X-ray photoelectron spectroscopy study of BaWO{sub 4} and Ba{sub 2}CaWO{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Capece, Angela M., E-mail: acapece@pppl.gov [California Institute of Technology, Pasadena, CA (United States); Polk, James E. [Jet Propulsion Laboratory, Pasadena, CA (United States); Shepherd, Joseph E. [California Institute of Technology, Pasadena, CA (United States)

2014-12-15

Highlights: • XPS reference spectra for Ba{sub 2}CaWO{sub 6} and BaWO{sub 4} are presented. • Binding energies of Ba 3d and W 4f lines are 0.7 eV higher for BaWO{sub 4} than Ba{sub 2}CaWO{sub 6}. • Ca 2p spectrum contains two sets of Ca 2p doublets attributed to Ba{sub 2}CaWO{sub 6} and CaCO{sub 3}. - Abstract: XPS reference spectra for Ba{sub 2}CaWO{sub 6} and BaWO{sub 4} are presented, including high resolution spectra of the Ba 3d, W 4f, C 1s, Ca 2p, and O 1s lines. The peak locations and full widths at half maximum are also given. The binding energies of the Ba 3d and W 4f lines are 0.7 eV higher for BaWO{sub 4} than for Ba{sub 2}CaWO{sub 6}. The Ca 2p spectrum contains two sets of Ca 2p doublets that were attributed to Ba{sub 2}CaWO{sub 6} and CaCO{sub 3}.

Polarizabilities of Ba and Ba2: Comparison of molecular beam experiments with relativistic quantum chemistry

International Nuclear Information System (INIS)

Schaefer, Sascha; Mehring, Max; Schaefer, Rolf; Schwerdtfeger, Peter

2007-01-01

The dielectric response to an inhomogeneous electric field has been investigated for Ba and Ba 2 within a molecular beam experiment. The ratio of the polarizabilities per atom of Ba 2 and Ba is determined to be 1.30±0.13. The experimental result is compared to a high level ab initio quantum chemical coupled cluster calculation with an energy-consistent scalar relativistic small-core pseudopotential for Ba. For the barium atom a polarizability of 40.82 A 3 is obtained and the isotropic value of the polarizability calculated for Ba 2 is 97.88 A 3 , which is in good agreement with the experimental results, demonstrating that a quantitative understanding of the interaction between two closed-shell heavy element metal atoms has been achieved

Precision machining and polishing of scintillating crystals for large calorimeters and hodoscopes

International Nuclear Information System (INIS)

Wuest, C.R.; Fuchs, B.A.; Holdener, F.R.; Heck, J.L. Jr.

1994-04-01

New machining and polishing techniques have been developed for large scintillating crystal arrays such as the Barium Fluoride Electromagnetic Calorimeter for the GEM Detector at SSCL, the Crystal Clear Collaboration's cerium fluoride or lead tungstenate calorimeter at the proposed LHC and CERN, the PHENIX Detector at RHIC (barium fluoride), and the cesium iodide Calorimeter for the BaBar Detector at PEP-2 B Factory at SLAC. The machining and polishing methods to be presented in this paper provide crystalline surfaces without sub-surface damage or deformation as verified by Rutherford Back-scattering (RBS) analysis. Surface roughness of about 10--20 angstroms and sub-micron mechanical tolerances have been demonstrated on large barium fluoride crystal samples. Mass production techniques have also been developed for machining the proper angled surfaces and polishing up to five 50 cm long crystals at one time. These techniques utilize kinematic mount technology developed at LLNL to allow precision machining and polishing of complex surfaces. They will present this technology along with detailed surface studies of barium fluoride and cerium fluoride crystals polished with this technique

Ba incorporation in benthic foraminifera

NARCIS (Netherlands)

de Nooijer, L.J.; Brombacher, Anieke; Mewes, A.; Langer, Gerald; Nehrke, G.; Bijma, Jelle; Reichart, G.J.

2017-01-01

Barium (Ba) incorporated in the calcite of many foraminiferal species is proportional to the concentration of Ba in seawater. Since the open ocean concentration of Ba closely follows seawater alkalinity, foraminiferal Ba ∕ Ca can be used to reconstruct the latter. Alternatively, Ba ∕ Ca from

Modeling of Residual Stress and Machining Distortion in Aerospace Components (PREPRINT)

Science.gov (United States)

2010-03-01

John Gayda, “The Effect of Heat Treatment on Residual Stress and Machining Distortions in Advanced Nickel Base Disk Alloys,” NASA/TM-2001-210717. 2...Wei-Tsu Wu, Guoji Li, Juipeng Tang, Shesh Srivatsa, Ravi Shankar, Ron Wallis, Padu Ramasundaram and John Gayda, “A process modeling system for heat...Materials Processing Technology 98 (2000) 189-195. 6. M.A. Rist, S. Tin, B.A. Roder, J.A. James, and M.R. Daymond , “Residual Stresses in a

Alpha decay of 114Ba

International Nuclear Information System (INIS)

Mazzocchi, C.; Janas, Z.; Batist, L.; Belleguic, V.; Doering, J.; Kapica, M.; Kirchner, R.; Roeckl, E.; Gierlik, M.; Zylicz, J.; Mahmud, H.; Schmidt, K.; Woods, P.J.

2003-01-01

The neutron-deficient isotope 114 Ba was produced in a fusion evaporation reaction at the GSI On-Line Mass Separator. We measured the α-particle energy of 114 Ba, the half-life of its daughter nucleus 110 Xe, and the α-decay branching ratios for 114 Ba, 110 Xe and 106 Te. (orig.)

Effect of local environment on crossluminescence kinetics in SrF{sub 2}:Ba and CaF{sub 2}:Ba solid solutions

Energy Technology Data Exchange (ETDEWEB)

Terekhin, M.A. [P.N. Lebedev Physical Institute, Leninskij Prospekt 53, 119991 Moscow (Russian Federation); Makhov, V.N., E-mail: makhov@sci.lebedev.ru [P.N. Lebedev Physical Institute, Leninskij Prospekt 53, 119991 Moscow (Russian Federation); Lebedev, A.I.; Sluchinskaya, I.A. [Lomonosov Moscow State University, Moscow 119991 (Russian Federation)

2015-10-15

Spectral and kinetic properties of extrinsic crossluminescence (CL) in SrF{sub 2}:Ba (1%) and CaF{sub 2}:Ba (1%) are compared with those of intrinsic CL in BaF{sub 2} and are analyzed taking into account EXAFS data obtained at the Ba L{sub III} edge and results of first-principles calculations. The CL decay time was revealed to be longer in SrF{sub 2}:Ba and CaF{sub 2}:Ba compared to BaF{sub 2}. This fact contradicts the expected acceleration of luminescence decay which could result from an increased overlap of wave functions in solid solutions due to shortening of the Ba-F distance obtained in both EXAFS measurements and first-principles calculations. This discrepancy is explained by the effect of migration and subsequent non-radiative decay of the Ba (5p) core holes in BaF{sub 2} and by decreasing of the probability of optical transitions between Ba (5p) states and the valence band in SrF{sub 2}:Ba and CaF{sub 2}:Ba predicted by first-principles calculations. - Highlights: • The crossluminescence kinetics in SrF{sub 2}:Ba and CaF{sub 2}:Ba is slower than in BaF{sub 2}. • Ba{sup 2+} ions substitute for host Ca{sup 2+}(Sr{sup 2+}) ions in the on-center positions. • The nearest Ba-F distances in SrF{sub 2}:Ba and CaF{sub 2}:Ba are shorter than in BaF{sub 2}. • EXAFS data and first-principles calculations of the local structure agree well. • First-principles calculations explain slower luminescence decay in solid solutions.

Improvement of wear resistance of machine elements by plasma spraying followed by hardening in the chlorine-barium melt

International Nuclear Information System (INIS)

Fominykh, V.V.; Stepanov, V.V.

1979-01-01

Proposed is the mathematical model, allowing to choose the optimal regime of sprayed coating hardening in the BaCl 2 salt melt. The method of hardening of machine elements by spraying wear resistance coatings of the Ni-Cr-B-Si alloys is described. It is established that diffusion heating followed by coating melting in the BaCl 2 solution increases the adhesion of sprayed layer to substrate metal. The formation of intermediate intermetallic compounds of the Ni 3 Si and Ni 3 Fe types takes place as a result of diffusion of interacting material atoms and valence electron joining

Research of influence of technological parameters on the noise characteristics of the machine for grinding meat

Directory of Open Access Journals (Sweden)

A. K. Pil’nenko

2016-01-01

Full Text Available Noise characteristics (NC machine is one of the main indicators of its quality and competitiveness on the world markets. Scientific and technical work to improve the noise characteristics are relevant and modern. Work focuses on the study of the emergence of the technological equipment of acoustic phenomena. Was selected method of determination and equipment, according to the international standards ISO “Acoustics” taking into account the acoustic properties of the surrounding space. Been established NC machines for grinding meat and fish under operating conditions the in various modes. The maximum value for the characteristic A sound power level (SPL machines produced at idling 79,7 dBA. When the machine comes with the product decline USM on the characteristics A 7.3 dB. It was found exceeding the maximum allowable sound power level at medium frequencies on 2 dB. Impact the components of machines on its NC depending on variables technological factors - the module of elasticity of the product and the effort on the pushrod. Increase modulus of elasticity SPL machines decreases and increase efforts on the pusher Machines USM increases. It was found negative impact construction machines part sat USM. Should be increased rigidity design of the machine.

Improvement of the field-trapping capabilities of bulk Nd Ba Cu O superconductors using Ba Cu O substrates

Science.gov (United States)

Matsui, Motohide; Nariki, Shinya; Sakai, Naomichi; Iwafuchi, Kengo; Murakami, Masato

2006-07-01

We used Ba-Cu-O substrates to fabricate bulk Nd-Ba-Cu-O superconductors using a top-seeded melt-growth method. There were several advantages for the use of Ba-Cu-O substrate compared to conventional substrate materials such as MgO, ZrO2, Al2O3, RE123 and RE211 (RE = rare earth). The Ba-Cu-O did not react with the precursor and minimized liquid loss. Accordingly, the introduction of large-sized cracks was suppressed. We also found that Tc values were high at the bottom regions, which was ascribed to the beneficial effect of Ba-Cu-O in suppressing Nd/Ba substitution. As a result, we obtained bulk Nd-Ba-Cu-O superconductors that exhibited fairly good field-trapping capabilities, even at the bottom surfaces.

Co2FeAl based magnetic tunnel junctions with BaO and MgO/BaO barriers

Directory of Open Access Journals (Sweden)

J. Rogge

2015-07-01

Full Text Available We succeed to integrate BaO as a tunneling barrier into Co2FeAl based magnetic tunnel junctions (MTJs. By means of Auger electron spectroscopy it could be proven that the applied annealing temperatures during BaO deposition and afterwards do not cause any diffusion of Ba neither into the lower Heusler compound lead nor into the upper Fe counter electrode. Nevertheless, a negative tunnel magnetoresistance (TMR ratio of -10% is found for Co2FeAl (24 nm / BaO (5 nm / Fe (7 nm MTJs, which can be attributed to the preparation procedure and can be explained by the formation of Co- and Fe-oxides at the interfaces between the Heusler and the crystalline BaO barrier by comparing with theory. Although an amorphous structure of the BaO barrier seems to be confirmed by high-resolution transmission electron microscopy (TEM, it cannot entirely be ruled out that this is an artifact of TEM sample preparation due to the sensitivity of BaO to moisture. By replacing the BaO tunneling barrier with an MgO/BaO double layer barrier, the electric stability could effectively be increased by a factor of five. The resulting TMR effect is found to be about +20% at room temperature, although a fully antiparallel state has not been realized.

Design and Application of the Reconstruction Software for the BaBar Calorimeter

International Nuclear Information System (INIS)

Strother, Philip David; Imperial Coll., London

2006-01-01

The BaBar high energy physics experiment will be in operation at the PEP-II asymmetric e + e - collider in Spring 1999. The primary purpose of the experiment is the investigation of CP violation in the neutral B meson system. The electromagnetic calorimeter forms a central part of the experiment and new techniques are employed in data acquisition and reconstruction software to maximize the capability of this device. The use of a matched digital filter in the feature extraction in the front end electronics is presented. The performance of the filter in the presence of the expected high levels of soft photon background from the machine is evaluated. The high luminosity of the PEP-II machine and the demands on the precision of the calorimeter require reliable software that allows for increased physics capability. BaBar has selected C++ as its primary programming language and object oriented analysis and design as its coding paradigm. The application of this technology to the reconstruction software for the calorimeter is presented. The design of the systems for clustering, cluster division, track matching, particle identification and global calibration is discussed with emphasis on the provisions in the design for increased physics capability as levels of understanding of the detector increase. The CP violating channel B 0 → J/Ψ K s 0 has been studied in the two lepton, two π 0 final state. The contribution of this channel to the evaluation of the angle sin 2β of the unitarity triangle is compared to that from the charged pion final state. An error of 0.34 on this quantity is expected after 1 year of running at design luminosity

Structural and electrical properties of Barium Titanate (BaTiO3 and Neodymium doped BaTiO3 (Ba0.995Nd0.005TiO3

Directory of Open Access Journals (Sweden)

Tuan Sulong Tuan Amirah

2017-01-01

Full Text Available Barium titanate (BaTiO3 and Neodymium (Nd doped BaTiO3 with composition Ba0.995Nd0.005TiO3 were prepared using conventional solid state reaction method to study the dielectric properties of materials. Pure phase samples were found at final heating temperature of 1400°C for overnight. X-ray diffraction analysis reveals the changes in the lattice parameter and unit cell volume of the pure perovskite tetragonal structure with space group (P4mm. Electrical analysis is carried out to investigate the dielectric properties, conductivity behaviour and dielectric loss of BaTiO3 and Ba0.995Nd0.005TiO3. Ba0.995Nd0.005TiO3 have a broaden dielectric peaks with high permittivity of 8000 and reasonably low loss tan δ which is about 0.004 (1 kHz.

Chalcogenidosilicates: Ba/sub 2/SiTe/sub 4/ and Ba/sub 2/SiSe/sub 4/

Energy Technology Data Exchange (ETDEWEB)

Brinkmann, C; Eisenmann, B; Schaefer, H [Technische Hochschule Darmstadt (Germany, F.R.). Fachbereich Anorganische Chemie und Kernchemie

1985-05-01

The new compounds Ba/sub 2/SiSe/sub 4/ and Ba/sub 2/SiTe/sub 4/ crystallize in the monoclinic system, space group: P2/sub 1//m (No. 11) with the lattice constants Ba/sub 2/SiSe/sub 4/: a = 918.4(5) pm, b = 703.3(3) pm, c = 687.2(3) pm, ..beta.. = 109.2(1)/sup 0/, Ba/sub 2/SiTe/sub 4/: a = 965.0(5) pm, b = 762.6(3) pm, c = 746.6(3) pm, ..beta.. = 108.9(1)/sup 0/. Both compounds are isotypic to the Sr/sub 2/GeS/sub 4/ structure. Ba/sub 2/SiTe/sub 4/ is the first o-telluridosilicate with discrete SiTe/sub 4//sup 4 -/ anions.

Stellar Laboratories: 3. New Ba 5, Ba 6, and Ba 7 Oscillator Strengths and the Barium Abundance in the Hot White Dwarfs G191-B2B and RE 0503-289

Science.gov (United States)

Rauch, T.; Werner, K.; Quinet, P.; Kruk, Jeffrey Walter

2014-01-01

Context. For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. Reliable Ba 5-7 oscillator strengths are used to identify Ba lines in the spectra of the DA-type white dwarf G191-B2B and the DO-type white dwarf RE 0503-289 and to determine their photospheric Ba abundances. Methods. We newly calculated Ba v-vii oscillator strengths to consider their radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models for the analysis of Ba lines exhibited in high-resolution and high-S/N UV observations of G191-B2B and RE 0503-289. Results. For the first time, we identified highly ionized Ba in the spectra of hot white dwarfs. We detected Ba vi and Ba vii lines in the Far Ultraviolet Spectroscopic Explorer (FUSE) spectrum of RE 0503-289. The Ba vi/Ba vii ionization equilibrium is well reproduced with the previously determined effective temperature of 70 000 K and surface gravity of log g=7.5. The Ba abundance is 3.5 +/- 0.5 × 10(exp-4) (mass fraction, about 23 000 times the solar value). In the FUSE spectrum of G191-B2B, we identified the strongest Ba vii line (at 993.41 Å) only, and determined a Ba abundance of 4.0 +/- 0.5 × 10(exp-6) (about 265 times solar). Conclusions. Reliable measurements and calculations of atomic data are a pre-requisite for stellar-atmosphere modeling. Observed Ba vi-vii line profiles in two white dwarfs' (G191-B2B and RE 0503-289) far-ultraviolet spectra were well reproduced with our newly calculated oscillator strengths. This allowed to determine the photospheric Ba abundance of these two stars precisely.

The BaBar Mini

International Nuclear Information System (INIS)

Brown, David N.

2003-01-01

BaBar has recently deployed a new event data format referred to as the Mini. The mini uses efficient packing and aggressive noise suppression to represent the average reconstructed BaBar event in under 7 KBytes. The Mini packs detector information into simple transient data objects, which are then aggregated into roughly 10 composite persistent objects per event. The Mini currently uses Objectivity persistence, and it is being ported to use Root persistence. The Mini contains enough information to support detailed detector studies, while remaining small and fast enough to be used directly in physics analysis. Mini output is customizable, allowing users to both truncate unnecessary content or add content, depending on their needs. The Mini has now replaced three older formats as the primary output of BaBar event reconstruction. A reduced form of the Mini will soon replace the physics analysis format as well, giving BaBar a single, flexible event data format covering all its needs

The BaBar mini

International Nuclear Information System (INIS)

Brown, David N.; BaBar Collaboration

2003-01-01

BaBar has recently deployed a new event data format referred to as the Mini. The mini uses efficient packing and aggressive noise suppression to represent the average reconstructed BaBar event in under 7 KBytes. The Mini packs detector information into simple transient data objects, which are then aggregated into roughly 10 composite persistent objects per event. The Mini currently uses Objectivity persistence, and it is being ported to use Root persistence. The Mini contains enough information to support detailed detector studies, while remaining small and fast enough to be used directly in physics analysis. Mini output is customizable, allowing users to both truncate unnecessary content or add content, depending on their needs. The Mini has now replaced three older formats as the primary output of BaBar event reconstruction. A reduced form of the Mini will soon replace the physics analysis format as well, giving BaBar a single, flexible event data format covering all its needs

Back-contacted BaSi

NARCIS (Netherlands)

Vismara, R.; Isabella, O.; Zeman, M.

2017-01-01

We present the optical investigation of a novel back-contacted architecture for solar cells based on a thin barium (di)silicide (BaSi₂) absorber. First, through the analysis of absorption limits of different semiconducting materials, we show the potential of BaSi₂ for

Melt-growth bulk superconductors and application to an axial-gap-type rotating machine

International Nuclear Information System (INIS)

Zhang, Yufeng; Zhou, Difan; Ida, Tetsuya; Miki, Motohiro; Izumi, Mitsuru

2016-01-01

The present manuscript addresses key issues in the course of our study of materials processing of bulk high-temperature superconductors, trapped flux and its application to a prototype axial-gap-type rotating machine. The TUMSAT group has conducted a series of studies since 2003 on the growth of GdBa 2 Cu 3 O 7−δ bulk material and its application in a compact low-speed high-torque rotating machine. In the stage of material growth, gaining the advantage of a large motive torque density requires large integrated flux in the motor/generators. A large grain surface might be required with sophisticated techniques for the melt-growth texture in the bulk with optimal flux pinning. In the second stage, the in situ magnetization procedure for bulk superconductors in the applied machine is a crucial part of the technology. Pulsed current excitation by using an armature copper winding has magnetized field pole bulks on the rotor. The axial-gap flux synchronous machine studied in the past decade is a condensed technology and indicates that further scientific development is required for a future compact machine to be superior to conventional ones in accordance with the cryogenic periphery and flux stabilization. (paper)

Octupole correlations in neutron-rich {sup 143,145}Ba and a type of superdeformed band in {sup 145}Ba

Energy Technology Data Exchange (ETDEWEB)

Zhu, S.J.; Wang, M.G.; Long, G.L.; Zhu, L.Y.; Gan, C.Y.; Yang, L.M.; Sakhaee, M.; Li, M.; Deng, J.K. [Physics Department, Tsinghua University, Beijing 100084, Peoples Republic of (China); Zhu, S.J.; Hamilton, J.H.; Ramayya, A.V.; Jones, E.F.; Hwang, J.K.; Zhang, X.Q.; Gore, P.M.; Peker, L.K.; Drafta, G.; Babu, B.R.; Deng, J.K.; Ginter, T.N.; Beyer, C.J.; Kormicki, J.; Ter-Akopian, G.M.; Daniel, A.V. [Physics Department, Vanderbilt University, Nashville, Tennessee 37235 (United States); Zhu, S.J.; Ter-Akopian, G.M.; Daniel, A.V. [Joint Institute for Heavy Ion Research, Oak Ridge, Tennessee 37831 (United States); Ma, W.C. [Physics Department, Mississippi State University, Mississippi 39762 (United States); Cole, J.D.; Aryaeinejad, R.; Drigert, M.W. [Idaho National Engineering Laboratory, Idaho Falls, Idaho 83415 (United States); Rasmussen, J.O.; Asztalos, S.; Lee, I.Y.; Macchiavelli, A.O.; Chu, S.Y.; Gregorich, K.E.; Mohar, M.F. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Ter-Akopian, G.M.; Daniel, A.V.; Oganessian, Y.T.; Kliman, J. [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna (Russia); Donangelo, R. [Universidade Federal do Rio de Janeiro, Caixa Postal 68528, RG (Brazil); Stoyer, M.A.; Lougheed, R.W.; Moody, K.J.; Wild, J.F. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Prussin, S.G. [Nuclear Engineering Department, University of California at Berkeley, Berkeley, California 94720 (United States); Kliman, J. [Institute of Physics, SASc, Dubravskacesta 9, 84228 Bratislava (Slovakia); Griffin, H.C. [University of Michigan, Ann Arbor, Michigan 48104 (United States)

1999-11-01

High spin states in neutron-rich odd-{ital Z} {sup 143,145}Ba nuclei have been investigated from the study of prompt {gamma} rays in the spontaneous fission of {sup 252}Cf by using {gamma}-{gamma}- and {gamma}-{gamma}-{gamma}- coincidence techniques. Alternating parity bands are identified for the first time in {sup 145}Ba and extended in {sup 143}Ba. A new side band, with equal, constant dynamic, and kinetic moments of inertia equal to the rigid body value, as found in superdeformed bands, is discovered in {sup 145}Ba. Enhanced E1 transitions between the negative- and positive-parity bands in these nuclei give evidence for strong octupole deformation in {sup 143}Ba and in {sup 145}Ba. These collective bands show competition and coexistence between symmetric and asymmetric shapes in {sup 145}Ba. Evidence is found for crossing M1 and E1 transitions between the s=+i and s={minus}i doublets in {sup 143}Ba. {copyright} {ital 1999} {ital The American Physical Society}

Phonon dispersion curves of BCC Ba

International Nuclear Information System (INIS)

Mizuki, J.; Stassis, C.; Zarestky, J.

1985-01-01

Ba, as well as Sr and Ca, is a divalent alkaline earth metal. At room temperature and ambient pressure, the structure of Ba is bcc, whereas that of Sr and Ca is fcc. Under pressure, the bcc phase of Ba transforms to an hcp structure at 55 kbar. Also, at 37 kbar Ba becomes a superconductor with T/sub c/ = 0.06 K. These properties are highly dependent on the position of the d bands relative to the Fermi level. Experimental investigation of the elastic and lattice dynamical properties of these metals has been hindered by difficulties in growing single crystals. However, recently the authors were able to grow several single crystals of bcc Ba of sufficient volume for inelastic neutron scattering experiments. Some of the results are summarized here

Design and Application of the Reconstruction Software for the BaBar Calorimeter

Energy Technology Data Exchange (ETDEWEB)

Strother, Philip David; /Imperial Coll., London

2006-07-07

The BaBar high energy physics experiment will be in operation at the PEP-II asymmetric e{sup +}e{sup -} collider in Spring 1999. The primary purpose of the experiment is the investigation of CP violation in the neutral B meson system. The electromagnetic calorimeter forms a central part of the experiment and new techniques are employed in data acquisition and reconstruction software to maximize the capability of this device. The use of a matched digital filter in the feature extraction in the front end electronics is presented. The performance of the filter in the presence of the expected high levels of soft photon background from the machine is evaluated. The high luminosity of the PEP-II machine and the demands on the precision of the calorimeter require reliable software that allows for increased physics capability. BaBar has selected C++ as its primary programming language and object oriented analysis and design as its coding paradigm. The application of this technology to the reconstruction software for the calorimeter is presented. The design of the systems for clustering, cluster division, track matching, particle identification and global calibration is discussed with emphasis on the provisions in the design for increased physics capability as levels of understanding of the detector increase. The CP violating channel B{sup 0} {yields} J/{Psi}K{sub S}{sup 0} has been studied in the two lepton, two {pi}{sup 0} final state. The contribution of this channel to the evaluation of the angle sin 2{beta} of the unitarity triangle is compared to that from the charged pion final state. An error of 0.34 on this quantity is expected after 1 year of running at design luminosity.

Hyperfine structure and isotope shift of the neutron-rich barium isotopes 139-146Ba and 148Ba

International Nuclear Information System (INIS)

Wendt, K.; Ahmad, S.A.; Klempt, W.; Neugart, R.; Otten, E.W.

1988-01-01

The hyperfine structure and isotope shift in the 6s 2 S 1/2 -6p 2 P 3/2 line of Ba II (455.4 nm) have been measured by collinear fast-beam laser spectroscopy for the neutron-rich isotopes 139-146 Ba and 148 Ba. Nuclear moments and mean square charge radii of these isotopes have been recalculated. The isotope shift of the isotope 148 Ba (T 1/2 = 0.64 s) could be studied for the first time, yielding δ 2 > 138,148 = 1.245(3) fm 2 . (orig.)

Syntheses, crystal structures and characterizations of BaZn(SeO3)2 and BaZn(TeO3)Cl2

International Nuclear Information System (INIS)

Jiang Hailong; Feng Meiling; Mao Jianggao

2006-01-01

Two new barium zinc selenite and tellurite, namely, BaZn(SeO 3 ) 2 and BaZn(TeO 3 )Cl 2 , have been synthesized by the solid state reaction. The structure of BaZn(SeO 3 ) 2 features double chains of [Zn(SeO 3 ) 2 ] 2- anions composed of four- and eight-member rings which are alternatively along a-axis. The double chains of [Zn 2 (TeO 3 ) 2 Cl 3 ] 3- anions in BaZn(TeO 3 )Cl 2 are formed by Zn 3 Te 3 rings in which each tellurite group connects with three ZnO 3 Cl tetrahedra. BaZn(SeO 3 ) 2 and BaZn(TeO 3 )Cl 2 are wide bandgap semiconductors based on optical diffuse reflectance spectrum measurements. -- Graphical abstract: Two new barium zinc selenite and tellurite, namely, BaZn(SeO 3 ) 2 and BaZn(TeO 3 )Cl 2 , have been synthesized by solid state reaction. The structure of BaZn(SeO 3 ) 2 features 1D double chains of [Zn(SeO 3 ) 2 ] 2- anions composed of four- and eight-member rings which are alternatively along a-axis. The 1D double chains of [Zn 2 (TeO 3 ) 2 Cl 3 ] 3- anions in BaZn(TeO 3 )Cl 2 are formed by Zn 3 Te 3 rings in which each tellurite group connects with one ZnO 3 Cl and two ZnO 2 Cl 2 tetrahedra. BaZn(SeO 3 ) 2 and BaZn(TeO 3 )Cl 2 are wide bandgap semiconductors based on optical diffuse reflectance spectrum measurements

Stellar laboratories. III. New Ba v, Ba vi, and Ba vii oscillator strengths and the barium abundance in the hot white dwarfs G191-B2B and RE 0503-289

Science.gov (United States)

Rauch, T.; Werner, K.; Quinet, P.; Kruk, J. W.

2014-06-01

Context. For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims: Reliable Ba v-vii oscillator strengths are used to identify Ba lines in the spectra of the DA-type white dwarf G191-B2B and the DO-type white dwarf RE 0503-289 and to determine their photospheric Ba abundances. Methods: We newly calculated Ba v-vii oscillator strengths to consider their radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models for the analysis of Ba lines exhibited in high-resolution and high-S/N UV observations of G191-B2B and RE 0503-289. Results: For the first time, we identified highly ionized Ba in the spectra of hot white dwarfs. We detected Ba vi and Ba vii lines in the Far Ultraviolet Spectroscopic Explorer (FUSE) spectrum of RE 0503-289. The Ba vi/Ba vii ionization equilibrium is well reproduced with the previously determined effective temperature of 70 000 K and surface gravity of log g = 7.5. The Ba abundance is 3.5 ± 0.5 × 10-4 (mass fraction, about 23 000 times the solar value). In the FUSE spectrum of G191-B2B, we identified the strongest Ba vii line (at 993.41 Å) only, and determined a Ba abundance of 4.0 ± 0.5 × 10-6 (about 265 times solar). Conclusions: Reliable measurements and calculations of atomic data are a pre-requisite for stellar-atmosphere modeling. Observed Ba vi-vii line profiles in two white dwarfs' (G191-B2B and RE 0503-289) far-ultraviolet spectra were well reproduced with our newly calculated oscillator strengths. This allowed to determine the photospheric Ba abundance of these two stars precisely. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for

High spin structure in 130,131Ba

International Nuclear Information System (INIS)

Kaur, Navneet; Kumar, A.; Singh, Amandeep; Kumar, S.; Kaur, Rajbir; Singh, Varinderjit; Behera, B.R.; Singh, K.P.; Singh, G.; Mukherjee, G.; Sharma, H.P.; Kumar, Suresh; Kumar Raju, M.; Madhusudhan Rao, P.V.; Muralithar, S.; Singh, R.P.; Kumar, Rakesh; Madhvan, N.; Bhowmik, R.K.

2014-01-01

High spin states of 130,131 Ba have been investigated via fusion evaporation reactions 122 Sn( 13 C,4n) 131 Ba and 122 Sn( 13 C, 5n) 130 Ba at E beam =65 MeV. The level schemes of 130,131 Ba have been extended by placing several new γ transitions. A few interband transitions connecting two negative-parity bands, which are the experimental fingerprints of signature partners, have been established in 130 Ba. Spin and parity of a side band have been assigned in 131 Ba and this dipole band is proposed to have a three-quasiparticle configuration, νh 11/2 x πh 11/2 x πg 7/2 . The observed band structures and nuclear shape evolution as a function of the angular momentum have been discussed in the light of Total-Routhian-Surface calculations. (orig.)

Thermal analysis of formation of nano-crystalline BaTiO3 using Ba(NO32 and TiO2

Directory of Open Access Journals (Sweden)

Md. Jawed Ansaree

2015-12-01

Full Text Available The reaction of Ba(NO32 with TiO2 was studied by thermogravimetric (TG and differential scanning calorimetric (DSC techniques up to 1000 °C and in nitrogen atmosphere. It was found that the formation of BaTiO3 takes place above 600 °C and that precursor mixing time and heating rate have no effect on the reaction temperature. BaTiO3 powder was prepared by calcination of Ba(NO32 and TiO2 precursor mixture at 800 °C for 8 h. X-ray diffraction analysis of the synthesized BaTiO3 confirmed the formation of tetragonal phase with lattice parameters a = 3.9950±0.0003 Å and c = 4.0318±0.0004 Å. Thermal analysis of the synthesized BaTiO3 powder showed weight loss within temperature range 40–1000 °C of only 0.40%. This small amount of weight loss was connected with some impurity phase, and identified as BaCO3 using Fourier transform infrared (FTIR technique.

Growth and characterization of acentric BaHf(BO{sub 3}){sub 2} and BaZr(BO{sub 3}){sub 2}

Energy Technology Data Exchange (ETDEWEB)

Mączka, Mirosław, E-mail: m.maczka@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław 2 (Poland); Szymborska-Małek, Katarzyna; Gągor, Anna [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław 2 (Poland); Majchrowski, Andrzej [Institute of Applied Physics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warszawa (Poland)

2015-05-15

Growth, single crystal X-ray diffraction, polarized Raman and infrared (IR) studies of BaHf(BO{sub 3}){sub 2} are presented. Raman and IR spectra of polycrystalline BaZr(BO{sub 3}){sub 2} are also reported to facilitate assignment of modes. BaHf(BO{sub 3}){sub 2} borate crystallizes in trigonal system, space group R3c, with lattice parameters: a=5.1540(4) Å, c=33.901(3) Å. It accommodates dolomite-like structure doubled in the c direction, which is built of alternating layers of HfO{sub 6} octahedra and BaO{sub 6} distorted trigonal prisms that are connected through borate groups. The obtained structural as well as spectroscopic data show that BaHf(BO{sub 3}){sub 2} is isostructural with BaZr(BO{sub 3}){sub 2} and the deviations from centrosymmetry is small. - Graphical abstract: Arrangement of BO{sub 3} groups in BaHf(BO{sub 3}){sub 2} along the c direction in one unit cell. Dark and light blue denote different borate groups. - Highlights: • BaHf(BO{sub 3}){sub 2} single crystals were grown. • X-ray diffraction showed that this borate crystallizes in the acentric R3c structure. • Raman and IR spectra were measured for BaHf(BO{sub 3}){sub 2} and BaZr(BO{sub 3}){sub 2}, respectively. • Assignment of modes is proposed.

The New BaBar Data Reconstruction Control System

International Nuclear Information System (INIS)

Ceseracciu, Antonio

2003-01-01

The BaBar experiment is characterized by extremely high luminosity, a complex detector, and a huge data volume, with increasing requirements each year. To fulfill these requirements a new control system has been designed and developed for the offline data reconstruction system. The new control system described in this paper provides the performance and flexibility needed to manage a large number of small computing farms, and takes full benefit of OO design. The infrastructure is well isolated from the processing layer, it is generic and flexible, based on a light framework providing message passing and cooperative multitasking. The system is actively distributed, enforces the separation between different processing tiers by using different naming domains, and glues them together by dedicated brokers. It provides a powerful Finite State Machine framework to describe custom processing models in a simple regular language. This paper describes this new control system, currently in use at SLAC and Padova on ∼450 CPUs organized in 12 farms

Synthesis of BaTiO3 nanoparticles from TiO2-coated BaCO3 particles derived using a wet-chemical method

Directory of Open Access Journals (Sweden)

Yuuki Mochizuki

2014-03-01

Full Text Available BaCO3 particles coated with amorphous TiO2 precursor are prepared by a wet chemical method to produce BaTiO3 nanoparticles at low temperatures. Subsequently, we investigate the formation behavior of BaTiO3 particles and the particle growth behavior when the precursor is subjected to heat treatment. The state of the amorphous TiO2 coating on the surface of BaCO3 particles depends on the concentration of NH4HCO3, and the optimum concentration is found to be in the range 0.5–1.0 M. Thermogravimetric curves of the BaCO3 particles coated with the TiO2 precursor, prepared from BaCO3 particles of various sizes, show BaTiO3 formation occurring mainly at 550–650 °C in the case of fine BaCO3 particles. However, as evidenced from the curves, the temperature of formation of BaTiO3 shifts to higher values with an increase in the size of the BaCO3 particles. The average particle size of single phase BaTiO3 at heat-treatment temperature of 650–900 °C is observed to be in the range 60–250 nm.

Spectral analysis of Pr{sup 3+} doped germanate glasses modified by BaO and BaF{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Pisarska, Joanna, E-mail: joanna.pisarska@us.edu.pl [University of Silesia, Institute of Chemistry, Szkolna 9 Street, 40-007 Katowice (Poland); Pisarski, Wojciech A. [University of Silesia, Institute of Chemistry, Szkolna 9 Street, 40-007 Katowice (Poland); Dorosz, Dominik; Dorosz, Jan [Bialystok University of Technology, Faculty of Electrical Engineering, Wiejska 45D Street, 15-351 Bialystok (Poland)

2016-03-15

Luminescence properties of Pr{sup 3+} ions in germanate glasses modified by BaF{sub 2} were investigated. Several luminescence bands originating to transitions from the {sup 3}P{sub 0} state to the lower-lying states of Pr{sup 3+} were registered under 450 nm excitation. The spectral analysis suggests that the positions of luminescence bands and their relative intensities are changed significantly with BaF{sub 2} content. The relative integrated luminescence intensities of {sup 3}P{sub 0}→{sup 3}H{sub 4} transition (blue) to the {sup 3}P{sub 0}→{sup 3}F{sub 2} transition (red) of Pr{sup 3+} ions strongly depend on fluoride modifier BaF{sub 2} in glass composition. The luminescence bands of Pr{sup 3+} ions are shifted to shorter wavelengths with increasing BaF{sub 2} content. - Highlights: • Praseodymium doped lead-free germanate glasses modified by BaF{sub 2} were prepared. • Emission spectra correspond to transitions from {sup 3}P{sub 0} state to lower-lying states of Pr{sup 3+}. • The relative emission band intensities of Pr{sup 3+} depend strongly on BaF{sub 2} content. • Emission bands of Pr{sup 3+} are shifted to shorter wavelengths with increasing BaF{sub 2} content.

High field-effect mobility at the (Sr,Ba)SnO{sub 3}/BaSnO{sub 3} interface

Energy Technology Data Exchange (ETDEWEB)

Fujiwara, Kohei, E-mail: kfujiwara@imr.tohoku.ac.jp; Nishihara, Kazuki; Shiogai, Junichi; Tsukazaki, Atsushi [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

2016-08-15

A perovskite oxide, BaSnO{sub 3}, has been classified as one of transparent conducting materials with high electron mobility, and its application for field-effect transistors has been the focus of recent research. Here we report transistor operation in BaSnO{sub 3}-based heterostructures with atomically smooth surfaces, fabricated on SrTiO{sub 3} substrates by the (Sr,Ba)SnO{sub 3} buffer technique. Indeed, modulation of band profiles at the channel interfaces with the insertion of wide bandgap (Sr,Ba)SnO{sub 3} as a barrier layer results in a significant improvement of field-effect mobility, implying effective carrier doping at the regulated heterointerface. These results provide an important step towards realization of high-performance BaSnO{sub 3}-based field-effect transistors.

Optical characteristics of BaGa2S4:Ho3+ and BaGa2Se4:Ho3+ single crystals

International Nuclear Information System (INIS)

Choe, Sung-Hyu; Jin, Moon-Seog; Kim, Wha-Tek

2005-01-01

BaGa 2 S 4 , BaGa 2 S 4 :Ho 3+ , BaGa 2 Se 4 , and BaGa 2 Se 4 :Ho 3+ single crystals were grown by using the chemical transport reaction method. The optical energy gaps of the single crystals were investigated in the temperature region from 11 K to 300 K. The temperature dependence of the optical energy gap was well fitted by the Varshni equation. Two broad emission bands were observed in the photoluminescence spectra of the single crystals. These bands were attributed to donor-acceptor pair recombinations. Sharp emission peaks were observed in the BaGa 2 S 4 :Ho 3+ and the BaGa 2 Se 4 :Ho 3+ single crystals and were assigned to radiation recombination between split Stark levels of Ho 3+ .

The BaBar Data Reconstruction Control System

International Nuclear Information System (INIS)

Ceseracciu, A

2005-01-01

The BaBar experiment is characterized by extremely high luminosity and very large volume of data produced and stored, with increasing computing requirements each year. To fulfill these requirements a Control System has been designed and developed for the offline distributed data reconstruction system. The control system described in this paper provides the performance and flexibility needed to manage a large number of small computing farms, and takes full benefit of OO design. The infrastructure is well isolated from the processing layer, it is generic and flexible, based on a light framework providing message passing and cooperative multitasking. The system is distributed in a hierarchical way: the top-level system is organized in farms, farms in services, and services in subservices or code modules. It provides a powerful Finite State Machine framework to describe custom processing models in a simple regular language. This paper describes the design and evolution of this control system, currently in use at SLAC and Padova on ∼450 CPUs organized in 9 farms

Incorporation of Ba in Al and Fe pollucite

Energy Technology Data Exchange (ETDEWEB)

Vance, Eric R., E-mail: erv@ansto.gov.au [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001 Kirrawee DC, NSW 2232 (Australia); Gregg, Daniel J.; Griffiths, Grant J. [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001 Kirrawee DC, NSW 2232 (Australia); Gaugliardo, Paul R. [Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Crawley, WA 6009 (Australia); Grant, Charmaine [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001 Kirrawee DC, NSW 2232 (Australia)

2016-09-15

Ba, the transmutation product of radioactive Cs, can be incorporated at levels of up to ∼0.07 formula units in Cs{sub (1−2x)}Ba{sub x}AlSi{sub 2}O{sub 6} aluminium pollucite formed by sol-gel methods and sintering at 1400 °C, with more Ba forming BaAl{sub 2}Si{sub 2}O{sub 8} phases. The effect of Ba substitution in pollucite-structured CsFeSi{sub 2}O{sub 6} was also studied and no evidence of Ba substitution in the pollucite structure via cation vacancies or Fe{sup 2+} formation was obtained. The Ba entered a Fe-silicate glass structure. Charge compensation was also attempted with a Cs{sup +} + Fe{sup 3+} ↔ Ba{sup 2+} + Ni{sup 2+} scheme but again the Ba formed a glass and NiO was evident. PCT leaching data showed CsFeSi{sub 2}O{sub 6} to be very leach resistant. - Highlights: • Barium can be incorporated into aluminium pollucite. • Positron annihilation lifetime spectroscopy supports a charge vacancy mechanism of incorporation. • Iron pollucite does not appear to incorporate any barium with either vacancy or charge compensation mechanisms. • Leaching data suggest iron pollucite is very leach resistant.

Submillimeter and microwave residual losses in epitaxial films of Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O

International Nuclear Information System (INIS)

Miller, D.; Richards, P.L.; Eom, C.B.; Geballe, T.H.; Etemad, S.; Inam, A.; Venkatesan, T.; Martens, J.S.; Lee, W.Y.

1992-12-01

We have used a novel bolometric technique and a resonant technique to obtain accurate submillimeter and microwave residual loss data for epitaxial thin films of YBa 2 Cu 3 O 7 , Tl 2 Ca 2 Ba 2 Cu 3 O 10 and Tl 2 CaBa 2 Cu 2 O 8 . For all films we obtain good agreement between the submillimeter and microwave data, with the residual losses in both the Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O films scaling approximately as frequency squared below ∼ 1 THz. We are able to fit the losses in the Y-Ba-Cu-O films to a two fluid and a weakly coupled grain model for the a-b planeconductivity, in good agreement with results from a Kramers-Kronig analysis of the loss data

Processing of R-Ba-Cu-O superconductors

International Nuclear Information System (INIS)

Wu, H.

1998-01-01

Precipitation processes were developed to introduce second phases as flux pinning centers in Gd-Ba-Cu-O and Nd-Ba-Cu-O superconductors. In Gd-Ba-Cu-O, precipitation is caused by the decrease of the upper solubility limit of Gd 1+x Ba 2-x Cu 3 O 7 solid solution (Gd123ss) in low oxygen partial pressure. Processing of supersaturated Gd 1.2 Ba 1.8 Cu 3 O 7 in low oxygen partial pressure can produce dispersed second phases. Gd211 is formed as a separate phase while extensive Gd124 type stacking fault is formed instead of a separate CuO phase. As a result of the precipitation reaction, the transition temperature and critical current density are increased. In Nd-Ba-Cu-O, precipitation is caused by the decrease of the lower solubility limit of Nd 1+x Ba 2-x Cu 3 O 7 solid solution (Nd123ss) in oxygen. DTA results reveal the relative stability of Nd123ss in different oxygen partial pressures. In 1 bar oxygen partial pressure, Nd123ss with x = 0.1 is the most stable phase. In lower oxygen partial pressures, the most stable composition shifts towards the stoichiometric composition. The relative stability changes faster with decreasing oxygen partial pressure. Therefore, processing in oxygen and air tends to produce broad superconducting transitions but sharp transitions can be achieved in 0.01 bar and 0.001 bar oxygen partial pressures. While the lower solubility limits in 0.01 bar and 0.001 bar oxygen partial pressures remain at x = 0.00, the solubility limits in oxygen and air show a narrowing with decreasing temperature. Because of the narrowing of the solubility range in oxygen, oxygen annealing of Nd123 initially processed in low oxygen partial pressures will result in precipitation of second phases. The equilibrium second phase is BaCuO 2 for temperature above 608 C, and at lower temperatures the equilibrium second phases are Ba 2 CuO 3.3 and Ba 2 Cu 3 O 5+y . However, annealing at low temperature may produce a fine metastable transition phase. A coherent intermediate

TRANSITIVITY AND THE BA CONSTRUCTION

Directory of Open Access Journals (Sweden)

Pei-Jung Kuo

2010-06-01

Full Text Available In this paper, I discuss the legitimacy of positing a Transitivity Projection (= TrP cf. Bowers 1993, 1997, 2001 and 2002 in the BA construction in Mandarin Chinese. BA has been proposed to be a semantically-bleached verb, inserted in the v position (Huang 1997 and Lin 2001. Several pieces of evidence such as manner adverbial placement (cf. Huang, Li and Li 2009 and GEI-insertion (cf. Tang 2001 indicate that there must be a functional projection between the vP and VP to host the BA NP. I propose that a TrP is probably the most apt candidate for the XP. I also argue, in contrast to the proposal by Huang, Li and Li (2009, that the present proposal which employs a TrP captures most of the properties of the BA construction. A comparison with the structure of the BEI construction also shows that the TrP proposal fits into the general picture of current linguistic theory on transitive constructions without extra stipulations.

Structural evolution of Ba8Ti3Nb4O24 from BaTiO3 using a series of Ba(Ti1−5xNb4x)O3 solid solutions

International Nuclear Information System (INIS)

Barrientos Hernández, F.R.; Lira Hernández, I.A.; Gómez Yáñez, C.; Arenas Flores, A.; Cabrera Sierra, R.; Pérez Labra, M.

2014-01-01

Highlights: • The evolution phase Ba 8 Ti 3 Nb 4 O 24 was obtained through the mechanism Ba(Ti 1-5x Nb 4x )O 3 . • Addition of niobium can accelerate grain growth of BaTiO 3 ceramics. • Ba 8 Ti 3 Nb 4 O 24 presents a dielectric loss of 0.0035 and permittivity value of 54.6. • Electrical measurements showed that Nb 5+ content drops Curie temperature. • Samples with x ⩾ 0.0625 shows an insulating behavior. -- Abstract: In this work, the structural evolution of hexagonal phase Ba 8 Ti 3 Nb 4 O 24 by adding Nb 2 O 5 to perovskite structure of BaTiO 3 was investigated. The compositions Ba(Ti 1-5x Nb 4x )O 3 ceramics, with 0.00025 ⩽ x ⩽ 0.125 were prepared by the conventional solid state route in air atmosphere, the powders precursors, BaTiO 3 , BaCO 3 and Nb 2 O 5 , were mixed in stoichiometric proportions and ground in a ball mill using alumina balls and acetone. The mixed powders were calcined at temperatures up to 1500 °C. The phase transformation of Ba 8 Ti 3 Nb 4 O 24 from BaTiO 3 was studied by DRX, Raman spectroscopy, SEM, electrical measurements (relative permittivity and P–E hysteresis loops); Rietveld’s refinement was used to structurally characterize the samples. For the devices obtained capacitance was measured at 1 kHz; with these values we calculated the relative permittivity. The samples show typical P–E hysteresis loops at room temperature accompanied by saturation polarization (Ps) and remnant polarization (Pr). The DRX and Rietveld’s refinement results show x ⩽ 0.01 has a ferroelectric behavior. When the doped level is increased x ⩾ 0.02, a peak displacement is observed, this is due to the phase transformation of tetragonal to cubic into the unit cell. Finally, with x = 0.125 the crystal structure transforms to the characteristic hexagonal phase Ba 8 Ti 3 Nb 4 O 24 which resonates at microwave frequencies

Analysis of machining and machine tools

CERN Document Server

Liang, Steven Y

2016-01-01

This book delivers the fundamental science and mechanics of machining and machine tools by presenting systematic and quantitative knowledge in the form of process mechanics and physics. It gives readers a solid command of machining science and engineering, and familiarizes them with the geometry and functionality requirements of creating parts and components in today’s markets. The authors address traditional machining topics, such as: single and multiple point cutting processes grinding components accuracy and metrology shear stress in cutting cutting temperature and analysis chatter They also address non-traditional machining, such as: electrical discharge machining electrochemical machining laser and electron beam machining A chapter on biomedical machining is also included. This book is appropriate for advanced undergraduate and graduate mechani cal engineering students, manufacturing engineers, and researchers. Each chapter contains examples, exercises and their solutions, and homework problems that re...

Addiction Machines

Directory of Open Access Journals (Sweden)

James Godley

2011-10-01

Full Text Available Entry into the crypt William Burroughs shared with his mother opened and shut around a failed re-enactment of William Tell’s shot through the prop placed upon a loved one’s head. The accidental killing of his wife Joan completed the installation of the addictation machine that spun melancholia as manic dissemination. An early encryptment to which was added the audio portion of abuse deposited an undeliverable message in WB. Wil- liam could never tell, although his corpus bears the in- scription of this impossibility as another form of pos- sibility. James Godley is currently a doctoral candidate in Eng- lish at SUNY Buffalo, where he studies psychoanalysis, Continental philosophy, and nineteenth-century litera- ture and poetry (British and American. His work on the concept of mourning and “the dead” in Freudian and Lacanian approaches to psychoanalytic thought and in Gothic literature has also spawned an essay on zombie porn. Since entering the Academy of Fine Arts Karlsruhe in 2007, Valentin Hennig has studied in the classes of Sil- via Bächli, Claudio Moser, and Corinne Wasmuht. In 2010 he spent a semester at the Dresden Academy of Fine Arts. His work has been shown in group exhibi- tions in Freiburg and Karlsruhe.

The Semi-Quantitative Study of Magnetization Process on Milling and Reannealing of Barium Hexaferrite (BaO.6Fe2O3

Directory of Open Access Journals (Sweden)

Ridwan

2009-07-01

Full Text Available Barium hexaferrite (BaO.6Fe2O3 is as a hard magnetic material with good chemical stability which has been intensively used as permanent magnet components. Many works have been done in order to improve their magnetic properties either through chemical process or powders metallurgy technique. In this work, commercial BaO.6Fe2O3 was milled using high-energy milling machine for 10, 20 and 30 hours and followed by reannealing for 3 hours at 1000⁰C in air. X-ray diffraction pattern indicate no phase decomposition occurred caused the mill processing, annealing of milled powders recovered the crystal system and promoted crystallite growth. The magnetic hysteresis curve measured by vibrating sample magnetometer (VSM shows the coercivity of annealed BaO.6Fe2O3 increases to two times higher than the original one. By using Jiles-Atherton model, all the hysteresis parameters Ms, k, α, a and c, have been determined adopted to the Genetic Algorithm (GA. The analyzed hysteretic parameters obtained from this work is congruent to the change of magnetic properties of as-milled and annealed powders of barium hexaferrite.

Separation of Sr from Ca, Ba and Ra by means of Ca(OH)2 and Ba(Ra)Cl2 or Ba(Ra)SO4 for the determination of radiostrontium

DEFF Research Database (Denmark)

Chen, Q.J.; Hou, Xiaolin; Yu, Y.X.

2002-01-01

be completed. The new separation procedure has been successfully used for the determination of Sr-90 in samples with high Ca content, such as 451 of seawater and 2001 of drinking water. The analytical quality of the results is comparable to that of the traditional method using fuming nitric acid and BaCrO4......A simple procedure is developed to separate Sr from a large amount of Ca, which relies on the insolubility of Ca(OH)(2) in alkaline solution. Calcium is quantitatively separated from Sr and more than 95% of Sr is recovered from a sample with as much as 50 g of Ca and a Ca/Sr mole ratio of 250....... A new procedure for the separation of Sr from Ba and Ra is also investigated, which is based on the difference in solubility of the chlorides of Sr, Ba and Ra in HCl media. In 9.5 mol 1(-1) HCl or 7.5 mol 1(-1) HCl-10% acetone media, >97% of Ba and Ra can be removed by Ba(Ra)Cl-2 precipitation, and >94...

Improving the Security and Performance of the BaBar Detector Controls System

International Nuclear Information System (INIS)

Kotturi, Karen D.

2003-01-01

It starts out innocently enough--users want to monitor Online data and so run their own copies of the detector control GUIs in their offices and at home. But over time, the number of processes making requests for values to display on GUIs, webpages and stripcharts can grow, and affect the performance of an Input/Output Controller (IOC) such that it is unable to respond to requests from requests critical to data-taking. At worst, an IOC can hang, its CPU having been allocated 100% to responding to network requests. For the BaBar Online Detector Control System, we were able to eliminate this problem and make great gains in security by moving all of the IOCs to a non-routed, virtual LAN and by enlisting a workstation with two network interface cards to act as the interface between the virtual LAN and the public BaBar network. On the interface machine, we run the Experimental Physics Industrial Control System (EPICS) Channel Access (CA) gateway software (originating from Advanced Photon Source). This software accepts as inputs, all the channels which are loaded into the EPICS databases on all the IOCs. It polls them to update its copy of the values. It answers requests from applications by sending them the currently cached value. We adopted the requirement that data-taking would be independent of the gateway, so that, in the event of a gateway failure, data-taking would be uninterrupted. In this way, we avoided introducing any new risk elements to data-taking. Security rules already in use by the IOC were propagated to the gateway's own security rules and the security of the IOCs themselves was improved by removing them from the public BaBar network

Characterization and dielectric properties of BaTiO3 prepared from Ba(NO3)2-TiO2 mixture

International Nuclear Information System (INIS)

Othman, K.I.; Hassan, A.A.; Ali, M.E.; Abdelal, O.A.; Salah El Dien, F.E.; El-Raghy, S.M.; Abdel-Karim, R.

2012-01-01

BaTiO 3 powder was prepared through a solid-state reaction between the Ba(NO 3 ) 2 and TiO 2 . The thermal analysis and XRD techniques were used to study its formation. A single phase BaTiO 3 was formed after calcination at 600 degree C for 6 hrs. The dielectric properties of the sintered BaTiO 3 were determined in the temperature range from room temperature to 20 degree C at a frequency ranging from 500 Hz to 100 khz. The relative permittivity and the dielectric loss of the sintered pellets at 1 khz, measured at room temperature,were 1805 and 0.419 respectively.

Synthesis, crystal structure and electrical properties of A-site cation ordered BaErMn2O5 and BaErMn2O6

International Nuclear Information System (INIS)

Świerczek, Konrad; Klimkowicz, Alicja; Zheng, Kun; Dabrowski, Bogdan

2013-01-01

In this paper, we report on a synthesis procedure, structural and electrical properties of BaErMn 2 O 5 and BaErMn 2 O 6 , A-site double perovskites having layered arrangement of Ba and Er cations. These materials belong to a family of BaLnMn 2 O 5+δ oxides, which up to now were successfully synthesized for Ln=Y and La–Ho lanthanides. Up to our knowledge, this is the first report on the successful synthesis of BaErMn 2 O 5 and BaErMn 2 O 6 , yielding>95 wt% of the considered compounds. Structural characterization of the materials is given at room temperature, together with in situ XRD studies, performed during oxidation of BaErMn 2 O 5 in air, at elevated temperatures up to 500 °C. A complex structural behavior was observed, with oxidation process of BaErMn 2 O 5 occurring at around 300 °C. The oxidized BaErMn 2 O 6 shows a structural phase transition at about 225 °C. Results of structural studies are supported by thermogravimetric measurements of the oxidation process, performed in air, as well as reduction process, preformed in 5 vol% of H 2 in Ar. Additionally, isothermal oxidation/reduction cycles were measured at 500 °C, showing interesting properties of BaErMn 2 O 5+δ , from a point of view of oxygen storage technology. Electrical conductivity of BaErMn 2 O 5 is of the order of 10 −4 S cm −1 at room temperature and shows activated character on temperature with activation energy E a =0.30(1) eV. Positive sign of Seebeck coefficient for this material indicates holes as dominant charge carriers. Oxidized BaErMn 2 O 6 possesses much higher electrical conductivity, almost 0.2 S cm −1 at room temperature. Additional, about 10-fold increase of electrical conductivity, occurring in the vicinity of 225 °C for this material, can be associated with phase transition from charge/orbital-ordered insulator COI(CE) to paramagnetic metal PM phase. The highest conductivity for BaErMn 2 O 6 was measured near 500 °C and is almost equal to 40 S cm −1 , while

Revisiting the BaO2/BaO redox cycle for solar thermochemical energy storage.

Science.gov (United States)

Carrillo, A J; Sastre, D; Serrano, D P; Pizarro, P; Coronado, J M

2016-03-21

The barium peroxide-based redox cycle was proposed in the late 1970s as a thermochemical energy storage system. Since then, very little attention has been paid to such redox couples. In this paper, we have revisited the use of reduction-oxidation reactions of the BaO2/BaO system for thermochemical heat storage at high temperatures. Using thermogravimetric analysis, reduction and oxidation reactions were studied in order to find the main limitations associated with each process. Furthermore, the system was evaluated through several charge-discharge stages in order to analyse its possible degradation after repeated cycling. Through differential scanning calorimetry the heat stored and released were also determined. Oxidation reaction, which was found to be slower than reduction, was studied in more detail using isothermal tests. It was observed that the rate-controlling step of BaO oxidation follows zero-order kinetics, although at high temperatures a deviation from Arrhenius behaviour was observed probably due to hindrances to anionic oxygen diffusion caused by the formation of an external layer of BaO2. This redox couple was able to withstand several redox cycles without deactivation, showing reaction conversions close to 100% provided that impurities are previously eliminated through thermal pre-treatment, demonstrating the feasibility of this system for solar thermochemical heat storage.

Synthesis and characterization of BaTiO3 ferroelectric material

International Nuclear Information System (INIS)

Osman, K.I.

2011-01-01

BaTiO 3 powder was prepared at low temperatures using the solid-state reaction, starting with two different precursors; the BaCO 3 /TiO 2 and the Ba(NO 3 ) 2 /TiO 2 powder mixtures. It was found that, a single phase BaTiO 3 was formed after calcination at 750 degree C for 10 h and at 600 degree C for 6 h for the first and second mixtures, respectively. Thermal and XRD analyses were used to study the formation kinetics of BaTiO 3 . Contracting volume reaction model was found to control both reactions. The SEM of the as milled powder, TMA, TG and thermodynamics analysis have been used to propose a realistic approach describing the reaction mechanism of BaTiO 3 . Characterization and the dielectric properties of the sintered BaTiO 3 were investigated. The relative permittivity and the dielectric loss measured at room temperature and at 1 khz were 2028.5 and 0.043 for BaTiO 3 prepared from BaCO 3 /TiO 2 , while they were 1805.33 and 0.41 for BaTiO 3 prepared from Ba(NO 3 ) 2 /TiO 2 .

Experimental investigation of decay properties of neutron deficient $^{116-118}$Ba isotopes and test of $^{112-115}$Ba beam counts

CERN Multimedia

We propose to study decay of neutron deficient isotopes $^{116-118}$Ba using Double Sided Silicon Strip Detector (DSSSD). To study delayed-proton and $\\alpha$-decay branching ratios of $^{116-118}$Ba are of special interest because of their vicinity to the proton drip line. The nuclear life-times and properties of the proton unstable states of Cs isotopes, populated through decay of $^{116-118}$Ba isotopes will be measured. In addition to that we propose beam development of $^{112-115}$Ba to study exotic decay properties of these neutron deficient nuclei and to search for super-allowed $\\alpha$-decay in future.

Enhanced 77 K vortex-pinning in Y Ba2Cu3O7−x films with Ba2Y TaO6 and mixed Ba2Y TaO6 + Ba2Y NbO6 nano-columnar inclusions with irreversibility field to 11 T

Directory of Open Access Journals (Sweden)

F. Rizzo

2016-06-01

Full Text Available Pulsed laser deposited thin Y Ba2Cu3O7−x (YBCO films with pinning additions of 5 at. % Ba2Y TaO6 (BYTO were compared to films with 2.5 at. % Ba2Y TaO6 + 2.5 at. % Ba2Y NbO6 (BYNTO additions. Excellent magnetic flux-pinning at 77 K was obtained with remarkably high irreversibility fields greater than 10 T (YBCO-BYTO and 11 T (YBCO-BYNTO, representing the highest ever achieved values in YBCO films.

(Ba+Sr)/Ti ratio dependence of the dielectric properties for (Ba0.5Sr0.5)TiO3 thin films prepared by ion beam sputtering

Science.gov (United States)

Yamamichi, Shintaro; Yabuta, Hisato; Sakuma, Toshiyuki; Miyasaka, Yoichi

1994-03-01

(Ba0.5Sr0.5)TiO3 thin films were prepared by ion beam sputtering from powder targets with (Ba+Sr)/Ti ratios ranging from 0.80 to 1.50. All of the perovskite (Ba,Sr)TiO3 films were single phase except for the film with a (Ba+Sr)/Ti ratio of 1.41. The dielectric constant values notably depended on the (Ba+Sr)/Ti ratio for films thicker than 70 nm. The highest dielectric constant of 580 was achieved for the 5% (Ba+Sr) rich film. This (Ba+Sr)/Ti ratio dependence was diminished by the thickness dependence for thinner films. The grain sizes for the 9% (Ba+Sr) rich film and for the 6% (Ba+Sr) poor film ranged from 70 to 100 nm and from 30 to 60 nm, respectively. This grain size difference could explain why slightly A-site rich (Ba,Sr)TiO3 films have a larger dielectric constant than A-site poor films.

Structural and thermodynamic characterization of the perovskite-related BA{sub 1+y}UO{sub 3+x} and (BA,SR){sub 1+y}UO{sub 3+x} phases

Energy Technology Data Exchange (ETDEWEB)

Cordfunke, E.H.P. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); Booij, A.S. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); Smit-Groen, V. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); Vlaanderen, P. van [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); IJdo, D.J.W. [Rijksuniversiteit Leiden (Netherlands). Gorlaeus Labs.

1996-11-01

The perovskite-type BaUO{sub 3} structure has been investigated by X-ray and neutron diffraction. The Ba/U ratio, the (Ba, Sr)/U ratio, and the oxygen stoichiometry in Ba{sub 1+y}UO{sub 3+x} were varied, and the integral enthalpies of formation determined by solution calorimetry. In addition, equilibrium oxygen partial pressures were measured using a reversible EMF cell. The chemical defect mechanism is discussed, and it is shown that a continuous series BaUO{sub 3}-Ba{sub 1+y}UO{sub 3+x}-Ba{sub 3}UO{sub 6} exist in which uranium vacancies are gradually filled up with barium ions, whereas uranium is oxidized via the pentavalent to the hexavalent state in Ba{sub 3}UO{sub 6}(=Ba{sub 2}(Ba, U)O{sub 6}). (orig.).

Dynamics of photoexcited Ba+ cations in 4He nanodroplets

International Nuclear Information System (INIS)

2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain))" data-affiliation=" (Departament ECM, Facultat de Física, and IN2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain))" >Leal, Antonio; 2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain))" data-affiliation=" (Departament ECM, Facultat de Física, and IN2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain))" >Pi, Martí; Zhang, Xiaohang; Drabbels, Marcel; 2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Laboratoire des Collisions, Agrégats, Réactivité, IRSAMC, UMR 5589, CNRS et Université Paul Sabatier-Toulouse 3, 118 route de Narbonne, F-31062 Toulouse Cedex 09 (France))" data-affiliation=" (Departament ECM, Facultat de Física, and IN2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Laboratoire des Collisions, Agrégats, Réactivité, IRSAMC, UMR 5589, CNRS et Université Paul Sabatier-Toulouse 3, 118 route de Narbonne, F-31062 Toulouse Cedex 09 (France))" >Barranco, Manuel; Cargnoni, Fausto; Hernando, Alberto; Mateo, David; Mella, Massimo

2016-01-01

We present a joint experimental and theoretical study on the desolvation of Ba + cations in 4 He nanodroplets excited via the 6p ← 6s transition. The experiments reveal an efficient desolvation process yielding mainly bare Ba + cations and Ba + He n exciplexes with n = 1 and 2. The speed distributions of the ions are well described by Maxwell-Boltzmann distributions with temperatures ranging from 60 to 178 K depending on the excitation frequency and Ba + He n exciplex size. These results have been analyzed by calculations based on a time-dependent density functional description for the helium droplet combined with classical dynamics for the Ba + . In agreement with experiment, the calculations reveal the dynamical formation of exciplexes following excitation of the Ba + cation. In contrast to experimental observation, the calculations do not reveal desolvation of excited Ba + cations or exciplexes, even when relaxation pathways to lower lying states are included.

The interaction of NO2 with BaO: from cooperative adsorption to Ba(NO3)2 formation

International Nuclear Information System (INIS)

Yi, Cheol-Woo W.; Kwak, Ja Hun H.; Szanyi, Janos

2007-01-01

The effect of water on the morphology of BaO/Al2O3-based NOx storage materials was investigated using Fourier transform infrared spectroscopy, temperature programmed desorption, and time-resolved synchrotron X-ray diffraction techniques. The results of this multi-spectroscopy study reveal that, in the presence of water, surface Ba-nitrates convert to bulk nitrates, and water facilitates the formation of large Ba(NO3)2 particles. The conversion of surface to bulk Ba-nitrates is completely reversible, i.e. after the removal of water from the storage material a significant fraction of the bulk nitrates re-convert to surface nitrates. NO2 exposure of a H2O-containing (wet) BaO/Al2O3 sample results in the formation of nitrites and bulk nitrates exclusively, i.e. no surface nitrates form. After further exposure to NO2, the nitrites completely convert to bulk nitrates. The amount of NOx taken up by the storage material is, however, essentially unaffected by the presence of water, regardless of whether the water was dosed prior to or after NO2 exposure. Based on the results of this study we are now able to explain most of the observations reported in the literature on the effect of water on NOx uptake on similar storage materials

Growth of BaSi2 continuous films on Ge(111) by molecular beam epitaxy and fabrication of p-BaSi2/n-Ge heterojunction solar cells

Science.gov (United States)

Takabe, Ryota; Yachi, Suguru; Tsukahara, Daichi; Toko, Kaoru; Suemasu, Takashi

2017-05-01

We grew BaSi2 films on Ge(111) substrates by various growth methods based on molecular beam epitaxy (MBE). First, we attempted to form BaSi2 films directly on Ge(111) by MBE without templates. We next formed BaSi2 films using BaGe2 templates as commonly used for MBE growth of BaSi2 on Si substrates. Contrary to our prediction, the lateral growth of BaSi2 was not promoted by these two methods; BaSi2 formed not into a continuous film but into islands. Although streaky patterns of reflection high-energy electron diffraction were observed inside the growth chamber, no X-ray diffraction lines of BaSi2 were observed in samples taken out from the growth chamber. Such BaSi2 islands were easily to get oxidized. We finally attempted to form a continuous BaSi2 template layer on Ge(111) by solid phase epitaxy, that is, the deposition of amorphous Ba-Si layers onto MBE-grown BaSi2 epitaxial islands, followed by post annealing. We achieved the formation of an approximately 5-nm-thick BaSi2 continuous layer by this method. Using this BaSi2 layer as a template, we succeeded in forming a-axis-oriented 520-nm-thick BaSi2 epitaxial films on Ge substrates, although (111)-oriented Si grains were included in the grown layer. We next formed a B-doped p-BaSi2(20 nm)/n-Ge(111) heterojunction solar cell. A wide-spectrum response from 400 to 2000 nm was achieved. At an external bias voltage of 1 V, the external quantum efficiency reached as high as 60%, demonstrating the great potential of BaSi2/Ge combination. However, the efficiency of a solar cell under AM1.5 illumination was quite low (0.1%). The origin of such a low efficiency was examined.

Laserspectroscopic studies of collective properties of neutron deficient Ba nuclei

International Nuclear Information System (INIS)

Bekk, K.; Andl, A.; Goering, S.; Hanser, A.; Nowicki, G.; Rebel, H.; Schatz, G.

1979-01-01

Isotope shifts and hyperfine structure of the BaI resonance-line (lambda=553.6 nm) have been measured by dye laser induced resonance fluorescence on an atomic beam for sup(135m,129g,129m,126) Ba thus extending previous high resolution measurements of neutron deficient Ba nuclides (N - isomers sup(135m) Ba and sup(135m) Ba show a decreased staggering. Conspicuously the isomer shift of the g 7/2 + isomer sup(129m) Ba proves to be negative. The nuclear structure information is discussed in the context of gamma-spectroscopic studies of transitional nuclei with 50 [de

Machine rates for selected forest harvesting machines

Science.gov (United States)

R.W. Brinker; J. Kinard; Robert Rummer; B. Lanford

2002-01-01

Very little new literature has been published on the subject of machine rates and machine cost analysis since 1989 when the Alabama Agricultural Experiment Station Circular 296, Machine Rates for Selected Forest Harvesting Machines, was originally published. Many machines discussed in the original publication have undergone substantial changes in various aspects, not...

Decrease in electrical contact resistance of Sb-doped n+-BaSi2 layers and spectral response of an Sb-doped n+-BaSi2/undoped BaSi2 structure for solar cells

Science.gov (United States)

Kodama, Komomo; Takabe, Ryota; Yachi, Suguru; Toko, Kaoru; Suemasu, Takashi

2018-03-01

We investigated how the electron concentration n in a 300-nm-thick Sb-doped n+-BaSi2 layer grown by molecular beam epitaxy affected the contact resistance R C to surface electrodes (Al, indium-tin-oxide). As the n of n-BaSi2 increased, R C decreased and reached a minimum of 0.019 Ω cm2 at n = 2.4 × 1018 cm-3 for the Al electrodes. This value was more than 1 order of magnitude smaller than that obtained for Al/B-doped p-BaSi2. We believe that this significant decrease in R C came from Sb segregation. Furthermore, the internal quantum efficiency (IQE) spectrum was evaluated for an Sb-doped n+-BaSi2 (20 nm)/undoped BaSi2 (500 nm)/n+-Si(111) structure. Its IQE reached as high as ˜50% over a wide wavelength range under a small bias voltage of 0.1 V applied between the top and bottom electrodes.

Phase relationships in the BaO-Ga2O3-Ta2O5 system and the structure of Ba6Ga21TaO40.

Science.gov (United States)

Cao, Jiang; Yu, Xiaodi; Kuang, Xiaojun; Su, Qiang

2012-07-16

Phase relationships in the BaO-Ga(2)O(3)-Ta(2)O(5) ternary system at 1200 °C were determined. The A(6)B(10)O(30) tetragonal tungsten bronze (TTB) related solution in the BaO-Ta(2)O(5) subsystem dissolved up to ~11 mol % Ga(2)O(3), forming a ternary trapezoid-shaped TTB-related solid solution region defined by the BaTa(2)O(6), Ba(1.1)Ta(5)O(13.6), Ba(1.58)Ga(0.92)Ta(4.08)O(13.16), and Ba(6)GaTa(9)O(30) compositions in the BaO-Ga(2)O(3)-Ta(2)O(5) system. Two ternary phases Ba(6)Ga(21)TaO(40) and eight-layer twinned hexagonal perovskite solid solution Ba(8)Ga(4-x)Ta(4+0.6x)O(24) were confirmed in the BaO-Ga(2)O(3)-Ta(2)O(5) system. Ba(6)Ga(21)TaO(40) crystallized in a monoclinic cell of a = 15.9130(2) Å, b = 11.7309(1) Å, c = 5.13593(6) Å, β = 107.7893(9)°, and Z = 1 in space group C2/m. The structure of Ba(6)Ga(21)TaO(40) was solved by the charge flipping method, and it represents a three-dimensional (3D) mixed GaO(4) tetrahedral and GaO(6)/TaO(6) octahedral framework, forming mixed 1D 5/6-fold tunnels that accommodate the Ba cations along the c axis. The electrical property of Ba(6)Ga(21)TaO(40) was characterized by using ac impedance spectroscopy.

Ruthenium perovskites of type Ba/sub 2/BRuO/sub 6/ and Ba/sub 3/BRu/sub 2/O/sub 9/ with B = indium, rhodium

Energy Technology Data Exchange (ETDEWEB)

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

1981-02-01

The black perovskites Ba/sub 2/InRu/sup 5 +/O/sub 6/ and Ba/sub 3/InRu/sub 2/O/sub 9/ (mean oxydation state of ruthenium: +4.5) adopt the hexagonal BaTiO/sub 3/ structure and form a continuous series of mixed crystals. According to the intensity calculations and analysis of the vibrational spectroscopic data an ordered distribution between indium and ruthenium is present: 1:1 order in Ba/sub 2/RuO/sub 6/ (space group P-3m1 respective Dsub(3d)/sup 3/; R' = 5.3%); 1:2 order in Ba/sub 3/InRu/sub 2/O/sub 9/ (space group P6/sub 3//mmc respective Dsub(6h)/sup 4/; R' = 4.6%). The corresponding black Rh compounds, Ba/sub 2/RhRuO/sub 6/ and Ba/sub 3/RhRu/sub 2/O/sub 9/, crystallize in the rhombohedral 9 L type of BaRuO/sub 3/ (author).

Scintillation and radiation damage of doped BaF2 crystals

International Nuclear Information System (INIS)

Gong Zufang; Xu Zizong; Chang Jin

1992-01-01

The emission spectra and the radiation damage of BaF 2 crystals doped Ce and Dy have been studied. The results indicate that the doped BaF 2 crystals have the intrinsic spectra of impurity besides the intrinsic spectra of BaF 2 crystals. The crystals colored and the transmissions decrease with the concentration of impurity in BaF 2 crystals after radiation by γ-ray of 60 Co. The doped Ce BaF 2 irradiated by ultraviolet has faster recover of transmissions but for doped Dy the effect is not obvious. The radiation resistance is not good as pure BaF 2 crystals

Chemiluminescence from the reaction of Ba 3D with nitric oxide

International Nuclear Information System (INIS)

Johnson, S.A.; Solarz, R.W.; Dubrin, J.W.; Brotzmann, R.

1977-01-01

The reaction of laser excited Ba*( 3 D) states with nitric oxide is presented. BaO product is not detected, although the channel is thermodynamically open, and instead chemiluminescence is observed. Experiments which suggest that radiative recombination, Ba + NO → BaNO* → BaNO, is the observed reaction channel will also be presented

Thermoelectric properties of doped BaHfO_3

International Nuclear Information System (INIS)

Dixit, Chandra Kr.; Bhamu, K. C.; Sharma, Ramesh

2016-01-01

We have studied the structural stability, electronic structure, optical properties and thermoelectric properties of doped BaHfO_3 by full potential linearized augmented plane wave (FP-LAPW) method. The electronic structure of BaHfO_3 doped with Sr shows enhances the indirect band gaps of 3.53 eV, 3.58 eV. The charge density plots show strong ionic bonding in Ba-Hf, and ionic and covalent bonding between Hf and O. Calculations of the optical spectra, viz., the dielectric function, refractive index and extinction coefficient are performed for the energy range are calculated and analyzed. Thermoelectric properties of semi conducting are also reported first time. The doped BaHfO_3 is approximately wide band gap semiconductor with the large p-type Seebeck coefficient. The power factor of BaHfO_3 is increased with Sr doping, decreases because of low electrical resistivity and thermal conductivity.

Crystal structure of a new natural (Ba, Nb) silicate

International Nuclear Information System (INIS)

Yamnova, N.A.; Pushcharovskii, D.Yu.; Voloshin, A.V.

1990-01-01

The structure of a new mineral Ba 3 (Ti 1.2 Nb 4.8 ) Si 4 O 25.4 is determined (166 reflections, method of least squares in anisotropic approximation, R = 0.040). The crystallographic parameters are: a = 9.03(1), c = 7.868(6) angstrom, Z = 1, space group P anti 62m. Like the previously investigated synthetic analogs Ba 3 Si 4 Nb 6 O 26 , Ba 3 Si 4 Ti 6 O 23 , and Ba 3 Si 4 Ta 6 O 26 , the structure contains a mixed framework of octahedral columns of triangular section, bound to the diortho groups [Si 2 O 7 ], of which the cavities contain the Ba atoms

AHP 45: REVIEW: PHYUR BA

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'Brug mo skyid འབྲུག་མོ་སྐྱིད། (Zhoumaoji 周毛吉

2017-03-01

Full Text Available Mkha' mo rgyal was born in Dgon gong ma Village, 'Ba' (Tongde County, Mtsho lho (Hainan Tibetan Autonomous Prefecture, Mtsho sngon (Qinghai Province. While attending the Tibetan Studies College of Mtsho sngon Nationalities University she began writing. In addition to editing and translating teaching materials for primary and secondary schools, she has also published short stories and poetry (Mkha' mo rgyal, 2015. Phyur ba is the first Tibetan women's novel (Robin 2016:86 and was recognized as an Outstanding Work by the Qinghai Writers Guild in 2014 (Duojiecairang and Limaoyou 2014. 1 The name, which translates as 'dried cheese' is a food eaten daily by many Tibetans. Made from fermented milk without cream, it is dried in the sun by women in pastoral areas. Both sweet and sour, phyur ba brings to mind the happiness and sadness, ups and downs, laughter and tears that life brings. ...

High-pressure BaCrO_3 polytypes and the 5H–BaCrO_2_._8 phase

International Nuclear Information System (INIS)

Arévalo-López, Angel M.; Paul Attfield, J.

2015-01-01

Polytypism of BaCrO_3 perovskites has been investigated at 900–1100 °C and pressures up to 22 GPa. Hexagonal 5H, 4H, and 6H perovskites are observed with increasing pressure, and the cubic 3C perovskite (a=3.99503(1) Å) is observed in bulk form for the first time at 19–22 GPa. An oxygen-deficient material with limiting composition 5H–BaCrO_2_._8 is synthesised at 1200 °C under ambient pressure. This contains double tetrahedral Cr"4"+ layers and orders antiferromagnetically below 260 K with a (0 0 1/2) magnetic structure. - Graphical abstract: Hexagonal 5H, 4H, and 6H perovskites polytypes of BaCrO_3 are observed with increasing pressure and the cubic 3C perovskite is stabilised in bulk form for the first time at 19–22 GPa. Oxygen-deficient 5H–BaCrO_2_._8 synthesised at ambient pressure contains double tetrahedral Cr"4"+ layers and orders antiferromagnetically below 260 K with a (0 0 1/2) magnetic structure.

[A new machinability test machine and the machinability of composite resins for core built-up].

Science.gov (United States)

Iwasaki, N

2001-06-01

A new machinability test machine especially for dental materials was contrived. The purpose of this study was to evaluate the effects of grinding conditions on machinability of core built-up resins using this machine, and to confirm the relationship between machinability and other properties of composite resins. The experimental machinability test machine consisted of a dental air-turbine handpiece, a control weight unit, a driving unit of the stage fixing the test specimen, and so on. The machinability was evaluated as the change in volume after grinding using a diamond point. Five kinds of core built-up resins and human teeth were used in this study. The machinabilities of these composite resins increased with an increasing load during grinding, and decreased with repeated grinding. There was no obvious correlation between the machinability and Vickers' hardness; however, a negative correlation was observed between machinability and scratch width.

Biodistribution and Radiation Dosimetry of the Integrin Marker 64Cu-BaBaSar-RGD2 Determined from Whole-Body PET/CT in a Non-Human Primate

Science.gov (United States)

Liu, Shuanglong; Vorobyova, Ivetta; Park, Ryan; Conti, Peter S.

2017-10-01

Introduction: 64Cu-BaBaSar-RGD2 is a positron emission radiotracer taken up by integrin αvβ3, which is overexpressed in many malignancies. The aim of this study was to evaluate the biodistribution of 64Cu-BaBaSar-RGD2 in a non-human primate with positron emission tomography and to estimate the absorbed doses in major organs for human. Materials and methods: Whole-body PET imaging was done in a Siemens Biograph scanner in a male macaque monkey. After an i.v. injection of 13.1–19.7 MBq/kg of 64Cu-BaBaSar-RGD2, whole body scan was collected for a total duration of 180 min. Attenuation and scatter corrections were applied to reconstruction of the whole-body emission scan. After image reconstruction, three-dimensional volumes of interest (VOI) were hand-drawn on the PET transaxial or coronal slices of the frame where the organ was most conspicuous. Time-activity curves for each VOI were obtained, and residence time of each organ was calculated by integration of the time-activity curves. Human absorbed doses were estimated using the standard human model in OLINDA/EXM software. Results: Injection of 64Cu-BaBaSar-RGD2 was well tolerated in the macaque monkey, with no serious tracer-related adverse events observed. 64Cu-BaBaSar-RGD2 was cleared rapidly from the blood pool, with a 12.1-min biological half-time. Increased 64Cu-BaBaSar-RGD2 uptake was observed in the kidneys, and bladder, with mean percentage injected dose (ID%) values at 1 h after injection approximately 35.50 ± 6.47 and 36.89 ± 5.48, respectively. The calculated effective dose was 15.30 ± 2.21 µSv/MBq, and the kidneys had the highest absorbed dose at 108.43 ± 16.41 µGy/MBq using the non-voiding model. For an injected activity of 925 MBq 64Cu for human, the effective dose would be 14.2 ± 2.1 mSv. Discussion: Due to the limitation of the monkey number, we evaluated 64Cu-BaBaSar-RGD2 in the same monkey of three imaging sessions. Measured absorbed doses and effective doses of 64Cu-BaBaSar-RGD2 are

An approach to WWER fuels with BaCo

International Nuclear Information System (INIS)

Marino, A.; Demarco, G.

2008-01-01

BaCo is a code for the simulation of the behaviour of a nuclear fuel rod under operation conditions. BaCo, a quasi 2D code based on a finite differences scheme, has been used for simulating PHWR, CANDU, PWR, BWR, MOX, WWER, and experimental fuel rods. We improve the performance of BaCo with a set of tools based on the method of finite elements for 3D analysis of the stress-strain state. We can simulate any UO 2 pellet geometry. Standard WWER-440 fuel assemblies irradiated in the Kola-3 reactor of the CRP FUMEX II of the IAEA were the first WWER simulations with BaCo. We find a very good agreement among our calculations, the experimental results and other qualified fuel codes. We present the BaCo code and our results for PWR and WWER fuels of the CRP FUMEX II, the 3D analysis of WWER fuel pellet and the projections of these results with the Argentinean nuclear fuels development. (authors)

Three new chalcohalides, Ba4Ge2PbS8Br2, Ba4Ge2PbSe8Br2 and Ba4Ge2SnS8Br2: Syntheses, crystal structures, band gaps, and electronic structures

International Nuclear Information System (INIS)

Lin, Zuohong; Feng, Kai; Tu, Heng; Kang, Lei; Lin, Zheshuai; Yao, Jiyong; Wu, Yicheng

2014-01-01

Highlights: • Three new chalcohalides: Ba 4 Ge 2 PbS 8 Br 2 , Ba 4 Ge 2 PbSe 8 Br 2 and Ba 4 Ge 2 SnS 8 Br 2 have been synthesized. • The MQ 5 Br octahedra and GeQ 4 tetrahedra form a three-dimensional framework with Ba 2+ in the channels. • Band Gaps and electronic structures of the three compounds were studied. - Abstract: Single crystals of three new chalcohalides: Ba 4 Ge 2 PbS 8 Br 2 , Ba 4 Ge 2 PbSe 8 Br 2 and Ba 4 Ge 2 SnS 8 Br 2 have been synthesized for the first time. These isostructural compounds crystallize in the orthorhombic space group Pnma. In the structure, the tetra-valent Ge atom is tetrahedrally coordinated with four Q (Q = S, Se) atoms, while the bi-valent M atom (M = Pb, Sn) is coordinated with an obviously distorted octahedron of five Q (Q = S, Se) atoms and one Br atom, showing the stereochemical activity of the ns 2 lone pair electron. The MQ 5 Br (M = Sn, Pb; Q = S, Se) distorted octahedra and the GeQ 4 (Q = S, Se) tetrahedra are connected to each other to form a three-dimensional framework with channels occupied by Ba 2+ cations. Based on UV–vis–NIR spectroscopy measurements and the electronic structure calculations, Ba 4 Ge 2 PbS 8 Br 2 , Ba 4 Ge 2 PbSe 8 Br 2 and Ba 4 Ge 2 SnS 8 Br 2 have indirect band gaps of 2.054, 1.952, and 2.066 eV respectively, which are mainly determined by the orbitals from the Ge, M and Q atoms (M = Pb, Sn; Q = S, Se)

Intermetallic and metal-rich phases in the system Li-Ba-In-N

International Nuclear Information System (INIS)

Smetana, Volodymyr; Vajenine, Grigori V.; Kienle, Lorenz; Duppel, Viola; Simon, Arndt

2010-01-01

Three new intermetallic phases, BaLi 2.1 In 1.9 , BaLi 1.12 In 0.98 , and BaLi 1.06 In 1.16 and two subnitrides Li 35 In 45 Ba 39 N 9 and LiIn 2 Ba 3 N 0.83 have been synthesized and their crystal structures have been determined. According to single crystal X-ray diffraction data BaLi 2.1 In 1.9 and BaLi 1.12 In 0.98 crystallize with hexagonal symmetry (BaLi 2.1 In 1.9 : P6 3 /mmc, a=10.410(2), c=8.364(2) A, Z=6, V=785.0(2) A 3 ) and BaLi 1.12 In 0.98 : P6/mmm, a=17.469(1), c=10.6409(7) A, Z=30, V=2813.5(8) A 3 ), while BaLi 1.06 In 1.16 has a rhombohedral structure (R-3c, a=18.894(3), c=85.289(17) A, Z=276, V=26368(8) A 3 ). BaLi 2.1 In 1.9 is isostructural with the known phase BaLi 4 . The phase BaLi 1.12 In 0.98 is structurally related to Na 8 K 23 Cd 12 In 48 , while BaLi 1.06 In 1.16 is isostructural with Li 33.3 Ba 13.1 Ca 3 . A sample containing structurally similar BaLi 1.12 In 0.98 and BaLi 1.02 In 1.16 was also investigated by transmission electron microscopy. Li 35 In 45 Ba 39 N 9 and LiIn 2 Ba 3 N 0.83 crystallize with tetragonal (I-42m, a=15.299(2), c=30.682(6) A, Z=2, V=7182(2) A 3 ) and cubic (Fd-3m, a=14.913(2) A, Z=8, V=3316.7(7) A 3 ) symmetry, respectively. While the first-mentioned subnitride belongs to the Li 80 Ba 39 N 9 structure type, the second extends the structural family of Ba 6 In 4.78 N 2.72 . The structural features of the new compounds are discussed in comparison to the known phases and the results of total energy calculations. - Graphical abstract: One-dimensional chain of face-sharing centered icosahedra in BaLi 2.1 In 1.9

Wet routes of high purity BaTiO3 nanopowders

International Nuclear Information System (INIS)

Wang Liqiu; Liu Liang; Xue Dongfeng; Kang Hongmin; Liu Changhou

2007-01-01

High purity BaTiO 3 nanopowders were prepared in wet routes through stearic acid gel (SAG) and acetic acid gel (AAG) techniques, respectively. BaTiO 3 samples were characterized by X-ray diffraction, transmission electron microscope, Fourier transform infrared spectrometry, X-ray fluorescence spectrometry, and thermal gravimetric analysis. The present results indicate that both methods have a similar reaction process during calcination, while BaTiO 3 crystallites were initially formed at 550 deg. C by SAG and 800 deg. C by AAG. Both methods could produce BaTiO 3 powders with a cubic perovskite structure, while they had different grain size distributions within 25-50 nm for SAG and 50-80 nm for AAG. BaTiO 3 samples prepared by SAG had a lower agglomeration than those by AAG. SAG has shown many distinctive advantages in the preparation of high purity BaTiO 3 nanopowders, without Ba and Ti losses and hazardous wastes

Ferroelectric relaxor Ba(TiCe)O3

International Nuclear Information System (INIS)

Chen Ang; Zhi Jing; Yu Zhi

2002-01-01

The dielectric behaviour of Ba(Ti 1-y Ce y )O 3 solid solutions (y=0-0.3) has been studied. A small amount of Ce doping (y=0.02) has weak influence on the dielectric behaviour of Ba(Ti 1-y Ce y )O 3 . With increasing Ce concentration, three phase transitions of pure BaTiO 3 are pinched into one rounded dielectric peak with frequency dispersion, and the relaxation time follows the Vogel-Fulcher relation. The evolution from a normal ferroelectric to a ferroelectric relaxor is emphasized. High strains (S=∼0.1-0.19%) with a small hysteresis under ac fields are obtained in ferroelectric relaxors Ba(Ti 1-y Ce y )O 3 . The physical mechanism of the relaxation process, the pinching effect of the phase transitions and their influence on the ferroelectric and electrostrictive behaviour are discussed. (author)

Metaplasia mieloide do baço na Ancilostomose

Directory of Open Access Journals (Sweden)

W. O. Cruz

1934-06-01

Full Text Available Pesquizamos, no figado e baço de dez casos puros de ancilostomose, elementos hemocitopoieticos; verificamos o peso do baço em 23 casos de individuos com idades compreendidas entre 3 e 60 anos; não encontramos, em nenhum caso, celulas hemoformadoras no figado. Em sete casos, encontramos, no baço, elementos da série vermelha em adiantado estado de evolução (eritroblastos ortocromaticos de nucleo picnotico. Em alguns destes casos observamos megacariocitos e numerosos mielocitos eosinofilos. Os tres casos que não apresentavam metaplasia mieloide no baço, eram os de individuos acima de 50 anos de idade. Entretanto, em outro caso de um individuo com 59 anos esta metaplasia foi verificada. Em individuos acima de 20 anos, o peso médio do baço, em nove casos, mostrou-se igual ao peso normal. Em 14 casos, compreendidos entre 3 e 14 anos, o peso deste orgão foi sempre sensivelmente mais elevado que nos normais de idade correspondente. Estes resultados sugerem a possibilidade de ser a metaplasia mieloide responsavel pelos aumentos de pezo nos baços de individuos jovens, vitimados pela anemia ancilostomica. A notavel proliferação dos eritroblastos ortocromaticos mostra que o grão e a rapidez da regeneração sanguinea, após a administração de ferro, são devidos, essencialmente, á grande quantidade de hemoglobina já preformada no baço e na medula ossea dos organismos ancilostomados.

Compounds of the type Ba/sub 3/Bsup(II)M/sub 2/sup(V)O/sub 9/ with Bsup(II) = Mg, Ca, Sr, Ba, and Msup(V) = Nb, Ta

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S; Thumm, I; Herrmann, M [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1981-08-01

The hexagonal perovskites Ba/sub 3/Bsup(II)M/sub 2/sup(V)O/sub 9/ (Msup(V) = Nb, Ta) crystallize with Bsup(II) = Mg, Ca in a 3 L structure (sequence (c)/sub 3/) and Bsup(II) = Sr in the hexagonal BaTiO/sub 3/ type (6 L; sequence (hcc)/sub 2/) with an 1:2 order for the B and M ions. Intensity calculations for Ba/sub 3/SrNb/sub 2/O/sub 9/ and Ba/sub 3/SrTa/sub 2/O/sub 9/ gave in the space group P6/sub 3//mmc a refined, intensity related R' value of 8.4% (Nb) and 9.0% (Ta) respectively. For Bsup(II) = Ba the perovskite Ba/sub 3/BaTa/sub 2/O/sub 9/ has an orthorhombic distorted 6 L structure and forms with Ba/sub 3/SrTa/sub 2/O/sub 9/ a continuous series of mixed crystals (Ba/sub 3/Srsub(1-x)Basub(x)Ta/sub 2/O/sub 9/). In the system Ba/sub 3/Srsub(1-x)Basub(x)Nb/sub 2/O/sub 9/ the range of existence of the hexagonal BaTiO/sub 3/ type is confined to the Sr richer end. The pure Ba compound posesses a proper structure type (5 L: Ba/sub 5/BaNb/sub 3/vacantOsub(13.5)vacantsub(1.5)).

The Machine within the Machine

CERN Multimedia

Katarina Anthony

2014-01-01

Although Virtual Machines are widespread across CERN, you probably won't have heard of them unless you work for an experiment. Virtual machines - known as VMs - allow you to create a separate machine within your own, allowing you to run Linux on your Mac, or Windows on your Linux - whatever combination you need.   Using a CERN Virtual Machine, a Linux analysis software runs on a Macbook. When it comes to LHC data, one of the primary issues collaborations face is the diversity of computing environments among collaborators spread across the world. What if an institute cannot run the analysis software because they use different operating systems? "That's where the CernVM project comes in," says Gerardo Ganis, PH-SFT staff member and leader of the CernVM project. "We were able to respond to experimentalists' concerns by providing a virtual machine package that could be used to run experiment software. This way, no matter what hardware they have ...

First-principles study of (Ba ,Ca ) TiO3 and Ba (Ti ,Zr ) O3 solid solutions

Science.gov (United States)

Amoroso, Danila; Cano, Andrés; Ghosez, Philippe

2018-05-01

(Ba ,Ca ) TiO3 and Ba (Ti ,Zr ) O3 solid solutions are the building blocks of lead-free piezoelectric materials that attract a renewed interest. We investigate the properties of these systems by means of first-principles calculations, with a focus on the lattice dynamics and the competition between different ferroelectric phases. We first analyze the four parent compounds in order to compare their properties and their different tendency towards ferroelectricity. The core of our study is systematic characterization of the binary systems (Ba ,Ca ) TiO3 and Ba (Ti ,Zr ) O3 within both the virtual crystal approximation and direct supercell calculations. In the case of Ca doping, we find a gradual transformation from B -site to A -site ferroelectricity due to steric effects that largely determines the behavior of the system. In the case of Zr doping, in contrast, the behavior is eventually dominated by cooperative Zr-Ti motions and the local electrostatics. In addition, our comparative study reveals that the specific microscopic physics of these solids sets severe limits to the applicability of the virtual crystal approximation for these systems.

Electronic structure of Ca, Sr, and Ba under pressure.

Science.gov (United States)

Animalu, A. O. E.; Heine, V.; Vasvari, B.

1967-01-01

Electronic band structure calculations phase of Ca, Sr and Ba over wide range of atomic volumes under pressure electronic band structure calculations for fcc phase of Ca, Sr and Ba over wide range of atomic volumes under pressure electronic band structure calculations for fcc phase of Ca, Sr and Ba over wide range of atomic volumes under pressure

Effect of Barium-Precursors on Reaction Kinetics in Y-Ba-Cu-O System

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

The reactions of stoichiometric Y2O3, CuO, and different Ba salts or oxides (BaCO3, Ba(NO3)2, BaO2, BaCuO2) for forming various compounds in the Y-Ba-Cu-O system (i.e., YBa2Cu3O7-δ, BaCuO2, Y2BaCuO5 and Y2Cu2O5) were systematically investigated by thermal analysis and X-ray diffractometry. The relevant activation energies were calculated from thermogravimetric data. It is found that the reaction pathway significantly depends on the thermal stability of the Ba precursors. Binary BaO-CuO phases form at low temperature (650～700 ℃) when in presence of easy-to-decompose Ba precursors, and then slowly transform to ternary compounds. On the contrary, when Ba ions are released at temperature higher than 900 ℃, ternary phases form directly from the components.

Strain induced optical properties of BaReO3

Science.gov (United States)

Kumavat, Sandip R.; Kansara, Shivam; Gupta, Sanjeev K.; Sonvane, Yogesh

2018-05-01

Here, we have performed strain induce optical properties of BaReO3 by using density functional theory (DFT). We noticed that after applying intrinsic and extrinsic strain to the BaReO3, it shows the metallic behavior. We also studied optical properties, which show good activity in the ultraviolet region. The results show that after applying intrinsic and extrinsic strain to BaReO3 the absorption peaks are shifted towards the high UV region of the spectrum. Thus, we concluded that, BaReO3 material with extrinsic strain can be useful for high frequency UV device and optoelectronic devices.

IR-spectroscopic study and electrical properties of glasses in the Ba(PO3)2-Ba(Hal)2 systems

International Nuclear Information System (INIS)

Sokolov, I.A.; Tarlakov, Yu.P.; Murin, I.V.; Pronkin, A.A.

2000-01-01

Temperature-concentration dependence of electric conductivity of glasses in the systems Ba(PO 3 ) 2 -Ba(Hal) 2 , where Hal = Cl, Br, I, is studied by the method of conductometry, the numbers of iodide-ions transfer are determined and their concentration dependence is found. Data of IR spectroscopy permitted ascertained participation of halide ions in formation of anionic constituent of the glass structure at the expense of bridge bonds formation, as well as formation of structural-chemical units of [(Hal) - Ba 2+ O - POO 2/2 ] type, their dissociation giving rise to formation of halide ions their dissociation giving rise to formation of halide ions taking part in electric current transfer [ru

High-Temperature Superconductivity in Doped BaFe2As2

International Nuclear Information System (INIS)

Martin, Marianne

2011-01-01

This thesis provides a detailed look on the synthesis, structural features and physical properties of iron arsenides. Especially the properties of BaFe 2 As 2 and the solid solutions (Ba 1-x K x )Fe 2 As 2 , (Ba 1-x Sr x )Fe 2 As 2 and BaFe 2 (As 1-x P x ) 2 which were all synthesized by solid state reactions by heating mixtures of the elements, were intensively investigated.

Molecular recognition at methyl methacrylate/n-butyl acrylate (MMA/nBA) monomer unit boundaries of phospholipids at p-MMA/nBA copolymer surfaces.

Science.gov (United States)

Yu, Min; Urban, Marek W; Sheng, Yinghong; Leszczynski, Jerzy

2008-09-16

Lipid structural features and their interactions with proteins provide a useful vehicle for further advances in membrane proteins research. To mimic one of potential lipid-protein interactions we synthesized poly(methyl methacrylate/ n-butyl acrylate) (p-MMA/nBA) colloidal particles that were stabilized by phospholipid (PLs). Upon the particle coalescence, PL stratification resulted in the formation of surface localized ionic clusters (SLICs). These entities are capable of recognizing MMA/nBA monomer interfaces along the p-MMA/nBA copolymer backbone and form crystalline SLICs at the monomer interface. By utilizing attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy and selected area electron diffraction (SAD) combined with ab initio calculations, studies were conducted that identified the origin of SLICs as well as their structural features formed on the surface of p-MMA/nBA copolymer films stabilized by 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) PL. Specific entities responsible for SLIC formation are selective noncovalent bonds of anionic phosphate and cationic quaternary ammonium segments of DLPC that interact with two neighboring carbonyl groups of nBA and MMA monomers of the p-MMA/nBA polymer backbone. To the best of our knowledge this is the first example of molecular recognition facilitated by coalescence of copolymer colloidal particles and the ability of PLs to form SLICs at the boundaries of the neighboring MMA and nBA monomer units of the p-MMA/nBA chain. The dominating noncovalent bonds responsible for the molecular recognition is a combination of H-bonding and electrostatic interactions.

The First NAFOSTED Conference on Information and Computer Science

CERN Document Server

Nguyen, Xuan; Le, Hoai; Nguyen, Viet; Bao, Vo

2015-01-01

This book includes the extended and revised versions of a set of selected papers from the First NAFOSTED Conference on Information and Computer Science (NICS’2014), held at Le Quy Don Technical Academy, Hanoi, Vietnam from 13/Mar./2014 to 14/Mar./2014. The conference was co-organized by The National Foundation for Science and Technology Development (NAFOSTED) and Le Quy Don Technical Academy. The purpose of the NICS conference series is to promote scientific publications in the country and to provide a platform for high quality academic exchange among scientists in the fields of computer science, information and communication. The conference includes five tracks, namely “Computer Science”, “Artificial Intelligence”, “Network Systems”, “Software Engineering”, and “Information Systems”.  The papers in this book are among the best contributions at NICS’2014 taken into account the quality of their presentation at the conference and the recommendation of the two experts in the extra round ...

Epitaxial thin-film growth of Ruddlesden-Popper-type Ba3Zr2O7 from a BaZrO3 target by pulsed laser deposition

International Nuclear Information System (INIS)

Butt, Shariqa Hassan; Rafique, M.S.; Siraj, K.; Latif, A.; Afzal, Amina; Awan, M.S.; Bashir, Shazia; Iqbal, Nida

2016-01-01

Ruddlesden-Popper Ba 3 Zr 2 O 7 thin films have been synthesized via pulsed laser deposition (PLD) technique. The optimization of deposition parameters in PLD enables the formation of thin film of metastable Ba 3 Zr 2 O 7 phase from BaZrO 3 target. In order to see the post-annealing effects on the structural and optical properties, the deposited Ba 3 Zr 2 O 7 thin films were annealed at 500, 600 and 800 C. X-ray diffraction (XRD) reveals the formation of Ba 3 Zr 2 O 7 phase with tetragonal structure. The changes in the surface of the deposited films were analysed by FE-SEM and AFM. The thin film post-annealed at 500 C exhibited the best structural, optical and surface properties. Furthermore, the chemical states and chemical composition of the films were determined by X-ray photoelectron spectroscopy (XPS) near the surface. The XPS results show that Ba, Zr and O exist mainly in the form of Ba 3 Zr 2 O 7 Ruddlesden-Popper-type perovskite structure. (orig.)

The effect of gender on the neuroanatomy of children with autism spectrum disorders: a support vector machine case-control study.

Science.gov (United States)

Retico, Alessandra; Giuliano, Alessia; Tancredi, Raffaella; Cosenza, Angela; Apicella, Fabio; Narzisi, Antonio; Biagi, Laura; Tosetti, Michela; Muratori, Filippo; Calderoni, Sara

2016-01-01

Genetic, hormonal, and environmental factors contribute since infancy to sexual dimorphism in regional brain structures of subjects with typical development. However, the neuroanatomical differences between male and female children with autism spectrum disorders (ASD) are an intriguing and still poorly investigated issue. This study aims to evaluate whether the brain of young children with ASD exhibits sex-related structural differences and if a correlation exists between clinical ASD features and neuroanatomical underpinnings. A total of 152 structural MRI scans were analysed. Specifically, 76 young children with ASD (38 males and 38 females; 2-7 years of age; mean = 53 months, standard deviation = 17 months) were evaluated employing a support vector machine (SVM)-based analysis of the grey matter (GM). Group comparisons consisted of 76 age-, gender- and non-verbal-intelligence quotient-matched children with typical development or idiopathic developmental delay without autism. For both genders combined, SVM showed a significantly increased GM volume in young children with ASD with respect to control subjects, predominantly in the bilateral superior frontal gyrus (Brodmann area -BA- 10), bilateral precuneus (BA 31), bilateral superior temporal gyrus (BA 20/22), whereas less GM in patients with ASD was found in right inferior temporal gyrus (BA 37). For the within gender comparisons (i.e., females with ASD vs. controls and males with ASD vs. controls), two overlapping regions in bilateral precuneus (BA 31) and left superior frontal gyrus (BA 9/10) were detected. Sex-by-group analyses revealed in males with ASD compared to matched controls two male-specific regions of increased GM volume (left middle occipital gyrus-BA 19-and right superior temporal gyrus-BA 22). Comparisons in females with and without ASD demonstrated increased GM volumes predominantly in the bilateral frontal regions. Additional regions of significantly increased GM volume in the right

Effect of Machining Velocity in Nanoscale Machining Operations

International Nuclear Information System (INIS)

Islam, Sumaiya; Khondoker, Noman; Ibrahim, Raafat

2015-01-01

The aim of this study is to investigate the generated forces and deformations of single crystal Cu with (100), (110) and (111) crystallographic orientations at nanoscale machining operation. A nanoindenter equipped with nanoscratching attachment was used for machining operations and in-situ observation of a nano scale groove. As a machining parameter, the machining velocity was varied to measure the normal and cutting forces. At a fixed machining velocity, different levels of normal and cutting forces were generated due to different crystallographic orientations of the specimens. Moreover, after machining operation percentage of elastic recovery was measured and it was found that both the elastic and plastic deformations were responsible for producing a nano scale groove within the range of machining velocities from 250-1000 nm/s. (paper)

Experimental study on Ra2+ uptake by barite (BaSO{sub 4}). Kinetics of solid solution formation via BaSO{sub 4} dissolution and Ra{sub x}Ba{sub 1-x}SO{sub 4} (re) precipitation

Energy Technology Data Exchange (ETDEWEB)

Bosbach, Dirk; Boettle, Melanie; Metz, Volker (Karlsruher Inst. fuer Technologie, Inst fuer Nukleare Entsorgung (INE), Karlsruhe (Germany))

2010-03-15

226Ra2+ and 133Ba2+ uptake by barite in aqueous solution is studied on the basis of batch type experiments with two different barite powders with different specific surface area (0.5 m2/g and 3.2 m2/g, respectively). The uptake of 226Ra2+ and 133Ba2+ is not only limited to adsorption reactions but proceeds significantly into the bulk of the barite crystals. 133Ba2+ uptake kinetics is affected by various parameters, such as amount of sample, specific surface area, sample type and solution composition. In the case of 133Ba2+, complete isotopic equilibration of the 133Ba2+ spiked solution with the barite powder occurs within 50 to 600 days. This information is derived by monitoring the aqueous 133Ba2+ concentration combined with simple mass balance calculations. In the case of 226Ra2+ a Ra{sub x}Ba{sub 1-x}SO{sub 4} solid solution forms and the uptake rate drops significantly within 400 days. The observed 226Ra2+ concentration in solution is controlled by the solubility of a Ra{sub x}Ba{sub 1-x}SO{sub 4} solid solution and several orders of magnitude below the Ra2+ solubility with respect to a pure RaSO{sub 4}(s) end member. It cannot be demonstrated unambiguously that a zero exchange rate and therefore thermodynamic equilibrium has been established within the observation period. The observed concentrations may be interpreted either as (1) a partial equilibration of 20 to 50% of the barite crystals with 226Ra2+ or (2) as complete equilibration of a Ra{sub 0.000128}Ba{sub 0.999872}SO{sub 4} solid solution with 226Ra2+ with no pure barite left. In both cases it is concluded that equilibration between aqueous Ra2+ and barite involves the replacement of a substantial fraction of the initial barite and proceeds significantly beyond pure surface adsorption processes

Enhancement of polarization property of silane-modified BaTiO3 nanoparticles and its effect in increasing dielectric property of epoxy/BaTiO3 nanocomposites

Directory of Open Access Journals (Sweden)

Thi Tuyet Mai Phan

2016-03-01

Full Text Available The surface modification of synthesized nano-BaTiO3 particles was carried out using γ-aminopropyl trimethoxy silane (γ-APS in an ethanol/water solution. The modified particles were characterized by FTIR, TGA, surface charge analysis, and by dielectric constant measurement. The silane molecules were attached to the surface of BaTiO3 particles through SiOBaTiO3 bonds. The γ-APS grafted on BaTiO3 made the dielectric constant of the particles increase at frequencies ≥0.3 kHz in a wide range of temperature (25 °C–140 °C, due to the presence of NH2 groups. The dependence of the polarization vs. electrical field was measured in order to elucidate the dielectric behavior of the silane treated BaTiO3 in comparison to untreated BaTiO3. The nanocomposite based on epoxy resin containing BaTiO3 nanoparticles untreated and treated with γ-APS was also prepared and characterized. The results indicated that the γ-APS-modified BaTiO3 surfaces significantly enhanced the dielectric property of the nanocomposite.

Controlled Confinement of Half-metallic 2D Electron Gas in BaTiO3/Ba2FeReO6/BaTiO3 Heterostructures: A First-principles Study

Science.gov (United States)

Saha-Dasgupta, Tanusri; Baidya, Santu; Waghmare, Umesh; Paramekanti, Arun

Using density functional theory calculations, we establish that the half-metallicity of bulk Ba2FeReO6 survives down i to 1 nm thickness in BaTiO3/Ba2FeReO6/BaTiO3 heterostructures grown along the (001) and (111) directions. The confinement of the two-dimensional (2D) electron gas in this quantum well structure arises from the suppressed hybridization between Re/Fe d states and unoccupied Ti d states, and it is further strengthened by polar fields for the (111) direction. This mechanism, distinct from the polar catastrophe, leads to an order of magnitude stronger confinement of the 2D electron gas than that at the LaAlO3/SrTiO3 interface. We further show low-energy bands of (111) heterostructure display nontrivial topological character. Our work opens up the possibility of realizing ultra-thin spintronic devices. Journal Ref: Phys. Rev. B 92, 161106(R) (2015) S.B. and T.S.D thank Department of Science and Technology, India for the support through Thematic Unit of Excellence. AP was supported by NSERC (Canada).

Prediction of Machine Tool Condition Using Support Vector Machine

International Nuclear Information System (INIS)

Wang Peigong; Meng Qingfeng; Zhao Jian; Li Junjie; Wang Xiufeng

2011-01-01

Condition monitoring and predicting of CNC machine tools are investigated in this paper. Considering the CNC machine tools are often small numbers of samples, a condition predicting method for CNC machine tools based on support vector machines (SVMs) is proposed, then one-step and multi-step condition prediction models are constructed. The support vector machines prediction models are used to predict the trends of working condition of a certain type of CNC worm wheel and gear grinding machine by applying sequence data of vibration signal, which is collected during machine processing. And the relationship between different eigenvalue in CNC vibration signal and machining quality is discussed. The test result shows that the trend of vibration signal Peak-to-peak value in surface normal direction is most relevant to the trend of surface roughness value. In trends prediction of working condition, support vector machine has higher prediction accuracy both in the short term ('One-step') and long term (multi-step) prediction compared to autoregressive (AR) model and the RBF neural network. Experimental results show that it is feasible to apply support vector machine to CNC machine tool condition prediction.

The new barium zinc mercurides Ba3ZnHg10 and BaZn0.6Hg3.4 – Synthesis, crystal and electronic structure

International Nuclear Information System (INIS)

Schwarz, Michael; Wendorff, Marco; Röhr, Caroline

2012-01-01

The title compounds Ba 3 ZnHg 10 and BaZn 0.6 Hg 3.4 were synthesized from stoichiometric ratios of the elements in Ta crucibles. Their crystal structures, which both represent new structure types, have been determined using single crystal X-ray data. The structure of Ba 3 ZnHg 10 (orthorhombic, oP28, space group Pmmn, a=701.2(3), b=1706.9(8), c=627.3(3)pm, Z=2, R1=0.0657) contains folded 4 4 Hg nets, where the meshes form the bases of flat rectangular pyramids resembling the structure of BaAl 4 . The flat pyramids are connected via Hg–Zn/Hg bonds, leaving large channels at the folds, in which Ba(1) and Hg(2) atoms alternate. Whereas the remaining Hg/Zn atoms form a covalent 3D network of three- to five-bonded atoms with short M–M distances (273–301 pm; CN 9–11), the Hg(2) atoms in the channels adopt a comparatively large coordination number of 12 and increased distances (317–348 pm) to their Zn/Hg neighbours. In the structure of BaZn 0.6 Hg 3.4 (cubic, cI320, space group I4 ¯ 3d, a=2025.50(7) pm, Z=64, R1=0.0440), with a chemical composition not much different from that of Ba 3 ZnHg 10 , the Zn/Hg atoms of the mixed positions M(1/2) are arranged in an slightly distorted primitive cubic lattice with a 4×4×4 subcell relation to the unit cell. The 24 of the originating 64 cubes contain planar cis tetramers Hg(5,6) 4 with Hg in a nearly trigonal planar or tetrahedral coordination. In another 24 of the small cubes, two opposing faces are decorated by Hg(3,4) 2 dumbbells, two by Ba(2) atoms respectively. The third type of small cubes are centered by Ba(1) atoms only. The complex 3D polyanionic Hg/Zn network thus formed is compared with the Hg partial structure in Rb 3 Hg 20 applying a group-subgroup relation. Despite their different overall structures, the connectivity of the negatively charged Hg atoms, the rather metallic Zn bonding characteristic (as obtained from FP-LAPW band structure calculations) and the coordination number of 16 for all Ba cations

Dynamics of photoexcited Ba{sup +} cations in {sup 4}He nanodroplets

Energy Technology Data Exchange (ETDEWEB)

Leal, Antonio; Pi, Martí [Departament ECM, Facultat de Física, and IN" 2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Zhang, Xiaohang; Drabbels, Marcel [Laboratoire de Chimie Physique Moléculaire, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Barranco, Manuel [Departament ECM, Facultat de Física, and IN" 2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Laboratoire des Collisions, Agrégats, Réactivité, IRSAMC, UMR 5589, CNRS et Université Paul Sabatier-Toulouse 3, 118 route de Narbonne, F-31062 Toulouse Cedex 09 (France); Cargnoni, Fausto [Istituto di Scienze e Tecnologie Molecolari (ISTM), Consiglio Nazionale delle Ricerche, via Golgi 19, 20133 Milano (Italy); Hernando, Alberto [Social Thermodynamics Applied Research (SThAR), EPFL Innovation Park, Bâtiment C, CH-1015 Lausanne (Switzerland); Mateo, David [Department of Chemistry and Biochemistry, California State University at Northridge, Northridge, California 91330 (United States); Mella, Massimo [Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell’Insubria, via Valleggio 11, 22100 Como (Italy)

2016-03-07

We present a joint experimental and theoretical study on the desolvation of Ba{sup +} cations in {sup 4}He nanodroplets excited via the 6p ← 6s transition. The experiments reveal an efficient desolvation process yielding mainly bare Ba{sup +} cations and Ba{sup +}He{sub n} exciplexes with n = 1 and 2. The speed distributions of the ions are well described by Maxwell-Boltzmann distributions with temperatures ranging from 60 to 178 K depending on the excitation frequency and Ba{sup +} He{sub n} exciplex size. These results have been analyzed by calculations based on a time-dependent density functional description for the helium droplet combined with classical dynamics for the Ba{sup +}. In agreement with experiment, the calculations reveal the dynamical formation of exciplexes following excitation of the Ba{sup +} cation. In contrast to experimental observation, the calculations do not reveal desolvation of excited Ba{sup +} cations or exciplexes, even when relaxation pathways to lower lying states are included.

Thermoelectric properties of doped BaHfO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Dixit, Chandra Kr., E-mail: ckparadise@gmail.com, E-mail: sharmarameshfgiet@gmail.com [Dept. of Physics, Dr. Shakuntala Misra National Rehabilitation University, Lucknow-229001, U.P India (India); Bhamu, K. C. [Department of Physics, Goa University, Goa-403 206 (India); Sharma, Ramesh, E-mail: ckparadise@gmail.com, E-mail: sharmarameshfgiet@gmail.com [Dept. of Physics, Feroze Gandhi Institute of Engineering & Technology, Raebareli-229001, U.P India (India)

2016-05-06

We have studied the structural stability, electronic structure, optical properties and thermoelectric properties of doped BaHfO{sub 3} by full potential linearized augmented plane wave (FP-LAPW) method. The electronic structure of BaHfO{sub 3} doped with Sr shows enhances the indirect band gaps of 3.53 eV, 3.58 eV. The charge density plots show strong ionic bonding in Ba-Hf, and ionic and covalent bonding between Hf and O. Calculations of the optical spectra, viz., the dielectric function, refractive index and extinction coefficient are performed for the energy range are calculated and analyzed. Thermoelectric properties of semi conducting are also reported first time. The doped BaHfO{sub 3} is approximately wide band gap semiconductor with the large p-type Seebeck coefficient. The power factor of BaHfO{sub 3} is increased with Sr doping, decreases because of low electrical resistivity and thermal conductivity.

Operability test procedure for 211BA flow proportional sampler

International Nuclear Information System (INIS)

Weissenfels, R.D.

1994-01-01

The purpose of this operability test procedure (OTP) is to verify the 211-BA flow proportional sampler system and components function correctly as intended by design. System test will include the sampling system, all associated instrumentation, and Facility Process Monitor and Control System (FPMCS). The combined chemical sewer stream from B Plant flows through sump 211BA-SMP-01 located in 211-BA and is continuously monitored for gamma and beta radiation and pH. 211-BA has been upgraded to include a flow proportional sampler. A specified sample volume will be withdrawn at programmed intervals from the 211BA sump and deposited in a 19 liter plastic carboy. The sampler will be programmed per the vendor installation and operations manual by B Plant instrument maintenance personnel. Samples will be taken during five consecutive sample cycles with the sample volumes and sample frequencies recorded for comparison purposes. Additional tests related to the sampler include the alarm circuitry for loss of power and failure to obtain sample

Ba-bah on tulnud / Liina Jänes

Index Scriptorium Estoniae

Jänes, Liina, 1977-

2005-01-01

Eesti noori disainereid-sisearhitekte ühendavast disainiagentuurist Ba-bah, selle eesmärgist. Agentuuri juhib Veiko Jääger. Mais 2005 Disaini- ja Arhitektuurigaleriis toimunud Ba-bahi avanäitusest, kus oli väljas töid EKA sisearhitektuuri, klaasi-, ehte- ja sepakunsti eriala üliõpilastelt ning metallmööbli valmistajalt Kalle Pruudenilt

The microscopic twins and their crystal phase in the high Tc Y-Ba-Cu-O and Dy-Ba-Cu-O superconductive ceramics

International Nuclear Information System (INIS)

Zu, Z.J.; Chen, Y.L.

1988-01-01

Most consider that the structure of Y-Ba- Cu-O and Dy-Ba-Cu-O stable superconductive crystals with high Tc is associated with the right-angled phase. The superconductivity is closely connected with the right-angled character of the crystalline texture; the better the right- angled character, the better the superconductivity. From statistical investigations of examples the authors have discovered that most of the Y-Ba-Cu-O and Dy-Ba-Cu-O superconductivity with high Tc ceramic crystals is in the monoclinic phase, which, consists of microscopic, lamellar, single twins. The long-columnar grains consisting of lamellar twin slabs show the optical characteristics of right-angled phase. The microscopic twinning and grain morphologies are summarized in this paper

Environmentally Friendly Machining

CERN Document Server

Dixit, U S; Davim, J Paulo

2012-01-01

Environment-Friendly Machining provides an in-depth overview of environmentally-friendly machining processes, covering numerous different types of machining in order to identify which practice is the most environmentally sustainable. The book discusses three systems at length: machining with minimal cutting fluid, air-cooled machining and dry machining. Also covered is a way to conserve energy during machining processes, along with useful data and detailed descriptions for developing and utilizing the most efficient modern machining tools. Researchers and engineers looking for sustainable machining solutions will find Environment-Friendly Machining to be a useful volume.

Local manifestations of a static magnetoelectric effect in nanostructured BaTiO3-BaFe12O9 composite multiferroics

Science.gov (United States)

Trivedi, Harsh; Shvartsman, Vladimir V.; Lupascu, Doru C.; Medeiros, Marco S. A.; Pullar, Robert C.; Kholkin, Andrei L.; Zelenovskiy, Pavel; Sosnovskikh, Andrey; Shur, Vladimir Ya.

2015-02-01

A study on magnetoelectric phenomena in the barium titanate-barium hexaferrite (BaTiO3-BaFe12O19) composite system, using high resolution techniques including switching spectroscopy piezoresponse force microscopy (SSPFM) and spatially resolved confocal Raman microscopy (CRM), is presented. It is found that both the local piezoelectric coefficient and polarization switching parameters change on the application of an external magnetic field. The latter effect is rationalized by the influence of magnetostrictive stress on the domain dynamics. Processing of the Raman spectral data using principal component analysis (PCA) and self-modelling curve resolution (SMCR) allowed us to achieve high resolution phase distribution maps along with separation of average and localized spectral components. A significant effect of the magnetic field on the Raman spectra of the BaTiO3 phase has been revealed. The observed changes are comparable with the classical pressure dependent studies on BaTiO3, confirming the strain mediated character of the magnetoelectric coupling in the studied composites.

The BaBar silicon vertex tracker

International Nuclear Information System (INIS)

Bozzi, C.; Carassiti, V.; Ramusino, A. Cotta; Dittongo, S.; Folegani, M.; Piemontese, L.; Abbott, B.K.; Breon, A.B.; Clark, A.R.; Dow, S.; Fan, Q.; Goozen, F.; Hernikl, C.; Karcher, A.; Kerth, L.T.; Kipnis, I.; Kluth, S.; Lynch, G.; Levi, M.; Luft, P.; Luo, L.; Nyman, M.; Pedrali-Noy, M.; Roe, N.A.; Zizka, G.; Roberts, D.; Barni, D.; Brenna, E.; Defendi, I.; Forti, A.; Giugni, D.; Lanni, F.; Palombo, F.; Vaniev, V.; Leona, A.; Mandelli, E.; Manfredi, P.F.; Perazzo, A.; Re, V.; Angelini, C.; Batignani, G.; Bettarini, S.; Bondioli, M.; Bosi, F.; Calderini, G.; Carpinelli, M.; Dutra, F.; Forti, F.; Gagliardi, D.; Giorgi, M.A.; Lusiani, A.; Mammini, P.; Morganti, M.; Morsani, F.; Paoloni, E.; Profeti, A.; Rama, M.; Rampino, G.; Rizzo, G.; Sandrelli, F.; Simi, G.; Triggiani, G.; Tritto, S.; Vitale, R.; Burchat, P.; Cheng, C.; Kirkby, D.; Meyer, T.; Roat, C.; Bona, M.; Bianchi, F.; Daudo, F.; Girolamo, B. Di; Gamba, D.; Giraudo, G.; Grosso, P.; Romero, A.; Smol, A.; Trapani, P.; Zanin, D.; Bosisio, L.; Ricca, G. Della; Lanceri, L.; Pompili, A.; Poropat, P.; Prest, M.; Rastelli, C.; Vallazza, E.; Vuagnin, G.; Hast, C.; Potter, E.P.; Sharma, V.; Burke, S.; Callahan, D.; Campagnari, C.; Dahmes, B.; Eppich, A.; Hale, D.; Hall, K.; Hart, P.; Kuznetsova, N.; Kyre, S.; Levy, S.; Long, O.; May, J.; Richman, J.; Verkerke, W.; Witherell, M.; Beringer, J.; Eisner, A.M.; Frey, A.; Grillo, A.; Grothe, M.; Johnson, R.; Kroeger, W.; Lockman, W.; Pulliam, T.; Rowe, W.; Schmitz, R.; Seiden, A.; Spencer, E.; Turri, M.; Wilder, M.; Charles, E.; Elmer, P.; Nielsen, J.; Orejudos, W.; Scott, I.; Walsh, J.; Zobernig, H.

2000-01-01

The BaBar Silicon Vertex Tracker (SVT) is designed to provide the high-precision vertexing necessary for making measurements of CP violation at the SLAC B-Factory PEP-II. The instrument consists of five layers of double-sided silicon strip detectors and has been installed in the BaBar experiment and taking colliding beam data since May 1999. An overview of the design as well as performance and experience from the initial running will be presented

Genome Sequence of African Swine Fever Virus BA71, the Virulent Parental Strain of the Nonpathogenic and Tissue-Culture Adapted BA71V.

Science.gov (United States)

Rodríguez, Javier M; Moreno, Leticia Tais; Alejo, Alí; Lacasta, Anna; Rodríguez, Fernando; Salas, María L

2015-01-01

The strain BA71V has played a key role in African swine fever virus (ASFV) research. It was the first genome sequenced, and remains the only genome completely determined. A large part of the studies on the function of ASFV genes, viral transcription, replication, DNA repair and morphogenesis, has been performed using this model. This avirulent strain was obtained by adaptation to grow in Vero cells of the highly virulent BA71 strain. We report here the analysis of the genome sequence of BA71 in comparison with that of BA71V. They possess the smallest genomes for a virulent or an attenuated ASFV, and are essentially identical except for a relatively small number of changes. We discuss the possible contribution of these changes to virulence. Analysis of the BA71 sequence allowed us to identify new similarities among ASFV proteins, and with database proteins including two ASFV proteins that could function as a two-component signaling network.

Praseodymium valency from crystal structure in Pr-Ba-Cu-O and (Y-Pr)-Ba-Cu-O single crystals

International Nuclear Information System (INIS)

Collin, G.; Albouy, P.A.; Monod, P.; Ribault, M.

1990-01-01

The substitution of Pr to Y leads to materials with a general formula (Y 1-v Pr v ) (Ba 2-x Pr x ) (Cu 3-y vac y ) O 6+x/2-y+z and with a structural transition around v + x' ∼ 0.5. For v + x 0.5 the crystals are tetragonal, La 1.5 Ba 1.5 Cu 3 O 7±z type, with the characteristic tri-twinning of this phase. The Pr valency, in the range 3-3.2 + depending on preparation conditions, is determined from interatomic distances. Orthorhombic crystals of Pr Ba Cu O prepared at high temperatures exhibit a high amount of defects, y ∼ 0.25 on the Cu(1) site and are semiconductors with a T -1/4 activation law attributed to the praseodymium valence fluctuation

Structural evolution of Ba{sub 8}Ti{sub 3}Nb{sub 4}O{sub 24} from BaTiO{sub 3} using a series of Ba(Ti{sub 1−5x}Nb{sub 4x})O{sub 3} solid solutions

Energy Technology Data Exchange (ETDEWEB)

Barrientos Hernández, F.R., E-mail: frbh68@hotmail.com [Academic Area of Earth Sciences and Materials, Autonomous University of Hidalgo State, Road Pachuca-Tulancingo km 4.5, Mineral de la Reforma zip code 42184, Hidalgo (Mexico); Department of Metallurgical and Materials Engineering, ESIQIE, National Polytechnic Institute, UPALM, Zacatenco, Mexico City, zip code 07738 (Mexico); Lira Hernández, I.A. [Department of Metallurgical and Materials Engineering, ESIQIE, National Polytechnic Institute, UPALM, Zacatenco, Mexico City, zip code 07738 (Mexico); Industrial Engineering Department, Technological Institute of Pachuca, Road México-Pachuca km. 87.5, Pachuca de Soto zip code 42080, Hidalgo (Mexico); Gómez Yáñez, C. [Department of Metallurgical and Materials Engineering, ESIQIE, National Polytechnic Institute, UPALM, Zacatenco, Mexico City, zip code 07738 (Mexico); Arenas Flores, A. [Academic Area of Earth Sciences and Materials, Autonomous University of Hidalgo State, Road Pachuca-Tulancingo km 4.5, Mineral de la Reforma zip code 42184, Hidalgo (Mexico); Cabrera Sierra, R. [Department of Metallurgical and Materials Engineering, ESIQIE, National Polytechnic Institute, UPALM, Zacatenco, Mexico City, zip code 07738 (Mexico); Pérez Labra, M. [Academic Area of Earth Sciences and Materials, Autonomous University of Hidalgo State, Road Pachuca-Tulancingo km 4.5, Mineral de la Reforma zip code 42184, Hidalgo (Mexico)

2014-01-15

Highlights: • The evolution phase Ba{sub 8}Ti{sub 3}Nb{sub 4}O{sub 24} was obtained through the mechanism Ba(Ti{sub 1-5x}Nb{sub 4x})O{sub 3}. • Addition of niobium can accelerate grain growth of BaTiO{sub 3} ceramics. • Ba{sub 8}Ti{sub 3}Nb{sub 4}O{sub 24} presents a dielectric loss of 0.0035 and permittivity value of 54.6. • Electrical measurements showed that Nb{sup 5+} content drops Curie temperature. • Samples with x ⩾ 0.0625 shows an insulating behavior. -- Abstract: In this work, the structural evolution of hexagonal phase Ba{sub 8}Ti{sub 3}Nb{sub 4}O{sub 24} by adding Nb{sub 2}O{sub 5} to perovskite structure of BaTiO{sub 3} was investigated. The compositions Ba(Ti{sub 1-5x}Nb{sub 4x})O{sub 3} ceramics, with 0.00025 ⩽ x ⩽ 0.125 were prepared by the conventional solid state route in air atmosphere, the powders precursors, BaTiO{sub 3}, BaCO{sub 3} and Nb{sub 2}O{sub 5}, were mixed in stoichiometric proportions and ground in a ball mill using alumina balls and acetone. The mixed powders were calcined at temperatures up to 1500 °C. The phase transformation of Ba{sub 8}Ti{sub 3}Nb{sub 4}O{sub 24} from BaTiO{sub 3} was studied by DRX, Raman spectroscopy, SEM, electrical measurements (relative permittivity and P–E hysteresis loops); Rietveld’s refinement was used to structurally characterize the samples. For the devices obtained capacitance was measured at 1 kHz; with these values we calculated the relative permittivity. The samples show typical P–E hysteresis loops at room temperature accompanied by saturation polarization (Ps) and remnant polarization (Pr). The DRX and Rietveld’s refinement results show x ⩽ 0.01 has a ferroelectric behavior. When the doped level is increased x ⩾ 0.02, a peak displacement is observed, this is due to the phase transformation of tetragonal to cubic into the unit cell. Finally, with x = 0.125 the crystal structure transforms to the characteristic hexagonal phase Ba{sub 8}Ti{sub 3}Nb{sub 4}O{sub 24} which

From Ba3Ta5O14N to LaBa2Ta5O13N2: Decreasing the optical band gap of a photocatalyst

International Nuclear Information System (INIS)

Anke, B.; Bredow, T.; Pilarski, M.; Wark, M.; Lerch, M.

2017-01-01

Yellow LaBa 2 Ta 5 O 13 N 2 was successfully synthesized as phase-pure material crystallizing isostructurally to previously reported Ba 3 Ta 5 O 14 N and mixed-valence Ba 3 Ta V 4 Ta IV O 15 . The electronic structure of LaBa 2 Ta 5 O 13 N 2 was studied theoretically with the range-separated hybrid method HSE06. The most stable structure was obtained when lanthanum was placed on 2a and nitrogen on 4h sites confirming Pauling's second rule. By incorporating nitrogen, the measured band gap decreases from ∼3.8 eV for the oxide via 2.74 eV for Ba 3 Ta 5 O 14 N to 2.63 eV for the new oxide nitride, giving rise to an absorption band well in the visible-light region. Calculated fundamental band gaps confirm the experimental trend. The atom-projected density of states has large contributions from N2p orbitals close to the valence band edge. These are responsible for the observed band gap reduction. Photocatalytic hydrogen formation was investigated and compared with that of Ba 3 Ta 5 O 14 N revealing significantly higher activity for LaBa 2 Ta 5 O 13 N 2 under UV-light. - Graphical abstract: X-ray powder diffraction pattern of LaBa 2 Ta 5 O 13 N 2 with the results of the Rietveld refinements. Inset: Unit cell of LaBa 2 Ta 5 O 13 N 2 and polyhedral representation of the crystal structure. - Highlights: • Synthesis of a new oxide nitride LaBa 2 Ta 5 O 13 N 2 . • Refinement of the crystal structure. • Quantum chemical calculations provided band gap close to the measured value. • New phase shows a higher photocatalytic H 2 evolution rate compared to prior tested Ba 3 Ta 5 O 14 N.

Flora da Paraíba, Brasil: Loganiaceae Flora of Paraíba, Brazil: Loganiaceae

Directory of Open Access Journals (Sweden)

Kiriaki Nurit

2005-06-01

Full Text Available Neste trabalho apresenta-se o tratamento taxonômico da família Loganiaceae, como parte do projeto "Flora da Paraíba", que vem sendo realizado com o objetivo de identificar e catalogar as espécies da flora local. Realizouse coletas e observações de campo para as identificações, descrições e ilustrações botânicas que foram efetuadas após estudos morfológicos, com o auxílio da bibliografia especializada, complementados pela análise de fotos de tipos, espécimes dos herbários EAN, JPB e IPA, e comparação com material identificado por especialistas. Registrou-se para a Paraíba quatro espécies: Spigelia anthelmia L., com ampla distribuição, e três espécies de Strychnos, somente coletadas em remanescentes de Mata Atlântica, S. atlantica Krukoff & Barneby, S. parvifolia A. DC. e S. trinervis (Vell. Mart.This work constitutes a taxonomic treatment of the Loganiaceae family as part of the project "Flora da Paraíba", which have been carried out with the objective to identify and catalogue the species of the local flora. The botanical identifications and illustrations were made by morphological studies supported by bibliography, analysis of the types, specimens from herbaria EAN, JPB and IPA, and comparison with samples previously identified by specialists, complemented by field observations. Four species of Loganiaceae belonging two genera were found in State of Paraíba: Spigelia anthelmia L. that has wide distribution and three species of Strychnos, found on remains of Atlantic forest, which are S. atlantica Krukoff & Barneby, S. parvifolia A. DC. and S. trinervis (Vell. Mart.

Optical characteristics of BaGa{sub 2}S{sub 4}:Ho{sup 3+} and BaGa{sub 2}Se{sub 4}:Ho{sup 3+} single crystals

Energy Technology Data Exchange (ETDEWEB)

Choe, Sung-Hyu [Chosun University, Kwangju (Korea, Republic of); Jin, Moon-Seog [Dongshin University, Naju (Korea, Republic of); Kim, Wha-Tek [Chonnam National University, Kwangju (Korea, Republic of)

2005-11-15

BaGa{sub 2}S{sub 4}, BaGa{sub 2}S{sub 4}:Ho{sup 3+}, BaGa{sub 2}Se{sub 4}, and BaGa{sub 2}Se{sub 4}:Ho{sup 3+} single crystals were grown by using the chemical transport reaction method. The optical energy gaps of the single crystals were investigated in the temperature region from 11 K to 300 K. The temperature dependence of the optical energy gap was well fitted by the Varshni equation. Two broad emission bands were observed in the photoluminescence spectra of the single crystals. These bands were attributed to donor-acceptor pair recombinations. Sharp emission peaks were observed in the BaGa{sub 2}S{sub 4}:Ho{sup 3+} and the BaGa{sub 2}Se{sub 4}:Ho{sup 3+} single crystals and were assigned to radiation recombination between split Stark levels of Ho{sup 3+}.

Non-observation of 12C cluster decay of 114Ba

International Nuclear Information System (INIS)

Guglielmetti, A.; Bonetti, R.; Poli, G.; Collatz, R.; Hu, Z.; Kirchner, R.; Roeckl, E.; Gunn, N.; Price, P.B.; Weaver, B.A.; Westphal, A.; California Univ., Berkeley, CA; Szerypo, J.

1997-10-01

By means of the on-line mass separator at Gesellschaft fuer Schwerionenforschung, Darmstadt, we produced 114 Ba through the 58 Ni( 58 Ni,2n) reaction, separated it as a 114 Ba 19 F + beam, and implanted it into a stopper foil positioned in the center of an array of track detectors, which were used to search for 12 C radioactivity of 114 Ba. A total number of (5.4±1.7).10 4 114 Ba atoms were implanted. No 12 C event was found after a total exposure time of 116 hours, corresponding to a 58 Ni beam dose of 1.3.10 17 . The resulting upper limit of 3.4.10 -5 (84% c. 1.) for the branching ratio for 12 C decay of 114 Ba is considerably lower than the limits obtained in previous experiments, which represents an inconsistency at levels of more than 90%. A semiempirical estimate of 19.3 MeV for the upper limit of the Q-value for 12 C decay of 114 Ba is derived. (orig.)

Analysis of oxygen binding-energy variations for BaO on W

Science.gov (United States)

Haas, G. A.; Shih, A.; Mueller, D.; Thomas, R. E.

Interatomic Auger analyses have been made of different forms of BaO layers on W substrates. Variations in Auger spectroscopy energies of the Ba4dBa5pO2p interatomic Auger transition were found to be largely governed by the O2p binding energy of the BaO adsorbate. This was illustrated by comparing results of the Auger data values with values derived from O2p binding energies using ultraviolet photoelectron spectroscopy. Very good agreement was observed not only for the W substrate but also for the W substrate which showed two oxygen-induced electronics state. Variations in binding energy were noted for different states of BaO lattice formation and for different amounts of oxidation, ranging from the transition of Ba to BaO and continuing to the BaO 2 stoichiometry and beyond. Effects were also reported for adsorbate alignment and thermal activation (i.e., reduction) of the oxidized state. An empirical relationship was found suggesting that the more tightly bound the O2p states of the BaO adsorbate were, the lower its work function would be. This link between binding energy and work function was observed to be valid not only for cases of poisoning by oxidation, but held as well during reactivation by the subsequent reduction of the oxide. In addition, this relationship also appeared to predict the low work function obtained through the introduction of substances such as Sc to the BaO-W system. Possible qualitative reasons which might contribute to this are discussed in terms of enhanced dipole effects and shifts in band structure.

Hybrid machining processes perspectives on machining and finishing

CERN Document Server

Gupta, Kapil; Laubscher, R F

2016-01-01

This book describes various hybrid machining and finishing processes. It gives a critical review of the past work based on them as well as the current trends and research directions. For each hybrid machining process presented, the authors list the method of material removal, machining system, process variables and applications. This book provides a deep understanding of the need, application and mechanism of hybrid machining processes.

Optical energy gaps and photoluminescence peaks of BaGa2S4:Er3+ and BaGa2Se4:Er3+ single crystals

International Nuclear Information System (INIS)

Choe, Sung-Hyu; Jin, Moon-Seog; Kim, Wha-Tek

2005-01-01

BaGa 2 S 4 :Er 3+ and BaGa 2 Se 4 :Er 3+ single crystals were grown by using the chemical transport reaction method. The optical energy gaps of the BaGa 2 S 4 :Er 3+ and the BaGa 2 Se 4 :Er 3+ single crystals were found to be 4.045 eV and 3.073 eV, respectively, at 11 K. The temperature dependence of the optical energy gap was well fitted by the Varshni equation. Sharp emission peaks were observed in the photoluminescence spectra of the single crystals and assigned to radiation recombination between split Stark levels of the Er 3+ ion.

MT3825BA: a 384×288-25µm ROIC for uncooled microbolometer FPAs

Science.gov (United States)

Eminoglu, Selim; Gulden, M. Ali; Bayhan, Nusret; Incedere, O. Samet; Soyer, S. Tuncer; Ustundag, Cem M. B.; Isikhan, Murat; Kocak, Serhat; Turan, Ozge; Yalcin, Cem; Akin, Tayfun

2014-06-01

This paper reports the development of a new microbolometer Readout Integrated Circuit (ROIC) called MT3825BA. It has a format of 384 × 288 and a pixel pitch of 25μm. MT3825BA is Mikro-Tasarim's second microbolometer ROIC product, which is developed specifically for resistive surface micro-machined microbolometer detector arrays using high-TCR pixel materials, such as VOx and a-Si. MT3825BA has a system-on-chip architecture, where all the timing, biasing, and pixel non-uniformity correction (NUC) operations in the ROIC are applied using on-chip circuitry simplifying the use and system integration of this ROIC. The ROIC is designed to support pixel resistance values ranging from 30 KΩ to 100 KΩ. MT3825BA is operated using conventional row based readout method, where pixels in the array are read out in a row-by-row basis, where the applied bias for each pixel in a given row is updated at the beginning of each line period according to the applied line based NUC data. The NUC data is applied continuously in a row-by-row basis using the serial programming interface, which is also used to program user configurable features of the ROIC, such as readout gain, integration time, and number of analog video outputs. MT3825BA has a total of 4 analog video outputs and 2 analog reference outputs, placed at the top and bottom of the ROIC, which can be programmed to operate in the 1, 2, and 4-output modes, supporting frames rates well above 60 fps at a 3 MHz pixel output rate. The pixels in the array are read out with respect to reference pixels implemented above and below actual array pixels. The bias voltage of the pixels can be programmed over a 1.0 V range to compensate for the changes in the detector resistance values due to the variations coming from the manufacturing process or changes in the operating temperature. The ROIC has an on-chip integrated temperature sensor with a sensitivity of better than 5 mV / K, and the output of the temperature sensor can be read out the

Preparation of Ba1-xSrxWO4 and Ba1-xCaxWO4 films on tungsten plate by mechanically assisted solution reaction at room temperature

International Nuclear Information System (INIS)

Rangappa, Dinesh; Fujiwara, Takeshi; Watanabe, Tomoaki; Yoshimura, Masahiro

2008-01-01

Preparation of the alkaline earth tungstate films such as Ba 1-x Sr x WO 4 and Ba 1-x Ca x WO 4 on the tungsten substrate was studied with a simple solution process assisted with the ball rotation at room temperature. The solid solution formation and limitations, the effect of oxidizing agent H 2 O 2 and alkaline earth ions concentration on the dissolution of W substrate and the growth of Ba 1-x Sr x WO 4 and Ba 1-x Ca x WO 4 films were studied in detail. The ball rotation assistance plays a very important role to enhance the dissolution of the W substrate and mass transport of the reactant species such as alkaline earth ions and WO 4 2- ions onto the solid/solution interface region, where precipitation occurs. Therefore, the rate of film formation was accelerated by the ball rotation assistance to the reaction system. Ba-rich Ba 1-x Sr x WO 4 and Ba 1-x Ca x WO 4 films were formed without high energy or high temperature treatment

Thermochemical investigations into the system Y-Ba-Cu-O

International Nuclear Information System (INIS)

Neuschuetz, D.; Zimmermann, E.; Hack, K.; Boudene, A.; Mohammad, A.

1992-01-01

For a consistent thermodynamic description of the quaternary system Y-Ba-Cu-O, the binary and ternary subsystems must be known. The metallic binaries and the ternary system Y-Ba-Cu have been evaluated by the authors. Discrepancies within the Cu-O system made a thorough experimental re-investigation necessary, leading to a new consistent thermodynamic data set for copper-oxygen which can now serve as a basis for the description of phase equilibria of all high temperature superconductors. Extensive experimental work on the ternaries Y-Cu-O and Ba-Cu-O, which are oxygen partial pressure dependent, revealed liquid phases down to 790degC. The ternary Y-Ba-O could be described more easily on the basis of literature values and present experimental results, because it does not contain any liquid phases at relevant temperatures. The representation of the quaternary Y-Ba-Cu-O is complicated both by its dependence on the oxygen potential and the existence of liquid oxide phases. In contrast to common practice, the present investigations had to start from Cu-free Ba-Y-O in order to avoid unknown liquid phases in the experiments. The present results being insufficient for a complete description of the quaternary system, the work is being continued within an EC joint research project. (orig.) With 84 refs., 8 tabs., 47 figs [de

Studi On Oxidation State Of U In Ba2NdUO6

International Nuclear Information System (INIS)

Firman Windarto, Hendri

1996-01-01

Ba 2 NdUO 6 is not of the important compounds that is formed from a solidification process for high level liquid waste using super high temperature method Ba 2 NdUO 6 has ordered perovskite structure. The objective of this study is to investigate oxidation state of U in Ba 2 NdUO 6 . The properties of Ba 2 NdUO 6 were observed by using Faraday-type torsion magnetometer and X-ray Photoelectron Spectrometer (XPS). The magnetic susceptibility measured in the temperature range of 4K to room temperature showed that the Ba 2 NdUO 6 is paramagnetism that obeys the Curie-Weiss law. The effective moment of Ba 2 NdUO 6 is 3.04 μB. The results of xPs spectrum showed that the peaks of U4f for Ba 2 NdUO 6 appeared exactly between binding energy of UO 2 and UO 3 . It can be concluded that Ba 2 NdUO 6 has binding energy peaks corresponding to pentavalent uranium

Thermoelectric transport properties of BaBiTe{sub 3}-based materials

Energy Technology Data Exchange (ETDEWEB)

Zhou, Yiming; Zhao, Li-Dong, E-mail: zhaolidong@buaa.edu.cn

2017-05-15

BaBiTe{sub 3}, a material with low thermal conductivity, is an inferior thermoelectric material due to the poor electrical properties originated from its narrow band gap. We choose two types of dopants, K and La, trying to optimize its electrical transport properties. The minority carriers, which harm the Seebeck coefficient in this system, are suppressed by La doping. With the increase of both electrical conductivity and Seebeck coefficient, the power factor of 3% La doped BaBiTe{sub 3} reaches 3.7 μW cm{sup −1} K{sup −2} which increased by 40% from undoped BaBiTe{sub 3}. Besides high power factor, the thermal conductivity is also reduced in it. Eventually, a high ZT value, 0.25 at 473 K, for n-type BaBiTe{sub 3} is achieved in 3% La doped BaBiTe{sub 3}. - Graphical abstract: BaBiTe{sub 3} possesses a low thermal conductivity. However, it is an inferior thermoelectric material due to the poor electrical properties originated from its narrow band gap. A high ZT value of 0.25 at 473 K for n-type BaBiTe{sub 3} can be achieved through optimizing electrical transport properties via La doping. - Highlights: • BaBiTe{sub 3} is an analogue of these promising thermoelectric materials: such as CsBi{sub 4}Te{sub 6} and K{sub 2}Bi{sub 8}Se{sub 13}, etc. • BaBiTe{sub 3} possesses a low thermal conductivity. • La is an effective dopant to enhance electrical transport properties. • A high ZT value of 0.25 at 473 K can be achieved in n-type La-doped BaBiTe{sub 3}.

Bound-bound transitions in the emission spectra of Ba+-He excimer

Science.gov (United States)

Moroshkin, P.; Kono, K.

2016-05-01

We present an experimental and theoretical study of the emission and absorption spectra of the Ba+ ions and Ba+*He excimer quasimolecules in the cryogenic Ba-He plasma. We observe several spectral features in the emission spectrum, which we assign to the electronic transitions between bound states of the excimer correlating to the 6 2P3 /2 and 5 2D3 /2 ,5 /2 states of Ba+. The resulting Ba+(5 2DJ) He is a metastable electronically excited complex with orbital angular momentum L =2 , thus expanding the family of known metal-helium quasimolecules. It might be suitable for high-resolution spectroscopic studies and for the search for new polyatomic exciplex structures.

Er3+ infrared fluorescence affected by spatial distribution synchronicity of Ba2+ and Er3+ in Er3+-doped BaO–SiO2 glasses

Directory of Open Access Journals (Sweden)

Atsunobu Masuno

2016-02-01

Full Text Available Glasses with the composition xBaO–(99.9 − xSiO2–0.1ErO3/2 (0 ≤x ≤ 34.9 were fabricated by a levitation technique. The glasses in the immiscibility region were opaque due to chemical inhomogeneity, while the other glasses were colorless and transparent. The scanning electron microscope observations and electron probe microanalysis scan profiles revealed that more Er3+ ions were preferentially distributed in the regions where more Ba2+ ions existed in the chemically inhomogeneous glasses. The synchronicity of the spatial distributions of the two ions initially increased with increasing x and then decreased when the Ba2+ concentration exceeded a certain value. The peak shape and lifetime of the fluorescence at 1.55 μm depended on x as well as the spatial distribution of both ions. These results indicate that although ErOn polyhedra are preferentially coordinated with Ba2+ ions and their local structure is affected by the coordination of Ba2+, there is a maximum in the amount of Ba2+ ions that can coordinate ErOn polyhedra since the available space for Ba2+ ions is limited. These findings provide us with efficient ways to design the chemical composition of glasses with superior Er3+ fluorescence properties for optical communication network systems.

Nuclear spectroscopy of doubly-even130,132Ba

Science.gov (United States)

Gupta, Anuradha; Gupta, Surbhi; Singh, Suram; Bharti, Arun

2018-05-01

A comparative study of some high-spin characteristic nuclear structure properties of doubly-even 130,132Ba nuclei has been made using two microscopic frameworks - CHFB and PSM. The yrast spectra, intrinsic quadrupole moment and deformation systematics of these nuclei have been successfully calculated. Further, the calculated data from both the frameworks is also compared with the available experimental data and a good agreement has been obtained. The present CHFB calculations describes very well the low spin structure of even-even 130,132Ba nuclei whereas PSM calculations provide a qualitative description of the high-spin band structure of doubly-even 130,132Ba nuclei.

Superconductivity in the U(Th)-Y-Ba-Cu-O systems

International Nuclear Information System (INIS)

Qin Qizong; He Adi; Jia Weijie; Ma Lidun; Cheng Huansheng; Hua Zhongyi

1989-01-01

High T c superconductivity has been observed both resistively and magnetically in the new U(Th)-Y-Ba-Cu-O systems. The zero resistance temperature of the three samples with nominal composition of U 0.1 Y 1.1 Ba 0.8 Cu O 4-z , U 0.15 Y 1.05 Ba 0.8 Cu 4-z and Th 0.3 Y 0.8 Ba 0.8 Cu 4-z is 87K, 79K and 74K, respectively. The result of ac magnetic susceptibility measurement implies that the superconducting state is realized in the U-doped samples below 90K. The stoichimetry of the U-Y-Ba-Cu O superconductors has the aid of Rutherford backscattering and nuclear reaction 16 O(d, p) 17 O. The analytical results show that the 'real composition' of somples may be different from that of the nomial composition. The X ray diffraction analysis of the U-Y-Ba-Cu-O system shows that none of the peaks can be fitted to the uranium oxides and the other raw materiale structure, and its pattern may be attributed to new multiple phases with structure different from the known singlephase superconducting oxides

Punta Pitt, Galapagos Ba/Ca Data for 1963-1982

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — File contains Ba/Ca data (in mmol/mol) presented by Lea et al. (1989). Samples were measured at the Massachusetts Institute of Technology by D. Lea. Ba...

Determination of the UO2-ZrO2-BaO equilibrium diagram

International Nuclear Information System (INIS)

Paschoal, J.O.A.; Kleykanp, H.; Thuemmler, F.

1984-01-01

It is determined the equilibrium diagram of UO 2 - ZrO 2 - BaO to interpret and predict changes in the chemical properties of ceramic (oxide) nuclear fuels during irradiation. The isothermal section of the system at 1700 0 C was determined experimentally, utilizing the techniques of ceramography, X-ray diffraction analysis, microprobe analysis and differential thermal analysis. The solid solubility limits at 1700 0 C between UO 2 and ZrO 2 , UO 2 and BaO, ZrO 2 and BaO, ZrO 2 and BaO and BaUO 3 and BaZrO 3 is presented. The influence of oxygen potential in relation to the different phases is discussed and the phase diagram of the system presented. (M.C.K.) [pt

Left posterior BA37 is involved in object recognition: a TMS study

DEFF Research Database (Denmark)

Stewart, Lauren; Meyer, Bernd-Ulrich; Frith, Uta

2001-01-01

Functional imaging studies have proposed a role for left BA37 in phonological retrieval, semantic processing, face processing and object recognition. The present study targeted the posterior aspect of BA37 to see whether a deficit, specific to one of the above types of processing could be induced...... to name pictures when TMS was given over lBA37 compared to vertex or rBA37. rTMS over lBA37 had no significant effect on word reading, nonword reading or colour naming. The picture naming deficit is suggested to result from a disruption to object recognition processes. This study corroborates the finding...... from a recent imaging study, that the most posterior part of left hemispheric BA37 has a necessary role in object recognition....

Particle-hole states in 138Ba

International Nuclear Information System (INIS)

Bondarenko, V.A.; Khitrov, V.A.; Popov, Yu.P.; Brant, S.; Paar, V.; Simicic, L.

1995-01-01

The thermal-neutron-capture gamma rays and γγ-coincidences were measured by means of Ge detectors. Using primary and secondary (n, γ) data, the level scheme of 138 Ba was established with 63 levels up to an excitation energy of 5 MeV. The level energies and (d, p) transfer data were compared with model predictions of the interacting boson-fermion-fermion model. As shown, this model provides a basic understanding of the neutron particle-hole states of 138 Ba in the energy range of 3.5-5.0 MeV. ((orig.))

Machine terms dictionary

Energy Technology Data Exchange (ETDEWEB)

NONE

1979-04-15

This book gives descriptions of machine terms which includes machine design, drawing, the method of machine, machine tools, machine materials, automobile, measuring and controlling, electricity, basic of electron, information technology, quality assurance, Auto CAD and FA terms and important formula of mechanical engineering.

Some relations between quantum Turing machines and Turing machines

OpenAIRE

Sicard, Andrés; Vélez, Mario

1999-01-01

For quantum Turing machines we present three elements: Its components, its time evolution operator and its local transition function. The components are related with the components of deterministic Turing machines, the time evolution operator is related with the evolution of reversible Turing machines and the local transition function is related with the transition function of probabilistic and reversible Turing machines.

The BaBar Data Acquisition System

CERN Document Server

Scott, I; Grosso, P; Huffer, M E; O'Grady, C; Russell, J J

1999-01-01

The BaBar experiment at the Stanford Linear Accelerator Center is designed to perform a search for CP violation by ana-lyzing the decays of a very large sample of B and B(Bar) mesons produced at the high luminosity PEP-II accelerator. The data acquisition system must cope with a sustained high event rate, while supporting real time feature extraction and data compression with minimal dead time. The BaBar data acquisition system is based around a common VME interface to the electronics read-out of the separate detec-tor subsystems. Data from the front end electronics is read into commercial VME processors via a custom "Personality Card" and PCI interface. The commercial CPUs run the Tornado operating system to provide a platform for detector subsystem code to perform the necessary data processing. The data is read out via a non-blocking network switch to a farm of commercial UNIX processors. The current implementation of the BaBar data acquisition sys-tem has been shown to sustain a Level 1 trigger rate of 1.3...

Support vector machine in machine condition monitoring and fault diagnosis

Science.gov (United States)

Widodo, Achmad; Yang, Bo-Suk

2007-08-01

Recently, the issue of machine condition monitoring and fault diagnosis as a part of maintenance system became global due to the potential advantages to be gained from reduced maintenance costs, improved productivity and increased machine availability. This paper presents a survey of machine condition monitoring and fault diagnosis using support vector machine (SVM). It attempts to summarize and review the recent research and developments of SVM in machine condition monitoring and diagnosis. Numerous methods have been developed based on intelligent systems such as artificial neural network, fuzzy expert system, condition-based reasoning, random forest, etc. However, the use of SVM for machine condition monitoring and fault diagnosis is still rare. SVM has excellent performance in generalization so it can produce high accuracy in classification for machine condition monitoring and diagnosis. Until 2006, the use of SVM in machine condition monitoring and fault diagnosis is tending to develop towards expertise orientation and problem-oriented domain. Finally, the ability to continually change and obtain a novel idea for machine condition monitoring and fault diagnosis using SVM will be future works.

Proton microbeam irradiation effects on PtBA polymer

Indian Academy of Sciences (India)

Microbeam irradiation effects on poly-tert-butyl-acrylate (PtBA) polymer using 2.0 MeV proton microbeam are reported. Preliminary results on pattern formation on PtBA are carried out as a function of fluence. After writing the pattern, a thin layer of Ge is deposited. Distribution of Ge in pristine and ion beam patterned surface ...

The 226Ra-Ba relationship in the North Atlantic during GEOTRACES-GA01

Science.gov (United States)

Le Roy, Emilie; Sanial, Virginie; Charette, Matthew A.; van Beek, Pieter; Lacan, François; Jacquet, Stéphanie H. M.; Henderson, Paul B.; Souhaut, Marc; García-Ibáñez, Maribel I.; Jeandel, Catherine; Pérez, Fiz F.; Sarthou, Géraldine

2018-05-01

We report detailed sections of radium-226 (226Ra, T1/2 = 1602 years) activities and barium (Ba) concentrations determined in the North Atlantic (Portugal-Greenland-Canada) in the framework of the international GEOTRACES program (GA01 section - GEOVIDE project, May-July 2014). Dissolved 226Ra and Ba are strongly correlated along the section, a pattern that may reflect their similar chemical behavior. Because 226Ra and Ba have been widely used as tracers of water masses and ocean mixing, we investigated their behavior more thoroughly in this crucial region for thermohaline circulation, taking advantage of the contrasting biogeochemical patterns existing along the GA01 section. We used an optimum multiparameter (OMP) analysis to distinguish the relative importance of physical transport (water mass mixing) from nonconservative processes (sedimentary, river or hydrothermal inputs, uptake by particles and dissolved-particulate dynamics) on the 226Ra and Ba distributions in the North Atlantic. Results show that the measured 226Ra and Ba concentrations can be explained by conservative mixing for 58 and 65 % of the samples, respectively, notably at intermediate depth, away from the ocean interfaces. 226Ra and Ba can thus be considered conservative tracers of water mass transport in the ocean interior on the space scales considered here, namely, on the order of a few thousand kilometers. However, regions in which 226Ra and Ba displayed nonconservative behavior and in some cases decoupled behaviors were also identified, mostly at the ocean boundaries (seafloor, continental margins and surface waters). Elevated 226Ra and Ba concentrations found in deepwater in the West European Basin suggest that lower Northeast Atlantic Deep Water (NEADWl) accumulates 226Ra and Ba from sediment diffusion and/or particle dissolution during transport. In the upper 1500 m of the West European Basin, deficiencies in 226Ra and Ba are likely explained by their incorporation in planktonic calcareous

Tritellurides of comples cations: Synthesis and crystal structure of (Ba(en)/sub 3/)Te/sub 3/ and (Ba(en)/sub 4,5/)Te/sub 3/

Energy Technology Data Exchange (ETDEWEB)

Zagler, R; Eisenmann, B; Schaefer, H

1987-02-01

The two title compounds have been prepared by reaction of appropriate mixtures of the elements in ethylenediamine. The structures have been determined on the basis of single crystal data. (Ba(en)/sub 3/Te/sub 3/ crystallizes in the monoclinic system, space group P2/sub 1/c with a = 918.0(4), b = 1203.7(6), c = 1639,9(6) pm, ..beta.. = 93.4(1)/sup 0/. In the structure there are bent tritelluride anions Te/sub 3//sup 2 -/ (bond lengths 273,9-278,5 pm, bond angle (105.7/sup 0/). The Ba/sup 2 +/ cations are six coordinate by the bidentate ligand ethylenediamine. (Ba(en)/sub 4,5/)Te/sub 3/ crystallizes in the monoclinic system, space group Cc with a = 1752.8(6), b = 938.9(4), c = 3041.7(8) pm, ..beta.. = 91.3(1)/sup 0/. In this structure the bond lengths in the TE/sub 3//sup 2 -/ anions are shorter (272.1-273.1 pm, bond angles 110.9-112.2/sup 0/). The cations are coordinated by four bidentate ligands, and are connected into pairs by a further ethylenediamine molecule. The resulting dinuclear (Ba(en)/sub 4/)en(Ba(en)/sub 4/)/sup 4 +/ units have the Ba/sup 2 +/ cations in CN 9.

Earth Observation for Biodiversity Assessment (EO-BA)

CSIR Research Space (South Africa)

Cho, Moses A

2012-10-01

Full Text Available in the Dukuduku coastal forest Earth Observation for Biodiversity Assessment (EO-BA) MA CHO, P DEBBA, R MATHIEU, A RAMOELO, L NAIDOO, H VAN DEVENTER, O MALAHLELA AND R MAIN CSIR Natural Resources and the Environment, Pretoria, South Africa PO Box 395... Observation for Biodiversity Assessment (EO-BA) programme is designed to enhance biodiversity assessment and conservation through the application of earth observation data, with particular focus on the African continent. MISSION To initiate and develop...

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Barium manganese oxide (BaMnO3). 721... Substances § 721.10010 Barium manganese oxide (BaMnO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as barium manganese oxide (BaMnO3) (PMN P-00...

Simulations of Quantum Turing Machines by Quantum Multi-Stack Machines

OpenAIRE

Qiu, Daowen

2005-01-01

As was well known, in classical computation, Turing machines, circuits, multi-stack machines, and multi-counter machines are equivalent, that is, they can simulate each other in polynomial time. In quantum computation, Yao [11] first proved that for any quantum Turing machines $M$, there exists quantum Boolean circuit $(n,t)$-simulating $M$, where $n$ denotes the length of input strings, and $t$ is the number of move steps before machine stopping. However, the simulations of quantum Turing ma...

Impact damage, hardness and tribology characterization of epoxy resin based composites reinforced with basalt fibers in combination with TiO_2, BaSO_4 and SiC

International Nuclear Information System (INIS)

Babu, T. Narendiranath; Mangalaraja, R.V.; Saravanan, S.; Prabha, D. Rama

2016-01-01

Impact damage, hardness characterization, frictional and wear behavior of epoxy resin based composites reinforced with basalt fibers in combination with TiO_2, BaSO_4 and SiC were investigated using an impact testing machine, a hardness testing machine and a pin on disc machine. The basalt contained different fillers and short fibers whose presence varied in steps of weight percentage from 23 % to 50 %. It was fabricated using the conventional hand-layup technique followed by the light compression moulding technique. The frictional behavior of the composite specimen was determined by testing on a pin on disc test machine under different operating conditions. The present investigation focused on the determination of the friction coefficient of epoxy resin based composites reinforced with basalt fibers in combination with the fillers. The effects of basalt short fibers content and load were examined under dry conditions. The results showed that the friction coefficient decreased with the filler contents increase. The hardness and the impact damage of epoxy resin reinforced with basalt fiber was examined and it was found that its reinforcement with basalt fiber along with fillers such as titanium oxide, silicon carbide, barium sulphate and graphite made it more advantageous than other specimens. Keywords: basalt fiber, impact behavior, hardness, wear resistance.

Characterization of the insulator barrier and the superconducting transition temperature in GdBa2Cu3O7−δ/BaTiO3 bilayers for application in tunnel junctions

International Nuclear Information System (INIS)

Navarro, H.; Sirena, M.; Haberkorn, N.; Yang, Ilkyu; Kim, Jeehoon

2015-01-01

The optimization of the superconducting properties in a bottom electrode and the quality of an insulator barrier are the first steps in the development of superconductor/insulator/superconductor tunnel junctions. Here, we study the quality of a BaTiO 3 tunnel barrier deposited on a 16 nm thick GdBa 2 Cu 3 O 7−δ thin film by using conductive atomic force microscopy. We find that the tunnel current is systematically reduced (for equal applied voltage) by increasing the BaTiO 3 barrier thickness between 1.6 and 4 nm. The BaTiO 3 layers present an energy barrier of ≈1.2 eV and an attenuation length of 0.35–0.5 nm (depending on the applied voltage). The GdBa 2 Cu 3 O 7−δ electrode is totally covered by a BaTiO 3 thickness above 3 nm. The presence of ferroelectricity was verified by piezoresponse force microscopy for a 4 nm thick BaTiO 3 top layer. The superconducting transition temperature of the bilayers is systematically suppressed by increasing the BaTiO 3 thickness. This fact can be associated with stress at the interface and a reduction of the orthorhombicity of the GdBa 2 Cu 3 O 7−δ . The reduction in the orthorhombicity is expected by considering the interface mismatch and it can also be affected by reduced oxygen stoichiometry (poor oxygen diffusion across the BaTiO 3 barrier)

Left cytoarchitectonic BA 44 processes syntactic gender violations in determiner phrases.

Science.gov (United States)

Heim, Stefan; van Ermingen, Muna; Huber, Walter; Amunts, Katrin

2010-10-01

Recent neuroimaging studies make contradictory predictions about the involvement of left Brodmann's area (BA) 44 in processing local syntactic violations in determiner phrases (DPs). Some studies suggest a role for BA 44 in detecting local syntactic violations, whereas others attribute this function to the left premotor cortex. Therefore, the present event-related functional magnetic resonance imaging (fMRI) study investigated whether left-cytoarchitectonic BA 44 was activated when German DPs involving syntactic gender violations were compared with correct DPs (correct: 'der Baum'-the[masculine] tree[masculine]; violated: 'das Baum'--the[neuter] tree[masculine]). Grammaticality judgements were made for both visual and auditory DPs to be able to generalize the results across modalities. Grammaticality judgements involved, among others, left BA 44 and left BA 6 in the premotor cortex for visual and auditory stimuli. Most importantly, activation in left BA 44 was consistently higher for violated than for correct DPs. This finding was behaviourally corroborated by longer reaction times for violated versus correct DPs. Additional brain regions, showing the same effect, included left premotor cortex, supplementary motor area, right middle and superior frontal cortex, and left cerebellum. Based on earlier findings from the literature, the results indicate the involvement of left BA 44 in processing local syntactic violations when these include morphological features, whereas left premotor cortex seems crucial for the detection of local word category violations. © 2010 Wiley-Liss, Inc.

Machine tool structures

CERN Document Server

Koenigsberger, F

1970-01-01

Machine Tool Structures, Volume 1 deals with fundamental theories and calculation methods for machine tool structures. Experimental investigations into stiffness are discussed, along with the application of the results to the design of machine tool structures. Topics covered range from static and dynamic stiffness to chatter in metal cutting, stability in machine tools, and deformations of machine tool structures. This volume is divided into three sections and opens with a discussion on stiffness specifications and the effect of stiffness on the behavior of the machine under forced vibration c

Luminescent properties of BaCl2-Eu microcrystals embedded in a CsI matrix

International Nuclear Information System (INIS)

Pushak, A.; Vistovskyy, V.; Voloshinovskii, A.; Savchyn, P.; Antonyak, O.; Demkiv, T.; Dacyuk, Yu.; Myagkota, S.; Gektin, A.

2013-01-01

The spectral-luminescent properties of CsI-BaCl 2 (1 mol%)-Eu(0.02 mol%) crystalline system are studied. Europium ion doped BaCl 2 microcrystals embedded in a CsI matrix are revealed on CsI-BaCl 2 (1 mol%)-Eu(0.02 mol%) freshly cleaved surface by the scanning electron microscopy. The size of microcrystals is shown to be within 0.5–5 microns. The luminescent parameters of the BaCl 2 -Eu 2+ microcrystals are shown to be similar to ones of a single crystal analogue. The 4f → 5d absorption transitions in europium ions and the reabsorption of the intrinsic emission of the CsI host are the main excitation mechanisms of europium luminescence in the BaCl 2 microcrystals. -- Highlights: ► The formation of chloride BaCl 2 :Eu microcrystals in the case of BaCl 2 doped CsI crystal has been revealed. ► The observed size of microcrystals at BaCl 2 concentration of 1% is about 0.5–5 μm. ► Majority of Eu 2+ ions in CsI-BaCl 2 -EuCl 3 crystalline system enters into BaCl 2 microcrystals. ► The luminescent parameters of the BaCl 2 :Eu 2+ microcrystals and its bulk analogue are similar

Electricity of machine tool

International Nuclear Information System (INIS)

Gijeon media editorial department

1977-10-01

This book is divided into three parts. The first part deals with electricity machine, which can taints from generator to motor, motor a power source of machine tool, electricity machine for machine tool such as switch in main circuit, automatic machine, a knife switch and pushing button, snap switch, protection device, timer, solenoid, and rectifier. The second part handles wiring diagram. This concludes basic electricity circuit of machine tool, electricity wiring diagram in your machine like milling machine, planer and grinding machine. The third part introduces fault diagnosis of machine, which gives the practical solution according to fault diagnosis and the diagnostic method with voltage and resistance measurement by tester.

Quo Vadis the B.A. degree: Perceptions and visions1

Directory of Open Access Journals (Sweden)

Annette L. Combrink

1993-03-01

Full Text Available Today is a very special day for all the graduates assembled to have a B.A. degree conferred on them. It is a day on which to celebrate the reward for hard work and for realized dreams. This is a very homogeneous group of people - in the sense that they will be receiving B.A. degrees, and for that reason it would be highly apposite to share some cherished thought and ideas about the B.A. degree.

Machine medical ethics

CERN Document Server

Pontier, Matthijs

2015-01-01

The essays in this book, written by researchers from both humanities and sciences, describe various theoretical and experimental approaches to adding medical ethics to a machine in medical settings. Medical machines are in close proximity with human beings, and getting closer: with patients who are in vulnerable states of health, who have disabilities of various kinds, with the very young or very old, and with medical professionals. In such contexts, machines are undertaking important medical tasks that require emotional sensitivity, knowledge of medical codes, human dignity, and privacy. As machine technology advances, ethical concerns become more urgent: should medical machines be programmed to follow a code of medical ethics? What theory or theories should constrain medical machine conduct? What design features are required? Should machines share responsibility with humans for the ethical consequences of medical actions? How ought clinical relationships involving machines to be modeled? Is a capacity for e...

Humanizing machines: Anthropomorphization of slot machines increases gambling.

Science.gov (United States)

Riva, Paolo; Sacchi, Simona; Brambilla, Marco

2015-12-01

Do people gamble more on slot machines if they think that they are playing against humanlike minds rather than mathematical algorithms? Research has shown that people have a strong cognitive tendency to imbue humanlike mental states to nonhuman entities (i.e., anthropomorphism). The present research tested whether anthropomorphizing slot machines would increase gambling. Four studies manipulated slot machine anthropomorphization and found that exposing people to an anthropomorphized description of a slot machine increased gambling behavior and reduced gambling outcomes. Such findings emerged using tasks that focused on gambling behavior (Studies 1 to 3) as well as in experimental paradigms that included gambling outcomes (Studies 2 to 4). We found that gambling outcomes decrease because participants primed with the anthropomorphic slot machine gambled more (Study 4). Furthermore, we found that high-arousal positive emotions (e.g., feeling excited) played a role in the effect of anthropomorphism on gambling behavior (Studies 3 and 4). Our research indicates that the psychological process of gambling-machine anthropomorphism can be advantageous for the gaming industry; however, this may come at great expense for gamblers' (and their families') economic resources and psychological well-being. (c) 2015 APA, all rights reserved).

THINNING OF ‘GALA’ AND 'GOLDEN DELICIOUS' APPLES WITH BA, NAA AND THEIR COMBINATIONS

Directory of Open Access Journals (Sweden)

M STOPAR

2002-07-01

Full Text Available Apple trees, eight-year-old ‘Gala’/M.9 and four-year-old ‘Golden Delicious’/M.9 have been thinned with 6- benzyladenine (BA 50 ppm, 100 ppm and 200 ppm, with 1-naphthaleneacetic acid (NAA 5 ppm, 10 ppm and 20 ppm, and with the tank mix combinations of BA 50 ppm + NAA 5 ppm or BA 20 ppm + NAA 5 ppm, all at 9-10 mm fruitlet diameter. All applied concentrations of BA and NAA thinned both cultivars significantly and no significant difference was found between BA or NAA thinning action. No concentration response on thinning was observed with neither BA nor NAA application. All BA or NAA separate treatments caused yield of fruit to shift to bigger size class. The only concentration response effect was found on evaluation of mean fruit weight data on ‘Golden Delicious’. The higher concentration of BA was used, the higher was the weight of ‘Golden Delicious’ fruit. On the opposite, the higher concentration of NAA was used, the lower was the weight of ‘Golden Delicious’ fruit (not significantly. When BA and NAA were sprayed on ‘Gala’ or ‘Golden Delicious’ as a tank mix combination, similar effect on thinning or fruit growth occurred comparing to BA or NAA when sprayed alone. Return bloom was enhanced on all thinned ‘Gala’ trees while flower formation of ‘Golden Delicious’ was better in the case of BA 200 ppm, NAA 5 ppm, NAA 20 ppm or tank mix spraying of BA 20 ppm + NAA 5 ppm.

Application of NAA and BA in chemical thinning of some commercial apple cultivars

Directory of Open Access Journals (Sweden)

Šebek Gordana

2015-01-01

Full Text Available This paper presents the fruit thinning response of some commercial apple cultivars to NAA and BA plant regulators. The experiment was designed to evaluate NAA applied separately at three concentrations - 13.2 ppm, 17.82 ppm and 26.73 ppm, and BA + NAA combinations (BA - 60 ppm, 100 ppm, 120 ppm or 140 ppm + NAA 4.29 ppm for thinning the assessed apple cultivars. All treatments with NAA and BA + NAA adequately thinned 'McIntosh' and 'Jonathan', whereas the application of NAA 17.82 ppm and 26.73 ppm and the combined treatment BA 140 ppm+ NAA 4.29 ppm were effective fruit thinners for 'Prima'. In terms of the average fruit weight, number of fruits categorized as large (> 75 mm or > 65 mm, and number of fruit per trunk cross-sectional area, the treatment BA 140 ppm + NAA 4.29 ppm was most effective on 'McIntosh' and 'Prima', whereas BA 100 ppm + NAA 4.29 ppm had the best effect on 'Jonathan'.

Epitaxial thin-film growth of Ruddlesden-Popper-type Ba{sub 3}Zr{sub 2}O{sub 7} from a BaZrO{sub 3} target by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Butt, Shariqa Hassan; Rafique, M.S.; Siraj, K.; Latif, A.; Afzal, Amina [University of Engineering and Technology, Laser and Optronics Centre, Department of Physics, Lahore (Pakistan); Awan, M.S. [Ibn-e-Sina Institute of Science and Technology (ISIT), Islamabad (Pakistan); Bashir, Shazia [Government College University, Centre for Advanced Studies in Physics, Lahore (Pakistan); Iqbal, Nida [Universiti Teknologi Malaysia, Medical Devices and Technology Group (MEDITEG), Faculty of Biosciences and Medical Engineering, Johor Bahru, Johor (Malaysia)

2016-07-15

Ruddlesden-Popper Ba{sub 3}Zr{sub 2}O{sub 7} thin films have been synthesized via pulsed laser deposition (PLD) technique. The optimization of deposition parameters in PLD enables the formation of thin film of metastable Ba{sub 3}Zr{sub 2}O{sub 7} phase from BaZrO{sub 3} target. In order to see the post-annealing effects on the structural and optical properties, the deposited Ba{sub 3}Zr{sub 2}O{sub 7} thin films were annealed at 500, 600 and 800 C. X-ray diffraction (XRD) reveals the formation of Ba{sub 3}Zr{sub 2}O{sub 7} phase with tetragonal structure. The changes in the surface of the deposited films were analysed by FE-SEM and AFM. The thin film post-annealed at 500 C exhibited the best structural, optical and surface properties. Furthermore, the chemical states and chemical composition of the films were determined by X-ray photoelectron spectroscopy (XPS) near the surface. The XPS results show that Ba, Zr and O exist mainly in the form of Ba{sub 3}Zr{sub 2}O{sub 7} Ruddlesden-Popper-type perovskite structure. (orig.)

Baština Starog grada Zrinskih

OpenAIRE

Kovač, Ivana

2017-01-01

Stari grad Zrinskih priča bogate, zanimljive i velike priče u svakom svojem kutku. Dvorac je prepun kulturne baštine koja će svakog ostaviti bez daha i dat će nam nove poglede na hrvatsku povijest, a još više na međimursku povijest. U ovom završnom radu pisat ću o ljepotama kraja, povijesnim zbivanjima i kulturnoj baštini grada, od samog početka pa do danas. Posebno ću se posvetiti predmetima koji su nam ostavili naši preci, a najviše umjetnosti grada i okolice. Čakovečki stari grad ima djelo...

Code-expanded radio access protocol for machine-to-machine communications

DEFF Research Database (Denmark)

Thomsen, Henning; Kiilerich Pratas, Nuno; Stefanovic, Cedomir

2013-01-01

The random access methods used for support of machine-to-machine, also referred to as Machine-Type Communications, in current cellular standards are derivatives of traditional framed slotted ALOHA and therefore do not support high user loads efficiently. We propose an approach that is motivated b...... subframes and orthogonal preambles, the amount of available contention resources is drastically increased, enabling the massive support of Machine-Type Communication users that is beyond the reach of current systems.......The random access methods used for support of machine-to-machine, also referred to as Machine-Type Communications, in current cellular standards are derivatives of traditional framed slotted ALOHA and therefore do not support high user loads efficiently. We propose an approach that is motivated...... by the random access method employed in LTE, which significantly increases the amount of contention resources without increasing the system resources, such as contention subframes and preambles. This is accomplished by a logical, rather than physical, extension of the access method in which the available system...

Magnetic and electrical properties in BaNiS2-type solid solutions

International Nuclear Information System (INIS)

Irizawa, Akinori; Yoshimura, Kazuyoshi; Kosuge, Koji

2000-01-01

The magnetic and electrical properties are reported in the new solid solutions BaCo 1-x Cu x S 2 and BaNi 1-x Fe x S 2 . Both compounds show spin-glass-like behavior, although the type of spin frustrations is different with each other. BaCo 1-x Cu x S 2 shows a competition type spin-glass behavior with reentrant phenomenon from antiferromagnetic to spin-glass at low temperatures. BaNi 1-x Fe x S 2 shows a dilute type spin-glass behavior together with super-paramagnetic properties. The temperature variation of 57 Fe Moessbauer spectra in BaNi 0.8 Fe 0.2 S 2 is explicable in a framework of cluster-glass. (author)

Photoluminescence properties of BaMoO4 amorphous thin films

International Nuclear Information System (INIS)

Marques, Ana Paula Azevedo; Melo, Dulce M.A. de; Longo, Elson; Paskocimas, Carlos A.; Pizani, Paulo S.; Leite, Edson R.

2005-01-01

BaMoO 4 amorphous and crystalline thin films were prepared from polymeric precursors. The BaMoO 4 was deposited onto Si wafers by means of the spinning technique. The structure and optical properties of the resulting films were characterized by FTIR reflectance spectra, X-ray diffraction (XRD), atomic force microscopy (AFM) and optical reflectance. The bond Mo-O present in BaMoO 4 was confirmed by FTIR reflectance spectra. XRD characterization showed that thin films heat-treated at 600 and 200 deg. C presented the scheelite-type crystalline phase and amorphous, respectively. AFM analyses showed a considerable variation in surface morphology by comparing samples heat-treated at 200 and 600 deg. C. The reflectivity spectra showed two bands, positioned at 3.38 and 4.37 eV that were attributed to the excitonic state of Ba 2+ and electronic transitions within MoO 2- 4 , respectively. The optical band gaps of BaMoO 4 were 3.38 and 2.19 eV, for crystalline (600 deg. C/2 h) and amorphous (200 deg. C/8 h) films, respectively. The room-temperature luminescence spectra revealed an intense single-emission band in the visible region. The PL intensity of these materials was increased upon heat-treatment. The excellent optical properties observed for BaMoO 4 amorphous thin films suggested that this material is a highly promising candidate for photoluminescent applications

Stability of Tl-Ba-Ca-Cu-O superconducting thin films

International Nuclear Information System (INIS)

Siegal, M. P.; Overmyer, D. L.; Venturini, E. L.; Padilla, R. R.; Provencio, P. N.

1999-01-01

We report the stability of TlBa 2 CaCu 2 O 7 and Tl 2 Ba 2 CaCu 2 O 8 on LaAlO 3 (100) epitaxial thin films, under a variety of conditions. All films are stable in acetone and methanol and with repeated thermal cycling to cryogenic temperatures. Moisture, especially vapor, degrades film quality rapidly. These materials are stable to high temperatures in either N 2 or O 2 ambients. While total degradation, resulting from Tl depletion, occurs at the same temperatures for both phases, 600 degree sign C in N 2 and 700 degree sign C in O 2 , the onset of degradation occurs at somewhat lower temperatures for TlBa 2 CaCu 2 O 7 than for Tl 2 Ba 2 CaCu 2 O 8 . (c) 1999 Materials Research Society

Performance simulation of BaBar DIRC bar boxes in TORCH

Science.gov (United States)

Föhl, K.; Brook, N.; Castillo García, L.; Cussans, D.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Harnew, N.; Piedigrossi, D.; Rademacker, J.; Ros García, A.; van Dijk, M.

2017-12-01

TORCH is a large-area precision time-of-flight detector based on the DIRC principle. The DIRC bar boxes of the BaBar experiment at SLAC could possibly be reused to form a part of the TORCH detector time-of-flight wall area, proposed to provide positive particle identification of low momentum kaons in the LHCb experiment at CERN. For a potential integration of BaBar bar boxes into TORCH, new imaging readout optics are required. From the several designs of readout optics that have been considered, two are used in this paper to study the effect of BaBar bar optical imperfections on the detector reconstruction performance. The kaon-pion separation powers obtained from analysing simulated photon hit patterns show the performance reduction for a BaBar bar of non-square geometry compared to a perfectly rectangular cross section.

Synthesis, Crystal Structure, and Chemical-Bonding Analysis of BaZn(NCN2

Directory of Open Access Journals (Sweden)

Alex J. Corkett

2017-12-01

Full Text Available The ternary carbodiimide BaZn(NCN2 was prepared by a solid-state metathesis reaction between BaF2, ZnF2, and Li2NCN in a 1:1:2 molar ratio, and its crystal structure was determined from Rietveld refinement of X-ray data. BaZn(NCN2 represents the aristotype of the LiBa2Al(NCN4 structure which is unique to carbodiimide/cyanamide chemistry and is well regarded as being constructed from ZnN4 tetrahedra, sharing edges and vertices through NCN2− units to form corrugated layers with Ba2+ in the interlayer voids. Structural anomalies in the shape of the cyanamide units are addressed via IR spectrometry and DFT calculations, which suggest the presence of slightly bent N=C=N2− carbodiimide units with C2v symmetry. Moreover, chemical-bonding analysis within the framework of crystal orbital Hamilton population (COHP reveals striking similarities between the bonding interactions in BaZn(NCN2 and SrZn(NCN2 despite their contrasting crystal structures. BaZn(NCN2 is only the second example of a ternary post-transition metal carbodiimide, and its realization paves the way for the preparation of analogues featuring divalent transition metals at the tetrahedral Zn2+ site.

Design, synthesis and luminescence properties of Ba2 YB2 O6 Cl- and Ba2 YB2 O6 F-based phosphors.

Science.gov (United States)

Chen, Wanping; Yang, Xin; Liu, Yan; Dai, Xiaoyan

2015-05-01

Using a high-temperature solid-state reaction, the chlorine in Ba2 YB2 O6 Cl is gradually replaced by F, and a new compound with the nominal chemical formula Ba2 YB2 O6 F and two phosphors doped with Ce(3+) and Eu(3+) , respectively, are obtained. X-Ray diffraction and photoluminescence spectroscopy are used to characterize the as-synthesized samples. The as-synthesized Ba2 YB2 O6 Cl exhibits bright blue emission in the spectral range ~ 330-410 nm with a maximum around 363 nm under X-ray or UV excitation. Ba2 YB2 O6 F:0.01Ce(3+) exhibits blue emission in the range ~ 340-570 nm with a maximum around 383 nm. Ba2 YB2 O6 F:0.01Eu(3+) exhibits a predominantly (5) D0 -(7)  F2 emission (~610 nm) and the relative intensities of the (5) D0 -(7)  F0,1,2 emissions are tunable under different wavelength UV excitation. The luminescence behaviors of the two phosphors are explained simply in terms of the host composition and site occupancy probability of Ce(3+) and Eu(3+) , respectively. The results indicate that these phosphors have potential application as a blue phosphor or as a red phosphor. Copyright © 2014 John Wiley & Sons, Ltd.

Simple machines

CERN Document Server

Graybill, George

2007-01-01

Just how simple are simple machines? With our ready-to-use resource, they are simple to teach and easy to learn! Chocked full of information and activities, we begin with a look at force, motion and work, and examples of simple machines in daily life are given. With this background, we move on to different kinds of simple machines including: Levers, Inclined Planes, Wedges, Screws, Pulleys, and Wheels and Axles. An exploration of some compound machines follows, such as the can opener. Our resource is a real time-saver as all the reading passages, student activities are provided. Presented in s

How Extended Is Wernicke’s Area? Meta-Analytic Connectivity Study of BA20 and Integrative Proposal

Directory of Open Access Journals (Sweden)

Alfredo Ardila

2016-01-01

Full Text Available Understanding the functions of different brain areas has represented a major endeavor of contemporary neurosciences. The purpose of this paper was to pinpoint the connectivity of Brodmann area 20 (BA20 (inferior temporal gyrus, fusiform gyrus in language tasks. A meta-analysis was conducted to assess the language network in which BA20 is involved. The DataBase of Brainmap was used; 11 papers corresponding to 12 experimental conditions with a total of 207 subjects were included in this analysis. Our results demonstrated seven clusters of activation including other temporal lobe areas (BA3, BA21, the insula, and the prefrontal cortex; minor clusters in the cingulate gyrus and the occipital lobe were observed; however, the volumes of all the activation clusters were small. Our results suggest that regardless of BA20 having certain participation in language processes it cannot be considered as a core language processing area (Wernicke’s area; nonetheless, it could be regarded as kind of language processing marginal area, participating in “extended Wernicke’s area” or simply “Wernicke’s system.” It is suggested that “core Wernicke’s area” roughly corresponds to BA21, BA22, BA41, and BA42, while a “language associations area” roughly corresponds to BA20, BA37, BA38, BA39, and BA40 (“extended Wernicke’s area” or “Wernicke’s system”.

Machine performance assessment and enhancement for a hexapod machine

Energy Technology Data Exchange (ETDEWEB)

Mou, J.I. [Arizona State Univ., Tempe, AZ (United States); King, C. [Sandia National Labs., Livermore, CA (United States). Integrated Manufacturing Systems Center

1998-03-19

The focus of this study is to develop a sensor fused process modeling and control methodology to model, assess, and then enhance the performance of a hexapod machine for precision product realization. Deterministic modeling technique was used to derive models for machine performance assessment and enhancement. Sensor fusion methodology was adopted to identify the parameters of the derived models. Empirical models and computational algorithms were also derived and implemented to model, assess, and then enhance the machine performance. The developed sensor fusion algorithms can be implemented on a PC-based open architecture controller to receive information from various sensors, assess the status of the process, determine the proper action, and deliver the command to actuators for task execution. This will enhance a hexapod machine`s capability to produce workpieces within the imposed dimensional tolerances.

Strain induced enhancement of magnetization in Ba{sub 2}FeMoO{sub 6} based heterostructure with (Ba{sub x}Sr{sub 1-x})TiO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyeong-Won; Norton, David P. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Ghosh, Siddhartha, E-mail: ghoshsid@gmail.com; Buvaev, Sanal; Hebard, Arthur F. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)

2016-05-14

High quality epitaxial Ba{sub 2}FeMoO{sub 6} thin films and Ba{sub 2}FeMoO{sub 6}–(Ba{sub x}Sr{sub 1−x})TiO{sub 3} bi-layer (BL) and superlattice (SL) structures were grown via pulsed laser deposition under low oxygen pressure, and their structural, magnetic, and magneto-transport properties were examined. Superlattice and bi-layer structures were confirmed by X-ray diffraction patterns. Low temperature magnetic measurement shows that the saturation magnetization (M{sub S}) is significantly higher for SLs and almost similar or lower for BLs, when compared to phase pure Ba{sub 2}FeMoO{sub 6} thin films. The variation of the coercive field (H{sub C}) follows exact opposite trend, where BL samples have higher H{sub C} and SL samples have lower H{sub C} than pure Ba{sub 2}FeMoO{sub 6} thin films. Also, a significant decrease of the Curie temperature is found in both BL and SL structures compared to pure Ba{sub 2}FeMoO{sub 6} thin films. Negative magneto-resistance is seen in all the BL and SL structures as well as in pure Ba{sub 2}FeMoO{sub 6} thin films. In contrast to the magnetic properties, the magneto-transport properties do not show much variation with induced strain.

Phase controlled synthesis of (Mg, Ca, Ba)-ferrite magnetic nanoparticles with high uniformity

International Nuclear Information System (INIS)

Wang, S.F.; Li, Q.; Zu, X.T.; Xiang, X.; Liu, W.; Li, S.

2016-01-01

(Mg, Ca, Ba)-ferrite magnetic nanoparticles were successfully synthesized through modifying the atomic ratio of polysaccharide and chelating agent at an optimal sintering temperature. In the process, the polysaccharide plays an important role in drastically shrinking the precursor during the gel drying process. In the metal-complex structure, M"2"+ ion active sites were coordinated by −OH of the water molecules except for EDTA anions. The MFe_2O_4 magnetic nanoparticles exhibited enhanced magnetic properties when compared with nano-MFe_2O_4 of similar particle size synthesized by other synthesis route reported in the literature. In particular, the sintering temperature improves the crystallinity and increases the hysteresis loop squareness ratio of (Mg, Ca, Ba)-ferrite nanoparticles significantly. - Graphical abstract: Schematic representation of the proposed model for MFe_2O_4 nanoparticle synthesis, starting from EDTA-chelated M"2"+ (M=Mg, Ca, or Ba) cations (left). High dispersion (Mg, Ca, Ba)-ferrite magnetic nanoparticles were prepared by a modified polyacrylamide gel route. Optimized utilization of polysaccharide, chelating agent, and sintering temperature allowed the formation of (Mg, Ca, Ba)-ferrite nanoparticles with a narrow diameter distribution. - Highlights: • We report a modified polyacrylamide gel route to synthesize (Mg, Ca, Ba)-ferrite magnetic nanoparticles. • Chelate mechanism of metal ions (Mg, Ca, Ba) and EDTA has been discussed. • Phase transformation process of (Mg, Ca, Ba)-ferrites has been discussed. • The preparation method increases the hysteresis loop squareness ratio of (Mg, Ca, Ba)-ferrite nanoparticles.

Superconducting rotating machines

International Nuclear Information System (INIS)

Smith, J.L. Jr.; Kirtley, J.L. Jr.; Thullen, P.

1975-01-01

The opportunities and limitations of the applications of superconductors in rotating electric machines are given. The relevant properties of superconductors and the fundamental requirements for rotating electric machines are discussed. The current state-of-the-art of superconducting machines is reviewed. Key problems, future developments and the long range potential of superconducting machines are assessed

The relationship of structure to superconductivity in the Pr-Ba-Cu-O system

Science.gov (United States)

Minseo, P.

1994-05-01

The relation of structure to lack of superconductivity in Pr-Ba-Cu-O was systematically investigated. First, the phase equilibria of this system was studied to find the processing parameters which maximize the cation-site ordering between Pr and Ba ions. Second, a comparative study between superconducting Nd-Ba-Cu-O and nonsuperconducting Pr-Ba-Cu-O was performed by forming solid-solution Nd-Pr-Ba-Cu-O. The relation between structure and superconductivity in Nd(1-x)Pr(x)Ba2Cu3O(7-delta) is investigated. T sub c decreases monotonically with increasing x and superconductivity disappears at around x = 0.3 to 0.4. T sub c is enhanced by 10 K when the sample is processed at an oxygen partial pressure (PO2) of 0.01 atm, followed by oxygenation at 450 C. Depression of T sub c as a function of x and PO2 is explained in terms of a charge-transfer model. It is suggested that destruction of superconductivity in the RE(1-x)Pr(x)Ba2Cu3O(7-delta) (RE=rare-earth) system can be viewed as disruption of four-fold planar coordinated Cu ions in the chain-site due to permanent occupation of extra Pr ions on Ba sites.

CONTRAST STUDY ON CT AND BA IN DIAGNOSIS OF PATIENTS WITH ATHEROTHROMBOTIC BRAIN INFARCTION

Institute of Scientific and Technical Information of China (English)

Mingshun Liu; Haixiang Gao; Xiaomei Fu; Po Ma

2007-01-01

Objectives: To explore applied value on CT and BA in diagnosis of patients with atherothrombotic brain infarction. Methods:CT and BA were examined in 246 patients with atherothrombotic brain infarction. Results:The different change of CT and BA were showed in 246 patients with atherothrombotic brain infarction. Conclusions: There were separately different advantage and shortcoming in CT and BA in diagnosis of atherothrombotic brain infarction. The value of clinical application of BA was important in diagnosis of atherothrombotic brain infarction.

Effect of lithium doping in BaTiO3 ceramics for vibration sensor application

Science.gov (United States)

Praveen, E.; Murugan, S.; Jayakumar, K.

2018-04-01

Phase pure undoped and Lithium doped BaTiO3 particles have been synthesized by high temperature solid-state reaction method. Substitution of Lithium at the Ba2+ site in BaTiO3 lattice has been investigated. The structural, vibrational, electrical and mechanical characterization have been carried out. The poled samples were used as a sensing element for the detection of mechanical oscillations and the presence of 80 Hz pulse in the output spectrum manifest the response of the sensor element to the applied mechanical stress. In comparison with pure BaTiO3 the sensitivity of Li doped BaTiO3 is 14 times greater than the pure BaTiO3. This confirms that Li doped BaTiO3 could be an efficient candidate for the functionalization of vibration sensors in space application.

Growth of BaTiO3-PVDF composite thick films by using aerosol deposition

Science.gov (United States)

Cho, Sung Hwan; Yoon, Young Joon

2016-01-01

Barium titanate (BaTiO3)-polyvinylidene fluoride (PVDF) composite thick films were grown by using aerosol deposition at room temperature with BaTiO3 and PVDF powders. To produce a uniform composition in ceramic and polymer composite films, which show a substantial difference in specific gravity, we used PVDF-coated BaTiO3 powders as the starting materials. An examination of the microstructure confirmed that the BaTiO3 were well distributed in the PVDF matrix in the form of a 0 - 3 compound. The crystallite size in the BaTiO3-PVDF composite thick films was 5 ˜ 50 times higher than that in pure BaTiO3 thick films. PVDF plays a role in suppressing the fragmentation of BaTiO3 powder during the aerosol deposition process and in controlling the relative permittivity.

Glass formation and physicochemical properties of glasses of Ba(PO3)2-LiRAlF6 (R=Mg, Ca, Sr, Ba) system

International Nuclear Information System (INIS)

Khalilev, V.D.; Chkhenkeli, G.D.; Vakhrameev, V.I.

1987-01-01

Glass formation regions, crystallizability, optical constants, thermal linear expansion coefficient and IR absorption spectra of glass are studied in Ba(PO) 3 ) 2 - LiRAlF 6 system where R=Mg, Ca, Sr, Ba. The carried out investigation confirms participation of introduced fluorides (as modified cryolites) in structural transformations manifested in increase of glass formation regions and nonlinear variations of properties

Crystallization of the HigBA2 toxin-antitoxin complex from Vibrio cholerae

DEFF Research Database (Denmark)

Hadǽi, San; Garcia-Pino, Abel; Martinez-Rodriguez, Sergio

2013-01-01

The genome of Vibrio cholerae encodes two higBA toxin-antitoxin (TA) modules that are activated by amino-acid starvation. Here, the TA complex of the second module, higBA2, as well as the C-terminal domain of the corresponding HigA2 antitoxin, have been purified and crystallized. The HigBA2 compl...

Superconductivity of Ba8Si46-xGax clathrates

Science.gov (United States)

Li, Yang; Zhang, Ruihong; Chen, Ning; Ma, Xingqiao; Cao, Guohui; Luo, Z. P.; Hu, C. R.; Ross, Joseph H., Jr.

2007-03-01

We have presented a combined experimental and theoretical study of the effect of Gallium substitution on the superconductivity of the type I clathrate Ba8Si46-xGax. In Ga-doped clathrates, the Ga state is found to be strongly hybridized with the cage conduction-band state. Ga substitution results in a shift toward to a lower energy, a decrease of density of states at Fermi level, a lowering of the carrier concentration and a breakage of integrity of the sp3 hybridized networks. These play key roles in the suppression of superconductivity. For Ba8Si40Ga6, the onset of the superconducting transition occurs at Tc=3.3 K. The investigation of the magnetic superconducting state shows that Ba8Si40Ga6 is a type II superconductor. The critical magnetic fields were measured to be Hc1=35 Oe and Hc2=8.5 kOe. Our estimate of the lectron-phonon coupling reveals that Ba8Si40Ga6 is a moderate phonon-mediated BCS superconductor.

Sustainable machining

CERN Document Server

2017-01-01

This book provides an overview on current sustainable machining. Its chapters cover the concept in economic, social and environmental dimensions. It provides the reader with proper ways to handle several pollutants produced during the machining process. The book is useful on both undergraduate and postgraduate levels and it is of interest to all those working with manufacturing and machining technology.

Growth and scintillation properties of BaMgF4

International Nuclear Information System (INIS)

Yanagida, Takayuki; Kawaguchi, Noriaki; Fujimoto, Yutaka; Sugiyama, Makoto; Furuya, Yuki; Kamada, Kei; Yokota, Yuui; Yoshikawa, Akira; Chani, Valery

2010-01-01

By using the micro-pulling down (μ-PD) method, the barium magnesium fluoride (BaMgF 4 ) single crystalline scintillator was produced. The crystal was cut and mirror polished to the physical dimensions of 1x2x10 mm 3 for examination of scintillation properties. BaMgF 4 demonstrated ∼70% transmittance in wavelength range above 170 nm, and strong emission peaking around 205 nm was observed under X-ray excitation. The absolute light yield of BaMgF 4 was 1300±100 ph/MeV, and the decay time profile showed two components as 0.57±0.01 (70%) and 2.2±0.31 (30%) ns at room temperature.

Improvement of β-phase crystal formation in a BaTiO3-modified PVDF membrane

Science.gov (United States)

Lin, SHEN; Lei, GONG; Shuhua, CHEN; Shiping, ZHAN; Cheng, ZHANG; Tao, SHAO

2018-04-01

In this paper, low temperature plasma is used to modify the surface of barium titanate (BaTiO3) nanoparticles in order to enhance the interfacial compatibility between ferroelectric poly(vinylidene fluoride) (PVDF) and BaTiO3 nanoparticles. The results demonstrate that oxygenic groups are successfully attached to the BaTiO3 surface, and the quantity of the functional groups increases with the treatment voltage. Furthermore, the effect of modified BaTiO3 nanoparticles on the morphology and crystal structure of the PVDF/BaTiO3 membrane is investigated. The results reveal that the dispersion of BaTiO3 nanoparticles in the PVDF matrix was greatly improved due to the modification of the BaTiO3 nanoparticles by air plasma. It is worth noting that the formation of a β-phase in a PVDF/modified BaTiO3 membrane is observably promoted, which results from the strong interaction between PVDF chains and oxygenic groups fixed on the BaTiO3 surface and the better dispersion of BaTiO3 nanoparticles in the PVDF matrix. Besides, the PVDF/modified BaTiO3 membrane at the treatment voltage of 24 kV exhibits a lower water contact angle (≈68.4°) compared with the unmodified one (≈86.7°). Meanwhile, the dielectric constant of PVDF/BaTiO3 nanocomposites increases with the increase of working voltage.

Advanced Electrical Machines and Machine-Based Systems for Electric and Hybrid Vehicles

Directory of Open Access Journals (Sweden)

Ming Cheng

2015-09-01

Full Text Available The paper presents a number of advanced solutions on electric machines and machine-based systems for the powertrain of electric vehicles (EVs. Two types of systems are considered, namely the drive systems designated to the EV propulsion and the power split devices utilized in the popular series-parallel hybrid electric vehicle architecture. After reviewing the main requirements for the electric drive systems, the paper illustrates advanced electric machine topologies, including a stator permanent magnet (stator-PM motor, a hybrid-excitation motor, a flux memory motor and a redundant motor structure. Then, it illustrates advanced electric drive systems, such as the magnetic-geared in-wheel drive and the integrated starter generator (ISG. Finally, three machine-based implementations of the power split devices are expounded, built up around the dual-rotor PM machine, the dual-stator PM brushless machine and the magnetic-geared dual-rotor machine. As a conclusion, the development trends in the field of electric machines and machine-based systems for EVs are summarized.

Asynchronized synchronous machines

CERN Document Server

Botvinnik, M M

1964-01-01

Asynchronized Synchronous Machines focuses on the theoretical research on asynchronized synchronous (AS) machines, which are "hybrids” of synchronous and induction machines that can operate with slip. Topics covered in this book include the initial equations; vector diagram of an AS machine; regulation in cases of deviation from the law of full compensation; parameters of the excitation system; and schematic diagram of an excitation regulator. The possible applications of AS machines and its calculations in certain cases are also discussed. This publication is beneficial for students and indiv

BaBar Data Aquisition

CERN Document Server

Scott, I; Grosso, P; Hamilton, R T; Huffer, M E; O'Grady, C; Russell, J J

1998-01-01

The BaBar experiment at the Stanford Linear Accelerator Center is designed to perform a search for CP violation by analysing the decays of a very large sample of B and Bbar mesons produced at the high luminosity PEP-11 accelerator. The data acquisition system must cope with a sustained high event rate, while supporting real time feature extraction and data compression with minimal dead time. The BaBar data acquisition system is based around a common VME interface to the electronics read-out of the separate detector subsystems. Data from the front end electronics is read into commercial VME processors via a custom "personality card" and PCI interface. The commercial CPUs run the Tornado operating system to provide a platform for detector subsystem code to perform the necessary data processing. The data are read out via a non-blocking network switch to a farm of commercial UNIX processors. Careful design of the core data acquisition code has enabled us to sustain events rates in excess of 20 kHz while maintaini...

Machine Shop Lathes.

Science.gov (United States)

Dunn, James

This guide, the second in a series of five machine shop curriculum manuals, was designed for use in machine shop courses in Oklahoma. The purpose of the manual is to equip students with basic knowledge and skills that will enable them to enter the machine trade at the machine-operator level. The curriculum is designed so that it can be used in…

Effect of Ba in the glass characteristics of cesium loaded iron phosphate glasses

International Nuclear Information System (INIS)

Joseph, Kitheri; Asuvathraman, R.; Vasudeva Rao, P.R.

2015-01-01

Radioactive 137 Cs extracted from high level nuclear waste, when immobilized in a suitable matrix can be used as a γsource in medical industry. Iron phosphate glass (IPG) is one of a suitable matrix for the immobilization of 137 Cs prior to the immobilization of 137 Cs in IPG, it is essential to optimize the immobilization conditions using natural (inactive) cesium. Glass characteristics of inactive Cs loaded iron phosphate glasses were already explored in our earlier studies. However, the change in glass characteristics of 137 Cs loaded iron phosphate glass to 137 Ba loaded iron phosphate glass need to be studied before the immobilization of 137 Cs in iron phosphate glass as 137 Cs transforms to 137 Ba due to nuclear transmutation ( 137 Cs(β,γ) 137 Ba). This paper reports the studies on such a behaviour by incorporating inactive Ba in cesium loaded iron phosphate glasses. Cs and Ba loaded iron phosphate glasses were prepared by melt quench technique in air using appropriate amounts of Fe 2 O 3 , NH 4 H 2 PO 4 , Ba(OH) 2.8 H 2 O and Cs 2 CO 3 . The chemicals were added such that the glass formed possesses the batch composition of (a) 21.4 wt. % Fe 2 O 3 -45 wt. % Cs 2 O-5 wt % BaO-P 2 O 5 (henceforth referred as IP50Cs45Ba5); (b) 21.4 wt. % Fe 2 O 3 -25 wt. % Cs 2 O-25 wt % BaO-P 2 O5 (henceforth referred as IP50Cs25Ba25). The thermal expansion measurements were also carried out using a home-built quartz push-rod dilatometer. The data related to change in thermal expansion behaviour, glass forming ability, glass stability and structural changes in phosphate network due to the partial replacement of Cs with Ba will also be discussed. (author)

The BaBar Software Architecture and Infrastructure

International Nuclear Information System (INIS)

Cosmo, Gabriele

2003-01-01

The BaBar experiment has in place since 1995 a software release system (SRT Software Release Tools) based on CVS (Concurrent Version System) which is in common for all the software developed for the experiment, online or offline, simulation or reconstruction. A software release is a snapshot of all BaBar code (online, offline, utilities, scripts, makefiles, etc.). This set of code is tested to work together, and is indexed by a release number (e.g., 6.8.2) so a user can refer to a particular release and get reproducible results. A release will involve particular versions of packages. A package generally consists of a set of code for a particular task, together with a GNU makefile, scripts and documentation. All BaBar software is maintained in AFS (Andrew File System) directories, so the code is accessible worldwide within the Collaboration. The combination SRT, CVS, AFS, has demonstrated to be a valid, powerful and efficient way of organizing the software infrastructure of a modern HEP experiment with collaborating Institutes distributed worldwide, both in a development and production phase

Structural phase transition of BaZrO3 under high pressure

International Nuclear Information System (INIS)

Yang, Xue; Li, Quanjun; Liu, Ran; Liu, Bo; Zhang, Huafang; Jiang, Shuqing; Zou, Bo; Cui, Tian; Liu, Bingbing; Liu, Jing

2014-01-01

We studied the phase transition behavior of cubic BaZrO 3 perovskite by in situ high pressure synchrotron X-ray diffraction experiments up to 46.4 GPa at room temperature. The phase transition from cubic phase to tetragonal phase was observed in BaZrO 3 for the first time, which takes place at 17.2 GPa. A bulk modulus 189 (26) GPa for cubic BaZrO 3 is derived from the pressure–volume data. Upon decompression, the high pressure phase transforms into the initial cubic phase. It is suggested that the unstable phonon mode caused by the rotation of oxygen octahedra plays a crucial role in the high pressure phase transition behavior of BaZrO 3

Phase controlled synthesis of (Mg, Ca, Ba)-ferrite magnetic nanoparticles with high uniformity

Energy Technology Data Exchange (ETDEWEB)

Wang, S.F., E-mail: wangshifa2006@yeah.net [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan (China); Science and technology on vacuum technology and physics laboratory, Lanzhou Institute of Physics, Lanzhou 730000, Gansu (China); Li, Q. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan (China); Zu, X.T., E-mail: xtzu@uestc.edu.cn [Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan (China); Xiang, X.; Liu, W. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan (China); Li, S., E-mail: sean.li@unsw.edu.au [School of Material Science and Engineering, University of New South Wales, Sydney 2052 (Australia)

2016-12-01

(Mg, Ca, Ba)-ferrite magnetic nanoparticles were successfully synthesized through modifying the atomic ratio of polysaccharide and chelating agent at an optimal sintering temperature. In the process, the polysaccharide plays an important role in drastically shrinking the precursor during the gel drying process. In the metal-complex structure, M{sup 2+} ion active sites were coordinated by −OH of the water molecules except for EDTA anions. The MFe{sub 2}O{sub 4} magnetic nanoparticles exhibited enhanced magnetic properties when compared with nano-MFe{sub 2}O{sub 4} of similar particle size synthesized by other synthesis route reported in the literature. In particular, the sintering temperature improves the crystallinity and increases the hysteresis loop squareness ratio of (Mg, Ca, Ba)-ferrite nanoparticles significantly. - Graphical abstract: Schematic representation of the proposed model for MFe{sub 2}O{sub 4} nanoparticle synthesis, starting from EDTA-chelated M{sup 2+} (M=Mg, Ca, or Ba) cations (left). High dispersion (Mg, Ca, Ba)-ferrite magnetic nanoparticles were prepared by a modified polyacrylamide gel route. Optimized utilization of polysaccharide, chelating agent, and sintering temperature allowed the formation of (Mg, Ca, Ba)-ferrite nanoparticles with a narrow diameter distribution. - Highlights: • We report a modified polyacrylamide gel route to synthesize (Mg, Ca, Ba)-ferrite magnetic nanoparticles. • Chelate mechanism of metal ions (Mg, Ca, Ba) and EDTA has been discussed. • Phase transformation process of (Mg, Ca, Ba)-ferrites has been discussed. • The preparation method increases the hysteresis loop squareness ratio of (Mg, Ca, Ba)-ferrite nanoparticles.

Microstructural properties of BaTiO3 ceramics and thin films

International Nuclear Information System (INIS)

Fundora C, A.; Portelles, J.J.; Siqueiros, J.M.

2000-01-01

A microstructural study of BaTiO 3 ceramics obtained by the conventional ceramic method is presented. Targets were produced to grow BaTiO 3 thin films by pulsed laser deposition on Pt/Ti/Si (100) substrates. X-ray diffraction, Auger Electron Spectroscopy, X-ray Photon Spectroscopy and Scanning Electron Microscopy were used to study the properties of the BaTiO 3 ceramic samples and thin films, as deposited and after an annealing process. (Author)

The Preparation and Characterization of Tourmaline-Containing Functional Copolymer p (VST/MMA/BA

Directory of Open Access Journals (Sweden)

Yingmo Hu

2018-01-01

Full Text Available Tourmaline was modified with vinyl triethoxysilane containing double bond to prepare the polymerizable organic vinylsiliconoxyl tourmaline (VST and then copolymerized with methyl methacrylate (MMA and butyl acrylate (BA to produce the tourmaline-containing functional copolymer p (VST/MMA/BA. The structures and morphologies of VST and p (VST/MMA/BA copolymer were characterized by IR, SEM, and EDX. The experimental results indicated that tourmaline was introduced into the copolymer via surface modification and the tourmaline-containing functional copolymer was obtained by a copolymerization process with MMA and BA. The prepared p (VST/MMA/BA copolymer displayed excellent storage stabilities, high far-infrared radiation and negative ion releasing performances, and good mechanical properties.

Design of optimal input–output scaling factors based fuzzy PSS using bat algorithm

Directory of Open Access Journals (Sweden)

D.K. Sambariya

2016-06-01

Full Text Available In this article, a fuzzy logic based power system stabilizer (FPSS is designed by tuning its input–output scaling factors. Two input signals to FPSS are considered as change of speed and change in power, and the output signal is considered as a correcting voltage signal. The normalizing factors of these signals are considered as the optimization problem with minimization of integral of square error in single-machine and multi-machine power systems. These factors are optimally determined with bat algorithm (BA and considered as scaling factors of FPSS. The performance of power system with such a designed BA based FPSS (BA-FPSS is compared to that of response with FPSS, Harmony Search Algorithm based FPSS (HSA-FPSS and Particle Swarm Optimization based FPSS (PSO-FPSS. The systems considered are single-machine connected to infinite-bus, two-area 4-machine 10-bus and IEEE New England 10-machine 39-bus power systems for evaluating the performance of BA-FPSS. The comparison is carried out in terms of the integral of time-weighted absolute error (ITAE, integral of absolute error (IAE and integral of square error (ISE of speed response for systems with FPSS, HSA-FPSS and BA-FPSS. The superior performance of systems with BA-FPSS is established considering eight plant conditions of each system, which represents the wide range of operating conditions.

Perovskite phases in the systems AO-SE/sub 2/O/sub 3/-UO/sub 2,x/ with A=alkaline earth metal and SE=rare earths, La, and Y. VII. The systems Ba/sub 2/CaUO/sub 6/-Ba/sub 2/Gd/sub 0. 67/UO/sub 6/ and Ba/sub 2/CaUO/sub 6/-Ba/sub 2/Y/sub 0. 67/UO/sub 6/

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S; Seemann, I; Schittenhelm, H J [Tuebingen Univ. (F.R. Germany). Institut fuer Anorganische Chemie

1976-05-01

The ordered perovskite Ba/sub 2/CaUO/sub 6/ forms a solid solution series with Ba/sub 2/Gdsub(0.67)UO/sub 6/ and Ba/sub 2/Ysub(0.67)UO/sub 6/, respectively. The deviations from the ideal behaviour are studied by X-ray, diffuse reflectance and vibrational methods.

Perovskite phases in the systems AO-SE/sub 2/O/sub 3/-UO/sub 2,x/ with A=alkaline earth metal and SE=rare earths, La, and Y. IX. The systems Ba/sub 2/SrUO/sub 6/-Ba/sub 2/Gd/sub 0. 67/UO/sub 6/ and Ba/sub 2/SrUO/sub 6/-Ba/sub 2/Y/sub 0. 67/UO/sub 6/

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S; Seemann, I [Tuebingen Univ. (F.R. Germany). Inst. fuer Anorganische Chemie I

1976-07-01

The ordered perovskite Ba/sub 2/SrUO/sub 6/ forms a solid solution series with Ba/sub 2/Gdsub(0.67)UO/sub 6/ and Ba/sub 2/Ysub(0.67)UO/sub 6/ respectively. The deviations from the ideal behaviour are studied by X-ray, diffuse reflectance and vibrational methods.

Benzo(A)pyrene (BaP) treatment results in complete infertility in female pigeons

Energy Technology Data Exchange (ETDEWEB)

Hough, J.L.; Darrow, D.; Eaton, J.; Baird, M.B. (Masonic Medical Research Lab., Utica, NY (United States))

1991-03-11

BaP is a carcinogenic polycyclic aromatic hydrocarbon (PAH) and a common environmental pollutant. Show Racer and White Carneau female pigeons injected weekly with BaP for 3 for 5 months were completely infertile, with ovaries appearing necrotic or oxidized. Fertility in benzo(e)pyrene (BeP, a noncarcinogenic PAH) treated birds was the same as for corn oil treated controls, as was embryo development. Thus, infertility in BaP treated birds appears to be related to its structure-carcinogenic potential. There was no readily apparent affect of BaP treatment on testes from male birds. In order to determine whether BaP metabolites covalently bind to DNA in the ovaries of these birds, pigeons were injected with BaP or BeP, controls were injected with corn oil. Animals were sacrificed 24h later, the ovaries or testes removed, and the DNA isolated and analyzed for PAH-DNA adducts by {sup 32}P-post labeling assay. One major and one minor PAH-DNA adduct was found in ovaries and testes from BaP treated birds. However, no PAH adducts were found in BeP treated or control animals. Thus, problems with fertility may arise because of the alteration in DNA by BaP metabolite binding in ovaries where rapid cell growth occurs during egg production.

Isothermal cross-sections of Sr-Al-Ge and Ba-Al-Ge systems at 673 K

International Nuclear Information System (INIS)

Kutsenok, N.L.; Yanson, T.I.

1987-01-01

X-ray and microstructural analyses are used to study phase equilibria in Sr-Al-Ge and Ba-Al-Ge systems. Existence of SrAl 2 Ge 2 , Sr(Al, Ge) 2 Ba(Al, Ge) 2 , Sr 3 Al 2 Ge 2 , Ba 3 Al 2 Ge 2 ternary compounds is confirmed, a new BaGe 4 binary compound and also new ternary compounds of approximate composition Sr 57 Al 30 Ge 13 and Ba 20 Al 40 Ge 40 , which crystal structure is unknown, are detected. Aluminium solubility in SrAl 4 and BaAl 4 binary compounds (0.05 atomic fraction) is determined. Ba(Al, Ge) 2 compound homogeneity region is defined more exactly (aluminium content varies from 0.27 to 0.51 at. fractions)

Water adsorption induced in-plane domain switching on BaTiO{sub 3} surface

Energy Technology Data Exchange (ETDEWEB)

Li, X.; Bai, Y.; Su, Y. J., E-mail: yjsu@ustb.edu.cn [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), University of Science and Technology Beijing, Beijing 100083 (China); Wang, B. C. [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), University of Science and Technology Beijing, Beijing 100083 (China); Multiscale Materials Modelling group, Department of Materials and Engineering, Royal Institute of Technology, SE-10044 Stockholm (Sweden)

2015-09-07

In this study, the influences of the adsorption of water molecules on the changes in the atomic and electric structures of BaTiO{sub 3} surface were investigated using ab initio calculation. Water molecules are molecularly and dissociatively adsorbed on the BaTiO{sub 3} surface, which makes electrons transfer from water molecules to the BaTiO{sub 3} surface. The redistribution of electrons in the BaTiO{sub 3} surface layers weakens the Ba-O interactions and strengthens the Ti-O interactions, so that the Ti atom shifts in TiO{sub 2} plane, i.e., an in-plane domain switching. The adsorption of water molecules on BaTiO{sub 3} surfaces also results in a reduction in the surface rumpling.

Advances in enlargement of melt-textured Gd-Ba-Cu-O superconductors

International Nuclear Information System (INIS)

Nariki, S; Sakai, N; Kita, M; Fujikura, M; Murakami, M; Hirabayashi, I

2006-01-01

We investigated the fabrication of melt-textured Gd-Ba-Cu-O bulk superconductors with the employment of a Gd 2 BaO 4 (Gd210)-BaCuO 2 -CuO precursor. This enabled us to synthesize a very large Gd-Ba-Cu-O bulk superconductor, 140 mm in diameter. The trapped field distribution measured at 77 K revealed that the sample had no serious cracks, and the maximum field was 2.3 T. The formation behaviour and depressing mechanism of cracking were studied using sintered Gd210-containing precursors. The Ba-Cu-O component in the precursor melted at around 900 deg. C. The formation of such a liquid phase enhanced the densification of the precursor by liquid phase sintering. The mechanical strength of the sintered precursor was increased compared to the conventional Gd123-Gd211 precursor. This will be effective in preventing crack formation in the texturing process of large single-grain samples. The superconducting properties of the bulk sample fabricated from Gd210-containing precursor have been discussed

Rattling of Ba-atoms in Ba8ZnxGe43-5x/8([]3-3x/8)

International Nuclear Information System (INIS)

Melnychenko, N.; Grytsiv, A.; Rotter, M.; Rogl, P.; Devishvili, A.

2006-01-01

Full text: In order to improve the figure of merit of thermoelectric materials, one of the key parameters to be minimized is the lattice thermal conductivity. It is thus essential for the design of new thermoelectric materials to understand the lattice dynamics, especially the scattering mechanism of low energy phonons. The present paper describes formation, phase relations at subsolidus temperatures as well as at 800 o C, crystal chemistry and physical properties of a series of ternary clathrates as part of the solid solution, Ba 8 Zn x (Ge 43-5x/8[]3-3x/8 ), deriving from binary Ba 8 Ge 43 []3 with a solubility limit of 8 Zn per formula unit at 800 o C. Structural investigations in all cases confirm cubic primitive symmetry with a lattice parameter a ∼ 1.1 nm consistent with the space group type Pm-3n. Studies of transport coefficients evidence electrons as the majority charge carriers in the systems. Thermal conductivity exhibits a pronounced low temperature maximum, dominated by the lattice contribution, while at higher temperatures the electronic part gains weight. Inelastic neutron scattering experiments are used to study the phonon spectrum for Ba 8 Zn 8 Ge 38 . (author)

Carbon-14 immobilization via the CO2-Ba(OH)2 hydrate gas-solid reaction

International Nuclear Information System (INIS)

Haag, G.L.

1981-08-01

For the treatment of an air-based off-gas stream, the use of packed beds of Ba(OH) 2 .8H 2 O flakes to remove CO 2 has been demonstrated. However, the operating conditions must be maintained between certain upper and lower limits with respect to the partial pressure of water. If the water vapor pressure in the gas is less than the dissociation vapor pressure of Ba(OH) 2 .8H 2 O, the bed will deactivate. If the vapor pressure is considerably greater, pressure drop problems will increase with increaseing humidity as the particles curl and degrade. Results have indicted that when operated in the proper regime, the bulk of the increase in pressure drop results from the conversion of Ba(OH) 2 .8H 2 O to BaCO 3 and not from the hydration of the commercial Ba(OH) 2 .8H 2 O (i.e., Ba(OH) 2 .7.50H 2 O) to Ba(OH) 2 .8H 2 O

The BaBar electromagnetic calorimeter

CERN Document Server

Lewandowski, B

2002-01-01

The BaBar electromagnetic calorimeter is a hermetic, total-absorption array of CsI(Tl)-crystals, operated at the asymmetric e sup - e sup + -collider PEP-II at SLAC. The design and the status of the performance as of February 2002 is presented.

Machining of Machine Elements Made of Polymer Composite Materials

Science.gov (United States)

Baurova, N. I.; Makarov, K. A.

2017-12-01

The machining of the machine elements that are made of polymer composite materials (PCMs) or are repaired using them is considered. Turning, milling, and drilling are shown to be most widely used among all methods of cutting PCMs. Cutting conditions for the machining of PCMs are presented. The factors that most strongly affect the roughness parameters and the accuracy of cutting PCMs are considered.

Phase formation, structural and microstructural characterization of novel oxynitride-perovskites synthesized by thermal ammonolysis of (Ca,Ba)MoO4 and (Ca,Ba)MoO3

International Nuclear Information System (INIS)

Logvinovich, D.; Aguirre, M.H.; Hejtmanek, J.; Aguiar, R.; Ebbinghaus, S.G.; Reller, A.; Weidenkaff, A.

2008-01-01

Reactions of AMoO 4 and AMoO 3 (A=Ca 2+ , Ba 2+ ) with ammonia were investigated at 873 K 3 and to study their crystal structure. CaMo(O,N) 3 and BaMo(O,N) 3 were prepared by thermal ammonolysis of the corresponding CaMoO 3 and BaMoO 3 precursors at T=898 and 998 K, respectively. The structural parameters of the oxynitrides were obtained from Rietveld refinements of X-ray and neutron powder diffraction data. CaMo(O,N) 3 crystallizes in the GdFeO 3 distorted perovskite structure with orthorhombic space group Pbnm and a=5.5029(1) A, b=5.5546(1) A, c=7.8248(1) A as determined by X-ray powder diffraction. Its O/N content refined from the neutron diffraction data corresponds to the composition CaMoO 1.7(1) N 1.3(1) . BaMo(O,N) 3 crystallizes in the cubic perovskite structure with space group Pm3-bar m and a=4.0657(1) A as determined by X-ray powder diffraction. Transmission electron microscopy reveals a complex microstructure for both CaMoO 3 and CaMoO 1.7(1) N 1.3(1) represented by twin domains of different orientation. - Graphical abstract: Reactions of AMoO 4 and AMoO 3 (A=Ca 2+ , Ba 2+ ) oxides with ammonia have been studied at T=873-1123 K. Orthorhombic CaMoO 1.7(1) N 1.3(1) (Pbnm) and cubic BaMo(O,N) 3 (Pm3-bar m) were prepared by thermal ammonolysis of the corresponding CaMoO 3 and BaMoO 3 precursors at T=898 and 998 K, respectively. Display Omitted

Evolution of deformation in neutron-rich Ba isotopes up to A =150

Science.gov (United States)

Licǎ, R.; Benzoni, G.; Rodríguez, T. R.; Borge, M. J. G.; Fraile, L. M.; Mach, H.; Morales, A. I.; Madurga, M.; Sotty, C. O.; Vedia, V.; De Witte, H.; Benito, J.; Bernard, R. N.; Berry, T.; Bracco, A.; Camera, F.; Ceruti, S.; Charviakova, V.; Cieplicka-Oryńczak, N.; Costache, C.; Crespi, F. C. L.; Creswell, J.; Fernandez-Martínez, G.; Fynbo, H.; Greenlees, P. T.; Homm, I.; Huyse, M.; Jolie, J.; Karayonchev, V.; Köster, U.; Konki, J.; Kröll, T.; Kurcewicz, J.; Kurtukian-Nieto, T.; Lazarus, I.; Lund, M. V.; Mǎrginean, N.; Mǎrginean, R.; Mihai, C.; Mihai, R. E.; Negret, A.; Orduz, A.; Patyk, Z.; Pascu, S.; Pucknell, V.; Rahkila, P.; Rapisarda, E.; Regis, J. M.; Robledo, L. M.; Rotaru, F.; Saed-Samii, N.; Sánchez-Tembleque, V.; Stanoiu, M.; Tengblad, O.; Thuerauf, M.; Turturica, A.; Van Duppen, P.; Warr, N.; IDS Collaboration

2018-02-01

The occurrence of octupolar shapes in the Ba isotopic chain was recently established experimentally up to N =90 . To further extend the systematics, the evolution of shapes in the most neutron-rich members of the Z =56 isotopic chain accessible at present, Ba,150148, has been studied via β decay at the ISOLDE Decay Station. This paper reports on the first measurement of the positive- and negative-parity low-spin excited states of 150Ba and presents an extension of the β -decay scheme of 148Cs. Employing the fast timing technique, half-lives for the 21+ level in both nuclei have been determined, resulting in T1 /2=1.51 (1 ) ns for 148Ba and T1 /2=3.4 (2 ) ns for 150Ba. The systematics of low-spin states, together with the experimental determination of the B (E 2 :2+→0+) transition probabilities, indicate an increasing collectivity in Ba-150148, towards prolate deformed shapes. The experimental data are compared to symmetry conserving configuration mixing (SCCM) calculations, confirming an evolution of increasingly quadrupole deformed shapes with a definite octupolar character.

Stability of Tl-Ba-Ca-Cu-O superconducting thin films

Energy Technology Data Exchange (ETDEWEB)

Siegal, M. P. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Overmyer, D. L. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Venturini, E. L. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Padilla, R. R. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Provencio, P. N. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States)

1999-12-01

We report the stability of TlBa{sub 2}CaCu{sub 2}O{sub 7} and Tl{sub 2}Ba{sub 2}CaCu{sub 2}O{sub 8} on LaAlO{sub 3}(100) epitaxial thin films, under a variety of conditions. All films are stable in acetone and methanol and with repeated thermal cycling to cryogenic temperatures. Moisture, especially vapor, degrades film quality rapidly. These materials are stable to high temperatures in either N{sub 2} or O{sub 2} ambients. While total degradation, resulting from Tl depletion, occurs at the same temperatures for both phases, 600 degree sign C in N{sub 2} and 700 degree sign C in O{sub 2}, the onset of degradation occurs at somewhat lower temperatures for TlBa{sub 2}CaCu{sub 2}O{sub 7} than for Tl{sub 2}Ba{sub 2}CaCu{sub 2}O{sub 8}. (c) 1999 Materials Research Society.

Surface structures and dielectric response of ultrafine BaTiO3 particles

International Nuclear Information System (INIS)

Jiang, B.; Peng, J.L.; Bursill, L.A.

1998-01-01

Characteristic differences are observed for the dielectric response and microstructures of BaTiO 3 nanoscale fine powders prepared using sol gel (SG) and steric acid gel (SAG) methods. The former exhibit a critical size below which there is no paraelectric/ferroelectric phase transition whereas BaTiO 3 prepared via the SAG route remained cubic for all conditions. Atomic resolution images of both varieties showed a high density of interesting surface steps and facets. Computer simulated images of surface structure models showed that the outer (100) surface was typically a BaO layer and that at corners and ledges the steps are typically finished with Ba+2 ions; i.e. the surfaces and steps are Ba-rich. Otherwise the surfaces were typically clean and free of amorphous layers. The relationship between the observed surfaces structures and theoretical models for size effects on the dielectric properties is discussed. (authors)

Identification of the neutron-rich nuclides /sup 147; 148/Ba and half- life determination of the heavy isotopes of Rb, Sr, Y, Cs, Ba and La

CERN Document Server

Amiel, S; Nir-El, Y; Shmid, M

1976-01-01

The neutron nuclides /sup 147; 148/Ba were produced in the thermal neutron induced fission of /sup 235/U. A new surface ionization integrated target ion source operating at temperatures in the region of 1800 degrees C permits the measurement of half-lives of isotopes down to about 0.1 sec due to the very fast release of atoms from the target. Isotopes of Rb, Sr, Cs, and Ba were separated by positive surface ionization and their half-lives measured using beta activity detected by a silicon surface barrier detector with a depletion depth of 300 mu . The isotopes /sup 147/Ba and /sup 148/Ba were identified for the first time and their half-lives were found to be 0.72+or-0.07 sec and 0.47+or-0.20 sec, respectively. (0 refs).

Bifunctional properties of hydrothermal synthesized BaMF4 (M = Co, Ni and Zn

Directory of Open Access Journals (Sweden)

Farheen N. Sayed

2013-07-01

Full Text Available BaMF4 (M = Co, Ni and Zn samples having orthorhombic structure have been synthesized by a mild hydrothermal method and characterized by x-ray diffraction (XRD, magnetic and electrical measurements. Single phase formation of these compounds has been found to be dependent on various factors like reaction time, pH, temperature etc. All the samples showed ferroelectricity, which decreases with increase in temperature. BaMF4 (M = Co, Ni samples show 10-15 times more leakage current compared to that of BaZnF4 at higher applied field. Absence of multivalent ions in BaZnF4 can be the reason for its minimum leakage current. All the samples except, BaZnF4, exhibit weak room temperature ferromagnetism also.

Estimation of the specific mass effect in the isotope shifts of energy levels in the optical spectrum of Ba I and Ba II

International Nuclear Information System (INIS)

Pendrill, L.R.

1984-01-01

A graphical method for separating mass and volume effects from purely optical isotope shift data is presented and compared with King's ''bunching'' method. Recent experimental data on isotope shifts for a wide range of spectral lines in the naturally abundant isotopes of Ba I and Ba II are analysed. Some agreement is found with muonic X-ray data concerning the nuclear size for the isotopes 136, 137 and 138, but there is disagreement (over 20%) for the other isotopes. The level isotope shifts are further parameterised in terms of a linear model, and the specific mass effect is decomposed into sums of one-electron and two-electron shift parameters with respect to the inert-gas like ground state of Ba III. (orig.)

Improving Machining Accuracy of CNC Machines with Innovative Design Methods

Science.gov (United States)

Yemelyanov, N. V.; Yemelyanova, I. V.; Zubenko, V. L.

2018-03-01

The article considers achieving the machining accuracy of CNC machines by applying innovative methods in modelling and design of machining systems, drives and machine processes. The topological method of analysis involves visualizing the system as matrices of block graphs with a varying degree of detail between the upper and lower hierarchy levels. This approach combines the advantages of graph theory and the efficiency of decomposition methods, it also has visual clarity, which is inherent in both topological models and structural matrices, as well as the resiliency of linear algebra as part of the matrix-based research. The focus of the study is on the design of automated machine workstations, systems, machines and units, which can be broken into interrelated parts and presented as algebraic, topological and set-theoretical models. Every model can be transformed into a model of another type, and, as a result, can be interpreted as a system of linear and non-linear equations which solutions determine the system parameters. This paper analyses the dynamic parameters of the 1716PF4 machine at the stages of design and exploitation. Having researched the impact of the system dynamics on the component quality, the authors have developed a range of practical recommendations which have enabled one to reduce considerably the amplitude of relative motion, exclude some resonance zones within the spindle speed range of 0...6000 min-1 and improve machining accuracy.

Machinability of nickel based alloys using electrical discharge machining process

Science.gov (United States)

Khan, M. Adam; Gokul, A. K.; Bharani Dharan, M. P.; Jeevakarthikeyan, R. V. S.; Uthayakumar, M.; Thirumalai Kumaran, S.; Duraiselvam, M.

2018-04-01

The high temperature materials such as nickel based alloys and austenitic steel are frequently used for manufacturing critical aero engine turbine components. Literature on conventional and unconventional machining of steel materials is abundant over the past three decades. However the machining studies on superalloy is still a challenging task due to its inherent property and quality. Thus this material is difficult to be cut in conventional processes. Study on unconventional machining process for nickel alloys is focused in this proposed research. Inconel718 and Monel 400 are the two different candidate materials used for electrical discharge machining (EDM) process. Investigation is to prepare a blind hole using copper electrode of 6mm diameter. Electrical parameters are varied to produce plasma spark for diffusion process and machining time is made constant to calculate the experimental results of both the material. Influence of process parameters on tool wear mechanism and material removal are considered from the proposed experimental design. While machining the tool has prone to discharge more materials due to production of high energy plasma spark and eddy current effect. The surface morphology of the machined surface were observed with high resolution FE SEM. Fused electrode found to be a spherical structure over the machined surface as clumps. Surface roughness were also measured with surface profile using profilometer. It is confirmed that there is no deviation and precise roundness of drilling is maintained.

The achievements of the Z-machine; Les exploits de la Z-machine

Energy Technology Data Exchange (ETDEWEB)

Larousserie, D

2008-03-15

The ZR-machine that represents the latest generation of Z-pinch machines has recently begun preliminary testing before its full commissioning in Albuquerque (Usa). During its test the machine has well operated with electrical currents whose intensities of 26 million Ampere are already 2 times as high as the intensity of the operating current of the previous Z-machine. In 2006 the Z-machine reached temperatures of 2 billions Kelvin while 100 million Kelvin would be sufficient to ignite thermonuclear fusion. In fact the concept of Z-pinch machines was imagined in the fifties but the technological breakthrough that has allowed this recent success and the reborn of Z-machine, was the replacement of gas by an array of metal wires through which the electrical current flows and vaporizes it creating an imploding plasma. It is not well understood why Z-pinch machines generate far more radiation than theoretically expected. (A.C.)

Quantum machine learning.

Science.gov (United States)

Biamonte, Jacob; Wittek, Peter; Pancotti, Nicola; Rebentrost, Patrick; Wiebe, Nathan; Lloyd, Seth

2017-09-13

Fuelled by increasing computer power and algorithmic advances, machine learning techniques have become powerful tools for finding patterns in data. Quantum systems produce atypical patterns that classical systems are thought not to produce efficiently, so it is reasonable to postulate that quantum computers may outperform classical computers on machine learning tasks. The field of quantum machine learning explores how to devise and implement quantum software that could enable machine learning that is faster than that of classical computers. Recent work has produced quantum algorithms that could act as the building blocks of machine learning programs, but the hardware and software challenges are still considerable.

Intertextuality in Ba's So Long a Letter and Umunnakwe's Dear ...

African Journals Online (AJOL)

Intertextuality takes for granted the interdependence of literary texts because every artistic creation is a re-echoing of past knowledge. Mariama Ba's So Long A Letter and Ndubisi Umunnakwe's Dear Ramatoulaye are African examples. This work examines how Ba's So Long A Letter intertextualises with Umunnakwe's Dear ...

A Dubious Distinction? The BA versus the BS in Psychology

Science.gov (United States)

Pfund, Rory A.; Norcross, John C.; Hailstorks, Robin; Aiken, Leona S.; Stamm, Karen E.; Christidis, Peggy

2016-01-01

Previous studies have documented small differences between the bachelor of arts (BA) and the bachelor of science (BS) psychology degrees in their general education core requirements, particularly mathematics and science courses. But are there differences between the BA and BS degrees within the psychology curriculum? Using data from the…

modified BiFeO3–BaTiO3

Indian Academy of Sciences (India)

based perovskite structures lead- free BiFeO3–BaTiO3 solid solutions are popularly studied due to the high Curie temperature (TC). It was reported that the BiFeO3–BaTiO3 system possessed high piezoelectric. ∗. Author for correspondence ...

CeF3(Ba) radiation hard scintillator for electromagnetic calorimeters

International Nuclear Information System (INIS)

Aseev, A.A.; Devitsin, E.G.; Kozlov, V.A.; Hovepyan, Yu.I.; Potashov, S.Yu.; Sokolovsky, K.A.; Uvarova, T.V.; Vasilchenko, V.G.

1992-01-01

The influence of divalent fluoride dopants BaF 2 , CaF 2 , SrF 2 on radiation and luminescent properties of CeF 3 crystal is studied. A high radiation hardness (>10 8 rad) has been obtained for CeF 3 crystals doped with BaF 2 . (orig.)

Electrodeposition of BaCO3 coatings on stainless steel substrates ...

Indian Academy of Sciences (India)

Administrator

Dedicated to the memory of the late Professor S K Rangarajan. *For correspondence. Electrodeposition of BaCO3 coatings on stainless steel substrates: Oriented growth ... orientation by an interfacial molecular recognition mechanism. BaCO3 has important applications in paint, ceramic, and paper industries. Also it is used ...

Machine protection systems

CERN Document Server

Macpherson, A L

2010-01-01

A summary of the Machine Protection System of the LHC is given, with particular attention given to the outstanding issues to be addressed, rather than the successes of the machine protection system from the 2009 run. In particular, the issues of Safe Machine Parameter system, collimation and beam cleaning, the beam dump system and abort gap cleaning, injection and dump protection, and the overall machine protection program for the upcoming run are summarised.

Beyond survival: fostering growth and innovation in doctoral study--a concept analysis of the Ba space.

Science.gov (United States)

Krahe, J A E; Lalley, Cathy; Solomons, Nan M

2014-01-25

This concept analysis examines the Ba space in the context of interdisciplinary doctoral study in nursing and healthcare innovation in a minimal residency program. The authors identified Ba in their small, highly diverse, self-selected doctoral study group and believe Ba is an educational innovation that will prove useful to nursing and healthcare educators. Ba originates from Japanese philosophy and is foundational to the birth and sustainment of environments fostering knowledge creation. Ba manifests in complex environments where participants are emotionally invested and relies on the tacit knowledge of each participant, allowing for synthesis of rationality and intuition. Walker and Avant's concept analysis methodology will explore Ba's centrality to interdisciplinary education. Ba's utility and application in fostering innovation in doctoral study will be illustrated. Ba is a true educational innovation, enriching learning environments promoting interdisciplinary collaboration. Ba permits each member a voice and fosters a safe environment where relationships are created and sustained.

Superconductivity in gallium-substituted Ba8Si46 clathrates

Science.gov (United States)

Li, Yang; Zhang, Ruihong; Liu, Yang; Chen, Ning; Luo, Z. P.; Ma, Xingqiao; Cao, Guohui; Feng, Z. S.; Hu, Chia-Ren; Ross, Joseph H., Jr.

2007-02-01

We report a joint experimental and theoretical investigation of superconductivity in Ga-substituted type-I silicon clathrates. We prepared samples of the general formula Ba8Si46-xGax , with different values of x . We show that Ba8Si40Ga6 is a bulk superconductor, with an onset at TC≈3.3K . For x=10 and higher, no superconductivity was observed down to T=1.8K . This represents a strong suppression of superconductivity with increasing Ga content, compared to Ba8Si46 with TC≈8K . Suppression of superconductivity can be attributed primarily to a decrease in the density of states at the Fermi level, caused by a reduced integrity of the sp3 -hybridized networks as well as the lowering of carrier concentration. These results are corroborated by first-principles calculations, which show that Ga substitution results in a large decrease of the electronic density of states at the Fermi level, which explains the decreased superconducting critical temperature within the BCS framework. To further characterize the superconducting state, we carried out magnetic measurements showing Ba8Si40Ga6 to be a type-II superconductor. The critical magnetic fields were measured to be HC1≈35Oe and HC2≈8.5kOe . We deduce the London penetration depth λ≈3700Å and the coherence length ξc≈200Å . Our estimate of the electron-phonon coupling reveals that Ba8Si40Ga6 is a moderate phonon-mediated BCS superconductor.

BaMa / Raivo Juurak

Index Scriptorium Estoniae

Juurak, Raivo, 1949-

2002-01-01

Eesti ülikoolide üleminekust 3+2 süsteemile. Lühend BaMa on tulnud kasutusele seoses Euroopa ülikoolide õppekavade reformimisega ning tähistab õppekava, kus esimese astme läbimise järel omandatakse bakalaureuse- ja teise järel magistrikraad. Õppekavade tüüpidest Eesti ja Euroopa Liidu kõrgkoolides ning Bologna deklaratsioonist

Hexagonal perovskites with cationic vacancies. 21. Structure of Ba/sub 4/Nb/sub 2/WvacantO/sub 12/ and Ba/sub 3/LaNb/sub 3/vacantO/sub 12/

Energy Technology Data Exchange (ETDEWEB)

Rother, H J; Kemmler-Sack, S; Treiber, U; Cyris, W R [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1980-07-01

Compounds of type Ba/sub 4/M/sub 2/sup(V)WvacantO/sub 12/ and Ba/sub 3/LaM/sub 3/sup(V)vacantO/sub 12/ with Msup(V) = Nb, Ta belong to the group of rhombohedral 12 L stacking polytypes (space group R-3m, sequence (hhcc)/sub 3/). The structure determinations on powder patterns for the Nb compounds gave a refined, intensity related R' value of 6.3% (Ba/sub 4/Nb/sub 2/WvacantO/sub 12/) and 6.6% (Ba/sub 3/LaNb/sub 3/vacantO/sub 12/). The octahedral net consists of blocks of three face connected octahedra with a central void (M/sub 2/vacantO/sub 12/ unit), which are linked to each other through single corner sharing octahedra. In both compounds the M atoms in the M/sub 2/vacantO/sub 12/ groups are displaced in the direction of the central void. The A atoms move in the same direction but the dislocation for A in the hexagonal packed sheets (neighbouring the vacancies) is stronger than in the cubic packed AO/sub 3/ sheets. The results of the vibrational spectroscopic investigations are reported for Ba/sub 4/Nb/sub 2/WvacantO/sub 12/, Ba/sub 4/Ta/sub 2/WvacantO/sub 12/, Ba/sub 3/LaNb/sub 3/vacantO/sub 12/ and Ba/sub 4/CeW/sub 2/vacantO/sub 12/; they are discussed in connection with the factor group analysis.

Preliminary Test of Upgraded Conventional Milling Machine into PC Based CNC Milling Machine

International Nuclear Information System (INIS)

Abdul Hafid

2008-01-01

CNC (Computerized Numerical Control) milling machine yields a challenge to make an innovation in the field of machining. With an action job is machining quality equivalent to CNC milling machine, the conventional milling machine ability was improved to be based on PC CNC milling machine. Mechanically and instrumentally change. As a control replacing was conducted by servo drive and proximity were used. Computer programme was constructed to give instruction into milling machine. The program structure of consists GUI model and ladder diagram. Program was put on programming systems called RTX software. The result of up-grade is computer programming and CNC instruction job. The result was beginning step and it will be continued in next time. With upgrading ability milling machine becomes user can be done safe and optimal from accident risk. By improving performance of milling machine, the user will be more working optimal and safely against accident risk. (author)

Adsorption removal of Sr by Barium impregnated 4A Zeolite(BaA) from high radioactive seawater waste

Energy Technology Data Exchange (ETDEWEB)

Lee, Eil Hee; Lee, Keun Young; Kim, Kwang Wook; Kim, Ik Soo; Chung, Dong Yong; Moon, Jei Kwon; Choi, Jong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-06-15

This study investigated the removal of Sr, which was one of the high radioactive nuclides, by adsorption with Barium (Ba) impregnated 4A zeolite (BaA) from high-radioactive seawater waste (HSW). Adsorption of Sr by BaA (BaA-Sr), in the impregnated Ba concentration of above 20.2wt%, was decreased by increasing the impregnated Ba concentration, and the impregnated Ba concentration was suitable at 20.2wt%. The BaA-Sr adsorption was added to the co-precipitation of Sr with BaSO4 precipitation in the adsorption of Sr by 4A (4A-Sr) within BaA. Thus, it was possible to remove Sr more than 99% at m/V (adsorbent weight/solution volume)=5 g/L for BaA and m/V >20 g/L for 4A, respectively, in the Sr concentration of less than 0.2 mg/L (actual concentration level of Sr in HSW). It shows that BaA-Sr adsorption is better than 4A-Sr adsorption in for the removal capacity of Sr per unit gram of adsorbent, and the reduction of the secondary solid waste generation (spent adsorbent etc.). Also, BaA-Sr adsorption was more excellent removal capacity of Sr in the seawater waste than distilled water. Therefore, it seems to be effective for the direct removal of Sr from HSW. On the other hand, the adsorption of Cs by BaA (BaA-Cs) was mainly performed by 4A within BaA. Accordingly, it seems to be little effect of impregnated Ba into BaA. Meanwhile, BaA-Sr adsorption kinetics could be expressed the pseudosecond order rate equation. By increasing the initial Sr concentrations and the ratios of V/m, the adsorption rate constants (k2) were decreased, but the equilibrium adsorption capacities (qe) were increasing. However, with increasing the temperature of solution, k2 was conversely increased, and qe was decreased. The activation energy of BaA-Sr adsorption was 38 kJ/mol. Thus, the chemical adsorption seems to be dominant rather than physical adsorption, although it is not a chemisorption with strong bonding form.

Stellar neutron capture cross sections of the Ba isotopes

International Nuclear Information System (INIS)

Voss, F.; Wisshak, K.; Guber, K.; Kaeppeler, F.; Reffo, G.

1994-03-01

The neutron capture cross sections of 134 Ba, 135 Ba, 136 Ba, and 137 Ba were measured in the energy range from 5 to 225 keV at the Karlsruhe 3.75 MV Van de Graaff accelerator. Neutrons were produced via the 7 Li(p,n) 7 Be reaction by bombarding metallic Li targets with a pulsed proton beam. Capture events were registered with the Karlsruhe 4π Barium Fluoride Detector. Several runs have been performed under different experimental conditions to study the systematic uncertainties, which resulted mainly from the large ratios of total to capture cross sections of up to 400. The cross section ratios were determined with an overall uncertainty of ∼3%, an improvement by factors of five to eight compared to existing data. Severe discrepancies were found with respect to previous results. Maxwellian averaged neutron capture cross sections were calculated for thermal energies between kT=10 keV and 100 keV. These stellar cross sections were used in an s-process analysis. For the s-only isotopes 134 Ba and 136 Ba the N s ratio was determined to 0.875±0.025. Hence, a significant branching of the s-process path at 134 Cs can be claimed for the first time, in contrast to predictions from the classical approach. This branching yields information on the s-process temperature, indicating values around T 8 =2. The new cross sections are also important for the interpretation of barium isotopic anomalies, which were recently discovered in SiC grains of carbonaceous chondrite meteorites. Together with the results from previous experiments on tellurium and samarium, a general improvement of the N s systematics in the mass range A=120 to 150 is achieved. This allows for a more reliable separation of s- and r-process yields, resulting in an improved assignment of the respective contributions to elemental barium that is required for comparison with stellar observations. (orig.) [de

BaFCl:Eu2+, a new phosphor for X-ray-intensifying screens

International Nuclear Information System (INIS)

Stevels, A.L.N.; Pingault, F.

1975-01-01

A number of phosphors for X-ray-intensifying screens have been evaluated by calculating figures of merit. On use in combination with standard (''blue''-sensitive) X-ray film, BaFCl:Eu 2+ and BaFBr:Eu 2+ give better performance than the traditional CaWO 4 and more recently developed UV or blue-emitting materials (e.g., sulphates and y-oxysulphides). The calculated figures of merit of BaFCl:Eu 2+ or BaFBr:Eu 2+ /standard-film combinations are comparable to those of Gd 2 O 2 S:Tb/green-sensitive X-ray film systems. The preparation of optimal fluorohalide:Eu 2+ phosphors involves proper formation of the host lattice, complete reduction of Eu 3+ ions as well as elimination of afterglow. Measurements on powders and experimental screens indicate that by using BaFCl:Eu 2+ screens in radiography, important dose reductions can be achieved without the necessity of using other than standard (''blue''-sensitive) X-ray films

Rapid preparation of ultrafine BaSO{sub 3} by SO{sub 2} storage material

Energy Technology Data Exchange (ETDEWEB)

Zhang, Fei; Sha, Feng; Qiao, Xian Shu; Zhao, Tian Xiang; Guo, Bo; Zhang, Jian Bin [College of Chemical Engineering, Inner Mongolia University of Technology, Huhhot (Korea, Republic of)

2017-01-15

In this work, a green and efficient process was developed for the preparation of ultrafine BaSO{sub 3} with layered nanostructure surface via the reaction of BaCl{sub 2} with a SO{sub 2} storage material (SO{sub 2}SM) at room temperature. The absorption of SO{sub 2} with equimolar ethylenediamine (EDA) and ethylene glycol (EG) afforded SO{sub 2}SM, which not only offered alkyl sulfite but also released EDA and EG that served as efficient surfactants to promote the formation of BaSO{sub 3} with spherical morphology and porous structure in the process of synthesis of ultrafine BaSO{sub 3}. The factors affecting the morphology and size of BaSO{sub 3} particle were assessed by investigating the effects of SO{sub 2}SM concentration, BaCl{sub 2} concentration, stirring time and speed. It was found that a higher SO{sub 2}SM concentration led to a higher degree of supersaturation, and the particle size of BaSO{sub 3} could be reduced by increasing SO{sub 2}SM concentration. Moreover, under the identified optimal reaction conditions, ultrafine BaSO{sub 3} was obtained with an average diameter of 450 nm. In addition, a plausible formation process of BaSO{sub 3} was proposed to explain the observed reaction results. Overall, the developed process in this work provides an efficient method for the capture, utilization, and conversion of SO{sub 2} into a valuable chemical.

Study of on-machine error identification and compensation methods for micro machine tools

International Nuclear Information System (INIS)

Wang, Shih-Ming; Yu, Han-Jen; Lee, Chun-Yi; Chiu, Hung-Sheng

2016-01-01

Micro machining plays an important role in the manufacturing of miniature products which are made of various materials with complex 3D shapes and tight machining tolerance. To further improve the accuracy of a micro machining process without increasing the manufacturing cost of a micro machine tool, an effective machining error measurement method and a software-based compensation method are essential. To avoid introducing additional errors caused by the re-installment of the workpiece, the measurement and compensation method should be on-machine conducted. In addition, because the contour of a miniature workpiece machined with a micro machining process is very tiny, the measurement method should be non-contact. By integrating the image re-constructive method, camera pixel correction, coordinate transformation, the error identification algorithm, and trajectory auto-correction method, a vision-based error measurement and compensation method that can on-machine inspect the micro machining errors and automatically generate an error-corrected numerical control (NC) program for error compensation was developed in this study. With the use of the Canny edge detection algorithm and camera pixel calibration, the edges of the contour of a machined workpiece were identified and used to re-construct the actual contour of the work piece. The actual contour was then mapped to the theoretical contour to identify the actual cutting points and compute the machining errors. With the use of a moving matching window and calculation of the similarity between the actual and theoretical contour, the errors between the actual cutting points and theoretical cutting points were calculated and used to correct the NC program. With the use of the error-corrected NC program, the accuracy of a micro machining process can be effectively improved. To prove the feasibility and effectiveness of the proposed methods, micro-milling experiments on a micro machine tool were conducted, and the results

Synthesis of BaTiO3 powder from barium titanyl oxalate (BTO ...

Indian Academy of Sciences (India)

Unknown

the synthesis of BaTiO3 from the mixture of barium car- bonate and titanium dioxide employing microwave heat- ing. They observed that hypostoichiometric TiO2 (TiO2–x) reacted with BaCO3 in the presence of microwave field at temperature as low as 350°C to give the mixture of hexa- gonal and tetragonal forms of BaTiO3 ...

National Machine Guarding Program: Part 1. Machine safeguarding practices in small metal fabrication businesses.

Science.gov (United States)

Parker, David L; Yamin, Samuel C; Brosseau, Lisa M; Xi, Min; Gordon, Robert; Most, Ivan G; Stanley, Rodney

2015-11-01

Metal fabrication workers experience high rates of traumatic occupational injuries. Machine operators in particular face high risks, often stemming from the absence or improper use of machine safeguarding or the failure to implement lockout procedures. The National Machine Guarding Program (NMGP) was a translational research initiative implemented in conjunction with two workers' compensation insures. Insurance safety consultants trained in machine guarding used standardized checklists to conduct a baseline inspection of machine-related hazards in 221 business. Safeguards at the point of operation were missing or inadequate on 33% of machines. Safeguards for other mechanical hazards were missing on 28% of machines. Older machines were both widely used and less likely than newer machines to be properly guarded. Lockout/tagout procedures were posted at only 9% of machine workstations. The NMGP demonstrates a need for improvement in many aspects of machine safety and lockout in small metal fabrication businesses. © 2015 The Authors. American Journal of Industrial Medicine published by Wiley Periodicals, Inc.

Non-conventional electrical machines

CERN Document Server

Rezzoug, Abderrezak

2013-01-01

The developments of electrical machines are due to the convergence of material progress, improved calculation tools, and new feeding sources. Among the many recent machines, the authors have chosen, in this first book, to relate the progress in slow speed machines, high speed machines, and superconducting machines. The first part of the book is dedicated to materials and an overview of magnetism, mechanic, and heat transfer.

Self-Organized Ni Nanocrystal Embedded in BaTiO3 Epitaxial Film

Directory of Open Access Journals (Sweden)

Ge FF

2010-01-01

Full Text Available Abstract Ni nanocrystals (NCs were embedded in BaTiO3 epitaxial films using the laser molecular beam epitaxy. The processes involving the self-organization of Ni NCs and the epitaxial growth of BaTiO3 were discussed. With the in situ monitoring of reflection high-energy electron diffraction, the nanocomposite films were engineered controllably by the fine alternation of the self-organization of Ni NCs and the epitaxial growth of BaTiO3. The transmission electron microscopy and the X-ray diffraction characterization confirmed that the composite film consists of the Ni NCs layers alternating with the (001/(100-oriented epitaxial BaTiO3 separation layers.

submitter Performance simulation of BaBar DIRC bar boxes in TORCH

CERN Document Server

Föhl, K; Castillo García, L; Cussans, D; Forty, R; Frei, C; Gao, R; Gys, T; Harnew, N; Piedigrossi, D; Rademacker, J; Ros García, A; van Dijk, M

2017-01-01

TORCH is a large-area precision time-of-flight detector based on the DIRC principle. The DIRC bar boxes of the BaBar experiment at SLAC could possibly be reused to form a part of the TORCH detector time-of-flight wall area, proposed to provide positive particle identification of low momentum kaons in the LHCb experiment at CERN. For a potential integration of BaBar bar boxes into TORCH, new imaging readout optics are required. From the several designs of readout optics that have been considered, two are used in this paper to study the effect of BaBar bar optical imperfections on the detector reconstruction performance. The kaon-pion separation powers obtained from analysing simulated photon hit patterns show the performance reduction for a BaBar bar of non-square geometry compared to a perfectly rectangular cross section.

Melatonin ve Bağışıklık Sistemi

OpenAIRE

ÇETİN, E.

2005-01-01

Melatonin, pineal bezin beta adrenerjik reseptörlerinin aktivasyonu ile triptofandan sentezlenen bir hormondur.Üretim ve salınımı karanlık ile başlar ve aydınlıkla sona erer. Melatonin, birçok biyolojik fonksiyonun düzenlenmesinderol oynar. Bu derlemede melatonin hakkında genel bilgiler verilerek, melatoninin lenfoid dokular, humoral bağışıklık,hücresel bağışıklık ve kanser üzerine etkileri tartışılmıştır

Advanced Machine learning Algorithm Application for Rotating Machine Health Monitoring

Energy Technology Data Exchange (ETDEWEB)

Kanemoto, Shigeru; Watanabe, Masaya [The University of Aizu, Aizuwakamatsu (Japan); Yusa, Noritaka [Tohoku University, Sendai (Japan)

2014-08-15

The present paper tries to evaluate the applicability of conventional sound analysis techniques and modern machine learning algorithms to rotating machine health monitoring. These techniques include support vector machine, deep leaning neural network, etc. The inner ring defect and misalignment anomaly sound data measured by a rotating machine mockup test facility are used to verify the above various kinds of algorithms. Although we cannot find remarkable difference of anomaly discrimination performance, some methods give us the very interesting eigen patterns corresponding to normal and abnormal states. These results will be useful for future more sensitive and robust anomaly monitoring technology.

Advanced Machine learning Algorithm Application for Rotating Machine Health Monitoring

International Nuclear Information System (INIS)

Kanemoto, Shigeru; Watanabe, Masaya; Yusa, Noritaka

2014-01-01

The present paper tries to evaluate the applicability of conventional sound analysis techniques and modern machine learning algorithms to rotating machine health monitoring. These techniques include support vector machine, deep leaning neural network, etc. The inner ring defect and misalignment anomaly sound data measured by a rotating machine mockup test facility are used to verify the above various kinds of algorithms. Although we cannot find remarkable difference of anomaly discrimination performance, some methods give us the very interesting eigen patterns corresponding to normal and abnormal states. These results will be useful for future more sensitive and robust anomaly monitoring technology

Phase equilibria, crystal chemistry, electronic structure and physical properties of Ag-Ba-Ge clathrates

Energy Technology Data Exchange (ETDEWEB)

Zeiringer, I.; Chen Mingxing [Institute of Physical Chemistry, University of Vienna, Waehringerstr. 42, 1090 Wien (Austria); Bednar, I.; Royanian, E.; Bauer, E. [Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10, 1040 Wien (Austria); Podloucky, R.; Grytsiv, A. [Institute of Physical Chemistry, University of Vienna, Waehringerstr. 42, 1090 Wien (Austria); Rogl, P., E-mail: peter.franz.rogl@univie.ac.at [Institute of Physical Chemistry, University of Vienna, Waehringerstr. 42, 1090 Wien (Austria); Effenberger, H. [Institute of Mineralogy and Crystallography, University of Vienna, A-1090 Wien (Austria)

2011-04-15

In the Ag-Ba-Ge system the clathrate type-{Iota} solid solution, Ba{sub 8}Ag{sub x}Ge{sub 46-x-y{open_square}y}, extends at 800 deg. C from binary Ba{sub 8}Ge{sub 43{open_square}3} ({open_square} is a vacancy) to Ba{sub 8}Ag{sub 5.3}Ge{sub 40.7}. For the clathrate phase (1 {<=} x {<=} 5.3) the cubic space group Pm3-bar n was established by X-ray powder diffraction and confirmed by X-ray single-crystal analyses of the samples Ba{sub 8}Ag{sub 2.3}Ge{sub 41.9{open_square}1.8} and Ba{sub 8}Ag{sub 4.4}Ge{sub 41.3{open_square}0.3}. Increasing the concentration of Ag causes the lattice parameters of the solid solution to increase linearly from a value of a = 1.0656 (x = 0, y = 3) to a = 1.0842 (x = 4.8, y = 0) nm. Site preference determination using X-ray refinement reveals that Ag atoms preferentially occupy the 6d site randomly mixed with Ge and vacancies, which become filled in the compound Ba{sub 8}Ag{sub 4.8}Ge{sub 41.2} when the Ag content increases. At 600 {sup o}C the phase region of the clathrate solution Ba{sub 8}Ag{sub x}Ge{sub 46-x-y{open_square}y} becomes separated from the Ba-Ge boundary and extends from 6.6 to 9.8 at.% Ag. The compound Ba{sub 6}Ge{sub 25} (clathrate type-{Iota}X) dissolves at 800 {sup o}C a maximum of 1.5 at.% Ag. The homogeneity regions of the two ternary compounds BaAg{sub 2-x}Ge{sub 2+x} (ThCr{sub 2}Si{sub 2}-type, 0.2 {<=} x {<=} 0.7) and Ba(Ag{sub 1-x}Ge{sub x}){sub 2} (AlB{sub 2}-type, 0.65 {<=} x {<=} 0.75) were established at 800 deg. C. Studies of transport properties for the series of Ba{sub 8}Ag{sub x}Ge{sub 46-x-y{open_square}y} compounds evidenced that electrons are the predominant charge carriers with the Fermi energy close to a gap. Its position can be fine-tuned by the substitution of Ge by Ag atoms and by mechanical processing of the starting material, Ba{sub 8}Ge{sub 43}. The proximity of the electronic structure at Fermi energy of Ba{sub 8}Ag{sub x}Ge{sub 46-x-y{open_square}y} to a gap is also corroborated by density

BaCO3 mediated modifications in structural and magnetic properties of natural nanoferrites

Science.gov (United States)

Widanarto, W.; Jandra, M.; Ghoshal, S. K.; Effendi, M.; Cahyanto, W. T.

2015-04-01

Preparing M-type barium hexaferrite and improving the magnetic response of natural ferrites by incorporating barium carbonate (BaCO3) is ever-demanding. Series of barium carbonate doped ferrites with composition (100-x)Fe3O4·xBaCO3 (x=0, 10, 20, 30 wt%) are prepared through solid state reaction method and sintered gradually at temperatures of 800 and 1000 °C. Nanoparticles of natural ferrite and commercial BaCO3 are used as raw materials. Impacts of BaCO3 on structural and magnetic properties of these synthesized ferrites are inspected. The obtained ferrites are characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) at room temperature. Uniform barium hexaferrite particles in terms of both morphology and size are not achieved. The average crystallite size of BaFe12O19 is observed to be within 30-600 nm. The sintering process results phase transformation from Fe3O4 (magnetite) to α-Fe2O3 (hematite) and the formation of hexagonal barium ferrite crystals. The occurrence of barium crystal is found to enhance with the increase of BaCO3 concentrations up to 20 wt% and suddenly drop at 30 wt%. Saturation and remanent magnetization of the doped ferrites are significantly augmented up to 16.37 and 8.92 emu g-1, respectively compared to their pure counterpart. Furthermore, the coercivity field is slightly decreased as BaCO3 concentrations are increased. BaCO3 mediated improvements in the magnetic response of natural ferrites are demonstrated.

Topological phases in Ba-Borate glasses

Science.gov (United States)

Holbrook, Chad; Czaja, Andrew; Boolchand, Punit

2015-03-01

Twelve compositions in the (BaO)x(B2O3)100-x pseudo binary, in the 15% Modulated- DSC and Raman scattering experiments were undertaken systematically as function of BaO content (x). Calorimetric measurements reveal Tg(x) to show a broad maximum and the non-reversing enthalpy to show a Gaussian-like reversibility window2, both centered near x = 28%. Raman scattering displays rich lineshapes with modes similar to those observed in Na-Borates2. Modes near 808 cm-1, 770 cm-1, 740 cm-1 and 705 cm-1 are observed, and identified with breathing modes of pure and mixed rings from characteristic structural groupings2. These preliminary results suggest that glasses at x 30% in the flexible phase. Supported by NSF Grant DMR 08-53957.

Electrical machines & drives

CERN Document Server

Hammond, P

1985-01-01

Containing approximately 200 problems (100 worked), the text covers a wide range of topics concerning electrical machines, placing particular emphasis upon electrical-machine drive applications. The theory is concisely reviewed and focuses on features common to all machine types. The problems are arranged in order of increasing levels of complexity and discussions of the solutions are included where appropriate to illustrate the engineering implications. This second edition includes an important new chapter on mathematical and computer simulation of machine systems and revised discussions o

BaSi2 formation mechanism in thermally evaporated films and its application to reducing oxygen impurity concentration

Science.gov (United States)

Hara, Kosuke O.; Yamamoto, Chiaya; Yamanaka, Junji; Arimoto, Keisuke; Nakagawa, Kiyokazu; Usami, Noritaka

2018-04-01

Thermal evaporation is a simple and rapid method to fabricate semiconducting BaSi2 films. In this study, to elucidate the BaSi2 formation mechanism, the microstructure of a BaSi2 epitaxial film fabricated by thermal evaporation has been investigated by transmission electron microscopy. The BaSi2 film is found to consist of three layers with different microstructural characteristics, which is well explained by assuming two stages of film deposition. In the first stage, BaSi2 forms through the diffusion of Ba atoms from the deposited Ba-rich film to the Si substrate while in the second stage, the mutual diffusion of Ba and Si atoms in the film leads to BaSi2 formation. On the basis of the BaSi2 formation mechanism, two issues are addressed. One is the as-yet unclarified reason for epitaxial growth. It is found important to quickly form BaSi2 in the first stage for the epitaxial growth of upper layers. The other issue is the high oxygen concentration in BaSi2 films around the BaSi2-Si interface. Two routes of oxygen incorporation, i.e., oxidation of the Si substrate surface and initially deposited Ba-rich layer by the residual gas, are identified. On the basis of this knowledge, oxygen concentration is decreased by reducing the holding time of the substrate at high temperatures and by premelting of the source. In addition, X-ray diffraction results show that the decrease in oxygen concentration can lead to an increased proportion of a-axis-oriented grains.

DNA-based machines.

Science.gov (United States)

Wang, Fuan; Willner, Bilha; Willner, Itamar

2014-01-01

The base sequence in nucleic acids encodes substantial structural and functional information into the biopolymer. This encoded information provides the basis for the tailoring and assembly of DNA machines. A DNA machine is defined as a molecular device that exhibits the following fundamental features. (1) It performs a fuel-driven mechanical process that mimics macroscopic machines. (2) The mechanical process requires an energy input, "fuel." (3) The mechanical operation is accompanied by an energy consumption process that leads to "waste products." (4) The cyclic operation of the DNA devices, involves the use of "fuel" and "anti-fuel" ingredients. A variety of DNA-based machines are described, including the construction of "tweezers," "walkers," "robots," "cranes," "transporters," "springs," "gears," and interlocked cyclic DNA structures acting as reconfigurable catenanes, rotaxanes, and rotors. Different "fuels", such as nucleic acid strands, pH (H⁺/OH⁻), metal ions, and light, are used to trigger the mechanical functions of the DNA devices. The operation of the devices in solution and on surfaces is described, and a variety of optical, electrical, and photoelectrochemical methods to follow the operations of the DNA machines are presented. We further address the possible applications of DNA machines and the future perspectives of molecular DNA devices. These include the application of DNA machines as functional structures for the construction of logic gates and computing, for the programmed organization of metallic nanoparticle structures and the control of plasmonic properties, and for controlling chemical transformations by DNA machines. We further discuss the future applications of DNA machines for intracellular sensing, controlling intracellular metabolic pathways, and the use of the functional nanostructures for drug delivery and medical applications.

Single pulsed-field magnetization on Gd-Ba-Cu-O Bulk HTS assembled for axial-gap type rotating machines

International Nuclear Information System (INIS)

Morita, E; Matsuzaki, H; Kimura, Y; Ohtani, I; Izumi, M; Nonaka, Y; Murakami, M; Ida, T; Sugimoto, H; Miki, M; Kitano, M

2006-01-01

We employed Gd-bulk HTS magnets as rotating poles for a smaller and lighter axial-gap type rotating machine. The bulk was placed between two vortex-type armature coils and cooled down to 77 K under zero-field. Pulsed current was applied to the vortex-type magnetizing coils. The trapped field distribution and transient flux behaviour strongly depend on the radial dimension of the armature vortex-type coil. In the present study, we show that there is an optimal radial dimension of magnetizing coils to the given bulk disk size to give a homogeneously conical distribution of the trapped flux

Machine translation

Energy Technology Data Exchange (ETDEWEB)

Nagao, M

1982-04-01

Each language has its own structure. In translating one language into another one, language attributes and grammatical interpretation must be defined in an unambiguous form. In order to parse a sentence, it is necessary to recognize its structure. A so-called context-free grammar can help in this respect for machine translation and machine-aided translation. Problems to be solved in studying machine translation are taken up in the paper, which discusses subjects for semantics and for syntactic analysis and translation software. 14 references.

Concentrations of Se, Ba, Zn and Mn in Brazil nuts

Energy Technology Data Exchange (ETDEWEB)

Armelin, Maria José A.; Maihara, Vera A.; Cardoso, Paulo S.; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Cozollino, Silvia M.F., E-mail: marmelin@ipen.br, E-mail: vmaihara@ipen.br, E-mail: msaiki@ipen.br, E-mail: pscsilva@ipen.br, E-mail: smfcozzo@usp.br [Universidade de São Paulo (USP), SP (Brazil). Faculdade de Ciências Farmacêuticas

2017-07-01

The concentrations of Se, Ba, Zn and Mn were determined in samples of Brazil nuts collected in two ways: a) in a production farm predominantly for export and, b) in various points of sale from different regions of Brazil. Instrumental neutron activation analysis was the analytical technique used in this study. Results indicate that the concentrations of Se and Ba varied greatly among the Brazil nut samples analyzed. This large variability may be related to the soil characteristics from which the nuts were produced. An inverse correlation was observed between the concentrations of Se and Ba. On the other hand, the concentrations of Zn and Mn did not show significant differences among these samples. (author)

Concentrations of Se, Ba, Zn and Mn in Brazil nuts

International Nuclear Information System (INIS)

Armelin, Maria José A.; Maihara, Vera A.; Cardoso, Paulo S.; Saiki, Mitiko; Cozollino, Silvia M.F.

2017-01-01

The concentrations of Se, Ba, Zn and Mn were determined in samples of Brazil nuts collected in two ways: a) in a production farm predominantly for export and, b) in various points of sale from different regions of Brazil. Instrumental neutron activation analysis was the analytical technique used in this study. Results indicate that the concentrations of Se and Ba varied greatly among the Brazil nut samples analyzed. This large variability may be related to the soil characteristics from which the nuts were produced. An inverse correlation was observed between the concentrations of Se and Ba. On the other hand, the concentrations of Zn and Mn did not show significant differences among these samples. (author)

Growth and scintillation properties of BaMgF{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Yanagida, Takayuki, E-mail: t_yanagi@tagen.tohoku.ac.j [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Kawaguchi, Noriaki [Tokuyama Corporation, Shibuya 3-chome, Shibuya-ku, Tokyo 150-8383 (Japan); Fujimoto, Yutaka; Sugiyama, Makoto; Furuya, Yuki; Kamada, Kei; Yokota, Yuui [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Yoshikawa, Akira [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Chani, Valery [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

2010-09-21

By using the micro-pulling down ({mu}-PD) method, the barium magnesium fluoride (BaMgF{sub 4}) single crystalline scintillator was produced. The crystal was cut and mirror polished to the physical dimensions of 1x2x10 mm{sup 3} for examination of scintillation properties. BaMgF{sub 4} demonstrated {approx}70% transmittance in wavelength range above 170 nm, and strong emission peaking around 205 nm was observed under X-ray excitation. The absolute light yield of BaMgF{sub 4} was 1300{+-}100 ph/MeV, and the decay time profile showed two components as 0.57{+-}0.01 (70%) and 2.2{+-}0.31 (30%) ns at room temperature.

Effect of Ba ions on the growth and mitochondrial metabolism of Mung bean seedlings

Energy Technology Data Exchange (ETDEWEB)

Minton, G A; Wilson, R H

1973-01-01

The presence of high concentrations of BaCl/sub 2/ in vermiculite grown Mung bean (Phaseolus aureus) resulted in a reduction in shoot growth compared with plants grown in equivalent concentrations of CaCl/sub 2/. A high level of Ba ion was found in the mitochondria from plants grown at high Ba ion concentrations. Respiration rates of isolated mitochondria from plants grown at high levels of Ba were more rapid with all substrates tested, while the coupling parameters, including respiratory control with all substrates tested and ADP/O ratios with pyruvate-malate were partially reduced. These results are discussed as a possible mechanism of inhibition of plants grown in high-Ba soils. 12 references, 1 figure, 3 tables.

Effect of BaSi2 template growth duration on the generation of defects and performance of p-BaSi2/n-Si heterojunction solar cells

Science.gov (United States)

Yachi, Suguru; Takabe, Ryota; Deng, Tianguo; Toko, Kaoru; Suemasu, Takashi

2018-04-01

We investigated the effect of BaSi2 template growth duration (t RDE = 0-20 min) on the defect generation and performance of p-BaSi2/n-Si heterojunction solar cells. The p-BaSi2 layer grown by molecular beam epitaxy (MBE) was 15 nm thick with a hole concentration of 2 × 1018 cm-3. The conversion efficiency η increased for films grown at long t RDE, owing to improvements of the open-circuit voltage (V OC) and fill factor (FF), reaching a maximum of η = 8.9% at t RDE = 7.5 min. However, η decreased at longer and shorter t RDE owing to lower V OC and FF. Using deep-level transient spectroscopy, we detected a hole trap level 190 meV above the valence band maximum for the sample grown without the template (t RDE = 0 min). An electron trap level 106 meV below the conduction band minimum was detected for a sample grown with t RDE = 20 min. The trap densities for both films were (1-2) × 1013 cm-3. The former originated from the diffusion of Ba into the n-Si region; the latter originated from defects in the template layer. The crystalline qualities of the template and MBE-grown layers were discussed. The root-mean-square surface roughness of the template reached a minimum of 0.51 nm at t RDE = 7.5 min. The a-axis orientation of p-BaSi2 thin films degraded as t RDE exceeded 10 min. In terms of p-BaSi2 crystalline quality and solar cell performance, the optimum t RDE was determined to be 7.5 min, corresponding to approximately 4 nm in thickness.

The BaBar instrumented flux return performance: lessons learned

CERN Document Server

Anulli, F; Baldini, R; Band, H R; Bionta, R; Brau, J E; Brigljevic, V; Buzzo, A; Calcaterra, A; Carpinelli, M; Cartaro, C; Cavallo, N; Crosetti, G; De Nardo, Gallieno; De Sangro, R; Eichenbaum, A; Fabozzi, F; Falciai, D; Ferrarotto, F; Ferroni, F; Finocchiaro, G; Forti, F; Frey, R; Gatto, C; Graug; Iakovlev, N I; Iwasaki, M; Johnson, J R; Lange, D J; Lista, L; Lo Vetere, M; Lü, C; Macri, M; Messner, R; Moore, T B; Morganti, S; Neal, H; Neri, N; Palano, A; Paoloni, E; Paolucci, P; Passaggio, S; Pastore, F C; Patteri, P; Peruzzi, I; Piccolo, D; Piccolo, M; Piredda, G; Robutti, E; Roodman, A; Santroni, A; Sciacca, C; Sinev, N B; Soha, A; Strom, D; Tosi, S; Vavra, J; Wisniewski, W J; Wright, D M; Xie, Y; Zallo, A

2002-01-01

The BaBar Collaboration has operated an instrumented flux return (IFR) system covering over 2000 m sup 2 with resistive plate chambers (RPCs) for nearly 3 years. The chambers are constructed of bakelite sheets separated by 2 mm. The inner surfaces are coated with linseed oil. This system provides muon and neutral hadron detection for BaBar. Installation and commissioning were completed in 1998, and operation began mid-year 1999. While initial performance of the system reached design, over time, a significant fraction of the RPCs demonstrated significant degradation, marked by increased currents and reduced efficiency. A coordinated effort of investigations have identified many of the elements responsible for the degradation. This article presents our current understanding of the aging process of the BaBar RPCs along with the action plan to combat performance degradation of the IFR system.

The new barium mercuride BaHg6 and ternary indium and gallium derivatives

International Nuclear Information System (INIS)

Wendorff, Marco; Röhr, Caroline

2013-01-01

Highlights: ► The new binary Hg-rich mercuride BaHg 6 crystallizes with a singular structure type. ► Ternary In substituted compounds are isotypic, whereas Ga substituted compounds are only structurally related. ► Structure relation to other Hg-rich alkali and alkaline earth mercurides. ► Discussion of covalent and metallic bonding aspects, as found by structure features and band structure calculations. - Abstract: The new binary barium mercuride BaHg 6 and the derived ternary indium and gallium containing compounds BaIn 1.2 Hg 4.8 and BaGa 0.8 Hg 5.2 were synthesized from melts of the elements, which were slowly cooled from 500 to 200 °C. Their crystal structures have been determined by means of single crystal X-ray diffraction. The binary mercuride BaHg 6 (Pnma, a = 1338.9(3), b = 519.39(13), c = 1042.6(4) pm, Z = 4, R1 = 0.0885) and the isotypic indium substituted compound BaIn 1.2 Hg 4.8 as well as the structurally related gallium mercuride BaGa 0.8 Hg 5.2 (Cmcm, a = 729.77(7), b = 1910.1(2), c = 507.48(5) pm, Z = 4, R1 = 0.0606) crystallize with new structure types. Common features of both structures are planar nets of five- and eight-membered Hg rings, stacked perpendicular to the shortest axes. According to their lengths, the Hg–Hg bonds can be classified into three groups: strong, short ones (I, 285–292 pm), which are only found inside the nets, and longer distances (II), still carrying bond critical points, around 300 pm. Further contacts (III) serve to complete the coordination spheres of Hg/M (320–358 pm). The overall coordination numbers of Hg/M range from 10 to 13. The Ba cations are positioned in the centers of the octagons of the Hg/M nets, thus exhibiting a 5:8:5, i.e. 18, coordination by Hg/M atoms. DFT calculations of the electronic band structure of pure BaHg 6 and ordered models of the indium ( ′ BaInHg 5 ′ ) and the gallium ( ′ BaGaHg 5 ′ ) mercurides were performed using the FP-LAPW method. The calculated Bader charges

Induction machine handbook

CERN Document Server

Boldea, Ion

2002-01-01

Often called the workhorse of industry, the advent of power electronics and advances in digital control are transforming the induction motor into the racehorse of industrial motion control. Now, the classic texts on induction machines are nearly three decades old, while more recent books on electric motors lack the necessary depth and detail on induction machines.The Induction Machine Handbook fills industry's long-standing need for a comprehensive treatise embracing the many intricate facets of induction machine analysis and design. Moving gradually from simple to complex and from standard to

Chaotic Boltzmann machines

Science.gov (United States)

Suzuki, Hideyuki; Imura, Jun-ichi; Horio, Yoshihiko; Aihara, Kazuyuki

2013-01-01

The chaotic Boltzmann machine proposed in this paper is a chaotic pseudo-billiard system that works as a Boltzmann machine. Chaotic Boltzmann machines are shown numerically to have computing abilities comparable to conventional (stochastic) Boltzmann machines. Since no randomness is required, efficient hardware implementation is expected. Moreover, the ferromagnetic phase transition of the Ising model is shown to be characterised by the largest Lyapunov exponent of the proposed system. In general, a method to relate probabilistic models to nonlinear dynamics by derandomising Gibbs sampling is presented. PMID:23558425

Rotating electrical machines

CERN Document Server

Le Doeuff, René

2013-01-01

In this book a general matrix-based approach to modeling electrical machines is promulgated. The model uses instantaneous quantities for key variables and enables the user to easily take into account associations between rotating machines and static converters (such as in variable speed drives).   General equations of electromechanical energy conversion are established early in the treatment of the topic and then applied to synchronous, induction and DC machines. The primary characteristics of these machines are established for steady state behavior as well as for variable speed scenarios. I

Thermodynamic model for the solubility of BaSeO4(cr) in the aqueous Ba2+-SeO42--Na+-H+-OH--H2O system. Extending to high selenate concentrations

International Nuclear Information System (INIS)

Rai, Dhanpat; Felmy, Andrew R.; Kitamura, Akira; Yoshikawa, Hideki; Doi, Reisuke; Yoshida, Yasushi; Moore, Dean A.

2014-01-01

The aqueous solubility of BaSeO 4 (cr) was studied at 23 ± 2 C as a function of Na 2 SeO 4 concentrations (0.0001 to 4.1 mol kg -1 ) and equilibration periods (3 to 596 d). The equilibrium, approached from both the under- and over-saturation directions, in this system was reached rather rapidly (≤ 3d). The SIT and Pitzer's ion-interaction models were used to interpret these data and the predictions based on both of these models agreed closely with the experimental data. Thermodynamic analyses of the data show that BaSeO 4 (cr) is the solubility-controlling phase for Na 2 SeO 4 concentrations -1 . The log 10 K 0 value for the BaSeO 4 (cr) solubility product (BaSeO 4 (cr) ↔ Ba 2+ + SeO 4 2- ) calculated by the SIT and Pitzer models were very similar (-7.32 ± 0.07 with Pitzer and -7.25 ± 0.11 with SIT). Although the BaSeO 4 (cr) solubility product and Ba concentrations as a function of Na 2 SeO 4 concentrations predicted by both the SIT and Pitzer models are similar, the models required different sets of fitting parameters. For examples, (1) interpretations using the SIT model required the inclusion of Ba(SeO 4 ) 2 2- species with log 10 K 0 = 3.44 ± 0.12 for the reaction (Ba 2+ + 2SeO 4 2- ↔ Ba(SeO 4 ) 2 2- ), whereas these species are not needed for Pitzer model, and (2) at Na 2 SeO 4 concentrations > 0.59 mol kg -1 it was also possible to calculate the value for log 10 K 0 for the solubility product of a proposed double salt (Na 2 Ba(SeO 4 ) 2 (s) ↔ 2Na + + Ba 2+ + 2SeO 4 2- ) which for the SIT model is -(8.70 ± 0.29) whereas for the Pitzer model it is -(9.19 ± 0.19). The ion-interaction/ion-association parameters hitherto unavailable for both the SIT and Pitzer models required to fit these extensive data extending to as high ionic strengths as 12.3 mol kg -1 were determined. The model developed in this study is consistent with all of the reliable literature data, which was also used to extend the model to barium concentrations as high as 0.22 mol kg

Preparation and self-assembly of nanostructured BaCrO4 from CTAB reverse microemulsions

International Nuclear Information System (INIS)

Li Zhonghao; Zhang Jianling; Du Jimin; Han Buxing; Mu Tiancheng; Gao Yanan; Liu Zhimin

2005-01-01

Well-defined superstructures of rectangular-shaped BaCrO 4 and extensive network of BaCrO 4 nanoparticles constructed by self-assembly were prepared in cetyltrimethylammonium bromide (CTAB) reverse microemulsions. The effects of aging time and reactant concentrations on the morphology and the self-assemble pattern of the nanostructured BaCrO 4 were investigated. TEM combined with the electron diffraction was used to characterize the morphology and the crystal structure of the prepared nanostructured BaCrO 4 at different conditions

Muon spin depolarization in Gd- and EuBa2Cu3Ox

International Nuclear Information System (INIS)

Cooke, D.W.; Hutson, R.L.; Kwok, R.S.; Maez, M.; Rempp, H.; Schillaci, M.E.; Smith, J.L.; Willis, J.O.; Lichti, R.L.; Chan, K.C.; Boekema, C.; Weathersby, S.; Oostens, J.

1989-01-01

Positive muon spin rotation (μSR) measurements on Gd- and EuBa 2 Cu 3 O x (x ∼ 7) have been conducted in the temperature interval 4 - 300 K. For each sample, muons stop both at grain boundaries and within the superconducting grains. Measured magnetic field penetration depths are 1550 and 1900 Angstrom for two specimens of GdBa 2 Cu 3 O x , and 1350 Angstrom for EuBa 2 Cu 3 O x

Your Sewing Machine.

Science.gov (United States)

Peacock, Marion E.

The programed instruction manual is designed to aid the student in learning the parts, uses, and operation of the sewing machine. Drawings of sewing machine parts are presented, and space is provided for the student's written responses. Following an introductory section identifying sewing machine parts, the manual deals with each part and its…

Machine Learning

CERN Multimedia

CERN. Geneva

2017-01-01

Machine learning, which builds on ideas in computer science, statistics, and optimization, focuses on developing algorithms to identify patterns and regularities in data, and using these learned patterns to make predictions on new observations. Boosted by its industrial and commercial applications, the field of machine learning is quickly evolving and expanding. Recent advances have seen great success in the realms of computer vision, natural language processing, and broadly in data science. Many of these techniques have already been applied in particle physics, for instance for particle identification, detector monitoring, and the optimization of computer resources. Modern machine learning approaches, such as deep learning, are only just beginning to be applied to the analysis of High Energy Physics data to approach more and more complex problems. These classes will review the framework behind machine learning and discuss recent developments in the field.

Le CRDI dans les Philippines

International Development Research Centre (IDRC) Digital Library (Canada)

Le CRDI appuie la recherche dans les. Philippines depuis 1972. Le travail qu'y ont accompli des universités et des instituts de recherche vigoureux et la participation active de la société civile ont entraîné d'importantes améliorations dans les domaines de l'agriculture, du suivi de la pauvreté et de la gestion des forêts.

Dependence of transfer number of fluorine on cation type in glasses of Ba(PO3)2-MeF2 systems (Me=Ba,Sr,Ca,Mg)

International Nuclear Information System (INIS)

Pronkin, A.A.

1978-01-01

The influence of Ba, Sr, Ca, Mg cations on transfer numbers of fluorine in glasses of Ba(PO 3 ) 2 - MeF 2 pseudobinary systems is studied. Transfer numbers are essentially different in one and the same fluorine ion concentration in glasses, containing various alkali-earth cations: increase of the cation field force brings about decrease of the transfer numbers of fluorine, and the glass-formation region in the Ba-Sr-Ca-Mg series rises. The dependence of transfer numbers of fluorine on the fluorine concentration logarithm is presented. It is established, that alkali-earth metals influence the transfer numbers of fluorine on account of selective interaction with the phosphate constituent of glass structure

Characterization of the insulator barrier and the superconducting transition temperature in GdBa{sub 2}Cu{sub 3}O{sub 7−δ}/BaTiO{sub 3} bilayers for application in tunnel junctions

Energy Technology Data Exchange (ETDEWEB)

Navarro, H., E-mail: henrynavarro@cab.cnea.gov.ar; Sirena, M.; Haberkorn, N. [Instituto Balseiro, Universidad Nacional de Cuyo and CNEA, 8400 Bariloche (Argentina); Centro Atómico Bariloche, Comisión Nacional de Energía Atómica. Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina); Yang, Ilkyu [Department of Physics, Pohang University of Science and Technology, Pohang (Korea, Republic of); Kim, Jeehoon [Department of Physics, Pohang University of Science and Technology, Pohang (Korea, Republic of); CALDES, Institute for Basic Science, Pohang (Korea, Republic of)

2015-07-28

The optimization of the superconducting properties in a bottom electrode and the quality of an insulator barrier are the first steps in the development of superconductor/insulator/superconductor tunnel junctions. Here, we study the quality of a BaTiO{sub 3} tunnel barrier deposited on a 16 nm thick GdBa{sub 2}Cu{sub 3}O{sub 7−δ} thin film by using conductive atomic force microscopy. We find that the tunnel current is systematically reduced (for equal applied voltage) by increasing the BaTiO{sub 3} barrier thickness between 1.6 and 4 nm. The BaTiO{sub 3} layers present an energy barrier of ≈1.2 eV and an attenuation length of 0.35–0.5 nm (depending on the applied voltage). The GdBa{sub 2}Cu{sub 3}O{sub 7−δ} electrode is totally covered by a BaTiO{sub 3} thickness above 3 nm. The presence of ferroelectricity was verified by piezoresponse force microscopy for a 4 nm thick BaTiO{sub 3} top layer. The superconducting transition temperature of the bilayers is systematically suppressed by increasing the BaTiO{sub 3} thickness. This fact can be associated with stress at the interface and a reduction of the orthorhombicity of the GdBa{sub 2}Cu{sub 3}O{sub 7−δ}. The reduction in the orthorhombicity is expected by considering the interface mismatch and it can also be affected by reduced oxygen stoichiometry (poor oxygen diffusion across the BaTiO{sub 3} barrier)

Investigation of the Machining Stability of a Milling Machine with Hybrid Guideway Systems

Directory of Open Access Journals (Sweden)

Jui-Pin Hung

2016-03-01

Full Text Available This study was aimed to investigate the machining stability of a horizontal milling machine with hybrid guideway systems by finite element method. To this purpose, we first created finite element model of the milling machine with the introduction of the contact stiffness defined at the sliding and rolling interfaces, respectively. Also, the motorized built-in spindle model was created and implemented in the whole machine model. Results of finite element simulations reveal that linear guides with different preloads greatly affect the dynamic responses and machining stability of the horizontal milling machine. The critical cutting depth predicted at the vibration mode associated with the machine tool structure is about 10 mm and 25 mm in the X and Y direction, respectively, while the cutting depth predicted at the vibration mode associated with the spindle structure is about 6.0 mm. Also, the machining stability can be increased when the preload of linear roller guides of the feeding mechanism is changed from lower to higher amount.

Introduction to AC machine design

CERN Document Server

Lipo, Thomas A

2018-01-01

AC electrical machine design is a key skill set for developing competitive electric motors and generators for applications in industry, aerospace, and defense. This book presents a thorough treatment of AC machine design, starting from basic electromagnetic principles and continuing through the various design aspects of an induction machine. Introduction to AC Machine Design includes one chapter each on the design of permanent magnet machines, synchronous machines, and thermal design. It also offers a basic treatment of the use of finite elements to compute the magnetic field within a machine without interfering with the initial comprehension of the core subject matter. Based on the author's notes, as well as after years of classroom instruction, Introduction to AC Machine Design: * Brings to light more advanced principles of machine design--not just the basic principles of AC and DC machine behavior * Introduces electrical machine design to neophytes while also being a resource for experienced designers * ...

Precision machining commercialization

International Nuclear Information System (INIS)

1978-01-01

To accelerate precision machining development so as to realize more of the potential savings within the next few years of known Department of Defense (DOD) part procurement, the Air Force Materials Laboratory (AFML) is sponsoring the Precision Machining Commercialization Project (PMC). PMC is part of the Tri-Service Precision Machine Tool Program of the DOD Manufacturing Technology Five-Year Plan. The technical resources supporting PMC are provided under sponsorship of the Department of Energy (DOE). The goal of PMC is to minimize precision machining development time and cost risk for interested vendors. PMC will do this by making available the high precision machining technology as developed in two DOE contractor facilities, the Lawrence Livermore Laboratory of the University of California and the Union Carbide Corporation, Nuclear Division, Y-12 Plant, at Oak Ridge, Tennessee

The Synthesis of BaAl2O4 Powder with High Surface Area%高比表面积BaAl2O4粉体合成研究

Institute of Scientific and Technical Information of China (English)

乔彦辉; 顾士甲; 王明辉; 田元; 李欢; 江莞

2017-01-01

BaAl2O4是优良的NOx存储催化剂材料,同时也是一种理想的荧光基体材料,受到了研究人员的广泛关注.但是一般的BaAl2O4粉体由于比表面积相对较小,使用受到了限制.虽然纳米颗粒有大的比表面积,但其团聚的缺陷严重限制了其应用.本文采用了一种简单的软模板法合成了BaAl2O4粉体.该粉体经过XRD表征表明为BaAl2O4,经BET表征具有较大比表面积.BaAl2O4粉体不仅化学稳定性好,而且具有相对较大的比表面积.其合成方法节省能源、生产效率高,在特定场合极有可能替代普通粉体做实际应用.%BaAl2O4 is an excellent NOx storage catalyst material. At the same time, it is also an ideal fluorescent matrix material and draws extensive attention. However, the general BaAl2O4 powder is limited by the relatively small surface area. Although the nanoparticles have larger surface area, the defect of their aggregation severely limits their applications. In this study, BaAl2O4 powder was synthesized by a simple soft template method, which not only had a good chemical stability, but also had a relatively large surface area. After characterizing by XRD, BET and TEM, the powder proved exactly the BaAl2O4 with a larger surface area. The synthesis method in this paper has high production efficiency and energy efficiency, and the powder is likely to replace the commonly-used powder on particular occasions.

Are there intelligent Turing machines?

OpenAIRE

Bátfai, Norbert

2015-01-01

This paper introduces a new computing model based on the cooperation among Turing machines called orchestrated machines. Like universal Turing machines, orchestrated machines are also designed to simulate Turing machines but they can also modify the original operation of the included Turing machines to create a new layer of some kind of collective behavior. Using this new model we can define some interested notions related to cooperation ability of Turing machines such as the intelligence quo...

Electrical properties and structure of glasses in the Ba(PO3)2-MF2 systems, where M = Mg, Ca, Sr, Ba

International Nuclear Information System (INIS)

Sokolov, I.A.; Tarlakov, Yu.P.; Murin, I.V.; Pronkin, A.A.

2000-01-01

Using the methods of conductometry and IR spectroscopy the concentrational dependences of electric conductivity are studied, the nature of current carriers is determined, the concentrational dependence of transfer numbers is ascertained and structural changes in glasses of the system Ba(PO 3 ) 2 -MF 2 (M = Mg, Ca, Sr, Ba), depending on MF 2 content, are considered. It is shown that F - ions take part in electric current transfer. Influence of crystallochemical nature of alkaline-earth cations on physicochemical properties and structure of the glasses studied is analyzed [ru

The Impact of Different Permissible Exposure Limits on Hearing Threshold Levels Beyond 25 dBA.

Science.gov (United States)

Sayapathi, Balachandar S; Su, Anselm Ting; Koh, David

2014-10-01

Development of noise-induced hearing loss is reliant on a few factors such as frequency, intensity, and duration of noise exposure. The occurrence of this occupational malady has doubled from 120 million to 250 million in a decade. Countries such as Malaysia, India, and the US have adopted 90 dBA as the permissible exposure limit. According to the US Occupational Safety and Health Administration (OSHA), the exposure limit for noise is 90 dBA, while that of the US National Institute of Occupational Safety and Health (NIOSH) is 85 dBA for 8 hours of noise exposure. This study aimed to assess the development of hearing threshold levels beyond 25 dBA on adoption of 85 dBA as the permissible exposure limit compared to 90 dBA. This is an intervention study done on two automobile factories. There were 203 employees exposed to noise levels beyond the action level. Hearing protection devices were distributed to reduce noise levels to a level between the permissible exposure limit and action level. The permissible exposure limits were 90 and 85 dBA in factories 1 and 2, respectively, while the action levels were 85 and 80 dBA, respectively. The hearing threshold levels of participants were measured at baseline and at first month of postshift exposure of noise. The outcome was measured by a manual audiometer. McNemar and chi-square tests were used in the statistical analysis. We found that hearing threshold levels of more than 25 dBA has changed significantly from pre-intervention to post-intervention among participants from both factories (3000 Hz for the right ear and 2000 Hz for the left ear). There was a statistically significant association between participants at 3000 Hz on the right ear at 'deteriorated' level ( χ² (1) = 4.08, φ = - 0.142, P = 0.043), whereas there was worsening of hearing threshold beyond 25 dBA among those embraced 90 dBA. The adoption of 85 dBA as the permissible exposure limit has preserved hearing threshold level among participants at 3000 Hz

Nuclear charge radii and nuclear moments of neutron deficient Ba isotopes from high resolution laser spectroscopy

International Nuclear Information System (INIS)

Nowicki, G.; Bekk, K.; Goering, S.; Hanser, A.; Rebel, H.; Schatz, G.

1978-07-01

Isotope shifts and hyperfine structure of the BaI 6s 2 1 S 0 -6s6p 1 P 1 transitions (lambda = 553.6 nm) in neutron deficient Ba nuclides (N 131 Ba, 128 Ba, in addition to remeasurements of all stable Ba nuclides. The extracted values of delta 2 >, the observed odd-even staggering and the nuclear moments are discussed in the light of other theoretical and experimental nuclear structure studies of the region 50 [de

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

Energy Technology Data Exchange (ETDEWEB)

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

1977-12-01

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

Sediment pollution in margins of the Lake Guaíba, Southern Brazil.

Science.gov (United States)

de Andrade, Leonardo Capeleto; Tiecher, Tales; de Oliveira, Jessica Souza; Andreazza, Robson; Inda, Alberto Vasconcellos; de Oliveira Camargo, Flávio Anastácio

2017-12-02

Sediments are formed by deposition of organic and inorganic particles on depth of water bodies, being an important role in aquatic ecosystems, including destination and potential source of essential nutrients and heavy metals, which may be toxic for living organisms. The Lake Guaíba supplies water for approximately two million people and it is located in the metropolitan region of Porto Alegre, Rio Grande do Sul State, Brazil. Thus, the aim of this study was to evaluate the sediment pollution in the margins of Lake Guaíba in the vicinity of Porto Alegre city. Surface sediment was sampled in 12 sites to assess the concentration of several elements (C, N, P, Fe, Al, Ca, Mg, Na, K, Mn, Ba, Zn, V, Pb, Cu, Cr, Ni, Cd, Mo, and Se) and the mineralogical composition. Sediment in margins of Lake Guaíba presented predominantly (> 95%) sandy fraction in all samples, but with significant differences between evaluated sites. Sediments in the margins of Lake Guaíba showed indications of punctual water pollution with Pb, Cu, Cr, Ni, TOC, TKN, and P, mainly derived from urban streams that flow into the lake. In order to solve these environmental liabilities, public actions should not focus only on Guaíba, but also in the streams that flow into the lake.

Photoluminescent BaMoO4 nanopowders prepared by complex polymerization method (CPM)

International Nuclear Information System (INIS)

Azevedo Marques, Ana Paula de; Melo, Dulce M.A. de; Paskocimas, Carlos A.; Pizani, Paulo S.; Joya, Miryam R.; Leite, Edson R.; Longo, Elson

2006-01-01

The BaMoO 4 nanopowders were prepared by the Complex Polymerization Method (CPM). The structure properties of the BaMoO 4 powders were characterized by FTIR transmittance spectra, X-ray diffraction (XRD), Raman spectra, photoluminescence spectra (PL) and high-resolution scanning electron microscopy (HR-SEM). The XRD, FTIR and Raman data showed that BaMoO 4 at 300 deg. C was disordered. At 400 deg. C and higher temperature, BaMoO 4 crystalline scheelite-type phases could be identified, without the presence of additional phases, according to the XRD, FTIR and Raman data. The calculated average crystallite sizes, calculated by XRD, around 40 nm, showed the tendency to increase with the temperature. The crystallite sizes, obtained by HR-SEM, were around of 40-50 nm. The sample that presented the highest intensity of the red emission band was the one heat treated at 400 deg. C for 2 h, and the sample that displayed the highest intensity of the green emission band was the one heat treated at 700 deg. C for 2 h. The CPM was shown to be a low cost route for the production of BaMoO 4 nanopowders, with the advantages of lower temperature, smaller time and reduced cost. The optical properties observed for BaMoO 4 nanopowders suggested that this material is a highly promising candidate for photoluminescent applications

Positron annihilation lifetime study of positive temperature coefficient BaTiO3 samples

International Nuclear Information System (INIS)

Ling Chen; Mingkang Teng; Guanghou Wang; Xiaoyun Li; Tianchang Lu

1989-01-01

In order to investigate the doped vacancies in BaTiO 3 samples as well as their influence on the positive temperature coefficient (PTC) the positron annihilation lifetime spectroscopy was applied. Two groups of BaTiO 3 samples with BaO excess were prepared by doping different concentrations of La 2 O 3 and Nb 2 O 5 , respectively in the range from 0.1 to 3 at%. A third group of samples of two Sb-doped PTC BaTiO 3 semiconductors with excess BaO or TiO 2 were studied by the aid of positron technique before and after being reduced. It is shown that the positron lifetime parameters are sensitive to changes in the vacancy concentration in BaTiO 3 ceramics near the 0.1 mol% region. But they are almost unchanged during reduction processing; the resistivity of samples changed by one to two orders of magnitude through the reduction. It can be concluded that the PTC effect is due to oxygen on the grain boundary rather than vacancies, and that the Heywang-Jonker model is more reasonable

Thermoelectric properties of Cu/Ag doped type-III Ba24Ge100 clathrates

Science.gov (United States)

Fu, Jiefei; Su, Xianli; Yan, Yonggao; Liu, Wei; Zhang, Zhengkai; She, Xiaoyu; Uher, Ctirad; Tang, Xinfeng

2017-09-01

Type-III Ba24Ge100 clathrates possess low thermal conductivity and high electrical conductivity at room temperature and, as such, have a great potential as thermoelectric materials for power generation. However, the Seebeck coefficient is very low due to the intrinsically high carrier concentration. In this paper, a series of Ba24CuxGe100-x and Ba24AgyGe100-y specimens were prepared by vacuum melting combined with the subsequent spark plasma sintering (SPS) process. Doping Cu or Ag on the Ge site not only suppresses the concentration of electrons but it also decreases the thermal conductivity. In addition, the carrier mobility and the Seebeck coefficient increase due to the decrease in the carrier concentration. Thus, the power factor is greatly improved, leading to an improvement in the dimensionless figure of merit ZT. Cu-doped Ba24Cu6Ge94 reaches the maximum ZT value of about 0.17 at 873 K, while Ag-doped Ba24Ag6Ge94 attains the dimensionless figure of merit ZT of 0.31 at 873 K, more than 2 times higher value compared to un-doped Ba24Ge100.

Coldness production and heat revalorization: particular machines; Production de froid et revalorisation de la chaleur: machines particulieres

Energy Technology Data Exchange (ETDEWEB)

Feidt, M. [Universite Henri Poincare - Nancy-1, 54 - Nancy (France)

2003-10-01

The machines presented in this article are not the common reverse cycle machines. They use some systems based on different physical principles which have some consequences on the analysis of cycles: 1 - permanent gas machines (thermal separators, pulse gas tube, thermal-acoustic machines); 2 - phase change machines (mechanical vapor compression machines, absorption machines, ejection machines, adsorption machines); 3 - thermoelectric machines (thermoelectric effects, thermodynamic model of a thermoelectric machine). (J.S.)

National machine guarding program: Part 1. Machine safeguarding practices in small metal fabrication businesses

Science.gov (United States)

Yamin, Samuel C.; Brosseau, Lisa M.; Xi, Min; Gordon, Robert; Most, Ivan G.; Stanley, Rodney

2015-01-01

Background Metal fabrication workers experience high rates of traumatic occupational injuries. Machine operators in particular face high risks, often stemming from the absence or improper use of machine safeguarding or the failure to implement lockout procedures. Methods The National Machine Guarding Program (NMGP) was a translational research initiative implemented in conjunction with two workers' compensation insures. Insurance safety consultants trained in machine guarding used standardized checklists to conduct a baseline inspection of machine‐related hazards in 221 business. Results Safeguards at the point of operation were missing or inadequate on 33% of machines. Safeguards for other mechanical hazards were missing on 28% of machines. Older machines were both widely used and less likely than newer machines to be properly guarded. Lockout/tagout procedures were posted at only 9% of machine workstations. Conclusions The NMGP demonstrates a need for improvement in many aspects of machine safety and lockout in small metal fabrication businesses. Am. J. Ind. Med. 58:1174–1183, 2015. © 2015 The Authors. American Journal of Industrial Medicine published by Wiley Periodicals, Inc. PMID:26332060

Compounds of type Ba/sub 2/Bsup(III)Ossup(V)O/sub 6/

Energy Technology Data Exchange (ETDEWEB)

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

1981-07-01

The black perovskites of type Ba/sub 2/Bsup(III)Ossup(V)O/sub 6/ crystallize cubic (Bsup(III) = Pr, Nd, Sm-Lu, Y) and rhombohedral (Bsup(III) = La) respectively; the cell volumina decrease linearily with (rsub(B)sup(III))/sup 3/. Intensity calculations on powder data for Ba/sub 2/YOsO/sub 6/ (space group Fm3m-Osub(h)/sup 5/) and Ba/sub 2/LaOsO/sub 6/ (space group R-3m-Dsub(3d)/sup 5/) gave the intensity related R'values of 4.6% and 5.0% respectively. The results of the vibrational spectroscopic investigations are reported in common with the bond orders, M-O distances and mean amplitudes and compared with the corresponding values of the series Ba/sub 2/Bsup(III)Irsup(V)O/sub 6/ and Ba/sub 2/Bsup(III)Rusup(V)O/sub 6/.

‘Machinic Trajectories’: Appropriated Devices as Post-Digital Drawing Machines

Directory of Open Access Journals (Sweden)

Andres Wanner

2014-12-01

Full Text Available This article presents a series of works called Machinic Trajectories, consisting of domestic devices appropriated as mechanical drawing machines. These are contextualized within the post-digital discourse, which integrates messy analog conditions into the digital realm. The role of eliciting and examining glitches for investigating a technology is pointed out. Glitches are defined as short-lived, unpremeditated aesthetic results of a failure; they are mostly known as digital phenomena, but I argue that the concept is equally applicable to the output of mechanical machines. Three drawing machines will be presented: The Opener, The Mixer and The Ventilator. In analyzing their drawings, emergent patterns consisting of unpremeditated visual artifacts will be identified and connected to irregularities of the specific technologies. Several other artists who work with mechanical and robotic drawing machines are introduced, to situate the presented works and reflections in a larger context of practice and to investigate how glitch concepts are applicable to such mechanical systems. 

Influence of Ba/Fe mole ratios on magnetic properties, crystallite size and shifting of X-ray diffraction peaks of nanocrystalline BaFe12O19 powder, prepared by sol gel auto combu

Science.gov (United States)

Suastiyanti, Dwita; Sudarmaji, Arif; Soegijono, Bambang

2012-06-01

Barium hexaferrite BaFe12O19 (BFO) is of great importance as permanent magnets, particularly for magnetic recording as well as in microwave devices. Nano-crystalline BFO powders were prepared by sol gel auto combustion method in citric acid - metal nitrates system. Hence the mole ratios of Ba/Fe were variated at 1:12; 1:11.5 and 1:11. Ratio of cation to fuel was fixed at 1:1. An appropriate amount of amonia solution was added dropwise to this solution with constant stirring until the PH reached 7 in all cases. Heating at 850oC for 10 hours for each sample to get final formation of BFO nanocrystalline. The data from XRD showing the lattice parameters a,c and the unit-cell volume V, confirm that BFO with ratio 1:12 has same crystall parameters with ratio 1:11. Ratio of Ba/Fe 1:12 and 1:11 have diffraction pattern similarly at almost each 2 θ for each samples. Ratio of Ba/Fe 1: 11.5 has the finest crystallite size 22 nm. Almost diffraction pattern peaks of Ba/Fe 1:11.5 move to the left from of Ba/Fe 1:12 then return to diffraction pattern of Ba/Fe 1:12 for Ba/Fe 1:11. SEM observations show the particle size less than 100 nm and the same shape for each sample. Ratio of Ba/Fe 1: 12 gives the highest intrinsic coercive Hc = 427.3 kA/m. The highest remanent magnetization is at ratio 1:11 with Mr = 0.170 T. BFO with mole ratio 1:11.5 has the finest grain 22 nm, good magnetic properties and the highest value of best FoM 89%.

Configuration Database for BaBar On-line

International Nuclear Information System (INIS)

Salnikov, Andrei

2003-01-01

The configuration database is one of the vital systems in the BaBar on-line system. It provides services for the different parts of the data acquisition system and control system, which require run-time parameters. The original design and implementation of the configuration database played a significant role in the successful BaBar operations since the beginning of experiment. Recent additions to the design of the configuration database provide better means for the management of data and add new tools to simplify main configuration tasks. We describe the design of the configuration database, its implementation with the Objectivity/DB object-oriented database, and our experience collected during the years of operation

Microstructural properties of BaTiO{sub 3} ceramics and thin films

Energy Technology Data Exchange (ETDEWEB)

Fundora C, A.; Portelles, J.J.; Siqueiros, J.M. [Posgrado en Fisica de Materiales, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada. Apartado Postal 2861, 22800 Ensenada, Baja California (Mexico)

2000-07-01

A microstructural study of BaTiO{sub 3} ceramics obtained by the conventional ceramic method is presented. Targets were produced to grow BaTiO{sub 3} thin films by pulsed laser deposition on Pt/Ti/Si (100) substrates. X-ray diffraction, Auger Electron Spectroscopy, X-ray Photon Spectroscopy and Scanning Electron Microscopy were used to study the properties of the BaTiO{sub 3} ceramic samples and thin films, as deposited and after an annealing process. (Author)

Structural, optical and electronic properties of K2Ba(NO3)4 crystal

Science.gov (United States)

Isaenko, L. I.; Korzhneva, K. E.; Goryainov, S. V.; Goloshumova, A. A.; Sheludyakova, L. A.; Bekenev, V. L.; Khyzhun, O. Y.

2018-02-01

Nitrate crystals reveal nonlinear optical properties and could be considered as converters of laser radiation in the short-wave region. The conditions for obtaining and basic properties of K2Ba(NO3)4 double nitrate crystals were investigated. Crystal growth was implemented by slow cooling in the temperature range of 72-49 °C and low rate evaporation. The structural analysis of K2Ba(NO3)4 formation on the basis of two mixed simple nitrate structures is discussed. The main groups of oscillations in K2Ba(NO3)4 crystal were revealed using Raman and IR spectroscopy, and the table of vibrations for this compound was compiled. The electronic structure of K2Ba(NO3)4 was elucidated in the present work from both experimental and theoretical viewpoints. In particular, X-ray photoelectron spectroscopy (XPS) was employed in the present work to measure binding energies of the atoms constituting the titled compound and its XPS valence-band spectrum for both pristine and Ar+ ion-bombarded surfaces. Further, total and partial densities of states of constituent atoms of K2Ba(NO3)4 have been calculated. The calculations reveal that the O 2p states dominate in the total valence-band region of K2Ba(NO3)4 except of its bottom, where K 3p and Ba 5p states are the principal contributors, while the bottom of the conduction band is composed mainly of the unoccupied O 2p states, with somewhat smaller contributions of the N 2p∗ states as well. With respect to the occupation of the valence band by the O 2p states, the present band-structure calculations are confirmed by comparison on a common energy scale of the XPS valence-band spectrum and the X-ray emission O Kα band for the K2Ba(NO3)4 crystal under study. Furthermore, the present calculations indicate that the K2Ba(NO3)4 compound is a direct-gap material.

High Pressure Properties of a Ba-Cu-Zn-P Clathrate-I

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Juli-Anna Dolyniuk

2016-08-01

Full Text Available The high pressure properties of the novel tetrel-free clathrate, Ba8Cu13.1Zn3.3P29.6, were investigated using synchrotron powder X-ray diffraction. The pressure was applied using a diamond anvil cell. No structural transitions or decomposition were detected in the studied pressure range of 0.1–7 GPa. The calculated bulk modulus for Ba8Cu13.1Zn3.3P29.6 using a third-order Birch-Murnaghan equation of state is 65(6 GPa at 300 K. This bulk modulus is comparable to the bulk moduli of Ge- and Sn-based clathrates, like A8Ga16Ge30 (A = Sr, Ba and Sn19.3Cu4.7P22I8, but lower than those for the transition metal-containing silicon-based clathrates, Ba8TxSi46−x, T = Ni, Cu; 3 ≤ x ≤ 5.

Molecular glues for manipulating enzymes: trypsin inhibition by benzamidine-conjugated molecular glues† †Electronic supplementary information (ESI) available: Synthesis of TEG–BA, Gluen–BA, mGluen–BA and Gluen–Ph; 1H NMR, 13C NMR, MALDI-TOF MS, electronic absorption, and CD spectra; zeta potential distributions; SLS plots; DLS histograms; and related experimental procedures. See DOI: 10.1039/c5sc00524h Click here for additional data file.

Science.gov (United States)

Mogaki, Rina

2015-01-01

Water-soluble bioadhesive polymers bearing multiple guanidinium ion (Gu+) pendants at their side-chain termini (Gluen–BA, n = 10 and 29) that were conjugated with benzamidine (BA) as a trypsin inhibitor were developed. The Gluen–BA molecules are supposed to adhere to oxyanionic regions of the trypsin surface, even in buffer, via a multivalent Gu+/oxyanion salt-bridge interaction, such that their BA group properly blocks the substrate-binding site. In fact, Glue10–BA and Glue29–BA exhibited 35- and 200-fold higher affinities for trypsin, respectively, than a BA derivative without the glue moiety (TEG–BA). Most importantly, Glue10–BA inhibited the protease activity of trypsin 13-fold more than TEG–BA. In sharp contrast, mGlue27–BA, which bears 27 Gu+ units along the main chain and has a 5-fold higher affinity than TEG–BA for trypsin, was inferior even to TEG–BA for trypsin inhibition. PMID:28706668

In vitro anticancer potential of BaCO3 nanoparticles synthesized via green route.

Science.gov (United States)

Nagajyothi, P C; Pandurangan, Muthuraman; Sreekanth, T V M; Shim, Jaesool

2016-03-01

Green synthesis of nanoparticles is a growing research area because of their potential applications in nanomedicine. Barium carbonate nanoparticles (BaCO3 NPs) were synthesized using an aqueous extract of Mangifera indica seed as a reducing agent. These particles were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Transmission electron microscopy (TEM), selected area electron diffraction (SAED), Energy-dispersive-X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) analysis. HR-TEM images are confirmed that green synthesized BaCO3 NPs have spherical, triangular and uneven shapes. EDX analysis confirmed the presence of Ba, C and O. The peaks at 2θ of 19.45, 23.90, 24.29, 27.72, 33.71, 34.08, 34.60, 41.98, 42.95, 44.18, 44.85, and 46.78 corresponding to (110), (111), (021), (002), (200), (112), (130), (221), (041), (202), (132) and (113) showed that BaCO3 NPs average size was ~18.3 nm. SAED pattern confirmed that BaCO3 NPs are crystalline nature. BaCO3 NPs significantly inhibited cervical carcinoma cells, as evidenced by cytotoxicity assay. Immunofluorescence and fluorescence assays showed that BaCO3 NPs increased the expression and activity of caspase-3, an autocatalytic enzyme that promotes apoptosis. According to the results, green synthesis route has great potential for easy, rapid, inexpensive, eco-friendly and efficient development of novel multifunctional nanoparticles for the treatment of cancer. Copyright © 2016 Elsevier B.V. All rights reserved.

Growth of single crystals of BaFe12O19 by solid state crystal growth

International Nuclear Information System (INIS)

Fisher, John G.; Sun, Hengyang; Kook, Young-Geun; Kim, Joon-Seong; Le, Phan Gia

2016-01-01

Single crystals of BaFe 12 O 19 are grown for the first time by solid state crystal growth. Seed crystals of BaFe 12 O 19 are buried in BaFe 12 O 19 +1 wt% BaCO 3 powder, which are then pressed into pellets containing the seed crystals. During sintering, single crystals of BaFe 12 O 19 up to ∼130 μm thick in the c-axis direction grow on the seed crystals by consuming grains from the surrounding polycrystalline matrix. Scanning electron microscopy-energy dispersive spectroscopy analysis shows that the single crystal and the surrounding polycrystalline matrix have the same chemical composition. Micro-Raman scattering shows the single crystal to have the BaFe 12 O 19 structure. The optimum growth temperature is found to be 1200 °C. The single crystal growth behavior is explained using the mixed control theory of grain growth. - Highlights: • Single crystals of BaFe 12 O 19 are grown by solid state crystal growth. • A single crystal up to ∼130 μm thick (c-axis direction) grows on the seed crystal. • The single crystal and surrounding ceramic matrix have similar composition. • Micro-Raman scattering shows the single crystal has the BaFe 12 O 19 structure.

Self-Improving CNC Milling Machine

OpenAIRE

Spilling, Torjus

2014-01-01

This thesis is a study of the ability of a CNC milling machine to create parts for itself, and an evaluation of whether or not the machine is able to improve itself by creating new machine parts. This will be explored by using off-the-shelf parts to build an initial machine, using 3D printing/rapid prototyping to create any special parts needed for the initial build. After an initial working machine is completed, the design of the machine parts will be adjusted so that the machine can start p...

High-pressure densified solid solutions of alkaline earth hexaborides (Ca/Sr, Ca/Ba, Sr/Ba) and their high-temperature thermoelectric properties

International Nuclear Information System (INIS)

Gürsoy, M.; Takeda, M.; Albert, B.

2015-01-01

Solid solutions of alkaline earth hexaborides were synthesized and densified by spark plasma sintering at 100 MPa. The high-temperature thermoelectric properties (Seebeck coefficients, electrical and thermal diffusivities, heat capacities) were measured between room temperature and 1073 K. CaB 6 , SrB 6 , BaB 6 and the ternary hexaborides Ca x Sr 1−x B 6 , Ca x Ba 1−x B 6 , Sr x Ba 1−x B 6 (x = 0.25, 0.5, 0.75) are n-type conducting compounds over the whole compositional and thermal ranges. The values of the figure of merit ZT for CaB 6 (ca. 0.3 at 1073 K) were found to be significantly increased compared to earlier investigations which is attributed to the densification process. - Highlights: • Solid solutions of alkaline earth hexaborides were synthesized. • High-temperature thermoelectric properties of mixed calcium borides are excellent. • Spark plasma source densification results in high ZT values. • Borides are rare-earth free and refractory materials

Machine Learning.

Science.gov (United States)

Kirrane, Diane E.

1990-01-01

As scientists seek to develop machines that can "learn," that is, solve problems by imitating the human brain, a gold mine of information on the processes of human learning is being discovered, expert systems are being improved, and human-machine interactions are being enhanced. (SK)

Machining of Metal Matrix Composites

CERN Document Server

2012-01-01

Machining of Metal Matrix Composites provides the fundamentals and recent advances in the study of machining of metal matrix composites (MMCs). Each chapter is written by an international expert in this important field of research. Machining of Metal Matrix Composites gives the reader information on machining of MMCs with a special emphasis on aluminium matrix composites. Chapter 1 provides the mechanics and modelling of chip formation for traditional machining processes. Chapter 2 is dedicated to surface integrity when machining MMCs. Chapter 3 describes the machinability aspects of MMCs. Chapter 4 contains information on traditional machining processes and Chapter 5 is dedicated to the grinding of MMCs. Chapter 6 describes the dry cutting of MMCs with SiC particulate reinforcement. Finally, Chapter 7 is dedicated to computational methods and optimization in the machining of MMCs. Machining of Metal Matrix Composites can serve as a useful reference for academics, manufacturing and materials researchers, manu...

Influence of Impurities on the Luminescence of Er3+ Doped BaTiO3 Nanophosphors

Directory of Open Access Journals (Sweden)

G. D. Webler

2014-01-01

Full Text Available The influence of the presence of barium carbonate (BaCO3 phase on the luminescence properties of barium titanate nanocrystals (BaTiO3 powders was investigated. Structural and optical characterizations of erbium (Er3+ doped BaTiO3 synthesized by the sol-emulsion-gel were performed. Using Fourier transform infrared spectroscopy and X-ray powder diffraction, we identified the presence of impurities related to BaCO3 and quantified its fraction. It was observed that the presence of BaCO3 phase, even at low levels, depletes significantly the infrared-to-visible upconverted luminescence efficiency of the produced nanopowders.

Machine technology: a survey

International Nuclear Information System (INIS)

Barbier, M.M.

1981-01-01

An attempt was made to find existing machines that have been upgraded and that could be used for large-scale decontamination operations outdoors. Such machines are in the building industry, the mining industry, and the road construction industry. The road construction industry has yielded the machines in this presentation. A review is given of operations that can be done with the machines available

From Ba{sub 3}Ta{sub 5}O{sub 14}N to LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2}: Decreasing the optical band gap of a photocatalyst

Energy Technology Data Exchange (ETDEWEB)

Anke, B. [Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin (Germany); Bredow, T. [Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Universität Bonn, Beringstr. 4, 53115 Bonn (Germany); Pilarski, M.; Wark, M. [Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg (Germany); Lerch, M., E-mail: martin.lerch@tu-berlin.de [Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin (Germany)

2017-02-15

Yellow LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} was successfully synthesized as phase-pure material crystallizing isostructurally to previously reported Ba{sub 3}Ta{sub 5}O{sub 14}N and mixed-valence Ba{sub 3}Ta{sup V}{sub 4}Ta{sup IV}O{sub 15}. The electronic structure of LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} was studied theoretically with the range-separated hybrid method HSE06. The most stable structure was obtained when lanthanum was placed on 2a and nitrogen on 4h sites confirming Pauling's second rule. By incorporating nitrogen, the measured band gap decreases from ∼3.8 eV for the oxide via 2.74 eV for Ba{sub 3}Ta{sub 5}O{sub 14}N to 2.63 eV for the new oxide nitride, giving rise to an absorption band well in the visible-light region. Calculated fundamental band gaps confirm the experimental trend. The atom-projected density of states has large contributions from N2p orbitals close to the valence band edge. These are responsible for the observed band gap reduction. Photocatalytic hydrogen formation was investigated and compared with that of Ba{sub 3}Ta{sub 5}O{sub 14}N revealing significantly higher activity for LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} under UV-light. - Graphical abstract: X-ray powder diffraction pattern of LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} with the results of the Rietveld refinements. Inset: Unit cell of LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} and polyhedral representation of the crystal structure. - Highlights: • Synthesis of a new oxide nitride LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2}. • Refinement of the crystal structure. • Quantum chemical calculations provided band gap close to the measured value. • New phase shows a higher photocatalytic H{sub 2} evolution rate compared to prior tested Ba{sub 3}Ta{sub 5}O{sub 14}N.

Wet chemical synthesis of LiBaF{sub 3} phosphor

Energy Technology Data Exchange (ETDEWEB)

Singh, Vartika S., E-mail: svmoharil@yahoo.com [Physics Department, Shri Ramdeobaba K.N. Engineering College, Katol Road, Nagpur 440 013 (India); Joshi, C.P. [Physics Department, Shri Ramdeobaba K.N. Engineering College, Katol Road, Nagpur 440 013 (India); Moharil, S.V. [Department of Physics, R.T.M. Nagpur University, Nagpur 440 010 (India)

2013-12-05

Highlights: •LiBaF{sub 3}:RE{sup 3+} phosphors synthesized by a simple wet chemical method. •Ce{sup 3+} and Tb{sup 3+} emissions observed in as-prepared powders without any thermal treatment. •Intense Eu{sup 2+} emission observed after annealing in reductive atmosphere. -- Abstract: LiBaF{sub 3} has great potential applications as X-ray storage phosphor, slow neutron imaging, scintillator, vacuum ultraviolet (VUV) optical lithography, etc. Conventionally, LiBaF{sub 3} is prepared by solid state reaction between the constituent fluorides. However, the preparation of phase pure material and especially single crystals is rather tricky due to incongruent melting. For the first time, a wet chemical preparation of rare earth activated LiBaF{sub 3} is described here. As precipitated powders containing Ce{sup 3+} or Tb{sup 3+} exhibited characteristic luminescence. For observing Eu{sup 2+} emission, it was necessary to heat the powders in a reductive atmosphere. It is suggested that phosphors prepared by this method may prove useful in applications like OSL, X-ray imaging, etc. which do not require large single crystals.

Characteristics of laser assisted machining for silicon nitride ceramic according to machining parameters

International Nuclear Information System (INIS)

Kim, Jong Do; Lee, Su Jin; Suh, Jeong

2011-01-01

This paper describes the Laser Assisted Machining (LAM) that cuts and removes softened parts by locally heating the ceramic with laser. Silicon nitride ceramics can be machined with general machining tools as well, because YSiAlON, which was made up ceramics, is soften at about 1,000 .deg. C. In particular, the laser, which concentrates on highly dense energy, can locally heat materials and very effectively control the temperature of the heated part of specimen. Therefore, this paper intends to propose an efficient machining method of ceramic by deducing the machining governing factors of laser assisted machining and understanding its mechanism. While laser power is the machining factor that controls the temperature, the CBN cutting tool could cut the material more easily as the material gets deteriorated from the temperature increase by increasing the laser power, but excessive oxidation can negatively affect the quality of the material surface after machining. As the feed rate and cutting depth increase, the cutting force increases and tool lifespan decreases, but surface oxidation also decreases. In this experiment, the material can be cut to 3 mm of cutting depth. And based on the results of the experiment, the laser assisted machining mechanism is clarified

Research into Noise Generated by Domestic Appliances in the Anechoic Chamber

Directory of Open Access Journals (Sweden)

Agnė Žukauskienė

2012-12-01

Full Text Available Loud noise has a negative impact on the entire body, especially on listening. We can hear daily noise everywhere – in the street, at work or at home. The Department of Environmental Protection of Vilnius Gediminas Technical University has adjusted an anechoic chamber adapted for suppressing sound. Under the above introduced conditions, 15 appliances (5 vacuum cleaners, 5 hair dryers and 5 shaving machines have been tested. Equivalent sound pressure level of the vacuum cleaner has varied from 66 dBA to 83 dBA, that of the hair dryer has made from 64 dBA to 70 dBA and for the shaving machine – from 39 to 56 dBA.Article in Lithuanian

Development of BaSO4:Eu thermoluminescence phosphor

International Nuclear Information System (INIS)

Madhusoodanan, U.; Jose, M.T.; Lakshmanan, A.R.

1999-01-01

A highly sensitive thermoluminescence (TL) phosphor based on BaSO 4 :Eu was developed following the coprecipitation technique and firing in argon atmosphere at 1123 K. Photoluminescence studies confirm that firing in argon atmosphere instead of air increased the incorporation of Eu ions in 2+ valence state. At low γ-ray doses, its TL sensitivity is nearly 2 to 3 times higher than that of CaSO 4 :Dy phosphor. The other salient features of this BaSO 4 :Eu TL phosphor are a constant glow curve shape and a nearly linear γ-ray dose response

History of the Balkan Stomatological Society (BaSS

Directory of Open Access Journals (Sweden)

Todorović Ljubomir

2014-11-01

Full Text Available Some of the main activities of the Balkan Stomatological Society (BaSS over a rich 19-year history are presented. These activities have been aimed at improving oral health care provided by the dentists throughout the Balkans, and to establish ties of friendship and collaboration between researchers and clinicians in this region, creating a foundation for mutual understanding and peace. To accomplish these goals, the BaSS annually organizes congresses and publishes a scientific journal, beside many other activities, such as public oral health promotion, bringing into accordance study programmes and curricula, supporting student exchange programmes, etc.

The study of the effect of Ba coverage through the accelerations lifetime of activated BaO/SrO cathodes

International Nuclear Information System (INIS)

Hashim, A.A.; Ray, A.K.; Hassan, A.K.; Barratt, D.S.

2005-01-01

A novel type of BaO/SrO oxide cathode with 5% addition of Ni powder by weight on a Ni cap containing an activating impurity was studied. The conductivity and the electron activation energy were studied as a function of temperature in the range of 300-1200 K after conversion and activation of the cathode at 1200 K for 1 h. The experimental results yield three values for the activation energy of 1.49, 2.23 and 3.3 eV, which are close to BaO band structure parameters with a small shift due to the effect of other oxide components and metallic fraction additions. The experiments furthermore confirm that the current density of the cathode was enhanced at high temperature range with the long operation. The conduction mechanisms observed a metallic conduction at low temperature after operation for several 100 h due to improvements in the Ba coverage layer on the grains of oxide layer. Additionally, there appears a qualified conduction stability of the current density J = 10-45 mA cm -2 at the acceleration temperature range of 1100-1150 K under the duty of low voltage. The low voltage duty V = 30 mV is focused on the conduction electrons faraway from the emission electrons

Oxygen excess in the '114' cobaltite hexagonal structure: The ferrimagnet CaBaCo4O7.50

International Nuclear Information System (INIS)

Pralong, V.; Caignaert, V.; Sarkar, T.; Lebedev, O.I.; Duffort, V.; Raveau, B.

2011-01-01

The study of the oxidation of the '114' orthorhombic cobaltite CaBaCo 4 O 7 , using first electrochemistry and then soft chemistry based on oxidation by NaClO, has allowed a new phase, CaBaCo 4 O 7.50 , to be prepared topotactically. The structural study of this phase shows that its hexagonal structure, closely related to that of orthorhombic CaBaCo 4 O 7 , is curiously similar to that of the members of the LnBaCo 4 O 7 series, in spite of its excess oxygen. Its magnetic study shows that this phase, like CaBaCo 4 O 7 , is ferrimagnetic with the same T C (60 K), but differently exhibits an unusual magnetic hysteresis. This exceptional behavior of CaBaCo 4 O 7 with respect to oxidation as well as the magnetic properties of CaBaCo 4 O 7.50 is interpreted in terms of the presence of defects due to oxidation. - Graphical Abstract: The study of the oxidation of the '114' orthorhombic cobaltite CaBaCo 4 O 7 , using first electrochemistry and then soft chemistry based on oxidation by NaClO, has allowed a new phase, CaBaCo 4 O 7.50 , to be prepared topotactically. The structural study of this phase shows that its hexagonal structure, closely related to that of orthorhombic CaBaCo 4 O 7 , is curiously similar to that of the members of the LnBaCo 4 O 7 series, in spite of its oxygen excess. Its magnetic study shows that this phase, like CaBaCo 4 O 7 , is ferrimagnetic. Highlights: → Topotactic oxidation by means of electrochemistry and soft chemistry of the '114' orthorhombic cobaltite CaBaCo 4 O 7 . → This new phase, CaBaCo 4 O 7.5 shows an hexagonal structure, is closely related to that of orthorhombic mother phase CaBaCo 4 O 7 . → CaBaCo 4 O 7.5 is ferrimagnetic and exhibits an unusual magnetic hysteresis, due to defect pinning centers.

Carbon-14 immobilization via the CO2-Ba(OH)2 hydrate gas-solid reaction

International Nuclear Information System (INIS)

Haag, G.L.

1980-01-01

Although no restrictions have been placed on the release of carbon-14, it has been identified as a potential health hazard due to the ease in which it may be assimilated into the biosphere. The intent of the Carbon-14 Immobilization Program, funded through the Airborne Waste Program Management Office, is to develop and demonstrate a novel process for restricting off-gas releases of carbon-14 from various nuclear facilities. The process utilizes the CO 2 -Ba(OH) 2 hydrate gas-solid reaction to directly remove and immobilize carbon-14. The reaction product, BaCO 3 , possesses both the thermal and chemical stability desired for long-term waste disposal. The process is capable of providing decontamination factors in excess of 1000 and reactant utilization of greater than 99% in the treatment of high volumetric, airlike (330 ppM CO 2 ) gas streams. For the treatment of an air-based off-gas stream, the use of packed beds of Ba(OH) 2 .8H 2 O flakes to remove CO 2 has been demonstrated. However, the operating conditions must be maintained between certain upper and lower limits with respect to the partial pressure of water. If the water vapor pressure in the gas is less than the dissociation vapor pressure of Ba(OH) 2 .8H 2 O, the bed will deactivate. If the vapor pressure is considerably greater, pressure drop problems will increase with increasing humidity as the particles curl and degrade. Results have indicated that when operated in the proper regime, the bulk of the increase in pressure drop results from the conversion of Ba(OH) 2 .8H 2 O to BaCO 3 and not from the hydration of the commercial Ba(OH) 2 .8H 2 O (i.e. Ba(OH) 2 .7.50H 2 O) to Ba(OH) 2 .8H 2 O

Optical energy gaps and photoluminescence peaks of BaGa{sub 2}S{sub 4}:Er{sup 3+} and BaGa{sub 2}Se{sub 4}:Er{sup 3+} single crystals

Energy Technology Data Exchange (ETDEWEB)

Choe, Sung-Hyu [Chosun University, Kwangju (Korea, Republic of); Jin, Moon-Seog [Dongshin University, Naju (Korea, Republic of); Kim, Wha-Tek [Chonnam National University, Kwangju (Korea, Republic of)

2005-12-15

BaGa{sub 2}S{sub 4}:Er{sup 3+} and BaGa{sub 2}Se{sub 4}:Er{sup 3+} single crystals were grown by using the chemical transport reaction method. The optical energy gaps of the BaGa{sub 2}S{sub 4}:Er{sup 3+} and the BaGa{sub 2}Se{sub 4}:Er{sup 3+} single crystals were found to be 4.045 eV and 3.073 eV, respectively, at 11 K. The temperature dependence of the optical energy gap was well fitted by the Varshni equation. Sharp emission peaks were observed in the photoluminescence spectra of the single crystals and assigned to radiation recombination between split Stark levels of the Er{sup 3+} ion.

Energy-efficient electrical machines by new materials. Superconductivity in large electrical machines

International Nuclear Information System (INIS)

Frauenhofer, Joachim; Arndt, Tabea; Grundmann, Joern

2013-01-01

The implementation of superconducting materials in high-power electrical machines results in significant advantages regarding efficiency, size and dynamic behavior when compared to conventional machines. The application of HTS (high-temperature superconductors) in electrical machines allows significantly higher power densities to be achieved for synchronous machines. In order to gain experience with the new technology, Siemens carried out a series of development projects. A 400 kW model motor for the verification of a concept for the new technology was followed by a 4000 kV A generator as highspeed machine - as well as a low-speed 4000 kW propeller motor with high torque. The 4000 kVA generator is still employed to carry out long-term tests and to check components. Superconducting machines have significantly lower weight and envelope dimensions compared to conventional machines, and for this reason alone, they utilize resources better. At the same time, operating losses are slashed to about half and the efficiency increases. Beyond this, they set themselves apart as a result of their special features in operation, such as high overload capability, stiff alternating load behavior and low noise. HTS machines provide significant advantages where the reduction of footprint, weight and losses or the improved dynamic behavior results in significant improvements of the overall system. Propeller motors and generators,for ships, offshore plants, in wind turbine and hydroelectric plants and in large power stations are just some examples. HTS machines can therefore play a significant role when it comes to efficiently using resources and energy as well as reducing the CO 2 emissions.

The synthesis and characterization of p(nBA-DEAEMA) polymer

Science.gov (United States)

Jiang, X. M.; Zhu, J.; Duan, Y. Y.

2018-01-01

In this paper, the polymer of p (nBA-DEAEMA) was polymerized and characterized. The structure of copolymer was characterized by FT-IR and 1HNMR, and the analysis of particle size, appearance and rheology was determined too. The results showed that, the p (nBA-DEAEMA) was synthesised successful, and it could become a surface modification for the inner face of artificial trachea, after further optimization.

Structural characterization of a new vacancy ordered perovskite modification found for Ba3Fe3O7F (BaFeO2.333F0.333): Towards understanding of vacancy ordering for different perovskite-type ferrites

International Nuclear Information System (INIS)

Clemens, Oliver

2015-01-01

The new vacancy ordered perovskite-type compound Ba 3 Fe 3 O 7 F (BaFeO 2.33 F 0.33 ) was prepared by topochemical low-temperature fluorination of Ba 2 Fe 2 O 5 (BaFeO 2.5 ) using stoichiometric amounts of polyvinylidene difluoride (PVDF). The vacancy order was found to be unique so far for perovskite compounds, and the connectivity pattern can be explained by the formula Ba 3 (FeX 6/2 ) (FeX 5/2 ) (FeX 3/2 X 1/1 ), with X=O/F. Mössbauer measurements were used to confirm the structural analysis and agree with the presence of Fe 3+ in the above mentioned coordination environments. Group–subgroup relationships were used to build a starting model for the structure solution and to understand the relationship to the cubic perovskite structure. Furthermore, a comparison of a variety of vacancy-ordered iron-containing perovskite-type structures is given, highlighting the factors which favour one structure type over the other depending on the composition. - Graphical abstract: The crystal structure of Ba 3 Fe 3 O 7 F in comparison to other perovskite type ferrites. - Highlights: • The crystal structure of Ba 3 Fe 3 O 7 F in comparison to other perovskite type ferrites. • Ba 3 Fe 3 O 7 F was synthesized by low temperature fluorination of Ba 2 Fe 2 O 5 . • Ba 3 Fe 3 O 7 F shows a unique vacancy order not found for other perovskite type compounds. • The structure of Ba 3 Fe 3 O 7 F was solved using group–subgroup relationships. • A systematic comparison to other ferrite type compounds reveals structural similarities and differences. • The A-site coordination of the cation is shown to play an important role for the type of vacancy order found

Dielectric enhancement of BaTiO3/SrTiO3 superlattices with embedded Ni nanocrystals

International Nuclear Information System (INIS)

Xiong Zhengwei; Sun Weiguo; Wang Xuemin; Jiang Fan; Wu Weidong

2012-01-01

Highlights: ► The BaTiO 3 /SrTiO 3 superlattices with embedded Ni NCs were successfully fabricated by L-MBE. ► The influence with the various concentrations of Ni nanocrystals embedded in BaTiO 3 /SrTiO 3 superlattices was also discussed. ► The BaTiO 3 /SrTiO 3 superlattices with lower concentration of embedded Ni NCs had higher permittivity and dielectric loss compared with the pure BaTiO 3 /SrTiO 3 superlattices. ► The dielectric enhancement of BaTiO 3 /SrTiO 3 superlattices with embedded Ni NCs was proposed to explained by Drude quasi-free-electron theory. - Abstract: The self-organized Ni nanocrystals (NCs) were embedded in BaTiO 3 /SrTiO 3 superlattices using laser molecular beam epitaxy (L-MBE). The stress of the composite films was increased with the increasing concentration of embedded Ni NCs, as investigation in stress calculation. The influence with the various concentrations of Ni NCs embedded in BaTiO 3 /SrTiO 3 superlattices was also discussed. The internal stress of the films was too strong to epitaxial growth of BaTiO 3 /SrTiO 3 superlattices. Compared with the pure BaTiO 3 /SrTiO 3 superlattices, the BaTiO 3 /SrTiO 3 superlattices with lower concentration of embedded Ni NCs had higher permittivity and dielectric loss. Furthermore, the dielectric enhancement of BaTiO 3 /SrTiO 3 superlattices with embedded Ni NCs was proposed to explained by Drude quasi-free-electron theory.

Impacts of Mining and Urbanization on the Qin-Ba Mountainous Environment, China

Directory of Open Access Journals (Sweden)

Xinliang Xu

2016-05-01

Full Text Available The Qin-Ba Ecological Functional Zone is a component of China’s ecological security pattern designed to protect the regional ecosystem and maintain biodiversity. However, due to the impact of mining and urban encroachment, the plight of a sustainable ecosystem in the Qin-Ba mountainous area is deteriorating. This paper has used a remote sensing and geographic information system (GIS to examine the impacts of mining and urban encroachment on the environment in the Qin-Ba mountainous area. The results indicate that the total mined area in 2013 was 22 km2 and is predicted to escalate. Results also show that the ecosystems in Fengxian County, Shaanxi Province and Baokang County, Hubei Province were most severely affected by mining. Urbanization in the Qin-Ba mountainous area has seen an increase of 85.58 km2 in urban land use from 2010 to 2013. In addition, infrastructure development including airport construction, tourism resorts and real estate development in the Qin-Ba mountainous area has intensified environmental and biodiversity disturbances since large areas of forest have been cleared. Our results should provide insight and assistance to city planners and government officials in making informed decisions.

Large linear magnetoresistance in a new Dirac material BaMnBi2

International Nuclear Information System (INIS)

Wang Yi-Yan; Yu Qiao-He; Xia Tian-Long

2016-01-01

Dirac semimetal is a class of materials that host Dirac fermions as emergent quasi-particles. Dirac cone-type band structure can bring interesting properties such as quantum linear magnetoresistance and large mobility in the materials. In this paper, we report the synthesis of high quality single crystals of BaMnBi 2 and investigate the transport properties of the samples. BaMnBi 2 is a metal with an antiferromagnetic transition at T N = 288 K. The temperature dependence of magnetization displays different behavior from CaMnBi 2 and SrMnBi 2 , which suggests the possible different magnetic structure of BaMnBi 2 . The Hall data reveals electron-type carriers and a mobility μ (5 K) = 1500 cm 2 /V·s. Angle-dependent magnetoresistance reveals the quasi-two-dimensional (2D) Fermi surface in BaMnBi 2 . A crossover from semiclassical MR ∼ H 2 dependence in low field to MR ∼ H dependence in high field, which is attributed to the quantum limit of Dirac fermions, has been observed in magnetoresistance. Our results indicate the existence of Dirac fermions in BaMnBi 2 . (rapid communication)

Ion conductivities of ZrF4-BaF2-CsF glasses

International Nuclear Information System (INIS)

Kawamoto, Yoji; Nohara, Ichiro

1987-01-01

The glass-forming region in the ZrF 4 -BaF 2 -CsF glass system has been determined and the ac conductivity and the transport number of fluoride ions have been measured. The conductivities of compounds β-Cs 2 ZrF 6 , α-SrZrF 6 , α-BaZrF 6 , β-BaZrF 6 and α-PbZrF 6 have also been measured. These results and a previous study of ZrF 4 -BaF 2 -MF n (M: the groups I-IV metals) glasses revealed the following: (1) the ZrF 4 -BaF 2 -CsF glasses are exclusively fluoride-ion conductors; (2) the ionic conductivities of ZrF 4 -based glasses are predominantly determined by the activation energies for conduction; (3) the activation energy for conduction decreases with an increase in the average polarizability of glass-constituting cations; (4) a decrease in average Zr-F bond length and a lowering of the average F coordination number of Zr are presumed to increase the activation energy for conduction. Principles of developing ZrF 4 -based glasses with higher conductivities have also been proposed. (Auth.)

VIRTUAL MACHINES IN EDUCATION – CNC MILLING MACHINE WITH SINUMERIK 840D CONTROL SYSTEM

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Ireneusz Zagórski

2014-11-01

Full Text Available Machining process nowadays could not be conducted without its inseparable element: cutting edge and frequently numerically controlled milling machines. Milling and lathe machining centres comprise standard equipment in many companies of the machinery industry, e.g. automotive or aircraft. It is for that reason that tertiary education should account for this rising demand. This entails the introduction into the curricula the forms which enable visualisation of machining, milling process and virtual production as well as virtual machining centres simulation. Siemens Virtual Machine (Virtual Workshop sets an example of such software, whose high functionality offers a range of learning experience, such as: learning the design of machine tools, their configuration, basic operation functions as well as basics of CNC.

Growth of single crystals of BaFe12O19 by solid state crystal growth

Science.gov (United States)

Fisher, John G.; Sun, Hengyang; Kook, Young-Geun; Kim, Joon-Seong; Le, Phan Gia

2016-10-01

Single crystals of BaFe12O19 are grown for the first time by solid state crystal growth. Seed crystals of BaFe12O19 are buried in BaFe12O19+1 wt% BaCO3 powder, which are then pressed into pellets containing the seed crystals. During sintering, single crystals of BaFe12O19 up to ∼130 μm thick in the c-axis direction grow on the seed crystals by consuming grains from the surrounding polycrystalline matrix. Scanning electron microscopy-energy dispersive spectroscopy analysis shows that the single crystal and the surrounding polycrystalline matrix have the same chemical composition. Micro-Raman scattering shows the single crystal to have the BaFe12O19 structure. The optimum growth temperature is found to be 1200 °C. The single crystal growth behavior is explained using the mixed control theory of grain growth.

Scheduling of hybrid types of machines with two-machine flowshop as the first type and a single machine as the second type

Science.gov (United States)

Hsiao, Ming-Chih; Su, Ling-Huey

2018-02-01

This research addresses the problem of scheduling hybrid machine types, in which one type is a two-machine flowshop and another type is a single machine. A job is either processed on the two-machine flowshop or on the single machine. The objective is to determine a production schedule for all jobs so as to minimize the makespan. The problem is NP-hard since the two parallel machines problem was proved to be NP-hard. Simulated annealing algorithms are developed to solve the problem optimally. A mixed integer programming (MIP) is developed and used to evaluate the performance for two SAs. Computational experiments demonstrate the efficiency of the simulated annealing algorithms, the quality of the simulated annealing algorithms will also be reported.

Simulation of iron impurity in BaTiO3 crystals

International Nuclear Information System (INIS)

Stashans, Arvids; Castillo, Darwin

2009-01-01

Iron-doped barium titanate (BaTiO 3 ) has been simulated taking into account cubic and tetragonal crystallographic lattices of the crystal. A quantum-chemical method based on the Hartree-Fock formalism has been used throughout the study. The calculated equilibrium structures of Fe-doped crystals reveal the defect-inward displacements of the Ti and O atoms whereas the shifts for the Ba atoms are encountered to be away with respect to the Fe impurity. According to the analysis of electron density population and electron band structure it is found that some unusual chemical bonding might take place between the Fe atom and its six adjacent O atoms. The role of Fe impurity in the ferroelectric polarization of the tetragonal BaTiO 3 crystal has been discussed too.

Synthesis and characterization of (Ba,Yb doped ceria nanopowders

Directory of Open Access Journals (Sweden)

Branko Matović

2011-06-01

Full Text Available Nanometric size (Ba, Yb doped ceria powders with fluorite-type structure were obtained by applying selfpropagating room temperature methods. Tailored composition was: Ce0.95−xBa0.05YbxO2−δ with fixed amount of Ba − 0.05 and varying Yb content “x” from 0.05 to 0.2. Powder properties such as crystallite and particle size and lattice parameters have been studied. Röntgen diffraction analyses (XRD were used to characterize the samples at room temperature. Also, high temperature treatment (up to 1550°C was used to follow stability of solid solutions. The mean diameters of the nanocrystals are determined from the full width at half maxima (FWHM of the XRD peaks. It was found that average diameter of crystallites is less than 3 nm. WilliamsonHall plots were used to separate the effect of the size and strain in the nanocrystals.

Synthesis and electrical properties of BaBiO3 and high resistivity BaTiO3–BaBiO3 ceramics

Directory of Open Access Journals (Sweden)

Nitish Kumar

2016-12-01

Full Text Available Ceramics of the composition BaBiO3 (BB were sintered in oxygen to obtain a single phase with monoclinic I2/m symmetry as suggested by high-resolution X-ray diffraction. X-ray photoelectron spectroscopy confirmed the presence of bismuth in two valence states — 3+ and 5+. Optical spectroscopy showed presence of a direct bandgap at ∼ 2.2eV and a possible indirect bandgap at ∼ 0.9eV. This combined with determination of the activation energy for conduction of 0.25eV, as obtained from ac impedance spectroscopy, suggested that a polaron-mediated conduction mechanism was prevalent in BB. The BB ceramics were crushed, mixed with BaTiO3 (BT, and sintered to obtain BT–BB solid solutions. All the ceramics had tetragonal symmetry and exhibited a normal ferroelectric-like dielectric response. Using ac impedance and optical spectroscopy, it was shown that resistivity values of BT–BB were orders of magnitude higher than BT or BB alone, indicating a change in the fundamental defect equilibrium conditions. A shift in the site occupancy of Bi to the A-site is proposed to be the mechanism for the increased electrical resistivity.

Solution based approaches for the morphology control of BaTiO3 particulates

Directory of Open Access Journals (Sweden)

Florentina Maxim

2010-09-01

Full Text Available Within the action COST 539 - ELENA our contribution was aimed at studying solution based approaches for the morphology control of BaTiO3 particulates. Initially, our kinetic analysis and systematic structural and morphological studies, demonstrated that during hydrothermal synthesis from layered titanate nanotubes (TiNTS, BaTiO3 forms via two mechanisms depending on the temperature and time. At low temperatures (90°C, “wild” type BaTiO3 dendritic particles with cubic structure were formed through a phase boundary topotactic reaction. At higher temperatures and/or for longer times time, the reaction is controlled by a dissolution precipitation mechanism and “seaweed” type BaTiO3 dendrites are formed. Our results unambiguously elucidated why TiNTs do not routinely act as templates for the formation of 1D BaTiO3.In our subsequent investigations, the effect of additives on the aqueous and hydrothermal synthesis of BaTiO3 was assessed. We reported that although the tested additives influenced the growth of BaTiO3, their behaviour varied; poly(acrylic acid (PAA adsorbed on specific crystallographic faces changing the growth kinetics and inducing the oriented attachment of the particles; poly(vinyl pyrrolidone (PVP, sodium dodecylsulfate (SDS and hydroxypropylmethylcellulose (HPMC act as growth inhibitors rather than crystal habit modifiers; and DFructose appeared to increase the activation energy for nucleation, resulting in small crystals (26 nm. Our work clearly indicates that the synthesis of 1D nanostructures of complex oxides by chemical methods is non trivial.

Growth of BaSi2 film on Ge(100) by vacuum evaporation and its photoresponse properties

Science.gov (United States)

Trinh, Cham Thi; Nakagawa, Yoshihiko; Hara, Kosuke O.; Kurokawa, Yasuyoshi; Takabe, Ryota; Suemasu, Takashi; Usami, Noritaka

2017-05-01

We have successfully grown a polycrystalline orthorhombic BaSi2 film on a Ge(100) substrate by an evaporation method. Deposition of an amorphous Si (a-Si) film on the Ge substrate prior to BaSi2 evaporation plays a critical role in obtaining a high-quality BaSi2 film. By controlling substrate temperature and the thickness of the a-Si film, a crack-free and single-phase polycrystalline orthorhombic BaSi2 film with a long carrier lifetime of 1.5 µs was obtained on Ge substrates. The photoresponse property of the ITO/BaSi2/Ge/Al structure was clearly observed, and photoresponsivity was found to increase with increasing substrate temperature during deposition of a-Si. Furthermore, the BaSi2 film grown on Ge showed a higher photoresponsivity than that grown on Si, indicating the potential application of evaporated BaSi2 on Ge to thin-film solar cells.

Machine-to-machine communications architectures, technology, standards, and applications

CERN Document Server

Misic, Vojislav B

2014-01-01

With the number of machine-to-machine (M2M)-enabled devices projected to reach 20 to 50 billion by 2020, there is a critical need to understand the demands imposed by such systems. Machine-to-Machine Communications: Architectures, Technology, Standards, and Applications offers rigorous treatment of the many facets of M2M communication, including its integration with current technology.Presenting the work of a different group of international experts in each chapter, the book begins by supplying an overview of M2M technology. It considers proposed standards, cutting-edge applications, architectures, and traffic modeling and includes case studies that highlight the differences between traditional and M2M communications technology.Details a practical scheme for the forward error correction code designInvestigates the effectiveness of the IEEE 802.15.4 low data rate wireless personal area network standard for use in M2M communicationsIdentifies algorithms that will ensure functionality, performance, reliability, ...

Preparation and characterization of BaFe12O19/Y3Fe5O12 composites

International Nuclear Information System (INIS)

Lin, Ying; Kang, Pan; Yang, Haibo; Liu, Miao

2015-01-01

Highlights: • BaM/YIG composites were fabricated by microwave sintering method. • A simple sol–gel method was used to synthesize BaM/YIG composite powders. • The BaM phase and YIG phase are well exchange coupled in the composites. • The (BH) max can be much enhanced by the introduction of YIG. - Abstract: BaFe 12 O 19 /Y 3 Fe 5 O 12 (BaM/YIG) composites with giant enhancement of magnetic energy product ((BH) max ) were fabricated by microwave sintering the BaM/YIG composite powders, which were firstly prepared using a simple sol–gel method. The phase composition and surface morphology of the as-synthesized composites were characterized by an X-ray diffractometer and a scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, respectively. The magnetic properties of the composites were investigated by a vibrating sample magnetometer. All the composites show single-phase-like magnetic hysteresis loops. The results reveal the hard phase (BaM) and soft phase (YIG) are well exchange coupled and the introduction of YIG could significantly enhance the remnant magnetization (M r ), coercivity (H c ) and (BH) max of BaM

Nonplanar machines

International Nuclear Information System (INIS)

Ritson, D.

1989-05-01

This talk examines methods available to minimize, but never entirely eliminate, degradation of machine performance caused by terrain following. Breaking of planar machine symmetry for engineering convenience and/or monetary savings must be balanced against small performance degradation, and can only be decided on a case-by-case basis. 5 refs

Ultraprecision machining. Cho seimitsu kako

Energy Technology Data Exchange (ETDEWEB)

Suga, T [The Univ. of Tokyo, Tokyo (Japan). Research Center for Advanced Science and Technology

1992-10-05

It is said that the image of ultraprecision improved from 0.1[mu]m to 0.01[mu]m within recent years. Ultraprecision machining is a production technology which forms what is called nanotechnology with ultraprecision measuring and ultraprecision control. Accuracy means average machined sizes close to a required value, namely the deflection errors are small; precision means the scattered errors of machined sizes agree very closely. The errors of machining are related to both of the above errors and ultraprecision means the combined errors are very small. In the present ultraprecision machining, the relative precision to the size of a machined object is said to be in the order of 10[sup -6]. The flatness of silicon wafers is usually less than 0.5[mu]m. It is the fact that the appearance of atomic scale machining is awaited as the limit of ultraprecision machining. The machining of removing and adding atomic units using scanning probe microscopes are expected to reach the limit actually. 2 refs.

Barium isotope fractionation during experimental formation of the double carbonate BaMn[CO3](2) at ambient temperature.

Science.gov (United States)

Böttcher, Michael E; Geprägs, Patrizia; Neubert, Nadja; von Allmen, Katja; Pretet, Chloé; Samankassou, Elias; Nägler, Thomas F

2012-09-01

In this study, we present the first experimental results for stable barium (Ba) isotope ((137)Ba/(134)Ba) fractionation during low-temperature formation of the anhydrous double carbonate BaMn[CO(3)](2). This investigation is part of an ongoing work on Ba fractionation in the natural barium cycle. Precipitation at a temperature of 21±1°C leads to an enrichment of the lighter Ba isotope described by an enrichment factor of-0.11±0.06‰ in the double carbonate than in an aqueous barium-manganese(II) chloride/sodium bicarbonate solution, which is within the range of previous reports for synthetic pure BaCO (3) (witherite) formation.

Theory and practice in machining systems

CERN Document Server

Ito, Yoshimi

2017-01-01

This book describes machining technology from a wider perspective by considering it within the machining space. Machining technology is one of the metal removal activities that occur at the machining point within the machining space. The machining space consists of structural configuration entities, e.g., the main spindle, the turret head and attachments such the chuck and mandrel, and also the form-generating movement of the machine tool itself. The book describes fundamental topics, including the form-generating movement of the machine tool and the important roles of the attachments, before moving on to consider the supply of raw materials into the machining space, and the discharge of swarf from it, and then machining technology itself. Building on the latest research findings “Theory and Practice in Machining System” discusses current challenges in machining. Thus, with the inclusion of introductory and advanced topics, the book can be used as a guide and survey of machining technology for students an...

Dosimetry of ultraviolet radiation with BaHfO{sub 3} powders; Dosimetria de radiacion ultravioleta con polvos de BaHfO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Barrera A, A. A.; Aguilar D, G. A.; Guzman M, J.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, Col. Irrigacion, 11500 Ciudad de Mexico (Mexico); Ceron R, V., E-mail: abalba1@hotmail.com [Universidad de Guanajuato, 37670 Leon, Guanajuato (Mexico)

2016-10-15

Ceramic materials based on pure barium hafnate (BaHfO{sub 3}) have been obtained as a powder by the co-precipitation method. The powders obtained have a cubic structure that favors the thermoluminescent and optical properties, through which a better detection of the non-ionizing radiation is allowed. With these powders various tests were performed in the ultraviolet range at different exposure times. These thermoluminescent (Tl) studies were carried out using a Tl 3500 hand held reader which yielded a brightness curve that ranged from room temperature to the 350 degrees Celsius. This BaHfO{sub 3} response exhibits a broad brightness curve with a single peak centered around 225 degrees Celsius. Finally, is reported that there are materials of barium hafnate (BaHfO{sub 3}) doped with some rare earths (Eu, Tb) which, instead of improving the performance of the powders, decrease it, so that the use of intrinsic barium hafnate is the most appropriate. (Author)

Improvement of the performance of microwave X band absorbers based on pure and doped Ba-hexaferrite

Energy Technology Data Exchange (ETDEWEB)

Seyyed Afghahi, Seyyed Salman [Department of Materials Science and Engineering, Imam Hossein University, Tehran (Iran, Islamic Republic of); Jafarian, Mojtaba, E-mail: m.jafarian@srbiau.ac.ir [Young Researchers and Elite Club, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Salehi, Mohsen [Young Researchers and Elite Club, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Atassi, Yomen [Department of Applied Physics, Higher Institute for Applied Sciences and Technology, Damascus (Syrian Arab Republic)

2017-01-01

Optimum Fe/Ba mole ratio is determined in doped Ba-hexaferrite prepared via mechanical activation. X-ray diffractometer (XRD), scanning electron microscope (SEM), vibrating sample magnetometer (VSM) and vector network analyzer are used to analyze phases, structures, electromagnetic and microwave absorption properties. The mole ratio of Fe/Ba=10 is detected to be optimum for doping and synthesizing the Ba-hexaferrite. In order to achieve high absorption in X band the ions of Zr{sup 4+}–Sn{sup 4+}–Ti{sup 4+}–M{sup 2+} (M=Mg{sup 2+}, Zn{sup 2+}, Cu{sup 2+}, Co{sup 2+}) are used as dopants. The results indicate the formation of single phase Ba-hexaferrite in either pure or doped compounds without any non-magnetic intermediate phases and with spherical and hexagonal morphologies respectively for the pure and doped ferrite. It is found out that BaCo{sub 2}Zr(SnTi){sub 0.5}Fe{sub 8}O{sub 19} compound has the maximum saturation magnetization (49.80 emu/g). Also the composite of BaCo{sub 2}Zr(SnTi){sub 0.5}Fe{sub 8}O{sub 19} 50 wt% in epoxy resin exhibits a minimum reflection loss of −29 dB at 12.2 GHz with 2.6 GHz bandwidth. - Highlights: • Optimum Fe/Ba mole ratio is determined in doped Ba-hexaferrite. • Formation of a single phase M-hexaferrite, pure or doped when Fe/Ba=10. • Preparation of microwave absorber of BaCo{sub 2}Zr(SnTi){sub 0.5}Fe{sub 8}O{sub 19}/epoxy resin, 50 wt%. • The absorber exhibits a minimum RL of −29 dB at 12.2 GHz with 2.6 GHz bandwidth.

Conduction Mechanisms in Multiferroic Multilayer BaTiO3/NiFe2O4/BaTiO3 Memristors

Science.gov (United States)

Samardzic, N.; Bajac, B.; Srdic, V. V.; Stojanovic, G. M.

2017-10-01

Memristive devices and materials are extensively studied as they offer diverse properties and applications in digital, analog and bio-inspired circuits. In this paper, we present an important class of memristors, multiferroic memristors, which are composed of multiferroic multilayer BaTiO3/NiFe2O4/BaTiO3 thin films, fabricated by a spin-coating deposition technique on platinized Si wafers. This cost-effective device shows symmetric and reproducible current-voltage characteristics for the actuating voltage amplitude of ±10 V. The origin of the conduction mechanism was investigated by measuring the electrical response in different voltage and temperature conditions. The results indicate the existence of two mechanisms: thermionic emission and Fowler-Nordheim tunnelling, which alternate with actuating voltage amplitude and operating temperature.

BACTERICIDAL COATINGS ON TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT

Science.gov (United States)

2017-07-07

TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT by Tobyn A. Branck Courtney M. Cowell Jennifer M. Rego and...October 2011 – September 2015 4. TITLE AND SUBTITLE BACTERICIDAL COATINGS ON TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT... REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT Introduction The Biological Sciences and Technology Team (BSTT), Warfighter

Two steps hydrothermal growth and characterisations of BaTiO3 films composed of nanowires

Science.gov (United States)

Zawawi, Che Zaheerah Najeehah Che Mohd; Salleh, Shahril; Oon Jew, Lee; Tufail Chaudhary, Kashif; Helmi, Mohamad; Safwan Aziz, Muhammad; Haider, Zuhaib; Ali, Jalil

2018-05-01

Barium titanate (BaTiO3) films composed of nanowires have gained considerable research interest due to their lead-free composition and strong energy conversion efficiency. BaTiO3 films can be developed with a simple two steps hydrothermal reactions, which are low cost effective. In this research, BaTiO3 films were fabricated on titanium foil through two steps hydrothermal method namely, the growth of TiO2 and followed by BaTiO3 films. The structural evolutions and the dielectric properties of the films were investigated as well. The structural evolutions of titanium dioxide (TiO2) and BaTiO3 nanowires were characterized using X-ray diffraction and scanning electron microscopy. First step of hydrothermal reaction, TiO2 nanowires were prepared in varied temperatures of 160 °C, 200 °C and 250 °C respectively. Second step of hydrothermal reaction was performed to produce a layer of BaTiO3 films.

Growth and self-assembly of BaTiO3 nanocubes for resistive switching memory cells

International Nuclear Information System (INIS)

Chu, Dewei; Lin, Xi; Younis, Adnan; Li, Chang Ming; Dang, Feng; Li, Sean

2014-01-01

In this work, the self-assembled BaTiO 3 nanocubes based resistive switching memory capacitors are fabricated with hydrothermal and drop-coating approaches. The device exhibits excellent bipolar resistance switching characteristics with ON/OFF ratio of 58–70, better reliability and stability over various polycrystalline BaTiO 3 nanostructures. It is believed that the inter cube junctions is responsible for such a switching behaviour and it can be described by the filament model. The effect of film thickness on switching ratio (ON/OFF) was also investigated in details. - Graphical abstract: This work describes a novel resistive switching memory cell based on self-assembled BaTiO 3 nanocubes. - Highlights: • BaTiO 3 nanocubes were prepared by one step facile hydrothermal method. • Self-assembled BaTiO 3 nanocubes thin films were obtained by drop-coating approach. • The BaTiO 3 nanocubes show excellent resistive switching properties for memory applications

Face machines

Energy Technology Data Exchange (ETDEWEB)

Hindle, D.

1999-06-01

The article surveys latest equipment available from the world`s manufacturers of a range of machines for tunnelling. These are grouped under headings: excavators; impact hammers; road headers; and shields and tunnel boring machines. Products of thirty manufacturers are referred to. Addresses and fax numbers of companies are supplied. 5 tabs., 13 photos.

Tattoo machines, needles and utilities.

Science.gov (United States)

Rosenkilde, Frank

2015-01-01

Starting out as a professional tattooist back in 1977 in Copenhagen, Denmark, Frank Rosenkilde has personally experienced the remarkable development of tattoo machines, needles and utilities: all the way from home-made equipment to industrial products of substantially improved quality. Machines can be constructed like the traditional dual-coil and single-coil machines or can be e-coil, rotary and hybrid machines, with the more convenient and precise rotary machines being the recent trend. This development has resulted in disposable needles and utilities. Newer machines are more easily kept clean and protected with foil to prevent crosscontaminations and infections. The machines and the tattooists' knowledge and awareness about prevention of infection have developed hand-in-hand. For decades, Frank Rosenkilde has been collecting tattoo machines. Part of his collection is presented here, supplemented by his personal notes. © 2015 S. Karger AG, Basel.

Design of rotating electrical machines

CERN Document Server

Pyrhonen , Juha; Hrabovcova , Valeria

2013-01-01

In one complete volume, this essential reference presents an in-depth overview of the theoretical principles and techniques of electrical machine design. This timely new edition offers up-to-date theory and guidelines for the design of electrical machines, taking into account recent advances in permanent magnet machines as well as synchronous reluctance machines. New coverage includes: Brand new material on the ecological impact of the motors, covering the eco-design principles of rotating electrical machinesAn expanded section on the design of permanent magnet synchronous machines, now repo

Investigation on microstructure and dielectric behaviour of (Ba0· 999 ...

Indian Academy of Sciences (India)

Ceramics of BaTiO3 co-doped with Gd and Cr at Ba-site was synthesized via solid-state reaction route. Surface morphology shows the increase in grain size with the increase of Cr-content below 3 mol%. The high value of in the synthesized samples is associated with space charge polarization and inhomogeneous ...

Searches for low-mass Higgs and dark bosons at BaBar

Energy Technology Data Exchange (ETDEWEB)

Oberhof, Benjamin, E-mail: benjamin.oberhof@pi.infn.it [INFN sezione di Pisa and Universitá di Pisa, Polo Fibonacci - Edificio C, Largo B. Pontecorvo 3, 56125 - Pisa (Italy)

2013-01-15

We present BaBar latest results for the direct search of a light CP-odd Higgs boson using radiative decays of the ϒ(nS) (n=1,2,3) resonances in different final states. We also present the results for the search of a hidden sector gauge and Higgs bosons using the full BaBar datasample.

Particle morphology as a control of permeation in polymer films obtained from MMA/nBA colloidal dispersions.

Science.gov (United States)

Lestage, David J; Urban, Marek W

2004-07-20

The combination of precision-controlled weight loss measurements and spectroscopic surface FT-IR analysis allowed us to identify unique behaviors of poly(methyl methacrylate) (p-MMA). When MMA and n-butyl acrylate (nBA) are polymerized into p-MMA and p-nBA homopolymer blends, MMA/nBA random copolymers, and p-MMA/p-nBA core-shell morphologies, a controlled mobility and stratification of low molecular weight components occurs in films formed from coalesced colloidal dispersions. Due to different affinities toward water, p-MMA and p-nBA are capable of releasing water at different rates, depending upon particle morphological features of initial dispersions. As coalescence progresses, water molecules are released from the high free volume p-nBA particles, whereas p-MMA retains water molecules for the longest time due to its hydrophilic nature. As a result, water losses at extended coalescence times are relatively small for p-MMA. MMA/nBA copolymer and p-MMA/p-nBA blends follow the same trends, although the magnitudes of changes are not as pronounced. The p-MMA/p-nBA core-shell behavior resembles that of p-nBA homopolymer, which is attributed to significantly lower content of the p-MMA component in particles. Annealing of coalesced colloidal films at elevated temperatures causes migration of SDOSS to the F-A interface, but for films containing primarily p-nBA, reverse diffusion back into the bulk is observed. These studies illustrate that the combination of different particle morphologies and temperatures leads to controllable permeation processes through polymeric films. Copyright 2004 American Chemical Society

VIRTUAL MODELING OF A NUMERICAL CONTROL MACHINE TOOL USED FOR COMPLEX MACHINING OPERATIONS

Directory of Open Access Journals (Sweden)

POPESCU Adrian

2015-11-01

Full Text Available This paper presents the 3D virtual model of the numerical control machine Modustar 100, in terms of machine elements. This is a CNC machine of modular construction, all components allowing the assembly in various configurations. The paper focused on the design of the subassemblies specific to the axes numerically controlled by means of CATIA v5, which contained different drive kinematic chains of different translation modules that ensures translation on X, Y and Z axis. Machine tool development for high speed and highly precise cutting demands employment of advanced simulation techniques witch it reflect on cost of total development of the machine.

Fabrication of Ba-K-Bi-O thick film artefacts with improved critical currents

International Nuclear Information System (INIS)

Moore, J.C.; Salter, C.J.; Jenkins, R.J.; Grovenor, C.R.M.; Jones, H.

1993-01-01

The Ba-K-Bi-O system has a maximum T c of around 30K for a composition of Ba 0.6 K 0.4 BiO 3 . Fabrication of good quality single phase samples is extremely difficult and requires careful control of the fabrication conditions. Successful synthesis procedures for Ba-K-Bi-O powder and melt cast material which allow some control of the potassium content of the product were established by Hinks et al. The process is based on a melt and sinter step in an inert atmosphere which creates oxygen vacancies and allows potassium to enter the lattice. The oxygen vacancies are then filled by a subsequent oxygen anneal to obtain superconductivity. Ba-K-Bi-O is, therefore, metastable and consequently difficult to synthesise. There have been few reports of transport measurements and even fewer reports of transport critical currents for bulk material. It is often accepted that Ba-K-Bi-O has an intrinsically low critical current, and extremely poor critical current densities of 0.05 Acm -2 have been quoted for melt cast material. It has been suggested that the presence of weak links is the cause. However, there has been little research into the relationship between process conditions and superconducting properties for melt processed Ba-K-Bi-O to confirm this. (orig.)

Mapping the involvement of BA 4a and 4p during Motor Imagery.

Science.gov (United States)

Sharma, Nikhil; Jones, P S; Carpenter, T A; Baron, Jean-Claude

2008-05-15

Motor Imagery (MI) is an attractive but intriguing means to access the motor network. There are marked inconsistencies in the functional imaging literature regarding the degree, extent and distribution of the primary motor cortex (BA 4) involvement during MI as compared to Executed Movement (EM), which may in part be related to the diverse role of BA 4 and its two subdivisions (i.e., 4a and 4p) in motor processes as well as to methodological issues. Here we used fMRI with monitoring of compliance to show that in healthy volunteers optimally screened for their ability to perform MI the contralateral BA 4 is involved during MI of a finger opposition sequence (2, 3, 4, 5; paced at 1 Hz), albeit less than during EM of the same sequence, and in a location sparing the hand area. Furthermore, both 4a and 4p subdivisions were found to be involved in MI, but the relative involvement of BA 4p appeared more robust and closer to that seen with EM. We suggest that during MI the role of BA 4 and its subdivisions may be non-executive, perhaps related to spatial encoding, though clearly further studies are needed. Finally, we report a similar hemispheric activation balance within BA 4 with both tasks, which extends the commonalities between EM and MI.

Nucleation control and inhibition of BaTiO3 films using hydrothermal-electrochemical method

International Nuclear Information System (INIS)

Escobar, Ivan; Silva, Carmen; Silva, Eric; Vargas, Tomas; Fuenzalida, Victor

1999-01-01

The microstructure of BaTiO 3 films on titanium by the hydrothermal-electrochemical method was investigated using a three electrode high pressure electrochemical cell in a 0.2 M Ba(OH) 2 electrolyte at 150 0 C. The spontaneous initial linked to pure hydrothermal BaTiO 3 formation can be inhibited by cathodically protecting titanium electrode since its immersion in the electrolyte. The application of initial nucleation pulses of varying the cathodic potentials affected the grain size of the deposit. It is suggested that the formation of a titanium oxide layers is a necessary step previous to the nucleation of BaTiO 3

Pulsed laser deposition of Tl-Ca-Ba-Cu-O films

International Nuclear Information System (INIS)

Ianno, N.J.; Liou, S.H.; Woollam, J.A.; Thompson, D.; Johs, B.

1990-01-01

Pulsed laser deposition is a technique commonly used to deposit high quality thin films of high temperature superconductors. This paper discusses the results obtained when this technique is applied to the deposition of Tl-Ca-Ba-Cu-O thin films using a frequency doubled Nd:YAG laser operating at 532 nm and an excimer laser operating at 248 nm. Films with onset temperatures of 125 K and zero resistance temperatures of 110 K deposited on (100) oriented MgO from a composite Tl2Ca2Ba2Cu3Ox target were obtained at both wavelengths upon appropriate post deposition annealing. Films deposited at 532 nm exhibit a rough surface, while those deposited at 248 nm are smooth and homogeneous. Upon annealing, films deposited at both wavelengths are single phase Tl2Ca2Ba2Cu3Ox. 12 refs

MITS machine operations

International Nuclear Information System (INIS)

Flinchem, J.

1980-01-01

This document contains procedures which apply to operations performed on individual P-1c machines in the Machine Interface Test System (MITS) at AiResearch Manufacturing Company's Torrance, California Facility

Accurate projected augmented wave datasets for BaFe2As2

International Nuclear Information System (INIS)

Cao Chao; Wu Yuing; Hamdan, Rashid; Wang, Yunpeng; Cheng Haiping

2010-01-01

By carefully choosing parameters and including more semi-core orbitals as valence electrons, we have constructed a high-quality projected augmented wave dataset that yields results comparable to existing full-potential linearized augmented plane-wave calculations. The dataset was then applied to BaFe 2 As 2 to study the effects of different levels of structure optimization, as well as different choices of exchange-correlation functionals. It was found that the local density approximation exchange-correlation functional fails to find the correct spin-density-wave anti-ferromagnetic (SDW-AFM) ground state under full optimization, while the Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional obtains the correct state but significantly overestimates the magnetism. The electronic structure of the SDW-AFM state is not very sensitive to structure optimizations with the PBE exchange-correlation functional because the positions of the As atoms are preserved under optimizations. We further investigated the Ba atom diffusion process on the BaFe 2 As 2 surface using the nudged elastic bands method. The Ba atom was found to be stable above the center of the squares formed by the surface As atoms, and a diffusion barrier of 1.2 eV was found. Our simulated scanning tunneling microscopy image suggests an ordered surface Ba atom structure, in agreement with Massee et al (2009 Phys. Rev. B 80 140507; van Heumen E et al 2010 arXiv:1009.3493v1).

Coordinate measuring machines

DEFF Research Database (Denmark)

De Chiffre, Leonardo

This document is used in connection with three exercises of 2 hours duration as a part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The exercises concern three aspects of coordinate measuring: 1) Measuring and verification of tolerances on coordinate measuring machines, 2) Traceabilit...... and uncertainty during coordinate measurements, 3) Digitalisation and Reverse Engineering. This document contains a short description of each step in the exercise and schemes with room for taking notes of the results.......This document is used in connection with three exercises of 2 hours duration as a part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The exercises concern three aspects of coordinate measuring: 1) Measuring and verification of tolerances on coordinate measuring machines, 2) Traceability...

The Danish Microbiology Database (MiBa) 2010 to 2013.

Science.gov (United States)

Voldstedlund, M; Haarh, M; Mølbak, K

2014-01-09

The Danish Microbiology Database (MiBa) is a national database that receives copies of reports from all Danish departments of clinical microbiology. The database was launched in order to provide healthcare personnel with nationwide access to microbiology reports and to enable real-time surveillance of communicable diseases and microorganisms. The establishment and management of MiBa has been a collaborative process among stakeholders, and the present paper summarises lessons learned from this nationwide endeavour which may be relevant to similar projects in the rapidly changing landscape of health informatics.

Preparation, photoluminescent properties and luminescent dynamics of BaAlF5:Eu2+ nanophosphors

International Nuclear Information System (INIS)

Zhang, Wei; Hua, Ruinian; Liu, Tianqing; Zhao, Jun; Na, Liyan; Chen, Baojiu

2014-01-01

Graphical abstract: Rice-shaped BaAlF 5 :Eu 2+ nanophosphors were synthesized via one-pot hydrothermal process. The as-prepared BaAlF 5 :Eu 2+ are composed of many particles with an average diameter of 40 nm. When excited at 260 nm, the sharp line emission located at 361 nm of Eu 2+ was observed. The optimum doping concentration of Eu 2+ was confirmed to be 5 mol%. The strong ultraviolet emission of Eu 2+ ions in BaAlF 5 :Eu 2+ nanoparticles suggests that these nanoparticles may have potential applications for sensing, solid-state lasers and spectrometer calibration. - Highlights: • BaAlF 5 :Eu 2+ nanophosphors were synthesized via a mild hydrothermal process. • The Van and Huang models were used to research the mechanism of concentration quenching. • The optimum doping concentration of Eu2+ was confirmed to be 5 mol%. - Abstract: Eu 2+ -doped BaAlF 5 nanophosphors were synthesized via a facile one-pot hydrothermal method. The final products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. XRD results showed that the prepared samples are single-phase. The FE-SEM and TEM images indicated that the prepared BaAlF 5 :Eu 2+ nanophosphors are composed of many rice-shaped particles with an average diameter of 40 nm. When excited at 260 nm, BaAlF 5 :Eu 2+ nanophosphors exhibit the sharp line emissions of Eu 2+ at room temperature. The optimum doping concentration of Eu 2+ was confirmed to be 5 mol%. The Van and Huang models were used to study the mechanism of concentration quenching and the electric dipole–dipole interaction between Eu 2+ can be deduced to be a dominant for quenching fluorescence in BaAlF 5 :Eu 2+ nanophosphors. The strong ultraviolet emission of Eu 2+ in BaAlF 5 :Eu 2+ nanophosphors suggests that these nanoparticles may have potential applications for sensing, spectrometer calibration and solid-state lasers

Sequential structural and antiferromagnetic transitions in BaFe2Se3 under pressure

Science.gov (United States)

Zhang, Yang; Lin, Ling-Fang; Zhang, Jun-Jie; Dagotto, Elbio; Dong, Shuai

2018-01-01

The discovery of superconductivity in the two-leg ladder compound BaFe2S3 has established the 123-type iron chalcogenides as a novel and interesting subgroup of the iron-based superconductor family. However, in this 123 series, BaFe2Se3 is an exceptional member, with a magnetic order and crystalline structure different from all others. Recently, an exciting experiment reported the emergence of superconductivity in BaFe2Se3 at high pressure [J. Ying et al., Phys. Rev. B 95, 241109(R) (2017), 10.1103/PhysRevB.95.241109]. In this paper, we report a first-principles study of BaFe2Se3 . Our analysis unveils a variety of qualitative differences between BaFe2S3 and BaFe2Se3 , including in the latter an unexpected chain of transitions with increasing pressure. First, by gradually reducing the tilting angle of iron ladders, the crystalline structure smoothly transforms from P n m a to C m c m at ˜6 GPa. Second, the system becomes metallic at 10.4 GPa. Third, its unique ambient-pressure Block antiferromagnetic ground state is replaced by the more common stripe (so-called CX-type) antiferromagnetic order at ˜12 GPa, the same magnetic state as the 123-S ladder. This transition is found at a pressure very similar to the experimental superconducting transition. Finally, all magnetic moments vanish at 30 GPa. This reported theoretical diagram of the complete phase evolution is important because of the technical challenges to capture many physical properties in high-pressure experiments. The information obtained in our calculations suggests different characteristics for superconductivity in BaFe2Se3 and BaFe2S3 : in 123-S pairing occurs when magnetic moments vanish, while in 123-Se the transition region from Block- to CX-type magnetism appears to catalyze superconductivity. Finally, an additional superconducting dome above ˜30 GPa is expected to occur.

Electric machine

Science.gov (United States)

El-Refaie, Ayman Mohamed Fawzi [Niskayuna, NY; Reddy, Patel Bhageerath [Madison, WI

2012-07-17

An interior permanent magnet electric machine is disclosed. The interior permanent magnet electric machine comprises a rotor comprising a plurality of radially placed magnets each having a proximal end and a distal end, wherein each magnet comprises a plurality of magnetic segments and at least one magnetic segment towards the distal end comprises a high resistivity magnetic material.

Structures, phase transitions and microwave dielectric properties of the 6H perovskites Ba3BSb2O9, B=Mg, Ca, Sr, Ba

International Nuclear Information System (INIS)

Ling, Chris D.; Rowda, Budwy; Avdeev, Maxim; Pullar, Robert

2009-01-01

We present a complete temperature-composition phase diagram for Ba 3 BSb 2 O 9 , B=Mg, Ca, Sr, Ba, along with their electrical behavior as a function of B. These compounds have long been recognized as 6H-type perovskites, but (with the exception of B=Mg) their exact structures and properties were unknown due to their low symmetries, temperature-dependent phase transitions, and difficulties in synthesizing pure samples. The full range of possible space group symmetries is observed, from ideal hexagonal P6 3 /mmc to monoclinic C2/c to triclinic P1-bar. Direct second-order transitions between these phases are plausible according to group theory, and no evidence was seen for any further intermediate phases. The phase diagram with respect to temperature and the effective ionic radius of B is remarkably symmetrical for B=Mg, Ca, and Sr. For B=Ba, a first-order phase transition to a locally distorted phase allows a metastable hexagonal phase to persist to lower temperatures than expected before decomposing around 600 K. Electrical measurements revealed that dielectric permittivity corrected for porosity does not change significantly as a function of B and is in a good agreement with the values predicted by the Clausius-Mossotti equation. - Graphical abstract: Thermodynamic phase diagram for Ba 3 BSb 2 O 9 , B=Mg, Ca, and Sr, as a function of temperature T and effective ionic radius (IR) of the B 2+ cation

Machine Learning and Radiology

Science.gov (United States)

Wang, Shijun; Summers, Ronald M.

2012-01-01

In this paper, we give a short introduction to machine learning and survey its applications in radiology. We focused on six categories of applications in radiology: medical image segmentation, registration, computer aided detection and diagnosis, brain function or activity analysis and neurological disease diagnosis from fMR images, content-based image retrieval systems for CT or MRI images, and text analysis of radiology reports using natural language processing (NLP) and natural language understanding (NLU). This survey shows that machine learning plays a key role in many radiology applications. Machine learning identifies complex patterns automatically and helps radiologists make intelligent decisions on radiology data such as conventional radiographs, CT, MRI, and PET images and radiology reports. In many applications, the performance of machine learning-based automatic detection and diagnosis systems has shown to be comparable to that of a well-trained and experienced radiologist. Technology development in machine learning and radiology will benefit from each other in the long run. Key contributions and common characteristics of machine learning techniques in radiology are discussed. We also discuss the problem of translating machine learning applications to the radiology clinical setting, including advantages and potential barriers. PMID:22465077

Tribology in machine design

CERN Document Server

Stolarski, Tadeusz

1999-01-01

""Tribology in Machine Design is strongly recommended for machine designers, and engineers and scientists interested in tribology. It should be in the engineering library of companies producing mechanical equipment.""Applied Mechanics ReviewTribology in Machine Design explains the role of tribology in the design of machine elements. It shows how algorithms developed from the basic principles of tribology can be used in a range of practical applications within mechanical devices and systems.The computer offers today's designer the possibility of greater stringen

Effects of Ce, La and Ba addition on the electrochemical behavior of super duplex stainless steels

International Nuclear Information System (INIS)

Yoo, Yun-Ha; Choi, Yoon-Seok; Kim, Jung-Gu; Park, Yong-Soo

2010-01-01

The effects of rare earth metal (REM: Ce, La) and Ba addition on aqueous corrosion properties of super duplex stainless steels (SDSS) were investigated by electrochemical tests and surface analyses. The results of potentiodynamic test indicated that the passive range increased by the addition of Ce, La, and Ba, indicating increased relative resistance to localized corrosion. The EIS measurements showed that the Ce-La-Ba-bearing alloys exhibited higher R ct and R p values than the Ce-La-Ba-free alloy at the passive and breakdown states. Furthermore, the additions of REMs and Ba together promoted the formation of dense chromium-enriched passive film.

Nuclear sub-structure in 112–122Ba nuclei within relativistic mean field theory

International Nuclear Information System (INIS)

Bhuyan, M.; Patra, S.K.; Arumugam, P.; Gupta, Raj K.

2011-01-01

Working within the framework of relativistic mean field theory, we study for the first time the clustering structure (nuclear sub-structure) of 112–122 Ba nuclei in an axially deformed cylindrical coordinate. We calculate the individual neutrons and protons density distributions for Ba-isotopes. From the analysis of the clustering configurations in total (neutrons-plus-protons) density distributions for various shapes of both the ground and excited states, we find different sub-structures inside the Ba nuclei considered here. The important step, carried out here for the first time, is the counting of number of protons and neutrons present in the clustering region(s). 12 C is shown to constitute the cluster configuration in prolate-deformed ground-states of 112–116 Ba and oblate-deformed first excited states of 118–122 Ba nuclei. Presence of other lighter clusters such as 2 H, 3 H and nuclei in the neighborhood of N = Z, 14 N, 34–36 Cl, 36 Ar and 42 Ca are also indicated in the ground and excited states of these nuclei. Cases with no cluster configuration are shown for 112–116 Ba in their first and second excited states. All these results are of interest for the observed intermediate-mass-fragments and fusion–fission processes, and the so far unobserved evaporation residues from the decaying Ba* compound nuclei formed in heavy ion reactions. (author)

Microwave-Hydrothermal Synthesis and Characterization of High-Purity Nb Doped BaTiO3 Nanocrystals

Directory of Open Access Journals (Sweden)

A. Khanfekr

2014-01-01

Full Text Available The synthesis of Nb doped BaTiO3 has been investigated under Microwave-Hydrothermal (MH conditions in the temperature of 150°C for only 2 h using C16H36O4Ti, BaH2O2.8H2O and NbCl5 as Ba, Ti and  Nb sources, respectively.  Typical experiments performed on MH processing have not yet reported for Nb doped BaTiO3.  In the MH process, the formation of high purity nano tetragonal Nb-BaTiO3 was strongly enhanced. New hydrothermal method was used instead of the previous solid state reaction for the BaTiO3±Nb2O3 system. The new method uses high pressure to create nano dimension particles in a lower time and temperature. In case of the phase evolution studies, the XRD pattern measurements and Raman spectroscopy were performed. TEM and FE-SEM images were taken for the detailed analysis of the particle size, surface and morphology.  Synthesis of Nb doped BaTiO3 with the Microwave-hydrothermal provides an advantage of fast crystallization and reduced crystal size when compared to existing methods.

Quadrilateral Micro-Hole Array Machining on Invar Thin Film: Wet Etching and Electrochemical Fusion Machining

Directory of Open Access Journals (Sweden)

Woong-Kirl Choi

2018-01-01

Full Text Available Ultra-precision products which contain a micro-hole array have recently shown remarkable demand growth in many fields, especially in the semiconductor and display industries. Photoresist etching and electrochemical machining are widely known as precision methods for machining micro-holes with no residual stress and lower surface roughness on the fabricated products. The Invar shadow masks used for organic light-emitting diodes (OLEDs contain numerous micro-holes and are currently machined by a photoresist etching method. However, this method has several problems, such as uncontrollable hole machining accuracy, non-etched areas, and overcutting. To solve these problems, a machining method that combines photoresist etching and electrochemical machining can be applied. In this study, negative photoresist with a quadrilateral hole array pattern was dry coated onto 30-µm-thick Invar thin film, and then exposure and development were carried out. After that, photoresist single-side wet etching and a fusion method of wet etching-electrochemical machining were used to machine micro-holes on the Invar. The hole machining geometry, surface quality, and overcutting characteristics of the methods were studied. Wet etching and electrochemical fusion machining can improve the accuracy and surface quality. The overcutting phenomenon can also be controlled by the fusion machining. Experimental results show that the proposed method is promising for the fabrication of Invar film shadow masks.

Apresentação Workshop Baía de Guanabara

Directory of Open Access Journals (Sweden)

Claudia Gutteres Vilela

2003-01-01

Full Text Available Ano 2003 Volume 26 - Workshop Baía de Guanabara Editor: Ismar de Souza Carvalho Coordenadora: Claudia Gutteres Vilela: Apresentação ISSN: 0101-9759 É com grande prazer que participo da edição do Anuário de 2003 do Instituto de Geociências, que inclui os trabalhos apresentados no Workshop Baía, realizado nos dias 12 e 13 de novembro de 2002, nesta instituição. O sucesso desse evento deve-se em grande parte aos trabalhos, apresentados sob a forma de palestras em mesas redondas ou painéis, por pesquisadores consagrados no Brasil e no exterior. O conteúdo dos trabalhos possui uma abrangência que se estende desde a Geologia até a Biologia, passando pela Oceanografia e Geografia, sempre com o objetivo comum de reunir dados sobre a Baía de Guanabara visando o diagnóstico ambiental. O Workshop Baía congregou diversas linhas de pesquisa desenvolvidas na Baía de Guanabara e regiões adjacentes, procurando uma integração das mesmas. Deste modo alguns trabalhos caracterizaram, em um contexto mais geral, a evolução do nível do mar na região sudeste durante o Holoceno, bem como apresentaram a neotectônica da região. Geoquímica orgânica de hidrocarbonetos e de metais pesados, sedimentologia e hidrogeologia integraram-se à distribuição de microorganismos nos sedimentos e na água, analisando diversas respostas a diferentes graus de poluição em regiões distintas. Um zoneamento ambiental ofereceu uma visão dinâmica das condições naturais e sociais do conjunto da Baía de Guanabara. A importância do workshop deve-se à busca de uma integração maior dos trabalhos acadêmicos para aplicação à gestão do desenvolvimento sustentável da Baía de Guanabara e seu entorno, que abriga a cidade do Rio de Janeiro e se constitui em uma das regiões com maior índice demográfico do Brasil. Seu impacto pode se avaliado pela presença de representantes de órgãos públicos como a SERLA, a Prefeitura de Niterói e ONGs ligadas a

A Universal Reactive Machine

DEFF Research Database (Denmark)

Andersen, Henrik Reif; Mørk, Simon; Sørensen, Morten U.

1997-01-01

Turing showed the existence of a model universal for the set of Turing machines in the sense that given an encoding of any Turing machine asinput the universal Turing machine simulates it. We introduce the concept of universality for reactive systems and construct a CCS processuniversal...

Emergence of the sub-THz central peak at phase transitions in artificial BaTiO3/(Ba,Sr)TiO3 superlattices

International Nuclear Information System (INIS)

Tikhonov, Yu.A.; Razumnaya, A.G.; Torgashev, V.I.; Zakharchenko, I.N.; Yuzyuk, Yu.I.; El Marssi, M.; Ortega, N.; Kumar, A.; Katiyar, R.S.

2015-01-01

A prominent central peak in the sub-THz frequency range was observed in the Raman spectra of BaTiO 3 /(Ba,Sr)TiO 3 (BT/BST) superlattice grown on (001)MgO substrate. Both soft and central mode show an anomaly around 200 K and 280 K, which can be correlated with orthorhombic to monoclinic phase transition of BST and BT, respectively. The observed temperature dependence of the central mode enabled us to explain rather broad temperature dependence of the dielectric permittivity previously observed in BT/BST superlattices. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Consequences of heavy machining vis à vis the machine structure – typical applications

International Nuclear Information System (INIS)

Leuch, M

2011-01-01

StarragHeckert has built 5 axis machines since the middle of the 80s for heavy duty milling. The STC-Centres are predominantly utilised in the aerospace industry, especially for milling structural workpieces, casings or Impellers made out of titanium and steel. StarragHeckert has a history of building machines for high performance milling. The machining of these components includes high forces thus spreading the wheat from the chaff. Although FEM calculations and multi-body simulations are carried out in the early stages of development, this paper will illustrate how the real process stability with modal analysis and cutting trials is determined. The experiment observes chatter stability to identify if the machine devices are adequate for the application or if the design has to be improved. Machining parameters of industrial applications are demonstrating the process stability for five axis heavy duties milling of StarragHeckert machine.

Virtual Machine in Automation Projects

OpenAIRE

Xing, Xiaoyuan

2010-01-01

Virtual machine, as an engineering tool, has recently been introduced into automation projects in Tetra Pak Processing System AB. The goal of this paper is to examine how to better utilize virtual machine for the automation projects. This paper designs different project scenarios using virtual machine. It analyzes installability, performance and stability of virtual machine from the test results. Technical solutions concerning virtual machine are discussed such as the conversion with physical...

First-principles calculations on the four phases of BaTiO3.

Science.gov (United States)

Evarestov, Robert A; Bandura, Andrei V

2012-04-30

The calculations based on linear combination of atomic orbitals basis functions as implemented in CRYSTAL09 computer code have been performed for cubic, tetragonal, orthorhombic, and rhombohedral modifications of BaTiO(3) crystal. Structural and electronic properties as well as phonon frequencies were obtained using local density approximation, generalized gradient approximation, and hybrid exchange-correlation density functional theory (DFT) functionals for four stable phases of BaTiO(3). A comparison was made between the results of different DFT techniques. It is concluded that the hybrid PBE0 [J. P. Perdew, K. Burke, M. Ernzerhof, J. Chem. Phys. 1996, 105, 9982.] functional is able to predict correctly the structural stability and phonon properties both for cubic and ferroelectric phases of BaTiO(3). The comparative phonon symmetry analysis in BaTiO(3) four phases has been made basing on the site symmetry and irreducible representation indexes for the first time. Copyright © 2012 Wiley Periodicals, Inc.

Commensurability oscillations in NdBa2Cu3Oy single crystals

Indian Academy of Sciences (India)

gated by angular dependent magnetization in very pure twinned and twin-free NdBa2 Cu3 Oy single ... The layered structure and the c-axis coherence length, ξc ≈ 4 ˚A, smaller than the lattice ... The high quality of both crystals is demonstrated by ... Commensurability oscillations in NdBa2Cu3Oy single crystals. 2. 3. 4. 5. 6.

Limited Streamer Tubes for the BaBar Instrumented Flux Return Upgrade

International Nuclear Information System (INIS)

Lu, C.

2005-01-01

Starting from the very beginning of their operation the efficiency of the RPC chambers in the BaBar Instrumented Flux Return (IFR) has suffered serious degradation. After intensive investigation, various remediation efforts had been carried out, but without success. As a result the BaBar collaboration decided to replace the dying barrel RPC chambers about two years ago. To study the feasibility of using the Limited Streamer Tube (LST) as the replacement of RPC we carried out an R and D program that has resulted in BaBar's deciding to replace the barrel RPC's with LST's. In this report we summarize the major detector R and D results, and leave other issues of the IFR system upgrade to the future publications

The Buttonhole Machine. Module 13.

Science.gov (United States)

South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

This module on the bottonhole machine, one in a series dealing with industrial sewing machines, their attachments, and operation, covers two topics: performing special operations on the buttonhole machine (parts and purpose) and performing special operations on the buttonhole machine (gauged buttonholes). For each topic these components are…

Introduction to machine learning.

Science.gov (United States)

Baştanlar, Yalin; Ozuysal, Mustafa

2014-01-01

The machine learning field, which can be briefly defined as enabling computers make successful predictions using past experiences, has exhibited an impressive development recently with the help of the rapid increase in the storage capacity and processing power of computers. Together with many other disciplines, machine learning methods have been widely employed in bioinformatics. The difficulties and cost of biological analyses have led to the development of sophisticated machine learning approaches for this application area. In this chapter, we first review the fundamental concepts of machine learning such as feature assessment, unsupervised versus supervised learning and types of classification. Then, we point out the main issues of designing machine learning experiments and their performance evaluation. Finally, we introduce some supervised learning methods.

First-principles studies on the adsorption of molecular oxygen on Ba(110) surface

International Nuclear Information System (INIS)

Li, S.F.; Xue Xinlian; Li Pinglin; Li Xinjian; Jia Yu

2006-01-01

The adsorption of O 2 on Ba(110) surface is studied with first-principles calculations based on density functional theory. Our calculations predict that O 2 may prefer to dissociative adsorption on Ba(110) surface without obvious barrier. Also our results do not support the model of charge transfer from the surface to the molecule as a bond breaking mechanism. Instead, the increasing hybridization between O 2 orbitals and the d states of Ba(110) surface may play an important role in the dissociation adsorption

Applied machining technology

CERN Document Server

Tschätsch, Heinz

2010-01-01

Machining and cutting technologies are still crucial for many manufacturing processes. This reference presents all important machining processes in a comprehensive and coherent way. It includes many examples of concrete calculations, problems and solutions.

Machine Learning

Energy Technology Data Exchange (ETDEWEB)

Chikkagoudar, Satish; Chatterjee, Samrat; Thomas, Dennis G.; Carroll, Thomas E.; Muller, George

2017-04-21

The absence of a robust and unified theory of cyber dynamics presents challenges and opportunities for using machine learning based data-driven approaches to further the understanding of the behavior of such complex systems. Analysts can also use machine learning approaches to gain operational insights. In order to be operationally beneficial, cybersecurity machine learning based models need to have the ability to: (1) represent a real-world system, (2) infer system properties, and (3) learn and adapt based on expert knowledge and observations. Probabilistic models and Probabilistic graphical models provide these necessary properties and are further explored in this chapter. Bayesian Networks and Hidden Markov Models are introduced as an example of a widely used data driven classification/modeling strategy.

Machine Protection

International Nuclear Information System (INIS)

Zerlauth, Markus; Schmidt, Rüdiger; Wenninger, Jörg

2012-01-01

The present architecture of the machine protection system is being recalled and the performance of the associated systems during the 2011 run will be briefly summarized. An analysis of the causes of beam dumps as well as an assessment of the dependability of the machine protection systems (MPS) itself is being presented. Emphasis will be given to events that risked exposing parts of the machine to damage. Further improvements and mitigations of potential holes in the protection systems will be evaluated along with their impact on the 2012 run. The role of rMPP during the various operational phases (commissioning, intensity ramp up, MDs...) will be discussed along with a proposal for the intensity ramp up for the start of beam operation in 2012

Machine Protection

Energy Technology Data Exchange (ETDEWEB)

Zerlauth, Markus; Schmidt, Rüdiger; Wenninger, Jörg [European Organization for Nuclear Research, Geneva (Switzerland)

2012-07-01

The present architecture of the machine protection system is being recalled and the performance of the associated systems during the 2011 run will be briefly summarized. An analysis of the causes of beam dumps as well as an assessment of the dependability of the machine protection systems (MPS) itself is being presented. Emphasis will be given to events that risked exposing parts of the machine to damage. Further improvements and mitigations of potential holes in the protection systems will be evaluated along with their impact on the 2012 run. The role of rMPP during the various operational phases (commissioning, intensity ramp up, MDs...) will be discussed along with a proposal for the intensity ramp up for the start of beam operation in 2012.

Machine Protection

CERN Document Server

Zerlauth, Markus; Wenninger, Jörg

2012-01-01

The present architecture of the machine protection system is being recalled and the performance of the associated systems during the 2011 run will be briefly summarized. An analysis of the causes of beam dumps as well as an assessment of the dependability of the machine protection systems (MPS) itself is being presented. Emphasis will be given to events that risked exposing parts of the machine to damage. Further improvements and mitigations of potential holes in the protection systems will be evaluated along with their impact on the 2012 run. The role of rMPP during the various operational phases (commissioning, intensity ramp up, MDs...) will be discussed along with a proposal for the intensity ramp up for the start of beam operation in 2012.

Dictionary of machine terms

International Nuclear Information System (INIS)

1990-06-01

This book has introduction of dictionary of machine terms, and a compilation committee and introductory remarks. It gives descriptions of the machine terms in alphabetical order from a to Z and also includes abbreviation of machine terms and symbol table, way to read mathematical symbols and abbreviation and terms of drawings.

HTS machine laboratory prototype

DEFF Research Database (Denmark)

machine. The machine comprises six stationary HTS field windings wound from both YBCO and BiSCOO tape operated at liquid nitrogen temperature and enclosed in a cryostat, and a three phase armature winding spinning at up to 300 rpm. This design has full functionality of HTS synchronous machines. The design...

Hydrothermal–galvanic couple synthesis of directionally oriented BaTiO3 thin films on TiN-coated substrates

International Nuclear Information System (INIS)

Yang, Chia-Jung; Tsai, Di-You; Chan, Pei-Hsuan; Wu, Chu-Tsun; Lu, Fu-Hsing

2013-01-01

BaTiO 3 films were synthesized on TiN-coated Si substrate below 100 °C by a hydrothermal–galvanic couple technique in barium contained alkaline solutions. X-ray diffraction and electron backscatter diffraction results show that the BaTiO 3 thin films were directionally oriented grown on the TiN/Si substrates, i.e., (111) BaTiO 3 over (111) TiN. The surface morphologies revealed that BaTiO 3 nucleated and grew over the TiN surface with a single layer. From kinetic analyses, the growth rates of BaTiO 3 films prepared by the hydrothermal–galvanic couple technique were faster than a hydrothermal method. The galvanic effects were confirmed by investigating the induced currents and energies. The galvanic currents were generated and controlled by both the dissolution of TiN and the formation of BaTiO 3 . The output electric energies increased rapidly with the reaction time and leveled off at the full coverage of BaTiO 3 . - Highlights: • Cubic BaTiO 3 films are synthesized by a hydrothermal–galvanic couple method (HT–GC). • Growth rates of BaTiO 3 films made by HT–GC are faster than a hydrothermal method. • BaTiO 3 films are directionally oriented grown on the TiN/Si substrates. • Galvanic currents are controlled by dissolution of TiN and formation of BaTiO 3

Factors influencing formation of highly dispersed BaTiO3 nanospheres with uniform sizes in static hydrothermal synthesis

International Nuclear Information System (INIS)

Gao, Jiabing; Shi, Haiyue; Dong, Huina; Zhang, Rui; Chen, Deliang

2015-01-01

Highly dispersed BaTiO 3 nanospheres with uniform sizes have important applications in micro/nanoscale functional devices. To achieve well-dispersed spherical BaTiO 3 nanocrystals, we carried out as reported in this paper the systematic investigation on the factors that influence the formation of BaTiO 3 nanospheres by the static hydrothermal process, including the NaOH concentrations [NaOH], molar Ba/Ti ratios (R Ba/Ti ), hydrothermal temperatures, and durations, with an emphasis on understanding the related mechanisms. Barium nitrate and TiO 2 sols derived from tetrabutyl titanate were used as the starting materials. The as-synthesized BaTiO 3 samples were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray analysis, thermogravimetry, differential thermal analysis, and FT-IR spectra. The highly dispersed BaTiO 3 nanospheres (76 ± 13 nm) were achieved under the optimum hydrothermal conditions at 200 °C for 10 h: [NaOH] = 2.0 mol L −1 and R Ba/Ti  = 1.5. Higher NaOH concentrations, higher Ba/Ti ratios, higher hydrothermal temperatures, and longer hydrothermal durations are favorable in forming BaTiO 3 nanospheres with larger fractions of tetragonal phase and higher yields; but too long hydrothermal durations resulted in abnormal growth and reduced the uniformity in particle sizes. The possible formation mechanisms for BaTiO 3 nanocrystals under the static hydrothermal conditions were investigated

Thin film hybrid Josephson junctions with Co doped Ba-122

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Stefan; Doering, Sebastian; Schmidl, Frank; Tympel, Volker; Grosse, Veit; Seidel, Paul [Friedrich-Schiller-Universitaet Jena, Institut fuer Festkoerperphysik, Helmholtzweg 5, 07743 Jena (Germany); Haindl, Silvia; Iida, Kazumasa; Kurth, Fritz; Holzapfel, Bernhard [IFW Dresden, Institut fuer Metallische Werkstoffe, Helmholtzstrasse 20, 01069 Dresden (Germany); Moench, Ingolf [IFW Dresden, Institut fuer Integrative Nanowissenschaften, Helmholtzstrasse 20, 01069 Dresden (Germany)

2011-07-01

Josephson junctions are a strong tool to investigate fundamental superconducting properties, such as gap behaviour, dependencies from external fields and the order parameter symmetry. Finding secure values enables the possibility of theoretical descriptions to understand the physical processes within the new iron-based superconductors. Based on Co-doped BaFe{sub 2}As{sub 2} (Ba-122) layers produced via pulsed laser deposition (PLD) on (La,Sr)(Al,Ta)O{sub 3} substrates, we manufactured superconductor-normal conductor-superconductor (S-N-S) junctions structures by using photolithography, ion beam etching as well as insulating SiO{sub 2} layers. We present working Ba-122/Au/PbIn thin film Josephson junctions with different contact areas and barrier thicknesses, their temperature dependence and response to microwave irradiation. The calculated I{sub c}R{sub N} product is in the range of a couple of microvolts.

Probability Machines: Consistent Probability Estimation Using Nonparametric Learning Machines

Science.gov (United States)

Malley, J. D.; Kruppa, J.; Dasgupta, A.; Malley, K. G.; Ziegler, A.

2011-01-01

Summary Background Most machine learning approaches only provide a classification for binary responses. However, probabilities are required for risk estimation using individual patient characteristics. It has been shown recently that every statistical learning machine known to be consistent for a nonparametric regression problem is a probability machine that is provably consistent for this estimation problem. Objectives The aim of this paper is to show how random forests and nearest neighbors can be used for consistent estimation of individual probabilities. Methods Two random forest algorithms and two nearest neighbor algorithms are described in detail for estimation of individual probabilities. We discuss the consistency of random forests, nearest neighbors and other learning machines in detail. We conduct a simulation study to illustrate the validity of the methods. We exemplify the algorithms by analyzing two well-known data sets on the diagnosis of appendicitis and the diagnosis of diabetes in Pima Indians. Results Simulations demonstrate the validity of the method. With the real data application, we show the accuracy and practicality of this approach. We provide sample code from R packages in which the probability estimation is already available. This means that all calculations can be performed using existing software. Conclusions Random forest algorithms as well as nearest neighbor approaches are valid machine learning methods for estimating individual probabilities for binary responses. Freely available implementations are available in R and may be used for applications. PMID:21915433

National machine guarding program: Part 1. Machine safeguarding practices in small metal fabrication businesses

OpenAIRE

Parker, David L.; Yamin, Samuel C.; Brosseau, Lisa M.; Xi, Min; Gordon, Robert; Most, Ivan G.; Stanley, Rodney

2015-01-01

Background Metal fabrication workers experience high rates of traumatic occupational injuries. Machine operators in particular face high risks, often stemming from the absence or improper use of machine safeguarding or the failure to implement lockout procedures. Methods The National Machine Guarding Program (NMGP) was a translational research initiative implemented in conjunction with two workers' compensation insures. Insurance safety consultants trained in machine guarding used standardize...

Machine vision systems using machine learning for industrial product inspection

Science.gov (United States)

Lu, Yi; Chen, Tie Q.; Chen, Jie; Zhang, Jian; Tisler, Anthony

2002-02-01

Machine vision inspection requires efficient processing time and accurate results. In this paper, we present a machine vision inspection architecture, SMV (Smart Machine Vision). SMV decomposes a machine vision inspection problem into two stages, Learning Inspection Features (LIF), and On-Line Inspection (OLI). The LIF is designed to learn visual inspection features from design data and/or from inspection products. During the OLI stage, the inspection system uses the knowledge learnt by the LIF component to inspect the visual features of products. In this paper we will present two machine vision inspection systems developed under the SMV architecture for two different types of products, Printed Circuit Board (PCB) and Vacuum Florescent Displaying (VFD) boards. In the VFD board inspection system, the LIF component learns inspection features from a VFD board and its displaying patterns. In the PCB board inspection system, the LIF learns the inspection features from the CAD file of a PCB board. In both systems, the LIF component also incorporates interactive learning to make the inspection system more powerful and efficient. The VFD system has been deployed successfully in three different manufacturing companies and the PCB inspection system is the process of being deployed in a manufacturing plant.

Hydrothermal growth of highly textured BaTiO3 films composed of nanowires

International Nuclear Information System (INIS)

Zhou Zhi; Tang Haixiong; Sodano, Henry A; Lin Yirong

2013-01-01

Textured barium titanate (BaTiO 3 ) films are attracting immense research interest due to their lead-free composition and excellent piezoelectric and dielectric properties. Most synthesis methods for these films require a high temperature, leading to the formation of a secondary phase and an overall decrease in the electrical properties of the ceramic. In order to alleviate these issues, a novel fabrication method is introduced by transferring oriented rutile TiO 2 nanowires to a textured BaTiO 3 film at temperatures below 160 °C. The microstructure and thickness of the fabricated BaTiO 3 films were characterized by scanning electron microscopy, and the crystal structure and degree of orientation were evaluated by x-ray diffraction patterns using the Lotgering method. It is shown that the thickness of the BaTiO 3 film can be controlled by the length of TiO 2 nanowire array template, and the degree of orientation of the textured BaTiO 3 films is highly dependent on the film thickness; the crystallographic orientation has been measured to reach up to 87%. The relative dielectric constant (ε r = 1300) and ferroelectric properties (P r = 2.7 μC cm −2 , E c = 4.0 kV mm −1 ) of the textured BaTiO 3 films were also characterized to demonstrate their potential application in sensors, random access memory, and micro-electromechanical systems. (paper)

Fluorine dynamics in BaF2 superionic conductors investigated by NMR

International Nuclear Information System (INIS)

Gumann, Patryk

2008-01-01

In this work the dynamics of fluorine in solid-state electrolytes having BaF 2 -structure was investigated using three different NMR-methods: field cycling relaxometry, lineshape analysis, and static field gradient NMR. For this purpose a pure BaF 2 crystal, as well as crystals doped with trivalent impurities (LaF 3 ), were studied as a function of temperature. Using MAS NMR it was possible to identify two lines in Ba 0.9 La 0.1 F 2.1 having different chemical shift, and to refer them to the modified crystal structure. On this basis a model for the fluorine lineshape has been developed, taking into account three motional processes characterized by their correlation times. It includes jump diffusion of the fluorine ions among equivalent sites within two crystallographically distinct sublattices, and inter-lattice exchange processes. By measuring frequency and temperature-dependent spin lattice relaxation times, it was possible to gain information about fluorine dynamics on microscopic length scales. An attempt was also made to analyze the data for pure BaF 2 and low admixture concentration samples with a non-exponential correlation function. (orig.)

Machine Directional Register System Modeling for Shaft-Less Drive Gravure Printing Machines

Directory of Open Access Journals (Sweden)

Shanhui Liu

2013-01-01

Full Text Available In the latest type of gravure printing machines referred to as the shaft-less drive system, each gravure printing roller is driven by an individual servo motor, and all motors are electrically synchronized. The register error is regulated by a speed difference between the adjacent printing rollers. In order to improve the control accuracy of register system, an accurate mathematical model of the register system should be investigated for the latest machines. Therefore, the mathematical model of the machine directional register (MDR system is studied for the multicolor gravure printing machines in this paper. According to the definition of the MDR error, the model is derived, and then it is validated by the numerical simulation and experiments carried out in the experimental setup of the four-color gravure printing machines. The results show that the established MDR system model is accurate and reliable.

Metrological activity determination of {sup 133}Ba by sum-peak absolute method

Energy Technology Data Exchange (ETDEWEB)

Silva, R.L. da; Delgado, J.U.; Poledna, R.; Santos, A.; Veras, E.V. de; Rangel, J.; Trindade, O.L. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Almeida, M.C.M. de, E-mail: marcandida@yahoo.com.br, E-mail: candida@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

2015-07-01

The National Laboratory for Metrology of Ionizing Radiation provides gamma sources of radionuclide and standardized in activity with reduced uncertainties. Relative methods require standards to determine the sample activity while the absolute methods, as sum-peak, not. The activity is obtained directly with good accuracy and low uncertainties. {sup 133}Ba is used in research laboratories and on calibration of detectors for analysis in different work areas. Classical absolute methods do not calibrate {sup 133}Ba due to its complex decay scheme. The sum-peak method using gamma spectrometry with germanium detector standardizes {sup 133}Ba samples. Uncertainties lower than 1% to activity results were obtained.

Machine learning and radiology.

Science.gov (United States)

Wang, Shijun; Summers, Ronald M

2012-07-01

In this paper, we give a short introduction to machine learning and survey its applications in radiology. We focused on six categories of applications in radiology: medical image segmentation, registration, computer aided detection and diagnosis, brain function or activity analysis and neurological disease diagnosis from fMR images, content-based image retrieval systems for CT or MRI images, and text analysis of radiology reports using natural language processing (NLP) and natural language understanding (NLU). This survey shows that machine learning plays a key role in many radiology applications. Machine learning identifies complex patterns automatically and helps radiologists make intelligent decisions on radiology data such as conventional radiographs, CT, MRI, and PET images and radiology reports. In many applications, the performance of machine learning-based automatic detection and diagnosis systems has shown to be comparable to that of a well-trained and experienced radiologist. Technology development in machine learning and radiology will benefit from each other in the long run. Key contributions and common characteristics of machine learning techniques in radiology are discussed. We also discuss the problem of translating machine learning applications to the radiology clinical setting, including advantages and potential barriers. Copyright © 2012. Published by Elsevier B.V.

Chemical correlations in Caetite (BA) region, Brazil

International Nuclear Information System (INIS)

Gennari, R.F.; Almeida, Geangela M.; Souza, S.O.

2013-01-01

Brazil's economic situation is responsible for an urgent demand for energy. There are several ways to generate energy, in some localities of our country, energy generation occurs almost exclusively by nuclear route, as in Rio de Janeiro state. Brazil has the sixth largest reserve of the uranium ore in the world. Nowadays there is only one mine under exploration (Uraniferous District of Lagoa Real - Caetite-BA). Unfortunately, nuclear power generation is better known, by common citizen, more for its unwanted effects than for its benefits. This fact is also powered by some Non-Governmental Organizations (NGOs), such as Greenpeace, who claim the uranium mine is dangerous since it causes environmental contamination. However, Industrias Nucleares do Brasil (INB) rejected these accusations. In a previous study, we demonstrated that doses of the Caetite (BA) population are consistent with those usually found in other countries. We stated also the higher concentration of 238 U determined, in only one water sample, is probably due to natural processes, as soil leaching. In order to verify the existing natural processes, macro and micro chemical elements present in water and soil samples collected in the Caetite (BA) region were determined by ICP-MS. The results were transformed into dendrograms where chemical correlations are evidenced and they are consistent with existing natural chemical processes. It was also possible to observe a correlation between samples corroborating with the Geographic Information Systems data to be presented in this same scientific event. (author)

Chemical correlations in Caetite (BA) region, Brazil

Energy Technology Data Exchange (ETDEWEB)

Gennari, R.F., E-mail: rgennari@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Inst. de Fisica. Dept. de Fisica Nuclear; Campos, S.S., E-mail: simaracampos@gmail.com [Universidade Estadual do Sudoeste da Bahia (UESB), Itapetinga, BA, (Brazil); Almeida, Geangela M.; Souza, S.O., E-mail: susanasouzalalic@gmail.com [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. de Fisica

2013-07-01

Brazil's economic situation is responsible for an urgent demand for energy. There are several ways to generate energy, in some localities of our country, energy generation occurs almost exclusively by nuclear route, as in Rio de Janeiro state. Brazil has the sixth largest reserve of the uranium ore in the world. Nowadays there is only one mine under exploration (Uraniferous District of Lagoa Real - Caetite-BA). Unfortunately, nuclear power generation is better known, by common citizen, more for its unwanted effects than for its benefits. This fact is also powered by some Non-Governmental Organizations (NGOs), such as Greenpeace, who claim the uranium mine is dangerous since it causes environmental contamination. However, Industrias Nucleares do Brasil (INB) rejected these accusations. In a previous study, we demonstrated that doses of the Caetite (BA) population are consistent with those usually found in other countries. We stated also the higher concentration of {sup 238}U determined, in only one water sample, is probably due to natural processes, as soil leaching. In order to verify the existing natural processes, macro and micro chemical elements present in water and soil samples collected in the Caetite (BA) region were determined by ICP-MS. The results were transformed into dendrograms where chemical correlations are evidenced and they are consistent with existing natural chemical processes. It was also possible to observe a correlation between samples corroborating with the Geographic Information Systems data to be presented in this same scientific event. (author)

Consideration of the band-gap tunability of BaSi2 by alloying with Ca or Sr based on the electronic structure calculations

International Nuclear Information System (INIS)

Imai, Yoji; Watanabe, Akio

2007-01-01

The electronic structures and total energies of BaSi 2 -SrSi 2 and BaSi 2 -CaSi 2 systems have been calculated using the first-principle pseudopotential method to clarify the band gap tunability of BaSi 2 by alloying with Sr or Ca. From an energetic consideration of the compounds where all the Ba I sites or all the Ba II sites of the BaSi 2 lattice are preferentially replaced by Sr or Ca, it is expected that the Ba I site will be preferentially replaced by Sr rather than the Ba II sites. Compounds where all the Ba II sites are replaced by Sr or all the Ba II or all the Ba I sites are replaced by Ca are energetically unfavorable compared to the undissolved system of BaSi 2 and SrSi 2 or CaSi 2 . The effect of the addition of Sr or Ca into the BaSi 2 lattice on the gap value is different depending on the replaced sites of Ba. The replacement of Ba I site by Sr will broaden the band gap of BaSi 2 , which is consistent with the observed results

Machining with abrasives

CERN Document Server

Jackson, Mark J

2011-01-01

Abrasive machining is key to obtaining the desired geometry and surface quality in manufacturing. This book discusses the fundamentals and advances in the abrasive machining processes. It provides a complete overview of developing areas in the field.

The Knife Machine. Module 15.

Science.gov (United States)

South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

This module on the knife machine, one in a series dealing with industrial sewing machines, their attachments, and operation, covers one topic: performing special operations on the knife machine (a single needle or multi-needle machine which sews and cuts at the same time). These components are provided: an introduction, directions, an objective,…

Improved the lithium storage capability of BaLi2Ti6O14 by electroless silver coating

International Nuclear Information System (INIS)

Lin, Xiaoting; Wang, Pengfei; Li, Peng; Yu, Haoxiang; Qian, Shangshu; Shui, Miao; Wang, Dongjie; Long, Nengbing; Shu, Jie

2015-01-01

Highlights: • BaLi 2 Ti 6 O 14 /Ag is fabricated via a facile electroless deposition. • Highly dispersed Ag nanoparticles are successively coated on BaLi 2 Ti 6 O 14 . • BaLi 2 Ti 6 O 14 /Ag is used as anode material for lithium storage. • BaLi 2 Ti 6 O 14 /Ag exhibits improved lithium storage capability. - Abstract: To form BaLi 2 Ti 6 O 14 /Ag, highly dispersed Ag nanoparticles are successfully deposited on the surface of BaLi 2 Ti 6 O 14 by a simple chemical deposition method. The morphology, quantity and size of Ag nanoparticles in BaLi 2 Ti 6 O 14 /Ag composites are significantly influenced by the Ag coating contents. Electrochemical results show that Ag nanoparticles play a positive role in reducing redox polarization and improving electrical conductivity of BaLi 2 Ti 6 O 14 during lithiation/delithiation processes. Among all the as-obtained products, 6 wt.% Ag coated BaLi 2 Ti 6 O 14 shows the highest initial charge specific capacity of 160 mAh g −1 at the current density of 100 mA g −1 (1C), which is much higher than the 149.1 mAh g −1 for bare BaLi 2 Ti 6 O 14 . After 100 charge/discharge cycles, the reversible capacity can be maintained at 117.0 mAh g −1 . Moreover, this sample also shows excellent rate performance with high reversible charge capacities of 147.5, 139.7, 132.6, and 126.7 mAh g −1 at the rates of 2C, 3C, 4C and 5C, respectively. Compared with bare BaLi 2 Ti 6 O 14 , the superior electrochemical performance indicates that BaLi 2 Ti 6 O 14 /Ag can be a good anode material in lithium ion batteries.

Large linear magnetoresistance in a new Dirac material BaMnBi2

Science.gov (United States)

Wang, Yi-Yan; Yu, Qiao-He; Xia, Tian-Long

2016-10-01

Dirac semimetal is a class of materials that host Dirac fermions as emergent quasi-particles. Dirac cone-type band structure can bring interesting properties such as quantum linear magnetoresistance and large mobility in the materials. In this paper, we report the synthesis of high quality single crystals of BaMnBi2 and investigate the transport properties of the samples. BaMnBi2 is a metal with an antiferromagnetic transition at T N = 288 K. The temperature dependence of magnetization displays different behavior from CaMnBi2 and SrMnBi2, which suggests the possible different magnetic structure of BaMnBi2. The Hall data reveals electron-type carriers and a mobility μ(5 K) = 1500 cm2/V·s. Angle-dependent magnetoresistance reveals the quasi-two-dimensional (2D) Fermi surface in BaMnBi2. A crossover from semiclassical MR ˜ H 2 dependence in low field to MR ˜ H dependence in high field, which is attributed to the quantum limit of Dirac fermions, has been observed in magnetoresistance. Our results indicate the existence of Dirac fermions in BaMnBi2. Project supported by the National Natural Science Foundation of China (Grant No. 11574391), the Fundamental Research Funds for the Central Universities, and the Research Funds of Renmin University of China (Grant No. 14XNLQ07).

Restrictions of process machine retooling at machine-building enterprises

Directory of Open Access Journals (Sweden)

Kuznetsova Elena

2017-01-01

Full Text Available The competitiveness of the national economy depends on the technological level of the machine-building enterprises production equipment. Today in Russia there are objective and subjective restrictions for the optimum policy formation of the manufacturing equipment renewal. The analysis of the manufacturing equipment age structure dynamics in the Russian machine-building complex indicates the negative tendencies intensification: increase in the equipment service life, reduction in the share of up-to-date equipment, and drop in its use efficiency. The article investigates and classifies the main restrictions of the manufacturing equipment renewal process, such as regulatory and legislative, financial, organizational, competency-based. The economic consequences of the revealed restrictions influence on the machine-building enterprises activity are shown.

Development of BaSO sub 4 :Eu thermoluminescence phosphor

CERN Document Server

Madhusoodanan, U; Lakshmanan, A R

1999-01-01

A highly sensitive thermoluminescence (TL) phosphor based on BaSO sub 4 :Eu was developed following the coprecipitation technique and firing in argon atmosphere at 1123 K. Photoluminescence studies confirm that firing in argon atmosphere instead of air increased the incorporation of Eu ions in 2+ valence state. At low gamma-ray doses, its TL sensitivity is nearly 2 to 3 times higher than that of CaSO sub 4 :Dy phosphor. The other salient features of this BaSO sub 4 :Eu TL phosphor are a constant glow curve shape and a nearly linear gamma-ray dose response.

Orthogonal Operation of Constitutional Dynamic Networks Consisting of DNA-Tweezer Machines.

Science.gov (United States)

Yue, Liang; Wang, Shan; Cecconello, Alessandro; Lehn, Jean-Marie; Willner, Itamar

2017-12-26

Overexpression or down-regulation of cellular processes are often controlled by dynamic chemical networks. Bioinspired by nature, we introduce constitutional dynamic networks (CDNs) as systems that emulate the principle of the nature processes. The CDNs comprise dynamically interconvertible equilibrated constituents that respond to external triggers by adapting the composition of the dynamic mixture to the energetic stabilization of the constituents. We introduce a nucleic acid-based CDN that includes four interconvertible and mechanically triggered tweezers, AA', BB', AB' and BA', existing in closed, closed, open, and open configurations, respectively. By subjecting the CDN to auxiliary triggers, the guided stabilization of one of the network constituents dictates the dynamic reconfiguration of the structures of the tweezers constituents. The orthogonal and reversible operations of the CDN DNA tweezers are demonstrated, using T-A·T triplex or K + -stabilized G-quadruplex as structural motifs that control the stabilities of the constituents. The implications of the study rest on the possible applications of input-guided CDN assemblies for sensing, logic gate operations, and programmed activation of molecular machines.

Mechanical design of machine components

CERN Document Server

Ugural, Ansel C

2015-01-01

Mechanical Design of Machine Components, Second Edition strikes a balance between theory and application, and prepares students for more advanced study or professional practice. It outlines the basic concepts in the design and analysis of machine elements using traditional methods, based on the principles of mechanics of materials. The text combines the theory needed to gain insight into mechanics with numerical methods in design. It presents real-world engineering applications, and reveals the link between basic mechanics and the specific design of machine components and machines. Divided into three parts, this revised text presents basic background topics, deals with failure prevention in a variety of machine elements and covers applications in design of machine components as well as entire machines. Optional sections treating special and advanced topics are also included.Key Features of the Second Edition:Incorporates material that has been completely updated with new chapters, problems, practical examples...

Soft computing in machine learning

CERN Document Server

Park, Jooyoung; Inoue, Atsushi

2014-01-01

As users or consumers are now demanding smarter devices, intelligent systems are revolutionizing by utilizing machine learning. Machine learning as part of intelligent systems is already one of the most critical components in everyday tools ranging from search engines and credit card fraud detection to stock market analysis. You can train machines to perform some things, so that they can automatically detect, diagnose, and solve a variety of problems. The intelligent systems have made rapid progress in developing the state of the art in machine learning based on smart and deep perception. Using machine learning, the intelligent systems make widely applications in automated speech recognition, natural language processing, medical diagnosis, bioinformatics, and robot locomotion. This book aims at introducing how to treat a substantial amount of data, to teach machines and to improve decision making models. And this book specializes in the developments of advanced intelligent systems through machine learning. It...

Mankind, machines and people

Energy Technology Data Exchange (ETDEWEB)

Hugli, A

1984-01-01

The following questions are addressed: is there a difference between machines and men, between human communication and communication with machines. Will we ever reach the point when the dream of artificial intelligence becomes a reality. Will thinking machines be able to replace the human spirit in all its aspects. Social consequences and philosophical aspects are addressed. 8 references.

Simulation of iron impurity in BaTiO{sub 3} crystals

Energy Technology Data Exchange (ETDEWEB)

Stashans, Arvids, E-mail: arvids@utpl.edu.e [Grupo de Fisicoquimica de Materiales, Instituto de Quimica Aplicada, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador); Castillo, Darwin [Grupo de Fisicoquimica de Materiales, Instituto de Quimica Aplicada, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador); Escuela de Electronica y Telecomunicaciones, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador)

2009-05-01

Iron-doped barium titanate (BaTiO{sub 3}) has been simulated taking into account cubic and tetragonal crystallographic lattices of the crystal. A quantum-chemical method based on the Hartree-Fock formalism has been used throughout the study. The calculated equilibrium structures of Fe-doped crystals reveal the defect-inward displacements of the Ti and O atoms whereas the shifts for the Ba atoms are encountered to be away with respect to the Fe impurity. According to the analysis of electron density population and electron band structure it is found that some unusual chemical bonding might take place between the Fe atom and its six adjacent O atoms. The role of Fe impurity in the ferroelectric polarization of the tetragonal BaTiO{sub 3} crystal has been discussed too.

A Concrete Framework for Environment Machines

DEFF Research Database (Denmark)

Biernacka, Malgorzata; Danvy, Olivier

2007-01-01

calculus with explicit substitutions), we extend it minimally so that it can also express one-step reduction strategies, and we methodically derive a series of environment machines from the specification of two one-step reduction strategies for the lambda-calculus: normal order and applicative order....... The derivation extends Danvy and Nielsen’s refocusing-based construction of abstract machines with two new steps: one for coalescing two successive transitions into one, and the other for unfolding a closure into a term and an environment in the resulting abstract machine. The resulting environment machines...... include both the Krivine machine and the original version of Krivine’s machine, Felleisen et al.’s CEK machine, and Leroy’s Zinc abstract machine....

Translations on Eastern Europe Scientific Affairs No. 530

Science.gov (United States)

1976-11-24

candidate of medical sciences, on the basis of his disserta- tion entitled "Glucose Metabolism and Insulin Uptake of Isolated Human Adi- pose Cells" 11...34; Istvan Fodor, candidate of geographical sciences, on the basis of his dis- sertation entitled "Climatological and Bioclimatological Features of the... Human Uterus" Tran Quy Tien, candidate of mathematical sciences, on the basis of his dis- sertation entitled "Investigations in the Field of Rees-Type

Findings From the National Machine Guarding Program-A Small Business Intervention: Machine Safety.

Science.gov (United States)

Parker, David L; Yamin, Samuel C; Xi, Min; Brosseau, Lisa M; Gordon, Robert; Most, Ivan G; Stanley, Rodney

2016-09-01

The purpose of this nationwide intervention was to improve machine safety in small metal fabrication businesses (3 to 150 employees). The failure to implement machine safety programs related to guarding and lockout/tagout (LOTO) are frequent causes of Occupational Safety and Health Administration (OSHA) citations and may result in serious traumatic injury. Insurance safety consultants conducted a standardized evaluation of machine guarding, safety programs, and LOTO. Businesses received a baseline evaluation, two intervention visits, and a 12-month follow-up evaluation. The intervention was completed by 160 businesses. Adding a safety committee was associated with a 10% point increase in business-level machine scores (P increase in LOTO program scores (P < 0.0001). Insurance safety consultants proved effective at disseminating a machine safety and LOTO intervention via management-employee safety committees.

Glassy and Metastable Crystalline BaTi2O5 by Containerless Processing

Science.gov (United States)

Yoda, Shinichi; Kentei Yu, Yu; Kumar, Vijaya; Kameko, Masashi

Many efforts have been devoted to forming bulk glass from the melt of ferroelectric crystalline materials without adding any network-forming oxides such as SiO2 due to the potential for producing transparent glass ceramics with high dielectric constant and enhanced piezoelectric, pyroelectric and electro-optic use. The containerless processing is an attractive synthesis tech-nique as it can prevent melt contamination, minimize heterogeneous nucleation, and allow melt to achieve deep undercooling for forming metastable and glassy materials. We have fabricated a new ferroelectric materiel BaTi2 O5 [1] as bulk glass from melt by us-ing containerless processing and studied the phase relationship between microstructure and ferroelectric properties of BaTi2 O5 [2]. The structures of glassy and metastable crystalline BaTi2 O5 fabricated by the containerless pro-cessing were comprehensively investigated by combined X-ray and neutron diffractions, XANES analyses and computer simulations [3]. The 3-dimensional atomic structure of glassy BaTi2 O5 (g-BaTi2 O5 ), simulated by Reverse Monte Carlo (RMC) modelling on diffraction data, shows that extremely distorted TiO5 polyhedra interconnected with both corner-and edge-shared oxy-gen, formed a higher packing density structure than that of conventional silicate glass linked with only corner-sharing of SiO4 polyhedra. In addition, XANES measurement reveales that five-coordinated TiO5 polyhedra were formable in the crystallized metastable a-and b-BaTi2 O5 phases. The structure of metastable b-BaTi2 O5 was solved by ab initio calculation, and refined by Rietveld refinement as group Pnma with unit lattices a = 10.23784 ˚, b = 3.92715 ˚, c A A = 10.92757 A ˚. Our results show that the glass-forming ability enhanced by containerless pro-cessing, not by `strong glass former', fabricated new bulk oxide glasses with peculiar structures and properties. The intermediate-range structure of g-BaTi2 O5 and the crystalline structure of

Dosimetry of ultraviolet radiation with BaHfO_3 powders

International Nuclear Information System (INIS)

Barrera A, A. A.; Aguilar D, G. A.; Guzman M, J.; Rivera M, T.; Ceron R, V.

2016-10-01

Ceramic materials based on pure barium hafnate (BaHfO_3) have been obtained as a powder by the co-precipitation method. The powders obtained have a cubic structure that favors the thermoluminescent and optical properties, through which a better detection of the non-ionizing radiation is allowed. With these powders various tests were performed in the ultraviolet range at different exposure times. These thermoluminescent (Tl) studies were carried out using a Tl 3500 hand held reader which yielded a brightness curve that ranged from room temperature to the 350 degrees Celsius. This BaHfO_3 response exhibits a broad brightness curve with a single peak centered around 225 degrees Celsius. Finally, is reported that there are materials of barium hafnate (BaHfO_3) doped with some rare earths (Eu, Tb) which, instead of improving the performance of the powders, decrease it, so that the use of intrinsic barium hafnate is the most appropriate. (Author)

Electronic States of IC60BA and PC71BM

International Nuclear Information System (INIS)

Sheng Chun-Qi; Wang Peng; Shen Ying; Li Wen-Jie; Li Hong-Nian; Zhang Wen-Hua; Zhu Jun-Fa; Lai Guo-Qiao

2013-01-01

We investigate the electronic states of IC 60 BA and PC 71 BM using first-principles calculations and photoelectron spectroscopy (PES) measurements. The energy level structures for all possible isomers are reported and compared with those of C 60 , C 70 and PC 61 BM. The attachment of the side chains can raise the LUMO energies and decrease the HOMO-LUMO gaps, and thus helps to increase the power-conversion efficiency of bulk heterojunction solar cells. In the PES studies, we prepared IC 60 BA and PC 71 BM films on Si:H(111) substrates to construct adsorbate/substrate interfaces describable with the integer charge-transfer (ICT) model. Successful measurements then revealed that one of the most important material properties for an electron acceptor, the energy of the negative integer charge-transfer state (E ICT− ), is 4.31 eV below the vacuum level for PC 71 BM. The E ICT− of IC 60 BA is smaller than 4.14 eV

Influence of seeding on crystallization behaviour of BaNaB9 glasses

Indian Academy of Sciences (India)

Administrator

Influence of seeding on crystallization behaviour of BaNaB9. O15 glasses. RAHUL VAISH and K B R VARMA*. Materials Research Centre, Indian Institute of Science, Bangalore 560 012, India. MS received 18 August 2008. Abstract. Transparent BaNaB9O15 (BNBO) glasses were fabricated via the conventional melt- ...

Laser-induced fluorescence spectra of Ba+*-He exciplexes produced in cold He gas

International Nuclear Information System (INIS)

Fukuyama, Yoshimitsu; Matsuo, Yukari; Moriwaki, Yoshiki

2004-01-01

We report the observation of laser-induced fluorescence spectra of Ba +* -He exciplexes. The experiment is carried out in an environment of cold gaseous helium at a temperature range of 3-30 K. We have observed the emission spectra of exciplexes by means of excitation of the 6p 2 P 32 2 S 12 transition of Ba + ions. It is found that these spectra are redshifted from the D2 emission line in the free space and are composed of several peaks. The experimental results are reproduced well by theoretical calculation of the emission spectra for vibrational levels of Ba +* -He. We also investigate the vibrational dynamics of the 6p 2 Π 32 state of Ba + *-He, and we have determined the collision-induced vibrational relaxation cross sections of the 6p 2 Π 32 state to be 9.7±1.1 A 2 at 15 K

Research on the proficient machine system. Theoretical part; Jukutatsu machine system no chosa kenkyu. Rironhen

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

The basic theory of the proficient machine system to be developed was studied. Important proficient techniques in manufacturing industries are becoming extinct because of insufficient succession to next generation. The proficient machine system was proposed to cope with such situation. This machine system includes the mechanism for progress and evolution of techniques and sensibilities to be adaptable to environmental changes by learning and recognizing various motions such as work and process. Consequently, the basic research fields are composed of thought, learning, perception and action. This machine requires not only deigned fixed functions but also introduction of the same proficient concept as human being to be adaptable to changes in situation, purpose, time and machine`s complexity. This report explains in detail the basic concept, system principle, approaching procedure and practical elemental technologies of the proficient machine system, and also describes the future prospect. 133 refs., 110 figs., 7 tabs.

Machining of uranium and uranium alloys

International Nuclear Information System (INIS)

Morris, T.O.

1981-01-01

Uranium and uranium alloys can be readily machined by conventional methods in the standard machine shop when proper safety and operating techniques are used. Material properties that affect machining processes and recommended machining parameters are discussed. Safety procedures and precautions necessary in machining uranium and uranium alloys are also covered. 30 figures

[Comparison of machinability of two types of dental machinable ceramic].

Science.gov (United States)

Fu, Qiang; Zhao, Yunfeng; Li, Yong; Fan, Xinping; Li, Yan; Lin, Xuefeng

2002-11-01

In terms of the problems of now available dental machinable ceramics, a new type of calcium-mica glass-ceramic, PMC-I ceramic, was developed, and its machinability was compared with that of Vita MKII quantitatively. Moreover, the relationship between the strength and the machinability of PMC-I ceramic was studied. Samples of PMC-I ceramic were divided into four groups according to their nucleation procedures. 600-seconds drilling tests were conducted with high-speed steel tools (Phi = 2.3 mm) to measure the drilling depths of Vita MKII ceramic and PMC-I ceramic, while constant drilling speed of 600 rpm and constant axial load of 39.2 N were used. And the 3-point bending strength of the four groups of PMC-I ceramic were recorded. Drilling depth of Vita MKII was 0.71 mm, while the depths of the four groups of PMC-I ceramic were 0.88 mm, 1.40 mm, 0.40 mm and 0.90 mm, respectively. Group B of PMC-I ceramic showed the largest depth of 1.40 mm and was statistically different from other groups and Vita MKII. And the strength of the four groups of PMC-I ceramic were 137.7, 210.2, 118.0 and 106.0 MPa, respectively. The machinability of the new developed dental machinable ceramic of PMC-I could meet the need of the clinic.

Ab Initio Calculations for the BaTiO3 (001) Surface Structure

Institute of Scientific and Technical Information of China (English)

XUE Xu-Yan; WANG Chun-Lei; ZHONG Wei-Lie

2004-01-01

@@ The ab initio method within the local density approximation is applied to calculate cubic BaTiO3 (001) surface relaxation and rumpling for two different terminations (BaO and TiO2). Our calculations demonstrate that cubic perovskite BaTiO3 crystals possess surface polarization, accompanied by the presence of the relevant electric field.We analyse their electronic structures (band structure, density of states and the electronic density redistribution with emphasis on the covalency effects). The results are also compared with that of the previous ab initio calculations. Considerable increases of Ti-O chemical bond covalency nearby the surface have been observed.The band gap reduces especially for the TiO2 termination.

Is Urgent Evoke a Digital Ba?

DEFF Research Database (Denmark)

Wichmand, Mette

2018-01-01

of such a platform, the World Bank’s online game Urgent Evoke, which has been designed with the pur- pose of engaging citizens in developing innovative solutions for sociopolitical problems like poverty. The analysis is based on Nonaka’s concept of Ba, which means “place” and is described as a platform for advancing...

Metal-insulator transition and magnetic properties of La - (Ba/Ca) - Mn - O compounds

International Nuclear Information System (INIS)

Anbarasu, V.; Manigandan, A.; Sathiyakumar, S.; Jayabalan, K.; Kaliyaperumal, L.K.

2009-01-01

The manganite compounds La 2 BaMn (3+x) P y (where x = 0, 0.5 and 1) and La 2 CaMn 3 O y have been prepared for the importance in the field of magneto resistance materials through solid-state reaction technique. From the Powder XRD patterns it was confirmed that both compounds were in single phase and the refined crystal system matches with superconducting perovskite structure and the lattice parameters were calculated as a = 3.892( 6) A, b = 3.899(3) A and c = 11.619(8) A for La 2 BaMn 3 O y ; a = 3.851(3) A, b = 3.891(9) A and c = 11.542(7) A for La 2 CaMn 3 O y . The low temperature resistivity measurement reveals that the compound La 2 BaMn 3 O y exhibiting M - I transition and the transition temperature was found to be 270 K. The study on magnetization nature of the La 2 BaMn 3+x Oy (where x = 0, 0.5 and I) compounds through vibrating sample magnetometer confirms the superparamagnetic nature at room temperature condition where as La 2 CaMn 3 O y exhibits paramagnetic nature. The structural relations between the prepared manganite systems La 2 BaMn 3 O y and La 2 CaMn 3 O y with superconducting perovskite compound LaBa 2 Cu 3 O 7-y was studied with the technological application of magneto resistive property of the prepared compounds. (author)

Bioaccessibility of Ba, Cu, Pb, and Zn in urban garden and orchard soils

International Nuclear Information System (INIS)

Cai, Meifang; McBride, Murray B.; Li, Kaiming

2016-01-01

Exposure of young children to toxic metals in urban environments is largely due to soil and dust ingestion. Soil particle size distribution and concentrations of toxic metals in different particle sizes are important risk factors in addition to bioaccessibility of these metals in the particles. Analysis of particle size distribution and metals concentrations for 13 soils, 12 sampled from urban gardens and 1 from orchard found that fine particles (<105 μm) comprised from 22 to 66% by weight of the tested soils, with Ba, Cu, Pb and Zn generally at higher concentrations in the finer particles. However, metal bioaccessibility was generally lower in finer particles, a trend most pronounced for Ba and Pb. Gastric was higher than gastrointestinal bioaccessibility for all metals except Cu. The lower bioaccessibility of Pb in urban garden soils compared to orchard soil is attributable to the higher organic matter content of the garden soils. - Highlights: • The bioaccessibility of metals in urban garden and orchard soils was measured. • Ba, Cu, Pb, Zn were concentrated in fine particles of the soils. • Bioaccessibilities of Ba and Pb were generally lower in fine particles of soils. • Pb bioaccessibility was generally lower in soils with higher organic matter content. • Pb bioaccessibility was lower in urban garden soils than in an orchard soil. - Pb and other trace metals (Ba, Cu, Zn) were concentrated in fine particles of urban and orchard soils, but the bioaccessibility of Ba and Pb was generally lower in finer particles.

Anomalous Ba/Ca signals associated with low temperature stresses in Porites corals from Daya Bay, northern South China Sea

Institute of Scientific and Technical Information of China (English)

Tianran Chen; Kefu Yu; Shu Li; Tegu Chen; Qi Shi

2011-01-01

Barium to calcium (Ba/Ca) ratio in corals has been considered as a useful geochemical proxy for upwelling,river flood and other oceanic processes.However,recent studies indicated that additional environmental or biological factors can influence the incorporation of Ba into coral skeletons.In this study,Ba/Ca ratios of two Porites corals collected from Daya Bay,northern South China Sea were analyzed.Ba/Ca signals in the two corals were 'anomalous' in comparison with Ba behaviors seen in other near-shore corals influenced by upwelling or riverine runoff.Our Ba/Ca profiles displayed similar and remarkable patterns characterized by low and randomly fluctuating background signals periodically interrupted by sharp and large synchronous peaks,clearly indicating an environmental forcing.Further analysis indicated that the Ba/Ca profiles were not correlated with previously claimed environmental factors such as precipitation,coastal upwelling,anthropogenic activities or phytoplankton blooms in other areas.The maxima of Ba/Ca appeared to occur in the period of Sr/Ca maxima,coinciding with the winter minimum temperatures,which suggests that the anomalous high Ba/Ca signals were related to winter-time low sea surface temperature.We speculated that the Ba/Ca peaks in corals of the Daya Bay were most likely the results of enrichment of Ba-rich particles in their skeletons when coral polyps retracted under the stresses of anomalous winter low temperatures.In this case,Ba/Ca ratio in relatively high-latitude corals can be a potential proxy for tracing the low temperature stress.

Advanced Electrical Machines and Machine-Based Systems for Electric and Hybrid Vehicles

OpenAIRE

Ming Cheng; Le Sun; Giuseppe Buja; Lihua Song

2015-01-01

The paper presents a number of advanced solutions on electric machines and machine-based systems for the powertrain of electric vehicles (EVs). Two types of systems are considered, namely the drive systems designated to the EV propulsion and the power split devices utilized in the popular series-parallel hybrid electric vehicle architecture. After reviewing the main requirements for the electric drive systems, the paper illustrates advanced electric machine topologies, including a stator perm...

Performances of RPCs in the BaBar Experiment

Energy Technology Data Exchange (ETDEWEB)

Messner, Robert

2003-09-26

The BaBar experiment uses a big system based on RPC detectors to discriminate muons from pions and to identify neutral hadrons. About 2000 m{sup 2} of RPC chambers have been working at SLAC since the end of 1998. We report on the performances of the RPC chambers focusing on new problems discovered in the RPC behavior. These problems started very soon after the installation of the chambers on the detector when the high ambient temperature triggered an increase of dark currents inside the chambers and a reduction of the efficiency. Careful analysis of the BaBar data and dedicated R&D efforts in the laboratory have helped to identify the main source of the trouble in the linseed oil varnish on the bakelite electrodes.

DIRC - a particle identification system for BaBar

International Nuclear Information System (INIS)

Hoecker, A.

1999-10-01

The DIRC (an acronym for Detection of Internally Reflected Cherenkov light) is a novel type of Cherenkov imaging device that has been developed, built and installed as part of the BaBar detector at the asymmetric B-factory PEP-II at SLAC. The DIRC is based on total internal reflection of Cherenkov photons produced and guided within thin, rectangular quartz bars covering the barrel region of BaBar. The photon detector is an array of photomultiplier tubes covering the photon phase space at the backward end of the bars. In its first few months of operation the DIRC performance has been found to achieve the design requirements. This note presents results from cosmic ray data and an analysis of the first beam collision runs. (author)

Findings from the National Machine Guarding Program–A Small Business Intervention: Machine Safety

Science.gov (United States)

Yamin, Samuel C.; Xi, Min; Brosseau, Lisa M.; Gordon, Robert; Most, Ivan G.; Stanley, Rodney

2016-01-01

Objectives The purpose of this nationwide intervention was to improve machine safety in small metal fabrication businesses (3 – 150 employees). The failure to implement machine safety programs related to guarding and lockout/tagout (LOTO) are frequent causes of OSHA citations and may result in serious traumatic injury. Methods Insurance safety consultants conducted a standardized evaluation of machine guarding, safety programs, and LOTO. Businesses received a baseline evaluation, two intervention visits and a twelve-month follow-up evaluation. Results The intervention was completed by 160 businesses. Adding a safety committee was associated with a 10-percentage point increase in business-level machine scores (p< 0.0001) and a 33-percentage point increase in LOTO program scores (p <0.0001). Conclusions Insurance safety consultants proved effective at disseminating a machine safety and LOTO intervention via management-employee safety committees. PMID:26716850

Structural, morphological and Raman studies on hybridized PVDF/BaTiO3 nanocomposites

Science.gov (United States)

Rajamanickam, N.; Jayakumar, K.; Ramachandran, K.

2017-05-01

Hybridized nanocomposites of polyvinylidene fluoride (PVDF) and nano - barium titanate (BaTiO3) were prepared using the solution casting method for different concentrations of nano-BaTiO3 and were characterized by X-ray diffraction and scanning electron microscopy. The flower like structure for morphology was observed in SEM. Raman analysis showed that the modified BaTiO3 particles, due to higher specific surfaces, induce, predominantly, the crystallization of the electrically active β-phase of PVDF, while the initial micron size particles induce the formation of the most common but non-polar α-crystal form.

Thermoluminescence of rare earth doped BaSO/sub 4/ phosphors and its applications

Energy Technology Data Exchange (ETDEWEB)

Nagpal, J.S.; Varadharajan, G. (Bhabha Atomic Research Centre, Bombay (India). Div. of Radiological Protection)

1982-03-01

Thermoluminescence of synthetic BaSO/sub 4/ samples individually doped with Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy and Tm has been studied after ..gamma..- and microwave irradiations. BaSO/sub 4/:Eu has the highest response for ..gamma..-radiation while BaSO/sub 4/:Tb exhibits highest reduction in its ..gamma..-induced TL after exposure to microwave radiation (2425 +- 25 MHz). The reduction depends on the microwave radiant exposure and is independent of the irradiance level in the range 25-200 mW . cm/sup -2/ and hence can be useful for microwave dosimetry.

Inter-atomic force constants of BaF{sub 2} by diffuse neutron scattering measurement

Energy Technology Data Exchange (ETDEWEB)

Sakuma, Takashi, E-mail: sakuma@mx.ibaraki.ac.jp; Makhsun,; Sakai, Ryutaro [Institute of Applied Beam Science, Ibaraki University, Mito 310-8512 (Japan); Xianglian [College of Physics and Electronics Information, Inner Mongolia University for the Nationalities, Tongliao 028043 (China); Takahashi, Haruyuki [Institute of Applied Beam Science, Ibaraki University, Hitachi 316-8511 (Japan); Basar, Khairul [Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung 40132 (Indonesia); Igawa, Naoki [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai 319-1195 (Japan); Danilkin, Sergey A. [Bragg Institute, Australian Nuclear Science and Technology Organisation, Kirrawee DC NSW 2232 (Australia)

2015-04-16

Diffuse neutron scattering measurement on BaF{sub 2} crystals was performed at 10 K and 295 K. Oscillatory form in the diffuse scattering intensity of BaF{sub 2} was observed at 295 K. The correlation effects among thermal displacements of F-F atoms were obtained from the analysis of oscillatory diffuse scattering intensity. The force constants among neighboring atoms in BaF{sub 2} were determined and compared to those in ionic crystals and semiconductors.

Muon spin depolarization in Gd- and EuBa1Cu3O/sub x/

International Nuclear Information System (INIS)

Cooke, D.W.; Hutson, R.L.; Kwok, R.S.

1988-01-01

Positive muon spin rotation (μSR) measurements on Gd- and EuBa 2 Cu 3 O/sub x/ (x ∼ 7) have been conducted in the temperature interval 4-300K. For each sample, muons stop both at grain boundaries and within the superconducting grains. Measured magnetic field penetration depths are 1550 and 1900/angstrom/ for two specimens of GdBa 2 Cu 3 O/sub x/, and 1350/angstrom/ for EuBa 2 Cu 3 O/sub x/. 2 refs., 5 figs

Polymorphism of tungsten perovskite compounds Ba/sub 2/SEsub(0. 67)WO/sub 6/

Energy Technology Data Exchange (ETDEWEB)

Schittenhelm, H J; Kemmler-Sack, S [Tuebingen Univ. (F.R. Germany). Inst. fuer Anorganische Chemie

1976-09-01

The compounds Ba/sub 2/SEsub(0.67)WO/sub 6/ with SE = Gd-Lu are polymorphic. Above 1200/sup 0/C the instable cubic modification (ordered perovskite with 4 formula units Ba/sub 2/SEsub(0.67)vacantsub(0.33)WO/sub 6/ per cell) transforms irreversibly into a hexagonal modification with completely filled cationic lattice. For Ba/sub 2/Eusub(0.67)WO/sub 6/ the transformation is incomplete. With SE = Nd and Sm only the cubic modification is formed.

Synthesis, structure, optical property, and electronic structure of Ba7AgGa5Se15

International Nuclear Information System (INIS)

Yin, Wenlong; He, Ran; Feng, Kai; Hao, Wenyu; Yao, Jiyong; Wu, Yicheng

2013-01-01

Graphical abstract: -- Highlights: •A new quaternary chalcogenide Ba 7 AgGa 5 Se 15 was synthesized. •It adopts a new structure type in the space group P31c of the trigonal system. •The structure contains a three-dimensional framework built from GaSe 4 and AgSe 4 tetrahedra. •Ba 7 AgGa 5 Se 15 is a direct semiconductor with the band gap of 2.60 (2) eV. •The electronic structure was calculated to explain the optical properties. -- Abstract: A new quaternary chalcogenide Ba 7 AgGa 5 Se 15 was synthesized by solid state reaction. It crystallizes in a new structure type in the noncentrosymmetric space group P31c of the trigonal system. In the structure, three Ga2Se 4 tetrahedra and one Ga1Se 4 tetrahedron are connected to each other by corner-sharing to form [Ga 4 Se 10 ] 8− anion clusters, which are further connected to AgSe 4 tetrahedra by corner-sharing to form a three-dimensional framework with Ba, Se7, and isolated Ga3Se 4 tetrahedra residing in the cavities. The optical band gap of 2.60 (2) eV for Ba 7 AgGa 5 Se 15 was deduced from the diffuse reflectance spectrum. From a band structure calculation, Ba 7 AgGa 5 Se 15 is a direct semiconductor and the transition between Se and Ba plays an important role in the band gap

Machine Tool Software

Science.gov (United States)

1988-01-01

A NASA-developed software package has played a part in technical education of students who major in Mechanical Engineering Technology at William Rainey Harper College. Professor Hack has been using (APT) Automatically Programmed Tool Software since 1969 in his CAD/CAM Computer Aided Design and Manufacturing curriculum. Professor Hack teaches the use of APT programming languages for control of metal cutting machines. Machine tool instructions are geometry definitions written in APT Language to constitute a "part program." The part program is processed by the machine tool. CAD/CAM students go from writing a program to cutting steel in the course of a semester.

Effect of 6-BA on nodal explant bud sproutings of Coffea arabica cv. Mundo Novo Efeito de 6-BA na brotação de gemas de explantes nodais de Coffea arabica cv. Mundo Novo

Directory of Open Access Journals (Sweden)

Luis Carlos da Silva Ramos

2005-01-01

Full Text Available Coffee plants can be micropropagated by nodal bud sprouting using the 6-benzylaminopurine (6-BA hormone. However, literature reports the use of a wide range of 6-BA, from 0.5 to 88.8 µM L-1. So, this study was performed to narrow that range. Nodal explants of Coffea arabica cv Mundo Novo obtained from in vitro plantlets were inoculated on gelled-MS medium supplemented with different concentrations of 6-BA. Two assays were carried out: in the first one, 6-BA was used at concentrations of 0, 5, 25, 50, and 100 µM L-1, being evaluated at 43 and 123 days. In the second experiment, dosis of 10, 20 and 30 µM L-1, have evaluated at 65 and 100 days. Treatments with 6-BA induced multiple sprouting from the nodal explants, which were best characterized around 100 days after inoculation. The nodal explants grew taller and showed multiple shoots, whereas the effect of 6-BA at 5 to 25 µM L-1 was similar to that with higher concentrations (50 and 100 µM L-1. Nodal explants yielded from 2.9 to 6.0 buds per node, achieving height of 1.3 to 1.5 cm at 5 to 25 µM L-1 of 6-BA, whereas they yielded from 4.3 to 4.9 buds per node but the sprouting grew about 0.8 cm at 50 and 100 µM L-1 of 6-BA. This study indicated that multiple sprouting of lateral buds can be induced by lower concentrations of 6-BA, for example, from 10 to 30 µM L-1, diminishing possible risks of somaclonal variation due to high levels of hormone concentration.O cafeeiro pode ser micropropagado via brotação de gemas laterais, aplicando o regulador de crescimento 6-benzilaminopurina (6-BA. Entretanto, a literatura apresenta ampla variação da dose empregada, desde 0.5 a 88.8 µM L-1. Assim, este estudo visou otimizar doses para explantes nodais do cafeeiro C. arabica cv Mundo Novo. Explantes nodais, obtidos de plântulas cultivadas in vitro, foram inoculados em meio MS geleificado, com adição de diferentes concentrações de 6-BA. Foram feitos dois experimentos: no primeiro, 6-BA foi

Machine Ethics: Creating an Ethical Intelligent Agent

OpenAIRE

Anderson, Michael; Anderson, Susan Leigh

2007-01-01

The newly emerging field of machine ethics (Anderson and Anderson 2006) is concerned with adding an ethical dimension to machines. Unlike computer ethics -- which has traditionally focused on ethical issues surrounding humans' use of machines -- machine ethics is concerned with ensuring that the behavior of machines toward human users, and perhaps other machines as well, is ethically acceptable. In this article we discuss the importance of machine ethics, the need for machines that represent ...

Nanocomposites for Machining Tools

Directory of Open Access Journals (Sweden)

Daria Sidorenko

2017-10-01

Full Text Available Machining tools are used in many areas of production. To a considerable extent, the performance characteristics of the tools determine the quality and cost of obtained products. The main materials used for producing machining tools are steel, cemented carbides, ceramics and superhard materials. A promising way to improve the performance characteristics of these materials is to design new nanocomposites based on them. The application of micromechanical modeling during the elaboration of composite materials for machining tools can reduce the financial and time costs for development of new tools, with enhanced performance. This article reviews the main groups of nanocomposites for machining tools and their performance.

Machine learning with R

CERN Document Server

Lantz, Brett

2013-01-01

Written as a tutorial to explore and understand the power of R for machine learning. This practical guide that covers all of the need to know topics in a very systematic way. For each machine learning approach, each step in the process is detailed, from preparing the data for analysis to evaluating the results. These steps will build the knowledge you need to apply them to your own data science tasks.Intended for those who want to learn how to use R's machine learning capabilities and gain insight from your data. Perhaps you already know a bit about machine learning, but have never used R; or

Heat capacity measurement of Ba3SrNb2O9

International Nuclear Information System (INIS)

Singh, B.M.; Samui, Pradeep; Agarwal, Renu; Mukerjee, S.K.

2016-01-01

Barium, Strontium and Niobium are important fission products in nuclear reactor with reasonable fission yields. During irradiation of oxide fuels, they can combine to form compounds of Ba-Sr-Nb-O system. Therefore, thermodynamic properties of Ba 3 SrNb 2 O 9 are required for modelling fuel behaviour however thermodynamic data of this compound is not available in literature. Ba 3 SrNb 2 O 9 was prepared by solid state route, by mixing stoichiometric amounts of finely grounded SrCO 3 , BaCO 3 and Nb 2 O 5 . Finally mixed powder was pressed into a pellet at 5 ton pressure for 2 minutes in a hydraulic press and the pellet was heated at 1123 K for 60 h in air. The pellet was cooled, finely grounded, re-pelletised and heated at 1473 K for 120 h. The formation of compound was confirmed by X-ray diffraction pattern, collected at room temperature using Cu-K α radiation (λ = 1.54 nm), scanned over the angular range 20-80° (2θ) with steps of 0.02°. Heat capacity of the compound was measured by the classical three-step method, in continuous mode, using LABSYS EVO, in temperature range of 370 and 950 K. No transition was observed in the investigated temperature range

Physical and magnetic properties of (Ba/Sr) substituted magnesium nano ferrites

Science.gov (United States)

Ateia, Ebtesam E.; Takla, E.; Mohamed, Amira T.

2017-10-01