Exclusion of mRNPs and ribosomal particles from a thin zone beneath the nuclear envelope revealed upon inhibition of transport

International Nuclear Information System (INIS)

Kylberg, Karin; Bjoerk, Petra; Fomproix, Nathalie; Ivarsson, Birgitta; Wieslander, Lars; Daneholt, Bertil

2010-01-01

We have studied the nucleocytoplasmic transport of a specific messenger RNP (mRNP) particle, named Balbiani ring (BR) granule, and ribosomal RNP (rRNP) particles in the salivary glands of the dipteran Chironomus tentans. The passage of the RNPs through the nuclear pore complex (NPC) was inhibited with the nucleoporin-binding wheat germ agglutinin, and the effects were examined by electron microscopy. BR mRNPs bound to the nuclear basket increased in number, while BR mRNPs translocating through the central channel decreased, suggesting that the initiation of translocation proper had been inhibited. The rRNPs accumulated heavily in nucleoplasm, while no or very few rRNPs were recorded within nuclear baskets. Thus, the transport of rRNPs had been blocked prior to the entry into the baskets. Remarkably, the rRNPs had been excluded both from baskets and the space in between the baskets. We propose that normally basket fibrils move freely and repel RNPs from the exclusion zone unless the particles have affinity for and bind to nucleoporins within the baskets.

Void distributions in liquid BiBr{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Maruyama, K [Faculty of Science, Niigata University, Niigata 950-2181 (Japan); Endo, H [Faculty of Science, Kyoto University, Kyoto 606-8224 (Japan); Hoshino, H [Faculty of Education, Hirosaki University, Hirosaki 036-8560 (Japan); Kawakita, Y [Faculty of Sciences, Kyushu University, Fukuoka 810-8560 (Japan); Kohara, S; Itou, M [Japan Synchrotron Radiation Research Institute(JASRI), Sayo-cho 679-5198 (Japan)

2008-02-15

The X-ray diffraction experiments and the reverse Monte Carlo analysis for liquid BiBr{sub 3} have been performed to clarify the distribution of Bi and Br ions around voids, comparing with previous results derived in the neutron diffraction experiments. The hexagonal cages involving voids are formed by the corner-sharing of the trigonal pyramidal BiBr{sub 3} blocks. The neighboring cages are linked together in highly correlated fashion. The observed pre-peak in S(Q) at 1.3A{sup -1} is related to the pre-peak of the void-based S'{sub CC} (Q) due to an intermediate chemical order in the structure. The pre-peak intensity increases with increasing temperature. This characteristic change for the pre-peak intensity is discussed by considering the modifications of the topology and stacking in the hexagonal cages.

Long term characterization of unidirectional fiberglass for ITER pre-compression rings

International Nuclear Information System (INIS)

Nardi, Claudio; Bettinali, Livio; Labanti, Martino

2010-01-01

In the frame of the development of pre-compression rings for ITER magnet system a unidirectional fiberglass composite has been developed having a ultimate tensile strength (UTS) as high as 2200 MPa at room temperature. During the development of the material a particular grip system has required to be developed, in order to limit the bearing stress on the sample and to obtain a sufficient load to test the sample. To understand the long term creep behaviour room temperature tests have been performed in ENEA Faenza facilities starting in 2007. The long term tests, performed at a constant stress level as high as 80% UTS, showed a behaviour of the material during the test similar to the one of creep tests, although different from the one of metallic materials. In these tests a very low creep strain and very low creep rates, in comparison with the ones of metallic materials, have been recorded, showing a marked dominance of the glass behaviour and a limited influence of the resin on the global behaviour of the composite. From the long term tests, performed at stress levels varying from 63 to 80% of UTS, very different failure times have been recorded for samples loaded at stresses of 75% of UTS and lower and samples loaded at greater stresses. The high stressed samples showed failure times of the order of tenths or hundreds of hours, while the low stresses are all in the order of thousands and more of hours. For the engineering work on the rings the results indicate that at the stress levels considered in the ITER pre-compression rings (50% or less of UTS) the failure time and the deformation of the rings during the ITER operating life are of limited concern. Future activities on this material foresee a set of tests at decreasing stress level (up to 40%), these tests presumably will not lead to an evaluation of the failure time of the material at such a low stress level, however they will give relevant results in order to understand the creep rate of the material at low

Saturn's Ring: Pre-Cassini Status and Mission Goals

Science.gov (United States)

Cuzzi, Jeff N.; DeVincenzi, Donald L. (Technical Monitor)

1999-01-01

In November 1980, and again in August 1981, identical Voyager spacecraft flew through the Saturn system, changing forever the way we think about planetary rings. Although Saturn's rings had been the only known ring system for three centuries, a ring system around Uranus had been discovered by stellar occultations from Earth in 1977, and the nearly transparent ring of Jupiter was imaged by Voyager in 1979 (the presence of material there had been inferred from charged particle experiments on Pioneer 10 and 11 several years earlier). While Saturn had thus temporarily lost its uniqueness as having the only ring system, with Voyager it handily recaptured the role of having the most fascinating one. The Voyager breakthroughs included spiral density and bending waves such as cause galactic structure; ubiquitous fine-scale radial 'irregular' structure, with the appearance of record-grooves; regional and local variations in particle color; complex, azimuthally variable ring structure; empty gaps in the rings, some containing very regular, sharp-edged, elliptical rings and one containing both a small moonlet and incomplete arcs of dusty material; and shadowy 'spokes' that flicker across the main rings. One of the paradigm shifts of this period was the realization that many aspects of planetary rings, and even the ring systems themselves, could be 'recent' on geological timescales. These early results are reviewed and summarized in the Arizona Space Science series volumes 'Saturn'. (An excellent review of ring dynamics at a formative stage is by Goldreich and Tremaine.) From the mid 1980's to the time of this writing, progress has been steady, while at a less heady pace, and some of the novel ring properties revealed by Voyager 1 and 2 are beginning to be better understood. It is clearly impossible to cite, much less review, every advance over the last decade; however, below we summarize the main advances in understanding of Saturn's rings since the mid 1980's, in the context

Correlations and fixation of some elements in tree rings

International Nuclear Information System (INIS)

Goldberg, E.L.; Zolotarev, K.B.; Maksimovskaya, V.V.; Kondratyev, V.I.; Ovchinnikov, D.V.; Naurzbaev, M.M.

2007-01-01

High-resolution scanning with Synchrotron Radiation X-ray Fluorescence Analysis (SRXFA) was applied to investigate element distributions in tree rings. Two cores of Siberia Larch have been investigated with resolution 100-200 mkm. Two groups of elements in tree rings with different trends have been found. The members of the first group are Br, Zn, Cl, whose trends correlate with each other. Moreover, trends of Br, Zn, Cl in tree rings are similar to the trend of atmosphere precipitation in the region investigated. Other group of elements are represented by K, Ca, Sr, Mn, Fe, but their trends differ sufficiently from trend of elements of the first group. Extended fixation of elements in tree rings is observed for elements of the first group over the whole interval investigated (150 years). In contrast, elements of the second group mainly accumulate in external part of tree stem

Continuum and discrete pulsed cavity ring down laser absorption spectra of Br2 vapor.

Science.gov (United States)

Sharma, Ramesh C; Huang, Hong-Yi; Chuang, Wang-Ting; Lin, King-Chuen

2005-07-01

The absorption cross-sections at room temperature are reported for the first time, of Br2 vapor in overlapping bound-free and bound-bound transition of A(3)pi1u Br2. We obtained discrete absorption cross-section in the rotational structure, the continuum absorption cross-sections, and were also able to measure the absorption cross-section in separate contribution of A(3)pi1u Br2. The absorption cross-sections are increasing with increasing excitation energy in the wavelength region 510-535 nm.

Pre-clinical development of a combination microbicide vaginal ring containing dapivirine and darunavir.

Science.gov (United States)

Murphy, Diarmaid J; Desjardins, Delphine; Dereuddre-Bosquet, Nathalie; Brochard, Patricia; Perrot, Ludivine; Pruvost, Alain; Le Grand, Roger; Lagatie, Ole; Vanhooren, Leen; Feyaerts, Maxim; van Roey, Jens; Malcolm, R Karl

2014-09-01

Combination microbicide vaginal rings may be more effective than single microbicide rings at reducing/preventing sexual transmission of HIV. Here, we report the pre-clinical development and macaque pharmacokinetics of matrix-type silicone elastomer vaginal rings containing dapivirine and darunavir. Macaque rings containing 25 mg dapivirine, 100 mg dapivirine, 300 mg darunavir or 100 mg dapivirine+300 mg darunavir were manufactured and characterized by differential scanning calorimetry. In vitro release was assessed into isopropanol/water and simulated vaginal fluid. Macaque vaginal fluid and blood serum concentrations for both antiretrovirals were measured during 28 day ring use. Tissue levels were measured on day 28. Ex vivo challenge studies were performed on vaginal fluid samples and IC50 values were calculated. Darunavir caused a concentration-dependent reduction in the dapivirine melting temperature in both solid drug mixes and in the combination ring. In vitro release from rings was dependent on drug loading, the number of drugs present and the release medium. In macaques, serum concentrations of both microbicides were maintained between 10(1) and 10(2) pg/mL. Vaginal fluid levels ranged between 10(3) and 10(4) ng/g and between 10(4) and 10(5) ng/g for dapivirine and darunavir, respectively. Both dapivirine and darunavir showed very similar concentrations in each tissue type; the range of drug tissue concentrations followed the general rank order: vagina (1.8 × 10(3)-3.8 × 10(3) ng/g)  > cervix (9.4 × 10(1)-3.9 × 10(2) ng/g)  > uterus (0-108 ng/g)  > rectum (0-40 ng/g). Measured IC50 values were >2 ng/mL for both compounds. Based on these results, and in light of recent clinical progress of the 25 mg dapivirine ring, a combination vaginal ring containing dapivirine and darunavir is a viable second-generation HIV microbicide candidate. © The Author 2014. Published by Oxford University Press on behalf of the British Society for

Preliminary Design Study of a Pre-booster Damping Ring for the FCC e+e− Injector

CERN Document Server

Etisken, O; Papaphilippou, Y

2017-01-01

The aim of the FCC e+e− lepton collider is to collide particles in the energy range 40–175 GeV. The FCC e+e− injector complex needs to produce and transport high-intensity e+e− beams at a fast repetition rate of about 0.1 Hz to top up the collider at its collision energy. A basic parameter set exists for all collider energies, assuming a 10 GeV linac operating with a large number of bunches accumulating in the existing SPS, which serves as pre-accelerator and damping ring before the bunches are transferred to the high-energy booster. The purpose of this study is to provide the conceptual design of an alternative damping and accelerator ring, replacing the SPS in the current scheme. This ring will have an injection energy of around 6 GeV and an extraction energy of around 20 GeV. Apart from establishing the basic ring parameters, the final study will include the optics design and layout, and single particle linear and non-linear dynamics optimization, including magnetic and alignment error tolerances. ...

Two genes in Balbiani ring 2 with metabolically different 75S transcripts

OpenAIRE

Galler, R.; Saiga, H.; Widmer, R. M.; Lezzi, M.; Edström, J.-E.

1985-01-01

Balbiani ring 2 (BR2) in salivary glands of Chironomus pallidivittatus and C. tentans (two sibling species of the subgenus Camptochironomus) is a favoured model system for studies of gene organization and transcript formation. Here we show that BR2 is more complex than hitherto believed, containing two 75S RNA-producing genes, BR2a and BR2b, present in different 35–40 kb blocks of DNA. The transcripts hybridizing to two different repeat units originating in BR2 differ in size. Further support...

Solvation dynamics through Raman spectroscopy: hydration of Br2 and Br3(-), and solvation of Br2 in liquid bromine.

Science.gov (United States)

Branigan, Edward T; Halberstadt, N; Apkarian, V A

2011-05-07

Raman spectroscopy of bromine in the liquid phase and in water illustrates uncommon principles and yields insights regarding hydration. In liquid Br(2), resonant excitation over the B((3)Π(0u)(+)) ← X((1)Σ(g)(+)) valence transition at 532 nm produces a weak resonant Raman (RR) progression accompanied by a five-fold stronger non-resonant (NR) scattering. The latter is assigned to pre-resonance with the C-state, which in turn must be strongly mixed with inter-molecular charge transfer states. Despite the electronic resonance, RR of Br(2) in water is quenched. At 532 nm, the homogeneously broadened fundamental is observed, as in the NR case at 785 nm. The implications of the quenching of RR scattering are analyzed in a simple, semi-quantitative model, to conclude that the inertial evolution of the Raman packet in aqueous Br(2) occurs along multiple equivalent water-Br(2) coordinates. In distinct contrast with hydrophilic hydration in small clusters and hydrophobic hydration in clathrates, it is concluded that the hydration shell of bromine in water consists of dynamically equivalent fluxional water molecules. At 405 nm, the RR progression of Br(3)(-) is observed, accompanied by difference transitions between the breathing of the hydration shell and the symmetric stretch of the ion. The RR scattering process in this case can be regarded as the coherent photo-induced electron transfer to the solvent and its radiative back-transfer.

Thermodynamic assessment of EuBr2 unary and LiBr-EuBr2 and NaBr-EuBr2 binary systems

International Nuclear Information System (INIS)

Gong, Weiping; Gaune-Escard, Marcelle

2009-01-01

As a basis for the design and development of molten salt mixtures, thermodynamic calculations of the phase diagrams and thermodynamic properties were carried out on the EuBr 2 unary and LiBr-EuBr 2 and NaBr-EuBr 2 binary systems over a wide temperature and composition range, respectively. The Gibbs energy of EuBr 2 was evaluated using an independent polynomial to fit the experimental heat capacity, the thermodynamic parameters for each phase in the LiBr-EuBr 2 and NaBr-EuBr 2 systems were optimized by using available experimental information on phase diagrams. A regular substitutional solution model for the liquid phase and Neumann-Kopp rule for the stoichiometric compound LiEu 2 Br 5 were adopted to reproduce the experimental data with reasonable excess Gibbs energy. Comparisons between the calculated phase diagrams and thermodynamic quantities show that all reliable experimental information is satisfactorily accounted for by the present thermodynamic description. Some thermodynamic properties were predicted to check the suitability of the present calculation.

Pathways for the OH + Br2 → HOBr + Br and HOBr + Br → HBr + BrO Reactions.

Science.gov (United States)

Wang, Hongyan; Qiu, Yudong; Schaefer, Henry F

2016-02-11

The OH radical reaction with Br2 and the subsequent reaction HOBr + Br are of exceptional importance to atmospheric chemistry and environmental chemistry. The entrance complex, transition state, and exit complex for both reactions have been determined using the coupled-cluster method with single, double, and perturbative triple excitations CCSD(T) with correlation consistent basis sets up to size cc-pV5Z and cc-pV5Z-PP. Coupled cluster effects with full triples (CCSDT) and full quadruples (CCSDTQ) are explicitly investigated. Scalar relativistic effects, spin-orbit coupling, and zero-point vibrational energy corrections are evaluated. The results from the all-electron basis sets are compared with those from the effective core potential (ECP) pseudopotential (PP) basis sets. The results are consistent. The OH + Br2 reaction is predicted to be exothermic 4.1 ± 0.5 kcal/mol, compared to experiment, 3.9 ± 0.2 kcal/mol. The entrance complex HO···BrBr is bound by 2.2 ± 0.2 kcal/mol. The transition state lies similarly well below the reactants OH + Br2. The exit complex HOBr···Br is bound by 2.7 ± 0.6 kcal/mol relative to separated HOBr + Br. The endothermicity of the reaction HOBr + Br → HBr + BrO is 9.6 ± 0.7 kcal/mol, compared with experiment 8.7 ± 0.3 kcal/mol. For the more important reverse (exothermic) HBr + BrO reaction, the entrance complex BrO···HBr is bound by 1.8 ± 0.6 kcal/mol. The barrier for the HBr + BrO reaction is 6.8 ± 0.9 kcal/mol. The exit complex (Br···HOBr) for the HBr + BrO reaction is bound by 1.9 ± 0.2 kcal/mol with respect to the products HOBr + Br.

Possible origin of Saturn's newly discovered outer ring

International Nuclear Information System (INIS)

Moehlmann, D.

1986-01-01

Within a planetogonic model the self-gravitationally caused formation of pre-planetary and pre-satellite rings from an earlier thin disk is reported. The theoretically derived orbital radii of these rings are compared with the orbital levels in the planetary system and the satellite systems of Jupiter, Saturn and Uranus. From this comparison it is concluded that at the radial position of Saturn's newly discovered outer ring an early pre-satellite ring of more or less evolved satellites could have existed. These satellites should have been disturbed in their evolution by the gravitation of the neighbouring massive satellite Titan. The comparison also may indicate similarities between the asteroidal belt and the newly discovered outer ring of Saturn

Thermodynamic assessment of NdBr3 unary and LiBr-NdBr3 binary system

International Nuclear Information System (INIS)

Gong Weiping; Gaune-Escard, Marcelle

2006-01-01

Phase diagram and thermodynamic properties calculations were carried out on the NdBr 3 unary and the LiBr-NdBr 3 binary systems over the entire temperature and composition range, respectively. The Gibbs energy of NdBr 3 was evaluated using an independent polynomial to fit the experimental thermodynamic properties. The liquid phase in the LiBr-NdBr 3 system was described by the two sub-lattice ionic solution model (Li + ) P : (Br - , NdBr 6 -3 , NdBr 3 ) Q . Comparisons between the calculated phase diagram and thermodynamic quantities show that all reliable experimental information was satisfactorily accounted for by the present thermodynamic description

Metathesis Polymerization Reactions Induced by the Bimetallic Complex (Ph4P2[W2(μ-Br3Br6

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Despoina Chriti

2015-12-01

Full Text Available The reactivity of the bimetallic complex (Ph4P2[W2(μ-Br3Br6] ({W 2.5 W}7+, a′2e3 towards ring opening metathesis polymerization (ROMP of norbornene (NBE and some of its derivatives, as well as the mechanistically related metathesis polymerization of phenylacetylene (PA, is presented. Our results show that addition of a silver salt (AgBF4 is necessary for the activation of the ditungsten complex. Polymerization of PA proceeds smoothly in tetrahydrofuran (THF producing polyphenylacetylene (PPA in high yields. On the other hand, the ROMP of NBE and its derivatives is more efficient in CH2Cl2, providing high yields of polymers. 13C Cross Polarization Magic Angle Spinning (CPMAS spectra of insoluble polynorbornadiene (PNBD and polydicyclopentadiene (PDCPD revealed the operation of two mechanisms (metathetic and radical for cross-linking, with the metathesis pathway prevailing.

CMB lensing and giant rings

Energy Technology Data Exchange (ETDEWEB)

Rathaus, Ben; Itzhaki, Nissan, E-mail: nitzhaki@post.tau.ac.il, E-mail: ben.rathaus@gmail.com [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel-Aviv University, Ramat-Aviv, 69978 (Israel)

2012-05-01

We study the CMB lensing signature of a pre-inationary particle (PIP), assuming it is responsible for the giant rings anomaly that was found recently in the WMAP data. Simulating Planck-like data we find that generically the CMB lensing signal to noise ratio associated with such a PIP is quite small and it would be difficult to cross correlate the temperature giant rings with the CMB lensing signal. However, if the pre-inationary particle is also responsible for the bulk flow measured from the local large scale structure, which happens to point roughly at the same direction as the giant rings, then the CMB lensing signal to noise ratio is fairly significant.

Photodissociation of dibromoethanes at 248 nm: an ignored channel of Br2 elimination.

Science.gov (United States)

Lee, Hsin-Lung; Lee, Ping-Chen; Tsai, Po-Yu; Lin, King-Chuen; Kuo, H H; Chen, P H; Chang, A H H

2009-05-14

Br(2) molecular elimination is probed in the photodissociation of 1,1- and 1,2-C(2)H(4)Br(2) isomeric forms at 248 nm by using cavity ring-down absorption spectroscopy. Their photodissociation processes differ markedly from each other. The quantum yield of the Br(2) fragment in 1,2-dibromoethane is 0.36+/-0.18, in contrast to a value of 0.05+/-0.03 in 1,1-dibromoethane. The vibrational population ratios of Br(2)(v=1)/Br(2)(v=0) are 0.8+/-0.1 and 0.5+/-0.2 for 1,2- and 1,1-dibromoethanes, respectively. The Br(2) yield densities are found to increase by a factor of 35% and 190% for 1,2- and 1,1-dibromoethanes within the same temperature increment. In the ab initio potential energy calculations, the transition state (TS) along the adiabatic ground state surface may correlate to the Br(2) products. The TS energy for 1,2-dibromoethane is well below the excitation energy at 483 kJ/mol, whereas that for 1,1-dibromoethane is slightly above. Such a small TS energy barrier impedes the photodissociation of the ground state 1,1-dibromoethane such that the production yield of Br(2) may become relatively low, but rise rapidly with the temperature. The TS structure shows a larger bond distance of Br-Br in 1,2-dibromoethane than that in 1,1-dibromoethane. That explains why the former isomer may result in hotter vibrational population of the Br(2) fragments.

Bromine-rich Zinc Bromides: Zn6Br12(18-crown-6)2×(Br2)5, Zn4Br8(18-crown-6)2×(Br2)3, and Zn6Br12(18-crown-6)2×(Br2)2.

Science.gov (United States)

Hausmann, David; Feldmann, Claus

2016-06-20

The bromine-rich zinc bromides Zn6Br12(18-crown-6)2×(Br2)5 (1), Zn4Br8(18-crown-6)2×(Br2)3 (2), and Zn6Br12(18-crown-6)2×(Br2)2 (3) are prepared by reaction of ZnBr2, 18-crown-6, and elemental bromine in the ionic liquid [MeBu3N][N(Tf)2] (N(Tf)2 = bis(trifluoromethylsulfonyl)amide). Zn6Br12(18-crown-6)2×(Br2)5 (1) is formed instantaneously by the reaction. Even at room temperature, compound 1 releases bromine, which was confirmed by thermogravimetry (TG) and mass spectrometry (MS). The release of Br2 can also be directly followed by the color and density of the title compounds. With controlled conditions (2 weeks, 25 °C, absence of excess Br2) Zn6Br12(18-crown-6)2×(Br2)5 (1) slowly releases bromine with conconcurrent generation of Zn4Br8(18-crown-6)2×(Br2)3 (2) (in ionic liquid) and Zn6Br12(18-crown-6)2×(Br2)2 (3) (in inert oil). All bromine-rich zinc bromides contain voluminous uncharged (e.g., Zn3Br6(18-crown-6), Zn2Br4(18-crown-6)) or ionic (e.g., [Zn2Br3(18-crown-6)](+), [(Zn2Br6)×(Br2)2](2-)) building units with dibromine molecules between the Zn oligomers and partially interconnecting the Zn-containing building units. Due to the structural similarity, the bromine release is possible via crystal-to-crystal transformation with retention of the crystal shape.

Contributions of BrCl, Br2, BrOCl, Br2O, and HOBr to regiospecific bromination rates of anisole and bromoanisoles in aqueous solution.

Science.gov (United States)

Sivey, John D; Bickley, Mark A; Victor, Daniel A

2015-04-21

When bromide-containing waters are chlorinated, conventional wisdom typically assumes HOBr is the only active brominating agent. Several additional and often-overlooked brominating agents (including BrCl, Br2, BrOCl, Br2O) can form in chlorinated waters, albeit at generally lower concentrations than HOBr. The extent to which these additional brominating agents influence bromination rates of disinfection byproduct precursors is, however, poorly understood. Herein, the influence of BrCl, Br2, BrOCl, Br2O, and HOBr toward rates of sequential bromination of anisole was quantified. Conditions affecting bromine speciation (e.g., pH, concentrations of chloride, bromide, and chlorine) were varied, and regiospecific second-order rate constants were calculated for reactions of each brominating agent with anisole, 2-bromoanisole, and 4-bromoanisole. The regioselectivity of anisole bromination changed with pH, consistent with the participation of more than one brominating agent. Under conditions representative of chlorinated drinking water, contributions to bromination rates decreased as BrCl > BrOCl > HOBr > Br2O (Br2 negligible). The second-order rate constant determined for net bromination of anisole by HOBr is up to 3000-times less than reported in previous studies (which assumed HOBr was the only active brominating agent). Accordingly, models that assume HOBr is the only kinetically relevant brominating agent in solutions of free bromine may be insufficient for reactions involving modestly nucleophilic organic compounds.

Temperature dependent absorption spectra of Br(-), Br2(•-), and Br3(-) in aqueous solutions.

Science.gov (United States)

Lin, Mingzhang; Archirel, Pierre; Van-Oanh, Nguyen Thi; Muroya, Yusa; Fu, Haiying; Yan, Yu; Nagaishi, Ryuji; Kumagai, Yuta; Katsumura, Yosuke; Mostafavi, Mehran

2011-05-05

The absorption spectra of Br(2)(•-) and Br(3)(-) in aqueous solutions are investigated by pulse radiolysis techniques from room temperature to 380 and 350 °C, respectively. Br(2)(•-) can be observed even in supercritical conditions, showing that this species could be used as a probe in pulse radiolysis at high temperature and even under supercritical conditions. The weak temperature effect on the absorption spectra of Br(2)(•-) and Br(3)(-) is because, in these two systems, the transition occurs between two valence states; for example, for Br(2)(-) we have (2)Σ(u) → (2)Σ(g) transition. These valence transitions involve no diffuse final state. However, the absorption band of Br(-) undergoes an important red shift to longer wavelengths. We performed classical dynamics of hydrated Br(-) system at 20 and 300 °C under pressure of 25 MPa. The radial distribution functions (rdf's) show that the strong temperature increase (from 20 to 300 °C) does not change the radius of the solvent first shell. On the other hand, it shifts dramatically (by 1 Å) the second maximum of the Br-O rdf and introduces much disorder. This shows that the first water shell is strongly bound to the anion whatever the temperature. The first two water shells form a cavity of a roughly spherical shape around the anion. By TDDFT method, we calculated the absorption spectra of hydrated Br(-) at two temperatures and we compared the results with the experimental data.

403 nm cavity ring-down measurements of brown carbon aerosol

Science.gov (United States)

Kwon, D.; Grassian, V. H.; Kleiber, P.; Young, M. A.

2017-12-01

Atmospheric aerosol influences Earth's climate by absorbing and scattering incoming solar radiation and outgoing terrestrial radiation. One class of secondary organic aerosol (SOA), called brown carbon (BrC), has attracted attention for its wavelength dependent light absorbing properties with absorption coefficients that generally increase from the visible (Vis) to ultraviolet (UV) regions. Here we report results from our investigation of the optical properties of BrC aerosol products from the aqueous phase reaction of ammonium sulfate (AS) with methylglyoxal (MG) using cavity ring-down spectroscopy (CRDS) at 403 nm wavelength. We have measured the optical constants of BrC SOA from the AS/MG reaction as a function of reaction time. Under dry flow conditions, we observed no apparent variation in the BrC refractive index with aging over the course of 22 days. The retrieved BrC optical constants are similar to those of AS with n = 1.52 for the real component. Despite significant UV absorption observed from the bulk BrC solution, the imaginary index value at 403 nm is below our minimum detection limit which puts an upper bound of k as 0.03. These observations are in agreement with results from our recent studies of the light scattering properties of this BrC aerosol.

Remote sensing observations of the coherent and non-coherent ring structures in the vicinity of Lesser Antilles

Directory of Open Access Journals (Sweden)

R. C. Cruz Gómez

2007-03-01

Full Text Available The North Brazil Current Rings (NBCR penetration into the Caribbean Sea is being investigated by employing a merged altimeter-derived sea height anomaly (TOPEX/Poseidon, Jason-1 and ERS-1, 2, the ocean surface color data (SeaWiFS and Global Drifter Program information. Four strategies are being applied to process the data: (1 calculations of the Okubo-Weiss parameter for NBCR identification, (2 longitude-time plots (also known as Hovmöller diagrams, (3 two-dimensional Radon transforms and (4 two-dimensional Fourier transforms. <br>> A twofold NBCR structure has been detected in the region under investigation. The results have shown that NBC rings mainly propagate into the Caribbean Sea along two principal pathways (near 12° N and 17° N in the ring translation corridor. Thus, rings following the southern pathway in the fall-winter period can enter through very shallow southern straits as non-coherent structures. A different behavior is observed near the northern pathway (~17° N, where NBC rings are thought to have a coherent structure during their squeezing into the eastern Caribbean, i.e. conserving the principal characteristics of the incident rings. We attribute this difference in the rings' behavior to the vertical scales of the rings and to the bottom topography features in the vicinity of the Lesser Antilles.

FUZZY RINGS AND ITS PROPERTIES

Directory of Open Access Journals (Sweden)

Karyati Karyati

2017-01-01

  One of algebraic structure that involves a binary operation is a group that is defined  an un empty set (classical with an associative binary operation, it has identity elements and each element has an inverse. In the structure of the group known as the term subgroup, normal subgroup, subgroup and factor group homomorphism and its properties. Classical algebraic structure is developed to algebraic structure fuzzy by the researchers as an example semi group fuzzy and fuzzy group after fuzzy sets is introduced by L. A. Zadeh at 1965. It is inspired of writing about semi group fuzzy and group of fuzzy, a research on the algebraic structure of the ring is held with reviewing ring fuzzy, ideal ring fuzzy, homomorphism ring fuzzy and quotient ring fuzzy with its properties. The results of this study are obtained fuzzy properties of the ring, ring ideal properties fuzzy, properties of fuzzy ring homomorphism and properties of fuzzy quotient ring by utilizing a subset of a subset level  and strong level  as well as image and pre-image homomorphism fuzzy ring.   Keywords: fuzzy ring, subset level, homomorphism fuzzy ring, fuzzy quotient ring

Studies on the phase diagram of LiBr-SrBr2 system

International Nuclear Information System (INIS)

Mahendran, K.H.; Sujatha, K.; Sridharan, R.; Gnanasekaran, T.

2003-01-01

Binary LiBr-SrBr 2 system was investigated using differential scanning calorimetry (DSC) and the equilibrium phases at different compositions were identified using X-ray diffraction (XRD). This system has a compound LiSr 2 Br 5 , and exhibits a eutectic reaction between this compound and LiBr at 434 deg. C and the eutectic has a composition of 35 mol% SrBr 2 . The compound LiSr 2 Br 5 undergoes peritectic decomposition at 484 deg. C. From the DSC and XRD results, phase diagram of the LiBr-SrBr 2 system is constructed

Integration of mRNP formation and export.

Science.gov (United States)

Björk, Petra; Wieslander, Lars

2017-08-01

Expression of protein-coding genes in eukaryotes relies on the coordinated action of many sophisticated molecular machineries. Transcription produces precursor mRNAs (pre-mRNAs) and the active gene provides an environment in which the pre-mRNAs are processed, folded, and assembled into RNA-protein (RNP) complexes. The dynamic pre-mRNPs incorporate the growing transcript, proteins, and the processing machineries, as well as the specific protein marks left after processing that are essential for export and the cytoplasmic fate of the mRNPs. After release from the gene, the mRNPs move by diffusion within the interchromatin compartment, making up pools of mRNPs. Here, splicing and polyadenylation can be completed and the mRNPs recruit the major export receptor NXF1. Export competent mRNPs interact with the nuclear pore complex, leading to export, concomitant with compositional and conformational changes of the mRNPs. We summarize the integrated nuclear processes involved in the formation and export of mRNPs.

Structural motifs of pre-nucleation clusters.

Science.gov (United States)

Zhang, Y; Türkmen, I R; Wassermann, B; Erko, A; Rühl, E

2013-10-07

Structural motifs of pre-nucleation clusters prepared in single, optically levitated supersaturated aqueous aerosol microparticles containing CaBr2 as a model system are reported. Cluster formation is identified by means of X-ray absorption in the Br K-edge regime. The salt concentration beyond the saturation point is varied by controlling the humidity in the ambient atmosphere surrounding the 15-30 μm microdroplets. This leads to the formation of metastable supersaturated liquid particles. Distinct spectral shifts in near-edge spectra as a function of salt concentration are observed, in which the energy position of the Br K-edge is red-shifted by up to 7.1 ± 0.4 eV if the dilute solution is compared to the solid. The K-edge positions of supersaturated solutions are found between these limits. The changes in electronic structure are rationalized in terms of the formation of pre-nucleation clusters. This assumption is verified by spectral simulations using first-principle density functional theory and molecular dynamics calculations, in which structural motifs are considered, explaining the experimental results. These consist of solvated CaBr2 moieties, rather than building blocks forming calcium bromide hexahydrates, the crystal system that is formed by drying aqueous CaBr2 solutions.

Crystal structure, hydrogen bonding, and sup 8 sup 1 Br NQR of low-temperature phase of 4-aminopyridinium tetrabromoantimonate (3)

CERN Document Server

Hashimoto, M; Fuess, H; Svoboda, I; Ehrenberg, H

2003-01-01

The crystal structure of the low-temperature phase (LTP) of the title compound was determined at 220 K (monoclinic, P2 sub 1 sub / sub c). The 4-aminopyridinium cations (4-NH sub 2 C sub 5 H sub 4 NH sup +) were found to be ordered in LTP, while being severely disordered in the room-temperature phase (monoclinic, C2/c). The tetrabromoantimonate anions (SbBr sub 4 sup -) were incorporated into the infinite polyanion chains of irregular SbBr sub 6 octahedra with two-edges sharing. The trans-Br-Sb-Br moiety in the SbBr sub 4 sup - anion was approximately symmetric differing from the asymmetric Br-Sb centre dot centre dot centre dot Br moiety found in LTP of pyridinium tetrabromoantimonate (3). The N-H moieties in both of the pyridine ring and the amino (-NH sub 2) group participate in the formation of N-H centre dot centre dot centre dot Br hydrogen bonds. It was shown that the sup 8 sup 1 Br NQR spectrum of LTP is closely related to the anion structure and the hydrogen bonds. The distinctive anion structures, a...

Evaluering for læring

Directory of Open Access Journals (Sweden)

Bent B. Andresen

2006-05-01

Full Text Available

Første gang publiceret i UNEV nr. 9: Evaluering og feedback i netstøttet uddannelse, sept. 2006, red. Simon Heilesen.<br />ISSN 1603-5518.

I fokus er løbende evalueringer af blended e-læring. Sammen med deres vejledere evaluerer deltagerne typisk deres arbejde med problemstillinger og med at nå mål og tilfredsstille forventninger. Spørgsmålet er, hvordan denne evalueringspraksis bedst kan tilrettelægges. Det er temaet i artiklen. Evalueringer foretages ofte på grundlag af eksamener og samtaler bordet rundt om et e-læringsforløbs samlede værdi. Sigtet er bagudrettet. Artiklen giver et bud på en praksis, som er fremadrettet og mere langsigtet. Især behandles evaluering for læring, som har til formål at skabe passende udfordringer for alle deltagere samt differentiere deres undervisning og vejledning – og dermed øge kvalitet af deres læring. Endvidere behandles spørgsmålet om, hvordan man løbende kan indsamle evalueringsdata og følge op på analyser heraf.

Surfactant-promoted reactions of Cl2 and Br2 with Br- in glycerol.

Science.gov (United States)

Faust, Jennifer A; Dempsey, Logan P; Nathanson, Gilbert M

2013-10-17

Gas-liquid scattering experiments are used to explore reactions of gaseous Cl2 and Br2 with a 0.03 M solution of the surfactant tetrahexylammonium bromide (THABr) dissolved in glycerol. At thermal collision energies, 79 ± 2% of incident Cl2 molecules react with Br(-) to form Cl2Br(-) in the interfacial region. This reaction probability is three times greater than the reactivity of Cl2 with 3 M NaBr-glycerol, even though the interfacial Br(-) concentrations are similar in each solution. We attribute the high 79% uptake to the presence of surface THA(+) ions that stabilize the Cl2Br(-) intermediate as it is formed in the charged, hydrophobic pocket created by the hexyl chains. Cl2Br(-) generates the single exchange product BrCl in a 1% yield close to the surface, while the remaining 99% desorbs as the double exchange product Br2 over >0.1 s after diffusing deeply into the bulk. When NaCl is added to the surfactant solution in a 20:1 Cl(-)/Br(-) ratio, the Cl2 reaction probability drops from 79% to 46 ± 1%, indicating that Cl(-) in the interfacial region only partially blocks reaction with Br(-). In parallel, we observe that gaseous Br2 molecules dissolve in 0.03 M THABr for 10(4) times longer than in 3 M NaBr. We attribute this change to formation of stabilizing interfacial and bulk-phase THA(+)Br3(-) ion pairs, in analogy with the capture of Cl2 and formation of THA(+)Cl2Br(-) pairs. The THA(+) ion appears to be a powerful interfacial catalyst for promoting reaction of Cl2 and Br2 with Br(-) and for ferrying the resultant ions into solution.

Mechanical improvement of metal reinforcement rings for a finite ring-shaped superconducting bulk

Science.gov (United States)

Huang, Chen-Guang; Zhou, You-He

2018-03-01

As a key technique, reinforcement of type-II superconducting bulks with metal rings can efficiently improve their mechanical properties to enhance the maximum trapped field. In this paper, we study the magnetostrictive and fracture behaviors of a finite superconducting ring bulk reinforced by three typical reinforcing structures composed of metal rings during the magnetizing process by means of the minimization of magnetic energy and the finite element method. After a field-dependent critical current density is adopted, the magnetostriction, pinning-induced stress, and crack tip stress intensity factor are calculated considering the demagnetization effects. The results show that the mechanical properties of the ring bulk are strongly dependent on the reinforcing structure and the material and geometrical parameters of the metal rings. Introducing the metal ring can significantly reduce the hoop stress, and the reduction effect by internal reinforcement is much improved relative to external reinforcement. By comparison, bilateral reinforcement seems to be the best candidate structure. Only when the metal rings have particular Young's modulus and radial thickness will they contribute to improve the mechanical properties the most. In addition, if an edge crack is pre-existing in the ring bulk, the presence of metal rings can effectively avoid crack propagation since it reduces the crack tip stress intensity factor by nearly one order of magnitude.

A comparative ab initio study of Br2*- and Br2 water clusters.

Science.gov (United States)

Pathak, A K; Mukherjee, T; Maity, D K

2006-01-14

The work presents ab initio results on structure and electronic properties of Br2*-.nH2O(n=1-10) and Br2.nH2O(n=1-8) hydrated clusters to study the effects of an excess electron on the microhydration of the halide dimer. A nonlocal density functional, namely, Becke's half-and-half hybrid exchange-correlation functional is found to perform well on the present systems with a split valence 6-31++G(d,p) basis function. Geometry optimizations for all the clusters are carried out with several initial guess structures and without imposing any symmetry restriction. Br2*-.nH2O clusters prefer to have symmetrical double hydrogen-bonding structures. Results on Br2.nH2O(n>or=2) cluster show that the O atom of one H2O is oriented towards one Br atom and the H atom of another H2O is directed to other Br atom making Br2 to exist as Br+-Br- entity in the cluster. The binding and solvation energies are calculated for the Br2*-.nH2O and Br2.nH2O clusters. Calculations of the vibrational frequencies show that the formation of Br2*- and Br2 water clusters induces significant shifts from the normal modes of isolated water. Excited-state calculations are carried out on Br2*-.nH2O clusters following configuration interaction with single electron excitation procedure and UV-VIS absorption profiles are simulated. There is an excellent agreement between the present theoretical UV-VIS spectra of Br2*-.10H2O cluster and the reported transient optical spectra for Br2*- in aqueous solution.

Die Interhalogenkationen [Br2F5]+ und [Br3F8].

Science.gov (United States)

Ivlev, Sergei; Karttunen, Antti; Buchner, Magnus; Conrad, Matthias; Kraus, Florian

2018-05-02

Wir berichten über die Synthese und Charakterisierung der bislang einzigen Polyhalogenkationen, in denen verbrückende Fluoratome vorliegen. Das [Br2F5]+-Kation enthält eine symmetrische [F2Br-µ-F-BrF2]-Brücke, das [Br3F8]+-Kation enthält unsymmetrische µ-F-Brücken. Die Fluoronium-Ionen wurden in Form ihrer [SbF6]--Salze erhalten und Raman-, und 19F-NMR-spektroskopisch, sowie durch Röntgenbeugung am Einkristall untersucht. Quantenchemische Rechnungen, sowohl für die isolierten Kationen in der Gasphase, als auch für die Festkörper selbst, wurden durchgeführt. Populationsanalysen zeigen, dass die µ-F-Atome die am stärksten negativ partialgeladenen Atome der Kationen sind. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ring faults and ring dikes around the Orientale basin on the Moon.

Science.gov (United States)

Andrews-Hanna, Jeffrey C; Head, James W; Johnson, Brandon; Keane, James T; Kiefer, Walter S; McGovern, Patrick J; Neumann, Gregory A; Wieczorek, Mark A; Zuber, Maria T

2018-08-01

The Orientale basin is the youngest and best-preserved multiring impact basin on the Moon, having experienced only modest modification by subsequent impacts and volcanism. Orientale is often treated as the type example of a multiring basin, with three prominent rings outside of the inner depression: the Inner Rook Montes, the Outer Rook Montes, and the Cordillera. Here we use gravity data from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission to reveal the subsurface structure of Orientale and its ring system. Gradients of the gravity data reveal a continuous ring dike intruded into the Outer Rook along the plane of the fault associated with the ring scarp. The volume of this ring dike is ~18 times greater than the volume of all extrusive mare deposits associated with the basin. The gravity gradient signature of the Cordillera ring indicates an offset along the fault across a shallow density interface, interpreted to be the base of the low-density ejecta blanket. Both gravity gradients and crustal thickness models indicate that the edge of the central cavity is shifted inward relative to the equivalent Inner Rook ring at the surface. Models of the deep basin structure show inflections along the crust-mantle interface at both the Outer Rook and Cordillera rings, indicating that the basin ring faults extend from the surface to at least the base of the crust. Fault dips range from 13-22° for the Cordillera fault in the northeastern quadrant, to 90° for the Outer Rook in the northwestern quadrant. The fault dips for both outer rings are lowest in the northeast, possibly due to the effects of either the direction of projectile motion or regional gradients in pre-impact crustal thickness. Similar ring dikes and ring faults are observed around the majority of lunar basins.

Matrix isolation and computational study of isodifluorodibromomethane (F2CBr-Br): a route to Br2 formation in CF2Br2 photolysis.

Science.gov (United States)

George, Lisa; Kalume, Aimable; El-Khoury, Patrick Z; Tarnovsky, Alexander; Reid, Scott A

2010-02-28

The photolysis products of dibromodifluoromethane (CF(2)Br(2)) were characterized by matrix isolation infrared and UV/Visible spectroscopy, supported by ab initio calculations. Photolysis at wavelengths of 240 and 266 nm of CF(2)Br(2):Ar samples (approximately 1:5000) held at approximately 5 K yielded iso-CF(2)Br(2) (F(2)CBrBr), a weakly bound isomer of CF(2)Br(2), which is characterized here for the first time. The observed infrared and UV/Visible absorptions of iso-CF(2)Br(2) are in excellent agreement with computational predictions at the B3LYP/aug-cc-pVTZ level. Single point energy calculations at the CCSD(T)/aug-cc-pVDZ level on the B3LYP optimized geometries suggest that the isoform is a minimum on the CF(2)Br(2) potential energy surface, lying some 55 kcal/mol above the CF(2)Br(2) ground state. The energies of various stationary points on the CF(2)Br(2) potential energy surface were characterized computationally; taken with our experimental results, these show that iso-CF(2)Br(2) is an intermediate in the Br+CF(2)Br-->CF(2)+Br(2) reaction. The photochemistry of the isoform was also investigated; excitation into the intense 359 nm absorption band resulted in isomerization to CF(2)Br(2). Our results are discussed in view of the rich literature on the gas-phase photochemistry of CF(2)Br(2), particularly with respect to the existence of a roaming atom pathway leading to molecular products.

Core electron binding energy shifts of AlBr3 and Al2Br6 vapor

International Nuclear Information System (INIS)

Mueller, Astrid M.; Plenge, Juergen; Leone, Stephen R.; Canton, Sophie E.; Rude, Bruce S.; Bozek, John D.

2006-01-01

The Al 2p and Br 3d inner-shell photoelectron spectra of aluminum tribromide monomer and dimer vapor were measured at 90 and 95 eV photon energy, respectively, to determine the core electron binding energies of the atoms in the two molecular species. While AlBr 3 has three identical Br atoms, Al 2 Br 6 exhibits four terminal and two bridging Br atoms. The species are identified by their distinct valence photoelectron spectra. Comparison of the observed Al 2p 1/2 and Al 2p 3/2 electron binding energies of AlBr 3 with those of Al 2 Br 6 shows that there is a chemical shift of (0.15 ± 0.03) eV to lower energy in the dimer. In Al 2 Br 6 , an assignment is proposed in which the Br 3d 3/2 and Br 3d 5/2 binding energies of terminal Br atoms are (1.18 ± 0.03) eV lower than those of bridging Br atoms. This assignment assumes that both types of Br atoms have similar cross-sections for ionization. With this result, the Br 3d 3/2 and Br 3d 5/2 binding energies of Br atoms in AlBr 3 are (0.81 ± 0.03) eV lower than those of bridging Br atoms of the dimer but (0.37 ± 0.03) eV higher than those of terminal Br atoms of the dimer. The obtained chemical shifts are considered in terms of the binding relations and electron density distributions in both molecules. Chemical shifts that are larger than a few hundred millielectron volts, as observed in the Al 2 Br 6 /AlBr 3 system, offer potential to study the dissociation dynamics of the dimer in a femtosecond visible or ultraviolet-pump/XUV-probe experiment

Two new 3-D cadmium bromoplumbates: the only example of heterometallic bromoplumbate based on crown [Cd(Pb4O4)Br2] clusters.

Science.gov (United States)

Xiao, Hong; Zhou, Jian; Liu, Xing

2018-04-03

Two new cadmium bromoplumbates [CdPb2Br2L2]n (1, L = ethylene glycol) and [CdPb6Br6L4]n (2) have been solvothermally synthesized and structurally characterized. 1 contains 1-D neutral heterometallic chains [CdPb2Br2L2]n, which are further connected via weak Pb-Br bonds, resulting in a 3-D network structure. The 3-D framework of 2 is constructed by the interconnection of a 2-D neutral layer [CdPb6Br6L4]nvia weak Pb-Br bonds. The [CdPb6Br6L4]n layer is based on the linkages of dimeric [Pb2Br4] units and heterometallic crown [Cd(Pb4O4)Br2] clusters containing a rare eight-membered [Pb4O4] ring. Although a few heterometallic bromoplumbate clusters have been reported, they usually exhibit molecular moieties. 2 represents the only example of 3-D heterometallic bromoplumbate based on the combination of heterometallic crown [Cd(Pb4O4)Br2] clusters and dimeric [Pb2Br4] units. Their optical properties are studied and density functional theory calculations for 1 and 2 have also been performed.

Matrix isolation and computational study of isodifluorodibromomethane (F2CBr-Br): A route to Br2 formation in CF2Br2 photolysis

International Nuclear Information System (INIS)

George, Lisa; Kalume, Aimable; Reid, Scott A.; El-Khoury, Patrick Z.; Tarnovsky, Alexander

2010-01-01

The photolysis products of dibromodifluoromethane (CF 2 Br 2 ) were characterized by matrix isolation infrared and UV/Visible spectroscopy, supported by ab initio calculations. Photolysis at wavelengths of 240 and 266 nm of CF 2 Br 2 :Ar samples (∼1:5000) held at ∼5 K yielded iso-CF 2 Br 2 (F 2 CBrBr), a weakly bound isomer of CF 2 Br 2 , which is characterized here for the first time. The observed infrared and UV/Visible absorptions of iso-CF 2 Br 2 are in excellent agreement with computational predictions at the B3LYP/aug-cc-pVTZ level. Single point energy calculations at the CCSD(T)/aug-cc-pVDZ level on the B3LYP optimized geometries suggest that the isoform is a minimum on the CF 2 Br 2 potential energy surface, lying some 55 kcal/mol above the CF 2 Br 2 ground state. The energies of various stationary points on the CF 2 Br 2 potential energy surface were characterized computationally; taken with our experimental results, these show that iso-CF 2 Br 2 is an intermediate in the Br+CF 2 Br→CF 2 +Br 2 reaction. The photochemistry of the isoform was also investigated; excitation into the intense 359 nm absorption band resulted in isomerization to CF 2 Br 2 . Our results are discussed in view of the rich literature on the gas-phase photochemistry of CF 2 Br 2 , particularly with respect to the existence of a roaming atom pathway leading to molecular products.

Formalized Linear Algebra over Elementary Divisor Rings in Coq

OpenAIRE

Cano , Guillaume; Cohen , Cyril; Dénès , Maxime; Mörtberg , Anders; Siles , Vincent

2016-01-01

International audience; This paper presents a Coq formalization of linear algebra over elementary divisor rings, that is, rings where every matrix is equivalent to a matrix in Smith normal form. The main results are the formalization that these rings support essential operations of linear algebra, the classification theorem of finitely pre-sented modules over such rings and the uniqueness of the Smith normal form up to multiplication by units. We present formally verified algorithms comput-in...

Computer simulation of the structure of liquid metal halides RbBr, CuCl, CuBr, CuI, and AgBr

International Nuclear Information System (INIS)

Belashchenko, D.K.; Ostrovskij, O.I.

2003-01-01

The computerized models of the RbBr, AgBr, CuCl, CuBr and CuI liquid ion systems of 498 ions dimension are simulated at the temperatures of 753-960 K on the basis of the known diffraction data through the BELION algorithm. Good agreement of diffraction and model partial pair correlation functions (PPCF), excluding the PPCF first peaks heights, is obtained in all the cases. The simulation is carried out by the varied ion charges (the atomization energy values, close to the real ones, are obtained by ion charges ±1.00 for the RbBr, ±1.15 for AgBr, ±1.20 for CuCl, ±1.48 for CuBr and ±1.367 for CuI). The noncoulomb contributions in the interparticle potentials are calculated [ru

Rate constant for the reaction SO + BrO yields SO2 + Br

Science.gov (United States)

Brunning, J.; Stief, L.

1986-01-01

The rate of the radical-radical reaction SO + BrO yields SO2 + Br has been determined at 298 K in a discharge flow system near 1 torr pressure with detection of SO and BrO via collision-free sampling mass spectrometry. The rate constant was determined using two different methods: measuring the decay of SO radicals in the presence of an excess of BrO and measuring the decay of BrO radicals in excess SO. The results from the two methods are in reasonable agreement and the simple mean of the two values gives the recommended rate constant at 298 K, k = (5.7 + or - 2.0) x 10 to the -11th cu cm/s. This represents the first determination of this rate constant and it is consistent with a previously derived lower limit based on SO2 formation. Comparison is made with other radical-radical reactions involving SO or BrO. The reaction SO + BrO yields SO2 + Br is of interest for models of the upper atmosphere of the earth and provides a potential coupling between atmospheric sulfur and bromine chemistry.

Dye adsorbates BrPDI, BrGly, and BrAsp on anatase TiO2(001) for dye-sensitized solar cell applications

Science.gov (United States)

Çakır, D.; Gülseren, O.; Mete, E.; Ellialtıoǧlu, Ş.

2009-07-01

Using the first-principles plane-wave pseudopotential method within density functional theory, we systematically investigated the interaction of perylenediimide (PDI)-based dye compounds (BrPDI, BrGly, and BrAsp) with both unreconstructed (UR) and reconstructed (RC) anatase TiO2(001) surfaces. All dye molecules form strong chemical bonds with surface in the most favorable adsorption structures. In UR-BrGly, RC-BrGly, and RC-BrAsp cases, we have observed that highest occupied molecular orbital and lowest unoccupied molecular orbital levels of molecules appear within band gap and conduction-band region, respectively. Moreover, we have obtained a gap narrowing upon adsorption of BrPDI on the RC surface. Because of the reduction in effective band gap of surface-dye system and possibly achieving the visible-light activity, these results are valuable for photovoltaic and photocatalytic applications. We have also considered the effects of hydration of surface to the binding of BrPDI. It has been found that the binding energy drops significantly for the completely hydrated surfaces.

Photodissociation of C3H5Br and C4H7Br at 234 nm

International Nuclear Information System (INIS)

Kim, Hyun Kook; Paul, Dababrata; Hong, Ki Ryong; Cho, Ha Na; Kim, Tae Kyu; Lee, Kyoung Seok

2012-01-01

The photodissociation dynamics of cyclopropyl bromide (C-3H 5 Br) and cyclobutyl bromide (C 4 H 7 Br) at 234 nm was investigated. A two-dimensional photofragment ion-imaging technique coupled with a [2+1] resonance enhanced multiphoton ionization scheme was utilized to obtain speed and angular distributions of the nascent Br( 2 P 3/2 ) and Br*( 2 P 1/2 ) atoms. The recoil anisotropies for the Br and Br* channels were measured to be βBr = 0.92 ± 0.03 and βBr* = 1.52 ± 0.04 for C 3 H 5 Br and βBr = 1.10 ± 0.03 and βBr* = 1.49 ± 0.05 for C 4 H 7 Br. The relative quantum yield for Br was found to be ΦBr = 0.13 ± 0.03 and for C 3 H 5 Br and C 4 H 7 Br, respectively. The soft radical limit of the impulsive model adequately modeled the related energy partitioning. The nonadiabatic transition probability from the 3A' and 4A' potential energy surfaces was estimated and discussed

Ring and jet study on the azimuthal substructure of pions at CERN ...

Indian Academy of Sciences (India)

Abstract. We have presented an investigation on the ring- and jet-like azimuthal angle sub- structures in the emission of secondary charged hadrons coming from 32S–Ag/Br interactions at. 200 A GeV/c. Nuclear photographic emulsion technique has been employed to collect the exper- imental data. The presence of such ...

Acceptability of microbicidal vaginal rings and oral pre-exposure prophylaxis for HIV prevention among female sex workers in a high-prevalence US city.

Science.gov (United States)

Peitzmeier, Sarah M; Tomko, Catherine; Wingo, Erin; Sawyer, Anne; Sherman, Susan G; Glass, Nancy; Beyrer, Chris; Decker, Michele R

2017-11-01

Biomedical HIV prevention tools including oral pre-exposure prophylaxis (PrEP) and vaginal microbicidal rings hold unique value for high-risk women who may have limited capacity for condom negotiation, including the key populations of sex workers and drug users. Commercial sex is a PrEP indicator in CDC guidelines, yet little is known about female sex workers' (FSWs) knowledge of and attitudes toward PrEP or the recently developed monthly vaginal microbicide rings. We describe knowledge and attitudes toward PrEP and microbicide rings in a sample of 60 mostly drug-using FSWs in Baltimore, Maryland, a high HIV-prevalence US city. Just 33% had heard of PrEP, but 65% were interested in taking daily oral PrEP and 76% were interested in a microbicide vaginal ring; 87% were interested in at least one of the two methods. Results suggest method mix will be important as biomedical tools for HIV prophylaxis are implemented and scaled up in this population, as 12% were interested in PrEP but not vaginal rings, while 19% were interested in vaginal rings but not in PrEP. Self-efficacy for daily oral adherence was high (79%) and 78% were interested in using PrEP even if condoms were still necessary. Women who had experienced recent client-perpetrated violence were significantly more interested in PrEP (86% vs 53%, p = 0.009) and microbicidal rings (91% vs 65%, p = 0.028) than women who had not recently experienced violence. No differences were observed by demographics nor HIV risk behaviors, suggesting broad potential interest in daily PrEP and monthly-use vaginal microbicides in this high-risk population.

Angular correlation for gamma-gamma transitions in 81Br and 83Br nuclei

International Nuclear Information System (INIS)

Matheus, R.

1984-01-01

The directional angular correlation of coincident gamma transitions in 81 Br and 83 Br have been measured following the β - decay of 81 Se(T sub(1/2) = 18.6 min) and 83 Se(T sub(1/2) = 22.6 min) respectively, using Ge(Li) - high purity Ge and Ge(Li)-NaI(Tl) spectrometers. The radioactive sources were prepared by irradiating with neutrons in the IEA-R1 reactor, metallic selenium (natural) to produce 81 Se and samples of metallic selenium enriched (to approx. 90% in 82 Se) to produce 83 Se. Measurements have been carried out for the gamma cascades 260-276 KeV, 290-276 KeV and 552-276 KeV in 81 Br and the gamma cascades 225(510)-356 KeV, 510-356 KeV, 572-(510)-356 KeV, 718-(225)-(510)-356 KeV, 1064-356 KeV, 718-225 KeV, 718-(225)-510 KeV, 836-718 KeV, 718-(225)-866 KeV, 883-718 KeV and 1895-799 KeV in 83 Br. The multipole mixing ratios, σ(E2/M1), were determined for 3 gamma transitions in 81 Br and 11 gamma transitions in 83 Br. In the case of 81 Br present results confirmed some of the earlier results. The spin and parity assignment were made to the majority of levels in 81 Br and 83 Br involved in the present study, some of them confirming the earlier results. A comparison of some of the nuclear properties of the 79 Br, 81 Br and 83 Br is made based on the available experimental data. The experimental results are also discussed qualitatively in terms of some nuclear models applicable for the description of the properties of odd-A bromine isotopes. (Author) [pt

$^{80}$Br $^{80}$Br-a new electron-gamma PAC probe

CERN Document Server

Correia, J G; Araújo, J P; Marques, J G; Soares, J C; Melo, A A

2001-01-01

Conversion electron-gamma PAC measurements of the 49-37 keV cascade in /sup 80/Br through the intermediate 2/sup -/ state with T/sub 1/2 /=7.4 ns were performed with a system of two magnetic lens spectrometers and two BaF/sub 2/ scintillation detectors. The parent /sup 80m/Br activity with a halflife of 4.4 hrs was implanted into Ni, Zn and graphite at the ISOLDE separator at CERN. The observed interaction frequency in the nickel matrix is in good agreement with the known value of the hyperfine field for Br in Ni and the magnetic moment of the 2/sup -/ state. From the measured quadrupole interaction in Zn and graphite the electric field gradients at Br were obtained. (7 refs).

Preparation of 80Br or 82Br-biomolecules via excitation labelling methods

International Nuclear Information System (INIS)

Wong, S.; Ache, H.J.

1975-01-01

The direct decay-induced 82 Br (or 80 Br) labelling by exposing the solid substrate molecules, such as deoxyuridine, L-tyrosine, guanosine, deoxycytidine, phenylalanine, and acetic acid, to gaseous CF 3 82 /sup m/Br (or CF 3 80 /sup m/Br) was studied. The radiochemical yields of the brominated products are relatively small and range from 1 percent in the case of bromo deoxyuridine to 11 percent for bromoacetic acid. The modification of this technique by adding Cl 2 gas to the reaction mixture improves the yields in several cases drastically (up to 80 percent for bromo-guanosine and bromo-L-tyrosine). Similar improvement can be achieved by exposing crystalline KBrO 3 for some time to CF 3 82 /sup m/Br (or CF 3 80 /sup m/Br) and dissolving subsequently the KBrO 3 in an acidic solution of the substrate. (auth)

Visible Light Driven Nanosecond Bromide Oxidation by a Ru Complex with Subsequent Br-Br Bond Formation.

Science.gov (United States)

Li, Guocan; Ward, William M; Meyer, Gerald J

2015-07-08

Visible light excitation of [Ru(deeb)(bpz)2](2+) (deeb = 4,4'-diethylester-2,2'-bipyridine; bpz = 2,2'-bipyrazine), in Br(-) acetone solutions, led to the formation of Br-Br bonds in the form of dibromide, Br2(•-). This light reactivity stores ∼1.65 eV of free energy for milliseconds. Combined (1)H NMR, UV-vis and photoluminescence measurements revealed two distinct mechanisms. The first involves diffusional quenching of the excited state by Br(-) with a rate constant of (8.1 ± 0.1) × 10(10) M(-1) s(-1). At high Br(-) concentrations, an inner-sphere pathway is dominant that involves the association of Br(-), most likely with the 3,3'-H atoms of a bpz ligand, before electron transfer from Br(-) to the excited state, ket = (2.5 ± 0.3) × 10(7) s(-1). In both mechanisms, the direct photoproduct Br(•) subsequently reacts with Br(-) to yield dibromide, Br(•) + Br(-) → Br2(•-). Under pseudo-first-order conditions, this occurs with a rate constant of (1.1 ± 0.4) × 10(10) M(-1) s(-1) that was, within experimental error, the same as that measured when Br(•) were generated with ultraviolet light. Application of Marcus theory to the sensitized reaction provided an estimate of the Br(•) formal reduction potential E(Br(•)/Br(-)) = 1.22 V vs SCE in acetone, which is about 460 mV less positive than the accepted value in H2O. The results demonstrate that Br(-) oxidation by molecular excited states can be rapid and useful for solar energy conversion.

Disability assessment scale for dementia – long version (DADL-BR

Directory of Open Access Journals (Sweden)

Mariana Boaro Fernandez Canon

2016-04-01

Full Text Available Introduction: There are no functional assessment tools for elderly with dementia available in the literature that will assess all occupations. Objective: To develop a Long Version of Disability Assessment for Dementia Scale (DADL-Br, covering all occupations provided by the American Association of Occupational Therapy (AOTA and the activities that compose them and evaluate its content validity. Method: With the permission of the original version main author (DAD, Isabelle Gélinas PhD, the new items of the Long Version (DADL-Br were developed based on the classification proposed by AOTA for occupations, considering the gaps in the original instrument. We reviewed the Cultural and Conceptual Equivalence by the Expert Committee and Multidisciplinary Committee. The suggestions of the Committees were accepted and the process followed for the pre-test and author analysis. Results: The first version of the instrument received 10 new fields and 64 new items, which after seven reviews of Cultural Equivalence (average concordance 89.2%, six reviews of Conceptual Equivalence (average concordance 81.2%, tree pre-tests and analysis of the original version main author, has resulted in the development of five versions, addition of twelve items and exclusion of seven items, and the final version consists of 20 fields and 109 items, being 10 new fields and 69 new items. Conclusion: This process conferred the content validity of DADL-Br, which includes all occupations proposed by AOTA and can be a useful tool to evaluate the profile of occupational performance of elderly with dementia.

RESONANCE CARS IN BR2 MOLECULES AND BR-ATOMS

NARCIS (Netherlands)

Aben, I.; Levelt, P.; Ubachs, W.M.G.; Hogervorst, W.

1991-01-01

Resonance-enhanced CARS processes were studied in molecular bromine. On the basis of the known spectroscopic constants of the two electronic states involved, the features in the spectra could be identified. CARS signals from Br-atoms produced from dissociation of Br2 were obtained by tuning (omega-1

New features of the MAX IV thermionic pre-injector

Energy Technology Data Exchange (ETDEWEB)

Andersson, J., E-mail: joel.andersson@maxiv.lu.se; Olsson, D., E-mail: david.olsson@maxiv.lu.se; Curbis, F.; Malmgren, L.; Werin, S.

2017-05-21

The MAX IV facility in Lund, Sweden consists of two storage rings for production of synchrotron radiation. The smaller 1.5 GeV ring is presently under construction, while the larger 3 GeV ring is being commissioned. Both rings will be operating with top-up injections from a full-energy injector. During injection, the electron beam is first delivered to the main injector from a thermionic pre-injector which consists of a thermionic RF gun, a chopper system, and an energy filter. In order to reduce losses of high-energy electrons along the injector and in the rings, the electron beam provided by the thermionic pre-injector should have the correct time structure and energy distribution. In this paper, the design of the MAX IV thermionic pre-injector with all its sub components is presented. The electron beam delivered by the pre-injector and its dependence on parameters such as optics, cathode temperature, and RF power are studied. Measurements are here compared with simulation results obtained by particle tracking and electromagnetic codes. The chopper system is described in detail, and different driving schemes that optimize the injection efficiency for the two storage rings are investigated. During operation, it was discovered that the structure of the beam delivered by the gun is affected by mode beating between the accelerating and a low-order mode. This mode beating is also studied in detail. Finally, initial measurements of the electron beam delivered to the 3 GeV ring during commissioning are presented.

Modification of radiation response of E. coli B/r cells by phenothiazines

International Nuclear Information System (INIS)

Maniar, H.S.; Singh, B.B.

1983-01-01

Promethazine and trimeprazine sensitized anoxic E. coli B/r cells to 60 Co gamma-rays, but both drugs showed a radioprotective effect under euoxic conditions. Their radiosensitizing effect was found to be due to the reaction of radiolytically induced hydroxyl radicals with the sensitizers. The radioprotective effect of these drugs is attributed to changes in the membrane structure conducive with chemical repair of the damaged sites in the gel region of the cellular membrane by intracellular sulphydryl compounds. Pre-irradiation depletion of sulphydryls from E. coli B/r by treatment with N-ethyl maleimide abolished the radioprotective effect of these drugs under euoxic conditions. (author)

Reactor BR2

Energy Technology Data Exchange (ETDEWEB)

Gubel, P

2000-07-01

The BR2 reactor is still SCK-CEN's most important nuclear facility. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. Various aspects concerning the operation of the BR2 Reactor, the utilisation of the CALLISTO loop and the irradiation programme, the BR2 R and D programme and the production of isotopes and of NTD-silicon are discussed. Progress and achievements in 1999 are reported.

Reactor BR2

International Nuclear Information System (INIS)

Gubel, P.

2000-01-01

The BR2 reactor is still SCK-CEN's most important nuclear facility. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. Various aspects concerning the operation of the BR2 Reactor, the utilisation of the CALLISTO loop and the irradiation programme, the BR2 R and D programme and the production of isotopes and of NTD-silicon are discussed. Progress and achievements in 1999 are reported

Hybridization of Single Nanocrystals of Cs4PbBr6 and CsPbBr3.

Science.gov (United States)

Weerd, Chris de; Lin, Junhao; Gomez, Leyre; Fujiwara, Yasufumi; Suenaga, Kazutomo; Gregorkiewicz, Tom

2017-09-07

Nanocrystals of all-inorganic cesium lead halide perovskites (CsPbX 3 , X = Cl, Br, I) feature high absorption and efficient narrow-band emission which renders them promising for future generation of photovoltaic and optoelectronic devices. Colloidal ensembles of these nanocrystals can be conveniently prepared by chemical synthesis. However, in the case of CsPbBr 3 , its synthesis can also yield nanocrystals of Cs 4 PbBr 6 and the properties of the two are easily confused. Here, we investigate in detail the optical characteristics of simultaneously synthesized green-emitting CsPbBr 3 and insulating Cs 4 PbBr 6 nanocrystals. We demonstrate that, in this case, the two materials inevitably hybridize, forming nanoparticles with a spherical shape. The actual amount of these Cs 4 PbBr 6 nanocrystals and nanohybrids increases for synthesis at lower temperatures, i.e., the condition typically used for the development of perovskite CsPbBr 3 nanocrystals with smaller sizes. We use state-of-the-art electron energy loss spectroscopy to characterize nanoparticles at the single object level. This method allows distinguishing between optical characteristics of a pure Cs 4 PbBr 6 and CsPbBr 3 nanocrystal and their nanohybrid. In this way, we resolve some of the recent misconceptions concerning possible visible absorption and emission of Cs 4 PbBr 6 . Our method provides detailed structural characterization, and combined with modeling, we conclusively identify the nanospheres as CsPbBr 3 /Cs 4 PbBr 6 hybrids. We show that the two phases are independent of each other's presence and merge symbiotically. Herein, the optical characteristics of the parent materials are preserved, allowing for an increased absorption in the UV due to Cs 4 PbBr 6 , accompanied by the distinctive efficient green emission resulting from CsPbBr 3 .

The TbBr3–LiBr binary system: Experimental thermodynamic investigation and assessment of phase diagram

International Nuclear Information System (INIS)

Rycerz, L.; Gong, W.; Gaune-Escard, M.

2013-01-01

Highlights: ► DSC measurements for the (LiBr + TbBr 3 ) system. ► congruently Li3TbBr 6 and incongruently melting Li5TbBr 8 compounds. ► Thermodynamic description of the liquid phase in the (LiBr + TbBr 3 ) system. ► Assessment with a two-sublattice ionic solution model. - Abstract: DSC was used to study the phase equilibrium in the TbBr 3 –LiBr binary system. The results obtained provided a basis for constructing the phase diagram of this system. It exhibits two compounds: Li 5 TbBr 8 , which decomposes in the solid state at 611 K, and Li 3 TbBr 6 , which melts congruently at 785 K with the related enthalpy 59.1 kJ·mol −1 . The binary LiBr–TbBr 3 system was then optimized using the available experimental information on phase diagram and thermodynamic properties. A two-sub-lattice ionic solution model (Li + ) P :(Br − , TbBr 6 −3 , TbBr 3 ) Q was adopted to describe the liquid phase. The present assessment of the binary LiBr–TbBr 3 system was in good agreement with the corresponding experimental data and confirmed their consistency.

$^{80m}$Br/$^{80}$Br a new electron-$\\gamma$ - PAC Probe

CERN Document Server

Correia, J G; Araújo, J P; Marques, J G; Soares, J C; Melo, A A

2001-01-01

Conversion electron-$\\gamma$ PAC measurements of the 49 keV - 37 keV cascade in $^{80}$Br through the intermediate 2$^{-}$ state with T$_{1/2}$=7.4 ns were performed with a system of two magnetic lens spectrometers and two BaF$_{2}$ scintillation detectors. The parent $^{80m}$Br activity with half-life of 4.4 hrs was implanted into Ni, Zn and graphite at the ISOLDE separator at CERN. The observed interaction frequency in the nickel matrix is in good agreement with the known value of the hyperfine field for Br in Ni and the magnetic moment of the 2$^{-}$ state. From the measured quadrupole interaction in Zn and graphite the electric field gradients at Br were obtained.

Elimination of nonspecific radioactivity from [76Br]bromide in PET study with [76Br]bromodeoxyuridine

International Nuclear Information System (INIS)

Li Lu; Bergstroem, Mats; Fasth, Karl-Johan; Wu Feng; Eriksson, Barbro; Laangstroem, Bengt

1999-01-01

[ 76 Br]Bromodeoxyuridine ([ 76 Br]BrdU) might allow a determination of proliferation in vivo using positron emission tomography (PET), but only with consideration of organ nonspecific radioactivity constituted by [ 76 Br]bromide. A first study assessed the potential of diuretics to eliminate [ 76 Br]bromide. [ 76 Br]Bromide was injected in the vein of rats and different diuretic combinations were given. Urine was collected and radioactivity measured. Torasemide plus sodium chloride gave better 76 Br elimination than the other diuretics. In a second experiment, rats were given [ 76 Br]BrdU. After the radioactivity injection, the rats of the treatment group were given torasemide plus NaCl. At 44 h after the radioactivity injection, the radioactivity concentration and the fraction incorporated into DNA were measured in different organs. Using diuretics, the elimination of [ 76 Br]bromide was increased. The radioactivity decreased 30-50% in most of the organs but the highest radioactivity uptake was found in the organs with more active DNA synthesis. This method may facilitate the use of [ 76 Br]BrdU as a tracer for DNA synthesis using PET

Improved production of Br atoms near zero speed by photodissociating laser aligned Br2 molecules.

Science.gov (United States)

Deng, L Z; Yin, J P

2014-10-28

We theoretically investigated the improvement on the production rate of the decelerated bromine (Br) atoms near zero speed by photodissociating laser aligned Br2 precursors. Adiabatic alignment of Br2 precursors exposed to long laser pulses with duration on the order of nanoseconds was investigated by solving the time-dependent Schrödinger equation. The dynamical fragmentation of adiabatically aligned Br2 precursors was simulated and velocity distribution of the Br atoms produced was analyzed. Our study shows that the larger the degree of the precursor alignment, ⟨cos(2) θ⟩, the higher the production rate of the decelerated Br atoms near zero speed. For Br2 molecules with an initial rotational temperature of ~1 K, a ⟨cos(2) θ⟩ value of ~0.88 can result in an improvement factor of over ~20 on the production rate of the decelerated Br atoms near zero speed, requiring a laser intensity of only ~1 × 10(12) W/cm(2) for alignment.

Dendro-analysis: the study of trace elements in tree rings

International Nuclear Information System (INIS)

Gilboy, W.B.; Tout, R.E.; Spyrou, N.M.

1976-01-01

In attempts to study environmental contamination over long time scales into the past, the levels of trace and minor elements in individual tree rings have been measured using instrumental neutron activation analysis. Most measurements so far have been done on elm tree samples which are widely available due to a current epidemic of Dutch Elm disease in southern England. Samples taken from every growth ring were individually activated for ten minutes in a thermal neutron flux of 1.5 x 10 12 n cm -2 sec -1 in the 100 kW London University research reactor. The activated samples were counted for ten minutes on a 42 cm 3 Ge(Li) gamma ray detector. These procedures enabled the following radioisotopes to be monitored for a large number of samples: 19 0, 24 Na, 27 Mg, 28 Al, 38 Cl, 42 K, 49 Ca, 56 Mn, 66 Cu, 80 Br, 87 /sup m/Sr, 41 Ar, 128 I, 139 Ba. Some of the above isotopes show striking systematic variations both from ring to ring in a radial direction, and also around individual rings. Results are described in detail for samples taken from trees grown in various locations and assesses the potential of this technique for studying past environmental conditions

All-Ambient Processed Binary CsPbBr3-CsPb2Br5 Perovskites with Synergistic Enhancement for High-Efficiency Cs-Pb-Br-Based Solar Cells.

Science.gov (United States)

Zhang, Xisheng; Jin, Zhiwen; Zhang, Jingru; Bai, Dongliang; Bian, Hui; Wang, Kang; Sun, Jie; Wang, Qian; Liu, Shengzhong Frank

2018-02-28

All-inorganic CsPbBr 3 perovskite solar cells display outstanding stability toward moisture, light soaking, and thermal stressing, demonstrating great potential in tandem solar cells and toward commercialization. Unfortunately, it is still challenging to prepare high-performance CsPbBr 3 films at moderate temperatures. Herein, a uniform, compact CsPbBr 3 film was fabricated using its quantum dot (QD)-based ink precursor. The film was then treated using thiocyanate ethyl acetate (EA) solution in all-ambient conditions to produce a superior CsPbBr 3 -CsPb 2 Br 5 composite film with a larger grain size and minimal defects. The achievement was attributed to the surface dissolution and recrystallization of the existing SCN - and EA. More specifically, the SCN - ions were first absorbed on the Pb atoms, leading to the dissolution and stripping of Cs + and Br - ions from the CsPbBr 3 QDs. On the other hand, the EA solution enhances the diffusion dynamics of surface atoms and the surfactant species. It is found that a small amount of CsPb 2 Br 5 in the composite film gives the best surface passivation, while the Br-rich surface decreases Br vacancies (V Br ) for a prolonged carrier lifetime. As a result, the fabricated device gives a higher solar cell efficiency of 6.81% with an outstanding long-term stability.

New measurement of BR(D→ρμν)BR(D→Kμν) branching ratio

Science.gov (United States)

FOCUS Collaboration; Link, J. M.; Yager, P. M.; Anjos, J. C.; Bediaga, I.; Castromonte, C.; Machado, A. A.; Magnin, J.; Massafferri, A.; de Miranda, J. M.; Pepe, I. M.; Polycarpo, E.; Dos Reis, A. C.; Carrillo, S.; Casimiro, E.; Cuautle, E.; Sánchez-Hernández, A.; Uribe, C.; Vá, F.; Agostino, L.; Cinquini, L.; Cumalat, J. P.; O'Reilly, B.; Segoni, I.; Stenson, K.; Butler, J. N.; Cheung, H. W. K.; Chiodini, G.; Gaines, I.; Garbincius, P. H.; Garren, L. A.; Gottschalk, E.; Kasper, P. H.; Kreymer, A. E.; Kutschke, R.; Wang, M.; Benussi, L.; Bertani, M.; Bianco, S.; Fabbri, F. L.; Pacetti, S.; Zallo, A.; Reyes, M.; Cawlfield, C.; Kim, D. Y.; Rahimi, A.; Wiss, J.; Gardner, R.; Kryemadhi, A.; Chung, Y. S.; Kang, J. S.; Ko, B. R.; Kwak, J. W.; Lee, K. B.; Cho, K.; Park, H.; Alimonti, G.; Barberis, S.; Boschini, M.; Cerutti, A.; D'Angelo, P.; Dicorato, M.; Dini, P.; Edera, L.; Erba, S.; Inzani, P.; Leveraro, F.; Malvezzi, S.; Menasce, D.; Mezzadri, M.; Moroni, L.; Pedrini, D.; Pontoglio, C.; Prelz, F.; Rovere, M.; Sala, S.; Davenport, T. F.; Arena, V.; Boca, G.; Bonomi, G.; Gianini, G.; Liguori, G.; Lopes Pegna, D.; Merlo, M. M.; Pantea, D.; Ratti, S. P.; Riccardi, C.; Vitulo, P.; Gö, C.; Otalora, J.; Hernandez, H.; Lopez, A. M.; Mendez, H.; Paris, A.; Quinones, J.; Ramirez, J. E.; Zhang, Y.; Wilson, J. R.; Handler, T.; Mitchell, R.; Engh, D.; Hosack, M.; Johns, W. E.; Luiggi, E.; Moore, J. E.; Nehring, M.; Sheldon, P. D.; Vaandering, E. W.; Webster, M.; Sheaff, M.

2006-06-01

Using data collected by the FOCUS experiment at Fermilab, we present a new measurement of the charm semileptonic branching ratio BR(D→ρμν)BR(D→Kμν). From a sample of 320±44 and 11372±161D→ρμν and D→Kπμν events respectively, we find BR(D→ρμν)BR(D→Kμν)=0.041±0.006 (stat)±0.004 (syst).

Exploring Polaronic, Excitonic Structures and Luminescence in Cs4PbBr6/CsPbBr3.

Science.gov (United States)

Kang, Byungkyun; Biswas, Koushik

2018-02-15

Among the important family of halide perovskites, one particular case of all-inorganic, 0-D Cs 4 PbBr 6 and 3-D CsPbBr 3 -based nanostructures and thin films is witnessing intense activity due to ultrafast luminescence with high quantum yield. To understand their emissive behavior, we use hybrid density functional calculations to first compare the ground-state electronic structure of the two prospective compounds. The dispersive band edges of CsPbBr 3 do not support self-trapped carriers, which agrees with reports of weak exciton binding energy and high photocurrent. The larger gap 0-D material Cs 4 PbBr 6 , however, reveals polaronic and excitonic features. We show that those lattice-coupled carriers are likely responsible for observed ultraviolet emission around ∼375 nm, reported in bulk Cs 4 PbBr 6 and Cs 4 PbBr 6 /CsPbBr 3 composites. Ionization potential calculations and estimates of type-I band alignment support the notion of quantum confinement leading to fast, green emission from CsPbBr 3 nanostructures embedded in Cs 4 PbBr 6 .

Yrityksen brändin uudistaminen

OpenAIRE

Saarimaa, Petri

2015-01-01

Brändin rakentaminen on tänä päivänä tärkeä osa yrityksen näkyvyyden ja kilpailukyvyn edistämisessä. Huolellisesti rakennetulla brändillä ja hyvällä markkinoinnilla yritys voi erottua kilpailijoistaan positiivisesti. Tie menestyvään brändiin on kuitenkin pitkä prosessi. Toimeksiantajana opinnäytetyössä toimi rakennusyritys Rakennus Vuoriot Oy. Opinnäytetyön tavoitteena oli toteuttaa yritykselle brändin uudistaminen luomalla kokonaan uusi perusta ja rakennusosat olemassa olevalle brändille...

Chanel-brändin nuorentaminen Suomessa

OpenAIRE

Auvinen, Elina

2017-01-01

Tämän opinnäytetyön tavoitteena oli kartoittaa Chanel-kosmetiikkabrändin imagoa ja asiakaskuntaa Suomessa sekä luoda saatujen tulosten pohjalta kehitysehdotuksia Chanel-brändin markkinointiin Suomessa brändin nuorentamisen näkökulmasta. Työn toimeksiantaja oli Chanel-brändin jakelija Oy Transmeri Ab. Teoriataustassa käsiteltiin laajasti erilaisia brändin nuorentamiseen liittyviä aihepiirejä; bränditeoriaa, brändien uudistamista, luksusbrändien erityispiirteitä sekä niiden asiakkaita, digitaal...

Recent Advances in Ring-Opening Functionalization of Cycloalkanols by C-C σ-Bond Cleavage.

Science.gov (United States)

Wu, Xinxin; Zhu, Chen

2018-06-01

Cycloalkanols prove to be privileged precursors for the synthesis of distally substituted alkyl ketones and polycyclic aromatic hydrocarbons (PAHs) by virtue of cleavage of their cyclic C-C bonds. Direct functionalization of cyclobutanols to build up other chemical bonds (e. g., C-F, C-Cl, C-Br, C-N, C-S, C-Se, C-C, etc.) has been achieved by using the ring-opening strategy. Mechanistically, the C-C cleavage of cyclobutanols can be involved in two pathways: (a) transition-metal catalyzed β-carbon elimination; (b) radical-mediated 'radical clock'-type ring opening. The recent advances of our group for the ring-opening functionalization of tertiary cycloalkanols are described in this account. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photoresponse of CsPbBr3 and Cs4PbBr6 Perovskite Single Crystals.

Science.gov (United States)

Cha, Ji-Hyun; Han, Jae Hoon; Yin, Wenping; Park, Cheolwoo; Park, Yongmin; Ahn, Tae Kyu; Cho, Jeong Ho; Jung, Duk-Young

2017-02-02

High-quality and millimeter-sized perovskite single crystals of CsPbBr 3 and Cs 4 PbBr 6 were prepared in organic solvents and studied for correlation between photocurrent generation and photoluminescence (PL) emission. The CsPbBr 3 crystals, which have a 3D perovskite structure, showed a highly sensitive photoresponse and poor PL signal. In contrast, Cs 4 PbBr 6 crystals, which have a 0D perovskite structure, exhibited more than 1 order of magnitude higher PL intensity than CsPbBr 3 , which generated an ultralow photoresponse under illumination. Their contrasting optoelectrical characteristics were attributed to different exciton binding energies, induced by coordination geometry of the [PbBr 6 ] 4- octahedron sublattices. This work correlated the local structures of lead in the primitive perovskite and its derivatives to PL spectra as well as photoconductivity.

In situ Spectroscopy of Solid-State Chemical Reaction in PbBr2-Deposited CsBr Crystals

Science.gov (United States)

Kondo, Shin-ichi; Matsunaga, Toshihiro; Saito, Tadaaki; Asada, Hiroshi

2003-09-01

It is possible to measure the fundamental optical absorption spectra of CsPbBr3 and Cs4PbBr6, whose stability is predicted by the study of phase diagram in the binary system CsBr-PbBr2, by means of in situ optical absorption and reflection spectroscopy of thermally induced solid-state chemical reaction in PbBr2-deposited CsBr crystals. On heavy annealing of the crystals, the Pb2+ ions are uniformly dispersed in the crystal matrix. The present experiment provides a novel method for measuring intrinsic optical absorption of ternary metal halides and also for in situ monitoring of doping metal halide crystal with impurities (metal ions or halogen ions).

Convenient synthesis of benzothiazoles and benzimidazoles through Brønsted acid catalyzed cyclization of 2-amino thiophenols/anilines with β-diketones.

Science.gov (United States)

Mayo, Muhammad Shareef; Yu, Xiaoqiang; Zhou, Xiaoyu; Feng, Xiujuan; Yamamoto, Yoshinori; Bao, Ming

2014-02-07

Brønsted acid catalyzed cyclization reactions of 2-amino thiophenols/anilines with β-diketones under oxidant-, metal-, and radiation-free conditions are described. Various 2-substituted benzothiazoles/benzimidazoles are obtained in satisfactory to excellent yields. Different groups such as methyl, chloro, nitro, and methoxy linked on benzene rings were tolerated under the optimized reaction conditions.

Tunable CsPbBr3/Cs4PbBr6 phase transformation and their optical spectroscopic properties.

Science.gov (United States)

Chen, Xiao; Chen, Daqin; Li, Junni; Fang, Gaoliang; Sheng, Hongchao; Zhong, Jiasong

2018-04-24

As a novel type of promising materials, metal halide perovskites are a rising star in the field of optoelectronics. On this basis, a new frontier of zero-dimensional perovskite-related Cs4PbBr6 with bright green emission and high stability has attracted an enormous amount of attention, even though its photoluminescence still requires to clarification. Herein, the controllable phase transformation between three-dimensional CsPbBr3 and zero-dimensional Cs4PbBr6 is easily achieved in a facile ligand-assisted supersaturated recrystallization synthesis procedure via tuning the amount of surfactants, and their unique optical properties are investigated and compared in detail. Both Cs4PbBr6 and CsPbBr3 produce remarkably intense green luminescence with quantum yields up to 45% and 80%, respectively; however, significantly different emitting behaviors are observed. The fluorescence lifetime of Cs4PbBr6 is much longer than that of CsPbBr3, and photo-blinking is easily detected in the Cs4PbBr6 product, proving that the zero-dimensional Cs4PbBr6 is indeed a highly luminescent perovskite-related material. Additionally, for the first time, tunable emissions over the visible-light spectral region are demonstrated to be achievable via halogen composition modulations in the Cs4PbX6 (X = Cl, Br, I) samples. Our study brings a simple method for the phase control of CsPbBr3/Cs4PbBr6 and demonstrates the intrinsic luminescence nature of the zero-dimensional perovskite-related Cs4PbX6 products.

Estimating BrAC from transdermal alcohol concentration data using the BrAC estimator software program.

Science.gov (United States)

Luczak, Susan E; Rosen, I Gary

2014-08-01

Transdermal alcohol sensor (TAS) devices have the potential to allow researchers and clinicians to unobtrusively collect naturalistic drinking data for weeks at a time, but the transdermal alcohol concentration (TAC) data these devices produce do not consistently correspond with breath alcohol concentration (BrAC) data. We present and test the BrAC Estimator software, a program designed to produce individualized estimates of BrAC from TAC data by fitting mathematical models to a specific person wearing a specific TAS device. Two TAS devices were worn simultaneously by 1 participant for 18 days. The trial began with a laboratory alcohol session to calibrate the model and was followed by a field trial with 10 drinking episodes. Model parameter estimates and fit indices were compared across drinking episodes to examine the calibration phase of the software. Software-generated estimates of peak BrAC, time of peak BrAC, and area under the BrAC curve were compared with breath analyzer data to examine the estimation phase of the software. In this single-subject design with breath analyzer peak BrAC scores ranging from 0.013 to 0.057, the software created consistent models for the 2 TAS devices, despite differences in raw TAC data, and was able to compensate for the attenuation of peak BrAC and latency of the time of peak BrAC that are typically observed in TAC data. This software program represents an important initial step for making it possible for non mathematician researchers and clinicians to obtain estimates of BrAC from TAC data in naturalistic drinking environments. Future research with more participants and greater variation in alcohol consumption levels and patterns, as well as examination of gain scheduling calibration procedures and nonlinear models of diffusion, will help to determine how precise these software models can become. Copyright © 2014 by the Research Society on Alcoholism.

Ring and jet-like structures and two-dimensional intermittency in nucleus-nucleus collisions at 200 AGeV/c

International Nuclear Information System (INIS)

Ghosh, M.K.; Haldar, P.K.; Manna, S.K.; Mukhopadhyay, A.; Singh, G.

2011-01-01

We have investigated the presence of ring and/or jet-like structures in the angular emission of secondary charged mesons (shower tracks) coming out of 16 O-Ag/Br and 32 S-Ag/Br interactions, each at an incident momentum of 200 AGeV/c. Nuclear photographic emulsion technique has been used to collect the experimental data. The experimental results have been compared with the results simulated by Monte Carlo method. The analysis indicates presence of ring and jet-like structures in the experimental data beyond statistical noise. This kind of jet structure is expected to give rise to a strong two-dimensional (2d) intermittency. The self-affine behaviour of 2d scaled factorial moments (SFM) has therefore been investigated and the strength of 2d intermittency has been determined. For each set of data the 2d results have been compared with the respective one-dimensional (1d) intermittency results.

Solid energy calibration standards for P K-edge XANES: electronic structure analysis of PPh4Br.

Science.gov (United States)

Blake, Anastasia V; Wei, Haochuan; Donahue, Courtney M; Lee, Kyounghoon; Keith, Jason M; Daly, Scott R

2018-03-01

P K-edge X-ray absorption near-edge structure (XANES) spectroscopy is a powerful method for analyzing the electronic structure of organic and inorganic phosphorus compounds. Like all XANES experiments, P K-edge XANES requires well defined and readily accessible calibration standards for energy referencing so that spectra collected at different beamlines or under different conditions can be compared. This is especially true for ligand K-edge X-ray absorption spectroscopy, which has well established energy calibration standards for Cl (Cs 2 CuCl 4 ) and S (Na 2 S 2 O 3 ·5H 2 O), but not neighboring P. This paper presents a review of common P K-edge XANES energy calibration standards and analysis of PPh 4 Br as a potential alternative. The P K-edge XANES region of commercially available PPh 4 Br revealed a single, highly resolved pre-edge feature with a maximum at 2146.96 eV. PPh 4 Br also showed no evidence of photodecomposition when repeatedly scanned over the course of several days. In contrast, we found that PPh 3 rapidly decomposes under identical conditions. Density functional theory calculations performed on PPh 3 and PPh 4 + revealed large differences in the molecular orbital energies that were ascribed to differences in the phosphorus oxidation state (III versus V) and molecular charge (neutral versus +1). Time-dependent density functional theory calculations corroborated the experimental data and allowed the spectral features to be assigned. The first pre-edge feature in the P K-edge XANES spectrum of PPh 4 Br was assigned to P 1s → P-C π* transitions, whereas those at higher energy were P 1s → P-C σ*. Overall, the analysis suggests that PPh 4 Br is an excellent alternative to other solid energy calibration standards commonly used in P K-edge XANES experiments.

Cabling design of booster and storage ring construction progress of TPS

International Nuclear Information System (INIS)

Wong, Y.-S.; Liu, K.-B.; Liu, C.-Y.; Wang, B.-S.

2017-01-01

The 2012 Taiwan Photon Source (TPS) cable construction project started after 10 months to complete the cable laying and installation of power supply. The circumference of the booster ring (BR) is 496.8 m, whereas that of the storage ring (SR) is 518.4 m. Beam current is set to 500 mA at 3.3 GeV. The paper on grounding systems discusses the design of the ground wire (< 0.2 Ω) with low impedance, power supply of the accelerator and cabling tray. The flow and size of the ground current are carefully evaluated to avoid grounded current from flowing everywhere, which causes interference problems. In the design of the TPS, special shielding will be established to isolate the effects of electromagnetic interference on the magnet and ground current. Booster ring dipoles are connected by a series of 54-magnet bending dipole; the cable size of its stranded wire measures 250 mm"2, with a total length of 5000 m. Booster ring and storage ring quadrupoles have 150 magnets; the cable size of their stranded wire is 250 mm"2, with a total length of 17000 m. Storage ring dipole consists of 48 magnets; the cable size of its stranded wire is 325 mm"2, with a total length of 6000 m. This study discusses the power supply cabling design of the storage ring and booster ring construction progress of TPS. The sections of this paper are divided into discussions of the construction of the control and instrument area, cabling layout of booster ring and storage ring, as well as the installation and commission machine. This study also discusses the use of a high-impedance meter to determine the effect of cabling insulation and TPS power supply machine on energy transfer to ensure the use of safe and correct magnet.

Brazilian Validation of the Attachment to God Inventory (IAD-Br

Directory of Open Access Journals (Sweden)

Hartmut August

2018-03-01

Full Text Available Bowlby’s Attachment Theory proposes that the person seeks protection and security with his or her caregiver, establishing a significant bond, which Bowlby characterizes as “attachment relationship”. The relationship with God can also be understood as an attachment relationship. Until now, there are no instruments in Brazil to measure one’s attachment to God. The purpose of this article is to present the adaptation and validation process of the Attachment to God Inventory for the Brazilian context, resulting in a Brazilian version of the Attachment to God Inventory (IAD-Br. The validation methodology for the IAD-Br consisted of Portuguese translation, reverse translation to English, pre-test, data collection, and validation through confirmatory factorial analysis (CFA. A total of 470 people participated in the study: 179 men and 291 women. Confirmatory factorial analysis presented unsatisfactory statistical parameters. Of the 28 items of the instrument, 11 items did not present adequate Item-Total Correlation. After excluding these 11 items, the instrument presented adequate adjustment indices. The IAD-Br, composed of 17 items, is able to be used to measure attachment to God in Brazil and constitutes a relevant instrument to identify the attachment to God style, being useful for application in the psychotherapeutic clinic and in contexts of spiritual care.

Elimination mechanisms of Br2+ and Br+ in photodissociation of 1,1- and 1,2-dibromoethylenes using velocity imaging technique

International Nuclear Information System (INIS)

Hua Linqiang; Zhang Bing; Lee, Wei-Bin; Chao, Meng-Hsuan; Lin, King-Chuen

2011-01-01

Elimination pathways of the Br 2 + and Br + ionic fragments in photodissociation of 1,2- and 1,1-dibromoethylenes (C 2 H 2 Br 2 ) at 233 nm are investigated using time-of-flight mass spectrometer equipped with velocity ion imaging. The Br 2 + fragments are verified not to stem from ionization of neutral Br 2 , that is a dissociation channel of dibromoethylenes reported previously. Instead, they are produced from dissociative ionization of dibromoethylene isomers. That is, C 2 H 2 Br 2 is first ionized by absorbing two photons, followed by the dissociation scheme, C 2 H 2 Br 2 + + hv→Br 2 + + C 2 H 2 . 1,2-C 2 H 2 Br 2 gives rise to a bright Br 2 + image with anisotropy parameter of -0.5 ± 0.1; the fragment may recoil at an angle of ∼66 deg. with respect to the C = C bond axis. However, this channel is relatively slow in 1,1-C 2 H 2 Br 2 such that a weak Br 2 + image is acquired with anisotropy parameter equal to zero, indicative of an isotropic recoil fragment distribution. It is more complicated to understand the formation mechanisms of Br + . Three routes are proposed for dissociation of 1,2-C 2 H 2 Br 2 , including (a) ionization of Br that is eliminated from C 2 H 2 Br 2 by absorbing one photon, (b) dissociation from C 2 H 2 Br 2 + by absorbing two more photons, and (c) dissociation of Br 2 + . Each pathway requires four photons to release one Br + , in contrast to the Br 2 + formation that involves a three-photon process. As for 1,1-C 2 H 2 Br 2 , the first two pathways are the same, but the third one is too weak to be detected.

Photodissociation of C{sub 3}H{sub 5}Br and C{sub 4}H{sub 7}Br at 234 nm

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun Kook; Paul, Dababrata; Hong, Ki Ryong; Cho, Ha Na; Kim, Tae Kyu [Pusan National University, Busan (Korea, Republic of); Lee, Kyoung Seok [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

2012-01-15

The photodissociation dynamics of cyclopropyl bromide (C-3H{sub 5}Br) and cyclobutyl bromide (C{sub 4}H{sub 7}Br) at 234 nm was investigated. A two-dimensional photofragment ion-imaging technique coupled with a [2+1] resonance enhanced multiphoton ionization scheme was utilized to obtain speed and angular distributions of the nascent Br({sup 2}P{sub 3/2}) and Br*({sup 2}P{sub 1/2}) atoms. The recoil anisotropies for the Br and Br* channels were measured to be βBr = 0.92 ± 0.03 and βBr* = 1.52 ± 0.04 for C{sub 3}H{sub 5}Br and βBr = 1.10 ± 0.03 and βBr* = 1.49 ± 0.05 for C{sub 4}H{sub 7}Br. The relative quantum yield for Br was found to be ΦBr = 0.13 ± 0.03 and for C{sub 3}H{sub 5}Br and C{sub 4}H{sub 7}Br, respectively. The soft radical limit of the impulsive model adequately modeled the related energy partitioning. The nonadiabatic transition probability from the 3A' and 4A' potential energy surfaces was estimated and discussed.

XeBr exciplex laser

International Nuclear Information System (INIS)

Searles, S.K.

1976-01-01

Laser emission from the recently discovered XeBr exciplex laser was investigated as a function of the partial pressures of Xe and Br 2 . An optical loss process appears to limit high-pressure operation

Elimination of nonspecific radioactivity from [{sup 76}Br]bromide in PET study with [{sup 76}Br]bromodeoxyuridine

Energy Technology Data Exchange (ETDEWEB)

Li Lu; Bergstroem, Mats E-mail: Mats.Bergstroem@pet.uu.se; Fasth, Karl-Johan; Wu Feng; Eriksson, Barbro; Laangstroem, Bengt

1999-10-01

[{sup 76}Br]Bromodeoxyuridine ([{sup 76}Br]BrdU) might allow a determination of proliferation in vivo using positron emission tomography (PET), but only with consideration of organ nonspecific radioactivity constituted by [{sup 76}Br]bromide. A first study assessed the potential of diuretics to eliminate [{sup 76}Br]bromide. [{sup 76}Br]Bromide was injected in the vein of rats and different diuretic combinations were given. Urine was collected and radioactivity measured. Torasemide plus sodium chloride gave better {sup 76}Br elimination than the other diuretics. In a second experiment, rats were given [{sup 76}Br]BrdU. After the radioactivity injection, the rats of the treatment group were given torasemide plus NaCl. At 44 h after the radioactivity injection, the radioactivity concentration and the fraction incorporated into DNA were measured in different organs. Using diuretics, the elimination of [{sup 76}Br]bromide was increased. The radioactivity decreased 30-50% in most of the organs but the highest radioactivity uptake was found in the organs with more active DNA synthesis. This method may facilitate the use of [{sup 76}Br]BrdU as a tracer for DNA synthesis using PET.

Analysis of pre-service and in-service views of evolution of Serbian teachers

Directory of Open Access Journals (Sweden)

Stanisavljević Jelena

2015-01-01

Full Text Available We analysed the potential differences between the conceptions of Serbian pre-service and in-service teachers using controlled parameters such as acceptance of the evolution theory. Our sample includes Primary School teachers as well as Secondary School teachers of Biology and of Language. We show that the ideas of pre-service (PreB and in-service biology teachers (InB are more evolutionary than those of their colleagues. In contrast, most creationist responses came from the groups of pre-service language (PreL and pre-service primary teachers (PreP. The agnostic teachers are more evolutionist than other teachers. The more a teacher believes in God and practices religion, the more creationist he or she is, but a great number of teachers who believe in God are evolutionist or simultaneously evolutionist and creationist. There is a positive correlation between evolutionist answers and the attitude that „Science and religion should be separated“, and „religion and politics should be separated“. [Projekat Ministarstva nauke Republike Srbije, br. 173038 i br. III 43001

Partial structures in molten AgBr

Energy Technology Data Exchange (ETDEWEB)

Ueno, Hiroki [Department of Condensed Matter Chemistry and Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Chuo-ku, Fukuoka 810-8560 (Japan)], E-mail: ueno@gemini.rc.kyushu-u.ac.jp; Tahara, Shuta [Faculty of Pharmacy, Niigata University of Pharmacy and Applied Life Science, Higashijima, Akiha-ku, Niigata 956-8603 (Japan); Kawakita, Yukinobu [Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Chuo-ku, Fukuoka 810-8560 (Japan); Kohara, Shinji [Research and Utilization Division, Japan Synchrotron Radiation Research Institute (JASRI, SPring-8), 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Takeda, Shin' ichi [Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Chuo-ku, Fukuoka 810-8560 (Japan)

2009-02-21

The structure of molten AgBr has been studied by means of neutron and X-ray diffractions with the aid of structural modeling. It is confirmed that the Ag-Ag correlation has a small but well-defined first peak in the partial pair distribution function whose tail penetrates into the Ag-Br nearest neighbor distribution. This feature on the Ag-Ag correlation is intermediate between that of molten AgCl (non-superionic melt) and that of molten AgI (superionic melt). The analysis of Br-Ag-Br bond angle reveals that molten AgBr preserves a rocksalt type local ordering in the solid phase, suggesting that molten AgBr is clarified as non-superionic melt like molten AgCl.

Investigations on the system Te/O/Br

International Nuclear Information System (INIS)

Oppermann, H.; Kunze, G.; Wolf, E.; Titov, V.A.; Kokovin, G.A.

1978-01-01

The melting point diagram of the system TeBr 4 -TeO 2 was obtained by total pressure measurements and DTA measurements. A congruent melting composition Te 6 O 11 Br 2 exists, the melting point is 570 0 C. The enthalpy of formation and the standard entropy of the species TeOBr 2 ,g was derived from measurements of the total pressure over Te 6 O 11 Br 2 /TeBr 4 and from the transport behaviour of the TeO 2 with Br 2 . From the decomposition-pressure measurements over Te 6 O 11 Br 2 /TeO 2 follow the partial pressures. The enthalpy of formation ΔH 0 (Te 6 O 11 Br 2 ,f,298) -453.5 kcal/Mol was obtained from the enthalpy of solution. The transport-behaviour of TeO 2 with HBr, TeBr 4 and Br 2 and that of Te 6 O 11 Br 2 is clear with the thermodynamic data of TeOBr 2 . (author)

Novel Br-DPQ blue light-emitting phosphors for OLED.

Science.gov (United States)

Dahule, H K; Thejokalyani, N; Dhoble, S J

2015-06-01

A new series of blue light-emitting 2,4-diphenylquinoline (DPQ) substituted blue light-emitting organic phosphors namely, 2-(4-methoxy-phenyl)-4-phenyl-quinoline (OMe-DPQ), 2-(4-methyl-phenyl)-4-phenylquinoline (M-DPQ), and 2-(4-bromo-phenyl)-4-phenylquinoline (Br-DPQ) were synthesized by substituting methoxy, methyl and bromine at the 2-para position of DPQ, respectively by Friedländer condensation of 2-aminobenzophenone and corresponding acetophenone. The synthesized phosphors were characterized by different techniques, e.g., Fourier transform infra-red (FTIR), differential scanning calorimeter (DSC), UV-visible absorption and photoluminescence spectra. FTIR spectra confirms the presence of chemical groups such as C=O, NH, or OH in all the three synthesized chromophores. DSC studies show that these complexes have good thermal stability. Although they are low-molecular-weight organic compounds, they have the potential to improve the stability and operating lifetime of a device made out of these complexes. The synthesized polymeric compounds demonstrate a bright emission in the blue region in the wavelength range of 405-450 nm in solid state. Thus the attachment of methyl, methoxy and bromine substituents to the diphenyl quinoline ring in these phosphors results in colour tuning of the phosphorescence. An electroluminescence (EL) cell of Br-DPQ phosphor was made and its EL behaviour was studied. A brightness-voltage characteristics curve of Br-DPQ cell revealed that EL begins at 400 V and then the brightness increases exponentially with applied AC voltage, while current-voltage (I-V) characteristics revealed that the turn on voltage of the fabricated EL cell was 11 V. Hence this phosphor can be used as a promising blue light material for electroluminescent devices. Copyright © 2014 John Wiley & Sons, Ltd.

Polymeric anionic networks using dibromine as a crosslinker; the preparation and crystal structure of [(C4H9)4N]2[Pt2Br10].(Br2)7 and [(C4H9)4N]2[PtBr4Cl2].(Br2)6.

Science.gov (United States)

Berkei, Michael; Bickley, Jamie F; Heaton, Brian T; Steiner, Alexander

2002-09-21

The reaction of M[PtX3(CO)] (M+ = [(C4H9)4N]+, X = Br, Cl) with an excess of Br2 gives the new platinum(IV) salts, [(C4H9)4N]2[Pt2Br10].(Br2)7, 1, and [(C4H9)4N]2[PtBr4Cl2].(Br2)6, 2, which, in the solid state, contain strong Br Br interactions resulting in the formation of polymeric networks; they could provide useful solid storage reservoirs for elemental bromine.

Addition reaction of adamantylideneadamantane with Br2 and 2Br2: a computational study.

Science.gov (United States)

Islam, Shahidul M; Poirier, Raymond A

2008-01-10

Ab initio calculations were carried out for the reaction of adamantylideneadamantane (Ad=Ad) with Br2 and 2Br2. Geometries of the reactants, transition states, intermediates, and products were optimized at HF and B3LYP levels of theory using the 6-31G(d) basis set. Energies were also obtained using single point calculations at the MP2/6-31G(d)//HF/6-31G(d), MP2/6-31G(d)//B3LYP/6-31G(d), and B3LYP/6-31+G(d)//B3LYP/6-31G(d) levels of theory. Intrinsic reaction coordinate (IRC) calculations were performed to characterize the transition states on the potential energy surface. Only one pathway was found for the reaction of Ad=Ad with one Br2 producing a bromonium/bromide ion pair. Three mechanisms for the reaction of Ad=Ad with 2Br2 were found, leading to three different structural forms of the bromonium/Br3- ion pair. Activation energies, free energies, and enthalpies of activation along with the relative stability of products for each reaction pathway were calculated. The reaction of Ad=Ad with 2Br2 was strongly favored over the reaction with only one Br2. According to B3LYP/6-31G(d) and single point calculations at MP2, the most stable bromonium/Br3- ion pair would form spontaneously. The most stable of the three bromonium/Br3- ion pairs has a structure very similar to the observed X-ray structure. Free energies of activation and relative stabilities of reactants and products in CCl4 and CH2ClCH2Cl were also calculated with PCM using the united atom (UA0) cavity model and, in general, results similar to the gas phase were obtained. An optimized structure for the trans-1,2-dibromo product was also found at all levels of theory both in gas phase and in solution, but no transition state leading to the trans-1,2-dibromo product was obtained.

Computations on the primary photoreaction of Br2 with CO2: stepwise vs concerted addition of Br atoms.

Science.gov (United States)

Xu, Kewei; Korter, Timothy M; Braiman, Mark S

2015-04-09

It was proposed previously that Br2-sensitized photolysis of liquid CO2 proceeds through a metastable primary photoproduct, CO2Br2. Possible mechanisms for such a photoreaction are explored here computationally. First, it is shown that the CO2Br radical is not stable in any geometry. This rules out a free-radical mechanism, for example, photochemical splitting of Br2 followed by stepwise addition of Br atoms to CO2-which in turn accounts for the lack of previously observed Br2+CO2 photochemistry in gas phases. A possible alternative mechanism in liquid phase is formation of a weakly bound CO2:Br2 complex, followed by concerted photoaddition of Br2. This hypothesis is suggested by the previously published spectroscopic detection of a binary CO2:Br2 complex in the supersonically cooled gas phase. We compute a global binding-energy minimum of -6.2 kJ mol(-1) for such complexes, in a linear geometry. Two additional local minima were computed for perpendicular (C2v) and nearly parallel asymmetric planar geometries, both with binding energies near -5.4 kJ mol(-1). In these two latter geometries, C-Br and O-Br bond distances are simultaneously in the range of 3.5-3.8 Å, that is, perhaps suitable for a concerted photoaddition under the temperature and pressure conditions where Br2 + CO2 photochemistry has been observed.

Breast cancer 1 (BrCa1 may be behind decreased lipogenesis in adipose tissue from obese subjects.

Directory of Open Access Journals (Sweden)

Francisco J Ortega

Full Text Available CONTEXT: Expression and activity of the main lipogenic enzymes is paradoxically decreased in obesity, but the mechanisms behind these findings are poorly known. Breast Cancer 1 (BrCa1 interacts with acetyl-CoA carboxylase (ACC reducing the rate of fatty acid biosynthesis. In this study, we aimed to evaluate BrCa1 in human adipose tissue according to obesity and insulin resistance, and in vitro cultured adipocytes. RESEARCH DESIGN AND METHODS: BrCa1 gene expression, total and phosphorylated (P- BrCa1, and ACC were analyzed in adipose tissue samples obtained from a total sample of 133 subjects. BrCa1 expression was also evaluated during in vitro differentiation of human adipocytes and 3T3-L1 cells. RESULTS: BrCa1 gene expression was significantly up-regulated in both omental (OM; 1.36-fold, p = 0.002 and subcutaneous (SC; 1.49-fold, p = 0.001 adipose tissue from obese subjects. In parallel with increased BrCa1 mRNA, P-ACC was also up-regulated in SC (p = 0.007 as well as in OM (p = 0.010 fat from obese subjects. Consistent with its role limiting fatty acid biosynthesis, both BrCa1 mRNA (3.5-fold, p<0.0001 and protein (1.2-fold, p = 0.001 were increased in pre-adipocytes, and decreased during in vitro adipogenesis, while P-ACC decreased during differentiation of human adipocytes (p = 0.005 allowing lipid biosynthesis. Interestingly, BrCa1 gene expression in mature adipocytes was restored by inflammatory stimuli (macrophage conditioned medium, whereas lipogenic genes significantly decreased. CONCLUSIONS: The specular findings of BrCa1 and lipogenic enzymes in adipose tissue and adipocytes reported here suggest that BrCa1 might help to control fatty acid biosynthesis in adipocytes and adipose tissue from obese subjects.

Density Functional Study of Structures and Electron Affinities of BrO4F/BrO4F-

Directory of Open Access Journals (Sweden)

Wei Li

2009-07-01

Full Text Available The structures, electron affinities and bond dissociation energies of BrO4F/BrO4F− species have been investigated with five density functional theory (DFT methods with DZP++ basis sets. The planar F-Br…O2…O2 complexes possess 3A' electronic state for neutral molecule and 4A' state for the corresponding anion. Three types of the neutral-anion energy separations are the adiabatic electron affinity (EAad, the vertical electron affinity (EAvert, and the vertical detachment energy (VDE. The EAad value predicted by B3LYP method is 4.52 eV. The bond dissociation energies De (BrO4F → BrO4-mF + Om (m = 1-4 and De- (BrO4F- → BrO4-mF- + Om and BrO4F- → BrO4-mF + Om- are predicted. The adiabatic electron affinities (EAad were predicted to be 4.52 eV for F-Br…O2…O2 (3A'← 4A' (B3LYP method.

The Rings of Saturn

Science.gov (United States)

Cuzzi, J. N.; Filacchione, G.; Marouf, E. A.

2018-03-01

One could become an expert on Saturn's iconic rings pretty easily in the early 1970s, as very little was known about them beyond the distinction between the A, B, and C rings, and the Cassini Division or "gap" between rings A and B (Alexander, 1962; Bobrov, 1970). Water ice was discovered spectroscopically on the ring particle surfaces, and radar and microwave emission observations proved that the particles must be centimeters to meters in size, consisting primarily, not just superficially, of water ice (Pollack, 1975). While a 2:1 orbital resonance with Mimas had long been suspected of having something to do with the Cassini Division, computers of the time were unable to model the subtle dynamical effects that we now know to dominate ring structure. This innocent state of affairs was exploded by the Voyager 1 and 2 encounters in 1980 and 1981. Spectacular images revealed filigree structure and odd regional color variations, and exquisitely detailed radial profiles of fluctuating particle abundance were obtained from the first stellar and radio occultations, having resolution almost at the scale of single particles. Voyager-era understanding was reviewed by Cuzzi et al. (1984) and Esposito et al. (1984). While the Voyager data kept ring scientists busy for decades, planning which led to the monumentally successful NASA-ESA-ASI Cassini mission, which arrived in 2004, had been under way even before Voyager got to Saturn. A review of pre-Cassini knowledge of Saturn's Rings can be found in Orton et al. (2009). This chapter will build on recent topical and process-specific reviews that treat the gamut of ring phenomena and its underlying physics in considerable detail (Colwell et al., 2009; Cuzzi et al., 2009; Horányi et al., 2009; Schmidt et al., 2009; Esposito, 2010; Tiscareno, 2013b; Esposito, 2014). We will follow and extend the general organization of Cuzzi et al. (2010), the most recent general discussion of Saturn's rings. For brevity and the benefit of the

An intercept study to measure the extent to which New Zealand university students pre-game.

Science.gov (United States)

Riordan, Benjamin C; Conner, Tamlin S; Flett, Jayde A M; Droste, Nic; Cody, Louise; Brookie, Kate L; Riordan, Jessica K; Scarf, Damian

2018-02-01

We aimed to quantify the degree to which students pre-gamed in New Zealand, using self-report and breathalysers. A total of 569 New Zealand undergraduate students were interviewed (men = 45.2%; first year = 81.4%) entering three university-run concerts. We asked participants to report how many drinks they had consumed, their self-reported intoxication and the duration of their pre-gaming session. We then recorded participants' Breath Alcohol Concentration (BrAC; µg/L) and the time they arrived at the event. The number of participants who reported consuming alcohol before the event was 504 (88.6%) and the number of standard drinks consumed was high (M=6.9; median=6.0). A total of 237 (41.7%) participants could not have their BrAC recorded due to having consumed alcohol ≤10 minutes before the interview. The remaining 332 participants (57.3%) recorded a mean BrAC of 288.8µg/L (median=280.0 µg/L). Gender, off-campus accommodation, length of pre-gaming drinking session, and time of arrival at the event were all associated with increased pre-gaming. Conclusion and implications for public health: Pre-gaming was the norm for students. Universities must take pre-gaming into account; policy implications include earlier start times of events and limiting students' access to alcohol prior to events. © 2017 The Authors.

Postsynthesis Transformation of Insulating Cs4PbBr6 Nanocrystals into Bright Perovskite CsPbBr3 through Physical and Chemical Extraction of CsBr.

Science.gov (United States)

Palazon, Francisco; Urso, Carmine; De Trizio, Luca; Akkerman, Quinten; Marras, Sergio; Locardi, Federico; Nelli, Ilaria; Ferretti, Maurizio; Prato, Mirko; Manna, Liberato

2017-10-13

Perovskite-related Cs 4 PbBr 6 nanocrystals present a "zero-dimensional" crystalline structure where adjacent [PbBr 6 ] 4- octahedra do not share any corners. We show in this work that these nanocrystals can be converted into "three-dimensional" CsPbBr 3 perovskites by extraction of CsBr. This conversion drastically changes the optoelectronic properties of the nanocrystals that become highly photoluminescent. The extraction of CsBr can be achieved either by thermal annealing (physical approach) or by chemical reaction with Prussian Blue (chemical approach). The former approach can be simply carried out on a dried film without addition of any chemicals but does not yield a full transformation. Instead, reaction with Prussian Blue in solution achieves a full transformation into the perovskite phase. This transformation was also verified on the iodide counterpart (Cs 4 PbI 6 ).

Dicty_cDB: FC-BR23 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available FC (Link to library) FC-BR23 (Link to dictyBase) - - - Contig-U15008-1 FC-BR23Z (Li...nk to Original site) - - FC-BR23Z 641 - - - - Show FC-BR23 Library FC (Link to library) Clone ID FC-BR23 (Li.../dictycdb.biol.tsukuba.ac.jp/CSM/FC/FC-BR/FC-BR23Q.Seq.d/ Representative seq. ID FC-BR2...3Z (Link to Original site) Representative DNA sequence >FC-BR23 (FC-BR23Q) /CSM/FC/FC-BR/FC-BR23Q.Seq....9 0.0 SLA211 (SLA211Q) /CSM/SL/SLA2-A/SLA211Q.Seq.d/ 1029 0.0 FC-BR23 (FC-BR23Q) /CSM/FC/FC-BR/FC-BR2

Balloon-borne stratospheric BrO measurements: comparison with Envisat/SCIAMACHY BrO limb profiles

Directory of Open Access Journals (Sweden)

M. Dorf

2006-01-01

Full Text Available For the first time, results of four stratospheric BrO profiling instruments, are presented and compared with reference to the SLIMCAT 3-dimensional chemical transport model (3-D CTM. Model calculations are used to infer a BrO profile validation set, measured by 3 different balloon sensors, for the new Envisat/SCIAMACHY (ENVIronment SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY satellite instrument. The balloon observations include (a balloon-borne in situ resonance fluorescence detection of BrO (Triple, (b balloon-borne solar occultation DOAS measurements (Differential Optical Absorption Spectroscopy of BrO in the UV, and (c BrO profiling from the solar occultation SAOZ (Systeme d'Analyse par Observation Zenithale balloon instrument. Since stratospheric BrO is subject to considerable diurnal variation and none of the measurements are performed close enough in time and space for a direct comparison, all balloon observations are considered with reference to outputs from the 3-D CTM. The referencing is performed by forward and backward air mass trajectory calculations to match the balloon with the satellite observations. The diurnal variation of BrO is considered by 1-D photochemical model calculation along the trajectories. The 1-D photochemical model is initialised with output data of the 3-D model with additional constraints on the vertical transport, the total amount and photochemistry of stratospheric bromine as given by the various balloon observations. Total [Bry]=(20.1±2.5 pptv obtained from DOAS BrO observations at mid-latitudes in 2003, serves as an upper limit of the comparison. Most of the balloon observations agree with the photochemical model predictions within their given error estimates. First retrieval exercises of BrO limb profiling from the SCIAMACHY satellite instrument on average agree to around 20% with the photochemically-corrected balloon observations of the remote sensing instruments (SAOZ

Energikravene i BR15

DEFF Research Database (Denmark)

Kragh, Jesper; Aggerholm, Søren

2015-01-01

Bygningsreglement 2015 – BR15 – gælder fra 1. januar 2016 med en overgangsfase frem til 1. juli 2016. Det bygger videre på BR10 og de tidligere udmeldte krav til nybyggeriet frem mod 2020. I denne kvikguide får du hurtigt overblik over, hvordan du sikrer, at de bygninger, du er med til at opføre...... eller renovere, lever op til BR15’s energikrav. Disse krav findes primært i reglementets kapitel 7 om energiforbrug og i kapitel 8 om installationer samt i kapitel 6 om indeklima....

17β-estradiol as precursors of Cl/Br-DBPs in the disinfection process of different water samples.

Science.gov (United States)

Shao, Yanan; Pan, Zihan; Rong, Chuan; Wang, Yinghui; Zhu, Hongxiang; Zhang, Yuanyuan; Yu, Kefu

2018-05-21

During chlorine disinfection process, reactions between the disinfectant and 17β-estradiol (E2) lead to the formation of halogenated disinfection byproducts (DBPs) which can be a risk to both ecosystem and human health. The degradation and transformation products of E2 in sodium hypochlorite (NaClO) disinfection processes of different water samples were investigated. The reaction kinetics research showed that the degradation rates of E2 were considerably dependent on the initial pH value and the types of water samples. In fresh water, synthetic marine aquaculture water and seawater, the reaction rate constant was 0.133 min -1 , 2.067 min -1 and 2.592 min -1 , respectively. The reasons for the above phenomena may be due to the different concentrations of bromide ions (Br - ) in these three water samples which could promote the reaction between NaClO and E2. Furthermore, Br - could also cause the formation of brominated DBPs (Br-DBPs). The main DBPs, reaction centers and conceivable reaction pathways were explored. Seven halogenated DBPs have been observed including three chlorinated DBPs (Cl-DBPs) and four Br-DBPs. The active sites of E2 were found to be the pentabasic cyclic ring and the ortho position of the phenol moiety as well as C9-C10 position. The identified Cl/Br-DBPs were also confirmed in actual marine aquaculture water from a shrimp pond. The comparison of bio-concentration factors (BCF) values based on calculation of EPI-suite showed that the toxicities of the Br-DBPs were stronger than that of their chloride analogues. The absorbable organic halogens (AOX) analysis also suggested that the DBPs produced in the marine aquaculture water were more toxic than that in the fresh water system. Copyright © 2018 Elsevier Ltd. All rights reserved.

Measurement of the ratio of branching ratios BR(B+ → J/ψK+)/BR(B0 → J/φK0) and BR(B+ → J/ψK+)/BR(B+ → J/ψK*+)

International Nuclear Information System (INIS)

Atavales, J. B. G.

1995-01-01

A preliminary measurement of the ratio of branching ratios BR(B + → J/ψK + )/BR(B 0 → J/ψK 0 ) and BR(B + → J/ψK + )/BR(B + → J/ψK *+ ) is made by fully reconstructing each mode, where J/ψ → μ + μ - , K *+ → K 0 s π + and K 0 s → π + π - . The data were taken with the CDF detector during the 1993 run. The total integrated luminosity is ∼ 20pb -1 resulting in a sample of about 170 J/ψK ± , 50 J/ψK 0 S and 25 J/ψK *± candidate events. The results will be reported

Reactivity of BrCl, Br₂, BrOCl, Br₂O, and HOBr toward dimethenamid in solutions of bromide + aqueous free chlorine.

Science.gov (United States)

Sivey, John D; Arey, J Samuel; Tentscher, Peter R; Roberts, A Lynn

2013-02-05

HOBr, formed via oxidation of bromide by free available chlorine (FAC), is frequently assumed to be the sole species responsible for generating brominated disinfection byproducts (DBPs). Our studies reveal that BrCl, Br(2), BrOCl, and Br(2)O can also serve as brominating agents of the herbicide dimethenamid in solutions of bromide to which FAC was added. Conditions affecting bromine speciation (pH, total free bromine concentration ([HOBr](T)), [Cl(-)], and [FAC](o)) were systematically varied, and rates of dimethenamid bromination were measured. Reaction orders in [HOBr](T) ranged from 1.09 (±0.17) to 1.67 (±0.16), reaching a maximum near the pK(a) of HOBr. This complex dependence on [HOBr](T) implicates Br(2)O as an active brominating agent. That bromination rates increased with increasing [Cl(-)], [FAC](o) (at constant [HOBr](T)), and excess bromide (where [Br(-)](o)>[FAC](o)) implicate BrCl, BrOCl, and Br(2), respectively, as brominating agents. As equilibrium constants for the formation of Br(2)O and BrOCl (aq) have not been previously reported, we have calculated these values (and their gas-phase analogues) using benchmark-quality quantum chemical methods [CCSD(T) up to CCSDTQ calculations plus solvation effects]. The results allow us to compute bromine speciation and hence second-order rate constants. Intrinsic brominating reactivity increased in the order: HOBr ≪ Br(2)O Br(2) < BrCl. Our results indicate that species other than HOBr can influence bromination rates under conditions typical of drinking water and wastewater chlorination.

Synthesis 1-(5-oxohexyl)-3,7-dimethyl-xanthyne labelled with tritium into 8 position from purinic ring

International Nuclear Information System (INIS)

Mihaila, V.; Corol, D.

1999-01-01

This paper presents the work on synthesis of 1-(5-oxohexyl)-3,7-dimethyl-xanthyne labelled with tritium into 8 position from purinic ring. The obtaining of tritium labelled compound is realized by initial labelling of theobromine with tritium into 8 position and by coupling the purinic derivative to 1-Br-5-hexanone. Theobromine-8- 3 H was obtained by the bromination of theobromine with elementary bromine and after that the bromine was substituted with tritium i.e.: C 7 H 8 O 2 N 4 theobromine Br 2 /(-HBr) C 7 H 7 O 2 N 4 Br (8-Br-theobromine) ( 3 H 2 /cat)/(-KOH) C 7 H 7 3 HO 2 N 4 (theobromine-8- 3 H). Theobromine-8- 3 H was purified by thin layer chromatography with a solvent system i.e. n-BuOH:AcOH:H 2 O (4:1:1, v/v/v) and characterized radiochemically. It was then diluted by unlabelled theobromine to specific activity of 50 mCi/g. After dilution, theobromine-8- 3 H was coupled to 1-Br-5-hexanone i.e.: C 7 H 7 3 HO 2 N 4 (theobromine-8- 3 H) + Br-(CH 2 ) 4 -CO-CH 3 (1-Br-5-hexanone) (NaOH)/(CH 3 OH) C 13 H 17 3 HO 3 N 4 (1-(5-oxohexyl)- 3,7-dimethyl-xanthine-8- 3 H). The raw compound was purified by recrystallization from 2-propanol and it was characterized radiochemically. (authors)

The BR eigenvalue algorithm

Energy Technology Data Exchange (ETDEWEB)

Geist, G.A. [Oak Ridge National Lab., TN (United States). Computer Science and Mathematics Div.; Howell, G.W. [Florida Inst. of Tech., Melbourne, FL (United States). Dept. of Applied Mathematics; Watkins, D.S. [Washington State Univ., Pullman, WA (United States). Dept. of Pure and Applied Mathematics

1997-11-01

The BR algorithm, a new method for calculating the eigenvalues of an upper Hessenberg matrix, is introduced. It is a bulge-chasing algorithm like the QR algorithm, but, unlike the QR algorithm, it is well adapted to computing the eigenvalues of the narrowband, nearly tridiagonal matrices generated by the look-ahead Lanczos process. This paper describes the BR algorithm and gives numerical evidence that it works well in conjunction with the Lanczos process. On the biggest problems run so far, the BR algorithm beats the QR algorithm by a factor of 30--60 in computing time and a factor of over 100 in matrix storage space.

Six-membered ring aliphatic compounds: A search for regularities in phase transitions

International Nuclear Information System (INIS)

Nagrimanov, Ruslan N.; Solomonov, Boris N.; Emel’yanenko, Vladimir N.; Verevkin, Sergey P.

2016-01-01

Highlights: • Thermodynamics of sublimation and solution of halogen adamantanes is studied. • Sublimation enthalpies derived from transpiration and solution calorimetry in agreement. • Enthalpies of fusion measured by DSC and used to derive vaporization enthalpies. • Structure-property analysis of vaporization enthalpies was performed. - Abstract: Absolute vapor pressures of 1-Cl-adamantane, 2-Cl-adamantane, 1-Br-adamantane, 2-Br-adamantane, as well as of Br-cyclohexane were measured by using the transpiration method. Standard molar enthalpies of sublimation of halogen substituted adamantanes at 298.15 K were derived from vapor pressure temperature dependences. Standard molar enthalpies of solution of adamantane and halogen adamantanes in cyclohexane were measured with a high-precision solution calorimeter. A theoretical procedure based on the solution calorimetry was applied to derive sublimation enthalpies of halogen adamantanes independently. Molar enthalpies of fusion were measured with help of DSC. The consistent data set of phase transitions for each compound was evaluated and used for discussion of structure-property relations in adamantane and cyclohexane derivatives. A simple way to predict enthalpies of vaporization of compounds containing six-membered rings was suggested for practical thermochemical calculations.

Dicty_cDB: FC-BR21 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available FC (Link to library) FC-BR21 (Link to dictyBase) - - - Contig-U15384-1 | Contig-U16443-1 FC-BR2...1P (Link to Original site) FC-BR21F 551 FC-BR21Z 122 FC-BR21P 673 - - Show FC-BR21 Library FC (L...ink to library) Clone ID FC-BR21 (Link to dictyBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig Cont...ig-U15384-1 | Contig-U16443-1 Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/FC/FC-BR/FC-BR2...1Q.Seq.d/ Representative seq. ID FC-BR21P (Link to Original site) Representative DNA sequence >FC-BR21 (FC-BR2

Oxidation mechanisms of CF2Br2 and CH2Br2 induced by air nonthermal plasma.

Science.gov (United States)

Schiorlin, Milko; Marotta, Ester; Dal Molin, Marta; Paradisi, Cristina

2013-01-02

Oxidation mechanisms in air nonthermal plasma (NTP) at room temperature and atmospheric pressure were investigated in a corona reactor energized by +dc, -dc, or +pulsed high voltage.. The two bromomethanes CF(2)Br(2) and CH(2)Br(2) were chosen as model organic pollutants because of their very different reactivities with OH radicals. Thus, they served as useful mechanistic probes: they respond differently to the presence of humidity in the air and give different products. By FT-IR analysis of the postdischarge gas the following products were detected and quantified: CO(2) and CO in the case of CH(2)Br(2), CO(2) and F(2)C ═ O in the case of CF(2)Br(2). F(2)C ═ O is a long-lived oxidation intermediate due to its low reactivity with atmospheric radicals. It is however removed from the NTP processed gas by passage through a water scrubber resulting in hydrolysis to CO(2) and HF. Other noncarbon containing products of the discharge were also monitored by FT-IR analysis, including HNO(3) and N(2)O. Ozone, an important product of air NTP, was never detected in experiments with CF(2)Br(2) and CH(2)Br(2) because of the highly efficient ozone depleting cycles catalyzed by BrOx species formed from the bromomethanes. It is concluded that, regardless of the type of corona applied, CF(2)Br(2) reacts in air NTP via a common intermediate, the CF(2)Br radical. The possible reactions leading to this radical are discussed, including, for -dc activation, charge exchange with O(2)(-), a species detected by APCI mass spectrometry.

Modelling of the ring current in Saturn's magnetosphere

Directory of Open Access Journals (Sweden)

G. Giampieri

2004-01-01

Full Text Available The existence of a ring current inside Saturn's magnetosphere was first suggested by Smith et al. (1980 and Ness et al. (1981, 1982, in order to explain various features in the magnetic field observations from the Pioneer 11 and Voyager 1 and 2 spacecraft. Connerney et al. (1983 formalized the equatorial current model, based on previous modelling work of Jupiter's current sheet and estimated its parameters from the two Voyager data sets. Here, we investigate the model further, by reconsidering the data from the two Voyager spacecraft, as well as including the Pioneer 11 flyby data set.

First, we obtain, in closed form, an analytic expression for the magnetic field produced by the ring current. We then fit the model to the external field, that is the difference between the observed field and the internal magnetic field, considering all the available data. In general, through our global fit we obtain more accurate parameters, compared to previous models. We point out differences between the model's parameters for the three flybys, and also investigate possible deviations from the axial and planar symmetries assumed in the model. We conclude that an accurate modelling of the Saturnian disk current will require taking into account both of the temporal variations related to the condition of the magnetosphere, as well as non-axisymmetric contributions due to local time effects.<br>> Key words. Magnetospheric physics (current systems; planetary magnetospheres; plasma sheet

Hybridization of Single Nanocrystals of Cs4PbBr6 and CsPbBr3

OpenAIRE

Weerd, Chris de; Lin, Junhao; Gomez, Leyre; Fujiwara, Yasufumi; Suenaga, Kazutomo; Gregorkiewicz, Tom

2017-01-01

Nanocrystals of all-inorganic cesium lead halide perovskites (CsPbX3, X = Cl, Br, I) feature high absorption and efficient narrow-band emission which renders them promising for future generation of photovoltaic and optoelectronic devices. Colloidal ensembles of these nanocrystals can be conveniently prepared by chemical synthesis. However, in the case of CsPbBr3, its synthesis can also yield nanocrystals of Cs4PbBr6 and the properties of the two are easily confused. Here, we investigate in de...

Simple and Regioselective Bromination of 5,6-Disubstituted-indan-1-ones with Br2 Under Acidic and Basic Conditions

Directory of Open Access Journals (Sweden)

Eunsook Ma

2007-01-01

Full Text Available Bromination of 5,6-dimethoxyindan-1-one with Br2 in acetic acid at room temperature produced exclusively the corresponding 2,4-dibromo compound in 95% yield. Reaction of 5,6-dimethoxyindan-1-one with Br2 in the presence of KOH, K2CO3 or Cs2CO3 at ~0°C gave the monobrominated product 4-bromo-5,6-dimethoxyindan-3-one in 79%, 81% and 67% yield, respectively. 5,6-Dihydroxyindan-1-one was dibrominated on the aromatic ring affording 4,7-dibromo-5,6-dihydroxyindan-1-one both in acetic acid at room temperature and in the presence of KOH at ~0°C. 5,6-Difluoroindan-1-one and 1-indanone were α-monobrominated in acetic acid and α,α-dibrominated under KOH conditions at room temperature.

Cd4As2Br3

Directory of Open Access Journals (Sweden)

Mohammed Kars

2014-03-01

Full Text Available Single crystals of Cd4As2Br3 (tetracadmium biarsenide tribromide were grown by a chemical transport reaction. The structure is isotypic with the members of the cadmium and mercury pnictidohalides family with general formula M4A2X3 (M = Cd, Hg; A = P, As, Sb; X = Cl, Br, I and contains two independent As atoms on special positions with site symmetry -3 and two independent Cd atoms, of which one is on a special position with site symmetry -3. The Cd4As2Br3 structure consists of AsCd4 tetrahedra sharing vertices with isolated As2Cd6 octahedra that contain As–As dumbbells in the centre of the octahedron. The Br atoms are located in the voids of this three-dimensional arrangement and bridge the different polyhedra through Cd...Br contacts.

PDC bit selection to drill the Brazilian pre-salt heterogeneous carbonates; Selecao de broca PDC para a perfuracao dos carbonatos heterogeneos do pre-sal brasileiro

Energy Technology Data Exchange (ETDEWEB)

Lima, Araken Dumont Ramos; Tocantins, Joao Pedro Tourinho [Schlumberger, Rio de Janeiro, RJ (Brazil)

2012-07-01

The well drilling operation to access the oil reserves of the Brazilian pre-salt find their highest challenge in the rock reservoir, which is formed from organic limestone and other sediments, and it can have different heterogeneous features that are hostile to drilling. Those features such as the silica nodules increase the rock formation strength and abrasiveness that together with the PDC bit vibrations generated during the rock cutting reduce the life of the cutting structure to a few meters. Because of these conditions, the development of more stable bits, with very low lateral and torsional vibration levels and with more strength PDC, has been one oil industry challenges to drill the pre-salt limestone with silica. This paper aims to present a dynamic comparative analysis between three PDC bits, called BR1, BR2 and BR3, of different generations, selected to drill a well design in a limestone heterogeneous and homogeneous (without silica nodules). This analysis was performed with dynamic three dimensional finite elements software, which considers the interaction between the bit cutter structure and the rock to be drilled, used to design bits, reamers and BHA (Bottom Hole Assembly). (author)

Concerning the generation of geomagnetic giant pulsations by drift-bounce resonance ring current instabilities

Directory of Open Access Journals (Sweden)

K.-H. Glassmeier

Full Text Available Giant pulsations are nearly monochromatic ULF-pulsations of the Earth's magnetic field with periods of about 100 s and amplitudes of up to 40 nT. For one such event ground-magnetic observations as well as simultaneous GEOS-2 magnetic and electric field data and proton flux measurements made in the geostationary orbit have been analysed. The observations of the electromagnetic field indicate the excitation of an odd-mode type fundamental field line oscillation. A clear correlation between variations of the proton flux in the energy range 30-90 keV with the giant pulsation event observed at the ground is found. Furthermore, the proton phase space density exhibits a bump-on-the-tail signature at about 60 keV. Assuming a drift-bounce resonance instability as a possible generation mechanism, the azimuthal wave number of the pulsation wave field may be determined using a generalized resonance condition. The value determined in this way, <br> m = - 21 ± 4, is in accord with the value m = - 27 ± 6 determined from ground-magnetic measurements. A more detailed examination of the observed ring current plasma distribution function f shows that odd-mode type eigenoscillations are expected for the case ∂f / ∂W > 0, much as observed. This result is different from previous theoretical studies as we not only consider local gradients of the distribution function in real space, but also in velocity space. It is therefore concluded that the observed giant pulsation is the result of a drift-bounce resonance instability of the ring current plasma coupling to an odd-mode fundamental standing wave. The generation of the bump-on-the-tail distribution causing ∂f / ∂W > 0 can be explained due to velocity dispersion of protons injected into the ring current. Both this velocity dispersion and the necessary substorm activity causing the injection of protons into the nightside magnetosphere are observed.<br>

Brændeovnes bidrag til luftforurening

DEFF Research Database (Denmark)

Pedersen, Jens Christian

2010-01-01

Brændeovnenes bidrag til luftforurening er blevet kortlagt med en hidtil uset detaljeringsgrad. Det er forskere fra Danmarks Miljøundersøgelser (DMU) på Aarhus Universitet som står bag kortlægningen. En omfattende målekampagne i Slagslunde viser at brændeovnene bidrager væsentligt til partikelfor......Brændeovnenes bidrag til luftforurening er blevet kortlagt med en hidtil uset detaljeringsgrad. Det er forskere fra Danmarks Miljøundersøgelser (DMU) på Aarhus Universitet som står bag kortlægningen. En omfattende målekampagne i Slagslunde viser at brændeovnene bidrager væsentligt til...

Emission characteristics of Xe-RbBr plasma

Science.gov (United States)

Heneral, A. A.; Avtaeva, S. V.

2017-12-01

The luminescence spectra of the longitudinal pulsed-periodic discharge in Xe-RbBr gas-vapour mixtures at low pressures are experimentally studied. Conditions for obtaining strong UV radiation of XeBr* exiplex molecules in the spectral range of 200-425 nm are found. The greatest output of the XeBr* UV radiation is provided at temperature of the gas-discharge tube walls of ~1000 K. The maximum UV emission power of the whole plasma volume is 4.8 W. Formation of XeBr* exciplex molecules in the pulsed-periodic discharge in Xe-RbBr gas-vapour mixtures at low pressures is discussed.

Free-tropospheric BrO investigations based on GOME

Science.gov (United States)

Post, P.; van Roozendael, M.; Backman, L.; Damski, J.; Thölix, L.; Fayt, C.; Taalas, P.

2003-04-01

Bromine compounds contribute significantly to the stratospheric ozone depletion. However measurements of most bromine compounds are sparse or non-existent, and experimental studies essentially rely on BrO observations. The differences between balloon and ground based measurements of stratospheric BrO columns and satellite total column measurements are too large to be explained by measurement uncertainties. Therefore, it has been assumed that there is a concentration of BrO in the free troposphere of about 1-3 ppt. In a previous work, we have calculated the tropospheric BrO abundance as the difference between total BrO and stratospheric BrO columns. The total vertical column densities of BrO are extracted from GOME measurements using IASB-BIRA algorithms. The stratospheric amount has been calculated using chemical transport models (CTM). Results from SLIMCAT and FinROSE simulations are used for this purpose. SLIMCAT is a widely used 3D CTM that has been tested against balloon measurements. FinROSE is a 3D CTM developed at FMI. We have tried several different tropospheric BrO profiles. Our results show that a profile with high BrO concentrations in the boundary layer usually gives unrealistically high tropospheric column values over areas of low albedo (like oceans). This suggests that the tropospheric BrO would be predominantly distributed in the free troposphere. In this work, attempts are made to identify the signature of a free tropospheric BrO content when comparing cloudy and non-cloudy scenes. The possible impact of orography on measured BrO columns is also investigated.

Measurement of the relative branching ratio BR(Ξc+-- >p+K- π+)/BR(Ξc+-->Ξ- π+π+)

Science.gov (United States)

FOCUS Collaboration; Link, J. M.; Reyes, M.; Yager, P. M.; Anjos, J. C.; Bediaga, I.; Göbel, C.; Magnin, J.; Massafferri, A.; de Miranda, J. M.; Pepe, I. M.; dos Reis, A. C.; Sima~o, F. R. A.; Carrillo, S.; Casimiro, E.; Sánchez-Hernández, A.; Uribe, C.; Vázquez, F.; Cinquini, L.; Cumalat, J. P.; O'Reilly, B.; Ramirez, J. E.; Vaandering, E. W.; Butler, J. N.; Cheung, H. W. K.; Gaines, I.; Garbincius, P. H.; Garren, L. A.; Gottschalk, E.; Kasper, P. H.; Kreymer, A. E.; Kutschke, R.; Bianco, S.; Fabbri, F. L.; Sarwar, S.; Zallo, A.; Cawlfield, C.; Kim, D. Y.; Rahimi, A.; Wiss, J.; Gardner, R.; Chung, Y. S.; Kang, J. S.; Ko, B. R.; Kwak, J. W.; Lee, K. B.; Park, H.; Alimonti, G.; Boschini, M.; Caccianiga, B.; D'Angelo, P.; DiCorato, M.; Dini, P.; Giammarchi, M.; Inzani, P.; Leveraro, F.; Malvezzi, S.; Menasce, D.; Mezzadri, M.; Milazzo, L.; Moroni, L.; Pedrini, D.; Pontoglio, C.; Prelz, F.; Rovere, M.; Sala, A.; Sala, S.; Davenport, T. F., III; Agostino, L.; Arena, V.; Boca, G.; Bonomi, G.; Gianini, G.; Liguori, G.; Merlo, M. M.; Pantea, D.; Ratti, S. P.; Riccardi, C.; Segoni, I.; Viola, L.; Vitulo, P.; Hernandez, H.; Lopez, A. M.; Mendez, H.; Mendez, L.; Mirles, A.; Montiel, E.; Olaya, D.; Paris, A.; Quinones, J.; Rivera, C.; Xiong, W.; Zhang, Y.; Wilson, J. R.; Cho, K.; Handler, T.; Engh, D.; Hosack, M.; Johns, W. E.; Nehring, M.; Sheldon, P. D.; Stenson, K.; Webster, M.; Sheaff, M.

2001-07-01

We report the observation of the Cabibbo suppressed decay Ξc+-->pK-π+ using data collected with the FOCUS spectrometer during the 1996-1997 Fermilab fixed target run. We find a Ξc+ signal peak of /202+/-35 events. We have measured the relative branching ratios BR(Ξ+c-->pK- π+)/BR(Ξ+c-->Ξ- π+π+)=0.234+/-0.047+/-0.022 and BR(Ξ+c-- >pK¯*(892)0)/BR(Ξ+c-->pK-π+)=0.54+/-0.09+/-0.05.

Analysis of I-Br-Cl in single fluid inclusions by LA-ICP-MS

Science.gov (United States)

Giehl, C.; Fusswinkel, T.; Beermann, O.; Garbe-Schönberg, D.; Scholten, L.; Wagner, T.

2017-12-01

Halogens are excellent tracers of hydrothermal fluid sources and in-situ LA-ICP-MS analysis of Cl and Br in single fluid inclusions has provided fundamentally new insight into hydrothermal fluid flow and ore formation. There is mounting evidence that enrichment and depletion of Br relative to Cl may be caused by a number of processes beyond seawater evaporation and halite dissolution which cannot be discriminated on the basis of Br/Cl ratios alone. Expanding the analytical capabilities of fluid inclusion LA-ICP-MS analysis to include iodine would allow to discern between selective and coupled enrichment processes of Cl, Br and I, even in geologically complex samples that are inaccessible to bulk extraction techniques. We present iodine concentration data determined by LA-ICP-MS analysis of synthetic fluid inclusions, using the Sca17 scapolite reference material for external standardization (Seo et al., 2011). Iodine concentrations in Sca17 were determined using the Durango apatite standard. Four starting solutions containing I (0.3, 1.5, 27, 78 µg/g), Br (941, 1403, 2868, 4275 µg/g), Na (30.7, 94.7 mg/g), and Cl (50, 137 mg/g) (analyzed by ICP-OES and ICP-MS at CAU Kiel) were prepared by dissolving reagent grade chemical powders in ultra-pure water. Spherical inclusions (up to 40 µm) were synthesized from the starting solutions in pre-cracked, HF-treated synthetic quartz crystals which were placed in gold capsules and equilibrated at 600°C, 100/200 MPa in cold seal pressure vessels. Fluid inclusion LA-ICP-MS analysis (University of Helsinki) yielded average I concentrations in excellent agreement with the starting solutions (27.3 µg/g ± 14 %RSD for the 27 µg/g solution and 77.6 µg/g ± 8.3 %RSD for the 78 µg/g solution). Average Br and I concentrations deviate less than 10 % from solution concentration values. For the low I concentration solutions, the synthetic inclusions were too small to detect I. Thus, given suitable standard materials and sufficient

The genus Actiniceps Berk. & Br

NARCIS (Netherlands)

Boedijn, K.B.

1959-01-01

The genus Actiniceps Berk. & Br. is shown to be a Basidiomycete. Wiesnerina Höhn. and Dimorphocystis Corner are regarded synonymous. The type species A. thwaitesii Berk. & Br. is redescribed with D. capitatus Corner as synonym. The following new combinations are proposed: A. horrida (Höhn.) Boedijn,

Brûlure chez l’épileptique: brûlure pas comme les autres

Science.gov (United States)

Boukind, S.; Elatiqi, O.K.; Dlimi, M.; Elamrani, D.; Benchamkha, Y.; Ettalbi, S.

2015-01-01

Summary L’association brûlure et épilepsie est une constatation fréquente au Maroc. Ces brûlures, souvent itératives, touchent le plus souvent des femmes jeunes de milieu rural. L’accident survient habituellement au domicile, le plus souvent dans la cuisine à la suite d’une chute sur un moyen de cuisson posé au sol. Elles peuvent être inaugurales de la maladie mais surviennent plus souvent chez des patients connus mais au traitement mal suivi. Les conséquences de ces brûlures, toujours profondes, sont souvent dramatiques en termes de séquelles, chez des patients ayant déjà une insertion sociale rendue difficile par l’épilepsie. La prise en charge doit être multidisciplinaire et concerner à la fois la brûlures et l’épilepsie. Des mesures de prévention simples, visant à équilibrer l’épilepsie et éviter au patient de se trouver seul à proximité d’une source de chaleur, doivent être mises en place. PMID:27252613

Reactions of N2O5 with Salty and Surfactant-Coated Glycerol: Interfacial Conversion of Br- to Br2 Mediated by Alkylammonium Cations.

Science.gov (United States)

Shaloski, Michael A; Gord, Joseph R; Staudt, Sean; Quinn, Sarah L; Bertram, Timothy H; Nathanson, Gilbert M

2017-05-18

Gas-liquid scattering and product-yield experiments are used to investigate reactions of N 2 O 5 with glycerol containing Br - and surfactant ions. N 2 O 5 oxidizes Br - to Br 2 for every solution tested: 2.7 M NaBr, 0.03 M tetrahexylammonium bromide (THABr), 0.03 M THABr + 0.5 M NaBr, 0.03 M THABr + 0.5 M NaCl, 0.03 M THABr + 0.01 M sodium dodecyl sulfate (SDS), and 0.01 M cetyltrimethylammonium bromide (CTABr). N 2 O 5 also reacts with glycerol itself to produce mono- and dinitroglycerin. Surface tension measurements indicate that 0.03 M THABr and 2.7 M NaBr have similar interfacial Br - concentrations, though their bulk Br - concentrations differ by 90-fold. We find that twice as much Br 2 is produced in the presence of THA + , implying that the conversion of Br - to Br 2 is initiated at the interface, perhaps mediated by the charged, hydrophobic pocket within the surface THA + cation. The addition of 0.5 M NaBr, 0.5 M NaCl, or 0.01 M SDS to 0.03 M THABr lowers the Br 2 production rate by 23%, 63%, and 67% of the THABr value, respectively. When CTA + is substituted for THA + , Br 2 production drops to 12% of the THABr value. The generation of Br 2 under such different conditions implies that trace amounts of surface-active alkylammonium ions can catalyze interfacial N 2 O 5 reactions, even when salts and other surfactants are present.

Insensitivity of Tree-Ring Growth to Temperature and Precipitation Sharpens the Puzzle of Enhanced Pre-Eruption NDVI on Mt. Etna (Italy).

Science.gov (United States)

Seiler, Ruedi; Kirchner, James W; Krusic, Paul J; Tognetti, Roberto; Houlié, Nicolas; Andronico, Daniele; Cullotta, Sebastiano; Egli, Markus; D'Arrigo, Rosanne; Cherubini, Paolo

2017-01-01

On Mt. Etna (Italy), an enhanced Normalized Difference in Vegetation Index (NDVI) signature was detected in the summers of 2001 and 2002 along a distinct line where, in November 2002, a flank eruption subsequently occurred. These observations suggest that pre-eruptive volcanic activity may have enhanced photosynthesis along the future eruptive fissure. If a direct relation between NDVI and future volcanic eruptions could be established, it would provide a straightforward and low-cost method for early detection of upcoming eruptions. However, it is unclear if, or to what extent, the observed enhancement of NDVI can be attributed to volcanic activity prior to the subsequent eruption. We consequently aimed at determining whether an increase in ambient temperature or additional water availability owing to the rise of magma and degassing of water vapour prior to the eruption could have increased photosynthesis of Mt. Etna's trees. Using dendro-climatic analyses we quantified the sensitivity of tree ring widths to temperature and precipitation at high elevation stands on Mt. Etna. Our findings suggest that tree growth at high elevation on Mt. Etna is weakly influenced by climate, and that neither an increase in water availability nor an increase in temperature induced by pre-eruptive activity is a plausible mechanism for enhanced photosynthesis before the 2002/2003 flank eruption. Our findings thus imply that other, yet unknown, factors must be sought as causes of the pre-eruption enhancement of NDVI on Mt. Etna.

Synthesis of poly(2-ethyl-2-oxazoline)-b-poly(styrene) copolymers via a dual initiator route combining cationic ring-opening polymerization and atom transfer radical polymerization

NARCIS (Netherlands)

Becer, C.R.; Paulus, R.M.; ppener, S.; Hoogenboom, R.; Fustin, C.A.; Gohy, J.M.W.; Schubert, U.S.

2008-01-01

Block copolymers of 2-ethyl-2-oxazoline (EtOx) and styrene were synthesized by a combination of cationic ring-opening polymerization (CROP) and atom transfer radical polymerization (ATRP). Initially, a detailed kinetic investigation for the ?-bromoisobutyrylbromide (BrEBBr) initiated CROP of EtOx

Preparation and characterization of (R,S)-[76Br]BrQNB: an analogue of QNB for PET

International Nuclear Information System (INIS)

Strijckmans, V.; Loc'h, C.; Ottaviani, M.; Maziere, B.; Lee, K.S.; Zeeberg, B.R.

1997-01-01

(R,S)-[ 76 Br]BrQNB was prepared for imaging mAChR by PET . (R,S)QNB was labelled with bromine-76 by electrophilic substitution of the tributylstannyl precursor using peracetic acid as oxidizing agent. The exchange between bromine-76 and the leaving group occurred in 20 min at room temperature. A chemically and radiochemically pure product was obtained with a final radiolabelling yield of 30%. Preliminary evaluation of pharmacological properties was performed in rats. In brain, biodistribution and autoradiography studies showed that the preferential localization of (R,S)-[ 76 Br]BrQNB was m-AChR rich structures. 6 h p.i. the radioactivity uptake in the posterior cortex was 1% ID/g and the striatum to cerebellum radioactivity ratio was 13.5. Metabolite study revealed that the radiotracer remains unchanged in brain for at least 3 h. (Author)

Z-(-,-)-[76Br]BrQNP: a high affinity PET radiotracer for central and cardiac muscarinic receptors

International Nuclear Information System (INIS)

Strijckmans, V.; Coulon, C.; Loc'h, C.; Maziere, B.; Luo, H.; McPherson, D.W.; Knapp, F.F.

1996-01-01

Racemic E-1-azabicyclo[2.2.2]oct-3-yl α-(1-bromo-1-1-propen-3-yl)-α -hydroxy-α-phenylacetate (BrQNP) was prepared and evaluated in vivo as a potential candidate for imaging muscarinic acetylcholinergic receptors by Positron Emission Tomography. Initial in vivo blocking studies utilizing Z-(-,-)-[ 125 I]IQNP as a radiolabelled muscarinic probe demonstrated that a preinjection of cold E-BrQNP effectively blocks the uptake of the radiolabelled probe in the brain and heart, by 71% and 86% respectively. Z-(-,-)-[ 76 Br]BrQNP was prepared by electrophilic substitution from a tributylstannyl precursor. Peracetic acid and chloramine T was evaluated as oxidizing agents. After purification by SPE and RP-HPLC, radiolabelling yields of 85% and 95% were obtained with peracetic acid and chloramine T, respectively. The final radiochemical yield was 70% for both oxidizing agents. (author)

New results for the formation of a muoniated radical in the Mu + Br2 system: a van der Waals complex or evidence for vibrational bonding in Br-Mu-Br?

Science.gov (United States)

Fleming, Donald G; Cottrell, Stephen P; McKenzie, Iain; Macrae, Roderick M

2012-08-21

New evidence is presented for the observation of a muoniated radical in the Mu + Br(2) system, from μSR longitudinal field (LF) repolarisation studies in the gas phase, at Br(2) concentrations of 0.1 bar in a Br(2)/N(2) mixture at 300 K and at 10 bar total pressure. The LF repolarisation curve, up to a field of 4.5 kG, reveals two paramagnetic components, one for the Mu atom, formed promptly during the slowing-down process of the positive muon, with a known Mu hyperfine coupling constant (hfcc) of 4463 MHz, and one for a muoniated radical formed by fast Mu addition. From model fits to the Br(2)/N(2) data, the radical component is found to have an unusually high muon hfcc, assessed to be ∼3300 MHz with an overall error due to systematics expected to exceed 10%. This high muon hfcc is taken as evidence for the observation of either the Br-Mu-Br radical, and hence of vibrational bonding in this H[combining low line]-L[combining low line]-H[combining low line] system, or of a MuBr(2) van der Waals complex formed in the entrance channel. Preliminary ab initio electronic structure calculations suggest the latter is more likely but fully rigorous calculations of the effect of dynamics on the hfcc for either system have yet to be carried out.

Genomic identification and characterization of the elite strains Bradyrhizobium yuanmingense BR 3267 and Bradyrhizobium pachyrhizi BR 3262 recommended for cowpea inoculation in Brazil.

Science.gov (United States)

Leite, Jakson; Passos, Samuel Ribeiro; Simões-Araújo, Jean Luiz; Rumjanek, Norma Gouvêa; Xavier, Gustavo Ribeiro; Zilli, Jerri Édson

2017-03-31

The leguminous inoculation with nodule-inducing bacteria that perform biological nitrogen fixation is a good example of an "eco-friendly agricultural practice". Bradyrhizobium strains BR 3267 and BR 3262 are recommended for cowpea (Vigna unguiculata) inoculation in Brazil and showed remarkable responses; nevertheless neither strain was characterized at species level, which is our goal in the present work using a polyphasic approach. The strains presented the typical phenotype of Bradyrhizobium with a slow growth and a white colony on yeast extract-mannitol medium. Strain BR 3267 was more versatile in its use of carbon sources compared to BR 3262. The fatty acid composition of BR 3267 was similar to the type strain of Bradyrhizobium yuanmingense; while BR 3262 was similar to Bradyrhizobium elkanii and Bradyrhizobium pachyrhizi. Phylogenetic analyses based on 16S rRNA and three housekeeping genes placed both strains within the genus Bradyrhizobium: strain BR 3267 was closest to B. yuanmingense and BR 3262 to B. pachyrhizi. Genome average nucleotide identity and DNA-DNA reassociation confirmed the genomic identification of B. yuanmingense BR 3267 and B. pachyrhizi BR 3262. The nodC and nifH gene analyses showed that strains BR 3267 and BR 3262 hold divergent symbiotic genes. In summary, the results indicate that cowpea can establish effective symbiosis with divergent bradyrhizobia isolated from Brazilian soils. Published by Elsevier Editora Ltda.

Stig Brøgger's Artists' Books

DEFF Research Database (Denmark)

Ørum, Tania; Hvis Kromann, Thomas

Introduction and presentation of the many artist's books made by the Danish artist Stig Brøgger......Introduction and presentation of the many artist's books made by the Danish artist Stig Brøgger...

Ring Theory

CERN Document Server

Jara, Pascual; Torrecillas, Blas

1988-01-01

The papers in this proceedings volume are selected research papers in different areas of ring theory, including graded rings, differential operator rings, K-theory of noetherian rings, torsion theory, regular rings, cohomology of algebras, local cohomology of noncommutative rings. The book will be important for mathematicians active in research in ring theory.

UV-Induced Anisotropy In CdBr2-CdBr2: Cu Nanostructures

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El-Naggar A. M.

2015-09-01

Full Text Available We have found an occurrence of anisotropy in the nanostructure CdBr2-CdBr2: Cu nanocrystalline films. The film thickness was varied from 4 nm up to 80 nm. The films were prepared by successive deposition of the novel layers onto the basic nanocrystals. The detection of anisotropy was performed by occurrence of anisotropy in the polarized light at 633 nm He-Ne laser wavelength. The occurrence of anisotropy was substantially dependent on the film thickness and the photoinduced power density. Possible mechanisms of the observed phenomena are discussed.

Finding the Missing Stratospheric Br(sub y): A Global Modeling Study of CHBr3 and CH2Br2

Science.gov (United States)

Liang, Q.; Stolarski, R. S.; Kawa, S. R.; Nielsen, J. E.; Douglass, A. R.; Rodriguez, J. M.; Blake, D. R.; Atlas, E. L.; Ott, L. E.

2010-01-01

Recent in situ and satellite measurements suggest a contribution of 5 pptv to stratospheric inorganic bromine from short-lived bromocarbons. We conduct a modeling study of the two most important short-lived bromocarbons, bromoform (CHBr3) and dibromomethane (CH2Br2), with the Goddard Earth Observing System Chemistry Climate Model (GEOS CCM) to account for this missing stratospheric bromine. We derive a "top-down" emission estimate of CHBr3 and CH2Br2 using airborne measurements in the Pacific and North American troposphere and lower stratosphere obtained during previous NASA aircraft campaigns. Our emission estimate suggests that to reproduce the observed concentrations in the free troposphere, a global oceanic emission of 425 Gg Br yr(exp -1) for CHBr3 and 57 Gg Br yr(exp -l) for CH2Br2 is needed, with 60% of emissions from open ocean and 40% from coastal regions. Although our simple emission scheme assumes no seasonal variations, the model reproduces the observed seasonal variations of the short-lived bromocarbons with high concentrations in winter and low concentrations in summer. This indicates that the seasonality of short-lived bromocarbons is largely due to seasonality in their chemical loss and transport. The inclusion of CHBr3 and CH2Br2 contributes 5 pptv bromine throughout the stratosphere. Both the source gases and inorganic bromine produced from source gas degradation (BrSLS) in the troposphere are transported into the stratosphere, and are equally important. Inorganic bromine accounts for half (2.5 pptv) of the bromine from the inclusion of CHBr3 and CHzBr2 near the tropical tropopause and its contribution rapidly increases to 100% as altitude increases. More than 85% of the wet scavenging of Br(sub y)(sup VSLS) occurs in large-scale precipitation below 500 hPa. Our sensitivity study with wet scavenging in convective updrafts switched off suggests that Br(sub y)(sup SLS) in the stratosphere is not sensitive to convection. Convective scavenging only

Imbedded Nanocrystals of CsPbBr3 in Cs4 PbBr6 : Kinetics, Enhanced Oscillator Strength, and Application in Light-Emitting Diodes.

Science.gov (United States)

Xu, Junwei; Huang, Wenxiao; Li, Peiyun; Onken, Drew R; Dun, Chaochao; Guo, Yang; Ucer, Kamil B; Lu, Chang; Wang, Hongzhi; Geyer, Scott M; Williams, Richard T; Carroll, David L

2017-11-01

Solution-grown films of CsPbBr 3 nanocrystals imbedded in Cs 4 PbBr 6 are incorporated as the recombination layer in light-emitting diode (LED) structures. The kinetics at high carrier density of pure (extended) CsPbBr 3 and the nanoinclusion composite are measured and analyzed, indicating second-order kinetics in extended and mainly first-order kinetics in the confined CsPbBr 3 , respectively. Analysis of absorption strength of this all-perovskite, all-inorganic imbedded nanocrystal composite relative to pure CsPbBr 3 indicates enhanced oscillator strength consistent with earlier published attribution of the sub-nanosecond exciton radiative lifetime in nanoprecipitates of CsPbBr 3 in melt-grown CsBr host crystals and CsPbBr 3 evaporated films. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of Stripline Kickers for Low Emittance Rings: Application to the Beam Extraction Kicker for CLIC Damping Rings

CERN Document Server

AUTHOR|(SzGeCERN)728476; Toral Fernandez, Fernando

In the framework of the design study of Future Linear Colliders, the Compact Linear Collider (CLIC) aims for electron-positron collisions with high luminosity at a nominal centre-of-mass energy of 3 TeV. To achieve the luminosity requirements, Pre-Damping Rings (PDRs) and Damping Rings (DRs) are required: they reduce the beam emittance before the beam is accelerated in the main linac. Several injection and extraction systems are needed to inject and extract the beam from the PDRs and DRs. The work of this Thesis consists of the design, fabrication and laboratory tests of the first stripline kicker prototype for beam extraction from the CLIC DRs, although the methodology proposed can be extended to stripline kickers for any low emittance ring. The excellent field homogeneity required, as well as a good transmission of the high voltage pulse through the electrodes, has been achieved by choosing a novel electrode shape. With this new geometry, it has been possible to benefit from all the advantages that the most...

Report of the eRHIC Ring-Ring Working Group

Energy Technology Data Exchange (ETDEWEB)

Aschenauer, E. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brennan, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fedotov, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Montag, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Palmer, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Parker, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Peggs, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Willeke, F. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-10-13

This report evaluates the ring-ring option for eRHIC as a lower risk alternative to the linac-ring option. The reduced risk goes along with a reduced initial luminosity performance. However, a luminosity upgrade path is kept open. This upgrade path consists of two branches, with the ultimate upgrade being either a ring-ring or a linac-ring scheme. The linac-ring upgrade could be almost identical to the proposed linac-ring scheme, which is based on an ERL in the RHIC tunnel. This linac-ring version has been studied in great detail over the past ten years, and its significant risks are known. On the other hand, no detailed work on an ultimate performance ring-ring scenario has been performed yet, other than the development of a consistent parameter set. Pursuing the ring-ring upgrade path introduces high risks and requires significant design work that is beyond the scope of this report.

High energy XeBr electric discharge laser

Science.gov (United States)

Sze, Robert C.; Scott, Peter B.

1981-01-01

A high energy XeBr laser for producing coherent radiation at 282 nm. The XeBr laser utilizes an electric discharge as the excitation source to minimize formation of molecular ions thereby minimizing absorption of laser radiation by the active medium. Additionally, HBr is used as the halogen donor which undergoes harpooning reactions with Xe.sub.M * to form XeBr*.

BrO measurements over the Eastern North-Atlantic

Directory of Open Access Journals (Sweden)

U. Platt

2009-12-01

Full Text Available The aim of the work presented here was to detect BrO in the marine boundary layer over the Eastern North-Atlantic by Multi AXis-Differential Optical Absorption Spectroscopy (MAX-DOAS of scattered sunlight. With this technique, information about the concentration and the vertical profile of trace gases in the atmosphere can be gained. BrO can be formed in the marine atmosphere by degradation of biogenic organohalogens or by oxidation of bromide in sea salt aerosol. BrO influences the chemistry in marine air in many ways, e.g. since it catalytically destroys ozone, changes the NO₂/NO-ratio as well as the OH/HO₂-ratio and oxidises DMS. However, the abundance and the significance of BrO in the marine atmosphere is not yet fully understood. <br>> We report on data collected during a ship cruise, which took place along the West African Coast in February 2007, within the framework of the Surface Ocean PRocesses in the ANthropocene project (SOPRAN. Tropospheric BrO could be detected during this cruise at peak mixing ratios of (10.2±3.7 ppt at an assumed layer height of 1 km on 18 February 2007. Furthermore, it was found that the mean BrO concentrations increased when cruising close to the African Coast suggesting that at least part of the BrO might have originated from there.

Stress analysis of HLW containers. Preliminary ring test exercise Compas project

International Nuclear Information System (INIS)

1989-01-01

This document describes the series of experiments and associated calculations performed as the Compas preliminary ring test exercise. A number of mild steel rings, representative of sections through HLW containers, some notched and pre-cracked, were tested in compression right up to and beyond their ultimate load. The Compas project partners independently modelled the behaviour of these rings using their finite element codes. Four different ring types were tested, and each test was repeated three times. For three of the ring types, the three test repetitions gave identical results. The fourth ring, which was not modelled by the partners, had a 4 mm thick layer of weld metal deposited on its surface. The three tests on this ring did not give identical results and suggested that the effect of welding methods should be addressed at a later stage of the project. Fracture was not found to be a significant cause of ring failure. The results of the ring tests were compared with the partners predictions, and additionally some time was spent assessing where the use of the codes could be improved. This exercise showed that the partners codes have the ability to produce results within acceptable limits. Most codes were unable to model stable crack growth. There were indications that some codes would not be able to cope with a significantly more complex three-dimensional analysis

The dynamics of the Hg + Br2 reaction: elucidation of the reaction mechanism for the Br exchange reaction.

Science.gov (United States)

Jambrina, P G; Menéndez, M; Aoiz, F J

2017-06-28

In spite of its importance in the Hg atmospheric chemistry, the dynamics of the Hg + Br 2 → HgBr + Br reaction is poorly understood. In this article, we have carried out a comprehensive study of the reaction mechanism of this reaction by means of quasiclassical trajectories (QCTs) on an existing ab initio potential energy surface (PES). The reaction has a non trivial dynamics, as a consequence of its large endothermicity, the presence of a deep potential well, and the competition between the Br exchange and the collision induced dissociation processes. Our calculations demonstrate that insertion is only relevant at energies just above the reaction threshold and that, at energies above 2.3 eV, HgBr formation typically takes place via a sort of frustrated dissociation. In order to compare directly with the results obtained in extensive cross molecular beam experiments for the homologous reaction with I 2 , angular distributions in the laboratory frame for Hg + Br 2 have been simulated under similar experimental conditions. The lack of agreement at the highest energies considered suggests that either the two reactions have substantially different mechanisms or that calculations on a single PES cannot account for the dynamics at those energies.

Rashba split surface states in BiTeBr

International Nuclear Information System (INIS)

Eremeev, S V; Rusinov, I P; Nechaev, I A; Chulkov, E V

2013-01-01

Within density functional theory, we study the bulk band structure and surface states of BiTeBr. We consider both ordered and disordered phases, which differ in atomic order in the Te–Br sublattice. On the basis of relativistic ab initio calculations, we show that the ordered BiTeBr is energetically preferable as compared with the disordered one. We demonstrate that both Te- and Br-terminated surfaces of the ordered BiTeBr hold surface states with a giant spin–orbit splitting. The Te-terminated surface-state spin splitting has Rashba-type behavior with the coupling parameter α R ∼ 2 eVÅ. (paper)

Brominated methanes as photoresponsive molecular storage of elemental Br2.

Science.gov (United States)

Kawakami, Kazumitsu; Tsuda, Akihiko

2012-10-01

The photochemical generation of elemental Br(2) from brominated methanes is reported. Br(2) was generated by the vaporization of carbon oxides and HBr through oxidative photodecomposition of brominated methanes under a 20 W low-pressure mercury lamp, wherein the amount and situations of Br(2) generation were photochemically controllable. Liquid CH(2)Br(2) can be used not only as an organic solvent but also for the photoresponsive molecular storage of Br(2), which is of great technical benefit in a variety of organic syntheses and in materials science. By taking advantage of the in situ generation of Br(2) from the organic solvent itself, many organobromine compounds were synthesized in high practical yields with or without the addition of a catalyst. Herein, Br(2) that was generated by the photodecomposition of CH(2)Br(2) retained its reactivity in solution to undergo essentially the same reactions as those that were carried out with solutions of Br(2) dissolved in CH(2)Br(2) that were prepared without photoirradiation. Furthermore, HBr, which was generated during the course of the photodecomposition of CH(2)Br(2), was also available for the substitution of the OH group for the Br group and for the preparation of the HBr salts of amines. Furthermore, the photochemical generation of Br(2) from CH(2)Br(2) was available for the area-selective photochemical bleaching of natural colored plants, such as red rose petals, wherein Br(2) that was generated photochemically from CH(2)Br(2) was painted onto the petal to cause radical oxidations of the chromophoric anthocyanin molecules. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zn2(TeO3Br2

Directory of Open Access Journals (Sweden)

Mats Johnsson

2008-05-01

Full Text Available Single crystals of dizinc tellurium dibromide trioxide, Zn2(TeO3Br2, were synthesized via a transport reaction in sealed evacuated silica tubes. The compound has a layered crystal structure in which the building units are [ZnO4Br] distorted square pyramids, [ZnO2Br2] distorted tetrahedra, and [TeO3E] tetrahedra (E being the 5s2 lone pair of Te4+ joined through sharing of edges and corners to form layers of no net charge. Bromine atoms and tellurium lone pairs protrude from the surfaces of each layer towards adjacent layers. This new compound Zn2(TeO3Br2 is isostructural with the synthetic compounds Zn2(TeO3Cl2, CuZn(TeO32, Co2(TeO3Br2 and the mineral sophiite, Zn2(SeO3Cl2.

On the electrodeposition of /sup 80m/Br, /sup 80/Br and /sup 82/Br species from (eta, gamma) activated dibromoethane - N,N-dimethyl aniline mixture

International Nuclear Information System (INIS)

Zaman, M.R.

1997-01-01

Thermal neutron activation have been carried out in dibromomethane (DBM)-n,n-dimethyl aniline (N,N-DMA) system and the /sup 80m/Br, /sup 82/Br species have been electrodeposited on Ag/AgBr electrodes under a constant electric field of 175 volts cm/sup -1/. With the addition of N,N-DMA, anodic deposition has been severely decreased for all the radiobromines and cathode plate shows zero activities. Results are critically discussed by explaining the chemical reactivity of the amine. Electrode deposition pattern and the chemical stabilization mode of the nucleogenic bromine species in this system are deduced to some extents. (author)

Solution-Grown CsPbBr3 /Cs4 PbBr6 Perovskite Nanocomposites: Toward Temperature-Insensitive Optical Gain.

Science.gov (United States)

Wang, Yue; Yu, Dejian; Wang, Zeng; Li, Xiaoming; Chen, Xiaoxuan; Nalla, Venkatram; Zeng, Haibo; Sun, Handong

2017-09-01

With regards to developing miniaturized coherent light sources, the temperature-insensitivity in gain spectrum and threshold is highly desirable. Quantum dots (QDs) are predicted to possess a temperature-insensitive threshold by virtue of the separated electronic states; however, it is never observed in colloidal QDs due to the poor thermal stability. Besides, for the classical II-VI QDs, the gain profile generally redshifts with increasing temperature, plaguing the device chromaticity. Herein, this paper addresses the above two issues simultaneously by embedding ligands-free CsPbBr 3 nanocrystals in a wider band gap Cs 4 PbBr 6 matrix by solution-phase synthesis. The unique electronic structures of CsPbBr 3 nanocrystals enable temperature-insensitive gain spectrum while the lack of ligands and protection from Cs 4 PbBr 6 matrix ensure the thermal stability and high temperature operation. Specifically, a color drift-free stimulated emission irrespective of temperature change (20-150 °C) upon two-photon pumping is presented and the characteristic temperature is determined to be as high as ≈260 K. The superior gain properties of the CsPbBr 3 /Cs 4 PbBr 6 perovskite nanocomposites are directly validated by a vertical cavity surface emitting laser operating at temperature as high as 100 °C. The results shed light on manipulating optical gain from the advantageous CsPbBr 3 nanocrystals and represent a significant step toward the temperature-insensitive frequency-upconverted lasers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Correlations between the anatomical traits of Gymnocladus canadensis Lam. in heartwood and sapwood of early- and latewood zones of growth rings

Directory of Open Access Journals (Sweden)

Jokanović Dušan

2015-01-01

Full Text Available This paper shows correlations between vessel characteristics and differences in growth-ring width in heartwood and sapwood. Analyzed samples were from an iron-wood tree (Gymnocladus canadensis Lam. that grew in the Mužljanski Rit area, of the Srpska Crnja municipality in Serbia. According to previous research, it was deduced that Gymnocladus canadensis Lam. belongs to ring-porous species with big vessel lumen in the earlywood zone and thicker cell walls in the latewood. Vessels were more numerous in the latewood zone, and the same was true for heartwood and sapwood. For both layers, sapwood possessed a few more vessels than heartwood, and a statistically significant difference was confirmed by t-test during the early phase. The greatest negative value of correlation coefficient was between the number of vessels and growth-ring width during the early phase for sapwood. The number of vessels decreased in the wider growth rings. The correlation between growth-ring width and the area of vessels had a statistically significant positive value of correlative coefficient, which means that wider growth rings had larger vessel areas in the early phase for sapwood. [Projekat Ministarstva nauke Republike Srbije, br. 31041

Performance of LiAlloy/Ag(2)CrO(4) Couples in Molten CsBr-LiBr-KBr Eutectic

International Nuclear Information System (INIS)

GUIDOTTI, RONALD A.; REINHARDT, FREDERICK W.

1999-01-01

The performance of Li-alloy/CsBr-LiBr-KBr/Ag(sub 2)CrO(sub 4) systems was studied over a temperature range of 250 C to 300 C, for possible use as a power source for geothermal borehole applications. Single cells were discharged at current densities of 15.8 and 32.6 mA/cm(sup 2) using Li-Si and Li-Al anodes. When tested in 5-cell batteries, the Li-Si/CsBr-LiBr-KBr/Ag(sub 2)CrO(sub 4) system exhibited thermal runaway. Thermal analytical tests showed that the Ag(sub 2)CrO(sub 4) cathode reacted exothermically with the electrolyte on activation. Consequently, this system would not be practical for the envisioned geothermal borehole applications

Structure and luminescence of α and β ThBr4: optical properties of U4+ in α ThBr4

International Nuclear Information System (INIS)

Simoni, E.

1988-05-01

The aim of this work is to understand the comparative structural and intrinsic luminescence properties of the pure matrices α and β - ThBr 4 , and to study the electronic structure by optical spectroscopy of the U 4+ ion in the α-ThBr 4 matrix. 1)Under U.V. excitation, βThBr 4 is intensively fluorescent in the blue-purple and α-ThBr 4 is fluorescent in the red. The main results concerning β-ThBr 4 are the following: -the optical absorption in the U.V. is under the form of a sudden absorption front and for a same temperature, its threshold energy has the same value as the threshold energy of the excitation function and of the photocurrent peak; -the intensity and the life time of the emission decrease when the temperature increases from 300 K until 400 K ( extinction temperature). All the obtained results have been explained either with the molecular orbitals levels of the ThBr 8 4- cluster or with the valence and conduction bands of the pure matrix. 2)The absorption and emission spectra of U 4+ in α-ThBr 4 (in which U 4+ has a point symmetry S 4 ) obtained between 300 K and 4.2 K have allowed to index 30 levels. The calculation of the spectroscopic parameters F k , ξ and B k q has been carried out in symmetry D 2d and S 4 . The comparison of these parameters with those calculated for U 4+ in β-ThBr 4 and β-ThCl 4 show that the global force of the crystalline field is practically the same in the three matrices, but that the structure transformation β→α occurs more on the values of these B k q than on the change of the ligands Br - →Cl - . On the other hand, it has been possible with the α-ThBr 4 matrix, or the β-ThBr 4 and the β-ThCl 4 , to observe the fluorescence spectra of the U 4+ ion (particularly weak phonons energies). (O.M.)

Sensitivity Analysis for the CLIC Damping Ring Inductive Adder

CERN Document Server

Holma, Janne

2012-01-01

The CLIC study is exploring the scheme for an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC pre-damping rings and damping rings will produce, through synchrotron radiation, ultra-low emittance beam with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse generators for the damping ring kickers must provide extremely flat, high-voltage pulses. The specifications for the extraction kickers of the CLIC damping rings are particularly demanding: the flattop of the output pulse must be 160 ns duration, 12.5 kV and 250 A, with a combined ripple and droop of not more than ±0.02 %. An inductive adder allows the use of different modulation techniques and is therefore a very promising approach to meeting the specifications. PSpice has been utilised to carry out a sensitivity analysis of the predicted output pulse to the value of both individual and groups of circuit compon...

Chemical consequences of radioactive decay. 1. Study of 249Cf ingrowth into crystalline 249BkBr3: a new crystalline phase of CfBr3

International Nuclear Information System (INIS)

Young, J.P.; Haire, R.G.; Peterson, J.R.; Ensor, D.D.; Fellows, R.L.

1980-01-01

Spectrophotometric and x-ray powder diffraction methods have been applied to a study of the ingrowth of californium-249 by β - decay of berkelium-249 in crystalline 249 BkBr 3 . It was found that the Cf daughter grows in with the same oxidation state and crystal structure as the parent. Thus, six-coordinate BkBr 3 (AlCl 3 -type monoclinic structure) generates six-coordinate CfBr 3 , and eight-coordinate BkBr 3 (PuBr 3 -type orthorhombic structure) generates eight-coordinate CfBr 3 , a previously unknown form of CfBr 3 . It was also found that the daughter Cf(III) in the BkBr 3 parent compound can be reduced to Cf(II) by treatment with H 2 , as it can in pure CfBr 3 . 5 figures

Academic gender stereotypes of pre-service teachers

Directory of Open Access Journals (Sweden)

Ćirović Ivana

2013-01-01

Full Text Available This research was aimed at studying the content of academic gender stereotypes of pre-service teachers who are being prepared for working in different cycles of education. The sample included 408 students of teaching programmes of the Teacher Training College, Faculty of Mathematics and Faculty of Philology in Belgrade. It has been established that future class and subject teachers have gender stereotypes about the interests and achievements of students in different school subjects. pre-service teachers from both groups are of the opinion that girls get interested more easily than boys in the majority of school subjects, as well as that girls are more talented for the subjects in the field of humanities and languages, while boys are more talented for the subjects in the field of sciences. Pre-service teachers estimate that boys typically have a low achievement in languages, arts and music, while girls have a low achievement in physics, computer science, technical sciences and physical education. Since teachers’ gender stereotypes can affect students’ achievement, educational and career choices, it is important to raise awareness about the content and consequences of such beliefs in teachers and focus on certain actions towards their altering. [Projekat Ministarstva nauke Republike Srbije, br. 179034: Od podsticanja inicijative, saradnje, stvaralaštva u obrazovanju do novih uloga i identiteta u društvu i br. 47008: Unapređivanje kvaliteta i dostupnosti obrazovanja u procesima modernizacije Srbije

Zn2(TeO3)Br2

Science.gov (United States)

Zhang, Dong; Johnsson, Mats

2008-01-01

Single crystals of dizinc tellurium dibromide trioxide, Zn2(TeO3)Br2, were synthesized via a transport reaction in sealed evacuated silica tubes. The compound has a layered crystal structure in which the building units are [ZnO4Br] distorted square pyramids, [ZnO2Br2] distorted tetra­hedra, and [TeO3 E] tetra­hedra (E being the 5s 2 lone pair of Te4+) joined through sharing of edges and corners to form layers of no net charge. Bromine atoms and tellurium lone pairs protrude from the surfaces of each layer towards adjacent layers. This new compound Zn2(TeO3)Br2 is isostructural with the synthetic compounds Zn2(TeO3)Cl2, CuZn(TeO3)2, Co2(TeO3)Br2 and the mineral sophiite, Zn2(SeO3)Cl2. PMID:21202162

Synthesis and Biological Evaluation of (S)-Amino-2-methyl-4-[(76)Br]bromo-3-(E)-butenoic Acid (BrVAIB) for Brain Tumor Imaging.

Science.gov (United States)

Burkemper, Jennifer L; Huang, Chaofeng; Li, Aixiao; Yuan, Liya; Rich, Keith; McConathy, Jonathan; Lapi, Suzanne E

2015-11-12

The novel compound, (S)-amino-2-methyl-4-[(76)Br]bromo-3-(E)-butenoic acid (BrVAIB, [(76)Br]5), was characterized against the known system A tracer, IVAIB ([(123)I]8). [(76)Br]5 was prepared in a 51% ± 19% radiochemical yield with high radiochemical purity (≥98%). The biological properties of [(76)Br]5 were compared with those of [(123)I]8. Results showed that [(76)Br]5 undergoes mixed amino acid transport by system A and system L transport, while [(123)I]8 had less uptake by system L. [(76)Br]5 demonstrated higher uptake than [(123)I]8 in DBT tumors 1 h after injection (3.7 ± 0.4% ID/g vs 1.5 ± 0.3% ID/g) and also showed higher uptake vs [(123)I]8 in normal brain. Small animal PET studies with [(76)Br]5 demonstrated good tumor visualization of intracranial DBTs up to 24 h with clearance from normal tissues. These results indicate that [(76)Br]5 is a promising PET tracer for brain tumor imaging and lead compound for a mixed system A and system L transport substrate.

Synthesis and structure of [(NH2)2CSSC(NH2)2]2[OsBr6]Br2 . 3H2O

International Nuclear Information System (INIS)

Rudnitskaya, O. V.; Kultyshkina, E. K.; Stash, A. I.; Glukhova, A. A.; Venskovskii, N. U.

2008-01-01

The complex [(NH 2 ) 2 CSSC(NH 2 ) 2 ] 2 [OsBr 6 ]Br 2 . 3H 2 O is synthesized by the reaction of K 2 OsBr 6 with thiocarbamide in concentrated HBr and characterized using electronic absorption and IR absorption spectroscopy. Its crystal structure is determined by X-ray diffraction. The crystals are orthorhombic, a = 11.730(2) A, b = 14.052(3) A, c = 16.994(3) A, space group Cmcm, and Z = 4. The [OsBr 6 ] 2- anionic complex has an octahedral structure. The Os-Br distances fall in the range 2.483-2.490 A. The α,α'-dithiobisformamidinium cation is a product of the oxidation of thiocarbamide. The S-S and C-S distances are 2.016 and 1.784 A, respectively. The H 2 O molecules, Br - ions, and NH 2 groups of the cation are linked by hydrogen bonds.

Irradiation techniques at BR2 reactor

International Nuclear Information System (INIS)

Hebel, W.

1978-01-01

Since 1963 the material testing reactor BR2 at Mol is operated for the realisation of numerous research programs and experiments on the behavior of materials under nuclear radiation and in particular under intensive neutron exposure. During this period special irradiation techniques and experimental devices were developed according to the desiderata of the different experiments and to the irradiation possibilities offered at BR2. The design and the operating characteristics of quite a number of those irradiation rigs of proven reliability may be used or can be made available for new irradiation experiments. A brief description is given of some typical irradiation devices designed and constructed by CEN/SCK, Technology and Energy Dpt. They are compiled according to their main use for the different research and development programs realized at BR2. Their eventual application however for different objectives could be possible. A final chapter summarizes the principal irradiation conditions offered by BR2 reactor. (author)

ASSOCIATIVE RINGS SOLVED AS LIE RINGS

Directory of Open Access Journals (Sweden)

M. B. Smirnov

2011-01-01

Full Text Available The paper has proved that an associative ring which is solvable of a n- class as a Lie ring has a nilpotent ideal of the nilpotent class not more than 3×10n–2  and a corresponding quotient ring satisfies an identity [[x1, x2, [x3, x4

Molecular characterization of BrMYB28 and BrMYB29 paralogous transcription factors involved in the regulation of aliphatic glucosinolate profiles in Brassica rapa ssp. pekinensis.

Science.gov (United States)

Baskar, Venkidasamy; Park, Se Won

2015-07-01

Glucosinolates (GSL) are one of the major secondary metabolites of the Brassicaceae family. In the present study, we aim at characterizing the multiple paralogs of aliphatic GSL regulators, such as BrMYB28 and BrMYB29 genes in Brassica rapa ssp. pekinensis, by quantitative real-time PCR (qRT-PCR) analysis in different tissues and at various developmental stages. An overlapping gene expression pattern between the BrMYBs as well as their downstream genes (DSGs) was found at different developmental stages. Among the BrMYB28 and BrMYB29 paralogous genes, the BrMYB28.3 and BrMYB29.1 genes were dominantly expressed in most of the developmental stages, compared to the other paralogs of the BrMYB genes. Furthermore, the differential expression pattern of the BrMYBs was observed under various stress treatments. Interestingly, BrMYB28.2 showed the least expression in most developmental stages, while its expression was remarkably high in different stress conditions. More specifically, the BrMYB28.2, BrMYB28.3, and BrMYB29.1 genes were highly responsive to various abiotic and biotic stresses, further indicating their possible role in stress tolerance. Moreover, the in silico cis motif analysis in the upstream regulatory regions of BrMYBs showed the presence of various putative stress-specific motifs, which further indicated their responsiveness to biotic and abiotic stresses. These observations suggest that the dominantly expressed BrMYBs, both in different developmental stages and under various stress treatments (BrMYB28.3 and BrMYB29.1), may be potential candidate genes for altering the GSL level through genetic modification studies in B. rapa ssp. pekinensis. Copyright © 2015. Published by Elsevier SAS.

Theoretical study and rate constant calculation for the reactions of SH (SD) with Cl2, Br2, and BrCl.

Science.gov (United States)

Wang, Li; Liu, Jing-Yao; Li, Ze-Sheng; Sun, Chia-Chung

2005-01-30

The mechanisms of the SH (SD) radicals with Cl2 (R1), Br2 (R2), and BrCl (R3) are investigated theoretically, and the rate constants are calculated using a dual-level direct dynamics method. The optimized geometries and frequencies of the stationary points are calculated at the MP2/6-311G(d,p) and MPW1K/6-311G(d,p) levels. Higher-level energies are obtained at the approximate QCISD(T)/6-311++G(3df, 2pd) level using the MP2 geometries as well as by the multicoefficient correlation method based on QCISD (MC-QCISD) using the MPW1K geometries. Complexes with energies less than those of the reactants or products are located at the entrance or the exit channels of these reactions, which indicate that the reactions may proceed via an indirect mechanism. The enthalpies of formation for the species XSH/XSD (X = Cl and Br) are evaluated using hydrogenation working reactions method. By canonical variational transition-state theory (CVT), the rate constants of SH and SD radicals with Cl2, Br2, and BrCl are calculated over a wide temperature range of 200-2000 K at the a-QCISD(T)/6-311++G(3df, 2pd)//MP2/6-311G(d, p) level. Good agreement between the calculated and experimental rate constants is obtained in the measured temperature range. Our calculations show that for SH (SD) + BrCl reaction bromine abstraction (R3a or R3a') leading to the formation of BrSH (BrSD) + Cl in a barrierless process dominants the reaction with the branching ratios for channels 3a and 3a' of 99% at 298 K, which is quite different from the experimental result of k3a'/k3' = 54 +/- 10%. Negative activation energies are found at the higher level for the SH + Br2 and SH + BrCl (Br-abstraction) reactions; as a result, the rate constants show a slightly negative temperature dependence, which is consistent with the determination in the literature. The kinetic isotope effects for the three reactions are "inverse". The values of kH/kD are 0.88, 0.91, and 0.69 at room temperature, respectively, and they increase

Reactor BR2: Introduction

International Nuclear Information System (INIS)

Gubel, P.

2000-01-01

The BR2 reactor is still SCK-CEN's most important nuclear facility. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. A safety audit was conduced by the IAEA, the conclusions of which demonstrated the excellent performance of the plant in terms of operational safety. In 1999, the CALLISTO facility was extensively used for various programmes involving LWR pressure vessel materials, IASCC of LWR structural materials, fusion reactor materials and martensic steels for use in ADS systems. In 1999, BR2's commercial programmes were further developed

Ab Initio Potential Energy Surfaces for Both the Ground (X̃1A′ and Excited (A∼1A′′ Electronic States of HSiBr and the Absorption and Emission Spectra of HSiBr/DSiBr

Directory of Open Access Journals (Sweden)

Anyang Li

2012-01-01

Full Text Available Ab initio potential energy surfaces for the ground (X̃1A′ and excited (A˜A′′1 electronic states of HSiBr were obtained by using the single and double excitation coupled-cluster theory with a noniterative perturbation treatment of triple excitations and the multireference configuration interaction with Davidson correction, respectively, employing an augmented correlation-consistent polarized valence quadruple zeta basis set. The calculated vibrational energy levels of HSiBr and DSiBr of the ground and excited electronic states are in excellent agreement with the available experimental band origins. In addition, the absorption and emission spectra of HSiBr and DSiBr were calculated using an efficient single Lanczos propagation method and are in good agreement with the available experimental observations.

Light-emitting diodes based on two-dimensional PA2(CsPbBr3)n-1PbBr4 layered perovskites%基于PA2(CsPbBr3)n-1PbBr4二维层状钙钛矿的电致发光二极管

Institute of Scientific and Technical Information of China (English)

孟妍; 牛连斌; 许龙; 林春燕; 熊自阳; 熊祖洪; 陈平

2018-01-01

进一步提高全无机卤铅钙钛矿材料CsPbBr3的发光效率,对制备高效率、高稳定性的电致发光二极管(PeLED)具有重要意义.制备纳米级的钙钛矿量子点,一方面有助于提高激子的束缚能和钙钛矿晶体的荧光效率,另一方面也有利于形成连续、致密的二维层状钙钛矿薄膜.本文采用“原位生长”的策略,将一种具有长链结构的丙基溴化胺(CH3CH2CH2NH3Br,PABr)作为添加剂,与CsPbBr3的前驱体溶液进行共混,得到PA2(CsPbBr3)n-1PbBr4钙钛矿量子点.形成的二维层状钙钛矿薄膜均匀致密,在光致发光条件下,呈现出明亮的蓝绿光发射(发光峰位于506 nm).在电致发光方面,基于PA2(CsPbBr3)n-1PbBr4的PeLED启亮电压为～4.2 V,最大亮度为～2370 cd/m2,最高电流效率为～1.06 cd/A,最高EQE为～0.57％.相较于传统方法,本工作在制作工艺、成膜质量以及PeLED的发光效率有了显著的提升,为将来进一步探索低成本、高效率的蓝光PeLEDs提供了一种可行的思路.%Solution-processed organometal halide perovskites (formulated as ABX3,where A is the methylammonium (CH3NH3+)(MA) or metal cesium cation (Cs+),B is the lead cation (Pb2+) and X is the halide anion (Br-,I-,Cl-)) are promising candidates for next generation light-emitting materials owing to their unique optoelectronic properties.These properties mainly include extremely high photoluminescence quantum yield (PLQY),easily tunable band gap and narrow emission characteristics.During the past two years,impressive progresses have been made in perovskite light-emitting diodes (PeLED) with hybrid organic-inorganic perovskite materials (i.e.,CH3NH3PbBr3).So far,the best external quantum efficiency (EQE) of CH3NH3PbBr3-based PeLED was reaching up to ～8.53％ which was close to the results of organic light-emitting diodes (OLED).Despite the remarkable performance of the devices demonstrated,the stability of organic-inorganic hybrid perovskites

Comparative study of α and β-ThBr4: structure and luminescence. Spectroscopy of U4+ in α-ThBr4

International Nuclear Information System (INIS)

Simoni, E.

1988-05-01

UV absorption of β-ThBr 4 : presents a plain absorption front and for the same temperature the threshold energy has the same value than the threshold energy of excitation function and photocurrent peak. Emission intensity and lifetime decrease when temperature increases from 300 K to 400K (extinction temperature). Results are interpreted either by molecular orbital levels of the ThBr 8 4- cluster or either by conduction and valence bands of the matrix above. Absorption and emission spectra of U 4+ in α-ThBr 4 (where U 4+ has a S 4 symmetry) between 300 K and 4.2 K allow indexation of 30 levels. Spectroscopic parameters are calculated in D 2d and S 4 symmetry. Comparison of these parameters with those of U 4+ in β-ThBr 4 and β-ThCl 4 shows that crystal field force is practically the same in the three matrices but the structure transformation from β to α has more influence on B q k than ligand change from Br - to Cl - . Owing to very low phonon energy, fluorescence spectra of U 4+ is easy to observe in α-ThBr 4 as it is in β-ThBr 4 and ThCl 4 [fr

Influences of magma chamber ellipticity on ring fracturing and eruption at collapse calderas

International Nuclear Information System (INIS)

Holohan, Eoghan P; Walsh, John J; Vries, Benjamin van Wyk de; Troll, Valentin R; Walter, Thomas R

2008-01-01

Plan-view ellipticity of a pre-caldera magma reservoir, and its influence on the development of caldera ring fracturing and eruptive behaviour, have not previously been subjected to dedicated evaluation. We experimentally simulated caldera collapse into elliptical magma chambers and found that collapse into highly-elliptical chambers produced a characteristic pattern of ring-fault localization and lateral propagation. Although results are preliminary, the general deformation pattern for elliptical resurgence shows strong similarities to elliptical collapse. Ring faults accommodating uplift again initiate around the chamberos short axis and are reverse, but dip inward. Field and geophysical observations at several elliptical calderas of varying scale (e.g. Long Valley, Katmai, and Rabaul calderas) are consistent with a control from elliptical magma chamber geometry on ring fracturing and eruption, as predicted from our experiments.

Influences of magma chamber ellipticity on ring fracturing and eruption at collapse calderas

Energy Technology Data Exchange (ETDEWEB)

Holohan, Eoghan P; Walsh, John J [Fault Analysis Group, School of Geological Sciences, University College Dublin, Belfield, Dublin 4 (Ireland); Vries, Benjamin van Wyk de [Laboratoire Magmas et Volcans, 5 rue Kessler, 63038 Clermont-Ferrand (France); Troll, Valentin R [Department of Earth Sciences, Uppsala University, SE-752 36, Uppsala (Sweden); Walter, Thomas R [GFZ Potsdam, Telegrafenberg, Potsdam, D-14473 (Germany)], E-mail: Eoghan.Holohan@ucd.ie

2008-10-01

Plan-view ellipticity of a pre-caldera magma reservoir, and its influence on the development of caldera ring fracturing and eruptive behaviour, have not previously been subjected to dedicated evaluation. We experimentally simulated caldera collapse into elliptical magma chambers and found that collapse into highly-elliptical chambers produced a characteristic pattern of ring-fault localization and lateral propagation. Although results are preliminary, the general deformation pattern for elliptical resurgence shows strong similarities to elliptical collapse. Ring faults accommodating uplift again initiate around the chamberos short axis and are reverse, but dip inward. Field and geophysical observations at several elliptical calderas of varying scale (e.g. Long Valley, Katmai, and Rabaul calderas) are consistent with a control from elliptical magma chamber geometry on ring fracturing and eruption, as predicted from our experiments.

Mapping Ring Particle Cooling across Saturn's Rings with Cassini CIRS

Science.gov (United States)

Brooks, Shawn M.; Spilker, L. J.; Edgington, S. G.; Pilorz, S. H.; Deau, E.

2010-10-01

Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and quick temperature responses are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid, coherent particles can be expected to have higher thermal inertias (Ferrari et al. 2005). Cassini's Composite Infrared Spectrometer has recorded millions of spectra of Saturn's rings since its arrival at Saturn in 2004 (personal communication, M. Segura). CIRS records far infrared radiation between 10 and 600 cm-1 (16.7 and 1000 µm) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn's rings peaks in this wavelength range. FP1 spectra can be used to infer ring temperatures. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The thermal budget of the rings is dominated by the solar radiation absorbed by its constituent particles. When ring particles enter Saturn's shadow this source of energy is abruptly cut off. As a result, ring particles cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

Uranium mobility across annual growth rings in three deciduous tree species.

Science.gov (United States)

McHugh, Kelly C; Widom, Elisabeth; Spitz, Henry B; Wiles, Gregory C; Glover, Sam E

2018-02-01

Black walnut (Juglans nigra), slippery elm (Ulmus rubra), and white ash (Fraxinus americana) trees were evaluated as potential archives of past uranium (U) contamination. Like other metals, U mobility in annual growth rings of trees is dependent on the tree species. Uranium concentrations and isotopic compositions (masses 234, 235, 236, and 238) were analyzed by thermal ionization mass spectrometry to test the efficacy of using tree rings to retroactively monitor U pollution from the FFMPC, a U purification facility operating from 1951 to 1989. This study found non-natural U (depleted U and detectable 236 U) in growth rings of all three tree species that pre-dated the start of operations at FFMPC and compositional trends that did not correspond with known contamination events. Therefore, the annual growth rings of these tree species cannot be used to reliably monitor the chronology of U contamination. Copyright © 2017 Elsevier Ltd. All rights reserved.

NY-BR-1 Antigen Expression and anti-NY-BR-1 IgG in Egyptian Breast Cancer Patients: Clinicopathological and Prognostic Significance.

Science.gov (United States)

Abu El-Nazar, Salma Y; Ghazy, Amany A; Ghoneim, Hossam E; Zoheir, Malak; Ahmed, Ahmed S; Sorour, Sally S; Abouelella, Amira M

2015-01-01

Breast cancer is the most common gynecological malignancy in the world. In Egypt, it ranks the first among female malignancies with incidence of 37.7%. Over the last decades, the integration of prognostic and predictive markers in treatment decisions has led to more individualized and optimized therapy. NY-BR-1 antigen has been shown to be frequently expressed in breast cancers. The study aimed to assess the tissue expression of NY-BR-1 antigen and serum IgG antibody to this antigen in Egyptian breast cancer females. The study was conducted on 60 females (10 healthy, 10 having benign breast lesions, 40 with malignant breast cancer). NY-BR-1 Ag expression was evaluated by immunohistochemistry and anti-NY-BR-1 IgG was assessed by ELISA. Results revealed a significant difference in NY-BR-1 Ag expression between benign and malignant breast cancer patients. There was a significant correlation between NY-BR-1 antigen expression and estrogen receptor's status (P = 0.019), stage of the disease (P = 0.008), menopausal status (P = 0.008), lymph node involvement (P = 0.022) and anti-NY-BR-1 IgG (P = 0.032) among the studied individuals. In addition, there was a statistically significant increase in anti-NY-BR-1 IgG O.D. results among malignant breast cancer group. It is correlated with tumor type (P < 0.001) and progesterone receptor status (P = 0.038). In conclusion, our work may represent a step towards identification of a new prognostic marker specific for breast cancer.

VARIABILITY OF DISK EMISSION IN PRE-MAIN SEQUENCE AND RELATED STARS. III. EXPLORING STRUCTURAL CHANGES IN THE PRE-TRANSITIONAL DISK IN HD 169142

Energy Technology Data Exchange (ETDEWEB)

Wagner, Kevin R.; Sitko, Michael L.; Swearingen, Jeremy R.; Champney, Elizabeth H.; Johnson, Alexa N.; Werren, Chelsea [Department of Physics, University of Cincinnati, Cincinnati, OH 45221 (United States); Grady, Carol A. [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States); Whitney, Barbara A. [Department of Astronomy, University of Wisconsin, 475 North CharterStreet, Madison, WI 53706-1582 (United States); Russell, Ray W. [The Aerospace Corporation, Los Angeles, CA 90009 (United States); Schneider, Glenn H. [Steward Observatory, 933 North Cherry Avenue, University of Arizona, Tucson, AZ 85721 (United States); Momose, Munetake [Ibaraki University, 310-0056 Ibaraki, Mito, Bunkyo, 11 (Japan); Muto, Takayuki [Kogakuin University, 1-24-2 Nishishinjuku, Shinjuku, Tokyo 163-8677 (Japan); Inoue, Akio K. [Osaka Sangyo University, College of General Education, 3-1-1 Nakagaito, Daito, Osaka 574-8530 (Japan); Lauroesch, James T.; Hornbeck, Jeremy [University of Louisville Research Foundation, Inc., 2301 South 3rd Street, Louisville, KY 40292 (United States); Brown, Alexander [Center for Astrophysics and Space Astronomy, Astrophysics Research Laboratory, 593 UCB, University of Colorado, Boulder, CO 80309-0593 (United States); Fukagawa, Misato [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Currie, Thayne M. [Oak Ridge Associated Universities, 100 ORAU Way, Oak Ridge, TN 37830-6218 (United States); Wisniewski, John P. [University of Oklahoma, 660 Parrington Oval, Norman, OK 73019 (United States); Woodgate, Bruce E., E-mail: wagnekr@mail.uc.edu, E-mail: sitkoml@ucmail.uc.edu, E-mail: swearijr@mail.uc.edu, E-mail: ehchampney@gmail.com, E-mail: astefank@andrew.cmu.edu, E-mail: ccwerren@yahoo.com, E-mail: carol.a.grady@nasa.gov, E-mail: bwhitney@astro.wisc.edu, E-mail: Ray.W.Russell@aero.org [NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)

2015-01-10

We present near-IR (NIR) and far-UV observations of the pre-transitional (gapped) disk in HD 169142 using NASA's Infrared Telescope Facility and Hubble Space Telescope. The combination of our data along with existing data sets into the broadband spectral energy distribution reveals variability of up to 45% between ∼1.5-10 μm over a maximum timescale of 10 yr. All observations known to us separate into two distinct states corresponding to a high near-IR state in the pre-2000 epoch and a low state in the post-2000 epoch, indicating activity within the ≲1 AU region of the disk. Through analysis of the Pa β and Br γ lines in our data we derive a mass accretion rate in 2013 May of M-dot ≈ (1.5-2.7) × 10{sup –9} M {sub ☉} yr{sup –1}. We present a theoretical modeling analysis of the disk in HD 169142 using Monte-Carlo radiative transfer simulation software to explore the conditions and perhaps signs of planetary formation in our collection of 24 yr of observations. We find that shifting the outer edge (r ≈ 0.3 AU) of the inner disk by 0.05 AU toward the star (in simulation of accretion and/or sculpting by forming planets) successfully reproduces the shift in NIR flux. We establish that the ∼40-70 AU dark ring imaged in the NIR by Quanz et al. and Momose et al. and at 7 mm by Osorio et al. may be reproduced with a 30% scaled density profile throughout the region, strengthening the link to this structure being dynamically cleared by one or more planetary mass bodies.

VARIABILITY OF DISK EMISSION IN PRE-MAIN SEQUENCE AND RELATED STARS. III. EXPLORING STRUCTURAL CHANGES IN THE PRE-TRANSITIONAL DISK IN HD 169142

International Nuclear Information System (INIS)

Wagner, Kevin R.; Sitko, Michael L.; Swearingen, Jeremy R.; Champney, Elizabeth H.; Johnson, Alexa N.; Werren, Chelsea; Grady, Carol A.; Whitney, Barbara A.; Russell, Ray W.; Schneider, Glenn H.; Momose, Munetake; Muto, Takayuki; Inoue, Akio K.; Lauroesch, James T.; Hornbeck, Jeremy; Brown, Alexander; Fukagawa, Misato; Currie, Thayne M.; Wisniewski, John P.; Woodgate, Bruce E.

2015-01-01

We present near-IR (NIR) and far-UV observations of the pre-transitional (gapped) disk in HD 169142 using NASA's Infrared Telescope Facility and Hubble Space Telescope. The combination of our data along with existing data sets into the broadband spectral energy distribution reveals variability of up to 45% between ∼1.5-10 μm over a maximum timescale of 10 yr. All observations known to us separate into two distinct states corresponding to a high near-IR state in the pre-2000 epoch and a low state in the post-2000 epoch, indicating activity within the ≲1 AU region of the disk. Through analysis of the Pa β and Br γ lines in our data we derive a mass accretion rate in 2013 May of M-dot ≈ (1.5-2.7) × 10 –9 M ☉ yr –1 . We present a theoretical modeling analysis of the disk in HD 169142 using Monte-Carlo radiative transfer simulation software to explore the conditions and perhaps signs of planetary formation in our collection of 24 yr of observations. We find that shifting the outer edge (r ≈ 0.3 AU) of the inner disk by 0.05 AU toward the star (in simulation of accretion and/or sculpting by forming planets) successfully reproduces the shift in NIR flux. We establish that the ∼40-70 AU dark ring imaged in the NIR by Quanz et al. and Momose et al. and at 7 mm by Osorio et al. may be reproduced with a 30% scaled density profile throughout the region, strengthening the link to this structure being dynamically cleared by one or more planetary mass bodies

Additions to the stoneflies (Plecoptera) of Mount Rainier National Park, Washington, U.S.A.

Science.gov (United States)

Kondratieff, B.C.; Lechleitner, R.A.; Zuellig, R.E.

2006-01-01

In summary, 88 species of stoneflies are now known from MRNP, representing 65% of the recorded Washington State fauna (Stark and Baumann 2005). At least two of these species are apparently restricted to the MRNP, Soliperla fenderi (Jewett) (Stark and Gustafson 2004) and P. lechleitneri.

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)

Operating Experience with the BR-5 Reactor; Experience acquise aupres du reacteur BR-5; Opyt ehkspluatatsii reaktora BR-5; Experiencia practica con el reactor BR-5

Energy Technology Data Exchange (ETDEWEB)

Lejpunskij, A. I.; Kazachkovskij, O. D.; Pinkhasik, M. S.; Aristarkhov, N. N.; Karpov, A. V.; Larin, E. P.; Efimov, I. A.

1963-10-15

The paper discusses the carrying-out of repair and maintenance work on the radioactive liquid-metal circuit of the BR-5 fast neutron reactor. Attention is also given to problems of reactor operation after achievement of the planned 2% fuel burn-up with some disturbance of leak-tightness in individual fuel elements. An account is given of experience in discharging the active section, examining the condition and leak-tightness of the fuel elements, and decontaminating the equipment and piping of the first radioactive circuit after reaching 5% fuel burn-up. (author) [French] Dans ce memoire les auteurs decrivent l'execution des reparations et des travaux d'entretien dans le circuit radioactif liquide-metal du reacteur a neutrons rapides BR-5. Ils etudient egalement les problemes lies au fonctionnement du reacteur au taux de combustion de 2% prevu avec quelques defauts d'etancheite dans des elements combustibles particuliers. Ils decrivent le dechargementen zone active et examinent les conditions d'etancheite des elements combustibles. Ainsi que la decontamination de l'appareillage et des tuyauteries du premier circuit radioactif apres avoir atteint un taux de combustion de 5%. (author) [Spanish] En la memoria se examinan los problemas planteados por el mantenimiento del circuito radiactivo de metal liquido del reactor de neutrones rapidos BR-5. Se tratan cuestiones relacionadas con la explotacion del reactor una vez alcanzado el grado de combustion de 2%, previsto en el proyecto y luego de producirse ciertas alteraciones de la densidad de determinados elementos combustibles. Se describen la experiencia adquirida durante la descarga del cuerpo del reactor, las investigaciones del estado general y de la hermeticidad de los elementos combustibles y las operaciones de descontaminacion de la instalacion y de las tuberias del circuito radiactivo primario despues de alcanzado un grado de combustion de 5%. (author) [Russian] V doklade rassmatrivayutsya voprosy proizvodstva

X-ray and NQR studies of bromoindate(III) complexes. [C2H5NH3]4InBr7, [C(NH2)3]3InBr6, and [H3NCH2C(CH3)2CH2NH3]InBr5

International Nuclear Information System (INIS)

Iwakiri, Takeharu; Ishihara, Hideta; Terao, Hiromitsu; Lork, Enno; Gesing, Thorsten M.

2017-01-01

The crystal structures of [C 2 H 5 NH 3 ] 4 InBr 7 (1), [C(NH 2 ) 3 ] 3 InBr 6 (2), and [H 3 NCH 2 C(CH 3 ) 2 CH 2 NH 3 ]InBr 5 (3) were determined at 100(2) K: monoclinic, P2 1 /n, a=1061.94(3), b=1186.40(4), c=2007.88(7) pm, β= 104.575(1) , Z=4 for 1; monoclinic, C2/c, a=3128.81(12), b=878.42(3), c=2816.50(10) pm, β=92.1320(10) , Z=16 for 2; orthorhombic, P2 1 2 1 2 1 , a=1250.33(5), b=1391.46(6), c=2503.22(9) pm, Z=4 for 3. The structure of 1 contains an isolated octahedral [InBr 6 ] 3- ion and a Br - ion. The structure of 2 contains three different isolated octahedral [InBr 6 ] 3- ions. The structure of 3 has a corner-shared double-octahedral [In 2 Br 11 ] 5- ion and an isolated tetrahedral [InBr 4 ] - ion. The 81 Br nuclear quadrupole resonance (NQR) lines of the terminal Br atoms of the compounds are widely spread in frequency, and some of them show unusual positive temperature dependence. These observations manifest the N-H..Br-In hydrogen bond networks developed between the cations and anions to stabilize the crystal structures. The 81 Br NQR and differential thermal analysis (DTA) measurements have revealed the occurrence of unique phase transitions in 1 and 3. When the bond angles were estimated from the electric field gradient (EFG) directions calculated by the molecular orbital (MO) methods, accurate values were obtained for [InBr 6 ] 3- of 1 and for [In 2 Br 11 ] 5- and [InBr 4 ] - of 3, except for several exceptions in those for the latter two ions. On the other hand, the calculations of 81 Br NQR frequencies have produced up to 1.4 times higher values than the observed ones.

A Computer Vision Approach to Identify Einstein Rings and Arcs

Science.gov (United States)

Lee, Chien-Hsiu

2017-03-01

Einstein rings are rare gems of strong lensing phenomena; the ring images can be used to probe the underlying lens gravitational potential at every position angles, tightly constraining the lens mass profile. In addition, the magnified images also enable us to probe high-z galaxies with enhanced resolution and signal-to-noise ratios. However, only a handful of Einstein rings have been reported, either from serendipitous discoveries or or visual inspections of hundred thousands of massive galaxies or galaxy clusters. In the era of large sky surveys, an automated approach to identify ring pattern in the big data to come is in high demand. Here, we present an Einstein ring recognition approach based on computer vision techniques. The workhorse is the circle Hough transform that recognise circular patterns or arcs in the images. We propose a two-tier approach by first pre-selecting massive galaxies associated with multiple blue objects as possible lens, than use Hough transform to identify circular pattern. As a proof-of-concept, we apply our approach to SDSS, with a high completeness, albeit with low purity. We also apply our approach to other lenses in DES, HSC-SSP, and UltraVISTA survey, illustrating the versatility of our approach.

Refurbishing the BR2 materials testing reactor

International Nuclear Information System (INIS)

Baugnet, J.M.; Dekeyser, J.; Gubel, P.

1995-01-01

SCK/CEN is refurbishing its BR2 reactor to allow its further operation during the next 15 years; in doing so, it chooses to keep BR2 available for future scientific and technological irradiation programs within an international context. (author) 2 figs

"Brücke dreht sich um!". A Deconstructionist Reading of Kafka's "Die Brücke"

Directory of Open Access Journals (Sweden)

Eva Hoffmann

2014-12-01

Full Text Available Franz Kafka's (1883-1924 "Die Brücke" is one of the less well-known texts by one of the most prolific authors of literary modernity. However, this short prose text embodies prevalent questions of literary modernity and philosophy as it reflects the crisis of language in regard of identity, communication, and literary production. Placed in the context of fin-de-siècle's discourse of language crisis, this article provides a dialogue between Kafka's "Die Brücke" and Hannah Arendt's (1906-1975 philosophy of thinking and speaking in The Life of the Mind. Contrary to Arendt's understanding of the metaphor as "a carrying over" between the mental activities of the solitude thinker and a reconciliation with the pluralistic world shared with others, this article argues for a deconstructionist reading of "Die Brücke" as a tool to reevaluate Arendt's notion of a shared human experience ensured through language and illustrates the advantages of poetic texts within philosophical discourses.

A system for the thermal insulation of a pre-stressed concrete vessel

International Nuclear Information System (INIS)

Aubert, Gilles; Petit, Guy.

1975-01-01

This invention concerns the thermal insulation of a pre-stressed concrete vessel for a pressurised water nuclear reactor, this vessel being fitted internally with a leak-proof metal lining. Two rings are placed at the lower and upper parts of the vessel respectively. The upper ring is closed with a cover. These rings differ in diameter, are fitted with a metal insulating and mark the limits of a chamber between the vaporisable fluid and the internal wall of the vessel. This chamber is filled with a fluid in the liquid phase up to the liquid/vapor interface level of the fluid and with a gas above that level, the covering of the rings forming a cold fluid liquid seal. Each ring is supported by the vessel. Leak-proof components take up the radial expansion of the rings [fr

Radiative forcing calculations for CH3Br

International Nuclear Information System (INIS)

Grossman, A.S.; Blass, W.E.; Wuebbles, D.J.

1995-06-01

Methyl Bromide, CH 3 Br, is the major organobromine species in the lower atmosphere and is a primary source of bromine in the stratosphere. It has a lifetime of 1.3 years. The IR methyl bromide spectra in the atmospheric window region, 7--13μ, was determined using a well tested Coriolis resonance and ell-doubling (and ell-resonance) computational system. A radiative forcing value of 0.00493 W/m 2 /ppbv was obtained for CH 3 Br and is approximately linear in the background abundance. This value is about 2 percent of the forcing of CFC-11 and about 278 times the forcing of C0 2 , on a per molecule basis. The radiative forcing calculation is used to estimate the global warming potential (GWP) of CH 3 Br. The results give GWPs for CH 3 Br of the order of 13 for an integration period of 20 years and 4 for an integration period of 100 years (assuming C0 2 = 1, following IPCC [1994]). While CH 3 Br has a GWP which is approximately 25 percent of the GWP of CH 4 , the current emission rates are too low to cause serious atmospheric greenhouse heating effects at this time

Brüssel Euroopa pealinnaks? / Ülar Mark

Index Scriptorium Estoniae

Mark, Ülar, 1968-

2009-01-01

Brüsseli Euroopa kvartali planeerimisvõistlusest, mille peakorraldaja oli Brüsseli pealinna piirkond koos Brüsseli linna ja Euroopa Komisjoniga. Eestist osales žüriis arhitekt Ülar Mark. Meeskonna Atelier Christian de Portzamparc võidutööst ja teiste teise vooru pääsenud nelja meeskonna (JDS / Julien De Smedt Architects, OMA / Office for Metropolitan Architecture, Xaveer De Geyter Architect, Fletcher Priest Architects) töödest

BR2 mixed core management

International Nuclear Information System (INIS)

Ponsard, B.; Beeckmans, A.

1997-01-01

The BR2 fuel cycle management can be optimized by the fabrication and the irradiation of fuel elements with uranium recovered from the reprocessing of BR2 spent fuel. The VIn E fuel performances could be upgraded by increasing the amount of burnable poisons, the fuel mass, the fuel density, ... in order to obtain a higher reactivity effect at a burnup of about β=12% and a longer cycle duration. The preliminary results of the calculations need however to be confirmed by measurements on effective reactor loads. (author)

Palveluprosessi toimivaksi, Case: BR-Lelut

OpenAIRE

Korpela, Jenni

2014-01-01

Tämä opinnäytetyö on tehty toimeksiantona TOP-TOY A/S –konserniin kuluvalle lelumyymäläketju BR-Leluille Suomessa. Opinnäyte on toteutettu produktiluontoisena ja sen tuloksena on syntynyt Asiakaspalvelun ja myynnin käsikirja BR-Lelujen myymälähenkilökunnalle. Ajatus opinnäytetyölle ja eritoten käsikirjalle syntyi, kun kirjoittaja työskenteli kyseisen myymäläketjun myymälässä ja samanaikaisesti opiskeli erilaisia myyntitekniikoita ammattikorkeakoulussa. Kirjoittaja huomasi, että myyntihen...

Flg22-Triggered Immunity Negatively Regulates Key BR Biosynthetic Genes.

Science.gov (United States)

Jiménez-Góngora, Tamara; Kim, Seong-Ki; Lozano-Durán, Rosa; Zipfel, Cyril

2015-01-01

In plants, activation of growth and activation of immunity are opposing processes that define a trade-off. In the past few years, the growth-promoting hormones brassinosteroids (BR) have emerged as negative regulators of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI), promoting growth at the expense of defense. The crosstalk between BR and PTI signaling was described as negative and unidirectional, since activation of PTI does not affect several analyzed steps in the BR signaling pathway. In this work, we describe that activation of PTI by the bacterial PAMP flg22 results in the reduced expression of BR biosynthetic genes. This effect does not require BR perception or signaling, and occurs within 15 min of flg22 treatment. Since the described PTI-induced repression of gene expression may result in a reduction in BR biosynthesis, the crosstalk between PTI and BR could actually be negative and bidirectional, a possibility that should be taken into account when considering the interaction between these two pathways.

Eddy current inspection of stationary blade rings

International Nuclear Information System (INIS)

Krzywosz, K.J.; Hastings, S.N.

1994-01-01

Stationary turbine blade rings in a US power plant have experienced chloride-induced cracking. Failure analysis determined two types of cracking mechanisms: corrosion fatigue cracking confined to the leading edge of the outer shroud; and stress corrosion cracking present all over the blade surface. Fluorescent dye penetrant is typically used to detect and size cracks. However, it requires cleaning the blade rings by sandblasting to obtain reliable inspection results. Sand blasting in turn requires sealing the lower half of the turbine housing to prevent sand from contaminating the rest of the power plant components. Furthermore, both the penetrant examination and the removal of the sand are time consuming and costly. An alternative NDE technique is desirable which requires no pre-cleaning of the blade and a quick go/no-go inspection with the capability of estimating the crack length. This paper presents an innovative eddy current technique which meets the desired objectives by incorporating the use of specially designed contoured scanners equipped with an array of pancake coils. A set of eddy current pancake coils housed in three different scanners is used to manually scan and inspect the convex side of the stationary blade rings. The pancake coils are operated in a transmit/receive mode using two separate eddy current instruments. This paper presents the inspection concept, including scanner and probe designs, and test results from the various stages of multiple blade rings

A novel conversion of C(19)-diterpenoid alkaloids into aconane-type diterpenes with eight-membered ring system via skeletal rearrangement of corresponding diazonium derivatives.

Science.gov (United States)

Ji, Hong; Chen, Qiao-Hong; Wang, Feng-Peng

2009-03-01

A new and efficient approach toward the conversion of C(19)-diterpenoid alkaloids into diterpenes with [6+8+5+6] ring system is reported. Treatment of imines 5, 14, and 24 derived from the C(19)-diterpenoid alkaloids with NaNO(2)-NaOAc-HOAc afforded a series of novel rearrangement diterpenes 6-8, 15-19, and 25-27, respectively. The lactone 11 was obtained in 41% yield by treating 5 with NaNO(2)-HBr-Br(2). The formation of diazonium intermediate is postulated, which was subsequently subjected to skeletal rearrangement, leading to the enlargement of B ring. All the new compounds were isolated and fully characterized.

Room-temperature synthesis of pure perovskite-related Cs4PbBr6 nanocrystals and their ligand-mediated evolution into highly luminescent CsPbBr3 nanosheets

Science.gov (United States)

Yang, Liu; Li, Dongmei; Wang, Cong; Yao, Wei; Wang, Hao; Huang, Kaixiang

2017-07-01

Currently, all-inorganic cesium lead-halide perovskite nanocrystals have attracted enormous attentions owing to their excellent optical performances. While great efforts have been devoted to CsPbBr3 nanocrystals, the perovskite-related Cs4PbBr6 nanocrystals, which were newly reported, still remained poorly understood. Here, we reported a novel room-temperature reaction strategy to synthesize pure perovskite-related Cs4PbBr6 nanocrystals. Size of the products could be adjusted through altering the amount of ligands, simply. A mixture of two good solvents with different polarity was innovatively used as precursor solvent, being one key to the high-yield Cs4PbBr6 nanocrystals synthesis. Other two keys were Cs+ precursor concentration and surface ligands. Ingenious experiments were designed to reveal the underlying reaction mechanism. No excitonic emission was observed from the prepared Cs4PbBr6 nanocrystals in our work. We considered the green emission which was observed in other reports originated from the avoidless transformation of Cs4PbBr6 into CsPbBr3 nanocrystals. Indeed, the new-prepared Cs4PbBr6 nanocrystals could transform into CsPbBr3 nanosheets with surface ligands mediated. The new-transformed two-dimensional CsPbBr3 nanosheets could evolve into large-size nanosheets. The influences of surface ligand density on the fluorescent intensity and stability of transformed CsPbBr3 nanosheets were also explained. Notably, the photoluminescence quantum yield of the as-transformed CsPbBr3 nanosheets could reach as high as 61.6% in the form of thin film. The fast large-scale synthesis of Cs4PbBr6 nanocrystals and their ligand-mediated transformation into high-fluorescent CsPbBr3 nanosheets will be beneficial to the future optoelectronic applications. Our work provides new approaches to understand the structural evolution and light-emitting principle of perovskite nanocrystals. [Figure not available: see fulltext.

Kuluttaja-asiakkaiden mielikuva Concept.10-brändistä

OpenAIRE

Väisänen, Janna-Mari

2011-01-01

Tutkimuksen tavoitteena on selvittää, millainen käsitys Concept.10:n kuluttaja-asiakkailla on brändin eri osa-alueista ja millaisia mielleyhtymiä brändin mainonta, nimi, tunnus ja slogan herättävät. Näillä tekijöillä on vaikutusta kokonaismielikuvan syntymiseen brändistä. Tutkimusongelmana on, millainen mielikuva kuluttaja-asiakkailla on Concept.10-brändistä. Concept.10 toimii yhteisenä markkinointinimenä Mikkelin Puhelin Oyj:n omistamille yhtiöille ja niiden palveluille. Teoreettisessa v...

Black rings

International Nuclear Information System (INIS)

Emparan, Roberto; Reall, Harvey S

2006-01-01

A black ring is a five-dimensional black hole with an event horizon of topology S 1 x S 2 . We provide an introduction to the description of black rings in general relativity and string theory. Novel aspects of the presentation include a new approach to constructing black ring coordinates and a critical review of black ring microscopics. (topical review)

Non-enzymatic antioxidant accumulations in BR-deficient and BR-insensitive barley mutants under control and drought conditions.

Science.gov (United States)

Gruszka, Damian; Janeczko, Anna; Dziurka, Michal; Pociecha, Ewa; Fodor, Jozsef

2017-12-07

Drought is one of the most adverse stresses that affect plant growth and yield. Disturbances in metabolic activity resulting from drought cause overproduction of reactive oxygen species. It is postulated that brassinosteroids (BRs) regulate plant tolerance to the stress conditions, but the underlying mechanisms remain largely unknown. An involvement of endogenous BRs in regulation of the antioxidant homeostasis is not fully clarified either. Therefore, the aim of this study was to elucidate the role of endogenous BRs in regulation of non-enzymatic antioxidants in barley (Hordeum vulgare) under control and drought conditions. The plant material included the 'Bowman' cultivar and a group of semi-dwarf near-isogenic lines (NILs), representing mutants deficient in BR biosynthesis or signaling. In general, accumulations of 11 compounds representing various types of non-enzymatic antioxidants were analyzed under both conditions. The analyses of accumulations of reduced and oxidized forms of ascorbate indicated that the BR mutants contain significantly higher contents of dehydroascorbic acid under drought conditions when compared with the 'Bowman' cultivar. The analysis of glutathione accumulation indicated that under the control conditions the BR-insensitive NILs contained significantly lower concentrations of this antioxidant when compared with the rest of genotypes. Therefore, we postulate that BR sensitivity is required for normal accumulation of glutathione. A complete accumulation profile of various tocopherols indicated that functional BR biosynthesis and signaling are required for their normal accumulation under both conditions. Results of this study provided an insight into the role of endogenous BRs in regulation of the non-enzymatic antioxidant homeostasis. © 2017 Scandinavian Plant Physiology Society.

Electronic structure of Co(III) doped bromo-bridged Ni complexes, [Ni1-xCox(chxn)2Br]Br2.

Science.gov (United States)

Xie, Jimin; Wu, Hashen; Kawakami, Daisuke; Iguchi, Hiroaki; Takaishi, Shinya; Yamashita, Masahiro; Matsuzaki, Hiroyuki; Okamoto, Hiroshi; Tanaka, Hisaaki; Kuroda, Shin-ichi

2008-03-17

This article describes the electronic structure of the Co(III) doped Br bridged Ni(III) complexes, [Ni(1-x)Cox(chxn)2Br]Br2 (x = 0.01, 0.02, 0.05, and 0.11) by using a optical spectroscopy, scanning tunneling microscopy (STM), and electron spin resonance spectroscopy. In the optical reflectivity spectrum, the new band was formed at about 0.5 eV, which is reasonably recognized as the d(z2) band of doped Co(III) ions. In the STM images of [Ni(1-x)Cox(chxn)2Br]Br2, the bright spots attributable to the tunnel current from the Fermi level of the STM tip to the conduction band of the sample were observed. In addition, some brighter spots were also observed. Because the number of the brighter spots is in good agreement with that of doped Co species, the brighter spots can be assigned to doped Co(III) sites. These are reasonably explained by the tunnel current from the Fermi level of the tip to the d(z2) band of Co(III). The Curie spin concentration was gradually increased with increasing Co(III) ions, which is explained by the scissions of the S = 1/2 1D antiferromagnetic chains.

KBr-Li Br and KBr-LiBr doped with Ti mixed single crystal by Czochralski method and glow curve studies

International Nuclear Information System (INIS)

Faripour, H.; Faripour, N.

2003-01-01

Mixed-single Crystals: pure KBr-LiBr and KBr-LiBr with Ti dopant were grown by Czochralski method. Because of difference between lattice parameters of KBr and LiBr, the growth speed of crystals were relatively low, and they were annealed in a special temperature condition providing some cleavages. They were exposed by β radiation and the glow curve was analysed for each crystal. Analysing of glow curve, showed that Ti impurity has been the curves of main peak curve appearance temperature decreasing

Hurtigste versus mest brændstoføkonomiske ruter

DEFF Research Database (Denmark)

Andersen, Ove; Krogh, Benjamin Bjerre; Lahrmann, Harry

2013-01-01

Der er stort fokus på at forbedre brændstoføkonomien i transportbranchen generelt. I denne artikel anvendes brændstoftallene fra Controller Area Network Bus (CANBus) kombineret med GPS data til at skabe et digitalt vejkort, hvor det er muligt at sammenligne de hurtigste ruter med de mest brændsto...

CsPb2Br5 Single Crystals: Synthesis and Characterization

KAUST Repository

Dursun, Ibrahim

2017-08-02

CsPb2Br5 is a ternary halogen-plumbate material with close characteristics to well-reported halide perovskites. Due to its unconventional two-dimensional structure, CsPb2Br5 is being looked at broadly for potential applications in optoelectronics. CsPb2Br5 investigations are currently limited to nanostructures and powder forms of the material, which present unclear and conflicting optical properties. In this study, we present the synthesis and characterization of CsPb2Br5 bulk single crystals, which enabled us to finally clarify the material\\'s optical features. Our CsPb2Br5 crystal has a two-dimensional structure with Pb2Br5- layers spaced by Cs+ cations, and exhibits a ~3.1 eV indirect bandgap with no emission in the visible spectrum.

Longpath DOAS observations of surface BrO at Summit, Greenland

Directory of Open Access Journals (Sweden)

J. Stutz

2011-09-01

Full Text Available Reactive halogens, and in particular bromine oxide (BrO, have frequently been observed in regions with large halide reservoirs, for example during bromine catalyzed coastal polar ozone depletion events. Much less is known about the presence and impact of reactive halogens in areas without obvious halide reservoirs, such as the polar ice sheets or continental snow. <br>> We report the first LP-DOAS measurements of BrO at Summit research station in the center of the Greenland ice sheet at an altitude of 3200 m. BrO mixing ratios in May 2007 and June 2008 were typically between 1–3 pmol mol⁻¹, with maxima of up to 5 pmol mol⁻¹. These measurements unequivocally show that halogen chemistry is occurring in the remote Arctic, far from known bromine reservoirs, such as the ocean. During periods when FLEXPART retroplumes show that airmasses resided on the Greenland ice sheet for 3 or more days, BrO exhibits a clear diurnal variation, with peak mixing ratios of up to 3 pmol mol⁻¹ in the morning and at night. The diurnal cycle of BrO can be explained by a changing boundary layer height combined with photochemical formation of reactive bromine driven by solar radiation at the snow surface. The shallow stable boundary layer in the morning and night leads to an accumulation of BrO at the surface, leading to elevated BrO despite the expected smaller release from the snowpack during these times of low solar radiation. During the day when photolytic formation of reactive bromine is expected to be highest, efficient mixing into a deeper neutral boundary layer leads to lower BrO mixing ratios than during mornings and nights. <br>> The extended period of contact with the Greenland snowpack combined with the diurnal profile of BrO, modulated by boundary layer height, suggests that photochemistry in the snow is a significant source of BrO measured at Summit during the 2008 experiment. In addition, a rapid transport event

Variations in Ring Particle Cooling across Saturn's Rings with Cassini CIRS

Science.gov (United States)

Brooks, S. M.; Spilker, L. J.; Pilorz, S.; Edgington, S. G.; Déau, E.; Altobelli, N.

2010-12-01

Cassini's Composite Infrared Spectrometer has recorded over two million of spectra of Saturn's rings in the far infrared since arriving at Saturn in 2004. CIRS records far infrared radiation between 10 and 600 cm-1 ( 16.7 and 1000 μ {m} ) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn’s rings peaks in this wavelength range. Ring temperatures can be inferred from FP1 data. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and rapidly changing temperatures are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid particles can be expected to have higher thermal inertias. Ferrari et al. (2005) fit thermal inertia values of 5218 {Jm)-2 {K}-1 {s}-1/2 to their B ring data and 6412 {Jm)-2 {K}-1 {s}-1/2 to their C ring data. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The rings’ thermal budget is dominated by its absorption of solar radiation. As a result, ring particles abruptly cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

Pre-big-bang cosmology and circles in the cosmic microwave background

International Nuclear Information System (INIS)

Nelson, William; Wilson-Ewing, Edward

2011-01-01

We examine the possibility that circles in the cosmic microwave background could be formed by the interaction of a gravitational wave pulse emitted in some pre-big-bang phase of the universe with the last scattering surface. We derive the expected size distribution of such circles, as well as their typical ring width and (for concentric circles) angular separation. We apply these results, in particular, to conformal cyclic cosmology, ekpyrotic cosmology as well as loop quantum cosmology with and without inflation in order to determine how the predicted geometric properties of these circles would vary from one model to the other, and thus, if detected, could allow us to differentiate between various pre-big-bang cosmological models. We also obtain a relation between the angular ring width and the angular radius of such circles that can be used in order to determine whether or not circles observed in the cosmic microwave background are due to energetic pre-big-bang events.

Elamusturundus: riigi brändimine ja Eesti bränd / Siiri Same

Index Scriptorium Estoniae

Same, Siiri

2015-01-01

Artikli autor oma 2015. a. Tallinna Tehnikaülikoolis kaitstud doktoritööst "Conceptualization of experience marketing and country branding from a marketing management perspective" ("Elamusturunduse ja riigi brändimise kontseptualiseerimine turunduse juhtimise vaatenurgast")

20 years of long-term water balance measurements of a landfill cover system with components constructed from pre-treated dredged material

NARCIS (Netherlands)

Berger, K.; Groengroeft, A.; Gebert, J.; Harms, C.; Eschenbach, A.

2017-01-01

The cover system of the mono-landfill Hamburg-Francop for disposal of dredged<br/>material comprises a mineral liner of pre-treated fine-grained dredged material (‘METHAmaterial’) and an overlying drainage layer of pre-treated sandy dredged material (‘METHAsand’). Water balance and effectiveness of

Reaction of Br2 with adsorbed CO on Pt, studied by the surface interrogation mode of scanning electrochemical microscopy.

Science.gov (United States)

Wang, Qian; Rodríguez-López, Joaquín; Bard, Allen J

2009-12-02

Scanning electrochemical microscopy surface interrogation (SI-SECM) in the cyclic voltammetry mode was successfully used to detect and quantify adsorbed CO on a Pt electrode by reaction with electrogenerated Br(2). The two-electrode setup used in this new technique allowed the production of Br(2) on an interrogator tip, which reported a transient positive feedback above a Pt substrate at open circuit as an indication of the reactivity of this halogen with CO((ads)). Br(-) and CO(2) are shown to be the main products of the reaction (in the absence of O(2)), which may involve the formation of bromophosgene as a hydrolyzable intermediate. Under saturation conditions, CO((ads)) was reproducibly quantified at the polycrystalline Pt surface with theta(CO) approximately = 0.5. The reaction is shown to be blocked by the action of pre-adsorbed cyanide, which demonstrates the surface character of the process. The formation of CO(2) as an end product was further tested in a bulk experiment: addition of Pt black to a mixture of Br(2) in 0.5 M H(2)SO(4) through which CO was bubbled gave a precipitate of BaCO(3) in a saturated solution of Ba(OH)(2). The use of SI-SECM allowed access to a reaction that would otherwise be difficult to prove through conventional electrochemistry on a single electrode.

Alternative loop rings

CERN Document Server

Goodaire, EG; Polcino Milies, C

1996-01-01

For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

Improved Growth Methods for LaBr3 Scintillation Radiation Detectors

International Nuclear Information System (INIS)

McGregor, Douglas S.

2011-01-01

The objective is to develop advanced materials for deployment as high-resolution gamma ray detectors. Both LaBr3 and CeBr3 are advanced scintillation materials, and will be studied in this research. Prototype devices, in collaboration Sandia National Laboratories, will be demonstrated along with recommendations for mass production and deployment. It is anticipated that improved methods of crystal growth will yield larger single crystals of LaBr3 for deployable room-temperature operated gamma radiation spectrometers. The growth methods will be characterized. The LaBr3 and CeBr3 scintillation crystals will be characterized for light yield, spectral resolution, and for hardness.

Primitivity and weak distributivity in near rings and matrix near rings

International Nuclear Information System (INIS)

Abbasi, S.J.

1993-08-01

This paper shows the structure of matrix near ring constructed over a weakly distributive and primative near ring. It is proved that a weakly distributive primitive near ring is a ring and the matrix near rings constructed over it is also a bag. (author). 14 refs

4-Benzyl-6-bromo-2-phenyl-4H-imidazo[4,5-b]pyridine

Directory of Open Access Journals (Sweden)

Y. Ouzidan

2010-04-01

Full Text Available The imidazopyridine fused ring in the title compound, C19H14BrN3, is almost coplanar with the phenyl ring at the 2-position of the five-membered ring [dihedral angle = 2.4 (1. The crystal structure features short Br...Br contacts [3.562 (1 Å].

Tracheal ceramic rings for tracheomalacia: a review after 17 years.

Science.gov (United States)

Göbel, Gyula; Karaiskaki, Niki; Gerlinger, Imre; Mann, Wolf J

2007-10-01

Despite different support techniques, the surgical management of tracheomalacia is still a challenging problem. Satisfactory results after internal stenting are above 80%, whereas, when performing external stenting using biocompatible ceramic rings, results are reported at over 90%. The purpose of this study was to examine the efficiency of surgical treatment in patients with segmentary tracheomalacia using external ceramic ring grafts. In this retrospective study, we collected data from 12 patients who underwent surgery during the last 17 years for symptomatic segmentary tracheomalacia by use of biocompatible aluminum-oxide ceramic rings. All except one patient had undergone previous tracheostomy, six had a history of long-term intubation, two had previous trauma, and two patients had previous cancer treatment including radiotherapy. One of the patients still had an existing tracheostoma, which was closed when a ceramic ring was implanted. Tracheal wall collapse with pseudoglottis formation or flattened anterior-posterior tracheal diameter was documented with fiberoscopy at rest, and both pre- and postoperative airway resistance measurements were performed in all 12 patients using a spirometer. After malacic segments were found to be expandable using rigid tracheoscopy while the patient was under general anesthesia, preparation of the trachea was performed using a midline vertical incision in the neck. Subsequently, the malacic trachea was expanded by placing and suturing proper-sized ceramic ring(s) around it. In all patients, surgical expansion of the malacic segment using ceramic rings was successfully carried out without major complications while inspiratory stridor was resolved. Airway resistance decreased significantly from an average of 0.62 to 0.385 kPascal. Although the results of applying internal tracheal stents are encouraging, complications such as stent migration, granulation tissue and fistula formation, and mucociliary transport arrest are possible

The plasmasheet H+ and O+ contribution on the storm time ring current

Science.gov (United States)

Mouikis, C.; Bingham, S.; Kistler, L. M.; Spence, H. E.; Gkioulidou, M.; Claudepierre, S. G.; Farrugia, C. J.

2015-12-01

The source population of the storm time ring current is the night side plasma sheet. We use Van Allen Probes and Cluster observations to determine the contribution of the convecting plasma sheet H+ and O+ particles in the storm time development of the ring current. Using the Volland-Stern model with a dipole magnetic field together with the identification of the observed energy cutoffs in the particle spectra, we specify the pressure contributed by H+ and O+ populations that are on open drift paths vs. the pressure contributed by the trapped populations, for different local times. We find that during the storm main phase most of the ring current pressure in the pre-midnight inner magnetosphere is contributed by particles on open drift paths that cause the development of a strong partial ring current that causes most of the main phase Dst drop. These particles can reach as deep as L~2 and their pressure compares to the local magnetic field pressure as deep as L~3. During the recovery phase, if these particles are not lost at the magnetopause, will become trapped and will contribute to the symmetric ring current.

La Alpaca -vaatemerkin brändäys

OpenAIRE

Lehtinen, Laura

2013-01-01

Tämä opinnäytetyö käsittelee brändin vahvistamista ja brändiohjeiston luomista vaa-tealan yritykselle La Alpacalle. La Alpaca on suomalainen vaatemerkki, joka suunnit-telee, tuottaa ja myy alpakanvillasta valmistettuja tuotteita. Materiaalin ainutlaatuisuus ja hienous ovat olleet osa yrityksen identiteettiä alusta asti. Brändin lisäksi työssä on tutkittu kaupankäynnin rakenteellista muuttumista perinteisestä myymälätoiminnasta verkkomyyntiin. Työn tavoitteena on ollut luoda materiaalin tun...

2-Amino-4-(4-bromophenyl-8-trifluoromethyl-3,4-dihydropyrimido[1,2-a][1,3,5]triazin-6(5H-onePart 13 in the series `Fused heterocyclic systems with an s-triazine ring'. For Part 12, see Dolzhenko et al. (2008b.

Directory of Open Access Journals (Sweden)

Anton V. Dolzhenko

2009-04-01

Full Text Available The title compound, C13H9BrF3N5O, crystallizes with two independent molecules in the asymmetric unit. The pyrimidine rings of the molecules are planar [maximum deviations 0.053 (3 and 0.012 (3 Å], while the triazine rings adopt flattened half-boat conformations with the p-bromophenyl rings in the flagpole positions. The crystal packing is stabilized by a three-dimensional network of intermolecular N—H...N, N—H...O and N—H...F hydrogen bonds.

Irradiation of novel MTR fuel plates in BR2

International Nuclear Information System (INIS)

Verboomen, B.; Aoust, Th.; Beeckmans De Westmeerbeeck, A.; De Raedt, Ch.

2000-01-01

Since the end of 1999, novel MTR fuel plates with very high-density meat are being irradiated in BR2. The purpose of the irradiation is to investigate the behaviour of these fuel plates under very severe reactor operation conditions. The novel fuel plates are inserted in two standard six-tube BR2 fuel elements in the locations normally occupied by the standard outer fuel plates. The irradiation in BR2 was prepared by carrying out detailed neutron Monte Carlo calculations of the whole BR2 core containing the two experimental fuel elements for various positions in the reactor and for various azimuthal orientations of the fuel elements. Comparing the thus determined fission density levels and azimuthal profiles in the new MTR fuel plates irradiated in the various channels allowed the experimenters to choose the most appropriate BR2 channel and the most appropriate fuel element orientation. (author)

Photoelectron Emission Studies in CsBr at 257 nm

International Nuclear Information System (INIS)

Maldonado, Juan R.; Liu, Zhi; Sun, Yun; Pianetta, Piero A.; Pease, Fabian W.

2006-01-01

CsBr/Cr photocathodes were found [1,2] to meet the requirements of a multi-electron beam lithography system operating with a light energy of 4.8 eV (257nm). The fact that photoemission was observed with a light energy below the reported 7.3 eV band gap for CsBr was not understood. This paper presents experimental results on the presence of intra-band gap absorption sites (IBAS) in CsBr thin film photo electron emitters, and presents a model based on IBAS to explain the observed photoelectron emission behavior at energies below band gap. A fluorescence band centered at 330 nm with a FWHM of about 0.34 eV was observed in CsBr/Cr samples under 257 nm laser illumination which can be attributed to IBAS and agrees well with previously obtained synchrotron photoelectron spectra[1] from the valence band of CsBr films

Elastic properties of Cs2HgBr4 and Cs2CdBr4 crystals

International Nuclear Information System (INIS)

Kityk, A.V.; Zadorozhna, A.V.; Shchur, Y.I.; Martynyuk-Lototska, Y.I.; Burak, Y.; Vlokh, O.G.

1998-01-01

Using ultrasonic velocity measurements, all components of the elastic constant matrix C ij , elastic compliances matrix S ij , and linear compressibility constants matrix K ij of orthorhombic Cs 2 HgBr 4 and Cs 2 CdBr 4 crystals have been determined over a wide temperature range, including the region of the phase transition from the normal to the incommensurate phase. Results obtained are considered within the framework of the phenomenological theory. Preliminary analysis of the acoustical properties at room temperature clearly indicates that both crystals are relatively important materials for acousto-optical applications. Copyright (1998) CSIRO Australia

Metal-free, mild, nonepimerizing, chemo- and enantio- or diastereoselective N-alkylation of amines by alcohols via oxidation/imine-iminium formation/reductive amination: a pragmatic synthesis of octahydropyrazinopyridoindoles and higher ring analogues.

Science.gov (United States)

Khan, Imran A; Saxena, Anil K

2013-12-06

A mild step and atom-economical nonepimerizing chemo- and enantioselective N-alkylating procedure has been developed via oxidation/imine-iminium formation/reduction cascade using TEMPO-BAIB-HEH-Brønsted acid catalysis in DMPU as solvent and a stoichiometric amount of amine. The optimized conditions were further extended for the nonenzymatic kinetic resolution of the chiral amine thus formed under nonenzymatic in situ hydrogen-transfer conditions using VAPOL-derived phosphoric acid (VAPOL-PA) as the Brønsted acid catalyst. The enantioselective cascade of the presented reaction was successfully utilized in the synthesis of octahydropyrazinopyridoindole and its higher ring analogues.

Interaction of ring dark solitons with ring impurities in Bose-Einstein condensates

International Nuclear Information System (INIS)

Xue Jukui

2005-01-01

The interaction of ring dark solitons/vortexes with the ring-shaped repulsive and attractive impurities in two-dimensional Bose-Einstein condensates is investigated numerically. Very rich interaction phenomena are obtained, i.e., not only the interaction between the ring soliton and the impurity, but also the interaction between vortexes and the impurity. The interaction characters, i.e., snaking of ring soliton, quasitrapping or reflection of ring soliton and vortexes by the impurity, strongly depend on initial ring soliton velocity, impurity strength, initial position of ring soliton and impurity. The numerical results also reveal that ring dark solitons/vortexes can be trapped and dragged by an adiabatically moving attractive ring impurity

Br...Br and van der Waals interactions along a homologous series: crystal packing of 1,2-dibromo-4,5-dialkoxybenzenes.

Science.gov (United States)

Suarez, Sebastián A; Muller, Federico; Gutiérrez Suburu, Matías E; Fonrouge, Ana; Baggio, Ricardo F; Cukiernik, Fabio D

2016-10-01

The crystalline structures of four homologues of the 1,2-dibromo-4,5-dialkoxybenzene series [Br 2 C 6 H 2 (OC n H 2n + 1 ) 2 for n = 2, 12, 14 and 18] have been solved by means of single-crystal crystallography. Comparison along the series, including the previously reported n = 10 and n = 16 derivatives, shows a clear metric trend (b and c essentially fixed along the series and a growing linearly with n), in spite of some subtle differences in space groups and/or packing modes. A uniform packing pattern for the aliphatic chains has been found for the n = 12 to 18 homologues, which slightly differs from that of the n = 10 derivative. The crystalline structures of all the higher homologues (n = 10-18) seem to arise from van der Waals interchain interactions and, to a lesser extent, type II Br...Br interactions. The dominant role of interchain interactions provides direct structural support for the usual interpretation of melting point trends like that found along this series. Atoms in Molecules (AIM) analysis allows a comparison of the relative magnitude of the interchain and Br...Br interactions, an analysis validated by the measured melting enthalpies.

Performance evaluation of LaBr3: Ce scintillator

International Nuclear Information System (INIS)

Xie Ming; Lin Li; Liu Shihao; Xiao Peng; Xie Qingguo

2012-01-01

The cerium doped lanthanum bromide crystal (LaBr 3 : Ce) is a new kind of scintillator with many advantages such as good energy resolution, high light output, short decay time, good proportionality response. These properties make the LaBr 3 : Ce attractive substantial interest to use in the radiation detection. The energy resolution were investigated with Φ25 × 25 mm LaBr 3 : Ce coupled to a Hamamatsu R8900 photomultiplier tube. Energy resolution of 3.6% (FWHM) have been achieved for 511 keV photons ( 18 F source) at room temperature. Decay time constant of 20 ns have been acquired with a Hamamatsu fast-time-response R9800 photomultiplier tube. The results approve the excellent characterizations of LaBr 3 : Ce and imply its enormous potentiality in the radiation detectors of gamma-ray spectroscopy and PET. (authors)

Synthesis and crystal structure determination of Br2SeIBr ...

Indian Academy of Sciences (India)

Unknown

termined by single crystal X-ray diffraction method. This compound was ... company and SeBr4 was prepared from the reaction of Se powder (0⋅1 g) with Br2 ... angles of Br2SeIBr and table 4 shows anisotropic displace- ment parameters.

Adsorption property of Br-PADAP-impregnated multiwall carbon nanotubes towards uranium and its performance in the selective separation and determination of uranium in different environmental samples.

Science.gov (United States)

Khamirchi, Ramzanali; Hosseini-Bandegharaei, Ahmad; Alahabadi, Ahmad; Sivamani, Selvaraju; Rahmani-Sani, Abolfazl; Shahryari, Taher; Anastopoulos, Ioannis; Miri, Mohammad; Tran, Hai Nguyen

2018-04-15

A newer efficient U(VI) ion adsorbent was synthesized by impregnating Br-PADAP [2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol] onto multiwall carbon nanotubes (MWCNTs). The effects of various operation conditions on uranium adsorption (i.e., pH contact time, temperature, and initial uranium concentration) were systematically evaluated using batch experiments. The results indicated that the uranium adsorption on modified MWNCTs (5.571 × 10 -3 g/mg × min) reached faster equilibrium than that on pristine MWNCTs (4.832 × 10 -3 g/mg × min), reflecting the involvement of appropriate functional groups of Br-PADAP on the chelating ion-exchange mechanism of U(VI) adsorption. Modified MWNCTs (83.4mg/g) exhibited significantly higher maximum Langmuir adsorption capacity than pristine MWNCTs (15.1mg/g). Approximately 99% of uranium adsorbed onto modified MWNCTs can be desorbed by 2.5mL of 1M HNO 3 solution. Therefore, Br-PADAP-modified MWNCTs can server as a promising adsorbent for efficient uranium adsorption applications in water treatment. Subsequently, the proposed solid-phase extraction (using a mini-column packed with Br-PADAP/MWCNT) was successfully utilized for analysing trace uranium levels by the ICP-AES method in different environmental samples with a pre-concentration factor of 300-fold. The coexistence of other ions demonstrated an insignificant interference on the separative pre-concentration of uranium. the detection limit was recognized as 0.14μg/L, and the relative standard deviation was approximately 3.3% (n = 7). Copyright © 2017 Elsevier Inc. All rights reserved.

Storage Rings

International Nuclear Information System (INIS)

Fischer, W.

2010-01-01

Storage rings are circular machines that store particle beams at a constant energy. Beams are stored in rings without acceleration for a number of reasons (Tab. 1). Storage rings are used in high-energy, nuclear, atomic, and molecular physics, as well as for experiments in chemistry, material and life sciences. Parameters for storage rings such as particle species, energy, beam intensity, beam size, and store time vary widely depending on the application. The beam must be injected into a storage ring but may not be extracted (Fig. 1). Accelerator rings such as synchrotrons are used as storage rings before and after acceleration. Particles stored in rings include electrons and positrons; muons; protons and anti-protons; neutrons; light and heavy, positive and negative, atomic ions of various charge states; molecular and cluster ions, and neutral polar molecules. Spin polarized beams of electrons, positrons, and protons were stored. The kinetic energy of the stored particles ranges from 10 -6 eV to 3.5 x 10 12 eV (LHC, 7 x 10 12 eV planned), the number of stored particles from one (ESR) to 1015 (ISR). To store beam in rings requires bending (dipoles) and transverse focusing (quadrupoles). Higher order multipoles are used to correct chromatic aberrations, to suppress instabilities, and to compensate for nonlinear field errors of dipoles and quadrupoles. Magnetic multipole functions can be combined in magnets. Beams are stored bunched with radio frequency systems, and unbunched. The magnetic lattice and radio frequency system are designed to ensure the stability of transverse and longitudinal motion. New technologies allow for better storage rings. With strong focusing the beam pipe dimensions became much smaller than previously possible. For a given circumference superconducting magnets make higher energies possible, and superconducting radio frequency systems allow for efficient replenishment of synchrotron radiation losses of large current electron or positron beams

Storage ring design of the 8 GeV synchrotron radiation facility (SPring-8)

International Nuclear Information System (INIS)

Hara, M.; Bc, S.H.; Motonaga, S.

1990-01-01

In Japan, RIKEN (Institute of Physical and Chemical Research) and JAERI (Japan Atomic Energy Research Institute) have organized a joint design team and started a design study for an 8 GeV synchrotron radiation X-ray source. This paper outlines the status of the design study for the 8 GeV highly brilliant synchrotron radiation X-ray source ring named Super Photon Ring (SPring-8). The facility consists of a main storage ring, a full-energy injector booster synchrotron and a pre-injector 1 GeV linac. The injector linac and synchrotron are laid outside the storage ring because to permit the use of the linac and synchrotron not only as an injector but also as an electron or positron beam source. The purpose of the facility is to provide stable photon beams with high brilliance in the X-ray region. The energy of the stored electrons (positrons) is fixed at 8 GeV to fulfill the required condition using conventional type insertion devices. (N.K.)

Water-resistant, monodispersed and stably luminescent CsPbBr3/CsPb2Br5 core-shell-like structure lead halide perovskite nanocrystals

Science.gov (United States)

Qiao, Bo; Song, Pengjie; Cao, Jingyue; Zhao, Suling; Shen, Zhaohui; Gao, Di; Liang, Zhiqin; Xu, Zheng; Song, Dandan; Xu, Xurong

2017-11-01

Lead halide perovskite materials are thriving in optoelectronic applications due to their excellent properties, while their instability due to the fact that they are easily hydrolyzed is still a bottleneck for their potential application. In this work, water-resistant, monodispersed and stably luminescent cesium lead bromine perovskite nanocrystals coated with CsPb2Br5 were obtained using a modified non-stoichiometric solution-phase method. CsPb2Br5 2D layers were coated on the surface of CsPbBr3 nanocrystals and formed a core-shell-like structure in the synthetic processes. The stability of the luminescence of the CsPbBr3 nanocrystals in water and ethanol atmosphere was greatly enhanced by the photoluminescence-inactive CsPb2Br5 coating with a wide bandgap. The water-stable enhanced nanocrystals are suitable for long-term stable optoelectronic applications in the atmosphere.

Shape and phase evolution from CsPbBr3 perovskite nanocubes to tetragonal CsPb2Br5 nanosheets with an indirect bandgap.

Science.gov (United States)

Li, Guopeng; Wang, Hui; Zhu, Zhifeng; Chang, Yajing; Zhang, Ting; Song, Zihang; Jiang, Yang

2016-09-13

Tetragonal CsPb 2 Br 5 nanosheets were obtained by an oriented attachment of orthorhombic CsPbBr 3 nanocubes, involving a lateral shape evolution from octagonal to square. Meanwhile, the experimental results, together with DFT simulation results, indicated that the tetragonal CsPb 2 Br 5 is an indirect bandgap semiconductor that is PL-inactive with a bandgap of 2.979 eV.

Reversible light-mediated compositional and structural transitions between CsPbBr3 and CsPb2Br5 nanosheets.

Science.gov (United States)

Shen, Wei; Ruan, Longfei; Shen, Zhitao; Deng, Zhengtao

2018-03-13

This communication describes a new method to achieve reversible light-induced chemical composition and phase structural transitions from polyvinylpyrrolidone-capped orthorhombic CsPbBr 3 to tetragonal CsPb 2 Br 5 nanosheets or vice versa. This work will deepen our understanding of the controlled synthesis, post-processing, and decomposition pathway of cesium lead halide perovskite nanocrystals.

Paysans du Brésil

Directory of Open Access Journals (Sweden)

Dominique Temple

2007-01-01

Full Text Available Eric Sabourin, « Paysans du Brésil : Entre échange marchand et réciprocité » Paris, Editions Quae, 241p, 30 euros, (préface de Maxime Haubert, 2007Dans la présentation du livre, Maxime Haubert dit :«Cet ouvrage propose une analyse socio-anthropologique et agronomique des sociétés rurales et paysannes du Brésil et des transformations qu'elles ont connues ces dernières décennies, en particulier face aux interventions de l'Etat et à l'expansion du marché capitaliste (.... «Le livre pose d'abor...

Rings in drugs.

Science.gov (United States)

Taylor, Richard D; MacCoss, Malcolm; Lawson, Alastair D G

2014-07-24

We have analyzed the rings, ring systems, and frameworks in drugs listed in the FDA Orange Book to understand the frequency, timelines, molecular property space, and the application of these rings in different therapeutic areas and target classes. This analysis shows that there are only 351 ring systems and 1197 frameworks in drugs that came onto the market before 2013. Furthermore, on average six new ring systems enter drug space each year and approximately 28% of new drugs contain a new ring system. Moreover, it is very unusual for a drug to contain more than one new ring system and the majority of the most frequently used ring systems (83%) were first used in drugs developed prior to 1983. These observations give insight into the chemical novelty of drugs and potentially efficient ways to assess compound libraries and develop compounds from hit identification to lead optimization and beyond.

Biomass conversion inhibitors furfural and 5-hydroxymethylfurfural induce formation of messenger RNP granules and attenuate translation activity in Saccharomyces cerevisiae.

Science.gov (United States)

Iwaki, Aya; Kawai, Takao; Yamamoto, Yosuke; Izawa, Shingo

2013-03-01

Various forms of stress can cause an attenuation of bulk translation activity and the accumulation of nontranslating mRNAs into cytoplasmic messenger RNP (mRNP) granules termed processing bodies (P-bodies) and stress granules (SGs) in eukaryotic cells. Furfural and 5-hydroxymethylfurfural (HMF), derived from lignocellulosic biomass, inhibit yeast growth and fermentation as stressors. Since there is no report regarding their effects on the formation of cytoplasmic mRNP granules, here we investigated whether furfural and HMF cause the assembly of yeast P-bodies and SGs accompanied by translational repression. We found that furfural and HMF cause the attenuation of bulk translation activity and the assembly of cytoplasmic mRNP granules in Saccharomyces cerevisiae. Notably, a combination of furfural and HMF induced the remarkable repression of translation initiation and SG formation. These findings provide new information about the physiological effects of furfural and HMF on yeast cells, and also suggest the potential usefulness of cytoplasmic mRNP granules as a warning sign or index of the deterioration of cellular physiological status in the fermentation of lignocellulosic hydrolysates.

Design and implementation of tutorials for PLC B&R Automation

OpenAIRE

Sýkora, Daniel

2014-01-01

Tato bakalářská práce se zabývá návrhem a realizací úloh pro PLC B&R a podrobným návodem práce v Automation Studio. Obsahuje také informace o firmě B&R Automation Ges. m. b. H. a jejích produktech. Návrh úloh probíhal ve vývojovém prostředí B&R Automation Studio. Praktická úloha na regulaci teploty byla řešena a odzkoušena na B&R PLC X20. This bachelor’s thesis deals with the design and the implementation tutorials for PLC B&R as well as the detailed instructions of work in the Automation ...

Production of 77 Br for medical application

International Nuclear Information System (INIS)

Bastos, M.A.V.

1982-01-01

Bromine-77 is produced with the variable energy cyclotron (CV-28) at the Instituto de Engenharia Nuclear, via the 75 As. (α, 2 n) 77 Br reaction, by bombarding arsenic trioxide with 28 MeV alpha-particles. The thick target yield is 0.3 mCi/μAh. The target is dissolved in concentrated N H 4 OH and 77 Br, separated from arsenic, by an anionic exchange resin, is obtained carrier-free with a separation yield greater than 90%. All the process is remotely controlled using electric and pneumatic systems, manipulators and tongs. The quality control is made by atomic absorption and gamma-ray spectroscopy. The present production rate of Br-77 is 2.3 mCi per irradiation. (author)

Characterization of the LiSi/CsBr-LiBr-KBr/FeS(2) System for Potential Use as a Geothermal Borehole Power Source

International Nuclear Information System (INIS)

GUIDOTTI, RONALD A.; REINHARDT, FREDERICK W.

1999-01-01

We are continuing to study the suitability of modified thermal-battery technology as a potential power source for geothermal borehole applications. Previous work focused on the LiSi/FeS(sub 2) couple over a temperature range of 350 C to 400 C with the LiBr-KBr-LiF eutectic, which melts at 324.5 C. In this work, the discharge processes that take place in LiSi/CsBr-LiBr-KBr eutectic/FeS(sub 2) thermal cells were studied at temperatures between 250 C and 400 C using pelletized cells with immobilized electrolyte. The CsBr-LiBr-KBr eutectic was selected because of its lower melting point (228.5 C). Incorporation of a quasi-reference electrode allowed the determination of the relative contribution of each electrode to the overall cell polarization. The results of single-cell tests and limited battery tests are presented, along with preliminary data for battery stacks tested in a simulated geothermal borehole environment

Is the 'Bromine Explosion' generated from the reaction BrO HO2 alone?

Science.gov (United States)

Behnke, Wolfgang; Zetzsch, Cornelius

2010-05-01

We observed bromine explosions (a fast production of atomic Br and Cl under tropospheric conditions) in various smog chamber experiments in Teflon bags at room temperature at a relative humidity of about 80% in the presence of NaCl/NaBr-aerosol, simulated sunlight and ozone (200 - 400 ppb). Time profiles of ozone and hydrocarbons (HCs: n-butane, 2,2-dimethylbutane, tetramethylbutane and toluene, initially about 2 ppb each) were monitored to determine concentrations and source strengths of OH radicals, atomic Cl and Br and the corresponding time profiles of BrCl and Br2 as their photolytic precursors. The number and size of aerosols are measured as well as their chemical composition (Br-, Cl- and oxalic acid). Full records of raw data from the smog chamber runs are available at www.eurochamp.org for potential users. Chemical box model calculations deliver concentrations of various intermediates, such as aldehydes, HO2 and RO2 radicals and the inorganic halogen compounds ClO, BrO, HOCl and HOBr, where HOBr from O3 + Br- => BrO- + O2 in the aqueous/adsorbed phase induces the following gas-phase/ heterogeneous chain reaction Br + O3 => BrO + O2(1) BrO + HO2 => HOBr + O2(2a) HOBr + (Aerosol) => HOBrad(3) Surface-adsorbed HOBr reacts with Br- or Cl- to produce Br2 or BrCl, both of which are released and photolysed. Formation of Br2 should prevail up to Cl-/Br- -ratios of about 104 (Fickert, S., J.W. Adams, J.N. Crowley, J. Geophys. Res., D104, 23719-23727, 1999). A maximum of this ratio is reached about 30 minutes after the beginning and decreases during the next hours - probably by reaction of Br2 with oxalate and absorption of HBr, formed from the reaction of Br with aldehydes. Parallel to chain reaction (1)-(3) a chain reaction replacing Br by Cl seems possible but can not be realized, since the main sink of atomic Cl is its reaction with hydrocarbons - leading to chain termination - in contrast to atomic Br (ratio of rates: kCl[O3]/kCl[HC] ~ 0.1; kBr[O3]/kBr

Facile synthesis of CsPbBr3/PbSe composite clusters.

Science.gov (United States)

Nguyen, Thang Phan; Ozturk, Abdullah; Park, Jongee; Sohn, Woonbae; Lee, Tae Hyung; Jang, Ho Won; Kim, Soo Young

2018-01-01

In this work, CsPbBr 3 and PbSe nanocomposites were synthesized to protect perovskite material from self-enlargement during reaction. UV absorption and photoluminescence (PL) spectra indicate that the addition of Se into CsPbBr 3 quantum dots modified the electronic structure of CsPbBr 3 , increasing the band gap from 2.38 to 2.48 eV as the Cs:Se ratio increased to 1:3. Thus, the emission color of CsPbBr 3 perovskite quantum dots was modified from green to blue by increasing the Se ratio in composites. According to X-ray diffraction patterns, the structure of CsPbBr 3 quantum dots changed from cubic to orthorhombic due to the introduction of PbSe at the surface. Transmission electron microscopy and X-ray photoemission spectroscopy confirmed that the atomic distribution in CsPbBr 3 /PbSe composite clusters is uniform and the composite materials were well formed. The PL intensity of a CsPbBr 3 /PbSe sample with a 1:1 Cs:Se ratio maintained 50% of its initial intensity after keeping the sample for 81 h in air, while the PL intensity of CsPbBr 3 reduced to 20% of its initial intensity. Therefore, it is considered that low amounts of Se could improve the stability of CsPbBr 3 quantum dots.

Reactor BR2. Introduction

International Nuclear Information System (INIS)

Gubel, P.

2001-01-01

The BR2 is a materials testing reactor and is still one of SCK-CEN's important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. During the last three years, the availability of the installation was maintained at an average level of 97.6 percent. In the year 2000, the reactor was operated for a total of 104 days at a mean power of 56 MW. In 2000, most irradiation experiments were performed in the CALLISTO PWR loop. The report describes irradiations achieved or under preparation in 2000, including the development of advanced facilities and concept studies for new programmes. An overview of the scientific irradiation programmes as well as of the R and D programme of the BR2 reactor in 2000 is given

Reactor BR2. Introduction

Energy Technology Data Exchange (ETDEWEB)

Gubel, P

2001-04-01

The BR2 is a materials testing reactor and is still one of SCK-CEN's important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. During the last three years, the availability of the installation was maintained at an average level of 97.6 percent. In the year 2000, the reactor was operated for a total of 104 days at a mean power of 56 MW. In 2000, most irradiation experiments were performed in the CALLISTO PWR loop. The report describes irradiations achieved or under preparation in 2000, including the development of advanced facilities and concept studies for new programmes. An overview of the scientific irradiation programmes as well as of the R and D programme of the BR2 reactor in 2000 is given.

A comparative study of LaBr3(Ce(3+)) and CeBr3 based gamma-ray spectrometers for planetary remote sensing applications.

Science.gov (United States)

Kozyrev, A; Mitrofanov, I; Owens, A; Quarati, F; Benkhoff, J; Bakhtin, B; Fedosov, F; Golovin, D; Litvak, M; Malakhov, A; Mokrousov, M; Nuzhdin, I; Sanin, A; Tretyakov, V; Vostrukhin, A; Timoshenko, G; Shvetsov, V; Granja, C; Slavicek, T; Pospisil, S

2016-08-01

The recent availability of large volume cerium bromide crystals raises the possibility of substantially improving gamma-ray spectrometer limiting flux sensitivities over current systems based on the lanthanum tri-halides, e.g., lanthanum bromide and lanthanum chloride, especially for remote sensing, low-level counting applications or any type of measurement characterized by poor signal to noise ratios. The Russian Space Research Institute has developed and manufactured a highly sensitive gamma-ray spectrometer for remote sensing observations of the planet Mercury from the Mercury Polar Orbiter (MPO), which forms part of ESA's BepiColombo mission. The Flight Model (FM) gamma-ray spectrometer is based on a 3-in. single crystal of LaBr3(Ce(3+)) produced in a separate crystal development programme specifically for this mission. During the spectrometers development, manufacturing, and qualification phases, large crystals of CeBr3 became available in a subsequent phase of the same crystal development programme. Consequently, the Flight Spare Model (FSM) gamma-ray spectrometer was retrofitted with a 3-in. CeBr3 crystal and qualified for space. Except for the crystals, the two systems are essentially identical. In this paper, we report on a comparative assessment of the two systems, in terms of their respective spectral properties, as well as their suitability for use in planetary mission with respect to radiation tolerance and their propensity for activation. We also contrast their performance with a Ge detector representative of that flown on MESSENGER and show that: (a) both LaBr3(Ce(3+)) and CeBr3 provide superior detection systems over HPGe in the context of minimally resourced spacecraft and (b) CeBr3 is a more attractive system than LaBr3(Ce(3+)) in terms of sensitivities at lower gamma fluxes. Based on the tests, the FM has now been replaced by the FSM on the BepiColombo spacecraft. Thus, CeBr3 now forms the central gamma-ray detection element on the MPO spacecraft.

Dissociative multiple photoionization of SiBr4 and GeBr4 in the VUV and X-ray regions: a comparative study of inner-shell processes involving Si(2p, 2s), Ge(3d, 3p, 3s), and Br(3d, 3p, 3s)

International Nuclear Information System (INIS)

Boo, Bong Hyun; Saito, Norio

2003-01-01

Dissociative multiple photoionization of MBr 4 (M=Si, Ge) in the Si(2p, 2s), Ge(3d, 3s, 3p), and Br(3d, 3p, 3s) inner-shell regions has been studied by using time-of-flight (TOF) mass spectrometry coupled to synchrotron radiation in the ranges of 50∼944 eV for SiBr 4 and 50∼467 eV for GeBr 4 . Total photoion and photoion-photoion coincidence (PIPICO) yields have been measured as functions of the photon energy. Here, giant shape resonances have been observed beyond the thresholds of the 3d shells owing to the Br(3d 10 )→Br(3d 9 -f) excitation, showing the similar patterns for both of the systems. The ranges and the intensities of the shape resonances are found to be tremendously broad and enhanced, respectively, by the tetrahedral arrangement of the bromine ligands. In addition to the giant resonances, we have observed discrete features corresponding to the Br(3d), Si(2p), and Si(2s) in SiBr 4 and to the Br(3d), Ge(3p), and Ge(3s) in GeBr 4 . The dissociation processes of multiply charged parent ions have also been evaluated from the variations of photoelectron-photoion coincidence (PEPICO) and PIPICO yields with the photon energy. Over the entire energies examined, most efficient PIPICO channels involve Br + -Br + , Br + -MBr + , and M + -Br + (M=Si, Ge), the formation of which indicates that the total destruction of the molecules is a dominant process in the dissociative photoionization of the molecules

Pyrolysis studies of PP/PE/PS/PVC/HIPS-Br plastics mixed with PET and dehalogenation (Br, Cl) of the liquid products

Energy Technology Data Exchange (ETDEWEB)

Bhaskar, Thallada; Kaneko, Jun; Muto, Akinori; Sakata, Yusaku [Department of Applied Chemistry, Faculty of Engineering, Okayama University, 3-1-1 Tsushima Naka, 700-8530 Okayama (Japan); Jakab, Emma [Research Laboratory of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences, P.O. Box 17, H-1525 Budapest (Hungary); Matsui, Toshiki [Toda Kogyo Co. Ltd., Hiroshima 739-0652 (Japan); Uddin, Md. Azhar [Process Safety and Environment Protection Group, School of Engineering, The University of Newcastle, Callaghan, NSW 2308 (Australia)

2004-08-01

Pyrolysis of polypropylene (PP)/polyethylene (PE)/polystyrene (PS)/poly(vinyl chloride) (PVC)/high impact polystyrene with brominated flame retardant (HIPS-Br) plastics mixed with poly(ethylene terephthalate) (PET) was performed at 430C under atmospheric pressure using a semi-batch operation. The presence of PET in the pyrolysis mixture of PP/PE/PS/PVC/HIPS-Br affected significantly the formation of decomposition products and the decomposition behavior of the plastic mixture. We observed the following effects of PET on the pyrolysis of PP/PE/PS/PVC/HIPS-Br mixed plastics: (1) the yield of liquid product decreased and the formation of gaseous products increased; (2) a waxy residue was formed in addition to the solid carbon residue; (3) the formation of SbBr{sub 3} was not detected in liquid products; (4) the yield of chlorinated branched alkanes increased as well as vinyl bromide and ethyl bromide were formed. The use of calcium carbonate carbon composite (Ca-C) completely removed the chlorine and bromine content from the liquid products during PP/PE/PS/PVC/HIPS-Br pyrolysis, however in the presence of PET, the catalytic experiment (Ca-C, 8g) yielded liquid products containing 310ppm of Br and 20ppm of Cl. In addition, the Ca-C increased the yield of liquid products about 3-6wt.%, as well as enhanced the gaseous product evolution and decreased the yield of residue. The halogen free liquid hydrocarbons can be used as a feedstock in a refinery or as a fuel.

Synthesis and characterization of silver nanoparticle composite with poly(p-Br-phenylsilane).

Science.gov (United States)

Kim, Myoung-Hee; Lee, Jun; Mo, Soo-Yong; Woo, Hee-Gweon; Yang, Kap Seung; Kim, Bo-Hye; Lee, Byeong-Gweon; Sohn, Honglae

2012-05-01

The one-pot synthesis and characterization of silver nanoparticle-poly(p-Br-phenylsilane) composites have been carried out. The conversion of silver(+1) salt to stable silver(0) nanoparticles is promoted by poly(p-Br-phenylsilane), Br-PPS possessing both possible reactive Si-H bonds in the polymer backbone and C-Br bonds in the substituents. The composites were characterized using XRD, TEM, FE-SEM, and solid-state UV-vis analytical techniques. TEM and FE-SEM data show the formation of the composites where large number of silver nanoparticles (less than 30 nm of size) are well dispersed throughout the Br-PPS matrix. XRD patterns are consistent with that for fcc-typed silver. The elemental analysis for Br atom and the polymer solubility confirm that the cleavage of C-Br bond and the Si-Br dative bonding were not occurred appreciably at ambient temperature. Nonetheless, TGA data suggest that some sort of cross-linking was occurred at high temperature. The size and processability of such nanoparticles depend on the ratio of metal to Br-PPS. In the absence of Br-PPS, most of the silver particles undergo macroscopic aggregation, which indicates that the polysilane is necessary for stabilizing the silver nanoparticles.

Revised and extended analysis of Br IV

International Nuclear Information System (INIS)

Riyaz, A.; Rahimullah, K.; Tauheed, A.

2014-01-01

The spectrum of three-times ionized bromine Br IV has been studied in the 319–2350 Å wavelength region. The spectrum was recorded on a 3-m normal incidence vacuum spectrograph at the St. Francis Xavier University, Antigonish (Canada) and 6.65-m grazing incidence spectrograph at the Zeeman laboratory (Amsterdam). The light sources used were a triggered spark and sliding spark, respectively. The ground configuration of Br IV 3d 10 4s 2 4p 2 , the excited configurations 3d 10 4s4p 3 +3d 10 4s 2 4p (4d+5d+6d+5s+6s+7s) in the odd parity system and 3d 10 4s 2 4p (5p+4f+5f)+3d 10 4s4p 2 (4d+5s)+3d 10 4p 4 in the even parity system have been studied. Relativistic Hartree–Fock (HFR) and least squares fitted (LSF) parametric calculations were used to interpret the observed spectrum. 120 Levels of Br IV have now been established, 58 being new. Among 424 spectral lines, 277 are newly classified. The levels 4s4p 35 S 2 , 4s 2 4p4d 3 F 4 and 4p5p ( 3 P 0,1 , 3 D 1,2 , 3 S 1 ) are revised. We estimate the accuracy of our measured wavelength for sharp and unblended lines to be ±0.005 Å. The ionization limit is determined as 385,390±100 cm −1 (47.782±0.012 eV). -- Highlights: • The spectrum of Br was recorded on a 3-m spectrograph with triggered spark source. • Atomic transitions for Br IV were identified to established new energy levels. • CI calculations with relativistic corrections were made for theoretical predictions. • Weighted oscillator strength (gf) and transition probabilities (gA) were calculated. • Ionization potential of Br IV was determined experimentally

Formation of new halogenothiocarbonylsulfenyl halides, XC(S)SY, through photochemical matrix reactions starting from CS2 and a dihalogen molecule XY (XY=Cl2, Br2, or BrCl).

Science.gov (United States)

Tobón, Yeny A; Romano, Rosana M; Védova, Carlos O Della; Downs, Anthony J

2007-05-28

Isolation of a dihalogen molecule XY (XY=Cl2, Br2, or BrCl) with CS2 in a solid Ar matrix at about 15 K leads, by broad-band UV-vis photolysis (200BrC(S)Cl, BrCCl3, and :CBrCl, the following new molecules have also been identified as products of the various photoreactions: syn-ClC(S)SCl, anti-ClC(S)SCl, syn-BrC(S)SBr, anti-BrC(S)SBr, syn-ClC(S)SBr, anti-ClC(S)SBr, syn-BrC(S)SCl, anti-BrC(S)SCl, ClC(S)S*, BrCS*, and Br*...SCS. The IR spectra of these hitherto unknown species have been interpreted with reference to the predictions of ab initio (HF and MP2) and density functional theory (DFT) calculations. The results are analyzed in relation to the reaction pathways accessed by matrix photolysis.

White Ring; White ring

Energy Technology Data Exchange (ETDEWEB)

Aoki, H.; Yuzawa, H. [Nikken Sekkei Ltd., Osaka (Japan)

1998-01-05

White Ring is a citizen`s gymnasium used for figure skating and short track speed skating games of 18th Winter Olympic Games in 1998. White Ring is composed of a main-arena and a sub-arena. For the main-arena with an area 41mtimes66m, an ice link can be made by disengaging the potable floor and by flowing brine in the bridged polystyrene pipes embedded in the concrete floor. Due to the fortunate groundwater in this site, well water is used for the outside air treatment energy in 63% during heating and in 35% during cooling. Ammonia is used as a cooling medium for refrigerating facility. For the heating of audience area in the large space, heat load from the outside is reduced by enhancing the heat insulation performance of the roof of arena. The audience seats are locally heated using heaters. For the White Ring, high quality environment is realized for games through various functions of the large-scale roof of the large space. Success of the big event was expected. 15 figs., 4 tabs.

Token Ring Project

Directory of Open Access Journals (Sweden)

Adela Ionescu

2007-01-01

Full Text Available Ring topology is a simple configuration used to connect processes that communicate among themselves. A number of network standards such as token ring, token bus, and FDDI are based on the ring connectivity. This article will develop an implementation of a ring of processes that communicate among themselves via pipe links. The processes are nodes in the ring. Each process reads from its standard input and writes in its standard output. N-1 process redirects the its standard output to a standard input of the process through a pipe. When the ring-structure is designed, the project can be extended to simulate networks or to implement algorithms for mutual exclusion

High Defect Tolerance in Lead Halide Perovskite CsPbBr3.

Science.gov (United States)

Kang, Jun; Wang, Lin-Wang

2017-01-19

The formation energies and charge-transition levels of intrinsic point defects in lead halide perovskite CsPbBr 3 are studied from first-principles calculations. It is shown that the formation energy of dominant defect under Br-rich growth condition is much lower than that under moderate or Br-poor conditions. Thus avoiding the Br-rich condition can help to reduce the defect concentration. Interestingly, CsPbBr 3 is found to be highly defect-tolerant in terms of its electronic structure. Most of the intrinsic defects induce shallow transition levels. Only a few defects with high formation energies can create deep transition levels. Therefore, CsPbBr 3 can maintain its good electronic quality despite the presence of defects. Such defect tolerance feature can be attributed to the lacking of bonding-antibonding interaction between the conduction bands and valence bands.

Brändin nykytila ja kehityskohtien identifiointi : case: Yritys X

OpenAIRE

Leinonen, Joonas

2017-01-01

Tämän opinnäytetyön tavoitteena on selvittää Yritys X:n brändin nykytila sekä identifioida eli tunnistaa sen heikkoudet sekä ryhmät, joiden keskuudessa brändimielikuva on heikompi. Tarkoituksena on käytännössä tarjota yritykselle osuus brändistrategiasuunnitelmasta, jonka avulla se pystyy keskittämään brändinehostustoimenpiteensä tiettyihin asioihin ja ryhmiin. Opinnäytetyön tutkimus suoritettiin määrällisenä tutkimuksena, sillä tavoitteena oli saada selville suuren yleisön käsitys Yrity...

Single crystal growth and surface chemical stability of KPb2Br5

Science.gov (United States)

Atuchin, V. V.; Isaenko, L. I.; Kesler, V. G.; Tarasova, A. Yu.

2011-03-01

Single crystal of KPb2Br5 has been grown using the Bridgman technique. Initially the synthesis of stoichiometric KPb2Br5 compound was performed from high purity bromide salts. Electronic structure of KPb2Br5 has been determined with X-ray photoelectron spectroscopy for powdered sample fabricated by grinding in air. Drastic chemical interaction of KPb2Br5 with atmosphere has not been detected. Chemical bonding in potassium- and lead-containing bromides is considered using binding energy differences ΔK=(BE K 2p3/2-BE Br 3d) and ΔPb=(BE Pb 4f7/2-BE Br 3d), respectively, as representative parameters.

Semi-algebraic function rings and reflectors of partially ordered rings

CERN Document Server

Schwartz, Niels

1999-01-01

The book lays algebraic foundations for real geometry through a systematic investigation of partially ordered rings of semi-algebraic functions. Real spectra serve as primary geometric objects, the maps between them are determined by rings of functions associated with the spectra. The many different possible choices for these rings of functions are studied via reflections of partially ordered rings. Readers should feel comfortable using basic algebraic and categorical concepts. As motivational background some familiarity with real geometry will be helpful. The book aims at researchers and graduate students with an interest in real algebra and geometry, ordered algebraic structures, topology and rings of continuous functions.

PbBr3 Perovskite Crystals

KAUST Repository

Wei, Tzu-Chiao

2018-01-31

Researchers have recently revealed that hybrid lead halide perovskites exhibit ferroelectricity, which is often associated with other physical characteristics, such as a large nonlinear optical response. In this work, the nonlinear optical properties of single crystal inorganic–organic hybrid perovskite CH3NH3PbBr3 are studied. By exciting the material with a 1044 nm laser, strong two-photon absorption-induced photoluminescence in the green spectral region is observed. Using the transmission open-aperture Z-scan technique, the values of the two-photon absorption coefficient are observed to be 8.5 cm GW−1, which is much higher than that of standard two-photon absorbing materials that are industrially used in nonlinear optical applications, such as lithium niobate (LiNbO3), LiTaO3, KTiOPO4, and KH2PO4. Such a strong two-photon absorption effect in CH3NH3PbBr3 can be used to modulate the spectral and spatial profiles of laser pulses, as well as to reduce noise, and can be used to strongly control the intensity of incident light. In this study, the superior optical limiting, pulse reshaping, and stabilization properties of CH3NH3PbBr3 are demonstrated, opening new applications for perovskites in nonlinear optics.

Predecommissioning radiological survey of BR3 infrastructures

International Nuclear Information System (INIS)

Cantrel, E.

2006-01-01

The decommissioning of the BR3 (Belgian Reactor 3) approaches its final phase, in which the buildings infrastructures are being decontaminated targeting either the reuse or the conventional demolition after denuclearisation. In a PWR with a significant operation lifetime, such as the BR3, maintenance operations, failure and/or leakages, incidents occurring in the different circuits of the plant result in the contamination of the buildings infrastructures at various activity levels with contaminants penetrating/migrating up to several cm inside the material bulk structure. Moreover, the BR3 bioshield has been exposed to rather high neutron leakage fluxes during the reactor operation and is therefore activated. The different radiological situations faced require the implementation of different characterization methodologies based on the use of an adequate combination of measurement devices and/or sampling devices. The non-destructive assay of activation depth using the ISOCS (In Situ Object Counting System) and a specific spectra analysis protocol has been tested in 2004. The first results obtained were encouraging and the qualification program for activated material is running. We are now investigating the possibilities to extend the methodology to building materials contaminated in-depth with 137 Cs. The overall process of dismantling/denuclearization of the BR3 building infrastructure consists of: (1) a preliminary characterization and determination of the contamination or activation depth; (2) the determination of the decontamination method; (3) the effective decontamination and clean up; (4) a possible intermediate characterization followed by an additional decontamination step; and (5) the characterization for clearance. The more accurate the preliminary survey is performed the less additional control/decontamination cycles are needed to reach clearance levels. The pre-decommissioning characterization process includes a preliminary categorisation (see picture

Measurement of BR(Bu to phi K)/BR(Bu to J/psi K) at the collider detector at Fermilab

Energy Technology Data Exchange (ETDEWEB)

Napora, Robert A. [Johns Hopkins Univ., Baltimore, MD (United States)

2004-01-01

This thesis presents evidence for the decay mode B^± → ΦK^± in p$\\bar{p}$ collisions at √s = 1.96 TeV using (120 ± 7)pb^-1 of data collected by the Collider Detector at Fermilab (CDF). This signal is then used to measure the branching ratio relative to the decay mode B^± → J/ΨK^±. The measurement starts from reconstructing the two decay modes: B^± → ΦK^±, where Φ → K⁺K^- and B^± → J/ΨK^±, where J/Ψ → μ⁺μ^-. The measurement yielded 23 ± 7 B^± → ΦK^± events, and 406 ± 26 B^± → J/ΨK^± events. The fraction of B^± → J/ΨK^± events where the J/Ψ subsequently decayed to two muons (as opposed to two electrons) was found to be f_μμ = 0.839 ± 0.066. The relative branching ratio of the two decays is then calculated based on the equation: BR(B^± → ΦK^±)/BR(B^± → J/ΨK^±) = N _ΦK/N_ΨK • f_μμ BR(J/Ψ → μ⁺μ^-)/BR(Φ → K⁺K^-) ϵ_μμK/ϵKKK R(ϵ_iso). The measurement finds BR(B^± → ΦK^±)/BR(B^± → J/ΨK^±) = 0.0068 ± 0.0021(stat.) ± 0.0007(syst.). The B^± → ΦK^± branching ratio is then found to be BR(B^± → ΦK^±) = [6.9 ± 2.1(stat.) ± 0.8(syst.)] x 10^-6. This value is consistent with similar measurements reported by the e⁺e^- collider experiments BaBar[1], Belle[2], and CLEO[3].

Rotating ring-ring electrode theory and experiment

NARCIS (Netherlands)

Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kellyb, J.J.

2000-01-01

A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

3-Benzyl-6-bromo-2-(2-furyl-3H-imidazo[4,5-b]pyridine

Directory of Open Access Journals (Sweden)

Younès Ouzidan

2010-07-01

Full Text Available In the title molecule, C17H12BrN3O, the imidazopyridine ring system is almost coplanar with the furan ring [dihedral angle = 2.0 (3°]. The benzyl phenyl ring is oriented at dihedral angles of 85.2 (2 and 85.5 (1°, respectively, with respect to the furan ring and the imidazopyridine ring system. In the crystal, molecules are linked into chains propagating along the b axis by C—H...N hydrogen bonds. Adjacent chains are linked via short Br...Br contacts [3.493 (1 Å].

Inhibition of hydrogen oxidation by HBr and Br₂

DEFF Research Database (Denmark)

Dixon-Lewis, Graham; Marshall, Paul; Ruscic, Branko

2012-01-01

O. Ab initio calculations were used to obtain rate coefficients for selected reactions of HBr and HOBr, and the hydrogen/bromine/oxygen reaction mechanism was updated. The resulting model was validated against selected experimental data from the literature and used to analyze the effect of HBr and Br2......The high-temperature bromine chemistry was updated and the inhibition mechanisms involving HBr and Br2 were re-examined. The thermochemistry of the bromine species was obtained using the Active Thermochemical Tables (ATcT) approach, resulting in improved data for, among others, Br, HBr, HOBr and Br...... on laminar, premixed hydrogen flames. Our work shows that hydrogen bromide and molecular bromine act differently as inhibitors in flames. For HBr, the reaction HBr+H⇌H2+Br (R2) is rapidly equilibrated, depleting HBr in favor of atomic Br, which is the major bromine species throughout the reaction zone...

Topological ring currents in the "empty" ring of benzo-annelated perylenes.

Science.gov (United States)

Dickens, Timothy K; Mallion, Roger B

2011-01-27

Cyclic conjugation in benzo-annelated perylenes is examined by means of the topological π-electron ring currents calculated for each of their constituent rings, in a study that is an exact analogy of a recent investigation by Gutman et al. based on energy-effect values for the corresponding rings in each of these structures. "Classical" approaches, such as Kekulé structures, Clar "sextet" formulas, and circuits of conjugation, predict that the central ring in perylene is "empty" and thus contributes negligibly to cyclic conjugation. However, conclusions from the present calculations of topological ring currents agree remarkably with those arising from the earlier study involving energy-effect values in that, contrary to what would be predicted from the classical approaches, rings annelated in an angular fashion relative to the central ring of these perylene structures materially increase the extent of that ring's involvement in cyclic conjugation. It is suggested that such close quantitative agreement between the predictions of these two superficially very different indices (energy effect and topological ring current) might be due to the fact that, ultimately, both depend, albeit in ostensibly quite different ways, only on an adjacency matrix that contains information about the carbon-carbon connectivity of the conjugated system in question.

Picosecond Water Radiolysis at High Temperature. Br- Oxidation - Experiments and MC-Simulations

International Nuclear Information System (INIS)

Baldacchino, G.; Saffre, D.; Jeunesse, J.P.; Schmidhammer, U.; Larbre, J.P.; Mostafavi, M.; Beuve, M.; Gervais, B.

2012-09-01

Acidic solutions of bromhydric acid have been irradiated by picosecond pulses of 7 MeV-electrons provided by ELYSE accelerator (LCP Orsay). At elevated temperatures up to 350 deg. C, salts like NaBr or KBr usually precipitate and organic compound are decomposed. Another choice of OH-scavenger may be acidic halogenates like HBr or HCl. In this situation, the processes involving H + and Br - must be considerate: while hydrated electrons are scavenged by H + , . OH reacts with Br - . Then the formations of BrOH . and Br 2 .- have been investigated by using a devoted picosecond pump-probe setup. A dedicated small-size high temperature optical flow cell has been developed for fitting the picosecond duration of the electron pulses. This cell replaces the one used also with nanosecond resolution. The picosecond time resolution remains roughly not affected by the material crossed by electrons (0.4 mm of Inconel 718) and by the white light continuum (20 mm of Sapphire windows and 6 mm of liquid solution). Depending on the concentration of HBr, the growing up of the signal can be attributed to mainly BrOH . or Br2 .- . Actually with a relatively low scavenging power ([HBr] = 25 mM), Br 2 .- is formed with a reaction between Br . and Br - which delays of around 4 ns the apparition of Br2 .- . In this particular case we then assume the absorbance is due to BrOH . . With higher and higher temperature, from 100 deg. C to 300 deg. C, the rate constant of this formation is lightly less and less. This observation must be associated to the fact that the formation of BrOH . is actually equilibrium with a lower and lower equilibrium constant value when temperature is increased. This presentation tries to explain this fact in detail by also considering Monte Carlo simulations. This will allows following all transient species from ps to μs. (authors)

An additional role for the Brønsted acid-base catalysts of mandelate racemase in transition state stabilization.

Science.gov (United States)

Nagar, Mitesh; Bearne, Stephen L

2015-11-10

Mandelate racemase (MR) catalyzes the interconversion of the enantiomers of mandelate and serves as a paradigm for understanding the enzyme-catalyzed abstraction of an α-proton from a carbon acid substrate with a high pKa. The enzyme utilizes a two-base mechanism with Lys 166 and His 297 acting as Brønsted acid and base catalysts, respectively, in the R → S reaction direction. In the S → R reaction direction, their roles are reversed. Using isothermal titration calorimetry (ITC), MR is shown to bind the intermediate/transition state (TS) analogue inhibitor benzohydroxamate (BzH) in an entropy-driven process with a value of ΔCp equal to -358 ± 3 cal mol(-1) K(-1), consistent with an increased number of hydrophobic interactions. However, MR binds BzH with an affinity that is ∼2 orders of magnitude greater than that predicted solely on the basis of hydrophobic interactions [St. Maurice, M., and Bearne, S. L. (2004) Biochemistry 43, 2524], suggesting that additional specific interactions contribute to binding. To test the hypothesis that cation-π/NH-π interactions between the side chains of Lys 166 and His 297 and the aromatic ring and/or the hydroxamate/hydroximate moiety of BzH contribute to the binding of BzH, site-directed mutagenesis was used to generate the MR variants K166M, K166C, H297N, and K166M/H297N and their binding affinity for various ligands determined using ITC. Comparison of the binding affinities of these MR variants with the intermediate/TS analogues BzH and cyclohexanecarbohydroxamate revealed that cation-π/NH-π interactions between His 297 and the hydroxamate/hydroximate moiety and the phenyl ring of BzH contribute approximately 0.26 and 0.91 kcal/mol to binding, respectively, while interactions with Lys 166 contribute approximately 1.74 and 1.74 kcal/mol, respectively. Similarly, comparison of the binding affinities of these mutants with substrate analogues revealed that Lys 166 contributes >2.93 kcal/mol to the binding of (R

Determination of essential trace elements in diets from pre-school children; Determinacao de elementos traco essenciais em dietas de criancas de idade pre-escolar

Energy Technology Data Exchange (ETDEWEB)

Maihara, Vera Akiko; San Miguel, Americo T.; Vasconcellos, Marina Beatriz A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

1995-12-31

The contents of Br, Ca, Cl, Co, Cr, Cs, Fe, K, Mn, Na, Rb, Se and Zn in the 19 diet samples taken from pre-school children were determined by neutron activation analysis. The diet samples were collected by duplicate portion method. The daily intake values obtained were compared with the RDA (Recommended Dietary Allowance) values. The precision and accuracy were evaluated by analyzing two biological reference materials. (author). 7 refs., 4 tabs.

Electronic structure of the CsPbBr3/polytriarylamine (PTAA) system

Science.gov (United States)

Endres, James; Kulbak, Michael; Zhao, Lianfeng; Rand, Barry P.; Cahen, David; Hodes, Gary; Kahn, Antoine

2017-01-01

The inorganic lead halide perovskite CsPbBr3 promises similar solar cell efficiency to its hybrid organic-inorganic counterpart CH3NH3PbBr3 but shows greater stability. Here, we exploit this stability for the study of band alignment between perovskites and carrier selective interlayers. Using ultraviolet, X-ray, and inverse photoemission spectroscopies, we measure the ionization energy and electron affinities of CsPbBr3 and the hole transport polymer polytriarylamine (PTAA). We find that undoped PTAA introduces a barrier to hole extraction of 0.2-0.5 eV, due to band bending in the PTAA and/or a dipole at the interface. p-doping the PTAA eliminates this barrier, raising PTAA's highest occupied molecular orbital to 0.2 eV above the CsPbBr3 valence band maximum and improving hole transport. However, IPES reveals the presence of states below the PTAA lowest unoccupied molecular level. If present at the CsPbBr3/PTAA interface, these states may limit the polymer's efficacy at blocking electrons in solar cells with wide band gap materials like CsPbBr3 and CH3NH3PbBr3.

Kayser-Fleischer Rings

Science.gov (United States)

... Support Contacts Lab Tracker/Copper Calculator Stories Programs & Research ... About Everything you need to know about Wilson Disease Kayser-Fleischer Rings Definition Kayser-Fleischer Ring: Clinical sign. Brownish-yellow ring visible around the corneo- ...

Br2 induced oxidative pore modification of a porous coordination network.

Science.gov (United States)

Ohtsu, Hiroyoshi; Kawano, Masaki

2016-01-14

Iodinated pores of a Zn-based coordination network were modified by Br2 oxidation to produce brominated pores in a polycrystalline-to-polycrystalline manner while maintaining the same network topology. Ab initio X-ray powder diffraction analysis and Raman spectroscopy revealed that the brominated pore can trap Br2 or I2 by strong σ/π-type interactions. A kinetic study in solution revealed that the pore modification by Br2 oxidation is much faster than the Br2 encapsulation process.

Planetary Rings

Science.gov (United States)

Nicholson, P. D.

2001-11-01

A revolution in the studies in planetary rings studies occurred in the period 1977--1981, with the serendipitous discovery of the narrow, dark rings of Uranus, the first Voyager images of the tenuous jovian ring system, and the many spectacular images returned during the twin Voyager flybys of Saturn. In subsequent years, ground-based stellar occultations, HST observations, and the Voyager flybys of Uranus (1986) and Neptune (1989), as well as a handful of Galileo images, provided much additional information. Along with the completely unsuspected wealth of detail these observations revealed came an unwelcome problem: are the rings ancient or are we privileged to live at a special time in history? The answer to this still-vexing question may lie in the complex gravitational interactions recent studies have revealed between the rings and their retinues of attendant satellites. Among the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto parent bodies. Perhaps most puzzling is Saturn's multi-stranded, clumpy F ring, which continues to defy a simple explanation 20 years after it was first glimpsed in grainy images taken by Pioneer 11. Voyager and HST images reveal a complex, probably chaotic, dynamical interaction between unseen parent bodies within this ring and its two shepherd satellites, Pandora and Prometheus. The work described here reflects contributions by Joe Burns, Jeff Cuzzi, Luke Dones, Dick French, Peter Goldreich, Colleen McGhee, Carolyn Porco, Mark Showalter, and Bruno Sicardy, as well as those of the author. This research has been supported by NASA's Planetary Geology and Geophysics program and the

Polymorphism in 2-X-adamantane derivatives (X = Cl, Br).

Science.gov (United States)

Negrier, Philippe; Barrio, María; Tamarit, Josep Ll; Mondieig, Denise

2014-08-14

The polymorphism of two 2-X-adamantane derivatives, X = Cl, X = Br, has been studied by X-ray powder diffraction and normal- and high-pressure (up to 300 MPa) differential scanning calorimetry. 2-Br-adamantane displays a low-temperature orthorhombic phase (space group P212121, Z = 4) and a high-temperature plastic phase (Fm3̅m, Z = 4) from 277.9 ± 1.0 K to the melting point at 413.4 ± 1.0 K. 2-Cl-adamantane presents a richer polymorphic behavior through the temperature range studied. At low temperature it displays a triclinic phase (P1̅, Z = 2), which transforms to a monoclinic phase (C2/c, Z = 8) at 224.4 ± 1.0 K, both phases being ordered. Two high-temperature orientationally disordered are found for this compound, one hexagonal (P63/mcm, Z = 6) at ca. 241 K and the highest one, cubic (Fm3̅m, Z = 4), being stable from 244 ± 1.0 K up to the melting point at 467.5 ± 1.0 K. No additional phase appears due to the increase in pressure within the studied range. The intermolecular interactions are found to be weak, especially for the 2-Br-adamantane compound for which the Br···Br as well as C-Br···H distances are larger than the addition of the van der Waals radii, thus confirming the availability of this compound for building up diamondoid blocks.

CeBr3 as a room-temperature, high-resolution gamma-ray detector

International Nuclear Information System (INIS)

Guss, Paul; Reed, Michael; Yuan Ding; Reed, Alexis; Mukhopadhyay, Sanjoy

2009-01-01

Cerium bromide (CeBr 3 ) has become a material of interest in the race for high-resolution gamma-ray spectroscopy at room temperature. This investigation quantified the potential of CeBr 3 as a room-temperature, high-resolution gamma-ray detector. The performance of CeBr 3 crystals was compared to other scintillation crystals of similar dimensions and detection environments. Comparison of self-activity of CeBr 3 to cerium-doped lanthanum tribromide (LaBr 3 :Ce) was performed. Energy resolution and relative intrinsic efficiency were measured and are presented.

Identification of Yellow Pigmentation Genes in Brassica rapa ssp. pekinensis Using Br300 Microarray

Directory of Open Access Journals (Sweden)

Hee-Jeong Jung

2014-01-01

Full Text Available The yellow color of inner leaves in Chinese cabbage depends on its lutein and carotene content. To identify responsible genes for yellow pigmentation in leaves, the transcriptome profiles of white (Kenshin and yellow leaves (Wheessen were examined using the Br300K oligomeric chip in Chinese cabbage. In yellow leaves, genes involved in carotene synthesis (BrPSY, BrPDS, BrCRTISO, and BrLCYE, lutein, and zeaxanthin synthesis (BrCYP97A3 and BrHYDB were upregulated, while those associated with carotene degradation (BrNCED3, BrNCED4, and BrNCED6 were downregulated. These expression patterns might support that the content of both lutein and total carotenoid was much higher in the yellow leaves than that in the white leaves. These results indicate that the yellow leaves accumulate high levels of both lutein and β-carotene due to stimulation of synthesis and that the degradation rate is inhibited. A large number of responsible genes as novel genes were specifically expressed in yellow inner leaves, suggesting the possible involvement in pigment synthesis. Finally, we identified three transcription factors (BrA20/AN1-like, BrBIM1, and BrZFP8 that are specifically expressed and confirmed their relatedness in carotenoid synthesis from Arabidopsis plants.

Reactor BR2. Introduction

International Nuclear Information System (INIS)

Gubel, P.

2002-01-01

The BR2 materials testing reactor is one of SCK-CEN's most important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. In 2001, the reactor was operated for a total of 123 days at a mean power of 59 MW in order to satisfy the irradiation conditions of the internal and external programmes using mainly the CALLISTO PWR loop. The mean consumption of fresh fuel elements was 5.26 per 1000 MWd. Main achievements in 2001 included the development of a three-dimensional full-scale model of the BR2 reactor for simulation and prediction of irradiation conditions for various experiments; the construction of the FUTURE-MT device designed for the irradiation of fuel plates under representative conditions of geometry, neutron spectrum, heat flux and thermal-hydraulic conditions and the development of in-pile instrumentation and a data acquisition system

Reactor BR2. Introduction

Energy Technology Data Exchange (ETDEWEB)

Gubel, P

2002-04-01

The BR2 materials testing reactor is one of SCK-CEN's most important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. In 2001, the reactor was operated for a total of 123 days at a mean power of 59 MW in order to satisfy the irradiation conditions of the internal and external programmes using mainly the CALLISTO PWR loop. The mean consumption of fresh fuel elements was 5.26 per 1000 MWd. Main achievements in 2001 included the development of a three-dimensional full-scale model of the BR2 reactor for simulation and prediction of irradiation conditions for various experiments; the construction of the FUTURE-MT device designed for the irradiation of fuel plates under representative conditions of geometry, neutron spectrum, heat flux and thermal-hydraulic conditions and the development of in-pile instrumentation and a data acquisition system.

Aagesta-BR3 Decommissioning Cost. Comparison and Benchmarking Analysis

International Nuclear Information System (INIS)

Varley, Geoff

2002-11-01

This report presents the results of decommissioning cost analyses focusing on discrete working packages within the decommissioning program of the BR3 reactor in Mol, Belgium and comparison of them with cost estimate data for the Aagesta research reactor in Sweden. The specific BR3 work packages analysed were: Primary coolant piping decontamination; Primary coolant piping dismantling; Vulcain reactor internals dismantling; Westinghouse reactor internals dismantling; Reactor vessel dismantling. The main conclusions to be drawn from the analyses are that: The fixed costs related to decontamination and dismantling activities generally are a very important part of the overall resources needed to execute the work, with the Reactor Pressure Vessel (RPV) seemingly being significantly more demanding than other major components. Cutting activities tend to need something like 150 to 200 labour hours per m 2 of reactor equipment dismantled. Fixed investment costs to set up the equipment needed to cut up major vessels or internals appear to be in the range of MSEK 4 to 8. Consumables costs vary according to the nature of the equipment being dismantled. The thicker the metal being cut, the higher the attrition rate for things such as cutting blades. The range of consumables costs at BR3 have been in the range of MSEK 0.1 to 0.2/m 2 dismantled. The extent of detailed information available in the 1996 Aagesta estimate is not sufficient to enable a full comparison with the BR3 decommissioning results. A global first comparison has been attempted by summing the resources expended on the BR3 work packages described in this report with the combined dismantling data presented in the 1996 Aagesta cost estimate report. Very broadly the cost of decontamination plus dismantling of the main process equipment at Aagesta appears to be in the order of MSEK 70, of which MSEK 4 is labour on preparatory/planning work, MSEK 40 is labour on actual decontamination and dismantling and MSEK 25 is

Structure and bonding of transition metal-boryl compounds. Theoretical study of [(PH3)2(CO)ClOs-BR2] and [(PH3)2(CO)2ClOs-BR2] (BR2 = BH2, BF2, B(OH)2, B(OCH=CHO), Bcat).

Science.gov (United States)

Giju, K T; Bickelhaupt, F M; Frenking, G

2000-10-16

Quantum chemical DFT calculations using the B3LYP functionals have been carried out for the electronically unsaturated 16 VE five-coordinate osmium boryl-complexes [(PH3)2(CO)ClOs-BR2] and the 18 VE six-coordinate complexes [(PH3)2(CO)2ClOs-BR2] with BR2 = BH2, BF2, B(OH)2, B(OHC=CHO), and Bcat (cat = catecholate O2C6H4). The bonding situation of the Os-BR2 bond was analyzed with the help of the NBO partitioning scheme. The Os-B bond dissociation energies of the 16 VE complexes are very high, and they do not change very much for the different boryl ligands. The 18 VE complexes have only slightly lower bond energies than the 16 VE species. The Os-B bond in both classes of compounds is provided by a covalent sigma-bond which is polarized toward osmium and by strong charge attraction. Os-->B pi-donation is not important for the Os-B binding interactions, except for the Os-BH2 complexes. The stability of the boryl complexes [Os]-BR2 comes mainly from BB pi-donation. The intraligand charge distribution of the BR2 group changes little when the Os-B bond is formed, except for BH2. The CO ligand in [(PH3)2(CO)2ClOs-BR2] which is trans to BR2 has a relatively weak bond to the osmium atom.

Magnetic diagnostic plasma position in the TCA/BR tokamak

International Nuclear Information System (INIS)

Galvao, R.M.O.; Kuznetsov, Yu.K.; Nascimento, I.C.

1996-01-01

The cross-section of the plasma column is TCA/BR has a nearly circular plasma shape. This allows implementation of simplified methods of magnetic diagnostics. Although these methods were in may tokamaks and are well described, their accuracies are not clearly defined because the very simplified theoretical model of plasma equilibrium on which they are based differs from the real conditions in tokamaks like TCA/BR. In this paper we present the methods of plasma position diagnostics in TCA/BR from external magnetic measurements with an error analysis. (author). 4 refs., 3 figs

Preparation for electron ring - plasma ring merging experiments in RECE-MERGE

International Nuclear Information System (INIS)

Taggart, D.; Sekiguchi, A.; Fleischmann, H.H.

1986-01-01

The formation of a mixed-CT using relativistic electron rings and gun-produced plasma rings by MERGE-ing them axially is simulated. This process is similar to the axial stacking of relativistic electron rings in RECE-Christa. The results of their first plasm production experiment are reported here. After study of the gun-produced plasma's properties is completed, the gun will be mounted at the downstream end of the vacuum tank and the source of relativistic electron rings will be at the upstream end. The two rings, formed at opposite ends of the tank, will be translated axially and merged

A chiral analog of the bicyclic guanidine TBD: synthesis, structure and Brønsted base catalysis

Directory of Open Access Journals (Sweden)

Mariano Goldberg

2016-08-01

Full Text Available Starting from (S-β-phenylalanine, easily accessible by lipase-catalyzed kinetic resolution, a chiral triamine was assembled by a reductive amination and finally cyclized to form the title compound 10. In the crystals of the guanidinium benzoate salt the six membered rings of 10 adopt conformations close to an envelope with the phenyl substituents in pseudo-axial positions. The unprotonated guanidine 10 catalyzes Diels–Alder reactions of anthrones and maleimides (25–30% ee. It also promotes as a strong Brønsted base the retro-aldol reaction of some cycloadducts with kinetic resolution of the enantiomers. In three cases, the retro-aldol products (48–83% ee could be recrystallized to high enantiopurity (≥95% ee. The absolute configuration of several compounds is supported by anomalous X-ray diffraction and by chemical correlation.

Does switching contraceptive from oral to a patch or vaginal ring change the likelihood of timely prescription refill?

Science.gov (United States)

Law, Amy; Lee, Yi-Chien; Gorritz, Magdaliz; Plouffe, Leo

2014-08-01

This study evaluated contraceptive refill patterns of women insured commercially in the US who switched from oral contraceptives (OCs) to the patch or vaginal ring and assessed if switching contraceptive methods changes refill patterns. Women aged 15-44 with ≥2 patch or ring prescriptions and ≥2 OC prescriptions before the first patch/ring prescription were identified from the MarketScan® Commercial database (1/1/2002-6/30/2011). Refill patterns 1-year pre- and postindex date (first patch/ring prescription) were evaluated, and women were categorized as timely or delayed refillers on OCs and patch/ring. Regression modeling was used to investigate the association between refill patterns and contraceptive methods and switching effects on refill patterns. Of 17,814 women identified, 7901 switched to the patch, and 9913 switched to the ring. Among timely OC refillers, the percentage of timely refills decreased (patch: 95.6% to 79.4%, pcontraceptive efficacy by simply switching to the patch or ring. The impact on timely refills of switching from OCs to either the patch or ring is complex and varies depending on the pattern of timely refills on OCs. Copyright © 2014 Elsevier Inc. All rights reserved.

Global observations of tropospheric BrO columns using GOME-2 satellite data

Science.gov (United States)

Theys, N.; van Roozendael, M.; Hendrick, F.; Yang, X.; de Smedt, I.; Richter, A.; Begoin, M.; Errera, Q.; Johnston, P. V.; Kreher, K.; de Mazière, M.

2011-02-01

Measurements from the GOME-2 satellite instrument have been analyzed for tropospheric BrO using a residual technique that combines measured BrO columns and estimates of the stratospheric BrO content from a climatological approach driven by O3 and NO2 observations. Comparisons between the GOME-2 results and BrO vertical columns derived from correlative ground-based and SCIAMACHY nadir observations, present a good level of consistency. We show that the adopted technique enables separation of stratospheric and tropospheric fractions of the measured total BrO columns and allows quantitative study of the BrO plumes in polar regions. While some satellite observed plumes of enhanced BrO can be explained by stratospheric descending air, we show that most BrO hotspots are of tropospheric origin, although they are often associated to regions with low tropopause heights as well. Elaborating on simulations using the p-TOMCAT tropospheric chemical transport model, this result is found to be consistent with the mechanism of bromine release through sea salt aerosols production during blowing snow events. No definitive conclusion can be drawn however on the importance of blowing snow sources in comparison to other bromine release mechanisms. Outside polar regions, evidence is provided for a global tropospheric BrO background with column of 1-3 × 1013 molec cm-2, consistent with previous estimates.

Aagesta-BR3 Decommissioning Cost. Comparison and Benchmarking Analysis

Energy Technology Data Exchange (ETDEWEB)

Varley, Geoff [NAC International, Henley on Thames (United Kingdom)

2002-11-01

This report presents the results of decommissioning cost analyses focusing on discrete working packages within the decommissioning program of the BR3 reactor in Mol, Belgium and comparison of them with cost estimate data for the Aagesta research reactor in Sweden. The specific BR3 work packages analysed were: Primary coolant piping decontamination; Primary coolant piping dismantling; Vulcain reactor internals dismantling; Westinghouse reactor internals dismantling; Reactor vessel dismantling. The main conclusions to be drawn from the analyses are that: The fixed costs related to decontamination and dismantling activities generally are a very important part of the overall resources needed to execute the work, with the Reactor Pressure Vessel (RPV) seemingly being significantly more demanding than other major components. Cutting activities tend to need something like 150 to 200 labour hours per m{sup 2} of reactor equipment dismantled. Fixed investment costs to set up the equipment needed to cut up major vessels or internals appear to be in the range of MSEK 4 to 8. Consumables costs vary according to the nature of the equipment being dismantled. The thicker the metal being cut, the higher the attrition rate for things such as cutting blades. The range of consumables costs at BR3 have been in the range of MSEK 0.1 to 0.2/m{sup 2} dismantled. The extent of detailed information available in the 1996 Aagesta estimate is not sufficient to enable a full comparison with the BR3 decommissioning results. A global first comparison has been attempted by summing the resources expended on the BR3 work packages described in this report with the combined dismantling data presented in the 1996 Aagesta cost estimate report. Very broadly the cost of decontamination plus dismantling of the main process equipment at Aagesta appears to be in the order of MSEK 70, of which MSEK 4 is labour on preparatory/planning work, MSEK 40 is labour on actual decontamination and dismantling and MSEK

Physical adsorption and charge transfer of molecular Br2 on graphene.

Science.gov (United States)

Chen, Zheyuan; Darancet, Pierre; Wang, Lei; Crowther, Andrew C; Gao, Yuanda; Dean, Cory R; Taniguchi, Takashi; Watanabe, Kenji; Hone, James; Marianetti, Chris A; Brus, Louis E

2014-03-25

We present a detailed study of gaseous Br2 adsorption and charge transfer on graphene, combining in situ Raman spectroscopy and density functional theory (DFT). When graphene is encapsulated by hexagonal boron nitride (h-BN) layers on both sides, in a h-BN/graphene/h-BN sandwich structure, it is protected from doping by strongly oxidizing Br2. Graphene supported on only one side by h-BN shows strong hole doping by adsorbed Br2. Using Raman spectroscopy, we determine the graphene charge density as a function of pressure. DFT calculations reveal the variation in charge transfer per adsorbed molecule as a function of coverage. The molecular adsorption isotherm (coverage versus pressure) is obtained by combining Raman spectra with DFT calculations. The Fowler-Guggenheim isotherm fits better than the Langmuir isotherm. The fitting yields the adsorption equilibrium constant (∼0.31 Torr(-1)) and repulsive lateral interaction (∼20 meV) between adsorbed Br2 molecules. The Br2 molecule binding energy is ∼0.35 eV. We estimate that at monolayer coverage each Br2 molecule accepts 0.09 e- from single-layer graphene. If graphene is supported on SiO2 instead of h-BN, a threshold pressure is observed for diffusion of Br2 along the (somewhat rough) SiO2/graphene interface. At high pressure, graphene supported on SiO2 is doped by adsorbed Br2 on both sides.

Pulse radiolysis of LiBr-KBr melts. Optical transient absorption spectra

International Nuclear Information System (INIS)

Sawamura, S.; Gebicki, J.L.; Mayer, J.; Kroh, J.

1990-01-01

Absorption spectra of the irradiated melts of LiBr and LiBr-KBr mixtures were investigated in the temperature range 673-873 K by nanosecond pulse radiolysis. The visible band ascribed to e s - shows the apparent shift towards longer wavelengths with increasing temperature and increasing content of KBr in the mixture. The UV transient absorption was attributed to superimposed Br 2 - and Br 3 - bands. The relation between the transition energy of visible band and the inverse mean ion distance is given for alkali bromide and chloride systems. (author)

Global observations of BrO in the troposphere using GOME-2 satellite data

Science.gov (United States)

Theys, N.; van Roozendael, M.; Hendrick, F.; Xin, Y.; Isabelle, D.; Richter, A.; Mathias, B.; Quentin, E.; Johnston, P. V.; Kreher, K.; Martine, D.

2010-12-01

Measurements from the GOME-2 satellite instrument have been analyzed for tropospheric BrO using a residual technique that combines measured BrO columns and estimates of the stratospheric BrO content from a climatological approach driven by O3 and NO2 observations. Comparisons between the GOME-2 results and correlative data including ground-based BrO vertical columns and total BrO columns derived from SCIAMACHY nadir observations, present a good level of consistency. We show that the adopted technique enables to separate the stratospheric and tropospheric fractions of the measured total BrO columns and allows studying the BrO plumes in polar region in more detail. While several satellite BrO plumes can largely be explained by an influence of stratospheric descending air, we show that numerous tropospheric BrO hotspots are associated to regions with low tropopause heights as well. Elaborating on simulations using the p-TOMCAT tropospheric chemical transport model, this finding is found to be consistent with the mechanism of bromine release through sea salt aerosols production during blowing snow events. Outside the polar region, evidences are provided for a global tropospheric BrO background with columns of 1-3 x 1013 molec/cm2.

Structure determination of K2ZnBr4 at 291 and 144 K

International Nuclear Information System (INIS)

Fabry, J.; Breczewski, T.; Zuniga, F.J.; Arnaiz, A.R.

1993-01-01

The room-temperature phase of K 2 ZnBr 4 is isomorphous with Sr 2 GeS 4 (P2 1 /m) while the low-temperature structure (P2 1 ) is slightly distorted [the phase transition occurs at 155 K]. Both structures contain highly deformed tetrahedral [ZnBr 4 ] 2- molecules with Br(3)-Zn-Br(3') angles of 103.06(5) and 102.49(9) at 291 and 144 K, respectively. This distortion is caused by the repulsion of Br atoms whose distance 3.712(1) and 3.661(2) A at 291 and 144 K, respectively, is below the Br-Br van der Waals distance (3.9 A). The phase transition is accompanied by minor shifts of cations and [ZnBr 4 ] 2- tetrahedra which are simultaneously rotated about a small angle. Below the phase transition point an inversion twin develops whose twin-fraction parameter was refined to 0.459(65). (orig.)

Kan lignin omdannes til flydende brændstof?

DEFF Research Database (Denmark)

Nielsen, Joachim Bachmann; Jensen, Anders; Felby, Claus

2015-01-01

Ved en solvolytisk omdannelse af plantematerialet lignin til et flydende brændstof behandles det ved høj temperatur og højt tryk i et passende opløsningsmiddel. En sådan proces kan gennemføres ikke-katalytisk og være med til at skabe flydende brændsler baseret på vedvarende energikilder. Her...

Propiconazole is a specific and accessible brassinosteroid (BR) biosynthesis inhibitor for Arabidopsis and maize.

Science.gov (United States)

Hartwig, Thomas; Corvalan, Claudia; Best, Norman B; Budka, Joshua S; Zhu, Jia-Ying; Choe, Sunghwa; Schulz, Burkhard

2012-01-01

Brassinosteroids (BRs) are steroidal hormones that play pivotal roles during plant development. In addition to the characterization of BR deficient mutants, specific BR biosynthesis inhibitors played an essential role in the elucidation of BR function in plants. However, high costs and limited availability of common BR biosynthetic inhibitors constrain their key advantage as a species-independent tool to investigate BR function. We studied propiconazole (Pcz) as an alternative to the BR inhibitor brassinazole (Brz). Arabidopsis seedlings treated with Pcz phenocopied BR biosynthetic mutants. The steady state mRNA levels of BR, but not gibberellic acid (GA), regulated genes increased proportional to the concentrations of Pcz. Moreover, root inhibition and Pcz-induced expression of BR biosynthetic genes were rescued by 24epi-brassinolide, but not by GA(3) co-applications. Maize seedlings treated with Pcz showed impaired mesocotyl, coleoptile, and true leaf elongation. Interestingly, the genetic background strongly impacted the tissue specific sensitivity towards Pcz. Based on these findings we conclude that Pcz is a potent and specific inhibitor of BR biosynthesis and an alternative to Brz. The reduced cost and increased availability of Pcz, compared to Brz, opens new possibilities to study BR function in larger crop species.

Facile synthesis and characterization of CsPbBr3 and CsPb2Br5 ...

Indian Academy of Sciences (India)

2018-03-23

Mar 23, 2018 ... All-inorganic caesium lead-halide perovskite CsPbBr3 and ... optoelectronic materials owing to their stabilities and highly efficient photoluminescence (PL). ... chemical tenability [2], hybrid organic–inorganic lead halide-.

Thallium trinitrate-mediated ring contraction of 1,2-dihydronaphthalenes: the effect of electron-donating and electron-withdrawing groups

International Nuclear Information System (INIS)

Silva Junior, Luiz F.; Sousa, Raquel M.F.; Ferraz, Helena M.C.; Aguilar, Andrea M.

2005-01-01

The oxidation of a series of 1,2-dihydronaphthalenes substituted in the aromatic ring was investigated with thallium trinitrate (TTN) in methanol or in trimethylorthoformate (TMOF) as solvent. In all cases, indans are produced, although the yield varied from excellent to poor, depending on the structure of the substrate. The presence of an electron-donating group in the substrate favors the rearrangement, whereas significant amounts of glycolic derivatives, as well as naphthalenes, were obtained in the oxidation of 1,2-dihydronaphthalenes bearing electron-withdrawing groups, such as Br and NO 2 . Mechanisms for the formation of each of these products are proposed. (author)

Groups, rings, modules

CERN Document Server

Auslander, Maurice

2014-01-01

This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

Global observations of tropospheric BrO columns using GOME-2 satellite data

Directory of Open Access Journals (Sweden)

N. Theys

2011-02-01

Full Text Available Measurements from the GOME-2 satellite instrument have been analyzed for tropospheric BrO using a residual technique that combines measured BrO columns and estimates of the stratospheric BrO content from a climatological approach driven by O₃ and NO₂ observations. Comparisons between the GOME-2 results and BrO vertical columns derived from correlative ground-based and SCIAMACHY nadir observations, present a good level of consistency. We show that the adopted technique enables separation of stratospheric and tropospheric fractions of the measured total BrO columns and allows quantitative study of the BrO plumes in polar regions. While some satellite observed plumes of enhanced BrO can be explained by stratospheric descending air, we show that most BrO hotspots are of tropospheric origin, although they are often associated to regions with low tropopause heights as well. Elaborating on simulations using the p-TOMCAT tropospheric chemical transport model, this result is found to be consistent with the mechanism of bromine release through sea salt aerosols production during blowing snow events. No definitive conclusion can be drawn however on the importance of blowing snow sources in comparison to other bromine release mechanisms. Outside polar regions, evidence is provided for a global tropospheric BrO background with column of 1–3 × 10¹³ molec cm⁻², consistent with previous estimates.

Saturn's Rings Edge-on

Science.gov (United States)

1995-01-01

In one of nature's most dramatic examples of 'now-you see-them, now-you-don't', NASA's Hubble Space Telescope captured Saturn on May 22, 1995 as the planet's magnificent ring system turned edge-on. This ring-plane crossing occurs approximately every 15 years when the Earth passes through Saturn's ring plane.For comparison, the top picture was taken by Hubble on December 1, 1994 and shows the rings in a more familiar configuration for Earth observers.The bottom picture was taken shortly before the ring plane crossing. The rings do not disappear completely because the edge of the rings reflects sunlight. The dark band across the middle of Saturn is the shadow of the rings cast on the planet (the Sun is almost 3 degrees above the ring plane.) The bright stripe directly above the ring shadow is caused by sunlight reflected off the rings onto Saturn's atmosphere. Two of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are, from left to right, Tethys (slightly above the ring plane) and Dione.This observation will be used to determine the time of ring-plane crossing and the thickness of the main rings and to search for as yet undiscovered satellites. Knowledge of the exact time of ring-plane crossing will lead to an improved determination of the rate at which Saturn 'wobbles' about its axis (polar precession).Both pictures were taken with Hubble's Wide Field Planetary Camera 2. The top image was taken in visible light. Saturn's disk appears different in the bottom image because a narrowband filter (which only lets through light that is not absorbed by methane gas in Saturn's atmosphere) was used to reduce the bright glare of the planet. Though Saturn is approximately 900 million miles away, Hubble can see details as small as 450 miles across.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and

Simple radiosensitizing of hypoxic tumor tissues by N2O/Br(-) mixture.

Science.gov (United States)

Billik, P

2015-07-01

The radiosensitization model of hypoxic tumor tissues based on the N2O/Br(-) mixture is described. The well-documented radiolysis of water in the presence of N2O and Br(-) ions at a low concentration supports this model. An aqueous solution saturated with N2O gas during the radiolysis generates OH radicals in a large extent. In N2O/Br- media at pHBr2 is formed. Br2 hydrolyzes in an aqueous solution to form a very reactive hypobromous (HOBr) acid. Such process is described by the following chemical reaction: H2O + Br(-) + N2O + ionizing radiation (IR) --> HOBr + OH(-). In vivo formed HOBr as a long-lived product with a high biological activity induces the hypoxic tumor cell damage via many unique mechanisms. A local application or inhalation of an N2O-O2 mixture before or during the radiotherapy to enhance the saturation of tissues with N2O is a key prerequisite. Since the extracellular concentration of Br(-) ions is very low (0.02-0.05 mM), an oral or local application of NaBr should be used to shift the extracellular concentration of Br(-) ions to the mM region. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bromide (Br)--Based Synthesis of Ag Nanocubes with High-Yield.

Science.gov (United States)

Wu, Fan; Wang, Wenhui; Xu, Zhongfeng; Li, Fuli

2015-06-09

The geometry of metal nanoparticles greatly affects the properties of the localized surface plasmon resonance and surface-enhanced Raman scattering. The synthesis of metal nanoparticles with controllable geometry has thus attracted extensive attentions. In this work, we report a modified polyol synthesis approach of silver (Ag) nanocubes through tuning the concentration of bromide ions (Br(-) ions). We have systematically investigated the effect of Br(-) ions in the polyol process, and find that higher concentration of Br(-) ions can enhance oxidative etching effect, which is the dominative factor in determining nanostructure geometry. Therefore, one can realize control over nanostructure geometry by manipulating the concentration of Br(-) ions. Our work provides an effective approach to control the shape of metallic nanostructures for potential applications.

Steering dissociation of Br2 molecules with two femtosecond pulses via wave packet interference.

Science.gov (United States)

Han, Yong-Chang; Yuan, Kai-Jun; Hu, Wen-Hui; Yan, Tian-Min; Cong, Shu-Lin

2008-04-07

The dissociation dynamics of Br2 molecules induced by two femtosecond pump pulses are studied based on the calculation of time-dependent quantum wave packet. Perpendicular transition from X 1Sigma g+ to A 3Pi 1u+ and 1Pi 1u+ and parallel transition from X 1Sigma g+ to B 3Pi 0u+, involving two product channels Br (2P3/2)+Br (2P3/2) and Br (2P3/2)+Br* (2P1/2), respectively, are taken into account. Two pump pulses create dissociating wave packets interfering with each other. By varying laser parameters, the interference of dissociating wave packets can be controlled, and the dissociation probabilities of Br2 molecules on the three excited states can be changed to different degrees. The branching ratio of Br*/(Br+Br*) is calculated as a function of pulse delay time and phase difference.

The Rotating Ring-Ring Electrode. Theory and Experiment

NARCIS (Netherlands)

Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kelly, J.J.

2000-01-01

A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

The so-called "Pre-Levantine" phase and the chronology of the Levantine Rock Painting. A critical review

Directory of Open Access Journals (Sweden)

Mateo Saura, Miguel Ángel

2002-06-01

Full Text Available The rejection of the principles on which the so-called "prelevantine phase" is based and the discussion about the neolithic material culture parallels for levantine art allow its attribution to Epipaleolithic groups of hunters and gatherers. In the same way, the data on the process of transition between the Epipaleolithic and the Neolithic, and the relationship between the levantine style and the schematic rock painting seem to support a pre-neolithic chronology of the levantine art, related to non-producing ways of living.<br>>El rechazo de las bases en las que se sustenta la llamada "fase pre-levantina" y la discusión de los paralelos mobiliares neolíticos propuestos para el arte levantino dejan expedito el camino para su adscripción a los grupos de cazadores y recolectores epipaleolíticos. Asimismo, los datos con que contamos sobre el proceso de transición Epipaleolítico/Neolítico, y la relación entre el estilo levantino y la pintura rupestre esquemática parecen abogar también por una cronología pre-neolítica de lo levantino, asociado a unos modos de vida no productores.

Facile synthesis of CsPbBr3/PbSe composite clusters

OpenAIRE

Nguyen, Thang Phan; Ozturk, Abdullah; Park, Jongee; Sohn, Woonbae; Lee, Tae Hyung; Jang, Ho Won; Kim, Soo Young

2017-01-01

Abstract In this work, CsPbBr3 and PbSe nanocomposites were synthesized to protect perovskite material from self-enlargement during reaction. UV absorption and photoluminescence (PL) spectra indicate that the addition of Se into CsPbBr3 quantum dots modified the electronic structure of CsPbBr3, increasing the band gap from 2.38 to 2.48 eV as the Cs:Se ratio increased to 1:3. Thus, the emission color of CsPbBr3 perovskite quantum dots was modified from green to blue by increasing the Se ratio ...

Influence of LiBr on photoluminescence properties of porous silicon

Energy Technology Data Exchange (ETDEWEB)

Dimassi, W., E-mail: dimassi_inrst@yahoo.f [Laboratoire de Photovoltaique, Centre de Recherches et des Technologies de l' Energie, Technopole de Borj-Cedria, BP 95 Hammam-Lif 2050 (Tunisia); Haddadi, I.; Bousbih, R.; Slama, S.; Ali Kanzari, M.; Bouaicha, M.; Ezzaouia, H. [Laboratoire de Photovoltaique, Centre de Recherches et des Technologies de l' Energie, Technopole de Borj-Cedria, BP 95 Hammam-Lif 2050 (Tunisia)

2011-05-15

A new method has been developed to improve the photoluminescence intensity of porous silicon (PS), which is first time that LiBr is used for passivation of PS. Immersion of the PS in a LiBr solution, followed by a thermal treatment at 100 {sup o}C for 30 min under nitrogen, leads to a nine fold increase in the intensity of the photoluminescence. The atomic force microscope (AFM) shows an increase of the nanoparticle dimension compared to the initial dimension of the PS nanostructure. The LiBr covers the nanoparticles of silicon without changing the wavelength distribution of the optical excitation and emission spectra. Moreover, a significant decrease of reflectivity was observed for the wavelength in the range of 350-500 nm. - Research highlights: {yields} A new method based on the use of LiBr was developed to enhance nine times the photoluminescence of porous silicon. {yields} The LiBr covers the silicon nanoparticles without changing in the optical excitation and emission spectra. {yields} We observed a significant decrease of the reflectivity in the 350-500 nm spectral range.

Influence of LiBr on photoluminescence properties of porous silicon

International Nuclear Information System (INIS)

Dimassi, W.; Haddadi, I.; Bousbih, R.; Slama, S.; Ali Kanzari, M.; Bouaicha, M.; Ezzaouia, H.

2011-01-01

A new method has been developed to improve the photoluminescence intensity of porous silicon (PS), which is first time that LiBr is used for passivation of PS. Immersion of the PS in a LiBr solution, followed by a thermal treatment at 100 o C for 30 min under nitrogen, leads to a nine fold increase in the intensity of the photoluminescence. The atomic force microscope (AFM) shows an increase of the nanoparticle dimension compared to the initial dimension of the PS nanostructure. The LiBr covers the nanoparticles of silicon without changing the wavelength distribution of the optical excitation and emission spectra. Moreover, a significant decrease of reflectivity was observed for the wavelength in the range of 350-500 nm. - Research highlights: → A new method based on the use of LiBr was developed to enhance nine times the photoluminescence of porous silicon. → The LiBr covers the silicon nanoparticles without changing in the optical excitation and emission spectra. → We observed a significant decrease of the reflectivity in the 350-500 nm spectral range.

XeBr excilamp based on a non-toxic component mixture

Energy Technology Data Exchange (ETDEWEB)

Kelman, V A; Shpenik, Yu O; Zhmenyak, Yu V, E-mail: mironkle@rambler.ru [Institute of Electron Physics, National Academy of Sciences of Ukraine, Universitetska 21, 88017 Uzhgorod (Ukraine)

2011-06-29

This paper presents the results of experimental studies on obtaining UV luminescence of XeBr* molecules at the excitation of a non-toxic Xe-CsBr gas-vapour mixture by a longitudinal pulse-periodic discharge. Effective UV emission yield of the exciplex XeBr* molecules (spectral maximum at 282 nm) is observed within a wide range of excitation conditions. The spectral distribution in the UV emission under the optimal excitation conditions does not differ essentially from that in other XeBr excilamps based on toxic components. The emission of the B {yields} X band of the XeBr* molecules provides the main contribution to the total power of the discharge UV emission. The determined average power of the UV emission for the experimental discharge tube is 12 W at an efficiency of 1%. Spectral, power-related and time-dependent parameters of the laboratory excilamp are presented for a wide range of excitation parameters. A new mechanism of exciplex molecule formation at the excitation of a rare gas/alkali halide vapour mixture is discussed.

XeBr excilamp based on a non-toxic component mixture

International Nuclear Information System (INIS)

Kelman, V A; Shpenik, Yu O; Zhmenyak, Yu V

2011-01-01

This paper presents the results of experimental studies on obtaining UV luminescence of XeBr* molecules at the excitation of a non-toxic Xe-CsBr gas-vapour mixture by a longitudinal pulse-periodic discharge. Effective UV emission yield of the exciplex XeBr* molecules (spectral maximum at 282 nm) is observed within a wide range of excitation conditions. The spectral distribution in the UV emission under the optimal excitation conditions does not differ essentially from that in other XeBr excilamps based on toxic components. The emission of the B → X band of the XeBr* molecules provides the main contribution to the total power of the discharge UV emission. The determined average power of the UV emission for the experimental discharge tube is 12 W at an efficiency of 1%. Spectral, power-related and time-dependent parameters of the laboratory excilamp are presented for a wide range of excitation parameters. A new mechanism of exciplex molecule formation at the excitation of a rare gas/alkali halide vapour mixture is discussed.

Comparison of aggregation behaviors between ionic liquid-type imidazolium gemini surfactant [C12-4-C12im]Br2 and its monomer [C12mim]Br on silicon wafer.

Science.gov (United States)

Ao, Mingqi; Xu, Guiying; Pang, Jinyu; Zhao, Taotao

2009-09-01

The aggregation of ionic liquid-type imidazolium gemini surfactant [C(12)-4-C(12)im]Br(2) on silicon wafer, which is compared with its monomer [C(12)mim]Br, have been studied. AFM morphology images and contact angle measurements suggest that the aggregations of [C(12)-4-C(12)im]Br(2) and [C(12)mim]Br on silicon wafer follow different mechanisms. Below the critical surface aggregation concentrations (CSAC), both surfactant molecules are adsorbed with their hydrophobic tails facing the air. But above the CSAC, [C(12)-4-C(12)im]Br(2) molecules finally form a bilayer structure with hydrophilic head groups facing the air, whereas [C(12)mim]Br molecules form a multilayer structure, and with increasing its concentration, the layer numbers increase with the hydrophobic chains and hydrophilic head groups facing the air by turns. Besides, the watery wettability of [C(12)-4-C(12)im]Br(2)-treated silica surface is lower than that of [C(12)mim]Br at the concentration of 5.0 cmc, and the infrared spectroscopy suggests that the poorer watery wettability of [C(12)-4-C(12)im]Br(2) may be relative to the less-ordered packing of methylene chains inside the aggregate. These different aggregation behaviors for the two surfactants ascribe to the different molecular structures and electrostatic interactions. This work would have certain theoretical guidance meaning on the modification of solid surface.

Kinetics of the Br2-CH3CHO Photochemical Chain Reaction

Science.gov (United States)

Nicovich, J. M.; Shackelford, C. J.; Wine, P. H.

1997-01-01

Time-resolved resonance fluorescence spectroscopy was employed in conjunction with laser flash photolysis of Br2 to study the kinetics of the two elementary steps in the photochemical chain reaction nBr2 + nCH3CHO + hv yields nCH3CBrO + nHBr. In the temperature range 255-400 K, the rate coefficient for the reaction Br((sup 2)P(sub 3/2)) + CH3CHO yields CH3CO + HBr is given by the Arrhenius expression k(sub 6)(T) = (1.51 +/- 0.20) x 10(exp -11) exp(-(364 +/- 41)/T)cu cm/(molecule.s). At 298 K, the reaction CH3CO + Br2 yields CH3CBrO + Br proceeds at a near gas kinetic rate, k(sub 7)(298 K) = (1.08 +/- 0.38) x 10(exp -10)cu cm/(molecule.s).

Wear Analysis of Top Piston Ring to Reduce Top Ring Reversal Bore Wear

Directory of Open Access Journals (Sweden)

P. Ilanthirayan

2017-12-01

Full Text Available The piston rings are the most important part in engine which controls the lubricating oil consumption and blowby of the gases. The lubricating film of oil is provided to seal of gases towards crankcase and also to give smooth friction free translatory motion between rings and liner. Of the three rings present top ring is more crucial as it does the main work of restricting gases downwards the crankcase. Boundary lubrication is present at the Top dead centre (TDC and Bottom dead centre (BDC of the liner surface. In addition to this, top ring is exposed to high temperature gases which makes the oil present near the top ring to get evaporated and decreasing its viscosity, making metal-metal contact most of the time. Due to this at TDC, excess wear happens on the liner which is termed as Top ring reversal bore wear. The wear rate depends upon many parameters such as lubrication condition, viscosity index, contact type, normal forces acting on ring, geometry of ring face, surface roughness, material property. The present work explores the wear depth for different geometries of barrel ring using Finite Element model with the help of Archard wear law and the same is validated through experimentation. The study reveals that Asymmetric barrel rings have less contact pressure which in turn reduces the wear at Top dead centre.

PREFACE: Special section on vortex rings Special section on vortex rings

Science.gov (United States)

Fukumoto, Yasuhide

2009-10-01

This special section of Fluid Dynamics Research includes five articles on vortex rings in both classical and quantum fluids. The leading scientists of the field describe the trends in and the state-of-the-art development of experiments, theories and numerical simulations of vortex rings. The year 2008 was the 150th anniversary of 'vortex motion' since Hermann von Helmholtz opened up this field. In 1858, Helmholtz published a paper in Crelle's Journal which put forward the concept of 'vorticity' and made the first analysis of vortex motion. Fluid mechanics before that was limited to irrotational motion. In the absence of vorticity, the motion of an incompressible homogeneous fluid is virtually equivalent to a rigid-body motion in the sense that the fluid motion is determined once the boundary configuration is specified. Helmholtz proved, among other things, that, without viscosity, a vortex line is frozen into the fluid. This Helmholtz's law immediately implies the preservation of knots and links of vortex lines and its implication is enormous. One of the major trends of fluid mechanics since the latter half of the 20th century is to clarify the topological meaning of Helmholtz's law and to exploit it to develop theoretical and numerical methods to find the solutions of the Euler equations and to develop experimental techniques to gain an insight into fluid motion. Vortex rings are prominent coherent structures in a variety of fluid motions from the microscopic scale, through human and mesoscale to astrophysical scales, and have attracted people's interest. The late professor Philip G Saffman (1981) emphasized the significance of studies on vortex rings. One particular motion exemplifies the whole range of problems of vortex motion and is also a commonly known phenomenon, namely the vortex ring or smoke ring. Vortex rings are easily produced by dropping drops of one liquid into another, or by puffing fluid out of a hole, or by exhaling smoke if one has the skill

Characterization of LWR fuel rod irradiations with power transients in the BR2 reflector

International Nuclear Information System (INIS)

Ponsard, B.; Bodart, S.; Meer, K. van der; Raedt, C. de

1996-01-01

Fuel rod irradiations in reflector positions of the materials testing reactor BR2 are becoming increasingly important. A typical example is that of irradiation devices containing single LWR fuel rods, to be tested in the framework of a new international fuel investigation and development programme. Some of the irradiations will comprise power transients with central fuel melting (at 2800 deg. C), the power increase being obtained by decreasing the pressure in a He-3 neutron absorbing screen and/or by varying the BR2 reactor operating power. A total power variation by a factor of at least 2.5 in the fuel rod irradiated could thus be achieved. In some of the rods, central temperature measurements (up to 2000 deg. C) will be carried out. Both fresh and pre-irradiated fuel rods are concerned in the programme. For these irradiations, the accurate knowledge of the neutron-induced fission heating and of the gamma heating is required, as one of the purposes of the programme consists in establishing the correlation among the thermal conductivity, the burn-up and the irradiation temperature. Calibration work among various measuring methods and between measurements and one- and two-dimensional calculations is being pursued. (author). 10 refs, 15 figs, 3 tabs

Accessory components in gas-lubricated floating ring seals; Zusatzeinrichtungen an gasgeschmierten Gleitringdichtungen

Energy Technology Data Exchange (ETDEWEB)

Kirchner, C.; Victor, K.H.

1995-12-31

The present paper uses existing designs of floating-ring seal systems to illustrate their use as accessory components in gas-lubricated axial-face seals. These floating-ring seals may be used as pre-seals on the side of the axial-face seal facing the product. Here they are subject to high ambient pressure and small pressure differences. On the side of the axial-face seal facing the sliding bearing they are used as post-seals, where they are subject to atmospheric conditions and small pressure differences. The authors present various purpose-specific designs of these seal systems. Theoretical calculation models are compared with measuring results obtained under conditions close to actual practice. (orig.) [Deutsch] Anhand von ausgefuehrten Konstruktionen werden Schwimmring-Dichtungssysteme als Zusatzeinrichtung an gasgeschmierten Gleitringdichtungen (GLRD) erlaeutert. Auf der produktzugewandten Seite der GLRD werden diese Schwimmringdichtungen als Vordichtung (Pre-Seal) eingesetzt, die bei hohen Umgebungsdruecken und geringen Druckdifferenzen betrieben werden. Auf der dem Gleitlager zugewandten Seite der GLRD werden Schwimmringdichtungen bei atmosphaerischen Bedingungen und ebenfalls geringen Druckdifferenzen als nachgeschaltete Dichtung (Post-Seal) eingesetzt. Es werden konstruktive Loesungen fuer die verschiedenen Aufgaben dieser Dichtungssysteme vorgestellt. Theoretische Berechnungsmodelle werden mit praxisnahen Messergebnissen verglichen. (orig.)

Vortex rings

CERN Document Server

Akhmetov, D G

2009-01-01

This text on vortex rings covers their theoretical foundation, systematic investigations, and practical applications such as the extinction of fires at gushing oil wells. It pays special attention to the formation and motion of turbulent vortex rings.

Study of Z > 18 elements concentration in tree rings from surroundings forests of the Mexico Valley using external beam PIXE

International Nuclear Information System (INIS)

Calva-Vazquez, G.; Razo-Angel, G.; Rodriguez-Fernandez, L.; Ruvalcaba-Sil, J.L.

2006-01-01

The concentration of elements with Z > 18 is measured in tree rings from forests at the surroundings of the Mexico Valley: El Chico National Park (ECP) and Desierto de los Leones National Park (DLP). The analysis was done by simultaneous PIXE-RBS using an external proton beam on tree rings of Pine and Sacred fir (species Pinus montezumae and Abies religiosa, respectively). This study provides information about the elemental concentration in trees of those parks during the years from 1965 to 2003. Typical elements such as K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Sr and Pb were detected using PIXE technique while the wood matrix composition (mainly C and O) was determined by RBS. In general, elemental contents present large variations but concentrations oscillate around the mean value during this period of time. Nevertheless, the measurements showed some trends for Fe and Zn in the tree-rings elemental composition that may be correlated to recent volcanic activities in the region. The low Mn contents indicate soil acidification in DLP from 1968 and the forest decline in ECP during the last 15 years

Using simulation to aid trial design: Ring-vaccination trials.

Directory of Open Access Journals (Sweden)

Matt David Thomas Hitchings

2017-03-01

Full Text Available The 2014-6 West African Ebola epidemic highlights the need for rigorous, rapid clinical trial methods for vaccines. A challenge for trial design is making sample size calculations based on incidence within the trial, total vaccine effect, and intracluster correlation, when these parameters are uncertain in the presence of indirect effects of vaccination.We present a stochastic, compartmental model for a ring vaccination trial. After identification of an index case, a ring of contacts is recruited and either vaccinated immediately or after 21 days. The primary outcome of the trial is total vaccine effect, counting cases only from a pre-specified window in which the immediate arm is assumed to be fully protected and the delayed arm is not protected. Simulation results are used to calculate necessary sample size and estimated vaccine effect. Under baseline assumptions about vaccine properties, monthly incidence in unvaccinated rings and trial design, a standard sample-size calculation neglecting dynamic effects estimated that 7,100 participants would be needed to achieve 80% power to detect a difference in attack rate between arms, while incorporating dynamic considerations in the model increased the estimate to 8,900. This approach replaces assumptions about parameters at the ring level with assumptions about disease dynamics and vaccine characteristics at the individual level, so within this framework we were able to describe the sensitivity of the trial power and estimated effect to various parameters. We found that both of these quantities are sensitive to properties of the vaccine, to setting-specific parameters over which investigators have little control, and to parameters that are determined by the study design.Incorporating simulation into the trial design process can improve robustness of sample size calculations. For this specific trial design, vaccine effectiveness depends on properties of the ring vaccination design and on the

Phase formation in systems Re-Se-Br-MBr (M=Li, Na, K, Rb, Cs

International Nuclear Information System (INIS)

Yarovoj, S.S.; Mironov, Yu.V.; Tkachev, S.V.; Fedorov, V.E.

2009-01-01

Phase formation in the systems Re-Se-Br-MBr (M=K, Rb, Cs) has been studied by NMR-spectroscopy and X-ray phase analysis. Polymer complexes Re 6 Se 8 Br 2 and M 2 Re 6 Se 8 Br 4 (M=Cs, Rb), and salts containing cluster anions [Re 6 Se 6 Br 8 ] 2- and [Re 6 Se 7 Br 7 ] 3- are the main products of reactions occurring in molten alkali metal halides in the number of cluster anions [{Re 6 Se 8-n Br n }Br 6 ] (4-n)- (0≤n≤4). Effect of alkali metal cation on the composition and ratios of formed products is established

Polarization Insensitivity in Double-Split Ring and Triple-Split Ring Terahertz Resonators

International Nuclear Information System (INIS)

Wu Qian-Nan; Lan Feng; Tang Xiao-Pin; Yang Zi-Qiang

2015-01-01

A modified double-split ring resonator and a modified triple-split ring resonator, which offer polarization-insensitive performance, are investigated, designed and fabricated. By displacing the two gaps of the conventional double-split ring resonator away from the center, the second resonant frequency for the 0° polarized wave and the resonant frequency for the 90° polarized wave become increasingly close to each other until they are finally identical. Theoretical and experimental results show that the modified double-split ring resonator and the modified triple-split ring resonator are insensitive to different polarized waves and show strong resonant frequency dips near 433 and 444 GHz, respectively. The results of this work suggest new opportunities for the investigation and design of polarization-dependent terahertz devices based on split ring resonators. (paper)

A comparative study of LaBr{sub 3}(Ce{sup 3+}) and CeBr{sub 3} based gamma-ray spectrometers for planetary remote sensing applications

Energy Technology Data Exchange (ETDEWEB)

Kozyrev, A., E-mail: kozyrev@mx.iki.rssi.ru; Mitrofanov, I.; Bakhtin, B.; Fedosov, F.; Golovin, D.; Litvak, M.; Malakhov, A.; Mokrousov, M.; Nuzhdin, I.; Sanin, A.; Tretyakov, V.; Vostrukhin, A. [Space Research Institute of the Russian Academy of Sciences (IKI), 84/32 Profsoyuznaya St., Moscow 117997 (Russian Federation); Owens, A.; Benkhoff, J. [European Space Agency, ESTEC, Keplerlaan, 2200 AG Noordwijk (Netherlands); Quarati, F. [AP, RST, FAME, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Gonitec BV, J. Bildersstraat 60, 2596 EJ Den Haag (Netherlands); Timoshenko, G.; Shvetsov, V. [Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980 (Russian Federation); Granja, C.; Slavicek, T.; Pospisil, S. [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 12800 Prague 2 (Czech Republic)

2016-08-15

The recent availability of large volume cerium bromide crystals raises the possibility of substantially improving gamma-ray spectrometer limiting flux sensitivities over current systems based on the lanthanum tri-halides, e.g., lanthanum bromide and lanthanum chloride, especially for remote sensing, low-level counting applications or any type of measurement characterized by poor signal to noise ratios. The Russian Space Research Institute has developed and manufactured a highly sensitive gamma-ray spectrometer for remote sensing observations of the planet Mercury from the Mercury Polar Orbiter (MPO), which forms part of ESA’s BepiColombo mission. The Flight Model (FM) gamma-ray spectrometer is based on a 3-in. single crystal of LaBr{sub 3}(Ce{sup 3+}) produced in a separate crystal development programme specifically for this mission. During the spectrometers development, manufacturing, and qualification phases, large crystals of CeBr{sub 3} became available in a subsequent phase of the same crystal development programme. Consequently, the Flight Spare Model (FSM) gamma-ray spectrometer was retrofitted with a 3-in. CeBr{sub 3} crystal and qualified for space. Except for the crystals, the two systems are essentially identical. In this paper, we report on a comparative assessment of the two systems, in terms of their respective spectral properties, as well as their suitability for use in planetary mission with respect to radiation tolerance and their propensity for activation. We also contrast their performance with a Ge detector representative of that flown on MESSENGER and show that: (a) both LaBr{sub 3}(Ce{sup 3+}) and CeBr{sub 3} provide superior detection systems over HPGe in the context of minimally resourced spacecraft and (b) CeBr{sub 3} is a more attractive system than LaBr{sub 3}(Ce{sup 3+}) in terms of sensitivities at lower gamma fluxes. Based on the tests, the FM has now been replaced by the FSM on the BepiColombo spacecraft. Thus, CeBr{sub 3} now forms

Transcription regulator TRIP-Br2 mediates ER stress-induced brown adipocytes dysfunction.

Science.gov (United States)

Qiang, Guifen; Whang Kong, Hyerim; Gil, Victoria; Liew, Chong Wee

2017-01-09

In contrast to white adipose tissue, brown adipose tissue (BAT) is known to play critical roles for both basal and inducible energy expenditure. Obesity is associated with reduction of BAT function; however, it is not well understood how obesity promotes BAT dysfunction, especially at the molecular level. Here we show that the transcription regulator TRIP-Br2 mediates ER stress-induced inhibition of lipolysis and thermogenesis in BAT. Using in vitro, ex vivo, and in vivo approaches, we demonstrate that obesity-induced inflammation upregulates brown adipocytes TRIP-Br2 expression via the ER stress pathway and amelioration of ER stress in mice completely abolishes high fat diet-induced upregulation of TRIP-Br2 in BAT. We find that increased TRIP-Br2 significantly inhibits brown adipocytes thermogenesis. Finally, we show that ablation of TRIP-Br2 ameliorates ER stress-induced inhibition on lipolysis, fatty acid oxidation, oxidative metabolism, and thermogenesis in brown adipocytes. Taken together, our current study demonstrates a role for TRIP-Br2 in ER stress-induced BAT dysfunction, and inhibiting TRIP-Br2 could be a potential approach for counteracting obesity-induced BAT dysfunction.

Pure Cs4PbBr6: Highly Luminescent Zero-Dimensional Perovskite Solids

KAUST Repository

Saidaminov, Makhsud I.

2016-09-26

So-called zero-dimensional perovskites, such as Cs4PbBr6, promise outstanding emissive properties. However, Cs4PbBr6 is mostly prepared by melting of precursors that usually leads to a coformation of undesired phases. Here, we report a simple low-temperature solution-processed synthesis of pure Cs4PbBr6 with remarkable emission properties. We found that pure Cs4PbBr6 in solid form exhibits a 45% photoluminescence quantum yield (PLQY), in contrast to its three-dimensional counterpart, CsPbBr3, which exhibits more than 2 orders of magnitude lower PLQY. Such a PLQY of Cs4PbBr6 is significantly higher than that of other solid forms of lower-dimensional metal halide perovskite derivatives and perovskite nanocrystals. We attribute this dramatic increase in PL to the high exciton binding energy, which we estimate to be ∼353 meV, likely induced by the unique Bergerhoff–Schmitz–Dumont-type crystal structure of Cs4PbBr6, in which metal-halide-comprised octahedra are spatially confined. Our findings bring this class of perovskite derivatives to the forefront of color-converting and light-emitting applications.

Modulation of electronic and optical properties in mixed halide perovskites CsPbCl3xBr3(1-x) and CsPbBr3xI3(1-x)

Science.gov (United States)

Zhou, Ziqi; Cui, Yu; Deng, Hui-Xiong; Huang, Le; Wei, Zhongming; Li, Jingbo

2017-03-01

The recent discovery of lead halide perovskites with band gaps in the visible presents important potential in the design of high efficient solar cells. CsPbCl3, CsPbBr3 and CsPbI3 are stable compounds within this new family of semiconductors. By performing the first-principles calculation, we explore the structural, electronic and optical properties of CsPbCl3xBr3(1-x) and CsPbBr3xI3(1-x) with various compositions of halide atoms. Structural stability is demonstrated with halide atoms distributing randomly at the halide atomic sites. CsPbCl3xBr3(1-x) and CsPbBr3xI3(1-x) exhibit the modulation of their band gaps by varying the halide composition. Our results also indicate that CsPbCl3xBr3(1-x) and CsPbBr3xI3(1-x) with different halide compositions are suitable to application to solar cells for the general features are well preserved. Good absorption to lights of different wavelengths has been obtained in these mixed halide perovskites.

Development of brain injury criteria (BrIC).

Science.gov (United States)

Takhounts, Erik G; Craig, Matthew J; Moorhouse, Kevin; McFadden, Joe; Hasija, Vikas

2013-11-01

Rotational motion of the head as a mechanism for brain injury was proposed back in the 1940s. Since then a multitude of research studies by various institutions were conducted to confirm/reject this hypothesis. Most of the studies were conducted on animals and concluded that rotational kinematics experienced by the animal's head may cause axonal deformations large enough to induce their functional deficit. Other studies utilized physical and mathematical models of human and animal heads to derive brain injury criteria based on deformation/pressure histories computed from their models. This study differs from the previous research in the following ways: first, it uses two different detailed mathematical models of human head (SIMon and GHBMC), each validated against various human brain response datasets; then establishes physical (strain and stress based) injury criteria for various types of brain injury based on scaled animal injury data; and finally, uses Anthropomorphic Test Devices (ATDs) (Hybrid III 50th Male, Hybrid III 5th Female, THOR 50th Male, ES-2re, SID-IIs, WorldSID 50th Male, and WorldSID 5th Female) test data (NCAP, pendulum, and frontal offset tests) to establish a kinematically based brain injury criterion (BrIC) for all ATDs. Similar procedures were applied to college football data where thousands of head impacts were recorded using a six degrees of freedom (6 DOF) instrumented helmet system. Since animal injury data used in derivation of BrIC were predominantly for diffuse axonal injury (DAI) type, which is currently an AIS 4+ injury, cumulative strain damage measure (CSDM) and maximum principal strain (MPS) were used to derive risk curves for AIS 4+ anatomic brain injuries. The AIS 1+, 2+, 3+, and 5+ risk curves for CSDM and MPS were then computed using the ratios between corresponding risk curves for head injury criterion (HIC) at a 50% risk. The risk curves for BrIC were then obtained from CSDM and MPS risk curves using the linear relationship

SU-F-I-08: CT Image Ring Artifact Reduction Based On Prior Image

Energy Technology Data Exchange (ETDEWEB)

Yuan, C; Qi, H; Chen, Z; Wu, S; Xu, Y; Zhou, L [Southern Medical University, Guangzhou, Guangdong (China)

2016-06-15

Purpose: In computed tomography (CT) system, CT images with ring artifacts will be reconstructed when some adjacent bins of detector don’t work. The ring artifacts severely degrade CT image quality. We present a useful CT ring artifacts reduction based on projection data correction, aiming at estimating the missing data of projection data accurately, thus removing the ring artifacts of CT images. Methods: The method consists of ten steps: 1) Identification of abnormal pixel line in projection sinogram; 2) Linear interpolation within the pixel line of projection sinogram; 3) FBP reconstruction using interpolated projection data; 4) Filtering FBP image using mean filter; 5) Forwarding projection of filtered FBP image; 6) Subtraction forwarded projection from original projection; 7) Linear interpolation of abnormal pixel line area in the subtraction projection; 8) Adding the interpolated subtraction projection on the forwarded projection; 9) FBP reconstruction using corrected projection data; 10) Return to step 4 until the pre-set iteration number is reached. The method is validated on simulated and real data to restore missing projection data and reconstruct ring artifact-free CT images. Results: We have studied impact of amount of dead bins of CT detector on the accuracy of missing data estimation in projection sinogram. For the simulated case with a resolution of 256 by 256 Shepp-Logan phantom, three iterations are sufficient to restore projection data and reconstruct ring artifact-free images when the dead bins rating is under 30%. The dead-bin-induced artifacts are substantially reduced. More iteration number is needed to reconstruct satisfactory images while the rating of dead bins increases. Similar results were found for a real head phantom case. Conclusion: A practical CT image ring artifact correction scheme based on projection data is developed. This method can produce ring artifact-free CT images feasibly and effectively.

SU-F-I-08: CT Image Ring Artifact Reduction Based On Prior Image

International Nuclear Information System (INIS)

Yuan, C; Qi, H; Chen, Z; Wu, S; Xu, Y; Zhou, L

2016-01-01

Purpose: In computed tomography (CT) system, CT images with ring artifacts will be reconstructed when some adjacent bins of detector don’t work. The ring artifacts severely degrade CT image quality. We present a useful CT ring artifacts reduction based on projection data correction, aiming at estimating the missing data of projection data accurately, thus removing the ring artifacts of CT images. Methods: The method consists of ten steps: 1) Identification of abnormal pixel line in projection sinogram; 2) Linear interpolation within the pixel line of projection sinogram; 3) FBP reconstruction using interpolated projection data; 4) Filtering FBP image using mean filter; 5) Forwarding projection of filtered FBP image; 6) Subtraction forwarded projection from original projection; 7) Linear interpolation of abnormal pixel line area in the subtraction projection; 8) Adding the interpolated subtraction projection on the forwarded projection; 9) FBP reconstruction using corrected projection data; 10) Return to step 4 until the pre-set iteration number is reached. The method is validated on simulated and real data to restore missing projection data and reconstruct ring artifact-free CT images. Results: We have studied impact of amount of dead bins of CT detector on the accuracy of missing data estimation in projection sinogram. For the simulated case with a resolution of 256 by 256 Shepp-Logan phantom, three iterations are sufficient to restore projection data and reconstruct ring artifact-free images when the dead bins rating is under 30%. The dead-bin-induced artifacts are substantially reduced. More iteration number is needed to reconstruct satisfactory images while the rating of dead bins increases. Similar results were found for a real head phantom case. Conclusion: A practical CT image ring artifact correction scheme based on projection data is developed. This method can produce ring artifact-free CT images feasibly and effectively.

Trapping molecular bromine: a one-dimensional bromobismuthate complex with Br2 as a linker.

Science.gov (United States)

Adonin, S A; Gorokh, I D; Abramov, P A; Plyusnin, P E; Sokolov, M N; Fedin, V P

2016-03-07

The reaction between solid (NMP)n{[BiBr4]}n (1) (NMP = N-methylpyridinium) and Br2, generated in situ in HBr solution, results in the formation of (NMP)3[Bi2Br9]·Br2 (2). In the structure of 2, dibromine molecules connect discrete binuclear [Bi2Br9](3-) anions into an extended network. Complex 2 is thermally stable (up to 150 °C).

RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

Energy Technology Data Exchange (ETDEWEB)

Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

2015-12-15

We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

Stirling engine piston ring

Science.gov (United States)

Howarth, Roy B.

1983-01-01

A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

Physics of quantum rings

International Nuclear Information System (INIS)

Fomin, Vladimir M.

2014-01-01

Presents the new class of materials of quantum rings. Provides an elemental basis for low-cost high-performance devices promising for electronics, optoelectronics, spintronics and quantum information processing. Explains the physical properties of quantum rings to cover a gap in scientific literature. Presents the application of most advanced nanoengineering and nanocharacterization techniques. This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is possible on the basis of modern characterization methods of nanostructures, such as Scanning Tunneling Microscopy. A high level of complexity is demonstrated to be needed for a dedicated theoretical model to adequately represent the specific features of quantum rings. The findings presented in this book contribute to develop low-cost high-performance electronic, spintronic, optoelectronic and information processing devices based on quantum rings.

How does the blue-ringed octopus (Hapalochlaena lunulata) flash its blue rings?

Science.gov (United States)

Mäthger, Lydia M; Bell, George R R; Kuzirian, Alan M; Allen, Justine J; Hanlon, Roger T

2012-11-01

The blue-ringed octopus (Hapalochlaena lunulata), one of the world's most venomous animals, has long captivated and endangered a large audience: children playing at the beach, divers turning over rocks, and biologists researching neurotoxins. These small animals spend much of their time in hiding, showing effective camouflage patterns. When disturbed, the octopus will flash around 60 iridescent blue rings and, when strongly harassed, bite and deliver a neurotoxin that can kill a human. Here, we describe the flashing mechanism and optical properties of these rings. The rings contain physiologically inert multilayer reflectors, arranged to reflect blue-green light in a broad viewing direction. Dark pigmented chromatophores are found beneath and around each ring to enhance contrast. No chromatophores are above the ring; this is unusual for cephalopods, which typically use chromatophores to cover or spectrally modify iridescence. The fast flashes are achieved using muscles under direct neural control. The ring is hidden by contraction of muscles above the iridophores; relaxation of these muscles and contraction of muscles outside the ring expose the iridescence. This mechanism of producing iridescent signals has not previously been reported in cephalopods and we suggest that it is an exceptionally effective way to create a fast and conspicuous warning display.

α-Skew π-McCoy Rings

Directory of Open Access Journals (Sweden)

Areej M. Abduldaim

2013-01-01

Full Text Available As a generalization of α-skew McCoy rings, we introduce the concept of α-skew π-McCoy rings, and we study the relationships with another two new generalizations, α-skew π1-McCoy rings and α-skew π2-McCoy rings, observing the relations with α-skew McCoy rings, π-McCoy rings, α-skew Armendariz rings, π-regular rings, and other kinds of rings. Also, we investigate conditions such that α-skew π1-McCoy rings imply α-skew π-McCoy rings and α-skew π2-McCoy rings. We show that in the case where R is a nonreduced ring, if R is 2-primal, then R is an α-skew π-McCoy ring. And, let R be a weak (α,δ-compatible ring; if R is an α-skew π1-McCoy ring, then R is α-skew π2-McCoy.

Hydrogen-bonded structure in highly concentrated aqueous LiBr solutions

International Nuclear Information System (INIS)

Imano, Masahiro; Kameda, Yasuo; Usuki, Takeshi; Uemura, Osamu

2001-01-01

Neutron diffraction measurements were carried out for H/D isotopically substituted aqueous 10, 25 and 33 mol% LiBr solutions in order to obtain structural information on the intermolecular hydrogen bonds among water molecules in highly concentrated aqueous solutions. Observed scattering cross sections for D 2 O (99.9 % D), 0 H 2 O(35.9 % D) and 0-2 H 2 O(68.0 % D) solutions were combined to deduce partial structure factors, a HH (Q), a XH (Q) and a XX (Q) (X: O, Br and Li). The least squares fitting analysis was applied to the observed partial structure factors to determine the nearest neighbor interatomic distance, root-mean-square amplitude and coordination number. Intermolecular distances, r OH =1.91(1) A, r HH =2.38(1) A and r OO =3.02(1) A, between the nearest neighbor water molecules, were obtained for the 10 mol% LiBr solution. On the other hand, the intermolecular O···H interaction was found to almost disappear in concentrated 25 and 33 mol% LiBr solutions. The result implies that the hydrogen-bonded network is completely broken in highly concentrated aqueous LiBr solutions. (author)

Neutron scattering study of MnX2 (X = Br, I)

International Nuclear Information System (INIS)

Sato, Taku; Kadowaki, Hiroaki.

1993-01-01

Successive magnetic phase transitions in MnX 2 (X = Br, I), found by bulk measurements, are studied by neutron scattering experiments. There occur two (T N1 = 2.32K, T N2 = 2.17K) and three (T N1 = 3.95K, T N2 = 3.8K, T N3 = 3.45K) phase transitions in MnBr 2 and MnI 2 , respectively. We have found that magnetic structures of the both compounds in the intermediate temperature phases (MnBr 2 : T N1 > T > T N2 ; MnI 2 : T N1 > T > T N3 ) are transverse sinusoidally-modulated structures with incommensurate wave-vectors which vary as a function of temperature. As the temperature is lowered into the lowest temperature phases, the magnetic structures change via first order transition into ↑↑↓↓ and a helical structure for MnBr 2 and MnI 2 , respectively, which were determined by previous experiments. The successive phase transitions in MnBr 2 are accounted for quantitatively using a mean field approximation of a Hamiltonian consisting of exchange interactions up to third inter- and third intra-layer neighbor sites and the dipolar interaction. (author)

Contrasting basin architecture and rifting style of the Vøring Basin, offshore mid-Norway and the Faroe-Shetland Basin, offshore United Kingdom

Science.gov (United States)

Schöpfer, Kateřina; Hinsch, Ralph

2017-04-01

The Vøring and the Faroe-Shetland basins are offshore deep sedimentary basins which are situated on the outer continental margin of the northeast Atlantic Ocean. Both basins are underlain by thinned continental crust whose structure is still debated. In particular the nature of the lower continental crust and the origin of high velocity bodies located at the base of the lower crust are a subject of discussion in recent literature. Regional interpretation of 2D and 3D seismic reflection data, combined with well data, suggest that both basins share several common features: (i) Pre-Cretaceous faults that are distributed across the entire basin width. (ii) Geometries of pre-Jurassic strata reflecting at least two extensional phases. (iii) Three common rift phases, Late Jurassic, Campanian-Maastrichtian and Palaeocene. (iv) Large pre-Cretaceous fault blocks that are buried by several kilometres of Cretaceous and Cenozoic strata. (iii). (v) Latest Cretaceous/Palaeocene inversion. (vi) Occurrence of partial mantle serpentinization during Early Cretaceous times, as proposed by other studies, seems improbable. The detailed analysis of the data, however, revealed significant differences between the two basins: (i) The Faroe-Shetland Basin was a fault-controlled basin during the Late Jurassic but also the Late Cretaceous extensional phase. In contrast, the Vøring Basin is dominated by the late Jurassic rifting and subsequent thermal subsidence. It exhibits only minor Late Cretaceous faults that are localised above intra-basinal and marginal highs. In addition, the Cretaceous strata in the Vøring Basin are folded. (ii) In the Vøring Basin, the locus of Late Cretaceous rifting shifted westwards, affecting mainly the western basin margin, whereas in the Faroe-Shetland Basin Late Cretaceous rifting was localised in the same area as the Late Jurassic phase, hence masking the original Jurassic geometries. (iii) Devono-Carboniferous and Aptian/Albian to Cenomanian rift phases

Extended analysis of fifth spectrum of bromine: Br V

International Nuclear Information System (INIS)

Riyaz, A.; Tauheed, A.; Rahimullah, K.

2014-01-01

The fifth spectrum of bromine (Br V) has been studied in the 200–2400 Å wavelength region. The spectrum was photographed on a 3-m normal incidence vacuum spectrograph at the St. Francis Xavier University, Antigonish (Canada) and 6.65-m grazing incidence spectrograph at the Zeeman laboratory (Amsterdam). The light sources used were a triggered spark and sliding spark. The ground configuration of Br V is 4s 2 4p. The excited configurations 4s4p 2 +4s 2 (4d+5d+5s+6s+7s+5g+6g)+4s4p(5p+4f)+4p 2 4d in the even parity system and the 4p 3 +4s 2 (5p+6p+7p+4f)+4s4p4d+4s4p5s configurations in the odd parity system have been studied. Relativistic Hartree–Fock (HFR) and least squares fitted (LSF) parametric calculations have been used to interpret the observed spectrum. 99 levels of Br V have now been established, 43 being new. Among 394 classified spectral lines, 181 are newly classified. The level 4s 2 7s 2 S 1/2 is revised. We estimate the accuracy of our measured wavelengths for sharp and unblended lines to be±0.005 Å. The ionization limit is determined as 479,657±200 cm −1 (59.470±0.025 eV). - Highlights: • The spectrum of Br was recorded on a 3-m spectrograph with triggered spark source. • Atomic transitions for Br V were identified to established new energy levels. • CI calculations with relativistic corrections were made for theoretical predictions. • Weighted oscillator strength (gf) and transition probabilities (gA) were calculated. • Ionization potential of Br V was determined experimentally

New Way of Characterizing the State of the Ring Current

Science.gov (United States)

Wolf, R.; Bao, S.; Gkioulidou, M.; Yang, J.; Toffoletto, F.

2017-12-01

The flux tube entropy S is invariant in ideal MHD and is a good way to characterize the degree to which a closed flux tube is loaded with particle energy. Flux tube entropy generally increases with increasing geocentric distance. A flux tube that is injected from the plasma sheet into the ring current tends to be a bubble that has a lower S value than typical plasma sheet flux tubes, and it tends to penetrate to a position where the surroundings matches its S. From this point of view, a good way to characterize the state of the ring current is through the function dF/dS, which specifies how much magnetic flux is occupied by tubes with different degrees of loading. By displaying dF/dS curves before and during storm main phases simulated with the RCM-E code, we determine that, in the model, the injection of the stormtime ring current consists of replacing pre-storm low-S flux tubes with tubes from the plasma sheet that have a certain limited range of S, which is well below typical plasma-sheet values. We also display dF/dS curves for passes by the Van Allen Probes before and during storm main phases, and compare with the RCM-E-derived curves, to gain insight into the nature of the flux tubes that are injected to form the real storm-time ring current.

Airborne Measurements of BrO and the Sum of HOBr and Br2 over the Tropical West Pacific from 1 to 15 Km During the CONvective TRansport of Active Species in the Tropics (CONTRAST) Experiment

Science.gov (United States)

Chen, Dexian; Huey, L. Gregory; Tanner, David J.; Salawitch, Ross J.; Anderson, Daniel C.; Wales, Pamela A.; Pan, Laura L.; Atlas, Elliot L.; Hornbrook, Rebecca S.; Apel, Eric C.;

Double-wall carbon nanotubes doped with different Br2 doping levels: a resonance Raman study.

Science.gov (United States)

do Nascimento, Gustavo M; Hou, Taige; Kim, Yoong Ahm; Muramatsu, Hiroyuki; Hayashi, Takuya; Endo, Morinobu; Akuzawa, Noboru; Dresselhaus, Mildred S

2008-12-01

This report focuses on the effects of different Br2 doping levels on the radial breathing modes of "double-wall carbon nanotube (DWNT) buckypaper". The resonance Raman profile of the Br2 bands are shown for different DWNT configurations with different Br2 doping levels. Near the maximum intensity of the resonance Raman profile, mainly the Br2 molecules adsorbed on the DWNT surface contribute strongly to the observed omega(Br-Br) Raman signal.

VUV optical ring resonator for Duke storage ring free electron laser

Energy Technology Data Exchange (ETDEWEB)

Park, S.H.; Litvinenko, V.N.; Madey, J.M.J. [Duke Univ., Durham, NC (United States)] [and others

1995-12-31

The conceptual design of the multifaceted-mirror ring resonator for Duke storage ring VUV FEL is presented. The expected performance of the OK-4 FEL with ring resonator is described. We discuss in this paper our plans to study reflectivity of VUV mirrors and their resistivity to soft X-ray spontaneous radiation from OK-4 undulator.

Identification of the transition arrays 3d74s-3d74p in Br X and 3d64s-3d64p in Br XI

International Nuclear Information System (INIS)

Zeng, X.T.; Jupen, C.; Bengtsson, P.; Engstroem, L.; Westerlind, M.; Martinson, I.

1991-01-01

We report a beam-foil study of multiply ionized bromine in the region 400-1300A, performed with 6 and 8 MeV Br ions from a tandem accelerator. At these energies transitions belonging to Fe-like Br X and Mn-like Br XI are expected to be prominent. We have identified 31 lines as 3d 7 4s-3d 7 4p transitions in Br X, from which 16 levels of the previously unknown 3d 7 4s configuration could be established. We have also added 6 new 3d 7 4p levels to the 99 previously known. For Br XI we have classified 9 lines as 3d 6 4s-3d 6 4p combinations. The line identifications have been corroborated by isoelectronic comparisons and theoretical calculations using the superposition-of-configurations technique. (orig.)

Tripodal polyphosphine ligands as inductors of chelate ring-opening processes in mononuclear palladium(II) and platinum(II) compounds. The X-ray crystal structure of two derivatives containing dangling phosphorus.

Science.gov (United States)

Fernández-Anca, Damián; García-Seijo, M Inés; García-Fernández, M Esther

2010-03-07

The reaction of NP(3) (tris[2-(diphenylphosphino)ethyl]amine and PP(3) (tris[2-(diphenylphosphino)ethyl]phosphine) with the five-coordinate complexes [PdCl(NP(3))]Cl (1) and [MX(PP(3))]X [M = Pd: X = Cl(2), Br(3), I(4); M = Pt: X = Cl(5), Br(6), I(7)], respectively, followed by (31)P{(1)H}NMR when X = Cl, led to the formation of unprecedented four-coordinate halides in a 1 : 2 metal to ligand ratio, [M(AP(3))(2)]X(2) [A = N, M = Pd: X = Cl(8); A = P, M = Pd: X = Cl(9), Br(10), I(11); A = P, M = Pt: X = Cl(12), Br(13), I (14)], containing reactive dangling phosphorus. Given the non characterised precursors [M(ONO(2))(PP(3))](NO(3))], the interaction between the heteronuclear species [MAg(NO(3))(3)(PP(3))] [M = Pd(15), Pt(16)] and PP(3) was explored. It was found that the addition of 1 equivalent of phosphine afforded [MAg(NO(3))(PP(3))(2)](NO(3))(2) [M = Pd(15*), Pt(16*)] containing Ag(I) bound to two dangling phosphorus while the reaction with 2 equivalents led to the complexes [M(PP(3))(2)](NO(3))(2) [M = Pd (17), Pt (18)] in coexistence with [Ag(2)(mu-PP(3))(2)](NO(3))(2). The fate of Ag(I) on the reaction of the mixed metal compounds with excess PP(3) consisted of preventing dissociation, observed in solution for halides, and acting as an assistant for crystallization. Colourless single crystals of 18 and 10, studied by X-ray diffraction, were afforded by reaction of 16 with 4 equivalents of PP(3) and from solutions of 10 in chloroform coexisting with red crystals of 3, respectively. The structures revealed the presence of dications [M(PP(3))(2)](2+) that show two five-membered chelate rings to M(II) in a square-planar arrangement and four uncoordinated phosphine arms with the counter anions being symmetrically placed at 4.431 (Br(-)) and 13.823 (NO(3)(-)) A from M(II) above and below its coordination, MP(4), plane. Complexes 9 and 12 were shown to undergo an interesting reactivity in solution versus group 11 monocations. The reactions consisted of conversions

Interaction Region Design for a Ring-Ring LHeC

CERN Document Server

Thompson, L N S; Bernard, N R; Fitterer, M; Holzer, B; Klein, M; Kostka, P

2011-01-01

tively low energy and moderately high intensity provides high luminosity TeV-scale e-p collisions at one of the LHC interaction points, running simultaneously with existing experiments. Two designs are studied; an electron ring situated in the LHC tunnel, and an electron linac. The focus of this paper is on the ring design. Designing an e-p machine presents interesting accelerator physics and design challenges, particularly when considering the interaction region. These include coupled optics, beam separation and unconventional mini-beta focusing schemes. Designs are constrained by an array of interdependent factors, including beam-beam interaction, detector dimensions and acceptance, luminosity and synchrotron radiation. Methods of addressing these complex issues are discussed. The current designs for the LHeC Ring-Ring interaction region and long straight section are presented and discussed, in the context of the project goals and design challenges encountered. Future developments and work are also discusse...

Rotationally asymmetric multifocal IOL implantation with and without capsular tension ring: refractive and visual outcomes and intraocular optical performance.

Science.gov (United States)

Alió, Jorge L; Plaza-Puche, Ana B; Piñero, David P

2012-04-01

To ascertain whether the refractive, visual, and intraocular optical quality outcomes of a rotationally asymmetric multifocal intraocular lens (IOL) are enhanced by the use of a capsular tension ring. Ninety consecutive eyes from 53 patients (age range: 36 to 82 years) were divided into two groups: the no ring group comprised 43 eyes implanted with the multifocal rotationally asymmetric Lentis Mplus LS-312 (Oculentis GmbH) without a capsular tension ring; and the ring group comprised 47 eyes with the same IOL with a capsular tension ring. Distance and near visual acuity and refractive outcomes were evaluated pre- and postoperatively. Contrast sensitivity, intraocular aberrations, and defocus curve were evaluated postoperatively. Significant postoperative differences between groups were found in sphere, spherical equivalent refraction, and near addition (P<.02). Regarding defocus curve, significantly better visual acuity was present in eyes with the capsular tension ring for intermediate vision conditions (P<.05). Intraocular aberrometry did not differ significantly between groups (P<.09). Refractive predictability and intermediate visual outcomes with the Lentis Mplus LS-312 IOL improved significantly when implanted in combination with a capsular tension ring. Copyright 2012, SLACK Incorporated.

Novel Co(III)/Co(II) mixed valence compound [Co(bapen)Br2]2[CoBr4] (bapen = N,N‧-bis(3-aminopropyl)ethane-1,2-diamine): Synthesis, crystal structure and magnetic properties

Science.gov (United States)

Smolko, Lukáš; Černák, Juraj; Kuchár, Juraj; Miklovič, Jozef; Boča, Roman

2016-09-01

Green crystals of Co(III)/Co(II) mixed valence compound [Co(bapen)Br2]2[CoBr4] (bapen = N,N‧-bis(3-aminopropyl)ethane-1,2-diamine) were isolated from the aqueous system CoBr2 - bapen - HBr, crystallographically studied and characterized by elemental analysis and IR spectroscopy. Its ionic crystal structure is built up of [Co(bapen)Br2]+ cations and [CoBr4]2- anions. The Co(III) central atoms within the complex cations are hexacoordinated (donor set trans-N4Br2) with bromido ligands placed in the axial positions. The Co(II) atoms exhibit distorted tetrahedral coordination. Beside ionic forces weak Nsbnd H⋯Br intermolecular hydrogen bonding interactions contribute to the stability of the structure. Temperature variable magnetic measurements confirm the S = 3/2 behavior with the zero-field splitting of an intermediate strength: D/hc = 8.7 cm-1.

BR-Explorer: A sound and complete FCA-based retrieval algorithm (Poster)

OpenAIRE

Messai , Nizar; Devignes , Marie-Dominique; Napoli , Amedeo; Smaïl-Tabbone , Malika

2006-01-01

In this paper we present BR-Explorer, a sound and complete biological data sources retrieval algorithm based on Formal Concept Analysis and domain ontologies. BR-Explorer addresses the problem of retrieving the relevant data sources for a given query. Initially, a formal context representing the relation between biological data sources and their metadata is provided and its corresponding concept lattice is built. Then BR-Explorer starts by generating the formal concept for the considered quer...

Uniquely Strongly Clean Group Rings

Institute of Scientific and Technical Information of China (English)

WANG XIU-LAN

2012-01-01

A ring R is called clean if every element is the sum of an idempotent and a unit,and R is called uniquely strongly clean (USC for short) if every element is uniquely the sum of an idempotent and a unit that commute.In this article,some conditions on a ring R and a group G such that RG is clean are given.It is also shown that if G is a locally finite group,then the group ring RG is USC if and only if R is USC,and G is a 2-group.The left uniquely exchange group ring,as a middle ring of the uniquely clean ring and the USC ring,does not possess this property,and so does the uniquely exchange group ring.

MM-rallin vaikutus Toyotan brändiin

OpenAIRE

Laurila, Heini

2017-01-01

Tämän insinöörityön tarkoituksena oli selvittää, millainen vaikutus MM-ralliin palaamisella on Toyotan brändiin Suomessa. Insinöörityö toteutettiin yhteistyössä Suomen Toyotan ja Lexuksen maahantuojayrityksen, Toyota Auto Finland Oy:n sekä AKK Sports Oy:n kanssa. AKK Sports Oy on vastuussa vuosittaisen Suomen MM-ralliosakilpailun, Neste Rallin, järjestämisestä. Tutkimuksen taustatyönä tutustuttiin ensin brändejä ja markkinointia koskevaan kirjallisuuteen. Sen lisäksi käytiin läpi Toyotan ...

Formation and Characterization of Silver Nanoparticle Composite with Poly(p-Br/F-phenylsilane).

Science.gov (United States)

Roh, Sung-Hee; Noh, Ji Eun; Woo, Hee-Gweon; Cho, Myong-Shik; Sohn, Honglae

2015-02-01

The one-pot production and structural characterization of composites of silver nanoparticles with poly(p-Br/F-phenylsilane), Br/F-PPS, have been performed. The conversion of Ag+ ions to stable Ag0 nanoparticles is mediated by the copolymer Br/F-PPS having both possibly reactive Si-H bonds in the polymer backbone and C-Br bonds in the substituents along with relatively inert C-F bonds. Transmission electron microscopy and field emission scanning electron microscopy analyses show the formation of the composites where silver nanoparticles (less than 30 nm of size) are well dispersed over the Br/F-PPS matrix. X-ray diffraction patterns are consistent with that for face-centered-cubic typed silver. The polymer solubility in toluene implys that the cleavage of C-Br bond and the Si-F dative bonding may not be occurred appreciably at ambient temperature. Nonetheless, thermogravimetric analysis data suggest that some sort of cross-linking could take place at high temperature. Most of the silver particles undergo macroscopic aggregation without Br/F-PPS, which indicates that the polysilane is necessary for stabilizing the silver nanoparticles.

Life extension of the BR2 aluminium vessel

International Nuclear Information System (INIS)

Koonen, E.; Fabry, A.; Chaouadi, R.; Verwerft, M.; Raedt, C. de; Winckel, S. van; Wacquier, W.; Dadoumont, J.; Verwimp, A.

2000-01-01

The BR2 reactor has recently undergone a major refurbishment comprising the replacement of all vessel internals. The vessel itself however was not replaced. An important requalification programme has been executed to prove that the vessel would remain fit during the contemplated life extension period of BR2. Representative material samples could be obtained from the shroud surrounding the vessel. A comprehensive in-service inspection was carried out and a vessel surveillance programme has been established. (author)

Influence of ring growth rate on damage development in hot ring rolling

NARCIS (Netherlands)

Wang, C.; Geijselaers, H. J.M.; Omerspahic, E.; Recina, V.; van den Boogaard, A. H.

2015-01-01

As an incremental forming process of bulk metal, ring rolling provides a cost effective process route to manufacture seamless rings. In the production of hot rolled rings, defects such as porosity can sometimes be found in high alloyed steel, manufactured from ingots having macro-segregation. For

Pan-Balti bränding - müüt või tegelikkus? / Joel Volkov

Index Scriptorium Estoniae

Volkov, Joel, 1972-

2006-01-01

Brändil pole kodumaad, on keel ja päritolumaa. Lokaalsed brändid valivad suhtlemiseks kohalikega nende kodukeele, globaalsed brändid harilikult inglise keele. Üks suuremaid ja tugevamaid lokaalsest süsteemist kasvanud Pan-Balti brände on Hansapank. Lisa: Sulev Vedler. Hansast võib saada Swedbank

Ring rotational speed trend analysis by FEM approach in a Ring Rolling process

Science.gov (United States)

Allegri, G.; Giorleo, L.; Ceretti, E.

2018-05-01

Ring Rolling is an advanced local incremental forming technology to fabricate directly precise seamless ring-shape parts with various dimensions and materials. In this process two different deformations occur in order to reduce the width and the height of a preform hollow ring; as results a diameter expansion is obtained. In order to guarantee a uniform deformation, the preform is forced toward the Driver Roll whose aim is to transmit the rotation to the ring. The ring rotational speed selection is fundamental because the higher is the speed the higher will be the axial symmetry of the deformation process. However, it is important to underline that the rotational speed will affect not only the final ring geometry but also the loads and energy needed to produce it. Despite this importance in industrial environment, usually, a constant value for the Driver Roll angular velocity is set so to result in a decreasing trend law for the ring rotational speed. The main risk due to this approach is not fulfilling the axial symmetric constrain (due to the diameter expansion) and to generate a high localized ring section deformation. In order to improve the knowledge about this topic in the present paper three different ring rotational speed trends (constant, linearly increasing and linearly decreasing) were investigated by FEM approach. Results were compared in terms of geometrical and dimensional analysis, loads and energies required.

Transient photoelectron spectroscopy of the dissociative Br2(1Piu) state.

Science.gov (United States)

Strasser, Daniel; Goulay, Fabien; Leone, Stephen R

2007-11-14

Photodissociation of bromine on the Br2(1Piu) state is probed with ultrafast extreme ultraviolet (53.7 nm) single-photon ionization. Time-resolved photoelectron spectra show simultaneously the depletion of ground state bromine molecules as well as the rise of Br(2P3/2) products due to 402.5 nm photolysis. A partial photoionization cross-section ratio of atomic versus molecular bromine is obtained. Transient photoelectron spectra of a dissociative wave packet on the excited state are presented in the limit of low-power-density, single-photon excitation to the dissociative state. Transient binding energy shifts of "atomic-like" photoelectron peaks are observed and interpreted as photoionization of nearly separated Br atom pairs on the Br2(1Piu) state to repulsive dissociative ionization states.

Ring correlations in random networks.

Science.gov (United States)

Sadjadi, Mahdi; Thorpe, M F

2016-12-01

We examine the correlations between rings in random network glasses in two dimensions as a function of their separation. Initially, we use the topological separation (measured by the number of intervening rings), but this leads to pseudo-long-range correlations due to a lack of topological charge neutrality in the shells surrounding a central ring. This effect is associated with the noncircular nature of the shells. It is, therefore, necessary to use the geometrical distance between ring centers. Hence we find a generalization of the Aboav-Weaire law out to larger distances, with the correlations between rings decaying away when two rings are more than about three rings apart.

The mechanical properties of radiation-vulcanized NR/BR blending system

Energy Technology Data Exchange (ETDEWEB)

Yan Aoshuang E-mail: yanas@public3.bta.net.cn; Guo Zhengtao; Li Li; Zhai Ying; Zhou Peng

2002-03-01

The effect of radiation dose on the mechanical properties of NR/BR blending system is reported in this paper. A comparison was made between sulphur vulcanization and radiation vulcanization for an optimal nature rubber (NR)/ butyl rubber (BR) blending ratio (60/40) at dose range from 10 to 150 kGy. The result shows that the mechanical properties, especially, tensile strength, elongation at break, and tear strength have been improved significantly by radiation-vulcanization. This finding was also proved by thermal aging experiment on a selected NR/BR blend at 70 deg. C for up to 168 h.

Fluorescence Blinking and Photoactivation of All-Inorganic Perovskite Nanocrystals CsPbBr3 and CsPbBr2I.

Science.gov (United States)

Seth, Sudipta; Mondal, Navendu; Patra, Satyajit; Samanta, Anunay

2016-01-21

Study of the emission behavior of all-inorganic perovskite nanocrystals CsPbBr3 and CsPbBr2I as a function of the excitation power employing fluorescence correlation spectroscopy and conventional techniques reveals fluorescence blinking in the microsecond time scale and photoinduced emission enhancement. The observation provides insight into the radiative and nonradiative deactivation pathways of these promising substances. Because both blinking and photoactivation processes are intimately linked to the charge separation efficiency and dynamics of the nanocrystals, these key findings are likely to be helpful in realizing the true potential of these substances in photovoltaic and optoelectronic applications.

Alpha - Skew Pi - Armendariz Rings

Directory of Open Access Journals (Sweden)

Areej M Abduldaim

2018-03-01

Full Text Available In this article we introduce a new concept called Alpha-skew Pi-Armendariz rings (Alpha - S Pi - ARas a generalization of the notion of Alpha-skew Armendariz rings.Another important goal behind studying this class of rings is to employ it in order to design a modern algorithm of an identification scheme according to the evolution of using modern algebra in the applications of the field of cryptography.We investigate general properties of this concept and give examples for illustration. Furthermore, this paperstudy the relationship between this concept and some previous notions related to Alpha-skew Armendariz rings. It clearly presents that every weak Alpha-skew Armendariz ring is Alpha-skew Pi-Armendariz (Alpha-S Pi-AR. Also, thisarticle showsthat the concepts of Alpha-skew Armendariz rings and Alpha-skew Pi- Armendariz rings are equivalent in case R is 2-primal and semiprime ring.Moreover, this paper proves for a semicommutative Alpha-compatible ringR that if R[x;Alpha] is nil-Armendariz, thenR is an Alpha-S Pi-AR. In addition, if R is an Alpha - S Pi -AR, 2-primal and semiprime ring, then N(R[x;Alpha]=N(R[x;Alpha]. Finally, we look forwardthat Alpha-skew Pi-Armendariz rings (Alpha-S Pi-ARbe more effect (due to their properties in the field of cryptography than Pi-Armendariz rings, weak Armendariz rings and others.For these properties and characterizations of the introduced concept Alpha-S Pi-AR, we aspire to design a novel algorithm of an identification scheme.

Molecular characterisation of an avihepadnavirus isolated from Psittacula krameri (ring-necked parrot).

Science.gov (United States)

Piasecki, Tomasz; Kurenbach, Brigitta; Chrząstek, Klaudia; Bednarek, Karolina; Kraberger, Simona; Martin, Darren P; Varsani, Arvind

2012-03-01

Avihepadnaviruses have been documented previously in ducks, herons, geese, storks and cranes. Here, we describe the full genome of a new avihepadnavirus isolated from Psittacula krameri (ring-necked parrot) in Poland. The parrot hepatitis B virus (PHBV) genome (3042 bp) shares <76% sequence identity with other avihepadnavirus isolates and is phylogenetically most closely related to heron and stork hepatitis B viruses isolates. PHBV has a genome organization similar to that of other hepadnaviruses and contains ORFs for a preC/C, preS/S and polyprotein. Additionally, we identified an X-like ORF in the genome of PHBV. The full-genome data will be useful in developing screening tools for avihepadnaviruses in parrots.

Stratospheric BrO abundance measured by a balloon-borne submillimeterwave radiometer

Directory of Open Access Journals (Sweden)

R. A. Stachnik

2013-03-01

Full Text Available Measurements of mixing ratio profiles of stratospheric bromine monoxide (BrO were made using observations of BrO rotational line emission at 650.179 GHz by a balloon-borne SIS (superconductor-insulator-superconductor submillimeterwave heterodyne limb sounder (SLS. The balloon was launched from Ft. Sumner, New Mexico (34° N on 22 September 2011. Peak mid-day BrO abundance varied from 16 ± 2 ppt at 34 km to 6 ± 4 ppt at 16 km. Corresponding estimates of total inorganic bromine (Bry, derived from BrO vmr (volume mixing ratio using a photochemical box model, were 21 ± 3 ppt and 11 ± 5 ppt, respectively. Inferred Bry abundance exceeds that attributable solely to decomposition of long-lived methyl bromide and other halons, and is consistent with a contribution from bromine-containing very short lived substances, BryVSLS, of 4 ppt to 8 ppt. These results for BrO and Bry were compared with, and found to be in good agreement with, those of other recent balloon-borne and satellite instruments.

Plasma-ring, fast-opening switch

International Nuclear Information System (INIS)

Hartman, C.W.; Eddleman, J.; Hammer, J.H.

1986-01-01

The authors discuss a fast-opening switch concept based on magnetically confined plasma rings, PROS (for Plasma Ring Opening Switch). In PROS, the plasma ring, confined by Bθ /sub and B/poloidal /sub fields of a compact torus, provide a low mass, localized conduction path between coaxial electrodes. To operate the switch, driver current is passed across the electrodes through the ring, storing inductive energy in external inductance and between the electrodes on the driver side of the ring. The ring is accelerated away from the driver by the field of the driver current and passes over a load gap transferring the current to the load. The authors distinguish two configurations in PROS, straight PROS where the electrodes are coaxial cylinders, and cone PROS with conical electrodes. In straight PROS ring acceleration takes place during the inductive store period as in foil switches, but with the localized ring providing the current path. Increased performance is predicted for the cone PROS (see figure) which employs compression of the ring in the cone during the inductive store period. Here, the B/θ /sub field of the driver forces the ring towards the apex of the cone but the force is in near balance with the opposing component of the radial equilibrium force of the ring along the cone. As a result, the ring undergoes a slow, quasistatic compression limited only by resistive decay of the ring field. Slow compression allows inductive storage with low-power drivers (homopoloar, magneto cumulative generators, high C-low V capacitor banks, etc.). Near the apex of the cone, near peak compression, the ring is allowed to enter a straight coaxial section where, because of low-mass, it rapidly accelerates to high velocity and crosses the load gap

Validade concorrente da versão Brasileira do SRS-22r com o Br-SF-36 Concurrent validity of the Brazilian version of SRS-22r with Br-SF-36

Directory of Open Access Journals (Sweden)

Giselle C. L. Rosanova

2010-04-01

Full Text Available CONTEXTUALIZAÇÃO: A validade concorrente, relevante na adaptação transcultural, refere-se à relação entre o desempenho do instrumento de interesse e o desempenho de instrumento semelhante com validade conhecida. OBJETIVO: Realizar a validação concorrente da versão brasileira do questionário revisado da Scoliosis Research Society (Br-SRS-22r com a versão brasileira do Short Form-36 (Br-SF-36. MÉTODOS: Foram selecionados 54 pacientes com escoliose idiopática com média de 19,9 anos (±7,7 e curvaturas com média de 31,6° (±20,5° graus Cobb, variando entre 10º e 92º. Os questionários tiveram seus resultados convertidos em escores, e a análise estatística correlacionou os domínios concorrentes utilizando o cálculo de coeficiente de Spearman. RESULTADOS: Os domínios de melhor correlação foram função do Br-SRS-22r com função física do Br-SF-36 (r=0,83 e dor do Br-SRS-22r com dor do Br-SF-36 (r=0,86. Entretanto, os domínios autoimagem e satisfação com o tratamento do Br-SRS-22r apresentaram baixa correlação com seus domínios concorrentes do Br-SF-36. DISCUSSÃO: Houve uma correlação satisfatória entre os questionários, sendo que as melhores correlações indicam maior semelhança nos parâmetros avaliados entre os respectivos instrumentos. As melhores correlações foram as dos domínios função e dor, não ocorrendo em saúde mental, possivelmente devido às dificuldades de interpretação de suas questões no Br-SF-36. Para os domínios autoimagem e satisfação com o tratamento do Br-SRS-22r, a correlação é pouco satisfatória por não serem especificamente abordados pelo SF-36. CONCLUSÃO: A versão brasileira do SRS-22r apresentou resultados satisfatórios para a validação concorrente com o Br-SF-36, sendo considerada válida para a versão adaptada à cultura brasileira.BACKGROUND: An important parameter in cross-cultural adaptations, and concurrent validity are the relationships between the

Physical properties of pre-crystallized mixtures of cocoa butter and cupuassu fat

Directory of Open Access Journals (Sweden)

Quast, L. B.

2011-03-01

Full Text Available The physical characteristics of pre-crystallized binary mixtures of cocoa butter (Bahia + Indonesian blend and 5, 10, 15, 20, 25 and 30% (w/w cupuassu fat were determined. Precrystallization was carried out using a lab-scale agitated jacket vessel reactor (700 mL. Samples were submitted to differential scanning calorimetry and X-Ray diffraction. The solid fat content and rupture force were also quantified. The snap values of the crystallized mixture decreased with an increase in the amount of alternative fat. A similar trend was observed with respect to the melting point values. The cocoa butter and cupuassu fat X-ray diffraction patterns confirmed the predominant formation of the β polimorph. The addition of up to 30% cupuassu fat did not significantly affect the values of the physical properties when compared to pure cocoa butter.<br>>Se han determinado las características físicas de mezclas binarias pre-cristalizadas de manteca de cacao (mezcla de Bahia + Indonesia con 5, 10, 15, 20, 25 y 30 % (m/m de grasa de cupuassu. La pre-cristalización se ha efectuado a escala de laboratorio utilizando un reactor de vidrio con camisa (700mL con agitación. Las muestras fueron analizadas mediante calorimetría diferencial de barrido, difracción de rayos- X, contenido en grasa solida y tensión de ruptura. Los valores de tensión de ruptura de las mezclas pre-cristalizadas disminuyeron con la incorporación de grasa de cupuassu, siendo este comportamiento observado también para el punto de fusión. Después de la pre-cristalización, manteca de cacao y grasa de cupuassu confirmaron la presencia de polimorfismo β, por medio de análisis de difracción de rayos-X. La adición de hasta 30% de grasa de cupuassu en la manteca de cacao no afecta de modo significativo en las propiedades físicas cuando son comparadas con la manteca de cacao pura.

Fusion Rings for Quantum Groups

DEFF Research Database (Denmark)

Andersen, Henning Haahr; Stroppel, Catharina

2014-01-01

We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction...... and a realisation as quotient of quantum cohomology. Adv. Math. 225(1), 200–268, (2010) and give a similar description of the sp2n-fusion ring in terms of non-commutative symmetric functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also...... compute the fusion rings for type G2....

The LSU Electron Storage Ring, the first commercially-built storage ring

International Nuclear Information System (INIS)

Sah, R.

1990-01-01

The Brobeck Division of Maxwell Laboratories, Inc., is building the first industrially-produced storage ring. It will be located at Louisiana State University (LSU) at the Center for Advanced Microstructures and Devices (CAMD) in Baton Rouge. The purpose of this electron storage ring is to provide intense beams of x-rays to advance the state-of-the-art in lithography and to permit research in a broad area. This facility consists of a 1.2 GeV, 400 mA electron storage ring with a 200 MeV linac injector. The magnet lattice is a Chasman-Green design (double-bend achromat), and the ring circumference is 55.2 meters. There are four 3.0 meter, dispersion-free straight sections, one for injection, one for the 500 MHz RF cavity, and two for possible future insertion devices. The storge ring construction project is in the detailed-design stage, and many systems are in the initial stages of fabrication. 4 figs., 1 tab

Fusion rings and fusion ideals

DEFF Research Database (Denmark)

Andersen, Troels Bak

by the so-called fusion ideals. The fusion rings of Wess-Zumino-Witten models have been widely studied and are well understood in terms of precise combinatorial descriptions and explicit generating sets of the fusion ideals. They also appear in another, more general, setting via tilting modules for quantum......This dissertation investigates fusion rings, which are Grothendieck groups of rigid, monoidal, semisimple, abelian categories. Special interest is in rational fusion rings, i.e., fusion rings which admit a finite basis, for as commutative rings they may be presented as quotients of polynomial rings...

Refurbishment programme for the BR2-reactor

Energy Technology Data Exchange (ETDEWEB)

Koonen, E [Centre d' Etude de l' Energie Nucleaire, Studiecentrum voor Kernenergie, BR2 Department, Boeretang, Mol (Belgium)

1992-07-01

BR2 is a high flux engineering test reactor, which differs from comparable material testing reactors by its specific core array (fig. 1). It is a heterogeneous, thermal, tank-in-pool type reactor, moderated by beryllium and light water, which serves also as coolant. The fuel elements consist of cylindrical assemblies loaded in channels materialized by hexagonal beryllium prisms. The central 200 mm channel is vertical, while all others are inclined and form a hyperbolical arrangement around the central one. This feature combines a very compact core with the requirement of sufficient space for individual access to all channels through penetrations in the top cover of the aluminium pressure vessel. Each channel may hold a fuel element, a control rod, an experiment, an irradiation device or a beryllium plug. The refurbishment Program According to the present programme of C.E.N./S.C.K., BR2 will be in operation until 1996. At that time, the beryllium matrix will reach its foreseen end-of-life. In order to continue operation beyond this point, a thorough refurbishment of the reactor is foreseen, in addition to the unavoidable replacement of the matrix, to ensure quality of the installation and compliance with modern standards. Some fundamental options have been taken as a starting point: BR2 will continue to be used as a classical MTR, i.e. fuel and material irradiations and safety experiments with some additional service-activities. The present configuration is optimized for that use and there is no specific experimental requirement to change the basic concepts and performance characteristics. From the customers viewpoint, it is desirable to go ahead with the well-known features of BR2, to maintain a high degree of availability and reliability and to minimize the duration of the long shutdown. It is also important to limit the amount of nuclear liabilities. So the objective of the refurbishment programme is the life extension of BR2 for about 15 years, corresponding to

Refurbishment programme for the BR2-reactor

International Nuclear Information System (INIS)

Koonen, E.

1992-01-01

BR2 is a high flux engineering test reactor, which differs from comparable material testing reactors by its specific core array (fig. 1). It is a heterogeneous, thermal, tank-in-pool type reactor, moderated by beryllium and light water, which serves also as coolant. The fuel elements consist of cylindrical assemblies loaded in channels materialized by hexagonal beryllium prisms. The central 200 mm channel is vertical, while all others are inclined and form a hyperbolical arrangement around the central one. This feature combines a very compact core with the requirement of sufficient space for individual access to all channels through penetrations in the top cover of the aluminium pressure vessel. Each channel may hold a fuel element, a control rod, an experiment, an irradiation device or a beryllium plug. The refurbishment Program According to the present programme of C.E.N./S.C.K., BR2 will be in operation until 1996. At that time, the beryllium matrix will reach its foreseen end-of-life. In order to continue operation beyond this point, a thorough refurbishment of the reactor is foreseen, in addition to the unavoidable replacement of the matrix, to ensure quality of the installation and compliance with modern standards. Some fundamental options have been taken as a starting point: BR2 will continue to be used as a classical MTR, i.e. fuel and material irradiations and safety experiments with some additional service-activities. The present configuration is optimized for that use and there is no specific experimental requirement to change the basic concepts and performance characteristics. From the customers viewpoint, it is desirable to go ahead with the well-known features of BR2, to maintain a high degree of availability and reliability and to minimize the duration of the long shutdown. It is also important to limit the amount of nuclear liabilities. So the objective of the refurbishment programme is the life extension of BR2 for about 15 years, corresponding to

Wafer-Level Packaging Method for RF MEMS Applications Using Pre-Patterned BCB Polymer

OpenAIRE

Zhuhao Gong; Yulong Zhang; Xin Guo; Zewen Liu

2018-01-01

A radio-frequency micro-electro-mechanical system (RF MEMS) wafer-level packaging (WLP) method using pre-patterned benzo-cyclo-butene (BCB) polymers with a high-resistivity silicon cap is proposed to achieve high bonding quality and excellent RF performance. In this process, the BCB polymer was pre-defined to form the sealing ring and bonding layer by the spin-coating and patterning of photosensitive BCB before the cavity formation. During anisotropic wet etching of the silicon wafer to gener...

Bréal, un antinaturalisme d’inspiration humboldtienne

Directory of Open Access Journals (Sweden)

Babu Jean-Philippe

2014-07-01

Full Text Available Dans De la forme et de la fonction des mots, Bréal formulait, dès 1866, outre une critique générale du formalisme de la philologie comparative depuis Bopp, une thèse radicalement opposée à l’orientation naturaliste de l’évolutionnisme linguistique de Schleicher. Cette thèse, que nous prendrons le risque de définir comme thèse du primat de la fonction sur la forme linguistique, est au coeur de ce programme de linguistique générale pour lequel Bréal allait forger, quelques années plus tard, le mot de sémantique. Fortement marqué par la notion humboldtienne d’innere Sprachform, Bréal, contrairement à Saussure, n'abandonnera jamais le changement linguistique au hasard de l'histoire et maintiendra l'intelligence comme premier moteur des langues, quitte à poser la nécessité de repenser cette intelligence.

Evaluation of pre-treatments for inhibiting bromate formation during ozonation

DEFF Research Database (Denmark)

Antoniou, Maria; Andersen, Henrik Rasmus

2011-01-01

This study compared several pre-treatment methods for inhibiting BrO3- formation during ozonation of tap water, from the DTU campus, including H2O2 addition (perozone), pH-depression, NH4+ and Cl2/NH4+ addition. At the same time, the inhibition of atrazine and carbamazepine removal was evaluated...... close to the 10 μg/L limit, however atrazine removal did not exceed 75%. Carbamazepine was completely removed under all the tested experimental conditions with the 3.5 mg/L O3 dose....

CsPb2Br5 Single Crystals: Synthesis and Characterization

KAUST Repository

Dursun, Ibrahim; de Bastiani, Michele; Turedi, Bekir; Alamer, Badriah Jaber; Shkurenko, Aleksander; Yin, Jun; Gereige, Issam; Alsaggaf, Ahmed; Mohammed, Omar F.; Eddaoudi, Mohamed; Bakr, Osman

2017-01-01

, which enabled us to finally clarify the material's optical features. Our CsPb2Br5 crystal has a two-dimensional structure with Pb2Br5- layers spaced by Cs+ cations, and exhibits a ~3.1 eV indirect bandgap with no emission in the visible spectrum.

Scientific activities in support of the BR2 operation and irradiation programmes

International Nuclear Information System (INIS)

Koonen, E.

2006-01-01

One of the major characteristics of the BR2 reactor is the fact that the core configuration is essentially variable. This allows to optimize the irradiation conditions of various experiments and to minimize the fuel consumption. In order to do that, BR2 has its own autonomous reactor physics cell. In order to allow for on-line measurements of the major irradiation parameters, BR2 has extended its own proven data acquisition system to serve this purpose. This system, called BIDASSE (for BR2 Integrated Data Acquisition System for Survey and Experiments), originally designed for the follow-up of all BR2 operational parameters, is since several years extensively used for experiments. The object rives of research at the BR2 are to evaluate and adjust provisional irradiation conditions by adjustments of the environment, axial and azimuthal positioning of the samples, global power level, ... ; to deliver reliable, well defined irradiation condition and fluence data during and after irradiation; to assist the designer of new irradiation devices by simulations and neutronic optimisations of design options and o provide the experimenters with accurate on-line information on the evolution of their ongoing irradiation projects

Atmospheric Lifetime of CHF2Br, a Proposed Substitute for Halons.

Science.gov (United States)

Talukdar, R; Mellouki, A; Gierczak, T; Burkholder, J B; McKeen, S A; Ravishankara, A R

1991-05-03

The rate coefficients, k(1), for the reaction of OH with CHF(2)Br have been measured using pulsed photolysis and discharge flow techniques at temperatures (T) between 233 and 432 K to be k(1), = (7.4 +/- 1.6) x 10(-13) exp[-(1300 +/- 100)/T] cubic centimeters per molecule per second. The ultraviolet absorption cross sections, sigma, of this molecule between 190 and 280 nanometers were measured at 296 K. The k(1), and sigma values were used in a one-dimensional model to obtain an atmospheric lifetime of approximately 7 years for CHF(2)Br. This lifetime is shorter by approximately factors of 10 and 2 than those for CF(3)Br and CF(2)ClBr, respectively. The ozone depletion potentials of the three compounds will reflect these lifetimes.

Effect of nepheline syenite particle size on diametrical compression strength and reliability of extruded ceramic Raschig rings used in packed towers

Directory of Open Access Journals (Sweden)

Salem, Amin

2013-04-01

Full Text Available In order to understand the effect of nepheline syenite particle size on physico-chemical properties of ceramic Raschig rings, the fluxing agent was grinded at different milling times. The compositions were prepared by blending the illitic-kaolinitic clay and pre-grinded particles. The rings were shaped by a laboratory extruder and then were sintered at 1200 ºC. The mechanical reliability of sintered specimens was mathematically described by Weibull theory and the effect of pre-grinding of fluxing agent on Weibull modulus was evaluated by measuring the diametrical compression strength. Weibull modulus and strength were the criteria for selecting the suitable particle size range of nepheline syenite. It was found that the pre-grinding of nepheline syenite acts as fairly strong parameter on microstructure of rings. The investigation concludes that reliable rings can be fabricated if the particle size of nepheline syenite is arranged between 53 and 75 μm. This enhancement in reliability is valuable in packed towers.Para conocer el efecto del tamaño de partícula de nefelina sienita sobre las propiedades fisicoquímicas de los anillos Raschig cerámicos, este fundente fue molido a diferentes tiempos. Las composiciones se prepararon mediante la mezcla de la arcilla caolinítica illitica y las partículas pre-molidas. Los anillos se obtuvieron en una extrusora de laboratorio y luego fueron sinterizados a 1200 ºC. La fiabilidad mecánica de las muestras sinterizadas se describe matemáticamente por la teoría de Weibull y el efecto de pre-molienda del fundente en el módulo de Weibull se evaluó midiendo la resistencia a la compresión diametral. El módulo de Weibull y la resistencia fueron los criterios para seleccionar el rango de tamaño de partícula adecuado de nefelina sienita para la fabricación de los anillos que se determinó estaba entre 53 y 75 μm comprobándose que influye considerablemente en la microestructura de los mismos. La

The carcinogenicity of 1-methyl-3(p-bromophenyl)-1-nitrosourea (Br-MPNU).

Science.gov (United States)

Warzok, R; Martin, J; Mendel, J; Thust, R; Schwarz, H

1983-01-01

In long-term experiments with Hooded rats the carcinogenic potential of 1-methyl-3(p-bromophenyl)-1-nitrosourea (Br-MPNU) could be demonstrated for the first time. Br-MPNU is formed also endogenously after combined administration of 1-methyl-3(p-bromophenyl)-urea (Br-MPU) and sodium nitrite. After repeated intragastric administration of 0.33 mmol Br-MPU and 0.73 mmol NaNO2 per kg b.w. papillomas and carcinomas of the forestomach developed in 83%. After repeated administration of 0.28 mmol Br-MPNU per kg b.w. these neoplasms were observed in 88%. The comparison of results obtained in similar experiments with 1-methyl-3-phenyl-1-nitrosourea shows that bromine substitution led to a reduction of the carcinogenic activity. The present paper is part of a complex program studying the interrelationships between structure, physico-chemical properties, mutagenicity and carcinogenicity of nitrosoureas.

Evaluation of ring impedance of the Photon Factory storage ring

International Nuclear Information System (INIS)

Kiuchi, T.; Izawa, M.; Tokumoto, S.; Hori, Y.; Sakanaka, S.; Kobayashi, M.; Kobayakawa, H.

1992-05-01

The loss parameters of the ducts in the Photon Factory (PF) storage ring were evaluated using the wire method and the code TBCI. Both the measurement and the calculation were done for a different bunch length (σ) ranging from 23 to 80 ps. The PF ring impedance was estimated to be |Z/n|=3.2 Ω using the broadband impedance model. The major contribution to the impedance comes from the bellows and the gate valve sections. Improvements of these components will lower the ring impedance by half. (author)

Determination of nuclear cross-section of 81Br (n,,,) Br82 reaction by ...

African Journals Online (AJOL)

... flux of 4.2 x 1013 n cm-2 s-1. The BaBr2 was chemically processed and measured as Hydrogen Bromide (HBr82). The value of nuclear cross-section was determined to be 2.1 0.2 barns, which falls within the range of values as previously reported elsewhere. (Journal of Applied Science and Technology: 2001 6(1-2): 4-6) ...

Status of the BR2 refurbishment programme

International Nuclear Information System (INIS)

Koonen, E.

1995-01-01

The operation of the BR2 reactor with its second beryllium matrix is foreseen up to mid-1995. A refurbishment programme has been established in order to allow for future operation during at least ten years. Recently a positive decision to effectively carry out this programme has been taken. The refurbishment action plan follows from a general assessment of the different systems of BR2, with respect to their actual status, the operational experience and the evolution of safety standards and criteria. Ageing considerations were of uppermost importance in those assessments, not only to assure safety of future operation, but also to guarantee future availability and reliability. (orig.)

Stratospheric BrONO2 observed by MIPAS

Directory of Open Access Journals (Sweden)

H. Fischer

2009-03-01

Full Text Available The first measurements of stratospheric bromine nitrate (BrONO2 are reported. Bromine nitrate has been clearly identified in atmospheric infrared emission spectra recorded with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS aboard the European Envisat satellite, and stratospheric concentration profiles have been determined for different conditions (day and night, different latitudes. The BrONO2 concentrations show strong day/night variations, with much lower concentrations during the day. Maximum volume mixing ratios observed during night are 20 to 25 pptv. The observed concentration profiles are in agreement with estimations from photochemical models and show that the current understanding of stratospheric bromine chemistry is generally correct.

Study on effects of gamma-ray irradiation on TlBr semiconductor detectors

International Nuclear Information System (INIS)

Matsumura, Motohiro; Watanabe, Kenichi; Yamazaki, Atsushi; Uritani, Akira; Kimura, Norihisa; Nagano, Nobumichi; Hitomi, Keitaro

2016-01-01

Radiation hardness of thallium bromide (TlBr) semiconductor detectors to 60 Co gamma-ray irradiation was evaluated. The energy spectra and μτ products of electrons were measured to evaluate the irradiation effects. No significant degradation of spectroscopic performance of the TlBr detector for 137 Cs gamma-rays was observed up to 45 kGy irradiation. Although the μτ products of electrons in the TlBr detector slightly decreased, position of the photo-peak was stable without significant degradation after the gamma-ray irradiation. We confirmed that the TlBr semiconductor detector has a high tolerance for gamma-ray irradiation at least up to 45 kGy. (author)

Ge14 Br8 (PEt3 )4 : A Subhalide Cluster of Germanium.

Science.gov (United States)

Kunz, Tanja; Schrenk, Claudio; Schnepf, Andreas

2018-04-03

Heating a metastable solution of Ge I Br to room temperature led to the first structurally characterized metalloid subhalide cluster Ge 14 Br 8 (PEt 3 ) 4 (1). Furthermore 1 can be seen as the first isolated binary halide cluster on the way from Ge I Br to elemental germanium, giving insight into the complex reaction mechanism of its disproportionation reaction. Quantum chemical calculations further indicate that a classical bonding situation is realized within 1 and that the last step of the formation of 1 might include the trapping of GeBr 2 units. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Skandaalin vaikutus brändin imagoon - Case Audi

OpenAIRE

Puntalo, Ville-Veikko

2016-01-01

Opinnäytetyössä tutkittiin Volkswagenin päästöhuijausskandaalin vaikutusta Audi-brändin imagoon. Tutkimuksessa pyrittiin selvittämään onko ennakoitavissa mahdollisia myyntitulosten muutoksia ja johtuivatko ne kyseisestä skandaalista. Opinnäytetyön teoriaosuudessa perehdyttiin ostokäyttäytymisen prosessiin, brändin rakentumiseen, positiivisen maineen saavuttamiseen ja tunnettuihin yritysmaailman skandaaleihin. Lisäksi käytiin läpi Volkswagen päästöskandaalin taustaa sekä sen seurauksia. ...

Metal Halide Perovskite Supercrystals: Gold-Bromide Complex Triggered Assembly of CsPbBr3 Nanocubes.

Science.gov (United States)

Wang, Kun-Hua; Yang, Jun-Nan; Ni, Qian-Kun; Yao, Hong-Bin; Yu, Shu-Hong

2018-01-16

Using nanocrystals as "artificial atoms" to construct supercrystals is an interesting process to explore the stacking style of nanoscale building blocks and corresponding collective properties. Various types of semiconducting supercrystals have been constructed via the assembly of nanocrystals driven by the entropic, electrostatic, or van der Waals interactions. We report a new type of metal halide perovskite supercrystals via the gold-bromide complex triggered assembly of newly emerged attractive CsPbBr 3 nanocubes. Through introducing gold-bromide (Au-Br) complexes into CsPbBr 3 nanocubes suspension, the self-assembly process of CsPbBr 3 nanocubes to form supercrystals was investigated with the different amount of Au-Br complexes added to the suspensions, which indicates that the driven force of the formation of CsPbBr 3 supercrystals included the van der Waals interactions among carbon chains and electrostatic interactions between Au-Br complexes and surfactants. Accordingly, the optical properties change with the assembly of CsPbBr 3 nanocubes and the variation of mesoscale structures of supercrystals with heating treatment was revealed as well, demonstrating the ionic characteristics of CsPbBr 3 nanocrystals. The fabricated CsPbBr 3 supercrystal presents a novel type of semiconducting supercrystals that will open an avenue for the assembly of ionic nanocrystals.

Phase 1 Safety, Pharmacokinetics, and Pharmacodynamics of Dapivirine and Maraviroc Vaginal Rings: A Double-Blind Randomized Trial.

Science.gov (United States)

Chen, Beatrice A; Panther, Lori; Marzinke, Mark A; Hendrix, Craig W; Hoesley, Craig J; van der Straten, Ariane; Husnik, Marla J; Soto-Torres, Lydia; Nel, Annalene; Johnson, Sherri; Richardson-Harman, Nicola; Rabe, Lorna K; Dezzutti, Charlene S

2015-11-01

Variable adherence limits effectiveness of daily oral and intravaginal tenofovir-containing pre-exposure prophylaxis. Monthly vaginal antiretroviral rings are one approach to improve adherence and drug delivery. MTN-013/IPM 026, a multisite, double-blind, randomized, placebo-controlled trial in 48 HIV-negative US women, evaluated vaginal rings containing dapivirine (DPV) (25 mg) and maraviroc (MVC) (100 mg), DPV only, MVC only, and placebo used continuously for 28 days. Safety was assessed by adverse events. Drug concentrations were quantified in plasma, cervicovaginal fluid (CVF), and cervical tissue. Cervical biopsy explants were challenged with HIV ex vivo to evaluate pharmacodynamics. There was no difference in related genitourinary adverse events between treatment arms compared with placebo. DPV and MVC concentrations rose higher initially before falling more rapidly with the combination ring compared with relatively stable concentrations with the single-drug rings. DPV concentrations in CVF were 1 and 5 log10 greater than cervical tissue and plasma for both rings. MVC was consistently detected only in CVF. DPV and MVC CVF and DPV tissue concentrations dropped rapidly after ring removal. Cervical tissue showed a significant inverse linear relationship between HIV replication and DPV levels. In this first study of a combination microbicide vaginal ring, all 4 rings were safe and well tolerated. Tissue DPV concentrations were 1000 times greater than plasma concentrations and single drug rings had more stable pharmacokinetics. DPV, but not MVC, demonstrated concentration-dependent inhibition of HIV-1 infection in cervical tissue. Because MVC concentrations were consistently detectable only in CVF and not in plasma, improved drug release of MVC rings is needed.

Tree Rings: Timekeepers of the Past.

Science.gov (United States)

Phipps, R. L.; McGowan, J.

One of a series of general interest publications on science issues, this booklet describes the uses of tree rings in historical and biological recordkeeping. Separate sections cover the following topics: dating of tree rings, dating with tree rings, tree ring formation, tree ring identification, sample collections, tree ring cross dating, tree…

Receptionsanalyse og Brødre

DEFF Research Database (Denmark)

Hansen, Lennard Højbjerg

2016-01-01

Receptionsanalysen omfatter både teori og empiriske undersøgelse. Det er dog først, når man foretager kvalitative undersøgelser af tilskuernes reception, man ser de interessante forskelle i oplevelserne af film. Susanne Biers film "Brødre" danner udgangspunkt for kvalitative interviews med 6...

Site selective excitation spectroscopy of CsCdBr sub 3 :U sup 3 sup +

CERN Document Server

Yin Min

2002-01-01

The CsCdBr sub 3 :U sup 3 sup + crystal was grown by the Bridgman technique from the starting materials CsBr, CdBr sub 2 and UBr sub 4. X-ray check showed that the sample crystallized in the CsNiBr sub 3 structure. Under selective excitation at low temperature, the emission spectra and the fluorescence decay curve were measured and discussed

Comparative Study of Antimicrobial Activity of AgBr and Ag Nanoparticles (NPs)

Science.gov (United States)

Suchomel, Petr; Kvitek, Libor; Panacek, Ales; Prucek, Robert; Hrbac, Jan; Vecerova, Renata; Zboril, Radek

2015-01-01

The diverse mechanism of antimicrobial activity of Ag and AgBr nanoparticles against gram-positive and gram-negative bacteria and also against several strains of candida was explored in this study. The AgBr nanoparticles (NPs) were prepared by simple precipitation of silver nitrate by potassium bromide in the presence of stabilizing polymers. The used polymers (PEG, PVP, PVA, and HEC) influence significantly the size of the prepared AgBr NPs dependently on the mode of interaction of polymer with Ag+ ions. Small NPs (diameter of about 60–70 nm) were formed in the presence of the polymer with low interaction as are PEG and HEC, the polymers which interact with Ag+ strongly produce nearly two times bigger NPs (120–130 nm). The prepared AgBr NPs were transformed to Ag NPs by the reduction using NaBH4. The sizes of the produced Ag NPs followed the same trends – the smallest NPs were produced in the presence of PEG and HEC polymers. Prepared AgBr and Ag NPs dispersions were tested for their biological activity. The obtained results of antimicrobial activity of AgBr and Ag NPs are discussed in terms of possible mechanism of the action of these NPs against tested microbial strains. The AgBr NPs are more effective against gram-negative bacteria and tested yeast strains while Ag NPs show the best antibacterial action against gram-positive bacteria strains. PMID:25781988

Bromine cycle in subduction zones through in situ Br monitoring in diamond anvil cells

Science.gov (United States)

Bureau, Hélène; Foy, Eddy; Raepsaet, Caroline; Somogyi, Andrea; Munsch, Pascal; Simon, Guilhem; Kubsky, Stefan

2010-07-01

The geochemical partitioning of bromine between hydrous haplogranitic melts, initially enriched with respect to Br and aqueous fluids, has been continuously monitored in situ during decompression. Experiments were carried out in diamond anvil cells from 890 °C to room temperature and from 1.7 GPa to room pressure, typically from high P, T conditions corresponding to total miscibility (presence of a supercritical fluid). Br contents were measured in aqueous fluids, hydrous melts and supercritical fluids. Partition coefficients of bromine were characterized at pressure and temperature between fluids, hydrous melts and/or glasses, as appropriate: DBrfluid/melt = (Br) fluid/(Br) melt, ranges from 2.18 to 9.2 ± 0.5 for conditions within the ranges 0.66-1.7 GPa, 590-890 °C; and DBrfluid/glass = (Br) fluid/(Br) glass ranges from 60 to 375 at room conditions. The results suggest that because high pressure melts and fluids are capable of accepting high concentrations of bromine, this element may be efficiently removed from the slab to the mantle source of arc magmas. We show that Br may be highly concentrated in subduction zone magmas and strongly enriched in subduction-related volcanic gases, because its mobility is strongly correlated with that of water during magma degassing. Furthermore, our experimental results suggest that a non negligible part of Br present in the subducted slab may remain in the down-going slab, being transported toward the transition zone. This indicates that the Br cycle in subduction zones is in fact divided in two related but independent parts: (1) a shallower one where recycled Br may leave the slab with a water and silica-bearing "fluid" leading to enriched arc magmas that return Br to the atmosphere. (2) A deeper cycle where Br may be recycled back to the mantle maybe to the transition zone, where it may be present in high pressure water-rich metasomatic fluids.

The Soleil detailed pre-project report

International Nuclear Information System (INIS)

1999-01-01

The aim of the joint CNRS/CEA Soleil project was to develop a facility equipped with several synchrotron radiation sources and their associated experimental devices in order to answer the estimated research needs in this domain for the 20 to 30 forthcoming years. This document is the detailed pre-project. It describes the studies carried out and relative to the infrastructures and buildings, to the accelerators and light sources (storage ring, injector, radiation production), to the program of experiments, to the computer science aspects, and to the administrative and organisational aspects. (J.S.)

Homogeneous Synthesis and Electroluminescence Device of Highly Luminescent CsPbBr3 Perovskite Nanocrystals.

Science.gov (United States)

Wei, Song; Yang, Yanchun; Kang, Xiaojiao; Wang, Lan; Huang, Lijian; Pan, Daocheng

2017-03-06

Highly luminescent CsPbBr 3 perovskite nanocrystals (PNCs) are homogeneously synthesized by mixing toluene solutions of PbBr 2 and cesium oleate at room temperature in open air. We found that PbBr 2 can be easily dissolved in nonpolar toluene in the presence of tetraoctylammonium bromide, which allows us to homogeneously prepare CsPbBr 3 perovskite quantum dots and prevents the use of harmful polar organic solvents, such as N,N-dimethylformamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone. Additionally, this method can be extended to synthesize highly luminescent CH 3 NH 3 PbBr 3 perovskite quantum dots. An electroluminescence device with a maximal luminance of 110 cd/m 2 has been fabricated by using high-quality CsPbBr 3 PNCs as the emitting layer.

Cross-cultural adaptation, reliability and construct validity of the Tampa scale for kinesiophobia for temporomandibular disorders (TSK/TMD-Br) into Brazilian Portuguese.

Science.gov (United States)

Aguiar, A S; Bataglion, C; Visscher, C M; Bevilaqua Grossi, D; Chaves, T C

2017-07-01

Fear of movement (kinesiophobia) seems to play an important role in the development of chronic pain. However, for temporomandibular disorders (TMD), there is a scarcity of studies about this topic. The Tampa Scale for Kinesiophobia for TMD (TSK/TMD) is the most widely used instrument to measure fear of movement and it is not available in Brazilian Portuguese. The purpose of this study was to culturally adapt the TSK/TMD to Brazilian Portuguese and to assess its psychometric properties regarding internal consistency, reliability, and construct and structural validity. A total of 100 female patients with chronic TMD participated in the validation process of the TSK/TMD-Br. The intraclass correlation coefficient (ICC) was used for statistical analysis of reliability (test-retest), Cronbach's alpha for internal consistency, Spearman's rank correlation for construct validity and confirmatory factor analysis (CFA) for structural validity. CFA endorsed the pre-specified model with two domains and 12-items (Activity Avoidance - AA/Somatic Focus - SF) and all items obtained a loading factor greater than 0·4. Acceptable levels of reliability were found (ICC > 0·75) for all questions and domains of the TSK/TMD-Br. For internal consistency, Cronbach's α of 0·78 for both domains were found. Moderate correlations (0·40 Br scores versus catastrophising, depression and jaw functional limitation. TSK/TMD-Br 12 items and two-factor demonstrated sound psychometric properties (transcultural validity, reliability, internal consistency and structural validity). In such a way, the instrument can be used in clinical settings and for research purposes. © 2017 John Wiley & Sons Ltd.

Tuning growth cycles of Brassica crops via natural antisense transcripts of BrFLC.

Science.gov (United States)

Li, Xiaorong; Zhang, Shaofeng; Bai, Jinjuan; He, Yuke

2016-03-01

Several oilseed and vegetable crops of Brassica are biennials that require a prolonged winter cold for flowering, a process called vernalization. FLOWERING LOCUS C (FLC) is a central repressor of flowering. Here, we report that the overexpression of natural antisense transcripts (NATs) of Brassica rapa FLC (BrFLC) greatly shortens plant growth cycles. In rapid-, medium- and slow-cycling crop types, there are four copies of the BrFLC genes, which show extensive variation in sequences and expression levels. In Bre, a biennial crop type that requires vernalization, five NATs derived from the BrFLC2 locus are rapidly induced under cold conditions, while all four BrFLC genes are gradually down-regulated. The transgenic Bre lines overexpressing a long NAT of BrFLC2 do not require vernalization, resulting in a gradient of shortened growth cycles. Among them, a subset of lines both flower and set seeds as early as Yellow sarson, an annual crop type in which all four BrFLC genes have non-sense mutations and are nonfunctional in flowering repression. Our results demonstrate that the growth cycles of biennial crops of Brassica can be altered by changing the expression levels of BrFLC2 NATs. Thus, BrFLC2 NATs and their transgenic lines are useful for the genetic manipulation of crop growth cycles. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Some Aspects of Ring Theory

CERN Document Server

Herstein, IN

2011-01-01

S. Amitsur: Associative rings with identities.- I.N. Herstein: Topics in ring theory.- N. Jacobson: Representation theory of Jordan algebras.- I. Kaplansky: The theory of homological dimension.- D. Buchsbaum: Complexes in local ring theory.- P.H. Cohn: Two topics in ring theory.- A.W. Goldie: Non-commutative localisation.

TRIP-Br2 promotes oncogenesis in nude mice and is frequently overexpressed in multiple human tumors.

Science.gov (United States)

Cheong, Jit Kong; Gunaratnam, Lakshman; Zang, Zhi Jiang; Yang, Christopher M; Sun, Xiaoming; Nasr, Susan L; Sim, Khe Guan; Peh, Bee Keow; Rashid, Suhaimi Bin Abdul; Bonventre, Joseph V; Salto-Tellez, Manuel; Hsu, Stephen I

2009-01-20

Members of the TRIP-Br/SERTAD family of mammalian transcriptional coregulators have recently been implicated in E2F-mediated cell cycle progression and tumorigenesis. We, herein, focus on the detailed functional characterization of the least understood member of the TRIP-Br/SERTAD protein family, TRIP-Br2 (SERTAD2). Oncogenic potential of TRIP-Br2 was demonstrated by (1) inoculation of NIH3T3 fibroblasts, which were engineered to stably overexpress ectopic TRIP-Br2, into athymic nude mice for tumor induction and (2) comprehensive immunohistochemical high-throughput screening of TRIP-Br2 protein expression in multiple human tumor cell lines and human tumor tissue microarrays (TMAs). Clinicopathologic analysis was conducted to assess the potential of TRIP-Br2 as a novel prognostic marker of human cancer. RNA interference of TRIP-Br2 expression in HCT-116 colorectal carcinoma cells was performed to determine the potential of TRIP-Br2 as a novel chemotherapeutic drug target. Overexpression of TRIP-Br2 is sufficient to transform murine fibroblasts and promotes tumorigenesis in nude mice. The transformed phenotype is characterized by deregulation of the E2F/DP-transcriptional pathway through upregulation of the key E2F-responsive genes CYCLIN E, CYCLIN A2, CDC6 and DHFR. TRIP-Br2 is frequently overexpressed in both cancer cell lines and multiple human tumors. Clinicopathologic correlation indicates that overexpression of TRIP-Br2 in hepatocellular carcinoma is associated with a worse clinical outcome by Kaplan-Meier survival analysis. Small interfering RNA-mediated (siRNA) knockdown of TRIP-Br2 was sufficient to inhibit cell-autonomous growth of HCT-116 cells in vitro. This study identifies TRIP-Br2 as a bona-fide protooncogene and supports the potential for TRIP-Br2 as a novel prognostic marker and a chemotherapeutic drug target in human cancer.

All-Inorganic Perovskite CsPb2Br5 Microsheets for Photodetector Application

Directory of Open Access Journals (Sweden)

Xiaosheng Tang

2018-01-01

Full Text Available Lead-halide perovskites have emerged as one kind of important optoelectronic materials with excellent performance in photovoltaic and light-emitting diode applications. Herein, we reported all-inorganic perovskite CsPb2Br5 microsheets prepared by a facile injection method. Through the X-ray diffraction (XRD and Scanning Electron Microscope (SEM, it could be seen that the CsPb2Br5 microsheets showed single tetragonal crystalline phase and kept uniform square shape. Moreover, the as-synthesized CsPb2Br5 microsheets exhibited photoluminescence emission at 513 nm, and the UV–vis absorption spectrum further indicated the band gap of CsPb2Br5 microsheets was ≈2.50 eV. Additionally, the as-fabricated CsPb2Br5 microsheets based photodetector exhibited faster photoresponse characteristics of short rise time (0.71 s and decay time (0.60 s, which demonstrated its promising application as high performance electronic and optoelectronic devices.

Effect of an in-plane ligand on the electronic structures of bromo-bridged nano-wire Ni-Pd mixed-metal complexes, [Ni(1-x)Pd(x)(bn)2Br]Br2 (bn = 2S,3S-diaminobutane).

Science.gov (United States)

Sasaki, Mari; Wu, Hashen; Kawakami, Daisuke; Takaishi, Shinya; Kajiwara, Takashi; Miyasaka, Hitoshi; Breedlove, Brian K; Yamashita, Masahiro; Kishida, Hideo; Matsuzaki, Hiroyuki; Okamoto, Hiroshi; Tanaka, Hisaaki; Kuroda, Shinichi

2009-08-03

Single crystals of quasi-one-dimensional bromo-bridged Ni-Pd mixed-metal complexes with 2S,3S-diaminobutane (bn) as an in-plane ligand, [Ni(1-x)Pd(x)(bn)(2)Br]Br(2), were obtained by using an electrochemical oxidation method involving mixed methanol/2-propanol (1:1) solutions containing different ratios of [Ni(II)(bn)(2)]Br(2) and [Pd(II)(bn)(2)]Br(2). To investigate the competition between the electron-correlation of the Ni(III) states, or Mott-Hubbard states (MH), and the electron-phonon interaction of the Pd(II)-Pd(IV) mixed valence states, or charge-density-wave states (CDW), in the Ni-Pd mixed-metal compounds, X-ray structure analyses, X-ray oscillation photograph, and Raman, IR, ESR, and single-crystal reflectance spectra were analyzed. In addition, the local electronic structures of Ni-Pd mixed-metal single crystals were directly investigated by using scanning tunneling microscopy (STM) at room temperature and ambient pressure. The oxidation states of [Ni(1-x)Pd(x)(bn)(2)Br]Br(2) changed from a M(II)-M(IV) mixed valence state to a M(III) MH state at a critical mixing ratio (x(c)) of approximately 0.8, which is lower than that of [Ni(1-x)Pd(x)(chxn)(2)Br]Br(2) (chxn = 1R,2R-diaminocyclohexane) (x(c) approximately 0.9) reported previously. The lower value of x(c) for [Ni(1-x)Pd(x)(bn)(2)Br]Br(2) can be explained by the difference in their CDW dimensionalities because the three-dimensional CDW ordering in [Pd(bn)(2)Br]Br(2) observed by using X-ray diffuse scattering stabilizes the Pd(II)-Pd(IV) mixed valence state more than two-dimensional CDW ordering in [Pd(chxn)(2)Br]Br(2) does, which has been reported previously.

Photostriction of CH3NH3PbBr3 Perovskite Crystals

KAUST Repository

Wei, Tzu-Chiao

2017-07-17

Organic-inorganic hybrid perovskite materials exhibit a variety of physical properties. Pronounced coupling between phonon, organic cations, and the inorganic framework suggest that these materials exhibit strong light-matter interactions. The photoinduced strain of CH3 NH3 PbBr3 is investigated using high-resolution and contactless in situ Raman spectroscopy. Under illumination, the material exhibits large blue shifts in its Raman spectra that indicate significant structural deformations (i.e., photostriction). From these shifts, the photostrictive coefficient of CH3 NH3 PbBr3 is calculated as 2.08 × 10-8 m2 W-1 at room temperature under visible light illumination. The significant photostriction of CH3 NH3 PbBr3 is attributed to a combination of the photovoltaic effect and translational symmetry loss of the molecular configuration via strong translation-rotation coupling. Unlike CH3 NH3 PbI3 , it is noted that the photostriction of CH3 NH3 PbBr3 is extremely stable, demonstrating no signs of optical decay for at least 30 d. These results suggest the potential of CH3 NH3 PbBr3 for applications in next-generation optical micro-electromechanical devices.

Improving the Accuracy of Laplacian Estimation with Novel Variable Inter-Ring Distances Concentric Ring Electrodes

Directory of Open Access Journals (Sweden)

Oleksandr Makeyev

2016-06-01

Full Text Available Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, the superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation, has been demonstrated in a range of applications. In our recent work, we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1-polar electrode with n rings using the (4n + 1-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2 and quadripolar (n = 3 electrode configurations are compared to their constant inter-ring distances counterparts. Finite element method modeling and analytic results are consistent and suggest that increasing inter-ring distances electrode configurations may decrease the truncation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration, the truncation error may be decreased more than two-fold, while for the quadripolar configuration more than a six-fold decrease is expected.

Improving the Accuracy of Laplacian Estimation with Novel Variable Inter-Ring Distances Concentric Ring Electrodes

Science.gov (United States)

Makeyev, Oleksandr; Besio, Walter G.

2016-01-01

Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, the superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation, has been demonstrated in a range of applications. In our recent work, we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1)-polar electrode with n rings using the (4n + 1)-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1)-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2) and quadripolar (n = 3) electrode configurations are compared to their constant inter-ring distances counterparts. Finite element method modeling and analytic results are consistent and suggest that increasing inter-ring distances electrode configurations may decrease the truncation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration, the truncation error may be decreased more than two-fold, while for the quadripolar configuration more than a six-fold decrease is expected. PMID:27294933

CaBr2 hydrolysis for HBr production using a direct sparging contactor

International Nuclear Information System (INIS)

Doctor, R.D.; Yang, J.; Panchal, Ch.B.; Lottes, St.A.; Lyczkowski, R.W.

2010-01-01

We investigated a novel, continuous hybrid cycle for hydrogen production employing both heat and electricity. Calcium bromide (CaBr 2 ) hydrolysis, which is endothermic, generates hydrogen bromide (HBr), and this is electrolysed to produce hydrogen. CaBr 2 hydrolysis at 1050 K is endothermic with a 181.5 KJ/mol heat of reaction and the free energy change is positive at 99.6 kJ/mol. What makes this hydrolysis reaction attractive is both its rate and the fact that well over half the thermodynamic requirements for water-splitting free energy of ΔG T = 285.8 KJ/mol are supplied at this stage using heat rather than electricity. These experiments provide support for a second order hydrolysis reaction in CaBr 2 forming a complex involving CaBr 2 and CaO and the system appears to be: 3CaBr 2 + H 2 O → (CaBr 2 ) 2 .CaO + 2HBr. This reaction is highly endothermic and the complex also includes some water of hydration. COMSOL TM multi-physics modelling of sparging steam into a calcium bromide melt guided the design of an experiment using a mullite tube (ID 70 mm) capable of holding 0.3-0.5 kg (1.5-2.5 10 -3 kmol) CaBr 2 forming a melt with a maximum 0.08 m depth. Half of the experiments employed packings. Sparging steam at a steam rate of 0.02-0.04 mol/mol of CaBr 2 per minute into this molten bath promptly yielded HBr in a stable operation that converted up to 19 mol% of the calcium bromide. The kinetic constant derived from the experimental data was kinetic constant was 2.17 10 -12 kmol s -1 m -2 MPa -1 for the hydrolysis reaction. (authors)

Structure and origin of Australian ring and dome features with reference to the search for asteroid impact events

Science.gov (United States)

Glikson, Andrew

2018-01-01

Ring, dome and crater features on the Australian continent and shelf include (A) 38 structures of confirmed or probable asteroid and meteorite impact origin and (B) numerous buried and exposed ring, dome and crater features of undefined origin. A large number of the latter include structural and geophysical elements consistent with impact structures, pending test by field investigations and/or drilling. This paper documents and briefly describes 43 ring and dome features with the aim of appraising their similarities and differences from those of impact structures. Discrimination between impact structures and igneous plugs, volcanic caldera and salt domes require field work and/or drilling. Where crater-like morphological patterns intersect pre-existing linear structural features and contain central morphological highs and unique thrust and fault patterns an impact connection needs to tested in the field. Hints of potential buried impact structures may be furnished by single or multi-ring TMI patterns, circular TMI quiet zones, corresponding gravity patterns, low velocity and non-reflective seismic zones.

Radar imaging of Saturn's rings

Science.gov (United States)

Nicholson, Philip D.; French, Richard G.; Campbell, Donald B.; Margot, Jean-Luc; Nolan, Michael C.; Black, Gregory J.; Salo, Heikki J.

2005-09-01

We present delay-Doppler images of Saturn's rings based on radar observations made at Arecibo Observatory between 1999 and 2003, at a wavelength of 12.6 cm and at ring opening angles of 20.1°⩽|B|⩽26.7°. The average radar cross-section of the A ring is ˜77% relative to that of the B ring, while a stringent upper limit of 3% is placed on the cross-section of the C ring and 9% on that of the Cassini Division. These results are consistent with those obtained by Ostro et al. [1982, Icarus 49, 367-381] from radar observations at |B|=21.4°, but provide higher resolution maps of the rings' reflectivity profile. The average cross-section of the A and B rings, normalized by their projected unblocked area, is found to have decreased from 1.25±0.31 to 0.74±0.19 as the rings have opened up, while the circular polarization ratio has increased from 0.64±0.06 to 0.77±0.06. The steep decrease in cross-section is at variance with previous radar measurements [Ostro et al., 1980, Icarus 41, 381-388], and neither this nor the polarization variations are easily understood within the framework of either classical, many-particle-thick or monolayer ring models. One possible explanation involves vertical size segregation in the rings, whereby observations at larger elevation angles which see deeper into the rings preferentially see the larger particles concentrated near the rings' mid-plane. These larger particles may be less reflective and/or rougher and thus more depolarizing than the smaller ones. Images from all four years show a strong m=2 azimuthal asymmetry in the reflectivity of the A ring, with an amplitude of ±20% and minima at longitudes of 67±4° and 247±4° from the sub-Earth point. We attribute the asymmetry to the presence of gravitational wakes in the A ring as invoked by Colombo et al. [1976, Nature 264, 344-345] to explain the similar asymmetry long seen at optical wavelengths. A simple radiative transfer model suggests that the enhancement of the azimuthal

5-Bromo-3-(4-chlorophenylsulfinyl-2-methyl-1-benzofuran

Directory of Open Access Journals (Sweden)

Hong Dae Choi

2010-11-01

Full Text Available In the title compound, C15H10BrClO2S, the 4-chlorophenyl ring is oriented approximately perpendicular to the mean plane of the benzofuran ring [dihedral angle = 89.55 (9°]. In the crystal, molecules are linked through weak intermolecular C—H...O hydrogen bonds and and a Br...Br contact [3.783 (3 Å].

Study of improvement in 1st ring`s gas-seal; Top ring no gas seal seino kojo no kento

Energy Technology Data Exchange (ETDEWEB)

Ando, H; Tateishi, Y; Fujimura, K; Hitosugi, H [Nippon Piston Ring Co. Ltd., Tokyo (Japan)

1997-10-01

The authors studied the effect of an angle of 1st ring twist on the amount of blow-by concerning higher speed/higher output engines for motorcycles. As a result, the authors found the twist made the ring restrained in a ring groove of piston , and confirmed its suitable range for blow-by. By means of the developed optimization method, the authors have achieved significant reduction in blow-by at high engine speed. 1 ref., 9 figs., 2 tabs.

Optical properties of Pb-based aggregated phases in CsBr crystal

Energy Technology Data Exchange (ETDEWEB)

Voloshinovskii, A. [Ivan Franko National University of Lviv, 8 Kyryla i Mefodiya Str., 79005 Lviv (Ukraine); Myagkota, S. [Ivan Franko National University of Lviv, 8 Kyryla i Mefodiya Str., 79005 Lviv (Ukraine); Garapyn, I. [Ivan Franko National University of Lviv, 8 Kyryla i Mefodiya Str., 79005 Lviv (Ukraine); Stryganyuk, G. [Ivan Franko National University of Lviv, 8 Kyryla i Mefodiya Str., 79005 Lviv (Ukraine); Rodnyi, P. [St. Petersburg State Polytechnical University, 29 Polyteknicheskaya Str., 195251 St. Petersburg (Russian Federation); Eijk, C.W.E. van [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands)]. E-mail: vaneijk@iri.tudelft.nl

2005-01-01

The emission and excitation spectra as well as luminescence decay kinetics of a CsBr:Pb (1.0mol%) crystal have been measured under pulsed synchrotron radiation excitation. The heat-treated ({approx}200 deg. C) crystal shows evidence of single lead centres and aggregated phases such as CsPbBr3 nanocrystals. The latter have been identified from comparison of the spectral-kinetic characteristics of the CsPbBr3 aggregated phases and single crystals. The process of energy transfer from the host to the aggregates is considered.

Optical properties of Pb-based aggregated phases in CsBr crystal

International Nuclear Information System (INIS)

Voloshinovskii, A.; Myagkota, S.; Garapyn, I.; Stryganyuk, G.; Rodnyi, P.; Eijk, C.W.E. van

2005-01-01

The emission and excitation spectra as well as luminescence decay kinetics of a CsBr:Pb (1.0mol%) crystal have been measured under pulsed synchrotron radiation excitation. The heat-treated (∼200 deg. C) crystal shows evidence of single lead centres and aggregated phases such as CsPbBr3 nanocrystals. The latter have been identified from comparison of the spectral-kinetic characteristics of the CsPbBr3 aggregated phases and single crystals. The process of energy transfer from the host to the aggregates is considered

X-ray and NQR studies of bromoindate(III) complexes. [C{sub 2}H{sub 5}NH{sub 3}]{sub 4}InBr{sub 7}, [C(NH{sub 2}){sub 3}]{sub 3}InBr{sub 6}, and [H{sub 3}NCH{sub 2}C(CH{sub 3}){sub 2}CH{sub 2}NH{sub 3}]InBr{sub 5}

Energy Technology Data Exchange (ETDEWEB)

Iwakiri, Takeharu; Ishihara, Hideta [Saga Univ. (Japan). Faculty of Culture and Education; Terao, Hiromitsu [Tokushima Univ. (Japan). Faculty of Integrated Arts and Sciences; Lork, Enno; Gesing, Thorsten M. [Bremen Univ. (Germany). Inst. of Inorganic Chemistry and Crystallography

2017-03-01

The crystal structures of [C{sub 2}H{sub 5}NH{sub 3}]{sub 4}InBr{sub 7}(1), [C(NH{sub 2}){sub 3}]{sub 3}InBr{sub 6}(2), and [H{sub 3}NCH{sub 2}C(CH{sub 3}){sub 2}CH{sub 2}NH{sub 3}]InBr{sub 5}(3) were determined at 100(2) K: monoclinic, P2{sub 1}/n, a=1061.94(3), b=1186.40(4), c=2007.88(7) pm, β= 104.575(1) , Z=4 for 1; monoclinic, C2/c, a=3128.81(12), b=878.42(3), c=2816.50(10) pm, β=92.1320(10) , Z=16 for 2; orthorhombic, P2{sub 1}2{sub 1}2{sub 1}, a=1250.33(5), b=1391.46(6), c=2503.22(9) pm, Z=4 for 3. The structure of 1 contains an isolated octahedral [InBr{sub 6}]{sup 3-} ion and a Br{sup -} ion. The structure of 2 contains three different isolated octahedral [InBr{sub 6}]{sup 3-} ions. The structure of 3 has a corner-shared double-octahedral [In{sub 2}Br{sub 11}]{sup 5-} ion and an isolated tetrahedral [InBr{sub 4}]{sup -} ion. The {sup 81}Br nuclear quadrupole resonance (NQR) lines of the terminal Br atoms of the compounds are widely spread in frequency, and some of them show unusual positive temperature dependence. These observations manifest the N-H..Br-In hydrogen bond networks developed between the cations and anions to stabilize the crystal structures. The {sup 81}Br NQR and differential thermal analysis (DTA) measurements have revealed the occurrence of unique phase transitions in 1 and 3. When the bond angles were estimated from the electric field gradient (EFG) directions calculated by the molecular orbital (MO) methods, accurate values were obtained for [InBr{sub 6}]{sup 3-} of 1 and for [In{sub 2}Br{sub 11}]{sup 5-} and [InBr{sub 4}]{sup -} of 3, except for several exceptions in those for the latter two ions. On the other hand, the calculations of {sup 81}Br NQR frequencies have produced up to 1.4 times higher values than the observed ones.

Numerical modeling of accelerated, pre-compressed CTs in RACE

International Nuclear Information System (INIS)

Eddleman, J.L.; Hammer, J.H.; Hartman, C.W.; Logan, B.G.; McLean, H.S.; Molvik, A.W.

1990-01-01

Numerical modeling of accelerated compact toroids in the RACE experiment has motivated the development and application of a wide range of computational tools. These tools have included the zero-dimensional RAC code for fast parameter and design studies, and the two-dimensional, Eulerian, axisymmetric, magneto-hydrodynamic code, HAM, used to model plasma ring formation in magnetized plasma guns and acceleration in straight cylindrical electrodes. Extension of the RACE geometry to include converging conical electrodes motivated the development of a new two-dimensional, Lagrangian, axisymmetric, magnetohydrodynamic code, TRAC. The code includes optional initialization of the ring magnetic fields to a Taylor-equilibrium profile as well as self-consistent external capacitor bank driving circuit. Stability of initial field configurations with toroidal mode number > 0 may also be determined. The new code is particularly suited for predicting the behavior of accelerated plasma rings in arbitrarily shaped conical electrodes, since the restriction to a rectilinear mesh is removed. In particular, application of the code to the new pre-compression geometry in the RACE experiment is discussed and compared with experimental results

Viscosity of ring polymer melts

KAUST Repository

Pasquino, Rossana

2013-10-15

We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

Viscosity of ring polymer melts

KAUST Repository

Pasquino, Rossana; Vasilakopoulos, Thodoris C.; Jeong, Youncheol; Lee, Hyojoon; Rogers, Simon A.; Sakellariou, Georgios; Allgaier, Jü rgen B.; Takano, Atsushi; Brá s, Ana Rita E; Chang, Taihyun; Gooß en, Sebastian; Pyckhout-Hintzen, Wim; Wischnewski, Andreas; Hadjichristidis, Nikolaos; Richter, Dieter R.; Rubinstein, Michael H.; Vlassopoulos, Dimitris

2013-01-01

We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

Polymorphism in Br2 clathrate hydrates.

Science.gov (United States)

Goldschleger, I U; Kerenskaya, G; Janda, K C; Apkarian, V A

2008-02-07

The structure and composition of bromine clathrate hydrate has been controversial for more than 170 years due to the large variation of its observed stoichiometries. Several different crystal structures were proposed before 1997 when Udachin et al. (Udachin, K. A.; Enright, G. D.; Ratcliffe, C. I.; Ripmeester, J. A. J. Am. Chem. Soc. 1997, 119, 11481) concluded that Br2 forms only the tetragonal structure (TS-I). We show polymorphism in Br2 clathrate hydrates by identifying two distinct crystal structures through optical microscopy and resonant Raman spectroscopy on single crystals. After growing TS-I crystals from a liquid bromine-water solution, upon dropping the temperature slightly below -7 degrees C, new crystals of cubic morphology form. The new crystals, which have a limited thermal stability range, are assigned to the CS-II structure. The two structures are clearly distinguished by the resonant Raman spectra of the enclathrated Br2, which show long overtone progressions and allow the extraction of accurate vibrational parameters: omega(e) = 321.2 +/- 0.1 cm(-1) and omega(e)x(e) = 0.82 +/- 0.05 cm(-1) in TS-I and omega(e) = 317.5 +/- 0.1 cm(-1) and omega(e)x(e) = 0.70 +/- 0.1 cm(-1) in CS-II. On the basis of structural analysis, the discovery of the CS-II crystals implies stability of a large class of bromine hydrate structures and, therefore, polymorphism.

Decommissioning of a small reactor (BR3 reactor, Belgium)

International Nuclear Information System (INIS)

Dadoumont, J.; Massaut, V.; Klein, M.; Demeulemeester, Y.

2002-01-01

Since 1989, SCK-CEN has been dismantling its PWR reactor BR3 (Belgian Reactor No. 3). After gaining a great deal of experience in remote dismantling of highly radioactive components during the actual dismantling of the two sets of internals, the BR3 team completed the cutting of its reactor pressure vessel (RPV). During the feasibility phase of the RPV dismantling, a decision was made to cut it under water in the refuelling pool of the plant, after having removed it from its cavity. The RPV was cut into segments using a milling cutter and a bandsaw machine. These mechanical techniques have shown their ability for this kind of operations. Prior to the segmentation, the thermal insulation situated around the RPV was remotely removed and disposed of. The paper will describe all these operations. The BR3 decommissioning activities also include the dismantling of contaminated loops and equipment. After a careful sorting of the pieces, optimized management routes are selected in order to minimize the final amount of radioactive waste to be disposed of. Some development of different methods of decontamination were carried out: abrasive blasting (or sand blasting), chemical decontamination (Oxidizing-Reducing process using Cerium). The main goal of the decontamination program is to recycle most of the metallic materials either in the nuclear world or in the industrial world by reaching the respective recycling or clearance level. Overall the decommissioning of the BR3 reactor has shown the feasibility of performing such a project in a safe and economical way. Moreover, BR3 has developed methodologies and decontamination processes to economically reduce the amount of radwaste produced. (author)

Læring og refleksion

DEFF Research Database (Denmark)

Wahlgren, B.; Rattleff, Pernille; Høyrup, S.

State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen.......State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen....

Birth Control Ring

Science.gov (United States)

... Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Birth Control Ring KidsHealth / For Teens / Birth Control Ring What's ...

Validation of the Brazilian Portuguese Version of Geriatric Anxiety Inventory--GAI-BR.

Science.gov (United States)

Massena, Patrícia Nitschke; de Araújo, Narahyana Bom; Pachana, Nancy; Laks, Jerson; de Pádua, Analuiza Camozzato

2015-07-01

The Geriatric Anxiety Inventory (GAI) is a recently developed scale aiming to evaluate symptoms of anxiety in later life. This 20-item scale uses dichotomous answers highlighting non-somatic anxiety complaints of elderly people. The present study aimed to evaluate the psychometric properties of the Brazilian Portuguese version GAI (GAI-BR) in a sample from community and outpatient psychogeriatric clinic. A mixed convenience sample of 72 subjects was recruited for answering the research protocol. The interview procedures were structured with questionnaires about sociodemographic data, clinical health status, anxiety, and depression previously validated instruments, Mini-Mental State Examination, Mini International Neuropsychiatric Interview, and GAI-BR. Twenty-two percent of the sample were interviewed twice for test-retest reliability. For internal consistency analyses, the Cronbach's α test was applied. The Spearman correlation test was applied to evaluate the test-retest GAI-BR reliability. A ROC (receiver operating characteristic) curve study was made to estimate the GAI-BR area under curve, cut-off points, sensitivity, and specificity for the Generalized Anxiety Disorder diagnosis. The GAI-BR version showed high internal consistency (Cronbach's α = 0.91) and strong and significant test-retest reliability (ρ = 0.85, p BR has demonstrated very good psychometric properties and can be a reliable instrument to measure anxiety in Brazilian elderly people.

Redetermination of the Crystal Structure of Al2Br6

DEFF Research Database (Denmark)

Berg, Rolf W.; Poulsen, Finn W.; Nielsen, Kurt

1997-01-01

. In accordance with previous results, the structure belongs to the monoclinic space group P2(1)/a, no. 14, C-2h(5), with a = 10.301(4), b = 7.095(2), c = 7.525(3) Angstrom, and beta = 96.44(3)degrees, and with two Al2Br6 molecules per unit cell. The single crystal was refined to R = 0.0746. Rather similar......The structure of aluminium bromide has been reinvestigated by X-ray diffraction in three different ways: (a) on a single crystal grown in a glass capillary, (b) on powder in a Debye-Scherrer glass capillary and (c) on an area of powder placed in a protective container for Bragg-Brentano geometry...... structural results were obtained from full-profile Rietveld refinements of powder data [goodness of fit = 1.38 and 2.54 for (b) and (c), respectively]. The Al2Br6 molecule consists of two edge-sharing, almost regular AlBr4 tetrahedra. The Al-Br bond distances are in the range 2.21-2.42 Angstrom...

Molecular dynamics simulation and x-ray structural studies of mode-coupling in monoclinic K2ZnBr4

International Nuclear Information System (INIS)

Machida, Mitsuo; Itoh, Hideaki; Koyano, Nobumitsu

2003-01-01

The mode-coupling between the rotational and translational motions in the monoclinic K 2 ZnBr 4 was studied by the molecular dynamics simulation and X-ray structure analysis. In the structure analysis, the Fourier analysis indicates that, in the paraelectric phase, electron densities of the bromines Br1 and Br2 on the mirror plane are fairly elongated in the b direction, while the density of the bromine Br3 at the general position spreads more or less in the a direction. In the ferroelectric phase, the elongation is suppressed in particular for Br1 and Br2, and the densities of Br3 and Br4, which are equivalent each other in the paraelectric phase, are nearly isotropic. In addition, Br1 and Br2 displace in the b direction through the rotation of the ZnBr 4 2- ion about the a axis. In the simulation, the ZnBr 4 2- ions are treated as rigid-bodies. The trajectories of the bromines reproduce satisfactorily the characteristic feature of the Fourier maps. This means that the ZnBr 4 2- ions are approximately regarded as rigid-bodies even in the real K 2 ZnBr 4 . The mode-coupling analysis shows that, in the ZnBr 4 2- rigid-bodies, the rotational motion about the a axis and the translational motion in the b direction couple strongly. Moreover, the displacements of rotational and translational motions in the b direction are almost synchronous for Br1 and Br2, and almost asynchronous for Br3 and Br4. (author)

From coffee ring to spherulites ring of poly(ethylene oxide) film from drying droplet

Science.gov (United States)

Hu, Yinchun; Zhang, Xuerong; Qiu, Maibo; Wei, Yan; Zhou, Qiong; Huang, Di

2018-03-01

We discuss how the "spherulites ring" morphology and "coffee ring" profile of PEO film formed by the drying droplet at glass substrate with different heating rate. Upon increasing the heating rate of substrate, it is found that deposited PEO film from drying droplet shows the unusually observed "coffee ring" profile and "spherulites ring" morphology. The main mechanism for this phenomenon is proposed to be an enhanced Marangoni convection which is induced by the increased solute concentration gradient and reduced viscous force above 70 °C. A simple formation mechanism of the unusually observed "coffee ring" profile and "spherulites ring" morphology is proposed. These findings can be exploited to trace the center of Marangoni convection, with potential applications in designing the spherulite patterns of crystalline polymer films in ink-jet printing and self-assembly fields.

Systematic Search for Rings around Kepler Planet Candidates: Constraints on Ring Size and Occurrence Rate

Science.gov (United States)