb, Vladimír

    2017-01-01

    Roč. 89, č. 4 (2017), s. 553-563 ISSN 0033-4545 R&D Projects: GA MŠk LO1409; GA ČR(CZ) GA16-03085S; GA ČR GJ17-19910Y; GA ČR(CZ) GA15-05095S Institutional support: RVO:68378271 ; RVO:67985858 Keywords : electrochemistry * silicon * spectroscopy * SSC-2016 * surface chemistry * wate * zirconium Subject RIV: JI - Composite Materials OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics Impact factor: 2.626, year: 2016

  7. Magnetic properties of Co-Rh and Ni-Rh nanowires

    International Nuclear Information System (INIS)

    Sondon, Tristana; Saul, Andres; Guevara, Javier

    2007-01-01

    We have calculated the magnetic properties of pure Ni, Co and Rh, and alloyed Co-Rh and Ni-Rh free-standing nanowires by an ab initio method. We have found that the pure Co and Ni wires present an enhanced magnetic moment with respect to their bulk values, and we have obtained that a magnetic order appears for pure Rh wires. For concentrations up to 50% Rh, in the alloyed Ni-Rh linear chains there is an enhancement of the total magnetic moment with respect to the pure nanowires, and in the case of Co-Rh the alloying with Rh enhances the Co magnetic moment. In both systems we obtain very high Rh magnetic moments

  8. Characterization of Rh films on Ta(110)

    International Nuclear Information System (INIS)

    Jiang, L.Q.; Ruckman, M.W.; Strongin, M.

    1989-01-01

    The surface and electronic structure of Rh films on Ta(110) up to several monolayers thick on Ta(110) are characterized by photoemission, Auger emission, low energy electron diffraction and low energy ion scattering. From the variation of the Rh Auger peak-to-peak intensity as a function of evaporation time, Rh/Ta(110) appears to grow in the Stranski-Krastanov mode at room temperature. However, the LEIS data show that the Rh adatoms begin to cluster on Ta(110) before growth of the monolayer is completed. Diffuse LEED scattering suggests that the Rh films are disordered. Photoemission shows that Rh chemisorption on Ta(110) generates two peaks located at 1.2 and 2. 5 eV binding energy during the initial phase of thin film growth (0 3.7 ML). Photoemission data for CO covered surfaces show that CO dissociates on the Rh/Ta(110) surface for Rh coverages less than 2.5 ML and also show that the Rh clusters develop at least one site capable of molecular CO adsorption above 0.3 ML Rh coverage. 38 refs., 5 figs

  9. Ab initio studies on electronic and magnetic properties of X{sub 2}PtGa (X=Cr, Mn, Fe, Co) Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Tufan, E-mail: aparnachakrabarti@gmail.com [Homi Bhaba National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094 (India); Chakrabarti, Aparna [Homi Bhaba National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094 (India); Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)

    2017-02-01

    Using first-principles calculations based on density functional theory, we probe the electronic and magnetic properties of X{sub 2}PtGa (X being Cr, Mn, Fe, Co) Heusler alloys. Our calculations predict that all these systems possess inverse Heusler alloy structure in the respective ground states. Application of tetragonal distortion leads to lowering of energy with respect to their cubic phase. The equilibrium volumes of both the phases are nearly the same. These indicate that the materials studied here are prone to undergo martensite transition, as has been recently shown theoretically for Mn{sub 2}PtGa in the literature. Ground state with a tetragonal symmetry is corroborated by the observation of soft tetragonal shear constants in the cubic phase. By comparing the energies of various types of magnetic configurations we predict that Cr{sub 2}PtGa and Mn{sub 2}PtGa possess ferrimagnetic configuration whereas Fe{sub 2}PtGa and Co{sub 2}PtGa possess ferromagnetic configuration in their respective ground states. - Highlights: • We predict stable martensitic phase of X{sub 2}PtGa (X=Cr, Mn, Fe, Co). • Co{sub 2}PtGa possesses least inherent brittleness among all the materials. • Martensite transitions are possible for the investigated materials. • A tetragonal ground state with high spin polarization is predicted for Co{sub 2}PtGa.

  10. First-principles study of mechanical, exchange interactions and the robustness in Co{sub 2}MnSi full Heusler compounds

    Energy Technology Data Exchange (ETDEWEB)

    Akriche, A., E-mail: akricheahmed@gmail.com [Laboratoire de Microscope Electronique et Sciences des Matériaux, Université d’Oran des Sciences et de la Technologie-USTO, Mohamed Boudiaf, Faculté de physique, Département de Génie Physique, Oran (Algeria); Bouafia, H. [Laboratoire de Génie Physique, Université Ibn-Khaldoun, Tiaret 14000 (Algeria); Hiadsi, S. [Laboratoire de Microscope Electronique et Sciences des Matériaux, Université d’Oran des Sciences et de la Technologie-USTO, Mohamed Boudiaf, Faculté de physique, Département de Génie Physique, Oran (Algeria); Abidri, B. [Laboratoire des Matériaux Magnétiques, Université Djillali Liabés, Sidi Bel-Abbes (Algeria); Sahli, B. [Laboratoire de Génie Physique, Université Ibn-Khaldoun, Tiaret 14000 (Algeria); Elchikh, M.; Timaoui, M.A.; Djebour, B. [Laboratoire de Microscope Electronique et Sciences des Matériaux, Université d’Oran des Sciences et de la Technologie-USTO, Mohamed Boudiaf, Faculté de physique, Département de Génie Physique, Oran (Algeria)

    2017-01-15

    In this work we report the results of ab-initio studies of structural, mechanical, electronic and magnetic properties of Co based Co{sub 2}MnSi Heusler compound in stoichiometric composition. All of which are accurately calculated by the full-potential (FP-LMTO) program combined with the spin polarized generalized gradient approximation in the density functional formalism (DFT). The total energy calculations clearly favor the ferromagnetic ground state. The lattice parameter, elastic constants and their related parameters were also evaluated and compared to experimental and theoretical values whenever possible. In this paper, the electronic properties are treated with GGA+U approach. The magnetic exchange constants temperature has been calculated using a mean field-approximation (MFA). The half-metal to metal transition was observed around 40 GPa. Increasing pressure has no impact on the total magnetic moment or the overall shape of the band structure that indicates the robustness of the electronic structure of this system. - Highlights: • In this work, we have studied some physical properties of Co{sub 2}MnSi Heusler compound. • The exchange-correlation energy is treated within GGA and (GGA+U) approximation. • The electronic band structure shows that Co{sub 2}MnSi is a half-metallic compound.

  11. Effect of Spark Plasma Sintering on the Structure and Properties of Ti1−xZrxNiSn Half-Heusler Alloys

    Directory of Open Access Journals (Sweden)

    Ruth A. Downie

    2014-10-01

    Full Text Available XNiSn (X = Ti, Zr and Hf half-Heusler alloys have promising thermoelectric properties and are attracting enormous interest for use in waste heat recovery. In particular, multiphase behaviour has been linked to reduced lattice thermal conductivities, which enables improved energy conversion efficiencies. This manuscript describes the impact of spark plasma sintering (SPS on the phase distributions and thermoelectric properties of Ti0.5Zr0.5NiSn based half-Heuslers. Rietveld analysis reveals small changes in composition, while measurement of the Seebeck coefficient and electrical resistivities reveals that all SPS treated samples are electron doped compared to the as-prepared samples. The lattice thermal conductivities fall between 4 W·m−1·K−1 at 350 K and 3 W·m−1·K−1 at 740 K. A maximum ZT = 0.7 at 740 K is observed in a sample with nominal Ti0.5Zr0.5NiSn composition.

  12. Ab initio studies on electronic and magnetic properties of X2PtGa (X=Cr, Mn, Fe, Co) Heusler alloys

    International Nuclear Information System (INIS)

    Roy, Tufan; Chakrabarti, Aparna

    2017-01-01

    Using first-principles calculations based on density functional theory, we probe the electronic and magnetic properties of X 2 PtGa (X being Cr, Mn, Fe, Co) Heusler alloys. Our calculations predict that all these systems possess inverse Heusler alloy structure in the respective ground states. Application of tetragonal distortion leads to lowering of energy with respect to their cubic phase. The equilibrium volumes of both the phases are nearly the same. These indicate that the materials studied here are prone to undergo martensite transition, as has been recently shown theoretically for Mn 2 PtGa in the literature. Ground state with a tetragonal symmetry is corroborated by the observation of soft tetragonal shear constants in the cubic phase. By comparing the energies of various types of magnetic configurations we predict that Cr 2 PtGa and Mn 2 PtGa possess ferrimagnetic configuration whereas Fe 2 PtGa and Co 2 PtGa possess ferromagnetic configuration in their respective ground states. - Highlights: • We predict stable martensitic phase of X 2 PtGa (X=Cr, Mn, Fe, Co). • Co 2 PtGa possesses least inherent brittleness among all the materials. • Martensite transitions are possible for the investigated materials. • A tetragonal ground state with high spin polarization is predicted for Co 2 PtGa.

  13. 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)

  14. A first principle study of phase stability, electronic structure and magnetic properties for Co{sub 2−x}Cr{sub x}MnAl Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Rached, H. [Laboratoire des Matériaux Magnétiques, Faculté des Sciences exactes, Université Djillali Liabès de Sidi Bel-Abbès, Sidi Bel-Abbès 22000 (Algeria); Rached, D., E-mail: rachdj@yahoo.fr [Laboratoire des Matériaux Magnétiques, Faculté des Sciences exactes, Université Djillali Liabès de Sidi Bel-Abbès, Sidi Bel-Abbès 22000 (Algeria); Khenata, R. [Laboratoire de Physique Quantique et de Modélisation Mathématique de la Matière, (LPQ3M), Université de Mascara, Mascara 29000 (Algeria); Abidri, B.; Rabah, M.; Benkhettou, N. [Laboratoire des Matériaux Magnétiques, Faculté des Sciences exactes, Université Djillali Liabès de Sidi Bel-Abbès, Sidi Bel-Abbès 22000 (Algeria); Omran, S. Bin [Department of Physics and Astronomy, College of Science, King Saud University, P.O.Box 2455, Riyadh 11451 (Saudi Arabia)

    2015-04-01

    The structural stabilities, electronic and magnetic properties of Co{sub 2−x}Cr{sub x}MnAl alloys with (x=0,1 and 2) were investigated using the full-potential linear muffin-tin orbital (FP-LMTO) method, in the framework of the density functional theory (DFT) within the generalized gradient approximation (GGA) for the exchange correlation functional. The ground state properties including lattice parameter, bulk modulus for the two considered crystal structures Hg{sub 2}CuTi-Type (X-Type) and Cu{sub 2}MnAl-Type (L2{sub 1}-Type) are calculated. The half-metallicity within ferromagnetic ground state starts to appear in CoCrMnAl and Cr2MnAl. In the objective for the proposition of the new HM-FM in the Full-Heusler alloys, our results classified CoCrMnAl as new HM-FM material with high spin polarization. - Highlights: • Based on DFT calculations, Co2-xCrxMnAl Heusler alloys have been investigated. • The magnetic phase stability was determined from the total energy calculations. • The LMTO calculations have classified CoCrMnAl as new HM-FM material with high spin polarization.

  15. Chemoselective hydrogenation of arenes by PVP supported Rh nanoparticles

    DEFF Research Database (Denmark)

    Ibrahim, Mahmoud; Poreddy, Raju; Philippot, Karine

    2016-01-01

    Polyvinylpyrrolidone-stabilized Rh nanoparticles (RhNPs/PVP) of ca. 2.2 nm in size were prepared by the hydrogenation of the organometallic complex [Rh(η3-C3H5)3] in the presence of PVP and evaluated as a catalyst in the hydrogenation of a series of arene substrates as well as levulinic acid...... for the hydrogenation of levulinic acid and methyl levulinate in water leading to quantitative formation of the fuel additive γ-valerolactone under moderate reaction conditions compared to previously reported catalytic systems....... and methyl levulinate. The catalyst showed excellent activity and selectivity towards aromatic ring hydrogenation compared to other reported transition metal-based catalysts under mild reaction conditions (room temperature and 1 bar H2). Furthermore, it was shown to be a highly promising catalyst...

  16. Peculiarities of thermoelectric half-Heusler phase formation in Zr–Co–Sb ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Romaka, V.V., E-mail: romakav@lp.edu.ua [Department of Applied Material Science and Materials Engineering, Lviv Polytechnic National University, Ustyyanovycha Str. 5, 79013 Lviv (Ukraine); Institut für Physikalische Chemie, Universität Wien, Währingerstr. 42, A-1090 Wien (Austria); Romaka, L. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine); Rogl, P. [Institut für Physikalische Chemie, Universität Wien, Währingerstr. 42, A-1090 Wien (Austria); Stadnyk, Yu. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine); Melnychenko, N. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine); Army Academy named after Hetman Petro Sahaydachnyi, Gvardijska Str. 32, 79012 Lviv (Ukraine); Korzh, R.; Duriagina, Z. [Department of Applied Material Science and Materials Engineering, Lviv Polytechnic National University, Ustyyanovycha Str. 5, 79013 Lviv (Ukraine); Horyn, A. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine)

    2014-02-05

    Highlights: • Phase relations for the Zr–Co–Sb system at 500 °C. • Homogeneity region for half-Heusler phase. • The distribution of DOS for Zr{sub 1+x}Co{sub 1−x}Sb predicts transition from semiconductor (x = 0) to metallic (x = 0.13) like behavior. • The existence of the solid solution Zr{sub 5}Co{sub x}Sb{sub 3+y} (x = 0.0–1.0, y = 0.0–1.0). -- Abstract: The phase equilibria in the Zr–Co–Sb ternary system were studied at 873 K by means of X-ray and metallographic analyses in the whole concentration range. The interaction between the elements results the formation of four ternary compounds at investigated temperature: ZrCoSb (MgAgAs-type), Zr{sub 6}CoSb{sub 2} (K{sub 2}UF{sub 6}-type), Zr{sub 5}CoSb{sub 3} (Hf{sub 5}CuSn{sub 3}-type) and Zr{sub 5}Co{sub 0.5}Sb{sub 2.5} (W{sub 5}Si{sub 3}-type). The limited composition Zr{sub 5}CoSb{sub 3} of the solid solution based on the Zr{sub 5}Sb{sub 3−4} binaries is considered as compound with Hf{sub 5}CuSn{sub 3} structure type. The influence of the disordering and defects in the crystal structure of ZrCoSb on the physical properties was analyzed. The performed electronic structure calculations are in good agreement with electrical and magnetic studies.

  17. Molecular cloning and protein structure of a human blood group Rh polypeptide

    International Nuclear Information System (INIS)

    Cherif-Zahar, B.; Bloy, C.; Le Van Kim, C.; Blanchard, D.; Bailly, P.; Hermand, P.; Salmon, C.; Cartron, J.P.; Colin, Y.

    1990-01-01

    cDNA clones encoding a human blood group Rh polypeptide were isolated from a human bone marrow cDNA library by using a polymerase chain reaction-amplified DNA fragment encoding the known common N-terminal region of the Rh proteins. The entire primary structure of the Rh polypeptide has been deduced from the nucleotide sequence of a 1384-base-pair-long cDNA clone. Translation of the open reading frame indicates that the Rh protein is composed of 417 amino acids, including the initiator methionine, which is removed in the mature protein, lacks a cleavable N-terminal sequence, and has no consensus site for potential N-glycosylation. The predicted molecular mass of the protein is 45,500, while that estimated for the Rh protein analyzed in NaDodSO 4 /polyacrylamide gels is in the range of 30,000-32,000. These findings suggest either that the hydrophobic Rh protein behaves abnormally on NaDodSO 4 gels or that the Rh mRNA may encode a precursor protein, which is further matured by a proteolytic cleavage of the C-terminal region of the polypeptide. Hydropathy analysis and secondary structure predictions suggest the presence of 13 membrane-spanning domains, indicating that the Rh polypeptide is highly hydrophobic and deeply buried within the phospholipid bilayer. These results suggest that the expression of the Rh gene(s) might be restricted to tissues or cell lines expressing erythroid characters

  18. Characterization of Rh films on Ta(110)

    International Nuclear Information System (INIS)

    Jiang, L.Q.; Ruckman, M.W.; Strongin, M.

    1990-01-01

    The surface and electronic structure of Rh films on Ta(110) up to several monolayers thick on Ta(110) are characterized by photoemission, Auger emission, low-energy electron diffraction (LEED) and low-energy ion scattering (LEIS). From the variation of the Rh Auger peak-to-peak intensity as a function of evaporation time, Rh appears to grow in the Stranski--Krastanov mode at room temperature. However, the LEIS data show that the Rh adatoms begin to cluster on Ta(110) before growth of the monolayer is completed. Diffuse LEED scattering suggests that the Rh films are disordered. Photoemission shows that Rh chemisorption on Ta(110) generates two peaks located at -1.5 and -2.5 eV binding energy during the initial phase of thin-film growth (0 3.7 ML). CO dissociates on the Rh/Ta(110) surface for Rh coverages<2.5 ML and the surface develops a site capable of molecular CO adsorption above 0.3-ML Rh coverage

  19. Electrocatalytic Azide Oxidation Mediated by a Rh(PNP) Pincer Complex

    NARCIS (Netherlands)

    Rebreyend, Christophe; Gloaguen, Yann; Lutz, Martin; Van Der Vlugt, Jarl Ivar; Siewert, Inke; Schneider, Sven; Bruin, Bas De

    2017-01-01

    One-electron oxidation of the rhodium(I) azido complex [Rh(N3)(PNP)] (5), bearing the neutral, pyridine-based PNP ligand 2,6-bis(di-tert-butylphosphinomethyl)pyridine, leads to instantaneous and selective formation of the mononuclear rhodium(I) dinitrogen complex [Rh(N2)(PNP)]+ (9+). Interestingly,

  20. Electrocatalytic Azide Oxidation Mediated by a Rh(PNP) Pincer Complex

    NARCIS (Netherlands)

    Rebreyend, C.; Gloaguen, Y.; Lutz, M.; van der Vlugt, J.I.; Siewert, I.; Schneider, S.; de Bruin, B.

    2017-01-01

    One-electron oxidation of the rhodium(I) azido complex [Rh(N3)(PNP)] ( 5 ), bearing the neutral, pyridine-based PNP ligand 2,6-bis(di-tert-butylphosphinomethyl)pyridine, leads to instantaneous and selective formation of the mononuclear rhodium(I) dinitrogen complex [Rh(N2)(PNP)]+ ( 9 +).

  1. Risk of severe ovarian hyperstimulation syndrome in GnRH antagonist versus GnRH agonist protocol

    DEFF Research Database (Denmark)

    Toftager, M.; Bogstad, J; Bryndorf, T

    2016-01-01

    interval (CI): 0.33-0.57) compared with the traditional GnRH agonist protocol. Previous trials comparing the two protocols mainly included selected patient populations, a limited number of patients and the applied OHSS criteria differed, making direct comparisons difficult. In two recent large meta...... IV, dual-centre, open-label, RCT including 1050 women allocated to either short GnRH antagonist or long GnRH agonist protocol in a 1:1 ratio and enrolled over a 5-year period using a web-based concealed randomization code. This is a superiority study designed to detect a difference in severe OHSS...... between the two arms. None of the women had undergone previous ART treatment. PARTICIPANTS/MATERIALS, SETTING, METHODS: All infertile women referred for their first IVF/ICSI at two public fertility clinics, less than 40 years of age and with no uterine malformations were asked to participate. A total...

  2. Cross section measurement for the reaction /sup 103/Rh (n,n') /sup 103m/Rh

    International Nuclear Information System (INIS)

    Paulsen, A.; Liskien, H.; Vaninbroukx, R.; Widera, R.

    1980-01-01

    The excitation function for the reaction /sup 103/Rh (n,n') /sup 103m/Rh was measured by the activation technique from 0.2 to 6.1 MeV in 0.1-MeV steps and from 13.0 to 16.7 MeV in 1-MeV steps. This excitation function is normalized through an absolute measurement at 1.8 MeV. This measurement is based on n-p scattering for neutron flux determination and on liquid scintillation counting of /sup 103m/Rh separated from /sup 103/Pd solutions for the activity determination. The total uncertainty of the cross-section results is typically + or -5% above 0.5 MeV (about + or -10% above 13 MeV). Concurrence with existing data is good except below 0.35 MeV, where the present results are considerably higher

  3. Thermal and electronic charge transport in bulk nanostructured Zr0.25Hf0.75NiSn composites with full-Heusler inclusions

    International Nuclear Information System (INIS)

    Makongo, Julien P.A.; Misra, Dinesh K.; Salvador, James R.; Takas, Nathan J.; Wang, Guoyu; Shabetai, Michael R.; Pant, Aditya; Paudel, Pravin; Uher, Ctirad; Stokes, Kevin L.; Poudeu, Pierre F.P.

    2011-01-01

    Bulk Zr 0.25 Hf 075 NiSn half-Heusler (HH) nanocomposites containing various mole fractions of full-Heusler (FH) inclusions were prepared by solid state reaction of pre-synthesized HH alloy with elemental Ni at 1073 K. The microstructures of spark plasma sintered specimens of the HH/FH nanocomposites were investigated using transmission electron microscopy and their thermoelectric properties were measured from 300 K to 775 K. The formation of coherent FH inclusions into the HH matrix arises from solid-state Ni diffusion into vacant sites of the HH structure. HH(1-y)/FH(y) composites with mole fraction of FH inclusions below the percolation threshold, y∼0.2, show increased electrical conductivity, reduced Seebeck coefficient and increased total thermal conductivity arising from gradual increase in the carrier concentration for composites. A drastic reduction (∼55%) in κ l was observed for the composite with y=0.6 and is attributed to enhanced phonon scattering due to mass fluctuations between FH and HH, and high density of HH/FH interfaces. - Graphical abstract: Large reduction in the lattice thermal conductivity of bulk nanostructured half-Heusler/full-Heusler (Zr 0.25 Hf 075 NiSn/ Zr 0.25 Hf 075 Ni 2 Sn) composites, obtained by solid-state diffusion at 1073 K of elemental Ni into vacant sites of the half-Heusler structure, arising from the formation of regions of spinodally decomposed HH and FH phases with a spatial composition modulation of ∼2 nm. Highlights: → Bulk composites from solid state transformation of half-Heusler matrix through Ni diffusion. → Formation of coherent phase boundaries between half-Heusler matrix and full-Heusler inclusion. → Alteration of thermal and electronic transports with increasing full-Heusler inclusion. → Enhanced phonon scattering at half-Heusler/ full-Heusler phase boundaries.

  4. Rh Variability in Multi-Ethnic Perspective: Consequences for RH Genotyping

    NARCIS (Netherlands)

    G.H.M. Tax

    2006-01-01

    textabstractThe RhD bloodgroup was first described by Levine en Stetson in 1939 after the manifestation of a hemolytic transfusion reaction in a woman who recently gave birth, after transfusion with her husbands red cells. The RhD-negative woman produced antibodies against the RhD present on the

  5. Human vaccination against RH5 induces neutralizing antimalarial antibodies that inhibit RH5 invasion complex interactions

    DEFF Research Database (Denmark)

    Payne, Ruth O; Silk, Sarah E; Elias, Sean C

    2017-01-01

    serum antibodies exhibited cross-strain functional growth inhibition activity (GIA) in vitro, targeted linear and conformational epitopes within RH5, and inhibited key interactions within the RH5 invasion complex. This is the first time to our knowledge that substantial RH5-specific responses have been...

  6. GnRH-agonist versus GnRH-antagonist IVF cycles

    DEFF Research Database (Denmark)

    Papanikolaou, E G; Pados, G; Grimbizis, G

    2012-01-01

    In view of the current debate concerning possible differences in efficacy between the two GnRH analogues used in IVF stimulated cycles, the current study aimed to explore whether progesterone control in the late follicular phase differs when GnRH antagonist is used as compared with GnRH agonist...

  7. Nanoscale structural heterogeneity in Ni-rich half-Heusler TiNiSn

    International Nuclear Information System (INIS)

    Douglas, Jason E.; Pollock, Tresa M.; Chater, Philip A.; Brown, Craig M.; Seshadri, Ram

    2014-01-01

    The structural implications of excess Ni in the TiNiSn half-Heusler compound are examined through a combination of synchrotron x-ray and neutron scattering studies, in conjunction with first principles density functional theory calculations on supercells. Despite the phase diagram suggesting that TiNiSn is a line compound with no solid solution, for small x in TiNi 1+x Sn there is indeed an appearance—from careful analysis of the scattering—of some solubility, with the excess Ni occupying the interstitial tetrahedral site in the half-Heusler structure. The analysis performed here would point to the excess Ni not being statistically distributed, but rather occurring as coherent nanoclusters. First principles calculations of energetics, carried out using supercells, support a scenario of Ni interstitials clustering, rather than a statistical distribution.

  8. New superconductor LaRhSb

    International Nuclear Information System (INIS)

    Nishigori, S.; Moriwaki, H.; Suzuki, T.; Fujita, T.; Tanaka, H.; Takabatake, T.; Fujii, H.

    1994-01-01

    Superconductivity in LaRhSb was newly found below the transition temperature T c = 2.67 K by the measurements of the electrical resistivity, magnetic susceptibility and specific heat in magnetic fields. The characteristics of the superconductivity determined in this study indicate that LaRhSb is a type II superconductor following the BCS theory. (orig.)

  9. A comparative DFT study on the dehydrogenation of methanol on Rh(100) and Rh(110)

    Science.gov (United States)

    Zhang, Minhua; Wu, Xingyu; Yu, Yingzhe

    2018-04-01

    Numerous density functional theory calculations have been performed to investigate the complete mechanisms of methanol dehydrogenation on Rh(100) and Rh(110) surfaces. The adsorption properties of relevant species were discussed in details. In addition, a comprehensive reaction network including four reaction pathways was built and analyzed. It is found that the initial Osbnd H bond scission of CH3OH seems to be more favorable than Csbnd H bond cleavage on both Rh(100) and Rh(110) surfaces from the perspective of activation barriers. It is also concluded that path1 (CH3OH → CH3O → CH2O → CHO → CO) is the predominant pathway on both Rh(100) and Rh (110) surfaces. On the whole, in most of the dehydrogenation reactions investigated, the energy barriers on Rh(100) are lower than those on Rh (110). Remarkable differences in the activity and predominant reaction pathway on Rh(100), Rh(110) and Rh(111) indicate that the dehydrogenation of methanol might be structure-sensitive.

  10. Martensitic transformation in Heusler alloys Mn2YIn (Y=Ni, Pd and Pt): Theoretical and experimental investigation

    International Nuclear Information System (INIS)

    Luo, Hongzhi; Liu, Bohua; Xin, Yuepeng; Jia, Pengzhong; Meng, Fanbin; Liu, Enke; Wang, Wenhong; Wu, Guangheng

    2015-01-01

    The martensitic transformation and electronic structure of Heusler alloys Mn 2 YIn (Y=Ni, Pd, Pt) have been investigated by both first-principles calculation and experimental investigation. Theoretical calculation reveals that, the energy difference ΔE between the tetragonal martensitic phase and cubic austenitic phase increases with Y varying from Ni to Pt in Mn 2 YIn. Thus a structural transition from cubic to tetragonal is most likely to happen in Heusler alloy Mn 2 PtIn. A single Heusler phase can be obtained in both Mn 2 PtIn and Mn 2 PdIn. A martensitic transformation temperature of 615 K has been identified in Mn 2 PtIn. And in Mn 2 PdIn, the austenitic phase is stable and no martensitic transformation is observed till 5 K. This indicates there may exist a positive relation between ΔE and martensitic transformation temperature. Calculated results show that Mn 2 YIn are all ferrimagnets in both austenitic and martensitic phases. The magnetic properties are mainly determined by the antiparallel aligned Mn spin moments. These findings can help to develop new FSMAs with novel properties. - Highlights: • Positive relation between ΔE and martensitic transformation temperature has been observed. • Heusler alloy Mn 2 PdIn has been synthesized successfully and investigated. • Martensitic transformation in Heusler alloys can be predicted by first -principles calculations

  11. Lattice dynamic properties of Rh2XAl (X=Fe and Y) alloys

    Science.gov (United States)

    Al, Selgin; Arikan, Nihat; Demir, Süleyman; Iyigör, Ahmet

    2018-02-01

    The electronic band structure, elastic and vibrational spectra of Rh2FeAl and Rh2YAl alloys were computed in detail by employing an ab-initio pseudopotential method and a linear-response technique based on the density-functional theory (DFT) scheme within a generalized gradient approximation (GGA). Computed lattice constants, bulk modulus and elastic constants were compared. Rh2YAl exhibited higher ability to resist volume change than Rh2FeAl. The elastic constants, shear modulus, Young modulus, Poisson's ratio, B/G ratio electronic band structure, total and partial density of states, and total magnetic moment of alloys were also presented. Rh2FeAl showed spin up and spin down states whereas Rh2YAl showed none due to being non-magnetic. The calculated total densities of states for both materials suggest that both alloys are metallic in nature. Full phonon spectra of Rh2FeAl and Rh2YA1 alloys in the L21 phase were collected using the ab-initio linear response method. The obtained phonon frequencies were in the positive region indicating that both alloys are dynamically stable.

  12. The N2O activation by Rh5 clusters. A quantum chemistry study.

    Science.gov (United States)

    Olvera-Neria, Oscar; Avilés, Roberto; Francisco-Rodríguez, Héctor; Bertin, Virineya; García-Cruz, Raúl; González-Torres, Julio César; Poulain, Enrique

    2015-04-01

    Nitrous oxide (N2O) is a by-product of exhaust pipe gases treatment produced by motor vehicles. Therefore, the N2O reduction to N2 is necessary to meet the actual environmental legislation. The N2O adsorption and dissociation assisted by the square-based pyramidal Rh5 cluster was investigated using the density functional theory and the zero-order regular approximation (ZORA). The Rh5 sextet ground state is the most active in N2O dissociation, though the quartet and octet states are also active because they are degenerate. The Rh5 cluster spontaneously activates the N2─O cleavage, and the reaction is highly exothermic ca. -75 kcal mol(-1). The N2─O breaking is obtained for the geometrical arrangement that maximizes the overlap and electron transfers between the N2O and Rh5 frontier orbitals. The Rh5 high activity is due to the Rh 3d orbitals are located between the N2O HOMO and LUMO orbitals, which makes possible the interactions between them. In particular, the O 2p states strongly interact with Rh 3d orbitals, which finally weaken the N2─O bond. The electron transfer is from the Rh5 HOMO orbital to the N2O antibonding orbital.

  13. Distribution of ABO/Rh blood groups and their association with hepatitis B virus infection in 3.8 million Chinese adults: A population-based cross-sectional study.

    Science.gov (United States)

    Liu, J; Zhang, S; Liu, M; Wang, Q; Shen, H; Zhang, Y

    2018-04-01

    ABO and Rh blood groups play a vital role in blood transfusion safety and clinical practice and are thought to be linked with disease susceptibility. The results from previous studies that focused on the association between blood groups and HBV infection remain controversial. China has the world's largest burden of HBV infection. We assessed the distribution of ABO/Rh blood groups in Chinese adults and examined the association between these groups and HBV infection. We did a nationwide cross-sectional study using data from a physical check-up programme from 31 provinces examined between 2010 and 2012. ELISA was used to test for HBsAg in serologic samples. Multivariable logistic regression was used to estimate aOR of the association between ABO and Rh blood groups and HBV infection. Among 3 827 125 participants, the proportion of participants with blood group A was highest (30.54%), followed by O (30.37%), B (29.42%) and AB (9.66%). A total of 38 907 (1.02%) were Rh-D negative. The prevalence of HBsAg in blood groups O, A, B and AB were 6.34%, 5.55%, 5.18% and 5.06%, respectively. HBsAg prevalence was 5.65% in Rh-D-positive and 3.96% in Rh-D-negative participants. After controlling for other potential risk factors, multivariate models showed that participants with blood group O (adjusted OR = 1.22, 95% CI: 1.20-1.25) were at higher risk of HBV infection compared with group AB. Rh-D-positive participants (adjusted OR = 1.44, 95% CI: 1.37-1.52) were at higher risk of HBV infection than Rh-D-negative participants. The associations between ABO/Rh blood groups and HBV infection were similar in subgroup analysis. The proportions of O, A, B and AB blood groups were approximately 3:3:3:1, and nearly 1 in 100 people was Rh-D negative among Chinese adults. Blood group O and Rh-D positivity were both associated with increased HBV infection. The risk of HBV infection and blood safety should be taken into consideration in clinical practice, especially when transfusing

  14. The Rh = ct universe in alternative theories of gravity

    Science.gov (United States)

    Sultana, Joseph; Kazanas, Demosthenes

    2017-12-01

    The Λ cold dark matter (ΛCDM) model (one comprising of a cosmological constant Λ and cold dark matter) is generally considered the standard model in cosmology. One of the alternatives that has received attention in the last few years is the Rh = ct universe, which provides an age for the Universe similar to that of ΛCDM and whose (vanishing) deceleration parameter is apparently not inconsistent with observations. Like the ΛCDM, the Rh = ct universe is based on a Friedmann-Robertson-Walker cosmology with the total energy density ρ and pressure p of the cosmic fluid satisfying the simple equation of state ρ + 3p = 0, i.e. a vanishing total active gravitational mass. In an earlier paper, we examined the possible sources for the Rh = ct universe within general relativity, and we have shown that it still contains a dark energy component, albeit not in the form of a cosmological constant. The growing interest in gravitational theories, alternative to Einstein's general relativity, in cosmology, is mainly driven by the need for cosmological models that attain a late-time accelerated expansion without the presence of a cosmological constant as in the ΛCDM, and thereby avoiding the problems associated with it. In this paper, we discuss some of these common alternative theories and show that the Rh = ct is also a solution to some of them.

  15. Rh-flash acquisition card

    International Nuclear Information System (INIS)

    Bourrion, O.

    2003-01-01

    The rh-flash card main purpose is to convert and store the image of the analog data present at input into an output buffer, namely in a given timing window besides a stop signal (like a digital oscilloscope). It is conceived in VME format 1U wide with an additional connector. Novelty of this card is its ability to sample at a high frequency, due to flash coders, and this at a high repetition rate. To do that the card allows the storage of the data considered 'useful' and that is done by storing only the data exceeding a certain threshold. This can be useful for instance for viewing peaks in a spectrum, and obtaining their relative location. The goal is to stock and process the data sampled before and after the arrival of a stop signal (what entails a storage depth). A threshold is defined and any peak exceeding its level will really be stored in the output buffer which is readable through the VME bus. The peak values will be stored as well as m preceding and n subsequent values (both programmable). Obviously, if the threshold is zero the system of data processing is off and all data will be stored. The document is structured on six sections titled: 1. Description; 2. Specifications; 3. Explaining the design of channels; 4. Explaining the shared part of the design; 5. Addressing (→ user guide); 6. Software precautions. (author)

  16. 103Ru/103mRh generator

    International Nuclear Information System (INIS)

    Bartos, B.; Kowalska, E.; Bilewicz, A.; Skarnemark, G.

    2009-01-01

    103m Rh is a very promising radionuclide for Auger electron therapy due to its very low photon/electron ratio. The goal of the present work was the elaboration a method for production of large quantities of 103m Rh for generator system. It was found that the combination of solvent extraction with evaporation of 103 RuO 4 followed by decomposition of H 5 IO 6 makes it possible to produce 103m Rh of high radionuclidic and chemical purity. (author)

  17. Reliable test for prenatal prediction of fetal RhD type using maternal plasma from RhD negative women

    DEFF Research Database (Denmark)

    Clausen, Frederik Banch; Krog, Grethe Risum; Rieneck, Klaus

    2005-01-01

    The objective of this study was to establish a reliable test for prenatal prediction of fetal RhD type using maternal plasma from RhD negative women. This test is needed for future prenatal Rh prophylaxis.......The objective of this study was to establish a reliable test for prenatal prediction of fetal RhD type using maternal plasma from RhD negative women. This test is needed for future prenatal Rh prophylaxis....

  18. [Bifunctional chelates of Rh-105, Au-199, and other metallic radionuclides as potential radiotherapeutic agents

    International Nuclear Information System (INIS)

    1991-01-01

    Progress during this period is reported under the following headings: Diethylenetriamine based and related bifunctional chelating agents and their complexation with Rh-105, Au-198, Pd-109, cu-67, In-111, and Co-57; studies of Pd-109, Rh-105 and Tc-99m with bifunctional chelates based on phenylenediamine; establishment of an appropriate protein assay method for conjugated proteins; studies of new bifunctional Bi, Tri and tetradentate amine oxime ligands with Rh-105; IgG and antibody B72.3 conjugation studies by HPLC Techniques with bifunctional metal chelates; and progress on ligand systems for Au(III)

  19. [Bifunctional chelates of Rh-105, Au-199, and other metallic radionuclides as potential radiotherapeutic agents

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-31

    Progress during this period is reported under the following headings: Diethylenetriamine based and related bifunctional chelating agents and their complexation with Rh-105, Au-198, Pd-109, cu-67, In-111, and Co-57; studies of Pd-109, Rh-105 and Tc-99m with bifunctional chelates based on phenylenediamine; establishment of an appropriate protein assay method for conjugated proteins; studies of new bifunctional Bi, Tri and tetradentate amine oxime ligands with Rh-105; IgG and antibody B72.3 conjugation studies by HPLC Techniques with bifunctional metal chelates; and progress on ligand systems for Au(III).

  20. (Bifunctional chelates of Rh-105, Au-199, and other metallic radionuclides as potential radiotherapeutic agents)

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    Progress during this period is reported under the following headings: Diethylenetriamine based and related bifunctional chelating agents and their complexation with Rh-105, Au-198, Pd-109, cu-67, In-111, and Co-57; studies of Pd-109, Rh-105 and Tc-99m with bifunctional chelates based on phenylenediamine; establishment of an appropriate protein assay method for conjugated proteins; studies of new bifunctional Bi, Tri and tetradentate amine oxime ligands with Rh-105; IgG and antibody B72.3 conjugation studies by HPLC Techniques with bifunctional metal chelates; and progress on ligand systems for Au(III).

  1. Enthalpies of formation of selected Co{sub 2}YZ Heusler compounds

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Ming, E-mail: myin1@hawk.iit.edu; Chen, Song; Nash, Philip

    2013-11-15

    Highlights: •Enthalpies of formation of selected Co{sub 2}YZ were measured by drop calorimeters. •Enthalpy decreases as the Z element approaches the top right corner of the periodic table. •For the Y element, enthalpy increases on increasing the number of d electrons. •Result of L2{sub 1} structured compounds agrees with first principles data. •Lattice parameters and related phase relationships were consistent with literature data. -- Abstract: Standard enthalpies of formation at 298 K of selected ternary Co{sub 2}-based Heusler compounds Co{sub 2}YZ (Y = Fe, Hf, Mn, Ti, V, Zr; Z = Al, Ga, In, Si, Ge, Sn) were measured by high temperature direct synthesis calorimetry. The measured enthalpies of formation (in kJ/mole of atoms) of the L2{sub 1} compounds are: Co{sub 2}FeGa (−25.8 ± 2.6); Co{sub 2}FeSi (−38.4 ± 2.2); Co{sub 2}FeGe (−11.6 ± 2.1); Co{sub 2}MnGa (−30.1 ± 2.3); Co{sub 2}MnSi (−42.4 ± 1.2); Co{sub 2}MnGe (−31.6 ± 3.0); Co{sub 2}MnSn (−15.6 ± 2.8); Co{sub 2}TiAl (−55.0 ± 3.7); Co{sub 2}TiGa (−54.2 ± 2.6); Co{sub 2}TiSi (−61.4 ± 1.7); Co{sub 2}TiGe (−59.3 ± 3.8); Co{sub 2}TiSn (−38.4 ± 2.0); Co{sub 2}VGa (−28.4 ± 1.1) and for the B2 compounds: Co{sub 2}FeAl (−22.5 ± 2.5), Co{sub 2}MnAl (−27.6 ± 2.7). Values are compared with those from first principles calculation when available and the extended semi-empirical model of Miedema. Trends in enthalpy of formation with element atomic number are discussed. Lattice parameters of the compounds with L2{sub 1} structure are determined by X-ray diffraction analysis.

  2. DFT investigations on mechanical stability, electronic structure and magnetism in Co2TaZ (Z = Al, Ga, In) heusler alloys

    Science.gov (United States)

    Khandy, Shakeel Ahmad; Gupta, Dinesh C.

    2017-12-01

    Ferromagnetic Heusler compounds have vast and imminent applications for novel devices, smart materials thanks to density functional theory (DFT) based simulations, which have scored out a new approach to study these materials. We forecast the structural stability of Co2TaZ alloys on the basis of total energy calculations and mechanical stability criteria. The elastic constants, robust spin-polarized ferromagnetism and electron densities in these half-metallic alloys are also discussed. The observed structural aspects calculated to predict the stability and equilibrium lattice parameters agree well with the experimental results. The elastic parameters like elastic constants, bulk, Young’s and shear moduli, poison’s and Pugh ratios, melting temperatures, etc have been put together to establish their mechanical properties. The elaborated electronic band structures along with indirect band gaps and spin polarization favour the application of these materials in spintronics and memory device technology.

  3. Half-metallic ferromagnetism in full-Heusler compounds ACaX2 (A = K and Rb; X = N and O)

    International Nuclear Information System (INIS)

    Umamaheswari, R.; Vijayalakshmi, D.; Yogeswari, M.; Kalpana, G.

    2014-01-01

    Electronic structure and magnetic properties of hypothetical ACaX 2 (A = K and Rb; X= N and O) compounds in full-Heusler phase have been investigated based on density functional theory (DFT) within the local density approximation (LDA). The electronic band structures and density of states of these compounds show that the spin-down electrons have metallic, and the spin-up electrons have a semi conducting gap resulting in stable half-metallic ferromagnetic behaviour. The strong spin polarization of 2p states of N and O atoms is found to be the origin of ferromagnetism which results in a total magnetic moment of 3 μB and 1 μB respectively

  4. Absolute calibration of the Rh-103(n,n')Rh-103m reaction rate

    International Nuclear Information System (INIS)

    Taylor, W.H.; Murphy, M.F.; March, M.R.

    1979-05-01

    The uncertainties in determining the absolute values of the Rh-103(n, n') Rh-103m reaction rate (which is widely used as a neutron damage flux monitor) have been reduced to approximately +-5%. This has been achieved with the use of a calibrated source of Pd-103-Rh-103m activity supplied by the IAEA. Agreement to within 3% between measured and calculated values of the reaction rate (normalised to the U-238 fission rate) has been achieved. (author)

  5. Computation of beam quality parameters for Mo/Mo, Mo/Rh, Rh/Rh, and W/Al target/filter combinations in mammography

    International Nuclear Information System (INIS)

    Kharrati, Hedi; Zarrad, Boubaker

    2003-01-01

    A computer program was implemented to predict mammography x-ray beam parameters in the range 20-40 kV for Mo/Mo, Mo/Rh, Rh/Rh, and W/Al target/filter combinations. The computation method used to simulate mammography x-ray spectra is based on the Boone et al. model. The beam quality parameters such as the half-value layer (HVL), the homogeneity coefficient (HC), and the average photon energy were computed by simulating the interaction of the spectrum photons with matter. The checking of this computation was done using a comparison of the results with published data and measured values obtained at the Netherlands Metrology Institute Van Swinden Laboratorium, National Institute of Standards and Technology, and International Atomic Energy Agency. The predicted values with a mean deviation of 3.3% of HVL, 3.7% of HC, and 1.5% of average photon energy show acceptable agreement with published data and measurements for all target/filter combinations in the 23-40 kV range. The accuracy of this computation can be considered clinically acceptable and can allow an appreciable estimation for the beam quality parameters

  6. Comparison of long GnRH agonist versus GnRH antagonist protocol in poor responders

    Directory of Open Access Journals (Sweden)

    Sadık Şahin

    2014-12-01

    Full Text Available Objective: To compare long GnRH agonist with GnRH antagonist protocol in poor responders. Materials and Methods: Medical charts of 531 poor responder women undergoing in-vitro fertilization (IVF cycle at Zeynep Kamil Maternity and Children’s Hospital, IVF Center were retrospectively analysed. Those who received at least 300 IU/daily gonadotropin and had ≤3 oocytes retrieved were enrolled in the study. Poor responders were categorized into two groups as those who received long GnRH agonist or GnRH antagonist regimen. Results: Treatment duration and total gonadotropin dosage were significantly higher in women undergoing the long GnRH agonist regimen compared with the GnRH antagonist regimen (p<0.001 for both. Although the number of total and mature oocytes retrieved was similar between the groups, good quality embryos were found to be higher in the GnRH antagonist regimen. The day of embryo transfer and number of transferred embryos were similar in the groups. No statistically significant differences were detected in pregnancy (10.5% vs 14.1%, clinical pregnancy (7.7% vs 10.6% and early pregnancy loss rates (27.2% vs 35% between the groups. Conclusion: GnRH antagonist regimen may be preferable to long GnRH regimen as it could decrease the cost and treatment duration in poor responders.

  7. Ab initio and Monte Carlo investigations of structural, electronic and magnetic properties of new ferromagnetic Heusler alloys with high Curie temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Dannenberg, Antje

    2011-08-30

    The mechanism which causes many of the unusual thermomechanical properties of martensitic alloys, as for example, superelasticity and the shape-memory effect, is the martensitic transformation. The prototype ferromagnetic shape memory alloy (FSMA) is Ni{sub 2}MnGa. But a technological breakthrough is missing due to its poor ductility and low operation temperatures. The goal of this thesis is the proposal of new FSMA appropriate for future technological applications. I focus on X{sub 2}YZ Heusler alloys which are mainly based on Mn, Fe, Co, and Ni for the X and Y sites and Z=Ga or Zn. The big challenge of this work is to find material classes which combine the unique magnetomechanical properties of FSMA which are large recoverable magnetostrictive strains, high magnetocrystalline anisotropy energy, and highly mobile twin boundaries with transformation temperatures clearly above room temperature and a reduced brittleness. Such a study, providing material classes which from a theoretical point of view are promising candidates for future FSMA, will help the experimental physicists to select interesting subgroups in the vast number of possible chemical compositions of X{sub 2}YZ Heusler alloys. I have systematically varied the composition in the new Heusler alloys in order to find trends indicating generic tendencies of the material properties, for instance, as a function of the valence electron concentration e/a. A main feature of this thesis is the attempt to find the origin of the competing structural ordering tendencies between conventional X{sub 2}YZ and inverse (XY)XZ Heusler structures which are observed for all systems investigated. In the first part of this work the accuracy and predictive power of ab initio and Monte Carlo simulations is demonstrated by reproducing the experimental phase diagram of Ni-Mn-(Ga,In,Sn,Sb). The linear increasing and decreasing slopes of T{sub M} and T{sub C} can be reproduced by total and free energy calculations and the analysis

  8. Mechanisms of spectral tuning in the RH2 pigments of Tokay gecko and American chameleon

    OpenAIRE

    Takenaka, Naomi; Yokoyama, Shozo

    2007-01-01

    At present, molecular bases of spectral tuning in rhodopsin-like (RH2) pigments are not well understood. Here, we have constructed the RH2 pigments of nocturnal Tokay gecko (Gekko gekko) and diurnal American chameleon (Anolis carolinensis) as well as chimeras between them. The RH2 pigments of the gecko and chameleon reconstituted with 11-cis-retinal had the wavelengths of maximal absorption (λmax’s) of 467 and 496 nm, respectively. Chimeric pigment analyses indicated that 76–86%, 14–24%, and ...

  9. The intermetallic ThRh5: microstructure and enthalpy increments

    International Nuclear Information System (INIS)

    Banerjee, Aparna; Joshi, A.R.; Kaity, Santu; Mishra, R.; Roy, S.B.

    2013-01-01

    Actinide intermetallics are one of the most interesting and important series of compounds. Thermochemistry of these compounds play significant role in understand the nature of bonding in alloys and nuclear fuel performance. In the present paper we report synthesis and characterization of thorium based intermetallic compound ThRh 5 (s) by SEM/EDX technique. The mechanical properties and enthalpy increment as a function of temperature of the alloy has been measured. (author)

  10. Electronic structure and physical properties of Heusler compounds for thermoelectric and spintronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Ouardi, Siham

    2012-03-19

    This thesis focuses on synthesis as well as investigations of the electronic structure and properties of Heusler compounds for spintronic and thermoelectric applications. The first part reports on the electronic and crystal structure as well as the mechanical, magnetic, and transport properties of the polycrystalline Heusler compound Co{sub 2}MnGe. The crystalline structure was examined in detail by extended X-ray absorption fine structure spectroscopy and anomalous X-ray diffraction. The low-temperature magnetic moment agrees well with the Slater-Pauling rule and indicates a half-metallic ferromagnetic state of the compound, as is predicted by ab-initio calculations. Transport measurements and hard X-ray photoelectron spectroscopy (HAXPES) were performed to explain the electronic structure of the compound. A major part of the thesis deals with a systematical investigation of Heusler compounds for thermoelectric applications. This thesis focuses on the search for new p-type Heusler compounds with high thermoelectric efficiency. The substitutional series NiTi{sub 1-x}M{sub x}Sn (where M=Sc, V and 0Heusler compound. The pure compounds showed n-type behavior, while under Sc substitution the system switched to p-type behavior. A maximum Seebeck coefficient of +230 {mu}V/K (350 K) was obtained for NiTi{sub 0.26}Sc{sub 0.04}Zr{sub 0.35}Hf{sub 0.35}Sn. HAXPES valence band measurement show massive in gap states for the parent compounds NiTiSn, CoTiSb and NiTi{sub 0.3}Zr{sub 0.35}Hf{sub 0.35}Sn. This proves that the electronic states close to the Fermi energy play a key role for the behavior of the transport properties. Furthermore, the electronic structure of the gapless Heusler compounds PtYSb, PtLaBi and PtLuSb were investigated by bulk

  11. Brain penetrant small molecule 18F-GnRH receptor (GnRH-R) antagonists: Synthesis and preliminary positron emission tomography imaging in rats

    International Nuclear Information System (INIS)

    Olberg, Dag E.; Bauer, Nadine; Andressen, Kjetil W.; Hjørnevik, Trine; Cumming, Paul; Levy, Finn O.; Klaveness, Jo; Haraldsen, Ira; Sutcliffe, Julie L.

    2016-01-01

    Introduction: The gonadotropin releasing hormone receptor (GnRH-R) has a well-described neuroendocrine function in the anterior pituitary. However, little is known about its function in the central nervous system (CNS), where it is most abundantly expressed in hippocampus and amygdala. Since peptide ligands based upon the endogenous decapetide GnRH do not pass the blood–brain-barrier, we are seeking a high-affinity small molecule GnRH-R ligand suitable for brain imaging by positron emission tomography. We have previously reported the radiosynthesis and in vitro evaluation of two novel [ 18 F]fluorinated GnRH-R ligands belonging to the furamide class of antagonists, with molecular weight less than 500 Da. We now extend this work using palladium coupling for the synthesis of four novel radioligands, with putatively reduced polar surface area and hydrophilicity relative to the two previously described compounds, and report the uptake of these 18 F-labeled compounds in brain of living rats. Methods: We synthesized reference standards of the small molecule GnRH-R antagonists as well as mesylate precursors for 18 F-labeling. The antagonists were tested for binding affinity for both human and rat GnRH-R. Serum and blood stability in vitro and in vivo were studied. Biodistribution and PET imaging studies were performed in male rats in order to assess brain penetration in vivo. Results: A palladium coupling methodology served for the synthesis of four novel fluorinated furamide GnRH receptor antagonists with reduced heteroatomic count. Radioligand binding assays in vitro revealed subnanomolar affinity of the new fluorinated compounds for both human and rat GnRH-R. The 18 F-GnRH antagonists were synthesized from the corresponding mesylate precursors in 5–15% overall radiochemical yield. The radiolabeled compounds demonstrated good in vivo stability. PET imaging with the 18 F-radiotracers in naive rats showed good permeability into brain and rapid washout, but absence of

  12. The effect of pressure on the structural, electronic, magnetic, and thermodynamic properties of the Mn{sub 2}RuGe inverse Heusler alloy

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ting, E-mail: songting_lzjtu@163.com [State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); College of Material Science and Engineering, Lanzhou University of Technology, Lanzhou 730050 (China); School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Sun, Xiao-Wei [School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Tian, Jun-Hong [School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Wei, Xiao-Ping; Wan, Gui-Xin [School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Ma, Qin, E-mail: maqin_lut@yeah.net [State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); College of Material Science and Engineering, Lanzhou University of Technology, Lanzhou 730050 (China)

    2017-04-15

    In the frame of density functional theory, first-principles calculations based on generalized gradient approximation and quasi-harmonic Debye approximation model in which the phononic effects are taken into account have been carried out to investigate the structural, electronic, magnetic, and thermodynamic properties of full-Heusler alloy Mn{sub 2}RuGe in CuHg{sub 2}Ti-type structure in the pressure range of 0–50 GPa. Present calculations predict that Mn{sub 2}RuGe is a ferrimagnet with an optimized lattice parameter of 5.854 Å. The calculated total magnetic moment of 2.01 μ{sub B} per formula unit is very close to integer value and agree well with the Slater-Pauling rule, where the partial spin moments of Mn (A) and Mn (B) which mainly contribute to the total magnetic moment are 2.66 μ{sub B} and −0.90 μ{sub B}, respectively. In the study of the energy band structures and density of states, Mn{sub 2}RuGe exhibits half-metallicity with an indirect gap of 0.235 eV in the spin-down channels, and the shifting of bands towards higher energies in spin-down channel under high pressure. Meanwhile, the high-pressure thermodynamic properties of Mn{sub 2}RuGe, such as the pressure-volume-temperature relationship, bulk modulus, thermal expansivity, heat capacity, Debye temperature, and Grüneisen parameter are evaluated systematically in the temperature range of 0–900 K. This set of data is considered as the useful information to understand the high-pressure and high-temperature properties for the Mn{sub 2}RuZ-type Heusler alloy family.

  13. Search for thermoelectrics with high figure of merit in half-Heusler compounds with multinary substitution

    Science.gov (United States)

    Choudhary, Mukesh K.; Ravindran, P.

    2018-04-01

    In order to improve the thermoelectric performance of TiCoSb we have substituted 50% of Ti equally with Zr and Hf at Ti site and Sb with Sn and Se equally at Sb site. The electronic structure of Ti0.5Zr0.25Hf0.25CoSn0.5Se0.5 is investigated using the full potential linearized augmented plane wave method and the thermoelectric transport properties are calculated on the basis of semi-classical Boltzmann transport theory. Our band structure calculations show that Ti0.5Zr0.25Hf0.25CoSn0.5Se0.5 has semiconducting behavior with indirect band gap value of 0.98 eV which follow the empirical rule of 18 valence-electron content to bring semiconductivity in half Heusler compounds, indicating that one can have semiconducting behavior in multinary phase of half Heusler compounds if they full fill the 18 VEC rule and this open-up the possibility of designing thermoelectrics with high figure of merit in half Heusler compounds. We show that at high temperature of around 700K Ti0.5Zr0.25Hf0.25CoSn0.5Se0.5 has high thermoelectric figure of merit of ZT = 1.05 which is higher than that of TiCoSb (˜ 0.95) suggesting that by going from ternary to multinary phase system one can enhance the thermoelectric figure of merit at higher temperatures.

  14. Ferromagnetic correlations in Yb based heavy fermions probed by NMR relaxation: YbNi{sub 4}P{sub 2} vs. Yb(Rh,Ir){sub 2}Si{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Baenitz, M.; Sarkar, R.; Khuntia, P.; Krellner, C.; Geibel, C.; Steglich, F. [Max - Planck Institute of Chemical Physics of Solids, 01187 Dresden, Germany (Germany)

    2012-07-01

    Intersite correlations in Ce-based heavy fermion systems close to the quantum critical point separating the magnetic ordered state from the paramagnetic Kondo lattice are in almost all cases predominantly antiferromagnetic (AFM) in nature. The NMR relaxation of these systems show an evolution from localized fluctuations with 1/T{sub 1} nearly constant above the Kondo temperature T{sub K}, to a linear in T Korringa- like behavior with a constant and enhanced (1/T{sub 1}T)- value below T{sub K}. We report on {sup 31}P-NMR results on the ferromagnetic (FM) quantum critical system YbNi{sub 4}P{sub 2} over a wide range in temperature (2-300 K) and field (0.2 - 9 T). Here, {sup 31}(1/T{sub 1}T)(T) does not show such a signature at T{sub K}, instead a continuous increase of (1/T{sub 1}T) down to lowest T is observed. A similar behavior has been reported for YbRh{sub 2}Si{sub 2}, which also exhibits strong FM correlations evidenced by {sup 29}Si - NMR and an enhanced Wilson ratio. Furthermore, in CeFePO, which is likely unique among Ce-based quantum critical system because of its strong FM correlations, (1/T{sub 1}T) also diverges continuously for T {yields}0. This suggests that the difference in the relaxation between most of the Ce systems and the Yb systems is predominantly related to a change from AFM to FM intersite correlations. NMR-results (shift, line width, T{sub 1}) are analyzed and discussed in different models (Korringa, Moriya).

  15. Hypersensitivity reaction with intravenous GnRH after pulsatile subcutaneous GnRH treatment in male hypogonadotrophic hypogonadism.

    OpenAIRE

    Popović, V.; Milosević, Z.; Djukanović, R.; Micić, D.; Nesović, M.; Manojlović, D.; Djordjević, P.; Mićić, J.

    1988-01-01

    Chronic pulsatile subcutaneous administration of low doses of gonadotrophin releasing hormone (GnRH) is an effective therapy for men with hypogonadotrophic hypogonadism. Hypersensitivity reactions to GnRH are rare. We wish to report hypersensitivity reactions with intravenous GnRH after low dose subcutaneous pulsatile GnRH treatment in two men with hypogonadotrophic hypogonadism due to suprasellar disease.

  16. Polymorphism in the Mr 32,000 Rh protein purified from Rh(D)-positive and -negative erythrocytes

    International Nuclear Information System (INIS)

    Saboori, A.M.; Smith, B.L.; Agre, P.

    1988-01-01

    A M r 32,000 integral membrane protein has previously been identified on erythrocytes bearing the Rh(D) antigen and is thought to contain the antigenic variations responsible for the different Rh phenotypes. To study it on a biochemical level, a simple large-scale method was developed to purify the M r 32,000 Rh protein from multiple units of Rh(D)-positive and -negative blood. Erythrocyte membrane vesicles were solubilized in NaDodSO 4 , and a tracer of immunoprecipitated 125 I surface-labeled Rh protein was added. The Rh protein was purified to homogeneity by hydroxylapatite chromatography followed by preparative NaDodSO 4 /PAGE. Approximately 25 nmol of pure Rh protein was recovered from each unit of Rh(D)-positive and -negative blood. Rh protein purified from both Rh phenotypes appeared similar by one-dimensional NaDodSO 4 /PAGE, and the N-terminal amino acid sequences for the first 20 residues were identical. Rh proteins purified from Rh(D)-positive and -negative blood were compared by two-dimensional iodopeptide mapping after 125 I-labeling and α-chymotrypsin digestion. The peptide maps were very similar. These data indicate that a similar core Rh protein exists in both Rh(D)-positive and -negative erythrocytes, and the Rh proteins from erythrocytes with different Rh phenotypes contain distinct structural polymorphisms

  17. Phenomenological analysis of thermal hysteresis in Ni-Mn-Ga Heusler alloys

    Science.gov (United States)

    Zagrebin, M. A.; Sokolovskiy, V. V.; Buchelnikov, V. D.

    2018-05-01

    The manipulation of thermal hysteresis in Ni-Mn-Ga Heusler alloys with coupled magnetostructural phase transition is studied theoretically using the Landau theory, including magnetic, elastic and crystal lattice modulation order parameters as well as an external magnetic field. It is shown that for the assigned combination of phenomenological parameters, in the phase diagrams, the Austenite-Martensite first-order phase transition has a finite (critical) point in which the thermal hysteresis is disappeared. Moreover, this point depends on the relation between modulation and elastic constants as well as on the magnetic field. Obtained results have been compared with other theoretical end experimental data.

  18. Electron dominated thermoelectric response in MNiSn (M: Ti, Zr, Hf) half-Heusler alloys

    KAUST Repository

    Gandi, Appala

    2016-05-09

    We solve the transport equations of the electrons and phonons to understand the thermoelectric behaviour of the technologically important half-Heusler alloys MNiSn (M: Ti, Zr, Hf). Doping is simulated within the rigid band approximation. We clarify the origin of the electron dominated thermoelectric response and determine the carrier concentrations with maximal figures of merit. The phonon mean free path is studied to calculate the grain size below which grain refinement methods can enforce ballistic heat conduction to enhance the figure of merit. © The Owner Societies 2016.

  19. Investigation of thermoelectricity in KScSn half-Heusler compound

    Science.gov (United States)

    Shrivastava, Deepika; Acharya, Nikita; Sanyal, Sankar P.

    2018-05-01

    The electronic and transport properties of KScSn half-Heusler (HH) compound have been investigated using first-principles density functional theory and semi classical Boltzmann transport theory. The electronic band structure and density of states (total and partial) show semiconducting nature of KScSn with band gap 0.48 eV which agree well with previously reported results. The transport coefficient such as electrical conductivity, Seebeck coefficient, electronic thermal conductivity and power factor as a function of chemical potential are evaluated. KScSn has high power factor for p-type doping and is a potential candidate for thermoelectric applications.

  20. Electron dominated thermoelectric response in MNiSn (M: Ti, Zr, Hf) half-Heusler alloys

    KAUST Repository

    Gandi, Appala; Schwingenschlö gl, Udo

    2016-01-01

    We solve the transport equations of the electrons and phonons to understand the thermoelectric behaviour of the technologically important half-Heusler alloys MNiSn (M: Ti, Zr, Hf). Doping is simulated within the rigid band approximation. We clarify the origin of the electron dominated thermoelectric response and determine the carrier concentrations with maximal figures of merit. The phonon mean free path is studied to calculate the grain size below which grain refinement methods can enforce ballistic heat conduction to enhance the figure of merit. © The Owner Societies 2016.

  1. High Thermoelectric Figure of Merit by Resonant Dopant in Half-Heusler Alloys

    OpenAIRE

    Chen, Long; Liu, Yamei; He, Jian; Tritt, Terry M.; Poon, S. Joseph

    2017-01-01

    Half-Heusler alloys have been one of the benchmark high temperature thermoelectric materials owing to their thermal stability and promising figure of merit ZT. Simonson et al. early showed that small amounts of vanadium doped in Hf0.75Zr0.25NiSn enhanced the Seebeck coefficient and correlated the change with the increased density of states near the Fermi level. We herein report a systematic study on the role of vanadium (V), niobium (Nb), and tantalum (Ta) as prospective resonant dopants in e...

  2. Half-Heusler (TiZrHf)NiSn Unileg Module with High Powder Density.

    Science.gov (United States)

    Populoh, Sascha; Brunko, Oliver C; Gałązka, Krzysztof; Xie, Wenjie; Weidenkaff, Anke

    2013-03-27

    (TiZrHf)NiSn half-Heusler compounds were prepared by arc melting and their thermoelectric properties characterized in the temperature range between 325 K and 857 K, resulting in a Figure of Merit ZT ≈ 0.45. Furthermore, the prepared samples were used to construct a unileg module. This module was characterized in a homemade thermoelectric module measurement stand and yielded 275 mW/cm² and a maximum volumetric power density of 700 mW/cm³. This was reached using normal silver paint as a contacting material; from an improved contacting, much higher power yields are to be expected.

  3. Energy gap formation mechanism through the interference phenomena of electrons in face-centered cubic elements and compounds with the emphasis on half-Heusler and Heusler compounds

    Science.gov (United States)

    Mizutani, U.; Sato, H.

    2018-05-01

    Many face-centred cubic elements and compounds with the number of atoms per unit cell N equal to 8, 12 and 16 are known to be stabilised by forming either a band gap or a pseudogap at the Fermi level. They are conveniently expressed as cF8, cF12 and cF16, respectively, in the Pearson symbol. From the cF8 family, we worked on three tetravalent elements C (diamond), Si and Ge, SZn-type AsGa compound and NaCl-type compounds like BiLu, AsSc, etc. From the cF12 family, more than 80 compounds were selected, with a particular emphasis on ABC- and half-Heusler-type ternary equiatomic compounds. Among cF16 compounds, both the Heusler compounds ABC2 and Zintl compounds were studied. We revealed that, regardless of whether or not the transition metal (TM) and/or rare-earth (RE) elements are involved as constituent elements, the energy gap formation mechanism for cF8, cF12 and cF16 compounds can be universally discussed in terms of interference phenomenon of itinerant electrons with set of reciprocal lattice planes with ? = 8, 11 and 12, where ? refers to square of the critical reciprocal of lattice vector of an fcc lattice. The number of itinerant electrons per unit cell, e/uc, for all these band gap/pseudogap-bearing compounds is found to fall on a universal line called "3/2-power law" when plotted against ? on a logarithmic scale. This proves the validity of the fulfilment of the interference condition ? in conformity with other pseudogap compounds with different crystal symmetries and different sizes of the unit cell reported in literature.

  4. Identification of Genes Enriched in GnRH Neurons by Translating Ribosome Affinity Purification and RNAseq in Mice.

    Science.gov (United States)

    Burger, Laura L; Vanacker, Charlotte; Phumsatitpong, Chayarndorn; Wagenmaker, Elizabeth R; Wang, Luhong; Olson, David P; Moenter, Suzanne M

    2018-04-01

    Gonadotropin-releasing hormone (GnRH) neurons are a nexus of fertility regulation. We used translating ribosome affinity purification coupled with RNA sequencing to examine messenger RNAs of GnRH neurons in adult intact and gonadectomized (GDX) male and female mice. GnRH neuron ribosomes were tagged with green fluorescent protein (GFP) and GFP-labeled polysomes isolated by immunoprecipitation, producing one RNA fraction enhanced for GnRH neuron transcripts and one RNA fraction depleted. Complementary DNA libraries were created from each fraction and 50-base, paired-end sequencing done and differential expression (enhanced fraction/depleted fraction) determined with a threshold of >1.5- or <0.66-fold (false discovery rate P ≤ 0.05). A core of ∼840 genes was differentially expressed in GnRH neurons in all treatments, including enrichment for Gnrh1 (∼40-fold), and genes critical for GnRH neuron and/or gonadotrope development. In contrast, non-neuronal transcripts were not enriched or were de-enriched. Several epithelial markers were also enriched, consistent with the olfactory epithelial origins of GnRH neurons. Interestingly, many synaptic transmission pathways were de-enriched, in accordance with relatively low innervation of GnRH neurons. The most striking difference between intact and GDX mice of both sexes was a marked downregulation of genes associated with oxidative phosphorylation and upregulation of glucose transporters in GnRH neurons from GDX mice. This may suggest that GnRH neurons switch to an alternate fuel to increase adenosine triphosphate production in the absence of negative feedback when GnRH release is elevated. Knowledge of the GnRH neuron translatome and its regulation can guide functional studies and can be extended to disease states, such as polycystic ovary syndrome.

  5. Preparation and Thermoelectric Characteristics of ITO/PtRh:PtRh Thin Film Thermocouple.

    Science.gov (United States)

    Zhao, Xiaohui; Wang, Hongmin; Zhao, Zixiang; Zhang, Wanli; Jiang, Hongchuan

    2017-12-15

    Thin film thermocouples (TFTCs) can provide more precise in situ temperature measurement for aerospace propulsion systems without disturbance of gas flow and surface temperature distribution of the hot components. ITO/PtRh:PtRh TFTC with multilayer structure was deposited on alumina ceramic substrate by magnetron sputtering. After annealing, the TFTC was statically calibrated for multiple cycles with temperature up to 1000 °C. The TFTC with excellent stability and repeatability was realized for the negligible variation of EMF in different calibration cycles. It is believed that owing to oxygen diffusion barriers by the oxidation of top PtRh layer and Schottky barriers formed at the grain boundaries of ITO, the variation of the carrier concentration of ITO film is minimized. Meanwhile, the life time of TFTC is more than 30 h in harsh environment. This makes ITO/PtRh:PtRh TFTC a promising candidate for precise surface temperature measurement of hot components of aeroengines.

  6. XANES and XMCD studies of FeRh and CoRh nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Smekhova, A; Wilhelm, F; Rogalev, A [European Synchrotron Radiation Facility, Grenoble Cedex 9, 38043 (France); Atamena, N; Ciuculescu, D; Amiens, C [Laboratoire de Chimie de Coordination, UPR 8241-CNRS, Toulouse Cedex 04, 31077 (France); Lecante, P, E-mail: smeal@esrf.f [Centre d' Elaboration de Materiaux et d' Etudes Structurales, UPR 8011-CNRS, Toulouse Cedex 04, 31055 (France)

    2010-01-01

    Element-selective magnetic properties of new core-shell bimetallic MRh (M=Fe or Co) nanoparticles (NP{sub S}) of 50/50 composition with either M-Rh or Rh-M core/shell order and an average diameter of {approx}2 nm have been investigated by X-ray Absorption Spectroscopy (XANES) and X-Ray Magnetic Circular Dichroism (XMCD) technique. XANES spectra at the Rh L{sub 2,3} edges exhibit the same characteristic features for all systems having the Rh metal enriched shell. XMCD experiments at the same edges have shown that 4d states of Rh atoms acquire a magnetic moment as a result of hybridization with iron or cobalt 3d states. As expected the value of this induced moment depends on the 3d transition metal and on the core/shell chemical order in the nanoparticle.

  7. Probing the random distribution of half-metallic Co2Mn1-xFexSi Heusler alloys

    NARCIS (Netherlands)

    Wurmehl, S.; Kohlhepp, J.T.; Swagten, H.J.M.; Koopmans, B.; Wójcik, M.; Balke, B.; Blum, C.G.F.; Ksenofontov, V.; Fecher, G.H.; Felser, C.

    2007-01-01

    Co2Mn1-xFexSi Heusler alloys crystallize in the L21 structure. This structure type requires random distribution of Mn and Fe in case of the mixed alloys. The spin echo nuclear magnetic resonance (NMR) technique probes the direct local environments of the active atoms and is thus able to resolve next

  8. Design of thermoelectrically highly efficient Heusler compounds using phase separations and nano-composites under an economic point of view

    Science.gov (United States)

    Balke, Benjamin

    Half-Heusler (HH) compounds are one of the most promising candidates for thermoelectric materials for automotive and industrial waste heat recovery applications. In this talk, I will give an overview about our recent investigations of phase separations in HH thermoelectrics, focusing on the ternary system TiNiSn-ZrNiSn-HfNiSn. I will show how we adapted this knowledge to design a p-type HH compound which exhibits a ZT that is increased by 130% compared to the best published bulk p-type Heusler. I will also present how we used the phase separation to design thermoelectric highly efficient nano-composites of different single-phase materials. Since the price for Hafnium doubled within the last year, our research focused on the design of HH compounds without Hafnium. I will present a very recent calculation on ZT per Euro and efficiency per Euro for various materials followed by our latest very promising results for n-type Heusler compunds without Hafnium resulting in 20 times higher ZT/Euro values. These results strongly underline the importance of phase separations as a powerful tool for designing highly efficient materials for thermoelectric applications that fulfill the industrial demands for a thermoelectric converter. The author gratefully acknowledges financial support by the thermoHEUSLER2 Project (Project No. 19U15006F) of the German Federal Ministry of Economics and Technology (BMWi).

  9. Melatonin Inhibits GnRH-1, GnRH-3 and GnRH Receptor Expression in the Brain of the European Sea Bass, Dicentrarchus labrax

    Directory of Open Access Journals (Sweden)

    José Antonio Muñoz-Cueto

    2013-04-01

    Full Text Available Several evidences supported the existence of melatonin effects on reproductive system in fish. In order to investigate whether melatonin is involved in the modulation of GnRH systems in the European sea bass, we have injected melatonin (0.5 µg/g body mass in male specimens. The brain mRNA transcript levels of the three GnRH forms and the five GnRH receptors present in this species were determined by real time quantitative PCR. Our findings revealed day–night variations in the brain expression of GnRH-1, GnRH-3 and several GnRH receptors (dlGnRHR-II-1c, -2a, which exhibited higher transcript levels at mid-light compared to mid-dark phase of the photocycle. Moreover, an inhibitory effect of melatonin on the nocturnal expression of GnRH-1, GnRH-3, and GnRH receptors subtypes 1c, 2a and 2b was also demonstrated. Interestingly, the inhibitory effect of melatonin affected the expression of hypophysiotrophic GnRH forms and GnRH receptors that exhibit day–night fluctuations, suggesting that exogenous melatonin reinforce physiological mechanisms already established. These interactions between melatoninergic and GnRH systems could be mediating photoperiod effects on reproductive and other rhythmic physiological events in the European sea bass.

  10. The effect of a fourth element (Co, Cu, Fe, Pd) on the standard enthalpy of formation of the Heusler compound Ni{sub 2}MnSn

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Ming, E-mail: myin1@hawk.iit.edu; Nash, Philip

    2016-05-15

    The standard enthalpies of formation of quaternary Heusler compounds (X, Ni){sub 2}MnSn (X = Co, Cu, Fe, Pd) were investigated experimentally using high temperature direct reaction calorimetry. Lattice parameters of these compounds were determined using X-ray diffraction analysis. Microstructures were identified using scanning electron microscopy and energy dispersive spectroscopy. The effect of an additional X element on the standard enthalpy of formation of the Heusler compound Ni{sub 2}MnSn is discussed. - Highlights: • Enthalpies of formation of (X,Ni){sub 2}YZ (X = Co, Cu, Fe, Pd) were measured by drop calorimeters. • Magnetic contribution to enthalpy of formation plays an important role. • Introducing a fourth element could stabilize an unstable Heusler structure. • Lattice parameters do not necessarily obey the Vegard's law. • It is possible to tailor properties of Heusler compounds with enough background information.

  11. NMR Evidence for the Topologically Nontrivial Nature in a Family of Half-Heusler Compounds

    KAUST Repository

    Zhang, Xiaoming

    2016-03-16

    Spin-orbit coupling (SOC) is expected to partly determine the topologically nontrivial electronic structure of heavy half-Heusler ternary compounds. However, to date, attempts to experimentally observe either the strength of SOC or how it modifies the bulk band structure have been unsuccessful. By using bulk-sensitive nuclear magnetic resonance (NMR) spectroscopy combined with first-principles calculations, we reveal that 209Bi NMR isotropic shifts scale with relativity in terms of the strength of SOC and average atomic numbers, indicating strong relativistic effects on NMR parameters. According to first-principles calculations, we further claim that nuclear magnetic shieldings from relativistic p1/2 states and paramagnetic contributions from low-lying unoccupied p3/2 states are both sensitive to the details of band structures tuned by relativity, which explains why the hidden relativistic effects on band structure can be revealed by 209Bi NMR isotropic shifts in topologically nontrivial half-Heusler compounds. Used in complement to surface-sensitive methods, such as angle resolved photon electron spectroscopy and scanning tunneling spectroscopy, NMR can provide valuable information on bulk electronic states.

  12. Electron spin resonance probed competing states in NiMnInSi Heusler alloy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.S. [Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan (China); Lin, J.G., E-mail: jglin@ntu.edu.tw [Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan (China); Titov, I.S.; Granovsky, A.B. [Faculty of Physics, Lomonosov Moscow State University, Vorob' evy Gory, 11999l Moscow (Russian Federation)

    2016-06-01

    Shape memory Heusler alloy Ni{sub 50}Mn{sub 35}In{sub 12}Si{sub 3} is investigated with electron spin resonance (ESR) technique in a temperature range of 200–300 K. ESR is a dynamic probe allowing us to separate the responses from various magnetic phases, thus to study the complex phase transitions. The sample shows three transition temperatures: T{sub c}{sup A} (271 K), T{sub M} (247 K) and T{sub c}{sup M} (212 K), where T{sub c}{sup A} is the Curie temperature of austenitic phase, T{sub M} and T{sub c}{sup M} are the temperatures of magnetostructural martensitic transition and the Curie temperature of martensitic phase, respectively. Furthermore, ESR data reveals the coexistence of two magnetic modes in whole temperature range of 200–300 K. Particularly in martensitic phase, two magnetic modes are attributed to two different kinds of lattice deformation, the slip and twinning deformations. - Highlights: • Electron spin resonance study on magnetocaloric Heusler alloy within 200–300 K. • Magnetic phase separation below and above the structural transition temperature. • Phase competing is in association with different types of lattice distortions. • Electron spin resonance results are complementary to the magnetization data.

  13. Synthesis and Thermoelectric Properties of Ni-Doped ZrCoSb Half-Heusler Compounds

    Directory of Open Access Journals (Sweden)

    Degang Zhao

    2018-01-01

    Full Text Available The Ni-doped ZrCo1−xNixSb half-Heusler compounds were prepared by arc-melting and spark plasma sintering technology. X-ray diffraction analysis results showed that all samples were crystallized in a half-Heusler phase. Thermoelectric properties of ZrCo1−xNixSb compounds were measured from room temperature to 850 K. The electrical conductivity and the absolute value of Seebeck coefficient increased with the Ni-doping content increasing due to the Ni substitution at Co. sites. The lattice thermal conductivity of ZrCo1−xNixSb samples was depressed dramatically because of the acoustic phonon scattering and point defect scattering. The figure of merit of ZrCo1−xNixSb compounds was improved due to the decreased thermal conductivity and improved power factor. The maximum ZT value of 0.24 was achieved for ZrCo0.92Ni0.08Sb sample at 850 K.

  14. NMR Evidence for the Topologically Nontrivial Nature in a Family of Half-Heusler Compounds

    KAUST Repository

    Zhang, Xiaoming; Hou, Zhipeng; Wang, Yue; Xu, Guizhou; Shi, Chenglong; Liu, EnKe; Xi, Xuekui; Wang, Wenhong; Wu, Guangheng; Zhang, Xixiang

    2016-01-01

    Spin-orbit coupling (SOC) is expected to partly determine the topologically nontrivial electronic structure of heavy half-Heusler ternary compounds. However, to date, attempts to experimentally observe either the strength of SOC or how it modifies the bulk band structure have been unsuccessful. By using bulk-sensitive nuclear magnetic resonance (NMR) spectroscopy combined with first-principles calculations, we reveal that 209Bi NMR isotropic shifts scale with relativity in terms of the strength of SOC and average atomic numbers, indicating strong relativistic effects on NMR parameters. According to first-principles calculations, we further claim that nuclear magnetic shieldings from relativistic p1/2 states and paramagnetic contributions from low-lying unoccupied p3/2 states are both sensitive to the details of band structures tuned by relativity, which explains why the hidden relativistic effects on band structure can be revealed by 209Bi NMR isotropic shifts in topologically nontrivial half-Heusler compounds. Used in complement to surface-sensitive methods, such as angle resolved photon electron spectroscopy and scanning tunneling spectroscopy, NMR can provide valuable information on bulk electronic states.

  15. Electronic structure and physical properties of Heusler compounds for thermoelectric and spintronic applications

    International Nuclear Information System (INIS)

    Ouardi, Siham

    2012-01-01

    This thesis focuses on synthesis as well as investigations of the electronic structure and properties of Heusler compounds for spintronic and thermoelectric applications. The first part reports on the electronic and crystal structure as well as the mechanical, magnetic, and transport properties of the polycrystalline Heusler compound Co 2 MnGe. The crystalline structure was examined in detail by extended X-ray absorption fine structure spectroscopy and anomalous X-ray diffraction. The low-temperature magnetic moment agrees well with the Slater-Pauling rule and indicates a half-metallic ferromagnetic state of the compound, as is predicted by ab-initio calculations. Transport measurements and hard X-ray photoelectron spectroscopy (HAXPES) were performed to explain the electronic structure of the compound. A major part of the thesis deals with a systematical investigation of Heusler compounds for thermoelectric applications. This thesis focuses on the search for new p-type Heusler compounds with high thermoelectric efficiency. The substitutional series NiTi 1-x M x Sn (where M=Sc, V and 0 0.26 Sc 0.04 Zr 0.35 Hf 0.35 Sn. HAXPES valence band measurement show massive in gap states for the parent compounds NiTiSn, CoTiSb and NiTi 0.3 Zr 0.35 Hf 0.35 Sn. This proves that the electronic states close to the Fermi energy play a key role for the behavior of the transport properties. Furthermore, the electronic structure of the gapless Heusler compounds PtYSb, PtLaBi and PtLuSb were investigated by bulk sensitive HAXPES. The linear behavior of the spectra close to εF proves the bulk origin of Dirac-cone type density of states. Furthermore, a systematic study on the optical and transport properties of PtYSb is presented. The compound exhibits promising thermoelectric properties with a high figure of merit (ZT=0.2) and a Hall mobility μh of 300 cm 2 /Vs at 350 K. The last part of this thesis describes the linear dichroism in angular-resolved photoemission from the valence band

  16. Absolute calibration of the Rh-103 (n, n') Rh-103m reaction rate

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, W.H.; Murphy, M.F.; March, M.R. [Reactor Physics Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1979-05-15

    The uncertainties in determining the absolute values of the Rh-103 (n, n') Rh-103m reaction rate (which is widely used as a neutron damage flux monitor) have been reduced to {approx}{+-}5%. This has been achieved with the use of a calibrated source of Pd-103-Rh-103m activity supplied by the I.A.E.A. Agreement to within 3% between measured and calculated values of the reaction rate (normalised to the U-238 fission rate) has been achieved. (author)

  17. Improvement of castable refractories for RH snorkel; RH shinshitsukanyo futeikeizai no kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Nishi, K.; Obana, T.; Fijii, T.; Shimizu, I. [Harima Ceramics Corp., Hyogo (Japan)

    1999-11-01

    Relating to corrosion of RH submerged nozzle, resistance against iron oxide of monolithic refractories was examined. Corrosion and seepage of refractories were measured by rotating corrosion, refractories include alumina-spinel castable, which is applied to RH under tank, and alumina-magnesia castable, which is generally used for RH, submerged nozzle. Alumina-spinel castable is superior in resistance against iron oxide than alumina-magnesia castable, and the resistance decreased with increase of stainless fiber addition to castable. Alumina-spinel castable without stainless fiber was suitable for bottom end of the dipping pipe. (NEDO)

  18. Absolute calibration of the Rh-103 (n, n') Rh-103m reaction rate

    International Nuclear Information System (INIS)

    Taylor, W.H.; Murphy, M.F.; March, M.R.

    1979-05-01

    The uncertainties in determining the absolute values of the Rh-103 (n, n') Rh-103m reaction rate (which is widely used as a neutron damage flux monitor) have been reduced to ∼±5%. This has been achieved with the use of a calibrated source of Pd-103-Rh-103m activity supplied by the I.A.E.A. Agreement to within 3% between measured and calculated values of the reaction rate (normalised to the U-238 fission rate) has been achieved. (author)

  19. Noninvasive fetal RhD genotyping

    DEFF Research Database (Denmark)

    Clausen, Frederik Banch; Damkjær, Merete Berthu; Dziegiel, Morten Hanefeld

    2014-01-01

    Immunization against RhD is the major cause of hemolytic disease of the fetus and newborn (HDFN), which causes fetal or neonatal death. The introduction of postnatal immune prophylaxis in the 1960s drastically reduced immunization incidents in pregnant, D-negative women. In several countries, ant...

  20. Preparation of a 102Rh tracer

    International Nuclear Information System (INIS)

    Gorski, B.; Heinig, W.

    1986-01-01

    Electronic emission detectors used in reactors for the control of the neutron flux density contain rhodium as an emitter material. By dissolving the emitter material in a mixture of hydrobromic acid and bromine it is possible to get 102 Rh labelled solutions of the spent detectors. The preparation and purification of the solutions are described. (author)

  1. Atomic and molecular adsorption on Rh(111)

    DEFF Research Database (Denmark)

    Mavrikakis, Manos; Rempel, J.; Greeley, Jeffrey Philip

    2002-01-01

    A systematic study of the chemisorption of both atomic (H, O, N, S, C), molecular (N-2, CO, NO), and radical (CH3, OH) species on Rh(111) has been performed. Self-consistent, periodic, density functional theory (DFT-GGA) calculations, using both PW91 and RPBE functionals, have been employed to de...

  2. Molecular – genetic variance of RH blood group system within human population of Bosnia and Herzegovina

    Directory of Open Access Journals (Sweden)

    Lejla Lasić

    2013-02-01

    Full Text Available There are two major theories for inheritance of Rh blood group system: Fisher - Race theory and Wiener theory. Aim of this study was identifying frequency of RHDCE alleles in Bosnian - Herzegovinian population and introduction of this method in screening for Rh phenotype in B&H since this type of analysis was not used for blood typing in B&H before. Rh blood group was typed by Polymerase Chain Reaction, using the protocols and primers previously established by other authors, then carrying out electrophoresis in 2-3% agarose gel. Percentage of Rh positive individuals in our sample is 84.48%, while the percentage of Rh negative individuals is 15.52%. Inter-rater agreement statistic showed perfect agreement (K=1 between the results of Rh blood system detection based on serological and molecular-genetics methods. In conclusion, molecular - genetic methods are suitable for prenatal genotyping and specific cases while standard serological method is suitable for high-throughput of samples.

  3. Preparation and properties of radio-frequency-sputtered half-Heusler films for use in solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kieven, D., E-mail: david.kieven@helmholtz-berlin.d [Helmholtz-Zentrum fuer Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Grimm, A. [Helmholtz-Zentrum fuer Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Beleanu, A.; Blum, C.G.F. [Johannes Gutenberg Universitaet, Institut fuer Anorganische Chemie und Analytische Chemie, Staudingerweg 9, 55128 Mainz (Germany); Schmidt, J. [Fraunhofer Institut Fertigungstechnik Materialforschung IFAM, Winterbergstrasse 28, 01277 Dresden (Germany); Rissom, T.; Lauermann, I. [Helmholtz-Zentrum fuer Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Gruhn, T.; Felser, C. [Johannes Gutenberg Universitaet, Institut fuer Anorganische Chemie und Analytische Chemie, Staudingerweg 9, 55128 Mainz (Germany); Klenk, R. [Helmholtz-Zentrum fuer Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany)

    2011-01-03

    The class of half-Heusler compounds opens possibilities to find alternatives for II-VI or III-V compound semiconductors. We aim to find suitable substitutes for the cadmium sulphide buffer layer in chalcopyrite-based thin film solar cells, where the buffer layer is located between the p-type chalcopyrite absorber and an n-type transparent window layer. We report here the preparation of radio-frequency-sputtered lithium copper sulphide 'LiCuS' and lithium zinc phosphide 'LiZnP' films. The optical analysis of these films revealed band gaps between 1.8 and 2.5 eV, respectively. Chemical properties of the film surface and both interfaces between the film and a Cu(In,Ga)Se{sub 2} layer and between the film and an (Zn,Mg)O layer were investigated by in-situ photoelectron spectroscopy. The valence band offsets to the Cu(In,Ga)Se{sub 2} layer were estimated to be (0.4 {+-} 0.1) eV for 'LiCuS'/Cu(In,Ga)Se{sub 2} and (0.5 {+-} 0.8) eV for 'LiZnP'/Cu(In,Ga)Se{sub 2}. This leads to positive conduction band offsets of > 1 eV. These rather large offsets are not compatible with efficient solar cell devices. Under atmospheric conditions 'LiCuS' and 'LiZnP' films show rapid decomposition.

  4. {sup 103}Rh NMR investigation of the superconductor Rh{sub 17}S{sub 15}

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, T., E-mail: t-koyama@sci.u-hyogo.ac.j [Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297 (Japan); Kanda, K.; Motoyama, G.; Ueda, K.; Mito, T.; Kohara, T. [Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297 (Japan); Nakamura, H. [Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501 (Japan)

    2010-12-15

    We present {sup 103}Rh NMR studies for the superconductor Rh{sub 17}S{sub 15} (T{sub c} 5.4 K). We have identified the observed NMR lines corresponding to four different Rh sites in the cubic unit cell and deduced the temperature (T) dependence of the Knight shift components in Rh 24m site whose point symmetry is not axial. The isotropic part of the Knight shift K decreases with T in the normal state, indicating the negative hyperfine coupling and the enhancement of the spin susceptibility at lower T. The sudden change of K below T{sub c} is an indication of the spin-singlet Cooper paring.

  5. Influence of disorder and interfaces on electronic and magnetic properties of Heusler systems; Einfluss von Unordnung und Grenzflaechen auf elektronische und magnetische Eigenschaften von Heusler-Systemen

    Energy Technology Data Exchange (ETDEWEB)

    Krumme, Bernhard

    2012-07-17

    A Moessbauer-spectroscopic investigation of Fe{sub 3} films on GaAs(100) and MgO(100) revealed a disordered growth mode of Fe{sub 3}Si on GaAs(100), which is caused by an interdiffusion of Ga/As atoms. Implementing a 3 nm thick MgO tunnelbarrier on the GaAs suface inhibits the interdiffusion and enables an epitaxial film growth of Fe{sub 3}Si. By comparing experimental X-ray absorption measurements with DFT calculations we are able to resolve the contribution of the different Fe sublattices to the XAS and XMCD signal. Taking into account atomic disorder arising from Ga/As atoms within DFT calculation yields a small reduction of the spin polarization of Fe{sub 3}Si, indicating that the system Fe{sub 3}Si/GaAs(100) still is an interesting candidate for spintronic applications. For the Heusler compounds Co{sub 2}MnSi and Co{sub 2}FeSi the influence of the 3d transition metals Mn/Fe on the hybridization was determined by X-ray absorption and DFT calculations. A depth-selective study of the electronic structure of Mn in Co{sub 2}MnSi at the vicinity to a MgO tunnelbarrier indicates an increased number of unoccupied d states referring a MnSi terminated interface. The electronic structure of Si-rich Co{sub 2}FeSi depends on the external magnetic field. This points to magnetostrictive effects in this compound. Furthermore, the Heusler compound Ni{sub 51.6}Mn{sub 32.9}Sn{sub 15.5} was studied in this work. The compound is a shape memory alloy exhibiting a large inverse magnetocaloric effect. In this work the focus was put on the element-specific magnetic properties of Ni and Mn. For Mn a strong increase of the ratio of orbital to spin magnetic moment m{sub l}/m{sub S} was observed. In the austenite phase this ratio accounts for 5 %, whereas in the martensite this value becomes 13.5 %. For Ni m{sub l}/m{sub S} is almost constant at 28 %. applying a magnetic field of 3 T in the martensite phase leads to a reduction of m{sub l}/m{sub S} for both elements, indicating a field

  6. Remarks on the 103Rh(n,n') sup(103m)Rh excitation curve

    International Nuclear Information System (INIS)

    Pazsit, A.; Peto, G.; Csikai, J.; Jozsa, I.; Bacso, J.

    1975-01-01

    The cross sections of the 103 Rh(n,n')sup(103m)Rh reaction have been measured at 2.7MeV and 14.8MeV neutron energies as well as for neutron spectra of 252 Cf and 239 Pu-α-Be sources; the results are 999+-111mb, 216+-26mb, 757+-53mb and 918+-64mb, respectively. (author)

  7. Origin of room temperature ferromagnetic moment in Rh-rich [Rh/Fe] multilayer thin films

    International Nuclear Information System (INIS)

    Kande, Dhishan; Laughlin, David; Zhu Jiangang

    2010-01-01

    B2 ordered FeRh thin films switch from antiferromagnetic (AFM) to ferromagnetic (FM) state on heating above 350 K and switch back on cooling, with a hysteresis. This property makes FeRh a very attractive choice as a write-assist layer material for low temperature heat assisted magnetic recording (HAMR) media. Studies have shown that as we decrease the thickness of the FeRh films, the B2 phase is no longer AFM even below 350 K and there is a thickness dependant FM stabilization of the B2 phase. It was also proved that slightly Rh-richer compositions (>50 at. % Rh) were more preferable to stabilize the AFM phase. The current study focuses on growing highly ordered FeRh films by alternate layer rf sputtering of thin layers of iron and rhodium onto a heated substrate. It has been shown that films with rhodium content beyond 55 at. % contain a disordered bcc FM phase which gives rise to residual moment at room temperature even for thicker films.

  8. Phase relations and Gibbs energies of spinel phases and solid solutions in the system Mg-Rh-O

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, K.T., E-mail: katob@materials.iisc.ernet.in [Department of Materials Engineering, Indian Institute of Science, Bangalore 560 012 (India); Prusty, Debadutta [Department of Materials Engineering, Indian Institute of Science, Bangalore 560 012 (India); Kale, G.M. [Institute for Materials Research, University of Leeds, Leeds, LS2 9JT (United Kingdom)

    2012-02-05

    Highlights: Black-Right-Pointing-Pointer Refinement of phase diagram for the system Mg-Rh-O and thermodynamic data for spinel compounds MgRh{sub 2}O{sub 4} and Mg{sub 2}RhO{sub 4} is presented. Black-Right-Pointing-Pointer A solid-state electrochemical cell is used for thermodynamic measurement. Black-Right-Pointing-Pointer An advanced design of the solid-state electrochemical cell incorporating buffer electrodes is deployed to minimize polarization of working electrode. Black-Right-Pointing-Pointer Regular solution model for the spinel solid solution MgRh{sub 2}O{sub 4} - Mg{sub 2}RhO{sub 4} based on ideal mixing of cations on the octahedral site is proposed. Black-Right-Pointing-Pointer Factors responsible for stabilization of tetravalent rhodium in spinel compounds are identified. - Abstract: Pure stoichiometric MgRh{sub 2}O{sub 4} could not be prepared by solid state reaction from an equimolar mixture of MgO and Rh{sub 2}O{sub 3} in air. The spinel phase formed always contained excess of Mg and traces of Rh or Rh{sub 2}O{sub 3}. The spinel phase can be considered as a solid solution of Mg{sub 2}RhO{sub 4} in MgRh{sub 2}O{sub 4}. The compositions of the spinel solid solution in equilibrium with different phases in the ternary system Mg-Rh-O were determined by electron probe microanalysis. The oxygen potential established by the equilibrium between Rh + MgO + Mg{sub 1+x}Rh{sub 2-x}O{sub 4} was measured as a function of temperature using a solid-state cell incorporating yttria-stabilized zirconia as an electrolyte and pure oxygen at 0.1 MPa as the reference electrode. To avoid polarization of the working electrode during the measurements, an improved design of the cell with a buffer electrode was used. The standard Gibbs energies of formation of MgRh{sub 2}O{sub 4} and Mg{sub 2}RhO{sub 4} were deduced from the measured electromotive force (e.m.f.) by invoking a model for the spinel solid solution. The parameters of the model were optimized using the measured

  9. Transport properties of Heusler Compound Mn3Si under high pressure

    International Nuclear Information System (INIS)

    Takaesu, Y; Uchima, K; Nakamura, S; Yogi, M; Niki, H; Hedo, M; Nakama, T; Tomiyoshi, S

    2014-01-01

    The electrical resistivity ρ and the thermopower S of the single crystalline sample of the Heusler compound Mn 3 Si have been measured in the temperature range between 2 and 300 K under high pressures up to 2.2 GPa. The temperature variations of ρ and S indicate the characteristic features at the Néel temperature T N . An additional anomaly in S(T), related to the 3Q satellites in SDW, is observed at P > 1 GPa, and it disappears at P > 1 GPa. The Néel temperature, obtained from ρ(T) and S(T) curves, increases with increasing pressure. The pressure dependences of the residual resistivity and the thermopower at T = 2 K show the discontinuous changes at P ≈ 1 GPa, indicating a pressure induced phase transition

  10. 119Sn Moessbauer spectroscopy in the magnetically diluted Heusler-type systems

    International Nuclear Information System (INIS)

    Ruebenbauer, K.

    1981-01-01

    119 Sn Moessbauer investigations of the ferromagnetically diluted Nisub(2)Mnsub(x)Bsub(1-x)Sn(B=Ti, V) and Pdsub(2)Mnsub(x)Vsub(1-x)Sn Heusler-type systems have been performed and the results are reviewed and discussed. It has been found that distributions of the transferred hyperfine magnetic field as seen by a tin nucleus are very sensitive for a type of the local magnetic interaction in these simple ferromagnets, especially when studied versus the sample temperature. This sensitivity allows to reach some conclusions about the coupling mechanism between localised manganese magnetic moments. Namely, it is concluded that the interaction beyond the second neighbour shell is practically irrelevant for the magnetic ordering process. This very fact means that the free electron approach to the calculation of exchange integrals can not be applied for these particular systems. (Author)

  11. NMR studies in the half-Heusler type compound YbPtSb

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, T; Abe, M; Mito, T; Ueda, K; Kohara, T [Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297 (Japan); Suzuki, H S, E-mail: t-koyama@sci.u-hyogo.ac.jp [National Institute for Materials Science, Tsukuba 305-0047 (Japan)

    2011-01-01

    {sup 121}Sb and {sup 19B}Pt nuclear magnetic resonance (NMR) has been studied in the half-Heusler type compound YbPtSb to obtain information on local magnetic behavior. The characteristics of the localized 4f spins are observed in the Cuire-Weiss type behavior of the Knight shifts K for both {sup 121}Sb and {sup 19B}Pt. From the slope of K-{sub {chi}} plots we estimated hyperfine coupling constants of -3.8 and -4.6 kOe/{mu}{sub B} at Sb and Pt sites, respectively. It was found that the spin-echo decay rate 1/T{sub 2} of {sup 121}Sb shows a clear peaks at 10 K. Similar tendency was also observed in case of {sup 19B}Pt. However, static properties do not show any anomalies near 10 K.

  12. Observation of giant exchange bias in bulk Mn50Ni42Sn8 Heusler alloy

    Science.gov (United States)

    Sharma, Jyoti; Suresh, K. G.

    2015-02-01

    We report a giant exchange bias (EB) field of 3520 Oe in bulk Mn50Ni42Sn8 Heusler alloy. The low temperature magnetic state of the martensite phase has been studied by DC magnetization and AC susceptibility measurements. Frequency dependence of spin freezing temperature (Tf) on critical slowing down relation and observation of memory effect in zero field cooling mode confirms the super spin glass (SSG) phase at low temperatures. Large EB is attributed to the strong exchange coupling between the SSG clusters formed by small regions of ferromagnetic order embedded in an antiferromagnetic (AFM) matrix. The temperature and cooling field dependence of EB have been studied and related to the change in unidirectional anisotropy at SSG/AFM interface. The training effect also corroborates with the presence of frozen (SSG) moments at the interface and their role in EB.

  13. Properties of half-Heusler compounds TaIrGe by using first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Wei, JunHong [Henan Normal University, College of Physics and Information Engineering, Xinxiang, Henan (China); Henan Institute of Science and Technology, School of Mechanical and Electrical Engineering, Xinxiang, Henan (China); Wang, Guangtao [Henan Normal University, College of Physics and Information Engineering, Xinxiang, Henan (China)

    2017-05-15

    The electronic structures, optical and thermoelectric properties of ternary half-Heusler compound TaIrGe were investigated by using the first-principles and Boltzmann transport theory. Spin-orbit coupling (SOC) removed the degeneracy of VBM, and then decreased the Seebeck coefficients and power factor. From the compressive to tensile strain, the band gap gradually increases from 0.96 to 1.11 eV, accompanied by the absorption coefficient peak red-shift. The effective mass (m{sup *}{sub DOS}) of VBM and CBM gradually increases from the compressive to tensile strain, which enhances the Seebeck coefficient and power factor. Our results indicate that the electronic structures, optical and thermoelectric properties of TaIrGe can be effectively tuned by the strain and TaIrGe can be used as an important photoelectric and thermoelectric material in the future. (orig.)

  14. Thermoelectric Properties of the XCoSb (X: Ti,Zr,Hf) Half-Heusler Alloys

    KAUST Repository

    Gandi, Appala

    2017-09-18

    We investigate the thermoelectric properties of the half-Heusler alloys XCoSb (X: Ti,Zr,Hf) by solving Boltzmann transport equations and discuss them in terms of the electronic band structure. The rigid band approximation is employed to address the effects of doping. While many half-Heuser alloys show excellent thermoelectric performance, the materials under study are special by supporting both n- and p-doping. We identify the reasons for this balanced thermoelectric transport and explain why experimentally p-doping is superior to n-doping. We also determine the spectrum of phonon mean free paths to guide grain refinement methods to enhance the thermoelectric figure of merit.

  15. Termination layer compensated tunnelling magnetoresistance in ferrimagnetic Heusler compounds with high perpendicular magnetic anisotropy.

    Science.gov (United States)

    Jeong, Jaewoo; Ferrante, Yari; Faleev, Sergey V; Samant, Mahesh G; Felser, Claudia; Parkin, Stuart S P

    2016-01-18

    Although high-tunnelling spin polarization has been observed in soft, ferromagnetic, and predicted for hard, ferrimagnetic Heusler materials, there has been no experimental observation to date of high-tunnelling magnetoresistance in the latter. Here we report the preparation of highly textured, polycrystalline Mn3Ge films on amorphous substrates, with very high magnetic anisotropy fields exceeding 7 T, making them technologically relevant. However, the small and negative tunnelling magnetoresistance that we find is attributed to predominant tunnelling from the lower moment Mn-Ge termination layers that are oppositely magnetized to the higher moment Mn-Mn layers. The net spin polarization of the current reflects the different proportions of the two distinct termination layers and their associated tunnelling matrix elements that result from inevitable atomic scale roughness. We show that by engineering the spin polarization of the two termination layers to be of the same sign, even though these layers are oppositely magnetized, high-tunnelling magnetoresistance is possible.

  16. Expression of the GnRH and GnRH receptor (GnRH-R) genes in the hypothalamus and of the GnRH-R gene in the anterior pituitary gland of anestrous and luteal phase ewes.

    Science.gov (United States)

    Ciechanowska, Magdalena; Lapot, Magdalena; Malewski, Tadeusz; Mateusiak, Krystyna; Misztal, Tomasz; Przekop, Franciszek

    2008-11-01

    Data exists showing that seasonal changes in the innervations of GnRH cells in the hypothalamus and functions of some neural systems affecting GnRH neurons are associated with GnRH release in ewes. Consequently, we put the question as to how the expression of GnRH gene and GnRH-R gene in the hypothalamus and GnRH-R gene in the anterior pituitary gland is reflected with LH secretion in anestrous and luteal phase ewes. Analysis of GnRH gene expression by RT-PCR in anestrous ewes indicated comparable levels of GnRH mRNA in the preoptic area, anterior and ventromedial hypothalamus. GnRH-R mRNA at different concentrations was found throughout the preoptic area, anterior and ventromedial hypothalamus, stalk/median eminence and in the anterior pituitary gland. The highest GnRH-R mRNA levels were detected in the stalk/median eminence and in the anterior pituitary gland. During the luteal phase of the estrous cycle in ewes, the levels of GnRH mRNA and GnRH-R mRNA in all structures were significantly higher than in anestrous ewes. Also LH concentrations in blood plasma of luteal phase ewes were significantly higher than those of anestrous ewes. In conclusion, results from this study suggest that low expression of the GnRH and GnRH-R genes in the hypothalamus and of the GnRH-R gene in the anterior pituitary gland, amongst others, may be responsible for a decrease in LH secretion and the anovulatory state in ewes during the long photoperiod.

  17. Adsorption of Rh(III) complexes from chloride solutions obtained by leaching chlorinated spent automotive catalysts on ion-exchange resin Diaion WA21J

    International Nuclear Information System (INIS)

    Shen Shaobo; Pan Tonglin; Liu Xinqiang; Yuan Lei; Wang Jinchao; Zhang Yongjian; Guo Zhanchen

    2010-01-01

    It was found that Rh, Pd and Pt contained in the spent ceramic automotive catalysts could be effectively extracted by dry chlorination with chlorine. In order to concentrate Rh(III) ions contained in the chloride solutions obtained, thermodynamic and kinetics studies for adsorption of Rh(III) complexes from the chloride solutions on an anionic exchange resin Diaion WA21J were carried out. Rh, Pd, Pt, Al, Fe, Si, Zn and Pb from the chloride solution could be adsorbed on the resin. The distribution coefficients (K d ) of Rh(III) decreased with the increase in initial Rh(III) concentration or in adsorption temperature. The isothermal adsorption of Rh(III) was found to fit Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich models under the adsorption conditions. The maximum monolayer adsorption capacities Q max based on Langmuir adsorption isotherms were 6.39, 6.61 and 5.81 mg/g for temperatures 18, 28 and 40 deg. C, respectively. The apparent adsorption energy of Rh was about -7.6 kJ/mol and thus Rh(III) adsorption was a physical type. The experimental data obtained could be better simulated by pseudo-first-order kinetic model and the activation energy obtained was 6.54 J/mol. The adsorption rate of Rh(III) was controlled by intraparticle diffusion in most of time of adsorption process.

  18. Measurement of 103mRh produced by the 103Rh(γ,γ')103mRh reaction with liquid scintillation counting

    International Nuclear Information System (INIS)

    Sekine, T.; Yoshihara, Kenji; Pavlicsek, I.; Lakosi, L.; Veres, A.

    1989-01-01

    A liquid scintillation counting technique was applied to measure the isotope 103m Rh (half life = 56.12 min) which is difficult to detect because its γ-ray is of low energy and low emission probability. Tris-(2,4-pentanedionato)rhodium(III) (Rh(acac) 3 ) was irradiated with bremsstrahlung of accelerated 3.2 MeV electrons by LINAC. The method has given a reliable calibration curve for the determination of 103m Rh radioactivity below Rh(acac) 3 concentrations of 2 mM. The integrated cross section of 103 Rh(γ,γ') 103m Rh determined by this method was found to be 6.8±3.4 μb MeV at 3.2 MeV. (author) 8 refs.; 5 figs

  19. Style et rhétorique

    DEFF Research Database (Denmark)

    Pedersen, Eva de la Fuente

    2006-01-01

    En se forgeant un style presque inimitable, qui paraît ébauché, Rembrandt a suscité l'admiration de ses contemporains. Au-delà son apparente spontanéité, ce style fait certainement écho aux préoccupations des théoriciens de l'art contemporains qui attendaient de la peinture, comme de la rhétorique...

  20. Photoaffinity labeling of pituitary GnRH receptors: significance of the position of photolabel on the ligand

    International Nuclear Information System (INIS)

    Nikolics, K.; Szonyi, E.; Ramachandran, J.

    1988-01-01

    Photoreactive derivatives of GnRH and its analogues were prepared by incorporation of the 2-nitro-4(5)-azidophenylsulfenyl [2,4(5)-NAPS] group into amino acid residues at position 1, 3, 6, or 8 of the decapeptide sequence. The modification of Trp 3 by the 2,4-NAPS group led to a complete loss of the luteinizing hormone (LH) releasing as well as LH-release-inhibiting activity of the peptide. The [D-Lys(2,4-NAPS)] 6 analog was a very potent agonist that, after covalent attachment by photoaffinity labeling, caused prolonged LH secretion at a submaximal rate. [Orn(2,4-NAPS)] 8 -GnRH, a full agonist with a relative potency of 7% of GnRH, after photoaffinity labeling caused prolonged maximal LH release from cultured pituitary cells. In contrast, [Orn(2,5-NAPS)] 8 -GnRH, although being equipotent with the 2,4-NAPS isomer in terms of LH releasing ability, was unable to cause prolonged LH release after photoaffinity labeling. Thus, [Orn(2,4-NAPS)] 8 GnRH is very effective photolabeling ligand of the functionally significant pituitary GnRH receptor. Based on this compound, a pituitary peptidase resistant derivative, D-Phe 6 , [Orn(2,4-NAPS)] 8 -GnRH-(1-9)-ethylamide, was synthesized. This derivative showed high-affinity binding to pituitary membranes with a K/sub d/ comparable to those of other GnRH analogues. A radioiodinated form of this peptide was used for pituitary GnRH-receptor labeling. This derivative labeled 59- and 57-kDa proteins in rat and 58- and 56-kDa proteins in bovine pituitary membrane preparations, respectively. This peptide also labeled pituitary GnRH receptors in the solubilized state and therefore appears to be a suitable ligand for the isolation and further characterization of the receptor

  1. Anti-phase boundaries and magnetic domain structures in Ni{sub 2}MnGa-type Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Venkateswaran, S.P. [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); Nuhfer, N.T. [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); De Graef, M. [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States)]. E-mail: degraef@cmu.edu

    2007-05-15

    The microstructure and magnetic domain structure of austenitic Heusler Ni{sub 2}MnGa are investigated as a function of heat treatment to study the interplay of anti-phase boundaries and magnetic domain walls. Conventional electron microscopy observations on arc-melted polycrystalline samples show that anti-phase boundaries in this system are invisible for standard two-beam imaging conditions, due to the large extinction distance of the Heusler superlattice reflections. Lorentz Fresnel and Foucault observations on quenched samples reveal a wavy magnetic domain morphology, reminiscent of curved anti-phase boundaries. A close inspection of the domain images indicates that the anti-phase boundaries have a magnetization state different from that of the matrix. Fresnel image simulations for a simple magnetization model are in good agreement with the observations. Magnetic coercivity measurements show a decrease in coercivity with annealing, which correlates with the microscopy observations of reduced anti-phase boundary density for annealed samples.

  2. Spin wave propagation detected over 100 μm in half-metallic Heusler alloy Co2MnSi

    Science.gov (United States)

    Stückler, Tobias; Liu, Chuanpu; Yu, Haiming; Heimbach, Florian; Chen, Jilei; Hu, Junfeng; Tu, Sa; Alam, Md. Shah; Zhang, Jianyu; Zhang, Youguang; Farrell, Ian L.; Emeny, Chrissy; Granville, Simon; Liao, Zhi-Min; Yu, Dapeng; Zhao, Weisheng

    2018-03-01

    The field of magnon spintronics offers a charge current free way of information transportation by using spin waves (SWs). Compared to forward volume spin waves for example, Damon-Eshbach (DE) SWs need a relatively weak external magnetic field which is suitable for small spintronic devices. In this work we study DE SWs in Co2MnSi, a half-metallic Heusler alloy with significant potential for magnonics. Thin films have been produced by pulsed laser deposition. Integrated coplanar waveguide (CPW) antennas with different distances between emitter and detection antenna have been prepared on a Co2MnSi film. We used a vector network analyzer to measure spin wave reflection and transmission. We observe spin wave propagation up to 100 μm, a new record for half-metallic Heusler thin films.

  3. Rh-Ni and Rh-Co Catalysts for Autothermal Reforming of Gasoline

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yeongyu; Lee, Daehyung; Kim, Yongmin; Lee, Jinhee; Nam, Sukwoo; Choi, Daeki; Yoon, Chang Won [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2014-01-15

    Rh doped Ni and Co catalysts, Rh-M/CeO{sub 2}(20 wt %)-Al{sub 2}O{sub 3} (0.2 wt % of Rh; M = Ni or Co, 20 wt %) were synthesized to produce hydrogen via autothermal reforming (ATR) of commercial gasoline at 700 .deg. C under the conditions of a S/C ratio of 2.0, an O/C ratio of 0.84, and a gas hourly space velocity (GHSV) of 20,000 h{sup -1}. The Rh-Ni/CeO{sub 2}(20 wt %)-Al{sub 2}O{sub 3} catalyst (1) exhibited excellent activities, with H{sub 2} and (H{sub 2}+CO) yields of 2.04 and 2.58 mol/mol C, respectively. In addition, this catalyst proved to be highly stable over 100 h without catalyst deactivation, as evidenced by energy dispersive spectroscopy (EDX) and elemental analyses. Compared to 1, Rh-Co/CeO{sub 2}(20 wt %)-Al{sub 2}O{sub 3} catalyst (2) exhibited relatively low stability, and its activity decreased after 57 h. In line with this observation, elemental analyses confirmed that nearly no carbon species were formed at 1 while carbon deposits (10 wt %) were found at 2 following the reaction, which suggests that carbon coking is the main process for catalyst deactivation.

  4. Study of electronic structure and magnetic properties of epitaxial Co{sub 2}FeAl Heusler Alloy Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Soni, S. [Department of Pure & Applied Physics, University of Kota, Kota 324007 (India); Dalela, S., E-mail: sdphysics@rediffmail.com [Department of Pure & Applied Physics, University of Kota, Kota 324007 (India); Sharma, S.S. [Department of Physics, Govt. Women Engineering College, Ajmer (India); Liu, E.K.; Wang, W.H.; Wu, G.H. [State Key Laboratory for Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Kumar, M. [Department of Physics, Malviya National Institute of Technology, Jaipur-302017 (India); Garg, K.B. [Department of Physics, University of Rajasthan, Jaipur-302004 (India)

    2016-07-25

    This work reports the magnetic and electronic characterization of plane magnetized buried Heusler Co{sub 2}FeAl nano thin films of different thickness by X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) measurements. . The spectra on both Fe- and Co L{sub 2,3} edges show a pronounced magnetic dichroic signal in remanence, corresponding to a ferromagnetically-aligned moments on Fe and Co atoms conditioning the peculiar characteristics of the Co{sub 2}FeAl Heusler compound (a half-metallic ferromagnet). The detailed knowledge of the related magnetic and electronic properties of these samples over a wide range of thickness of films are indispensable for achieving a higher tunnel magnetoresistance ratio, and thus for spintronics device applications. - Highlights: • Electronic structure and Magnetic Properties of Epitaxial Co{sub 2}FeAl Heusler Films. • X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD). • Fe- and Co L{sub 2,3} edges show a pronounced magnetic dichroic signal in remanence. • Calculated Orbital, Spin and total magnetic moments of Fe and Co for 30 nm Co{sub 2}FeAl thin film. • The total magnetic moment of Fe at L{sub 2,3} edges increases with the thickness of the Co2FeAl films.

  5. The Association between ABO and Rh Blood Groups and Risk of Endometriosis in Iranian Women.

    Science.gov (United States)

    Malekzadeh, Farideh; Moini, Ashraf; Amirchaghmaghi, Elham; Daliri, Leila; Akhoond, Mohammad Reza; Talebi, Mehrak; Hosseini, Rihaneh

    2018-06-01

    Endometriosis is a common gynaecological disease that affects quality of life for women. Several studies have revealed that both environmental and genetic factors contribute to the development of endometriosis. The aim of this study was to investigate the distribution of ABO and Rh blood groups in Iranian women with endometriosis who presented to two referral infertility centers in Tehran, Iran. In this case-control study, women who referred to Royan Institute and Arash Women's Hospital for diagnostic laparoscopy between 2013 and 2014 were assessed. Based on the laparoscopy findings, we categorized the women into two groups: endometriosis and control (women without endometriosis and normal pelvis). Chi-square and logistic regression tests were used for data analysis. In this study, we assessed 433 women, of which 213 patients were assigned to the endometriosis group while the remaining 220 subjects comprised the control group. The most frequent ABO blood group was O (40.6%). The least frequent blood group was AB (4.8%). In terms of Rh blood group, Rh+ (90.1%) was more frequent than Rh- (9.9%). There was no significant correlation between ABO (P=0.091) and Rh (P=0.55) blood groups and risk of endometriosis. Also, there was no significant difference between the two groups with regards to the stage of endometriosis and distribution of ABO and Rh blood groups (P>0.05). Although the O blood group was less dominant in Iranian women with endometriosis, we observed no significant correlation between the risk of endometriosis and the ABO and Rh blood groups. Endometriosis severity was not correlated to any of these blood groups. Copyright© by Royan Institute. All rights reserved.

  6. Preparation and evaluation of self-microemulsions for improved bioavailability of ginsenoside-Rh1 and Rh2.

    Science.gov (United States)

    Yang, Feifei; Zhou, Jing; Hu, Xiao; Yu, Stephanie Kyoungchun; Liu, Chunyu; Pan, Ruile; Chang, Qi; Liu, Xinmin; Liao, Yonghong

    2017-10-01

    Due to intestinal cytochrome P450 (CYP450)-mediated metabolism and P-glycoprotein (P-gp) efflux, poor oral bioavailability hinders ginsenoside-Rh1 (Rh1) and ginsenoside-Rh2 (Rh2) from clinical application. In this study, Rh1 and Rh2 were incorporated into two self-microemulsions (SME-1 and SME-2) to improve oral bioavailability. SME-1 contained both CYP450 and P-gp inhibitory excipients while SME-2 only consisted of P-gp inhibitory excipients. Results for release, cellular uptake, transport, and lymph node distribution demonstrated no significant difference between either self-microemulsions in vivo, but were elevated significantly in comparison to the free drug. The pharmaceutical profiles in vivo showed that the bioavailability of Rh1 in SME-1 (33.25%) was significantly higher than that in either SME-2 (21.28%) or free drug (12.92%). There was no significant difference in bioavailability for Rh2 between SME-1 (48.69%) or SME-2 (41.73%), although they both had remarkable increase in comparison to free drug (15.02%). We confirmed that SME containing CYP450 and P-gp inhibitory excipient could distinctively improve the oral availabilities of Rh1 compared to free drug or SME containing P-gp inhibitory excipient. No notable increase was observed between either SME for Rh2, suggesting that Rh2 undergoes P-gp-mediated efflux, but may not undergo distinct CYP450-mediated metabolism.

  7. A re-evaluation of k0 and related nuclear data for the 555.8 keV gamma-line emitted by the 104mRh-104Rh mother-daughter pair for use in NAA

    International Nuclear Information System (INIS)

    Corte, Frans de; Lierde, Stijn van; Simonits, Andras; Bossus, Danieel; Sluijs, Robbert van; Pomme, Stefaan

    1999-01-01

    A re-evaluation is made of the k 0 -factor and related nuclear data for the 555.8 keV gamma-ray of the 104m Rh- 104 Rh mother-daughter pair that are important in neutron activation analysis (NAA). This study considers that the relevant level is also fed by the 4.34 min 104m Rh mother (with an absolute gamma-ray emission probability γ 2 =0.13%) and not only, as assumed in former work, by the 42.3 s 104 Rh daughter isotope (with γ 3 =2.0%). In view of this, generalised equations were developed for both the experimental determination and the analytical use of the k 0 -factor and of the associated parameters k 0 (m)/k 0 (g), Q 0 (m) and Q 0 (g) [(m): 104m Rh; (g): 104 Rh], requiring the introduction of the γ 2 and γ 3 data and also of the 104m Rh→ 104 Rh fractional decay factor F 2 (=0.9987). The experimental determinations were based on irradiations performed in the BR1 reactor in Mol and the WWR-M reactor in Budapest. Furthermore, considering the special formation of the 555.8 keV gamma-ray, the procedure for true-coincidence correction was revised as well. All this led to the compilation and recommendation of a new set of 'k 0 -NAA' data

  8. Bone Morphogenic Protein-2 (rhBMP2)-Loaded Silk Fibroin Scaffolds to Enhance the Osteoinductivity in Bone Tissue Engineering

    Science.gov (United States)

    Du, Guang-Yu; He, Sheng-Wei; Sun, Chuan-Xiu; Mi, Li-Dong

    2017-10-01

    There is an increasing demand for formulations of silk fibroin (SF) scaffolds in biomedical applications. SF was crosslinked via glutaraldehyde with osteoinductive recombinant human bone morphogenic protein-2 (rhBMP2) of different ratios viz. (i) 3% SF with no rhBMP2 (SF), (ii) 3% SF with equal amount of rhBMP2 (SF+BMP2), and (iii) 12% SF with 3% of rhBMP2 (4SF+BMP2), and these solutions were used in electrospinning-based fabrication of nanoscaffolds for evaluating increased osteoinductive potential of SF scaffolds with rhBMP2. Stress-strain relationship suggested there is no loss in mechanical strength of fibers with addition of rhBMP2, and mechanical strength of scaffold was improved with increase in concentration of SF. rhBMP2 association increased the water retention capacity of scaffold as evident from swelling studies. Viability of hMSCs was found to be higher in conjugated scaffolds, and scaffolds do not exhibit any cytotoxicity towards guest cells. Cells were found to have higher alkaline phosphatase activity in conjugated scaffolds under in vitro and in vivo conditions which establishes the increased osteoinductivity of the novel construct. The scaffolds were found to be effective for in vivo bone formation as well.

  9. Theoretical investigation of electronic and magnetic properties of HoRh layers

    International Nuclear Information System (INIS)

    Masrour, R.; Hlil, E.K.; Hamedoun, M.; Benyoussef, A.; Mounkachi, O.; Bahmad, L.; El Moussaoui, H.

    2013-01-01

    Self-consistent ab initio calculations, based on Density Functional Theory (DFT) approach and using Full potential Linear Augmented Plane Wave (FLAPW) method, are performed to investigate both electronic and magnetic properties of the HoRh layers. Polarized spin and spin–orbit coupling are included in calculations within the framework of the antiferromagnetic state between two sites of Ho. Magnetic moment considered to lie along (001) axes are computed. The data obtained from the ab initio calculations are then used as input for the high temperature series expansions (HTSEs) calculations to compute other magnetic parameters. The exchange integrals between the magnetic atoms in the same sites are given by using mean field theory. The HTSEs of the magnetic susceptibility of HoRh layers spin-S through the Ising model for HoRh layers, are studied to tenth order series in β=1/k B T. The critical exponent γ associated with the magnetic susceptibility is deduced for two models. - Highlights: • Ab initio calculations is using to investigate both electronic and magnetic properties of the HoRh layers. • Obtained data from ab initio calculations are used as input for the HTSEs. • The Néel temperature is obtained for HoRh layers

  10. Theoretical investigation of electronic and magnetic properties of HoRh layers

    Energy Technology Data Exchange (ETDEWEB)

    Masrour, R., E-mail: rachidmasrour@hotmail.com [Laboratory of Materials, Processes, Environment and Quality, Cady Ayyed University, National School of Applied Sciences, Sidi Bouzid, Safi (Morocco); LMPHE (URAC 12), Faculty of Science, Mohammed V-Agdal University, Rabat (Morocco); Hlil, E.K. [Institut Néel, CNRS et Université Joseph Fourier, BP 166, F-38042 Grenoble cedex 9 (France); Hamedoun, M. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Benyoussef, A. [LMPHE (URAC 12), Faculty of Science, Mohammed V-Agdal University, Rabat (Morocco); Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Hassan II Academy of Science and Technology, Rabat (Morocco); Mounkachi, O. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Bahmad, L. [LMPHE (URAC 12), Faculty of Science, Mohammed V-Agdal University, Rabat (Morocco); El Moussaoui, H. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco)

    2013-10-15

    Self-consistent ab initio calculations, based on Density Functional Theory (DFT) approach and using Full potential Linear Augmented Plane Wave (FLAPW) method, are performed to investigate both electronic and magnetic properties of the HoRh layers. Polarized spin and spin–orbit coupling are included in calculations within the framework of the antiferromagnetic state between two sites of Ho. Magnetic moment considered to lie along (001) axes are computed. The data obtained from the ab initio calculations are then used as input for the high temperature series expansions (HTSEs) calculations to compute other magnetic parameters. The exchange integrals between the magnetic atoms in the same sites are given by using mean field theory. The HTSEs of the magnetic susceptibility of HoRh layers spin-S through the Ising model for HoRh layers, are studied to tenth order series in β=1/k{sub B}T. The critical exponent γ associated with the magnetic susceptibility is deduced for two models. - Highlights: • Ab initio calculations is using to investigate both electronic and magnetic properties of the HoRh layers. • Obtained data from ab initio calculations are used as input for the HTSEs. • The Néel temperature is obtained for HoRh layers.

  11. Superconductivity induced by doping Rh in CaFe2-xRhxAs2

    International Nuclear Information System (INIS)

    Qi Yanpeng; Wang Lei; Gao Zhaoshun; Wang Dongliang; Zhang Xianping; Wang Chunlei; Yao Chao; Ma Yanwei

    2011-01-01

    In this paper, we report the synthesis of iron-based superconductors CaFe 2-x Rh x As 2 using a one-step solid state reaction method that crystallizes in the ThCr 2 Si 2 -type structure with a space group I4/mmm. The systematic evolution of the lattice constants demonstrates that the Fe ions are successfully replaced by the Rh. By increasing the doping content of Rh, the spin-density-wave (SDW) transition in the parent compound is suppressed and superconductivity emerges. The maximum superconducting transition temperature is found at 18.5 K with a doping level of x=0.15. The temperature dependence of dc magnetization confirms superconducting transitions at around 15 K. The general phase diagram was obtained and found to be similar to the case of the Rh-doping Sr122 system. Our results explicitly demonstrate the feasibility of inducing superconductivity in Ca122 compounds by higher d-orbital electron doping; however, different Rh-doping effects between FeAs122 compounds and FeAs1111 systems still remains an open question.

  12. Waste Isolation Pilot Plant RH TRU waste preoperational checkout: Final report

    International Nuclear Information System (INIS)

    1988-06-01

    This report documents the results of the Waste Isolation Pilot Plant (WIPP) Remote-Handled Transuranic (RH TRU) Waste Preoperational Checkout. The primary objective of this checkout was to demonstrate the process of handling RH TRU waste packages, from receipt through emplacement underground, using equipment, personnel, procedures, and methods to be used with actual waste packages. A further objective was to measure operational time lines to provide bases for confirming the WIPP design through put capability and for projecting operator radiation doses. Successful completion of this checkout is a prerequisite to the receipt of actual RH TRU waste. This checkout was witnessed in part by members of the Environmental Evaluation Group (EEG) of the state of New Mexico. Further, this report satisfies a key milestone contained in the Agreement for Consultation and Cooperation with the state of New Mexico. 4 refs., 26 figs., 4 tabs

  13. Photonuclear excitation of 103Rh by synchrotron radiation

    International Nuclear Information System (INIS)

    Kaji, Harumi; Yoshihara, Kenji; Mukoyama, Takeshi; Nakajima, Tetsuo

    1989-01-01

    Photonuclear excitation of 103 Rh nucleus was studied by the use of synchrotron radiation at KEK. Formation of excited state was confirmed by observing Rh K X-rays emitted following the isomeric transition of 103m Rh with a low-energy photon spectrometer. The induced activity due to 103 Rh(γ,γ') 103m Rh reaction was determined carefully by subtracting the fluorescent K X-rays due to natural background radiation. The integral cross-section for 103m Rh by resonance absorption at 295 keV is found to be (1∼2)x10 -28 cm 2 ·eV and is compared with that estimated from the previous experimental value for the 1277-keV level and the calculated value

  14. Extracellular Matrix (ECM) Multilayer Membrane as a Sustained Releasing Growth Factor Delivery System for rhTGF-β3 in Articular Cartilage Repair

    Science.gov (United States)

    Park, Sang-Hyug; Kim, Moon Suk; Kim, Young Jick; Choi, Byung Hyune; Lee, Chun Tek; Park, So Ra; Min, Byoung-Hyun

    2016-01-01

    Recombinant human transforming growth factor beta-3 (rhTGF-β3) is a key regulator of chondrogenesis in stem cells and cartilage formation. We have developed a novel drug delivery system that continuously releases rhTGF-β3 using a multilayered extracellular matrix (ECM) membrane. We hypothesize that the sustained release of rhTGF-β3 could activate stem cells and result in enhanced repair of cartilage defects. The properties and efficacy of the ECM multilayer-based delivery system (EMLDS) are investigated using rhTGF-β3 as a candidate drug. The bioactivity of the released rhTGF-ß3 was evaluated through chondrogenic differentiation of mesenchymal stem cells (MSCs) using western blot and circular dichroism (CD) analyses in vitro. The cartilage reparability was evaluated through implanting EMLDS with endogenous and exogenous MSC in both in vivo and ex vivo models, respectively. In the results, the sustained release of rhTGF-ß3 was clearly observed over a prolonged period of time in vitro and the released rhTGF-β3 maintained its structural stability and biological activity. Successful cartilage repair was also demonstrated when rabbit MSCs were treated with rhTGF-β3-loaded EMLDS ((+) rhTGF-β3 EMLDS) in an in vivo model and when rabbit chondrocytes and MSCs were treated in ex vivo models. Therefore, the multilayer ECM membrane could be a useful drug delivery system for cartilage repair. PMID:27258120

  15. Extracellular Matrix (ECM Multilayer Membrane as a Sustained Releasing Growth Factor Delivery System for rhTGF-β3 in Articular Cartilage Repair.

    Directory of Open Access Journals (Sweden)

    Soon Sim Yang

    Full Text Available Recombinant human transforming growth factor beta-3 (rhTGF-β3 is a key regulator of chondrogenesis in stem cells and cartilage formation. We have developed a novel drug delivery system that continuously releases rhTGF-β3 using a multilayered extracellular matrix (ECM membrane. We hypothesize that the sustained release of rhTGF-β3 could activate stem cells and result in enhanced repair of cartilage defects. The properties and efficacy of the ECM multilayer-based delivery system (EMLDS are investigated using rhTGF-β3 as a candidate drug. The bioactivity of the released rhTGF-ß3 was evaluated through chondrogenic differentiation of mesenchymal stem cells (MSCs using western blot and circular dichroism (CD analyses in vitro. The cartilage reparability was evaluated through implanting EMLDS with endogenous and exogenous MSC in both in vivo and ex vivo models, respectively. In the results, the sustained release of rhTGF-ß3 was clearly observed over a prolonged period of time in vitro and the released rhTGF-β3 maintained its structural stability and biological activity. Successful cartilage repair was also demonstrated when rabbit MSCs were treated with rhTGF-β3-loaded EMLDS ((+ rhTGF-β3 EMLDS in an in vivo model and when rabbit chondrocytes and MSCs were treated in ex vivo models. Therefore, the multilayer ECM membrane could be a useful drug delivery system for cartilage repair.

  16. Ginsenoside Rh2 Induces Human Hepatoma Cell Apoptosisvia Bax/Bak Triggered Cytochrome C Release and Caspase-9/Caspase-8 Activation

    Directory of Open Access Journals (Sweden)

    Xiao-Xi Guo

    2012-11-01

    Full Text Available Ginsenoside Rh2 (G-Rh2 has been shown to induce apoptotic cell death in a variety of cancer cells. However, the details of the signal transduction cascade involved in G-Rh2-induced cell death is unclear. In this manuscript we elucidate the molecular mechanism of G-Rh2-induced apoptosis in human hepatoma SK-HEP-1 cells by demonstrating that G-Rh2 causes rapid and dramatic translocation of both Bak and Bax, which subsequently triggers mitochondrial cytochrome c release and consequent caspase activation. Interestingly, siRNA-based gene inactivation of caspase-8 effectively delays caspase-9 activation and apoptosis induced by G-Rh2, indicating that caspase-8 also plays an important role in the G-Rh2-induced apoptosis program. Taken together, our results indicate that G-Rh2 employs a multi pro-apoptotic pathway to execute cancer cell death, suggesting a potential role for G-Rh2 as a powerful chemotherapeutic agent.

  17. Routine noninvasive prenatal screening for fetal RHD in plasma of RhD-negative pregnant women-2years of screening experience from Denmark

    DEFF Research Database (Denmark)

    Clausen, F. Banch; Steffensen, R.; Christiansen, M.

    2014-01-01

    Objective: Prenatal and postnatal RhD prophylaxis reduces the risk of RhD immunization in pregnancies of RhD-negative women. Based on the result from prenatal screening for the fetal RHD gene, prenatal RhD prophylaxis in Denmark is targeted to RhD-negative women who carry an RhD-positive fetus...... of newborns in 12,668 pregnancies. Early compliance was assessed for 690 pregnancies. Results: The sensitivity for the detection of fetal RHD was 99.9% (95% CI: 99.7-99.9%). Unnecessary recommendation of prenatal RhD prophylaxis was avoided in 97.3% of the women carrying an RhD-negative fetus. Fetuses...... that were seropositive for RhD were not detected in 11 pregnancies (0.087%). The sample uptake percentage was 84.2%, and the compliance for prenatal anti-D administration was 93.2%. Conclusion: The high sensitivity, maintained over 2years, underlines the reliability of routine prenatal fetal RHD screening...

  18. High-spin states in odd-odd 106,108,110,112Rh

    International Nuclear Information System (INIS)

    Fotiades, N.; Cizewski, J.A.; Kruecken, R.; McNabb, D.P.; Becker, J.A.; Bernstein, L.A.; Younes, W.; Clark, R.M.; Fallon, P.; Lee, I.Y.; Macchiavelli, A.O.

    2003-01-01

    The level structures of 106,108,110,112 Rh have been studied in the fission of the compound system formed in three different heavy-ion induced reactions. Sequences of five transitions, together with weak crossover transitions, have been assigned to each isotope based on coincidences with known transitions in the complementary fragments. Comparison with the lighter odd-odd Rh isotopes supports assignment of these sequences as the yrast bands built on the πg 9/2 xνh 11/2 configuration

  19. 35Cl/37Cl isotope effects in 103Rh NMR of [RhCln(H2O)6−n]3−n complex anions in hydrochloric acid solution as a unique ‘NMR finger-print’ for unambiguous speciation

    International Nuclear Information System (INIS)

    Geswindt, Theodor E.; Gerber, Wilhelmus J.; Brand, D. Jacobus; Koch, Klaus R.

    2012-01-01

    Graphical abstract: 35 Cl/ 37 Cl isotope effects in 103 Rh NMR as a unique ‘NMR-fingerprints’ leading to the unambiguous assignment of [RhCl n (H 2 O) 6−n ] 3−n (n = 3–6) complexes without reliance on accurate δ( 103 Rh) chemical shifts. Highlights: ► Direct 103 Rh NMR (19.11 MHz) spectroscopic method of speciation of [RhCl n (H 2 O) 6−n ] 3−n in HCl. ► 35 Cl/ 37 Cl isotope effects in 103 Rh NMR of [RhCl n (H 2 O) 6−n ] 3−n anions isotopologue and isotopomer induced 103 Rh NMR ‘finger-print’ for unambiguous identification. ► 103 Rh NMR identification of stereoisomers without a need for accurate chemical shifts. - Abstract: A detailed analysis of the 35 Cl/ 37 Cl isotope effects observed in the 19.11 MHz 103 Rh NMR resonances of [RhCl n (H 2 O) 6−n ] 3−n complexes (n = 3–6) in acidic solution at 292.1 K, shows that the ‘fine structure’ of each 103 Rh resonance can be understood in terms of the unique isotopologue and in certain instances the isotopomer distribution in each complex. These 35 Cl/ 37 Cl isotope effects in the 103 Rh NMR resonance of the [Rh 35/37 Cl 6 ] 3− species manifest only as a result of the statistically expected 35 Cl/ 37 Cl isotopologues, whereas for the aquated species such as for example [Rh 35/37 Cl 5 (H 2 O)] 2− , cis-[Rh 35/37 Cl 4 (H 2 O) 2 ] − as well as the mer-[Rh 35/37 Cl 3 (H 2 O) 3 ] complexes, additional fine-structure due to the various possible isotopomers within each class of isotopologues, is visible. Of interest is the possibility of the direct identification of stereoisomers cis-[RhCl 4 (H 2 O) 2 ] − , trans-[RhCl 4 (H 2 O) 2 ] − , fac-[RhCl 3 (H 2 O) 3 ] and mer-[RhCl 3 (H 2 O) 3 ] based on the 103 Rh NMR line shape, other than on the basis of their very similar δ( 103 Rh) chemical shift. The 103 Rh NMR resonance structure thus serves as a novel and unique ‘NMR-fingerprint’ leading to the unambiguous assignment of [RhCl n (H 2 O) 6−n ] 3−n complexes (n = 3–6

  20. Observation of strong ferromagnetism in the half-Heusler compound CoTiSb system

    Energy Technology Data Exchange (ETDEWEB)

    Sedeek, K., E-mail: KamiliaSedeek@yahoo.com; Hantour, H.; Makram, N.; Said, Sh. A.

    2016-06-01

    Strong ferromagnetism has been detected in the semiconducting half-Heusler CoTiSb compound. The synthesis process was carried out by direct fusion of highly pure Co, Ti, and Sb in an evacuated quartz tube. The structural, micro structural and magnetic properties were investigated. The crystal structure was refined from X-ray powder diffraction data by the Rietveld method. Applying the search match program, three nano-crystalline phases of CoTiSb, Ti{sub 3}Sb and CoTi{sub 2} (50%, 33.3% and 16.7% respectively) were identified for the prepared system. The term “phase” is used to address the co-existence of different stable chemical composition for the same half-Heusler alloy. The scanning electron microscope SEM and the high resolution transmission electron microscope HR-TEM were applied to characterize the morphology, size, shape, crystallinity and lattice spacing. A mixture of ordered and disordered arrangement was detected. Well defined nano-crystalline structure with an average interatomic distance equals 0.333 nm and sharp diffraction spots were measured. Contrary to this, the HR-TEM and electron diffraction image shows distorted structured planes and smeared halo surrounded by weak rings. Thermo-magnetic measurements (M–T) have been measured between 640 °K and 920 °K. Clear magnetic phase transition is detected above 900 °K (T{sub c}), in addition to a second possible phase transition (T{sub FF}) around 740 °K. The latter is clarified by plotting ΔM/ΔT vs. T. To determine the type of the detected phase transitions, the field dependence of magnetization was measured at 300 °K and 740 °K. Arrot plots (M{sup 2}−H/M) confirm the ferromagnetic character at both temperatures. It may be reasonable to assume the T{sub FF} transition as an additional ferromagnetic contribution stemming from some sort of exchange interactions. A tentative magnetic phase diagram is given. Overall, the present results suggest that the prepared multiphases CoTiSb system does

  1. Electronic Structure Properties and a Bonding Model of Thermoelectric Half-Heusler and Boride Phases

    Science.gov (United States)

    Simonson, Jack William

    Half-Heusler alloys MNiSn and MCoSb (M = Ti, Zr, Hf) and layered boride intermetallics with structure types YCrB4 and Er 3CrB7 were designed, synthesized, and characterized. The thermoelectric properties of these two classes of alloys were measured from room temperature to 1100 K with the intent of indirectly studying their electronic structure properties and gauging not only their suitability but that of related alloys for high temperature thermoelectric power generation. In the case of the half-Heusler alloys, transition metals were substituted to both the M and Ni/Co sites to study the resultant modifications of the d-orbital-rich portion of the electronic structure near the Fermi energy. This modification and subsequent pinning of the Fermi energy within the gap is discussed herein in terms of first principles electronic structure calculations from the literature. In the half-Heusler alloys, it was found that substitution of transition metals invariably led to a decrease in the thermopower, while the resistivity typically maintained its semiconducting trend. On the other hand, Sn doping in MCoSb type alloys -- a dopant that has been known for some time to be efficient -- was shown to result in high ZT at temperatures in excess of 1000 K. Moreover, the band gaps of the transition metal-doped alloys measured in this work offer insight into the discrepancy between the predicted and measured band gaps in the undoped parent compositions. In the case of the layered boride alloys, on the other hand, few electronic calculations have been published, thus prompting the generalization of a well-known electron counting rule -- which is typically used to study molecular organometallics, boranes, and metallocenes -- to predict the trends in the densities of states of crystalline solids that possess the requisite deltahedral bonding geometry. In accordance with these generalized electronic counting rules, alloys of the form RMB4 (R = Y, Gd, Ho; M = Cr, Mo, W) were measured to

  2. Synthesis of New Chiral Benzimidazolylidene–Rh Complexes and Their Application in Asymmetric Addition Reactions of Organoboronic Acids to Aldehydes

    Directory of Open Access Journals (Sweden)

    Weiping He

    2016-09-01

    Full Text Available A series of novel chiral N-heterocyclic carbene rhodium complexes (NHC–Rh based on benzimidazole have been prepared, and all of the NHC–Rh complexes were fully characterized by NMR and mass spectrometry. These complexes could be used as catalysts for the asymmetric 1,2-addition of organoboronic acids to aldehydes, affording chiral diarylmethanols with high yields and moderate enantioselectivities.

  3. Lattice constant changes leading to significant changes of the spin-gapless features and physical nature in a inverse Heusler compound Zr2MnGa

    Science.gov (United States)

    Wang, Xiaotian; Cheng, Zhenxiang; Khenata, Rabah; Wu, Yang; Wang, Liying; Liu, Guodong

    2017-12-01

    The spin-gapless semiconductors with parabolic energy dispersions [1-3] have been recently proposed as a new class of materials for potential applications in spintronic devices. In this work, according to the Slater-Pauling rule, we report the fully-compensated ferrimagnetic (FCF) behavior and spin-gapless semiconducting (SGS) properties for a new inverse Heusler compound Zr2MnGa by means of the plane-wave pseudo-potential method based on density functional theory. With the help of GGA-PBE, the electronic structures and the magnetism of Zr2MnGa compound at its equilibrium and strained lattice constants are systematically studied. The calculated results show that the Zr2MnGa is a new SGS at its equilibrium lattice constant: there is an energy gap between the conduction and valence bands for both the majority and minority electrons, while there is no gap between the majority electrons in the valence band and the minority electrons in the conduction band. Remarkably, not only a diverse physical nature transition, but also different types of spin-gapless features can be observed with the change of the lattice constants. Our calculated results of Zr2MnGa compound indicate that this material has great application potential in spintronic devices.

  4. The effect of Pd on martensitic transformation and magnetic properties for Ni50Mn38−xPdxSn12Heusler alloys

    Directory of Open Access Journals (Sweden)

    C. Jing

    2016-05-01

    Full Text Available In the past decade, Mn rich Ni-Mn based alloys have attained considerable attention due to their abundant physics and potential application as multifunctional materials. In this paper, polycrystalline Ni50Mn38−xPdxSn12 (x = 0, 2, 4, 6 Heusler alloys have been prepared, and the martensitic phase transformation (MPT together with the shape memory effect and the magnetocaloric effect has been investigated. The experimental result indicates that the MPT evidently shifts to a lower temperature with increase of Pd substitution for Mn atoms, which can be attributed to the weakness of the hybridization between the Ni atom and excess Mn on the Sn site rather than the electron concentration. The physics properties study focused on the sample of Ni50Mn34Pd4Sn12 shows a good two-way shape memory behavior, and the maximum value of strain Δ L/L reaches about 0.13% during the MPT. The small of both entropy change Δ ST and magnetostrain can be ascribed to the inconspicuous influence of magnetic field induced MPT.

  5. Effect of Coulomb interactions and Hartree-Fock exchange on structural, elastic, optoelectronic and magnetic properties of Co{sub 2}MnSi Heusler: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Lantri, T. [Laboratory of Technology and Solid’s Properties, Faculty of Sciences and Technology, Abdelhamid Ibn Badis University, BP 227, Mostaganem 27000 (Algeria); Bentata, S., E-mail: sam_bentata@yahoo.com [Laboratory of Technology and Solid’s Properties, Faculty of Sciences and Technology, Abdelhamid Ibn Badis University, BP 227, Mostaganem 27000 (Algeria); Bouadjemi, B.; Benstaali, W. [Laboratory of Technology and Solid’s Properties, Faculty of Sciences and Technology, Abdelhamid Ibn Badis University, BP 227, Mostaganem 27000 (Algeria); Bouhafs, B. [Modelling and Simulation in Materials Science Laboratory, Djillali Liabès University of Sidi Bel-Abbès, 22000 Sidi Bel-Abbes (Algeria); Abbad, A. [Laboratory of Technology and Solid’s Properties, Faculty of Sciences and Technology, Abdelhamid Ibn Badis University, BP 227, Mostaganem 27000 (Algeria); Modelling and Simulation in Materials Science Laboratory, Djillali Liabès University of Sidi Bel-Abbès, 22000 Sidi Bel-Abbes (Algeria); Zitouni, A. [Laboratory of Technology and Solid’s Properties, Faculty of Sciences and Technology, Abdelhamid Ibn Badis University, BP 227, Mostaganem 27000 (Algeria)

    2016-12-01

    Using the first-principle calculations, we have investigated the structural, elastic, optoelectronic and magnetic properties of Co{sub 2}MnSi Heusler alloy. Based on the density functional theory (DFT) and hiring the full-potential linearized augmented plane wave (FP-LAPW) method, we have used five approaches: the Hybrid on-site exact exchange, the Local Spin Density Approximation (LSDA), the LSDA+U, the Generalized Gradient Approximation GGA and GGA+U; where the Hubbard on-site Coulomb interaction correction U is calculated by constraint local density approximation for Co and Mn atoms. Our results show that the highly-ordered Co{sub 2}MnSi alloy is a ductile, stiff and anisotropic material. It has a half-metallic ferromagnetic character with an integer magnetic moment of 5 µB which is in good agreement with the Slater-Pauling rule. - Highlights: • Each approach gives a half magnetic compound. • EECE gives the largest gap. • Elastic properties show a stiff, ductile and anisotropic material. • Electronic properties are similar for the five approaches. • Total magnetic moment is the same for the five approaches (5 µB).

  6. Impact of local order and stoichiometry on the ultrafast magnetization dynamics of Heusler compounds

    International Nuclear Information System (INIS)

    Steil, Daniel; Schmitt, Oliver; Fetzer, Roman; Aeschlimann, Martin; Cinchetti, Mirko; Kubota, Takahide; Naganuma, Hiroshi; Oogane, Mikihiko; Ando, Yasuo; Rodan, Steven; Blum, Christian G F; Wurmehl, Sabine; Balke, Benjamin

    2015-01-01

    Nowadays, a wealth of information on ultrafast magnetization dynamics of thin ferromagnetic films exists in the literature. Information is, however, scarce on bulk single crystals, which may be especially important for the case of multi-sublattice systems. In Heusler compounds, representing prominent examples for such multi-sublattice systems, off-stoichiometry and degree of order can significantly change the magnetic properties of thin films, while bulk single crystals may be generally produced with a much more well-defined stoichiometry and a higher degree of ordering. A careful characterization of the local structure of thin films versus bulk single crystals combined with ultrafast demagnetization studies can, thus, help to understand the impact of stoichiometry and order on ultrafast spin dynamics.Here, we present a comparative study of the structural ordering and magnetization dynamics for thin films and bulk single crystals of the family of Heusler alloys with composition Co 2 Fe 1 − x Mn x Si. The local ordering is studied by 59 Co nuclear magnetic resonance (NMR) spectroscopy, while the time-resolved magneto-optical Kerr effect gives access to the ultrafast magnetization dynamics. In the NMR studies we find significant differences between bulk single crystals and thin films, both regarding local ordering and stoichiometry. The ultrafast magnetization dynamics, on the other hand, turns out to be mostly unaffected by the observed structural differences, especially on the time scale of some hundreds of femtoseconds. These results confirm hole-mediated spin-flip processes as the main mechanism for ultrafast demagnetization and the robustness of this demagnetization channel against defect states in the minority band gap as well as against the energetic position of the band gap with respect to the Fermi energy. The very small differences observed in the magnetization dynamics on the picosecond time-scale, on the other hand, can be explained by considering the

  7. Band structure and thermoelectric properties of half-Heusler semiconductors from many-body perturbation theory

    Science.gov (United States)

    Zahedifar, Maedeh; Kratzer, Peter

    2018-01-01

    Various ab initio approaches to the band structure of A NiSn and A CoSb half-Heusler compounds (A = Ti, Zr, Hf) are compared and their consequences for the prediction of thermoelectric properties are explored. Density functional theory with the generalized-gradient approximation (GGA), as well as the hybrid density functional HSE06 and ab initio many-body perturbation theory in the form of the G W0 approach, are employed. The G W0 calculations confirm the trend of a smaller band gap (0.75 to 1.05 eV) in A NiSn compared to the A CoSb compounds (1.13 to 1.44 eV) already expected from the GGA calculations. While in A NiSn materials the G W0 band gap is 20% to 50% larger than in HSE06, the fundamental gap of A CoSb materials is smaller in G W0 compared to HSE06. This is because G W0 , similar to PBE, locates the valence band maximum at the L point of the Brillouin zone, whereas it is at the Γ point in the HSE06 calculations. The differences are attributed to the observation that the relative positions of the d levels of the transition metal atoms vary among the different methods. Using the calculated band structures and scattering rates taking into account the band effective masses at the extrema, the Seebeck coefficients, thermoelectric power factors, and figures of merit Z T are predicted for all six half-Heusler compounds. Comparable performance is predicted for the n -type A NiSn materials, whereas clear differences are found for the p -type A CoSb materials. Using the most reliable G W0 electronic structure, ZrCoSb is predicted to be the most efficient material with a power factor of up to 0.07 W/(K2 m) at a temperature of 600 K. We find strong variations among the different ab initio methods not only in the prediction of the maximum power factor and Z T value of a given material, but also in comparing different materials to each other, in particular in the p -type thermoelectric materials. Thus we conclude that the most elaborate, but also most costly G W0

  8. {sup 103}Rh-NMR studies in the superconductor Rh{sub 17}S{sub 15}

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, T; Kanda, K; Ueda, K; Mito, T; Kohara, T [Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297 (Japan); Nakamura, H, E-mail: t-koyama@sci.u-hyogo.ac.j [Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501 (Japan)

    2010-01-15

    {sup 103}Rh nuclear magnetic resonance (NMR) measurements have been performed in the superconductor Rh{sub 17}S{sub 15} with the transition temperature T{sub C}=5.4 K. The observed {sup 103}Rh-NMR spectrum shows an asymmetric shape with several peaks, reflecting the local symmetry around each Rh site. We have identified the observed NMR lines corresponding to four different Rh sites and obtained the temperature (T) dependence of the Knight shift of 24m site. The isotropic part of the Knight shift K{sub iso} decreases with decreasing T, indicating the existence of the electron correlation in Rh{sub 17}S{sub 15}. In the superconducting state, the resonance lines shift to higher frequencies owing to a decrease of the spin part of the Knight shift with negative hyperfine coupling.

  9. Prenatal typing of Rh and Kell blood group system antigens: the edge of a watershed.

    Science.gov (United States)

    van der Schoot, C Ellen; Tax, G H Martine; Rijnders, Robbert J P; de Haas, Masja; Christiaens, Godelieve C M L

    2003-01-01

    Knowledge of the molecular basis of the blood group systems has enabled the development of assays for blood group genotyping. At this time, polymerase chain reaction (PCR)-based assays validated on fetal material obtained by invasive means (chorionic villus sampling or amniocentesis) are available for all clinically relevant fetal blood groups, However, only Rh typing (D, C, c, E, and e) and K1 genotyping assays are discussed in this review. Importantly, one must remember that results of genotyping assays will not always be concordant with serological typing. Thus, the RhD genotyping assays have to be modified in response to increased understanding of the molecular biology of this blood group system. RhD typing assays should produce negative results when tested on the black RhD-negative RHD alleles, RHDpsi and r's. PCR-based assays can be used to determine paternal zygosity. For RhD zygosity testing, the real-time quantitative PCR approach and the direct detection of the hybrid Rhesus box, which is the result of the deletion of the RHD gene are available. Recently, methods for noninvasive prenatal genotyping have been investigated. The use of fetal cells circulating in the maternal circulation has been explored; however, the scarcity of circulating fetal cells has limited the use of this approach. More promising are the results obtained with RhD typing assays with cell-free fetal DNA, which is present in the maternal circulation in a concentration of 25 genomic equivalents per milliliter of maternal blood in early pregnancy increasing to 100 copies per milliliter in the third trimester, which is cleared from the circulation within a few hours of delivery. The positive predictive value of this approach is virtually 100%, but false-negative results are (infrequently) encountered. Therefore, this assay can at present only be used for screening of RhD-negative women to make the use of antenatal prophylaxis more targeted and hence more cost-effective. For the clinical

  10. The Mechanism of Rh-Catalyzed Transformation of Fatty Acids to Linear Alpha olefins

    Directory of Open Access Journals (Sweden)

    Sondre H. Hopen Eliasson

    2017-12-01

    Full Text Available Linear alpha olefins (LAOs are key commodity chemicals and petrochemical intermediates that are currently produced from fossil resources. Fatty acids are the obvious renewable starting material for LAOs, which can be obtained via transition-metal-catalyzed decarbonylative dehydration. However, even the best catalysts that have been obtained to date, which are based on palladium, are not active and stable enough for industrial use. To provide insight for design of better catalysts, we here present the first computationally derived mechanism for another attractive transition-metal for this reaction, rhodium. By comparing the calculated mechanisms and free energy profiles for the two metals, Pd and Rh, we single out important factors for a facile, low-barrier reaction and for a stable catalyst. While the olefin formation is rate limiting for both of the metals, the rate-determining intermediate for Rh is, in contrast to Pd, the starting complex, (PPh32Rh(COCl. This complex largely draws its stability from the strength of the Rh(I–CO bond. CO is a much less suitable ligand for the high-oxidation state Rh(III. However, for steric reasons, rhodium dissociates a bulkier triphenylphosphine and keeps the carbonyl during the oxidative addition, which is less favorable than for Pd. When compared to Pd, which dissociates two phosphine ligands at the start of the reaction, the catalytic activity of Rh also appears to be hampered by its preference for high coordination numbers. The remaining ancillary ligands leave less space for the metal to mediate the reaction.

  11. Is a third-trimester antibody screen in Rh+ women necessary?

    Science.gov (United States)

    Rothenberg, J M; Weirermiller, B; Dirig, K; Hurd, W W; Schilder, J; Golichowski, A

    1999-09-01

    To determine the need for routine third-trimester antibody screening in Rh+ women. An analytic case-control study. We identified Rh+ pregnant women who had received prenatal care and retrospectively analyzed their laboratory data. Patients were grouped into those with a positive third-trimester antibody screen (cases) and those with a negative third-trimester screen (controls). Because entry into a group was decided by the investigators, it could not be randomized. We reviewed the maternal medical records for antibody identification and final pregnancy outcome. We also reviewed the neonatal medical records for evidence of direct Coombs-positive cord blood, anemia, need for transfusion or phototherapy, other medical complications, and death. Using a computerized laboratory database from 2 teaching hospitals, we identified 10,581 obstetric patients who underwent routine first- and third-trimester antibody screening between 1988 and 1997. Of these, 1233 patients were Rh- and 9348 were Rh+. Among the Rh+ patients, 178 (1.9%) had 1 or more atypical antibodies at the first-trimester screen, and 53 (0.6%) had a positive third-trimester antibody screen despite a negative first-trimester screen. Although 6 of these 53 patients (0.06% of the study population) had clinically relevant antibodies for hemolytic disease of the new-born, no significant neonatal sequelae occurred among these 6 patients. Based on the patient and hospital records studied, a repeat third-trimester antibody screen for Rh+ patients is clinically and economically unjustified. Eliminating this laboratory test from clinical practice will not adversely affect pregnancy outcomes and will decrease the costs of prenatal care.

  12. μSR and NMR study of the superconducting Heusler compound YPd2Sn

    Science.gov (United States)

    Saadaoui, H.; Shiroka, T.; Amato, A.; Baines, C.; Luetkens, H.; Pomjakushina, E.; Pomjakushin, V.; Mesot, J.; Pikulski, M.; Morenzoni, E.

    2013-09-01

    We report on muon-spin rotation and relaxation (μSR) and 119Sn nuclear magnetic resonance (NMR) measurements to study the microscopic superconducting and magnetic properties of the Heusler compound with the highest superconducting transition temperature, YPd2Sn (Tc=5.4 K). Measurements in the vortex state provide the temperature dependence of the effective magnetic penetration depth λ(T) and the field dependence of the superconducting gap Δ(0). The results are consistent with a very dirty s-wave BCS superconductor with a gap Δ(0)=0.85(3) meV, λ(0)=212(1) nm, and a Ginzburg-Landau coherence length ξGL(0)≅23 nm. In spite of its very dirty character, the effective density of condensed charge carriers is high compared to that in the normal state. The μSR data in a broad range of applied fields are well reproduced by taking into account a field-related reduction of the effective superconducting gap. Zero-field μSR measurements, sensitive to the possible presence of very small magnetic moments, do not show any indications of magnetism in this compound.

  13. Intermartensitic transitions in Ni-Mn-Fe-Cu-Ga Heusler alloys

    International Nuclear Information System (INIS)

    Khan, Mahmud; Gautam, Bhoj; Pathak, Arjun; Dubenko, Igor; Stadler, Shane; Ali, Naushad

    2008-01-01

    A series of Fe doped Ni 2 Mn 0.75-x Fe x Cu 0.25 Ga Heusler alloys have been investigated by means of x-ray diffraction, magnetizations, thermal expansion, and electrical resistivity measurements. In Ni 2 Mn 0.75 Cu 0.25 Ga, martensitic and ferromagnetic transitions occur at the same temperature. Partial substitution of Mn by Fe results in a decrease of the martensitic transition temperature, T M , and an increase of the ferromagnetic transition temperature, T C , resulting in separation of the two transitions. In addition to the martensitic transition, complete thermoelastic intermartensitic transformations have been observed in the Fe doped Ni 2 Mn 0.75-x Fe x Cu 0.25 Ga samples with x>0.04. An unusual transition is observed in the alloy with x = 0.04. The magnetization curve as a function of increasing temperature shows only one first-order transition in the temperature range 5-400 K, which is identified as a typical coupled magnetostructural martensitic transformation. The magnetization curve as a function of decreasing temperature shows three different transitions, which are characterized as the ferromagnetic transition, the martensitic transition and the intermartensitic transition.

  14. Spin transport at high temperatures in epitaxial Heusler alloy/n-GaAs lateral spin valves

    Science.gov (United States)

    Peterson, Timothy A.; Christie, Kevin D.; Patel, Sahil J.; Crowell, Paul A.; Palmstrøm, Chris J.

    2015-03-01

    We report on electrical injection and detection of spin accumulation in ferromagnet/ n-GaAs lateral spin-valve devices, observed up to and above room temperature. The ferromagnet in these measurements is the Heusler alloy Co2FeSi, and the semiconductor channel is GaAs doped at 3 ×1016 cm-3. The spin signal is enhanced by operating the detection contact under forward bias. The enhancement originates from drift effects at low-temperatures and an increase of the detection efficiency at all temperatures. The detector bias dependence of the observed spin-valve signal is interpreted by taking into account the quantum well (QW) which forms in the degenerately doped region immediately behind the Schottky tunnel barrier. In particular, we believe the QW is responsible for the minority spin accumulation (majority spin current) under large forward bias. The spin diffusion length and lifetime are determined by measuring the separation dependence of the non-local spin valve signal in a family of devices patterned by electron beam lithography. A spin diffusion length of 700 nm and lifetime of 46 picoseconds are found at a temperature of 295 K. This work was supported by the NSF under DMR-1104951, the NSF MRSEC program and C-SPIN, a SRC STARNET center sponsored by MARCO and DARPA.

  15. Materials Screening for the Discovery of New Half-Heuslers: Machine Learning versus ab Initio Methods.

    Science.gov (United States)

    Legrain, Fleur; Carrete, Jesús; van Roekeghem, Ambroise; Madsen, Georg K H; Mingo, Natalio

    2018-01-18

    Machine learning (ML) is increasingly becoming a helpful tool in the search for novel functional compounds. Here we use classification via random forests to predict the stability of half-Heusler (HH) compounds, using only experimentally reported compounds as a training set. Cross-validation yields an excellent agreement between the fraction of compounds classified as stable and the actual fraction of truly stable compounds in the ICSD. The ML model is then employed to screen 71 178 different 1:1:1 compositions, yielding 481 likely stable candidates. The predicted stability of HH compounds from three previous high-throughput ab initio studies is critically analyzed from the perspective of the alternative ML approach. The incomplete consistency among the three separate ab initio studies and between them and the ML predictions suggests that additional factors beyond those considered by ab initio phase stability calculations might be determinant to the stability of the compounds. Such factors can include configurational entropies and quasiharmonic contributions.

  16. Magnetic and transport properties of granular and Heusler-type glass-coated microwires

    Energy Technology Data Exchange (ETDEWEB)

    Zhukov, Arcady, E-mail: arkadi.joukov@ehu.es [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20018 San Sebastian (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain); Garcia, Carlos [Bogazici Univ., Dept. Phys., TR-34342 Istanbul (Turkey); Ilyn, Maxim [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20018 San Sebastian (Spain); Varga, Rastislav [Inst. Phys., Fac. Sci., UPJS, Park Angelinum 9, Kosice (Slovakia); Val, Juan Jose del [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20018 San Sebastian (Spain); Granovsky, Alexander [IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain); Moscow State University, Moscow 119991 (Russian Federation); Rodionova, Valeria [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20018 San Sebastian (Spain); Moscow State University, Moscow 119991 (Russian Federation); Ipatov, Mihail; Zhukova, Valentina [Dpto. Fisica de Materiales, Fac. Quimicas, UPV/EHU, 20018 San Sebastian (Spain)

    2012-10-15

    We studied magnetic and structural properties of granular Co{sub x}Cu{sub 100-x} (5Heusler-type Ni{sub 2}MnGa glass-coated microwires. We found that the structure of Co-Cu microwires consists of two phases: fcc Cu for all the samples and fcc {alpha}-Co present for higher Co content. In the case of low Co content, Co atoms are distributed within the Cu matrix. The quantity and the size of grains strongly depend on the geometry of the microwire. Co-Cu and Fe-Cu microwires exhibited considerable magnetoresistance (MR). For Co{sub x}Cu{sub 100-x} microwires at x{>=}30 the anisotropic contribution to MR has been observed. Temperature dependences of magnetization measured without an external magnetic field (ZFC) and in the presence of a field (FC) show considerable difference below 20 K, indicating the presence of small {alpha}-Fe or Co grains embedded in the Cu matrix. Annealed Ni{sub 2}MnGa microwires showed ferromagnetic behavior with Curie temperature about 330 K and polycrystalline structure with space group I4/mmm and lattice parameters a=3.75 A and c=6.78 A.

  17. Magnetic and transport properties of granular and Heusler-type glass-coated microwires

    International Nuclear Information System (INIS)

    Zhukov, Arcady; Garcia, Carlos; Ilyn, Maxim; Varga, Rastislav; Val, Juan Jose del; Granovsky, Alexander; Rodionova, Valeria; Ipatov, Mihail; Zhukova, Valentina

    2012-01-01

    We studied magnetic and structural properties of granular Co x Cu 100−x (5 63 Fe 37 and Heusler-type Ni 2 MnGa glass-coated microwires. We found that the structure of Co–Cu microwires consists of two phases: fcc Cu for all the samples and fcc α-Co present for higher Co content. In the case of low Co content, Co atoms are distributed within the Cu matrix. The quantity and the size of grains strongly depend on the geometry of the microwire. Co–Cu and Fe–Cu microwires exhibited considerable magnetoresistance (MR). For Co x Cu 100−x microwires at x≥30 the anisotropic contribution to MR has been observed. Temperature dependences of magnetization measured without an external magnetic field (ZFC) and in the presence of a field (FC) show considerable difference below 20 K, indicating the presence of small α-Fe or Co grains embedded in the Cu matrix. Annealed Ni 2 MnGa microwires showed ferromagnetic behavior with Curie temperature about 330 K and polycrystalline structure with space group I4/mmm and lattice parameters a=3.75 Å and c=6.78 Å.

  18. Magnetotransport properties of Ni-Mn-In Heusler Alloys: Giant Hall angle

    Energy Technology Data Exchange (ETDEWEB)

    Dubenko, I; Pathak, A K; Ali, N [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Kovarskii, Y A; Prudnikov, V N; Perov, N S; Granovsky, A B, E-mail: granov@magn.r [Faculty of Physics, Moscow State University, Moscow, 111991 (Russian Federation)

    2010-01-01

    We report experimental results on phase transitions, magnetic properties, resistivity, and Hall effect in Ni{sub 50}Mn{sub 50-x}In{sub x} (15Heusler alloys. Several distinguishing features of magnetotransport properties were clearly observed in the vicinity of the first order structural martensitic transition at T{sub M} and the ferromagnetic-paramagnetic transition at the Curie temperature T{sub C} of the austenitic phase. It was found that the Hall resistivity {rho}{sub H}(at H = 15 kOe) is positive in martensitic and negative in austenitic phase, sharply increases in the vicinity of T{sub M} up to {rho}{sub H}(15 kOe)= 50 {mu}{Omega}{center_dot}cm. This value is almost two orders of magnitude larger than that observed at high temperature (T{approx}200 K) for any common magnetic materials, and comparable to the giant Hall effect resistivity in magnetic nanogranular alloys. The Hall angle {Theta}{sub H}=tan{sup -} {sup 1}({rho}{sub H}/{rho}) close to T{sub M} reaches tan{sup -1}(0.5) which is the highest value for known magnetic materials.

  19. Magnetic and thermodynamic properties of Heusler alloys Ni55Mn26Al19

    Science.gov (United States)

    Ito, Masakazu; Onda, Keijiro; Taira, Atsushi; Sonoda, Kazuki; Hiroi, Masahiko; Uwatoko, Yoshiya

    2018-05-01

    The temperature dependence of magnetization, M(T), specific heat, Cp(T), and thermal expansion, ΔL/L300K(T) were investigated for the Heusler compound Ni55Mn26Al19 with B2 structure. M(T) has a cusp-type anomaly for the antiferromagnetic (AF) transition at the Néel temperature TN = 280 K that is irreversible between the field-cooled and zero-field-cooled processes below Tf ˜ 60 K, which is characteristic of spin glass. Cp(T) also has an anomaly at TN = 280 K. For temperatures T transformation. TN increases proportionally with pressure, P, because of the enhancement of the AF interaction. The value of its initial rate is estimated to be d/TN d P = 5.25 K/GPa. Tf also increases proportionally with P with d/Tf d P = 2.21 K/GPa, and hence magnetic frustration, which promotes the spin glass system, is enhanced under pressurization.

  20. Structural, transport, magnetic, magnetocaloric properties and critical analysis of Ni-Co-Mn-Ga Heusler alloys

    Science.gov (United States)

    Arumugam, S.; Devarajan, U.; Esakki Muthu, S.; Singh, Sanjay; Thiyagarajan, R.; Raja, M. Manivel; Rama Rao, N. V.; Banerjee, Alok

    2017-11-01

    In this work, we have investigated structural, transport, magnetic, magnetocaloric (MC) properties and critical exponents analysis of the (Ni2.1-xCox)Mn0.9 Ga (x = 0, 0.04, 0.12 and 0.2) Heusler alloys. For all compositions, cubic austenite (A) phase with metallic character is observed at room temperature (RT). With increasing of Co content, magnitude of resistivity decreases, whereas residual resistivity (ρ0) and electron scattering factor (A) increases linearly. Magnetic measurements exhibit that ferromagnetic (FM) Curie temperature (TCA) increases towards RT by increasing Co concentration. All samples show conventional MC and maximum magnetic entropy change (ΔSMpeak) of -2.8 Jkg-1 K-1 is observed for x = 0.12 at 147 K under 5 T. Further, hysteresis is observed between cooling and warming cycles around FM-PM (TCA) transition in x = 0, 0.04 samples, which suggests that first order nature of transition. However, there is no hysteresis across TCA for x = 0.12 and 0.2 samples suggesting second-order nature of the transition. The critical exponents are calculated for x = 0.12 sample around TCA using Arrott plot and Kouvel-Fisher method, the estimated critical exponents are found closer to the mean-field model reveals the long range ferromagnetic ordering in this composition.

  1. Structural, magnetic and transport properties of Co2FeAl Heusler films with varying thickness

    International Nuclear Information System (INIS)

    Wang, Xiaotian; Li, Yueqing; Du, Yin; Dai, Xuefang; Liu, Guodong; Liu, Enke; Liu, Zhongyuan; Wang, Wenhong; Wu, Guangheng

    2014-01-01

    We report on a systematic study of the structural, magnetic properties and the anomalous Hall effect, in the Heusler alloy Co 2 FeAl (CFA) epitaxial films on MgO (001), as a function of film thickness. It was found that the epitaxial CFA films show a highly ordered B2 structure with an in-plane uniaxial magnetic anisotropy. The electrical transport properties reveal that the lattice and magnon scattering contributions to the longitudinal resistivity. Independent on the thickness of films, the anomalous Hall resistivity of CFA films is found to be dominated by skew scattering only. Moreover, the anomalous Hall resistivity shows weakly temperature dependent behavior, and its absolute value increases as the thickness decreases. We attribute this temperature insensitivity in the anomalous Hall resistivity to the weak temperature dependent of tunneling spin-polarization in the CFA films, while the thickness dependence behavior is likely due to the increasing significance of interface or free surface electronic states. - Highlights: ●Highly ordered CFA films with various thicknesses were prepared on MgO substrates. ●The magnon scattering contributions to the longitudinal resistivity in the CFA films. ●The anomalous Hall resistivity of the CFA films shows weakly temperature dependent. ●The CFA films show weak temperature dependent of tunneling spin-polarization

  2. High electron mobility and large magnetoresistance in the half-Heusler semimetal LuPtBi

    KAUST Repository

    Hou, Zhipeng

    2015-12-18

    Materials with high carrier mobility showing large magnetoresistance (MR) have recently received much attention because of potential applications in future high-performance magnetoelectric devices. Here, we report on an electron-hole-compensated half-Heusler semimetal LuPtBi that exhibits an extremely high electron mobility of up to 79000cm2/Vs with a nonsaturating positive MR as large as 3200% at 2 K. Remarkably, the mobility at 300 K is found to exceed 10500cm2/Vs, which is among the highest values reported in three-dimensional bulk materials thus far. The clean Shubnikov–de Haas quantum oscillation observed at low temperatures and the first-principles calculations together indicate that the high electron mobility is due to a rather small effective carrier mass caused by the distinctive band structure of the crystal. Our findings provide a different approach for finding large, high-mobility MR materials by designing an appropriate Fermi surface topology starting from simple electron-hole-compensated semimetals.

  3. Growth dependent magnetization reversal in Co2MnAl full Heusler alloy thin films

    Science.gov (United States)

    Barwal, Vineet; Husain, Sajid; Behera, Nilamani; Goyat, Ekta; Chaudhary, Sujeet

    2018-02-01

    Angular dependent magnetization reversal has been investigated in Co2MnAl (CMA) full Heusler alloy thin films grown on Si(100) at different growth temperatures (Ts) by DC-magnetron sputtering. An M -shaped curve is observed in the in-plane angular (0°-360°) dependent coercivity (ADC) by magneto-optical Kerr effect measurements. The dependence of the magnetization reversal on Ts is investigated in detail to bring out the structure-property correlation with regards to ADC in these polycrystalline CMA thin films. This magnetization reversal ( M -shaped ADC behavior) is well described by the two-phase model, which is a combination of Kondorsky (domain wall motion) and Stoner Wohlfarth (coherent rotation) models. In this model, magnetization reversal starts with depinning of domain walls, with their gradual displacement explained by the Kondorsky model, and at a higher field (when the domain walls merge), the system follows coherent rotation before reaching its saturation following the Stoner Wohlfarth model. Further, the analysis of angular dependent squareness ratio (Mr/Ms) indicates that our films clearly exhibited twofold uniaxial anisotropy, which is related to self-steering effect arising due to the obliquely incident flux during the film-growth.

  4. Electronic structure, magnetism and disorder in the Heusler compound Co2TiSn

    International Nuclear Information System (INIS)

    Kandpal, Hem Chandra; Ksenofontov, Vadim; Wojcik, Marek; Seshadri, Ram; Felser, Claudia

    2007-01-01

    Polycrystalline samples of the Heusler compound Co 2 TiSn have been prepared and studied using bulk techniques (x-ray diffraction and magnetization) as well as local probes ( 119 Sn Moessbauer spectroscopy and 59 Co nuclear magnetic resonance spectroscopy) in order to determine how disorder affects the half-metallic behaviour and also to establish the joint use of Moessbauer and NMR spectroscopies as a quantitative probe of local atom ordering in these compounds. Additionally, density functional electronic structure calculations on ordered and partially disordered Co 2 TiSn compounds have been carried out at a number of different levels of theory in order to simultaneously understand how the particular choice of DFT scheme as well as disorder affects the computed magnetization. Our studies suggest that a sample which seems well ordered by x-ray diffraction and magnetization measurements can possess up to 10% of antisite (Co/Ti) disordering. Computations similarly suggest that even 12.5% antisite Co/Ti disorder does not destroy the half-metallic character of this material. However, the use of an appropriate level of non-local DFT is crucial

  5. Synthesize and microstructure characterization of Ni43Mn41Co5Sn11 Heusler alloy

    International Nuclear Information System (INIS)

    Elwindari, Nastiti; Manaf, Azwar

    2016-01-01

    The ferromagnetic heusler alloys are promising materials in many technical applications due to their multifunctional properties such as shape memory effect, magnetocaloric effect, giant magnetoresistance, etc. In this work, synthesize and characterization of polycrystalline Ni 43 Mn 41 Co 5 Sn 11 (NMCS) alloy are reported. Alloy preparation was conducted by melting the constitute elements under an innert Argon (Ar) atmosphere in a vacuum mini arc-melting furnace. Homogenization of the microstructure of the as-cast ingot was obtained after annealing process at 750°C for 48 hours. It is shown that the dendrites structure has changed to equaixed grains morphology after homogenization. Microstructure characteristics of material by x-ray diffraction revealed that the alloy has a L 21 -type cubic crystal structure as the main phase at room temperature. In order to induce the shape anisotropy, a forging treatment was applied to show the shape orientation of material. Various enhancements of magnetic properties in a longitudinal direction were observed at various degree of anisotropy. The microstructure changes of as-cast NMCS and effects of homogenization treatments as studied by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) are discussed in details.

  6. Large magnetoresistance in Er7Rh3

    International Nuclear Information System (INIS)

    Sengupta, Kaushik; Sampathkumaran, E.V.

    2005-01-01

    The compound Er 2 Rh 3 has been known to order antiferromagnetically below (T N =14K), and to exhibit a change in the sign of temperature coefficient of electrical resistivity (ρ) in the paramagnetic state around 120 K. Here we report the influence of external magnetic field (H) on the ρ(T) behavior of this compound (1.8-300 K). While the ρ behavior in the paramagnetic state, qualitatively speaking, is found to be robust to the application of H, the magnitude of the magnetoresistance (MR) is significant for moderate applications of H, even at temperatures for above T N untypical of metallic systems. In addition, large values are observed in the magnetically ordered state. (author)

  7. Investigation to determine the absolute sensitivity of Rh SPNDs

    International Nuclear Information System (INIS)

    Adorian, F.; Patai Szabo, S.; Pos, I.

    1998-01-01

    The goal of the work was to find an empirical sensitivity function of the Rh SPNDs used in VVER-440 reactors and to investigate the accuracy and adequateness of the detector signal predicting capability of the associated model. In our case the model was based on the HELIOS transport code and the C-PORCA nodal code. A statistical sensitivity analysis versus some selected parameters (e.g. enrichment, burn-up) has been carried out by using a substantial amount of measured data. We also investigated the stability of the electron collecting probability of the detectors versus their burn-up and other parameters with the aim of obtaining a tuned semi-empirical formula for the detector burnup correction. (Authors)

  8. Electronic, magnetic and thermal properties of Co{sub 2}Cr{sub x}Fe{sub 1−x}X (X=Al, Si) Heusler alloys: First-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Guezlane, M. [Department of Physics, Faculty of Science, University of Batna, 05000 Batna (Algeria); Baaziz, H., E-mail: baaziz_hakim@yahoo.fr [Physics Department, Faculty of Science, University of M' sila, 28000 M' sila (Algeria); El Haj Hassan, F., E-mail: hassan.f@ul.edu.lb [Université Libanaise, Faculté des Sciences (I), Laboratoire de Physique et d’Electronique (LPE), Elhadath, Beirut (Lebanon); Charifi, Z. [Physics Department, Faculty of Science, University of M' sila, 28000 M' sila (Algeria); Djaballah, Y. [Laboratoire d’étude Physico-Chimique des Matériaux, Département de Physique, Faculté des Sciences, Université de Batna, Rue Chahid Boukhlouf, 05000 Batna (Algeria)

    2016-09-15

    Density functional theory (DFT) based on the full-potential linearized augmented plane wave (FP-LAPW) method is used to investigate the structural, electronic, magnetic and thermal properties of Co{sub 2}Cr{sub x}Fe{sub 1−x}X (X=Al, Si) full Heusler alloys, with L2{sub 1} structure. The structural properties and spin magnetic moments are investigated by the generalized gradient approximations (GGA) minimizing the total energy. For band structure calculations, GGA, the Engel–Vosko generalized gradient approximation (EVGGA) and modified Becke–Johnson (mBJ) schemes are used. Results of density of states (DOS) and band structures show that these alloys are half-metallic ferromagnets (HMFS). A regular-solution model has been used to investigate the thermodynamic stability of the compounds Co{sub 2}Cr{sub x}Fe{sub 1−x}X that indicates a phase miscibility gap. The thermal effects using the quasi-harmonic Debye model are investigated within the lattice vibrations. The temperature and pressure effects on the heat capacities, Debye temperatures and entropy are determined from the non-equilibrium Gibbs functions. - Highlights: • We present electronic, magnetic and thermal properties of Co{sub 2}Cr{sub x}Fe{sub 1−x}X (X=Al, Si) Heusler alloys. • The calculated phase diagram indicates a significant phase miscibility gap. • The computed band structures of ternary compounds using GGA, EVGGA and mBJ schemes indicate an indirect band gap (Γ-X) for the ternary compounds Co{sub 2}FeAl, Co{sub 2}CrAl, Co{sub 2}FeSi and Co{sub 2}CrSi while both alloys have a direct band gap. • The quasi-harmonic Debye model is successfully applied to determine the thermal properties.

  9. Rh Factor: How It Can Affect Your Pregnancy

    Science.gov (United States)

    ... father or the mother. Can the Rh factor cause problems during pregnancy? Yes. During pregnancy, problems can occur if you ... can die from anemia. Can the Rh factor cause problems during my first pregnancy? Health problems usually do not occur during an ...

  10. Photoelectrochemical properties of LaRhO3

    International Nuclear Information System (INIS)

    Viswanathan, B.; Narayanan, S.R.; Viswanath, R.P.; Varadrajan, T.K.

    1982-01-01

    The photoelectrochemical properties of LaRhO 3 at different values of pH were studied by current-voltage measurements and cyclic voltammetry and the results obtained are compared with those obtained for LaRhO 3 , a potential photoelectrode. (author)

  11. GnRH injection before artificial insemination (AI) alters follicle ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... releasing hormone (GnRH) injection on day 6 of the estrous cycle. The estrous cycles ... follicle at the time of GnRH injection (Silcox et al., 1993;. Twagiramungu .... Waves and their Effect on pregnancy rate in the Cow. Reprod.

  12. Influence of defects and disorder on anomalous Hall effect and spin Seebeck effect on permalloy and Heusler compounds

    Energy Technology Data Exchange (ETDEWEB)

    Vilanova Vidal, Enrique

    2012-09-19

    In this work Heusler thin films have been prepared and their transport properties have been studied. Of particularly interest is the anomalous Hall effect (AHE). The effect is a long known but still not fully understood transport effect. Most theory papers focus on the influence of one particular contribution to the AHE. Actual measured experimental data, however, often are not in accordance with idealized assumptions. This thesis discusses the data analysis for materials with low residual resistivity ratios. As prototypical materials, half metallic Heusler compounds are studied. Here, the influence of defects and disorder is apparent in a material with a complex topology of the Fermi surface. Using films with different degrees of disorder, the different scattering mechanisms can be separated. For Co{sub 2}FeSi{sub 0.6}Al{sub 0.4} and Co{sub 2}FeGa{sub 0.5}Ge{sub 0.5}, the AHE induced by B2-type disorder and temperature-dependent scattering is positive, while DO{sub 3}-type disorder and possible intrinsic contributions possess a negative sign. For these compounds, magneto-optical Kerr effects (MOKE) are investigated. First order contributions as a function of intrinsic and extrinsic parameters are qualitatively analyzed. The relation between the crystalline ordering and the second order contributions to the MOKE signal is studied. In addition, sets of the Heusler compound Co{sub 2}MnAl thin films were grown on MgO(100) and Si(100) substrates by radio frequency magnetron sputtering. Composition, magnetic and transport properties were studied systematically for samples deposited at different conditions. In particular, the anomalous Hall effect resistivity presents an extraordinarily temperature independent behavior in a moderate magnetic field range from 0 to 0.6 T. The off-diagonal transport at temperatures up to 300 C was analyzed. The data show the suitability of the material for Hall sensors working well above room temperature. Recently, the spin Seebeck effect

  13. Low-temperature electron properties of Heusler alloys Fe2VAl and Fe2CrAl: Effect of annealing

    International Nuclear Information System (INIS)

    Podgornykh, S. M.; Svyazhin, A. D.; Shreder, E. I.; Marchenkov, V. V.; Dyakina, V. P.

    2007-01-01

    We present the results of measurements of low-temperature heat capacity, as well as electrical and magnetic properties of Heusler alloys Fe 2 VAl and Fe 2 CrAl prepared in different ways using various heat treatment regimes. The density of states at the Fermi level is estimated. A contribution of ferromagnetic clusters in the low-temperature heat capacity of the Fe 2 VAl alloy is detected. The change in the number and volume of clusters as a result of annealing of an alloy affects the behavior of their low-temperature heat capacity, resistivity, and magnetic properties

  14. Co2FeSi Heusler alloy prepared by arc melting and planar flow casting methods: microstructure and magnetism.

    Czech Academy of Sciences Publication Activity Database

    Titov, Andrii; Životský, O.; Hendrych, A.; Janičkovič, D.; Buršík, Jiří; Jirásková, Yvonna

    2017-01-01

    Roč. 131, č. 4 (2017), s. 654-656 ISSN 0587-4246. [CSMAG 2016 - Czech and Slovak Conference on Magnetism /16./. Košice, 13.06.2016-17.06.2016] Institutional support: RVO:68081723 Keywords : Heusler alloy * Surface morphology * Magnetic properties * Arc melting * Planar flow casting Subject RIV: BM - Solid Matter Physics ; Magnetism; BM - Solid Matter Physics ; Magnetism (UFM-A) OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 0.469, year: 2016

  15. Magnetism and electronic transport in (Cu,Ni)2MnSn Heusler alloys under ambient and elevated pressures

    Czech Academy of Sciences Publication Activity Database

    Bose, S. K.; Kudrnovský, Josef; Drchal, Václav

    2011-01-01

    Roč. 8, Suppl. 1 (2011), P137/1-P137/7 ISSN 1708-5284 R&D Projects: GA ČR GA202/09/0775 Institutional research plan: CEZ:AV0Z10100520 Keywords : Curie temprature * resistivity * spin-disorder resistivity * Heusler alloys * first-principles Subject RIV: BM - Solid Matter Physics ; Magnetism http://wjoe.hebeu.edu.cn/sup.1.2011/B/Bose,%20S.K.%20(Brock%20U.,%20Ontario,%20Canada)%20137.pdf

  16. Photonuclear excitation of 103Rh by synchrotron radiation

    International Nuclear Information System (INIS)

    Yoshihara, Kenji; Kaji, Harumi; Sekine, Tsutomu; Mukoyama, Takeshi

    1989-01-01

    Photonuclear excitation of the 103 Rh nucleus was studied using synchrotron radiation. Formation of the excited state was confirmed by observing K X-rays emitted following the isomeric transition of the 103m Rh with a low-energy photon spectrometer. The intensity of induced activity due to 103 Rh(γ,γ') 103m Rh reaction was determined carefully by subtracting the fluorescent K X-rays due to natural background radiation. The integral cross-section for isomer production of 103m Rh by resonance absorption of photons at 295 keV is found to be (2.1±0.8) x 10 -28 cm 2 eV and is compared with that estimated from the previous experimental value for the 1277-keV level. (author)

  17. Recombinant human GLP-1(rhGLP-1) alleviating renal tubulointestitial injury in diabetic STZ-induced rats.

    Science.gov (United States)

    Yin, Weiqin; Xu, Shiqing; Wang, Zai; Liu, Honglin; Peng, Liang; Fang, Qing; Deng, Tingting; Zhang, Wenjian; Lou, Jinning

    2018-01-01

    GLP-1-based treatment improves glycemia through stimulation of insulin secretion and inhibition of glucagon secretion. Recently, more and more findings showed that GLP-1 could also protect kidney from diabetic nephropathy. Most of these studies focused on glomeruli, but the effect of GLP-1 on tubulointerstitial and tubule is not clear yet. In this study, we examined the renoprotective effect of recombinant human GLP-1 (rhGLP-1), and investigated the influence of GLP-1 on inflammation and tubulointerstitial injury using diabetic nephropathy rats model of STZ-induced. The results showed that rhGLP-1 reduced urinary albumin without influencing the body weight and food intake. rhGLP-1 could increased the serum C-peptide slightly but not lower fasting blood glucose significantly. In diabetic nephropathy rats, beside glomerular sclerosis, tubulointerstitial fibrosis was very serious. These lesions could be alleviated by rhGLP-1. rhGLP-1 decreased the expression of profibrotic factors collagen I, α-SMA, fibronectin, and inflammation factors MCP-1 and TNFα in tubular tissue and human proximal tubular cells (HK-2 cells). Furthermore, rhGLP-1 significantly inhibited the phosphorylation of NF-κB, MAPK in both diabetic tubular tissue and HK-2 cells. The inhibition of the expression of TNFα, MCP-1, collagen I and α-SMA in HK-2 cells by GLP-1 could be mimicked by blocking NF-κB or MAPK. These results indicate that rhGLP-1 exhibit renoprotective effect by alleviation of tubulointerstitial injury via inhibiting phosphorylation of MAPK and NF-κB. Therefore, rhGLP-1 may be a potential drug for treatment of diabetic nephropathy. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Activity of PtSnRh/C nanoparticles for the electrooxidation of C1 and C2 alcohols

    International Nuclear Information System (INIS)

    Teran, Freddy E.; Santos, Deise M.; Ribeiro, Josimar; Kokoh, Kouakou B.

    2012-01-01

    A systematic investigation of alcohol adsorption and oxidation on binary and ternary electrocatalysts in acid medium was performed. Binary (PtRh) and ternary (PtRhSn) were prepared by the Pechini modified method on carbon Vulcan XC-72, and different nominal compositions were characterized by energy dispersive X-ray and X-ray diffraction (XRD) techniques. The XRD results showed that the Pt 80 Rh 20 /C and Pt 70 Sn 10 Rh 20 /C electrocatalysts consisted of the Pt displaced phase, suggesting the formation of a solid solution between the metals Pt/Rh and Pt/Sn. Electrochemical investigations on these different electrode materials were carried out as a function of the electrocatalyst composition, in acid medium (0.5 mol dm −3 H 2 SO 4 ), and in the absence and presence of different alcohols (methanol, ethanol and ethylene glycol). The electrochemical results obtained at room temperature have shown that the Pt 70 Sn 10 Rh 20 /C catalyst display better catalytic activity for alcohol oxidation compared with the binary catalyst. In situ reflectance infrared spectroscopy measurements have shown that the oxidation of alcohols mentioned produced CO 2 at low potentials indicating that the materials synthesized could be used as efficient anodes in the fuel cell applications. - Highlights: ► Pt-based catalysts were synthesized by thermal decomposition polymeric precursors. ► Pt 70 Sn 10 Rh 20 /C displays better catalytic activity for the oxidation of alcohols. ► The co-catalysts tin and rhodium promote the removal of CO to CO 2 at low potentials. ► Ethylene glycol is oxidizing strongly to CO 2 at low potentials. ► Pt 70 Sn 10 Rh 20 /C catalyst is an efficient anode material for a direct alcohol fuel cell.

  19. Administration of single-dose GnRH agonist in the luteal phase in ICSI cycles: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Oliveira João

    2010-09-01

    Full Text Available Abstract Background The effects of gonadotrophin-releasing hormone agonist (GnRH-a administered in the luteal phase remains controversial. This meta-analysis aimed to evaluate the effect of the administration of a single-dose of GnRH-a in the luteal phase on ICSI clinical outcomes. Methods The research strategy included the online search of databases. Only randomized studies were included. The outcomes analyzed were implantation rate, clinical pregnancy rate (CPR per transfer and ongoing pregnancy rate. The fixed effects model was used for odds ratio. In all trials, a single dose of GnRH-a was administered at day 5/6 after ICSI procedures. Results All cycles presented statistically significantly higher rates of implantation (P Conclusions These findings demonstrate that the luteal-phase single-dose GnRH-a administration can increase implantation rate in all cycles and CPR per transfer and ongoing pregnancy rate in cycles with GnRH antagonist ovarian stimulation protocol. Nevertheless, by considering the heterogeneity between the trials, it seems premature to recommend the use of GnRH-a in the luteal phase. Additional randomized controlled trials are necessary before evidence-based recommendations can be provided.

  20. Preparation of Rh/Ag bimetallic nanoparticles as effective catalyst for hydrogen generation from hydrolysis of KBH4

    Science.gov (United States)

    Huang, Liang; Jiao, Chengpeng; Wang, Liqiong; Huang, Zili; Liang, Feng; Liu, Simin; Wang, Yuhua; Zhang, Haijun; Zhang, Shaowei

    2018-01-01

    ISOBAM-104 protected Rh/Ag bimetallic nanoparticles (NPs) with average diameter less than 3.0 nm were synthesized by a co-reduction method. Ultraviolet-visible spectroscopy, transmission electron microscopy (TEM), high-resolution TEM and x-ray photoelectron spectroscopy (XPS) were employed to characterize the structure, particle size, and electronic structure of the prepared bimetallic NPs. The catalytic activities of prepared bimetallic NPs for hydrogen generation from hydrolysis of a basic KBH4 solution were evaluated in detail. The results indicated that as-prepared Rh/Ag bimetallic NPs showed a higher catalytic activity than corresponding monometallic NPs. Among all the monometallic NPs and bimetallic NPs, Rh80Ag20 bimetallic NPs exhibited the highest catalytic activity with a value of 6010 mol-H2·h-1·mol-catalyst-1 at pH = 12 and 303 K. The high catalytic activities of Rh/Ag bimetallic NPs could be attributed to presence of negatively charged Rh atoms and positively charged Ag atoms, which is supported by the results of XPS and density functional theory calculation. Based on the kinetic study, the apparent activation energy for the hydrolysis reaction of the basic KBH4 solution catalyzed by Rh80Ag20 bimetallic NPs was about 47.0 ± 3.9 kJ mol-1.

  1. GnRH agonist versus GnRH antagonist in in vitro fertilization and embryo transfer (IVF/ET

    Directory of Open Access Journals (Sweden)

    Depalo Raffaella

    2012-04-01

    Full Text Available Abstract Several protocols are actually available for in Vitro Fertilization and Embryo Transfer. The review summarizes the main differences and the clinic characteristics of the protocols in use with GnRH agonists and GnRH antagonists by emphasizing the major outcomes and hormonal changes associated with each protocol. The majority of randomized clinical trials clearly shows that in “in Vitro” Fertilization and Embryo Transfer, the combination of exogenous Gonadotropin plus a Gonadotropin Releasing Hormone (GnRH agonist, which is able to suppress pituitary FSH and LH secretion, is associated with increased pregnancy rate as compared with the use of gonadotropins without a GnRH agonist. Protocols with GnRH antagonists are effective in preventing a premature rise of LH and induce a shorter and more cost-effective ovarian stimulation compared to the long agonist protocol. However, a different synchronization of follicular recruitment and growth occurs with GnRH agonists than with GnRH antagonists. Future developments have to be focused on timing of the administration of GnRH antagonists, by giving a great attention to new strategies of stimulation in patients in which radio-chemotherapy cycles are needed.

  2. Hydrodeoxygenation of Phenol to Benzene and Cyclohexane on Rh(111) and Rh(211) Surfaces: Insights from Density Functional Theory

    DEFF Research Database (Denmark)

    Garcia-Pintos, Delfina; Voss, Johannes; Jensen, Anker Degn

    2016-01-01

    Herein we describe the C-O cleavage of phenol and cyclohexanol over Rh (111) and Rh (211) surfaces using density functional theory calculations. Our analysis is complemented by a microkinetic model of the reactions, which indicates that the C-O bond cleavage of cyclohexanol is easier than that of...

  3. Extraordinary magnetic and structural properties of the off-stoichiometric and the Co-doped Ni.sub.2./sub.MnGa Heusler alloys under high pressure

    Czech Academy of Sciences Publication Activity Database

    Kamarád, Jiří; Albertini, F.; Arnold, Zdeněk; Fabbrici, S.; Kaštil, Jiří

    2014-01-01

    Roč. 77, Sep (2014), s. 60-67 ISSN 1359-6454 R&D Projects: GA ČR GAP204/12/0692 Institutional support: RVO:68378271 Keywords : Heusler alloys * martensitic transformation * magnetic properties * high pressure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.465, year: 2014

  4. Strong magneto-volume effects and hysteresis reduction in the In-doped (NiCo).sub.2./sub.MnGa Heusler alloys

    Czech Academy of Sciences Publication Activity Database

    Kamarád, Jiří; Fabbrici, S.; Kaštil, Jiří; Míšek, Martin; Cabassi, R.; Cugini, F.; Albertini, F.; Arnold, Zdeněk

    2016-01-01

    Roč. 685, Nov (2016), s. 142-146 ISSN 0925-8388 R&D Projects: GA ČR GA15-03777S Institutional support: RVO:68378271 Keywords : Heusler alloys * martensitic transformation * magnetic properties * high pressure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.133, year: 2016

  5. In-beam γ-spectroscopic study of rotational bands in 103Rh

    International Nuclear Information System (INIS)

    Kuti, I.; Timar, J.; Sohler, D.; Koike, T.; Lee, I.Y.; Machiavelli, A.O.

    2012-01-01

    Complete text of publication follows. Earlier studies revealed the existence of chiral partner candidate bands in 103 Rh. In order to construct a more complex level scheme, and to collect more information on the band structure, we studied the experimental properties of the rotational bands of this nucleus. For this analysis, excited states of 103 Rh were populated through the 96 Zr( 11 B,4n) reaction at a beam energy of 40 MeV. The beam, provided by the 88-in. cyclotron of the Lawrence Berkeley National Laboratory (LBNL), impinged on a 500 μg/cm 2 self-supporting target foil. For detection of the emitted γ-rays, the GAMMASPHERE spectrometer was used. Out of a sum of 9x10 9 events, about the 65% could be assigned to 103 Rh. In the present phase of the study, the level scheme was constructed based on γγγ-coincidence relationships, as well as energy and intensity balances of the observed γ-rays. The analysis included the evaluation of 2- and 3-dimensional histograms, using the RADWARE software package. Three typical γγγ-coincidence spectra are shown in Figure 1. We doubled the number of transitions assigned to 103 Rh and we established five new bands to the formerly known six ones. In order to assign firm spin-parities to the states, we plan to make an angular correlation (DCO) analysis for the observed transitions.

  6. Determination of equilibrium humidities using temperature and humidity controlled X-ray diffraction (RH-XRD)

    International Nuclear Information System (INIS)

    Linnow, Kirsten; Steiger, Michael

    2007-01-01

    Confined growth of crystals in porous building materials is generally considered to be a major cause of damage. We report on the use of X-ray diffraction under controlled conditions of temperature and relative humidity (RH-XRD) for the investigation of potentially deleterious phase transition reactions. An improved procedure based on rate measurements is used for the accurate and reproducible determination of equilibrium humidities of deliquescence and hydration reactions. The deliquescence humidities of NaCl (75.4 ± 0.5% RH) and Ca(NO 3 ) 2 .4H 2 O (50.8 ± 0.7% RH) at 25 deg. C determined with this improved RH-XRD technique are in excellent agreement with available literature data. Measurement of the hydration of anhydrous Ca(NO 3 ) 2 to form Ca(NO 3 ) 2 .2H 2 O revealed an equilibrium humidity of 10.2 ± 0.3%, which is also in reasonable agreement with available data. In conclusion, dynamic X-ray diffraction measurements are an appropriate method for the accurate and precise determination of equilibrium humidities with a number of interesting future applications

  7. Hydroformylation of 1-Hexene over Rh/Nano-Oxide Catalysts

    Directory of Open Access Journals (Sweden)

    Sari Suvanto

    2013-03-01

    Full Text Available The effect of nanostructured supports on the activity of Rh catalysts was studied by comparing the catalytic performance of nano- and bulk-oxide supported Rh/ZnO, Rh/SiO2 and Rh/TiO2 systems in 1-hexene hydroformylation. The highest activity with 100% total conversion and 96% yield of aldehydes was obtained with the Rh/nano-ZnO catalyst. The Rh/nano-ZnO catalyst was found to be more stable and active than the corresponding rhodium catalyst supported on bulk ZnO. The favorable morphology of Rh/nano-ZnO particles led to an increased metal content and an increased number of weak acid sites compared to the bulk ZnO supported catalysts. Both these factors favored the improved catalytic performance. Improvements of catalytic properties were obtained also with the nano-SiO2 and nano-TiO2 supports in comparison with the bulk supports. All of the catalysts were characterized by scanning electron microscope (SEM, inductively coupled plasma mass spectrometry (ICP-MS, BET, powder X-ray diffraction (PXRD and NH3- temperature-programmed desorption (TPD.

  8. Enhancement of magnetic properties of Co{sub 2}MnSi Heusler alloy prepared by mechanical alloying method

    Energy Technology Data Exchange (ETDEWEB)

    Rabie, Naeemeh; Gordani, Gholam Reza; Ghasemi, Ali, E-mail: ali13912001@yahoo.com

    2017-07-15

    Highlights: • Ferromagnetic Heusler alloys of Co{sub 2}MnSi were synthesized at low temperature. • There is an at least 30% reduction in the phase formation temperature. • Saturation magnetization of alloy was increased significantly after annealing. - Abstract: Ferromagnetic Heusler alloys of Co{sub 2}MnSi were synthesized by mechanical alloying method at low temperature. The effect of milling time and annealing process on structural and magnetic properties of ferromagnetic alloy samples were studied by X-ray diffraction, scanning electron microscopy and vibration sample magnetometer methods, respectively. Structural characteristics such as crystallite size, phase percentage, and lattice parameter determined using the Rietveld method. The values of these parameters were obtained 362.9 nm, 5.699 Å and 98.7%, respectively for annealed sample. Magnetization studies show that the Co2MnSi phase is formed at 15 h of milling and is optimized after 20 h of milling. VSM results showed that saturation magnetization (M{sub s}) of milled samples reduces from 112 to 75 (emu/g) with increasing milling time and then increased gradually to 95 emu/g. The effect of post-annealing on the structural and magnetic properties of milled samples was also investigated. The saturation magnetization of annealed sample (120 emu/g) is higher than the optimum milled sample (95 emu/g) due to increasing preferential ordered L2{sub 1} structure.

  9. Magnetic properties of Heusler alloy Mn2RuGe and Mn2RuGa ribbons

    International Nuclear Information System (INIS)

    Yang, Ling; Liu, Bohua; Meng, Fanbin; Liu, Heyan; Luo, Hongzhi; Liu, Enke; Wang, Wenhong; Wu, Guangheng

    2015-01-01

    Heusler alloys Mn 2 RuGe and Mn 2 RuGa have been prepared by melt-spinning method successfully. Theoretical and experimental studies reveal a ferrimagnetic ground state in the two alloys. The Curie temperatures are 303 K for Mn 2 RuGe and 272 K for Mn 2 RuGa. The calculated total spin moments of Mn 2 RuGe and Mn 2 RuGa are integral values of 2.00 μ B and 1.03 μ B , respectively. And the theoretical spin polarization ratio is also quite high. However, due to the atomic disorder in the ribbons, the saturation moments of them measured at 5 K are smaller than the calculated values, especially that of Mn 2 RuGa. This coincides with the disappearance of the superlattice reflection (111) and (200) peaks in the XRD pattern of Mn 2 RuGa. Annealing Mn 2 RuGa ribbon at 773 K can enhance the atomic ordering. Both saturation magnetic moment and Curie temperature increase obviously after the heat treatment. - Highlights: • Mn 2 RuGe and Mn 2 RuGa have been prepared by melt-spinning successfully. • Ferrimagnetic ground state has been confirmed in Mn 2 RuGe and Mn 2 RuGa. • High spin polarization has been predicted in Mn 2 RuGe. • Melt-spinning can be a possible way to adjust the atomic order of Heusler alloys

  10. Evolution of the electronic structure and physical properties of Fe2MeAl (Me = Ti, V, Cr) Heusler alloys

    International Nuclear Information System (INIS)

    Shreder, E; Streltsov, S V; Svyazhin, A; Makhnev, A; Marchenkov, V V; Lukoyanov, A; Weber, H W

    2008-01-01

    We present the results of experiments on the optical, electrical and magnetic properties and electronic structure and optical spectrum calculations of the Heusler alloys Fe 2 TiAl, Fe 2 VAl and Fe 2 CrAl. We find that the drastic transformation of the band spectrum, especially near the Fermi level, when replacing the Me element (Me = Ti, V, Cr), is accompanied by a significant change in the electrical and optical properties. The electrical and optical properties of Fe 2 TiAl are typical for metals. The abnormal behavior of the electrical resistivity and the optical properties in the infrared range for Fe 2 VAl and Fe 2 CrAl are determined by electronic states at the Fermi level. Both the optical spectroscopic measurements and the theoretical calculations demonstrate the presence of low-energy gaps in the band spectrum of the Heusler alloys. In addition, we demonstrate that the formation of Fe clusters may be responsible for the large enhancement of the total magnetic moment in Fe 2 CrAl

  11. Band structure of the quaternary Heusler alloys ScMnFeSn and ScFeCoAl

    Science.gov (United States)

    Shanthi, N.; Teja, Y. N.; Shaji, Shephine M.; Hosamani, Shashikala; Divya, H. S.

    2018-04-01

    In our quest for materials with specific applications, a theoretical study plays an important role in predicting the properties of compounds. Heusler alloys or compounds are the most studied in this context. More recently, a lot of quaternary Heusler compounds are investigated for potential applications in fields like Spintronics. We report here our preliminary study of the alloys ScMnFeSn and ScFeCoAl, using the ab-initio linear muffin-tin orbital method within the atomic sphere approximation (LMTO-ASA). The alloy ScMnFeSn shows perfect half-metallicity, namely, one of the spins shows a metallic behaviour and the other spin shows semi-conducting behaviour. Such materials find application in devices such as the spin-transfer torque random access memory (STT-MRAM). In addition, the alloy ScMnFeSn is found to have an integral magnetic moment of 4 µB, as predicted by the Slater-Pauling rule. The alloy ScFeCoAl does not show half-metallicity.

  12. Enhancement of magnetic properties of Co2MnSi Heusler alloy prepared by mechanical alloying method

    International Nuclear Information System (INIS)

    Rabie, Naeemeh; Gordani, Gholam Reza; Ghasemi, Ali

    2017-01-01

    Highlights: • Ferromagnetic Heusler alloys of Co 2 MnSi were synthesized at low temperature. • There is an at least 30% reduction in the phase formation temperature. • Saturation magnetization of alloy was increased significantly after annealing. - Abstract: Ferromagnetic Heusler alloys of Co 2 MnSi were synthesized by mechanical alloying method at low temperature. The effect of milling time and annealing process on structural and magnetic properties of ferromagnetic alloy samples were studied by X-ray diffraction, scanning electron microscopy and vibration sample magnetometer methods, respectively. Structural characteristics such as crystallite size, phase percentage, and lattice parameter determined using the Rietveld method. The values of these parameters were obtained 362.9 nm, 5.699 Å and 98.7%, respectively for annealed sample. Magnetization studies show that the Co2MnSi phase is formed at 15 h of milling and is optimized after 20 h of milling. VSM results showed that saturation magnetization (M s ) of milled samples reduces from 112 to 75 (emu/g) with increasing milling time and then increased gradually to 95 emu/g. The effect of post-annealing on the structural and magnetic properties of milled samples was also investigated. The saturation magnetization of annealed sample (120 emu/g) is higher than the optimum milled sample (95 emu/g) due to increasing preferential ordered L2 1 structure.

  13. Surface thermodynamic stability, electronic and magnetic properties in various (001) surfaces of Zr2CoSn Heusler alloy

    Science.gov (United States)

    Yang, Yan; Feng, Zhong-Ying; Zhang, Jian-Min

    2018-05-01

    The spin-polarized first-principles are used to study the surface thermodynamic stability, electronic and magnetic properties in various (001) surfaces of Zr2CoSn Heusler alloy, and the bulk Zr2CoSn Heusler alloy are also discussed to make comparison. The conduction band minimum (CBM) of half-metallic (HM) bulk Zr2CoSn alloy is contributed by ZrA, ZrB and Co atoms, while the valence band maximum (VBM) is contributed by ZrB and Co atoms. The SnSn termination is the most stable surface with the highest spin polarizations P = 77.1% among the CoCo, ZrCo, ZrZr, ZrSn and SnSn terminations of the Zr2CoSn (001) surface. In the SnSn termination of the Zr2CoSn (001) surface, the atomic partial density of states (APDOS) of atoms in the surface, subsurface and third layers are much influenced by the surface effect and the total magnetic moment (TMM) is mainly contributed by the atomic magnetic moments of atoms in fourth to ninth layers.

  14. An integrated architecture for the ITER RH control system

    International Nuclear Information System (INIS)

    Hamilton, David Thomas; Tesini, Alessandro

    2012-01-01

    Highlights: ► Control system architecture integrating ITER remote handling equipment systems. ► Standard control system architecture for remote handling equipment systems. ► Research and development activities to validate control system architecture. ► Standardization studies to select standard parts for control system architecture. - Abstract: The ITER remote handling (RH) system has been divided into 7 major equipment system procurements that deliver complete systems (operator interfaces, equipment controllers, and equipment) according to task oriented functional specifications. Each equipment system itself is an assembly of transporters, power manipulators, telemanipulators, vehicular systems, cameras, and tooling with a need for controllers and operator interfaces. From an operational perspective, the ITER RH systems are bound together by common control rooms, operations team, and maintenance team; and will need to achieve, to a varying degree, synchronization of operations, co-operation on tasks, hand-over of components, and sharing of data and resources. The separately procured RH systems must, therefore, be integrated to form a unified RH system for operation from the RH control rooms. The RH system will contain a heterogeneous mix of specially developed RH systems and off-the-shelf RH equipment and parts. The ITER Organization approach is to define a control system architecture that supports interoperable heterogeneous modules, and to specify a standard set of modules for each system to implement within this architecture. Compatibility with standard parts for selected modules is required to limit the complexity for operations and maintenance. A key requirement for integrating the control system modules is interoperability, and no module should have dependencies on the implementation details of other modules. The RH system is one of the ITER Plant systems that are integrated and coordinated through the hierarchical structure of the ITER CODAC system

  15. First-principle study of silicon cluster doped with rhodium: Rh{sub 2}Si{sub n} (n = 1–11) clusters

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shuai; Luo, Chang Geng; Li, Hua Yang [Department of Physics, Nanyang Normal University, Nanyang 473061 (China); Lu, Cheng, E-mail: lucheng@calypso.cn [Department of Physics, Nanyang Normal University, Nanyang 473061 (China); State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Li, Gen Quan; Lu, Zhi Wen [Department of Physics, Nanyang Normal University, Nanyang 473061 (China)

    2015-06-15

    The geometries, stabilities and electronic properties of rhodium-doped silicon clusters Rh{sub 2}Si{sub n} (n = 1–11) have been systematically studied by using density functional calculations at the B3LYP/GENECP level. The optimized results show that the lowest-energy isomers of Rh{sub 2}Si{sub n} clusters favor three-dimensional structures for n = 2–11. Based on the averaged binding energy, fragmentation energy, second-order energy difference and HOMO-LUMO energy gap, the stabilities of Rh{sub 2}Si{sub n} (n = 1–11) clusters have been analyzed. The calculated results suggest that the Rh{sub 2}Si{sub 6} cluster has the strongest relative stability and the doping with rhodium atoms can reduce the chemical stabilities of Si{sub n} clusters. The natural population and natural electron configuration analysis indicate that there is charge transfer from the Si atoms and 5s orbital of the Rh atoms to the 4d and 5p orbitals of Rh atoms. The analysis of electron localization function reveal that the Si–Si bonds are mainly covalent bonds and the Si–Rh bonds are almost ionic bonds. Moreover, the vertical ionization potential, vertical electron affinity, chemical hardness, chemical potential, vibrational spectrum and polarizability are also discussed. - Highlights: • The geometric structures of Rh{sub 2}Si{sub n} (n = 1–11) clusters are determined. • The stabilities and electronic properties of Rh{sub 2}Si{sub n} clusters are discussed. • The Rh{sub 2}Si{sub 6} cluster has the higher stability than other clusters. • The doped rhodium atoms can reduce the chemical stabilities of Si{sub n} clusters.

  16. Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, C.A., E-mail: carlos.nogueira@lneg.pt [Laboratório Nacional de Energia e Geologia, I.P., Campus do Lumiar, 1649-038 Lisboa (Portugal); Paiva, A.P., E-mail: appaiva@fc.ul.pt [Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa (Portugal); Oliveira, P.C. [Laboratório Nacional de Energia e Geologia, I.P., Campus do Lumiar, 1649-038 Lisboa (Portugal); Costa, M.C., E-mail: mcorada@ualg.pt [Centro de Ciências do Mar, Departamento de Química e Farmácia, Faculdade de Ciências e de Tecnologia, Campus de Gambelas, 8005-139 Faro (Portugal); Costa, A.M. Rosa da, E-mail: amcosta@ualg.pt [Centro de Investigação em Química do Algarve, Departamento de Química e Farmácia, Faculdade de Ciências e de Tecnologia, Campus de Gambelas, 8005-139 Faro (Portugal)

    2014-08-15

    Highlights: • A new leaching process based on Cu{sup 2+}/HCl media for recovering Pd and Rh from spent autocatalytic converters is presented. • Palladium and rhodium were efficiently leached, with attained maximum yields of 95% and 86%, respectively. • Temperature, time, and HCl and Cu{sup 2+} concentrations were found to be significant factors in the leaching of Pd and Rh. - Abstract: The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu{sup 2+} concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80 °C, t = 4 h, [HCl] = 6 M, [Cu{sup 2+}] = 0.3 M)

  17. Investigation of spin-gapless semiconductivity and half-metallicity in Ti2MnAl-based compounds

    International Nuclear Information System (INIS)

    Lukashev, P.; Staten, B.; Hurley, N.; Kharel, P.; Gilbert, S.; Fuglsby, R.; Huh, Y.; Valloppilly, S.; Zhang, W.; Skomski, R.; Sellmyer, D. J.; Yang, K.

    2016-01-01

    The increasing interest in spin-based electronics has led to a vigorous search for new materials that can provide a high degree of spin polarization in electron transport. An ideal candidate would act as an insulator for one spin channel and a conductor or semiconductor for the opposite spin channel, corresponding to the respective cases of half-metallicity and spin-gapless semiconductivity. Our first-principle electronic-structure calculations indicate that the metallic Heusler compound Ti 2 MnAl becomes half-metallic and spin-gapless semiconducting if half of the Al atoms are replaced by Sn and In, respectively. These electronic structures are associated with structural transitions from the regular cubic Heusler structure to the inverted cubic Heusler structure.

  18. An electro-hydraulic servo control system research for CFETR blanket RH

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Changqi [Hefei University of Technology, Hefei 230009, Anhui (China); Tang, Hongjun, E-mail: taurustang@126.com [Hefei University of Technology, Hefei 230009, Anhui (China); Qi, Songsong [Hefei University of Technology, Hefei 230009, Anhui (China); Cheng, Yong; Feng, Hansheng; Peng, Xuebing; Song, Yuntao [Institute of Plasma Physics Chinese Academy of Sciences, Hefei 230031, Anhui (China)

    2014-11-15

    Highlights: • We discussed the conceptual design of CFETR blanket RH maintenance system. • The mathematical model of electro-hydraulic servo system was calculated. • A fuzzy adaptive PD controller was designed based on control theory and experience. • The co-simulation models of the system were established with AMESim/Simulink. • The fuzzy adaptive PD algorithm was designed as the core strategy of the system. - Abstract: Based on the technical design requirements of China Fusion Engineering Test Reactor (CFETR) blanket remote handling (RH) maintenance, this paper focus on the control method of achieving high synchronization accuracy of electro-hydraulic servo system. Based on fuzzy control theory and practical experience, a fuzzy adaptive proportional-derivative (PD) controller was designed. Then a more precise co-simulation model was established with AMESim/Simulink. Through the analysis of simulation results, a fuzzy adaptive PD control algorithm was designed as the core strategy of electro-hydraulic servo control system.

  19. An electro-hydraulic servo control system research for CFETR blanket RH

    International Nuclear Information System (INIS)

    Chen, Changqi; Tang, Hongjun; Qi, Songsong; Cheng, Yong; Feng, Hansheng; Peng, Xuebing; Song, Yuntao

    2014-01-01

    Highlights: • We discussed the conceptual design of CFETR blanket RH maintenance system. • The mathematical model of electro-hydraulic servo system was calculated. • A fuzzy adaptive PD controller was designed based on control theory and experience. • The co-simulation models of the system were established with AMESim/Simulink. • The fuzzy adaptive PD algorithm was designed as the core strategy of the system. - Abstract: Based on the technical design requirements of China Fusion Engineering Test Reactor (CFETR) blanket remote handling (RH) maintenance, this paper focus on the control method of achieving high synchronization accuracy of electro-hydraulic servo system. Based on fuzzy control theory and practical experience, a fuzzy adaptive proportional-derivative (PD) controller was designed. Then a more precise co-simulation model was established with AMESim/Simulink. Through the analysis of simulation results, a fuzzy adaptive PD control algorithm was designed as the core strategy of electro-hydraulic servo control system

  20. RhD Specific Antibodies Are Not Detectable in HLA-DRB11501* Mice Challenged with Human RhD Positive Erythrocytes

    Directory of Open Access Journals (Sweden)

    Lidice Bernardo

    2014-01-01

    Full Text Available The ability to study the immune response to the RhD antigen in the prevention of hemolytic disease of the fetus and newborn has been hampered by the lack of a mouse model of RhD immunization. However, the ability of transgenic mice expressing human HLA DRB11501* to respond to immunization with purified RhD has allowed this question to be revisited. In this work we aimed at inducing anti-RhD antibodies by administering human RhD+ RBCs to mice transgenic for the human HLA DRB11501* as well as to several standard inbred and outbred laboratory strains including C57BL/6, DBA1/J, CFW(SW, CD1(ICR, and NSA(CF-1. DRB11501* mice were additionally immunized with putative extracellular immunogenic RhD peptides. DRB11501* mice immunized with RhD+ erythrocytes developed an erythrocyte-reactive antibody response. Antibodies specific for RhD could not however be detected by flow cytometry. Despite this, DRB11501* mice were capable of recognizing immunogenic sequences of Rh as injection with Rh peptides induced antibodies reactive with RhD sequences, consistent with the presence of B cell repertoires capable of recognizing RhD. We conclude that while HLA DRB11501* transgenic mice may have the capability of responding to immunogenic sequences within RhD, an immune response to human RBC expressing RhD is not directly observed.

  1. The Design, Synthesis and Study of Mixed-Metal Ru,Rh and Os, Rh Complexes with Biologically Relevant Reactivity

    OpenAIRE

    Wang, Jing

    2013-01-01

    A series of mixed-metal bimetallic complexes [(TL)2M(dpp)RhCl2(TL)]3 (M = Ru and Os, terminal ligands (TL) = phen, Ph2phen, Me2phen and bpy, terminal ligands (TL) = phen, bpy and Me2bpy ), which couple one Ru or Os polyazine light absorber (LA) to a cis-RhIIICl2 center through a dpp bridging ligand (BL), were synthesized using a building block method. These are related to previously studied trimetallic systems [{(TL)2M(dpp)2RhCl2]5+, but the bimetallics are synthetically more complex to prepa...

  2. A Radiation Hardened Housekeeping Slave Node (RH-HKSN) ASIC

    Data.gov (United States)

    National Aeronautics and Space Administration — This projects seeks to continue the development of the Radiation Hardened Housekeeping Slave Node (RH-HKSN) ASIC. The effort has taken parallel paths by implementing...

  3. Comparative frequency and allelic distribution of ABO and Rh (D ...

    African Journals Online (AJOL)

    Gourab Dewan

    2015-02-18

    Feb 18, 2015 ... desh and having borders with India and Myanmar (Fig. 1). It is a hilly area with ..... calculated allelic frequencies for ABO/Rh systems previously. Therefore, allelic .... in backward caste population of Uttar Pradesh, India. Not Sci.

  4. Frequency distribution 0f ABO, RH blood groups and blood ...

    African Journals Online (AJOL)

    user

    2006-11-16

    Nov 16, 2006 ... blood genotypes among the cell biology and genetics students of ... problem in some pregnancies when the mother is Rh – negative and the foetus ... electrophoresis technique was used to determine haemoglobin genotype.

  5. Ontogenic and sexual differences in pituitary GnRH receptors and intracellular Ca2+ mobilization induced by GnRH.

    Science.gov (United States)

    Lacau-Mengido, I M; González Iglesias, A; Lux-Lantos, V; Libertun, C; Becú-Villalobos, D

    1998-04-01

    The present experiments were designed in order to elucidate the participation of the developing hypophysis in determining the changing sensitivity of gonadotrophins to gonadotropin-releasing hormone (GnRH) during ontogeny in the rat. To that end, we chose two well defined developmental ages that differ markedly in sexual and ontogenic characteristics of hypophyseal sensitivity to GnRH, 15 and 30 d. In order to study sex differences and the role of early sexual organization of the hypothalamus, experiments were carried out in males, females, and neonatally androgenized females (TP females). We evaluated (1) the characteristics of pituitary GnRH receptors, and (2) associated changes in GnRH-induced mobilization of intracellular Ca2+ (a second messenger involved in gonadotropins exocytosis). We measured binding characteristics of the GnRH analog D-Ser(TBu)6-des-Gly10-GnRH ethylamide in pituitary homogenates. We found that Kds did not vary among the different sex groups. Total number and concentration of receptors decreased in the female rat from 15-30 d of age, whereas in the male and TP female, receptors/pituitary increased, and the concentration/mg tissue did not change. Also, at 30 days of age, males presented higher content and concentration of receptors than females, and higher content than TP females. In order to evaluate if developmental and sexual differences in pituitary sensitivity to GnRH might be expressed through variations in the intracellular Ca2+ signal, we studied the mobilization of intracellular Ca2+ induced by GnRH (1 x 10(-8) to 1 x 10(-11) M) in a suspension of dispersed pituitary cells in the six groups. In cells from 15-d-old females, Ca2+ response was greater than in 30-d-old females at the doses of 10(-8) to 10(-10) M, indicating that in the infantile female rat activation of highly concentrated GnRH receptors is reflected in an increase in signal transduction mediated by Ca2+. In males and in female rats androgenized at birth, there was also

  6. Regulation versus modulation in GnRH receptor function

    International Nuclear Information System (INIS)

    Zolman, J.C.; Theodoropoulos, T.J.

    1985-01-01

    Serum luteinizing hormone (LH) concentration after exposure to gonadotropin-releasing hormone (GnRH) indicates that an instantaneous increase occurs in the rate of release of LH directly from the anterior pituitary, as measured dynamically during superfusion in vitro. On the other hand, estradiol-17 beta (E2) alone shows no such instantaneous effect on LH release rate (at least for the first four hours), in either physiologic or pharmacologic concentrations. At the same time, brief (ten to 30 minute) exposure of isolated anterior pituitary plasma membranes to physiologic concentrations of E2 significantly alters the binding of a fully biologically active 125 I-GnRH to its plasma membrane receptor protein. In order to characterize the effect of E2 on GnRH binding further, dispersed bovine anterior pituitary cells were preincubated for six hours in the presence or absence of physiologic concentrations of E2 (10(-10)M). Following preincubation in the presence of E2, the cell suspension was incubated for 30 minutes with physiologic concentrations (5 x 10(-11) - 5 x 10(-10)M) of a fully biologically active 125 I-GnRH. The treatment, at least, doubled the number of biologically important high affinity GnRH binding sites (Kd's . 7.5 x -10(-11) - 4.5 x 10(-10)M), and changed the binding capacity of some of the binding sites up to three fold, which altered the cooperativity of GnRH-receptor interaction. Thus, the interaction of E2 with GnRH at the level of GnRH receptor is mandatory for the short-term pituitary effect of E2 on LH release in vitro and in vivo

  7. Reorientation precession measurements of quadrupole moments in 103Rh

    International Nuclear Information System (INIS)

    Gelberg, A.; Herskind, B.; Kalish, R.; Neiman, M.

    1976-01-01

    The quadrupole moments of the 3/2 - and 5/2 - states in 103 Rh have been determined by measuring the precession of the gamma-ray angular distribution following Coulomb excitation; 16 O and 32 S beams have been used. The structure of the negative-parity states in 103 Rh is found to be in agreement with the model of Arima and Iachello. (orig.) [de

  8. The Rh allele frequencies in Gaza city in Palestine

    Directory of Open Access Journals (Sweden)

    Skaik Younis

    2011-01-01

    Full Text Available Background: The Rh blood group system is the second most clinically significant blood group system. It includes 49 antigens, but only five (D, C, E, c and e are the most routinely identified due to their unique relation to hemolytic disease of the newborn (HDN and transfusion reactions. Frequency of the Rh alleles showed variation, with regard to race and ethnic. Objectives: The purpose of the study was to document the Rh alleles′ frequencies amongst males (M and females (F in Gaza city in Palestine. Materials and Methods: Two hundred and thirty-two blood samples (110 M and 122 F were tested against monoclonal IgM anti-C,anti-c, anti-E, anti-e and a blend of monoclonal/polyclonal IgM/IgG anti-D. The expected Rh phenotypes were calculated using gene counting method. Results: The most frequent Rh antigen in the total sample was e, while the least frequent was E.The order of the combined Rh allele frequencies in both M and F was CDe > cDe > cde > CdE > cDE > Cde > CDE. A significant difference was reported between M and F regarding the phenotypic frequencies (P < 0.05. However, no significance (P > 0.05 was reported with reference to the observed and expected Rh phenotypic frequencies in either M or F students. Conclusion: It was concluded that the Rh antigens, alleles and phenotypes in Gaza city have unique frequencies, which may be of importance to the Blood Transfusion Center in Gaza city and anthropology.

  9. Letrozole+ GnRH antagonist stimulation protocol in poor ovarian responders undergoing intracytoplasmic sperm injection cycles: An RCT

    Directory of Open Access Journals (Sweden)

    Mahbod Ebrahimi

    2017-08-01

    Full Text Available Background: Gonadotropin-releasing hormone (GnRH antagonist protocol has been proposed as a potentially proper option for the patients with limited ovarian reserve. Nevertheless, there is no significant difference in terms of clinical pregnancy between the GnRH antagonist and agonist cycles. The use of aromatase inhibitors such as letrozole was suggested by some studies. Objective: The object of this study was to evaluate the efficacy of letrozole cotreatment with GnRH-antagonist protocol in ovarian stimulation of poor responder patients undergoing intracytoplasmic sperm injection. Materials and Methods: A double-blinded randomized control trial was conducted on 70 infertile women with poor ovarian response based on Bologna criteria in two groups: letrozole+GnRH-antagonist (LA group and placebo+GnRH-antagonist (PA group (n=35/each. The LA group involved at letrozole 2.5 mg daily over 5 days and recombinant human follicle stimulating hormone 225 IU/daily. The PA group received placebo over 5 days and recombinant human follicle stimulating hormone at the same starting day and dose, similar to LA group. GnRH-antagonist was introduced once one or more follicle reached ≥14 mm. The main outcome measures were the number of oocytes retrieved, fertilization rate, implantation rate, cycle cancellation rate, and clinical pregnancy rate. Results: There were no significant differences in demographic characteristics between groups. There were no significant differences between groups regarding the number of oocytes retrieved (p=0.81, number of embryos transferred (p=0.82, fertilization rate (p=0.225, implantation rate (p=0.72, total cycle cancelation rate (p=0.08, and clinical pregnancy rate (p=0.12. Conclusion: The use of letrozole in GnRH-antagonist cycles does not improve clinical outcomes in poor responder patients undergoing intracytoplasmic sperm injection.

  10. Tuning Fermi level of Cr{sub 2}CoZ (Z=Al and Si) inverse Heusler alloys via Fe-doping for maximum spin polarization

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mukhtiyar [Department of Physics, Kurukshetra University, Kurukshetra-136119, Haryana (India); Saini, Hardev S. [Department of Physics, Panjab University, Chandigarh-160014 (India); Thakur, Jyoti [Department of Physics, Kurukshetra University, Kurukshetra-136119, Haryana (India); Reshak, Ali H. [New Technologies—Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Kashyap, Manish K., E-mail: manishdft@gmail.com [Department of Physics, Kurukshetra University, Kurukshetra-136119, Haryana (India)

    2014-12-15

    We report full potential treatment of electronic and magnetic properties of Cr{sub 2−x}Fe{sub x}CoZ (Z=Al, Si) Heusler alloys where x=0.0, 0.25, 0.5, 0.75 and 1.0, based on density functional theory (DFT). Both parent alloys (Cr{sub 2}CoAl and Cr{sub 2}CoSi) are not half-metallic frromagnets. The gradual replacement of one Cr sublattice with Fe induces the half-metallicity in these systems, resulting maximum spin polarization. The half-metallicity starts to appear in Cr{sub 2−x}Fe{sub x}CoAl and Cr{sub 2−x}Fe{sub x}CoSi with x=0.50 and x=0.25, respectively, and the values of minority-spin gap and half-metallic gap or spin-flip gap increase with further increase of x. These gaps are found to be maximum for x=1.0 for both cases. An excellent agreement between the structural properties of CoFeCrAl with available experimental study is obtained. The Fermi level tuning by Fe-doping makes these alloys highly spin polarized and thus these can be used as promising candidates for spin valves and magnetic tunnelling junction applications. - Highlights: • Tuning of E{sub F} in Cr{sub 2}CoZ (Z=Al, Si) has been demonstrated via Fe doping. • Effect of Fe doping on half-metallicity and magnetism have been discussed. • The new alloys have a potential of being used as spin polarized electrodes.

  11. Evolution of phase transformation and magnetic properties with Fe content in Ni55-x Fe x Mn20Ga25 Heusler alloys

    Science.gov (United States)

    Zhang, Yuanlei; Li, Zhe; He, Xijia; Huang, Yinsheng; Xu, Kun; Jing, Chao

    2018-02-01

    A series of Ni55-x Fe x Mn20Ga25 (0  ⩽  x  ⩽  5) Heusler alloys was prepared to investigate their phase transitions and magnetic properties. At room temperature, these alloys present various crystal structures, and the unit cell volume enlarges with increase of Fe content in both austenite and martensite. Multiple magneto-structural transformations were observed in the parent alloy (x  =  0). In the process of cooling, it undergoes martensitic transformation (MT) from L21-type paramagnetic austenite to L10-type ferromagnetic martensite, accompanying an intermartensitic transformation (IMT, 7M  →  L10). By establishing a detailed phase diagram, we found that both MT and IMT shift to lower temperature simultaneously, while the ferromagnetic (FM) transition of austenite moves to higher temperature as Fe increases. With the further increase of Fe content beyond a critical value, both the IMT and the FM transitions split off from MT, and the former follows with the transforming sequence of 7M  →  5M. Based on the experimental data, some key magnetic parameters have been obtained in this system. The calculated magnetocrystalline anisotropy constant ({{K}1} ) of martensite quickly increases as Fe increases, and then it almost reaches a saturated value (~5.5  ×  105 J m-3) for the alloys with x  >  3. However, the spontaneous magnetic moment ({μs} ) attains a peak value of about 4.2 μ B/f.u. in the alloy with x  =  4, which is not consistent with the linear increasing of effective magnetic moment ({μef f} ). Further magnetic measurements with hydrostatic pressure indicate that such a discrepancy could be ascribed to the competition between the magnetic exchange interaction and the volume change of unit cell governed by the dopant Fe content.

  12. Successful synthesis and thermal stability of immiscible metal Au-Rh, Au-Ir andAu-Ir-Rh nanoalloys

    Science.gov (United States)

    Shubin, Yury; Plyusnin, Pavel; Sharafutdinov, Marat; Makotchenko, Evgenia; Korenev, Sergey

    2017-05-01

    We successfully prepared face-centred cubic nanoalloys in systems of Au-Ir, Au-Rh and Au-Ir-Rh, with large bulk miscibility gaps, in one-run reactions under thermal decomposition of specially synthesised single-source precursors, namely, [AuEn2][Ir(NO2)6], [AuEn2][Ir(NO2)6] х [Rh(NO2)6]1-х and [AuEn2][Rh(NO2)6]. The precursors employed contain all desired metals ‘mixed’ at the atomic level, thus providing significant advantages for obtaining alloys. The observations using high-resolution transmission electron microscopy show that the nanoalloy structures are composed of well-dispersed aggregates of crystalline domains with a mean size of 5 ± 3 nm. Еnergy dispersive x-ray spectroscopy and x-ray powder diffraction (XRD) measurements confirm the formation of AuIr, AuRh, AuIr0.75Rh0.25, AuIr0.50Rh0.50 and AuIr0.25Rh0.75 metastable solid solutions. In situ high-temperature synchrotron XRD (HTXRD) was used to study the formation mechanism of nanoalloys. The observed transformations are described by the ‘conversion chemistry’ mechanism characterised by the primary development of particles comprising atoms of only one type, followed by a chemical reaction resulting in the final formation of a nanoalloy. The obtained metastable nanoalloys exhibit essential thermal stability. Exposure to 180 °C for 30 h does not cause any dealloying process.

  13. Origins of gonadotropin-releasing hormone (GnRH) in vertebrates: identification of a novel GnRH in a basal vertebrate, the sea lamprey.

    Science.gov (United States)

    Kavanaugh, Scott I; Nozaki, Masumi; Sower, Stacia A

    2008-08-01

    We cloned a cDNA encoding a novel (GnRH), named lamprey GnRH-II, from the sea lamprey, a basal vertebrate. The deduced amino acid sequence of the newly identified lamprey GnRH-II is QHWSHGWFPG. The architecture of the precursor is similar to that reported for other GnRH precursors consisting of a signal peptide, decapeptide, a downstream processing site, and a GnRH-associated peptide; however, the gene for lamprey GnRH-II does not have introns in comparison with the gene organization for all other vertebrate GnRHs. Lamprey GnRH-II precursor transcript was widely expressed in a variety of tissues. In situ hybridization of the brain showed expression and localization of the transcript in the hypothalamus, medulla, and olfactory regions, whereas immunohistochemistry using a specific antiserum showed only GnRH-II cell bodies and processes in the preoptic nucleus/hypothalamus areas. Lamprey GnRH-II was shown to stimulate the hypothalamic-pituitary axis using in vivo and in vitro studies. Lamprey GnRH-II was also shown to activate the inositol phosphate signaling system in COS-7 cells transiently transfected with the lamprey GnRH receptor. These studies provide evidence for a novel lamprey GnRH that has a role as a third hypothalamic GnRH. In summary, the newly discovered lamprey GnRH-II offers a new paradigm of the origin of the vertebrate GnRH family. We hypothesize that due to a genome/gene duplication event, an ancestral gene gave rise to two lineages of GnRHs: the gnathostome GnRH and lamprey GnRH-II.

  14. Experimental Treatment of Prostate Cancer Models with Rh2, an Isolated Ginsenoside Compound

    Science.gov (United States)

    2003-03-01

    ppendices ......................................................................................... 8 3 Annual Summary of Research Project...20%/- 0% 0 5 10 15 20 25 30 35 Days Figure 2. Body weight changes of nude mice in toxicology study Based on the findings of the acute toxicity study...test, pɘ.01 **). Key Research Accomplishments 1) Acute toxicity study showed that 4 weeks’ treatment with Rh2 (50 mg/kg p.o. 5 days/week) + Taxol (6

  15. Ionic liquids as recyclable and separable reaction media in Rh-catalyzed decarbonylation of aromatic and aliphatic aldehydes

    DEFF Research Database (Denmark)

    Malcho, Phillip; Garcia-Suarez, Eduardo J.; Riisager, Anders

    2014-01-01

    Ionic liquids (ILs) have been applied as recyclable reaction media in the decarbonylation of aldehydes in the presence of a rhodium-phosphine complex catalyst. The performance of several new catalytic systems based on imidazolium-based ILs and [Rh(dppp)2]Cl (dppp: 1,3-diphenylphosphinopropane) were...

  16. Thermal Methane Conversion to Syngas Mediated by Rh1-Doped Aluminum Oxide Cluster Cations RhAl3O4.

    Science.gov (United States)

    Li, Ya-Ke; Yuan, Zhen; Zhao, Yan-Xia; Zhao, Chongyang; Liu, Qing-Yu; Chen, Hui; He, Sheng-Gui

    2016-10-05

    Laser ablation generated RhAl 3 O 4 + heteronuclear metal oxide cluster cations have been mass-selected using a quadrupole mass filter and reacted with CH 4 or CD 4 in a linear ion trap reactor under thermal collision conditions. The reactions have been characterized by state-of-the-art mass spectrometry and quantum chemistry calculations. The RhAl 3 O 4 + cluster can activate four C-H bonds of a methane molecule and convert methane to syngas, an important intermediate product in methane conversion to value-added chemicals. The Rh atom is the active site for activation of the C-H bonds of methane. The high electron-withdrawing capability of Rh atom is the driving force to promote the conversion of methane to syngas. The polarity of Rh oxidation state is changed from positive to negative after the reaction. This study has provided the first example of methane conversion to syngas by heteronuclear metal oxide clusters under thermal collision conditions. Furthermore, the molecular level origin has been revealed for the condensed-phase experimental observation that trace amounts of Rh can promote the participation of lattice oxygen of chemically very inert support (Al 2 O 3 ) to oxidize methane to carbon monoxide.

  17. Effect of site disorder on the electronic properties of Fe2VAl Heusler alloy

    International Nuclear Information System (INIS)

    Venkatesh, Ch.; Srinivas, V.; Rao, V.V.; Srivastava, S.K.; Babu, P. Sudheer

    2013-01-01

    Highlights: •The role of site-disorder on physical properties of Fe 2 VAl has been investigated through experiments as well as DFT calculations. •Metal to semiconductor-like behaviour in electrical transport of anti-site disordered Fe 2 VAl was consistently explained. •Both itinerant and localized magnetic behaviours of anti-site disordered Fe 2 VAl are discussed. •Justification of metallic-like transition in site-disordered Fe 2 VAl is given. -- Abstract: Ab initio calculations on ordered L2 1 structure of Fe 2 VAl alloy have been carried out by introducing B2, DO 3 , A2′ and XY–XZ type disorders in order to understand the role of anti-site disorder on magnetic and transport properties. These studies show an enhancement of individual spin moments of anti-site Fe atoms in DO 3 , A2′ and XY–XZ type anti-site disorder, making the Fe 2 VAl alloy magnetically active. These calculations also show that hybridization due to covalent distribution of valance states among the atoms is important in Fe 2 VAl, defining its unusual physical properties. From the density of states spectrum obtained near the Fermi level, we have noticed formation of intermediate defect-like states that couple the edges of the pseudo gap on both sides of the Fermi level, driving the material from semi-metallic to metallic type in electrical transport. We also present experimental results on structural, magnetic and electrical properties of Fe 2 VAl Heusler alloy. A comparison of present experimental data with calculations shows an existence of DO 3 type anti-site disorder due to the Al-deficiency in Fe 2 VAl alloy which causes deviations in theoretical results on the magnetic and transport behaviour of pure Fe 2 VAl. The temperature dependence of electrical transport and magnetic data analysed on the basis of impurity band model which provides convincing evidence for itinerant character of this alloy system with an anti-site disorder

  18. Application of Humidity-Controlled Dynamic Mechanical Analysis (DMA-RH to Moisture-Sensitive Edible Casein Films for Use in Food Packaging

    Directory of Open Access Journals (Sweden)

    Laetitia M. Bonnaillie

    2015-01-01

    Full Text Available Protein-based and other hydrophilic thin films are promising materials for the manufacture of edible food packaging and other food and non-food applications. Calcium caseinate (CaCas films are highly hygroscopic and physical characterization under broad environmental conditions is critical to application development and film optimization. A new technology, humidity-controlled dynamic mechanical analysis (DMA-RH was explored to characterize CaCas/glycerol films (3:1 ratio during isohume temperature (T ramps and steps, and isothermal RH ramps and steps, to determine their mechanical and moisture-sorption properties during extensive T and RH variations. When RH and/or T increased, CaCas/Gly films became strongly plasticized and underwent several primary and secondary humidity-dependent transition temperatures (or transition humidities; the CaCas/Gly network hypothetically rearranged itself to adapt to the increased water-content and heat-induced molecular mobility. Between 5–40 °C and 20%–61% RH, moisture-sorption was rapid and proportional to humidity between transition points and accelerated greatly during transitions. CaCas/Gly films seemed unsuitable for storage or utilization in warm/humid conditions as they lost their mechanical integrity around Tm ~ 40 °C at 50% RH and Tm decreased greatly with increased RH. However, below Tm, both moisture- and heat-induced structural changes in the films were fully reversible and casein films may withstand a variety of moderate abuse conditions.

  19. Continuity resection of the mandible after ameloblastoma - feasibility of oral rehabilitation with rhBMP-2 associated to bovine xenograft followed by implant installation.

    Science.gov (United States)

    Lustosa, Romulo Maciel; Macedo, Diogo de Vasconcelos; Iwaki, Lilian Cristina Vessoni; Tolentino, Elen de Souza; Hasse, Paulo Norberto; Marson, Giordano Bruno de Oliveira; Iwaki Filho, Liogi

    2015-10-01

    Recombinant human morphogenetic protein (rhBMP) is a graft alternative for extensive mandibular reconstruction after tumor resections. However, the feasibility of rhBMP-2 to receive osseointegrated implants and prosthetic rehabilitation has been rarely reported. This study reports on a case of an extensive solid ameloblastoma along the mandibular body. The treatment consisted of resection followed by off-label use of rhBMP type 2 associated with bovine bone xenograft. Eleven months postoperatively, the patient was prosthetically rehabilitated with dental implants, without evidence of resorption or complications. The literature on mandibular reconstructions using rhBMP and their feasibility for future osseointegrated implant placement was also reviewed. Based on the presented case, the association between rhBMP-2 and a bovine bone xenograft could be considered a feasible option for the reconstruction and rehabilitation of large mandibular defects after tumor resection. According to the literature, the use of rhBMP as a graft material is encouraging, with good clinical outcome. However, there are no long-term studies demonstrating success and survival rates of implants placed in these grafts. Future investigations will be required to ascertain the long-term survival of implants in areas grafted with rhBMP. Also, there is a lack of information regarding the prosthetic rehabilitation of these patients. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  20. Magnetic spin configuration in Fe{sub 50}Pt{sub 50-x}Rh{sub x} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Fenske, J.; Lott, D.; Schreyer, A. [GKSS Research Centre (Germany); Mankey, G.J. [University of Alabama, MINT Center (United States); Schmidt, W.; Schmalzl, K. [Juelich Research Centre (Germany); Tartakowskaya, E. [Institute for Magnetism, National Ukrainian Accademy of Science (Ukraine)

    2010-07-01

    FePt-based alloys are typically the material of choice for magnetic information storage media. The high magnetic moment of Fe gives a large magnetization and the large atomic number of Pt results in a high magnetic anisotropy. This combination enables the written bits to be smaller than ever before. One way to control the magnetic properties in these materials is through the introduction of a third element into the crystal matrix e.g. Rh. When Rh is added to replace Pt in the equiatomic alloy, new magnetic phases emerge. Bulk samples of Fe{sub 50}Pt{sub 50-x}Rh{sub x} studied by magnetization measurements refer to three different phase transitions with increasing temperature: (I) An antiferromagnetic (AF)-paramagnetic (PM) transition for 30Rh{sub x} films with different Rh concentrations. These films were examined by neutron diffraction in dependence of temperature and magnetic field. By the use of polarized and unpolarized neutron diffraction we could develop a detailed model of the magnetic spin structure in these thin films.

  1. Characteristics of a granular electronic system in Heusler-type Fe2+xV1−xAl

    International Nuclear Information System (INIS)

    Naka, T; Sato, K; Taguchi, M; Nakane, T; Matsushita, A; Shirakawa, N; Ishikawa, F; Yamada, Yuh; Takaesu, Y; Nakama, T

    2013-01-01

    We report comprehensive measurements of the magnetic, transport, and thermal properties of the Heusler-type compound Fe 2+x V 1−x Al, with x values near the ferromagnetic quantum critical point, x c ∼ 0.05. At T ∼ 60 K, a prominent Schottky-like anomaly appeared in the specific heat; this anomaly was correlated with a smaller pseudo-gap formation in magnetic susceptibility, magnetoresistance, and thermoelectric power. Furthermore, a magnetic anomaly observed in the magnetic susceptibility and resistivity at T ∼ 4 K was suppressed significantly by applying a magnetic field. A magnetically inhomogeneous phase arose below T ∼ 60 K, which appeared to consist of ferromagnetic and paramagnetic clusters. (paper)

  2. Anomalous Hall effect in ion-beam sputtered Co2FeAl full Heusler alloy thin films

    Science.gov (United States)

    Husain, Sajid; Kumar, Ankit; Akansel, Serkan; Svedlindh, Peter; Chaudhary, Sujeet

    2017-11-01

    Investigations of temperature dependent anomalous Hall effect and longitudinal resistivity in Co2FeAl (CFA) thin films grown on Si(1 0 0) at different substrate temperature Ts are reported. The scaling of the anomalous Hall conductivity (AHC) and the associated phenomenological mechanisms (intrinsic and extrinsic) are analyzed vis-à-vis influence of Ts. The intrinsic contribution to AHC is found to be dominating over the extrinsic one. The appearance of a resistivity minimum at low temperature necessitates the inclusion of quantum corrections on account of weak localization and electron-electron scattering effects whose strength reduces with increase in Ts. The study establishes that the optimization of Ts plays an important role in the improvement of atomic ordering which indicates the higher strength of spin-orbit coupling and leads to the dominant intrinsic contribution to AHC in these CFA full Heusler alloy thin films.

  3. Dirac cone and pseudogapped density of states in the topological half-Heusler compound YPtBi

    Science.gov (United States)

    Kronenberg, A.; Braun, J.; Minár, J.; Elmers, H.-J.; Kutnyakhov, D.; Zaporozhchenko, A. V.; Wallauer, R.; Chernov, S.; Medjanik, K.; Schönhense, G.; Kläui, M.; Chadov, S.; Ebert, H.; Jourdan, M.

    2016-10-01

    Topological insulators (TIs) are exciting materials, which exhibit unprecedented properties, such as helical spin-momentum locking, which leads to large torques for magnetic switching and highly efficient spin current detection. Here we explore the compound YPtBi, an example from the class of half-Heusler materials, for which the typical band inversion of topological insulators was predicted. We prepared this material as thin films by conventional cosputtering from elementary targets. By in situ time-of-flight momentum microscopy, a Dirac conelike surface state with a Dirac point ≃300 meV below the Fermi energy was observed, in agreement with electronic structure-photoemission calculations. Only little additional spectral weight due to other states was observed at EF, which corroborates the identification of the topologically protected surface state and is highly relevant for spintronics applications.

  4. Magnetic and magnetocaloric properties of martensitic Ni2Mn1.4Sn0.6 Heusler alloy

    International Nuclear Information System (INIS)

    Chernenko, Volodymyr A.; Barandiarán, Jose M.; Rodriguez Fernández, Jesus; Rojas, Daniel P.; Gutiérrez, Jon; Lázpita, Patricia; Orue, Iñaki

    2012-01-01

    The evolutions of magnetic properties at low temperatures and the influence of magnetic field on the temperature dependence of specific heat in martensitic Ni 2 Mn 1.4 Sn 0.6 Heusler alloy are studied. The frequency-dependent blocking temperature and considerable exchange bias below it are measured in the martensitic phase. From the analysis of the specific heat curves under magnetic field, a large inverse magnetocaloric effect manifested as the magnetic field induced rise of isothermal magnetic entropy and/or magnetic field induced adiabatic temperature decrease in the vicinity of the reverse magnetostructural transformation and a significant value of the conventional magnetocaloric effect at the Curie temperature are obtained. The Debye temperature and electronic coefficient equal to Θ D =310±2 K and γ= 16.6±0.3 mJ/K 2 mol, respectively, do not depend on the magnetic field.

  5. Magnetic and magnetocaloric properties of Ni-Mn-Cr-Sn Heusler alloys under the effects of hydrostatic pressure

    Science.gov (United States)

    Pandey, Sudip; Us Saleheen, Ahmad; Quetz, Abdiel; Chen, Jing-Han; Aryal, Anil; Dubenko, Igor; Stadler, Shane; Ali, Naushad

    2018-05-01

    The magnetic, thermal, and magnetocaloric properties of Ni45Mn43CrSn11 Heusler alloy have been investigated using differential scanning calorimetry and magnetization with hydrostatic pressure measurements. A shift in the martensitic transition temperature (TM) to higher temperatures was observed with the application of pressure. The application of pressure stabilizes the martensitic state and demonstrated that pressure can be a parameter used to control and tune the martensitic transition temperature (the temperature where the largest magnetocaloric effect is observed). The magnetic entropy change significantly decreases from 33 J/kg K to 16 J/kg K under the application of a hydrostatic pressure of 0.95 GPa. The critical field of the direct metamagnetic transition increases, whereas the initial susceptibility (dM/dH) in the low magnetic field region drastically decreases with increasing pressure. The relevant parameters that affect the magnetocaloric properties are discussed.

  6. The effects of substituting Ag for In on the magnetoresistance and magnetocaloric properties of Ni-Mn-In Heusler alloys

    Directory of Open Access Journals (Sweden)

    Sudip Pandey

    2016-05-01

    Full Text Available The effect of substituting Ag for In on the structural, magnetocaloric, and thermomagnetic properties of Ni50Mn35In15−xAgx (x = 0.1, 0.2, 0.5, and 1 Heusler alloys was studied. The magnitude of the magnetization change at the martensitic transition temperature (TM decreased with increasing Ag concentration. Smaller magnetic entropy changes (ΔSM were observed for the alloys with larger Ag concentrations and the martensitic transition shifted to higher temperature. A shift of TM by about 25 K to higher temperature was observed for an applied hydrostatic pressure of P = 6.6 kbar with respect to ambient pressure. A large drop in resistivity was observed for large Ag concentration. The magnetoresistance was dramatically suppressed due to an increase in the disorder of the system with increasing Ag concentration. Possible mechanisms responsible for the observed behavior are discussed.

  7. Monocrystalline Heusler Co2FeSi alloy glass-coated microwires: Fabrication and magneto-structural characterization

    Science.gov (United States)

    Galdun, L.; Ryba, T.; Prida, V. M.; Zhukova, V.; Zhukov, A.; Diko, P.; Kavečanský, V.; Vargova, Z.; Varga, R.

    2018-05-01

    Large scale production of single crystalline phase of Heusler Co2FeSi alloy microwire is reported. The long microwire (∼1 km) with the metallic nucleus diameter of about 2 μm is characterized by well oriented monocrystalline structure (B2 phase, with the lattice parameter a = 5.615 Å). Moreover, the crystallographic direction [1 0 1] is parallel to the wire's axis along the entire length. Additionally, the wire is characterized by exhibiting a high Curie temperature (Tc > 800 K) and well-defined magnetic anisotropy mainly governed by shape. Electrical resistivity measurement reveals the exponential suppression of the electron-magnon scattering which provides strong evidence on the half-metallic behaviour of this material in the low temperature range.

  8. Pulsed high-magnetic-field experiments: New insights into the magnetocaloric effect in Ni-Mn-In Heusler alloys

    International Nuclear Information System (INIS)

    Salazar Mejía, C.; Nayak, A. K.; Felser, C.; Nicklas, M.; Ghorbani Zavareh, M.; Wosnitza, J.; Skourski, Y.

    2015-01-01

    The present pulsed high-magnetic-field study on Ni 50 Mn 35 In 15 gives an extra insight into the thermodynamics of the martensitic transformation in Heusler shape-memory alloys. The transformation-entropy change, ΔS, was estimated from field-dependent magnetization experiments in pulsed high magnetic fields and by heat-capacity measurements in static fields. We found a decrease of ΔS with decreasing temperature. This behavior can be understood by considering the different signs of the lattice and magnetic contributions to the total entropy. Our results further imply that the magnetocaloric effect will decrease with decreasing temperature and, furthermore, the martensitic transition is not induced anymore by changing the temperature in high magnetic fields

  9. RhNAC2 and RhEXPA4 Are Involved in the Regulation of Dehydration Tolerance during the Expansion of Rose Petals1[C][W][OA

    Science.gov (United States)

    Dai, Fanwei; Zhang, Changqing; Jiang, Xinqiang; Kang, Mei; Yin, Xia; Lü, Peitao; Zhang, Xiao; Zheng, Yi; Gao, Junping

    2012-01-01

    Dehydration inhibits petal expansion resulting in abnormal flower opening and results in quality loss during the marketing of cut flowers. We constructed a suppression subtractive hybridization library from rose (Rosa hybrida) flowers containing 3,513 unique expressed sequence tags and analyzed their expression profiles during cycles of dehydration. We found that 54 genes were up-regulated by the first dehydration, restored or even down-regulated by rehydration, and once again up-regulated by the second dehydration. Among them, we identified a putative NAC family transcription factor (RhNAC2). With transactivation activity of its carboxyl-terminal domain in yeast (Saccharomyces cerevisiae) cell and Arabidopsis (Arabidopsis thaliana) protoplast, RhNAC2 belongs to the NAC transcription factor clade related to plant development in Arabidopsis. A putative expansin gene named RhEXPA4 was also dramatically up-regulated by dehydration. Silencing RhNAC2 or RhEXPA4 in rose petals by virus-induced gene silencing significantly decreased the recovery of intact petals and petal discs during rehydration. Overexpression of RhNAC2 or RhEXPA4 in Arabidopsis conferred strong drought tolerance in the transgenic plants. RhEXPA4 expression was repressed in RhNAC2-silenced rose petals, and the amino-terminal binding domain of RhNAC2 bound to the RhEXPA4 promoter. Twenty cell wall-related genes, including seven expansin family members, were up-regulated in Arabidopsis plants overexpressing RhNAC2. These data indicate that RhNAC2 and RhEXPA4 are involved in the regulation of dehydration tolerance during the expansion of rose petals and that RhEXPA4 expression may be regulated by RhNAC2. PMID:23093360

  10. Construction of porous covalent organic polymer as photocatalysts for RhB degradation under visible light

    Institute of Scientific and Technical Information of China (English)

    Pingxiao Liu; Lingbao Xing; Hongtao Lin; Haining Wang; Ziyan Zhou; Zhongmin Su

    2017-01-01

    In the present work,a novel porous,and chemically stable amine-based covalent organic polymer (POP-1) was designed and synthesized under solvothermal conditions.The porosity,crystallinity,chemical stability,electrochemical properties,and diffuse reflectance of POP-1 were investigated via N2 sorption experiment,power X-ray diffraction,thermogravimetric analysis,cyclic voltammetry,and ultraviolet visible near infrared spectrometry,respectively.POP-1 exhibits good chemical stability in both acidic and alkaline aqueous solutions,as well as in organic solvents.Undoped POP-1 can be directly used as a photocatalyst for rhodamine B irradiation degradation under light-emitting diode and natural light.The Ea of POP-1 for RhB degradation is 82.37 kJ/mol.Furthermore,POP-1 can be reused as a catalyst in RhB degradation without degraded catalytic activity.

  11. Flattening and manipulation of the electronic structure of h-BN/Rh(111) nanomesh upon Sn intercalation

    Science.gov (United States)

    Sugiyama, Yuya; Bernard, Carlo; Okuyama, Yuma; Ideta, Shin-ichiro; Tanaka, Kiyohisa; Greber, Thomas; Hirahara, Toru

    2018-06-01

    We have deposited Sn on corrugated hexagonal boron nitride (h-BN) nanomeshs formed on Rh(111) and found that Sn atoms are intercalated between h-BN and Rh, flattening the h-BN. Our reflection high-energy electron diffraction (RHEED) analysis showed that the average in-plane lattice constant of h-BN increases due to the loss of the corrugation. Furthermore, electronic structure measurements based on angle-resolved photoemission spectroscopy (ARPES) showed that the h-BN π band width increases significantly while the σ band width does not change as much. These behaviors were partly different from previous reports on the intercalation of h-BN/Rh system. Our results offer a novel, simple method to control the electronic structure of h-BN.

  12. Cloning and functional analysis of promoters of three GnRH genes in a cichlid

    International Nuclear Information System (INIS)

    Kitahashi, Takashi; Sato, Hideki; Sakuma, Yasuo; Parhar, Ishwar S.

    2005-01-01

    Mechanisms regulating gonadotropin-releasing hormone (GnRH) types, a key molecule for reproductive physiology, remain unclear. In the present study, we cloned the promoters of GnRH1, GnRH2, and GnRH3 genes in the tilapia, Oreochromis niloticus; and found putative binding sites for glucocorticoid receptors, Sp1, C/EBP, GATA, and Oct-1, but not for androgen receptors in all three GnRH promoters using computer analysis. The presence of binding sites for progesterone receptors in GnRH1, estrogen receptors in GnRH1 and GnRH2, and thyroid hormone receptors in GnRH1 and GnRH3 suggests direct action of steroid hormones on GnRH types. Our observation of SOX and LINE-like sequences exclusively in GnRH1, COUP in GnRH2, and retinoid X receptors in GnRH3 suggests their role in sexual differentiation, midbrain segmentation, and visual cue integration, respectively. Thus, the characteristic binding sites for nuclear receptors and transcription factors support the notion that each GnRH type is regulated differently and has distinct physiological roles

  13. Sensitive criterion for chirality; Chiral doublet bands in 104Rh59

    International Nuclear Information System (INIS)

    Koike, T.; Starosta, K.; Vaman, C.; Ahn, T.; Fossan, D.B.; Clark, R.M.; Cromaz, M.; Lee, I.Y.; Macchiavelli, A.O.

    2003-01-01

    A particle plus triaxial rotor model was applied to odd-odd nuclei in the A ∼ 130 region in order to study the unique parity πh11/2xνh11/2 rotational bands. With maximum triaxiality assumed and the intermediate axis chosen as the quantization axis for the model calculations, the two lowest energy eigenstates of a given spin have chiral properties. The independence of the quantity S(I) on spin can be used as a new criterion for chirality. In addition, a diminishing staggering amplitude of S(I) with increasing spin implies triaxiality in neighboring odd-A nuclei. Chiral quartet bases were constructed specifically to examine electromagnetic properties for chiral structures. A set of selection rules unique to chirality was derived. Doublet bands built on the πg9/2xνh11/2 configuration have been discovered in odd-odd 104Rh using the 96Zr(11B, 3n) reaction. Based on the discussed criteria for chirality, it is concluded that the doublet bands observed in 104Rh exhibit characteristic chiral properties suggesting a new region of chirality around A ∼110. In addition, magnetic moment measurements have been performed to test the πh11/2xνh11/2 configuration in 128Cs and the πg9/2xνh11/2 configuration in 104Rh

  14. Effect of graphene tunnel barrier on Schottky barrier height of Heusler alloy Co2MnSi/graphene/n-Ge junction

    International Nuclear Information System (INIS)

    Li Gui-fang; Hu Jing; Lv Hui; Cui Zhijun; Hou Xiaowei; Liu Shibin; Du Yongqian

    2016-01-01

    We demonstrate that the insertion of a graphene tunnel barrier between Heusler alloy Co 2 MnSi and the germanium (Ge) channel modulates the Schottky barrier height and the resistance–area product of the spin diode. We confirm that the Fermi level is depinned and a reduction in the electron Schottky barrier height (SBH) occurs following the insertion of the graphene layer between Co 2 MnSi and Ge. The electron SBH is modulated in the 0.34 eV–0.61 eV range. Furthermore, the transport mechanism changes from rectifying to symmetric tunneling following the insertion. This behavior provides a pathway for highly efficient spin injection from a Heusler alloy into a Ge channel with high electron and hole mobility. (paper)

  15. Effect of graphene tunnel barrier on Schottky barrier height of Heusler alloy Co2MnSi/graphene/n-Ge junction

    Science.gov (United States)

    Gui-fang, Li; Jing, Hu; Hui, Lv; Zhijun, Cui; Xiaowei, Hou; Shibin, Liu; Yongqian, Du

    2016-02-01

    We demonstrate that the insertion of a graphene tunnel barrier between Heusler alloy Co2MnSi and the germanium (Ge) channel modulates the Schottky barrier height and the resistance-area product of the spin diode. We confirm that the Fermi level is depinned and a reduction in the electron Schottky barrier height (SBH) occurs following the insertion of the graphene layer between Co2MnSi and Ge. The electron SBH is modulated in the 0.34 eV-0.61 eV range. Furthermore, the transport mechanism changes from rectifying to symmetric tunneling following the insertion. This behavior provides a pathway for highly efficient spin injection from a Heusler alloy into a Ge channel with high electron and hole mobility. Project supported by the National Natural Science Foundation of China (Grant No. 61504107) and the Fundamental Research Funds for the Central Universities, China (Grant Nos. 3102014JCQ01059 and 3102015ZY043).

  16. Influence of intermetallic Fe and Co on crystal structure disorder and magnetic property of Ni50Mn32Al18 Heusler alloy

    International Nuclear Information System (INIS)

    Notonegoro, H. A.; Kurniawan, B.; Manaf, A.; Setiawan, J.; Nanto, D.

    2016-01-01

    This works reports a study on structure and magnetic properties influenced by both Fe and Co on Ni 50 Mn 32 Al 18 Heusler alloy as a candidate of magnetocaloric effect (MCE) materials. The Ni-Fe-Mn-Co-Al sample was prepared by arc melting furnace (AMF) in high purity argon atmosphere. X-ray diffraction investigation and magnetic hysteresis were conducted to characterize the synthesized sample. X-ray diffraction using Cu-Kα pattern shows that both Fe and Co introduce a tungsten type disorder of Ni 50 Mn 32 Al 18 Heusler alloy which partially replace the site position of Ni and Mn respectively. However, in this tungsten type disorder, it is difficult to distinguish the exact position of each constituent atom. Therefore, we believe it may allow any exchange interaction of each electron possessed the atom. Interestingly, it produced a significant increase in the value of the hysteresis magnetic saturation. (paper)

  17. Corifollitropin alfa followed by rFSH in a GnRH antagonist protocol for poor ovarian responder patients

    DEFF Research Database (Denmark)

    Polyzos, Nikolaos P; Devos, Michel; Humaidan, Peter

    2013-01-01

    OBJECTIVE: To identify whether women with poor ovarian response may benefit from treatment with corifollitropin alfa in a GnRH antagonist protocol. DESIGN: Retrospective pilot study. SETTING: University-based tertiary care center. PATIENT(S): Poor ovarian responders fulfilling the Bologna criteria...... developed by European Society for Human Reproduction and Embryology Consensus Group. INTERVENTION(S): Corifollitropin alfa (150 μg) followed by 300 IU rFSH in a GnRH antagonist protocol. MAIN OUTCOME MEASURE(S): Endocrinologic profile and ongoing pregnancy rates. RESULT(S): Among 43 women treated...

  18. Bifunctional chelates of Rh-105 and Au-199 as potential radiotherapeutic agents

    International Nuclear Information System (INIS)

    Troutner, D.E.; Schlemper, E.O.

    1990-01-01

    Since last year we have: continued the synthesis of pentadentate bifunctional chelating agents based on diethylene triamine; studied the chelation Rh-105, Au-198 (as model for Au-199) and Tc-99m with these agents as well as chelation of Pd-109, Cu-67, In-111, and Co-57 with some of them; synthesized a new class of potential bifunctional chelating agents based on phenylene diamine; investigated the behavior of Au-198 as a model for Au-199; begun synthesis of bifunctional chelating agents based on terpyridly and similar ligands; and continued attempts to produce tetradentate bifunctional chelates based on diaminopropane. Each of these will be addressed in this report

  19. The system Cu-Rh-S at 900 degrees, 700 degrees, 540 degrees and 500 degrees C

    DEFF Research Database (Denmark)

    Karup-Møller, Sven; Makovicky, E.

    2007-01-01

    Phase relations in the dry condensed system Cu-Rh-S were determined at 900, 700, 540 and 500 degrees C. At 900 degrees C, the system contains digenite, four rhodium sulfides (Rh17S15, Rh3S4, Rh2S3 and RhS similar to 3), three ternary sulfides (CuRh2S4, CuxRhS3+x and a fibrous sulfide in the range...

  20. Magnetocaloric effect in “reduced” dimensions: Thin films, ribbons, and microwires of Heusler alloys and related compounds: Magnetocaloric effect in “reduced” dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Khovaylo, Vladimir V. [National University of Science and Technology MISiS, Moscow 119049 Russia; ITMO University, St. Petersburg 197101 Russia; Rodionova, Valeria V. [National University of Science and Technology MISiS, Moscow 119049 Russia; Innovation Park and Institute of Physics & Technology, Immanuel Kant Baltic Federal University, Kaliningrad 236041 Russia; Shevyrtalov, Sergey N. [Innovation Park and Institute of Physics & Technology, Immanuel Kant Baltic Federal University, Kaliningrad 236041 Russia; Novosad, Val [Materials Science Division, Argonne National Laboratory, Argonne IL 60439 USA

    2014-08-19

    Room temperature magnetic refrigeration is an energy saving and environmentally-friendly technology which has developed rapidly from a basic idea to prototype devices. The performance of magnetic refrigerators crucially depends on the magnetocaloric properties and the geometry of the employed refrigerants. Here we review the magnetocaloric properties of Heusler alloys and related compounds with a high surface to volume ratio such as films, ribbons and microwires, and compare them with their bulk counterparts.

  1. Thermoelectric properties of fine-grained FeVSb half-Heusler alloys tuned to p-type by substituting vanadium with titanium

    International Nuclear Information System (INIS)

    Zou, Minmin; Li, Jing-Feng; Kita, Takuji

    2013-01-01

    Fine-grained Ti-doped FeVSb half-Heusler alloys were synthesized by combining mechanical alloying and spark plasma sintering and their thermoelectric properties were investigated with an emphasis on the influences of Ti doping and phase purity. It was found that substituting V with Ti can change the electrical transport behavior from n-type to p-type due to one less valence electron of Ti than V, and the sample with nominal composition FeV 0.8 Ti 0.4 Sb exhibits the largest Seebeck coefficient and the maximum power factor. By optimizing the sintering temperature and applying annealing treatment, the power factor is significantly improved and the thermal conductivity is reduced simultaneously, resulting in a ZT value of 0.43 at 500 °C, which is relatively high as for p-type half-Heusler alloys containing earth-abundant elements. - Graphical abstract: Fine-grained Ti-doped FeVSb alloys were prepared by the MA-SPS method. The maximum ZT value reaches 0.43 at 500 °C, which is relatively high for p-type half-Heusler alloys. Highlights: ► Ti-doped FeVSb half-Heusler alloys were synthesized by combining MA and SPS. ► Substituting V with Ti changes the electrical behavior from n-type to p-type. ► Thermoelectric properties are improved by optimizing sintering temperature. ► Thermoelectric properties are further improved by applying annealing treatment. ► A high ZT value of 0.43 is obtained at 500 °C for p-type Ti-doped FeVSb alloys.

  2. Electrical resistivity at high temperatures of Heusler alloys of the Cu2MnAl sub(1-x) Sn sub (x)

    International Nuclear Information System (INIS)

    Grandi, T.A.

    1978-01-01

    The structural fase L2 1 of the Heusler alloys Cu 2 MnAl sub (1-x) Sn sub(x), with x varying between 0 and 1, was studied. X-ray diffraction, metallography and diferential termoanalysis techniques were employed. For the alloys with x = 0; 0,05; 0,10 and 0,15 the electrical resistivity measurements were performed in the temperature range 300 K [pt

  3. Electronic and magnetic properties of the Co{sub 2}MnAl/Au interface: Relevance of the Heusler alloy termination

    Energy Technology Data Exchange (ETDEWEB)

    Makinistian, L., E-mail: lmakinistian@santafe-conicet.gov.ar [Instituto de Física del Litoral (CONICET-UNL), Güemes 3450, 3000 Santa Fe (Argentina); Facultad de Ingeniería, Universidad Nacional de Entre Ríos, 3101 Oro Verde (Argentina); Albanesi, E.A. [Instituto de Física del Litoral (CONICET-UNL), Güemes 3450, 3000 Santa Fe (Argentina); Facultad de Ingeniería, Universidad Nacional de Entre Ríos, 3101 Oro Verde (Argentina)

    2015-07-01

    We present ab initio calculations of electronic and magnetic properties of the ferromagnetic metal/normal metal (F/N) interface of the Heusler alloy Co{sub 2}MnAl and gold. Two structural models are implemented: one with the ferromagnet slab terminated in a pure cobalt plane (“Co{sub 2}-t”), and the other with it terminated with a plane of MnAl (“MnAl-t”). The relaxed optimum distance between the slabs is determined for the two models before densities of states, magnetic moments, and the electric potential are resolved and analyzed layer by layer through the interface. Complementary, calculations for the free surfaces of gold and the Heusler alloy (for both models, Co{sub 2}-t and MnAl-t) are performed for a better interpretation of the physics of the interface. We predict important differences between the two models, suggesting that both terminations are to be expected to display sensibly different spin injection performances. - Highlights: • Ab initio electronic and magnetic properties of the interface Co{sub 2}MnAl/Au. • Two terminations were studied: Co{sub 2} and MnAl terminated. • The termination of the Heusler alloy sensibly determines the interface properties. • The Co{sub 2} terminated interface displays a higher spin polarization.

  4. Evolution of triaxial shapes at large isospin: Rh isotopes

    Directory of Open Access Journals (Sweden)

    A. Navin

    2017-04-01

    Full Text Available The rotational response as a function of neutron–proton asymmetry for the very neutron-rich isotopes of Rh (116–119Rh has been obtained from the measurement of prompt γ rays from isotopically identified fragments, produced in fission reactions at energies around the Coulomb barrier. The measured energy “signature” splitting of the yrast bands, when compared with the Triaxial Projected Shell Model (TPSM calculations, shows the need for large, nearly constant, triaxial deformations. The present results are compared with global predictions for the existence of non axial shapes in the periodic table in the case of very neutron-rich nuclei Rh isotopes. The predicted trend of a second local maximum for a triaxial shape around N∼74 is not found.

  5. Physical Modelling Of The Steel Flow In RH Apparatus

    Directory of Open Access Journals (Sweden)

    Pieprzyca J.

    2015-09-01

    Full Text Available The efficiency of vacuum steel degassing using RH methods depends on many factors. One of the most important are hydrodynamic processes occurring in the ladle and vacuum chamber. It is always hard and expensive to determine the flow character and the way of steel mixing in industrial unit; thus in this case, methods of physical modelling are applied. The article presents the results of research carried out on the water physical model of RH apparatus concerning the influence of the flux value of inert gas introduced through the suck legs on hydrodynamic conditions of the process. Results of the research have visualization character and are presented graphically as a RTD curves. The main aim of such research is to optimize the industrial vacuum steel degassing process by means of RH method.

  6. Evaluation of (101)Rh as a brachytherapy source.

    Science.gov (United States)

    Pakravan, Delaram; Ghorbani, Mahdi; Meigooni, Ali Soleimani

    2015-04-01

    Recently a number of hypothetical sources have been proposed and evaluated for use in brachytherapy. In the present study, a hypothetical (101)Rh source with mean photon energy of 121.5 keV and half-life of 3.3 years, has been evaluated as an alternative to the existing high-dose-rate (HDR) sources. Dosimetric characteristics of this source model have been determined following the recommendation of the Task Group 43 (TG-43) of the American Association of the Physicist in Medicine (AAPM), and the results are compared with the published data for (57)Co source and Flexisource (192)Ir sources with similar geometries. MCNPX Monte Carlo code was used for simulation of the (101)Rh hypothetical HDR source design. Geometric design of this hypothetical source was considered to be similar to that of Flexisource (192)Ir source. Task group No. 43 dosimetric parameters, including air kerma strength per mCi, dose rate constant, radial dose function, and two dimensional (2D) anisotropy functions were calculated for the (101)Rh source through simulations. Air kerma strength per activity and dose rate constant for the hypothetical (101)Rh source were 1.09 ± 0.01 U/mCi and 1.18 ± 0.08 cGy/(h.U), respectively. At distances beyond 1.0 cm in phantom, radial dose function for the hypothetical (101)Rh source is higher than that of (192)Ir. It has also similar 2D anisotropy functions to the Flexisource (192)Ir source. (101)Rh is proposed as an alternative to the existing HDR sources for use in brachytherapy. This source provides medium energy photons, relatively long half-life, higher dose rate constant and radial dose function, and similar 2D anisotropy function to the Flexisource (192)Ir HDR source design. The longer half-life of the source reduces the frequency of the source exchange for the clinical environment.

  7. Mechanisms of spectral tuning in the RH2 pigments of Tokay gecko and American chameleon.

    Science.gov (United States)

    Takenaka, Naomi; Yokoyama, Shozo

    2007-09-01

    At present, molecular bases of spectral tuning in rhodopsin-like (RH2) pigments are not well understood. Here, we have constructed the RH2 pigments of nocturnal Tokay gecko (Gekko gekko) and diurnal American chameleon (Anolis carolinensis) as well as chimeras between them. The RH2 pigments of the gecko and chameleon reconstituted with 11-cis-retinal had the wavelengths of maximal absorption (lambda(max)'s) of 467 and 496 nm, respectively. Chimeric pigment analyses indicated that 76-86%, 14-24%, and 10% of the spectral difference between them could be explained by amino acid differences in transmembrane (TM) helices I-IV, V-VII, and amino acid interactions between the two segments, respectively. Evolutionary and mutagenesis analyses revealed that the lambda(max)'s of the gecko and chameleon pigments diverged from each other not only by S49A (serine to alanine replacement at residue 49), S49F (serine to phenylalanine), L52M (leucine to methionine), D83N (aspartic acid to asparagine), M86T (methionine to threonine), and T97A (threonine to alanine) but also by other amino acid replacements that cause minor lambda(max)-shifts individually.

  8. Mechanisms of spectral tuning in the RH2 pigments of Tokay gecko and American chameleon

    Science.gov (United States)

    Takenaka, Naomi; Yokoyama, Shozo

    2009-01-01

    At present, molecular bases of spectral tuning in rhodopsin-like (RH2) pigments are not well understood. Here, we have constructed the RH2 pigments of nocturnal Tokay gecko (Gekko gekko) and diurnal American chameleon (Anolis carolinensis) as well as chimeras between them. The RH2 pigments of the gecko and chameleon reconstituted with 11-cis-retinal had the wavelengths of maximal absorption (λmax’s) of 467 and 496 nm, respectively. Chimeric pigment analyses indicated that 76–86%, 14–24%, and 10% of the spectral difference between them could be explained by amino acid differences in transmembrane (TM) helices I~IV, V~VII, and amino acid interactions between the two segments, respectively. Evolutionary and mutagenesis analyses revealed that the λmax’s of the gecko and chameleon pigments diverged from each other not only by S49A (serine to alanine replacement at residue 49), S49F (serine to phenylalanine), L52M (leucine to methionine), D83N (aspartic acid to asparagine), M86T (methionine to thereonine), and T97A (threonine to alanine) but also by other amino acid replacements that cause minor λmax-shifts individually. PMID:17590287

  9. 211At-Rh(16-S4-diol) complex as a precursor for astatine radiopharmaceuticals

    International Nuclear Information System (INIS)

    Pruszynski, M.; Bilewicz, A.

    2006-01-01

    211 At is one of the most promising radionuclides in α-radioimmunotherapy (α-RIT). Unfortunately, biomolecules labeled by direct electrophilic astatination are unstable due to the rapid loss of 211 At under both in vitro and in vivo conditions. The present paper describes the results of our studies on attaching At - to the rhodium(III) complex with thioether ligand: 1,5,9,13-etrathiacyclohexadecane-3,11-diol (16-S4-diol). Rh 3+ was chosen as a moderately soft metal cation which should form very strong bonds with soft At - anions, but first of all because of the kinetic inertness of low spin rhodium(III) d 6 complexes. The 16-S4-diol ligand was selected due to formation of stable complexes with Rh 3+ . The experiments related to optimization of the reaction conditions were performed with the 131 I, basing on a chemical similarity of I - to At - . The experiments with 211 At were then carried out under the conditions found optimal for I - . The preliminary results are promising, and indicate a possibility for astatination of biomolecules by using the 211 At-Rh(16-S4-diol) complex

  10. Radiation chemical behavior of Rh(III) in HClO4 and HNO3

    International Nuclear Information System (INIS)

    Vladimirova, M.V.; Khalkina, E.V.

    1995-01-01

    The radiation chemical behavior of Rh is very interesting since Rh accumulates in irradiated U but has not been reported in the literature. Scattered data do exist for the radiation chemical behavior of Rh(III) in weakly acidic and alkaline solutions. Pulsed radiolysis was used to investigate the formation of unstable oxidation states of Rh during reduction and oxidation of Rh(III) in neutral solutions. The rate constant of the reaction Rh(III) + e aq - was found to be 6·10 10 liter/mole·sec. The radiation chemical behavior of Rh(III) toward γ-radiolysis in neutral, weakly acidic (up to 0.1 N), and alkaline solutions was examined. In neutral solutions of [Rh(NH 3 ) 5 Cl]Cl 2 and RhCl 3 , metallic Rh is formed. The degree of reduction is ∼ 1%. In neutral and weakly acidic solutions of Rh(NO 3 ) 3 , Rh 2 O 3 ·xH 2 O is formed. Irradiation of Rh(ClO 4 ) 3 solutions produces no reduction. The radiation chemical behavior of Rh(III) in HClO 4 and HNO 3 solutions at concentrations > 1 M is studied in the present work

  11. Partitioning of rhodium and ruthenium between Pd–Rh–Ru and (Ru,Rh)O{sub 2} solid solutions in high-level radioactive waste glass

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, Toru, E-mail: toru@gipc.akita-u.ac.jp [Center for Engineering Science, Akita University, 1-1, Tegatagakuenmachi, Akita City, Akita 010-8502 (Japan); Ohira, Toshiaki [Center for Engineering Science, Akita University, 1-1, Tegatagakuenmachi, Akita City, Akita 010-8502 (Japan); Komamine, Satoshi; Ochi, Eiji [Research and Development Department, Reprocessing Business Division, Japan Nuclear Fuel Limited, 4-108, Okitsuke, Obuchi, Rokkasho-mura, Aomori 039-3212 (Japan)

    2015-10-15

    The partitioning of rhodium and ruthenium between Pd–Rh–Ru alloy with a face-centered cubic (FCC) structure and (Ru,Rh)O{sub 2} solid solution has been investigated between 1273 and 1573 K at atmospheric oxygen fugacity. The rhodium and ruthenium contents in FCC increase, while the RhO{sub 2} content in (Ru,Rh)O{sub 2} decreases with increasing temperature due to progressive reduction of the system. Based on the experimental results and previously reported thermodynamic data, the thermodynamic mixing properties of FCC phase and (Ru,Rh)O{sub 2} have been calibrated in an internally consistent manner. Phase equilibrium of platinum grope metals in an HLW glass was calculated by using the obtained thermodynamic parameters.

  12. Structure sensitivity of CO dissociation on Rh surfaces

    DEFF Research Database (Denmark)

    Mavrikakis, Manos; Baumer, M.; Freund, H.J.

    2002-01-01

    than the flat surface, but the effect is considerably weaker than the effect of surface structure on the dissociation barrier. Our findings are compared with available experimental data, and the consequences for CO activation in methanation and Fischer-Tropsch reactions are discussed.......Using periodic self-consistent density functional calculations it is shown that the barrier for CO dissociation is similar to120 kJ/mol lower on the stepped Rh(211) surface than on the close-packed Rh(111) surface. The stepped surface binds molecular CO and the dissociation products more strongly...

  13. Reproductive physiology of a humanized GnRH receptor mouse model: application in evaluation of human-specific analogs.

    Science.gov (United States)

    Tello, Javier A; Kohout, Trudy; Pineda, Rafael; Maki, Richard A; Scott Struthers, R; Millar, Robert P

    2013-07-01

    The human GnRH receptor (GNRHR1) has a specific set of properties with physiological and pharmacological influences not appropriately modeled in laboratory animals or cell-based systems. To address this deficiency, we have generated human GNRHR1 knock-in mice and described their reproductive phenotype. Measurement of pituitary GNRHR1 transcripts from homozygous human GNRHR1 knock-in (ki/ki) mice revealed a severe reduction (7- to 8-fold) compared with the mouse Gnrhr1 in wild-type mice. ¹²⁵I-GnRH binding assays on pituitary membrane fractions corroborated reduced human GNRHR1 protein expression in ki/ki mice, as occurs with transfection of human GNRHR1 in cell lines. Female homozygous knock-in mice displayed normal pubertal onset, indicating that a large reduction in GNRHR1 expression is sufficient for this process. However, ki/ki females exhibited periods of prolonged estrous and/or metestrous and reduced fertility. No impairment was found in reproductive maturity or adult fertility in male ki/ki mice. Interestingly, the serum LH response to GnRH challenge was reduced in both knock-in males and females, indicating a reduced GNRHR1 signaling capacity. Small molecules targeting human GPCRs usually have poor activities at homologous rodent receptors, thus limiting their use in preclinical development. Therefore, we tested a human-specific GnRH1 antagonist, NBI-42902, in our mouse model and demonstrated abrogation of a GnRH1-induced serum LH rise in ki/ki mice and an absence of effect in littermates expressing the wild-type murine receptor. This novel model provides the opportunity to study the human receptor in vivo and for screening the activity of human-specific GnRH analogs.

  14. Tritium and radiocarbon levels in the Rhône river delta and along the French Mediterranean coastline.

    Science.gov (United States)

    Jean-Baptiste, P; Fontugne, M; Fourré, E; Marang, L; Antonelli, C; Charmasson, S; Siclet, F

    2018-07-01

    The Rhône is characterised by a heavy concentration of nuclear-based industries including nuclear power stations and nuclear sites housing civilian and military facilities. Here, we report the results of a four-year survey (2010-2013) of tritium and radiocarbon levels in a variety of matrices within the Rhône delta and along the French Mediterranean coastline. The aim of the study is to create a spatial reference framework of environmental levels of these two radionuclides, which are the most prevalent in radioactive effluents from nuclear power stations. Although both tritium and radiocarbon levels in the samples analysed are very low and can only be detected using ultra-sensitive analytical techniques, they clearly show the influence of the tritium and radiocarbon discharges carried by the Rhône plume along the Mediterranean coast. The tritium content of suspended matter and sediments of the Rhône is a special case, which shows elevated tritium values not seen in other French rivers with similar nuclear facilities. The north-south spatial distribution of this tritium anomaly shows that these trace values are at their highest in the upper Rhône, close to the Swiss border and upstream of Creys Malville, the northernmost nuclear power station on the Rhône. This points to a legacy of past tritium releases by the watchmaking industry. A dedicated study would be needed to clearly identify the source and the exact nature of this contamination. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Direct Functionalization of Nitrogen Heterocycles via Rh-Catalyzed C-H Bond Activation

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Jared; Bergman, Robert; Ellman, Jonathan

    2008-02-04

    heterocycles, including azoles, azolines, dihydroquinazolines, pyridines, and quinolines, with a wide range of functionalized olefins. They demonstrated the utility of this methodology in the synthesis of natural products, drug candidates, and other biologically active molecules. In addition, they developed conditions to directly arylate these heterocycles with aryl halides. The initial conditions that used PCy{sub 3} as a ligand were successful only for aryl iodides. However, efforts designed to avoid catalyst decomposition led to the development of ligands based on 9-phosphabicyclo[4.2.1]nonane (Phoban) that also facilitated the coupling of aryl bromides. They then replicated the unique coordination environment, stability, and catalytic activity of this complex using the much simpler tetrahydrophosphepine ligands and developed conditions that coupled aryl bromides bearing diverse functional groups without the use of a glovebox or purified reagents. With further mechanistic inquiry, they anticipate that researchers will better understand the details of the aforementioned Rh-catalyzed C-H bond functionalization reactions, resulting in the design of more efficient and robust catalysts, expanded substrate scope, and new transformations.

  16. Treatment of extremely severe acute hemopoietic radiation sickness beagles with RhG-CSF and RhIL-11

    International Nuclear Information System (INIS)

    Zhao Jianzhi; Zhang Ri; Li Ming; Xing Shuang; Luo Qingliang; Zhang Xueguang; Miao Jingcheng; Zhu Nankang

    2010-01-01

    Objective: To evaluate the effects of treatment combined recombinant human G-CSF (rhG-CSF) and recombinant human interleukin-11 (rhIL-11) on severe acute hemopoietic radiation sickness (ARS) beagles. Methods: Beagles were irradiated with 4.5 Gy 60 Co γ-ray to establish ARS models, and animals were divided into the irradiated control group and the supportive care and combined cytokines treatment cohort. After irradiation the irradiated control beagles was given no treatment, the supportive care beagles received purely symptomatic treatment including blood transfusion and anti-infection while the combined cytokines treatment beagles received rhG-CSF and rhIL-11 subcutaneously for three weeks besides symptomatic treatment.Results After irradiation, all kinds of cells' population declined sharply, but rebounded to normal basically in the combined cytokines treatment rate in the cohort. The mean blood transfusion volume of cytokines in the cohort and the period of blood transfusion all were less than those in the supportive care cohort (P<0.01). The period of administrated antibiotic of cytokines in the cohort was shorter than that in the supportive care cohort (P<0.05). In the observe period of 45 d, survival rate in the irradiated controls cohort was 0%, in the supportive care cohort was 80%, and in the combined cytokines treatment cohort was 100%(P<0.01). Conclusion: Administration of rhG-CSF and rhIL-11 early after irradiation and continued daily, in combined with supportive care in severe acute hemopoietic radiation sickness beagles can improve hematopoietic function restoration, stimulate blood cells to restore to the normal level quickly, significantly decrease the reguired volume of blood transfusion, shorten the period of anti-infection and increase survival of irradiated canines. (authors)

  17. GnRH Analogues in the Prevention of Ovarian Hyperstimulation Syndrome

    Science.gov (United States)

    Alama, Pilar; Bellver, Jose; Vidal, Carmen; Giles, Juan

    2013-01-01

    The GnRH analogue (agonist and antagonist GnRH) changed ovarian stimulation. On the one hand, it improved chances of pregnancy to obtain more oocytes and better embryos. This leads to an ovarian hyper-response, which can be complicated by the ovarian hyperstimulation syndrome (OHSS). On the other hand, the GnRH analogue can prevent the incidence of OHSS: GnRH antagonist protocols, GnRH agonist for triggering final oocyte maturation, either together or separately, coasting, and the GnRH analogue may prove useful for avoiding OHSS in high-risk patients. We review these topics in this article. PMID:23825982

  18. Red cell autoantibodies characterized by competitive inhibition of iodine 125 Rh alloantibody binding and by immunoprecipitation of membrane proteins

    International Nuclear Information System (INIS)

    Pierce, S.W.; Victoria, E.J.; Masouredis, S.P.

    1990-01-01

    The relationship between determinants recognized by warm-type immunoglobulin G red cell autoantibodies and the Rh antigens was characterized by autoantibody competitive inhibition of iodine 125 Rh alloantibody binding and autoantibody immunoprecipitation of iodine 125 red blood cell membrane proteins. The majority of blood donor autoantibody recognized epitopes that are closely related to Rh antigens as determined by competitive inhibition studies. Eighteen of 20 (90%) autoantibodies inhibited anti-Rh(c) binding, 15 inhibited anti-Rh(E), 5 inhibited anti-Rh(D), and only 2 failed to inhibit any of the three Rh alloantibodies tested. Autoantibodies that inhibited anti-Rh(D) also inhibited anti-Rh(c) and anti-Rh(E) and all those that inhibited anti-Rh(E) also inhibited anti-Rh(c). Autoantibodies that inhibited all three Rh alloantibodies immunoprecipitated 30 kd membrane polypeptides, as did two of the three autoantibodies that inhibited only anti-Rh(c) and anti-Rh(E). One autoantibody in this group and two autoantibodies that inhibited only anti-Rh(c), as well as an autoantibody that did not inhibit any of the Rh alloantibodies, immunoprecipitated only a single membrane polypeptide identified as band 3. The majority of normal donor red blood cell autoantibodies inhibited the binding of Rh alloantibodies, which indicates that they either bound to the Rh polypeptides or to epitopes on band 3 that were closely associated with the Rh complex

  19. GnRH signalling pathways and GnRH-induced homologous desensitization in a gonadotrope cell line (alphaT3-1).

    Science.gov (United States)

    Poulin, B; Rich, N; Mas, J L; Kordon, C; Enjalbert, A; Drouva, S V

    1998-07-25

    Exposure of the gonadotrope cells to gonadotropin-releasing hormone (GnRH) reduces their responsiveness to a new GnRH stimulation (homologous desensitization). The time frame as well as the mechanisms underlying this phenomenon are yet unclear. We studied in a gonadotrope cell line (alphaT3-1) the effects of short as well as long term GnRH pretreatments on the GnRH-induced phospholipases-C (PLC), -A2 (PLA2) and -D (PLD) activities, by measuring the production of IP3, total inositol phosphates (IPs), arachidonic acid (AA) and phosphatidylethanol (PEt) respectively. We demonstrated that although rapid desensitization of GnRH-induced IP3 formation did not occur in these cells, persistent stimulation of cells with GnRH or its analogue resulted in a time-dependent attenuation of GnRH-elicited IPs formation. GnRH-induced IPs desensitization was potentiated after direct activation of PKC by the phorbol ester TPA, suggesting the involvement of distinct mechanisms in the uncoupling exerted by either GnRH or TPA on GnRH-stimulated PI hydrolysis. The levels of individual phosphoinositides remained unchanged under any desensitization condition applied. Interestingly, while the GnRH-induced PLA2 activity was rapidly desensitized (2.5 min) after GnRH pretreatments, the neuropeptide-evoked PLD activation was affected at later times, indicating an important time-dependent contribution of these enzymatic activities in the sequential events underlying the GnRH-induced homologous desensitization processes in the gonadotropes. Under GnRH desensitization conditions, TPA was still able to induce PLD activation and to further potentiate the GnRH-evoked PLD activity. AlphaT3-1 cells possess several PKC isoforms which, except PKCzeta, were differentially down-regulated by TPA (PKCalpha, betaII, delta, epsilon, eta) or GnRH (PKCbetaII, delta, epsilon, eta). In spite of the presence of PKC inhibitors or down-regulation of PKC isoforms by TPA, the desensitizing effect of the neuropeptide on

  20. Activity of PtSnRh/C nanoparticles for the electrooxidation of C1 and C2 alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Teran, Freddy E. [Universite de Poitiers, IC2MP UMR CNRS 7285, ' Equipe E-lyse' , 4 rue Michel Brunet-B27, BP 633, 86022 Poitiers cedex (France); Santos, Deise M. [Departamento de Quimica, CCE-UFES, Av. Fernando Ferrari, 514, Goiabeiras-Vitoria, ES (Brazil); Ribeiro, Josimar, E-mail: josimar.ribeiro@ufes.br [Universite de Poitiers, IC2MP UMR CNRS 7285, ' Equipe E-lyse' , 4 rue Michel Brunet-B27, BP 633, 86022 Poitiers cedex (France); Departamento de Quimica, CCE-UFES, Av. Fernando Ferrari, 514, Goiabeiras-Vitoria, ES (Brazil); Kokoh, Kouakou B. [Universite de Poitiers, IC2MP UMR CNRS 7285, ' Equipe E-lyse' , 4 rue Michel Brunet-B27, BP 633, 86022 Poitiers cedex (France)

    2012-07-01

    A systematic investigation of alcohol adsorption and oxidation on binary and ternary electrocatalysts in acid medium was performed. Binary (PtRh) and ternary (PtRhSn) were prepared by the Pechini modified method on carbon Vulcan XC-72, and different nominal compositions were characterized by energy dispersive X-ray and X-ray diffraction (XRD) techniques. The XRD results showed that the Pt{sub 80}Rh{sub 20}/C and Pt{sub 70}Sn{sub 10}Rh{sub 20}/C electrocatalysts consisted of the Pt displaced phase, suggesting the formation of a solid solution between the metals Pt/Rh and Pt/Sn. Electrochemical investigations on these different electrode materials were carried out as a function of the electrocatalyst composition, in acid medium (0.5 mol dm{sup -3} H{sub 2}SO{sub 4}), and in the absence and presence of different alcohols (methanol, ethanol and ethylene glycol). The electrochemical results obtained at room temperature have shown that the Pt{sub 70}Sn{sub 10}Rh{sub 20}/C catalyst display better catalytic activity for alcohol oxidation compared with the binary catalyst. In situ reflectance infrared spectroscopy measurements have shown that the oxidation of alcohols mentioned produced CO{sub 2} at low potentials indicating that the materials synthesized could be used as efficient anodes in the fuel cell applications. - Highlights: Black-Right-Pointing-Pointer Pt-based catalysts were synthesized by thermal decomposition polymeric precursors. Black-Right-Pointing-Pointer Pt{sub 70}Sn{sub 10}Rh{sub 20}/C displays better catalytic activity for the oxidation of alcohols. Black-Right-Pointing-Pointer The co-catalysts tin and rhodium promote the removal of CO to CO{sub 2} at low potentials. Black-Right-Pointing-Pointer Ethylene glycol is oxidizing strongly to CO{sub 2} at low potentials. Black-Right-Pointing-Pointer Pt{sub 70}Sn{sub 10}Rh{sub 20}/C catalyst is an efficient anode material for a direct alcohol fuel cell.

  1. Update of the evaluation of the cross section of the neutron dosimetry reaction 103Rh(n,n')103mRh

    International Nuclear Information System (INIS)

    Pavlik, A.; Miah, M.M.H.; Strohmaier, B.; Vonach, H.

    1995-10-01

    On the occasion of a new measurement of the excitation function of the reaction 103 Rh(n,n') 103m Rh in the energy range between 5.69 and 12.0 MeV performed at the present institute in collaboration wit the PTB Braunschweig, the cross section of this reaction, which is part of the International Reactor Dosimetry Field (IRDF-90), was re-evaluated. Whereas the energy range of the evaluation, namely from threshold to 20 MeV, was kept unchanged with respect to IRDF-90, the underlying data base was extended by the experiment mentioned as well as by another measurement, and revised with regard to judgement and normalization of older data in the light of recent information. Based on the experimental data upgraded in this way, new model calculations were carried out, which in the energy region 14 - 20 MeV served to supplement the experimental cross sections for this evaluation. The cross sections and their uncertainties were evaluated in energy groups with widths of 0.2 to 1.0 MeV, and the relative correlation matrix of the evaluated cross sections at the different energies was calculated. The results presented here supersede the corresponding values published in Physics Data 13-5 and included to the IRDF-90. (author). 26 refs, 4 figs, 6 tabs

  2. Ethylene decomposition on Rh(100): theory and experiment

    NARCIS (Netherlands)

    Nieskens, D.L.S.; Bavel, van A.P.; Curulla Ferre, D.; Niemantsverdriet, J.W.

    2004-01-01

    The decompn. of ethylene on a Rh(100) single crystal has been studied by a combination of exptl. techniques: static secondary ion mass spectrometry (SSIMS), temp.-programmed desorption (TPD), LEED, and high-resoln. electron energy loss spectroscopy (HREELS), to gain insight into the nature of the

  3. The Disintegration of {sup 103}Rh{sup m}

    Energy Technology Data Exchange (ETDEWEB)

    Czock, K. H.; Haselberger, N.; Reichel, F. [International Atomic Energy Agency, Vienna (Austria)

    1974-09-15

    A technique for determination of the disintegration rate of {sup 103}Rh{sup m} in thick foils is described. In addition values for the following parameters were determined: - total internal conversion coefficient {alpha} = 1531 {+-} 30; - K shell internal conversion coefficient {alpha}{sub K} = 127 {+-} 6; - conversion ratio R= K/L+M+..... = 0.0914 {+-} 0.0043. (author)

  4. Altering properties of cerium oxide thin films by Rh doping

    International Nuclear Information System (INIS)

    Ševčíková, Klára; Nehasil, Václav; Vorokhta, Mykhailo; Haviar, Stanislav; Matolín, Vladimír

    2015-01-01

    Highlights: • Thin films of ceria doped by rhodium deposited by RF magnetron sputtering. • Concentration of rhodium has great impact on properties of Rh–CeO x thin films. • Intensive oxygen migration in films with low concentration of rhodium. • Oxygen migration suppressed in films with high amount of Rh dopants. - Abstract: Ceria containing highly dispersed ions of rhodium is a promising material for catalytic applications. The Rh–CeO x thin films with different concentrations of rhodium were deposited by RF magnetron sputtering and were studied by soft and hard X-ray photoelectron spectroscopies, Temperature programmed reaction and X-ray powder diffraction techniques. The sputtered films consist of rhodium–cerium mixed oxide where cerium exhibits a mixed valency of Ce 4+ and Ce 3+ and rhodium occurs in two oxidation states, Rh 3+ and Rh n+ . We show that the concentration of rhodium has a great influence on the chemical composition, structure and reducibility of the Rh–CeO x thin films. The films with low concentrations of rhodium are polycrystalline, while the films with higher amount of Rh dopants are amorphous. The morphology of the films strongly influences the mobility of oxygen in the material. Therefore, varying the concentration of rhodium in Rh–CeO x thin films leads to preparing materials with different properties

  5. Isomer 103Rh excitation in the electron beam

    International Nuclear Information System (INIS)

    Alpatov, V.G.; Berezkin, V.V.; Vysotskij, S.A.

    1993-01-01

    Rhodium foil targets were irradiated by a beam of electrons from a linear accelerator containing a minor impurity of bremsstrahlung. X-ray and γ-quanta from decay of 103m Rh isomer states were detected. The ratio of isomer cross section activation by bremsstrahlung, formed in the target, and electrons, equals 89. 7 refs.; 3 figs.; 2 tabs

  6. Thermodynamics of Rh nuclear spins calculated by exact diagonalization

    DEFF Research Database (Denmark)

    Lefmann, K.; Ipsen, J.; Rasmussen, F.B.

    2000-01-01

    We have employed the method of exact diagonalization to obtain the full-energy spectrum of a cluster of 16 Rh nuclear spins, having dipolar and RK interactions between first and second nearest neighbours only. We have used this to calculate the nuclear spin entropy, and our results at both positi...

  7. NdRhSn: A ferromagnet with an antiferromagnetic precursor

    Czech Academy of Sciences Publication Activity Database

    Mihalik, M.; Prokleška, J.; Kamarád, Jiří; Prokeš, K.; Isnard, O.; McIntyre, G. J.; Dönni, A.; Yoshii, S.; Kitazawa, H.; Sechovský, V.; de Boer, F.R.

    2011-01-01

    Roč. 83, č. 10 (2011), "104403-1"-"104403-10" ISSN 1098-0121 R&D Projects: GA ČR GA202/09/1027 Institutional research plan: CEZ:AV0Z10100521 Keywords : NdRhSn * ferromagnet * antiferromagnetic precursor Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.691, year: 2011

  8. Frequency distribution 0f ABO, RH blood groups and blood ...

    African Journals Online (AJOL)

    One hundred and fifty students (150) were randomly selected from the Department of Cell Biology and Genetics of University of Lagos, Akoka, Nigeria for ABO, RH blood groups and 6 haemoglobin genotypes studies. Blood group O was the highest with the percentage frequency of 55.3%, followed by blood group A (25.3%) ...

  9. Itinerant magnetism in CeRh3B2

    DEFF Research Database (Denmark)

    Eriksson, Olle; Johansson, Börje; Brooks, M. S. S.

    1989-01-01

    Spin-polarized energy-band calculations, including spin-orbit coupling in the band Hamiltonian, have been performed on CeRh3B2. Good agreement is obtained between theory and experiment concerning the magnetic moment. It is also found that the magnetic moment varies strongly with volume and from...

  10. Association of ABO and Rh blood groups with breast cancer.

    Science.gov (United States)

    Meo, Sultan Ayoub; Suraya, Faryal; Jamil, Badar; Rouq, Fwziah Al; Meo, Anusha Sultan; Sattar, Kamran; Ansari, Mohammad Javed; Alasiri, Saleh A

    2017-11-01

    The aim of this study was to determine the association of "ABO" and "Rhesus" blood groups with incidence of breast cancer. In this study, we identified 70 research documents from data based search engines including "PubMed", "ISI-Web of Knowledge", "Embase" and "Google Scholar". The research papers were selected by using the primary key-terms including "ABO blood type", "Rhesus" blood type and "breast cancer". The research documents in which "ABO" and "Rhesus" blood types and breast cancer was debated were included. After screening, we reviewed 32 papers and finally we selected 25 research papers which met the inclusion criteria and remaining documents were excluded. Blood group "A" has high incidence of breast cancer (45.88%), blood group "O" has (31.69%); "B" (16.16%) and blood group "AB" has (6.27%) incidence of breast cancer. Blood group "A" has highest and blood group "AB" has least association with breast cancer. Furthermore, "Rhesus +ve" blood group has high incidence of breast cancer (88.31%) and "Rhesus -ve" blood group has least association with breast cancer (11.68%). Blood group "A" and "Rhesus +ve" have high risk of breast cancer, while blood type "AB" and "Rhesus -ve" are at low peril of breast cancer. Physicians should carefully monitor the females with blood group "A" and "Rh +ve" as these females are more prone to develop breast cancer. To reduce breast cancer incidence and its burden, preventive and screening programs for breast cancer especially in young women are highly recommended.

  11. Gamma-ray solid laser: variety of work nuclei and host matrixes in Mendeleev Table screened with use of system of criteria based on joint GG&RH theory

    Science.gov (United States)

    Karyagin, Stanislav V.

    2001-03-01

    The hosts and nuclei-candidates (mass approximately 46 - 243, transition energy approximately 1 - 200 keV, decay's time 10-7 - 10+2 s) for gamma-laser (GL) realization are represented over Mendeleev Table. The choice of active media (nuclei-candidates, hosts) for GL is based on the joint theory of (gamma) -generation and radiation-heat regime which accounts a big complex of hindrances against GL and thus discards many tentative candidates. Nuclei- candidates are screened at the analyzing of data banks for nuclear transitions. Chosen candidates (approximately 20) could be used due to author's method SPTEN (Soft Prompt Transplantation of Excited Nuclei). The discarded tentative nuclei (approximately 80) with the life-times 10-6 - 10+2 are represented too. All analyzed long-lived (approximately 0.5 - 10+2 s) isomers are turned to be not fit for GL without use of very strong multi-wave Borrman effect even at the supposition of natural line's width. The application of the revealed candidates in two different (gamma) -laser's categories (residential and non- residential) is discussed.

  12. Intravenous immunoglobulin in ABO and Rh hemolytic diseases of newborn.

    Science.gov (United States)

    Nasseri, Fatemeh; Mamouri, Gholam A; Babaei, Homa

    2006-12-01

    To evaluate whether the use of intravenous immunoglobulin in newborn infants with isoimmune hemolytic jaundice due to Rh and ABO incompatibility is an effective treatment in reducing the need for exchange transfusion. This study included all direct Coombs' test positive Rh and ABO isoimmunized babies, who admitted in the Neonatal Intensive Care Unit of Ghaem Hospital of Mashhad University of Medical Sciences, Iran, from October 2003 to October 2004. Significant hyperbilirubinemia was defined as rising by >or=0.5 mg/dl per hour. Babies were randomly assigned to received phototherapy with intravenous immunoglobulin (IVIg) 0.5 g/kg over 4 hours, every 12 hours for 3 doses (study group) or phototherapy alone (control group). Exchange transfusion was performed in any group if serum bilirubin exceeded >or=20mg/dl or rose by >or=1mg/dl/h. A total of 34 babies were eligible for this study (17 babies in each group). The number of exchange transfusion, duration of phototherapy and hospitalization days, were significant shorter in the study group versus control group. When we analyzed the outcome results in ABO and Rh hemolytic disease separately, the efficacy of IVIg was significantly better in Rh versus ABO isoimmunization. Late anemia was more common in the IVIg group 11.8% versus 0%, p=0.48. Adverse effects were not observed during IVIg administration. Administration of IVIg to newborns with significant hyperbilirubinemia due to Rh hemolytic disease reduced the need for exchange transfusion but in ABO hemolytic disease there was no significant difference between IVIg and double surface blue light phototherapy.

  13. Probing the interaction of Rh, Co and bimetallic Rh-Co nanoparticles with the CeO2 support: catalytic materials for alternative energy generation.

    Science.gov (United States)

    Varga, E; Pusztai, P; Óvári, L; Oszkó, A; Erdőhelyi, A; Papp, C; Steinrück, H-P; Kónya, Z; Kiss, J

    2015-10-28

    The interaction of CeO2-supported Rh, Co and bimetallic Rh-Co nanoparticles, which are active catalysts in hydrogen production via steam reforming of ethanol, a process related to renewable energy generation, was studied by X-ray diffraction (XRD), high resolution electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and low energy ion scattering (LEIS). Furthermore, diffuse reflectance infrared spectroscopy (DRIFTS) of adsorbed CO as a probe molecule was used to characterize the morphology of metal particles. At small loadings (0.1%), Rh is in a much dispersed state on ceria, while at higher contents (1-5%), Rh forms 2-8 nm particles. Between 473-673 K pronounced oxygen transfer from ceria to Rh is observed and at 773 K significant agglomeration of Rh occurs. On reduced ceria, XPS indicates a possible electron transfer from Rh to ceria. The formation of smaller ceria crystallites upon loading with Co was concluded from XRD and HRTEM; for 10% Co, the CeO2 particle size decreased from 27.6 to 10.7 nm. A strong dissolution of Co into ceria and a certain extent of encapsulation by ceria were deduced by XRD, XPS and LEIS. In the bimetallic system, the presence of Rh enhances the reduction of cobalt and ceria. During thermal treatments, reoxidation of Co occurs, and Rh agglomeration as well as oxygen migration from ceria to Rh are hindered in the presence of cobalt.

  14. X = Pt, Os, Ru, Ir, Rh

    African Journals Online (AJOL)

    Timothy Ademakinwa

    The compressibility of five compounds in the stoichiometry X Al was evaluated from 0K to 2000K using the. 3 ... atom model framework, using the Sutton and Chen potentials. Keywords: ... However, alloys based on these ... computer code (Turodov et al., 2006). DL-POLY is a molecular dynamics (MD) simulation package.

  15. Martensitic transformation and magnetic properties of manganese-rich Ni-Mn-In and Ni-Mn-Sn Heusler alloys

    International Nuclear Information System (INIS)

    Krenke, T.

    2007-01-01

    In the present work, the martensitic transition and the magnetic properties of Manganese rich Ni 50 Mn 50-x Sn x and Ni 50 Mn 50-y In y alloys with 5 at%≤x(y)≤25 at% were investigated. Calorimetry, X-ray and neutron diffraction, magnetization, and strain measurements were performed on polycrystalline samples. It was shown that alloys close to the stoichiometric composition Ni 50 Mn 25 Sn 25 and Ni 50 Mn 25 Sn 25 do not exhibit a structural transition on lowering of the temperature, whereas alloys with x≤15 at% Tin and y≤16 at% Indium transform martensitically. The structural transition temperatures increase linearly with decreasing Tin or Indium content. The crystal structures of the low temperature martensite are modulated as well as unmodulated. Alloys with compositions close to stoichiometry are dominated by ferromagnetic interactions, whereas those close to the binary composition Ni 50 Mn 50 order antiferromagnetically. Ferromagnetic order and structural instability coexist in a narrow composition range between 13 at%≤x≤15 at% and 15 at%≤x≤16 at% for Ni 50 Mn 50-x Sn x and Ni 50 Mn 50-y In y respectively. As a consequence, interesting magnetoelastic effects are observed. The Ni 50 Mn 34 In 16 alloy shows a magnetic field-induced structural transition, whereby application of an external magnetic field in the martensitic state stabilizes the high temperature L2 1 structure. Evidence for this was given by neutron diffraction experiments in external magnetic fields. Moreover, the structural transition temperatures of this alloy show large magnetic field dependencies. By use of calorimetry, M(T), and strain measurements, changes in M s up to -11 K/Tesla are observed. Such large values have, until now, not been observed in Heusler alloys. Since during transformation the volume changes reversibly, magnetic field-induced strains of about 0.12 % appear. Additionally, the alloys Ni 50 Mn 35 Sn 15 , Ni 50 Mn 37 Sn 13 , Ni 50 Mn 34 In 16 , Ni 51.5 Mn 33 In

  16. Spectroscopy of the odd-odd chiral candidate nucleus 102Rh

    Directory of Open Access Journals (Sweden)

    Yavahchova M.S.

    2014-03-01

    Full Text Available Excited states in 102Rh were populated in the fusion-evaporation reaction 94Zr(11B, 3n102Rh at a beam energy of 36 MeV, using the INGA spectrometer at IUAC, New Delhi. The angular correlations and the electromagnetic character of some of the 03B3-ray transitions observed in 102Rh were investigated in detail. A new candidate for achiral twin band was identified in 102Rh for the first time.

  17. Vacancy site occupation by Co and Ir in half-Heusler ZrNiSn and conversion of the thermoelectric properties from n-type to p-type

    International Nuclear Information System (INIS)

    Kimura, Yoshisato; Tanoguchi, Toshiyasu; Kita, Takuji

    2010-01-01

    The n-type thermoelectric properties of the half-Heusler compound ZrNiSn can be converted to p-type by the addition of Co and Ir. We found that Co and Ir atoms preferably occupy the vacancy sites instead of substituting at Ni sites. This implies that the phase stability of the compound gradually changes towards that of the Heusler compound Zr(Ni,M) 2 Sn, where M is Co and/or Ir. The occupation of vacancy sites by Co and Ir atoms leads to a drastic reduction in lattice thermal conductivity owing to the enhancement of phonon scattering by the solid solution effect.

  18. Effects of GnRH immunization in sexually mature pony stallions

    NARCIS (Netherlands)

    Turkstra, J.A.; Meer, F.J.U.M.; Knaap, J.; Rottier, P.J.M.; Teerds, K.J.; Colenbrander, B.; Meloen, R.H.

    2005-01-01

    Immunization against gonadotrophin releasing hormone (GnRH) was studied as an alternative for the commonly used surgical castration in stallions. Two GnRH vaccines comprising non-mineral oil adjuvants were evaluated for their potential to induce high antibody titers directed against GnRH and

  19. Prevalence of weak RhD phenotype in the blood donor population ...

    African Journals Online (AJOL)

    Background: The weak RhD phenotype is a form of RhD antigen that, in routine RhD typing, does not react by agglutination with potent monoclonal anti-D serum, but requires addition of antiglobulin serum to demonstrate the presence of the antigen. However, the weak D antigen can cause immunization or sensitization ...

  20. Hybridization and magnetism in U(Ru, Rh)X, X=Al, Ga

    NARCIS (Netherlands)

    Sechovsky, V.; Havela, L.; Boer, de F.R.; Veenhuizen, P.A.; Sugiyama, K.; Kuroda, T.; Sugiura, T.; Ono, M.; Date, M.; Yamagishi, A.

    1992-01-01

    Results of magnetic studies of pseudoternary U(Ru, Rh)Al and U(Ru, Rh)Ga systems are presented. Reduction of the 5f-4d hybridization with increasing Rh content is reflected in a gradual transition from paramagnetic (spin fluctuation) behaviour of URuX to ferromagnetism in URhX. The huge uniaxial

  1. Spectroscopic and DFT Study of RhIII Chloro Complex Transformation in Alkaline Solutions.

    Science.gov (United States)

    Vasilchenko, Danila B; Berdyugin, Semen N; Korenev, Sergey V; O'Kennedy, Sean; Gerber, Wilhelmus J

    2017-09-05

    The hydrolysis of [RhCl 6 ] 3- in NaOH-water solutions was studied by spectrophotometric methods. The reaction proceeds via successive substitution of chloride with hydroxide to quantitatively form [Rh(OH) 6 ] 3- . Ligand substitution kinetics was studied in an aqueous 0.434-1.085 M NaOH matrix in the temperature range 5.5-15.3 °C. Transformation of [RhCl 6 ] 3- into [RhCl 5 (OH)] 3- was found to be the rate-determining step with activation parameters of ΔH † = 105 ± 4 kJ mol -1 and ΔS † = 59 ± 10 J K -1 mol -1 . The coordinated hydroxo ligand(s) induces rapid ligand substitution to form [Rh(OH) 6 ] 3- . By simulating ligand substitution as a dissociative mechanism, using density functional theory (DFT), we can now explain the relatively fast and slow kinetics of chloride substitution in basic and acidic matrices, respectively. Moreover, the DFT calculated activation energies corroborated experimental data that the kinetic stereochemical sequence of [RhCl 6 ] 3- hydrolysis in an acidic solution proceeds as [RhCl 6 ] 3- → [RhCl 5 (H 2 O)] 2- → cis-[RhCl 4 (H 2 O) 2 ] - . However, DFT calculations predict in a basic solution the trans route of substitution [RhCl 6 ] 3- → [RhCl 5 (OH)] 3- → trans-[RhCl 4 (OH) 2 ] 3- is kinetically favored.

  2. Evaluation of 101Rh as a brachytherapy source

    Science.gov (United States)

    Ghorbani, Mahdi; Meigooni, Ali Soleimani

    2015-01-01

    Purpose Recently a number of hypothetical sources have been proposed and evaluated for use in brachytherapy. In the present study, a hypothetical 101Rh source with mean photon energy of 121.5 keV and half-life of 3.3 years, has been evaluated as an alternative to the existing high-dose-rate (HDR) sources. Dosimetric characteristics of this source model have been determined following the recommendation of the Task Group 43 (TG-43) of the American Association of the Physicist in Medicine (AAPM), and the results are compared with the published data for 57Co source and Flexisource 192Ir sources with similar geometries. Material and methods MCNPX Monte Carlo code was used for simulation of the 101Rh hypothetical HDR source design. Geometric design of this hypothetical source was considered to be similar to that of Flexisource 192Ir source. Task group No. 43 dosimetric parameters, including air kerma strength per mCi, dose rate constant, radial dose function, and two dimensional (2D) anisotropy functions were calculated for the 101Rh source through simulations. Results Air kerma strength per activity and dose rate constant for the hypothetical 101Rh source were 1.09 ± 0.01 U/mCi and 1.18 ± 0.08 cGy/(h.U), respectively. At distances beyond 1.0 cm in phantom, radial dose function for the hypothetical 101Rh source is higher than that of 192Ir. It has also similar 2D anisotropy functions to the Flexisource 192Ir source. Conclusions 101Rh is proposed as an alternative to the existing HDR sources for use in brachytherapy. This source provides medium energy photons, relatively long half-life, higher dose rate constant and radial dose function, and similar 2D anisotropy function to the Flexisource 192Ir HDR source design. The longer half-life of the source reduces the frequency of the source exchange for the clinical environment. PMID:26034499

  3. Stacking reactions of the borole complex Cp*Rh(η5-C4H4BPh) with the dicationic fragments [Cp*M]2+ (M = Rh or Ir)

    International Nuclear Information System (INIS)

    Loginov, D.A.; Muratov, D.V.; Starikova, Z.A.; Petrovskij, P.V.; Kudinov, A.R.

    2006-01-01

    The reaction of the (borole)rhodium iodide complex [(η-C 4 H 4 BPh)RhI] 4 with Cp*Li afforded the sandwich compound Cp*Rh(η-C 4 H 4 BPh) (1). The reactions of compound 1 with the solvated complexes [Cp*M(MeNO 2 ) 3 ] 2+ (BF 4 - ) 2 gave triple-decker cationic complexes with the central borole ligand [Cp*Rh(μ-η 5 :η 5 -C 4 H 4 BPh)MCp*] 2+ (BF 4 - ) 2 (M = Rh or Ir). The structure of complex 1 was established by X-ray diffraction [ru

  4. Quasi-two-dimensional Fermi-liquid state in Sr2RhO4-δ

    International Nuclear Information System (INIS)

    Nagai, Ichiro; Shirakawa, Naoki; Umeyama, Norio; Ikeda, Shin-ichi

    2010-01-01

    Single crystals of layered perovskite Sr 2 RhO 4-δ (δ=0.0 and 0.1) are successfully grown by the floating-zone method. Stoichiometric single crystals (Sr 2 RhO 4.0 ) are obtained by O 2 -annealing the as-grown crystals (Sr 2 RhO 3.9 ). Sr 2 RhO 4.0 and Sr 2 RhO 3.9 show quasi-two-dimensional Fermi-liquid behavior at low temperatures, whereas there are large differences in the anisotropy of electrical resistivity ρ c (3 K)/ρ ab (3 K) and Wilson ratio R w between Sr 2 RhO 4.0 and Sr 2 RhO 3.9 : ρ c (3 K)/ρ ab (3 K)=2400 (19000) and R w =3.8 (6.4) for Sr 2 RhO 4.0 (Sr 2 RhO 3.9 ). The differences observed between the temperature dependence of the in-plane electrical resistivity (T 2 RhO 4.0 and Sr 2 RhO 3.9 are mainly derived from those between the density of states and band structure near the corresponding Fermi level. This indicates that the changes in these physical properties, which are accompanied by oxygen defects in the Sr 2 RhO 4-δ system, can be explained by the rigid band model. Moreover, these results suggest that t 2g band-filling can be controlled by adjusting the oxygen defect content δ in the Sr 2 RhO 4-δ system. Although many similarities are observed in this study between the physical properties of Sr 2 RhO 4.0 and Sr 2 RuO 4 . Sr 2 RhO 4.0 does not exhibit superconductivity down to 36 mK. (author)

  5. Lattice dynamics of KxRhO2 single crystals

    Directory of Open Access Journals (Sweden)

    Bin-Bin Zhang

    2015-08-01

    Full Text Available A series of crystals KxRhO2 (x = 0.72, 0.63, 0.55, 0.39, and 0.24 have been synthesized and their vibrational properties have been studied by first principles calculations, Raman spectroscopy, and inelastic neutron scattering. The measured vibrational spectra of KxRhO2 for x = 0.72 and 0.63 are consistent with the theoretical prediction for the stoichiometric KRhO2. For samples with x = 0.55, 0.39 and 0.24, extra vibrational modes have been observed and they are believed to be due to the symmetry reduction and the loss of translational symmetry induced by K disorder. The good agreement was found for the phonon density of states among the Raman spectroscopic observations, inelastic neutron scattering and the first principles calculations, as an evidence for the generation of structure disorder by K deficiency.

  6. Antiferromagnetic ordering in GdRhIn{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Latka, K.; Rams, M. [Marian Smoluchowski Inst. of Physics, Jagiellonian Univ., Krakow (Poland); Kmiec, R.; Pacyna, A.W. [Henryk Niewodniczanski Inst. of Nuclear Physics, Polish Academy of Sciences, Krakow (Poland); Zaremba, V.I. [Inorganic Chemistry Dept., Ivan Franko National Univ. of Lviv, Lviv (Ukraine); Inst. fuer Anorganische und Analytische Chemie, Westfaelische Wilhelms-Univ. Muenster (Germany); Poettgen, R. [Inst. fuer Anorganische und Analytische Chemie, Westfaelische Wilhelms-Univ. Muenster (Germany)

    2004-09-01

    A polycrystalline sample of tetragonal GdRhIn{sub 5} (HoCoGa{sub 5} type, space group P4/mmm) was obtained by induction melting of the elements in a glassy carbon crucible in a water-cooled sample chamber and subsequent annealing at 670 K. X-ray powder data yielded the cell parameters a = 460.65(7), c = 743.52(12) pm. The magnetic and electronic properties of GdRhIn{sub 5} have been studied by magnetic susceptibility, electrical resistivity, and {sup 155}Gd Moessbauer spectroscopic measurements. Antiferromagnetic ordering is detected at 41.0(2) K. The results are discussed using a simple molecular field approximation. (orig.)

  7. Strain and order-parameter coupling in Ni-Mn-Ga Heusler alloys from resonant ultrasound spectroscopy

    Science.gov (United States)

    Salazar Mejía, C.; Born, N.-O.; Schiemer, J. A.; Felser, C.; Carpenter, M. A.; Nicklas, M.

    2018-03-01

    Resonant ultrasound spectroscopy and magnetic susceptibility experiments have been used to characterize strain coupling phenomena associated with structural and magnetic properties of the shape-memory Heusler alloy series Ni50 +xMn25 -xGa25 (x =0 , 2.5, 5.0, and 7.5). All samples exhibit a martensitic transformation at temperature TM and ferromagnetic ordering at temperature TC, while the pure end member (x =0 ) also has a premartensitic transition at TP M, giving four different scenarios: TC>TP M>TM,TC>TM without premartensitic transition, TC≈TM , and TC

  8. Impact of Interstitial Ni on the Thermoelectric Properties of the Half-Heusler TiNiSn

    Directory of Open Access Journals (Sweden)

    Sonia A. Barczak

    2018-03-01

    Full Text Available TiNiSn is an intensively studied half-Heusler alloy that shows great potential for waste heat recovery. Here, we report on the structures and thermoelectric properties of a series of metal-rich TiNi1+ySn compositions prepared via solid-state reactions and hot pressing. A general relation between the amount of interstitial Ni and lattice parameter is determined from neutron powder diffraction. High-resolution synchrotron X-ray powder diffraction reveals the occurrence of strain broadening upon hot pressing, which is attributed to the metastable arrangement of interstitial Ni. Hall measurements confirm that interstitial Ni causes weak n-type doping and a reduction in carrier mobility, which limits the power factor to 2.5–3 mW m−1 K−2 for these samples. The thermal conductivity was modelled within the Callaway approximation and is quantitively linked to the amount of interstitial Ni, resulting in a predicted value of 12.7 W m−1 K−1 at 323 K for stoichiometric TiNiSn. Interstitial Ni leads to a reduction of the thermal band gap and moves the peak ZT = 0.4 to lower temperatures, thus offering the possibility to engineer a broad ZT plateau. This work adds further insight into the impact of small amounts of interstitial Ni on the thermal and electrical transport of TiNiSn.

  9. Low Temperature Electrical Spin Injection from Highly Spin Polarized Co₂CrAl Heusler Alloy into p-Si.

    Science.gov (United States)

    Kar, Uddipta; Panda, J; Nath, T K

    2018-06-01

    The low temperature spin accumulation in p-Si using Co2CrAl/SiO2 tunnel junction has been investigated in detail. The heterojunction has been fabricated using electron beam evaporation (EBE) technique. The 3-terminal contacts in Hanle geometry has been made for spin transport measurements. The electrical transport properties have been investigated at different isothermal conditions in the temperature range of 10-300 K. The current-voltage characteristics of the junction shows excellent rectifying magnetic diode like behaviour in lower temperature range (below 200 K). At higher temperature, the junction shows nonlinear behaviour without rectifying characteristics. We have observed spin accumulation signal in p-Si semiconductor using SiO2/Co2CrAl tunnel junction in the low temperature regime (30-100 K). Hence the highly spin polarized Full Heusler alloys compounds, like Co2CrAl etc., are very attractive and can act as efficient tunnel device for spin injection in the area of spintronics devices in near future. The estimated spin life time is τ = 54 pS and spin diffusion length inside p-Si is LSD = 289 nm at 30 K for this heterostructure.

  10. Phase transitions, magnetotransport and magnetocaloric effects in a new family of quaternary Ni-Mn-In-Z Heusler alloys.

    Science.gov (United States)

    Kazakov, Alexander; Prudnikov, Valerii; Granovsky, Alexander; Perov, Nikolai; Dubenko, Igor; Pathak, Arjun Kumar; Samanta, Tapas; Stadler, Shane; Ali, Naushad; Zhukov, Arcady; Ilyin, Maxim; Gonzalez, Julian

    2012-09-01

    The magnetic, magnetotransport, and magnetocaloric properties near compound phase transitions in Ni50Mn35In14Z (Z = In, Ge, Al), and Ni48Co2Mn35In15 Heusler alloys have been studied using VSM and SQUID magnetometers (at magnetic fields (H) up to 5 T), four-probe method (at H = 0.005-1.5 T), and an adiabatic magnetocalorimeter (for H changes up to deltaH = 1.8 T), respectively. The martensitic transformation (MT) is accompanied by large magnetoresistance (up to 70%), a significant change in resistivity (up to 200%), and a sign reversal of the ordinary Hall effect coefficient, all related to a strong change in the electronic spectrum at the MT. The field dependences of the Hall resistance are complex in the vicinity of the MT, indicating a change in the relative concentrations of the austenite and martensite phases at strong fields. Negative and positive changes in adiabatic temperatures of about -2 K and +2 K have been observed in the vicinity of MT and Curie temperatures, respectively, for deltaH = 1.8 T.

  11. 27Al, 63Cu NMR spectroscopy and electrical transport in Heusler Cu-Mn-Al alloy powders

    Science.gov (United States)

    Nadutov, V. M.; Perekos, A. O.; Kokorin, V. V.; Trachevskii, V. V.; Konoplyuk, S. M.; Vashchuk, D. L.

    2018-02-01

    The ultrafine powder of the Heusler Cu-13,1Mn-12,6Al (wt.%) alloy produced by electrical spark dispersion (ESD) in ethanol and the pellets prepared by pressing of the powders and aged in various gas environment (air, Ar, vacuum) were studied by XRD, nuclear magnetic resonance, magnetic and electric transport methods. The constituent phases were identified as b.c.c. α-Cu-Mn-Al, f.c.c. γ-Cu-Mn-Al, Cu2MnAl, and oxides. The sizes of the coherently scattering domains (CSD) and the saturation magnetizations were in the range of 4-90 nm and 0-1.5 Am2/kg, respectively. 27Al and 63Cu NMR spectra of the powders and pellets have shown hyperfine structure caused by contributions from atomic nuclei of the constituent phases. The aging of pellets in different gas environments had effect on their phase composition but no effect on dispersion of the phases. In contrast to the as-cast alloy, electrical resistance of the pellets evidenced semiconducting behavior at elevated temperatures due to the presence of metal oxides formed on the surfaces of nanoparticles.

  12. Large tunnel magnetoresistance at room temperature with a Co2FeAl full-Heusler alloy electrode

    International Nuclear Information System (INIS)

    Okamura, S.; Miyazaki, A.; Sugimoto, S.; Tezuka, N.; Inomata, K.

    2005-01-01

    Magnetic tunnel junctions (MTJs) with a Co 2 FeAl Heusler alloy electrode are fabricated by the deposition of the film using an ultrahigh vacuum sputtering system followed by photolithography and Ar ion etching. A tunnel magnetoresistance (TMR) of 47% at room temperature (RT) are obtained in a stack of Co 2 FeAl/Al-O x /Co 75 Fe 25 magnetic tunnel junction (MTJ) fabricated on a thermally oxidized Si substrate despite the A2 type atomic site disorder for Co 2 FeAl. There is no increase of TMR in MTJs with the B2 type Co 2 FeAl, which is prepared by the deposition on a heated substrate. X-ray photoelectron spectroscopy (XPS) depth profiles in Co 2 FeAl single layer films reveal that Al atoms in Co 2 FeAl are oxidized preferentially at the surfaces. On the other hand, at the interfaces in Co 2 FeAl/Al-O x /Co 75 Fe 25 MTJs, the ferromagnetic layers are hardly oxidized during plasma oxidation for a formation of Al oxide barriers

  13. Transformation Paths from Cubic to Low-Symmetry Structures in Heusler Ni2MnGa Compound.

    Science.gov (United States)

    Zelený, Martin; Straka, Ladislav; Sozinov, Alexei; Heczko, Oleg

    2018-05-08

    In order to explain the formation of low-temperature phases in stoichiometric Ni 2 MnGa magnetic shape memory alloy, we investigate the phase transformation paths from cubic austenite with Heusler structure to low-symmetry martensitic structures. We used ab initio calculations combined with the generalized solid state nudged elastic band method to determine the minimum energy path and corresponding changes in crystal lattice. The four-, five-, and seven-layered modulated phases of martensite (4O, 10M, and 14M) are built as the relaxed nanotwinned non-modulated (NM) phase. Despite having a total energy larger than the other martensitic phases, the 10M phase will spontaneously form at 0 K, because there is no energy barrier on the path and the energy decreases with a large negative slope. Moreover, a similar negative slope in the beginning of path is found also for the transformation to the 6M premartensite, which appears as a local minimum on the path leading further to 10M martensite. Transformation paths to other structures exhibit more or less significant barriers in the beginning hindering such a transformation from austenite. These findings correspond to experiment and demonstrates that the kinetics of the transformation is decisive for the selection of the particular low-symmetry structure.

  14. Thermoelectric performance and the role of anti-site disorder in the 24-electron Heusler TiFe2Sn

    Science.gov (United States)

    Buffon, Malinda L. C.; Laurita, Geneva; Lamontagne, Leo; Levin, Emily E.; Mooraj, Shahryar; Lloyd, Demetrious L.; White, Natalie; Pollock, Tresa M.; Seshadri, Ram

    2017-10-01

    Heusler compounds XY 2 Z with 24 valence electrons per formula unit are potential thermoelectric materials, given their thermal and chemical stability and their relatively earth-abundant constituent elements. We present results on the 24-electron compound TiFe2Sn here. First principles calculations on this compound suggest semiconducting behavior. A relatively flat conduction band that could be associated with a high Seebeck coefficient upon electron doping is found. A series of compounds have been prepared and characterized using a combination of synchrotron x-ray and neutron diffraction studies to understand the effects of site order/disorder phenomena and n-type doping. Samples fabricated by a three step processing approach were subjected to high temperature Seebeck and electrical resistivity measurements. Ti:Fe anti-site disorder is present in the stoichiometric compound and these defects are reduced when starting Ti-rich compositions are employed. Additionally, we investigate control of the Seebeck coefficient through the introduction of carriers through the substitution of Sb on the Sn site in these intrinsically p-type materials.

  15. Structural, magnetic and transport properties of Co{sub 2}FeAl Heusler films with varying thickness

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaotian [School of Material Sciences and Engineering, Hebei University Technology, Tianjin 300130 (China); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Li, Yueqing [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); State Key Laboratory of Metastable Material Sciences and Technology, Yanshan University, Qinhuangdao 066004 (China); Du, Yin [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Dai, Xuefang; Liu, Guodong [School of Material Sciences and Engineering, Hebei University Technology, Tianjin 300130 (China); Liu, Enke [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Zhongyuan [State Key Laboratory of Metastable Material Sciences and Technology, Yanshan University, Qinhuangdao 066004 (China); Wang, Wenhong, E-mail: wenhong.wang@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wu, Guangheng [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-08-01

    We report on a systematic study of the structural, magnetic properties and the anomalous Hall effect, in the Heusler alloy Co{sub 2}FeAl (CFA) epitaxial films on MgO (001), as a function of film thickness. It was found that the epitaxial CFA films show a highly ordered B2 structure with an in-plane uniaxial magnetic anisotropy. The electrical transport properties reveal that the lattice and magnon scattering contributions to the longitudinal resistivity. Independent on the thickness of films, the anomalous Hall resistivity of CFA films is found to be dominated by skew scattering only. Moreover, the anomalous Hall resistivity shows weakly temperature dependent behavior, and its absolute value increases as the thickness decreases. We attribute this temperature insensitivity in the anomalous Hall resistivity to the weak temperature dependent of tunneling spin-polarization in the CFA films, while the thickness dependence behavior is likely due to the increasing significance of interface or free surface electronic states. - Highlights: ●Highly ordered CFA films with various thicknesses were prepared on MgO substrates. ●The magnon scattering contributions to the longitudinal resistivity in the CFA films. ●The anomalous Hall resistivity of the CFA films shows weakly temperature dependent. ●The CFA films show weak temperature dependent of tunneling spin-polarization.

  16. Hall effect and the magnetotransport properties of Co2MnSi1-xAlx Heusler alloys

    Science.gov (United States)

    Prestigiacomo, Joseph C.; Young, David P.; Adams, Philip W.; Stadler, Shane

    2014-01-01

    We have investigated the transport properties of the quaternary Heusler alloys Co2MnSi1-xAlx (0≤x≤1), which have been theoretically predicted to develop a half-metallic band structure as x →0. Resistivity versus temperature measurements as a function of Al concentration (x) revealed a systematic reduction in the residual resistivity ratio as well as a transition from weakly localized to half-metallic conduction as x →0. From measurements of the ordinary and anomalous Hall effects, the charge carrier concentration was found to increase, while the anomalous Hall coefficient decreased by nearly an order of magnitude with each sample as x →0 (Δx=0.25.). Scaling of the anomalous Hall effect with longitudinal resistivity reveals that both the skew-scattering and intrinsic contributions grow quickly as x →1, indicating that disorder and band-structure effects cause the large anomalous Hall effect magnitudes observed for Co2MnAl.

  17. Studying the hopping parameters of half-Heusler NaAuS using maximally localized Wannier function

    Science.gov (United States)

    Sihi, Antik; Lal, Sohan; Pandey, Sudhir K.

    2018-04-01

    Here, the electronic behavior of half-Heusler NaAuS is studied using PBEsol exchange correlation functional by plotting the band structure curve. These bands are reproduced using maximally localized Wannier function using WANNIER90. Tight-binding bands are nicely matched with density functional theory bands. By fitting the tight-binding model, hopping parameter for NaAuS is obtained by including Na 2s, 2p, Au 6s, 5p, 5d and S 3s, 3p orbitals within the energy interval of -5 to 16 eV around the Fermi level. In present study, hopping integrals for NaAuS are computed for the first primitive unit cell atoms as well as the first nearest neighbor primitive unit cell. The most dominating hopping integrals are found for Na (3s) - S (3s), Na (2px) - S (2px), Au (6s) - S (3px), Au (6s) - S (3py) and Au (6s) - S (3pz) orbitals. The hopping integrals for the first nearest neighbor primitive unit cell are also discussed in this manuscript. In future, these hopping integrals are very important to find the topological invariant for NaAuS compound.

  18. Magnetocaloric effect in Heusler alloys Ni50Mn34In16 and Ni50Mn34Sn16

    Science.gov (United States)

    Sharma, V. K.; Chattopadhyay, M. K.; Kumar, Ravi; Ganguli, Tapas; Tiwari, Pragya; Roy, S. B.

    2007-12-01

    We present results of detailed ac susceptibility, magnetization and specific heat measurements in Heusler alloys Ni50Mn34In16 and Ni50Mn34Sn16. These alloys undergo a paramagnetic to ferromagnetic transition around 305 K, which is followed by a martensitic transition in the temperature regime around 220 K. Inside the martensite phase both the alloys show signatures of field-induced transition from martensite to austenite phase. Both field- and temperature-induced martensite-austenite transitions are relatively sharp in Ni50Mn34In16. We estimate the isothermal magnetic entropy change and adiabatic temperature change across the various phase transitions in these alloys and investigate the possible influence of these transitions on the estimated magnetocaloric effect. The sharp martensitic transition in Ni50Mn34In16 gives rise to a comparatively large inverse magnetocaloric effect across this transition. On the other hand the magnitudes of the conventional magnetocaloric effect associated with the paramagnetic to ferromagnetic transition are quite comparable in these alloys.

  19. Prospective high thermoelectric performance of the heavily p-doped half-Heusler compound CoVSn

    International Nuclear Information System (INIS)

    Shi, Hongliang; Ming, Wenmei; Parker, David S.; Du, Mao-Hua; Singh, David J.

    2017-01-01

    The electronic structure and transport properties of the half-Heusler compound CoVSn are studied in this paper systematically by combining first-principles electronic structure calculations and Boltzmann transport theory. The band structure at the valence-band edge is complex with multiple maxima derived from hybridized transition element d states. The result is a calculated thermopower larger than 200 μV /Κ within a wide range of doping concentrations and temperatures for heavily doped p-type CoVSn. The thermoelectric properties additionally benefit from the corrugated shapes of the hole pockets in our calculated isoenergy surfaces. Our calculated power factor S"2σ/τ (with respect to an average unknown scattering time) of CoVSn is comparable to that of FeNbSb. A smaller lattice thermal conductivity can be expected from the smaller group velocities of acoustical modes compared to FeNbSb. Finally, overall, good thermoelectric performance for CoVSn can be expected by considering the electronic transport and lattice thermal conductivity.

  20. Direct and indirect measurement of the magnetocaloric effect in bulk and nanostructured Ni-Mn-In Heusler alloy

    Science.gov (United States)

    Ghahremani, Mohammadreza; Aslani, Amir; Hosseinnia, Marjan; Bennett, Lawrence H.; Della Torre, Edward

    2018-05-01

    A systematic study of the magnetocaloric effect of a Ni51Mn33.4In15.6 Heusler alloy converted to nanoparticles via high energy ball-milling technique in the temperature range of 270 to 310 K has been performed. The properties of the particles were characterized by x-ray diffraction, electron microscopy, and magnetometer techniques. Isothermal magnetic field variation of magnetization exhibits field hysteresis in bulk Ni51Mn33.4In15.6 alloy across the martensitic transition which significantly lessened in the nanoparticles. The magnetocaloric effects of the bulk and nanoparticle samples were measured both with direct method, through our state of the art direct test bed apparatus with controllability over the applied fields and temperatures, as well as an indirect method through Maxwell and thermodynamic equations. In direct measurements, nanoparticle sample's critical temperature decreased by 6 K, but its magnetocaloric effect enhanced by 17% over the bulk counterpart. Additionally, when comparing the direct and indirect magnetocaloric curves, the direct method showed 14% less adiabatic temperature change in the bulk and 5% less adiabatic temperature change in the nanostructured sample.

  1. Diffusive-like effects and possible non trivial local topology on the half-Heusler YPdBi compound

    Science.gov (United States)

    Souza, J. C.; Lesseux, G. G.; Urbano, R. R.; Rettori, C.; Pagliuso, P. G.

    2018-05-01

    The non-ambiguous experimental identification of topological states of matter is one of the main interesting problems regarding this new quantum state of matter. In particular, the half-Heusler family RMT (R = rare-earth, T = Pd, Pt or Au and T = Bi, Sb, Pb or Sn) could be a useful platform to explore these states due to their cubic symmetry and the topological properties tunable via their unit cell volume and/or the nuclear charges of the M and T atoms. In this work, we report electron spin resonance (ESR) and complementary macroscopic measurements in the Nd3 + -doped putative topologically trivial semimetal YPdBi. Following the Nd3 + ESR lineshape as a function of microwave power, size of the particle and temperature, we have been able to observe an evolution from a Dysonian lineshape to a diffusive-like lineshape. Furthermore, the Nd3 + ESR intensity saturation is concentration dependent, which could be due to a phonon-bottleneck process. Comparing these results with the Nd3 + -doped YPtBi, we discuss a possible scenario in which the Nd3 + ions could locally tune the topological properties of the system.

  2. Thermoelectric performance and the role of anti-site disorder in the 24-electron Heusler TiFe2Sn.

    Science.gov (United States)

    Buffon, Malinda L C; Laurita, Geneva; Lamontagne, Leo; Levin, Emily E; Mooraj, Shahryar; Lloyd, Demetrious L; White, Natalie; Pollock, Tresa M; Seshadri, Ram

    2017-10-11

    Heusler compounds XY 2 Z with 24 valence electrons per formula unit are potential thermoelectric materials, given their thermal and chemical stability and their relatively earth-abundant constituent elements. We present results on the 24-electron compound TiFe 2 Sn here. First principles calculations on this compound suggest semiconducting behavior. A relatively flat conduction band that could be associated with a high Seebeck coefficient upon electron doping is found. A series of compounds have been prepared and characterized using a combination of synchrotron x-ray and neutron diffraction studies to understand the effects of site order/disorder phenomena and n-type doping. Samples fabricated by a three step processing approach were subjected to high temperature Seebeck and electrical resistivity measurements. Ti:Fe anti-site disorder is present in the stoichiometric compound and these defects are reduced when starting Ti-rich compositions are employed. Additionally, we investigate control of the Seebeck coefficient through the introduction of carriers through the substitution of Sb on the Sn site in these intrinsically p-type materials.

  3. Doping effects on structural and magnetic properties of Heusler alloys Fe2Cr1-xCoxSi

    Science.gov (United States)

    Liu, Yifan; Ren, Lizhu; Zheng, Yuhong; He, Shikun; Liu, Yang; Yang, Ping; Yang, Hyunsoo; Teo, Kie Leong

    2018-05-01

    In this work, 30nm Fe2Cr1-xCoxSi (FCCS) magnetic films were deposited on Cr buffered MgO (100) substrates by sputtering. Fe2Cr0.5Co0.5Si exhibits the largest magnetization and optimal ordered L21 cubic structure at in-situ annealing temperature (Tia) of 450°C. The Co composition dependence of crystalline structures, surface morphology, defects, lattice distortions and their correlation with the magnetic properties are analyzed in detail. The Co-doped samples show in-plane M-H loops with magnetic squareness ratio of 1 and increasing anisotropy energy density with Co composition. Appropriate Co doping composition promotes L21 phase but higher Co composition converts L21 to B2 phase. Doping effect and lattice mismatch both are proved to increase the defect density. In addition, distortions of the FCCS lattice are found to be approximately linear with Co composition. The largest lattice distortion (c/a) is 0.969 for Fe2Cr0.25Co0.75Si and the smallest is 0.983 for Fe2CrSi. Our analyses suggest that these tetragonal distortions mainly induced by an elastic stress from Cr buffer account for the large in-plane anisotropy energy. This work paves the way for further tailoring the magnetic and structural properties of quaternary Heusler alloys.

  4. Tuning martensitic transformation, large magnetoresistance and strain in Ni50-xFexMn36Sn14 Heusler alloys

    Science.gov (United States)

    Liao, Pan; Jing, Chao; Zheng, Dong; Li, Zhe; Kang, Baojuan; Deng, Dongmei; Cao, Shixun; Lu, Bo; Zhang, Jincang

    2015-09-01

    We have investigated the martensitic transformation, exchange bias, magnetoresistance (MR) and strain in Ni50-xFexMn36Sn14 (x=1, 2, 3, 4) Heusler alloys. With the increase of Fe content, the austenite phase could be stabilized with L21 structure and hence the martensitic transition shifts to a lower temperature and finally disappears. This behavior can be understood by the weakening of Ni-Mn hybridization to suppress AFM interactions and enhancement of Fe-Fe ferromagnetic exchange interactions. The same reason can account for the slight decrease of exchange bias field (HEB) with the increase of the Fe content from x=1 to 2 and the disappearance of HEB for x=3. We observed MR effect for x=3, and a maximum MR value of -52% was achieved, which can be explained by the change in the electronic structure during martensitic transformation induced by the magnetic field. In addition, a large strain of 0.207% in Ni49Fe1Mn36Sn14 was observed due to the changes of lattice parameters during the martensitic transformation induced by temperature.

  5. [Standardization of the quantitative flow cytometric test with anti-D antibodies for fetomaternal hemorrhage in RhD negative women].

    Science.gov (United States)

    Spychalska, Justyna; Uhrynowska, Małgorzata; Pyl, Hanna; Klimczak-Jajor, Edyta; Kopeć, Izabella; Peciakowska, Małgorzata; Gutowska, Renata; Gawlak, Maciej; Słomska, Sylwia; Dąbkowska, Syiwia; Szczecina, Roman; Dębska, Marzena; Brojer, Ewa

    2015-07-01

    In order to determine the appropriate dose of anti-D immunoglobulin to be administered as a preventive measure against hemolytic disease of the fetus/newborn in the subsequent pregnancy it is necessary to assess the number of fetal red blood cells that infiltrate/penetrate into the maternal circulation as a result of fetomaternal hemorrhage (FMH). One of the quantitative methods of FMH analysis is based on flow cytometry (FACS) which makes use of monoclonal antibodies to RhD antigen (anti-D test). The aim of the study was to further develop the method, evaluate its sensitivity and reproducibility and to compare it with the test based on the detection of fetal hemoglobin (HbF). The FACS study involved 20 RhD negative pregnant women and 80 RhD negative women after delivery. The following monoclonal antibodies were used: BRAD 3 FITC (anti-RhD antigen), CD45 PerCP (anti leukocyte antigen CD45), and anti-HbF PE. The fluorescence intensity of cells incubated with BRAD 3 FITC was demonstrated to depend on the RhD antigen expression, though the anti-D test also detects the weak D variant. The CD45 PerCP antibodies increased the sensitivity of anti-D test since they eliminated the leukocytes which non-specifically bind anti-D from the analysis. The presence of anti-D antibodies in maternal plasma does not affect the quantitative assessment of the fetal RhD positive fetal cells with BRAD 3 FITC. In case of FMH, the results of the anti-D test were similar to those with anti-HbF antibodies. The flow cytometric test with anti-D and anti-CD45 is useful in the assessment of the fetomaternal hemorrhage in RhD negative women. The sensitivity of the test is estimated at 0.05%.

  6. A Stable Coordination Complex of Rh(IV) in an N,O-Donor Environment

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Shashi B. [Department of Chemistry, Yale University, 225 Prospect; Shopov, Dimitar Y. [Department of Chemistry, Yale University, 225 Prospect; Sharninghausen, Liam S. [Department of Chemistry, Yale University, 225 Prospect; Vinyard, David J. [Department of Chemistry, Yale University, 225 Prospect; Mercado, Brandon Q. [Department of Chemistry, Yale University, 225 Prospect; Brudvig, Gary W. [Department of Chemistry, Yale University, 225 Prospect; Crabtree, Robert H. [Department of Chemistry, Yale University, 225 Prospect

    2015-12-10

    We describe facial and meridional isomers of [RhIII(pyalk)3], as well as meridional [RhIV(pyalk)3]+ {pyalk =2-(2-pyridyl)-2-propanoate}, the first coordination complex in an N,O-donor environment to show a clean, reversible RhIII/IV redox couple and to have a stable Rh(IV) form, which we characterize by EPR and UV–visible spectroscopy as well as X-ray crystallography. The unprecedented stability of the Rh(IV) species is ascribed to the exceptional donor strength of the ligands, their oxidation resistance, and the meridional coordination geometry.

  7. Gama-gama angular correlations in the 105Rh nucleus

    International Nuclear Information System (INIS)

    Esteves, V.A.P.

    1979-01-01

    The Directional Correlation of γ transitions in 105 Rh have been measured from the β - decay of 105 Ru using a Ge(Li) - Nal(Tl) spectrometers. The measurements were carried out for the (316-469), (500-469), (845-499), (875-469), (878-499), (907-469), (1017-469), (350-326), (393-263), (413-263), (489-149) and (575-149) KeV gama cascades. The present results confirm the spin assignments to several levels in 105 Rh obtained in previous studies. The multipole mixing ratios Δ(E2/M1) for several gama transitions have been calculated from the measured angular correlations. The results are Δ(149)=0.34+-0.01,Δ(262)=-1.27+-0.02 or -0.14+-0.01,Δ(326)=-1.79+-0.01 or 0.014+-0.002, Δ(393)=-7.1+-0.3 or -0.36+-0.01, Δ(489)=0.25+-0.002, Δ(500)=0.7+-0.3 and Δ(907)=-21.7 +8 -31.1 or 0.21+-0.03. The structure of nuclear levels in 105 Rh is discussed briefly in terms of models applicable for nuclide in this mass region [pt

  8. GnRH-Analoga und Add-back-Verfahren

    Directory of Open Access Journals (Sweden)

    Kleinstein J

    2008-01-01

    Full Text Available GnRH-Analoga haben eine große Bedeutung in der medikamentösen Therapie der Endometriose erlangt. Sie sind in der Lage, Endometrioseassoziierte Schmerzen zu beseitigen und sind Bestandteil der Therapie der endometriosebedingten Infertilität. Aufgrund der Chronizität der Endometriose bedarf es in vielen Fällen der Prolongation der GnRH-A-Therapie über den Zeitraum von 6 Monaten hinaus. Für diese Fälle eignet sich eine Add-back- Therapie nach dem Format von Hormonersatztherapien, um vasomotorischen Nebeneffekten und dem Knochensubstanzverlust entgegenwirken zu können. Dabei wird der Estrogenanteil niedrig dosiert eingesetzt, um innerhalb eines "therapeutischen Fensters" den Hypoestrogenismus auszugleichen, ohne das Endometriosewachstum zu fördern. Prinzipiell kann dazu das Estrogen oral, aber auch transdermal appliziert werden. Die Effektivität der Kombination aus GnRH-A plus Add-back bezüglich der Knochenprotektion konnte bereits für einen Zeitraum von bis zu 10 Jahren bestätigt werden, sodass damit eine Langzeitkonzeption für Frauen mit rezidivierender Endometriose und wiederholten operativen Eingriffen existiert. Alternativen zur klassischen Add-back mit Sexualsteroiden existieren vielfältig, aber ihr Einsatz ist durch Partialwirkungen und eigene Nebenwirkungen limitiert.

  9. First-principles study of new series of quaternary Heusler alloys CsSrCZ (Z=Si, Ge, Sn, P, As, and Sb)

    Energy Technology Data Exchange (ETDEWEB)

    Bouabça, A. [Condensed Matter and Sustainable Development Laboratory (LMCDD), University of Sidi Bel-Abbes, Sidi Bel-Abbes 22000 (Algeria); Rozale, H., E-mail: hrozale@yahoo.fr [Condensed Matter and Sustainable Development Laboratory (LMCDD), University of Sidi Bel-Abbes, Sidi Bel-Abbes 22000 (Algeria); Amar, A. [Condensed Matter and Sustainable Development Laboratory (LMCDD), University of Sidi Bel-Abbes, Sidi Bel-Abbes 22000 (Algeria); Wang, X.T. [School of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 400044 (China); Sayade, A. [UCCS, CNRS-UMR 8181, Université d’Artois, Faculté des Sciences Jean Perrin, Rue Jean Souvraz, SP 18, 62307 Lens Cedex (France); Chahed, A. [Condensed Matter and Sustainable Development Laboratory (LMCDD), University of Sidi Bel-Abbes, Sidi Bel-Abbes 22000 (Algeria)

    2016-12-01

    The structural, electronic, magnetic, and thermal properties of new quaternary Heusler alloys CsSrCZ (Z=Si, Ge, Sn, P, As, and Sb) were investigated using the full-potential linearized augmented plane wave (FPLAPW) within the generalized gradient approximation (GGA) and GGA plus modified Becke and Johnson as the exchange correlation. The results showed that all Heusler compounds were stable in Type (I) structure. The CsSrCZ (Z=Si, Ge, Sn) compounds had a nearly HM characteristic, and CsSrCZ (Z=P, As, Sb) compounds were true half-metallic (HM) ferromagnets. The strong spin polarization of p orbital for C, Si, Ge, Sn, P, As, and Sb atoms is found to be the origin of ferromagnetic. The half-metallicity is preserved up to a lattice contraction of 3.45%, 1.69%, 1.69%, 7.16%, 7.16%, and 11.2% for all six quaternary Heusler compounds. We also investigated the thermal effects using the quasi-harmonic Debye model. - Highlights: • Electronic, magnetic, and thermodynamic properties of CsSrCZ (Z=Si, Ge, Sn, P, As, and Sb) are investigated. • Until now, there have been no reports theoretical and experimental studies on d{sup 0} half-metals with quaternary structures. • The strong spin polarization of p orbital for C, Si, Ge, Sn, P, As, and Sb atoms is found to be the origin of ferromagnetic. • The half-metallicity is preserved up to a lattice contraction.

  10. The Octyl Ester of Ginsenoside Rh2 Induces Lysosomal Membrane Permeabilization via Bax Translocation

    Directory of Open Access Journals (Sweden)

    Fang Chen

    2016-04-01

    Full Text Available Ginsenoside Rh2 is a potential pharmacologically active metabolite of ginseng. Previously, we have reported that an octyl ester derivative of ginsenoside Rh2 (Rh2-O, has been confirmed to possess higher bioavailability and anticancer effect than Rh2 in vitro. In order to better assess the possibility that Rh2-O could be used as an anticancer compound, the underlying mechanism was investigated in this study. The present results revealed that lysosomal destabilization was involved in the early stage of cell apoptosis in HepG2 cells induced by Rh2-O. Rh2-O could induce an early lysosomal membrane permeabilization with the release of lysosomal protease cathepsins to the cytosol in HepG2 cells. The Cat B inhibitor (leu and Cat D inhibitor (pepA inhibited Rh2-O-induced HepG2 apoptosis as well as tBid production and Δφm depolarization, indicating that lysosomal permeabilization occurred upstream of mitochondrial dysfunction. In addition, Rh2-O induced a significant increase in the protein levels of DRAM1 and Bax (p < 0.05 in lysosomes of HepG2 cells. Knockdown of Bax partially inhibited Rh2-O-induced Cat D release from lysosomes. Thus it was concluded that Rh2-O induced apoptosis of HepG2 cells through activation of the lysosomal-mitochondrial apoptotic pathway involving the translocation of Bax to the lysosome.

  11. The role of GABA in the regulation of GnRH neurons

    Directory of Open Access Journals (Sweden)

    Miho eWatanabe

    2014-11-01

    Full Text Available Gonadotropin-releasing hormone (GnRH neurons form the final common pathway for the central regulation of reproduction. Gamma-amino butyric acid (GABA has long been implicated as one of the major players in the regulation of GnRH neurons. Although GABA is typically an inhibitory neurotransmitter in the mature adult central nervous system, most mature GnRH neurons show the unusual characteristic of being excited by GABA. While many reports have provided much insight into the contribution of GABA to the activity of GnRH neurons, the precise physiological role of the excitatory action of GABA on GnRH neurons remains elusive. This brief review presents the current knowledge of the role of GABA signaling in GnRH neuronal activity. We also discuss the modulation of GABA signaling by neurotransmitters and neuromodulators and the functional consequence of GABAergic inputs to GnRH neurons in both the physiology and pathology of reproduction.

  12. Energy barriers for interlayer diffusion in Pt/Pt(111) and Rh/Rh(111) homoepitaxy: small islands

    Czech Academy of Sciences Publication Activity Database

    Máca, František; Kotrla, Miroslav; Trushin, O. S.

    1999-01-01

    Roč. 49, č. 11 (1999), s. 1591-1596 ISSN 0011-4626. [Symposium on Surface Physics /8./. Třešť, 28.06.1999-02.07.1999] R&D Projects: GA MŠk OC P3.80 Institutional research plan: CEZ:AV0Z1010914 Keywords : molecular statics * energy barriers * Pt and Rh Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.328, year: 1999

  13. GnRH-I and GnRH-II-induced calcium signaling and hormone secretion in neonatal rat gonadotrophs

    Czech Academy of Sciences Publication Activity Database

    Balík, Aleš; Jindřichová, Marie; Bhattacharyya, Sharmistha; Zemková, Hana

    2009-01-01

    Roč. 58, č. 5 (2009), s. 709-716 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA305/07/0681; GA AV ČR(CZ) IAA500110702; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50110509 Keywords : gonadotrophs * GnRH-II * melatonin Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 1.430, year: 2009

  14. Half-Heusler compounds with a 1 eV (1.7 eV) direct band gap, lattice-matched to GaAs (Si), for solar cell application: A first-principles study

    KAUST Repository

    Belmiloud, N.; Boutaiba, F.; Belabbes, Abderrezak; Ferhat, M.; Bechstedt, F.

    2016-01-01

    -Heusler compounds ScAgC, YCuC, CaZnC, NaAgO, and LiCuS are studied by density functional theory for potential applications in multi-junction solar cells. The calculated formation enthalpies indicate that these materials are thermodynamically stable. Using state

  15. Half-Heusler compounds with a 1 eV (1.7 eV) direct band gap, lattice-matched to GaAs (Si), for solar cell application: A first-principles study

    KAUST Repository

    Belmiloud, N.

    2016-01-10

    A systematic theoretical study of the structural and electronic properties of new half-Heusler compounds is performed to find the appropriate target key physical parameters for photovoltaic application. As a result, five ternary half-Heusler compounds ScAgC, YCuC, CaZnC, NaAgO, and LiCuS are studied by density functional theory for potential applications in multi-junction solar cells. The calculated formation enthalpies indicate that these materials are thermodynamically stable. Using state-of-the-art modified Becke-Johnson exchange potential approximation, we find a direct band gap close to 1eV (∼1.88eV) for ScAgC, YCuC, CaZnC, NaAgO (LiCuS) being quasi-lattice matched to GaAs (Si). In addition, the band offsets between half-Heusler compounds and GaAs (Si) and their consequences for heterostructures are derived using the modified Tersoff method for the branch-point energy. Furthermore, the elastic constants and phonon dispersion curves are calculated. They indicate the respective mechanical and dynamical stability of these half-Heusler compounds. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Pharmacological and toxicological assessment of a potential GnRH vaccine in young-adult male pigs

    NARCIS (Netherlands)

    Turkstra, J.A.; Staay, van der F.J.; Stockhofe-Zurwieden, N.; Woelders, H.; Meloen, R.H.; Schuurman, T.

    2011-01-01

    Active immunization against gonadotrophin-releasing hormone (GnRH) is successfully applied to prevent boar taint in pork. In men, GnRH immunization could be an alternative to hormone therapy in patients with prostate cancer. In this study, a new GnRH vaccine formulation (a modified GnRH peptide

  17. Mental distress and personality in women undergoing GnRH agonist versus GnRH antagonist protocols for assisted reproductive technology

    DEFF Research Database (Denmark)

    Stenbæk, D. S.; Toftager, M.; Hjordt, L. V.

    2015-01-01

    STUDY QUESTION: Do mental distress and mood fluctuations in women undergoing GnRH agonist and GnRH antagonist protocols for assisted reproductive technology (ART) differ depending on protocol and the personality trait, neuroticism? SUMMARY ANSWER: ART treatment did not induce elevated levels...... of mental distress in either GnRH antagonist or agonist protocols but neuroticism was positively associated with increased mental distress, independent of protocols. WHAT IS KNOWN ALREADY: ART treatment may increase mental distress by mechanisms linked to sex hormone fluctuations. General psychological...... characteristics, such as personality traits indexing negative emotionality, e.g. neuroticism, are likely to affect mental distress during ART treatment. STUDY DESIGN, SIZE, DURATION: A total of 83 women undergoing their first ART cycle were consecutively randomized 1:1 to GnRH antagonist (n = 42) or GnRH agonist...

  18. The comparision of effect of microdose GnRH-a flare-up, GnRH antagonist/aromatase inhibitor letrozole and GnRH antagonist/clomiphene citrate protocols on IVF outcomes in poor responder patients.

    Science.gov (United States)

    Ozcan Cenksoy, Pinar; Ficicioglu, Cem; Kizilkale, Ozge; Suhha Bostanci, Mehmet; Bakacak, Murat; Yesiladali, Mert; Kaspar, Cigdem

    2014-07-01

    To compare the effects of microdose GnRH-a flare-up, GnRH antagonist/aromatase inhibitor letrozole and GnRH antagonist/clomiphene citrate protocols on IVF outcomes in poor responder patients. Of 225 patients, 83 patients were in microdose flare-up group (Group 1), 70 patients were in GnRH antagonist/letrozole group (Group 2) and 72 patients were in GnRH antagonist/clomiphene citrate group (Group 3). Demographic and endocrine characteristics, the total number of oocytes retrieved, cancellation rate and clinical pregnancy rate were collected Results: Total dosage of gonadotropins (p=0.002) and serum E2 levels on the day of hCG administration (p=0.010) were significantly higher and duration of stimulations (p=0.03) was significantly longer in group 1. The number of oocytes retrieved was significantly greater in group 1 and 2 when compare to those of group 3 (p=0,000). There was a trend towards increasing cycle cancellation rates with GnRH antagonist/clomiphene citrate and GnRH antagonist/letrozole. Our finding suggest that the results of microdose flare-up protocol are better than other two used treatment protocols, in terms of maximum estradiol levels, number of mature oocytes retrieved, and cancellation rate and it still seems to be superior the ovarian stimulation regime for the poor responder patients.

  19. Experimental investigation of air relative humidity (RH) cycling tests on MEA/cell aging in PEMFC. Pt. II. Study of low RH cycling test with air RH at 62%/0%

    Energy Technology Data Exchange (ETDEWEB)

    Huang, B.T.; Chatillon, Y.; Bonnet, C.; Lapicque, F. [Laboratoire Reactions et Genie des Procedes, CNRS-Nancy University, Nancy (France); Leclerc, S. [Laboratoire d' Energetique et de Mecanique Theorique et Appliquee, CNRS-Nancy University, Vandoeuvre-les-Nancy (France); Hinaje, M.; Rael, S. [Groupe de Recherche en Electrotechnique et Electronique de Nancy, Nancy University, Vandoeuvre-les-Nancy (France)

    2012-06-15

    The effect of low relative humidity (RH) cycling (RH{sub C} 62%/0%) on the degradation mechanisms of a single proton exchange membrane fuel cell (5 x 5 cm{sup 2}) was investigated and compared to a cell operated at constant humidification (RH{sub C} = 62%). The overall cell performance loss was near 33 {mu}V h{sup -1}, which is greater than the voltage decay under constant RH condition near 3 {mu}V h{sup -1}. The electroactive surface was reduced but to an acceptable level. Impedance spectroscopy revealed that the ohmic and charge transfer resistances were reduced by the likely improved hydration of the ionomeric layer at the catalyst due to hydrogen crossover. This was so important that H{sub 2} starvation was finally responsible for the collapse of the cell after 650 h. Transmission electron microscopy showed occurrence of various phenomena, e.g., bubbles and pinholes formation in the membrane due to local overheat from hydrogen combustion at the cathode, and thickness reduction of catalytic layers. The water up take obtained by {sup 1}H NMR within the membrane electrode assembly (MEA) after low RH cycling reduced by 24% compared to a fresh MEA. Observations are also compared to those obtained at high RH cycling (RH{sub C} 62%/100%) presented in Part I of this study [1]. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Cost-effectiveness of the management of rh-negative pregnant women.

    Science.gov (United States)

    Duplantie, Julie; Gonzales, Odilon Martinez; Bois, Antoine; Nshimyumukiza, Léon; Gekas, Jean; Bujold, Emmanuel; Morin, Valérie; Vallée, Maud; Giguère, Yves; Gagné, Christian; Rousseau, François; Reinharz, Daniel

    2013-08-01

    The purpose of this study was to determine the most cost-effective option to prevent alloimmunization against the Rh factor. A virtual population of Rh-negative pregnant women in Quebec was built to simulate the cost-effectiveness of preventing alloimmunization. The model considered four options: (1) systematic use of anti-D immunoglobulin; (2) fetal Rh(D) genotyping; (3) immunological determination of the father's Rh type; (4) mixed screening: immunological determination of the father's Rh type, followed if positive by fetal Rh(D) genotyping. Two outcomes were considered, in addition to the estimated costs: (1) the number of babies without hemolytic disease, and (2) the number of surviving infants. In a first pregnancy, two options emerged as the most cost-effective options: systematic prophylaxis and immunological Rh typing of the father, with overlapping confidence intervals between them. In a second pregnancy, the results were similar. In all cases (first or second pregnancy or a combination of the two) fetal genotyping was not found to be a cost-effective option. Routine prophylaxis and immunological Rh typing of the father are the most cost-effective options for the prevention of Rh alloimmunization. Considering that immunological typing of the father would probably not be carried out by the majority of clinicians, routine prophylaxis remains the preferred option. However, this could change if the cost of Rh(D) fetal genotyping fell below $140 per sample.

  1. A conserved non-reproductive GnRH system in chordates.

    Directory of Open Access Journals (Sweden)

    Takehiro G Kusakabe

    Full Text Available Gonadotropin-releasing hormone (GnRH is a neuroendocrine peptide that plays a central role in the vertebrate hypothalamo-pituitary axis. The roles of GnRH in the control of vertebrate reproductive functions have been established, while its non-reproductive function has been suggested but less well understood. Here we show that the tunicate Ciona intestinalis has in its non-reproductive larval stage a prominent GnRH system spanning the entire length of the nervous system. Tunicate GnRH receptors are phylogenetically closest to vertebrate GnRH receptors, yet functional analysis of the receptors revealed that these simple chordates have evolved a unique GnRH system with multiple ligands and receptor heterodimerization enabling complex regulation. One of the gnrh genes is conspicuously expressed in the motor ganglion and nerve cord, which are homologous structures to the hindbrain and spinal cord of vertebrates. Correspondingly, GnRH receptor genes were found to be expressed in the tail muscle and notochord of embryos, both of which are phylotypic axial structures along the nerve cord. Our findings suggest a novel non-reproductive role of GnRH in tunicates. Furthermore, we present evidence that GnRH-producing cells are present in the hindbrain and spinal cord of the medaka, Oryzias latipes, thereby suggesting the deep evolutionary origin of a non-reproductive GnRH system in chordates.

  2. Gene Frequency and Heritability of Rh Blood Group Gene in 44 Human Populations

    Directory of Open Access Journals (Sweden)

    Supriyo CHAKRABORTY

    2010-09-01

    Full Text Available The frequency of RhD and Rhd alleles of Rh blood group gene was estimated in 44 human populations distributed all over the world from the RhD phenotypic data. The average frequency of RhD and Rhd allele over these populations was 0.70 and 0.30, respectively. Higher frequency of RhD allele than the expected estimate (0.50 in all the populations, under Hardy-Weinberg equilibrium condition assuming equal frequency of both alleles in the initial population, indicated inbreeding at RhD/d locus as well as natural selection for RhD allele. Very high heritability estimate (84.04% of Rh allele frequency revealed that this trait was under weak selection pressure and resulted in greater genetic variation in existing populations. It is consistent with Fishers fundamental theorem of natural selection. The results from the present study suggest that inbreeding at RhD/d locus and some other factors (possibly mutation, migration and genetic drift other than natural selection alone played major roles in changing the Rh allele frequency in these populations.

  3. Experimental investigation of air relative humidity (RH) cycling tests on MEA/cell aging in PEMFC. Pt. I. Study of high RH cycling test with air RH at 62%/100%

    Energy Technology Data Exchange (ETDEWEB)

    Huang, B.T.; Chatillon, Y.; Bonnet, C.; Lapicque, F. [Laboratoire Reactions et Genie des Procedes, CNRS-Nancy University, Nancy (France); Leclerc, S. [Laboratoire d' Energetique et de Mecanique Theorique et Appliquee, CNRS-Nancy University, Vandoeuvre-les-Nancy (France); Hinaje, M.; Rael, S. [Groupe de Recherche en Electrotechnique et Electronique de Nancy, CNRS-Nancy University, Vandoeuvre-les-Nancy (France)

    2012-06-15

    The effect of high air relative humidity (RH) cycling (RH{sub C} 62%/100%) on the degradation mechanisms of a single (5 x 5 cm{sup 2}) proton exchange membrane fuel cells was investigated. The cell performance was compared to a cell operated at constant humidification (RH{sub C} = 62%). Runs were conducted over approximately 1,500 h at 0.3 A cm{sup -2}. The overall loss in cell performance for the high RH cycling test was 12 {mu}V h{sup -1} whereas it was at 3 {mu}V h{sup -1} under constant humidification. Impedance spectroscopy reveals that the ohmic and charge transfer resistances were little modified in both runs. H{sub 2} crossover measurement indicated that both high RH cycling and constant RH test did not promote serious effect on gas permeability. The electroactive surface loss for anode and cathode during high air RH cycling was more significant than at constant RH operation. The water uptake determined by {sup 1}H nuclear magnetic resonance within the membrane electrode assembly (MEA) after high RH cycling was reduced by 12% in comparison with a fresh MEA. Transmission electron microscopy showed bubbles and pinholes formation in the membrane, catalyst particles agglomeration (also observed by X-ray diffraction), catalyst particles migration in the membrane and thickness reduction of the catalytic layers. Scanning electron microscopy was conducted to observe the changes in morphology of gas diffusion layers after the runs. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Efficacy of rhBMP-2 loaded PCL/PLGA/β-TCP guided bone regeneration membrane fabricated by 3D printing technology for reconstruction of calvaria defects in rabbit

    International Nuclear Information System (INIS)

    Shim, Jin-Hyung; Jeong, Chang-Mo; Huh, Jung-Bo; Jang, Jinah; Jeong, Sung-In; Cho, Dong-Woo; Yoon, Min-Chul

    2014-01-01

    We successfully fabricated a three-dimensional (3D) printing-based PCL/PLGA/β-TCP guided bone regeneration (GBR) membrane that slowly released rhBMP-2. To impregnate the GBR membrane with intact rhBMP-2, collagen solution encapsulating rhBMP-2 (5 µg ml −1 ) was infused into pores of a PCL/PLGA/β-TCP membrane constructed using a 3D printing system with four dispensing heads. In a release profile test, sustained release of rhBMP-2 was observed for up to 28 d. To investigate the efficacy of the GBR membrane on bone regeneration, PCL/PLGA/β-TCP membranes with or without rhBMP-2 were implanted in an 8 mm calvaria defect of rabbits. Bone formation was evaluated at weeks 4 and 8 histologically and histomorphometrically. A space making ability of the GBR membrane was successfully maintained in both groups, and significantly more new bone was formed at post-implantation weeks 4 and 8 by rhBMP-2 loaded GBR membranes. Interestingly, implantation with rhBMP-2 loaded GBR membranes led to almost entire healing of calvaria defects within 8 weeks. (paper)

  5. Half metallic ferromagnetism in tri-layered perovskites Sr{sub 4}T{sub 3}O{sub 10}(T = Co, Rh)

    Energy Technology Data Exchange (ETDEWEB)

    Ghimire, Madhav Prasad, E-mail: ghimire.mpg@gmail.com [Faculty of Science, Nepal Academy of Science and Technology, P. O. Box 3323, Khumaltar, Lalitpur (Nepal); International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Tsukuba 305-0044 (Japan); Thapa, R. K.; Sandeep [Department of Physics, Mizoram University, Aizawl 796-004 (India); Rai, D. P. [Department of Physics, Pachhunga University College, Aizawl 796-001 (India); Sinha, T. P. [Department of Physics, Bose Institute, Kolkata 700-009 (India); Hu, Xiao [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Tsukuba 305-0044 (Japan)

    2015-02-14

    First-principles density functional theory (DFT) is used to investigate the electronic and magnetic properties of Sr{sub 4}Rh{sub 3}O{sub 10}, a member of the Ruddlesden-Popper series. Based on the DFT calculations taking into account the co-operative effect of Coulomb interaction (U) and spin-orbit couplings (SOC), Sr{sub 4}Rh{sub 3}O{sub 10} is found to be a half metallic ferromagnet (HMF) with total magnetic moment μ{sub tot} = 12 μ{sub B} per unit cell. The material has almost 100% spin-polarization at the Fermi level despite of sizable SOC. Replacement of Rh atom by the isovalent Co atom is considered. Upon full-replacement of Co, a low-spin to intermediate spin transition happens resulting in a HMF state with the total magnetic moment three-time larger (i.e., μ{sub tot} = 36 μ{sub B} per unit cell), compared to Sr{sub 4}Rh{sub 3}O{sub 10}. We propose Sr{sub 4}Rh{sub 3}O{sub 10} and Sr{sub 4}Co{sub 3}O{sub 10} as candidates of half metals.

  6. Half-metallic ferromagnetic features in d{sup 0} quaternary-Heusler compounds KCaCF and KCaCCl: A first-principles description

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jiangtao [Department of Physics, Faculty of Science, Tianjin University, Tianjin 300350 (China); Dong, Shengjie [Department of Physics, Tianjin Normal University, Tianjin 300387 (China); Lu, Yi-Lin [Department of Physics, Faculty of Science, Tianjin University, Tianjin 300350 (China); Zhao, Hui [Department of Physics, Tianjin Normal University, Tianjin 300387 (China); Feng, Liefeng, E-mail: fengliefeng@tju.edu.cn [Department of Physics, Faculty of Science, Tianjin University, Tianjin 300350 (China); Wang, L.Y. [Department of Physics, Faculty of Science, Tianjin University, Tianjin 300350 (China)

    2017-04-15

    The electronic structures and magnetic properties of quaternary Heusler alloys KCaCF and KCaCCl have been analyzed by means of first-principles calculations on the basis of density functional theory. We found that type-3 structure is the most stable configuration where C occupies (0, 0, 0) site, K (0.25, 0.25, 0.25), F/Cl (0.5, 0.5, 0.5), and Ca (0.75, 0.75, 0.75). Type-1 arrangement is the metastable structure in which K, Ca, C, and X occupy (0, 0, 0), (0.25, 0.25, 0.25), (0.5, 0.5, 0.5), and (0.75, 0.75, 0.75) sites, respectively. Both of them are half metals with equilibrium volume. The spin polarization is predominantly from C 2p states. With the variation of the lattice constant, spin-gapless semiconducting characteristic is achieved for type-1 KCaCCl as volume increases. - Highlights: • KCaCX (X=F and Cl) alloys with quaternary-Heusler structure were designed. • They exhibit a half-metallic ferromagnetic behavior at equilibrium lattice parameter. • The spin polarization is mainly from the partially-filled p state and p-d interaction. • KCaCCl can become spin-gapless semiconductor with the variation of lattice parameter.

  7. First-principles study of half-metallic properties in RbCaNZ (Z = O, S, and Se) quaternary Heusler compounds

    Science.gov (United States)

    Rezaei, S.; Ahmadian, F.

    2018-06-01

    On the basis of first principles calculations, the electronic structures and magnetic properties of quaternary Heusler alloys RbCaNZ (Z = O, S, and Se) were studied. The negative formation energies indicated that all these compounds were thermodynamically stable and thus may be experimentally synthesized at appropriate conditions in the future. The results showed that YI structure was the most favorable configuration among the three possible structures. All compounds were found to be half-metallic ferromagnets. The characteristic of energy bands and origin of half-metallicity were also verified. The total magnetic moments of RbCaNZ (Z = O, S, and Se) compounds were obtained 2μB per formula unit, which were in an agreement with Slater-Pauling rule (Mtot = 12 - Ztot). Half-metallicity was preserved at ranges of 5.06-8.36 Å, 5.96-8.81 Å, and 6.13-8.73 Å for RbCaNO, RbCaNS, and RbCaNSe compounds, respectively, which show that these quaternary Heusler compounds may be potential candidates in spintronic applications.

  8. Synthesis and thermoelectric properties of fine-grained FeVSb system half-Heusler compound polycrystals with high phase purity

    International Nuclear Information System (INIS)

    Zou Minmin; Li Jingfeng; Guo Peijun; Kita, Takuji

    2010-01-01

    Nearly single-phased FeVSb half-Heusler compound thermoelectric materials with fine grains of diameter 100-200 nm were prepared from their elemental powders by combining mechanical alloying (MA) and spark plasma sintering. The resultant bulk samples showed a relatively low room-temperature electrical resistivity on the order of 10 μΩm, and a moderate negative Seebeck coefficient with a maximum value of -175 μV K -1 at 300 0 C. It was found that proper excessive addition of V relative to the stoichiometric composition (FeVSb) during MA enhanced the phase purity and hence the power factor of the spark plasma sintered samples, resulting in a large power factor value of 2480 μW m -1 K -2 when the elemental powders were mixed with the composition FeV 1.15 Sb. Its thermal conductivity was significantly reduced mainly due to refined grain sizes, resulting in a high dimensionless figure of merit ZT of 0.31 at a low-to-mid temperature (300 0 C) as for undoped half-Heusler compounds.

  9. Study of the structural, electronic and magnetic properties of ScFeCrT (T=Si, Ge) Heusler alloys by first principles approach

    Energy Technology Data Exchange (ETDEWEB)

    Rasool, Muhammad Nasir [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur (Pakistan); Hussain, Altaf, E-mail: altafiub@yahoo.com [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur (Pakistan); Javed, Athar, E-mail: athar.physics@pu.edu.pk [Department of Physics, University of the Punjab, Lahore 54590 (Pakistan); Khan, Muhammad Azhar [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur (Pakistan)

    2017-03-15

    Spin polarized structural, electronic, magnetic and bonding properties of ScFeCrT (T=Si, Ge) Heusler alloys are studied by employing density functional theory. The total energy calculation (for a static lattice) shows that both alloys are structurally stable in ferromagnetic phase with compressibility C{sub ScFeCrSi}>C{sub ScFeCrGe}. The electronic and band structure analysis show that the ScFeCrT alloys exhibit half-metallic ferromagnetic (HMF) behaviour for spin ↑ channel while semiconducting behaviour in spin ↓ channel. Both alloys exhibit total magnetic moment, M{sub Total}=3.0 µ{sub B}/cell obeying the Slater Pauling rule, M{sub SPR}=(N{sub v} –18)μ{sub B}. For ScFeCrSi and ScFeCrGe alloys, the charge density and interatomic bonding character show highly covalent and polar covalent character, respectively. For both alloys, 100% spin polarization (for spin ↑ state) is expected which is an indication of their suitability for applications in spintronic devices. - Highlights: • Heusler alloys ScFeCrT (T= Si, Ge) are studied by first principles approach. • Structural, electronic, magnetic and bonding properties are reported. • Both alloys show half-metallicity and ferromagnetic behaviour. • Combination of properties shows the suitability of alloys in spintronic devices.

  10. Magnetic hyperfine fields on 181Ta at the Nb and V sites in Heusler alloys CO2YAL (Y=NB,V)

    International Nuclear Information System (INIS)

    Pendl Junior, W.

    1990-01-01

    Magnetic hyperfine fields (MHF) acting on sup(181)Ta at the Nb and V sites have been determined in the Heusler alloys Co sub(2) NbA1 and Co sub(2) VA1 by the time differential perturbed angular correlation (TDPAC) technique utilizing the well known 133-482 Kev gamma cascade in sup(181)Ta. The measurement were carried out using an automatic spectrometer consisting of three NaI(T1) detectors and a fast-slow coincidence system. The measurements were performed at 77 K with and without an externally applied magnetic field ( ∼ 4.5 KGauss) to determine the sign as well as the magnitude of the hyperfine fields in both alloys. For the alloy Co sub(2) NbA1 a unique field of -138(4) KOe was observed whereas in the case of Co sub(2)VA1 two distinct magnetic sites were observed. The present result show that approximately 24% of the sup(181)Ta atoms in this alloy probe a field of -116(4) KOe while the other ∼ 76% of the atoms feel -83(3) KOe. Present data along with the existing results on similar alloys Co sub(2)T1,Hf,Zr (Al,Ga,Sn) are discussed and compared with the magnetic hyperfine field systematics in Heusler alloys. (author)

  11. Magnetism and electronic structure of CoFeCrX (X = Si, Ge) Heusler alloys

    International Nuclear Information System (INIS)

    Jin, Y.; O'Connell, A.; Kharel, P.; Lukashev, P.; Staten, B.; Tutic, I.; Valloppilly, S.; Herran, J.; Mitrakumar, M.; Bhusal, B.; Huh, Y.; Yang, K.; Skomski, R.; Sellmyer, D. J.

    2016-01-01

    The structural, electronic, and magnetic properties of CoFeCrX (X = Si, Ge) Heusler alloys have been investigated. Experimentally, the alloys were synthesized in the cubic L2 1 structure with small disorder. The cubic phase of CoFeCrSi was found to be highly stable against heat treatment, but CoFeCrGe disintegrated into other new compounds when the temperature reached 402 °C (675 K). Although the first-principle calculation predicted the possibility of tetragonal phase in CoFeCrGe, the tetragonal phase could not be stabilized experimentally. Both CoFeCrSi and CoFeCrGe compounds showed ferrimagnetic spin order at room temperature and have Curie temperatures (T C ) significantly above room temperature. The measured T C for CoFeCrSi is 790 K but that of CoFeCrGe could not be measured due to its dissociation into new compounds at 675 K. The saturation magnetizations of CoFeCrSi and CoFeCrGe are 2.82 μ B /f.u. and 2.78 μ B /f.u., respectively, which are close to the theoretically predicted value of 3 μ B /f.u. for their half-metallic phases. The calculated band gaps for CoFeCrSi and CoFeCrGe are, respectively, 1 eV and 0.5 eV. These materials have potential for spintronic device applications, as they exhibit half-metallic electronic structures with large band gaps, and Curie temperatures significantly above room temperature.

  12. Magnetic anomaly in superconducting TmRh4B4

    International Nuclear Information System (INIS)

    Smith, J.L.; Huang, C.Y.; Tsou, J.J.; Ho, J.C.

    1978-01-01

    The magnetic and superconducting properties of TmRh 4 B 4 (which becomes superconducting at 9.6 K) by means of ac and dc magnetic susceptibility and specific heat measurements are investigated. At 10.7 K, an ac susceptibility peak similar to those found in spin glasses has been observed. In addition, a pronounced specific heat peak has been observed at 11.4 K. The susceptibility peak is essentially unaffected by substitution of 1% Lu or Er for the Tm, but it diminishes when much larger amounts of Er are substituted. The physical origin of this anomalous peak will be discussed

  13. Association of ABO and Rh blood groups with type 2 diabetes mellitus.

    Science.gov (United States)

    Meo, S A; Rouq, F A; Suraya, F; Zaidi, S Z

    2016-01-01

    The phenotypic "ABO" blood groups are inherited antigenic substances which are found on the surface of red blood cells in addition to other tissues. Certain hypothesis advocates that genetic predisposition like "ABO" blood group would be associated with occurrence of diseases including type 2 diabetes. This study aimed to investigate the potential association between "ABO" and "Rhesus" blood groups with type 2 diabetes. We identified 47 research documents in a data based search including ISI-Web of Science, EMBASE and PubMed. Literature was explored using the key terms including "ABO blood groups" "type 2 diabetes". Studies in which "ABO" blood types and diabetes mellitus were discussed included without restrictions of research documents, types, status and language of the publications. Finally, 15 publications which matched our criteria were included, and remaining studies were excluded. Blood group "B" was associated with high incidence of type 2 diabetes and blood group "O" has a minimum association with type 2 diabetes. Blood group "A" and "AB" were almost equally distributed in both diabetic and non-diabetic population. However, we were unable to find an association between "Rh+ve" and "Rh-ve" blood groups with type 2 diabetes. Subjects with blood group "B" are at high risk while individuals with blood group "O" are at low peril of evolving type 2 diabetes. It is suggested that subjects with blood group "B" should be closely monitored by physicians as these subjects have an increased risk of type 2 diabetes.

  14. THE USE OF GnRH ANTAGONISTS IN OVARIAN STIMULATION FOR INTRAUTERINE INSEMINATION

    Directory of Open Access Journals (Sweden)

    Mete Işıkoğlu

    2013-12-01

    Full Text Available The first paper entitled intrauterine insemination (IUI was published in 1962. By time, several methods involving the technique and the ovulation induction schedules have evolved in order to improve the success rates. Although gonadotrophin releasing hormone antagonists (GnRHa is a crucial part of assisted reproductive treatments now, concerns also arouse regarding the need for the use of it in IUI cycles. These drugs may be considered in IUI programs basically in order to prevent premature LH surges and related cycle cancellations. Although administration of a GnRH antagonist almost completely abolishes premature luteinization, it does not substantially improve the pregnancy rate. The decision of using GnRH antagonists in IUI cycles should be based primarily on the local cost/benefit analysis of individual centers. It will be prudent to limit the involvement of the antagonists in ovulation induction protocols to: patients who frequently exhibit premature LH discharges and therefore either fail to complete treatment or result in unsuccessful outcome; initiated cycles intented for IUI but converted to ART; if it is not possible for logistic reasons (weekend to perform the insemination or for medical centers in which a gynecologist on call is not available and in order to decrease clinical task burden resulting from strict cycle monitoring such as serial transvaginal sonography and/or frequent urine tests.

  15. Development of a Ga-68 labeled triptorelin analog for GnRH receptor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zoghi, Masoumeh; Niazi, Ali [Islamic Azad Univ., Arak (Iran, Islamic Republic of). Dept. of Chemistry; Jalilian, Amir R.; Johari-daha, Fariba; Alirezapour, Behrouz [Nuclear Science and Technology Research Institute (NSTRI) (Iran, Islamic Republic of). Radiation Application Research School; Ramezanpour, Sorour [K.N. Toosi Univ. of Technology, Tehran (Iran, Islamic Republic of). Peptide Chemistry Research Center

    2016-08-01

    Optimized total synthesis, radiolabeling and quality control of [{sup 68}Ga]-DOTA-Hyd-TRP as an efficient and possible PET radiotracer for GnRH receptor imaging in various tumors is of great interest. DOTA-Hyd-TRP was synthesized using solid phase peptide synthesis followed by conjugation to DOTA using pSCN-Bn-DOTA. [{sup 68}Ga]-DOTA-Hyd-TRP was prepared using generator-based [{sup 68}Ga]GaCl{sub 3} and DOTA-Hyd-TRP under optimized conditions for time, temperature, ligand amount, gallium content and column cartridge purification followed by proper formulation. The biodistribution of the tracer in rats was studied using tissue counting up to 120 min. [{sup 68}Ga]-DOTA-Hyd-TRP was prepared at optimized conditions in 5-7 min at 95 C followed by separation using C{sub 18} cartridge (radiochemical purity ∼99 ± 0.88% ITLC, > 99% HPLC, specific activity: 300 ± 15 MBq/nM). The biodistribution of the tracer demonstrated high kidney uptake of the tracer in 10-20 min as well as significant testicular uptake consistent with reported GnRH receptor mappings. Block test studies by triptorelin pretreatment of the animals prior to tracer administration demonstrated significant specific uptake in receptor rich organs including testes and stomach.

  16. Balancing selected medication costs with total number of daily injections: a preference analysis of GnRH-agonist and antagonist protocols by IVF patients

    Directory of Open Access Journals (Sweden)

    Sills E

    2012-08-01

    Full Text Available Abstract Background During in vitro fertilization (IVF, fertility patients are expected to self-administer many injections as part of this treatment. While newer medications have been developed to substantially reduce the number of these injections, such agents are typically much more expensive. Considering these differences in both cost and number of injections, this study compared patient preferences between GnRH-agonist and GnRH-antagonist based protocols in IVF. Methods Data were collected by voluntary, anonymous questionnaire at first consultation appointment. Patient opinion concerning total number of s.c. injections as a function of non-reimbursed patient cost associated with GnRH-agonist [A] and GnRH-antagonist [B] protocols in IVF was studied. Results Completed questionnaires (n = 71 revealed a mean +/− SD patient age of 34 +/− 4.1 yrs. Most (83.1% had no prior IVF experience; 2.8% reported another medical condition requiring self-administration of subcutaneous medication(s. When out-of-pocket cost for [A] and [B] were identical, preference for [B] was registered by 50.7% patients. The tendency to favor protocol [B] was weaker among patients with a health occupation. Estimated patient costs for [A] and [B] were $259.82 +/− 11.75 and $654.55 +/− 106.34, respectively (p  Conclusions This investigation found consistently higher non-reimbursed direct medication costs for GnRH-antagonist IVF vs. GnRH-agonist IVF protocols. A conditional preference to minimize downregulation (using GnRH-antagonist was noted among some, but not all, IVF patient sub-groups. Compared to IVF patients with a health occupation, the preference for GnRH-antagonist was weaker than for other patients. While reducing total number of injections by using GnRH-antagonist is a desirable goal, it appears this advantage is not perceived equally by all IVF patients and its utility is likely discounted heavily by patients when nonreimbursed medication costs

  17. Balancing selected medication costs with total number of daily injections: a preference analysis of GnRH-agonist and antagonist protocols by IVF patients.

    Science.gov (United States)

    Sills, E Scott; Collins, Gary S; Salem, Shala A; Jones, Christopher A; Peck, Alison C; Salem, Rifaat D

    2012-08-30

    During in vitro fertilization (IVF), fertility patients are expected to self-administer many injections as part of this treatment. While newer medications have been developed to substantially reduce the number of these injections, such agents are typically much more expensive. Considering these differences in both cost and number of injections, this study compared patient preferences between GnRH-agonist and GnRH-antagonist based protocols in IVF. Data were collected by voluntary, anonymous questionnaire at first consultation appointment. Patient opinion concerning total number of s.c. injections as a function of non-reimbursed patient cost associated with GnRH-agonist [A] and GnRH-antagonist [B] protocols in IVF was studied. Completed questionnaires (n = 71) revealed a mean +/- SD patient age of 34 +/- 4.1 yrs. Most (83.1%) had no prior IVF experience; 2.8% reported another medical condition requiring self-administration of subcutaneous medication(s). When out-of-pocket cost for [A] and [B] were identical, preference for [B] was registered by 50.7% patients. The tendency to favor protocol [B] was weaker among patients with a health occupation. Estimated patient costs for [A] and [B] were $259.82 +/- 11.75 and $654.55 +/- 106.34, respectively (p cost difference increased. This investigation found consistently higher non-reimbursed direct medication costs for GnRH-antagonist IVF vs. GnRH-agonist IVF protocols. A conditional preference to minimize downregulation (using GnRH-antagonist) was noted among some, but not all, IVF patient sub-groups. Compared to IVF patients with a health occupation, the preference for GnRH-antagonist was weaker than for other patients. While reducing total number of injections by using GnRH-antagonist is a desirable goal, it appears this advantage is not perceived equally by all IVF patients and its utility is likely discounted heavily by patients when nonreimbursed medication costs reach a critical level.

  18. High-pressure and high-temperature physical properties of half-metallic full-Heusler alloy Mn{sub 2}RuSi by first-principles and quasi-harmonic Debye model

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ting [State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Ma, Qin, E-mail: maqin_lut@yeah.net [State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); Sun, Xiao-Wei [School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Liu, Zi-Jiang [School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Department of Physics, Lanzhou City University, Lanzhou 730070 (China); Wei, Xiao-Ping [School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Tian, Jun-Hong [School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China)

    2017-02-15

    First-principles calculations based on density functional theory and quasi-harmonic Debye model are used to investigate the high-pressure and high-temperature physical properties, including the lattice constant, magnetic moment, density of states, pressure-volume-temperature relationship, bulk modulus, thermal expansivity, heat capacity, and Grüneisen parameter for the new Mn-based full-Heusler alloy Mn{sub 2}RuSi in CuHg{sub 2}Ti-type structure. The optimized equilibrium lattice constant is consistent with experimental and other theoretical results. The calculated total spin magnetic moment remains an integral value of 2.0 μ{sub B} in the lattice constant range of 5.454–5.758 Å, and then decreases very slowly with the decrease of lattice constant to 5.333 Å. By the spin resolved density of states calculations, we have shown that Mn{sub 2}RuSi compound presents half-metallic ferrimagnetic properties under the equilibrium lattice constant. The effects of temperature and pressure on bulk modulus, thermal expansivity, heat capacity, and Grüneisen parameter are opposite, which are consistent with a compression rate of volume. Furthermore, the results show that the effect of temperature is larger than pressure for heat capacity and the effect of high temperature and pressure on thermal expansion coefficient is small. All the properties of Mn{sub 2}RuSi alloy are summarized in the pressure range of 0–100 GPa and the temperature up to 1200 K. - Highlights: • High-pressure and high-temperature physical properties of Mn2RuSi were investigated. • Ferrimagnetic ground state has been confirmed in Mn2RuSi alloy. • The first-principle calculations and quasi-harmonic Debye model were used. • The pressure up to 100 GPa and the temperature up to 1200 K.

  19. Unraveling the role of support surface hydroxyls and its effect on the selectivity of C{sub 2} species over Rh/γ-Al{sub 2}O{sub 3} catalyst in syngas conversion: A theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Riguang; Duan, Tian; Wang, Baojun, E-mail: wangbaojun@tyut.edu.cn; Ling, Lixia

    2016-08-30

    Highlights: • The selectivity toward CH{sub x} (x = 1–3) depends on γ-Al{sub 2}O{sub 3} support and its surface properties. • Rh/γ-Al{sub 2}O{sub 3} catalyst exhibits the higher selectivity toward CH{sub x} (x = 1,2) formation from syngas. • C{sub 2} species (C{sub 2}H{sub 2},CHCO,CH{sub 2}CHO) are the main products on Rh/γ-Al{sub 2}O{sub 3} catalyst. • γ-Al{sub 2}O{sub 3} surface hydroxyls affect the selectivity of C{sub 2} species over Rh/γ-Al{sub 2}O{sub 3} catalyst. - Abstract: The supported Rh-based catalysts exhibit the excellent catalytic performances for syngas conversion to C{sub 2} species. In this study, all possible elementary steps leading to C{sub 2} species from syngas have been explored to identify the role of support and its surface hydroxyls over Rh/γ-Al{sub 2}O{sub 3} catalyst; Here, the results are obtained using density functional theory (DFT) method. Two models: Rh4 cluster supported on the dry γ-Al{sub 2}O{sub 3}(110) surface, D(Rh4), and on the hydroxylated γ-Al{sub 2}O{sub 3}(110) surface, H(Rh4), have been used to model Rh/γ-Al{sub 2}O{sub 3} catalyst. Our results show that CO prefers to be hydrogenated to CHO, subsequently, starting from CHO species, CH and CH{sub 2} species are the dominate monomers among CH{sub x}(x = 1–3) species rather than CH{sub 3} and CH{sub 3}OH on D(Rh4) and H(Rh4) surfaces, suggesting that γ-Al{sub 2}O{sub 3}-supported Rh catalyst exhibits the high selectivity towards CH{sub x} formation compared to the pure Rh catalyst. On the other hand, D(Rh4) is more favorable for C{sub 2} hydrocarbon (C{sub 2}H{sub 2}) formation, whereas H(Rh4) surface easily produces C{sub 2} hydrocarbon (C{sub 2}H{sub 2}) and C{sub 2} oxygenates (CHCO,CH{sub 2}CHO), indicating that the surface hydroxyls of support can affect the selectivity of C{sub 2} species over Rh/γ-Al{sub 2}O{sub 3} catalyst in syngas conversion. Moreover, compared to the pure Rh(111) surface, Rh/γ-Al{sub 2}O{sub 3} catalyst can achieve the

  20. Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters.

    Science.gov (United States)

    Nogueira, C A; Paiva, A P; Oliveira, P C; Costa, M C; da Costa, A M Rosa

    2014-08-15

    The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu(2+) concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80 °C, t = 4h, [HCl] = 6M, [Cu(2+)] = 0.3M). Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Multicomponent Synthesis of Isoindolinone Frameworks via RhIII -Catalysed in situ Directing Group-Assisted Tandem Oxidative Olefination/Michael Addition.

    Science.gov (United States)

    Wang, Liang; Liu, Xi; Liu, Jian-Biao; Shen, Jun; Chen, Qun; He, Ming-Yang

    2018-04-04

    A Rh III -catalysed three-component synthesis of isoindolinone frameworks via direct assembly of benzoyl chlorides, o-aminophenols and activated alkenes has been developed. The process involves in situ generation of o-aminophenol (OAP)-based bidentate directing group (DG), Rh III -catalysed tandem ortho C-H olefination and subsequent cyclization via aza-Michael addition. This protocol exhibits good chemoselectivity and functional group tolerance. Computational studies showed that the presence of hydroxyl group on the N-aryl ring could enhance the chemoselectivity of the reaction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Structural analysis of the RH-like blood group gene products in nonhuman primates

    Energy Technology Data Exchange (ETDEWEB)

    Salvignol, I. [Centre Regional de Transfusion Sanguine, Toulouse (France); Calvas, P.; Blancher, A. [Universitaire d`Immunogenetique moleculaire, Toulouse (France); Socha, W.W. [University Medical Center, New York, NY (United States); Colin, Y.; Le Van Kim, C.; Bailly, P.; Cartron, J.P. [Institut National de la Transfusion Sanguine, Paris (France); Ruffie, J.; Blancher, A. [College de France, Paris (France)

    1995-03-01

    Rh-related transcripts present in bone marrow samples from several species of nonhuman primates (chimpanzee, gorilla, gibbon, crab-eating macaque) have been amplified by RT-polymerase chain reaction using primers deduced from the sequence of human RH genes. Nucleotide sequence analysis of the nonhuman transcripts revealed a high degree of similarity to human blood group Rh sequences, suggesting a great conservation of the RH genes throughout evolution. Full-length transcripts, potentially encoding 417 amino acid long proteins homologous to Rh polypeptides, were characterized, as well as mRNA isoforms which harbored nucleotide deletions or insertions and potentially encode truncated proteins. Proteins of 30-40,000 M{sub r}, immunologically related to human Rh proteins, were detected by western blot analysis with antipeptide antibodies, indicating that Rh-like transcripts are translated into membrane proteins. Comparison of human and nonhuman protein sequences was pivotal in clarifying the molecular basis of the blood group C/c polymorphism, showing that only the Pro103Ser substitution was correlated with C/c polymorphism. In addition, it was shown that a proline residue at position 102 was critical in the expression of C and c epitopes, most likely by providing an appropriate conformation of Rh polypeptides. From these data a phylogenetic reconstruction of the RH locus evolution has been calculated from which an unrooted phylogenetic tree could be proposed, indicating that African ape Rh-like genes would be closer to the human RhD gene than to the human RhCE gene. 55 refs., 4 figs., 1 tab.

  3. Identification of the GnRH-(1-5) Receptor and Signaling Pathway

    Science.gov (United States)

    2013-03-22

    expression in immortalized GnRH neurons and to facilitate lordosis behavior in female rats. Interestingly, EP24.15 colocalizes with vii...expression in immortalized GnRH neurons (73) and facilitates lordosis behavior in female rats (72). Interestingly, EP24.15 is expressed along the...biologically active by facilitating lordosis behavior in ovariectomized estrogen-primed rats (72); and can increase the mRNA expression of GnRH in immortalized

  4. Frequency distribution of ABO and Rh (D) blood group alleles in Silte Zone, Ethiopia

    OpenAIRE

    Kassahun Tesfaye; Yohannes Petros; Mebeaselassie Andargie

    2015-01-01

    Background: Frequency distribution of blood groups is important as it is used in modern medicine, genetic research, anthropology, and tracing ancestral relations of humans. The ABO and Rh blood groups are the most important blood groups despite the long list of several other blood groups discovered so far. Aim of the study: To study and document the frequency of ABO and Rh (D) blood groups in three ethnic groups of Silte Zone, Ethiopia. Subjects and methods: ABO and Rh (D) typing was ca...

  5. Selective enhancement of main olfactory input to the medial amygdala by GnRH.

    Science.gov (United States)

    Blake, Camille Bond; Meredith, Michael

    2010-03-04

    In male hamsters mating behavior is dependent on chemosensory input from the main olfactory and vomeronasal systems, whose central pathways contain cell bodies and fibers of gonadotropin-releasing hormone (GnRH) neurons. In sexually naive males, vomeronasal organ removal (VNX), but not main olfactory lesions, impairs mating behavior. Intracerebroventricular (i.c.v.)-GnRH restores mating in sexually naive VNX males and enhances medial amygdala (Me) immediate-early gene activation by chemosensory stimulation. In sexually experienced males, VNX does not impair mating and i.c.v.-GnRH suppresses Me activation. Thus, the main olfactory system is sufficient for mating in experienced-VNX males, but not in naive-VNX males. We investigated the possibility that GnRH enhances main olfactory input to the amygdala in naive-VNX males using i.c.v.-GnRH and pharmacological stimulation (bicuculline/D,L-homocysteic acid mixture) of the main olfactory bulb (MOB). In sexually naive intact males there was a robust increase of Fos protein expression in the anteroventral medial amygdala (MeAv) with MOB stimulation, but no effect of GnRH. There was no effect of stimulation or GnRH in posterodorsal medial amygdala (MePd). In naive-VNX animals, GnRH increased Fos in MeAv and MePv. Only combined MOB stimulation and i.c.v.-GnRH produced a significant increase in Fos in the dorsal (reproduction-related) portion of MeP (MePd). When the animals were sexually experienced before VNX, a condition in which GnRH does not enhance mating, i.c.v.-GnRH combined with MOB stimulation suppressed Fos expression in MePd. This suggests a more selective effect of GnRH on olfactory input in MePd than elsewhere in medial amygdala of VNX males. 2009 Elsevier B.V. All rights reserved.

  6. Dynamic GnRH and hCG testing

    DEFF Research Database (Denmark)

    Bang, A. Kirstine; Nordkap, Loa; Almstrup, Kristian

    2017-01-01

    OBJECTIVE: Gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG) stimulation tests may be used to evaluate the pituitary and testicular capacity. Our aim was to evaluate changes in follicular-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone after Gn...... influence of the tests was illustrated by results from 45 patients suspected of disordered hypothalamic-pituitary-gonadal axis. METHODS: Baseline, stimulated, relative and absolute changes in serum FSH and LH were determined by ultrasensitive TRIFMA, and testosterone was determined by LC-MS/MS. RESULTS......: For the reference group, LH and FSH increased almost 400% and 40% during GnRH testing, stimulated levels varied from 4.4 to 58.8 U/L and 0.2 to 11.8 U/L and FSH decreased in nine men. Testosterone increased approximately 110% (range: 18.7-67.6 nmol/L) during hCG testing. None of the polymorphisms had any major...

  7. [rhDNase: scientific background, cloning and production].

    Science.gov (United States)

    Shak, S

    1995-07-01

    Despite the hopes raised by the first attempts in gene therapy, direct correction of the defect in CFTR protein associated with cystic fibrosis is still beyond clinical reach. Therefore we have to set upon the consequences of the defect. Respiratory distress and progressive lung destruction in cystic fibrosis can be accounted for by infectious exacerabations and the accumulation of viscous purulent secretions in the airways. For a long time we have known that purulent secretions that accumulate in the airways of patients with cystic fibrosis contain large amounts of DNA, a complex macromolecule that contributes mostly to the viscosity and hinders the mucociliary function. Hence we hypothesized that enzymatic cleaving of DNA molecules by desoxyribonuclease (DNase) should reduce the viscosity of sputum, and slow or prevent the deterioration of pulmonary function. Using the techniques of molecular biology and genetic engineering, we identified the gene of human DNase I, which was cloned in mammalian cells to produce large amounts of a glycosylated protein for therapeutic use. Catalytic amounts of rhDNase greatly reduce the viscosity of purulent cystic fibrosis sputum, transforming it within minutes from a nonflowing viscous gel to a flowing liquid. This effect was associated with a decrease in size of DNA fragments in the sputum. Our studies suggested that inhalation of a rhDNase aerosol might be a simple direct approach to reduce the viscosity of purulent secretions and thereby help patients with cystic fibrosis clear their airways and breathe more easily.

  8. Solvent effects on lasing characteristics for Rh B laser dye

    Energy Technology Data Exchange (ETDEWEB)

    Peter, Jaison, E-mail: jaison.peter@gmail.com [International School of Photonics, Cochin University of Science and Technology, Cochin 682022 (India); Kumar, Mahesh [Department of Applied Chemistry, Cochin University of Science and Technology, Cochin 682022 (India); Ananad, V.R.; Saleem, Rasool; Sebastian, Ananthu; Radhakrishnan, P.; Nampoori, V.P.N.; Vallabhan, C.P.G. [International School of Photonics, Cochin University of Science and Technology, Cochin 682022 (India); Prabhu, Radhakrishna [School of Engineering, Robert Gordon University, Aberdeen AB10 1FR, Scotland (United Kingdom); Kailasnath, M. [International School of Photonics, Cochin University of Science and Technology, Cochin 682022 (India)

    2016-01-15

    We demonstrate pulsed, photopumped multimode laser emission in the visible spectral range from rhodamine B dye dissolved in various solvents. The laser emission is characterized by a well-defined, low threshold pump power at which the emission spectral intensity dramatically increases and collapsed into several dominant laser modes with reduced mode spacing and spectral width. The modes were found to originate from the subcavities formed by the plane-parallel walls of the cuvette containing the gain medium. The cavity lasing spectral structure and the numbers of longitudinal modes were easily controlled by changing the solvents. A shift in the emission spectra has been also observed by changing the solvents will allow a limited range of tuning of laser emission wavelength. We also determined the gain coefficient and stimulated emission cross-section for the Rh B dye dissolved liquid laser system. A detailed discussion of the solvent effect in the lasing characteristics of Rh B in different solution is explained along with the computational data. - Highlights: • Report multimode laser emission from rhodamine B dye dissolved in various solvents. • Modes are originated from the plane-parallel walls of the cuvette. • Spectral range and the number of modes can be controlled by changing the solvents. • Changing solvents also allows a limited range of tuning of laser emission.

  9. Transport and NMR characteristics of the skutterudite-related compound Ca3Rh4Sn13

    Science.gov (United States)

    Tseng, C. W.; Kuo, C. N.; Li, B. S.; Wang, L. M.; Gippius, A. A.; Kuo, Y. K.; Lue, C. S.

    2018-02-01

    We report the electronic properties of the Yb3Rh4Sn13-type single crystalline Ca3Rh4Sn13 by means of the electrical resistivity, Hall coefficient, Seebeck coefficient, thermal conductivity, as well as 119Sn nuclear magnetic resonance (NMR) measurements. The negative sign of the Hall coefficient and Seebeck coefficient at low temperatures suggests that the n-type carriers dominate the electrical transport in Ca3Rh4Sn13, in contrast to the observations in Sr3Rh4Sn13 which has a p-type conduction. Such a finding indicates a significant difference in the electronic features between these two stannides. Furthermore, we analyzed the temperature-dependent 119Sn NMR spin-lattice relaxation rate for Ca3Rh4Sn13, (Sr0.7Ca0.3)3Rh4Sn13, and Sr3Rh4Sn13 to examine the change of the electronic Fermi-level density of states (DOS) in (Sr1-xCax)3Rh4Sn13. It indicates that the Sn 5s partial Fermi-level DOS enhances with increasing the Ca content, being consistent with the trend of the superconducting temperature. Since the total Fermi-level DOS usually obeys the same trend of the partial Fermi-level DOS, the NMR analysis provides microscopic evidence for the correlation between the electronic DOS and superconductivity of the (Sr1-xCax)3Rh4Sn13 system.

  10. Cell saver filtering of extravasated rhBMP-2 after degenerative scoliosis reconstruction

    Directory of Open Access Journals (Sweden)

    Gabriel Liu, MBBCh, MSc, FRCS, FAMS (Orth

    2015-06-01

    Full Text Available RhBMP-2 is a bone fusion enhancer commonly used in scoliosis reconstruction surgery. It is delivered via an absorbable collagen sponge but has been known to migrate away from its delivery site. RhBMP-2 extravasation in surgical drainage has been noted during first two days post-surgery. Cell savers are widely used in scoliosis reconstruction to limit transfusion requirements and are commonly deployed in cases where rhBMP-2 is used for fusion augmentation. It is not known whether rhBMP-2 is present in salvaged blood or filtered away during cell saver recycling. Through this case series of four patients who underwent scoliosis reconstruction, we assess cell saver efficacy in filtering rhBMP-2 molecules by quantifying the amount of rhBMP-2 present in salvaged blood obtained after postoperative drainage recycling by OrthoPAT® cell saver and comparing it to rhBMP-2 leakage in postoperative drainage without cell saver recycling. We report an almost 10-fold reduction of rhBMP-2 concentration in salvaged blood obtained after cell saver recycling of postoperative drainage, suggesting cell saver effectiveness in filtering rhBMP-2 molecules.

  11. Functional reconstitution into liposomes of purified human RhCG ammonia channel.

    Directory of Open Access Journals (Sweden)

    Isabelle Mouro-Chanteloup

    Full Text Available BACKGROUND: Rh glycoproteins (RhAG, RhBG, RhCG are members of the Amt/Mep/Rh family which facilitate movement of ammonium across plasma membranes. Changes in ammonium transport activity following expression of Rh glycoproteins have been described in different heterologous systems such as yeasts, oocytes and eukaryotic cell lines. However, in these complex systems, a potential contribution of endogenous proteins to this function cannot be excluded. To demonstrate that Rh glycoproteins by themselves transport NH(3, human RhCG was purified to homogeneity and reconstituted into liposomes, giving new insights into its channel functional properties. METHODOLOGY/PRINCIPAL FINDINGS: An HA-tag introduced in the second extracellular loop of RhCG was used to purify to homogeneity the HA-tagged RhCG glycoprotein from detergent-solubilized recombinant HEK293E cells. Electron microscopy analysis of negatively stained purified RhCG-HA revealed, after image processing, homogeneous particles of 9 nm diameter with a trimeric protein structure. Reconstitution was performed with sphingomyelin, phosphatidylcholine and phosphatidic acid lipids in the presence of the C(12E(8 detergent which was subsequently removed by Biobeads. Control of protein incorporation was carried out by freeze-fracture electron microscopy. Particle density in liposomes was a function of the Lipid/Protein ratio. When compared to empty liposomes, ammonium permeability was increased two and three fold in RhCG-proteoliposomes, depending on the Lipid/Protein ratio (1/300 and 1/150, respectively. This strong NH(3 transport was reversibly inhibited by mercuric and copper salts and exhibited a low Arrhenius activation energy. CONCLUSIONS/SIGNIFICANCE: This study allowed the determination of ammonia permeability per RhCG monomer, showing that the apparent Punit(NH3 (around 1x10(-3 microm(3xs(-1 is close to the permeability measured in HEK293E cells expressing a recombinant human RhCG (1.60x10

  12. Zebrafish adult-derived hypothalamic neurospheres generate gonadotropin-releasing hormone (GnRH neurons

    Directory of Open Access Journals (Sweden)

    Christian Cortés-Campos

    2015-09-01

    Full Text Available Gonadotropin-releasing hormone (GnRH is a hypothalamic decapeptide essential for fertility in vertebrates. Human male patients lacking GnRH and treated with hormone therapy can remain fertile after cessation of treatment suggesting that new GnRH neurons can be generated during adult life. We used zebrafish to investigate the neurogenic potential of the adult hypothalamus. Previously we have characterized the development of GnRH cells in the zebrafish linking genetic pathways to the differentiation of neuromodulatory and endocrine GnRH cells in specific regions of the brain. Here, we developed a new method to obtain neural progenitors from the adult hypothalamus in vitro. Using this system, we show that neurospheres derived from the adult hypothalamus can be maintained in culture and subsequently differentiate glia and neurons. Importantly, the adult derived progenitors differentiate into neurons containing GnRH and the number of cells is increased through exposure to either testosterone or GnRH, hormones used in therapeutic treatment in humans. Finally, we show in vivo that a neurogenic niche in the hypothalamus contains GnRH positive neurons. Thus, we demonstrated for the first time that neurospheres can be derived from the hypothalamus of the adult zebrafish and that these neural progenitors are capable of producing GnRH containing neurons.

  13. A possible in vivo generator 103Pd/103mRh-Recoil considerations

    International Nuclear Information System (INIS)

    Rooyen, Johann van; Szucs, Zoltan; Rijn Zeevaart, Jan

    2008-01-01

    The use of Auger emitters as potential radiopharmaceuticals is increasingly investigated. One such radionuclide of interest is 103m Rh. This can be produced from 103 Ru or from 103 Pd in an in vivo generator. A potential problem with this concept is the recoil of the 103m Rh out of the carrier molecule and even out of the target cell. In order to determine whether this would happen in the 103 Pd/ 103m Rh case calculations were done to prove that this does not happen. From theoretical considerations it seems that the 103 Pd/ 103m Rh in vivo generator system would be possible

  14. Measurement of cross-sections for the reaction 103Rh (n,n')103mRh in the energy range 5.69 - 12 MeV and its evaluation from the threshold up to 20 MeV

    International Nuclear Information System (INIS)

    Hossain, M.M.M.

    1995-05-01

    The cross-sections for the reaction 103 R(n,n') 103m Rh were measured by the method of activation in the neutron energy range 5.69-12.00 MeV produced by the D(d,n) 3 He reaction. The irradiation of Rh foils was performed at zero degree to the incident beam direction and the activities of KX-rays from the decay of 103m Rh were measured by means of a calibrated Si(Li) detector. During irradiation, the neutron fluence was measured with a fission chamber in which a thin deposit of 238 U was located immediately behind the Rh foil. The measured cross-section with the corresponding uncertainty in the stated energy range is more accurate than all previous measurements in spite of rather large corrections due to break-up neutrons. The update of the evaluation for the same reaction in the energy range from threshold up to 20 MeV was carried out by using the weighted average of cross-sections based on both the experimental data including the present one and theoretical model calculations. The experimental data were renormalized with respect to the recent precision KX-ray emission probability (7.66 + 0.14) % where necessary. To perform the evaluation, the whole excitation function was divided into 33 energy groups of 0.2-1.0 MeV widths. The uncertainties of the evaluated cross-sections especially 6-12 MeV have been improved due to the inclusion of the new measurement. Overall, the results of the updated evaluation are a considerable improvement compared to the previous evaluation of this reaction and also to the recommended cross-section data of IRDF (International Reactor Dosimetry File). (author)

  15. Fanconi Anemia a Is a Nucleocytoplasmic Shuttling Molecule Required for Gonadotropin-Releasing Hormone (GnRH) Transduction of the GnRH Receptor

    OpenAIRE

    Larder, Rachel; Karali, Dimitra; Nelson, Nancy; Brown, Pamela

    2006-01-01

    GnRH binds its cognate G protein-coupled GnRH receptor (GnRHR) located on pituitary gonadotropes and drives expression of gonadotropin hormones. There are two gonadotropin hormones, comprised of a common α- and hormone-specific β-subunit, which are required for gonadal function. Recently we identified that Fanconi anemia a (Fanca), a DNA damage repair gene, is differentially expressed within the LβT2 gonadotrope cell line in response to stimulation with GnRH. FANCA is mutated in more than 60%...

  16. Environmental application of millimetre-scale sponge iron (s-Fe"0) particles (IV): New insights into visible light photo-Fenton-like process with optimum dosage of H_2O_2 and RhB photosensitizers

    International Nuclear Information System (INIS)

    Ju, Yongming; Yu, Yunjiang; Wang, Xiaoyan; Xiang, Mingdeng; Li, Liangzhong; Deng, Dongyang; Dionysiou, Dionysios D.

    2017-01-01

    Highlights: • Synergistic action of Rhodamine B (RhB), visible light, H_2O_2 and s-Fe"0 is essential. • The complexes of RhB and Fe"3"+ eject one electron via ligand-to-metal charge-transfer. • RhB assists the photo-Fenton-like removal of tetrabromobisphenol A (TBBPA). - Abstract: In this study, we firstly develop the photo-Fenton-like system with millimetric sponge iron (s-Fe"0), H_2O_2, visible light (vis, λ ≥ 420 nm) and rhodamine B (RhB), and present a comprehensive study concerning the mechanism. Thus, we investigate (1) the adsorption of RhB onto s-Fe"0, (2) the photo-Fenton-like removal of RhB over iron oxides generated from the corrosion of s-Fe"0, (3) the homogeneous photo-Fenton removal of RhB over Fe"2"+ or Fe"3"+, (4) the Fe"3"+-RhB complexes, and (5) the photo-Fenton-like removal of tetrabromobisphenol A (TBBPA). The results show that neither the adsorption process over s-Fe"0 nor the photo-Fenton-like process over FeOOH, Fe_3O_4 and Fe_2O_3, achieved efficient removal of RhB. For comparison, in homogeneous photo-Fenton process, the presence of Fe"3"+ ions, rather than Fe"2"+ ions, effectively eliminated RhB. Furthermore, the UV–vis spectra showing new absorbance at ∼ 285 nm indicate the complexes of RhB and Fe"3"+ ions, adopting vis photons to form excited state and further eject one electron via ligand-to-metal charge-transfer to activate H_2O_2. Additionally, efficient TBBPA removal was obtained only in the presence of RhB. Accordingly, the s-Fe"0– based photo-Fenton-like process assisted with dyestuff wastewater is promising for removing a series of persistent organic pollutants.

  17. Modeling biogeochemical processes in sediments from the Rhône River prodelta area (NW Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    L. Pastor

    2011-05-01

    Full Text Available In situ oxygen microprofiles, sediment organic carbon content, and pore-water concentrations of nitrate, ammonium, iron, manganese, and sulfides obtained in sediments from the Rhône River prodelta and its adjacent continental shelf were used to constrain a numerical diagenetic model. Results showed that (1 the organic matter from the Rhône River is composed of a fraction of fresh material associated to high first-order degradation rate constants (11–33 yr−1; (2 the burial efficiency (burial/input ratio in the Rhône prodelta (within 3 km of the river outlet can be up to 80 %, and decreases to ~20 % on the adjacent continental shelf 10–15 km further offshore; (3 there is a large contribution of anoxic processes to total mineralization in sediments near the river mouth, certainly due to large inputs of fresh organic material combined with high sedimentation rates; (4 diagenetic by-products originally produced during anoxic organic matter mineralization are almost entirely precipitated (>97 % and buried in the sediment, which leads to (5 a low contribution of the re-oxidation of reduced products to total oxygen consumption. Consequently, total carbon mineralization rates as based on oxygen consumption rates and using Redfield stoichiometry can be largely underestimated in such River-dominated Ocean Margins (RiOMar environments.

  18. Magnetic surface domain imaging of uncapped epitaxial FeRh(001) thin films across the temperature-induced metamagnetic transition

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xianzhong; Matthes, Frank; Bürgler, Daniel E., E-mail: d.buergler@fz-juelich.de; Schneider, Claus M. [Peter Grünberg Institut, Electronic Properties (PGI-6) and Jülich-Aachen Research Alliance, Fundamentals of Future Information Technology (JARA-FIT), Forschungszentrum Jülich, D-52425 Jülich (Germany)

    2016-01-15

    The surface magnetic domain structure of uncapped epitaxial FeRh/MgO(001) thin films was imaged by in-situ scanning electron microscopy with polarization analysis (SEMPA) at various temperatures between 122 and 450 K. This temperature range covers the temperature-driven antiferromagnetic-to-ferromagnetic phase transition in the body of the films that was observed in-situ by means of the more depth-sensitive magneto-optical Kerr effect. The SEMPA images confirm that the interfacial ferromagnetism coexisting with the antiferromagnetic phase inside the film is an intrinsic property of the FeRh(001) surface. Furthermore, the SEMPA data display a reduction of the in-plane magnetization occuring well above the phase transition temperature which, thus, is not related to the volume expansion at the phase transition. This observation is interpreted as a spin reorientation of the surface magnetization for which we propose a possible mechanism based on temperature-dependent tetragonal distortion due to different thermal expansion coefficients of MgO and FeRh.

  19. Female-Specific Glucose Sensitivity of GnRH1 Neurons Leads to Sexually Dimorphic Inhibition of Reproduction in Medaka.

    Science.gov (United States)

    Hasebe, Masaharu; Kanda, Shinji; Oka, Yoshitaka

    2016-11-01

    Close interaction exists between energy-consuming reproduction and nutritional status. However, there are differences in costs and priority for reproduction among species and even between sexes, which leads to diversification of interactions between reproduction and nutritional status. Despite such diversified interactions among species and sexes, most of the analysis of the nutritional status-dependent regulation of reproduction has been limited to an endothermic vertebrate, mammalian species of either sex. Therefore, the mechanisms underlying the diversified interactions remain elusive. In the present study, we demonstrated the effects of malnutritional status on reproduction at both organismal and cellular levels in an ectothermic vertebrate, a teleost medaka of both sexes. First, we analyzed the effects of malnutrition by fasting on gonadosomatic index, number of spawned/fertilized eggs, and courtship behavior. Fasting strongly suppressed reproduction in females but, surprisingly, not in males. Next, we analyzed the effects of fasting on firing activity of hypothalamic GnRH1 neurons, which form the final common pathway for the control of reproduction. An electrophysiological analysis showed that low glucose, which is induced by fasting, directly suppresses the firing activity of GnRH1 neurons specifically in females through intracellular ATP-sensitive potassium channels and AMP-activated protein kinase pathways. Based on the fact that such suppressions occurred only in females, we conclude that nutritional status-dependent, glucose-sensing in GnRH1 neurons may contribute to the most fitted reproductive regulation for each sex.

  20. Relationship of ABO and Rh blood groups with history of gastritis in the undergraduate medical and dental students: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Nilu Manandhar

    2017-12-01

    Full Text Available Background & Objectives: The various ABO and Rh blood groups with different distribution frequencies in the general population have been found to be associated with different diseases, most notably gastritis. Many studies have claimed Rh groups to be indifferent to such association. Nonetheless, ABO group is found to linked with chronic gastritis. The aim of this study was to estimate the frequencies of ABO and Rh blood groups and the gastritis amongst the first and second year undergraduate medical and dental students; and to study their relationships. Materials & Methods: In a descriptive, cross-sectional study, 247 study participants were enrolled. After procuring clearance from the institutional review committee and the informed and written consent from the study participants, data collection was done on the variables, year of study (first or second year, gender, blood groups (ABO and Rh and history of gastritis (present or absent.Results: Blood group O was the commonest (n=99; 40.1% followed by group B (n=77; 31.2%. Similarly, 239 (96.8% participants were Rh-positive as compared to 8 (3.2% Rh-negative. Interestingly, 46 (18.6% of the participants reported positive history of gastritis. Participants with blood group O had the greatest odds (OR=1.64 of having history of gastritis compared with those with other blood groups combined. Distribution of study participants based on gender and history of gastritis in either systems of blood grouping shoed no significant difference in their proportions (p>0.05. Conclusion: In light of the above findings, further longitudinal studies can be designed to better asses the relationship.