WorldWideScience

Sample records for coordination isomer selection

  1. Quantification of Structural Isomers via Mode-Selective Irmpd

    Science.gov (United States)

    Polfer, Nicolas C.

    2016-06-01

    Mixtures of structural isomers can pose a challenge for vibrational ion spectroscopy. In cases where particular structures display diagnostic vibrations, these structures can be selectively "burned away". In ion traps, the ion population can be subjected to multiple laser shots, in order to fully deplete a particular structure, in effect allowing a quantification of this structure. Protonated para-amino benzoic acid (PABA) serves as an illustrative example. PABA is known to preferentially exist in the N-protonated (N-prot) form in solution, but in the gas phase it is energetically favorable in the O-protonated (O-prot) form. As shown in Figure 1, the N-prot structure can be kinetically trapped in the gas phase when sprayed from non-protic solvent, whereas the O-prot structure is obtained when sprayed from protic solvents, analogous to results by others [1,2]. y parking the light source on the diagnostic 3440 wn mode, the percentage of the O-prot structure can be determined, and by default the remainder is assumed to adopt the N-prot structure. It will be shown that the relative percentages of O-prot vs N-prot are highly dependent on the solvent mixture, going from close to 0% O-prot in non-protic solvents, to 99% in protic solvents. Surprisingly, water behaves much more like a non-protic solvent than methanol. It is observed that the capillary temperature, which aids droplet desolvation by black-body radiation in the ESI source, is critical to promote the appearance of O-prot structures. These results are consistent with the picture that a protic bridge mechanism is at play to facilitate proton transfer, and thus allow conversion from N-prot to O-prot, but that this mechanism is subject to appreciable kinetic barriers on the timescale of solvent evaporation. 1. J. Phys. Chem. A 2011, 115, 7625. 2. Anal. Chem. 2012, 84, 7857.

  2. Post-synthetic transformation of a Zn(ii) polyhedral coordination network into a new supramolecular isomer of HKUST-1.

    Science.gov (United States)

    Chen, Yao; Wojtas, Lukasz; Ma, Shengqian; Zaworotko, Michael J; Zhang, Zhenjie

    2017-08-03

    A Zn-based porphyrin containing metal-organic material (porphMOM-1) was transformed into a novel Cu-based porphyrin-encapsulating metal-organic material (porph@HKUST-1-β) via a one-pot post-synthetic modification (PSM) process involving both metal ion exchange and linker installation of trimesic acid. HKUST-1-β is the first example of yao topology and is to our knowledge the first supramolecular isomer of the archetypal coordination network HKUST-1.

  3. Natural and bioremediated selective degradation of polycyclic aromatic alkyl isomers in oil-contaminated soils

    International Nuclear Information System (INIS)

    Sauer, T.C.; McCarthy, K.; Uhler, A.; Porta, A.

    1995-01-01

    In studies where 2- to 6-ring polycyclic aromatic hydrocarbons (PAHs) are determined as part of characterizing released oil constituents in environmental samples, the changes in composition of PAHs from weathering (e.g., evaporation, dissolution) and biodegradation are most often represented by PAH alkyl homologue distributions. Concentrations of PAH alkyl groups are the sum of individual PAH isomers of similar carbon number; such as for C2-naphthalenes, the C2 alkyl group consists of dimethyl and ethyl substitutions on the parent naphthalene. In weathering and degradation studies, the changes in relative concentration of the individual isomers within an alkyl group are rarely reported. In a field study of oiled soils, the authors looked at the selective losses, for a period of a year, of individual PAH alkyl isomers that occur both naturally by weathering processes and through the use of bioremediation technology. Results showed that decreases in alkyl group concentrations were not always represented by similar losses of each isomer in the alkyl group, but were often due to the preferential or selective loss of certain isomers in the group

  4. Exploring Solvent Shape and Function Using - and Isomer-Selective Vibrational Spectroscopy

    Science.gov (United States)

    Johnson, Mark

    2010-06-01

    We illustrate the new types of information than can be obtained through isomer-selective ``hole-burning'' spectroscopy carried out in the vibrational manifolds of Ar-tagged cluster ions. Three examples of increasing complexity will be presented where the changes in a solute ion are correlated with different morphologies of a surrounding solvent cage. In the first, we discuss the weak coupling limit where different hydration morphologies lead to small distortions of a covalent ion. We then introduce the more interesting case of the hydrated electron, where different shapes of the water network lead to dramatic changes in the extent of delocalization in the diffuse excess electron cloud. We then turn to the most complex case involving hydration of the nitrosonium ion, where different arrangements of the same number of water molecules span the range in behavior from simple solvation to actively causing a chemical reaction. The latter results are particularly interesting as they provide a microscopic, molecular-level picture of the ``solvent coordinate'' commonly used to describe solvent mediated processes.

  5. Selective Placement Program Coordinator (SPPC) Directory

    Data.gov (United States)

    Office of Personnel Management — List of the Selective Placement Program Coordinators (SPPC) in Federal agencies, updated as needed. Users can filter the list by choosing a state and/or agency name.

  6. Experimental determination of the energy difference between competing isomers of deposited, size-selected gold nanoclusters.

    Science.gov (United States)

    Foster, D M; Ferrando, R; Palmer, R E

    2018-04-03

    The equilibrium structures and dynamics of a nanoscale system are regulated by a complex potential energy surface (PES). This is a key target of theoretical calculations but experimentally elusive. We report the measurement of a key PES parameter for a model nanosystem: size-selected Au nanoclusters, soft-landed on amorphous silicon nitride supports. We obtain the energy difference between the most abundant structural isomers of magic number Au 561 clusters, the decahedron and face-centred-cubic (fcc) structures, from the equilibrium proportions of the isomers. These are measured by atomic-resolution scanning transmission electron microscopy, with an ultra-stable heating stage, as a function of temperature (125-500 °C). At lower temperatures (20-125 °C) the behaviour is kinetic, exhibiting down conversion of metastable decahedra into fcc structures; the higher state is repopulated at higher temperatures in equilibrium. We find the decahedron is 0.040 ± 0.020 eV higher in energy than the fcc isomer, providing a benchmark for the theoretical treatment of nanoparticles.

  7. Kinetics and selectivity of permanganate chemiluminescence: a study of hydroxyl and amino disubstituted benzene positional isomers.

    Science.gov (United States)

    Slezak, Teo; Smith, Zoe M; Adcock, Jacqui L; Hindson, Christopher M; Barnett, Neil W; Nesterenko, Pavel N; Francis, Paul S

    2011-11-30

    Examination of the chemiluminescence reactions of dihydroxybenzenes, aminophenols and phenylenediamines with acidic potassium permanganate has provided a new understanding of the relationships between analyte structure, reaction conditions, kinetics of the light-producing pathway and emission intensity, with broad implications for this widely utilised chemiluminescence detection system. Using a permanganate reagent prepared in a polyphosphate solution and adjusted to pH 2.5, large differences in the rate of reaction with different positional isomers were observed, with the meta-substituted forms reacting far slower and therefore exhibiting much lower chemiluminescence intensities in flow analysis systems. The preliminary partial reduction of permanganate to form significant concentrations of Mn(III) increased the rate of reaction with all analytes tested, resulting in comparable or (in the case of aminophenol and phenylenediamine) even greater emission intensities for the meta-isomers, demonstrating the opportunity to tune the selectivity of the reagent towards certain classes of compound or even specific positional isomers of the same compound. Using more acidic permanganate reagents, in which polyphosphates are not required, the discrepancy between the chemiluminescence intensities was still observed, but was less prominent due to the generally faster rates of reaction. The enhancement of these chemiluminescence reactions by on-line addition of formic acid or formaldehyde can in part also be attributed to the generation of significant pools of the key Mn(III) precursor to the emitting species. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. UTSA-74: A MOF-74 Isomer with Two Accessible Binding Sites per Metal Center for Highly Selective Gas Separation

    KAUST Repository

    Luo, Feng

    2016-04-26

    A new metal-organic framework Zn2(H2O)-(dobdc)·0.5(H2O) (UTSA-74, H4dobdc = 2,5-dioxido-1,4-benzenedicarboxylic acid), Zn-MOF-74/CPO-27-Zn isomer, has been synthesized and structurally characterized. It has a novel four coordinated fgl topology with one-dimensional channels of about 8.0 Å. Unlike metal sites in the wellestablished MOF-74 with a rod-packing structure in which each of them is in a five coordinate square pyramidal coordination geometry, there are two different Zn2+ sites within the binuclear secondary building units in UTSA-74 in which one of them (Zn1) is in a tetrahedral while another (Zn2) in an octahedral coordination geometry. After activation, the two axial water molecules on Zn2 sites can be removed, generating UTSA-74a with two accessible gas binding sites per Zn2 ion. Accordingly, UTSA-74a takes up a moderately high and comparable amount of acetylene (145 cm3/cm3) to Zn-MOF-74. Interestingly, the accessible Zn2+ sites in UTSA-74a are bridged by carbon dioxide molecules instead of being terminally bound in Zn-MOF-74, so UTSA-74a adsorbs a much smaller amount of carbon dioxide (90 cm3/cm3) than Zn-MOF-74 (146 cm3/cm3) at room temperature and 1 bar, leading to a superior MOF material for highly selective C2H2/CO2 separation. X-ray crystal structures, gas sorption isotherms, molecular modeling, and simulated and experimental breakthroughs comprehensively support this result. © 2016 American Chemical Society.

  9. Chiral stationary phase optimized selectivity liquid chromatography: A strategy for the separation of chiral isomers.

    Science.gov (United States)

    Hegade, Ravindra Suryakant; De Beer, Maarten; Lynen, Frederic

    2017-09-15

    Chiral Stationary-Phase Optimized Selectivity Liquid Chromatography (SOSLC) is proposed as a tool to optimally separate mixtures of enantiomers on a set of commercially available coupled chiral columns. This approach allows for the prediction of the separation profiles on any possible combination of the chiral stationary phases based on a limited number of preliminary analyses, followed by automated selection of the optimal column combination. Both the isocratic and gradient SOSLC approach were implemented for prediction of the retention times for a mixture of 4 chiral pairs on all possible combinations of the 5 commercial chiral columns. Predictions in isocratic and gradient mode were performed with a commercially available and with an in-house developed Microsoft visual basic algorithm, respectively. Optimal predictions in the isocratic mode required the coupling of 4 columns whereby relative deviations between the predicted and experimental retention times ranged between 2 and 7%. Gradient predictions led to the coupling of 3 chiral columns allowing baseline separation of all solutes, whereby differences between predictions and experiments ranged between 0 and 12%. The methodology is a novel tool allowing optimizing the separation of mixtures of optical isomers. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. A correlation between isomer shifts of 237Np Moessbauer spectra and coordination numbers of Np atoms in neptunyl(V) compounds

    International Nuclear Information System (INIS)

    Saeki, M.; Nakada, M.; Nakamoto, T.; Yamashita, T.; Masaki, N.M.; Krot, N.N.

    1999-01-01

    Five neptunyl(V) compounds were synthesized and studied by 237 Np Moessbauer spectroscopy. The isomer shifts (δ) of the Moessbauer spectra ranged from -18.6 to -19.1 mm/s for the compounds with Np atoms surrounded by 7 oxygen atoms (coordination number (CN) 7). On the other hand, the larger value of δ was obtained for the compound with CN 8. From the comparison of the present results with those reported on neptunyl(V) and (VI) compounds, it is concluded that there is a correlation between the δ and the CN for neptunyl(V) compounds, and the distribution of δ is narrower for neptunyl(V) compounds than that of neptunyl(VI) compounds. (author)

  11. Selective bioaccumulation, biomagnification, and dissipation of hexachlorocyclohexane isomers in a freshwater food chain.

    Science.gov (United States)

    Di, Shanshan; Liu, Ruiquan; Chen, Li; Diao, Jinling; Zhou, Zhiqiang

    2018-04-30

    Hexachlorocyclohexane isomers (HCHs) are persistent organic pollutants (POPs), having potential risks to humans and ecosystem. This work evaluated the propensity of organisms to accumulate, eliminate, and transfer HCHs along the food chain (Tubifex tubifex and common carp (Cyprinus carpio)). The accumulation of HCHs from water by worms and carp was observed, and the concentrations increased with exposure time. After 8 days, the HCH concentrations in organisms remained stable. The accumulation factor (AF) values of HCHs in T. tubifex were higher than those in carp, indicating that the bioaccumulation abilities of HCHs in T. tubifex were higher than those in carp. The contaminated worms as a dietary source in the food chain led to significantly higher bioaccumulation in carp. The biomagnification factor (BMF) values of HCH isomers were all greater than 1. In the dissipation experiments, the elimination was fast and the half-lives were shorter than 2.5 days. The enantioselective accumulation and dissipation of α-HCH enantiomers were observed in worms and carp (food chain), and the enantiomeric differences should be taken into consideration in the study of contaminants risk assessment. The results on trophic transfer of HCHs in a freshwater food chain should be helpful for better understanding the fate, transport, and transfer of HCHs in freshwater environments.

  12. Variationally optimal selection of slow coordinates and reaction coordinates in macromolecular systems

    Science.gov (United States)

    Noe, Frank

    To efficiently simulate and generate understanding from simulations of complex macromolecular systems, the concept of slow collective coordinates or reaction coordinates is of fundamental importance. Here we will introduce variational approaches to approximate the slow coordinates and the reaction coordinates between selected end-states given MD simulations of the macromolecular system and a (possibly large) basis set of candidate coordinates. We will then discuss how to select physically intuitive order paremeters that are good surrogates of this variationally optimal result. These result can be used in order to construct Markov state models or other models of the stationary and kinetics properties, in order to parametrize low-dimensional / coarse-grained model of the dynamics. Deutsche Forschungsgemeinschaft, European Research Council.

  13. Selective detection of isomers with photoionization mass spectrometry for studies of hydrocarbon flame chemistry

    International Nuclear Information System (INIS)

    Cool, Terrill A.; Nakajima, Koichi; Mostefaoui, Toufik A.; Qi, Fei; McIlroy, Andrew; Westmoreland, Phillip R.; Law, Matthew E.; Poisson, Lionel; Peterka, Darcy S.; Ahmed, Musahid

    2003-01-01

    We report the first use of synchrotron radiation, continuously tunable from 8 to 15 eV, for flame-sampling photoionization mass spectrometry (PIMS). Synchrotron radiation offers important advantages over the use of pulsed vacuum ultraviolet lasers for PIMS; these include superior signal-to-noise, soft ionization, and access to photon energies outside the limited tuning ranges of current VUV laser sources. Near-threshold photoionization efficiency measurements were used to determine the absolute concentrations of the allene and propyne isomers of C 3 H 4 in low-pressure laminar ethylene-oxygen and benzene-oxygen flames. Similar measurements of the isomeric composition of C 2 H 4 O species in a fuel-rich ethylene-oxygen flame revealed the presence of substantial concentrations of ethenol (vinyl alcohol) and acetaldehyde. Ethenol has not been previously detected in hydrocarbon flames. Absolute photoionization cross sections were measured for ethylene, allene, propyne, and acetaldehyde, using propene as a calibration standard. PIE curves are presented for several additional reaction intermediates prominent in hydrocarbon flames

  14. Selective arc-discharge synthesis of Dy2S-clusterfullerenes and their isomer-dependent single molecule magnetism.

    Science.gov (United States)

    Chen, Chia-Hsiang; Krylov, Denis S; Avdoshenko, Stanislav M; Liu, Fupin; Spree, Lukas; Yadav, Ravi; Alvertis, Antonis; Hozoi, Liviu; Nenkov, Konstantin; Kostanyan, Aram; Greber, Thomas; Wolter, Anja U B; Popov, Alexey A

    2017-09-01

    A method for the selective synthesis of sulfide clusterfullerenes Dy 2 S@C 2 n is developed. Addition of methane to the reactive atmosphere reduces the formation of empty fullerenes in the arc-discharge synthesis, whereas the use of Dy 2 S 3 as a source of metal and sulfur affords sulfide clusterfullerenes as the main fullerene products along with smaller amounts of carbide clusterfullerenes. Two isomers of Dy 2 S@C 82 with C s (6) and C 3v (8) cage symmetry, Dy 2 S@C 72 - C s (10528), and a carbide clusterfullerene Dy 2 C 2 @C 82 - C s (6) were isolated. The molecular structure of both Dy 2 S@C 82 isomers was elucidated by single-crystal X-ray diffraction. SQUID magnetometry demonstrates that all of these clusterfullerenes exhibit hysteresis of magnetization, with Dy 2 S@C 82 - C 3v (8) being the strongest single molecule magnet in the series. DC- and AC-susceptibility measurements were used to determine magnetization relaxation times in the temperature range from 1.6 K to 70 K. Unprecedented magnetization relaxation dynamics with three consequent Orbach processes and energy barriers of 10.5, 48, and 1232 K are determined for Dy 2 S@C 82 - C 3v (8). Dy 2 S@C 82 - C s (6) exhibits faster relaxation of magnetization with two barriers of 15.2 and 523 K. Ab initio calculations were used to interpret experimental data and compare the Dy-sulfide clusterfullerenes to other Dy-clusterfullerenes. The smallest and largest barriers are ascribed to the exchange/dipolar barrier and relaxation via crystal-field states, respectively, whereas an intermediate energy barrier of 48 K in Dy 2 S@C 82 - C 3v (8) is assigned to the local phonon mode, corresponding to the librational motion of the Dy 2 S cluster inside the carbon cage.

  15. SEPARATION OF ISOMERS OF NONYLPHENOL AND SELECT NONPHENYL POLYETHOXYLATES BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY ON A GRAPHITIC CARBON COLUMN

    Science.gov (United States)

    p-Nonylphenol (NP) is ubiquitous degradation product of nonylphenol polyethoxylate (NPE) surfactants and has been reported to be an endocrine disrupter. It is composed of numerous structural isomers resulting from ;the various branching patterns of the C-9 group. Twenty-two isome...

  16. Seniority isomers in nuclei

    International Nuclear Information System (INIS)

    Van Isacker, P

    2011-01-01

    Seniority isomers are nuclear states with an electromagnetic decay that is hindered by selection rules related to the seniority quantum number. A simple analysis is presented of their possible formation with reference to the nickel isotopes 70–76 Ni and the N = 50 isotones from molybdenum to cadmium. It is shown that the existence of seniority isomers in a j = 9/2 shell is predominantly governed by the quadrupole pairing matrix element of the nucleon-nucleon interaction. The analysis is generalized to shells with larger j.

  17. Ionization-induced solvent migration in acetanilide-methanol clusters inferred from isomer-selective infrared spectroscopy.

    Science.gov (United States)

    Weiler, Martin; Nakamura, Takashi; Sekiya, Hiroshi; Dopfer, Otto; Miyazaki, Mitsuhiko; Fujii, Masaaki

    2012-12-07

    We present the resonance-enhanced multiphoton ionization, infrared-ultraviolet hole burning (IR-UV HB), and IR dip spectra of the trans-acetanilide-methanol (AA-MeOH) cluster in the S(0), S(1), and cationic ground state (D(0)) in a supersonic jet. The IR-UV HB spectra demonstrate the co-existence of two isomers in S(0,1), in which MeOH binds either to the NH or the CO site of the peptide linkage in AA, denoted as AA(NH)-MeOH and AA(CO)-MeOH. When AA(CO)-MeOH is selectively ionized, its IR spectrum in D(0) is the same as that measured for AA(+) (NH)-MeOH. Thus, photoionization of AA(CO)-MeOH induces migration of MeOH from the CO to the NH site with 100% yield. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Topologically guided tuning of Zr-MOF pore structures for highly selective separation of C6 alkane isomers

    KAUST Repository

    Wang, Hao; Dong, Xinglong; Lin, Junzhong; Teat, Simon J.; Jensen, Stephanie; Cure, Jeremy; Alexandrov, Eugeny V.; Xia, Qibin; Tan, Kui; Wang, Qining; Olson, David H.; Proserpio, Davide M.; Chabal, Yves J.; Thonhauser, Timo; Sun, Junliang; Han, Yu; Li, Jing

    2018-01-01

    As an alternative technology to energy intensive distillations, adsorptive separation by porous solids offers lower energy cost and higher efficiency. Herein we report a topology-directed design and synthesis of a series of Zr-based metal-organic frameworks with optimized pore structure for efficient separation of C6 alkane isomers, a critical step in the petroleum refining process to produce gasoline with high octane rating. Zr6O4(OH)4(bptc)3 adsorbs a large amount of n-hexane but excluding branched isomers. The n-hexane uptake is ~70% higher than that of a benchmark adsorbent, zeolite-5A. A derivative structure, Zr6O4(OH)8(H2O)4(abtc)2, is capable of discriminating all three C6 isomers and yielding a high separation factor for 3-methylpentane over 2,3-dimethylbutane. This property is critical for producing gasoline with further improved quality. Multicomponent breakthrough experiments provide a quantitative measure of the capability of these materials for separation of C6 alkane isomers. A detailed structural analysis reveals the unique topology, connectivity and relationship of these compounds.

  19. Topologically guided tuning of Zr-MOF pore structures for highly selective separation of C6 alkane isomers

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hao [Rutgers Univ., Piscataway, NJ (United States). Department of Chemistry and Chemical Biology; Dong, Xinglong [King Abdullah University of Science and Technology, Thuwal (Saudi Arabia). Advanced Membranes and Porous Materials Center, Physical Sciences and Engineering Division; Lin, Junzhong [Peking University, Beijing (China). College of Chemistry and Molecular Engineering; Teat, Simon J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); Jensen, Stephanie [Wake Forest University, Winston-Salem, NC (United States). Department of Physics; Cure, Jeremy [Univ. of Texas-Dallas, Richardson, TX (United States). Department of Materials Science & Engineering; Alexandrov, Eugeny V. [Samara University (Russia). Samara Center for Theoretical Materials Science (SCTMS; Xia, Qibin [Rutgers Univ., Piscataway, NJ (United States). Department of Chemistry and Chemical Biology; South China University of Technology, Guangzhou (China). School of Chemistry and Chemical Engineering; Tan, Kui [Univ. of Texas-Dallas, Richardson, TX (United States). Department of Materials Science & Engineering; Wang, Qining [Rutgers Univ., Piscataway, NJ (United States). Department of Chemistry and Chemical Biology; Olson, David H. [Rutgers Univ., Piscataway, NJ (United States). Department of Chemistry and Chemical Biology; Proserpio, Davide M. [Samara University (Russia). Samara Center for Theoretical Materials Science (SCTMS; Università degli Studi di Milano, Milano (Italy). Dipartimento di Chimica; Chabal, Yves J. [Univ. of Texas-Dallas, Richardson, TX (United States). Department of Materials Science & Engineering; Thonhauser, Timo [Wake Forest University, Winston-Salem, NC (United States). Department of Physics; Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Department of Chemistry; Sun, Junliang [Peking University, Beijing (China). College of Chemistry and Molecular Engineering; Han, Yu [King Abdullah University of Science and Technology, Thuwal (Saudi Arabia). Advanced Membranes and Porous Materials Center, Physical Sciences and Engineering Division; Li, Jing [Rutgers Univ., Piscataway, NJ (United States). Department of Chemistry and Chemical Biology

    2018-05-01

    As an alternative technology to energy intensive distillations, adsorptive separation by porous solids offers lower energy cost and higher efficiency. Herein we report a topology-directed design and synthesis of a series of Zr-based metal-organic frameworks with optimized pore structure for efficient separation of C6 alkane isomers, a critical step in the petroleum refining process to produce gasoline with high octane rating. Zr6O4(OH)4(bptc)3 adsorbs a large amount of n-hexane but excluding branched isomers. The n-hexane uptake is ~70% higher than that of a benchmark adsorbent, zeolite-5A. A derivative structure, Zr6O4(OH)8(H2O)4(abtc)2, is capable of discriminating all three C6 isomers and yielding a high separation factor for 3-methylpentane over 2,3-dimethylbutane. This property is critical for producing gasoline with further improved quality. Multicomponent breakthrough experiments provide a quantitative measure of the capability of these materials for separation of C6 alkane isomers. A detailed structural analysis reveals the unique topology, connectivity and relationship of these compounds.

  20. Topologically guided tuning of Zr-MOF pore structures for highly selective separation of C6 alkane isomers

    KAUST Repository

    Wang, Hao

    2018-04-25

    As an alternative technology to energy intensive distillations, adsorptive separation by porous solids offers lower energy cost and higher efficiency. Herein we report a topology-directed design and synthesis of a series of Zr-based metal-organic frameworks with optimized pore structure for efficient separation of C6 alkane isomers, a critical step in the petroleum refining process to produce gasoline with high octane rating. Zr6O4(OH)4(bptc)3 adsorbs a large amount of n-hexane but excluding branched isomers. The n-hexane uptake is ~70% higher than that of a benchmark adsorbent, zeolite-5A. A derivative structure, Zr6O4(OH)8(H2O)4(abtc)2, is capable of discriminating all three C6 isomers and yielding a high separation factor for 3-methylpentane over 2,3-dimethylbutane. This property is critical for producing gasoline with further improved quality. Multicomponent breakthrough experiments provide a quantitative measure of the capability of these materials for separation of C6 alkane isomers. A detailed structural analysis reveals the unique topology, connectivity and relationship of these compounds.

  1. Post-synthetic transformation of a Zn( ii ) polyhedral coordination network into a new supramolecular isomer of HKUST-1

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yao [State Key Laboratory of Medicinal Chemical Biology; Nankai University; Tianjin 300071; P. R. China; College of Pharmacy; Wojtas, Lukasz [Department of Chemistry; University of South Florida; 4202 East Fowler Avenue; Tampa; USA; Ma, Shengqian [Department of Chemistry; University of South Florida; 4202 East Fowler Avenue; Tampa; USA; Zaworotko, Michael J. [Department of Chemistry & Environmental Sciences, Bernal Institute, University of Limerick; Limerick; Republic of Ireland; Zhang, Zhenjie [College of Chemistry, Nankai University; Tianjin; P. R. China; State Key Laboratory of Medicinal Chemical Biology; Nankai University

    2017-01-01

    A Zn-based porphyrin containing metal–organic material (porphMOM-1) was post-synthetically transformed into a Cu-based porphyrin-encapsulating metal–organic material (porph@HKUST-1-β).HKUST-1-βis a new supramolecular isomer ofHKUST-1.

  2. Selective identification of specialized pro-resolving lipid mediators from their biosynthetic double di-oxygenation isomers.

    Science.gov (United States)

    Hansen, Trond V; Dalli, Jesmond; Serhan, Charles N

    The n-3 polyunsaturated fatty acids are substrates for lipoxygenases and cyclooxygenases. During inflammatory processes, these enzymes form several distinct families of oxygenated polyunsaturated fatty acids coined specialized pro-resolving lipid mediators. Structural elucidation of these natural products using LC-MS/MS based metabololipidomics with the pico- to nanogram amounts of biosynthetic material available have been performed. The specialized pro-resolving lipid mediators display stereospecific and potent anti-inflammatory and pro-resolving actions. Most often the different families among these mediators are chemically characterized by two or three chiral, secondary alcohols, separated by either an E,E,Z -triene or an E,Z,E,E -tetraenemoiety. The lipoxygenases also form other oxygenated polyunsaturated natural products, coined double di-oxygenation products, that are constitutional isomers of the protectin and maresin families of specialized pro-resolving lipid mediators. Very often these products exhibit similar chromatographic properties and mass spectrometrical fragment ions as the pro-resolving mediators. In addition, the double di-oxygenation products are sometimes formed in larger amounts than the specialized pro-resolving lipid mediators. Thus, it is not always possible to distinguish between the specialized pro-resolving mediators and their double di-oxygenation isomers in biological systems, using LC/MS-based techniques. Herein, a convenient and easy-to-use protocol to meet this challenge is presented.

  3. Selection of Optical Glasses Using Buchdahl's Chromatic Coordinate

    Science.gov (United States)

    Griffin, DeVon W.

    1999-01-01

    This investigation attempted to extend the method of reducing the size of glass catalogs to a global glass selection technique with the hope of guiding glass catalog offerings. Buchdahl's development of optical aberration coefficients included a transformation of the variable in the dispersion equation from wavelength to a chromatic coordinate omega defined as omega = (lambda - lambda(sub 0))/ 1 + 2.5(lambda - lambda(sub 0)) where lambda is the wavelength at which the wavelength is calculated and lambda(sub 0) is a base wavelength about which the expansion is performed. The advantage of this approach is that the dispersion equation may be written in terms of a simple power series and permits direct calculation of dispersion coefficients. While several promising examples were given, a systematic application of the technique to an entire glass catalog and analysis of the subsequent predictions was not performed. The goal of this work was to apply the technique in a systematic fashion to glasses in the Schoft catalog and assess the quality of the predictions.

  4. When feeling skillful impairs coordination in a lottery selection task.

    Directory of Open Access Journals (Sweden)

    Anna Dorfman

    Full Text Available Choosing a major field of study to secure a good job after graduation is a tacit coordination problem that requires considering others' choices. We examine how feeling skillful, either induced (Experiment 1 or measured (Experiment 2, affects coordination in this type of task. In both experiments participants chose between two lotteries, one offering a larger prize than the other. Participants' entry into the chosen lottery was either related or unrelated to their skill, with the final prize allocated randomly to one of the entrants in each lottery. Importantly, across conditions skill was irrelevant to choosing between lotteries. Notwithstanding, when skill was related to determining lottery entrants, participants who felt highly skillful chose the high prize lottery excessively. Results further suggest that this stems from high confidence in self skill, rather than incorrect expectations regarding others.

  5. Residue-based Coordinated Selection and Parameter Design of Multiple Power System Stabilizers (PSSs)

    DEFF Research Database (Denmark)

    Su, Chi; Hu, Weihao; Fang, Jiakun

    2013-01-01

    data from time domain simulations. Then a coordinated approach for multiple PSS selection and parameter design based on residue method is proposed and realized in MATLAB m-files. Particle swarm optimization (PSO) is adopted in the coordination process. The IEEE 39-bus New England system model...

  6. Metal selective co-ordinative self-assembly of π-donors

    Indian Academy of Sciences (India)

    Metal selective co-ordinative nanostructures were constructed by the supramolecular ... observed an anomalous binding of metal ion to the core sulphur groups causing redox changes in the TTF ... attention on metal-assisted co-ordinative self-assembly ..... M TTF-Py in 1:1 CHCl3: MeCN and (c) photographs showing visual.

  7. Amorphous infinite coordination polymer microparticles: a new class of selective hydrogen storage materials

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, You-Moon; Heo, Jungseok; Mirkin, Chad A [Department of Chemistry, International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL (United States); Armatas, Gerasimos S [Department of Chemistry, Northwestern University, Evanston, IL (United States); Kanatzidis, Mercouri G [Materials Science Division, Argonne National Laboratory, Argonne, IL (United States)

    2008-06-04

    A new class of micrometer-sized amorphous infinite coordination particles is selectively prepared from the coordination chemistry of a metallo-salen building block and Zn{sup 2+} ions. The particles show moderately high H{sub 2} uptake and almost no N{sub 2} adsorption, even though they are amorphous and do not have the well-defined channels typically used to explain such selectivity in metal-organic framework systems. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  8. Geomorphometric analysis of selected Martian craters using polar coordinate transformation

    Science.gov (United States)

    Magyar, Zoltán; Koma, Zsófia; Székely, Balázs

    2016-04-01

    Centrally symmetric landform elements are very common features on the surface of the planet Mars. The most conspicuous ones of them are the impact craters of various size. However, a closer look on these features reveals that they show often asymmetric patterns as well. These are partially related to the geometry of the trajectory of the impacting body, but sometimes it is a result of surface processes (e.g., freeze/thaw cycles, mass movements). Geomorphometric studies have already been carried out to reveal these pecularities. Our approach, the application of polar coordinate transformation (PCT) very sensitively enhances the non-radial and non-circular shapes. We used digital terrain models (DTMs) derived from the ESA Mars Express HRSC imagery. The original DTM or its derivatives (e.g. slope angle or aspect) are PCT transformed. We analyzed the craters inter alia with scattergrams in polar coordinates. The resulting point cloud can be used directly for the analysis, but in some cases an interpolation should be applied to enhance certain non-circular features (especially in case of smaller craters). Visual inspection of the crater slopes, coloured by the aspect, reveals smaller features. Some of them are processing artefacts, but many of them are related to local undulations in the topography or indications of mass movements. In many cases the undulations of the crater rim are due to erosional processes. The drawbacks of the technology are related to the uneven resolution of the projected image: features in the crater centre should be left out from the analysis because PCT has a low resolution around the projection center. Furthermore, the success of the PCT depends on the correct definition of the projection centre: erroneously centered images are not suitable for analysis. The PCT transformed images are also suitable for radial averaging and calculation of standard deviations, resulting in typical, comparable craters shapes. These studies may lead to a deeper

  9. Selectivity issues in targeted metabolomics: Separation of phosphorylated carbohydrate isomers by mixed-mode hydrophilic interaction/weak anion exchange chromatography

    NARCIS (Netherlands)

    Hinterwirth, Helmut; Lämmerhofer, Michael; Preinerstorfer, Beatrix; Gargano, Andrea; Reischl, Roland; Bicker, Wolfgang; Trapp, Oliver; Brecker, Lothar; Lindner, Wolfgang

    2010-01-01

    Phosphorylated carbohydrates are important intracellular metabolites and thus of prime interest in metabolomics research. Complications in their analysis arise from the existence of structural isomers that do have similar fragmentation patterns in MS/MS and are hard to resolve chromatographically.

  10. Atlas of Nuclear Isomers

    International Nuclear Information System (INIS)

    Jain, Ashok Kumar; Maheshwari, Bhoomika; Garg, Swati; Patial, Monika; Singh, Balraj

    2015-01-01

    We present an atlas of nuclear isomers containing the experimental data for the isomers with a half-life ≥ 10 ns together with their various properties such as excitation-energy, half-life, decay mode(s), spin-parity, energies and multipolarities of emitted gamma transitions, etc. The ENSDF database complemented by the XUNDL database has been extensively used in extracting the relevant data. Recent literature from primary nuclear physics journals, and the NSR bibliographic database have been searched to ensure that the compiled data Table is as complete and current as possible. The data from NUBASE-12 have also been checked for completeness, but as far as possible original references have been cited. Many interesting systematic features of nuclear isomers emerge, some of them new; these are discussed and presented in various graphs and figures. The cutoff date for the extraction of data from the literature is August 15, 2015

  11. Atlas of Nuclear Isomers

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Ashok Kumar, E-mail: ajainfph@iitr.ac.in [Department of Physics, Indian Institute of Technology, Roorkee-247667 (India); Maheshwari, Bhoomika; Garg, Swati; Patial, Monika [Department of Physics, Indian Institute of Technology, Roorkee-247667 (India); Singh, Balraj [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario-L8S 4M1 (Canada)

    2015-09-15

    We present an atlas of nuclear isomers containing the experimental data for the isomers with a half-life ≥ 10 ns together with their various properties such as excitation-energy, half-life, decay mode(s), spin-parity, energies and multipolarities of emitted gamma transitions, etc. The ENSDF database complemented by the XUNDL database has been extensively used in extracting the relevant data. Recent literature from primary nuclear physics journals, and the NSR bibliographic database have been searched to ensure that the compiled data Table is as complete and current as possible. The data from NUBASE-12 have also been checked for completeness, but as far as possible original references have been cited. Many interesting systematic features of nuclear isomers emerge, some of them new; these are discussed and presented in various graphs and figures. The cutoff date for the extraction of data from the literature is August 15, 2015.

  12. The level of selected coordinative motor abilities of basketball players aged 16-18.

    Science.gov (United States)

    Popowczak, M; Struzik, A; Rokita, A; Pietraszewski, B

    2015-10-01

    Coordinative abilities play a very important role in sport. Unfortunately, researchers do not confine appropriate attention to this issue. Therefore, the aim of this study was an attempt at analysing results of the selected coordinative motor abilities: kinesthetic differentiation, quick reaction and spatial orientation. It was intended to find out whether the results of trials determining manifestations of the particular coordinative abilities exhibit any mutual relationships. Forasmuch as a static torque is a parameter determining the level of force components of the ability of kinaesthetic differentiation, it would like to find out whether its maximum level influences the final result. Research was carried out on 20 young basketball players with the use of a torque meter and Fusion Smart Speed System. It was noticed a lack of statistically significant relationships between the results of trials assessing manifestations of the ability of kinaesthetic differentiation, quick reaction and spatial orientation. However, it was noted statistically significant correlation between the maximum static torque and the accuracy of releasing a particular value of a static torque. The accuracy of releasing a particular value of a static torque ought to be classified as a comprehensive ability that comprises manifestations of strength abilities and kinaesthetic differentiation. Presented trials to evaluation manifestations of the selected coordinative abilities could be used by coaches during a training process. Coaches should also focus on the development of muscle strength of the upper body and upper limbs of basketball players.

  13. Deadlines in space: Selective effects of coordinate spatial processing in multitasking.

    Science.gov (United States)

    Todorov, Ivo; Del Missier, Fabio; Konke, Linn Andersson; Mäntylä, Timo

    2015-11-01

    Many everyday activities require coordination and monitoring of multiple deadlines. One way to handle these temporal demands might be to represent future goals and deadlines as a pattern of spatial relations. We examined the hypothesis that spatial ability, in addition to executive functioning, contributes to individual differences in multitasking. In two studies, participants completed a multitasking session in which they monitored four digital clocks running at different rates. In Study 1, we found that individual differences in spatial ability and executive functions were independent predictors of multiple-task performance. In Study 2, we found that individual differences in specific spatial abilities were selectively related to multiple-task performance, as only coordinate spatial processing, but not categorical, predicted multitasking, even beyond executive functioning and numeracy. In both studies, males outperformed females in spatial ability and multitasking and in Study 2 these sex differences generalized to a simulation of everyday multitasking. Menstrual changes moderated the effects on multitasking, in that sex differences in coordinate spatial processing and multitasking were observed between males and females in the luteal phase of the menstrual cycle, but not between males and females at menses. Overall, these findings suggest that multiple-task performance reflects independent contributions of spatial ability and executive functioning. Furthermore, our results support the distinction of categorical versus coordinate spatial processing, and suggest that these two basic relational processes are selectively affected by female sex hormones and differentially effective in transforming and handling temporal patterns as spatial relations in the context of multitasking.

  14. Ligand design for site-selective metal coordination: synthesis of transition-metal complexes with η{sup 6}-coordination of the central ring of anthracene

    Energy Technology Data Exchange (ETDEWEB)

    Karslyan, Eduard E.; Borissova, Alexandra O.; Perekalin, Dmitry S. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow (Russian Federation)

    2017-05-08

    A polycyclic aromatic ligand for site-selective metal coordination was designed by using DFT calculations. The computational prediction was confirmed by experiments: 2,3,6,7-tetramethoxy-9,10-dimethylanthracene initially reacts with [(C{sub 5}H{sub 5})Ru(MeCN){sub 3}]BF{sub 4} to give the kinetic product with a [(C{sub 5}H{sub 5})Ru]{sup +} fragment coordinated at the terminal ring, which is then transformed into the thermodynamic product with coordination through the central ring. These isomeric complexes have markedly different UV/Vis spectra, which was explained by analysis of the frontier orbitals. At the same time, the calculations suggest that electrostatic interactions are mainly responsible for the site selectivity of the coordination. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Selective Generation of the Radical Cation Isomers [CH3CN](•+) and [CH2CNH](•+) via VUV Photoionization of Different Neutral Precursors and Their Reactivity with C2H4.

    Science.gov (United States)

    Polášek, Miroslav; Zins, Emilie-Laure; Alcaraz, Christian; Žabka, Ján; Křížová, Věra; Giacomozzi, Linda; Tosi, Paolo; Ascenzi, Daniela

    2016-07-14

    Experimental and theoretical studies have been carried out to demonstrate the selective generation of two different C2H3N(+) isomers, namely, the acetonitrile [CH3CN](•+) and the ketenimine [CH2CNH](•+) radical cations. Photoionization and dissociative photoionization experiments from different neutral precursors (acetonitrile and butanenitrile) have been performed using vacuum ultraviolet (VUV) synchrotron radiation in the 10-15 eV energy range, delivered by the DESIRS beamline at the SOLEIL storage ring. For butanenitrile (CH3CH2CH2CN) an experimental ionization threshold of 11.29 ± 0.05 eV is obtained, whereas the appearance energy for the formation of [CH2CNH](•+) fragments is 11.52 ± 0.05 eV. Experimental findings are fully supported by theoretical calculations at the G4 level of theory (ZPVE corrected energies at 0 K), giving a value of 11.33 eV for the adiabatic ionization energy of butanenitrile and an exothermicity of 0.49 for fragmentation into [CH2CNH](•+) plus C2H4, hampered by an energy barrier of 0.29 eV. The energy difference between [CH3CN](•+) and [CH2CNH](•+) is 2.28 eV (with the latter being the lowest energy isomer), and the isomerization barrier is 0.84 eV. Reactive monitoring experiments of the [CH3CN](•+) and [CH2CNH](•+) isomers with C2H4 have been performed using the CERISES guided ion beam tandem mass spectrometer and exploiting the selectivity of ethylene that gives exothermic charge exchange and proton transfer reactions with [CH3CN](•+) but not with [CH2CNH](•+) isomers. In addition, minor reactive channels are observed leading to the formation of new C-C bonds upon reaction of [CH3CN](•+) with C2H4, and their astrochemical implications are briefly discussed.

  16. Revisiting shape selectivity in liquid chromatography for polycyclic aromatic hydrocarbons (PAHs) - six-ring and seven-ring Cata-condensed PAH isomers of molecular mass 328 Da and 378 Da.

    Science.gov (United States)

    Oña-Ruales, Jorge O; Sander, Lane C; Wilson, Walter B; Wise, Stephen A

    2018-01-01

    The relationship of reversed-phase liquid chromatography (RPLC) retention on a polymeric C 18 stationary phase and the shape of polycyclic aromatic hydrocarbons (PAHs) was investigated for three-ring to seven-ring cata-condensed isomers. We report the first RPLC separation for six-ring and seven-ring cata-condensed PAH isomers. Correlations of LC retention and shape parameters (length-to-breath ratio, L/B and thickness, T) were investigated for 2 three-ring isomers (molecular mass 178 Da), 5 four-ring isomers (molecular mass 228 Da), 11 five-ring isomers (molecular mass 278 Da), 17 six-ring isomers (molecular mass 328 Da), and 20 seven-ring isomers (molecular mass 378 Da). Significant linear correlations were found for all isomer groups (r = 0.71 to 0.94). Nonplanarity of the PAH isomers was found to influence retention (i.e., nonplanar isomers eluting earlier than expected based on L/B) and linear correlations of retention vs. T for isomer groups containing nonplanar isomers were significant (r = 0.71 to 0.86). Graphical abstract.

  17. Gas to liquid to solid transition in halogen hot atom chemistry. 6. Product formation routes and chemical selectivity of high energy iodine reactions with butyne isomers

    International Nuclear Information System (INIS)

    Garmestani, S.K.; Firouzbakht, M.L.; Rack, E.P.

    1979-01-01

    Reactions of recoil produced iodine-128 with isomers of butyne were studied in gaseous, high pressure, and condensed phase conditions, with rare gas additives and in the presence and absence of radical scavengers (I 2 and O 2 ). It was found that recoil iodine-128 reactions were initiated by thermal electronically excited I + species for both 1-butyne and 2-butyne systems. While the diverse and complex nature of the reactions cannot be explained by simple chemical parameters, comparisons among the alkyne systems demonstrate preferential attack of iodine at the triple bond resulting, mainly, in electronically excited intermediates. A comparison of the various product formation routes results in the characterization of general traits common to the alkynes. 6 figures, 4 tables

  18. Iptycene-based stationary phase with three-dimensional aromatic structure for highly selective separation of H-bonding analytes and aromatic isomers.

    Science.gov (United States)

    Yang, Xiaohong; Han, Ying; Qi, Meiling; Chen, Chuanfeng

    2016-05-06

    Unique structures and molecular recognition ability endow iptycene derivatives with great potential as stationary phases in chromatography, which, however, has not been explored yet. Herein, we report the first example of utilizing a pentiptycene quinone (PQ) for gas chromatographic (GC) separations. Remarkably, the statically coated capillary column with the stationary phase achieved extremely high column efficiency of 4800 plates/m. It exhibited preferential retention and high resolving capability for H-bonding and aromatic analytes and positional isomers, showing advantages over the ordinary polysiloxane phase. Moreover, the fabricated iptycene column showed excellent separation repeatability with RSD values of 0.02-0.06% for intra-day, 0.20-0.35% for inter-day and 3.1-5.5% for between-column, respectively. In conclusion, iptycene derivatives as a new class of stationary phases show promising future for their use in GC separations. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. A dynamical model of hierarchical selection and coordination in speech planning.

    Directory of Open Access Journals (Sweden)

    Sam Tilsen

    Full Text Available studies of the control of complex sequential movements have dissociated two aspects of movement planning: control over the sequential selection of movement plans, and control over the precise timing of movement execution. This distinction is particularly relevant in the production of speech: utterances contain sequentially ordered words and syllables, but articulatory movements are often executed in a non-sequential, overlapping manner with precisely coordinated relative timing. This study presents a hybrid dynamical model in which competitive activation controls selection of movement plans and coupled oscillatory systems govern coordination. The model departs from previous approaches by ascribing an important role to competitive selection of articulatory plans within a syllable. Numerical simulations show that the model reproduces a variety of speech production phenomena, such as effects of preparation and utterance composition on reaction time, and asymmetries in patterns of articulatory timing associated with onsets and codas. The model furthermore provides a unified understanding of a diverse group of phonetic and phonological phenomena which have not previously been related.

  20. HEURISTIC METHOD OF SHIPS SELECTION FOR THE COORDINATED WORK OF WATER TRANSPORT

    Directory of Open Access Journals (Sweden)

    O. V. Shcherbina

    2018-02-01

    Full Text Available Purpose. The study aims to develop a formulation methodology for ship selection in the coordinated work of sea and river transport using a heuristic approach. Methodology. To realize the purpose set in the study, the authors carried out an analysis of domestic and foreign literature sources on the current topic, studied specifics and conditions for the effective operation of marine mono-hulled ships and composite tug/barge towing ones. Findings. The analysis results allowed formulating the heuristics methods that ensure the selection of the type sizes of tug/barge towing ships for the mixed «river-sea» navigation from the priority range of ships of the existing fleet. The proposed method makes it possible to select ships in a more appropriate manner according to the established scheme of work. Rational combinations of technical and operational characteristics of such pairs as «barges and tows», «tug/barge towing ship and sea-going ship», «tug/barge towing ship and restrictive characteristics of the area of navigation» are a prerequisite for the shipping company profit growth by increasing the capacity of ships. Originality. For the first time, the authors applied a heuristic approach to the selection of tug/barge towing ships and sea-going ones for coordinated work with the performance of cargo operations on the raid of the estuary port when transporting bulk goods. The basis of the approach is the selection of a rational mix of technical and operational characteristics of barges and tugs. The proposed approach allows determining the best combination of ship type sizes in the organization of coordinated work of sea and river transport. At the same time, the continuity of the goods transportation process from the sea ports to the river ones located in the depth of the country (and in the opposite direction is ensured. Practical value. The presented methodology is a logical continuation of the cycle of studies performed by the authors. The

  1. Comparison of the Weisskopf estimates in spin and K-isomers

    International Nuclear Information System (INIS)

    Garg, Swati; Maheshwari, B.; Rajput, Rohit; Srivastava, P.C.; Jain, A.K.

    2014-01-01

    Nuclear isomers are the excited metastable states, which exist due to the hindrance on their decay. Study of isomers has recently become very popular due to advances in the experimental techniques and also the arrival of radioactive beams. Large amount of new experimental data is becoming available. The very first 'Atlas of nuclear isomers' lists more than 2460 nuclear isomers with the half-life cut off at 10 ns. Spin isomers mostly exist due to the difficulty in meeting the spin selection rules and cluster around the semi-magic regions. The isomers far from the magic-numbers, which lie in the well-deformed region, mostly exist due to the goodness of the K-quantum number and large K-difference between the decaying states. They are known as K-isomers

  2. Selected Coordination Motor Abilities of Students of the University of Physical Education During Survival Training

    Directory of Open Access Journals (Sweden)

    Tomczak Andrzej

    2017-06-01

    Full Text Available Introduction. Taking up emergency actions when fighting various types of natural disasters requires appropriate psychophysical preparation. Thanks to the development of technique, coordination motor abilities have gained greater importance than physical strength and endurance in such activities. The purpose of the present work was to assess the impact of 36 hours of survival activities and sleep deprivation on selected coordination motor abilities in students of the University of Physical Education. Material and methods. The study involved 12 male students of the University of Physical Education in Warsaw, specialising in “Physical Education in Uniformed Services”. The age of the participants was 21.0 ± 0.74 years, their body height was 179.5 ± 5.6 cm, and their body mass was 74.6 ± 8.0 kg. The assessment was performed based on the following coordination motor ability tests: a test measuring the differentiation of the use of forearm muscle strength, a running motor adjustment test, and a measurement of divided attention. A test involving shooting from a pneumatic gun and a measurement of the maximal force of the forearm were also carried out. Tests and trials were conducted before training (P1, after 24 hours of training (P2, after completing the training - that is after 36 hours of training (P3, and after 12 hours of rest (P4. During the training, the participants completed 12 km on foot, paddled for approximately 6 hours, rowed kayaks for about 4 hours, and performed survival tasks. Results. The analysis of the results of the study of maximal force and the ability to differentiate forearm muscle strength showed that the forearm muscle strength remained at the same level during the entire training. The ability to differentiate forearm muscle strength deteriorated after night training. There were no statistically significant differences in the results of the running motor adjustment tests and in shooting performance between individual

  3. A monofunctional platinum complex coordinated to a rhodium metalloinsertor selectively binds mismatched DNA in the minor groove.

    Science.gov (United States)

    Weidmann, Alyson G; Barton, Jacqueline K

    2015-10-05

    We report the synthesis and characterization of a bimetallic complex derived from a new family of potent and selective metalloinsertors containing an unusual Rh-O axial coordination. This complex incorporates a monofunctional platinum center containing only one labile site for coordination to DNA, rather than two, and coordinates DNA nonclassically through adduct formation in the minor groove. This conjugate displays bifunctional, interdependent binding of mismatched DNA via metalloinsertion at a mismatch as well as covalent platinum binding. DNA sequencing experiments revealed that the preferred site of platinum coordination is not the traditional N7-guanine site in the major groove, but rather N3-adenine in the minor groove. The complex also displays enhanced cytotoxicity in mismatch repair-deficient and mismatch repair-proficient human colorectal carcinoma cell lines compared to the chemotherapeutic cisplatin, and it triggers cell death via an apoptotic pathway, rather than the necrotic pathway induced by rhodium metalloinsertors.

  4. Can voltammetry distinguish glycan isomers?

    Czech Academy of Sciences Publication Activity Database

    Trefulka, Mojmír; Paleček, Emil

    2015-01-01

    Roč. 69, č. 1 (2015), s. 241-244 ISSN 0366-6352 R&D Projects: GA ČR(CZ) GAP301/11/2055 Institutional support: RVO:68081707 Keywords : oligosaccharide isomers * Os(VI) complexes * chemical modification Subject RIV: BO - Biophysics Impact factor: 1.326, year: 2015

  5. Development of high-spin isomer beams

    International Nuclear Information System (INIS)

    Zhou Xiaohong

    2000-01-01

    The physical motivations with high-spin isomer beams were introduced. Taking HSIB of RIKEN as an example, the methods to produce, separate, transport and purity high-spin isomer beams were described briefly, and the detection of γ rays emitted from the reactions induced by the high-spin isomer beams was presented. Finally, the progress to develop the high-spin isomers in the N = 83 isotones as second beams was stressed

  6. Thermosensitive gating effect and selective gas adsorption in a porous coordination nanocage

    NARCIS (Netherlands)

    Zhao, D.; Yuan, D.; Krishna, R.; van Baten, J.M.; Zhou, H.C.

    2010-01-01

    A porous coordination nanocage functionalized with 24 triisopropylsilyl groups exhibits a remarkable thermosensitive gate opening phenomenon and demonstrates a molecular sieving effect at a certain temperature range, which can be used for gas separation purposes.

  7. Treatment of isomers in nucleosynthesis codes

    Science.gov (United States)

    Reifarth, René; Fiebiger, Stefan; Göbel, Kathrin; Heftrich, Tanja; Kausch, Tanja; Köppchen, Christoph; Kurtulgil, Deniz; Langer, Christoph; Thomas, Benedikt; Weigand, Mario

    2018-03-01

    The decay properties of long-lived excited states (isomers) can have a significant impact on the destruction channels of isotopes under stellar conditions. In sufficiently hot environments, the population of isomers can be altered via thermal excitation or de-excitation. If the corresponding lifetimes are of the same order of magnitude as the typical time scales of the environment, the isomers have to be treated explicitly. We present a general approach to the treatment of isomers in stellar nucleosynthesis codes and discuss a few illustrative examples. The corresponding code is available online at http://exp-astro.de/isomers/.

  8. Calorimetric study of bromoacetophenone isomers

    International Nuclear Information System (INIS)

    Amaral, Luísa M.P.F.; Ribeiro da Silva, Manuel A.V.

    2014-01-01

    Highlights: • A calorimetric study of bromoacetophenone isomers was performed. • Enthalpies of formation were derived by rotating-bomb combustion calorimetry. • Enthalpies of phase transition were determined by Calvet microcalorimetry. • Cox scheme was applied for the estimation of Δ f H m o (g) for the compounds. • The values of Δ f H m o (g) were compared with literature values for similar compounds. - Abstract: The standard (p o = 0.1 MPa) molar enthalpies of formation of 2-, 2′-, 3′- and 4′-bromoacetophenones were derived from the standard molar energies of combustion in oxygen, to yield CO 2 (g) and HBr·600H 2 O (l) at T = 298.15 K, measured by rotating bomb combustion calorimetry. The standard molar enthalpies associated with phase transitions of the isomers studied at T = 298.15 K, were obtained by high temperature Calvet microcalorimetry. The standard (p o = 0.1 MPa) molar enthalpies of formation of all the bromoacetophenone isomers in the gaseous phase at T = 298.15 K were derived from the experimental results. The gas-phase enthalpies of formation were also estimated by the empirical scheme developed by Cox and the values obtained were compared with the experimental ones. The results are interpreted in terms of the energetic increments for the introduction of the substituents in the benzene ring

  9. Isomers chart; Table des isomeres

    Energy Technology Data Exchange (ETDEWEB)

    Dupont-Gautier, P; Chantelot, S; Moisson, N [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    The nuclear isomers are nuclides offering the same mass number and the same atomic number, but different energy levels. In the following chart the zero energy ground states are omitted and the metastable isomers, i.e. of non-zero energy, known and of measurable lifetime, are listed. The lower limit of this lifetime was set here to 0.1 x 10{sup -6} s. The various isomers were classified in increasing lifetimes. (authors) [French] Les isomeres nucleaires sont des nucleides presentant le meme nombre de masse et le meme numero atomique, mais des niveaux energetiques differents. Dans la table suivante, on a neglige les etats fondamentaux d'energie nulle et on a recense les isomeres metastables, c'est-a-dire d'energie non nulle, connus et de periode mesurable. La limite inferieure de cette periode a ete fixee ici a 0,1 x 10{sup -6} s. Les differents isomeres ont ete classes par periodes croissantes. (auteurs)

  10. Isomers chart; Table des isomeres

    Energy Technology Data Exchange (ETDEWEB)

    Dupont-Gautier, P.; Chantelot, S.; Moisson, N. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    The nuclear isomers are nuclides offering the same mass number and the same atomic number, but different energy levels. In the following chart the zero energy ground states are omitted and the metastable isomers, i.e. of non-zero energy, known and of measurable lifetime, are listed. The lower limit of this lifetime was set here to 0.1 x 10{sup -6} s. The various isomers were classified in increasing lifetimes. (authors) [French] Les isomeres nucleaires sont des nucleides presentant le meme nombre de masse et le meme numero atomique, mais des niveaux energetiques differents. Dans la table suivante, on a neglige les etats fondamentaux d'energie nulle et on a recense les isomeres metastables, c'est-a-dire d'energie non nulle, connus et de periode mesurable. La limite inferieure de cette periode a ete fixee ici a 0,1 x 10{sup -6} s. Les differents isomeres ont ete classes par periodes croissantes. (auteurs)

  11. Cardiac effects of r-79595 and its isomers (r-80122 and r-80123) in an acute heart-failure model - a new class of cardiotonic agents with highly selective phosphodiesterase-iii inhibitory properties

    NARCIS (Netherlands)

    SCHNEIDER, J; BECK, E; HEERS, C; CONRAD, C; DECOURCELLES, DD; WILFFERT, B; Peters, Thies

    1992-01-01

    R 79595 (N-cyclohexyl-N-methyl-2-[[[phenyl (1,2,3,5-tetrahydro-2 oxoimidazo [2,1-b]-quinazolin-7-yl) methylene] amin] oxy] acetamide) and its isomers represent a novel class of compounds with phosphodiesterase (PDE) inhibitory and cardiotonic (positive inotropic) actions. The cardiac effects of this

  12. MCS and sub-band selection for downlink interference coordination in LTE-A Femtocells

    OpenAIRE

    Muñoz Medina, Olga; Agustín de Dios, Adrián; Vidal Manzano, José

    2012-01-01

    This paper proposes a decentralized algorithm for interference coordination in LTE-A networks, based on the exchange of information (pricing) at control plane level. In our approach, every user equipment (UE) report the maximum modulation and coding scheme (MCS) that can be used within several sets (sub-bands) of available resource blocks, along with a parameter (cost) that measures the MCS degradation due to the transmission from an interfering neighbor. Through the e...

  13. A coordination polymer based magnetic adsorbent material for hemoglobin isolation from human whole blood, highly selective and recoverable

    Science.gov (United States)

    Zhang, Xiaoxing; Tan, Jipeng; Xu, Xinxin; Shi, Fanian; Li, Guanglu; Yang, Yiqiao

    2017-09-01

    A composite material has been obtained successfully through the loading of nanoscale coordination polymer on magnetic Fe3O4@SiO2 core-shell particle. In this composite material, coordination polymer nanoparticles distribute uniformly on Fe3O4@SiO2 and these two components are "tied" together firmly with chemical bonds. Adsorption experiments suggest this composite material exhibits very excellent selectivity to hemoglobin. But under the same condition, its adsorption to bovine serum albumin can almost be ignored. This selectivity can be attributed to the existence of hydrophobic interactions between coordination polymer nanoparticle and hemoglobin. For composite material, the hemoglobin adsorption process follows Langmuir model perfectly with high speed. The adsorbed hemoglobin can be eluted easily by sodium dodecyl sulfate stripping reagent with structure and biological activity of hemoglobin keeps well. The composite material was also employed to separate hemoglobin from human whole blood, which receives a very satisfactory result. Furthermore, magnetic measurement reveals ferromagnetic character of this composite material with magnetization saturation 3.56 emu g-1 and this guarantees its excellent magnetic separation performance from the treated solution.

  14. Ligand substitution and selective surface coordination studies of iodine and 2,5-dihydroxythiophenol at platinum electrodes

    International Nuclear Information System (INIS)

    Berry, G.M.; Soriaga, M.P.

    1989-01-01

    The relative surface coordination strengths of 2,5-dihydroxythiophenol (DHT) and iodine at a smooth polycrystalline platinum electrode have been investigated by thin-layer electrochemical techniques. The competitive chemisorption was studied by exposing the Pt electrode to solutions of varying mole fractions of I and DHT. Studies of ligand substitution were carried out by the introduction of an iodine-coated Pt electrode into DHT solutions, and the introduction of a DHT-coated into I solutions. Surface coverage measurements indicated that DHT is preferentially adsorbed and will displace chemisorbed iodine at the Pt electrode. Chemisorbed DHT is not appreciably displaced by iodine. These results and their contribution to the trend in the selective surface coordination chemistry of platinum electrodes will be discussed

  15. Atlas of nuclear isomers and their systematics

    International Nuclear Information System (INIS)

    Jain, Ashok Kumar; Maheshwari, Bhoomika

    2015-01-01

    Isomers can be viewed as a separate class of nuclei and offer interesting possibilities to study the behavior of nuclei under varied conditions of excitation energy, spin, life-time and particle configuration. We have completed a horizontal evaluation of nuclear isomers and the resulting data set contains a wealth of information which offers new insights in the nuclear structure of a wide range of configurations, nuclei approaching the drip lines etc. We now have reliable data on approximately 2460 isomers having a half-life ≥ 10 ns. A few of the systematics of the properties of nuclear isomers like excitation energy, half-life, spin, abundance etc. will be presented. The data set of semi-magic isomers strongly supports the existence of seniority isomers originating from the higher spin orbitals. (author)

  16. High spin isomer beam line at RIKEN

    Energy Technology Data Exchange (ETDEWEB)

    Kishida, T.; Ideguchi, E.; Wu, H.Y. [Institute of Physical and Chemical Research, Saitama (Japan)] [and others

    1996-12-31

    Nuclear high spin states have been the subject of extensive experimental and theoretical studies. For the production of high spin states, fusion reactions are usually used. The orbital angular momentum brought in the reaction is changed into the nuclear spin of the compound nucleus. However, the maximum induced angular momentum is limited in this mechanism by the maximum impact parameter of the fusion reaction and by the competition with fission reactions. It is, therefore, difficult to populate very high spin states, and as a result, large {gamma}-detector arrays have been developed in order to detect subtle signals from such very high spin states. The use of high spin isomers in the fusion reactions can break this limitation because the high spin isomers have their intrinsic angular momentum, which can bring the additional angular momentum without increasing the excitation energy. There are two methods to use the high spin isomers for secondary reactions: the use of the high spin isomers as a target and that as a beam. A high spin isomer target has already been developed and used for several experiments. But this method has an inevitable shortcoming that only {open_quotes}long-lived{close_quotes} isomers can be used for a target: {sup 178}Hf{sup m2} (16{sup +}) with a half-life of 31 years in the present case. By developing a high spin isomer beam, the authors can utilize various short-lived isomers with a short half-life around 1 {mu}s. The high spin isomer beam line of RIKEN Accelerator Facility is a unique apparatus in the world which provides a high spin isomer as a secondary beam. The combination of fusion-evaporation reaction and inverse kinematics are used to produce high spin isomer beams; in particular, the adoption of `inverse kinematics` is essential to use short-lived isomers as a beam.

  17. Optical absorption spectra of Ag-11 isomers

    DEFF Research Database (Denmark)

    Martinez, Jose Ignacio; Fernandez, E. M.

    2009-01-01

    The optical absorption spectra of the three most; stable structural isomers of the Ag-11 cluster were calculated using the time-dependent, density functional theory within the Casida formalism. The slightly different, spectra, of the isomers may permit the identification of the ground-stale confi......The optical absorption spectra of the three most; stable structural isomers of the Ag-11 cluster were calculated using the time-dependent, density functional theory within the Casida formalism. The slightly different, spectra, of the isomers may permit the identification of the ground...

  18. Impact of selected family socio-economic factors on coordinational predispositions of children

    Directory of Open Access Journals (Sweden)

    Jarosław Domaradzki

    2011-03-01

    Full Text Available Introduction: Biological growth of children is genetically determined but there are a lot of factors modifying trends of growth. Among them the most important seems to be parents’ education and number of children in family – socio-economical factors. Factors don’t affect organism individually. Interactions between them can increase or decrease. So the aim of the work was to estimate the influence of socio-economic factors like parents’ education and number of children in family on coordinational traits of children aged 10–11. Material and methods: 199 children aged 10-11 underwent medical examination in 2008 in Polkowice and data collected were used in this study.. Information on parents’ education and number of children was used to divide children into four groups: lower education and 3 or more children in family, lower education and less than 3 children in family, higher education and more than 3 children in family and higher education and less than 3 children in family. Three coordinational traits were measured: short time memory, precision of hand and speed movement of the hand. MANOVA test was used to estimate differences between groups and to check interactions between factors. Results: From among 4 groups of boys, these from the worst socio-economic status of family received the worst results in all three tests. Differences between them and the rest of the groups were statistically significant. Differences between the rest of the groups were not statistically significant. In the girls groups children from families with higher parents’ education received statistically significant better results in test of memory. There were not differences between all 4 groups in precision of the hand test. Girls from family with higher parents’ education and 3 or more children in family received the best results in speed of the hand test. Conclusions: Boys are the gender more eco-sensitive. The family with more than 2 children in family

  19. Weak cooperativity in selected iron(II) 1D coordination polymers

    International Nuclear Information System (INIS)

    Dîrtu, Marinela M.; Gillard, Damien; Naik, Anil D.; Rotaru, Aurelian; Garcia, Yann

    2012-01-01

    The spin crossover behaviour of a new class of Fe II coordination polymers [Fe(phtptrz) 3 ]I 2 (1), [Fe(phtptrz) 3 ](ReO 4 ) 2 •CH 3 OH (2) and [Fe(phtptrz) 3 ]TaF 7 •6H 2 O (3) based on a novel ligand 4-(3 ′ -N-phtalimido-propyl)-1,2,4-triazole (phtptrz), were investigated by temperature dependent 57 Fe Mössbauer spectroscopy and magnetic susceptibility measurements. The adverse effect of bulky substituent on 1,2,4-triazole, favorable supramolecular interactions and influence of increasing anion size on spin crossover profile is discussed. 1 and 2 show thermally induced spin conversions of gradual and incomplete nature with associated thermochromism, and transition temperatures T 1/2 ∼ 163 K and 137 K, respectively. A spin state crossover is also identified for 3.

  20. The influence of coordination geometry and valency on the K-edge absorption near edge spectra of selected chromium compounds

    International Nuclear Information System (INIS)

    Pantelouris, A.; Modrow, H.; Pantelouris, M.; Hormes, J.; Reinen, D.

    2004-01-01

    X-ray absorption spectra at the chromium K-edge are reported for a number of selected chromium compounds of known chemical structure. The spectra were obtained with use of synchrotron radiation available at the ELectron Stretcher Accelerator ELSA in Bonn. The compounds studied include the tetrahedrally coordinated compounds Ca 2 Ge 0.8 Cr 0.2 O 4 , Ba 2 Ge 0.1 Cr 0.9 O 4 , Sr 2 CrO 4 , Ca 2 (PO 4 ) x (CrO 4 ) 1-x Cl (x=0.25,0.5), Ca 5 (CrO 4 ) 3 Cl, CrO 3 , the octahedrally coordinated compounds Cr(II)-acetate, CrCl 3 , CrF 3 , Cr 2 O 3 , KCr(SO 4 ) 2 · 12H 2 O, CrO 2 and cubic coordinated metallic chromium. In these compounds chromium exhibits a wide range of formal oxidation states (0 to VI). The absorption features in the near edge region are shown to be characteristic of the spatial environment of the absorbing atom. The occurrence of a single pre-edge line easily allows one to distinguish between tetrahedral and octahedral coordination geometry, whereas the energy position of the absorption edge is found to be very sensitive to the valency of the excited chromium atom. Calculations of the ionisation potential of Cr in different oxidation states using the non-relativistic Hartree-Fock method (Froese-Fischer) confirm that the ionisation limit shifts to higher energy with increasing Cr valency. More detailed information on the electronic structure of the different compounds is gained by real-space full multiple scattering calculations using the FEFF8 code

  1. The influence of coordination geometry and valency on the K-edge absorption near edge spectra of selected chromium compounds

    Energy Technology Data Exchange (ETDEWEB)

    Pantelouris, A.; Modrow, H.; Pantelouris, M.; Hormes, J.; Reinen, D

    2004-05-10

    X-ray absorption spectra at the chromium K-edge are reported for a number of selected chromium compounds of known chemical structure. The spectra were obtained with use of synchrotron radiation available at the ELectron Stretcher Accelerator ELSA in Bonn. The compounds studied include the tetrahedrally coordinated compounds Ca{sub 2}Ge{sub 0.8}Cr{sub 0.2}O{sub 4}, Ba{sub 2}Ge{sub 0.1}Cr{sub 0.9}O{sub 4}, Sr{sub 2}CrO{sub 4}, Ca{sub 2}(PO{sub 4}){sub x}(CrO{sub 4}){sub 1-x}Cl (x=0.25,0.5), Ca{sub 5}(CrO{sub 4}){sub 3}Cl, CrO{sub 3}, the octahedrally coordinated compounds Cr(II)-acetate, CrCl{sub 3}, CrF{sub 3}, Cr{sub 2}O{sub 3}, KCr(SO{sub 4}){sub 2} {center_dot} 12H{sub 2}O, CrO{sub 2} and cubic coordinated metallic chromium. In these compounds chromium exhibits a wide range of formal oxidation states (0 to VI). The absorption features in the near edge region are shown to be characteristic of the spatial environment of the absorbing atom. The occurrence of a single pre-edge line easily allows one to distinguish between tetrahedral and octahedral coordination geometry, whereas the energy position of the absorption edge is found to be very sensitive to the valency of the excited chromium atom. Calculations of the ionisation potential of Cr in different oxidation states using the non-relativistic Hartree-Fock method (Froese-Fischer) confirm that the ionisation limit shifts to higher energy with increasing Cr valency. More detailed information on the electronic structure of the different compounds is gained by real-space full multiple scattering calculations using the FEFF8 code.

  2. The influence of coordination geometry and valency on the K-edge absorption near edge spectra of selected chromium compounds

    Science.gov (United States)

    Pantelouris, A.; Modrow, H.; Pantelouris, M.; Hormes, J.; Reinen, D.

    2004-05-01

    X-ray absorption spectra at the chromium K-edge are reported for a number of selected chromium compounds of known chemical structure. The spectra were obtained with use of synchrotron radiation available at the ELectron Stretcher Accelerator ELSA in Bonn. The compounds studied include the tetrahedrally coordinated compounds Ca 2Ge 0.8Cr 0.2O 4, Ba 2Ge 0.1Cr 0.9O 4, Sr 2CrO 4, Ca 2(PO 4) x(CrO 4) 1- xCl ( x=0.25,0.5), Ca 5(CrO 4) 3Cl, CrO 3, the octahedrally coordinated compounds Cr(II)-acetate, CrCl 3, CrF 3, Cr 2O 3, KCr(SO 4) 2 · 12H 2O, CrO 2 and cubic coordinated metallic chromium. In these compounds chromium exhibits a wide range of formal oxidation states (0 to VI). The absorption features in the near edge region are shown to be characteristic of the spatial environment of the absorbing atom. The occurrence of a single pre-edge line easily allows one to distinguish between tetrahedral and octahedral coordination geometry, whereas the energy position of the absorption edge is found to be very sensitive to the valency of the excited chromium atom. Calculations of the ionisation potential of Cr in different oxidation states using the non-relativistic Hartree-Fock method (Froese-Fischer) confirm that the ionisation limit shifts to higher energy with increasing Cr valency. More detailed information on the electronic structure of the different compounds is gained by real-space full multiple scattering calculations using the FEFF8 code.

  3. Double level selection in a constitutional dynamic library of coordination driven supramolecular polygons.

    Science.gov (United States)

    Rancan, Marzio; Tessarolo, Jacopo; Casarin, Maurizio; Zanonato, Pier Luigi; Quici, Silvio; Armelao, Lidia

    2014-07-21

    A constitutional dynamic library (CDL) of Cu(II) metallo-supramolecular polygons has been studied as a bench test to examine an interesting selection case based on molecular recognition. Sorting of the CDL polygons is achieved through a proper guest that is hosted into the triangular metallo-macrocycle constituent. Two selection mechanisms are observed, a guest induced path and a guest templated self-assembly (virtual library approach). Remarkably, the triangular host can accommodate several guests with a degree of selectivity ranging from ∼1 to ∼10(4) for all possible guest pairs. A double level selection operates: guests drive the CDL toward the triangular polygon, and, at the same time, this is able to pick a specific guest from a set of competitive molecules, according to a selectivity-affinity correlation. Association constants of the host-guest systems have been determined. Guest competition and exchange studies have been analyzed through variable temperature UV-Vis absorption spectroscopy and single crystal X-ray diffraction studies. Molecular structures and electronic properties of the triangular polygon and of the host-guest systems also have been studied by means of all electrons density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations including dispersive contributions. DFT outcomes ultimately indicate the dispersive nature of the host-guest interactions, while TDDFT results allow a thorough assignment of the host and host-guests spectral features.

  4. Alpha and gamma spectroscopy of fission isomers

    International Nuclear Information System (INIS)

    Makarenko, V.E.

    1988-01-01

    The attempts to discover in the experiment decay of fission isomers of heavy nuclei in the U-Am range by emitting α particles or γ quanta are considered. Some facilities for searching αdecay of spontaneously fissile isomers are given in brief. The first experimental results are discussed

  5. Comparative aerobic soil metabolism of fenvalerate isomers

    International Nuclear Information System (INIS)

    Lee, P.W.; Powell, W.R.; Stearns, S.M.; McConnell, O.J.

    1987-01-01

    An aerobic soil metabolism study was conducted to determine the degradation rate of individual isomer of fenvalerate and to assess the potential influence of the RS, SR, and RR isomers to the metabolism of the most insecticidally active SS isomer. Individual [phenoxyphenyl- 14 C]fenvalerate isomers degraded at different rates. The calculated half-lives for the SR, RS, SS, and RR isomers in fenvalerate (racemic mixture) were 155, 89, 108, and 178 days, respectively. The resolved SS isomer degraded at a faster rate with a calculated half-life of 74 days. Racemization of the resolved SS isomer did not occur. A qualitative difference in the chemical nature of soil metabolites between fenvalerate and the resolved SS isomer was not observed. Soil degradation products, phenoxybenzoic acid, 3-(4-hydroxyphenoxy)benzoic acid, and 4'-OH- and CONH 2 -fenvalerate, each accounted for less than 2% of the applied radioactivity. Extensive degradation of these soil metabolites was evident since approximately 50% of the applied radioactivity was recovered as 14 C 2 and as unextractable bound residues

  6. Evidence for an isomer in 76Ni

    International Nuclear Information System (INIS)

    Sawicka, M.; Pfuetzner, M.; Grzywacz, R.; Daugas, J.M.; Belier, G.; Sauvestre, J.E.; Matea, I.; Lewitowicz, M.; Georgiev, G.; Grawe, H.; Mayet, P.; Becker, F.; Bingham, C.; Borcea, R.; Hammache, F.; Ibrahim, F.; Bouchez, E.; Buta, A.; Dragulescu, E.; Giovinazzo, J.; Meot, V.; Negoita, F.; De Oliveira Santos, F.; Perru, O.; Roig, O.; Rykaczewski, K.P.; Saint-Laurent, M.G.; Sorlin, O.; Stanoiu, M.; Stefan, I.; Stodel, C.; Theisen, C.; Verney, D.

    2004-01-01

    In the experiment performed at the LISE2000 spectrometer at GANIL neutron-rich nickel isotopes were studied by microsecond isomer spectroscopy. Evidence for an isomer in 76 Ni is found, consistently with the shell model prediction of an 8 + state of ν(g 9/2 ) 2 structure. (orig.)

  7. B(E2)s of high-spin isomers in generalized seniority scheme

    International Nuclear Information System (INIS)

    Maheshwari, Bhoomika; Jain, Ashok Kumar

    2015-01-01

    In this paper, we focus on the isomers that arise due to the seniority selection rules and the role played by generalized seniority when multi-j configurations are involved. In particular, we concentrate on explaining the B(E2) values in the semi-magic isomeric chains by using a simple approach. In this paper, we study the B(E2) variation of these isomers by using the generalized seniority scheme, applicable to many-j degenerate orbits. We show that the isomers known to arise mainly from the high-j intruder orbitals, do require the configuration mixing as an essential requirement

  8. Weak cooperativity in selected iron(II) 1D coordination polymers

    Energy Technology Data Exchange (ETDEWEB)

    Dirtu, Marinela M.; Gillard, Damien; Naik, Anil D. [Universite Catholique de Louvain, Institute of Condensed Matter and Nanosciences, MOST - Inorganic Chemistry (Belgium); Rotaru, Aurelian [' Stefan cel Mare' University, Department of Electrical Engineering and Computer Science (Romania); Garcia, Yann, E-mail: ann.garcia@uclouvain.be [Universite Catholique de Louvain, Institute of Condensed Matter and Nanosciences, MOST - Inorganic Chemistry (Belgium)

    2012-03-15

    The spin crossover behaviour of a new class of Fe{sup II} coordination polymers [Fe(phtptrz){sub 3}]I{sub 2} (1), [Fe(phtptrz){sub 3}](ReO{sub 4}){sub 2} Bullet CH{sub 3}OH (2) and [Fe(phtptrz){sub 3}]TaF{sub 7} Bullet 6H{sub 2}O (3) based on a novel ligand 4-(3{sup Prime} -N-phtalimido-propyl)-1,2,4-triazole (phtptrz), were investigated by temperature dependent {sup 57}Fe Moessbauer spectroscopy and magnetic susceptibility measurements. The adverse effect of bulky substituent on 1,2,4-triazole, favorable supramolecular interactions and influence of increasing anion size on spin crossover profile is discussed. 1 and 2 show thermally induced spin conversions of gradual and incomplete nature with associated thermochromism, and transition temperatures T{sub 1/2} {approx} 163 K and 137 K, respectively. A spin state crossover is also identified for 3.

  9. Isomer-specific combustion chemistry in allene and propyne flames

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Nils; Miller, James A. [Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551 (United States); Westmoreland, Phillip R. [Department of Chem. Engineering, University of Massachusetts, Amherst, MA 01003 (United States); Kasper, Tina [Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551 (United States); Department of Chemistry, Bielefeld University, D-33615 Bielefeld (Germany); Kohse-Hoeinghaus, Katharina [Department of Chemistry, Bielefeld University, D-33615 Bielefeld (Germany); Wang, Juan; Cool, Terrill A. [School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853 (United States)

    2009-11-15

    A combined experimental and modeling study is performed to clarify the isomer-specific combustion chemistry in flames fueled by the C{sub 3}H{sub 4} isomers allene and propyne. To this end, mole fraction profiles of several flame species in stoichiometric allene (propyne)/O{sub 2}/Ar flames are analyzed by means of a chemical kinetic model. The premixed flames are stabilized on a flat-flame burner under a reduced pressure of 25 Torr (=33.3 mbar). Quantitative species profiles are determined by flame-sampling molecular-beam mass spectrometry, and the isomer-specific flame compositions are unraveled by employing photoionization with tunable vacuum-ultraviolet synchrotron radiation. The temperature profiles are measured by OH laser-induced fluorescence. Experimental and modeled mole fraction profiles of selected flame species are discussed with respect to the isomer-specific combustion chemistry in both flames. The emphasis is put on main reaction pathways of fuel consumption, of allene and propyne isomerization, and of isomer-specific formation of C{sub 6} aromatic species. The present model includes the latest theoretical rate coefficients for reactions on a C{sub 3}H{sub 5} potential [J.A. Miller, J.P. Senosiain, S.J. Klippenstein, Y. Georgievskii, J. Phys. Chem. A 112 (2008) 9429-9438] and for the propargyl recombination reactions [Y. Georgievskii, S.J. Klippenstein, J.A. Miller, Phys. Chem. Chem. Phys. 9 (2007) 4259-4268]. Larger peak mole fractions of propargyl, allyl, and benzene are observed in the allene flame than in the propyne flame. In these flames virtually all of the benzene is formed by the propargyl recombination reaction. (author)

  10. An Unusual Ligand Coordination Gives Rise to a New Family of Rhodium Metalloinsertors with Improved Selectivity and Potency

    Science.gov (United States)

    2015-01-01

    Rhodium metalloinsertors are octahedral complexes that bind DNA mismatches with high affinity and specificity and exhibit unique cell-selective cytotoxicity, targeting mismatch repair (MMR)-deficient cells over MMR-proficient cells. Here we describe a new generation of metalloinsertors with enhanced biological potency and selectivity, in which the complexes show Rh–O coordination. In particular, it has been found that both Δ- and Λ-[Rh(chrysi)(phen)(DPE)]2+ (where chrysi =5,6 chrysenequinone diimmine, phen =1,10-phenanthroline, and DPE = 1,1-di(pyridine-2-yl)ethan-1-ol) bind to DNA containing a single CC mismatch with similar affinities and without racemization. This is in direct contrast with previous metalloinsertors and suggests a possible different binding disposition for these complexes in the mismatch site. We ascribe this difference to the higher pKa of the coordinated immine of the chrysi ligand in these complexes, so that the complexes must insert into the DNA helix with the inserting ligand in a buckled orientation; spectroscopic studies in the presence and absence of DNA along with the crystal structure of the complex without DNA support this assignment. Remarkably, all members of this new family of compounds have significantly increased potency in a range of cellular assays; indeed, all are more potent than cisplatin and N-methyl-N′-nitro-nitrosoguanidine (MNNG, a common DNA-alkylating chemotherapeutic agent). Moreover, the activities of the new metalloinsertors are coupled with high levels of selective cytotoxicity for MMR-deficient versus proficient colorectal cancer cells. PMID:25254630

  11. Selective high capacity adsorption of Congo red, luminescence and antibacterial assessment of two new cadmium(II) coordination polymers

    Science.gov (United States)

    Beheshti, Azizolla; Nozarian, Kimia; Ghamari, Narges; Mayer, Peter; Motamedi, Hossein

    2018-02-01

    Coordination polymers [CdCl(NCS)L]n (1) and {[Cd2I4(L)2]·H2O·DMF}n (2) (where L = 1, 1-(1,4-butanediyl)bis(1,3-dihydro-3-methyl-1H-imidazole- 2-thione)) were synthesized and structurally characterized. Compounds 1 and 2 both possess a tetrahedral arrangement with CdS2NCl and CdS2I2 cores, respectively. In these structures, the flexible thione ligands adopt a μ- bridging coordination mode to form 1D chains along the b-axis. The 1D chains are join together by C-H--Cl hydrogen bonds (in 1) and water molecules (in 2) to create a 2D supramolecular framework with an ABAB…packing mode. Remarkably, compounds 1 and 2 in particular polymer 1 exhibit excellent capacity to adsorb Congo red (CR) with high selectivity. The experimental data demonstrate that the mechanism of sorption process can be described by the Elovich and pseudo second order kinetic models for 1 and 2, respectively. Furthermore, the possible mechanism of CR absorption was investigated by UV-Vis and solid state fluorescence spectra for the title polymers. In addition, the antibacterial assessment of these compounds have also been studied.

  12. Microwave-Assisted Synthesis of Nanoporous Aluminum-Based Coordination Polymers as Catalysts for Selective Sulfoxidation Reaction

    Directory of Open Access Journals (Sweden)

    Madhan Vinu

    2017-10-01

    Full Text Available A series of aluminum-based coordination polymers or metal–organic frameworks (Al–MOFs, i.e., DUT-4, DUT-5, MIL-53, NH2-MIL-53, and MIL-100, have been facile prepared by microwave (MW-assisted reactions and used as catalysts for selective sulfoxidation reactions. The MW-assisted synthesis drastically reduced the reaction time from few days to hours. The prepared MOFs have smaller and uniform particle sizes and better yield compared to conventional hydrothermal method. Furthermore, the Al–MOFs have been successfully demonstrated as catalysts in oxidation reaction of methyl phenyl sulfide with H2O2 as oxidant, even under mild conditions, with more than 95% conversion.

  13. Independent isomer yield ratio of 90Rb

    International Nuclear Information System (INIS)

    Reeder, P.L.; Warner, R.A.; Ford, G.P.; Willmes, H.

    1985-05-01

    The independent isomer yield ratio for 90 Rb from thermal neutron fission of 235 U has been measured by use of a new technique involving a pulsed reactor and an on-line mass spectrometer facility. The apparent isomer yield ratio was measured for different ion collection time intervals and extrapolated to zero collection time to eliminate interference from 90 Kr decay. The observed isomer yield ratio of 8.7 +- 1.0 is one of the largest ratios measured for a low energy fission process. However, a statistical model analysis shows that the average angular momentum ( = 4.5) deduced from this isomer yield ratio is consistent with average angular momentum for other products from low energy fission. 7 refs

  14. Selective mRNA translation coordinates energetic and metabolic adjustments to cellular oxygen deprivation and reoxygenation in Arabidopsis thaliana.

    Science.gov (United States)

    Branco-Price, Cristina; Kaiser, Kayla A; Jang, Charles J H; Larive, Cynthia K; Bailey-Serres, Julia

    2008-12-01

    Cellular oxygen deprivation (hypoxia/anoxia) requires an acclimation response that enables survival during an energy crisis. To gain new insights into the processes that facilitate the endurance of transient oxygen deprivation, the dynamics of the mRNA translation state and metabolites were quantitatively monitored in Arabidopsis thaliana seedlings exposed to a short (2 h) or prolonged (9 h) period of oxygen and carbon dioxide deprivation and following 1 h of re-aeration. Hypoxia stress and reoxygenation promoted adjustments in the levels of polyribosomes (polysomes) that were highly coordinated with cellular ATP content. A quantitative comparison of steady-state and polysomal mRNA populations revealed that over half of the cellular mRNAs were restricted from polysome complexes during the stress, with little or no change in abundance. This selective repression of translation was rapidly reversed upon reoxygenation. Comparison of the adjustment in gene transcripts and metabolites demonstrated that profiling of polysomal mRNAs strongly augments the prediction of cellular processes that are altered during cellular oxygen deprivation. The selective translation of a subset of mRNAs promotes the conservation of ATP and facilitates the transition to anaerobic metabolism during low-oxygen stress.

  15. Nuclear isomers and their possible applications

    International Nuclear Information System (INIS)

    Jain, Ashok Kumar

    2016-01-01

    Nuclear isomers are the long lived excited states of nuclei having half-lives much larger than the half-lives of normal excited states. They are also known as the meta-stable states of atomic nuclei which are formed in nuclear reactions or, in radioactive decay of nuclei. Typical half-lives of isomers may range from nanoseconds to years. One of the most direct applications of nuclear isomers is in nuclear medicine. Radioisotopes are being widely used for imaging and therapeutic applications. They are particularly suitable for Single Photon Emission Computer Tomography (SPECT) imaging, where a single and relatively low energy γ ray photon is emitted. The most common example is "9"9"mTc (T_1_/_2 = 6 hours) which decays via a 142 keV γ ray photon. Examples of other isomers that are used in medical applications will be presented. Relatively long-lived isomers, such as "1"9"3"mPt and "1"9"5"mPt, for example, are being used in certain cancer treatments. Because of the high multi-pole order of the decaying transitions, most of the decays occur via internal conversion electrons, with subsequent emission of Auger electrons that can be used to kill various cancer cells. There are also some cases where the isomer decays by positron emission and is used for Positron Emission Tomography (PET) imaging

  16. Nuclear structure via isomer tagging of fission fragments

    Science.gov (United States)

    Wu, C. Y.; Cline, D.; Simon, M. W.; Stoyer, M. A.

    1997-10-01

    The high efficiency for detecting high-fold γ rays by large Ge arrays makes it possible to study the detailed spectroscopy of many neutron-rich nuclei produced by fission. Major progress has been made using sealed spontaneous fission sources. Considerable improvement in selectivity is provided, with an open source, both by gating on isomers and by detection of both fission fragments in coincidence with the deexcitation γ rays (see the preceding contribution). The reconstructed kinematics allows a measure of fragment mass and the Doppler shift correction of γ rays. In a recent experiment, fission fragments were detected using half of the CHICO array and an annular PPAC in coincidence with deexcitation γ rays detected by the Rochester array of eight Compton-suppressed Ge detectors. The annular PPAC was located only 1.0" from a 3.7 μCi ^252Cf source for efficient isomer tagging. The correlation was studied between delayed, within a time window between 150 ns and 10 μs after a fission occurring, and prompt γ rays. Several prominent feeding patterns to isomers in the mass region around 100 and 130 are identified by such correlation study. Experimental details and results will be presented.

  17. Fixed-bed adsorption separation of xylene isomers over sio2/silicallite-1 core-shell adsorbents

    KAUST Repository

    Khan, Easir A.

    2013-12-29

    SiO2/Silicalite-1 core-shell material has been demonstrated as potential shape selective adsorbent in gas phase separation of p-xylene from a mixture of p/o-xylene isomers. The core-shell composite comprised of large silica core and thin polycrystalline silicalite-1 shell which was synthesized via a self-assembly of silicalite-1 nanocrystals on core silica surface followed by a secondary seeded growth method. The core materials, SiO2 used in this study has mesoporosity with an average pore diameter of 60Å and hence offers no shape selectivity for xylene isomers. However, the shell, silicalite-1 contains rigid pore structures and preferentially adsorbs p-xylene from their isomers mixtures. A series of adsorption fixed bed breakthrough adsorption/desorption experiment was performed to obtain the equilibrium isotherms and adsorption isotherm parameters of xylene isomers. The equilibrium isotherms of xylene isomers follow the Langmuir\\'s model. A chromatographic adsorption model has been used to describe the fixed-bed breakthrough profiles of xylene isomers. The model has successfully predicted the responses of the binary mixtures of p/o-xylene isomers. The SiO2/silicalite-1 core-shell adsorbents have shown para-selectivity as high as 15. © Bangladesh Uni. of Engg. & Tech.

  18. Shape isomers: Mean-field description and beyond

    International Nuclear Information System (INIS)

    Bonche, P.; Krieger, S.J.; Weiss, M.S.; Dobaczewski, J.; Meyer, J.

    1990-01-01

    Nuclear Hartree-Fock (HF) + BCS calculations have led to predictions of shape isomerism in isotopes of Pt, Hg and Os nuclei. These have been confirmed through the observation of superdeformed rotational bands in 190,hor-ellipsis,194 Hg. Encouraged by these measurements and similar observations in 194 Pb, we have extended these calculations to a wide range of contiguous nuclei. These HF results, for 192,194 Pt, 190,hor-ellipsis,198 Hg and 194 Pb, have been employed in a Generator Coordinate Method (GCM) calculation utilizing the quadrupole deformation as the generating variable. The resulting spectra confirm the conclusions drawn from the HF results and agree with those experiments which have been performed. Adding a phenomenological assumption for the moments of inertia of our GCM states, we can construct the radiative transitions within and out of the superdeformed band. The results are in good agreement with the observed de-population of the superdeformed band built upon the shape isomer both in minimum angular momentum and in rapidity of de-population. Inferences for the existence of shape isomers will be drawn. 19 refs., 4 figs

  19. K isomers as probes of nuclear structure

    Science.gov (United States)

    Tandel, S. K.

    2014-08-01

    K isomers are studied in Pu and Cm isotopes, and also in Hf and W nuclei. Many high-K states, several of which are isomeric, are identified. Lifetime measurements spanning the ns-s range have been performed, and decay paths of isomers established. Rotational bands built on high-K states are also identified in many cases. Isomer decays are considerably hindered in many instances, both in the A≈180 and 250 regions indicating that K is an approximately conserved quantum number. High-K states become the favored excitation mode at high spins in the A≈180 region. The energies of the 2-quasiparticle high-K states in Cm isotopes suggest the presence of a deformed subshell gap at N=152.

  20. K isomers as probes of nuclear structure

    Energy Technology Data Exchange (ETDEWEB)

    Tandel, S. K., E-mail: sujit.tandel@cbs.ac.in [UM-DAE Centre for Excellence in Basic Sciences, Mumbai 400098 (India)

    2014-08-14

    K isomers are studied in Pu and Cm isotopes, and also in Hf and W nuclei. Many high-K states, several of which are isomeric, are identified. Lifetime measurements spanning the ns-s range have been performed, and decay paths of isomers established. Rotational bands built on high-K states are also identified in many cases. Isomer decays are considerably hindered in many instances, both in the A≈180 and 250 regions indicating that K is an approximately conserved quantum number. High-K states become the favored excitation mode at high spins in the A≈180 region. The energies of the 2-quasiparticle high-K states in Cm isotopes suggest the presence of a deformed subshell gap at N=152.

  1. Ultrafast time-resolved absorption spectroscopy of geometric isomers of carotenoids

    International Nuclear Information System (INIS)

    Niedzwiedzki, Dariusz M.; Sandberg, Daniel J.; Cong, Hong; Sandberg, Megan N.; Gibson, George N.; Birge, Robert R.; Frank, Harry A.

    2009-01-01

    The structures of a number of stereoisomers of carotenoids have been revealed in three-dimensional X-ray crystallographic investigations of pigment-protein complexes from photosynthetic organisms. Despite these structural elucidations, the reason for the presence of stereoisomers in these systems is not well understood. An important unresolved issue is whether the natural selection of geometric isomers of carotenoids in photosynthetic pigment-protein complexes is determined by the structure of the protein binding site or by the need for the organism to accomplish a specific physiological task. The association of cis isomers of a carotenoid with reaction centers and trans isomers of the same carotenoid with light-harvesting pigment-protein complexes has led to the hypothesis that the stereoisomers play distinctly different physiological roles. A systematic investigation of the photophysics and photochemistry of purified, stable geometric isomers of carotenoids is needed to understand if a relationship between stereochemistry and biological function exists. In this work we present a comparative study of the spectroscopy and excited state dynamics of cis and trans isomers of three different open-chain carotenoids in solution. The molecules are neurosporene (n = 9), spheroidene (n = 10), and spirilloxanthin (n = 13), where n is the number of conjugated π-electron double bonds. The spectroscopic experiments were carried out on geometric isomers of the carotenoids purified by high performance liquid chromatography (HPLC) and then frozen to 77 K to inhibit isomerization. The spectral data taken at 77 K provide a high resolution view of the spectroscopic differences between geometric isomers. The kinetic data reveal that the lifetime of the lowest excited singlet state of a cis-isomer is consistently shorter than that of its corresponding all-trans counterpart despite the fact that the excited state energy of the cis molecule is typically higher than that of the trans

  2. Study of the Si fullerene cage isomers

    NARCIS (Netherlands)

    Fthenakis, Z.G.; Havenith, R.W.A.; Menon, M.; Fowler, P.W.

    2005-01-01

    We present the results of a study on the structural and electronic properties of the Si38 fullerene isomers, which are constructed by making all possible permutations among their pentagons and hexagons. These structures were firstly fully optimized with a tight binding molecular dynamics method and

  3. Studies of high-K isomers in hafnium nuclei

    International Nuclear Information System (INIS)

    Sletten, G.; Gjoerup, N.L.

    1991-01-01

    K-isomeric states built on high-Ω Nilsson orbitals from deformation-aligned high-j levels near the Fermi surface are found to cluster in the neutron rich Hf, W and Os nuclei. It has been shown that some of the high seniority states of this type have decay properties that indicate strong mixing of configurations and that in Osmium nuclei γ-softness cause strong deviations from the well established K-selection rule. Also in the Hafnium nuclei is the expected forbiddenness in isomeric decays an order of magnitude smaller than expected from the K-selection rule. A new 9 quasiparticle isomer has been discovered in 175 Hf at I=57/2. This isomer has the anomalous decay as the dominant mode. Other lower seniority states are also identified. At spin 35/2 and 45/2 the deformation aligned states become yrast, but the structure of the yrast line to even higher spins is not yet understood. (author)

  4. Stability and isomerization reactions of phenyl cation C{sub 6}H{sub 5}{sup +} isomers

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Dandan [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012 (China); Yang, Xue [College of Science, Jilin Institute of Chemical Technology, Jilin 132022 (China); Zhang, Xiaomei; Shan, Shimin [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012 (China); Xu, Haifeng, E-mail: xuhf@jlu.edu.cn [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012 (China); Yan, Bing, E-mail: yanbing@jlu.edu.cn [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012 (China)

    2016-03-01

    Highlights: • A total of 60 isomers of C{sub 6}H{sub 5}{sup +} cations were obtained at density functional theory. • The stability and isomerization reactions of C{sub 6}H{sub 5}{sup +} isomers were performed. • The structures, frequencies, thermodynamic properties of isomers were summarized. • Ring to ring or chain isomerization pathways were investigated using IRC method. • Result shows reactions contain hydrogen transfer, bond broken and reconstruction. - Abstract: As a key polyatomic molecular cation that plays a pivotal role in growth of the polycyclic aromatic hydrocarbons, phenyl cation C{sub 6}H{sub 5}{sup +} exhibits various isomers and isomerization reactions. Investigation on the structure and stability of the isomers as well as the isomerization is important for better understanding the chemical reactions involving C{sub 6}H{sub 5}{sup +} cations. In this work, we have performed a theoretical study on the stability and isomerization reactions of C{sub 6}H{sub 5}{sup +} isomers at density functional theory B3LYP/6-311G (d, p) level. We have obtained a total of 60 isomers of C{sub 6}H{sub 5}{sup +} cations, most of which are reported for the first time. The geometries, vibrational frequencies, thermodynamic properties and stability of 28 out of 60 isomers have been summarized in detail. Different ring-to-ring and ring-to-chain isomerization pathways, which are connected via 28 transition states, have been investigated using the intrinsic reaction coordinate method. The results show that the isomerization reactions occur via hydrogen migration followed by bond-breaking and reconstruction.

  5. Application of terahertz spectroscopy and theoretical calculation in dimethylurea isomers investigation

    Science.gov (United States)

    Zhao, Yonghong; Li, Zhi; Liu, Jianjun; Chen, Tao; Zhang, Huo; Qin, Binyi; Wu, Yifang

    2018-03-01

    The characteristic absorption spectra of two structural isomers of dimethylurea(DMU) in 0.6-1.8 THz region have been measured using terahertz time-domain spectroscopy (THZ-TDS) at room temperature. Significant differences have been found between their terahertz spectra and implied that the THZ-TDS is an effective means of identifying structural isomers. To simulate their spectra, calculations on single molecule and cluster of 1,1-DMU and 1,3-DMU were performed, and we found that the cluster calculations using DFT-D3 method are better to predict the experimental spectra. Using the normal mode as displacements in redundant internal coordinates and the GaussView program, most observed THz vibrational modes are assigned to bending and rocking modes related to the intermolecular hydrogen bonding interactions, and twisting mode of ethyl groups. The different spectral features of two isomers mainly arise from different intermolecular hydrogen bonds resulting from different atom arrangements in molecules and different molecule arrangements in crystals. Using the reduced-density-gradient (RDG) analysis, the positions and types of intermolecular hydrogen bonding interactions in 1,1-DMU and 1,3-DMU crystals are visualized. Therefore, we can confirm that THz-TDS can be used as an effective means for the recognition of structural isomers and detection of intermolecular hydrogen bonding interactions in these crystals.

  6. High-spin isomers in 212Rn in the region of triple neutron core-excitations

    Science.gov (United States)

    Dracoulis, G. D.; Lane, G. J.; Byrne, A. P.; Davidson, P. M.; Kibédi, T.; Nieminen, P.; Watanabe, H.; Wilson, A. N.

    2008-04-01

    The level scheme of 212Rn has been extended to spins of ∼ 38 ℏ and excitation energies of about 13 MeV using the 204Hg(13C, 5n)212Rn reaction and γ-ray spectroscopy. Time correlated techniques have been used to obtain sensitivity to weak transitions and channel selectivity. The excitation energy of the 22+ core-excited isomer has been established at 6174 keV. Two isomers with τ = 25 (2) ns and τ = 12 (2) ns are identified at 12211 and 12548 keV, respectively. These are the highest-spin nuclear isomers now known, and are attributed to configurations involving triple neutron core-excitations coupled to the aligned valence protons. Semi-empirical shell-model calculations can account for most states observed, but with significant energy discrepancies for some configurations.

  7. High-spin isomers in 212Rn in the region of triple neutron core-excitations

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Lane, G.J.; Byrne, A.P.; Davidson, P.M.; Kibedi, T.; Nieminen, P.; Watanabe, H.; Wilson, A.N.

    2008-01-01

    The level scheme of 212 Rn has been extended to spins of ∼38h and excitation energies of about 13 MeV using the 204 Hg( 13 C, 5n) 212 Rn reaction and γ-ray spectroscopy. Time correlated techniques have been used to obtain sensitivity to weak transitions and channel selectivity. The excitation energy of the 22 + core-excited isomer has been established at 6174 keV. Two isomers with τ=25(2) ns and τ=12(2) ns are identified at 12211 and 12548 keV, respectively. These are the highest-spin nuclear isomers now known, and are attributed to configurations involving triple neutron core-excitations coupled to the aligned valence protons. Semi-empirical shell-model calculations can account for most states observed, but with significant energy discrepancies for some configurations

  8. Colour isomers in multiquark systems

    International Nuclear Information System (INIS)

    Hoegaasen, H.

    1979-01-01

    If we select configurations where a high angular momentum separates coloured groups of quarks the states can be sufficiently stable to show up as resonances. The kind of states I shall talk about are mesons of the following kind (C=6,7), (C=3 bar,3) and baryons: (C=8,8), (C=6 bar,6). In each state the quarks on each end of the colourelectric flux tube are taken to be in relative s-waves. Models for baryonium and of narrow mesobaryonium states have been proposed on the basis of these configurations. The theoretical input in these models is an extrapolation of what is known about quark-quark interactions from ordinary q anti q and qqq spectroscopy. (author)

  9. Resolution and Assignment of Differential Ion Mobility Spectra of Sarcosine and Isomers

    Science.gov (United States)

    Berthias, Francis; Maatoug, Belkis; Glish, Gary L.; Moussa, Fathi; Maitre, Philippe

    2018-02-01

    Due to their central role in biochemical processes, fast separation and identification of amino acids (AA) is of importance in many areas of the biomedical field including the diagnosis and monitoring of inborn errors of metabolism and biomarker discovery. Due to the large number of AA together with their isomers and isobars, common methods of AA analysis are tedious and time-consuming because they include a chromatographic separation step requiring pre- or post-column derivatization. Here, we propose a rapid method of separation and identification of sarcosine, a biomarker candidate of prostate cancer, from isomers using differential ion mobility spectrometry (DIMS) interfaced with a tandem mass spectrometer (MS/MS) instrument. Baseline separation of protonated sarcosine from α- and β-alanine isomers can be easily achieved. Identification of DIMS peak is performed using an isomer-specific activation mode where DIMS- and mass-selected ions are irradiated at selected wavenumbers allowing for the specific fragmentation via an infrared multiple photon dissociation (IRMPD) process. Two orthogonal methods to MS/MS are thus added, where the MS/MS(IRMPD) is nothing but an isomer-specific multiple reaction monitoring (MRM) method. The identification relies on the comparison of DIMS-MS/MS(IRMPD) chromatograms recorded at different wavenumbers. Based on the comparison of IR spectra of the three isomers, it is shown that specific depletion of the two protonated α- and β-alanine can be achieved, thus allowing for clear identification of the sarcosine peak. It is also demonstrated that DIMS-MS/MS(IRMPD) spectra in the carboxylic C=O stretching region allow for the resolution of overlapping DIMS peaks. [Figure not available: see fulltext.

  10. Thermochemical study of four isomers of dichloroanisole

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Lobo Ferreira, Ana I.M.C.

    2008-01-01

    The present work reports the values of the gaseous standard (p 0 = 0.1 MPa) molar enthalpies of formation of four isomers of dichloroanisole: 2,3-, 2,4-, 2,6-, and 3,5-dichloroanisole, at T = 298.15 K. For all compounds, those values were derived from measurements of the standard molar energies of combustion in the condensed phase, using a rotating bomb combustion calorimeter, together with measurements of the standard molar enthalpies of sublimation or vaporization, measured by high temperature Calvet microcalorimetry. Moreover, the enthalpies and the temperatures of fusion for the crystalline isomers of dichloroanisoles were measured by differential scanning calorimetry. The derived standard molar enthalpies of formation in the gaseous phase, at T = 298.15 K, for the title compounds were compared with the same parameters estimated by the Cox scheme and interpreted in terms of molecular structure

  11. Measurements of Short-Lived Fission Isomers

    Science.gov (United States)

    Finch, Sean; Bhike, Megha; Howell, Calvin; Krishichayan, Fnu; Tornow, Werner

    2016-09-01

    Fission yields of the short lived isomers 134mTe (T1 / 2 = 162 ns) and 136mXe (T1 / 2 = 2 . 95 μs) were measured for 235U and 238U. The isomers were detected by the γ rays associated with the decay of the isomeric states using high-purity germanium detectors. Fission was induced using both monoenergetic γ rays and neutrons. At TUNL's High-Intensity Gamma-ray Source (HI γS), γ rays of 9 and 11 MeV were produced . Monoenergetic 8 MeV neutrons were produced at TUNL's tandem accelerator laboratory. Both beams were pulsed to allow for precise time-gated spectroscopy of both prompt and delayed γ rays following fission. This technique offers a non-destructive probe of special nuclear materials that is sensitive to the isotopic identity of the fissile material.

  12. Theoretical investigation of the photophysics of methyl salicylate isomers

    Science.gov (United States)

    Massaro, Richard D.; Blaisten-Barojas, Estela

    2011-10-01

    The photophysics of methyl salicylate (MS) isomers has been studied using time-dependent density functional theory and large basis sets. First electronic singlet and triplet excited states energies, structure, and vibrational analysis were calculated for the ketoB, enol, and ketoA isomers. It is demonstrated that the photochemical pathway involving excited state intramolecular proton transfer (ESIPT) from the ketoB to the enol tautomer agrees well with the dual fluorescence in near-UV (from ketoB) and blue (from enol) wavelengths obtained from experiments. Our calculation confirms the existence of a double minimum in the excited state pathway along the O-H-O coordinate corresponding to two preferred energy regions: (1) the hydrogen belongs to the OH moiety and the structure of methyl salicylate is ketoB; (2) the hydrogen flips to the closest carboxyl entailing electronic rearrangement and tautomerization to the enol structure. This double well in the excited state is highly asymmetric. The Franck-Condon vibrational overlap is calculated and accounts for the broadening of the two bands. It is suggested that forward and backward ESIPT through the barrier separating the two minima is temperature-dependent and affects the intensity of the fluorescence as seen in experiments. When the enol fluoresces and returns to its ground state, a barrier-less back proton transfer repopulates the ground state of methyl salicylate ketoB. It is also demonstrated that the rotamer ketoA is not stable in an excited state close to the desired emission wavelength. This observation eliminates the conjecture that the near-UV emission of the dual fluorescence originates from the ketoA rotamer. New experimental results for pure MS in the liquid state are reported and theoretical results compared to them.

  13. Fingerprints of Both Watson-Crick and Hoogsteen Isomers of the Isolated (Cytosine-Guanine)H+ Pair.

    Science.gov (United States)

    Cruz-Ortiz, Andrés F; Rossa, Maximiliano; Berthias, Francis; Berdakin, Matías; Maitre, Philippe; Pino, Gustavo A

    2017-11-16

     Gas phase protonated guanine-cytosine (CGH + ) pair was generated using an electrospray ionization source from solutions at two different pH (5.8 and 3.2). Consistent evidence from MS/MS fragmentation patterns and differential ion mobility spectra (DIMS) point toward the presence of two isomers of the CGH + pair, whose relative populations depend strongly on the pH of the solution. Gas phase infrared multiphoton dissociation (IRMPD) spectroscopy in the 900-1900 cm -1 spectral range further confirms that the Watson-Crick isomer is preferentially produced (91%) at pH = 5.8, while the Hoogsteen isomer predominates (66%) at pH = 3.2). These fingerprint signatures are expected to be useful for the development of new analytical methodologies and to trigger isomer selective photochemical studies of protonated DNA base pairs.

  14. Experimental thermochemical study of the monochloronitrobenzene isomers

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Lobo Ferreira, Ana I.M.C.; Moreno, Ana Rita G.

    2009-01-01

    The standard (p 0 = 0.1 MPa) molar enthalpies of formation of 2-, 3-, and 4-chloronitrobenzene isomers, in the crystalline state, at T = 298.15 K, were derived from the standard (p 0 = 0.1 MPa) massic energies of combustion, in oxygen, at T = 298.15 K, measured by rotating bomb combustion calorimetry. The standard molar enthalpies of sublimation of the isomers, at T = 298.15 K, were obtained by high temperature Calvet microcalorimetry. From the determined experimental data, the values of the gaseous standard (p 0 = 0.1 MPa) molar enthalpies of formation for the three monochloronitrobenzene isomers were derived. The gas-phase enthalpies of formation were also estimated by the empirical scheme developed by Cox showing that for meta- and para-chloronitrobenzene the estimated values are in close agreement with the experimental ones whereas, in the case of ortho-chloronitrobenzene it is shown that a different enthalpic interaction increment is needed, when the substituents in the adjacent carbon ring atoms are a chlorine atom and a nitro group

  15. An EPR Monitoring of Isomerism and coordination sphere dynamics in five-coordinated pincer nickel complexes

    OpenAIRE

    Kozhanov, K.; Bubnov, M.; Cherkasov, V.; Fukin, G.; Vavilina, N.; Efremova, L.; Abakumov, G.

    2006-01-01

    A number of five-coordinated paramagnetic pincer nickel complexes have been obtained and investigated by X-band EPR spectroscopy. In general, these complexes can exist in solution as a pair of interconverting structure isomers. Activation parameters of this interconversion were estimated for several complexes.

  16. A selected ion flow tube study of the reactions of H3O+, NO+ and O-2(+center dot) with seven isomers of hexanol in support of SIFT-MS

    Czech Academy of Sciences Publication Activity Database

    Smith, D.; Sovová, Kristýna; Španěl, Patrik

    2012-01-01

    Roč. 319, MAY 1 2012 (2012), s. 25-30 ISSN 1387-3806 R&D Projects: GA ČR GA203/09/0256 Institutional support: RVO:61388955 Keywords : selected ion flow tube mass spectrometry * proton transfer * ion molecule reaction Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.142, year: 2012

  17. The proportion of lycopene isomers in human plasma is modulated by lycopene isomer profile in the meal but not by lycopene preparation

    OpenAIRE

    Richelle, Myriam; Lambelet, Pierre; Rytz, Andreas; Tavazzi, Isabelle; Mermoud, Anne-France; Juhel, Christine; Borel, Patrick; Bortlik, Karlheinz

    2011-01-01

    Dietary lycopene consists mostly of the (all-E) isomer. Upon absorption, (all-E) lycopene undergoes isomerisation into various (Z)-isomers. Because these isomers offer potentially better health benefits than the (all-E) isomer, the aim of the present study was to investigate if the profile of lycopene isomers in intestinal lipoproteins is affected by the profile of lycopene isomers in the meal and by the tomato preparation. Six postprandial, crossover tests were performed in healthy men. Thre...

  18. Thermochemical study of the monobromonitrobenzene isomers

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Lobo Ferreira, Ana I.M.C.; Santos, Ana Filipa L.O.M.; Rocha, Ines M.

    2010-01-01

    The standard (p o = 0.1 MPa) molar enthalpies of formation, of the 2-, 3-, and 4-monobromonitrobenzene isomers, in the crystalline phase, at T = 298.15 K, were derived from the standard massic energies of combustion, in oxygen, at T = 298.15 K, measured by rotating bomb combustion calorimetry. From the temperature dependence of the vapour pressures of these compounds, measured by the Knudsen effusion technique, their standard molar enthalpies of sublimation, at T = 298.15 K, were derived using the Clausius-Clapeyron equation.

  19. Target-Triggered Switching on and off the Luminescence of Lanthanide Coordination Polymer Nanoparticles for Selective and Sensitive Sensing of Copper Ions in Rat Brain.

    Science.gov (United States)

    Huang, Pengcheng; Wu, Fangying; Mao, Lanqun

    2015-07-07

    Copper ions (Cu(2+)) in the central nervous system play a crucial role in the physiological and pathological events, so simple, selective, and sensitive detection of cerebral Cu(2+) is of great importance. In this work, we report a facile yet effective fluorescent method for sensing of Cu(2+) in rat brain using one kind of lanthanide coordination polymer nanoparticle, adenosine monophosphate (AMP) and terbium ion (Tb(3+)), i.e., AMP-Tb, as the sensing platform. Initially, a cofactor ligand, 5-sulfosalicylic acid (SSA), as the sensitizer, was introduced into the nonluminescent AMP-Tb suspension, resulting in switching on the luminescence of AMP-Tb by the removal of coordinating water molecules and concomitant energy transfer from SSA to Tb(3+). The subsequent addition of Cu(2+) into the resulting SSA/AMP-Tb can strongly quench the fluorescence because the specific coordination interaction between SSA and Cu(2+) rendered energy transfer from SSA to Tb(3+) inefficient. The decrease ratio of the fluorescence intensities of SSA/AMP-Tb at 550 nm show a linear relationship for Cu(2+) within the concentration range from 1.5 to 24 μM with a detection limit of 300 nM. The method demonstrated here is highly selective and is free from the interference of metal ions, amino acids, and the biological species commonly existing in the brain such as dopamine, lactate, and glucose. Eventually, by combining the microdialysis technique, the present method has been successfully applied in the detection of cerebral Cu(2+) in rat brain with the basal dialysate level of 1.91 ± 0.40 μM (n = 3). This method is very promising to be used for investigating the physiological and pathological events that cerebral Cu(2+) participates in.

  20. Report of second FAO/IAEA research coordination meeting on in vitro techniques for selection of radiation-induced mutants adapted to adverse environmental conditions. Working material

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The meeting was attended by scientists from nine countries: Bangladesh, China P.R., Colombia, Egypt, Ghana, India, Pakistan, Peru and United States of America. The participants in this Research Coordination Meeting are working on the improvement of potato, sweet potato, garlic, sugarcane, pineapple and alfalfa by combining in vitro techniques with induced mutagenesis to select for resistance to salinity, freezing, heat, drought, and water-logging depending upon adverse condition prevailing in their region. The participants reported results of their experiments on the radio-sensitivity tests on in vitro cultured plant material, such as micropropagated plants and organogenic or embryogenic callus cultures. In addition, reports on the modifications of culture media required to regenerate and multiply local varieties and to carry out in vitro selection for specific stress conditions were presented. Refs, figs, tabs.

  1. Report of second FAO/IAEA research coordination meeting on in vitro techniques for selection of radiation-induced mutants adapted to adverse environmental conditions. Working material

    International Nuclear Information System (INIS)

    1997-07-01

    The meeting was attended by scientists from nine countries: Bangladesh, China P.R., Colombia, Egypt, Ghana, India, Pakistan, Peru and United States of America. The participants in this Research Coordination Meeting are working on the improvement of potato, sweet potato, garlic, sugarcane, pineapple and alfalfa by combining in vitro techniques with induced mutagenesis to select for resistance to salinity, freezing, heat, drought, and water-logging depending upon adverse condition prevailing in their region. The participants reported results of their experiments on the radio-sensitivity tests on in vitro cultured plant material, such as micropropagated plants and organogenic or embryogenic callus cultures. In addition, reports on the modifications of culture media required to regenerate and multiply local varieties and to carry out in vitro selection for specific stress conditions were presented. Refs, figs, tabs

  2. Report of the first research co-ordination meeting on the co-ordinated research programme: Development and selection of analytical techniques for measuring accidentally released radionuclides in environment

    International Nuclear Information System (INIS)

    2001-01-01

    The participants at the second Research Co-ordination Meeting (Vienna, 12-16 August 1991) of the CRP on 'Rapid Instrumental and Separation Methods for Monitoring Radionuclides in Food and Environmental Samples', recommended that a new CRP be established. The current CRP on 'Development and Selection of Analytical Techniques and Procedures for Measuring Accidentally Released Radionuclides in Environment' was established based on this recommendation. The objectives of this CRP are to conduct research and development on applicable methodologies for response to accidental releases, and to improve and maintain the capabilities of the network of laboratories and provide training of individuals within member states. Thus, the CRP serves as a vehicle to maintain contact within the network of laboratories, while developing and transferring analytical techniques and procedures for measuring accidentally released radioactivity. The purpose of the Research Co-ordination Meeting is to discuss the proposed research programs, the status to date and the work planned for the duration of the CRP. The meeting also provides the opportunity for the CRP participants to exchange ideas and possibly develop collaborations in their research. The members of the CRP also need to discuss issues related to the previous CRP on Rapid methods. These include: the preparation of the final report of the previous CRP, the preparation of an addendum to TRS-295 and the ultimate revision or updating of TRS-295. Finally, it is intended that the members of the CRP should discuss the mandate and scope of work of the network of analytical laboratories and the steps needed to firmly establish this network

  3. Infrared spectroscopy of the acetyl cation and its protonated ketene isomer

    Science.gov (United States)

    Mosley, J. D.; Young, J. W.; Duncan, M. A.

    2014-07-01

    [C2,H3,O]+ ions are generated with a pulsed discharge in a supersonic expansion containing methyl acetate or acetone. These ions are mass selected and their infrared spectra are recorded via laser photodissociation and the method of argon tagging. Computational chemistry is employed to investigate structural isomers and their spectra. The acetyl cation (CH3CO+) is the global minimum and protonated ketene (CH2COH+) is the next lowest energy isomer (+176.2 kJ/mol). When methyl acetate is employed as the precursor, the infrared spectrum reveals that only the acetyl cation is formed. Partially resolved rotational structure reveals rotation about the C3 axis. When acetone is used as the precursor, acetyl is still the most abundant cation, but there is also a minor component of protonated ketene. Computations reveal a significant barrier to interconversion between the two isomers (+221 kJ/mol), indicating that protonated ketene must be obtained via kinetic trapping. Both isomers may be present in interstellar environments, and their implications for astrochemistry are discussed.

  4. Geometry directed self-selection in the coordination-driven self-assembly of irregular supramolecular polygons.

    Science.gov (United States)

    Zheng, Yao-Rong; Northrop, Brian H; Yang, Hai-Bo; Zhao, Liang; Stang, Peter J

    2009-05-01

    The self-assembly of irregular metallo-supramolecular hexagons and parallelograms has been achieved in a self-selective manner upon mixing 120 degrees unsymmetrical dipyridyl ligands with 60 degrees or 120 degrees organoplatinum acceptors in a 1:1 ratio. The polygons have been characterized using (31)P and (1)H multinuclear NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS) as well as X-ray crystallography. Geometric features of the molecular subunits direct the self-selection process, which is supported by molecular force field computations.

  5. Table of superdeformed nuclear bands and fission isomers

    International Nuclear Information System (INIS)

    Firestone, R.B.; Singh, B.

    1994-06-01

    A minimum in the second potential well of deformed nuclei was predicted and the associated shell gaps are illustrated in the harmonic oscillator potential shell energy surface calculations shown in this report. A strong superdeformed minimum in 152 Dy was predicted for β 2 -0.65. Subsequently, a discrete set of γ-ray transitions in 152 DY was observed and, assigned to the predicted superdeformed band. Extensive research at several laboratories has since focused on searching for other mass regions of large deformation. A new generation of γ-ray detector arrays is already producing a wealth of information about the mechanisms for feeding and deexciting superdeformed bands. These bands have been found in three distinct regions near A=l30, 150, and 190. This research extends upon previous work in the actinide region near A=240 where fission isomers were identified and also associated with the second potential well. Quadrupole moment measurements for selected cases in each mass region are consistent with assigning the bands to excitations in the second local minimum. As part of our committment to maintain nuclear structure data as current as possible in the Evaluated Nuclear Structure Reference File (ENSDF) and the Table of Isotopes, we have updated the information on superdeformed nuclear bands. As of April 1994, we have complied data from 86 superdeformed bands and 46 fission isomers identified in 73 nuclides for this report. For each nuclide there is a complete level table listing both normal and superdeformed band assignments; level energy, spin, parity, half-life, magneto moments, decay branchings; and the energies, final levels, relative intensities, multipolarities, and mixing ratios for transitions deexciting each level. Mass excess, decay energies, and proton and neutron separation energies are also provided from the evaluation of Audi and Wapstra

  6. Table of superdeformed nuclear bands and fission isomers

    Energy Technology Data Exchange (ETDEWEB)

    Firestone, R.B. [Lawrence Berkeley Lab., CA (United States); Singh, B. [McMaster Univ., Hamilton, ON (Canada)

    1994-06-01

    A minimum in the second potential well of deformed nuclei was predicted and the associated shell gaps are illustrated in the harmonic oscillator potential shell energy surface calculations shown in this report. A strong superdeformed minimum in {sup 152}Dy was predicted for {beta}{sub 2}-0.65. Subsequently, a discrete set of {gamma}-ray transitions in {sup 152}DY was observed and, assigned to the predicted superdeformed band. Extensive research at several laboratories has since focused on searching for other mass regions of large deformation. A new generation of {gamma}-ray detector arrays is already producing a wealth of information about the mechanisms for feeding and deexciting superdeformed bands. These bands have been found in three distinct regions near A=l30, 150, and 190. This research extends upon previous work in the actinide region near A=240 where fission isomers were identified and also associated with the second potential well. Quadrupole moment measurements for selected cases in each mass region are consistent with assigning the bands to excitations in the second local minimum. As part of our committment to maintain nuclear structure data as current as possible in the Evaluated Nuclear Structure Reference File (ENSDF) and the Table of Isotopes, we have updated the information on superdeformed nuclear bands. As of April 1994, we have complied data from 86 superdeformed bands and 46 fission isomers identified in 73 nuclides for this report. For each nuclide there is a complete level table listing both normal and superdeformed band assignments; level energy, spin, parity, half-life, magneto moments, decay branchings; and the energies, final levels, relative intensities, multipolarities, and mixing ratios for transitions deexciting each level. Mass excess, decay energies, and proton and neutron separation energies are also provided from the evaluation of Audi and Wapstra.

  7. Anaerobic Degradation of Lindane and Other HCH Isomers

    NARCIS (Netherlands)

    Mehboob, F.; Langenhoff, A.A.M.; Schraa, G.; Stams, A.J.M.

    2013-01-01

    Lindane (¿-HCH) is a pesticide that has mainly been used in agriculture. Lindane and the other HCH isomers are highly chlorinated hydrocarbons. The presence of a large number of electron withdrawing chlorine groups makes some of the HCH isomers rather recalcitrant in oxic environments. Especially

  8. Search for isomers in nuclei near N = 50

    International Nuclear Information System (INIS)

    Taras, P.; Haas, B.; Merdinger, J.C.; Styczen, J.

    1979-01-01

    Targets of sup (58, 60, 61, 62, 64) Ni, Co, and Cu have been bombarded with 42 MeV 16 O beams. Several isomers were produced but no new isomer was found, in particular in 74 Kr which is expected to be a good candidate for yrast traps in the N = 50 region. (author)

  9. Isomer 103Rh excitation in the electron beam

    International Nuclear Information System (INIS)

    Alpatov, V.G.; Berezkin, V.V.; Vysotskij, S.A.

    1993-01-01

    Rhodium foil targets were irradiated by a beam of electrons from a linear accelerator containing a minor impurity of bremsstrahlung. X-ray and γ-quanta from decay of 103m Rh isomer states were detected. The ratio of isomer cross section activation by bremsstrahlung, formed in the target, and electrons, equals 89. 7 refs.; 3 figs.; 2 tabs

  10. Evidence for an isomer in {sup 76}Ni

    Energy Technology Data Exchange (ETDEWEB)

    Sawicka, M.; Pfuetzner, M. [Institute of Experimental Physics, Warsaw University, PL-00-681, Warszawa (Poland); Grzywacz, R. [Institute of Experimental Physics, Warsaw University, PL-00-681, Warszawa (Poland); Physics Division, ORNL, TN 37831-6371, Oak Ridge (United States); Daugas, J.M.; Belier, G.; Sauvestre, J.E. [CEA Bruyeres-le-Chatel DIF/DPTA/SPN, BP 12, F-91680, Bruyeres-le-Chatel (France); Matea, I.; Lewitowicz, M.; Georgiev, G. [GANIL, BP 5027, F-14021, Caen Cedex (France); Grawe, H.; Mayet, P. [GSI, Planckstrasse 1, D-64291, Darmstadt (Germany); Becker, F. [GANIL, BP 5027, F-14021, Caen Cedex (France); GSI, Planckstrasse 1, D-64291, Darmstadt (Germany); Bingham, C. [Department of Physics and Astronomy, University of Tennessee, TN 37996, Knoxville (United States); Borcea, R.; Hammache, F.; Ibrahim, F. [IPN, 91406, Orsay Cedex (France); Bouchez, E. [CEA Saclay, DSM/DAPNIA/SPhN, F-91191, Gif-sur-Yvette Cedex (France); Buta, A.; Dragulescu, E. [IFIN-HH, P.O. Box MG6, 76900, Bucharest-Magurele (Romania); Giovinazzo, J. [CENBG, BP 120, F-33175, Gradignan Cedex (France); Meot, V.; Negoita, F.; De Oliveira Santos, F.; Perru, O.; Roig, O.; Rykaczewski, K.P.; Saint-Laurent, M.G.; Sorlin, O.; Stanoiu, M.; Stefan, I.; Stodel, C.; Theisen, C.; Verney, D.

    2004-04-01

    In the experiment performed at the LISE2000 spectrometer at GANIL neutron-rich nickel isotopes were studied by microsecond isomer spectroscopy. Evidence for an isomer in {sup 76}Ni is found, consistently with the shell model prediction of an 8{sup +} state of {nu}(g{sub 9/2}){sup 2} structure. (orig.)

  11. Energetics and Vibrational Analysis of Methyl Salicylate Isomers

    Science.gov (United States)

    Massaro, Richard D.; Dai, Yafei; Blaisten-Barojas, Estela

    2009-08-01

    Energetics and vibrational analysis study of six isomers of methyl salicylate in their singlet ground state and first excited triple state is put forward in this work at the density functional theory level and large basis sets. The ketoB isomer is the lowest energy isomer, followed by its rotamer ketoA. For both ketoB and ketoA their enolized tautomers are found to be stable as well as their open forms that lack the internal hydrogen bond. The calculated vibrational spectra are in excellent agreement with IR experiments of methyl salicylate in the vapor phase. It is demonstrated that solvent effects have a weak influence on the stability of these isomers. The ionization reaction from ketoB to ketoA shows a high barrier of 0.67 eV ensuring that thermal and chemical equilibria yield systems containing mostly the ketoB isomer at normal conditions.

  12. Short-lived isomers in 94Rb

    International Nuclear Information System (INIS)

    Tsekhanovich, I.; Dare, J. A.; Smith, A. G.; Varley, B. J.; Simpson, G. S.; Urban, W.; Soldner, T.; Jolie, J.; Linnemann, A.; Orlandi, R.; Smith, J. F.; Scherillo, A.; Rzaca-Urban, T.; Zlomaniec, A.; Dorvaux, O.; Gall, B. J. P.; Roux, B.

    2008-01-01

    The medium-spin structure of the neutron-rich, odd-odd nucleus 94 Rb was studied by means of γ-ray spectroscopy. Excited levels were populated in the neutron-induced fission of 235 U and in the spontaneous fission of 252 Cf and 248 Cm. Two isomeric states were found at 1485.2 and 2074.8 keV with half-lives of 18 and 107 ns, respectively. The probable structures of the two isomers involve the fully aligned, proton-neutron configurations [π(g 9/2 ) x ν(g 7/2 )] 8 + and [π(g 9/2 ) x ν(h 11/2 )] 10 - , respectively. These new data give information on the single-particle energies in the region

  13. Complete Hexose Isomer Identification with Mass Spectrometry

    Science.gov (United States)

    Nagy, Gabe; Pohl, Nicola L. B.

    2015-04-01

    The first analytical method is presented for the identification and absolute configuration determination of all 24 aldohexose and 2-ketohexose isomers, including the D and L enantiomers for allose, altrose, galactose, glucose, gulose, idose, mannose, talose, fructose, psicose, sorbose, and tagatose. Two unique fixed ligand kinetic method combinations were discovered to create significant enough energetic differences to achieve chiral discrimination among all 24 hexoses. Each of these 24 hexoses yields unique ratios of a specific pair of fragment ions that allows for simultaneous determination of identification and absolute configuration. This mass spectrometric-based methodology can be readily employed for accurate identification of any isolated monosaccharide from an unknown biological source. This work provides a key step towards the goal of complete de novo carbohydrate analysis.

  14. Optimization of C20 isomers structure

    International Nuclear Information System (INIS)

    Ndjaka, J.M.B.; Charlier, J.C.

    2001-07-01

    We have performed geometry optimization of various possible planar and three-dimensional C 20 geometries. The planar structures considered include a linear chain, a monoclinic ring, and a bicyclic bow tie; while the three-dimensional geometric; consisted of a bowl or corranulene structure and a fullerene cage. In agreement with Wang et al MP2's calculations, our results predict the corranulene bowl to be the lowest energy structure. From the ground state geometry to the highest energy, considered C 20 structures, listed in increasing energy, are bowl, cage, bow tie, ring and chain. For the ring and bow tie isomers, the shape of the optimized structure deviates from that of the initial configuration; while the shape of the optimised bowl, cage and chain remain unchanged. (author)

  15. Identification of isomers of organometallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Mbue, Sona Peter; Cho, Kwang Hwi [Dept. of Bioinformatics and Life Science, School of Systems Biomedical Science, Soongsil University,Seoul (Korea, Republic of)

    2015-06-15

    The yaChI is a newly suggested chemical naming system. However, yaChI is a derivative of the IUPAC InChI with a modified algorithm that includes additional layers of chemical structure information. Consequently, yaChI string contains more structure details while preserving the original structure file information and can distinctively identify very closely related compounds reducing the chances of ambiguity in chemical compound databases as opposed to the general SMILES, InChI, and InChIKey. This study examines the relative performances of yaChI, SMILES, InChI, and InChIKey in duplication check for isomers. For simplicity, a small data set of 28 organometallic compounds (structural isomers of Rh-containing compounds) subdivided into three major groups (A, B, and C) based on the number and the type of ligands attached to the center atom was used to study the performances of each encoding scheme in describing chemical structures. SMILES, InChI, and InChIKey were generated using Openbabel and RDkit, whereas yaChI strings were generated with in-house program. Strings generated from SMILES, InChI, and InChIKey though different, resulted to only three unique chemical identifiers, with each belonging to one group indicating the presence of only three unique compounds in the study data. However, yaChI results depicted that all structures in each group are indeed unique and differ among themselves as well as those from other groups, mapping each structure with a unique identifier given a total number of 28 unique structures in the study data. This high perception of yaChI probe justifies its accuracy and reliability in duplication check among closely related compounds especially structures exhibiting stereo properties.

  16. Selective RNA targeting and regulated signaling by RIG-I is controlled by coordination of RNA and ATP binding.

    Science.gov (United States)

    Fitzgerald, Megan E; Rawling, David C; Potapova, Olga; Ren, Xiaoming; Kohlway, Andrew; Pyle, Anna Marie

    2017-02-17

    RIG-I is an innate immune receptor that detects and responds to infection by deadly RNA viruses such as influenza, and Hepatitis C. In the cytoplasm, RIG-I is faced with a difficult challenge: it must sensitively detect viral RNA while ignoring the abundance of host RNA. It has been suggested that RIG-I has a ‘proof-reading’ mechanism for rejecting host RNA targets, and that disruptions of this selectivity filter give rise to autoimmune diseases. Here, we directly monitor RNA proof-reading by RIG-I and we show that it is controlled by a set of conserved amino acids that couple RNA and ATP binding to the protein (Motif III). Mutations of this motif directly modulate proof-reading by eliminating or enhancing selectivity for viral RNA, with major implications for autoimmune disease and cancer. More broadly, the results provide a physical explanation for the ATP-gated behavior of SF2 RNA helicases and receptor proteins.

  17. A label-free colorimetric aptasensor for simple, sensitive and selective detection of Pt (II) based on platinum (II)-oligonucleotide coordination induced gold nanoparticles aggregation.

    Science.gov (United States)

    Fan, Daoqing; Zhai, Qingfeng; Zhou, Weijun; Zhu, Xiaoqing; Wang, Erkang; Dong, Shaojun

    2016-11-15

    Herein, a gold nanoparticles (AuNPs) based label-free colorimetric aptasensor for simple, sensitive and selective detection of Pt (II) was constructed for the first time. Four bases (G-G mismatch) mismatched streptavidin aptamer (MSAA) was used to protect AuNPs from salt-induced aggregation and recognize Pt (II) specifically. Only in the presence of Pt (II), coordination occurs between G-G bases and Pt (II), leading to the activation of streptavidin aptamer. Streptavidin coated magnetic beads (MBs) were used as separation agent to separate Pt (II)-coordinated MSAA. The residual less amount of MSAA could not efficiently protect AuNPs anymore and aggregation of AuNPs will produce a colorimetric product. With the addition of Pt (II), a pale purple-to-blue color variation could be observed by the naked eye. A detection limit of 150nM and a linear range from 0.6μM to 12.5μM for Pt (II) could be achieved without any amplification. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. High-K isomers in {sup 176}W and mechanisms of K-violation

    Energy Technology Data Exchange (ETDEWEB)

    Crowell, B.; Janssens, R.V.F.; Blumenthal, D.J. [and others

    1995-08-01

    K-isomers are states in deformed nuclei whose {gamma}-decay is hindered by selection rules involving K, the projection of the angular momentum along the axis of symmetry of the nucleus. Previous work with the Argonne Notre Dame BGO Array delineated the existence of two K-isomers in {sup 176}W, one of which had a very unusual pattern of decay. A short description of this work was published as a letter, and a more complete account is being readied for submission. These results provided evidence that quantum-mechanical fluctuations in the nuclear shape may be responsible for some of the observed K-violating transitions. In addition, hints were present in the data of the existence of another K-isomer with an even higher in. An experiment was performed in September 1994 to observe this isomer, using the reaction {sup 50}Ti({sup 130}Te,4n), and a technique in which recoiling {sup 176}W nuclei were created 17-cm upstream of the center of the array and caught on a Pb catcher foil at the center. Intense ({approximately} 3 pnA) beams of {sup 130}Te were supplied by the ECR source using a new sputtering technique. The recoil-shadow geometry was highly successful at removing the background from non-isomeric decays, allowing the weakly populated K-isomers to be detected cleanly. In addition, the availability of pulsed beams from ATLAS and the timing data from the BGO array provided a second technique for isolating the decays of interest, by selecting events in which a given number of BGO detectors fired between beam pulses. This method was used in the previous experiment, and was also applied in this experiment as a second level of selection. As a result, gamma-ray transitions were detected in the present experiment with intensities as small as {approximately} 0.02 % of the {sup 176}W reaction channel. The existence of the new isomer was confirmed, and a partial level-scheme was constructed.

  19. Photocrystallographic structure determination of a new geometric isomer of [Ru(NH3)4(H2O)(eta1-OSO)][MeC6H4SO3]2.

    Science.gov (United States)

    Bowes, Katharine F; Cole, Jacqueline M; Husheer, Shamus L G; Raithby, Paul R; Savarese, Teresa L; Sparkes, Hazel A; Teat, Simon J; Warren, John E

    2006-06-21

    The structure of a new metastable geometric isomer of [Ru(NH3)4(H2O)(SO2)][MeC6H4SO3]2 in which the SO2 group is coordinated through a single oxygen in an eta1-OSO bonding mode has been determined at 13 K; the new isomer was obtained as a 36% component of the structure within a single crystal upon irradiation using a tungsten lamp.

  20. Evolution of High Cellulolytic Activity in Symbiotic Streptomyces through Selection of Expanded Gene Content and Coordinated Gene Expression

    Science.gov (United States)

    McDonald, Bradon R.; Takasuka, Taichi E.; Wendt-Pienkowski, Evelyn; Doering, Drew T.; Raffa, Kenneth F.; Fox, Brian G.; Currie, Cameron R.

    2016-01-01

    The evolution of cellulose degradation was a defining event in the history of life. Without efficient decomposition and recycling, dead plant biomass would quickly accumulate and become inaccessible to terrestrial food webs and the global carbon cycle. On land, the primary drivers of plant biomass deconstruction are fungi and bacteria in the soil or associated with herbivorous eukaryotes. While the ecological importance of plant-decomposing microbes is well established, little is known about the distribution or evolution of cellulolytic activity in any bacterial genus. Here we show that in Streptomyces, a genus of Actinobacteria abundant in soil and symbiotic niches, the ability to rapidly degrade cellulose is largely restricted to two clades of host-associated strains and is not a conserved characteristic of the Streptomyces genus or host-associated strains. Our comparative genomics identify that while plant biomass degrading genes (CAZy) are widespread in Streptomyces, key enzyme families are enriched in highly cellulolytic strains. Transcriptomic analyses demonstrate that cellulolytic strains express a suite of multi-domain CAZy enzymes that are coregulated by the CebR transcriptional regulator. Using targeted gene deletions, we verify the importance of a highly expressed cellulase (GH6 family cellobiohydrolase) and the CebR transcriptional repressor to the cellulolytic phenotype. Evolutionary analyses identify complex genomic modifications that drive plant biomass deconstruction in Streptomyces, including acquisition and selective retention of CAZy genes and transcriptional regulators. Our results suggest that host-associated niches have selected some symbiotic Streptomyces for increased cellulose degrading activity and that symbiotic bacteria are a rich biochemical and enzymatic resource for biotechnology. PMID:27276034

  1. Selective recovery of Ag(I) coordination anion from simulate nickel electrolyte using corn stalk based adsorbent modified by ammonia–thiosemicarbazide

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Ying, E-mail: xiongying_1977@hotmail.com; Wan, Li; Xuan, Jing; Wang, Yongwei; Xing, Zhiqing; Shan, Weijun; Lou, Zhenning

    2016-01-15

    Highlights: • We developed a “green” corn stalk adsorbent treated by thiosemicarbazide–glutaraldehyde. • Adsorption mechanism of AgCl{sub i}{sup 1−i} could be electrostatic interaction with C−SH{sup +}−N and C=SH{sup +} group. • The gel could selectively adsorb AgCl{sub i}{sup 1−i} coordination anion from the Ag(I)–Cu(II)–Ni(II) simulate nickel electrolyte. - Abstract: In nickel electrolyte, Ag(I) was present at trace level concentration (10–20 mg L{sup −1}) and existed in the form of AgCl{sub i}{sup 1−i} coordination anion, instead of Ag{sup +} positive ion usually in several sources. In the present study, TSC-NH{sub 3}-OCS adsorbent based on natural corn stalk modified by ammonia (NH{sub 3})–thiosemicarbazide (TSC) was synthesized and characterized using some instrumental techniques. The TSC-NH{sub 3}-OCS adsorbent could selectively adsorb Ag(I) as AgCl{sub i}{sup 1−i} coordination anion from the Ag(I)–Cu(II)–Ni(II) simulate nickel electrolyte, especially in the case of the very high levels of Cu(II) and Ni(II), which significantly outperforms the commercial available resins. The adsorption mechanism was believed to be electrostatic interaction of the protonated bands of AgCl{sub 4}{sup 3−} with protonated thiol form of the thioamide units by FTIR and XPS analysis. The maximum adsorption capacity in the Ag(I) single and Ag(I)–Cu(II)–Ni(II) ternary system were obtained and calculated as 153.54 and 46.69 mg g{sup −1}, respectively. The reasons that the maximum adsorption capacity of AgCl{sub i}{sup 1−i} from the single and ternary system varied widely could be explained by adsorption kinetic and thermodynamic results. In addition, three successive sorption/desorption cycle runs from ternary system were performed which indicated that the TSC-NH{sub 3}-OCS adsorbent has a good performance for recovery Ag(I) from simulate nickel electrolyte.

  2. 17O NMR Studies of the Solvation State of cis/trans Isomers of Amides and Model Protected Peptides

    Science.gov (United States)

    Gerothanassis, Ioannis P.; Vakka, Constantina; Troganis, Anastasios

    1996-06-01

    17O shielding constants have been utilized to investigate solvation differences of the cis/trans isomers ofN-methylformamide (NMF),N-ethylformamide (NEF), andtert-butylformamide (TBF) in a variety of solvents with particular emphasis on aqueous solution. Comparisons are also made with protected peptides of the formulas CH3CO-YOH, CH3CO-Y-NHR (Y = Pro, Sar), and CH3CO-Y-Z-NHR (Y = Pro; Z =D-Ala) selectively enriched in17O at the acetyl oxygen atom. Hydration at the amide oxygen induces large and specific modifications of the17O shielding constants, which are practically the same for the cis and trans isomers of NMF, NEF, and the protected peptides. Fortert-butylformamide, the strong deshielding of the trans isomer compared to that of the cis isomer may be attributed to an out-of-plane (torsion-angle) deformation of the amide bond and/or a significant reduction of solvation of the trans isomer due to steric inhibition of the bulkytert-butyl group. Good linear correlation between δ(17O) of amides and δ(17O) of acetone was found for different solvents which have varying dielectric constants and solvation abilities. Sum-over-states calculations, within the solvaton model, underestimate effects of the dielectric constant of the medium on17O shielding, while finite-perturbation-theory calculations give good agreement with the experiment.

  3. 17O NMR Studies of the Solvation State of cissolidustrans Isomers of Amides and Model Protected Peptides

    Science.gov (United States)

    Gerothanassis; Vakka; Troganis

    1996-06-01

    17O shielding constants have been utilized to investigate solvation differences of the cissolidustrans isomers of N-methylformamide (NMF), N-ethylformamide (NEF), and tert-butylformamide (TBF) in a variety of solvents with particular emphasis on aqueous solution. Comparisons are also made with protected peptides of the formulas CH3CO-YOH, CH3CO-Y-NHR (Y = Pro, Sar), and CH3CO-Y-Z-NHR (Y = Pro; Z = D-Ala) selectively enriched in 17O at the acetyl oxygen atom. Hydration at the amide oxygen induces large and specific modifications of the 17O shielding constants, which are practically the same for the cis and trans isomers of NMF, NEF, and the protected peptides. For tert-butylformamide, the strong deshielding of the trans isomer compared to that of the cis isomer may be attributed to an out-of-plane (torsion-angle) deformation of the amide bond andsolidusor a significant reduction of solvation of the trans isomer due to steric inhibition of the bulky tert-butyl group. Good linear correlation between delta(17O) of amides and delta(17O) of acetone was found for different solvents which have varying dielectric constants and solvation abilities. Sum-over-states calculations, within the solvaton model, underestimate effects of the dielectric constant of the medium on 17O shielding, while finite-perturbation-theory calculations give good agreement with the experiment.

  4. Fixed-bed adsorption separation of xylene isomers over sio2/silicallite-1 core-shell adsorbents

    KAUST Repository

    Khan, Easir A.; Rajendran, Arvind; Lai, Zhiping

    2013-01-01

    SiO2/Silicalite-1 core-shell material has been demonstrated as potential shape selective adsorbent in gas phase separation of p-xylene from a mixture of p/o-xylene isomers. The core-shell composite comprised of large silica core and thin

  5. Separation of Opiate Isomers Using Electrospray Ionization and Paper Spray Coupled to High-Field Asymmetric Waveform Ion Mobility Spectrometry

    Science.gov (United States)

    Manicke, Nicholas E.; Belford, Michael

    2015-05-01

    One limitation in the growing field of ambient or direct analysis methods is reduced selectivity caused by the elimination of chromatographic separations prior to mass spectrometric analysis. We explored the use of high-field asymmetric waveform ion mobility spectrometry (FAIMS), an ambient pressure ion mobility technique, to separate the closely related opiate isomers of morphine, hydromorphone, and norcodeine. These isomers cannot be distinguished by tandem mass spectrometry. Separation prior to MS analysis is, therefore, required to distinguish these compounds, which are important in clinical chemistry and toxicology. FAIMS was coupled to a triple quadrupole mass spectrometer, and ionization was performed using either a pneumatically assisted heated electrospray ionization source (H-ESI) or paper spray, a direct analysis method that has been applied to the direct analysis of dried blood spots and other complex samples. We found that FAIMS was capable of separating the three opiate structural isomers using both H-ESI and paper spray as the ionization source.

  6. Trans-dinitroglycoluril isomers-A DFT treatment

    Directory of Open Access Journals (Sweden)

    Lemi Türker

    2017-02-01

    Full Text Available Isomers of trans-1,4-Dinitroglycoluril (trans-DINGU and their 1,3-tautomers are considered within the constraints of B3LYP/6-31++G (d,p and B3LYP/CC-PVTZ levels of DFT calculations. Additionally, the interactions of these isomers and proton in vacuum are investigated. The data have revealed that two of the three isomers undergo CH bond cleavage as the result of interaction with proton in vacuum. The total energies, some structural properties, the calculated IR and UV spectra are discussed.

  7. Properties of neutron-rich hafnium high-spin isomers

    CERN Multimedia

    Tungate, G; Walker, P M; Neyens, G; Billowes, J; Flanagan, K; Koester, U H; Litvinov, Y

    It is proposed to study highly-excited multi-quasiparticle isomers in neutron-rich hafnium (Z=72) isotopes. Long half-lives have already been measured for such isomers in the storage ring at GSI, ensuring their accessibility with ISOL production. The present proposal focuses on:\\\\ (i) an on-line experiment to measure isomer properties in $^{183}$Hf and $^{184}$Hf, and\\\\ (ii) an off-line molecular breakup test using REXTRAP, to provide Hf$^{+}$ beams for future laser spectroscopy and greater sensitivity for the future study of more neutron-rich isotopes.

  8. Elucidation of structural isomers from the homogeneous rhodium-catalyzed isomerization of vegetable oils.

    Science.gov (United States)

    Andjelkovic, Dejan D; Min, Byungrok; Ahn, Dong; Larock, Richard C

    2006-12-13

    The structural isomers formed by the homogeneous rhodium-catalyzed isomerization of several vegetable oils have been elucidated. A detailed study of the isomerization of the model compound methyl linoleate has been performed to correlate the distribution of conjugated isomers, the reaction kinetics, and the mechanism of the reaction. It has been shown that [RhCl(C8H8)2]2 is a highly efficient and selective isomerization catalyst for the production of highly conjugated vegetable oils with a high conjugated linoleic acid (CLA) content, which is highly desirable in the food industry. The combined fraction of the two major CLA isomers [(9Z,11E)-CLA and (10E,12Z)-CLA] in the overall CLA mixture is in the range from 76.2% to 93.4%. The high efficiency and selectivity of this isomerization method along with the straightforward purification process render this approach highly promising for the preparation of conjugated oils and CLA. Proposed improvements in catalyst recovery and reusability will only make this method more appealing to the food, paint, coating, and polymer industries in the future.

  9. Separation behavior of octadecadienoic acid isomers and identification of cis- and trans-isomers using gas chromatography.

    Science.gov (United States)

    Shibamoto, Shigeaki; Gooley, Andrew; Yamamoto, Kouhei

    2015-01-01

    Using a strongly polar cyanopropyl capillary column we have investigated the gas chromatography (GC) separation behaviors of 24 octadecadienoic acid methyl ester (18:2ME) isomers compared against saturated methyl stearate (18:0ME) and arachidic acid methyl ester (20:0ME), and the dependency on the GC column temperature. The 24 isomers were obtained by performing cis-to trans-isomerization of six regioisomers: five of the 18:2ME isomers were prepared by the partial reduction of methyl α-linolenate and methyl γ-linolenate C18 trienoic acids with different double bond positions, whereas the sixth isomer, 18:2ME (c5, c9), was obtained from a raw constituent fatty acid methyl ester (FAME) sample extracted from Japanese yew seeds. There are no reference standards commercially available for 18:2ME isomers, and in elucidating the elution order of these isomers this study should help the future identification of cis- and trans-type of 18:2ME. We also report the identification method of cis- and trans-type of FAME using equivalent chain lengths and attempt the identification of cis- and trans-type of 18:2ME isomers from partially hydrogenated canola oil.

  10. Experimental thermochemical study of two chlorodinitroaniline isomers

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Ribeiro da Silva, Maria D.M.C.; Santos, Ana Filipa L.O.M.; Ferreira, Ana I.M.C. Lobo; Galvao, Tiago L.P.

    2010-01-01

    The standard (p 0 =0.1MPa) molar enthalpies of formation of 2-chloro-4,6-dinitroaniline and 4-chloro-2,6-dinitroaniline, in the gaseous phase, at T = 298.15 K, were derived from the combination of the values of the standard molar enthalpies of formation, in the crystalline phase, and of the standard molar enthalpies of sublimation, at the same temperature. The standard molar enthalpies of formation, in the crystalline phase, were derived from the standard massic energies of combustion, in oxygen, measured by rotating-bomb combustion calorimetry. The standard molar enthalpies of sublimation were calculated, by the application of the Clausius-Clapeyron equation, to the vapour pressures at several temperatures, measured by Knudsen effusion technique. The values of the standard molar enthalpies of formation of 2-chloro-4,6-dinitroaniline and 4-chloro-2,6-dinitroaniline, in the gaseous phase, at T = 298.15 K, are discussed in terms of enthalpic increments, and the enthalpy of isomerization between the two compounds is compared with the same parameter for two isomers of chloronitroaniline, studied in previous works.

  11. In vitro techniques for selection of radiation induced mutations adapted to adverse environmental conditions. Proceedings of a final research co-ordination meeting

    International Nuclear Information System (INIS)

    2001-06-01

    The ever increasing human population and dwindling land and water resources worldwide make it essential to produce more food, fibre and fodder from less and less land. During the last century, plant breeding contributed remarkably to increasing food by producing varieties which give higher yield, have improved quality and nutrition, and resist diseases and pests. Nearly 50% of the increase in food production in Asia during the last fifty years can be attributed to the high yielding, short height varieties of rice and wheat, the remaining to the improved agronomic inputs and management. Many crops, such as cassava, potato, pineapple, sweet potato, sugarcane, banana and plantain are major food crops, and others such as sugarcane and pineapple are important to the economies of many developing countries. One of the solutions to have a sustainable and secure food production is to breed varieties which are tolerant of stress conditions during their growth and development. Hence a Co-ordinated Research Project on In vitro Techniques for Selection of Radiation Induced Mutations Adapted to Adverse Environmental Conditions was initiated and focused primarily on the improvement of vegetatively propagated plants. Since the inception of this project, several participating scientists established the optimal dose requirement for in vitro cultured material. Investigations were carried out on the effect of radiation to alter traits which affect survival under stress conditions and high temperature stress in potato, pineapple, sweet potato and garlic. The possibility to change traits such as tolerance to saline and water logged soils in sugarcane and gene regulation for salinity tolerance were studied. The limited number of available reports suggest that callus cultures are much more sensitive to radiation treatment and require much lower doses (2 to 5 Gy) than stem cuttings or seeds, and that relatively higher doses (15 to 20 Gy) cause necrosis or loss of regenerative capacity. The

  12. In vitro techniques for selection of radiation induced mutations adapted to adverse environmental conditions. Proceedings of a final research co-ordination meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-06-01

    The ever increasing human population and dwindling land and water resources worldwide make it essential to produce more food, fibre and fodder from less and less land. During the last century, plant breeding contributed remarkably to increasing food by producing varieties which give higher yield, have improved quality and nutrition, and resist diseases and pests. Nearly 50% of the increase in food production in Asia during the last fifty years can be attributed to the high yielding, short height varieties of rice and wheat, the remaining to the improved agronomic inputs and management. Many crops, such as cassava, potato, pineapple, sweet potato, sugarcane, banana and plantain are major food crops, and others such as sugarcane and pineapple are important to the economies of many developing countries. One of the solutions to have a sustainable and secure food production is to breed varieties which are tolerant of stress conditions during their growth and development. Hence a Co-ordinated Research Project on In vitro Techniques for Selection of Radiation Induced Mutations Adapted to Adverse Environmental Conditions was initiated and focused primarily on the improvement of vegetatively propagated plants. Since the inception of this project, several participating scientists established the optimal dose requirement for in vitro cultured material. Investigations were carried out on the effect of radiation to alter traits which affect survival under stress conditions and high temperature stress in potato, pineapple, sweet potato and garlic. The possibility to change traits such as tolerance to saline and water logged soils in sugarcane and gene regulation for salinity tolerance were studied. The limited number of available reports suggest that callus cultures are much more sensitive to radiation treatment and require much lower doses (2 to 5 Gy) than stem cuttings or seeds, and that relatively higher doses (15 to 20 Gy) cause necrosis or loss of regenerative capacity. The

  13. Simultaneous Determination of Two Isomers of Asarone in Piper ...

    African Journals Online (AJOL)

    Simultaneous Determination of Two Isomers of Asarone in Piper sarmentosum Roxburgh (Piperaceae) Extracts using Different Chromatographic Columns. Mohd Shahrul Ridzuan Hamil, Abdul Hakeem Memon, Amin Malik Shah Abdul Majid, Zhari Ismail ...

  14. Carotenoids and Their Isomers: Color Pigments in Fruits and Vegetables

    Directory of Open Access Journals (Sweden)

    Yueming Jiang

    2011-02-01

    Full Text Available Fruits and vegetables are colorful pigment-containing food sources. Owing to their nutritional benefits and phytochemicals, they are considered as ‘functional food ingredients’. Carotenoids are some of the most vital colored phytochemicals, occurring as all-trans and cis-isomers, and accounting for the brilliant colors of a variety of fruits and vegetables. Carotenoids extensively studied in this regard include β-carotene, lycopene, lutein and zeaxanthin. Coloration of fruits and vegetables depends on their growth maturity, concentration of carotenoid isomers, and food processing methods. This article focuses more on several carotenoids and their isomers present in different fruits and vegetables along with their concentrations. Carotenoids and their geometric isomers also play an important role in protecting cells from oxidation and cellular damages.

  15. The importance of stimulated gamma release from isomers

    International Nuclear Information System (INIS)

    Roberts, H.

    1997-01-01

    The potential applications of the gamma-ray laser are discussed to illustrate the potential benefit of the development of this field of nuclear science, as well as the risks and responsibilities associated with isomer development beyond their current status as nuclear curiosities. The similarities and differences between the development of a gamma-ray laser based on nuclear isomers and the initial development of nuclear science and engineering are compared

  16. Poisson Coordinates.

    Science.gov (United States)

    Li, Xian-Ying; Hu, Shi-Min

    2013-02-01

    Harmonic functions are the critical points of a Dirichlet energy functional, the linear projections of conformal maps. They play an important role in computer graphics, particularly for gradient-domain image processing and shape-preserving geometric computation. We propose Poisson coordinates, a novel transfinite interpolation scheme based on the Poisson integral formula, as a rapid way to estimate a harmonic function on a certain domain with desired boundary values. Poisson coordinates are an extension of the Mean Value coordinates (MVCs) which inherit their linear precision, smoothness, and kernel positivity. We give explicit formulas for Poisson coordinates in both continuous and 2D discrete forms. Superior to MVCs, Poisson coordinates are proved to be pseudoharmonic (i.e., they reproduce harmonic functions on n-dimensional balls). Our experimental results show that Poisson coordinates have lower Dirichlet energies than MVCs on a number of typical 2D domains (particularly convex domains). As well as presenting a formula, our approach provides useful insights for further studies on coordinates-based interpolation and fast estimation of harmonic functions.

  17. Isomer spectroscopy of {sup 125,127}Cd

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, F. [Institut fuer Kernphysik, Universitaet Koeln (Germany); GSI, Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Gorska, M.; Grawe, H.; Pietri, S. [GSI, Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Caceres, L. [GSI, Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Departmento de Fisicia Teorica, Universidad Autonoma de Madrid (Spain); Jungclaus, A. [Departmento de Fisicia Teorica, Universidad Autonoma de Madrid (Spain); Pfuetzner, M. [IEP, Warsaw University, Warsaw (Poland); Regan, P.H; Podolyak, Z. [Department of Physics, University of Surrey, Guildford (United Kingdom); Rudolf, D. [Department of Physics, Lund University (Sweden)

    2010-07-01

    The results of investigations of isomeric decay in odd mass heavy Cd isotopes namely {sup 125,127}Cd are reported. To date information has been obtained on even mass heavy Cd isotopes and the systematics show evolution of single particle energies for them. The experiment was performed at GSI, Darmstadt to investigate the single particle level structure of odd mass heavy Cd isotopes. Nuclei of interest were produced in fragmentation reaction of {sup 136}Xe beam at energy 750MeV/u on a {sup 9}Be target of 4g/cm{sup 2} thickness. Selection of ions from unwanted reaction products and event by event identification was facilitated by FRagment Separator (FRS). Isomers populated in the reaction were implanted in a plastic catcher surrounded by 15 Ge cluster detectors from RISING array to detect gamma radiations. Level schemes based on the intensity balance and life time information were constructed for the first time for these nuclei. Comparison of the experimental results with shell model calculation are discussed.

  18. Thermochemical study of some dichloroacetophenone isomers

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro da Silva, Manuel A.V., E-mail: risilva@fc.up.p [Centro de Investigacao em Quimica, Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal); Amaral, Luisa M.P.F. [Centro de Investigacao em Quimica, Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal)

    2011-03-15

    The standard (p{sup 0}=0.1MPa) molar enthalpies of formation in the condensed phase, {Delta}{sub f}H{sub m}{sup 0}(cr,l), for 2',4'-, 2',5'-, and 3',4'-dichloroacetophenones were derived from the standard molar energies of combustion, {Delta}{sub c}U{sub m}{sup 0} in oxygen, to yield CO{sub 2}(g) and HCl . 600H{sub 2}O(l), at T = 298.15 K, measured by rotating bomb combustion calorimetry. The standard molar enthalpies of vapourization or sublimation, {Delta}{sub cr,l}{sup g}H{sub m}{sup 0}, of these compounds, at T = 298.15 K were determined by Calvet microcalorimetry. For the 3',4'-dichoroacetophenone, the standard molar enthalpy of sublimation, at T = 298.15 K, was derived by the Clausius-Clapeyron equation, from the temperature dependence of the vapour pressures of this compound, measured by the Knudsen effusion technique. From the values of {Delta}{sub f}H{sub m}{sup 0}(cr,l) and {Delta}{sub cr,l}{sup g}H{sub m}{sup 0} the standard molar enthalpies of formation of the three isomers, in the gaseous phase, {Delta}{sub f}H{sub m}{sup 0}(g), at T = 298.15 K were derived and compared with the same parameters estimated by the Cox Scheme. (table)

  19. g-factor of the Kπ = 14+ isomer in 176 W

    International Nuclear Information System (INIS)

    Ionescu-Bujor, M.; Iordachescu, A.; Marginean, N.; Brandolini, F.; Pavan, P.; Lenzi, S.M.; De Poli, M.; Gadea, A.; Martinez, T.; Medina, N.H.; Ribas, R.V.; Podolyak, Zs.

    2000-01-01

    In the deformed A ≅ 180 nuclei with β 2 ≅ 0.25 multi-quasiparticle intrinsic states are able to compete with rotational structures as both proton and neutron Fermi surfaces are close to nucleon orbits with large projections Ω on the prolate symmetry axis. Due to the approximate conservation of the K quantum number, these states often have hindered decays with half-lives ranging from nanoseconds to years. The decay characteristics of the high-K isomers, as well as the properties of the collective bands built on them, were subject of detailed experimental studies over the last decade. Particular attention has been devoted to the apparent breakdown of the K-selection rule observed experimentally in the decay of several high-spin isomeric states of the A ≅ 180 region. A very interesting high-K isomer showing in its decay a severe violation of the K-selection rule has been recently found in 176 W. The isomeric state, with K π = 14 + , T 1/2 = 35(10) ns and E x =3746 keV, de-excites predominantly to states with K=0, bypassing available levels of intermediate K. To elucidate the isomer underlying structure, an experiment to determine its the g-factor has been performed at the LNL XTU-tandem, by applying the time-differential perturbed angular distribution (TDPAD) method in an external magnetic field. The isomer was populated in the 164 Dy( 16 O,4n) 176 W reaction at a bombarding energy of 83 MeV. The 16 O beam has been pulsed with a pulse width of 1.5 ns at a repetition period of 800 ns. In view of the very low isomer population (about 2% of the 4n channel), a high suppression of the continuous beam in-between the beam bursts was necessary for a proper observation of the isomeric decay γ-lines. The target consisted of 0.5 mg/cm 2 metallic 164 Dy on thick Pb backing in which both the recoiling 176 W nuclei and the projectiles were stopped. Two planar Ge detectors and two Ge detectors of 25% efficiency placed at the angles ± 135 angle and ± 45 angle with respect

  20. Serum Metabolic Fingerprinting Identified Putatively Annotated Sphinganine Isomer as a Biomarker of Wolfram Syndrome.

    Science.gov (United States)

    Zmyslowska, Agnieszka; Ciborowski, Michal; Borowiec, Maciej; Fendler, Wojciech; Pietrowska, Karolina; Parfieniuk, Ewa; Antosik, Karolina; Pyziak, Aleksandra; Waszczykowska, Arleta; Kretowski, Adam; Mlynarski, Wojciech

    2017-11-03

    Wolfram syndrome (WFS) is an example of a rare neurodegenerative disease with coexisting endocrine symptoms including diabetes mellitus as the first clinical symptom. Treatment of WFS is still only symptomatic and associated with poor prognosis. Potential markers of disease progression that could be useful for possible intervention trials are not available. Metabolomics has potential to identify such markers. In the present study, serum fingerprinting by LC-QTOF-MS was performed in patients with WFS (n = 13) and in patients with T1D (n = 27). On the basis of the obtained results, aminoheptadecanediol (17:0 sphinganine isomer) (+50%, p = 0.02), as the most discriminatory metabolite, was selected for validation. The 17:0 sphinganine isomer level was determined using the LC-QQQ method in the samples from WFS patients at two time points and compared with samples obtained from patients with T1D (n = 24) and healthy controls (n = 24). Validation analysis showed higher 17:0 sphinganine isomer level in patients with WFS compared to patients with T1D (p = 0.0097) and control group (p < 0.0001) with progressive reduction of its level after two-year follow-up period. Patients with WFS show a unique serum metabolic fingerprint, differentiating them from patients with T1D. Sphinganine derivate seems to be a marker of the ongoing process of neurodegeneration in WFS patients.

  1. Spectrally Undiscerned Isomers Might Lead to Erroneous Determination of Water Exchange Rates of paraCEST Eu(III) Agents.

    Science.gov (United States)

    Cakić, Nevenka; Tickner, Ben; Zaiss, Moritz; Esteban-Gómez, David; Platas-Iglesias, Carlos; Angelovski, Goran

    2017-07-17

    We report a detailed study of the solution structure and water exchange rate of a Eu(III) complex with the cyclen-based ligand L 1 , containing (S)-2-(2-acetamido)-3-(4-(trifluoromethyl)phenyl)propanoate pendant arms at positions 1 and 7 of the cyclen ring and acetylglycinate pendants at positions 4 and 10. The EuL 1 complex was characterized by a combination of NMR and luminescence spectroscopy and density functional theory (DFT) calculations. The chemical exchange saturation transfer (CEST) spectra obtained at different temperatures and saturation powers present a CEST signal attributed to the coordinated water molecule. However, the spectra recorded at low temperatures (10 °C) and low saturation powers revealed the presence of two different species with coordinated water molecules having very similar chemical shifts. Determination of the water exchange rates of the coordinated water molecules was carried out by using the Bloch four-pool model that accounts for the presence of these isomers, and this model was compared to conventional methods for CEST quantification, namely the Omega plot and QUESP (quantification of exchange rate as a function of saturation power), which assume the presence of a single CEST active species. The results indicated that only the four-pool Bloch equations provide reasonable water exchange rates and activation parameters. Solution NMR studies and DFT calculations indicated that the two isomers present in solution correspond to the SS-Δ(λλλλ) and SS-Λ(δδδδ) isomers, which present capped square-antiprismatic (SAP) coordination environments. Additional NMR studies on the EuL 2 and EuL 3 complexes, which present four (S)-2-(2-acetamido)-3-(4-(trifluoromethyl)phenyl)propanoate or acetylglycinate pendant arms, respectively, confirm the results obtained for EuL 1 .

  2. A new high-spin isomer in {sup 195}Bi

    Energy Technology Data Exchange (ETDEWEB)

    Roy, T.; Mukherjee, G.; Rana, T.K.; Bhattacharya, Soumik; Asgar, Md.A.; Bhattacharya, C.; Bhattacharya, S.; Bhattacharyya, S.; Pai, H. [Variable Energy Cyclotron Centre, Kolkata (India); Madhavan, N.; Bala, I.; Gehlot, J.; Gurjar, R.K.; Jhingan, A.; Kumar, R.; Muralithar, S.; Nath, S.; Singh, R.P.; Varughese, T. [Inter University Acclerator Centre, New Delhi (India); Basu, K.; Bhattacharjee, S.S.; Ghugre, S.S.; Raut, R.; Sinha, A.K. [UGC-DAE-CSR Kolkata Centre, Kolkata (India); Palit, R. [Tata Institute of Fundamental Research, Department of Nuclear and Atomic Physics, Mumbai (India)

    2015-11-15

    A new high-spin isomer has been identified in {sup 195}Bi at the focal plane of the HYbrid Recoil mass Analyser (HYRA) used in the gas-filled mode. The fusion evaporation reactions {sup 169}Tm ({sup 30}Si, x n) {sup 193,} {sup 195}Bi were used with the beam energies on targets of 168 and 146MeV for 6n and 4n channels, respectively. The evaporation residues, separated from the fission fragments, and their decays were detected at the focal plane of HYRA using MWPC, Si-Pad and clover HPGe detectors. The half-life of the new isomer in {sup 195}Bi has been measured to be 1.6(1) μs. The configuration of the new isomer has been proposed and compared with the other isomers in this region. The Total Routhian Surface (TRS) calculations for the three-quasiparticle configurations corresponding to the new isomer suggest an oblate deformation for this isomeric state. The same calculations for different configurations in {sup 195}Bi and for the even-even {sup 194}Pb core indicate that the proton i{sub 13/2} orbital has a large shape driving effect towards oblate shape in these nuclei. (orig.)

  3. Substitution effects on the absorption spectra of nitrophenolate isomers.

    Science.gov (United States)

    Wanko, Marius; Houmøller, Jørgen; Støchkel, Kristian; Suhr Kirketerp, Maj-Britt; Petersen, Michael Åxman; Nielsen, Mogens Brøndsted; Nielsen, Steen Brøndsted; Rubio, Angel

    2012-10-05

    Charge-transfer excitations highly depend on the electronic coupling between the donor and acceptor groups. Nitrophenolates are simple examples of charge-transfer systems where the degree of coupling differs between ortho, meta and para isomers. Here we report the absorption spectra of the isolated anions in vacuo to avoid the complications of solvent effects. Gas-phase action spectroscopy was done with two different setups, an electrostatic ion storage ring and an accelerator mass spectrometer. The results are interpreted on the basis of CC2 quantum chemical calculations. We identified absorption maxima at 393, 532, and 399 nm for the para, meta, and ortho isomer, respectively, with the charge-transfer transition into the lowest excited singlet state. In the meta isomer, this π-π* transition is strongly redshifted and its oscillator strength reduced, which is related to the pronounced charge-transfer character, as a consequence of the topology of the conjugated π-system. Each isomer's different charge distribution in the ground state leads to a very different solvent shift, which in acetonitrile is bathochromic for the para and ortho, but hypsochromic for the meta isomer.

  4. Syntheses, structures and selective dye adsorption of five formic-based coordination polymers prepared by in-situ hydrolysis of N, N′-dimethylformamide

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Zheng; Meng, Xiang-min; Zhang, Dong-mei; Zhang, Xia; Wang, Mei [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, Shandong 266100 (China); Jin, Fan [Max Planck Institute for Terrestrial Microbiology & LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg 35043 (Germany); Fan, Yu-hua [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, Shandong 266100 (China)

    2017-04-15

    Five functional coordination polymers (formic-based CPs) namely: ([Cu{sub 2}(CHOO){sub 3}(bibp){sub 2}]·CHOO){sub n} (1), ([Co{sub 2}(CHOO){sub 3}(bibp){sub 2}]·NO{sub 3}·H{sub 2}O)n (2), ([Ni{sub 2}(CHOO){sub 3}(bibp){sub 2}]·NO{sub 3}·H{sub 2}O){sub n} (3) [Co(CHOO){sub 2}(bbibp)]{sub n} (4) and [Zn(CHOO){sub 2}(bbibp)]{sub n} (5) (bibp=4,4′-bis(imidazolyl)biphenyl, bbibp=4,4′-bis(benzoimidazo-1-yl)biphenyl) have been successfully hydrothermally synthesized using the in-situ hydrolysis of N, N′-dimethylformamide (DMF) as the source of formate. All of these five polymers were characterized by single-crystal X-ray diffraction, elemental analysis, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analysis. Complexes 1–3 have the similar three-dimensional 3D kag topological framework built from the bibp ligand as the support member between the neighboring formic planes. Both complexes 4 and 5 have the similar one-dimensional 1D linear chain which is further assembled into 3D supermolecular structure by C–H…O hydrogen bonds. The dyes adsorption experiments have also been investigated systematically. The results show that complexes 2 and 3 exhibit high selective adsorption ability towards anionic dyes in their aqueous solution. Moreover, complex 2 displays good reversibility in the process of the dyes adsorption-release. Meanwhile, the unusual blocking phenomenon was firstly observed when complex 2 was in MO/OIV aqueous solutions with different concentration.

  5. Coordination cycles

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    -, č. 274 (2005), s. 1-26 ISSN 1211-3298 Institutional research plan: CEZ:AV0Z70850503 Keywords : coordination * crises * cycles and fluctuations Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp274.pdf

  6. Coordination cycles

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    2008-01-01

    Roč. 63, č. 1 (2008), s. 308-327 ISSN 0899-8256 Institutional research plan: CEZ:AV0Z70850503 Keywords : global games * coordination * crises * cycles and fluctuations Subject RIV: AH - Economics Impact factor: 1.333, year: 2008

  7. Isomers of Cu6 cluster: a density function theory study

    International Nuclear Information System (INIS)

    Jia Yanhui; Wang Shanshan; Li Gongping

    2008-01-01

    The possible structure of Cu 6 cluster has been given with the GaussView that is a graphical user interface software. The structure optimization was performed on the B3LYP functional and SDD basic set of the quantum computational software of Gaussian03. And eight isomers of Cu 6 cluster were calculated. The binding energy and the structure of eight isomers have been investigated in detail. The result showed that the value of the binding energy was in reasonable agreement with available experimental data, as well as with other theoretical results, and the most stable structure was the triangle of plane. Three new isomers of the Cu 6 cluster have been got in our work, which would be the valuable data for the further theoretical and experimental study. (authors)

  8. A pocketful of tin isomers from heavy-ion collisions

    International Nuclear Information System (INIS)

    Daly, P.J.; Broda, R.; Fornal, B.; Mayer, R.H.; Nisius, D.; Bearden, I.; Benet, P.; Grabowski, Z.W.; Lauritsen, T.; Carpenter, M.; Janssens, R.V.F.; Khoo, T.L.; Liang, Y.; Lunardi, S.; Blomqvist, J.

    1992-01-01

    Reaction products of 122,124 Sn + 76 Ge( 8O Se) collisions 10--15% above the barrier have been studied by γ-ray spectroscopy, and new yrast isomers in 119--124 Sn isotopes have been identified and characterized. B(E2) values determined for (νh 11/2 ) n 10 + → 8 + transitions in even-A Sn nuclei pinpoint half-filling of the νh 11/2 subshell close to N = 73. In odd-A Sn isotopes, 19/2 + isomers with 1--10 μs half-lives occur systematically, and higher-lying (νh ll/2 ) n v=3 27/2 - isomers in 119 Sn and 121 Sn have also been identified. These deep inelastic excitation processes were found to populate a large number of neutron-rich nuclei strongly enough for yrast spectroscopy studies

  9. Simultaneous determination of naphthol isomers at poly(3-methylthiophene)-nano-Au modified electrode with the enhancement of surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Li, Linlin [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Shandong Institute for Product Quality Inspection, Jinan 250100 (China); Liu, Enli; Wang, Xiaolin; Chen, Jia [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Zhang, Xiaoli, E-mail: zhangxl@sdu.edu.cn [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China)

    2015-08-01

    A polymer film incorporated gold nanoparticle modified electrode was fabricated. The fabricated process involved eletrodeposition of gold nanoparticles and electropolymerization of the 3-methylthiophene (abbreviated 3MT) onto the glassy carbon electrode (GCE). The resulting electrode (P3MT-nano-Au/GCE) was characterized by scanning electron microscopy (SEM), and a simultaneous determination of naphthol isomers at P3MT-nano-Au/GCE was studied using semi-derivative voltammetry. Because of the synergistic effect of gold nanoparticles and poly(3MT), the sensitivity and distinguishability in the simultaneous determination of naphthol isomers were greatly increased. Besides, a further increase in the detecting sensitivity of naphthol isomers could be obtained in the presence of surfactant, cetyl trimethyl ammonium bromide (CTAB). Also, the role of different kinds of surfactants was texted and the action mechanism was discussed in detail. Under the optimal conditions, the linear calibration ranges of the determination of naphthols were 7.0 × 10{sup −7} to 1.5 × 10{sup −4} mol/L for 1-naphthol and 1.0 × 10{sup −6} to 1.5 × 10{sup −4} mol/L for 2-naphthol with detection limits of 1.0 × 10{sup −7} and 3.0 × 10{sup −7} mol/L (S/N = 3), respectively. - Highlights: • Nano-Au-polymer film was fabricated by eletrodeposition and electropolymerization. • Naphthol isomers were detected simultaneously. • Surfactant improved the sensitivity and selectivity.

  10. Theoretical Study of the Diastereofacial Isomers of Aldrin and Dieldrin

    Directory of Open Access Journals (Sweden)

    Zoran Zdravkovski

    2006-02-01

    Full Text Available The Diels-Alder reaction of hexachlorocyclopentadiene with norbornadiene givesaldrin but theoretically three other diastereofacial isomers are possible. On oxidation theseisomers can generate eight adducts one of which is known as dieldrin. All these, as well asthe corresponding reactions with hexafluorocyclopenadiene were studied by semiempirical(AM1 and PM3 and hybrid density functional (B3LYP methods. Besides the energy levels,the transition states were calculated for the reactions leading to the diastereofacial isomers ofaldrin, which indicate that aldrin is the favored product of the reaction both fromthermodynamic and kinetic point of view.

  11. Laser isotope and isomer separations: History and trends

    International Nuclear Information System (INIS)

    Letok'ov, V.S.

    1990-01-01

    Paper will review history and principles of laser isotope and nuclear isomer separation: laser multistep photoionization of isotopic and isomeric atoms, laser IR-UV two-step photodissociation of molecules, laser IR multiphoton photodissociation of polyatomic molecules. The comparison and areas of applications of these methods will be considered. Paper will discuss a present state of art of technology of these methods in practical scale in various countries. In conclusion the trends of research in this field including applications of laser-separated isotopes and isomers will be considered

  12. Induced γ emission for nuclear isomer long-lived

    International Nuclear Information System (INIS)

    Yang Tianli; Hao Fanhua

    2007-06-01

    It is pointed that the induced 7 emission for long lived isomer 178m2 Hf by low energy X rays has been a topic subject in the nuclear field recently. The background and development status are described. A principle for T ray transitions induced by X rays and the theoretical about magnificent induced emission have been related. In addition, the possible method of 178m2 Hf produce has been introduced also. Although the argument has existed for the experimental results of induced 7 emission, it can push forward in solving energy crisis and in future military field after controlling effectively the releasing of high excited energy for isomer. (authors)

  13. UV laser induced photochemistry of nitrobenzene and nitrotoluene isomers

    International Nuclear Information System (INIS)

    Kosmidis, C.; Clark, A.; Deas, R.M.; Ledingham, K.W.D.; Marshall, A.; Singhal, R.P.

    1995-01-01

    The photofragmentation of nitrobenzene and the isomers of nitrotoluene in the gas phase are studied in the wavelength region 210-270 nm using a pulsed UV laser in conjunction with a time of flight mass spectrometer. Laser induced mass spectra are analysed and compared with those produced by the electron impact (EI) technique. The generation of the observed fragment ions is explained by invoking different fragmentation pathways followed by these molecules. Observed differences in the mass spectra of the o-, m-, and p-nitrotoluene isomers are discussed as a possible way for a laser based method for their identification. (author)

  14. Comparison of UVA induced cytotoxicity by iodoHoechst isomers

    International Nuclear Information System (INIS)

    Karagiannis, T.C.; Lobachevsky, P.N.; Martin, R.F.

    2003-01-01

    Full text: Isomers of the DNA minor groove binding ligand, iodoHoechst, have been shown to sensitise DNA to cleavage by ultraviolet type A (UVA). The DNA damage has been attributed to formation of a carbon-centred radical upon UVA induced dehalogenation of the drugs. Comparison of the efficacy of the ligands in inducing DNA single strand breaks in plasmid DNA has indicated that the ortho isomer is more efficient than the para- and meta-isomers, mainly due to a greater cross-section for dehalogenation, and to some extent from increased efficiency of DNA damage per dehalogenation event. In the present study, the efficiency of dehalogenation and cytotoxicity of the three iodoHoechst isomers has been compared in human erythroleukemic, K562 cells. The uptake of the iodoHoechst compounds in K562 nuclei has been measured, and the photoefficiency of the cellular associated dehalogenation by UVA has been established for the three isomers. The results indicate that the sensitivity to UVA mediated dehalogenation is much higher for the ortho analogue compared to the para and meta-analogues. Values of the UVA D37 doses for the ortho, para and meta isomers are 49 ± 2, 327 ± 29 and 251 ± 32 J/m 2 , respectively. Clonogenic survival assays have been used to compare the efficiency of sensitisation of cells to UVA irradiation by the analogues. The ortho analogue exhibits higher efficiency compared to the meta and para analogues. The numbers of dehalogenation events required for cell kill have been calculated from the clonogenic survival at various levels of drug uptake, and the results for the ortho, para and meta isomers are 1.2x10 4 , 3.9x10 4 and 11.6x10 4 , respectively. These results indicate that the ortho analogue is the most efficient isomer in sensitising cell kill by UVA irradiation due to both the high quantum yield for dehalogenation and the higher cytotoxic efficiency of dehalogenation events

  15. Reaction of the phosphorus, niobium and tantalum pentafluorides with dioxides of diphosphjines cis-isomers

    International Nuclear Information System (INIS)

    Il'in, E.G.; Nesterova, N.P.; Kovalev, V.V.; Simonov, M.V.; Medved', T.Ya.; Kabachnik, M.I.; Buslaev, Yu.A.

    1991-01-01

    NbF 5 and TaF 5 complex formation reactions with cis-isomers of diphosphine dioxides in methylene chloride are studied by NMR 19 F and 31 P method. Interaction of TaF 5 with Ph 2 P(0)CH=CHP(0)Ph 2 (L) results information of three basic foprms in the solution: TaF 5 molecular complex, TaF 6 - anion and TaF 4 L + octahedral cation. At NbF 5 interaction with L besides NbF 6 anion trifluorocomplex, the NMP 19 F spectrum of which testifies to the presence of short-linked ligand in the first coordination sphere is observed. It is shown that cis-vinylenediphosphine dioxides in octahedral complexes of transition and nontransition elements may play the role of mono-and bidentant ligands, forming a bridge group or closing 7 member chelating cycle

  16. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball

    Overview From a technical perspective, CMS has been in “beam operation” state since 6th November. The detector is fully closed with all components operational and the magnetic field is normally at the nominal 3.8T. The UXC cavern is normally closed with the radiation veto set. Access to UXC is now only possible during downtimes of LHC. Such accesses must be carefully planned, documented and carried out in agreement with CMS Technical Coordination, Experimental Area Management, LHC programme coordination and the CCC. Material flow in and out of UXC is now strictly controlled. Access to USC remains possible at any time, although, for safety reasons, it is necessary to register with the shift crew in the control room before going down.It is obligatory for all material leaving UXC to pass through the underground buffer zone for RP scanning, database entry and appropriate labeling for traceability. Technical coordination (notably Stephane Bally and Christoph Schaefer), the shift crew and run ...

  17. Synthesis and comparative biological evaluation of L- and D-isomers of {sup 18}F-labeled fluoroalkyl phenylalanine derivatives as tumor imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Wang Limin [Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104 (United States); Lieberman, Brian P.; Ploessl, Karl; Qu Wenchao [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Kung, Hank F., E-mail: kunghf@gmail.co [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104 (United States)

    2011-04-15

    Introduction: L-Amino acid-based tracers have established their important role as tumor metabolic imaging agents. Recently, a number of studies demonstrated that D-amino acids may have improved imaging properties than their corresponding L-isomers. We synthesized and evaluated the D-isomer of a new phenylalanine derivative, p-(2-[{sup 18}F]fluoroethyl)-phenylalanine ([{sup 18}F]FEP), in comparison to its L-isomer and previously reported the L- and D-isomers of O-(2-[{sup 18}F]fluoroethyl)-tyrosine ([{sup 18}F]FET). Methods: L- and D-Isomers of [{sup 18}F]FET and [{sup 18}F]FEP were successfully synthesized via a rapid and efficient two-step nucleophilic fluorination and deprotection reaction. In vitro studies were carried out in 9L glioma cells. In in vivo studies, Fisher 344 rats bearing the 9L tumor model were used. Results: L- and D-Isomers of {sup 18}F-fluoroalkyl tyrosine and phenylalanine derivatives were efficiently labeled with high enantiomeric purity (>95%), good yield (11-45%) and high specific activity (21-75 GBq/{mu}mol). D-[{sup 18}F]FEP showed a similar linear time-dependent uptake as D-[{sup 18}F]FET, while their corresponding L-isomers had much faster and higher uptake (4.3- to 16.0-fold at maximum uptake). The maximum uptake of the new compounds, L- and D-[{sup 18}F]FEP, was 1.4- and 5.2-fold of that reported for L- and D-[{sup 18}F]FET, respectively. Transport characterization studies indicated that both L- and D-[{sup 18}F]FEP were selective substrates for system L. While L-[{sup 18}F]FEP exhibited preference towards one subtype of system L, LAT1, D-[{sup 18}F]FEP did not exhibit the same preference. Small animal PET imaging studies showed that both L- and D-[{sup 18}F]FEP had higher uptake in 9L tumor compared to surrounding tissues, but D-isomer had lower tumor-to-muscle ratio in comparison with its L-isomer. Conclusion: Both L- and D-[{sup 18}F]FEP are substrates for system L amino acid transporter with different preference toward its

  18. Isomer-specific analysis of nonylphenols with estrogenic activity and their distribution in aquatic environment in relation to endocrine disrupters

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y.S.; Katase, T.; Inoue, T. [Nihon Univ., Fujisawa, Kanagawa (Japan). College of Bioresource Sciences; Horii, Y.; Yamashita, N. [National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki (Japan); Makino, M.; Uchiyama, T.; Fujimoto, Y. [Nihon Univ., Chiba (Japan). College of Pharmacy

    2004-09-15

    The effect of estrogen-exposure on levels of a larval storage protein of Balanus amphitrite, cypris major protein (CMP), which is related to barnacle vitellin, has been examined at low concentrations (0.01-1.0 {mu}g/l) of 4-nonylphenol (NP) and 17{beta}-estradiol (E2) (1.0 {mu}g/l) from egg hatching until the nauplius cypris stage. Eventually, the exposure to 0.01 {mu}g/l of NP led to a ca. 50% increase in the optical density of the CMP. There are theoretically ca. 170 kinds of isomers of NP, based on the structure of the nonyl side chain in NP. We fractionated a commercial NP by high performance liquid chromatography (HPLC) to give six fractions (Fr. 1- Fr. 6). Fr. 3 - Fr. 5 were further separated to afford 14 fractions by using gas chromatograph equipped with a preparative fraction collector (GC-PFC) and 11 NP isomers were identified by gas chromatograph equipped with mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). The chemical structures of 11 isomers (NP1 to NP14) were characterized and estrogenicities of the selected isomers were tested in recombinant yeast screen system. The 4-(1,1-dimethyl-2-ethyl-pentyl)- phenol (NP7) was found to exhibit the highest estrogenic activity corresponding to 1.9 x 10{sup -3} that of E2. The NP4 and 6 were structurally in diastereomer. The individual isomer of NP in aquatic samples taken from Ariake Sea and Tokyo, Japan was analyzed by steam distillation extraction in the present study.

  19. Co-ordinated research programme on assessment of environmental exposure to mercury in selected human populations as studied by nuclear and other techniques. Report on the second research co-ordination meeting held in Kuala Lumpur, Malaysia, 24-28 August 1992

    International Nuclear Information System (INIS)

    1992-01-01

    A Coordinated Research Programme (CRP) on assessment of environmental exposure to mercury in selected human populations as studied by nuclear and other techniques was initiated by the IAEA in 1990 in collaboration with WHO. The purpose of this CRP is to promote national and regional studies to evaluate the exposure of selected population groups to mercury and methylmercury and to estimate potential health risks in these groups. The programme is focused on the analysis of human head hair for the determination of mercury and methylmercury. This CRP has two main components: (i) identifying population groups that are at risk, and (ii) studying health effects in the exposed persons, particularly pregnant women and the babies born to them. This report contains the discussions held during the second Research Co-ordination Meeting (RCM) for the CRP which took place in Kuala Lumpur, Malaysia, under the sponsorship of the University Kebangsaan Malaysia and papers presented at this meeting. Refs, figs and tabs

  20. Pregnanolone isomers, pregnenolone and their polar conjugates around parturition

    Czech Academy of Sciences Publication Activity Database

    Klak, J.; Hill, M.; Pařízek, A.; Havlíková, H.; Bičíková, M.; Hampl, R.; Fait, T.; Šulcová, J.; Pouzar, Vladimír; Kancheva, R.; Stárka, L.

    2003-01-01

    Roč. 52, - (2003), s. 211-221 ISSN 0862-8408 R&D Projects: GA ČR GA303/00/1559 Institutional research plan: CEZ:AV0Z4055905 Keywords : pregnanolone isomers * pregnanolone * maternal plasma Subject RIV: CC - Organic Chemistry Impact factor: 0.939, year: 2003

  1. Study of nano - second isomers near 146Gd

    International Nuclear Information System (INIS)

    Pramanik, Dibyadyuti; Sarkar, S.; Bisoi, Abhijit; Ray, Sudatta; Ray, I.; Pradhan, M.K.; Goswami, A.; Banerjee, P.; Mukherjee, A.; Bhattacharya, S.; Saha Sarkar, M.; Chakraborty, A.; Dey, Gautam; Krishichayan; Kshetri, R.; Ganguly, S.; Raut, R.; Ray Basu, M.; Ganguly, G.; Ghugre, S.S.; Sinha, A.K.; Basu, S.K.

    2010-01-01

    The nuclei near 146 Gd show rich variety in their excitation spectra. Spectra exhibiting characteristics of extreme single particle, multi-particle-hole excitation, magnetic bands to strong collectivity manifested through superdeformation, and triaxial superdeformation have been widely studied. In the present work, a few isomers in the mass ≅150 region using the RF - gamma coincidence data are studied

  2. The molecular properties of nitrobenzanthrone isomers and their mutagenic activities.

    Science.gov (United States)

    Ostojić, Bojana D; Stanković, Branislav; Ðorđević, Dragana S

    2014-06-01

    The mutagenic activity of five mono-substituted nitrobenzanthrones (NBA) has been determined in the Ames assay (Takamura-Enya et al., 2006). In the present study, a theoretical investigation of the electronic properties of all mono-substituted NBA isomers and their relation to mutagenic activity are presented. Equilibrium geometries, vertical ionization potentials (VIP), vertical electron affinities (VEA), relative energies, dipole moments and electronic dipole polarizabilities, and the IR and Raman spectra of NBA isomers calculated by Density Functional Theory (DFT) methods are presented. The position of the nitro group affects the spectral features of the IR and Raman spectra of the NBA isomers. The results show that a good linear relationship exists between the summation of Raman activities (∑ARaman) over all the 3N-6 vibrational modes and the mutagenic activity of the NBA isomers in Salmonella typhimurium strains. The spectroscopic results suggest that the unknown mutagenic activities of 4-NBA, 5-NBA, 6-NBA, 8-NBA and 10-NBA are predicted to follow the order 4-NBA>10-NBA>5-NBA>8-NBA>6-NBA. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Simultaneous Determination of Two Isomers of Asarone in Piper ...

    African Journals Online (AJOL)

    HPLC) method to quantify the two isomers of asarones in P. sarmentosum ... ethanol and 50 % ethanol extracts, but absent in all water extracts. β-Asarone occurred in the range of ... In food and herbal industries it is required that .... Where δ = is the standard deviation of the Y ..... Cho J, Kim YH, Kong J-Y, Yang CH, Park CG.

  4. Isomer shifts of the octupole doublet in muonic 207Pb

    International Nuclear Information System (INIS)

    Budick, B.; Anigstein, R.; Kast, J.W.

    1980-01-01

    Isomer shifts in the doublet 5/2 + , 7/2 + levels in muonic 207 Pb have been measured. The shifts are essentially the same as in the core 3 - collective state. They support the hypothesis that the octupole vibration does not conserve volume. (orig.)

  5. Heme isomers substantially affect heme's electronic structure and function

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta

    2017-01-01

    Inspection of heme protein structures in the protein data bank reveals four isomers of heme characterized by different relative orientations of the vinyl side chains; remarkably, all these have been reported in multiple protein structures. Density functional theory computations explain this as du...

  6. FY2011 Annual Report for the Actinide Isomer Detection Project

    International Nuclear Information System (INIS)

    Warren, Glen A.; Francy, Christopher J.; Ressler, Jennifer J.; Erikson, Luke E.; Tatishvili, Gocha; Hatarik, R.

    2011-01-01

    This project seeks to identify a new signature for actinide element detection in active interrogation. This technique works by exciting and identifying long-lived nuclear excited states (isomers) in the actinide isotopes and/or primary fission products. Observation of isomers in the fission products will provide a signature for fissile material. For the actinide isomers, the decay time and energy of the isomeric state is unique to a particular isotope, providing an unambiguous signature for SNM. This project entails isomer identification and characterization and neutron population studies. This document summarizes activities from its third year - completion of the isomer identification characterization experiments and initialization of the neutron population experiments. The population and decay of the isomeric state in 235U remain elusive, although a number of candidate gamma rays have been identified. In the course of the experiments, a number of fission fragment isomers were populated and measured (Ressler 2010). The decays from these isomers may also provide a suitable signature for the presence of fissile material. Several measurements were conducted throughout this project. This report focuses on the results of an experiment conducted collaboratively by PNNL, LLNL and LBNL in December 2010 at LBNL. The measurement involved measuring the gamma-rays emitted from an HEU target when bombarded with 11 MeV neutrons. This report discussed the analysis and resulting conclusions from those measurements. There was one strong candidate, at 1204 keV, of an isomeric signature of 235U. The half-life of the state is estimated to be 9.3 μs. The measured time dependence fits the decay time structure very well. Other possible explanations for the 1204-keV state were investigated, but they could not explain the gamma ray. Unfortunately, the relatively limited statistics of the measurement limit, and the lack of understanding of some of the systematic of the experiment, limit

  7. Coordinating controls

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1986-07-15

    While physics Laboratories are having to absorb cuts in resources, the machines they rely on are becoming more and more complex, requiring increasingly sophisticated systems. Rather than being a resourceful engineer or physicist able to timber together solutions in his 'backyard', the modern controls specialist has become a professional in his own right. Because of possible conflicts between increasing sophistication on one hand and scarcer resources on the other, there was felt a need for more contacts among controls specialists to exchange experiences, coordinate development and discuss 'family problems', away from meetings where the main interest is on experimental physics.

  8. Coordinated unbundling

    DEFF Research Database (Denmark)

    Timmermans, Bram; Zabala-Iturriagagoitia, Jon Mikel

    2013-01-01

    Public procurement for innovation is a matter of using public demand to trigger innovation. Empirical studies have demonstrated that demand-based policy instruments can be considered to be a powerful tool in stimulating innovative processes among existing firms; however, the existing literature has...... not focused on the role this policy instrument can play in the promotion of (knowledge-intensive) entrepreneurship. This paper investigates this link in more detail and introduces the concept of coordinated unbundling as a strategy that can facilitate this purpose. We also present a framework on how...

  9. Coordinating controls

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    While physics Laboratories are having to absorb cuts in resources, the machines they rely on are becoming more and more complex, requiring increasingly sophisticated systems. Rather than being a resourceful engineer or physicist able to timber together solutions in his 'backyard', the modern controls specialist has become a professional in his own right. Because of possible conflicts between increasing sophistication on one hand and scarcer resources on the other, there was felt a need for more contacts among controls specialists to exchange experiences, coordinate development and discuss 'family problems', away from meetings where the main interest is on experimental physics

  10. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball

    2010-01-01

    Operational Experience At the end of the first full-year running period of LHC, CMS is established as a reliable, robust and mature experiment. In particular common systems and infrastructure faults accounted for <0.6 % CMS downtime during LHC pp physics. Technical operation throughout the entire year was rather smooth, the main faults requiring UXC access being sub-detector power systems and rack-cooling turbines. All such problems were corrected during scheduled technical stops, in the shadow of tunnel access needed by the LHC, or in negotiated accesses or access extensions. Nevertheless, the number of necessary accesses to the UXC averaged more than one per week and the technical stops were inevitably packed with work packages, typically 30 being executed within a few days, placing a high load on the coordination and area management teams. It is an appropriate moment for CMS Technical Coordination to thank all those in many CERN departments and in the Collaboration, who were involved in CMS techni...

  11. The Role of Equivalence and Order Relations in the Development and Coordination of the Concepts of Unit Size and Number of Units in Selected Conservation Type Measurement Problems.

    Science.gov (United States)

    Carpenter, Thomas P.

    The major purpose of this study was 1) to investigate the development of the concept of a unit of measure and the coordination of unit size and the number of units 2) to relate this development to the development of conservation and 3) to determine the role of equivalence and nonequivalence relations in certain conservation and measurement…

  12. Highly efficient high-performance liquid chromatographic separation of xylene isomers and phthalate acid esters on a homemade DUT-67(Zr) packed column.

    Science.gov (United States)

    Chen, Sha; Li, Xiao-Xin; Feng, Fan; Li, Sumei; Han, Jia-Hui; Jia, Zi-Yi; Shu, Lun; Somsundaran, P; Li, Jian-Rong

    2018-04-16

    In this study, the baseline separations of xylene isomers and phthalate acid esters on a homemade DUT-67(Zr) packed column were achieved, respectively. The high selectivity for xylene isomers and phthalate acid esters was obtained with the increase of temperature and decrease of the retention time. The hydrophobicity of xylene isomers and phthalate acid esters caused the different separation time on the DUT-67(Zr) packed column. The relative standard deviation values of retention time, peak area, peak height and half peak width for five repeat separation of the xylene isomers were 0.26-0.35, 2.11-2.26, 1.51-2.03, and 0.29-0.77%, and the values of the phthalate acid esters on DUT-67(Zr) column were 0.1-0.4, 4.4-5.2, 3.9-6.3, and 0.6-2.1%, respectively. The thermodynamic properties indicated that the separation of xylene isomers was controlled by ΔH and ΔS, but the separation of phthalate acid esters was mainly controlled by ΔS. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Supramolecular Isomers of Metal-Organic Frameworks Derived from a Partially Flexible Ligand with Distinct Binding Motifs

    KAUST Repository

    Abdul Halim, Racha Ghassan

    2016-01-04

    Three novel metal-organic frameworks (MOFs) were isolated upon reacting a heterofunctional ligand 4 (pyrimidin-5 yl)benzoic acid (4,5-pmbc) with mixed valence Cu(I,II) under solvothermal conditions. X-ray crystal structural analysis reveals that the first compound is a layered structure composed of one type of inorganic building block, dinuclear paddlewheel [Cu2(O2C–)4], which are linked through 4,5-pmbc ligands. The two other supramolecular isomers are composed of the same Cu(II) dinuclear paddlewheel and a dinuclear Cu2I2 cluster, which are linked via the 4,5-pmbc linkers to yield two different 3-periodic frameworks with underlying topologies related to lvt and nbo. The observed structural diversity in these structures is due to the distinct coordination modes of the two coordinating moieties (the carboxylate group on the phenyl ring and the N-donor atoms from the pyrimidine moiety).

  14. Supramolecular Isomers of Metal-Organic Frameworks Derived from a Partially Flexible Ligand with Distinct Binding Motifs

    KAUST Repository

    AbdulHalim, Rasha; Shkurenko, Aleksander; Al Kordi, Mohamed; Eddaoudi, Mohamed

    2016-01-01

    Three novel metal-organic frameworks (MOFs) were isolated upon reacting a heterofunctional ligand 4 (pyrimidin-5 yl)benzoic acid (4,5-pmbc) with mixed valence Cu(I,II) under solvothermal conditions. X-ray crystal structural analysis reveals that the first compound is a layered structure composed of one type of inorganic building block, dinuclear paddlewheel [Cu2(O2C–)4], which are linked through 4,5-pmbc ligands. The two other supramolecular isomers are composed of the same Cu(II) dinuclear paddlewheel and a dinuclear Cu2I2 cluster, which are linked via the 4,5-pmbc linkers to yield two different 3-periodic frameworks with underlying topologies related to lvt and nbo. The observed structural diversity in these structures is due to the distinct coordination modes of the two coordinating moieties (the carboxylate group on the phenyl ring and the N-donor atoms from the pyrimidine moiety).

  15. Coordination of Conditional Poisson Samples

    Directory of Open Access Journals (Sweden)

    Grafström Anton

    2015-12-01

    Full Text Available Sample coordination seeks to maximize or to minimize the overlap of two or more samples. The former is known as positive coordination, and the latter as negative coordination. Positive coordination is mainly used for estimation purposes and to reduce data collection costs. Negative coordination is mainly performed to diminish the response burden of the sampled units. Poisson sampling design with permanent random numbers provides an optimum coordination degree of two or more samples. The size of a Poisson sample is, however, random. Conditional Poisson (CP sampling is a modification of the classical Poisson sampling that produces a fixed-size πps sample. We introduce two methods to coordinate Conditional Poisson samples over time or simultaneously. The first one uses permanent random numbers and the list-sequential implementation of CP sampling. The second method uses a CP sample in the first selection and provides an approximate one in the second selection because the prescribed inclusion probabilities are not respected exactly. The methods are evaluated using the size of the expected sample overlap, and are compared with their competitors using Monte Carlo simulation. The new methods provide a good coordination degree of two samples, close to the performance of Poisson sampling with permanent random numbers.

  16. The Search for High Spin State Isomers in the Atomic Mass Region 178-192

    International Nuclear Information System (INIS)

    Ellahrah, M.S.; Arfa, N.S.

    2007-01-01

    Isomers for elements far a way from line of stability are a new field for research to produce artificial isomers that can store considerable amount of energy in small amount of mass without the dangerous hazards on life and environment. These isomers could have very short life time or very long one 10th and 100th of years. It will be possible to get the stored energy by stimulated emission . The purpose of this work to use a theorical model based on Bcs method to find out the possible isomers in the mass reg on 178-192 even -even isotopes so that experimentalists can concentrate their research on these predicted isomers.

  17. Cyclic Versus Linear Isomers Produced by Reaction of the Methylidyne Radical (CH) with Small Unsaturated Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Goulay, Fabien; Trevitt, Adam J.; Meloni, Giovanni; Selby, Talitha M.; Osborn, David L.; Taatjes, Craig A.; Vereecken, Luc; Leone, Stephen R.

    2008-12-05

    The reactions of the methylidyne radical (CH) with ethylene, acetylene, allene, and methylacetylene are studied at room temperature using tunable vacuum ultraviolet (VUV) photoionization and time-resolved mass spectrometry. The CH radicals are prepared by 248 nm multiphoton photolysis of CHBr3 at 298 K and react with the selected hydrocarbon in a helium gas flow. Analysis of photoionization efficiency versus VUV photon wavelength permits isomer-specific detection of the reaction products and allows estimation of the reaction product branching ratios. The reactions proceed by either CH insertion or addition followed by H atom elimination from the intermediate adduct. In the CH + C2H4 reaction the C3H5 intermediate decays by H atom loss to yield 70(+-8)percent allene, 30(+-8)percent methylacetylene and less than 10percent cyclopropene, in agreement with previous RRKM results. In the CH + acetylene reaction, detection of mainly the cyclic C3H2 isomer is contrary to a previous RRKM calculation that predicted linear triplet propargylene to be 90percent of the total H-atom co-products. High-level CBS-APNO quantum calculations and RRKM calculation for the CH + C2H2 reaction presented in this manuscript predict a higher contribution of the cyclic C3H2 (27.0percent) versus triplet propargylene (63.5percent) than these earlier predictions. Extensive calculations on the C3H3 and C3H2D system combined with experimental isotope ratios for the CD + C2H2 reaction indicate that H-atom assisted isomerization in the present experiments is responsible for the discrepancy between the RRKM calculations and the experimental results. Cyclic isomers are also found to represent 30(+-6)percent of the detected products in the case of CH + methylacetylene, together with 33(+-6)percent 1,2,3-butatriene and 37(+-6)percent vinylacetylene. The CH + allene reaction gives 23(+-5)percent 1,2,3-butatriene and 77(+-5)percent vinylacetylene, whereas cyclic isomers are produced below the detection limit

  18. Identification of isomers and control of ionization and dissociation processes using dual-mass-spectrometer scheme and genetic algorithm optimization

    International Nuclear Information System (INIS)

    Chen Zhou; Qiu-Nan Tong; Zhang Cong-Cong; Hu Zhan

    2015-01-01

    Identification of acetone and its two isomers, and the control of their ionization and dissociation processes are performed using a dual-mass-spectrometer scheme. The scheme employs two sets of time of flight mass spectrometers to simultaneously acquire the mass spectra of two different molecules under the irradiation of identically shaped femtosecond laser pulses. The optimal laser pulses are found using closed-loop learning method based on a genetic algorithm. Compared with the mass spectra of the two isomers that are obtained with the transform limited pulse, those obtained under the irradiation of the optimal laser pulse show large differences and the various reaction pathways of the two molecules are selectively controlled. The experimental results demonstrate that the scheme is quite effective and useful in studies of two molecules having common mass peaks, which makes a traditional single mass spectrometer unfeasible. (paper)

  19. Process for separating the ortho- and para- isomers of hydroxymandelic acid or a salt thereof, the isomers thus obtained, the use of the ortho-isomer for the preparation of eddha

    NARCIS (Netherlands)

    Hoefnagel, A.J.; Van Bekkum, H.

    1994-01-01

    Abstract of WO 9414746 (A1) The invention relates to a method for separating the ortho- and para-isomers of hydroxymandelic acid or a salt thereof. For that purpose the starting material is a solid mixture of these ortho- and para-isomers in the alkali metal salt form. This mixture is extracted with

  20. The gamma-ray spectra of 5-carbon alkane isomers in the positron annihilation process

    International Nuclear Information System (INIS)

    Ma, Xiaoguang; Zhu, Yinghao; Liu, Yang

    2016-01-01

    The gamma-ray spectra of pentane (C_5H_1_2) and its two isomers, i.e., 2-Methylbutane (CH_3C(CH_3)HC_2H_5) and 2,2-Dimethylpropane (C(CH_3)_4) have been studied theoretically in the present work. The recent experimental gamma-ray spectra of these three molecules show that they have the same Doppler shifts, although their molecular structures are dramatically different. In order to reveal why the gamma-ray spectra of these molecules are less sensitive to the molecular structures, the one-dimensional gamma-ray spectra and spherically averaged momentum (SAM) distributions, the two-dimensional angular correlation of annihilation radiation (ACAR), and the three-dimensional momentum distributions of the positron–electron pair are studied. The one-centered momentum distributions of the electrons are found to play more important role than the multi-centered coordinate distributions. The present theoretical predictions have confirmed the experimental findings for the first time. The dominance of the inner valence electrons in the positron–electron annihilation process has also been suggested in the present work. - Highlights: • The structure effects only play a minor role in the one-dimension gamma-ray spectra. • The present study further confirms the dominance of the inner valence electrons in the positron–electron annihilation process. • The momentum distributions of the electrons play more important role than the coordinate distributions.

  1. Electronic structure and isomer shifts of Sn halides

    International Nuclear Information System (INIS)

    Terra, J.; Guenzburger, D.

    1988-01-01

    The all-electron first-principles Discrete Variational method was employed to study the electronic structure of SnF 4 , SnCl 4 , SnBr 4 and SnI 4 . Values of the electronic density at the Sn nucleus were derived and related to 119 Sn Isomer Shifts to obtain the nuclear constant Δ 2 >. Differences in values of ρ(o) area discussed in terms of the chemical bonding between Sn and halogen atoms. (author) [pt

  2. Shape Isomer in 236U Populated by Thermal Neutron Capture

    DEFF Research Database (Denmark)

    Andersen, Verner; Christensen, Carl Jørgen; Borggreen, J.

    1976-01-01

    The 116 ns shape isomer in 236U was populated by thermal neutron capture. Conversion electrons and X-rays were detected simultaneously in delayed coincidence with fission. The ratio of delayed to prompt fission was measured with the result, σIIf/σf = (1.0±0.2) × 10−5. A branching of the isomeric ...... decay σIIγ/σIIf = 7±2 was deduced from this number. No definite electron line structure was observed....

  3. Butane isomer separation with composite zeolite MFI mebranes

    Czech Academy of Sciences Publication Activity Database

    Hrabánek, Pavel; Zikánová, Arlette; Bernauer, B.; Fíla, V.; Kočiřík, Milan

    2009-01-01

    Roč. 245, 1-3 (2009), s. 437-443 ISSN 0011-9164 R&D Projects: GA ČR GA203/07/1443; GA AV ČR KAN400720701; GA AV ČR(CZ) 1QS401250509 Institutional research plan: CEZ:AV0Z40400503 Keywords : zeolite MFI * membranes * separation * butane isomers Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.034, year: 2009

  4. High spin states and Yrast isomers in 211Rn

    International Nuclear Information System (INIS)

    Poletti, A.R.; Dracoulis, G.D.; Fahlander, C.; Morrison, I.

    1981-01-01

    Excited states in 211 Rn with spins up to 53/2 have been identified using (HI,xn) reactions and γ-ray techniques. A shell model calculation can reproduce the ordering of the yrast sequence up to spin 41/2 - . Several yrast isomers have been identified. Enhanced E3 transitions are observed and their systematic occurrence in this region discussed. The influence of the neutron hole, and possible core excitations on the effective moment of inertia are also pointed out

  5. Island of high-spin isomers near N = 82

    International Nuclear Information System (INIS)

    Pedersen, J.; Back, B.B.; Bernthal, F.M.; Bjornholm, S.; Borggreen, J.; Christensen, O.; Folkmann, F.; Herskind, B.; Khoo, T.L.; Neiman, M.; Puehlhofer, F.; Sletten, G.

    1977-01-01

    Experiments aimed at testing for the existence of yrast traps are reported. A search for delayed γ radiation of lifetimes longer than approx. 10 ns and of high multiplicity has been performed by producing more than 100 compound nuclei between Ba and Pb in bombardments with 40 Ar, 50 Ti, and 65 Cu projectiles. An island of high-spin isomers is found to exist in the region 64 or approx. = 71 and N < or approx. = 82

  6. High spin states and yrast isomers in 211Rn

    International Nuclear Information System (INIS)

    Poletti, A.R.; Dracoulis, G.D.; Fahlander, C.; Morrison, I.

    1980-12-01

    Excited states in 211 Rn with spins up to 53/2 have been identified using (HI,xn) reactions and γ-ray techniques. A shell model calculation can reproduce the ordering of the yrast sequence up to spin 41/2. Several yrast isomers have been identified. Enhanced E3 transitions are observed and their systematic occurrence in this region discussed. The influence of the neutron hole, and possible core excitations on the effective moment of inertia are also pointed out

  7. Characteristics of Butanol Isomers Oxidation in a Micro Flow Reactor

    KAUST Repository

    Bin Hamzah, Muhamad Firdaus

    2017-05-01

    Ignition and combustion characteristics of n-butanol/air, 2-butanol.air and isobutanol/air mixtures at stoichiometric (ϕ = 1) and lean (ϕ = 0.5) conditions were investigated in a micro flow reactor with a controlled temperature profile from 323 K to 1313 K, under atmospheric pressure. Sole distinctive weak flame was observed for each mixture, with inlet fuel/air mixture velocity set low at 2 cm/s. One-dimensional computation with comprehensive chemistry and transport was conducted. At low mixture velocities, one-stage oxidation was confirmed from heat release rate profiles, which was broadly in agreement with the experimental results. The weak flame positions were congruent with literature describing reactivity of the butanol isomers. These weak flame responses were also found to mirror the trend in Anti-Knock Indexes of the butanol isomers. Flux and sensitivity analyses were performed to investigate the fuel oxidation pathways at low and high temperatures. Further computational investigations on oxidation of butanol isomers at higher pressure of 5 atm indicated two-stage oxidation through the heat release rate profiles. Low temperature chemistry is accentuated in the region near the first weak cool flame for oxidation under higher pressure, and its impact on key species – such as hydroxyl radical, hydrogen peroxide and carbon monoxide – were considered. Both experimental and computational findings demonstrate the advantage of employing the micro flow reactor in investigating oxidation processes in the temperature region of interest along the reactor channel. By varying physical conditions such as pressure, the micro flow reactor system is proven to be highly beneficial in elucidating oxidation behavior of butanol isomers in conditions in engines such as those that mirror HCCI operations.

  8. Isomer spectroscopy in 92Ru and 95Pd

    International Nuclear Information System (INIS)

    Gorska, M.; Rejmund, M.; Schubart, R.; Grawe, H.; Heese, J.; Maier, K.H.; Spohr, K.; Fitzgerald, J.B.; Fossan, D.B.

    1996-01-01

    The parity changing γ-transitions like E1, M2, E3 in 92 Ru and 95 Pd nuclei have been investigated to probe the purity of the Shell Model. Two isomers of 92 Ru and 95 Pd have been produced in the 58 Ni + 40 Ca heavy ion reaction at 58 Ni beams energy 215 MeV. The gamma-ray transition strength have been deduced

  9. Observation of the new isomer 32mAl

    International Nuclear Information System (INIS)

    Robinson, M.; Halse, P.; Lewitowicz, M.; Saint-Laurent, M.G.

    1995-01-01

    A new isomer in the neutron-rich isotope 32 Al has been identified among the fragmentation products of a 40 Ar 16+ beam using the LISE spectrometer at GANIL. The population of the isomeric state was inferred from the detection of γ-radiation following its decay in coincidence with its respective heavy-ion implantation signal. The half-life of 32m Al was determined to be 240 ± 30 ns. (author)

  10. Prolactin releasing effect of sulpiride isomers in rats and man

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, E E; Stefanini, E; Spano, P F [Cagliari Univ. (Italy). Inst. of Pharmacology and Pharmacognosy; Camanni, F; Massara, F [Turin Univ. (Italy). Chair of Endocrinology; Locatelli, V; Cocchi, D

    1979-01-01

    Sulpiride, an antipsychotropic drug of the benzamide class, reportedly displaces stereospecifically (/sup 3/H)-butyrophenones from putative dopamine (DA) binding sites in rat striatum. To evaluate if sulpiride displays the same stereospecifity in the inhibition of pituitary DA receptors, the effect of the two(-)-and (+)-sulpiride isomers was tested with regard to their ability to stimulate prolactin (PRL) secretion in rats and man and to displace (/sup 3/H)-spiroperidol bound to rat anterior pituitary receptors. In male rats, (-)-sulpiride at doses of 0.1 and 0.1 mg/kg i.p., induced a maximum PRL-releasing effect, not different from that evoked by a dose of 10 mg/kg of the compound. (+)-Sulpiride was active only at the dose of 10mg/kg i.p., and its PRL-releasing effect was superimposable to that evoked by the same dose of (-)-sulpiride. Similarily, in 8 normal subjects (4 men and 4 women) only (-)-sulpiride was active as PRL releaser when the low dose of 0.25 mg i.v. was used; when the higher dose of sulpiride was used (4.0 mg i.v.), it induced a rise in plasma PRL of the same entity for both isomers at early post-injection times (15-30 min) but greater with the (-)-isomer at the following time intervals (45-120 min). (-)-Sulpiride displaced (/sup 3/H)-spiroperidol bound to rat anterior pituitary homogenates with a potency about 100 times greater as that showed by (+)-sulpiride. In all, these data indicate that sulpiride isomers display at the level of pituitary DA receptors for PRL control the same stereospecifity exhibited on a population of striatal DA receptors.

  11. 6/sup +/ isomer state in /sup 46/Ca

    Energy Technology Data Exchange (ETDEWEB)

    Bizzeti, P G; Maurenzig, P R; Poggi, G [Florence Univ. (Italy). Istituto di Fisica; Lo Bianco, G [Milan Univ. (Italy). Istituto di Fisica

    1975-01-11

    The decay of the expected isomer, obtained from the reaction /sup 48/Ca(p,p2n)/sup 46/Ca, has been observed as a delayed activity after bombardment of a 97.2% enriched /sup 48/CaC0/sub 3/ target with 35 MeV protons. The experimental apparatus used at AUF cyclotron of Milan is described. Data are reported and discussed.

  12. Lubricating and Waxy Esters. VI. Effect of Symmetry about Ester on Crystallization of Linear Monoester Isomers

    Directory of Open Access Journals (Sweden)

    Laziz Bouzidi

    2014-08-01

    Full Text Available The crystal structure development of jojoba-like esters incorporating either 1-decenoic acid and/or 1-decenol, namely octadec-9-enyl dec-9-enoate (JLE-281, and its isomer dec-9-enyl oleate (JLE-282 was investigated to reveal the effect of symmetry about the ester group on crystallization of aliphatic fatty monoesters. The phase transformation path was investigated with temperature-time resolved X-ray diffraction during stepped isothermal crystallization, and while cooling from the melt at a fixed rate. Startling differences in phase behavior were uncovered between the isomers. When stepped isothermals were used, selective extinctions occurred at a transition temperature for JLE-281 but not for JLE-282. The extinctions, which are due to dramatic changes in the electronic density of certain families of planes, indicate a phase transition attributed to a brusque rearrangement of the oxygen atoms in the crystal subcell. The phase transition did not occur when the JLEs were cooled continuously. The crucial role played by the position of the alkyl chain and its orientation relative to the easy rotation site of the C–O bond in the phase trajectories of the JLEs was particularly highlighted.

  13. Effects of isomers of apomorphines on dopamine receptors in striatal and limbic tissue of rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Kula, N.S.; Baldessarini, R.J.; Bromley, S.; Neumeyer, J.L.

    1985-09-16

    The optical isomers of apomorphine (APO) and N-propylnorapomorphine (NPA) were interacted with three biochemical indices of dopamine (Da) receptors in extrapyramidal and limbic preparations of rat brain tissues. There were consistent isomeric preferences for the R(-) configuration of both DA analogs in stimulation adenylate cyclase (D-1 sites) and in competing for high affinity binding of /sup 3/H-spiroperidol (D-2 sites) and of /sup 3/H-ADTN (DA agonist binding sites) in striatal tissue, with lesser isomeric differences in the limbic tissue. The S(+) apomorphines did not inhibit stimulation of adenylate cyclase by DA. The tendency for greater activity of higher apparent affinity of R(-) apomorphines in striatum may reflect the evidently greater abundance of receptor sites in that region. There were only small regional differences in interactions of the apomorphine isomers with all three receptor sites, except for a strong preference of (-)NPA for striatal D-2 sites. These results do not parallel our recent observations indicating potent and selective antidopaminergic actions of S(+) apomorphines in the rat limbic system. They suggest caution in assuming close parallels between current biochemical functional, especially behavioral, methods of evaluating dopamine receptors of mammalian brain.

  14. Ternary fission of spontaneously fissile uranium isomers excited by neutrons

    International Nuclear Information System (INIS)

    Makarenko, V.E.; Molchanov, Y.D.; Otroshchenko, G.A.; Yan'kov, G.B.

    1989-01-01

    Spontaneously fissile isomers (SFI) of uranium were excited in the reactions 236,238 U(n,n') at an average neutron energy 4.5 MeV. A pulsed electrostatic accelerator and time analysis of the fission events were used. Fission fragments were detected by the scintillation method, and long-range particles from fission were detected by an ionization method. The relative probability of fission of nuclei through a spontaneously fissile isomeric state was measured: (1.30±0.01)·10 -4 ( 236 U) and (1.48±0.02)·10 -4 ( 238 U). Half-lives of the isomers were determined: 121±2 nsec (the SFI 236 U) and 267±13 nsec (the SFI 238 U). In study of the ternary fission of spontaneously fissile isotopes of uranium it was established that the probability of the process amounts to one ternary fission per 163±44 binary fissions of the SFI 236 U and one ternary fission per 49±14 binary fissions of the SFI 238 U. The substantial increase of the probability of ternary fission of SFI of uranium in comparison with the case of ternary fission of nuclei which are not in an isomeric state may be related to a special nucleon configuration of the fissile isomers of uranium

  15. Tautomeric preferences of the cis and trans isomers of axitinib

    Science.gov (United States)

    Mirzaei, M. Saeed; Taherpour, Avat Arman

    2018-05-01

    The tautomeric preferences of axitinib, a potent anticancer drug, as tyrosine kinase inhibitor have been investigated using quantum chemical calculations and docking methods. The energy differences between the two tautomers of trans-isomer are around 4 and 3 kcal mol-1 in vacuo and water, respectively, and for its cis-isomer (major photochemical isomerization product) this equilibrium reversed completely in favour of the second tautomer (not considered previously), which is about 7-8 kcal mol-1 more stable in both gas and aqueous media. The results indicate a very high activation energy for proton exchange for both [1,2] and [1,5] H-shift (around 50 kcal mol-1) in the gas phase, but inclusion of protic solvents (e.g. water) decrease this barrier to around 14 and 35 kcal mol-1 for the both hydrogen shift processes, respectively. In order to have better insight about the electronic structure of axitinib tautomers, the NBO, HOMO-LUMO, NICS and molecular electrostatic potential surfaces (MESP) calculations have been carried out. Docking investigations on the two more stable tautomers revealed that binding of the trans isomer of tautomer I to the active site of the receptor is the most favourable in the terms of energy and structure. This more stability could be attributed to the more hydrogen bonding of this tautomer with the protein residues in comparison to the second tautomer.

  16. Calorimetric and computational studies for three nitroimidazole isomers

    International Nuclear Information System (INIS)

    Carvalho, Tânia M.T.; Amaral, Luísa M.P.F.; Morais, Victor M.F.; Ribeiro da Silva, Maria D.M.C.

    2017-01-01

    Highlights: • Energy of combustion of 4-nitroimidazole was measured by static bomb calorimetry. • Enthalpy of sublimation of 4-nitroimidazole was determined by Calvet microcalorimetry. • Gas-phase enthalpy of formation of 4-nitroimidazole derived from experimental measurements. • Gas-phase enthalpies of nitroimidazole isomers formation estimated from G3 calculations. - Abstract: In the present work, a combined experimental and computational thermochemical study of nitroimidazole isomers was carried out. The standard (p° = 0.1 MPa) molar enthalpy of combustion, in the crystalline phase, for 4-nitroimidazole was determined, at the temperature of 298.15 K, using a static bomb combustion calorimeter. Calvet microcalorimetry experiments were performed to measure its standard molar enthalpy of sublimation. The standard molar enthalpy of formation of 4-nitroimidazole, in the gaseous phase, at T = 298.15 K, (116.9 ± 2.9) kJ·mol −1 , has been derived from the corresponding standard molar enthalpy of formation in the crystalline phase and the standard molar enthalpy of sublimation. Computational studies for 4-nitroimidazole were performed to complement the experimental work. These were also extended to the 2- and 5-nitroimidazole isomers. The gas-phase enthalpies of formation were estimated from high level ab initio molecular orbital calculations, at the G3 level. Also investigated were the tautomeric equilibrium of 4(5)-nitroimidazole in the gaseous phase and it was concluded that the two tautomers are equally stable.

  17. Experimental and computational thermochemistry of the dihydroxypyridine isomers

    International Nuclear Information System (INIS)

    Morais, Victor M.F.; Miranda, Margarida S.; Matos, M. Agostinha R.

    2006-01-01

    The standard (p 0 = 0.1 MPa) molar enthalpy of formation for crystalline 2,3-dihydroxypyridine was measured, at T = 298.15 K, by static bomb calorimetry and the standard molar enthalpy of sublimation, at T 298.15 K, was obtained using Calvet microcalorimetry. These values were used to derive the standard molar enthalpy of formation of 2,3-dihydroxypyridine in gaseous phase, at T = 298.15 K, -(263.9 ± 4.6) kJ . mol -1 . Additionally, high-level density functional theory calculations using the B3LYP hybrid exchange-correlation energy functional with extended basis sets have been performed for all dihydroxypyridine isomers to determine the thermochemical order of stability of these systems. The agreement between experiment and theory for the 2,3-dihydroxypyridine isomer gives confidence to the estimates of the enthalpies of formation concerning the other five isomers. It is found that the enthalpic increment for the dihydroxy substitution of pyridine is equal to the sum of the respective enthalpic increment of the monosubstituted pyridines

  18. Nuclear Structure Studies of Microsecond Isomers Near A=100

    Science.gov (United States)

    Simpson, G.; Genevey, J.; Pinston, J. A.; Urban, W.; Zlomaniec, A.; Orlandi, R.; Scherillo, A.; Tsekhanovich, I.; Smith, A. G.; Thallon, A.; Varley, B. J.; Jolie, J.; Warr, N.

    2007-04-01

    A large variety of shapes may be observed in Sr and Zr nuclei of the A = 100 region when the number of neutrons increases from N = 58 to N = 64. The lighter isotopes are rather spherical. It is also well established that three shapes co-exist in the transitional odd-A, N = 59, Sr and Zr nuclei. For N > 59, strongly deformed axially symmetric bands are observed. Recently, a new isomer of half-life 1.4(2) mu s was observed in 95Kr, the odd-odd 96Rb has been reinvestigated and a new high-spin isomer observed in the even-even 98Zr. These nuclei were studied by means of prompt gamma -ray spectroscopy of the spontaneous fission of 248Cm using the EUROGAM 2 Ge array and/or measurements of mu s isomers produced by fission of 239,241Pu with thermal neutrons at the ILL (Grenoble). To allow spectroscopic studies of isomeric states with lifetimes around 100 ns, across a broad range of medium-heavy neutron-rich nuclei, an experiment was performed at a neutron guide of the ILL using thermal-neutron-induced fission. Fission fragments were identified using a small spectrometer consisting of a section to measure time-of-flight and an ionization chamber. Isomeric gamma rays emitted from complementary fragments were detected in an array of Ge detectors.

  19. RUN COORDINATION

    CERN Multimedia

    Christophe Delaere

    2013-01-01

    The focus of Run Coordination during LS1 is to monitor closely the advance of maintenance and upgrade activities, to smooth interactions between subsystems and to ensure that all are ready in time to resume operations in 2015 with a fully calibrated and understood detector. After electricity and cooling were restored to all equipment, at about the time of the last CMS week, recommissioning activities were resumed for all subsystems. On 7 October, DCS shifts began 24/7 to allow subsystems to remain on to facilitate operations. That culminated with the Global Run in November (GriN), which   took place as scheduled during the week of 4 November. The GriN has been the first centrally managed operation since the beginning of LS1, and involved all subdetectors but the Pixel Tracker presently in a lab upstairs. All nights were therefore dedicated to long stable runs with as many subdetectors as possible. Among the many achievements in that week, three items may be highlighted. First, the Strip...

  20. RUN COORDINATION

    CERN Multimedia

    C. Delaere

    2013-01-01

    Since the LHC ceased operations in February, a lot has been going on at Point 5, and Run Coordination continues to monitor closely the advance of maintenance and upgrade activities. In the last months, the Pixel detector was extracted and is now stored in the pixel lab in SX5; the beam pipe has been removed and ME1/1 removal has started. We regained access to the vactank and some work on the RBX of HB has started. Since mid-June, electricity and cooling are back in S1 and S2, allowing us to turn equipment back on, at least during the day. 24/7 shifts are not foreseen in the next weeks, and safety tours are mandatory to keep equipment on overnight, but re-commissioning activities are slowly being resumed. Given the (slight) delays accumulated in LS1, it was decided to merge the two global runs initially foreseen into a single exercise during the week of 4 November 2013. The aim of the global run is to check that we can run (parts of) CMS after several months switched off, with the new VME PCs installed, th...

  1. Isomer separation of $^{70g}Cu$ and $^{70m}Cu$ with a resonance ionization laser ion source

    CERN Document Server

    Köster, U; Mishin, V I; Weissman, L; Huyse, M; Kruglov, K; Müller, W F; Van Duppen, P; Van Roosbroeck, J; Thirolf, P G; Thomas, H C; Weisshaar, D W; Schulze, W; Borcea, R; La Commara, M; Schatz, H; Schmidt, K; Röttger, S; Huber, G; Sebastian, V; Kratz, K L; Catherall, R; Georg, U; Lettry, Jacques; Oinonen, M; Ravn, H L; Simon, H

    2000-01-01

    Radioactive copper isotopes were ionized with the resonance ionization laser ion source at the on-line isotope separator ISOLDE (CERN). Using the different hyperfine structure in the 3d/sup 10/ 4s /sup 2/S/sub 1/2/-3d/sup 10/ 4p /sup 2/P/sub 1/2//sup 0/ transition the low- and high-spin isomers of /sup 70/Cu were selectively enhanced by tuning the laser wavelength. The light was provided by a narrow-bandwidth dye laser pumped by copper vapor lasers and frequency doubled in a BBO crystal. The ground state to isomeric state intensity ratio could be varied by a factor of 30, allowing to assign gamma transitions unambiguously to the decay of the individual isomers. It is shown that the method can also be used to determine magnetic moments. In a first experiment for the 1/sup +/ ground state of /sup 70/Cu a magnetic moment of (+)1.8(3) mu /sub N/ and for the high-spin isomer of /sup 70/Cu a magnetic moment of (+or-)1.2(3) mu /sub N/ could be deduced. (20 refs).

  2. Self-assembly of triangular metallomacrocycles using unsymmetrical bisterpyridine ligands: isomer differentiation via TWIM mass spectrometry.

    Science.gov (United States)

    Liang, Yen-Peng; He, Yun-Jui; Lee, Yin-Hsuan; Chan, Yi-Tsu

    2015-03-21

    Three unsymmetrical, 60°-bended bisterpyridine ligands with varying phenylene spacer lengths have been synthesized via the Suzuki-Miyaura coupling reactions. Their self-assembly processes were found to be strongly dependent on the ligand geometry. Upon complexation with Zn(II) ions, only 2,4''-di(4'-terpyridinyl)-1,1':4',1''-terphenyl underwent self-selection to give a trinuclear metallomacrocycle with perfect heteroleptic connectivity and the other two afforded a mixture of constitutional isomers. The metallosupramolecular assemblies were characterized by NMR spectroscopy, electrospray mass spectrometry (ESI MS), and single-crystal X-ray diffraction. In particular, the identification of isomeric architecture was accomplished using tandem mass spectrometry (MS(2)) coupled with traveling wave ion mobility mass spectrometry (TWIM MS).

  3. Structural characterization of a D-isomer specific 2-hydroxyacid dehydrogenase from Lactobacillus delbrueckii ssp. bulgaricus.

    Science.gov (United States)

    Holton, Simon J; Anandhakrishnan, Madhankumar; Geerlof, Arie; Wilmanns, Matthias

    2013-02-01

    Hydroxyacid dehydrogenases, responsible for the stereospecific conversion of 2-keto acids to 2-hydroxyacids in lactic acid producing bacteria, have a range of biotechnology applications including antibiotic synthesis, flavor development in dairy products and the production of valuable synthons. The genome of Lactobacillus delbrueckii ssp. bulgaricus, a member of the heterogeneous group of lactic acid bacteria, encodes multiple hydroxyacid dehydrogenases whose structural and functional properties remain poorly characterized. Here, we report the apo and coenzyme NAD⁺ complexed crystal structures of the L. bulgaricusD-isomer specific 2-hydroxyacid dehydrogenase, D2-HDH. Comparison with closely related members of the NAD-dependent dehydrogenase family reveals that whilst the D2-HDH core fold is structurally conserved, the substrate-binding site has a number of non-canonical features that may influence substrate selection and thus dictate the physiological function of the enzyme. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. An Isomer-Specific Approach to Endocrine-Disrupting Nonylphenol in Infant Food.

    Science.gov (United States)

    Günther, Klaus; Räcker, Torsten; Böhme, Roswitha

    2017-02-15

    Nonylphenols (NPs) are persistent endocrine disruptors that are priority hazardous substances of the European Union Water Framework Directive. Their presence in the environment has caused growing concern regarding their impact on human health. Recent studies have shown that nonylphenol is ubiquitous in commercially available foodstuffs and is also present in human blood. The isomer distribution of 4-nonylphenol was analyzed by gas chromatography - mass spectrometry in 44 samples of infant food. Our study shows that the distribution of nonylphenol isomers is dependent on the foodstuff analyzed. Although some isomer groups prevail, different distributions are frequent. Variations are even found in the same food group. Nonylphenol is a complex mixture of isomers, and the estrogenic potentials of each of these isomers are very different. Consequently, to determine the potential toxicological impact of NP in food, an isomer-specific approach is necessary.

  5. Four-quasiparticle isomers and K-forbidden transitions in 176Lu

    International Nuclear Information System (INIS)

    McGoram, T.R.; Dracoulis, G.D.; Kibedi, T.; Mullins, M.; Byrne, A.P.; Baxter, A.M.

    2000-01-01

    Full text: The odd-odd nucleus 176 Lu has been the subject of extensive experimental and theoretical investigation over the last forty years. Much of this interest has stemmed from the role of 176 Lu in the s-process in nucleosynthesis. From a nuclear structure perspective, 176 Lu resides in a region of the nuclear chart where collective rotation and high-K, multi-quasiparticle states compete to form the yrast line (the locus of state with the lowest energy at a given angular momentum). The electromagnetic decay of intermediate and high-K states is often hindered due to the K-selection rule, while apparent violations of this selection rule have been ascribed to Coriolis mixing, shape changes in the gamma-degree of freedom, and so-called 'statistical' mixing. The relative importance of these mechanisms remains an open question. We present here the results of gamma-ray and conversion-electron spectroscopic measurements, performed at the Heavy Ion Facility at the Australian National University in Canberra, using the reaction 176 Yb( 7 Li, α3n) at a beam energy of 45 MeV. Two new four-quasiparticle isomers have been established, with mean lives of 400(100)ns and 58(5)μs, and spin projections and parities of 12 + and (14 + ) respectively. The shorter--lived isomer displays both normal and anomalous K-forbidden decays, which we show is the result of two-state mixing between the isomeric state and a member of a two-quasiparticle rotational band. The implied mixing matrix element of only 5 eV shows explicitly that very small mixing matrix elements may be responsible for anomalous K-hindered decays

  6. Shape isomer excitation by mu-minus capture

    International Nuclear Information System (INIS)

    Kaplan, S.N.; Monard, J.A.; Nagamiya, S.

    1975-06-01

    In a search for back-decay gamma rays from the shape isomer in 238 U following mu-minus capture, no candidates have been found with yields greater than 2 percent of the muon stoppings. The intensities of the gamma rays are insufficient to permit definitive lifetime measurements of individual peaks; however, for 500-keV energy ranges of gamma ray pulses, lifetimes have been determined that give results consistent with recent electron lifetime measurements. (6 figures, 2 tables) (U.S.)

  7. Decays of 116Sb isomers to levels in 116Sn

    International Nuclear Information System (INIS)

    Gacsi, Z.; Raman, S.

    1994-01-01

    The excited states of 116 Sn were studied by means of the decays of the 15.8-min, 3 + 116 Sb ground state, and the 60.3-min, 8 - 116 Sb isomer. Over 50 γ rays were observed; these were incorporated into a level scheme consisting of 32 excited states. Except for one new level proposed at 3.986 MeV, the current study fully supports an exhaustive study of levels in 116 Sn reported earlier. The previous study was an attempt to develop a nearly ''complete'' level scheme of 116 Sn up to an excitation energy of 4.3 MeV

  8. Spins, Electromagnetic Moments, and Isomers of 107-129Cd

    CERN Document Server

    Yordanov, D T; Bieron, J; Bissell, M L; Blaum, K; Budincevic, I; Fritzsche, S; Frommgen, N; Georgiev, G; Geppert, Ch; Hammen, M; Kowalska, M; Kreim, K; Krieger, A; Neugart, R; Nortershauser, W; Papuga, J; Schmidt, S

    2013-01-01

    The neutron-rich isotopes of cadmium up to the N=82 shell closure have been investigated by high-resolution laser spectroscopy. Deep-UV excitation at 214.5 nm and radioactive-beam bunching provided the required experimental sensitivity. Long-lived isomers are observed in 127Cd and 129Cd for the first time. One essential feature of the spherical shell model is unambiguously confirmed by a linear increase of the 11/2- quadrupole moments. Remarkably, this mechanism is found to act well beyond the h11/2 shell.

  9. Isomers of fluoroamphetamines detected in forensic cases in Denmark

    DEFF Research Database (Denmark)

    Johansen, Sys Stybe; Hansen, Tina Maria

    2012-01-01

    A study was performed on the detection, separation and quantification of isomers from the new designer drugs named fluoroamphetamines (FAs) in forensic cases in eastern Denmark. The drugs were detected in whole blood extracts by ultraperformance liquid chromatography with time of flight mass...... of drugs (DUID) cases, involving 4-fluoroamphetamine (4-FA) have been observed with whole blood concentrations ranging from 0.006 to 0.58 mg/kg. One autopsy case involved 4-FA; however, it was determined to be a combined intoxication. In 2010, ortho-fluoroamphetamine (2-FA) was discovered in forensic...

  10. Identification of absolute geometries of cis and trans molecular isomers by Coulomb Explosion Imaging.

    Science.gov (United States)

    Ablikim, Utuq; Bomme, Cédric; Xiong, Hui; Savelyev, Evgeny; Obaid, Razib; Kaderiya, Balram; Augustin, Sven; Schnorr, Kirsten; Dumitriu, Ileana; Osipov, Timur; Bilodeau, René; Kilcoyne, David; Kumarappan, Vinod; Rudenko, Artem; Berrah, Nora; Rolles, Daniel

    2016-12-02

    An experimental route to identify and separate geometric isomers by means of coincident Coulomb explosion imaging is presented, allowing isomer-resolved photoionization studies on isomerically mixed samples. We demonstrate the technique on cis/trans 1,2-dibromoethene (C 2 H 2 Br 2 ). The momentum correlation between the bromine ions in a three-body fragmentation process induced by bromine 3d inner-shell photoionization is used to identify the cis and trans structures of the isomers. The experimentally determined momentum correlations and the isomer-resolved fragment-ion kinetic energies are matched closely by a classical Coulomb explosion model.

  11. The behaviour of EDDHA isomers in soils as influenced by soil properties.

    OpenAIRE

    Schenkeveld, W.D.C.; Reichwein, A.M.; Temminghoff, E.J.M.; Riemsdijk, van, W.H.

    2007-01-01

    FeEDDHA products are applied to correct iron chlorosis in plants and consist of a mixture of EDDHA isomers chelated to iron. In this study such mixtures have been divided into four (groups of) isomers: racemic o,o-EDDHA, meso o,o-EDDHA, o,p-EDDHA and rest-EDDHA. The physical and chemical properties of these isomers differ and hence does their ability to deliver Fe to plants. To come to a soil-specific iron fertilization recommendation, the behaviour of the EDDHA isomers in the soil needs to b...

  12. A high-spin isomer at high excitation energy in the neutron deficient nucleus $^{152}$Dy

    CERN Document Server

    Jansen, J F W; Chmielewska, D; De Meijer, R J

    1976-01-01

    A T/sub 1/2/=60+or-5 ns isomer at E/sub x/ approximately=5 MeV is found in the /sup 154/Gd( alpha ,6n)/sup 152/Dy reaction. The possible spin values are 15isomer are observed. The isomer may be interpreted as a four-quasi-particle state situated on the yrast line. The regular level sequence above the isomer may then be an evidence for a decoupled rotational band built on top of this state. (10 refs).

  13. Identifying isomers of C-78 by means of x-ray spectroscopy

    DEFF Research Database (Denmark)

    Bassan, Arianna; Nyberg, Mats; Luo, Yi

    2002-01-01

    X-ray photoelectron and absorption spectra of C-78 isomers have been generated using density functional theory with inclusion of the full core-hole potentials. Strong isomer dependence has been found in absorption, but not in the photoelectron spectra. C-78 isomers can be thought to be formed by ...... by inserting 18 carbon atoms into an opened C-60. We have shown how the different local arrangements of these 18 carbon atoms are responsible for the significant isomer dependence observed. Our calculated spectra are in excellent agreement with the experimental counterparts....

  14. Conformational isomers of dichloro bis(1,3-diaminopropane copper(II: Synthesis, characterization and DFT modeling

    Directory of Open Access Journals (Sweden)

    Seema Yadav

    2017-02-01

    Full Text Available Three isomers of [Cu(pn2Cl2] in solid state have been synthesized, isolated and characterized by elemental analysis, molar conductance, FTIR, TGA, EPR, electronic spectra and DFT calculation. The molar conductance of 1 mM solution of the complexes measured in DMSO falls in 40–44 Scm2 mol−1. All the isomers in aqueous medium show similar absorption pattern in the UV–visible region of the spectra. They are nearly identical in solution although in the solid state they exist in three distinct colors. The change in the color of complexes is due to change in conformations of the propanediamine molecule. Cu(II in [Cu(pn2Cl2] lies on an inversion center. It is octahedrally coordinated to four nitrogen of 1,3-diaminopropane (pn and two chloride ions displaying three different spatial conformations namely chair–chair, chair–boat and boat–boat. The TGA of the complexes suggest that Cu is left as final residue at 600 °C. The entire data have been supported by DFT calculation.

  15. Product state resolved excitation spectroscopy of He-, Ne-, and Ar-Br2 linear isomers: experiment and theory.

    Science.gov (United States)

    Pio, Jordan M; van der Veer, Wytze E; Bieler, Craig R; Janda, Kenneth C

    2008-04-07

    Valence excitation spectra for the linear isomers of He-, Ne-, and Ar-Br2 are reported and compared to a two-dimensional simulation using the currently available potential energy surfaces. Excitation spectra from the ground electronic state to the region of the inner turning point of the Rg-Br2 (B,nu') stretching coordinate are recorded while probing the asymptotic Br2 (B,nu') state. Each spectrum is a broad continuum extending over hundreds of wavenumbers, becoming broader and more blueshifted as the rare gas atom is changed from He to Ne to Ar. In the case of Ne-Br2, the threshold for producing the asymptotic product state reveals the X-state linear isomer bond energy to be 71+/-3 cm(-1). The qualitative agreement between experiment and theory shows that the spectra can be correctly regarded as revealing the one-atom solvent shifts and also provides new insight into the one-atom cage effect on the halogen vibrational relaxation. The measured spectra provide data to test future ab initio potential energy surfaces in the interaction of rare gas atoms with the halogen valence excited state.

  16. Selective sensing of two novel coordination polymers based on tris(4-carboxylphenyl)phosphine oxide for organic molecules and Fe3+ and Hg2+ ions

    Science.gov (United States)

    Huo, Liangqin; Zhang, Jie; Gao, Lingling; Wang, Xiaoqing; Fan, Liming; Fang, Kegong; Hu, Tuoping

    2017-12-01

    Two novel coordination polymers, formulated as {[Zn(HTPO)(bib)]·4H2O}n (1), {[Cu3(TPO)2 (bib)3]·2DMF·0.5EtOH·0.5H2O}n (2) (H3TPO = tris(4-carboxylphenyl)phosphine oxide; bib = 1,4-bis(1H-imidazol-4-yl) benzene), have been synthesized under solvothermal method and characterized by single-crystal X-ray diffraction, elemental analysis (EA), IR spectra, thermogravimetric (TG) analysis, powder X-ray diffraction (PXRD). Structural analysis reveals that complex 1 is a 2D 4-connected sheet with an intriguing 2D + 2D→2D network. Complex 2 displays a 3D 3,4-connected net with the point symbol of {103}2{106}3. Furthermore, the photoluminescence properties of 1 and 2 were investigated in the solid state and various solvent emulsions, the results show that 1 and 2 have better fluorescent recognition for organic molecules, Fe3+ and Hg2+ ions.

  17. Methanation on mass-selected Ru nanoparticles on a planar SiO2 model support: The importance of under-coordinated sites

    DEFF Research Database (Denmark)

    Masini, Federico; Strebel, Christian Ejersbo; McCarthy, David Norman

    2013-01-01

    Mass-selected Ru nanoparticles were deposited onto planar SiO2 support and their capability for the methanation reaction investigated. The catalytic activity for the methanation reaction at 100mbar under hydrogen rich conditions (1:99 CO/H2 ratio) was measured as a function of particle size. We f...

  18. Measurements of isomers at the FRS ion catcher

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, Christine [Justus-Liebig Universitaet Giessen (Germany); Collaboration: FRS Ion Catcher-Collaboration

    2016-07-01

    Projectile fragmentation and fission reactions at in-flight facilities are important production mechanisms to access short-lived exotic nuclei. It is a challenge to describe the angular momentum distribution after the collision of relativistic nuclei. This can be experimentally accessed by measuring the population of isomeric states. Isomeric ratios and excitation energies of isomers of short-lived exotic nuclei can be determined at the FRS Ion Catcher at GSI. At the FRS, projectile and fission fragments are produced at relativistic energies, separated in-flight and range-focused. They are slowed down and thermalized in a cryogenic stopping cell. In a multi-purpose RFQ beamline alpha spectroscopy can be performed. Alternatively the ions can be transported to a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS), where masses of the ground and isomeric states can be measured simultaneously with high resolving power. The MR-TOF-MS can also be used to spatially separate the ions in order to provide isomerically clean ion beams. During a recent experiment isomer-to-ground state ratios and excitation energies of uranium projectile and fission fragments produced at 1 GeV/u were measured. The ratios, measured with the MR-TOF-MS, were verified by alpha spectroscopy. Furthermore the ratios were compared to calculations based on an abrasion-ablation model of fragmentation.

  19. Calculations of long-lived isomer production in neutron reactions

    International Nuclear Information System (INIS)

    Chadwick, M.B.; Young, P.G.

    1992-01-01

    We present theoretical calculations for the production of the long-lived isomers 93m Nb (1/2-, 16 yr), 121m Sn (11/2-, 55 yr), 166m Ho (7-, 1200 yr), 184m Re (8+, 165 d), 186m Re (8+, 2x10 5 yr), 178 Hf (16+, 31 yr), 179m Hf (25/2-, 25 d), and 192m Ir (9+, 241 yr), all of which pose potential radiation activation problems in nuclear fusion reactors if produced in 14-MeV neutron-induced reactions. We consider (n,2n), (n,n'), and (n,γ) production modes and compare our results both with experimental data (where available) and systematics. We also investigate the dependence of the isomeric cross section ratio on incident neutron energy for the isomers under consideration. The statistical Hauser-Feshbach plus preequilibrium code GNASH was used for the calculations. Where discrete state experimental information was lacking, rotational band members above the isomeric state, which can be justified theoretically but have not been experimentally resolved, were reconstructed. (author). 16 refs, 10 figs, 4 tabs

  20. High-spin, multiparticle isomers in 121,123Sb

    International Nuclear Information System (INIS)

    Jones, G. A.; Walker, P. M.; Podolyak, Zs.; Cullen, I. J.; Garnsworthy, A. B.; Liu, Z.; Thompson, N. J.; Williams, S. J.; Zhu, S.; Carpenter, M. P.; Janssens, R. V. F.; Khoo, T. L.; Seweryniak, D.; Carroll, J. J.; Chakrawarthy, R. S.; Hackman, G.; Chowdhury, P.; Dracoulis, G. D.; Lane, G. J.; Kondev, F. G.

    2008-01-01

    Isomers in near-spherical Z=51, antimony isotopes are reported here for the first time using fusion-fission reactions between 27 Al and a pulsed 178 Hf beam of energy, 1150 MeV. γ rays were observed from the decay of isomeric states with half-lives, T 1/2 =200(30) and 52(3)μs, and angular momenta I=((25/2)) and I π =(23/2) + , in 121,123 Sb, respectively. These states are proposed to correspond to ν(h (11/2) ) 2 configurations, coupled to an odd d (5/2) or g (7/2) proton. Nanosecond isomers were also identified at I π =(19/2) - [T 1/2 =8.5(5) ns] in 121 Sb and I π =((15/2) - ) [T 1/2 =37(4) ns] in 123 Sb. Information on spins and parities of states in these nuclei was obtained using a combination of angular correlation and intensity-balance measurements. The configurations of states in these nuclei are discussed using a combination of spin/energy systematics and shell-model calculations for neighboring tin isotones and antimony isotopes

  1. Degradation of a chiral nonylphenol isomer in two agricultural soils

    International Nuclear Information System (INIS)

    Zhang Haifeng; Spiteller, Michael; Guenther, Klaus; Boehmler, Gabriele; Zuehlke, Sebastian

    2009-01-01

    The degradation of a chiral nonylphenol isomer, 4-(1-ethyl-1,4-dimethylpentyl)phenol (NP 112 ), in two agricultural soils from Monheim and Dortmund, Germany has been studied. The degradation of NP 112 and the formation of a nitro-nonylphenol metabolite were determined by means of GC-MS analysis. The degradation followed bi-exponential order kinetics, with half-life of less than 5 days in both soils. The nitro-metabolite was found at different concentration levels in the two soils. The nitro-metabolite of NP 112 was more persistent than its parent compound. After 150 days about 13% of the initially applied NP 112 remained in the Monheim soil as its nitro-metabolite. Results of the E-screen assay revealed that the nitro-NP 112 has oestrogenic potency of 85% of that of NP 112 . Furthermore, the results of chiral GC-MS analysis revealed that no chiral degradation of NP 112 occurred in this study. - The degradation of a chiral nonylphenol isomer in agricultural soils followed bi-exponential order kinetics resulting in a more persistent nitro-metabolite.

  2. Chemical Simulations of Prebiotic Molecules: Interstellar Ethanimine Isomers

    Science.gov (United States)

    Quan, Donghui; Herbst, Eric; Corby, Joanna F.; Durr, Allison; Hassel, George

    2016-06-01

    The E- and Z-isomers of ethanimine (CH3CHNH) were recently detected toward the star-forming region Sagittarius (Sgr) B2(N) using the Green Bank Telescope PRIMOS cm-wave spectral data, and imaged by the Australia Telescope Compact Array. Ethanimine is not reported in the hot cores of Sgr B2, but only in gas that absorbs at +64 and +82 km s-1 in the foreground of continuum emission generated by H II regions. The ethanimine isomers can serve as precursors of the amino acid alanine and may play important roles in forming biological molecules in the interstellar medium. Here we present a study of the chemistry of ethanimine using a gas-grain simulation based on rate equations, with both isothermal and warm-up conditions. In addition, the density, kinetic temperature, and cosmic ray ionization rate have been varied. For a variety of physical conditions in the warm-up models for Sgr B2(N) and environs, the simulations show reasonable agreement with observationally obtained abundances. Isothermal models of translucent clouds along the same line of sight yield much lower abundances, so that ethanimine would be much more difficult to detect in these sources despite the fact that other complex molecules have been detected there.

  3. CHEMICAL SIMULATIONS OF PREBIOTIC MOLECULES: INTERSTELLAR ETHANIMINE ISOMERS

    Energy Technology Data Exchange (ETDEWEB)

    Quan, Donghui; Durr, Allison [Department of Chemistry, Eastern Kentucky University, Richmond, KY 40475 (United States); Herbst, Eric [Departments of Chemistry and Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Corby, Joanna F. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Hassel, George [Physics and Astronomy Department, Siena College, Loudonville, NY 12211 (United States)

    2016-06-20

    The E- and Z- isomers of ethanimine (CH{sub 3}CHNH) were recently detected toward the star-forming region Sagittarius (Sgr) B2(N) using the Green Bank Telescope PRIMOS cm-wave spectral data, and imaged by the Australia Telescope Compact Array. Ethanimine is not reported in the hot cores of Sgr B2, but only in gas that absorbs at +64 and +82 km s{sup −1} in the foreground of continuum emission generated by H ii regions. The ethanimine isomers can serve as precursors of the amino acid alanine and may play important roles in forming biological molecules in the interstellar medium. Here we present a study of the chemistry of ethanimine using a gas-grain simulation based on rate equations, with both isothermal and warm-up conditions. In addition, the density, kinetic temperature, and cosmic ray ionization rate have been varied. For a variety of physical conditions in the warm-up models for Sgr B2(N) and environs, the simulations show reasonable agreement with observationally obtained abundances. Isothermal models of translucent clouds along the same line of sight yield much lower abundances, so that ethanimine would be much more difficult to detect in these sources despite the fact that other complex molecules have been detected there.

  4. Direct transitions from high-K isomers to low-K bands -- {gamma} softness or coriolis coupling

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Yoshifumi R.; Narimatsu, Kanako; Ohtsubo, Shin-Ichi [Kyushu Univ., Fukuoka (Japan)] [and others

    1996-12-31

    Recent measurements of direct transitions from high-K isomers to low-K bands reveal severe break-down of the K-selection rule and pose the problem of how to understand the mechanism of such K-violation. The authors recent systematic calculations by using a simple {gamma}-tunneling model reproduced many of the observed hindrances, indicating the importance of the {gamma} softness. However, there are some data which cannot be explained in terms of the {gamma}-degree of freedom. In this talk, the authors also discuss the results of conventional Coriolis coupling calculations, which is considered to be another important mechanism.

  5. Branched alkanes from ancient and modern sediments: isomer discrimination by GC/MS with multiple reaction monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Summons, R.E.

    1987-01-01

    Linked scanning of a tandem sector mass spectrometer has been used to identify abundant, first field free region (FFR1) unimolecular fragmentations in branched and isoprenoid hydrocarbons. The most intense, structure-specific reactions were selected to establish multiple reaction monitoring (MRM) parameters for GC/MS analysis. This methodology has been used to study the identify of co-eluting and closely eluting hydrocarbon biomarkers from modern and ancient sediments and from extant microorganisms. Some sediments of Cambrian and Proterozoic age have been found to contain suites of monomethylalkanes with all possible isomers present and with little apparent preference for the site of branching.

  6. Three luminescent d{sup 10} metal coordination polymers assembled from a semirigid V-shaped ligand with high selective detecting of Cu{sup 2+} ion and nitrobenzene

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wei-Ping [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, Shaanxi Key Laboratory of Physico-Inorg. Chem., College of Chemistry & Materials Science, Northwest University, Xi’an 710069 (China); Institute of Functional Materials, College of Chemistry and Pharmaceutical Engineering, Sichuan University of Science & Engineering, Zigong 643000 (China); Liu, Ping; Liang, Yu-Tong; Cui, Lin; Xi, Zheng-Ping [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, Shaanxi Key Laboratory of Physico-Inorg. Chem., College of Chemistry & Materials Science, Northwest University, Xi’an 710069 (China); Wang, Yao-Yu, E-mail: wyaoyu@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, Shaanxi Key Laboratory of Physico-Inorg. Chem., College of Chemistry & Materials Science, Northwest University, Xi’an 710069 (China)

    2015-08-15

    Three 2D luminescent coordination polymers with helical frameworks, [ZnL{sub 2}]{sub n} (1) and ([ML{sub 2}]·(H{sub 2}O)){sub n} (M=Zn (2), Cd (3)) (HL=4-((2-methyl-1 H-imidazol-1-yl)methyl)benzoic acid), have been assembled under hydro(solvo)thermal conditions. Complex 1 is in chiral space group and displays a rare 2D→2D 2-fold parallel interpenetrated layer network with two types of chiral double helixes. Interestingly, the single crystal structure analyses indicate the coexistence of enantiomers la and 1b in one pot, while the bulk crystallization of 1 are racemic mixtures based on the CD measurement. 2 and 3 are isostructural, in the structure, there are two kinds of 2D chiral helical-layers which stack in an -ABAB- sequence leading to the overall structure are mesomer and achiral. All compounds display intense luminescence in solid state at room temperature with high chemical and thermal stability. More importantly, 1 has been successfully applied in the detection of Cu{sup 2+} ions in aqueous media and nitrobenzene and the probable detecting mechanism was also discussed. - Graphical abstract: Three luminescent d{sup 10} metal coordination polymers with helical-layer based on 4-((2-methyl-1H-imidazol-1-yl)methyl)benzoic acid have been obtained. Compound 1 shows high selective detecting for Cu{sup 2+} ion in aqueous and nitrobenzene. - Highlights: • Three coordination polymers with chiral helical-layer have been obtained. • 1 Can luminescent detect Cu{sup 2+} ion in aqueous media and nitrobenzene. • Racemic mixture or mesomer compounds can be obtained by controlling the reaction conditions.

  7. Co-ordinated Classroom Lectures.

    Science.gov (United States)

    Harmon, Darell Boyd

    From a series of lectures, a selection of eight are oriented principally toward the biologically developing child, and the physiological operations in visual process. The numbered lectures are--(1) The Coordinated Classroom, its Philosophy and Principles, (2) An Outline of a Biological Point of View, (3) The Evolution of Structure--despite man's…

  8. Direct nuclear magnetic resonance identification and quantification of geometric isomers of conjugated linoleic acid in milk lipid fraction without derivatization steps: Overcoming sensitivity and resolution barriers

    International Nuclear Information System (INIS)

    Tsiafoulis, Constantinos G.; Skarlas, Theodore; Tzamaloukas, Ouranios; Miltiadou, Despoina; Gerothanassis, Ioannis P.

    2014-01-01

    Highlights: • The first NMR quantification of four geometric 18:2 CLA isomers has been achieved. • Sensitivity and resolution NMR barriers have been overcome. • Selective suppression and reduced 13 C spectral width have been utilized. • The method is applied in the milk lipid fraction without derivatization steps. • The method is selective, sensitive with very good analytical characteristics. - Abstract: We report the first successful direct and unequivocal identification and quantification of four minor geometric (9-cis, 11-trans) 18:2, (9-trans, 11-cis) 18:2, (9-cis, 11-cis) 18:2 and (9-trans, 11-trans) 18:2 conjugated linoleic acid (CLA) isomers in lipid fractions of lyophilized milk samples with the combined use of 1D 1 H-NMR, 2D 1 H- 1 H TOCSY and 2D 1 H- 13 C HSQC NMR. The significant sensitivity barrier has been successfully overcome under selective suppression of the major resonances, with over 10 4 greater equilibrium magnetization of the -(CH 2 ) n - 1 H spins compared to that of the 1 H spins of the conjugated bonds of the CLA isomers. The resolution barrier has been significantly increased using reduced 13 C spectral width in the 2D 1 H- 13 C HSQC experiment. The assignment was confirmed with spiking experiments with CLA standard compounds and the method does not require any derivatization steps for the lipid fraction. The proposed method is selective, sensitive and compares favorably with the GS-MS method of analysis

  9. Mitochondrial Biogenesis in Diverse Cauliflower Cultivars under Mild and Severe Drought. Impaired Coordination of Selected Transcript and Proteomic Responses, and Regulation of Various Multifunctional Proteins

    Directory of Open Access Journals (Sweden)

    Michał Rurek

    2018-04-01

    Full Text Available Mitochondrial responses under drought within Brassica genus are poorly understood. The main goal of this study was to investigate mitochondrial biogenesis of three cauliflower (Brassica oleracea var. botrytis cultivars with varying drought tolerance. Diverse quantitative changes (decreases in abundance mostly in the mitochondrial proteome were assessed by two-dimensional gel electrophoresis (2D PAGE coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS. Respiratory (e.g., complex II, IV (CII, CIV and ATP synthase subunits, transporter (including diverse porin isoforms and matrix multifunctional proteins (e.g., components of RNA editing machinery were diversely affected in their abundance under two drought levels. Western immunoassays showed additional cultivar-specific responses of selected mitochondrial proteins. Dehydrin-related tryptic peptides (found in several 2D spots immunopositive with dehydrin-specific antisera highlighted the relevance of mitochondrial dehydrin-like proteins for the drought response. The abundance of selected mRNAs participating in drought response was also determined. We conclude that mitochondrial biogenesis was strongly, but diversely affected in various cauliflower cultivars, and associated with drought tolerance at the proteomic and functional levels. However, discussed alternative oxidase (AOX regulation at the RNA and protein level were largely uncoordinated due to the altered availability of transcripts for translation, mRNA/ribosome interactions, and/or miRNA impact on transcript abundance and translation.

  10. Mitochondrial Biogenesis in Diverse Cauliflower Cultivars under Mild and Severe Drought. Impaired Coordination of Selected Transcript and Proteomic Responses, and Regulation of Various Multifunctional Proteins

    Science.gov (United States)

    Rurek, Michał; Czołpińska, Magdalena; Staszak, Aleksandra Maria; Nowak, Witold; Krzesiński, Włodzimierz; Spiżewski, Tomasz

    2018-01-01

    Mitochondrial responses under drought within Brassica genus are poorly understood. The main goal of this study was to investigate mitochondrial biogenesis of three cauliflower (Brassica oleracea var. botrytis) cultivars with varying drought tolerance. Diverse quantitative changes (decreases in abundance mostly) in the mitochondrial proteome were assessed by two-dimensional gel electrophoresis (2D PAGE) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Respiratory (e.g., complex II, IV (CII, CIV) and ATP synthase subunits), transporter (including diverse porin isoforms) and matrix multifunctional proteins (e.g., components of RNA editing machinery) were diversely affected in their abundance under two drought levels. Western immunoassays showed additional cultivar-specific responses of selected mitochondrial proteins. Dehydrin-related tryptic peptides (found in several 2D spots) immunopositive with dehydrin-specific antisera highlighted the relevance of mitochondrial dehydrin-like proteins for the drought response. The abundance of selected mRNAs participating in drought response was also determined. We conclude that mitochondrial biogenesis was strongly, but diversely affected in various cauliflower cultivars, and associated with drought tolerance at the proteomic and functional levels. However, discussed alternative oxidase (AOX) regulation at the RNA and protein level were largely uncoordinated due to the altered availability of transcripts for translation, mRNA/ribosome interactions, and/or miRNA impact on transcript abundance and translation. PMID:29642585

  11. The behaviour of EDDHA isomers in soils as influenced by soil properties.

    NARCIS (Netherlands)

    Schenkeveld, W.D.C.; Reichwein, A.M.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2007-01-01

    FeEDDHA products are applied to correct iron chlorosis in plants and consist of a mixture of EDDHA isomers chelated to iron. In this study such mixtures have been divided into four (groups of) isomers: racemic o,o-EDDHA, meso o,o-EDDHA, o,p-EDDHA and rest-EDDHA. The physical and chemical properties

  12. A new isomer in 195Bi identified at the focal plane of HYRA

    International Nuclear Information System (INIS)

    Roy, T.; Mukherjee, G.; Asgar, Md. A.

    2014-01-01

    Due to the presence of high-j (h 9/2 and i 13/2 ) orbitals near the proton and neutron Fermi levels, high spin isomers are expected to occur for neutron deficient Bismuth nuclei (Z = 83) in A = 190 region. A 750 ns isomer has been known for a long time in 195 Bi whose excitation energy and decay path have been reported recently. A rotational band has been reported in this nucleus based on 13/2 + isomer, originated from the deformation driving i 13/2 orbital. This band reported to have prompt feeding through a 457 keV γ-ray apart from a strong feeding from the 750 ns isomer. In 193 Bi, the 29/2 - state is a 3μs isomer, another isomer with half-life >10μs is also known in this nucleus but its excitation energy, spin and parity are not known. Similar isomer has not yet been observed in 195 Bi. The aim of the present work was to find isomers and their decays in 193,195 Bi

  13. Nano-Second Isomers in Neutron-Rich Ni Region Produced by Deep-Inelastic Collisions

    International Nuclear Information System (INIS)

    Ishii, T.; Asai, M.; Matsuda, M.; Ichikawa, S.; Makishima, A.; Hossain, I.; Kleinheinz, P.; Ogawa, M.

    2001-01-01

    Nuclear structure of the doubly magic 68 Ni and its neighbors has been studied by spectroscopic techniques. Developing a new instrument isomer-scope, we have measured γ rays from nano-second isomers produced in heavy-ion deep-inelastic collisions with great sensitivity. (author)

  14. Kinetics of photoirradiation-induced synthesis of soy oil-conjugated linoleic acid isomers.

    Science.gov (United States)

    Jain, Vishal P; Proctor, Andrew

    2007-02-07

    Photoirradiation of soy oil with UV/visible light has been shown to produce significant amounts of trans,trans conjugated linoleic acid (CLA) isomers through conversion of various synthesized intermediate cis,trans isomers. The objective of this study was to determine the kinetics of CLA isomers synthesis to better understand the production of various isomers. Soy oil was irradiated with UV/visible light for 144 h in the presence of an iodine catalyst and CLA isomers analyzed by gas chromatography (GC). Arrhenius plots were developed for the conversion of soy oil linoleic acid (A) to form cis-, trans/trans-, cis-CLA (B), conversion of cis-, trans/trans-, cis-CLA to form trans,trans-CLA (C) with respect to B, and formation of trans,trans-CLA isomers with respect to C. The kinetics of consumption of linoleic acid (LA) to form cis-, trans/trans-, cis-CLA was found to be of second-order with a rate constant of 9.01 x 10-7 L/mol s. The rate of formation of cis-, trans/trans-, cis-CLA isomers depends on the rate of formation from LA and its rate of consumption to form trans,trans-CLA isomers. The conversion of cis-, trans/trans-, cis-CLA isomers to trans,trans-CLA isomers was found to be of first-order with a rate constant of 2.75 x 10-6 s-1. However, the formation of thermodynamically stable trans,trans-CLA isomers (C) with respect to C was found to be a zero-order reaction with a rate constant of 10.66 x 10-7 mol/L s. The consumption of LA was found to be the rate-determining step in the CLA isomers formation reaction mechanism. The findings provide a better understanding of the mechanism of CLA isomers synthesis by photoirradiation and the factors controlling the ratio of various isomers.

  15. Critical pathway studies for selected radionuclides. Part of a coordinated programme on environmental monitoring for radiological protection in Asia and the Far East

    International Nuclear Information System (INIS)

    Bhat, I.S.

    1980-04-01

    The programme carried out critical pathway studies for selected radionuclides ( 60 Co, 63 Ni, 59 Fe, 54 Mn, sup(110m)Ag, 106 Ru and 144 Ce) and assessed population exposure in the vicinity of Tarapur Atomic Power Station. The following topics are covered under the programme. (i) Demographic study of dietary habits and consumption data for Tarapur population. (ii) Concentration and accumulation of radionuclides in food products. (iii) Determination of radionuclides in sea water, silt, marine algae and marine organisms at Tarapur Atomic Power Station (TAPS) Site. (iv) Behaviour of radionuclides released to marine environment. (v) Evaluation of critical exposure pathway. (vi) Population exposure in the vicinity of Tarapur Atomic Power Station

  16. K-Isomers as a Probe of Nuclear Structure and Advanced Applications

    Science.gov (United States)

    Kondev, F. G.

    2005-05-01

    Nuclear K-isomers play a pivotal role in understanding the structure of deformed, axially symmetric nuclei. Examples are presented of recent studies of exotic multi-quasiparticle isomers in the A˜180 rare-earth region at the extreme of angular momentum and neutron number. A specific band-mixing scenario is invoked to explain the unusual decay path of the Kπ=57/2- isomer (T1/2=22 ns) in 175Hf, the highest spin K-isomer known in nature. The discovery of a suite of high-K isomers, above the previously known Kπ=23/2- (T1/2=160 d) state in 177Lu, using deep-inelastic and multi-nucleon transfer reactions is discussed.

  17. K-Isomers as a Probe of Nuclear Structure and Advanced Applications

    International Nuclear Information System (INIS)

    Kondev, F.G.

    2005-01-01

    Nuclear K-isomers play a pivotal role in understanding the structure of deformed, axially symmetric nuclei. Examples are presented of recent studies of exotic multi-quasiparticle isomers in the A∼180 rare-earth region at the extreme of angular momentum and neutron number. A specific band-mixing scenario is invoked to explain the unusual decay path of the Kπ=57/2- isomer (T1/2=22 ns) in 175Hf, the highest spin K-isomer known in nature. The discovery of a suite of high-K isomers, above the previously known Kπ=23/2- (T1/2=160 d) state in 177Lu, using deep-inelastic and multi-nucleon transfer reactions is discussed

  18. Aqueous phase partitioning of hexachlorocyclohexane (HCH) isomers by biosurfactant produced by Pseudomonas aeruginosa WH-2

    International Nuclear Information System (INIS)

    Sharma, Suman; Singh, Partapbir; Raj, Mayil; Chadha, Bhupinder Singh; Saini, Harvinder Singh

    2009-01-01

    The different isomers of technical-grade hexachlorocyclohexane (t-HCH) including the insecticidal γ-isomer, commonly known as lindane, have been reported to be toxic, carcinogenic and endocrine disrupters. The spatial arrangements of the chlorine atoms on different isomers and low aqueous phase solubility contribute to their persistence in environment, β-HCH being the most resistance to transformation. The biosurfactant preparation of Pseudomonas aeruginosa isolate WH-2 was evaluated for its ability to improve the aqueous phase partitioning of different isomers of HCH-muck. Further, the ability of biosurfactant preparation to emulsify HCH and n-hexadecane was checked under different conditions, usually characteristic of sites contaminated with pollutants viz. wide range of pH, temperature, and salinity. The data obtained from this study will be helpful in designing suitable bioremediation strategies for huge stock piles of HCH-muck and sites polluted by reckless use/disposal of HCH-isomers.

  19. Correlating states across isomers in 152Ho isotope

    International Nuclear Information System (INIS)

    Pramanik, Dibyadyuti; Dey, G.; Sarkar, S.; Bisoi, A.; Ray, S.; Kshetri, R.; Ray, I.; Pradhan, M.K.; Goswami, A.; Banerjee, P.; Mukherjee, A.; Bhattacharya, S.; Saha Sarkar, M.; Chakraborty, A.; Krishichayan; Ganguly, S.; Ray Basu, M.; Ganguly, G.; Raut, R.; Ghugre, S.S.; Sinha, A.K.; Basu, S.K.

    2011-01-01

    The odd-odd 152 Ho (N = 85) is a very interesting candidate for investigation of interplay of single - particle oblate states and prolate collective states, because it is situated between the N=82 shell closure and the strongly collective N > 87 region. It has been shown that there is a possibility of shape coexistence even at lower spins in 153 Ho. The structural evolution of Ho isotopes from A = 151 to 154 has also been studied. The features observed have been interpreted theoretically using shell model as well as Total Routhian surface calculations. Results have been combined with that for 153 Ho to study the evolution of structural features in these Ho isotopes with increasing neutron numbers and increasing spin. In the present work, experimental data on 152 Ho have been analysed to connect the three groups of transitions and confirm the possibility of a fourth isomer in the excitation spectrum

  20. Energetics of cyclohexane isomers: a density-functional study

    International Nuclear Information System (INIS)

    Lee, Chang Yol

    1999-01-01

    The binding energies and the geometric structures of conformational isomers of cyclohexane (C 6 H 12 ) are determined from the density-functional theory combined with ultrasoft pseudopotentials and gradient-corrected nonlocal exchange-correlation functionals. The ground-state chair conformation is found to have a binding energy of 99.457 eV, and the metastable twist-boat conformation has 99.161 eV. The chair conformation converts to another conformation via a half-chair conformation with an energy barrier of 0.507 eV whereas the twist-boat conformation converts to another twist-boat conformation via a boat conformation with a much smaller energy barrier of 0.015 eV

  1. Standard molar enthalpies of formation of monochloroacetophenone isomers

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Amaral, Luisa M.P.F.

    2010-01-01

    The standard (p 0 =0.1MPa) molar enthalpies of formation of the liquids 2'-, 3'-, and 4'-chloroacetophenones were derived from the standard molar energies of combustion, in oxygen, to yield CO 2 (g) and HCl . 600H 2 O(l), at T = 298.15 K, measured by rotating-bomb combustion calorimetry. The Calvet microcalorimetry was used to measure the enthalpies of vaporization of the three compounds. These two thermodynamic parameters yielded the standard molar enthalpies of formation of the chloroacetophenone isomers, in the gaseous phase, at T = 298.15 K. (table) An empirical scheme, developed by Cox, was used to estimate the gas-phase enthalpies of formation and the obtained values were compared with the experimental ones.

  2. Lutein and Zeaxanthin Isomers in Eye Health and Disease.

    Science.gov (United States)

    Mares, Julie

    2016-07-17

    Current evidence suggests lutein and its isomers play important roles in ocular development in utero and throughout the life span, in vision performance in young and later adulthood, and in lowering risk for the development of common age-related eye diseases in older age. These xanthophyll (oxygen-containing) carotenoids are found in a wide variety of vegetables and fruits, and they are present in especially high concentrations in leafy green vegetables. Additionally, egg yolks and human milk appear to be bioavailable sources. The prevalence of lutein, zeaxanthin, and meso-zeaxanthin in supplements is increasing. Setting optimal and safe ranges of intake requires additional research, particularly in pregnant and lactating women. Accumulating evidence about variable interindividual response to dietary intake of these carotenoids, based on genetic or metabolic influences, suggests that there may be subgroups that benefit from higher levels of intake and/or alternate strategies to improve lutein and zeaxanthin status.

  3. Communication: "Position" does matter: The photofragmentation of the nitroimidazole isomers

    Science.gov (United States)

    Bolognesi, P.; Casavola, A. R.; Cartoni, A.; Richter, R.; Markus, P.; Borocci, S.; Chiarinelli, J.; Tošić, S.; Sa'adeh, H.; Masič, M.; Marinković, B. P.; Prince, K. C.; Avaldi, L.

    2016-11-01

    A combined experimental and theoretical approach has been used to disentangle the fundamental mechanisms of the fragmentation of the three isomers of nitroimidazole induced by vacuum ultra-violet (VUV) radiation, namely, 4-, 5-, and 2-nitroimidazole. The results of mass spectrometry as well as photoelectron-photoion coincidence spectroscopy display striking differences in the radiation-induced decomposition of the different nitroimidazole radical cations. Based on density functional theory (DFT) calculations, a model is proposed which fully explains such differences, and reveals the subtle fragmentation mechanisms leading to the release of neutral species like NO, CO, and HCN. Such species have a profound impact in biological media and may play a fundamental role in radiosensitising mechanisms during radiotherapy.

  4. Quantification of minerals and tocopherols isomers in chestnuts approach chemometrics

    Directory of Open Access Journals (Sweden)

    Nilson Evelazio de Souza

    2014-10-01

    Full Text Available The levels of the ?, ?, and (?+?-tocopherol isomers and the amounts of the minerals Se, Zn, Ca, Fe, K, Mn, Mg, and Cu were analyzed in chestnuts. High contents of Zn (>65% relative to the recommended dietary intake (RDI were found in all chestnuts except macadamia nuts (25% of the RDI. All samples had Se contents higher than the RDI: Brazil nuts > macadamia nuts, cashew nuts > pecans > almonds > pistachio nuts > hazelnuts > European nuts. A greater concentration of ?-tocopherol was found in almonds (30% of RDI. All samples, except for hazelnuts, almonds, and macadamia nuts, had (?+?- tocopherols, with the largest amount found in pistachios. Only pecan nuts and European nuts had ?-tocopherol and only in low amounts. Multivariate analysis allowed for better characterization and distinction of the chestnuts

  5. Standard molar enthalpies of formation of monochloroacetophenone isomers

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro da Silva, Manuel A.V., E-mail: risilva@fc.up.p [Centro de Investigacao em Quimica, Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal); Amaral, Luisa M.P.F. [Centro de Investigacao em Quimica, Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal)

    2010-12-15

    The standard (p{sup 0}=0.1MPa) molar enthalpies of formation of the liquids 2'-, 3'-, and 4'-chloroacetophenones were derived from the standard molar energies of combustion, in oxygen, to yield CO{sub 2}(g) and HCl . 600H{sub 2}O(l), at T = 298.15 K, measured by rotating-bomb combustion calorimetry. The Calvet microcalorimetry was used to measure the enthalpies of vaporization of the three compounds. These two thermodynamic parameters yielded the standard molar enthalpies of formation of the chloroacetophenone isomers, in the gaseous phase, at T = 298.15 K. (table) An empirical scheme, developed by Cox, was used to estimate the gas-phase enthalpies of formation and the obtained values were compared with the experimental ones.

  6. The near-UV absorber OSSO and its isomers.

    Science.gov (United States)

    Wu, Zhuang; Wan, Huabin; Xu, Jian; Lu, Bo; Lu, Yan; Eckhardt, André K; Schreiner, Peter R; Xie, Changjian; Guo, Hua; Zeng, Xiaoqing

    2018-05-01

    Disulfur dioxide, OSSO, has been proposed as the enigmatic "near-UV absorber" in the yellowish atmosphere of Venus. However, the fundamentally important spectroscopic properties and photochemistry of OSSO are scarcely documented. By either condensing gaseous SO or 266 laser photolysis of an S2O2 complex in Ar or N2 at 15 K, syn-OSSO, anti-OSSO, and cyclic OS([double bond, length as m-dash]O)S were identified by IR and UV/Vis spectroscopy for the first time. The observed absorptions (λmax) for OSSO at 517 and 390 nm coincide with the near-UV absorption (320-400 nm) found in the Venus clouds by photometric measurements with the Pioneer Venus orbiter. Subsequent UV light irradiation (365 nm) depletes syn-OSSO and anti-OSSO and yields a fourth isomer, syn-OSOS, with concomitant dissociation into SO2 and elemental sulfur.

  7. Strategies to distinguish new synthetic cannabinoid FUBIMINA (BIM-2201) intake from its isomer THJ-2201: metabolism of FUBIMINA in human hepatocytes.

    Science.gov (United States)

    Diao, Xingxing; Scheidweiler, Karl B; Wohlfarth, Ariane; Zhu, Mingshe; Pang, Shaokun; Huestis, Marilyn A

    Since 2013, a new drugs-of-abuse trend attempts to bypass drug legislation by marketing isomers of scheduled synthetic cannabinoids (SCs), e.g., FUBIMINA (BIM-2201) and THJ-2201. It is much more challenging to confirm a specific isomer's intake and distinguish it from its structural analog because the isomers and their major metabolites usually have identical molecular weights and display the same product ions. Here, we investigated isomers FUBIMINA and THJ-2201 and propose strategies to distinguish their consumption. THJ-2201 was scheduled in the US, Japan, and Europe; however, FUBIMINA is easily available on the Internet. We previously investigated THJ-2201 metabolism in human hepatocytes, but human FUBIMINA metabolism is unknown. We aim to characterize FUBIMINA metabolism in human hepatocytes, recommend optimal metabolites to confirm its consumption, and propose strategies to distinguish between intakes of FUBIMINA and THJ-2201. FUBIMINA (10 μM) was incubated in human hepatocytes for 3 h, and metabolites were characterized with high-resolution mass spectrometry (HR-MS). We identified 35 metabolites generated by oxidative defluorination, further carboxylation, hydroxylation, dihydrodiol formation, glucuronidation, and their combinations. We recommend 5'-OH-BIM-018 (M34), BIM-018 pentanoic acid (M33), and BIM-018 pentanoic acid dihydrodiol (M7) as FUBIMINA specific metabolites. THJ-2201 produced specific metabolite markers 5'-OH-THJ-018 (F26), THJ-018 pentanoic acid (F25), and hydroxylated THJ-2201 (F13). Optimized chromatographic conditions to achieve different retention times and careful selection of specific product ion spectra enabled differentiation of isomeric metabolites, in this case FUBIMINA from THJ-2201. Our HR-MS approach should be applicable for differentiating future isomeric SCs, which is especially important when different isomers have different legal status.

  8. Microsecond and nanosecond isomers populated in fission reactions

    International Nuclear Information System (INIS)

    Jones, G. A.; Walker, P. M.; Podolyak, Zs.; Regan, P. H.; Williams, S. J.; Cullen, I. J.; Garnsworthy, A. B.; Liu, Z.; Thompson, N. J.; Carpenter, M. P.; Janssens, R. V. F.; Khoo, T. L.; Seweryniak, D.; Zhu, S.; Carroll, J. J.; Chakrawarthy, R. S.; Chowdhury, P.; Dracoulis, G. D.; Lane, G. J.; Hackman, G.

    2006-01-01

    Fusion-fission reactions were induced by bombarding a thick 27Al target with 178Hf projectiles at a laboratory energy of 1150 MeV using the ATLAS accelerator at Argonne National Laboratory. The subsequent γ-ray decays were measured using the GAMMASPHERE germanium detector array. The beam was pulsed at two different ON/OFF cycles of 82.5/825 ns and 25/75 μs in order to observe the γ rays from the decay of isomeric states. In 121Sb 2721+Δ keV, Iπ=(25/2+) and 2434 keV, Iπ=19/2- states have measured half-lives of T1/2=200(30) μs and 8.2(2) ns respectively. The 2614+Δ keV, Iπ=(27/2+) and 2486 keV, Iπ=19/2+ states in 123Sb have measured half-lives of T1/2=52(3) μs and 7.9(4) ns respectively. The positive parity isomers in these nuclei correspond to a πd5/2 or πg7/2 configuration, in 121Sb and 123Sb respectively, coupled to aligned (h11/2)2 neutrons. The Iπ=19/2- isomeric state in 121Sb is proposed to have a νh11/2 x νd3/2 x πd5/2 configuration. A previously unobserved isomer has been identified in 99Mo at an energy of 3010 keV, decaying with T1/2=18(5) ns. This state is interpreted as an energetically favoured 3 quasi-particle alignment of ν ( d 5/2 g 7/2 ) x π(g 9/2 ) 2 configuration which is observed systematically in the even-Z N=57 isotones

  9. Comparative Autoignition Trends in Butanol Isomers at Elevated Pressure

    KAUST Repository

    Weber, Bryan W.

    2013-03-21

    Autoignition experiments of stoichiometric mixtures of s-, t-, and i-butanol in air have been performed using a heated rapid compression machine (RCM). At compressed pressures of 15 and 30 bar and for compressed temperatures in the range 715-910 K, no evidence of a negative temperature coefficient region in terms of ignition delay response is found. The present experimental results are also compared with previously reported RCM data of n-butanol in air. The order of reactivity of the butanols is n-butanol > s-butanol ≈ i-butanol > t-butanol at the lower pressure but changes to n-butanol > t-butanol > s-butanol > i-butanol at higher pressure. In addition, t-butanol shows preignition heat release behavior, which is especially evident at higher pressures. To help identify the controlling chemistry leading to this preignition heat release, off-stoichiometric experiments are further performed at 30 bar compressed pressure, for t-butanol at φ = 0.5 and φ = 2.0 in air. For these experiments, higher fuel loading (i.e., φ = 2.0) causes greater preignition heat release (as indicated by greater pressure rise) than the stoichiometric or φ = 0.5 cases. Comparison of the experimental ignition delays with the simulated results using two literature kinetic mechanisms shows generally good agreement, and one mechanism is further used to explore and compare the fuel decomposition pathways of butanol isomers. Using this mechanism, the importance of peroxy chemistry in the autoignition of the butanol isomers is highlighted and discussed. © 2013 American Chemical Society.

  10. Conventions and institutions in coordination problems

    NARCIS (Netherlands)

    van der Lecq, S.G.

    1996-01-01

    This survey article starts with a game-theory interpretation of coordination problems that occur in an economy. Three types of games are discussed in which the degree of coordination versus conflict varies. It is shown that game-theoretic techniques for equilibrium selection or securing the highest

  11. Enhanced E3 transitions and mixed configurations for core excited isomers in 210At and 211At

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Steed, C.A.; Byrne, A.P.; Poletti, S.J.; Stuchbery, A.E.; Bark, R.A.

    1986-09-01

    The lifetime and branching ratio of the 19 + isomer in 210 At have been measured. Its enhanced E3 decay and g-factor, and those of the related 39/2 - isomer in 211 At are compared with the results of a semi-empirical shell model calculation which includes couplings to the 3 - octupole vibration, resulting in mixed configurations. Lifetimes were also obtained for the 15 - isomer in 210 At, and he 29/2 + isomer in 209 At

  12. The influence of isomer purity on trap states and performance of organic thin-film transistors.

    Science.gov (United States)

    Diemer, Peter J; Hayes, Jacori; Welchman, Evan; Hallani, Rawad; Pookpanratana, Sujitra J; Hacker, Christina A; Richter, Curt A; Anthony, John E; Thonhauser, Timo; Jurchescu, Oana D

    2017-01-01

    Organic field-effect transistor (OFET) performance is dictated by its composition and geometry, as well as the quality of the organic semiconductor (OSC) film, which strongly depends on purity and microstructure. When present, impurities and defects give rise to trap states in the bandgap of the OSC, lowering device performance. Here, 2,8-difluoro-5,11-bis(triethylsilylethynyl)-anthradithiophene is used as a model system to study the mechanism responsible for performance degradation in OFETs due to isomer coexistence. The density of trapping states is evaluated through temperature dependent current-voltage measurements, and it is discovered that OFETs containing a mixture of syn - and anti -isomers exhibit a discrete trapping state detected as a peak located at ~ 0.4 eV above the valence-band edge, which is absent in the samples fabricated on single-isomer films. Ultraviolet photoelectron spectroscopy measurements and density functional theory calculations do not point to a significant difference in electronic band structure between individual isomers. Instead, it is proposed that the dipole moment of the syn -isomer present in the host crystal of the anti -isomer locally polarizes the neighboring molecules, inducing energetic disorder. The isomers can be separated by applying gentle mechanical vibrations during film crystallization, as confirmed by the suppression of the peak and improvement in device performance.

  13. Chemometric deconvolution of gas chromatographic unresolved conjugated linoleic acid isomers triplet in milk samples.

    Science.gov (United States)

    Blasko, Jaroslav; Kubinec, Róbert; Ostrovský, Ivan; Pavlíková, Eva; Krupcík, Ján; Soják, Ladislav

    2009-04-03

    A generally known problem of GC separation of trans-7;cis-9; cis-9,trans-11; and trans-8,cis-10 CLA (conjugated linoleic acid) isomers was studied by GC-MS on 100m capillary column coated with cyanopropyl silicone phase at isothermal column temperatures in a range of 140-170 degrees C. The resolution of these CLA isomers obtained at given conditions was not high enough for direct quantitative analysis, but it was, however, sufficient for the determination of their peak areas by commercial deconvolution software. Resolution factors of overlapped CLA isomers determined by the separation of a model CLA mixture prepared by mixing of a commercial CLA mixture and CLA isomer fraction obtained by the HPLC semi-preparative separation of milk fatty acids methyl esters were used to validate the deconvolution procedure. Developed deconvolution procedure allowed the determination of the content of studied CLA isomers in ewes' and cows' milk samples, where dominant isomer cis-9,trans-11 is eluted between two small isomers trans-7,cis-9 and trans-8,cis-10 (in the ratio up to 1:100).

  14. Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in ^{254}Rf.

    Science.gov (United States)

    David, H M; Chen, J; Seweryniak, D; Kondev, F G; Gates, J M; Gregorich, K E; Ahmad, I; Albers, M; Alcorta, M; Back, B B; Baartman, B; Bertone, P F; Bernstein, L A; Campbell, C M; Carpenter, M P; Chiara, C J; Clark, R M; Cromaz, M; Doherty, D T; Dracoulis, G D; Esker, N E; Fallon, P; Gothe, O R; Greene, J P; Greenlees, P T; Hartley, D J; Hauschild, K; Hoffman, C R; Hota, S S; Janssens, R V F; Khoo, T L; Konki, J; Kwarsick, J T; Lauritsen, T; Macchiavelli, A O; Mudder, P R; Nair, C; Qiu, Y; Rissanen, J; Rogers, A M; Ruotsalainen, P; Savard, G; Stolze, S; Wiens, A; Zhu, S

    2015-09-25

    Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73) μs have been discovered in the heavy ^{254}Rf nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the K^{π}=8^{-}, ν^{2}(7/2^{+}[624],9/2^{-}[734]) two-quasineutron and the K^{π}=16^{+}, 8^{-}ν^{2}(7/2^{+}[624],9/2^{-}[734])⊗8^{-}π^{2}(7/2^{-}[514],9/2^{+}[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N=150 isotones. The four-quasiparticle isomer is longer lived than the ^{254}Rf ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1) μs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state.

  15. Structural-based differences in ecotoxicity of benzoquinoline isomers to the zebra mussel (Dreissena polymorpha)

    Energy Technology Data Exchange (ETDEWEB)

    Kraak, M.H.S.; Wijnands, P.; Govers, H.A.J.; Admiraal, W.; Voogt, P. de [Univ. of Amsterdam (Netherlands)

    1997-10-01

    Effects of four benzoquinoline isomers on the filtration rate of the zebra mussel (Dreissena polymorpha) were analyzed, to study the effect of minor differences in chemical structure on adverse biological effects. Filtration rates were measured after 48 h of exposure to different concentrations of acridine, phenanthridine, benzo[f]quinoline, and benzo[h]quinoline in the water. The 50% effective concentration (EC50) values for filtration rate of the four isomers differed significantly. Effects increased in the order benzo[f], -[h], -[b], and -[c]quinoline, and the difference between the most toxic isomer and the least toxic isomer amounted to a factor of 30. Attempts were made to relate these differences in toxicity to the structure of the isomers. Size- or topology-related molecular descriptors provided insufficient resolution to distinguish between the benzoquinoline isomers, and none of the electronic descriptors separately provided a significant correlation with the observed effects. In an alternative approach, molecular shape, accessibility, and minimum agent-macromolecule distance were used to represent repulsive and attractive forces between the benzoquinoline isomers and biological membranes. This approach could tentatively explain the observed effects and is supported by a high correlation between the EC50 data and the reversed-phase C18-HPLC behavior of the benzoquinolines (k{sub 0}), which is likely to be governed by similar processes.

  16. Membrane Materials and Technology for Xylene Isomers Separation and Isomerization via Pervaporation

    KAUST Repository

    Bilaus, Rakan

    2014-11-01

    P-xylene is one of the highly influential commodities in the petrochemical industry. It is used to make 90% of the world’s third largest plastic production, polyethylene terephthalate (PET). With a continuously increasing demand, the current technology’s high energy intensity has become a growing concern. Membrane separation technology is a potential low-energy alternative. Polymeric membranes were investigated in a pervaporation experiment to separate xylene isomers. Polymers of intrinsic microporosity (PIMs) as well as polyimides (PIM-PI), including thermally cross-linked PIM-1, PIM-6FDA-OH and thermally-rearranged PIM-6FDA-OH were investigated as potential candidates. Although they exhibited extremely high permeability to xylenes, selectivity towards p-xylene was poor. This was attributed to the polymers low chemical resistance which was apparent in their strong tendency to swell in xylenes. Consequently, a perfluoro-polymer, Teflon AF 2400, with a high chemical resistance was tested, which resulted in a slightly improved selectivity. A super acid sulfonated perfluoro-polymer (Nafion-H) was used as reactive membrane for xylenes isomerization. The membrane exhibited high catalytic activity, resulting in 19.5% p-xylene yield at 75ᵒC compared to 20% p-xylene yield at 450ᵒC in commercial fixed bed reactors. Nafion-H membrane outperforms the commercial technology with significant energy savings.

  17. Evaluation of D-isomers of 4-borono-2-18F-fluoro-phenylalanine and O-11C-methyl-tyrosine as brain tumor imaging agents: a comparative PET study with their L-isomers in rat brain glioma.

    Science.gov (United States)

    Kanazawa, Masakatsu; Nishiyama, Shingo; Hashimoto, Fumio; Kakiuchi, Takeharu; Tsukada, Hideo

    2018-06-13

    The potential of the D-isomerization of 4-borono-2- 18 F-fluoro-phenylalanine ( 18 F-FBPA) to improve its target tumor to non-target normal brain tissue ratio (TBR) was evaluated in rat brain glioma and compared with those of L- and D- 11 C-methyl-tyrosine ( 11 C-CMT). The L- or D-isomer of 18 F-FBPA was injected into rats through the tail vein, and their whole body kinetics and distributions were assessed using the tissue dissection method up to 90 min after the injection. The kinetics of L- and D- 18 F-FBPA or L- and D- 11 C-CMT in the C-6 glioma-inoculated rat brain were measured for 90 or 60 min, respectively, using high-resolution animal PET, and their TBRs were assessed. Tissue dissection analyses showed that D- 18 F-FBPA uptake was significantly lower than that of L- 18 F-FBPA in the brain and abdominal organs, except for the kidney and bladder, reflecting the faster elimination rate of D- 18 F-FBPA than L- 18 F-FBPA from the blood to the urinary tract. PET imaging using 18 F-FBPA revealed that although the brain uptake of D- 18 F-FBPA was significantly lower than that of L- 18 F-FBPA, the TBR of the D-isomer improved to 6.93 from 1.45 for the L-isomer. Similar results were obtained with PET imaging using 11 C-CMT with a smaller improvement in TBR to 1.75 for D- 11 C-CMT from 1.33 for L- 11 C-CMT. The present results indicate that D- 18 F-FBPA is a better brain tumor imaging agent with higher TBR than its original L-isomer and previously reported tyrosine-based PET imaging agents. This improved TBR of D- 18 F-FBPA without any pre-treatments, such as tentative blood-brain barrier disruption using hyperosmotic agents or sonication, suggests that the D-isomerization of BPA results in the more selective accumulation of 10 B in tumor cells that is more effective and less toxic than conventional L-BPA.

  18. Identification of (2-aminopropyl)indole positional isomers in forensic samples.

    Science.gov (United States)

    Scott, Kenneth R; Power, John D; McDermott, Seán D; O'Brien, John E; Talbot, Brian N; Barry, Michael G; Kavanagh, Pierce V

    2014-01-01

    In 2012, 5-(2-aminopropyl)indole (5-API, 5-IT) was reported by Norwegian authorities to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) via the Early Warning System (EWS). The 3- isomer, 3-(2-aminopropyl)indole (3-API, AMT, alpha-methyltryptamine), has been available on the recreational drugs market for a somewhat longer time, having first been reported to the EMCDDA by Finnish authorities in 2001. Both isomers are available from online vendors of 'legal highs'. Recently, three forensic drug cases (two tablets and one powder) were presented for routine analysis and the active constituent was tentatively identified as an API isomer. The six positional isomers (2-, 3-, 4-, 5-, 6- and 7-(2-aminopropyl)indoles) were synthesized and analyses by a combination gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS) showed that these could be readily discriminated thus facilitating the identification of 3-API in the tablets and 5-API in the powder. With exception of 5- and 6-APIs, which co-eluted, it was found possible to separate the isomers by GC without derivatization. LC separation also proved to be a feasible method for the discrimination of the isomers. Although the 2- and 7- isomers were not fully resolved by LC, it was found possible to distinguish them using their product ion spectra as the 2- isomer produced the m/z 132 fragment ion formed by loss of vinylamine, whereas the 7- isomer formed m/z 158 through loss of methylamine. In the synthesis 2-API, a novel tricyclic by-product was formed in an annulation reaction where the reaction solvent, tetrahydrofuran, was incorporated into the molecule. Copyright © 2013 John Wiley & Sons, Ltd.

  19. Photoactive devices including porphyrinoids with coordinating additives

    Science.gov (United States)

    Forrest, Stephen R; Zimmerman, Jeramy; Yu, Eric K; Thompson, Mark E; Trinh, Cong; Whited, Matthew; Diev, Vlacheslav

    2015-05-12

    Coordinating additives are included in porphyrinoid-based materials to promote intermolecular organization and improve one or more photoelectric characteristics of the materials. The coordinating additives are selected from fullerene compounds and organic compounds having free electron pairs. Combinations of different coordinating additives can be used to tailor the characteristic properties of such porphyrinoid-based materials, including porphyrin oligomers. Bidentate ligands are one type of coordinating additive that can form coordination bonds with a central metal ion of two different porphyrinoid compounds to promote porphyrinoid alignment and/or pi-stacking. The coordinating additives can shift the absorption spectrum of a photoactive material toward higher wavelengths, increase the external quantum efficiency of the material, or both.

  20. Effects of high-order deformation on high-K isomers in superheavy nuclei

    International Nuclear Information System (INIS)

    Liu, H. L.; Bertulani, C. A.; Xu, F. R.; Walker, P. M.

    2011-01-01

    Using, for the first time, configuration-constrained potential-energy-surface calculations with the inclusion of β 6 deformation, we find remarkable effects of the high-order deformation on the high-K isomers in 254 No, the focus of recent spectroscopy experiments on superheavy nuclei. For shapes with multipolarity six, the isomers are more tightly bound and, microscopically, have enhanced deformed shell gaps at N=152 and Z=100. The inclusion of β 6 deformation significantly improves the description of the very heavy high-K isomers.

  1. pH-dependent fluorescence property of methyl red isomers in silver colloids

    International Nuclear Information System (INIS)

    Wong, Jian-How; Lee, Szetsen

    2012-01-01

    We report the use of silver (Ag) colloids in the spectroscopic differentiation of methyl red (MR) isomers (o-MR, m-MR, p-MR) by fluorescence techniques. Under different pH conditions, the formation of MR-Ag complex has an impact on the fluorescence band shapes and peak position shift, which are distinctive between MR isomers. The fluorescence quenching between 400 and 414 nm accompanied by simultaneous enhancement between 510 and 541 nm changes with pH are closely related to energy transfer efficiency and the interaction between the MR isomers and the Ag surface.

  2. Solvation effect on isomer stability and electronic structures of protonated serotonin

    Science.gov (United States)

    Omidyan, Reza; Amanollahi, Zohreh; Azimi, Gholamhassan

    2017-07-01

    Microsolvation effect on geometry and transition energies of protonated serotonin has been investigated by MP2 and CC2 quantum chemical methods. Also, conductor-like screening model, implemented recently in the MP2 and ADC(2) methods, was examined to address the bulk water environment's effect on the isomer stability and electronic transition energies of protonated serotonin. It has been predicted that the dipole moment of gas phase isomers plays the main role on the isomer stabilization in water solution and electronic transition shifts. Also, both red- and blue-shift effects have been predicted to take place on electronic transition energies, upon hydration.

  3. Isomer-specific regulation of metabolism and PPARgamma signaling by CLA in human preadipocytes

    DEFF Research Database (Denmark)

    Brown, J Mark; Boysen, Maria Sandberg; Jensen, Søren Skov

    2003-01-01

    Trans-10,cis-12 conjugated linoleic acid (CLA) has previously been shown to be the CLA isomer responsible for CLA-induced reductions in body fat in animal models, and we have shown that this isomer, but not the cis-9,trans-11 CLA isomer, specifically decreased triglyceride (TG) accumulation...... transporter 4 gene expression. Furthermore, trans-10,cis-12 CLA reduced oleic acid uptake and oxidation when compared with all other treatments. In parallel to CLA's effects on metabolism, trans-10,cis-12 CLA decreased, whereas cis-9,trans-11 CLA increased, the expression of peroxisome proliferator...

  4. Histidine, lysine, and arginine radical cations: isomer control via the choice of auxiliary ligand (L) in the dissociation of [CuII(L)amino acid]*2+ complexes.

    Science.gov (United States)

    Ke, Yuyong; Zhao, Junfang; Verkerk, Udo H; Hopkinson, Alan C; Siu, K W Michael

    2007-12-27

    Histidine, lysine, and arginine radical cations have been generated through collision-induced dissociation (CID) of complexes [CuII(auxiliary ligand)namino acid]*2+, using tri-, bi-, as well as monodentate auxiliary ligands. On the basis of the observed CID products, the existence of two isomeric amino-acid populations is postulated. The Type 1 radical cations of histidine and lysine, stable on the mass spectrometer time scale, were found to lose water, followed by the loss of carbon monoxide under more energetic CID conditions. The arginine Type 1 radical cation behaved differently, losing dehydroalanine. The Type 2 radical cations were metastable and easily fragmented by the loss of carbon dioxide, effectively preventing direct observation. Type 1 radical cations are proposed to result from neutral (canonical) amino-acid coordination, whereas Type 2 radical cations are from zwitterionic amino-acid coordination to copper in the complex. The ratio of Type 1/Type 2 ions was found to be dependent on the auxiliary ligand, providing a method of controlling which radical cation would be formed primarily. Density functional calculations at B3LYP/6-311++G(d,p) have been used to determine the relative energies of five His*+ isomers. Barriers against interconversion between the isomers and against fragmentation have been calculated, giving insight as to why the Type 1 ions are stable, while only fragmentation products of the Type 2 ions are observable under CID conditions.

  5. Toroidal high-spin isomers in the nucleus 304120

    Science.gov (United States)

    Staszczak, A.; Wong, Cheuk-Yin; Kosior, A.

    2017-05-01

    Background: Strongly deformed oblate superheavy nuclei form an intriguing region where the toroidal nuclear structures may bifurcate from the oblate spheroidal shape. The bifurcation may be facilitated when the nucleus is endowed with a large angular moment about the symmetry axis with I =Iz . The toroidal high-K isomeric states at their local energy minima can be theoretically predicted using the cranked self-consistent Skyrme-Hartree-Fock method. Purpose: We use the cranked Skyrme-Hartree-Fock method to predict the properties of the toroidal high-spin isomers in the superheavy nucleus 120304184. Method: Our method consists of three steps: First, we use the deformation-constrained Skyrme-Hartree-Fock-Bogoliubov approach to search for the nuclear density distributions with toroidal shapes. Next, using these toroidal distributions as starting configurations, we apply an additional cranking constraint of a large angular momentum I =Iz about the symmetry z axis and search for the energy minima of the system as a function of the deformation. In the last step, if a local energy minimum with I =Iz is found, we perform at this point the cranked symmetry- and deformation-unconstrained Skyrme-Hartree-Fock calculations to locate a stable toroidal high-spin isomeric state in free convergence. Results: We have theoretically located two toroidal high-spin isomeric states of 120304184 with an angular momentum I =Iz=81 ℏ (proton 2p-2h, neutron 4p-4h excitation) and I =Iz=208 ℏ (proton 5p-5h, neutron 8p-8h) at the quadrupole moment deformations Q20=-297.7 b and Q20=-300.8 b with energies 79.2 and 101.6 MeV above the spherical ground state, respectively. The nuclear density distributions of the toroidal high-spin isomers 120304184(Iz=81 ℏ and 208 ℏ ) have the maximum density close to the nuclear matter density, 0.16 fm-3, and a torus major to minor radius aspect ratio R /d =3.25 . Conclusions: We demonstrate that aligned angular momenta of Iz=81 ℏ and 208 ℏ arising from

  6. Distribution and fate of HCH isomers and DDT metabolites in a tropical environment–case study Cameron Highlands–Malaysia

    Directory of Open Access Journals (Sweden)

    Saadati Naghmeh

    2012-11-01

    Full Text Available Abstract Background The serious impact effects of persistent organic pollutants such as organochlorine pesticides, especially dichlorodiphenyltrichloroethane family (DDTs and hexachlorocyclohexane isomers (HCHs have been causing widespread concern, despite effective control on their manufacturing, agricultural and vector practices. In that, in addition to the previous global limitations on DDTs usage, α-HCH, β-HCH and lindane have also became an on-going topic of global relevance based on the latest Stockholm Convention list on 10th of May 2009. Concentrations of dichlorodiphenyltrichloroethane family (DDTs and hexachlorocyclohexane isomers (HCHs were determined by GC-ECD in Cameron Highlands, the main vegetables and flowers farming area in Malaysia as an agricultural tropical environment. A total of 112 surface water and sediment samples at eight points were collected along the main rivers in the area namely Telom and Bertam in the dry and wet seasons of 2011. Results Total concentration of HCH isomers ranged from not detected to 25.03 ng/L in the water (mean of 5.55 ±6.0 ng/L, while, it ranged from 0.002 to 59.17 ng/g (mean of 8.06±9.39 ng/g in the sediment. Total concentration of DDT and its metabolites in the water samples varied from not detected to 8.0 ng/L (mean of 0.90±1.66 ng/g, whereas, it was in the range of 0.025 to 23.24 ng/g (mean of 2.55±4.0 ng/g in the surface sediment samples. The ratio of HCHs and DDTs composition indicated an obvious historical usage and new inputs of these pesticides. Among alpha, beta, gamma and delta isomers of HCH, gamma was the most dominant component in the sediment and water as well. Some seasonal variations in the level of selected pesticides were noted. Conclusions The results illustrate distribution, behaviour and fate of HCHs, and DDTs have closely connected with topological and meteorological properties of the area beyond their chemical characterizations. The features of environmental

  7. Distribution and fate of HCH isomers and DDT metabolites in a tropical environment-case study Cameron Highlands-Malaysia.

    Science.gov (United States)

    Saadati, Naghmeh; Abdullah, Md Pauzi; Zakaria, Zuriati; Rezayi, Majid; Hosseinizare, Nader

    2012-11-07

    The serious impact effects of persistent organic pollutants such as organochlorine pesticides, especially dichlorodiphenyltrichloroethane family (DDTs) and hexachlorocyclohexane isomers (HCHs) have been causing widespread concern, despite effective control on their manufacturing, agricultural and vector practices. In that, in addition to the previous global limitations on DDTs usage, α-HCH, β-HCH and lindane have also became an on-going topic of global relevance based on the latest Stockholm Convention list on 10th of May 2009. Concentrations of dichlorodiphenyltrichloroethane family (DDTs) and hexachlorocyclohexane isomers (HCHs) were determined by GC-ECD in Cameron Highlands, the main vegetables and flowers farming area in Malaysia as an agricultural tropical environment. A total of 112 surface water and sediment samples at eight points were collected along the main rivers in the area namely Telom and Bertam in the dry and wet seasons of 2011. Total concentration of HCH isomers ranged from not detected to 25.03 ng/L in the water (mean of 5.55 ±6.0 ng/L), while, it ranged from 0.002 to 59.17 ng/g (mean of 8.06±9.39 ng/g) in the sediment. Total concentration of DDT and its metabolites in the water samples varied from not detected to 8.0 ng/L (mean of 0.90±1.66 ng/g), whereas, it was in the range of 0.025 to 23.24 ng/g (mean of 2.55±4.0 ng/g) in the surface sediment samples. The ratio of HCHs and DDTs composition indicated an obvious historical usage and new inputs of these pesticides. Among alpha, beta, gamma and delta isomers of HCH, gamma was the most dominant component in the sediment and water as well. Some seasonal variations in the level of selected pesticides were noted. The results illustrate distribution, behaviour and fate of HCHs, and DDTs have closely connected with topological and meteorological properties of the area beyond their chemical characterizations. The features of environmental circumstances exceed one or more of these characters in

  8. Coordinating Group report

    International Nuclear Information System (INIS)

    1994-01-01

    In December 1992, western governors and four federal agencies established a Federal Advisory Committee to Develop On-site Innovative Technologies for Environmental Restoration and Waste Management (the DOIT Committee). The purpose of the Committee is to advise the federal government on ways to improve waste cleanup technology development and the cleanup of federal sites in the West. The Committee directed in January 1993 that information be collected from a wide range of potential stakeholders and that innovative technology candidate projects be identified, organized, set in motion, and evaluated to test new partnerships, regulatory approaches, and technologies which will lead to improve site cleanup. Five working groups were organized, one to develop broad project selection and evaluation criteria and four to focus on specific contaminant problems. A Coordinating Group comprised of working group spokesmen and federal and state representatives, was set up to plan and organize the routine functioning of these working groups. The working groups were charged with defining particular contaminant problems; identifying shortcomings in technology development, stakeholder involvement, regulatory review, and commercialization which impede the resolution of these problems; and identifying candidate sites or technologies which could serve as regional innovative demonstration projects to test new approaches to overcome the shortcomings. This report from the Coordinating Group to the DOIT Committee highlights the key findings and opportunities uncovered by these fact-finding working groups. It provides a basis from which recommendations from the DOIT Committee to the federal government can be made. It also includes observations from two public roundtables, one on commercialization and another on regulatory and institutional barriers impeding technology development and cleanup

  9. Standard molar enthalpy of formation of methoxyacetophenone isomers

    International Nuclear Information System (INIS)

    Amaral, Luísa M.P.F.; Morais, Victor M.F.; Ribeiro da Silva, Manuel A.V.

    2014-01-01

    Highlights: • Experimental and computational energetic study of methoxyacetophenone isomers. • Enthalpies of formation and phase transition determined by calorimetric techniques. • Quantum chemical calculations allowed estimation of enthalpies of formation. • Structure and energy correlations were established. - Abstract: Values of the standard (p o = 0.1 MPa) molar enthalpy of formation of 2′-, 3′- and 4′-methoxyacetophenones were derived from their standard molar energy of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry. The Calvet high temperature vacuum sublimation technique was used to measure the enthalpies of sublimation/vaporization of the compounds studied. The standard molar enthalpies of formation of the three compounds, in the gaseous phase, at T = 298.15 K, have been derived from the corresponding standard molar enthalpies of formation in the condensed phase and the standard molar enthalpies for the phase transition. The results obtained are −(232.0 ± 2.5), −(237.7 ± 2.7) and −(241.1 ± 2.1) kJ · mol −1 for 2′-, 3′- and 4′-methoxyacetophenone, respectively. Standard molar enthalpies of formation were also estimated from different methodologies: the Cox scheme as well as two different computational approaches using density functional theory-based B3LYP and the multilevel G3 methodologies

  10. Experimental standard molar enthalpies of formation of some methylbenzenediol isomers

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Lobo Ferreira, Ana I.M.C.

    2009-01-01

    The present work is part of a research program on the energetics of formation of alkyl substituted benzenediols, aiming the study of the enthalpic effect of the introduction of methyl substituents into benzenediols. In this work we present the results of the thermochemical research on 2-methylresorcinol, 3-methylresorcinol, 4-methylresorcinol, and methylhydroquinone. The standard (p 0 =0.1MPa) molar enthalpies of formation, in the crystalline phase, at T = 298.15 K, of the compounds mentioned above were derived from their standard massic energies of combustion, measured by static-bomb combustion calorimetry, while the standard molar enthalpies of sublimation of those compounds were obtained by the temperature dependence of their vapour pressures determined by the Knudsen effusion technique. From experimental values, the standard molar enthalpies of formation of the studied methylbenzenediols in the gaseous phase, at T = 298.15 K were then derived. The results are interpreted in terms of structural contributions to the energetics of the substituted benzenediols and compared with the same parameters estimated from the Cox Scheme. Moreover, the standard (p 0 =0.1MPa) molar enthalpies, entropies, and Gibbs energies of sublimation, at T = 298.15 K, were derived for the four isomers of methylbenzenediols.

  11. Occurrence of β-N-methylamino-l-alanine (BMAA and Isomers in Aquatic Environments and Aquatic Food Sources for Humans

    Directory of Open Access Journals (Sweden)

    Emilie Lance

    2018-02-01

    Full Text Available The neurotoxin β-N-methylamino-l-alanine (BMAA, a non-protein amino acid produced by terrestrial and aquatic cyanobacteria and by micro-algae, has been suggested to play a role as an environmental factor in the neurodegenerative disease Amyotrophic Lateral Sclerosis-Parkinsonism-Dementia complex (ALS-PDC. The ubiquitous presence of BMAA in aquatic environments and organisms along the food chain potentially makes it public health concerns. However, the BMAA-associated human health risk remains difficult to rigorously assess due to analytical challenges associated with the detection and quantification of BMAA and its natural isomers, 2,4-diamino butyric acid (DAB, β-amino-N-methyl-alanine (BAMA and N-(2-aminoethyl glycine (AEG. This systematic review, reporting the current knowledge on the presence of BMAA and isomers in aquatic environments and human food sources, was based on a selection and a score numbering of the scientific literature according to various qualitative and quantitative criteria concerning the chemical analytical methods used. Results from the best-graded studies show that marine bivalves are to date the matrix containing the higher amount of BMAA, far more than most fish muscles, but with an exception for shark cartilage. This review discusses the available data in terms of their use for human health risk assessment and identifies knowledge gaps requiring further investigations.

  12. Ion mobility studies of carbohydrates as group I adducts: isomer specific collisional cross section dependence on metal ion radius.

    Science.gov (United States)

    Huang, Yuting; Dodds, Eric D

    2013-10-15

    Carbohydrates play numerous critical roles in biological systems. Characterization of oligosaccharide structures is essential to a complete understanding of their functions in biological processes; nevertheless, their structural determination remains challenging in part due to isomerism. Ion mobility spectrometry provides the means to resolve gas phase ions on the basis of their shape-to-charge ratios, thus providing significant potential for separation and differentiation of carbohydrate isomers. Here, we report on the determination of collisional cross sections for four groups of isomeric carbohydrates (including five isomeric disaccharides, four isomeric trisaccharides, two isomeric pentasaccharides, and two isomeric hexasaccharides) as their group I metal ion adducts (i.e., [M + Li](+), [M + Na](+), [M + K](+), [M + Rb](+), and [M + Cs](+)). In all, 65 collisional cross sections were measured, the great majority of which have not been previously reported. As anticipated, the collisional cross sections of the carbohydrate metal ion adducts generally increase with increasing metal ion radius; however, the collisional cross sections were found to scale with the group I cation size in isomer specific manners. Such measurements are of substantial analytical value, as they illustrate how the selection of charge carrier influences carbohydrate ion mobility determinations. For example, certain pairs of isomeric carbohydrates assume unique collisional cross sections upon binding one metal ion, but not another. On the whole, these data suggest a role for the charge carrier as a probe of carbohydrate structure and thus have significant implications for the continued development and application of ion mobility spectrometry for the distinction and resolution of isomeric carbohydrates.

  13. Occurrence of β-N-methylamino-l-alanine (BMAA) and Isomers in Aquatic Environments and Aquatic Food Sources for Humans.

    Science.gov (United States)

    Lance, Emilie; Arnich, Nathalie; Maignien, Thomas; Biré, Ronel

    2018-02-14

    The neurotoxin β- N -methylamino-l-alanine (BMAA), a non-protein amino acid produced by terrestrial and aquatic cyanobacteria and by micro-algae, has been suggested to play a role as an environmental factor in the neurodegenerative disease Amyotrophic Lateral Sclerosis-Parkinsonism-Dementia complex (ALS-PDC). The ubiquitous presence of BMAA in aquatic environments and organisms along the food chain potentially makes it public health concerns. However, the BMAA-associated human health risk remains difficult to rigorously assess due to analytical challenges associated with the detection and quantification of BMAA and its natural isomers, 2,4-diamino butyric acid (DAB), β-amino- N -methyl-alanine (BAMA) and N -(2-aminoethyl) glycine (AEG). This systematic review, reporting the current knowledge on the presence of BMAA and isomers in aquatic environments and human food sources, was based on a selection and a score numbering of the scientific literature according to various qualitative and quantitative criteria concerning the chemical analytical methods used. Results from the best-graded studies show that marine bivalves are to date the matrix containing the higher amount of BMAA, far more than most fish muscles, but with an exception for shark cartilage. This review discusses the available data in terms of their use for human health risk assessment and identifies knowledge gaps requiring further investigations.

  14. Study on Separation of Structural Isomer with Magneto-Archimedes method

    Science.gov (United States)

    Kobayashi, T.; Mori, T.; Akiyama, Y.; Mishima, F.; Nishijima, S.

    2017-09-01

    Organic compounds are refined by separating their structural isomers, however each separation method has some problems. For example, distillation consumes large energy. In order to solve these problems, new separation method is needed. Considering organic compounds are diamagnetic, we focused on magneto-Archimedes method. With this method, particle mixture dispersed in a paramagnetic medium can be separated in a magnetic field due to the difference of the density and magnetic susceptibility of the particles. In this study, we succeeded in separating isomers of phthalic acid as an example of structural isomer using MnCl2 solution as the paramagnetic medium. In order to use magneto-Archimedes method for separating materials for food or medicine, we proposed harmless medium using oxygen and fluorocarbon instead of MnCl2 aqueous solution. As a result, the possibility of separating every structural isomer was shown.

  15. The Creation and Destruction of Hf-178m2 Isomer by Neutron Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsiao-Hua [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); TechSource, Inc. Los Alamos, NM (United States); Talbert, Willard L. [TechSource, Inc. Los Alamos, NM (United States); Ward, Tom [TechSource, Inc. Los Alamos, NM (United States)

    2017-03-06

    The property of the isomer state in 178m2Hf was an interesting topic in nuclear structure studies during the time period 1970 to 1980. The state at 2.446 MeV with spin and parity Kπ = 16+, has a half-life of 31 years. The isomer is described as a four-quasi-particle state. The K forbidden deexcitatiion by gamma emission is the reason for long half-life. During 1980, the isomer became a troublesome issue for radiation safety workers, because this isomer can also be produced in the first wall of a fussion reactor containing tungsten and also in a tungsten beam stop of a high-energy accelerator.

  16. Identifying Tm-C82 isomers with density functional theory calculations

    International Nuclear Information System (INIS)

    Zheng Limin; He Hongqing; Yang Minghui; Zeng Qun; Yang Mingli

    2010-01-01

    Density functional theory calculations have been performed to study the geometrical and electronic properties of endohedral metallofullerene Tm-C 82 isomers. Three energetically favorable isomers (with C s , C 2 and C 2v symmetry, respectively) are identified which are consistent with the nuclear magnetic resonance (NMR) observations. The simulated ultraviolet photoelectron spectra (UPS) based on the three structures agree well with the measurements. Particularly, the parent cage of the experimentally observed Tm-C 82 isomer with C s symmetry is newly assigned, which matches the experiments better than early assignments. In addition, strong interaction between an endohedral Tm atom and the C 82 cage is discussed and is thought to be responsible for the dramatic change in the relative stability of C 82 isomers when Tm is encapsulated.

  17. Conformational inversion-topomerization mechanism of ethylcyclohexyl isomers and its role in combustion kinetics

    KAUST Repository

    Bian, Huiting; Wang, Zhandong; Sun, Jinhua; Zhang, Feng

    2016-01-01

    the formation of subsequent decomposition products. In this work, the conformational inversion-topomerization mechanism and H-migration reactions for six ethylcyclohexyl radical isomers were systematically studied by ab initio calculations and the transition

  18. G-factor for the K-6, Jsup(π) = 6+ isomer in 178Hf

    International Nuclear Information System (INIS)

    Faestermann, T.; Haeusser, O.; Ward, D.; Andrews, H.R.; Alexander, T.K.; Horn, D.

    1978-01-01

    High-K isomers are prevalent towards the end of the rare-earth region of deformed nuclei where the valence particles fill high Ω orbitals. Very little is known about the g-factors for these isomers mainly because in the half-life range encountered, 50 ns-50 μs, quadrupole and paramagnetic relaxation effects can destroy the nuclear alignment very rapidly. In 178 Hf a Isub(π)K=6 + 6 isomer with a half-life of 78 ns has recently been found. It decays predominantly to the ground band (K=O) 6 + and 4 + levels with gamma rays of 921.8 keV and 1247.3 keV respectively. The authors have measured the g-factor of this isomer with the method of perturbed angular distributions. (Auth.)

  19. Membrane Materials and Technology for Xylene Isomers Separation and Isomerization via Pervaporation

    KAUST Repository

    Bilaus, Rakan

    2014-01-01

    technology’s high energy intensity has become a growing concern. Membrane separation technology is a potential low-energy alternative. Polymeric membranes were investigated in a pervaporation experiment to separate xylene isomers. Polymers of intrinsic

  20. Three- and five-quasiparticle isomers, rotational bands and residual interactions in 175Hf

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Walker, P.M.

    1980-03-01

    Two 3-quasiparticle isomers with spins, parities and half lives of 19/2 + , 1.1 μ and 23/2 - , 1.2 ns have been identified at 1433 and 1766 keV in 175 Hf. A third isomer possibly 35/2 - with a 1.2 μs half-life is found at 3015 keV. The first two are characterised as a 7/2 + (633) neutron coupled to the known 6 + and 8 - 2-proton isomers of the core nuclei. Rotational bands based on the 3-qp isomers are highly perturbed, due to Coriolis mixing, and their structure is reproduced in a band mixing calculation. The energy depression of the 3-quasiparticle states relative to the 2-quasiproton core states is attributed mainly to the residual proton-neutron interaction, and possibly also to blocking effects through neutron admixtures

  1. Isomer shift and magnetic moment of the long-lived 1/2$^{+}$ isomer in $^{79}_{30}$Zn$_{49}$: signature of shape coexistence near $^{78}$Ni

    CERN Document Server

    Yang, X.F.; Xie, L.; Babcock, C.; Billowes, J.; Bissell, M.L.; Blaum, K.; Cheal, B.; Flanagan, K.T.; Garcia Ruiz, R. F.; Gins, W.; Gorges, C.; Grob, L.K.; Heylen, H.; Kaufmann, S.; Kowalska, M.; Kraemer, J.; Malbrunot-Ettenauer, S.; Neugart, R.; Neyens, G.; Nörtershäuser, W.; Papuga, J.; Sánchez, R.; Yordanov, D.T.

    2016-01-01

    Collinear laser spectroscopy has been performed on the $^{79}_{30}$Zn$_{49}$ isotope at ISOLDE-CERN. The existence of a long-lived isomer with a few hundred milliseconds half-life was confirmed, and the nuclear spins and moments of the ground and isomeric states in $^{79}$Zn as well as the isomer shift were measured. From the observed hyperfine structures, spins $I = 9/2$ and $I = 1/2$ are firmly assigned to the ground and isomeric states. The magnetic moment $\\mu$ ($^{79}$Zn) = $-$1.1866(10) $\\mu_{\\rm{N}}$, confirms the spin-parity $9/2^{+}$ with a $\

  2. Discovery of a 7.6-hour high-spin isomer of einsteinium-256

    International Nuclear Information System (INIS)

    Hoffman, D.C.; Daniels, W.R.; Wilhelmy, J.B.; Bunker, M.E.; Starner, J.W.; Jackson, S.V.; Lougheed, R.W.; Landrum, J.H.

    1976-01-01

    A 7.6-hour, beta-emitting isomer of 256 Es has been produced via the (t,p) reaction by bombarding /sup 254g/Es with 16-MeV tritons. No evidence for an alpha branch was found. A number of gamma rays were observed, on the basis of which a partial decay scheme is proposed. It is concluded that the isomer has spin 7 or 8

  3. Study on gamma-ray transitions induced in nuclear spin isomers by X-rays

    International Nuclear Information System (INIS)

    Yang Tianli; Hao Fanhua; Liu Xiaoya; Gong Jian

    2005-10-01

    The development of induced X-ray has been summarized for high spin isomer. the radiation model, transition mechanism and experiment plan have been introduced. The experiments about isomers 180m Ta and 178m2 Hf have been narrated in detail respectively, and the analysis between those results have been obtained. The reasonable theoretical frame and good experimental data have offered the powerful technique base for pumping γ-ray laser with low energy. (authors)

  4. Magnetic moments of ns-isomers in 105Ag and 103Pd

    International Nuclear Information System (INIS)

    Schneider, L.; Kaeubler, L.; Prade, H.; Hagemann, U.; Story, F.

    1979-01-01

    In recent years a considerable amount of experimental work has been done in order to study the structure of odd-A transitional nuclei around Z=50. In order to obtain additional experimental information on excited states in 105 Ag and 103 Pd the magnetic moments of the 15/2 + isomer in 105 Ag and the 11/2 - isomer in 103 Pd were determined. (author)

  5. Studies on the decay of high-spin isomers in the W and Os isotopes

    International Nuclear Information System (INIS)

    Kraemer-Flecken, A.

    1988-01-01

    From the two experiments performed on the nucleus 180 Os the properties of the new high-spin isomer could be found. The excitation energy amounts to 5208 keV and the spin of the isomer amounts probably to I=19ℎ. The new measured half-life amounts to T 1/2 =41±10 ns. It is populated with an intensity of 1.6±0.4% relative to the (4 + → 2 +) transition in the Yrast band in an experiment with out use of the recoil-shadow technique. A preliminary decay scheme could be established from the sum spectra and exhibits similarities with the decay of the high-spin isomer in 182 Os. From the analysis of the experiment on the nucleus 178 W a new isomer with an excitation energy of 5271 keV and a half-life of T 1/2 =39±10 ns could be identified. The spin of the level has been determined to I=20±1. The half-life of the 3527 keV isomer has been determined to T 1/2 =28±4 ns. The spin of the isomer could be determined from the analysis of DCO ratios to I π =14 - . The configuration of the isomer could be fixed to ν6 + 5/2 - 5 512 7 x 7/2 5 514 7 +π8 - 7/2 + 5 404 7 x 9/2 5 514 7 because of the comparison with the 14 - isomer in 176 Hf and the comparison of the excitation energy for certain configurations with I π =14 - . (orig./HSI)

  6. Isomer effect on the near-infrared electrochromism of anthraquinone imides

    International Nuclear Information System (INIS)

    Yao, Bin; Chen, Fengkun; Jiang, Hong; Zhang, Jie; Wan, Xinhua

    2015-01-01

    Graphical abstract: Display Omitted - Highlights: • Two pairs of unsubstituted isomers (Ia and Ib) and nitro-substituted isomers (IIa and IIb) of anthraquinone imides (AQIs), which are a unique type of cathodically-colouring NIR electrochromic materials bearing both quinone and imide moieties, were synthesized. • Isomer effect on the NIR electrochromism of n-type optoelectric materials was first approached. • A meaningful reference to design cathodically active NIR EC materials, in which the molecular planarity and the orientation of polar groups are two key elements must to be carefully considered, is provided. - Abstract: To deeply explore the interplay between molecular structure and near-infrared electrochromism of anthraquinone imides, two pairs of unsubstituted isomers (Ia and Ib) and nitro-substituted isomers (IIa and IIb) of anthraquinone imides were synthesized, in which the molecules Ia and IIa took more linear shapes than Ib and IIb. Cyclic voltammetry and spectroelectrochemistry were combined to investigate their electrochemical properties. Cyclic voltammetry showed that Ib and IIb revealed decreased first reduction potentials and low cyclic stability compared to their isomers, indicating that the isomerization weakened the stabilization effect. Upon one-electron reduction, both the absorption wavelengths and absorption intensities of radical anions were greatly dependent on the structures of isomers. The radical anions of Ia, IIa, and IIb illustrated NIR absorptions peaked at 820, 1260, and 1380 nm, respectively, but that of Ib exhibited only weak absorption in the visible region centered at 660 nm. Gaussian calculations suggested that the electrons were delocalized over the whole molecular skeletons of Ia and IIa radical anions, but the effective conjugation length was interrupted on the imide section in both Ib and IIb. The isomer effects on the effective conjugation length and electron density distribution were considered to rationalize the

  7. Acute toxicity of subcutaneously administered vitamin E isomers delta- and gamma-tocotrienol in mice.

    Science.gov (United States)

    Swift, Sibyl N; Pessu, Roli L; Chakraborty, Kushal; Villa, Vilmar; Lombardini, Eric; Ghosh, Sanchita P

    2014-01-01

    The toxicity of parenterally administered vitamin E isomers, delta-tocotrienol (DT3) and gamma-tocotrienol (GT3), was evaluated in male and female CD2F1 mice. In an acute toxicity study, a single dose of DT3 or GT3 was administered subcutaneously in a dose range of 200 to 800 mg/kg. A mild to moderately severe dermatitis was observed clinically and microscopically in animals at the injection site at doses above 200 mg/kg. The severity of the reaction was reduced when the drug concentration was lowered. Neither drug produced detectable toxic effects in any other tissue at the doses tested. Based on histopathological analysis for both DT3 and GT3, and macroscopic observations of inflammation at the injection site, a dose of 300 mg/kg was selected as the lowest toxic dose in a 30-day toxicity study performed in male mice. At this dose, a mild skin irritation occurred at the injection site that recovered completely by the end of the experimental period. At a dose of 300 mg/kg of DT3 or GT3, no adverse effects were observed in any tissues or organs. © The Author(s) 2014.

  8. Characterization of a single-isomer carboxymethyl-beta-cyclodextrin in chiral capillary electrophoresis.

    Science.gov (United States)

    Fejős, Ida; Varga, Erzsébet; Benkovics, Gábor; Malanga, Milo; Sohajda, Tamás; Szemán, Julianna; Béni, Szabolcs

    2017-08-01

    In this work, the synthesis, characterization, and chiral capillary electrophoretic study of heptakis-(2,3-di-O-methyl-6-O-carboxymethyl)-β-CD (HDMCM), a single-isomer carboxymethylated CD, are presented. The pH-dependent and selector concentration-dependent enantiorecognition properties of HDMCM were investigated and discussed herein. The enantioseparation was assessed applying a structurally diverse set of noncharged, basic, and zwitterionic racemates. The increase in the selector concentration and gross negative charge of HDMCM improved the enantioseparation that could be observed in the majority of the cases. HDMCM was also successfully applied as BGE additive in NACE using a methanol-based system in order to prove the separation selectivity features and to highlight the broad applicability of HDMCM. Over 25 racemates showed partial or baseline separation with HDMCM under the conditions investigated, among which optimal enantiomer migration order was found for the four stereoisomers of tadalafil, tapentadol, and dapoxetine, offering the possibility of a chiral CE method development for chiral purity profiling of these drugs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Roles of the tyrosine isomers meta-tyrosine and ortho-tyrosine in oxidative stress.

    Science.gov (United States)

    Ipson, Brett R; Fisher, Alfred L

    2016-05-01

    The damage to cellular components by reactive oxygen species, termed oxidative stress, both increases with age and likely contributes to age-related diseases including Alzheimer's disease, atherosclerosis, diabetes, and cataract formation. In the setting of oxidative stress, hydroxyl radicals can oxidize the benzyl ring of the amino acid phenylalanine, which then produces the abnormal tyrosine isomers meta-tyrosine or ortho-tyrosine. While elevations in m-tyrosine and o-tyrosine concentrations have been used as a biological marker of oxidative stress, there is emerging evidence from bacterial, plant, and mammalian studies demonstrating that these isomers, particularly m-tyrosine, directly produce adverse effects to cells and tissues. These new findings suggest that the abnormal tyrosine isomers could in fact represent mediators of the effects of oxidative stress. Consequently the accumulation of m- and o-tyrosine may disrupt cellular homeostasis and contribute to disease pathogenesis, and as result, effective defenses against oxidative stress can encompass not only the elimination of reactive oxygen species but also the metabolism and ultimately the removal of the abnormal tyrosine isomers from the cellular amino acid pool. Future research in this area is needed to clarify the biologic mechanisms by which the tyrosine isomers damage cells and disrupt the function of tissues and organs and to identify the metabolic pathways involved in removing the accumulated isomers after exposure to oxidative stress. Published by Elsevier B.V.

  10. Detection method of prawn irradiated in frozen state using tyrosine isomers as a marker

    International Nuclear Information System (INIS)

    Oikawa, H.; Satomi, M.; Omura, Y.; Yano, Y.

    2001-01-01

    Internationally the use of food irradiation has been expanding. And therefore a method is needed to detect whether food has been irradiated or not. We examined the content of the tyrosine isomers, m-tyrosine and omicron-tyrosine, of prawns irradiated in the frozen state (< -30 deg C) as a marker of the detection method. The tyrosine isomer content linearly increased with increasing dose, and the level of tyrosine isomers in the frozen-irradiated prawn was 50 - 60 % of the un frozen ones. But the difference in the content of tyrosine isomers between non-irradiated and irradiated at 5.0 kGy, that is the approved dose for frozen shellfish in countries where this technique is approved, is enough for discrimination. In addition, the content of tyrosine isomers showed little change during the frozen storage for 120 days. So we think the method using tyrosine isomers is suitable for practical use in Japan for imports of many kinds of frozen shellfish

  11. Mechanism, reactivity, and selectivity of nickel-catalyzed [4 + 4 + 2] cycloadditions of dienes and alkynes.

    Science.gov (United States)

    Hong, Xin; Holte, Dane; Götz, Daniel C G; Baran, Phil S; Houk, K N

    2014-12-19

    Density functional theory (DFT) calculations with B3LYP and M06 functionals elucidated the reactivities of alkynes and Z/E selectivity of cyclodecatriene products in the Ni-catalyzed [4 + 4 + 2] cycloadditions of dienes and alkynes. The Ni-mediated oxidative cyclization of butadienes determines the Z/E selectivity. Only the oxidative cyclization of one s-cis to one s-trans butadiene is facile and exergonic, leading to the observed 1Z,4Z,8E-cyclodecatriene product. The same step with two s-cis or s-trans butadienes is either kinetically or thermodynamically unfavorable, and the 1Z,4E,8E- and 1Z,4Z,8Z-cyclodecatriene isomers are not observed in experiments. In addition, the competition between the desired cooligomerization and [2 + 2 + 2] cycloadditions of alkynes depends on the coordination of alkynes. With either electron-deficient alkynes or alkynes with free hydroxyl groups, the coordination of alkynes is stronger than that of dienes, and alkyne trimerization prevails. With alkyl-substituted alkynes, the generation of alkyne-coordinated nickel complex is much less favorable, and the [4 + 4 + 2] cycloaddition occurs.

  12. Explicitly computing geodetic coordinates from Cartesian coordinates

    Science.gov (United States)

    Zeng, Huaien

    2013-04-01

    This paper presents a new form of quartic equation based on Lagrange's extremum law and a Groebner basis under the constraint that the geodetic height is the shortest distance between a given point and the reference ellipsoid. A very explicit and concise formulae of the quartic equation by Ferrari's line is found, which avoids the need of a good starting guess for iterative methods. A new explicit algorithm is then proposed to compute geodetic coordinates from Cartesian coordinates. The convergence region of the algorithm is investigated and the corresponding correct solution is given. Lastly, the algorithm is validated with numerical experiments.

  13. A Stable Coordination Complex of Rh(IV) in an N,O-Donor Environment

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Shashi B. [Department of Chemistry, Yale University, 225 Prospect; Shopov, Dimitar Y. [Department of Chemistry, Yale University, 225 Prospect; Sharninghausen, Liam S. [Department of Chemistry, Yale University, 225 Prospect; Vinyard, David J. [Department of Chemistry, Yale University, 225 Prospect; Mercado, Brandon Q. [Department of Chemistry, Yale University, 225 Prospect; Brudvig, Gary W. [Department of Chemistry, Yale University, 225 Prospect; Crabtree, Robert H. [Department of Chemistry, Yale University, 225 Prospect

    2015-12-10

    We describe facial and meridional isomers of [RhIII(pyalk)3], as well as meridional [RhIV(pyalk)3]+ {pyalk =2-(2-pyridyl)-2-propanoate}, the first coordination complex in an N,O-donor environment to show a clean, reversible RhIII/IV redox couple and to have a stable Rh(IV) form, which we characterize by EPR and UV–visible spectroscopy as well as X-ray crystallography. The unprecedented stability of the Rh(IV) species is ascribed to the exceptional donor strength of the ligands, their oxidation resistance, and the meridional coordination geometry.

  14. Strategies to distinguish new synthetic cannabinoid FUBIMINA (BIM-2201) intake from its isomer THJ-2201: metabolism of FUBIMINA in human hepatocytes

    OpenAIRE

    Diao, Xingxing; Scheidweiler, Karl B.; Wohlfarth, Ariane; Zhu, Mingshe; Pang, Shaokun; Huestis, Marilyn A.

    2016-01-01

    Since 2013, a new drugs-of-abuse trend attempts to bypass drug legislation by marketing isomers of scheduled synthetic cannabinoids (SCs), e.g., FUBIMINA (BIM-2201) and THJ-2201. It is much more challenging to confirm a specific isomer?s intake and distinguish it from its structural analog because the isomers and their major metabolites usually have identical molecular weights and display the same product ions. Here, we investigated isomers FUBIMINA and THJ-2201 and propose strategies to dist...

  15. Quadrupole moment of the 7/21- isomer state in 43S. Shell model study of sulfur isotopes around N=28

    International Nuclear Information System (INIS)

    Chevrier, Raphael

    2013-01-01

    The goal of this work consists in providing new insights in the shape coexistence expected in neutron-rich nuclei around the N=28 shell closure. In 43 S, recent experimental data as well as their interpretation in the shell model framework were used to predict the coexistence between a J π =3/2 1 - prolate deformed ground state and a 7/2 1 - rather spherical isomer state. We report on the quadrupole moment measurement Q s of the 7/2 1 - isomer state [E*=320.5(5) keV, T 1/2 =415(3) ns] in 43 S. The TDPAD method was applied on 43 S nuclei produced by the fragmentation of a 48 Ca primary beam at 345 A.MeV, and selected in-flight through the BigRIPS spectrometer at RIKEN (Japan). The measured value, |Q s |=23(3) efm 2 , is in remarkable agreement with that calculated in the shell model framework, although it is significantly larger than that expected for a single-particle state. In order to understand the nature of the correlations responsible for the departure of the isomer state from a pure spherical shape, we report on the results of a shell model study using the modern SDPF-U interaction of the neighbors sulfur isotopes 42,44,46 S. Those calculations allowed to identify a slight triaxial degree of freedom in the structure of these nuclei, although the latter happens to be highly hindered at N=28 in 44 S. Spectroscopic factor calculations show that this slight triaxial degree of freedom also impacts the low-lying structure in 43 S. It allows to better understand the deviation of the spectroscopic quadrupole moment value of the isomer state from the limit case of a pure spherical state. (author) [fr

  16. Lanthanide(III) complexes of a mono(methylphosphonate) analogue of H4dota: the influence of protonation of the phosphonate moiety on the TSAP/SAP isomer ratio and the water exchange rate.

    Science.gov (United States)

    Rudovský, Jakub; Cígler, Petr; Kotek, Jan; Hermann, Petr; Vojtísek, Pavel; Lukes, Ivan; Peters, Joop A; Vander Elst, Luce; Muller, Robert N

    2005-04-08

    A monophosphonate analogue of H4dota, 1,4,7,10-tetraazacyclododecane-4,7,10-tris(carboxymethyl)-1-methylphosphonic acid (H5do3aP), and its complexes with lanthanides were synthesized. Multinuclear NMR studies reveal that, in aqueous solution, lanthanide(III) complexes of the ligand exhibit structures analogous to those of H4dota complexes. Thus, the central ion is nine-coordinate, surrounded by four nitrogen atoms, three acetate and one phosphonate oxygen atoms, and one water molecule in an apical position. For complexes of H5do3aP with Ln(III) ions in the middle of the series, the abundance of the desired twisted square-antiprismatic (TSAP) isomer is higher than for the corresponding H4dota complexes. The TSAP/square-antiprismatic (SAP) isomer ratio is highly sensitive to protonation of the phosphonate group: a higher abundance of the TSAP isomer was found in acidic solutions. The microscopic protonation constants of the TSAP isomers are higher than those of the SAP isomers. The presence of one water molecule in the first coordination sphere of the complexes in the pH region studied (pH 2.5-7.0) is confirmed by 17O NMR spectroscopy. The results of a simultaneous fit of variable-temperature 17O NMR relaxation data and 1H NMRD profiles show that the residence time of water (tauM) in the Gd(III) complex is much smaller than for [Gd(dota)(H2O)]-. The exchange rate appears to be dependent on the pH of the solution. The values of tauM are 37, 40, and 14 ns at pH 2.5, 4.7, and 7.0, respectively. These observations can be explained by an extensive second-sphere hydrogen-bonding network that varies with the state of protonation of the phosphonate moiety. Upon protonation of the complex, the second-sphere hydration probably becomes more ordered, which may result in a decrease in penetrability and an increase in tauM. The relaxivity of the Gd(III) complex is almost independent of the pH and is equal to 4.7 s(-1) mM(-1) (20 MHz, pH 7 and 37 degrees C). The solid

  17. COORDINATING SUPPLY CHAIN INVENTORIES IN MULTI-ECHELON NETWORKS

    OpenAIRE

    SYAM SUNDAR K,; NARAYANAN S

    2011-01-01

    Coordination is the management of dependencies between activities. The purpose of coordination is to achieve collectively goals that individual actors cannot meet. Coordination within a supply chain is strategic responses to the problems that arise from inter – organizational dependencies within the chain. Given the increasing importance of inventory management and cost reduction to be gained through supply chain coordination, the challenge to an organization is how to select the appropriate ...

  18. The curvature coordinate system

    DEFF Research Database (Denmark)

    Almegaard, Henrik

    2007-01-01

    The paper describes a concept for a curvature coordinate system on regular curved surfaces from which faceted surfaces with plane quadrangular facets can be designed. The lines of curvature are used as parametric lines for the curvature coordinate system on the surface. A new conjugate set of lin...

  19. The GSAM software: A global search algorithm of minima exploration for the investigation of low lying isomers of clusters

    Energy Technology Data Exchange (ETDEWEB)

    Marchal, Rémi; Carbonnière, Philippe; Pouchan, Claude [Université de Pau et des Pays de l' Adour, IPREM/ECP, UMR CNRS 5254 (France)

    2015-01-22

    The study of atomic clusters has become an increasingly active area of research in the recent years because of the fundamental interest in studying a completely new area that can bridge the gap between atomic and solid state physics. Due to their specific properties, such compounds are of great interest in the field of nanotechnology [1,2]. Here, we would present our GSAM algorithm based on a DFT exploration of the PES to find the low lying isomers of such compounds. This algorithm includes the generation of an intial set of structure from which the most relevant are selected. Moreover, an optimization process, called raking optimization, able to discard step by step all the non physically reasonnable configurations have been implemented to reduce the computational cost of this algorithm. Structural properties of Ga{sub n}Asm clusters will be presented as an illustration of the method.

  20. Coordinate measuring machines

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo

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

  1. Chiral recognition of pinacidil and its 3-pyridyl isomer by canine cardiac and smooth muscle: Antagonism by sulfonylureas

    International Nuclear Information System (INIS)

    Steinberg, M.I.; Wiest, S.A.; Zimmerman, K.M.; Ertel, P.J.; Bemis, K.G.; Robertson, D.W.

    1991-01-01

    Pinacidil, a potassium channel opener (PCO), relaxes vascular smooth muscle by increasing potassium ion membrane conductance, thereby causing membrane hyperpolarization. PCOs also act on cardiac muscle to decrease action potential duration (APD) selectively. To examine the enantiomeric selectivity of pinacidil, the stereoisomers of pinacidil (a 4-pyridylcyanoguanidine) and its 3-pyridyl isomer (LY222675) were synthesized and studied in canine Purkinje fibers and cephalic veins. The (-)-enantiomers of both pinacidil and LY222675 were more potent in relaxing phenylephrine-contracted cephalic veins and decreasing APD than were their corresponding (+)-enantiomers. The EC50 values for (-)-pinacidil and (-)-LY222675 in relaxing cephalic veins were 0.44 and 0.09 microM, respectively. In decreasing APD, the EC50 values were 3.2 microM for (-)-pinacidil and 0.43 microM for (-)-LY222675. The eudismic ratio was greater for the 3-pyridyl isomer than for pinacidil in both cardiac (71 vs. 22) and vascular (53 vs. 17) tissues. (-)-LY222675 and (-)-pinacidil (0.1-30 microM) also increased 86Rb efflux from cephalic veins to a greater extent than did their respective optical antipodes. The antidiabetic sulfonylurea, glyburide (1-30 microM), shifted the vascular concentration-response curve of (-)-pinacidil to the right by a similar extent at each inhibitor concentration. Glipizide also antagonized the response to (-)-pinacidil, but was about 1/10 as potent with a maximal shift occurring at 10 and 30 microM. Glyburide antagonized the vascular relaxant effects of 0.3 microM (-)-LY222675 (EC50, 2.3 microM) and reversed the decrease in APD caused by 3 microM (-)-LY222675 (EC50, 1.9 microM). Nitroprusside did not alter 86Rb efflux, and vascular relaxation induced by sodium nitroprusside was unaffected by sulfonylureas

  2. Online Ozonolysis Combined with Ion Mobility-Mass Spectrometry Provides a New Platform for Lipid Isomer Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Poad, Berwyck L.; Zheng, Xueyun; Mitchell, Todd A.; Smith, Richard D.; Baker, Erin M.; Blanksby, Stephen J.

    2017-12-21

    One of the most significant challenges in contemporary lipidomics lies in the separation and identification of lipid isomers that differ only in site(s) of unsaturation or geometric configuration of the carbon-carbon double bonds. While analytical separation techniques including ion mobility spectrometry (IMS) and liquid chromatography (LC) can separate isomeric lipids under appropriate conditions, conventional tandem mass spectrometry cannot provide unequivocal identification. To address this challenge, we have implemented ozone-induced dissociation (OzID) in-line with LC, IMS and high resolution mass spectrometry. Modification of an IMS- capable quadrupole time-of-flight mass spectrometer was undertaken to allow the introduction of ozone into the high-pressure trapping ion funnel region preceding the IMS cell. This enabled the novel LC-OzID-IMS-MS configuration where ozonolysis of ionized lipids occurred rapidly (10 ms) without prior mass-selection. LC-elution time alignment combined with accurate mass and arrival time extraction of ozonolysis products facilitated correlation of precursor and product ions without mass-selection (and associated reductions in duty cycle). Unsaturated lipids across 11 classes were examined using this workflow in both positive and negative ion modalities and in all cases the positions of carbon-carbon double bonds were unequivocally assigned based on predictable OzID transitions. Under these conditions geometric isomers exhibited different IMS arrival time distributions and distinct OzID product ion ratios providing a means for discrimination of cis/trans double bonds in complex lipids. The combination of OzID with multidimensional separations shows significant promise for facile profiling of unsaturation patterns within complex lipidomes.

  3. Deep inelastic reactions and isomers in neutron-rich nuclei across the perimeter of the A = 180 - 190 deformed region

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Lane, G.J.; Byrne, A.P.; Watanabe, H.; Hughes, R.O.; Kondev, F.G.; Carpenter, M.P.; Janssens, R.V.F.; Lauritsen, T.; Lister, C.J.; Seweryniak, D.; Zhu, S.; Chowdhury, P.; Shi, Y.; Xu, F.R.

    2014-01-01

    Recent results on high-spin isomers populated in deep-inelastic reactions in the transitional tungsten-osmium region are outlined with a focus on 190 Os, 192 Os and 194 Os. As well as the characterization of several two-quasineutron isomers, the 12 + and 20 + isomers in 192 Os are interpreted as manifestations of maximal rotation alignment within the neutron i(13/2) and possibly proton h(11/2) shells at oblate deformation. (authors)

  4. Solvation effects on brain uptakes of isomers of 99mTc brain imaging agents

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Analysis of electrostatic hydration free energies of the isomers of the 99mTc-BAT and 99mTc-DADT complexes is carried out using the computer simulation technique. The results show that not only a correlation exists between the logarithm of the brain uptake and the electrostatic hydration free energy for the isomers of 99mTc-brain radiopharmaceuticals, but also a linear relationship exists between the logarithm of the ratio of the brain uptake of the syn isomer to that of the anti one and the difference between the electrostatic hydration free energy of the syn-isomer and that of the anti one. Furthermore, the investigation on the important factors influencing the brain uptakes of 99mTc-radiopharmaceuticals and the reasons of the different biodistribution of the isomers of the 99mTc-complexes is explored at the molecular level. The results may provide a reference for the rational drug design of brain imaging agents.

  5. Three-quasiparticle isomer in 173Ta and the excitation energy dependence of K -forbidden transition rates

    OpenAIRE

    Wood, RT; Walker, PM; Lane, G J; Carroll, R. J.; Cullen, David; Dracoulis, G D; Hota, S. S.; Kibédi, T.; Palalani, N; Podolyak, Zs.; Reed, MW; Schiffl, K; Wright, A.M

    2017-01-01

    Using the 168Er(10B,5n) reaction at a beam energy of 68 MeV, new data have been obtained for the population and decay of a T1/2=148ns, Kπ=21/2− three-quasiparticle isomer at 1717 keV in 173Ta. Revised decay energies and intensities have been determined, together with newly observed members of a rotational band associated with the isomer. By comparison with other isomers in the A≈180 deformed region, the 173Ta isomer properties help to specify the key degrees of freedom that determine K-forbid...

  6. Statistical model calculation of fission isomer excitation functions in (n,n') and (n,γ) reactions

    International Nuclear Information System (INIS)

    Chatterjee, A.; Athougies, A.L.; Mehta, M.K.

    1977-01-01

    A statistical model developed by Britt and others (1971, 1973) to analyze isomer excitation functions in spallation type reactions like (α,2n) has been adopted in fission isomer calculations for (n,n') and (n,γ) reactions. Calculations done for 235 U(n,n')sup(238m)U and 235 U(n,γ)sup(236m)U reactions have been compared with experimental measurements. A listing of the computer program ISOMER using FORTRAN IV to calculate the isomer to prompt ratios is given. (M.G.B.)

  7. Nonparametric variational optimization of reaction coordinates

    Energy Technology Data Exchange (ETDEWEB)

    Banushkina, Polina V.; Krivov, Sergei V., E-mail: s.krivov@leeds.ac.uk [Astbury Center for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2015-11-14

    State of the art realistic simulations of complex atomic processes commonly produce trajectories of large size, making the development of automated analysis tools very important. A popular approach aimed at extracting dynamical information consists of projecting these trajectories into optimally selected reaction coordinates or collective variables. For equilibrium dynamics between any two boundary states, the committor function also known as the folding probability in protein folding studies is often considered as the optimal coordinate. To determine it, one selects a functional form with many parameters and trains it on the trajectories using various criteria. A major problem with such an approach is that a poor initial choice of the functional form may lead to sub-optimal results. Here, we describe an approach which allows one to optimize the reaction coordinate without selecting its functional form and thus avoiding this source of error.

  8. Activation of Reactive MALDI Adduct Ions Enables Differentiation of Dihydroxylated Vitamin D Isomers

    Science.gov (United States)

    Qi, Yulin; Müller, Miriam J.; Volmer, Dietrich A.

    2017-12-01

    Vitamin D compounds are secosteroids, which are best known for their role in bone health. More recent studies have shown that vitamin D metabolites and catabolites such as dihydroxylated species (e.g., 1,25- and 24,25-dihydroxyvitamin D3) play key roles in the pathologies of various diseases. Identification of these isomers by mass spectrometry is challenging and currently relies on liquid chromatography, as the isomers exhibit virtually identical product ion spectra under collision induced dissociation conditions. Here, we developed a simple MALDI-CID method that utilizes ion activation of reactive analyte/matrix adducts to distinguish isomeric dihydroxyvitamin D3 species, without the need for chromatography separation or chemical derivatization techniques. Specifically, reactive 1,5-diaminonaphthalene adducts of dihydroxyvitamin D3 compounds formed during MADI were activated and specific cleavages in the secosteroid's backbone structure were achieved that produced isomer-diagnostic fragment ions. [Figure not available: see fulltext.

  9. Discovery and identification of a series of alkyl decalin isomers in petroleum geological samples.

    Science.gov (United States)

    Wang, Huitong; Zhang, Shuichang; Weng, Na; Zhang, Bin; Zhu, Guangyou; Liu, Lingyan

    2015-07-07

    The comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/TOFMS) has been used to characterize a crude oil and a source rock extract sample. During the process, a series of pairwise components between monocyclic alkanes and mono-aromatics have been discovered. After tentative assignments of decahydronaphthalene isomers, a series of alkyl decalin isomers have been synthesized and used for identification and validation of these petroleum compounds. From both the MS and chromatography information, these pairwise compounds were identified as 2-alkyl-decahydronaphthalenes and 1-alkyl-decahydronaphthalenes. The polarity of 1-alkyl-decahydronaphthalenes was stronger. Their long chain alkyl substituent groups may be due to bacterial transformation or different oil cracking events. This systematic profiling of alkyl-decahydronaphthalene isomers provides further understanding and recognition of these potential petroleum biomarkers.

  10. Pronounced photosensitivity of molecular [Ru(bpy)2(OSO)]+ solutions based on two photoinduced linkage isomers.

    Science.gov (United States)

    Dieckmann, Volker; Eicke, Sebastian; Rack, Jeffrey J; Woike, Theo; Imlau, Mirco

    2009-08-17

    Photosensitive properties of [Ru(bpy)(2)(OSO)] PF(6) dissolved in propylene carbonate originating from photoinduced linkage isomerism have been studied by temperature and exposure dependent transmission and UV/Vis absorption spectroscopy. An exceeding photochromic photosensitivity of S = (63 +/- 10) x 10(3) cm l J(-1) mol(-1) is determined. It is attributed to a maximum population of 100% molecules in the photoinduced isomers, a unique absorption cross section per molecule and a very low light exposure of Q(0) = (0.25 +/- 0.03) Ws cm(-2) for isomerism. Relaxation studies of O-bonded to S-bonded isomers at different temperatures verify the existence of two distinct structures of linkage isomers determined by the activation energies of E(A,1) = (0.76 +/- 0.08) eV and E(A,2) = (1.00 +/- 0.14) eV.

  11. Effect of isomers of hydroxybenzoic acid on the growth and metabolism of Chlorella vulgaris Beijerinck (Chlorophyceae

    Directory of Open Access Journals (Sweden)

    Andrzej Bajguz

    2014-01-01

    Full Text Available The isomers o-, m-, and p- of hydroxybenzoic acid (HBA in the concentration range 10-1-10-4 M in the unicellular green alga Chlorella vulgaris (Chlorophyceae display marked biological activity. The o-HBA isomer, commonly known as salicylic acid, in a concentration of 10-4 M exerted the most stimulating effect on the parameters analysed (the number of cells, dry mass, the content of chlorophylls a and h, carotenoids, soluble proteins and their secretion, monosaccharides, DNA and RNA whereas p-HBA had weak stimulating properties. On the other hand, m-HBA had a weak inhibitory effect on the growth of C. vulgaris and all the biochemical parameters analysed in comparison with the control culture of algae devoid of HBA isomers.

  12. Study on the formation of fission isomer via 232Th + α reaction

    International Nuclear Information System (INIS)

    Vianna, D.M.

    1982-01-01

    The formation of fission isomer through 232 Th+α reaction is studied using the distance-recoil method, employing policarbonate MAKROFOL detector. The total isomeric half-life measured has the value T 1/2 = 0.23 ± 0.03 ns and an ratio of formation of isomeric fission relative to prompt fission(σ i /σ p =0.75x10 -5 ). According to the energy of incident particle (Eα = 28 MeV), the cross-sections presented in the literature and the low value found for the total isomeric half-life, we attribute these half-life value to the 234 U isomer (even-even nucleus). The results were compared with those existent in the literature (La69, E170, Re70, Wo70, Po70, Br71) for this isomer. (author) [pt

  13. HPLC analysis of o-, m- and p-isomers using a betacyclodextrin column

    International Nuclear Information System (INIS)

    Haeger, J.

    1994-01-01

    The irradiation of foodstuffs containing protein leads to the hydroxylation of phenylalanine, due to which the position isomers o-tyrosine and m-tyrosine are formed in addition to the naturally occurring p-tyrosine. HPLC analysis of tyrosine isomers following sample processing and purification is generally carried out in a RP-C 18 column. In actual practice, the peaks of p-tyrosine and m-tyrosine overlap and a separation of o-tyrosine from baseline cannot always be achieved. Those separation problems may be solved, if a beta-cyclodextrin column is used in addition or as an alternative to the RP-C 18 column. The completely different separation characteristics of the latter provide a new pattern of elution for the tyrosine isomers. It is thus possible for p-tyrosine, which occurs in much higher concentrations than the other tyrosines, to be clearly separated chromatographically. (orig./vhe) [de

  14. Magnetic moment of the fragmentation-aligned F61e (9/2+) isomer

    International Nuclear Information System (INIS)

    Matea, I.; Georgiev, G.; Lewitowicz, M.; Santos, F. de Oliveira; Daugas, J.M.; Belier, G.; Goutte, H.; Meot, V.; Roig, O.; Hass, M.; Baby, L.T.; Goldring, G.; Neyens, G.; Borremans, D.; Himpe, P.; Astabatyan, R.; Lukyanov, S.; Penionzhkevich, Yu.E.; Balabanski, D.L.; Sawicka, M.

    2004-01-01

    We report on the g factor measurement of an isomer in the neutron-rich F 26 61 e (E * =861 keV and T 1/2 =239(5) ns). The isomer was produced and spin aligned via a projectile-fragmentation reaction at intermediate energy, the time dependent perturbed angular distribution method being used for the measurement of the g factor. For the first time, due to significant improvements of the experimental technique, an appreciable residual alignment of the nuclear spin ensemble has been observed, allowing a precise determination of its g factor, including the sign: g=-0.229(2). In this way we open the possibility to study moments of very neutron-rich short-lived isomers, not accessible via other production and spin-orientation methods

  15. Separation of toluene and heptane by liquid-liquid extraction using z-methyl-N-butylpyridinium tetrafluoroborate isomers (z = 2, 3, or 4) at T = 313.2 K

    International Nuclear Information System (INIS)

    Garcia, Julian; Garcia, Silvia; Torrecilla, Jose S.; Oliet, Mercedes; Rodriguez, Francisco

    2010-01-01

    The (liquid + liquid) equilibrium (LLE) data for three ternary systems containing heptane, toluene, and a z-methyl-N-butylpyridinium tetrafluoroborate ionic liquid ([zbmpy][BF 4 ] IL, where z = 2, 3, or 4) were determined at T = 313.2 K and atmospheric pressure. The effect of IL cation isomers on the LLE data was evaluated for the first time. The selectivity and extractive capacity from these LLE data were calculated and compared to those previously reported in the literature for the systems (heptane + toluene + [4bmpy][BF 4 ]) and (heptane + toluene + sulfolane). The results show that the LLE data for the systems comprising the ILs with the metha- and para-substituted cations do not differ significantly from isomer to isomer. On the other hand, significant differences were observed among the systems with the ortho-substituted cation and the other two cation isomers. The degree of consistency of the experimental LLE data was ascertained by applying the Othmer-Tobias correlation. In addition, the LLE data were satisfactorily correlated by means of the thermodynamic NRTL model.

  16. Regional transit coordination guidebook.

    Science.gov (United States)

    2009-01-01

    Constant growth in rural areas and extensive suburban development have contributed to increasingly more people needing seamless and adequate public transportation into and from nearby cities. Coordinating existing services or determining the need for...

  17. Supercritical Airfoil Coordinates

    Data.gov (United States)

    National Aeronautics and Space Administration — Rectangular Supercritical Wing (Ricketts) - design and measured locations are provided in an Excel file RSW_airfoil_coordinates_ricketts.xls . One sheet is with Non...

  18. Developmental coordination disorder

    Science.gov (United States)

    Developmental coordination disorder can lead to: Learning problems Low self-esteem resulting from poor ability at sports and teasing by other children Repeated injuries Weight gain as a result of not wanting to participate ...

  19. Environmental Compliance Issue Coordination

    Science.gov (United States)

    An order to establish the Department of Energy (DOE) requirements for coordination of significant environmental compliance issues to ensure timely development and consistent application of Departmental environmental policy and guidance

  20. Data Management Coordinators (DMC)

    Science.gov (United States)

    The Regional Data Management Coordinators (DMCs) were identified to serve as the primary contact for each region for all Water Quality Framework activities. They will facilitate and communicate information to the necessary individuals at the region and tra

  1. Molecular modeling and biological evaluation of 2-N,N-dimethylaminecyclohexyl 1-N‧,N‧-dimethylcarbamate isomers and their methylsulfate salts as cholinesterases inhibitors

    Science.gov (United States)

    Bocca, Cleverson C.; Rittner, Roberto; Höehr, Nelci F.; Pinheiro, Glaucia M. S.; Abiko, Layara A.; Basso, Ernani A.

    2010-11-01

    This work presents a detailed theoretical and experimental study on the inhibitory properties of 2- N,N-dimethylaminecyclohexyl 1- N',N'-dimethylcarbamate isomers and their methylsulfate salts against the cholinesterases enzymes. The in vitro inhibition test performed by the Ellman's method showed that the salt form compounds were more active than the neutral ones in cholinesterases inhibition. The trans salt showed good selectivity towards the inhibition of erythrocyte cholinesterase with a maximum limit around 90% and 55% for the plasma cholinesterase inhibition. Molecular modeling, docking and experimental results performed in this study showed to be important initial steps toward the development of a novel pharmaceuticals in the fight against Alzheimer's disease.

  2. Identification of an isomer in 110Ag at 1-keV excitation energy

    International Nuclear Information System (INIS)

    Clark, D.D.; Kostroun, V.O.; Siems, N.E.

    1975-01-01

    The existence of a new isomeric state in 110 Ag at approx. 1 keV excitation has been established in two experiments using a new instrument, the inner-shell-vacancy (ISV) detector. In the first experiment, a transition with a half-life of 660 plus-or-minus 40 ns was observed to follow the well-known 116-keV M4 transition that depopulates the 6 + 250-day isomeric level in 110 Ag; the energy of the new transition was deduced to be 109 Ag(n, γ) 110 Ag reaction to follow γ transitions previously assigned by others to populate a 1-keV excited state. The two results indicate the existence of a 2 - 660-ns isomer at 1.11 keV. Under the assumption that the newly observed transition is from a 2 - 1.11-keV state to the 1 + ground state, its hindrance factor with respect to the Moszkowski estimate is approx. 2.6 times 10 3 . Possible chemical-state perturbations of the measured half-life are estimated to be much smaller than the measurement error. In both experiments the approx. 1-keV transition was detected with the ISV detector, a new device based on the well-established atomic effect that within approx. 10 -14 s after the formation of an inner shell vacancy an atom will undergo a multiple loss of []lectrons ranging from several to 20 or more, the number being a function of Z and subshell. The emitted electrons, which are very soft, are collected with an accelerating and focusing electrostatic lens and detected with a plastic scintillator and a photomultiplier tube. Nuclear transitions that cause ISVs can thus be sensed. Experiments are described that show the detector is fast, sensitive, selective, and efficient in responding to ISVs.

  3. Analysis of conjugated linoleic acid and trans 18:1 isomers in synthetic and animal products.

    Science.gov (United States)

    Kramer, John K G; Cruz-Hernandez, Cristina; Deng, Zeyuan; Zhou, Jianqiang; Jahreis, Gerhard; Dugan, Michael E R

    2004-06-01

    The chemistry of conjugated fatty acids, specifically octadecadienoic acids (18:2; commonly referred to as conjugated linoleic acid, or CLA), has provided many challenges to lipid analysts because of their unique physical properties and the many possible positional and geometric isomers. After the acid-labile properties of CLAs during analytic procedures were overcome, it became evident that natural products, specifically dairy fats, contain one dominant (c9,t11-CLA), 3 intermediate (t7,c9-, t9,c11-, and t11,c13-CLA), and up to 20 more minor CLA isomers. The best analytic techniques to date include a combination of gas chromatography that uses 100-m highly polar capillary columns, silver ion-HPLC, and a combination of silver ion-thin-layer chromatography and gas chromatography to analyze the CLA and trans 18:1 isomers, because some of them serve as precursors of CLA in biological systems. These analytic techniques have assisted commercial suppliers to prepare pure CLA isomers and have permitted the evaluation of individual CLA isomers for their nutritional and biological activity in animal and human systems. It is increasingly evident that different CLA isomers have distinctly different physiologic and biochemical properties. These techniques are essential to evaluate dairy fats for their CLA content, to design experimental diets to increase the amount of CLA in dairy fats, and to determine the CLA profile in these CLA-enriched dairy fats. These improved techniques are used to evaluate the CLA profile in pork products from pigs fed different commercial CLA mixtures.

  4. New isomers and medium-spin structure of the 95Y nucleus

    International Nuclear Information System (INIS)

    Urban, W.; Sieja, K.; Simpson, G. S.; Faust, H.; Rzaca-Urban, T.; Zlomaniec, A.; Lukasiewicz, M.; Smith, A. G.; Durell, J. L.; Smith, J. F.; Varley, B. J.; Nowacki, F.; Ahmad, I.

    2009-01-01

    Excited states in 95 Y, populated following the spontaneous fission of 248 Cm and 252 Cf and following fission of 235 U induced by thermal neutrons, were studied by means of γ spectroscopy using the EUROGAM2 and GAMMASPHERE multidetector Ge arrays and the LOHENGRIN fission-fragment separator, respectively. We have found a new (17/2 - ) isomer in 95 Y at 3142.2 keV with a half-life of T 1/2 =14.9(5) ns. Another isomer was identified in 95 Y at 5022.1 keV and it was assigned a spin-parity (27/2 - ). For this isomer a half-life of T 1/2 =65(4) ns was determined and four decay branches were found, including an E3 decay. A new E3 decay branch was also found for the known, 1087.5-keV isomer in 95 Y, for which we measured a half-life of 51.2(9) μs. The B(E3) and B(E1) transition rates, of 2.0 and 3.8x10 -7 W.u., respectively, observed in 95 Y are significantly lower than in the neighboring 96 Zr core, suggesting that octupole correlations in this region are mainly due to the coupling of proton Δj=3 orbitals. Shell-model calculations indicate that the (27/2 - ) isomer in 95 Y corresponds to the πg 9/2 ν(g 7/2 h 11/2 ) maximally aligned configuration and that all three isomers in 95 Y decay, primarily, by M2 transitions between proton g 9/2 and f 5/2 orbitals.

  5. Accumulation of D- vs. L-isomers of alanine and leucine in rat prostatic adenocarcinoma

    International Nuclear Information System (INIS)

    Conti, P.S.; Schmall, B.; Bigler, R.E.; Zanzonico, P.B.; Kleinert, E.; Whitmore, W.F. Jr.

    1985-01-01

    It has been reported that tumor tissue may accumulate some D-amino acids preferentially over the L-isomers. In order to investigate the potential use of carbon-11 labeled amino acid isomers for in vivo tumor studies with positron emission tomography in patients, the tissue distributions of alanine and leucine, substrates for the A-type and L-type amino acid transport systems, respectively, were studied in Copenhagen rates bearing the Dunning R3327G prostatic adenocarcinoma. The authors have previously reported differences in the accumulation of A-type vs. L-type amino acids in rat prostatic adenocarcinoma and normal tissues. All compounds were labeled with C-14 in the carboxyl position with specific activities of 30.0-56.6 mCi/mmol. Higher levels of C-14 activity (Relative Concentration (RC)=dpm found per gm tissue + dpm inject per gm animal mass) were observed in tumor tissue using D-alanine (0.71) compared to L- (0.21) or DL-alanine (0.27) at 45 min post-injection. While tumor/prostate and tumor/liver ratios were above 2 for all three substrates, tumor/blood and tumor/muscle were above one for only the D-isomer. Comparisons made with D-, L-, and DL-leucine also demonstrated a higher level of RC in tumor tissue with the D-isomer (0.84) vs. the L-(0.66) and DL-leucine (0.63). In this case, however, tumor/blood, tumor/prostate, and tumor/muscle ratios were above one for all three substrates, while tumor/liver ratios were below one. These results support the observation of a preferential accumulation of D-amino acids in tumor tissue over the natural L-isomers. Observed differences in the accumulation of the isomers in normal tissues are discussed

  6. Differential Potency of 2,6-Dimethylcyclohexanol Isomers for Positive Modulation of GABAA Receptor Currents.

    Science.gov (United States)

    Chowdhury, Luvana; Croft, Celine J; Goel, Shikha; Zaman, Naina; Tai, Angela C-S; Walch, Erin M; Smith, Kelly; Page, Alexandra; Shea, Kevin M; Hall, C Dennis; Jishkariani, D; Pillai, Girinath G; Hall, Adam C

    2016-06-01

    GABAA receptors meet all of the pharmacological requirements necessary to be considered important targets for the action of general anesthetic agents in the mammalian brain. In the following patch-clamp study, the relative modulatory effects of 2,6-dimethylcyclohexanol diastereomers were investigated on human GABAA (α1β3γ2s) receptor currents stably expressed in human embryonic kidney cells. Cis,cis-, trans,trans-, and cis,trans-isomers were isolated from commercially available 2,6-dimethylcyclohexanol and were tested for positive modulation of submaximal GABA responses. For example, the addition of 30 μM cis,cis-isomer resulted in an approximately 2- to 3-fold enhancement of the EC20 GABA current. Coapplications of 30 μM 2,6-dimethylcyclohexanol isomers produced a range of positive enhancements of control GABA responses with a rank order for positive modulation: cis,cis > trans,trans ≥ mixture of isomers > > cis,trans-isomer. In molecular modeling studies, the three cyclohexanol isomers bound with the highest binding energies to a pocket within transmembrane helices M1 and M2 of the β3 subunit through hydrogen-bonding interactions with a glutamine at the 224 position and a tyrosine at the 220 position. The energies for binding to and hydrogen-bond lengths within this pocket corresponded with the relative potencies of the agents for positive modulation of GABAA receptor currents (cis,cis > trans,trans > cis,trans-2,6-dimethylcyclohexanol). In conclusion, the stereochemical configuration within the dimethylcyclohexanols is an important molecular feature in conferring positive modulation of GABAA receptor activity and for binding to the receptor, a consideration that needs to be taken into account when designing novel anesthetics with enhanced therapeutic indices. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  7. Coordinating Work with Groupware

    DEFF Research Database (Denmark)

    Pors, Jens Kaaber; Simonsen, Jesper

    2003-01-01

    One important goal of employing groupware is to make possible complex collaboration between geographically distributed groups. This requires a dual transformation of both technology and work practice. The challenge is to re­duce the complexity of the coordination work by successfully inte....... Using the CSCW frame­work of coordination mechanisms, we have elicited six general factors influencing the integration of the groupware application in two situations....

  8. Luminescent lanthanide coordination polymers

    Energy Technology Data Exchange (ETDEWEB)

    Ma, L.; Evans, O.R.; Foxman, B.M.; Lin, W.

    1999-12-13

    One-dimensional lanthanide coordination polymers with the formula Ln(isonicotinate){sub 3}(H{sub 2}O){sub 2} (Ln = Ce, Pr, Nd, Sm, Eu, Tb; 1a-f) were synthesized by treating nitrate or perchlorate salts of Ln(III) with 4-pyridinecarboxaldehyde under hydro(solvo)thermal conditions. Single-crystal and powder X-ray diffraction studies indicate that these lanthanide coordination polymers adopt two different structures. While Ce(III), Pr(III), and Nd(III) complexes adopt a chain structure with alternating Ln-(carboxylate){sub 2}-Ln and Ln-(carboxylate){sub 4}-Ln linkages, Sm(III), Eu(III), and Tb(III) complexes have a doubly carboxylate-bridged infinite-chain structure with one chelating carboxylate group on each metal center. In both structures, the lanthanide centers also bind to two water molecules to yield an eight-coordinate, square antiprismatic geometry. The pyridine nitrogen atoms of the isonicotinate groups do not coordinate to the metal centers in these lanthanide(III) complexes; instead, they direct the formation of Ln(III) coordination polymers via hydrogen bonding with coordinated water molecules. Photoluminescence measurements show that Tb(isonicotinate){sub 3}(H{sub 2}O){sub 2} is highly emissive at room temperature with a quantum yield of {approximately}90%. These results indicate that highly luminescent lanthanide coordination polymers can be assembled using a combination of coordination and hydrogen bonds. Crystal data for 1a: monoclinic space group P2{sub 1}/c, a = 9.712(2) {angstrom}, b = 19.833(4) {angstrom}, c = 11.616(2) {angstrom}, {beta} = 111.89(3){degree}, Z = 4. Crystal data for 1f: monoclinic space group C2/c, a = 20.253(4) {angstrom}, b = 11.584(2) {angstrom}, c = 9.839(2) {angstrom}, {beta} = 115.64(3){degree}, Z = 8.

  9. Coordinate-invariant regularization

    International Nuclear Information System (INIS)

    Halpern, M.B.

    1987-01-01

    A general phase-space framework for coordinate-invariant regularization is given. The development is geometric, with all regularization contained in regularized DeWitt Superstructures on field deformations. Parallel development of invariant coordinate-space regularization is obtained by regularized functional integration of the momenta. As representative examples of the general formulation, the regularized general non-linear sigma model and regularized quantum gravity are discussed. copyright 1987 Academic Press, Inc

  10. Magnetic Coordinate Systems

    Science.gov (United States)

    Laundal, K. M.; Richmond, A. D.

    2017-03-01

    Geospace phenomena such as the aurora, plasma motion, ionospheric currents and associated magnetic field disturbances are highly organized by Earth's main magnetic field. This is due to the fact that the charged particles that comprise space plasma can move almost freely along magnetic field lines, but not across them. For this reason it is sensible to present such phenomena relative to Earth's magnetic field. A large variety of magnetic coordinate systems exist, designed for different purposes and regions, ranging from the magnetopause to the ionosphere. In this paper we review the most common magnetic coordinate systems and describe how they are defined, where they are used, and how to convert between them. The definitions are presented based on the spherical harmonic expansion coefficients of the International Geomagnetic Reference Field (IGRF) and, in some of the coordinate systems, the position of the Sun which we show how to calculate from the time and date. The most detailed coordinate systems take the full IGRF into account and define magnetic latitude and longitude such that they are constant along field lines. These coordinate systems, which are useful at ionospheric altitudes, are non-orthogonal. We show how to handle vectors and vector calculus in such coordinates, and discuss how systematic errors may appear if this is not done correctly.

  11. Conversion-electron experiment to characterize the decay of the 237Np shape isomer

    International Nuclear Information System (INIS)

    Henry, E.A.; Becker, J.A.; Bauer, R.W.; Gardner, D.G.; Decman, D.J.; Meyer, R.A.; Roy, N.; Sale, K.E.

    1987-01-01

    Conversion electrons from the decay of low-lying levels of 237 Np have been measured to detect the population of these levels by gamma-ray decay of the 237 Np shape isomer. Analysis of the 208-keV transition L conversion-electron peak gives an upper limit of about 17 μb for the population of the 3/2 - 267-keV level in 237 Np from the shape isomer decay. Model calculations are compared with the measured limit. Improvements are suggested for this experiment. 9 refs., 4 figs

  12. Electric quadruple moments of high-spin isomers in 209Po

    International Nuclear Information System (INIS)

    Ivanov, E.A.; Nicolescu, G.; Plostinaru, D.

    1998-01-01

    The electric quadrupole interaction of the 209 Po (17/2) - and (13/2) - isomers in a Bi single-crystal was measured. The results for the quadrupole moments are connected with studies of isomers in Po isotopes. A two level analysis procedure was employed for the combined data of (17/2) - and (13/2) - isomers. The quadrupole moments of the Po isotopes are of special interest for testing nuclear models because of supposed simple nuclear structure with two protons outside a closed magic number shell. While the g-factors are significant for the predominant few-particle structures often present at high spins, the quadrupole moments are sensitive to additional contributions arising from core deformation effects. A systematic study of quadrupole moments of 12 + isomers in Pb isotopes has indeed demonstrated that the valence neutron effective charge increases as more particle pairs are removed from the 208 Pb core. In the present work, quadrupole coupling constants were measured for the isomers by the time-differential perturbed angular distribution (TDPAD) technique, in the presence of quadrupole interactions from the internal electric field gradient (EFG) in Bi crystal. The experiments were performed using a pulsed deuteron-beam of 13 MeV. The (17/2) - isomer state (T 1/2 = 88 ns) and the (13/2) - isomer state (T 1/2 = 24 ns) were populated and aligned by the 209 Bi(d,2n) reaction. The repetition time of the pulse was 10 μs and the width was around 5 ns (FWHM). The rather low bombardment energy was chosen to reduce population of higher spin isomers and to optimize the population of 209 Po((17/2) - ) and 209 Po((13/2) - ). The 209 Po single crystal target was held at a temperature of 470 K in order to reduce possible radiation damage effects. The experiments have been performed with the c axis of the single crystal at 45 angle and 90 angle to the beam direction. We chose to use a calibration based on isomers with well-understood nuclear structure allowing a reliable

  13. Isomeric and high-spin states of 94Tc and the search for yrast isomers near Napprox.50

    International Nuclear Information System (INIS)

    Lee, I.Y.; Johnson, N.R.; McGowan, F.K.; Young, G.R.; Guidry, M.W.; Yates, S.W.

    1981-01-01

    A search for isomers in the Napprox.50 region has produced no evidence of high-spin yrast isomerism. A new 4.5-ns low-multiplicity isomer has been identified and assigned to 94 Tc, while the yrast sequence of 94 Tc has been established to more than 5 MeV in excitation energy

  14. 40 CFR 180.438 - Lambda-cyhalothrin and an isomer gamma-cyhalothrin; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Lambda-cyhalothrin and an isomer gamma... FOOD Specific Tolerances § 180.438 Lambda-cyhalothrin and an isomer gamma-cyhalothrin; tolerances for residues. (a) General. (1) Tolerances are established for the combined residues of the pyrethroid lambda...

  15. [Cardiotoxicity of lindane, a gamma isomer of hexachlorocyclohexane].

    Science.gov (United States)

    Sauviat, Martin-Pierre; Pages, Nicole

    2002-01-01

    The goal of the present review is to collect information concerning membrane effects induced by lindane intoxication, a y isomer of hexachiorocyclohexane (gamma-HCH) that has been largely used as an insecticide and disinfectant in agriculture and entered also in the composition of some lotions, creams and shampoos used against parasites (lice and scabies). Absorbed through respiratory, digestive or transcutaneous pathways, lindane accumulates within lipid rich tissues. Lindane accumulation depends on the duration of the exposure and affects tissues in the following order: adipose tissues > brain > kidney > muscle > lungs > heart > liver > blood. Whatever the mode of lindane absorption, it accumulates in blood and is distributed throughout the body. It may affect human health by exerting systemic, immunologic, teratogenic, and/or cancerogenic effects. The symptoms of lindane intoxication are different according to the mode of intoxication, acute or chronic. The absorption of high doses of gamma-HCH is particularly toxic for the central nervous system and for the female and male reproduction apparatus in mammals where lindane is considered as an endocrine disruptor. Lindane is highly lipophilic and incorporates into biological membranes according to the following sequence: mitochondria > sarcoplasmic reticulum > myelin > brain microsomes > erythrocytes. Lindane exerts a stimulating action on synaptic transmission and inhibits the chloride current activated by gamma-amino butyric acid (GABA) of many muscular and nervous preparations by interacting with the receptors GABA-chloride channel complex. It seems to affect calcium homeostasis of many tissues. The similarity between lindane and inositol (1, 4, 5) phosphate (IP3) suggested that lindane releases Ca2+ from IP3-sensitive intracellular stores in macrophages and myometrial cells. Ca2+ release from reticulum endoplasmic, mitochondria and other Ca2+ stores has been reported in cat kidney cells. Lindane altered

  16. Differences in gene expression profiles in the liver between carcinogenic and non-carcinogenic isomers of compounds given to rats in a 28-day repeat-dose toxicity study

    International Nuclear Information System (INIS)

    Nakayama, Koji; Kawano, Yukiko; Kawakami, Yuuki; Moriwaki, Norichika; Sekijima, Masaru; Otsuka, Masanori; Yakabe, Yoshikuni; Miyaura, Hideki; Saito, Koichi; Sumida, Kayo; Shirai, Tomoyuki

    2006-01-01

    Some compounds have structural isomers of which one is apparently carcinogenic, and the other not. Because of the similarity of their chemical structures, comparisons of their effects can allow gene expression elicited in response to the basic skeletons of the isomers to be disregarded. We compared the gene expression profiles of male Fischer 344 rats administered by daily oral gavage up to 28 days using an in-house oligo microarray. 2-Acetylaminofluorene (2-AAF), 2,4-diaminotoluene (2,4-DAT), 2-nitropropane (2-NP), and 2-nitro-p-phenylenediamine (2-NpP) are hepatocarcinogenic. However, their isomers, 4-acetylaminofluorene (4-AAF), 2,6-diaminotoluene (2,6-DAT), 1-nitropropane (1-NP), and 4-nitro-o-phenylenediamine (4-NoP), are non-hepatocarcinogenic. Because of the limited carcinogenicity of 2-NpP, we attempted to perform two-parametric comparison analyses with (1) a set of 4 isomers: 2-AAF, 2,4-DAT, 2-NP, and 2-NpP as 'carcinogenic', and 4-AAF, 2,6-DAT, 1-NP, and 4-NoP as 'non-carcinogenic'; and (2) a set of 3 isomers: 2-AAF, 2,4-DAT, and 2-NP, as 'carcinogenic', and 4-AAF, 2,6-DAT, and 1-NP as 'non-carcinogenic'. After ratio filtering and Welch's approximate t-test analysis, 54 and 28 genes were selected from comparisons between the sets of 3 and 4 isomers, respectively, for day 28 data. Using hierarchical clustering analysis with the 54 or 28 genes, 2-AAF, 2,4-DAT, and 2-NP clustered into a 'carcinogenic' branch. 2-NpP was in the same cluster as 4-NoP and 4-AAF. This clustering corresponded to the previous finding that 2-NpP is not carcinogenic in male Fischer 344 rats, which indicates that comparing the differences in gene expression elicited by different isomers is an effective method of developing a prediction system for carcinogenicity

  17. Mixed diphosphine/diamine ruthenium (II) isomers: Synthesis, structural characterization and catalytic hydrogenation of ketones

    Science.gov (United States)

    Nascimento, Rebecca D.; Silva, Andressa K.; Lião, Luciano M.; Deflon, Victor M.; Ueno, Leonardo T.; Dinelli, Luis R.; Bogado, André L.

    2018-01-01

    The complexes trans-[RuCl2(dppb)(cydn)] (1), trans-[RuCl2(dppb)(opda)] (2) and cis-[RuCl2(dppb)(cydn)] (3) were synthesized from [{RuCl2(dppb)}2-μ-(dppb)] {where: dppb = 1,4-bis(diphenylphosphino)butane; cydn = cis and trans (±) 1,2-diaminocyclohexane, and opda = o-phenylenediamine}. The complexes were characterized by nuclear magnetic resonance of phosphorus (31P{1H} NMR), cyclic voltammetry (CV), infrared and ultraviolet/visible spectra (IR and UV/vis) as well as elemental analyses (CHN). The X-ray structures of (1) and (3) were determined and they are presented here. DFT calculations and experimental data showed that the trans isomers are obtained as thermodynamic products while the cis isomers are kinetic products. This behavior is different than described in the literature for similar complexes, where the cis isomer is obtained from the trans isomer. Additionally, the catalytic activity of the complexes (1), (2) and (3) was investigated, as pre-catalysts, in the reduction of the acetophenone and 4-methylacetophenone by transfer-hydrogenation.

  18. Effects of retinoic acid isomers on proteomic pattern in human breast cancer MCF-7 cell line

    Czech Academy of Sciences Publication Activity Database

    Flodrová, Dana; Benkovská, Dagmar; Macejová, D.; Bialešová, L.; Bobálová, Janette; Brtko, J.

    2013-01-01

    Roč. 47, č. 4 (2013), s. 205-209 ISSN 1210-0668 R&D Projects: GA MŠk(CZ) 7AMB12SK151 Institutional support: RVO:68081715 Keywords : retinoic acid isomers * retinoid * breast cancer * malignant cells * proteomic analysis Subject RIV: CB - Analytical Chemistry, Separation

  19. Quantum Zeno paradox and decay of the 235m U isomer in matter

    International Nuclear Information System (INIS)

    Panov, A.D.

    1995-01-01

    The known quantum Zeno paradox is considered from microscopic viewpoint as applied to observation of nuclear decay. It is shown that some phenomena, related with this paradox can produce sufficient effect on the constant of 235m U isomer decay during its implantation in metallic matrices. 43 refs., 3 figs

  20. Preparation, isolation and identification of non-conjugated C18:2 fatty acid isomers.

    Science.gov (United States)

    Fardin-Kia, Ali Reza

    2016-12-01

    Non-conjugated geometric/positional isomers of linoleic acid (c9,c12-18:2) are often present in processed foods and oils. The following work presents a simple addition/elimination reaction for preparation of non-conjugated 18:2 fatty acid isomers. A mixture containing positional and geometric isomers of C18:2 fatty acids was produced by addition of hydrobromic acid to the fatty acid double bonds, followed by its elimination with a strong sterically hindered base. Pure 8,12-, 8,13-, 9,12-, and 9,13-18:2 fatty acid methyl esters were isolated from the synthetic mixture by a combination of sub-ambient RP-HPLC and Ag + -HPLC. The determination of the double bond position was achieved by GC-MS using picolinyl esters derivatives. The determination of the fatty acid double bond geometric configuration was obtained by partial hydrogenation of the isolated isomer with hydrazine, followed by the GC-FID analysis. Published by Elsevier Ireland Ltd.

  1. Isomers in neutron-rich A ∼ 190 nuclides from 208Pb fragmentation

    International Nuclear Information System (INIS)

    Rykaczewski, Krzysztof Piotr; Caamano, M.; Banu, A.; Walker, P.M.; Morton, N.H.; Regan, P. H.; Regan, Patrick H; Pfutzner, M.; Podolyak, Zs.; Gerl, J.; Hellstrom, M.; Mayet, P.; Miernik, K.; Mineva, M.N.; Aprahamian, A.; Benlliure, J.; Bruce, A.M.; Butler, P.A.; Cortina Gil, D.; Cullen, D.M.; Doring, J.; Enqvist, T.; Fox, C.; Garces Narro, J.; Geissel, H.; Gelletly, W.; Giovinazzo, J.; Gorska, M.; Grawe, H.; Grzywacz, R.; Kleinbohl, A.; Korten, W.; Lewitowicz, M.; Lucas, R.; Mach, H.; O'Leary, C.D.; De Oliveira, F.; Pearson, C.J.; Rejmund, F.

    2004-01-01

    Relativistic projectile fragmentation of 208 Pb has been used to produce isomers in neutron-rich, A ∼ 190 nuclides. A forward-focusing spectrometer provided ion-by-ion mass and charge identification. The detection of gamma-rays emitted by stopped ions has led to the assignment of isomers in 188 Ta, 190 W, 192 Re, 193 Re, 195 Os, 197 Ir, 198 Ir, 200 Pt, 201 Pt, 202 Pt and 203 Au, with half-lives ranging from approximately 10 ns to 1 ms. Tentative isomer information has been found also for 174 Er, 175 Er, 185 Hf, 191 Re, 194 Re and 199 Ir. In most cases, time-correlated, singles gamma-ray events provided the first spectroscopic data on excited states for each nuclide. In 200 Pt and 201 Pt, the assignments are supported by gamma-gamma coincidences. Isomeric ratios provide additional information, such as half-life and transition energy constraints in particular cases. The level structures of the platinum isotopes are discussed, and comparisons are made with isomer systematics

  2. Determination of activation level energy of nuclear isomers by calibration of microspectra of radioactive sources

    International Nuclear Information System (INIS)

    Veres, A.; Pavlicsek, I.

    1980-01-01

    Nuclear isomers with unknown activation level were irradiated by calibrated radioactive sources. The integral cross sections were calculated for different energies of the sources. The activation energy was given by values coinciding with each other within the limits of error. The method made the determination of the unknown level of 1180+-10 keV of 195 Pt nucleus possible. (author)

  3. High-spin isomer in 211Rn, and the shape of the yrast line

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Fahlander, C.; Poletti, A.R.

    1981-08-01

    High spin yrast states in 211 Rn have been identified. A 61/2 - , 380 ns isomer found at 8856 keV is characterised as a core-excited configuration. The average shape of the yrast line shows a smooth behaviour with spin, in contrast to its neighbour 212 Rn. This difference is attributed to the presence of the neutron hole

  4. Observation of a new high-spin isomer in 94Pd

    International Nuclear Information System (INIS)

    Brock, T. S.; Nara Singh, B. S.; Wadsworth, R.; Boutachkov, P.; Gorska, M.; Grawe, H.; Pietri, S.; Domingo-Pardo, C.; Caceres, L.; Engert, T.; Farinon, F.; Gerl, J.; Goel, N.; Kojuharov, I.; Kurz, N.; Nociforo, C.; Prochazka, A.; Schaffner, H.; Weick, H.; Braun, N.

    2010-01-01

    A second γ-decaying high-spin isomeric state, with a half-life of 197(22)ns, has been identified in the N=Z+2 nuclide 94 Pd as part of a stopped-beam Rare Isotope Spectroscopic INvestigation at GSI (RISING) experiment. Weisskopf estimates were used to establish a tentative spin/parity of 19 - , corresponding to the maximum possible spin of a negative parity state in the restricted (p 1/2 , g 9/2 ) model space of empirical shell model calculations. The reproduction of the E3 decay properties of the isomer required an extension of the model space to include the f 5/2 and p 3/2 orbitals using the CD-Bonn potential. This is the first time that such an extension has been required for a high-spin isomer in the vicinity of 100 Sn and reveals the importance of such orbits for understanding the decay properties of high-spin isomers in this region. However, despite the need for the extended model space for the E3 decay, the dominant configuration for the 19 - state remains (πp 1/2 -1 g 9/2 -3 ) 11 x (νg 9/2 -2 ) 8 . The half-life of the known, 14 + , isomer was remeasured and yielded a value of 499(13) ns.

  5. Stability Computations for Isomers of La@Cn (n = 72, 74, 76

    Directory of Open Access Journals (Sweden)

    Ludwik Adamowicz

    2012-11-01

    Full Text Available Density-functional theory calculations are presented for low-energy La@C72, La@C74 and La@C76 isomers with IPR (isolated pentagon rule and non-IPR cages. The relative isomeric production yields at high temperatures are evaluated using the calculated terms, and the relationships to observations are discussed.

  6. 57Fe quadrupole splitting and isomer shift in various oxyhemoglobins: study using Mössbauer spectroscopy

    International Nuclear Information System (INIS)

    Oshtrakh, M. I.; Berkovsky, A. L.; Kumar, A.; Kundu, S.; Vinogradov, A. V.; Konstantinova, T. S.; Semionkin, V. A.

    2010-01-01

    A comparative study of normal human, rabbit and pig oxyhemoglobins and oxyhemoglobin from patients with chronic myeloleukemia and multiple myeloma using Mössbauer spectroscopy with a high velocity resolution demonstrated small variations of the 57 Fe quadrupole splitting and isomer shift. These variations may be a result of small structural differences in the heme iron stereochemistry of various hemoglobins.

  7. {sup 57}Fe quadrupole splitting and isomer shift in various oxyhemoglobins: study using Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Oshtrakh, M. I., E-mail: oshtrakh@mail.utnet.ru [Ural Federal University (The former Ural State Technical University-UPI), Faculty of Physical Techniques and Devices for Quality Control (Russian Federation); Berkovsky, A. L. [Hematological Scientific Center of the Russian Academy of Sciences (Russian Federation); Kumar, A.; Kundu, S., E-mail: sumankundu@south.du.ac.in [University of Delhi South Campus, Department of Biochemistry (India); Vinogradov, A. V.; Konstantinova, T. S. [Ural State Medical Academy, Faculty of Internal Diseases Propedeutics (Russian Federation); Semionkin, V. A. [Ural Federal University (The former Ural State Technical University-UPI), Faculty of Physical Techniques and Devices for Quality Control (Russian Federation)

    2010-04-15

    A comparative study of normal human, rabbit and pig oxyhemoglobins and oxyhemoglobin from patients with chronic myeloleukemia and multiple myeloma using Moessbauer spectroscopy with a high velocity resolution demonstrated small variations of the {sup 57}Fe quadrupole splitting and isomer shift. These variations may be a result of small structural differences in the heme iron stereochemistry of various hemoglobins.

  8. Cool diffusion flames of butane isomers activated by ozone in the counterflow

    KAUST Repository

    Alfazazi, Adamu; Al Omier, Abdullah Abdulaziz; Secco, Andrea; Selim, Hatem; Ju, Yiguang; Sarathy, Mani

    2018-01-01

    and sustenance of cool diffusion flames; as ozone-less cool diffusion flame of butane isomers could not be established even at high fuel mole fractions. The structure of a stable n-butane cool diffusion flame was qualitatively examined using a time of flight mass

  9. Differentiation of 2- and 6-isomers of (2-dimethylaminopropylbenzofuran by tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    V. A. Shevyrin

    2016-07-01

    Full Text Available Reliable identification of new psychoactive substances of 2-(2-methylaminopropylbenzofuran and 6-(2-methylaminopropylbenzofuran is problematic when analyzing by gas chromatography–mass spectrometry method. It found that these two isomers can be reliably differentiated by MS/MS spectra obtained by collision-induced dissociation of their protonated molecules.

  10. Chromatographic retention and structure roofing tile effect of isomers and its fine structure

    NARCIS (Netherlands)

    Walraven, J.J.; Ladon, A.W.; Keulemans, A.I.M.

    1968-01-01

    Logarithmic plots of gas chromatographic retention data for different classes of compds. on different pairs of stationary phases were constructed. A remarkable effect was found. Isomers are spread along parallel lines in a repeated pattern, forming a \\"roofing-tile\\" series. The scattering of points

  11. Dibenzoheptazethrene isomers with different biradical characters: An exercise of clar's aromatic sextet rule in singlet biradicaloids

    KAUST Repository

    Sun, Zhe; Lee, Sangsu; Park, Kyuhyung; Zhu, Xiaojian; Zhang, Wenhua; Zheng, Bin; Hu, Pan; Zeng, Zebing; Das, Soumyajit; Li, Yuan; Chi, Chunyan; Li, Runwei; Huang, Kuo-Wei; Ding, Jun; Kim, Dongho; Wu, Jishan

    2013-01-01

    that the number of aromatic sextet rings plays an important role in determination of their ground states. In order to test the validity of this rule in singlet biradicaloids, the two soluble and stable dibenzoheptazethrene isomers DBHZ1 and DBHZ2 were prepared

  12. Response of Dendroctonus mexicanus (Hopkins) to two optical isomers of verbenone

    Science.gov (United States)

    Vicente Diaz-Nunez; Guillermo Sanchez-Martinez; Nancy E. Gillette

    2006-01-01

    Given the need for diminishing the use of pesticides in natural environments, in this research we investigated the efficacy of two optical isomers of verbenone (4, 6, 6-trimethylbicyclo[3.1.1] hepto-3-en-e-1) as controls of the attack of Dendroctonus mexicanus (Hopkins) (Coleoptera: Curculionidae: Scolytinae).Two experiments were established in the...

  13. Ultrafast time-resolved absorption spectroscopy of geometric isomers of xanthophylls

    Science.gov (United States)

    Niedzwiedzki, Dariusz M.; Enriquez, Miriam M.; LaFountain, Amy M.; Frank, Harry A.

    2010-07-01

    This paper presents an ultrafast optical spectroscopic investigation of the excited state energies, lifetimes and spectra of specific geometric isomers of neoxanthin, violaxanthin, lutein, and zeaxanthin. All- trans- and 15,15'- cis-β-carotene were also examined. The spectroscopy was done on molecules purified by HPLC frozen immediately to inhibit isomerization. The spectra were taken at 77 K to maintain the configurations and to provide better spectral resolution than seen at room temperature. The kinetics reveal that for all of the molecules except neoxanthin, the S 1 state lifetime of the cis isomers is shorter than that of the all- trans isomers. The S 1 excited state energies of all the isomers were determined by recording S 1 → S 2 transient absorption spectra. The results obtained in this manner at cryogenic temperatures provide an unprecedented level of precision in the measurement of the S 1 energies of these xanthophylls, which are critical components in light-harvesting pigment-protein complexes of green plants.

  14. [Binocular coordination during reading].

    Science.gov (United States)

    Bassou, L; Granié, M; Pugh, A K; Morucci, J P

    1992-01-01

    Is there an effect on binocular coordination during reading of oculomotor imbalance (heterophoria, strabismus and inadequate convergence) and of functional lateral characteristics (eye preference and perceptually privileged visual laterality)? Recordings of the binocular eye-movements of ten-year-old children show that oculomotor imbalances occur most often among children whose left visual perceptual channel is privileged, and that these subjects can present optomotor dissociation and manifest lack of motor coordination. Close binocular motor coordination is far from being the norm in reading. The faster reader displays saccades of differing spatial amplitude and the slower reader an oculomotor hyperactivity, especially during fixations. The recording of binocular movements in reading appears to be an excellent means of diagnosing difficulties related to visual laterality and to problems associated with oculomotor imbalance.

  15. Quantifying linguistic coordination

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Tylén, Kristian

    task (Bahrami et al 2010, Fusaroli et al. 2012) we extend to linguistic coordination dynamical measures of recurrence employed in the analysis of sensorimotor coordination (such as heart-rate (Konvalinka et al 2011), postural sway (Shockley 2005) and eye-movements (Dale, Richardson and Kirkham 2012......). We employ nominal recurrence analysis (Orsucci et al 2005, Dale et al 2011) on the decision-making conversations between the participants. We report strong correlations between various indexes of recurrence and collective performance. We argue this method allows us to quantify the qualities...

  16. Stochastic Strategy Adjustment in Coordination Games

    NARCIS (Netherlands)

    Kosfeld, M.

    1999-01-01

    We explore a model of equilibrium selection in coordination games, where agents stochastically adjust their strategies to changes in their local environment. Instead of playing perturbed best-response, we assume that agents follow a rule of "switching to better strategies more likely". We relate

  17. Reprint of: Energetics of 2- and 3-coumaranone isomers: A combined calorimetric and computational study

    International Nuclear Information System (INIS)

    Sousa, Clara C.S.; Matos, M. Agostinha R.; Santos, Luís M.N.B.F.; Morais, Victor M.F.

    2014-01-01

    Highlights: • Experimental standard molar enthalpies of formation, sublimation of 2- and 3-coumaranone. • Mini-bomb combustion calorimetry, sublimation Calvet microcalorimetry. • DFT methods and high level composite ab initio calculations. • Theoretical estimate of the enthalpy of formation of isobenzofuranone. • Chemical shift (NICS) and the relative stability of the isomers. - Abstract: Condensed phase standard (p° = 0.1 MPa) molar enthalpies of formation for 2-coumaranone and 3-coumaranone were derived from the standard molar enthalpies of combustion, in oxygen, at T = 298.15 K, measured by mini-bomb combustion calorimetry. Standard molar enthalpies of sublimation of both isomers were determined by Calvet microcalorimetry. These results were combined to derive the standard molar enthalpies of formation of the compounds, in gas phase, at T = 298.15 K. Additionally, accurate quantum chemical calculations have been performed using DFT methods and high level composite ab initio calculations. Theoretical estimates of the enthalpies of formation of the compounds are in good agreement with the experimental values thus supporting the predictions of the same parameters for isobenzofuranone, an isomer which has not been experimentally studied. The relative stability of these isomers has been evaluated by experimental and computational results. The importance of some stabilizing electronic intramolecular interactions has been studied and quantitatively evaluated through Natural Bonding Orbital (NBO) analysis of the wave functions and the nucleus independent chemical shift (NICS) of the studied systems have been calculated in order to study and establish the effect of electronic delocalization upon the relative stability of the isomers

  18. Energetics of 2- and 3-coumaranone isomers: A combined calorimetric and computational study

    International Nuclear Information System (INIS)

    Sousa, Clara C.S.; Matos, M. Agostinha R.; Santos, Luís M.N.B.F.; Morais, Victor M.F.

    2013-01-01

    Highlights: • Experimental standard molar enthalpies of formation, sublimation of 2- and 3-coumaranone. • Mini-bomb combustion calorimetry, sublimation Calvet microcalorimetry. • DFT methods and high level composite ab initio calculations. • Theoretical estimate of the enthalpy of formation of isobenzofuranone. • Chemical shift (NICS) and the relative stability of the isomers. -- Abstract: Condensed phase standard (p° = 0.1 MPa) molar enthalpies of formation for 2-coumaranone and 3-coumaranone were derived from the standard molar enthalpies of combustion, in oxygen, at T = 298.15 K, measured by mini-bomb combustion calorimetry. Standard molar enthalpies of sublimation of both isomers were determined by Calvet microcalorimetry. These results were combined to derive the standard molar enthalpies of formation of the compounds, in gas phase, at T = 298.15 K. Additionally, accurate quantum chemical calculations have been performed using DFT methods and high level composite ab initio calculations. Theoretical estimates of the enthalpies of formation of the compounds are in good agreement with the experimental values thus supporting the predictions of the same parameters for isobenzofuranone, an isomer which has not been experimentally studied. The relative stability of these isomers has been evaluated by experimental and computational results. The importance of some stabilizing electronic intramolecular interactions has been studied and quantitatively evaluated through Natural Bonding Orbital (NBO) analysis of the wave functions and the nucleus independent chemical shift (NICS) of the studied systems have been calculated in order to study and establish the effect of electronic delocalization upon the relative stability of the isomers

  19. CYANOMETHANIMINE ISOMERS IN COLD INTERSTELLAR CLOUDS: INSIGHTS FROM ELECTRONIC STRUCTURE AND KINETIC CALCULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Vazart, Fanny; Latouche, Camille; Skouteris, Dimitrios; Barone, Vincenzo [Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56125 Pisa (Italy); Balucani, Nadia [Dipartimento di Chimica, Biologia e Biotecnologie, Universitá degli Studi di Perugia, Via Elce di Sotto 8, I-06123 Perugia (Italy)

    2015-09-10

    New insights into the formation of interstellar cyanomethanimine, a species of great relevance in prebiotic chemistry, are provided by electronic structure and kinetic calculations for the reaction CN + CH{sub 2} = NH. This reaction is a facile formation route of Z,E-C-cyanomethanimine, even under the extreme conditions of density and temperature typical of cold interstellar clouds. E-C-cyanomethanimine has been recently identified in Sgr B2(N) in the Green Bank Telescope (GBT) PRIMOS survey by P. Zaleski et al. and no efficient formation routes have been envisaged so far. The rate coefficient expression for the reaction channel leading to the observed isomer E-C-cyanomethanimine is 3.15 × 10-10 × (T/300){sup 0.152} × e{sup (−0.0948/T)}. According to the present study, the more stable Z-C-cyanomethanimine isomer is formed with a slightly larger yield (4.59 × 10{sup −10} × (T/300){sup 0.153} × e{sup (−0.0871/T)}. As the detection of E-isomer is favored due to its larger dipole moment, the missing detection of the Z-isomer can be due to the sensitivity limit of the GBT PRIMOS survey and the detection of the Z-isomer should be attempted with more sensitive instrumentation. The CN + CH{sub 2} = NH reaction can also play a role in the chemistry of the upper atmosphere of Titan where the cyanomethanimine products can contribute to the buildup of the observed nitrogen-rich organic aerosols that cover the moon.

  20. Providing theoretical data for detection of four formamidic acid isomers in astrophysical media

    Science.gov (United States)

    Vichietti, R. M.; da Silva, A. B. F.; Haiduke, R. L. A.

    2018-03-01

    We present a theoretical study, so that molecular data (geometrical parameters, vibrational frequencies, infrared intensities, electronic energies, enthalpies, and Gibbs energies) of four formamidic acid (FA) isomers (labeled here as FA1, FA2, FA3, and FA4) and formamide (HCONH2) are obtained from CCSD/cc-pVTZ, CCSD/aug-cc-pVTZ, CCSD/cc-pVQZ, and CCSD(T)/cc-pVTZ calculations. Furthermore, on the basis of insufficient or even lacking theoretical and experimental results in the literature, we employed the aforementioned theory levels to determine benchmark values of dipole moments and rotational constants for these four FA isomers in order to contribute for their detection in astrophysical environments. Besides, we provide for the first time data about forward and reverse rate constants (200-4000 K) and Arrhenius' parameters for each interconversion reaction between pairs of FA isomers as well as for the tautomeric process involving FA4 and formamide, which were calculated from a Complete Basis Set (CBS) extrapolation equation obtained at CCSD/cc-pVTZ optimized geometries. Our kinetic analysis indicated a faster interconversion between the FA structures in comparison with the FA4 ↔ HCONH2 process, suggesting that these isomers could co-exist in astrophysical media. Finally, we estimated that these isomers may be detected with relative abundances, [FAx]/[HCONH2] (x = 1, 2, 3, and 4), between ∼0.01 and ∼0.1% in astrophysical sources at chemical equilibrium conditions and temperatures around 1000 K. However, these ratios can become as high as ∼1, ∼3, and ∼5%, respectively, in hotter regions with temperatures around 2000, 3000, and 4000 K (expected, for example, in massive star-forming regions).

  1. Coordination studies of copper(II), cobalt(II) and iron(II) with isomeric pyridyl-tetrazole ligands

    DEFF Research Database (Denmark)

    Bond, A. D.; Fleming, A.; Gaire, J.

    2012-01-01

    The reaction of 2-(2H-tetrazol-5-yl)pyridine (L1) with 1,6-dibromohexane results in formation of the isomers 2-(6 ''-bromohexyl)-(1-tetrazol-5-yl)pyridine (12) and 2-(6 ''-bromohexyl)-(2-tetrazol-5-yl)pyridine (L3). Coordination reactions of 12 and 13 with CuCl2 center dot 2H(2)O, Co(SCN)(2) and ...... conformation in its equatorial plane. Complex 5 contains water molecules coordinated to Fe(II) in the axial sites, which form hydrogen bonds to the perchlorate counter anions. (C) 2011 Elsevier Ltd. All rights reserved....

  2. Dimensions of Organizational Coordination

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt; Aldewereld, Huib; Dignum, Virginia

    2013-01-01

    be supported to include organizational objectives and constraints into their reasoning processes by considering two alternatives: agent reasoning and middleware regulation. We show how agents can use an organizational specification to achieve organizational objectives by delegating and coordinating...... their activities with other agents in the society, using the GOAL agent programming language and the OperA organizational model....

  3. Reusability of coordination programs

    NARCIS (Netherlands)

    F. Arbab (Farhad); C.L. Blom (Kees); F.J. Burger (Freek); C.T.H. Everaars (Kees)

    1996-01-01

    textabstractIsolating computation and communication concerns into separate pure computation and pure coordination modules enhances modularity, understandability, and reusability of parallel and/or distributed software. This can be achieved by moving communication primitives (such as SendMessage and

  4. [Civilian-military coordination].

    Science.gov (United States)

    de Montravel, G

    2002-01-01

    Current humanitarian emergencies create complex, mutidimensional situations that stimulate simultaneous responses from a wide variety of sources including governments, non-governmental organizations (NGO), United Nations agencies, and private individuals. As a result, it has become essential to establish a coherent framework in which each actor can contribute promptly and effectively to the overall effort. This is the role of the United Nations Office for the Coordination of Humanitarian Affairs. Regardless of the circumstances and level of coordination, cooperation and collaboration between humanitarian and military personnel, it is necessary to bear in mind their objectives. The purpose of humanitarian action is to reduce human suffering. The purpose of military intervention is to stop warfare. The author of this article will discuss the three major obstacles to civilian-military coordination (strategic, tactical, and operational). Operations cannot be conducted smoothly and differences cannot be ironed out without mutual respect between the two parties, an explicit definition of their respective duties and responsibilities, a clear understanding of their cultural differences, and the presence of an organization and facilities for coordination and arbitrage by a neutral referee.

  5. Coordination of hand shape.

    Science.gov (United States)

    Pesyna, Colin; Pundi, Krishna; Flanders, Martha

    2011-03-09

    The neural control of hand movement involves coordination of the sensory, motor, and memory systems. Recent studies have documented the motor coordinates for hand shape, but less is known about the corresponding patterns of somatosensory activity. To initiate this line of investigation, the present study characterized the sense of hand shape by evaluating the influence of differences in the amount of grasping or twisting force, and differences in forearm orientation. Human subjects were asked to use the left hand to report the perceived shape of the right hand. In the first experiment, six commonly grasped items were arranged on the table in front of the subject: bottle, doorknob, egg, notebook, carton, and pan. With eyes closed, subjects used the right hand to lightly touch, forcefully support, or imagine holding each object, while 15 joint angles were measured in each hand with a pair of wired gloves. The forces introduced by supporting or twisting did not influence the perceptual report of hand shape, but for most objects, the report was distorted in a consistent manner by differences in forearm orientation. Subjects appeared to adjust the intrinsic joint angles of the left hand, as well as the left wrist posture, so as to maintain the imagined object in its proper spatial orientation. In a second experiment, this result was largely replicated with unfamiliar objects. Thus, somatosensory and motor information appear to be coordinated in an object-based, spatial-coordinate system, sensitive to orientation relative to gravitational forces, but invariant to grasp forcefulness.

  6. Block coordination copolymers

    Science.gov (United States)

    Koh, Kyoung Moo; Wong-Foy, Antek G; Matzger, Adam J; Benin, Annabelle I; Willis, Richard R

    2012-11-13

    The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

  7. Coordination failure caused by sunspots

    DEFF Research Database (Denmark)

    Beugnot, Julie; Gürgüç, Zeynep; Øvlisen, Frederik Roose

    2012-01-01

    on the efficient equilibrium, we consider sunspots as a potential reason for coordination failure. We conduct an experiment with a three player 2x2x2 game in which coordination on the efficient equilibrium is easy and should normally occur. In the control session, we find almost perfect coordination on the payoff......-dominant equilibrium, but in the sunspot treatment, dis-coordination is frequent. Sunspots lead to significant inefficiency, and we conclude that sunspots can indeed cause coordination failure....

  8. Development of a high performance liquid chromatography method for quantification of isomers β-caryophyllene and α-humulene in copaiba oleoresin using the Box-Behnken design.

    Science.gov (United States)

    de Almeida Borges, Vinícius Raphael; Ribeiro, Ana Ferreira; de Souza Anselmo, Carina; Cabral, Lúcio Mendes; de Sousa, Valéria Pereira

    2013-12-01

    The sesquiterpene isomers, β-Cariofileno (CAR) and α-Humuleno (HUM) are the primary constituents of the copaiba oleoresin species. These natural products are primarily used by the Amazonian population and marketed as phytotherapies and cosmetics. The aim of this study was to develop and validate a method that simultaneously assays the isomers present in copaiba oleoresins by high performance liquid chromatography using the Box-Behnken design. After preliminary studies, the reverse phase chromatographic system was selected using a cyano column and a mobile phase consisting of acetonitrile and phosphate buffer. The Box-Behnken design was applied at three levels and with four independent variables: flow rate (X1), gradient slope time (X2), proportion of organic compounds at the end of the gradient (X3) and at the beginning of the gradient (X4). Also, the responses of the dependent variables: CAR retention time (Y1) and the resolution between the CAR and HUM peaks (Y2) was assessed. The mathematical model obtained from the regression results was satisfactory (R(2)>0.98, n=27) and showed a quadratic relationship where the effects of interactions between the variables, was observed by response surface graphs. The simultaneous optimization method was used to establish the best compromise of the resolution between the CAR and HUM isomers while adjusting the retention time of CAR. This method was successfully optimized by BBD obtaining chromatographic peaks with good symmetry, resolution and separation efficiency. The validation of the developed method confirmed its specificity, precision, accuracy and linearity in the range of 5.0-11.0 and 0.4-1.0μg/mL for CAR and HUM, respectively, and is considered suitable for routine applications which assure quality control. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Variations of structures and solid-state conductivity of isomeric silver(I) coordination polymers having linear and V-shaped thiophene-centered ditriazole ligands

    International Nuclear Information System (INIS)

    Hu, Bin; Geng, Jiao; Zhang, Lie; Huang, Wei

    2014-01-01

    A pair of new linear and V-shaped acceptor–donor–acceptor (A−D−A) thiophene-centered ditriazole structural isomers, i.e., 2,5-di(1H-1,2,4-triazol-1-yl)thiophene (L 1 ) and 3,4-di(1H-1,2,4-triazol-1-yl)thiophene (L 2 ), has been synthesized and characterized. They are used as μ 2 -bridging ligands to prepare a pair of silver(I) coordination polymers formulated as [Ag(L 1 )(NO 3 )] n (1) and [Ag(L 2 )(NO 3 )] n (2), which are also structural isomers at the supramolecular level. X-ray single-crystal diffraction analyses for 1 and 2 reveal that they exhibit the same one-dimensional (1D) coordination polymers but different structural architectures because of the distinguishable shape and configuration of isomeric ligands (L 1 and L 2 ) and the alterations of the coordination numbers. More interestingly, compared with the free ligands, 1D silver(I) polymeric isomers 1 and 2 show significant enhancement of solid-state conductivity to different extents (1.42×10 4 and 2.17×10 3 times), where 6.96 times' enhancement of solid-state conductivity from 1 to 2 has been observed. The formation of Ag–N coordinative bonds and the configurational discrepancy of L 1 and L 2 are believed to play important roles in facilitating the electron transport between molecules, which can also be supported by Density Function Theory calculations of their band gaps. - Graphical abstract: A pair of linear and V-shaped isomeric thiophene-centered ditriazole ligands (L 1 ) and L 2 are used to prepare a pair of silver(I) polymeric isomers (1 and 2), where significant enhancement of solid-state conductivity to different extents are observed originating from the distinguishable shape and configuration of isomeric ligands. - Highlights: • A pair of linear and V-shaped thiophene-centered ditriazole structural isomers is prepared. • They are used as µ 2 -bridging ligands to prepare a pair of silver(I) polymeric isomers. • Significant enhancement of solid-state conductivity is observed

  10. Structure of two-, four-, and six-quasiparticle isomers in 174Yb and K-forbidden decays

    Science.gov (United States)

    Dracoulis, G. D.; Lane, G. J.; Kondev, F. G.; Byrne, A. P.; Kibédi, T.; Watanabe, H.; Ahmad, I.; Carpenter, M. P.; Freeman, S. J.; Janssens, R. V.; Hammond, N. J.; Lauritsen, T.; Lister, C. J.; Mukherjee, G.; Seweryniak, D.; Chowdhury, P.; Tandel, S. K.

    2005-04-01

    The stable nucleus 174Yb has been studied using deep-inelastic reactions and time-correlated γ-ray spectroscopy. New intrinsic states assigned include a 370-ns isomer at 1765 keV, which we associate with a predicted Kπ=7- two-quasineutron configuration. Analysis of the alignment and in-band properties of its rotational band, identified using time-correlated coincidences, allows characterization of the configuration. The properties of a newly identified rotational band built on the known 830-μs isomer at 1518 keV support the 6+, 2-quasineutron configuration assignment proposed previously. The 6+ band is fed by a four-quasiparticle, Kπ=14+ isomer at 3699 keV and several higher multiquasiparticle states, including a six-quasiparticle isomer at 6147 keV with K=(22,23). The results are discussed in terms of the states predicted on the basis of multiquasiparticle calculations. The anomalously fast K-forbidden transition strengths from the 14+ isomer are attributed to either K mixing in the neutron configuration or to random mixing in the high-level-density region. The 7- isomer decays are not abnormal, whereas the very hindered E2 transition from the 6+ isomer to the ground-state band remains unexplained.

  11. Linear and branched perfluorooctane sulfonate (PFOS) isomer patterns differ among several tissues and blood of polar bears.

    Science.gov (United States)

    Greaves, Alana K; Letcher, Robert J

    2013-09-01

    Perfluorooctane sulfonate (PFOS) is a globally distributed persistent organic pollutant that has been found to bioaccumulate and biomagnify in aquatic food webs. Although principally in its linear isomeric configuration, 21-35% of the PFOS manufactured via electrochemical fluorination is produced as a branched structural isomer. PFOS isomer patterns were investigated in multiple tissues of polar bears (Ursus maritimus) from East Greenland. The liver (n = 9), blood (n = 19), brain (n = 16), muscle (n = 5), and adipose (n = 5) were analyzed for linear PFOS (n-PFOS), as well as multiple mono- and di-trifluoromethyl-substituted branched isomers. n-PFOS accounted for 93.0 ± 0.5% of Σ-PFOS isomer concentrations in the liver, whereas the proportion was significantly lower (p<0.05) in the blood (85.4 ± 0.5%). Branched isomers were quantifiable in the liver and blood, but not in the brain, muscle, or adipose. In both the liver and blood, 6-perfluoromethylheptane sulfonate (P6MHpS) was the dominant branched isomer (2.61 ± 0.10%, and 3.26 ± 0.13% of Σ-PFOS concentrations, respectively). No di-trifluoromethyl-substituted isomers were detectable in any of the tissues analyzed. These tissue-specific isomer patterns suggest isomer-specific pharmacokinetics, perhaps due to differences in protein affinities, and thus differences in protein interactions, as well transport, absorption, and/or metabolism in the body. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  12. Gas chromatography and silver-ion high-performance liquid chromatography analysis of conjugated linoleic acid isomers in free fatty acid form using sulphuric acid in methanol as catalyst.

    Science.gov (United States)

    Luna, Pilar; Juárez, Manuela; de la Fuente, Miguel Angel

    2008-09-12

    This study used GC and silver-ion HPLC to examine the effects of temperature and time on methylation of individual and mixtures of conjugated linoleic acid (CLA) isomers in free fatty acid form using sulphuric acid as catalyst. In the conditions tested (temperatures between 20 and 50 degrees C and times between 10 and 60 min) methylation was complete while avoiding isomerization of conjugated dienes and the formation of artefacts that could interfere with chromatographic determinations. An analytical method using solvent extraction of the lipids followed by selective elution of the free fatty acids from aminopropyl bonded phase columns and methylation with H(2)SO(4) in mild conditions was then applied to determine the CLA isomers in free fatty acid form in rumen fluid, and the results were evaluated.

  13. Improving Project Manufacturing Coordination

    Directory of Open Access Journals (Sweden)

    Korpivaara Ville

    2014-09-01

    Full Text Available The objective of this research is to develop firms’ project manufacturing coordination. The development will be made by centralizing the manufacturing information flows in one system. To be able to centralize information, a deep user need assessment is required. After user needs have been identified, the existing system will be developed to match these needs. The theoretical background is achieved through exploring the literature of project manufacturing, development project success factors and different frameworks and tools for development project execution. The focus of this research is rather in customer need assessment than in system’s technical expertise. To ensure the deep understanding of customer needs this study is executed by action research method. As a result of this research the information system for project manufacturing coordination was developed to respond revealed needs of the stakeholders. The new system improves the quality of the manufacturing information, eliminates waste in manufacturing coordination processes and offers a better visibility to the project manufacturing. Hence it provides a solid base for the further development of project manufacturing.

  14. Universal mechatronics coordinator

    Science.gov (United States)

    Muir, Patrick F.

    1999-11-01

    Mechatronic systems incorporate multiple actuators and sensor which must be properly coordinated to achieve the desired system functionality. Many mechatronic systems are designed as one-of-a-kind custom projects without consideration for facilitating future system or alterations and extensions to the current syste. Thus, subsequent changes to the system are slow, different, and costly. It has become apparent that manufacturing processes, and thus the mechatronics which embody them, need to be agile in order to more quickly and easily respond to changing customer demands or market pressures. To achieve agility, both the hardware and software of the system need to be designed such that the creation of new system and the alteration and extension of current system is fast and easy. This paper describes the design of a Universal Mechatronics Coordinator (UMC) which facilitates agile setup and changeover of coordination software for mechatronic systems. The UMC is capable of sequencing continuous and discrete actions that are programmed as stimulus-response pairs, as state machines, or a combination of the two. It facilitates the modular, reusable programing of continuous actions such as servo control algorithms, data collection code, and safety checking routines; and discrete actions such as reporting achieved states, and turning on/off binary devices. The UMC has been applied to the control of a z- theta assembly robot for the Minifactory project and is applicable to a spectrum of widely differing mechatronic systems.

  15. Distributed Coordinate Descent Method for Learning with Big Data

    OpenAIRE

    Richtárik, Peter; Takáč, Martin

    2013-01-01

    In this paper we develop and analyze Hydra: HYbriD cooRdinAte descent method for solving loss minimization problems with big data. We initially partition the coordinates (features) and assign each partition to a different node of a cluster. At every iteration, each node picks a random subset of the coordinates from those it owns, independently from the other computers, and in parallel computes and applies updates to the selected coordinates based on a simple closed-form formula. We give bound...

  16. Synthesis and characterization of tissue-retainable methylsulfonyl polychlorinated biphenyl isomers

    International Nuclear Information System (INIS)

    Haraguchi, K.; Kuroki, H.; Masuda, Y.

    1987-01-01

    Eighty-six positional isomers of methylsulfonyl polychlorinated biphenyls (MSF-PCBs) have been synthesized by three synthetic routes: (1) the diazo coupling reaction of 3-(methylsulfonyl)chloroaniline with chlorobenzene; (2) nucleophilic substitution of PCB with methanethiolate and successive oxidation of the corresponding methyl sulfide; (3) the diazo coupling reaction of chloroaniline with chlorothioanisole and successive oxidation of the methyl sulfide. Pure isomers were characterized by their proton magnetic resonance and mass spectra and used to unambiguously identify the MSF metabolites retained in human tissues by using high-resolution capillary gas chromatography (GC). The GC analysis showed that 40 MSF derivatives were positively identified in the tissue of a patient with Yusho on the basis of comparisons of their GC retention data with those of the standard compounds

  17. Optimizing recoil-isomer tagging with the Argonne fragment mass analyzer

    International Nuclear Information System (INIS)

    Garnsworthy, A.B.; Lister, C.J.; Regan, P.H.; Blank, B.B.; Cullen, I.J.; Gros, S.; Henderson, D.J.; Jones, G.A.; Liu, Z.; Seweryniak, D.; Shumard, B.R.; Thompson, N.J.; Williams, S.J.; Zhu, S.

    2008-01-01

    A new focal plane detector arrangement for the Fragment Mass Analyzer (FMA) has been built and tested at Argonne National Laboratory. This set-up is particularly sensitive for performing Recoil-Isomer Tagging on nuclei with isomeric states with lifetimes in the microsecond range. Recoiling nuclei from fusion-evaporation reactions at the target position are dispersed by their ratio of mass to charge (A/q) by the FMA and stopped in low pressure gas (air) at the focal plane. Subsequent gamma decays from isomeric states in the reaction products are observed using Ge detectors. A constant gas flow through the focal plane chamber efficiently removes longer-lived beta-decaying species from sight of the detectors. This set-up has been commissioned successfully with the microsecond isomer in 80 Rb, populated via the 52 Cr( 32 S, 3pn) reaction at 135 MeV

  18. Identification of (2-aminopropyl)benzofuran (APB) phenyl ring positional isomers in internet purchased products.

    Science.gov (United States)

    Stanczuk, Andrzej; Morris, Noreen; Gardner, Elizabeth A; Kavanagh, Pierce

    2013-04-01

    5-(2-Aminopropyl)benzofuran (5-APB), a 'research chemical' that was first reported by UK authorities to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) in 2010, is anecdotally reported to produce a combination of stimulant and entactogenic effects. More recently, in 2011, 6-(2-aminopropyl)benzofuran (6-APB) was identified by Hungarian authorities. To confirm positional isomer identity in Internet purchased products, 4- 5- 6- and 7-APBs were synthesized and found to be separable by gas chromatography (as heptafluorobutyramide derivatives) and liquid chromatography. The analyses of products purchased from online vendors of 'research chemicals' identified the presence of 5- or 6-APBs. These findings were further confirmed by liquid chromatography-mass spectrometry and (1) H nuclear magnetic resonance spectroscopy. In products containing 6-APB, the 4- positional isomer was also identified and this may have arisen during the manufacturing process. Copyright © 2013 John Wiley & Sons, Ltd.

  19. Standard molar enthalpies of formation and of sublimation of the terphenyl isomers

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Santos, Luis M.N.B.F.; Lima, Luis M. Spencer S.

    2008-01-01

    The standard (p 0 = 0.1 MPa) molar enthalpies of formation in the crystalline phases of ortho, meta and para-terphenyl isomers, at T = 298.15 K, were derived from the standard molar energies of combustion, measured by mini-bomb combustion calorimetry. The Knudsen mass-loss effusion technique was used to measure the dependence of the vapour pressure of the crystals with the temperature, thus deriving their standard molar enthalpies of sublimation by means of the Clausius-Clapeyron equation. Combining the standard molar enthalpies of formation and sublimation of the crystalline terphenyls, the standard molar enthalpies of formation in the gaseous state, at T = 298.15 K, were derived for the three isomers. Results are provided in a table. The results show small but detectable isomerization enthalpies between the terphenyls, indicating the following relative enthalpic stabilities: m- > p- ∼ o-terphenyl

  20. Experimental thermochemical study of the three methyl substituted 2-acetylthiophene isomers

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Santos, Ana Filipa L.O.M.

    2008-01-01

    A rotating-bomb combustion calorimeter was used to determine the standard (p 0 = 0.1 MPa) molar enthalpies of combustion, Δ c H m 0 , of the liquids 2-acetyl-3-methylthiophene, 2-acetyl-4-methylthiophene, and 2-acetyl-5-methylthiophene, from which the standard molar enthalpies of formation, Δ f H m 0 , in the liquid phase, at the temperature of 298.15 K, were derived. The standard molar enthalpies of vaporization, Δ l g H m 0 , at T = 298.15 K, for those compounds, were obtained by high temperature Calvet microcalorimetry. From the experimental results, the standard molar enthalpies of formation of the three methyl substituted 2-acetylthiophene isomers, in the gaseous phase, were calculated and a comparison between the relative stability and the energetic of the three isomers was carried out

  1. Effect of food processing on degradation of hexachlorocyclohexane and its isomers in milk.

    Science.gov (United States)

    Singh, Sujatha; Nelapati, Krishnaiah

    2017-03-01

    To study the effect of different food processing techniques on the degradation of organochlorine compounds (α, β, ɣ and δ hexachlorocyclohexane isomers (HCH)) residues in both natural and fortified samples of milk. Raw milk samples are collected from the local areas of Hyderabad, India. Naturally and fortified milk samples (HCH) were subjected to various food processing techniques, pasteurization (63ºC for ½ h), sterilization (121ºC for 15 min) and boiling for 5 min and analyzed by gas chromatography with electron capture detector using quick, easy, cheap, effective, rugged and safe method for multiresidue analysis of pesticides in milk with slight modification. The final mean residual concentration of pesticide in milk after heat processing and percentage of degradation were calculated with respective treatments. Heat treatments are highly effective on reduction of mean residual concentration of HCH in milk. In which Sterilization and boiling proved to be more effective in degradation of HCH isomers.

  2. Resolution of the 179W isomer anomaly: exposure of a fermi aligned s-band

    International Nuclear Information System (INIS)

    Walker, P.M.; Surrey Univ., Guildford; Dracoulis, G.D.; Byrne, A.P.; Fabricius, B.; Kibedi, T.; Stuchbery, A.E.

    1991-06-01

    The K Π = 35/2 - , five quasiparticle isomer in 179 W is shown to decay into the region of a backbend in the 7/2 - [514] band, allowing for the first time the identification of a full set of aligned-band states. Destructive interference results from level-mixing in the band-crossing region. The deduced γ-ray branching ratios are used to establish the mixing matrix elements and to show that the aligned band has a high value of the K-quantum number. The properties of well-defined alignment and yet also high-K, provided the first clear example of a Fermi Aligned s-band. The anomalous decay of the isomer itself is now explained. 11 refs., 1 tab., 3 figs

  3. Electronic single-molecule identification of carbohydrate isomers by recognition tunnelling

    Science.gov (United States)

    Im, Jongone; Biswas, Sovan; Liu, Hao; Zhao, Yanan; Sen, Suman; Biswas, Sudipta; Ashcroft, Brian; Borges, Chad; Wang, Xu; Lindsay, Stuart; Zhang, Peiming

    2016-12-01

    Carbohydrates are one of the four main building blocks of life, and are categorized as monosaccharides (sugars), oligosaccharides and polysaccharides. Each sugar can exist in two alternative anomers (in which a hydroxy group at C-1 takes different orientations) and each pair of sugars can form different epimers (isomers around the stereocentres connecting the sugars). This leads to a vast combinatorial complexity, intractable to mass spectrometry and requiring large amounts of sample for NMR characterization. Combining measurements of collision cross section with mass spectrometry (IM-MS) helps, but many isomers are still difficult to separate. Here, we show that recognition tunnelling (RT) can classify many anomers and epimers via the current fluctuations they produce when captured in a tunnel junction functionalized with recognition molecules. Most importantly, RT is a nanoscale technique utilizing sub-picomole quantities of analyte. If integrated into a nanopore, RT would provide a unique approach to sequencing linear polysaccharides.

  4. Structure and phase transitions of the 6,6-cyclopropane isomer of C61H2

    International Nuclear Information System (INIS)

    Stetzer, M.R.; Heiney, P.A.; Stephens, P.W.; Dinnebier, R.E.; Zhu, Q.; McGhie, A.R.; Strongin, R.M.; Brandt, B.M.; Smith, A.B. III

    2000-01-01

    We have used x-ray powder diffraction and differential scanning calorimetry to study the crystalline structures and thermal behavior of the 6,6-cyclopropane isomer of C 61 H 2 . At room temperature, the C 61 H 2 cyclopropane molecules, like those of the 6,5-annulene isomer and C 60 O epoxide, are orientationally disordered and crystallize on a face-centered-cubic lattice such that their methylene groups are statistically disordered among the octahedral voids. Unlike 6,5-C 61 H 2 and C 60 O, the low-temperature structure is not Pa3-bar, but rather a low-symmetry orthorhombic lattice in which a≅b< c. The orientational melting takes place via a two-step transition centered around 198-213 K

  5. IR and Raman spectra of nitroanthracene isomers: substitional effects based on density functional theory study.

    Science.gov (United States)

    Alparone, Andrea; Librando, Vito

    2012-04-01

    Structure, IR and Raman spectra of 1-, 2- and 9-nitroanthracene isomers (1-NA, 2-NA and 9-NA) were calculated and analyzed through density functional theory computations using the B3LYP functional with the 6-311+G** basis set. Steric and π-conjugative effects determine the characteristic ONCC dihedral angles, which vary from 0° (2-NA) to 28-29° (1-NA) and 59° (9-NA), influencing the relative order of stability along the series 9-NA3000 cm(-1) and utility to discriminate the NA isomers. Structural and spectroscopic results suggest that the unknown mutagenic activity of 1-NA is expected to be between that of 9-NA and 2-NA. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Isospin quantum number and structure of the excited states in halo nuclei. Halo-isomers

    International Nuclear Information System (INIS)

    Izosimov, I.N.

    2015-01-01

    It has been shown that isobar-analog (IAS), double isobar-analog (DIAS), configuration (CS), and double configuration states (DCS) can simultaneously have n-n, n-p, and p-p halo components in their wave functions. Differences in halo structure of the excited and ground states can result in the formation of isomers (halo-isomers). Both the Borromean and tango halo types can be observed for n-p configurations of atomic nuclei. The structure of the ground and excited states with different isospin quantum number in halo-like nuclei is discussed. B(Mλ) and B(Eλ) for γ-transitions in 6-8 Li, 8-10 Be, 8,10,11 B, 10-14 C, 13-17 N, 15-17,19 O, and 17 F are analyzed. Special attention is given to nuclei whose ground state does not exhibit halo structure, but the excited state may have one.

  7. Resolution of the 179W-isomer anomaly: Exposure of a Fermi-aligned s band

    International Nuclear Information System (INIS)

    Walker, P.M.; Dracoulis, G.D.; Byrne, A.P.; Fabricius, B.; Kibedi, T.; Stuchbery, A.E.; Department of Physics, University of Surrey, Guildford, GU2 5XH United Kingdom)

    1991-01-01

    The K π =35/2 - , five-quasiparticle isomer in 179 W is shown to decay into the region of a backbend in the 7/2 - [514] band, allowing for the first time the identification of a full set of aligned-band states. Destructive interference results from level mixing in the band-crossing region. The deduced γ-ray branching ratios are used to establish the mixing matrix elements and to show that the aligned band has a high value of the K quantum number. The properties of well-defined alignment and yet also high K provide the first clear example of a Fermi-aligned s band. The anomalous decay of the isomer itself is now explained

  8. Energy of the 4(+) isomer and new bands in the odd-odd nucleus 74Br

    International Nuclear Information System (INIS)

    Doering, J.; Holcomb, J.W.; Johnson, T.D.; Riley, M.A.; Tabor, S.L.; Womble, P.C.; Winter, G.

    1993-01-01

    High-spin states of the odd-odd nucleus 74 Br were investigated via the reactions 58 Ni ( 19 F,2pn) 74 Br and 65 Cu( 12 C,3n) 74 Br at beam energies of 62 and 50 MeV, respectively. On the basis of coincidence data new levels have been introduced and partly grouped into rotational bands. Some of these new states decay to known levels of negative-parity bands built on both the ground state and the long-lived 4 (+) isomer. Thus, an excitation energy of 13.8 keV has been deduced for the long-lived isomer in 74 Br. The level sequences observed are interpreted in terms of Nilsson configurations in conjunction with collective excitations

  9. The nuclear isomer transition in Thorium-229. Search for the VUV photon

    Energy Technology Data Exchange (ETDEWEB)

    Stellmer, Simon [TU Wien (Austria). Atominstitut; VCQ, Vienna (Austria); Schreitl, Matthias; Schumm, Thorsten [TU Wien (Austria). Atominstitut; Yoshimura, Koji [Okayama University (Japan)

    2015-07-01

    The isotope {sup 229}Th is believed to possess a low-lying nuclear excitation, at an energy of about 7.8(5) eV, corresponding to a wavelength of 160(10) nm. Convincing direct evidence of the existence of this state, for instance by observation of its excitation or decay, is still pending. Optical excitation of the isomer state is an exceptional challenge, as the required wavelength is not known, the transition is believed to be extremely narrow, and the choice of suitable lasers is limited. Instead, we use synchrotron radiation at 29 keV to populate the second excited state, which then decays into the desired isomer state. This state proceeds further into the ground state under emission of the much sought-after VUV photon. This photon is detected in a spectrometer. The measurements are performed at the SPring-8 facility in Japan; we will report on the latest status of the experiment.

  10. Structural, kinetic, and thermodynamic characterization of the interconverting isomers of MS-325, a gadolinium(III)-based magnetic resonance angiography contrast agent.

    Science.gov (United States)

    Tyeklar, Zoltan; Dunham, Stephen U; Midelfort, Katarina; Scott, Daniel M; Sajiki, Hirano; Ong, Karen; Lauffer, Randall B; Caravan, Peter; McMurry, Thomas J

    2007-08-06

    The amphiphilic gadolinium complex MS-325 ((trisodium-{(2-(R)-[(4,4-diphenylcyclohexyl) phosphonooxymethyl] diethylenetriaminepentaacetato) (aquo)gadolinium(III)}) is a contrast agent for magnetic resonance angiography (MRA). MS-325 comprises a GdDTPA core with an appended phosphodiester moiety linked to a diphenylcyclohexyl group to facilitate noncovalent binding to serum albumin and extension of the plasma half-life in vivo. The chiral DTPA ligand (R) was derived from L-serine, and upon complexation with gadolinium, forms two interconvertible diastereomers, denoted herein as isomers A and B. X-ray crystallography of the tris(ethylenediamine)cobalt(III) salt derivative of isomer A revealed a structure in the polar acentric space group P32. The structure consisted of three independent molecules of the gadolinium complex in the asymmetric unit along with three Delta-[Co(en)3]3+ cations, and it represents an unusual example of spontaneous Pasteur resolution of the cobalt cation. The geometry of the coordination core was best described as a distorted trigonal prism, and the final R factor was 5.6%. The configuration of the chiral central nitrogen of the DTPA core was S. The Gd-water (2.47-2.48 A), the Gd-acetate oxygens (2.34-2.42 A), and the Gd-N bond distances (central N, 2.59-2.63 A; terminal N, 2.74-2.80 A) were similar to other reported GdDTPA structures. The structurally characterized single crystal was one of two interconvertable diastereomers (isomers A and B) that equilibrated to a ratio of 1.81 to 1 at pH 7.4 and were separable at elevated pH by ion-exchange chromatography. The rate of isomerization was highly pH dependent: k1 = (1.45 +/- 0.08) x 102[H+] + (4.16 +/- 0.30) x 105[H+]2; k-1 = (2.57 +/- 0.17) x 102[H+] + (7.54 +/- 0.60) x 105[H+]2.

  11. Simple and effective method for nuclear tellurium isomers separation from antimony cyclotron targets

    International Nuclear Information System (INIS)

    Bondarevskij, S.I.; Eremin, V.V.

    1999-01-01

    Simple and effective method of generation of tellurium nuclear isomers from irradiated on cyclotron metallic antimony is suggested. Basically this method consists in consideration of the big difference in volatilities of metallic forms of antimony, tin and tellurium. Heating of the tin-antimony alloy at 1200 K permits to separate about 90 % of produced quantity of 121m Te and 123m Te (in this case impurity of antimony radionuclides is not more than 1 % on activity) [ru

  12. Analysis of shape isomer yields of Pu in the framework of dynamical ...

    Indian Academy of Sciences (India)

    c Indian Academy of Sciences. Vol. 78, No. 2 ... Abstract. Data on shape isomer yield for α+235U reaction at Elab α. = 20–29 MeV are ... a fissionable nucleus via different channels can be calculated using a standard Monte ... the liquid drop potential energy Vld(r, J) of a rotating nucleus with an angular momentum. J and the ...

  13. New decay modes of the high-spin isomer of 124Cs

    Science.gov (United States)

    Radich, A. J.; Garrett, P. E.; Andreoiu, C.; Ball, G. C.; Bianco, L.; Bildstein, V.; Chagnon-Lessard, S.; Cross, D. S.; Demand, G. A.; Diaz Varela, A.; Dunlop, R.; Finlay, P.; Garnsworthy, A. B.; Hackman, G.; Hadinia, B.; Jigmeddorj, B.; Laffoley, A. T.; Leach, K. G.; McGee, E.; Michetti-Wilson, J.; Orce, J. N.; Rajabali, M. M.; Rand, E. T.; Starosta, K.; Sumithrarachchi, C. S.; Svensson, C. E.; Triambak, S.; Wang, Z. M.; Williams, S. J.; Wong, J.; Wood, J. L.; Yates, S. W.

    2017-09-01

    A new β+/EC branch of 0.11± 0.02% from the (7)+ isomer of 124Cs was identified in a measurement of the decay of 124Cs using the 8π spectrometer at TRIUMF. Combinations of γ-γ, γ-e-, and e--e- coincidence data were used to further investigate the isomeric decay. Six new transitions were observed and their branching ratios were measured.

  14. Stereospecific Synthesis of Two Isomers of (4,8 - Dimethyldecanal: The Aggregation Pheromone of Tribolium spp

    Directory of Open Access Journals (Sweden)

    Zarbin Paulo H.G.

    1998-01-01

    Full Text Available A straightforward stereospecific synthesis of two stereoisomers, (4R, 8S and (4S, 8S, of 4,8-dimethyldecanal (1, out of four possible isomers, is described. The key step employs the coupling reaction of tosylates (3 and (3a, which are obtained from (R- and (S- citronellol, with the chiral Grignard reagent prepared from comercial (S-(+-1-bromo-2-methylbutane (4.

  15. The g-factor of the K=25 isomer in sup 182 Os

    Energy Technology Data Exchange (ETDEWEB)

    Alderson, A.; Fallon, P.; Goldring, G.; Roberts, J.; Sharpey-Schafer, J.; Twin P. (Liverpool Univ. (UK). Oliver Lodge Lab.); Bentley, M.; Bruce, A. (Science and Engineering Research Council, Daresbury (UK). Daresbury Lab.); Broude, C. (Weizmann Inst. of Science, Rehovoth (Israel). Dept. of Nuclear Physics); Dafni, E. (Rochester Univ., NY (USA). Nuclear Structure Research Lab.); Hass, M. (Argonne National Lab. (USA)); Nyberg, J.; Sletten, G. (Niels Bohr Inst., Roskilde (Denmark))

    1989-09-28

    The g-factor of the K=I=25 isomer in {sup 182}Os has been measured by observing the angular precession of the decay {gamma}-ray angular distribution in an external magnetic field as g=+0.425(8). This result is compared with predictions based on experimental g-factors of single-particle Nilsson orbitals in this mass region. (orig.).

  16. Constitutional Isomers of Dendrimer-like Star Polymers: Design, Synthesis and Conformational and Structural Properties; TOPICAL

    International Nuclear Information System (INIS)

    Pople, John A.

    2001-01-01

    The design, synthesis and solution properties of six constitutional isomers of dendrimer-like star polymers is described. Each of the polymers have comparable molecular weights ((approx) 80,000 g/mol), narrow polydispersities ( and lt; 1.19) and an identical number of branching junctures (45) and surface hydroxyl functionalities (48). The only difference in the six isomers is the placement of the branching junctures. The polymers are constructed from high molecular weight poly(e-caprolactone) with branching junctures derived from 2,2'-bis(hydroxylmethyl) propionic acid (bis-MPA) emanating from a central core. The use of various generations of dendritic initiators and dendrons coupled with the ring opening polymerization of e-caprolactones allowed a modular approach to the dendrimer-like star polymer isomers. The most pronounced effects on the physical properties/morphology and hydrodynamic volume was for those polymers in which the branching was distributed throughout the sample in a dendrimer-like fashion. The versatility of this approach has provided the possibility of understanding the relationship between architecture and physical properties. Dynamic light scattering and small angle X-ray scattering techniques were used to determine the hydrodynamic radius Rh and radius of gyration Rg respectively. The relationship between Rg and molecular weight was indicative of a compact star-like structure, and did not show advanced bias towards either the dense core or dense shell models. The radial density distribution of the isomers was therefore modeled according to a many arm star polymer, and good agreement was found with experimental measures of Rh/Rg

  17. Low and High Temperature Combustion Chemistry of Butanol Isomers in Premixed Flames and Autoignition Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sarathy, S M; Pitz, W J; Westbrook, C K; Mehl, M; Yasunaga, K; Curran, H J; Tsujimura, T; Osswald, P; Kohse-Hoinghaus, K

    2010-12-12

    Butanol is a fuel that has been proposed as a bio-derived alternative to conventional petroleum derived fuels. The structural isomer in traditional 'bio-butanol' fuel is n-butanol, but newer conversion technologies produce iso-butanol as a fuel. In order to better understand the combustion chemistry of bio-butanol, this study presents a comprehensive chemical kinetic model for all the four isomers of butanol (e.g., 1-, 2-, iso- and tert-butanol). The proposed model includes detailed high temperature and low temperature reaction pathways. In this study, the primary experimental validation target for the model is premixed flat low-pressure flame species profiles obtained using molecular beam mass spectrometry (MBMS). The model is also validated against previously published data for premixed flame velocity and n-butanol rapid compression machine and shock tube ignition delay. The agreement with these data sets is reasonably good. The dominant reaction pathways at the various pressures and temperatures studied are elucidated. At low temperature conditions, we found that the reaction of alphahydroxybutyl with O{sub 2} was important in controlling the reactivity of the system, and for correctly predicting C{sub 4} aldehyde profiles in low pressure premixed flames. Enol-keto isomerization reactions assisted by HO{sub 2} were also found to be important in converting enols to aldehydes and ketones in the low pressure premixed flames. In the paper, we describe how the structural features of the four different butanol isomers lead to differences in the combustion properties of each isomer.

  18. New decay modes of the high-spin isomer of {sup 124}Cs

    Energy Technology Data Exchange (ETDEWEB)

    Radich, A.J.; Garrett, P.E.; Bianco, L.; Bildstein, V.; Chagnon-Lessard, S.; Demand, G.A.; Diaz Varela, A.; Dunlop, R.; Finlay, P.; Hadinia, B.; Jigmeddorj, B.; Laffoley, A.T.; Leach, K.G.; McGee, E.; Michetti-Wilson, J.; Rand, E.T.; Svensson, C.E.; Wong, J. [University of Guelph, Department of Physics, Guelph, ON (Canada); Andreoiu, C.; Cross, D.S.; Starosta, K. [Simon Fraser University, Department of Chemistry, Burnaby, BC (Canada); Ball, G.C.; Garnsworthy, A.B.; Hackman, G.; Rajabali, M.M. [TRIUMF, Vancouver, BC (Canada); Orce, J.N. [TRIUMF, Vancouver, BC (Canada); University of the Western Cape, Department of Physics, Bellville (South Africa); Sumithrarachchi, C.S. [University of Guelph, Department of Physics, Guelph, ON (Canada); Michigan State University, National Superconducting Cyclotron Laboratory, East Lansing, MI (United States); Triambak, S. [TRIUMF, Vancouver, BC (Canada); University of the Western Cape, Department of Physics, Bellville (South Africa); iThemba LABS, Somerset West (South Africa); Wang, Z.M. [Simon Fraser University, Department of Chemistry, Burnaby, BC (Canada); TRIUMF, Vancouver, BC (Canada); Williams, S.J. [TRIUMF, Vancouver, BC (Canada); Michigan State University, National Superconducting Cyclotron Laboratory, East Lansing, MI (United States); Wood, J.L. [Georgia Institute of Technology, School of Physics, Atlanta, GA (United States); Yates, S.W. [University of Kentucky, Departments of Chemistry and Physics and Astronomy, Lexington, KY (United States)

    2017-09-15

    A new β{sup +}/EC branch of 0.11 ± 0.02 % from the (7){sup +} isomer of {sup 124}Cs was identified in a measurement of the decay of {sup 124}Cs using the 8 π spectrometer at TRIUMF. Combinations of γ-γ, γ-e{sup -}, and e{sup -}-e{sup -} coincidence data were used to further investigate the isomeric decay. Six new transitions were observed and their branching ratios were measured. (orig.)

  19. Calibration of Sn-119 isomer shift using ab initio wave function methods

    NARCIS (Netherlands)

    Kurian, Reshmi; Filatov, Michael

    2009-01-01

    The isomer shift for the 23.87 keV M1 resonant transition in the Sn-119 nucleus is calibrated with the help of ab initio calculations. The calibration constant alpha(Sn-119) obtained from Hartree-Fock (HF) calculations (alpha(HF)(Sn-119)=(0.081 +/- 0.002)a(0)(-3) mm/s) and from second-order

  20. Indirect and direct measurement of thermal neutron acceleration by inelastic scattering on the 177Lu isomer

    International Nuclear Information System (INIS)

    Belier, G.; Roig, O.; Meot, V.; Daugas, J.M.; Aupiais, J.; Jutier, Ch.; Le Petit, G.; Veyssiere, Ch.

    2008-01-01

    When neutrons interact with isomers, these isomers can de-excite and in such a reaction the outgoing neutron has an energy greater than the in-going one. This process is referred as Inelastic Neutron Acceleration or Super-elastic Scattering. Up to now this process was observed for only two nucleus, 152m Eu and 180m Hf by measuring the number of fast neutrons produced by isomeric targets irradiated with thermal neutrons. In these experiments the energies of the accelerated neutrons were not measured. This report presents an indirect measurement of inelastic neutron acceleration on 177m Lu, based on the burn-up and the radiative capture cross sections measurements. Since at thermal energies the inelastic scattering and the radiative capture are the only processes that contribute to the isomer burn-up, the inelastic cross section can be deduced from the difference between the two measured quantities. Applying this method for the 177 Lu isomer with different neutron fluxes we obtained a value of (257 ± 50) barns (for a temperature of 323 K) and determined that there is no integral resonance for this process. In addition the radiative capture cross section on 177g Lu was measured with a much better accuracy than the accepted value. Since the acceleration cross section is quite high, a direct measurement of this process was undertaken, sending thermal neutrons and measuring the fast neutrons. The main goal now is to measure the outgoing neutron energies in order to identify the neutron transitions in the exit channel. In particular the K conservation question can be addressed by such a measurement. (author)

  1. Investigation of HNCO isomer formation in ice mantles by UV and thermal processing: An experimental approach

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez-Escobar, A.; Giuliano, B. M.; Caro, G. M. Muñoz; Cernicharo, J. [Centro de Astrobiología, INTA-CSIC, Carretera de Ajalvir, km 4, Torrejón de Ardoz, E-28850 Madrid (Spain); Marcelino, N., E-mail: bgiuliano@cab.inta-csic.es [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States)

    2014-06-10

    Current gas-phase models do not account for the abundances of HNCO isomers detected in various environments, suggesting their formation in icy grain mantles. We attempted to study a formation channel of HNCO and its possible isomers by vacuum-UV photoprocessing of interstellar ice analogs containing H{sub 2}O, NH{sub 3}, CO, HCN, CH{sub 3}OH, CH{sub 4}, and N{sub 2} followed by warm-up under astrophysically relevant conditions. Only the H{sub 2}O:NH{sub 3}:CO and H{sub 2}O:HCN ice mixtures led to the production of HNCO species. The possible isomerization of HNCO to its higher energy tautomers following irradiation or due to ice warm-up has been scrutinized. The photochemistry and thermal chemistry of H{sub 2}O:NH{sub 3}:CO and H{sub 2}O:HCN ices were simulated using the Interstellar Astrochemistry Chamber, a state-of-the-art ultra-high-vacuum setup. The ice was monitored in situ by Fourier transform mid-infrared spectroscopy in transmittance. A quadrupole mass spectrometer detected the desorption of the molecules in the gas phase. UV photoprocessing of H{sub 2}O:NH{sub 3}:CO and H{sub 2}O:HCN ices lead to the formation of OCN{sup –} as a main product in the solid state and a minor amount of HNCO. The second isomer HOCN has been tentatively identified. Despite its low efficiency, the formation of HNCO and the HOCN isomers by UV photoprocessing of realistic simulated ice mantles might explain the observed abundances of these species in photodissociation regions, hot cores, and dark clouds.

  2. Fast quantitation of opioid isomers in human plasma by differential mobility spectrometry/mass spectrometry via SPME/open-port probe sampling interface.

    Science.gov (United States)

    Liu, Chang; Gómez-Ríos, Germán Augusto; Schneider, Bradley B; Le Blanc, J C Yves; Reyes-Garcés, Nathaly; Arnold, Don W; Covey, Thomas R; Pawliszyn, Janusz

    2017-10-23

    Mass spectrometry (MS) based quantitative approaches typically require a thorough sample clean-up and a decent chromatographic step in order to achieve needed figures of merit. However, in most cases, such processes are not optimal for urgent assessments and high-throughput determinations. The direct coupling of solid phase microextraction (SPME) to MS has shown great potential to shorten the total sample analysis time of complex matrices, as well as to diminish potential matrix effects and instrument contamination. In this study, we demonstrate the use of the open-port probe (OPP) as a direct and robust sampling interface to couple biocompatible-SPME (Bio-SPME) fibres to MS for the rapid quantitation of opioid isomers (i.e. codeine and hydrocodone) in human plasma. In place of chromatography, a differential mobility spectrometry (DMS) device was implemented to provide the essential selectivity required to quantify these constitutional isomers. Taking advantage of the simplified sample preparation process based on Bio-SPME and the fast separation with DMS-MS coupling via OPP, a high-throughput assay (10-15 s per sample) with limits of detection in the sub-ng/mL range was developed. Succinctly, we demonstrated that by tuning adequate ion mobility separation conditions, SPME-OPP-MS can be employed to quantify non-resolved compounds or those otherwise hindered by co-extracted isobaric interferences without further need of coupling to other separation platforms. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. The influence hydrogen atom addition has on charge switching during motion of the metal atom in endohedral Ca@C60H4 isomers

    Science.gov (United States)

    Raggi, G.; Besley, E.; Stace, A. J.

    2016-01-01

    Density functional theory has been applied in a study of charge transfer between an endohedral calcium atom and the fullerene cage in Ca@C60H4 and [Ca@C60H4]+ isomers. Previous calculations on Ca@C60 have shown that the motion of calcium within a fullerene is accompanied by large changes in electron density on the carbon cage. Based on this observation, it has been proposed that a tethered endohedral fullerene might form the bases of a nanoswitch. Through the addition of hydrogen atoms to one hemisphere of the cage it is shown that, when compared with Ca@C60, asymmetric and significantly reduced energy barriers can be generated with respect to motion of the calcium atom. It is proposed that hydrogen atom addition to a fullerene might offer a route for creating a bi-stable nanoswitch that can be fine-tuned through the selection of an appropriate isomer and number of atoms attached to the cage of an endohedral fullerene. This article is part of the themed issue ‘Fullerenes: past, present and future, celebrating the 30th anniversary of Buckminster Fullerene’. PMID:27501967

  4. Rhenium(V) oxo complexes relevant to technetium renal imaging agents derived from mercaptoacetylglycylglycylaminobenzoic acid isomers. Structural and molecular mechanics studies

    International Nuclear Information System (INIS)

    Hansen, L.; Taylor, A. Jr; Marzilli, L.G.; Cini, R.

    1992-01-01

    The synthesis and characterization of three rhenium(V) oxo complexes derived from isomers of mercaptoacetylglycylglycylaminobenzoic acid (MAG 2 -ABAH 5 ) are reported. The isomers were synthesized from o-, m- and p-aminobenzoic acid and differed in the position of the terminal carboxyl group. The anions of 8-10, [ReO(MAG 2 -*ABAH)] - (* = para (8), meta (9), ortho (10)), contained the tetraanionic form of the ligands with the carboxyl group protonated. Compounds 8,9, and 10 were synthesized by exchange reactions of ReOCl 3 (Me 2 SO)(Ph 3 P) under moderate conditions and were isolated as [Ph 4 P] + , [Bu 4 N] + , and [Ph 4 P] + salts, respectively. The structures of 8 and 10 were determined by X-ray diffraction methods; except for the location of the carboxyl group, the structures are similar. The coordination geometry is pseudo square pyramidal, with nitrogen and sulfur donor atoms forming a square base and the oxo ligand at the apex. The orientation of the carboxyl group in 10 is anti to the Re double-bond O group. Since the carboxyl groups are protonated in 8 and 10 and in other relevant structures from this class of radiopharmaceuticals including [Ph 4 As][TcO(MAG 3 H)] (MAG 3 H = tetraanionic form of mercaptoacetyltriglycine), the authors developed molecular mechanics parameters that allowed them to calculate the structures of 8, 10, and [TcO(MAG 3 H)] - . They then extended the calculations to all three isomeric complexes in their deprotonated forms and to [TcO(MAG 3 )] 2- in order to approximate their solution phase structures. They conclude that the [TcO(MAG 3 )] 2- species is conformationally flexible, and they have made an initial assessment of structures vs renal clearance

  5. Coordinator, Translation Services | IDRC - International ...

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

    The Coordinator, Translation Services coordinates the overall operations of the ... services in IDRC by acting as the main resource person for internal clients ... all operational issues in order to ensure good quality products delivered on time.

  6. Isomer shift calibration of 61Ni by lifetime variation measurements in the electron capture decay of 57Ni

    International Nuclear Information System (INIS)

    Devillers, M.; Ladriere, J.

    1987-01-01

    In the present work, differential ionization chambers are used in order to measure the difference in the electron capture decay rate of 57 Ni nuclei in several pairs of different chemical compounds. Combination of these values with the corresponding Moessbauer isomer shifts provides a reliable experimental method to determine differences in electron densities at the nucleus. This allows to calibrate the isomer shift scale of the concerned nuclide. By using 61 Ni isomer shifts given in the literature, this work leads to the first experimental determination of the 61 Ni isomer shift calibration constant α = -(1.8±0.9).10 -3 .a 0 3 mm.s -1 . This corresponds to a change in the mean-square charge radius Δ 2 > = -(7.2±3.4).10 -4 fm 2 during the 67.4 keV Moessbauer transition of 61 Ni. (orig.)

  7. Ab initio correlated study of the Al13H- anion: Isomers, their kinetic stability and vertical detachment energies

    Science.gov (United States)

    Moc, Jerzy

    2012-01-01

    We report correlated ab initio calculations for the Al13H- cluster anion isomers, their kinetic stability and vertical detachment energies (VDEs). Of the two most energetically favored anion structures involving H atom in terminal and threefold bridged sites of the icosahedral Al13-, the higher energy ‘threefold bridged' isomer is shown to be of low kinetic stability. Our results are consistent with the recent photoelectron spectroscopy (PE) study of Grubisic et al. who observed two distinct Al13H- isomers, one of them identified as ‘metastable'. The VDE energies computed at the CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVDZ level for the ‘terminal' and ‘threefold bridged' Al13H- isomers of 3.21 and 2.32 eV are in good agreement with those determined in the PE study.

  8. Isomer Information from Ion Mobility Separation of High-Mannose Glycan Fragments.

    Science.gov (United States)

    Harvey, David J; Seabright, Gemma E; Vasiljevic, Snezana; Crispin, Max; Struwe, Weston B

    2018-05-01

    Extracted arrival time distributions of negative ion CID-derived fragments produced prior to traveling-wave ion mobility separation were evaluated for their ability to provide structural information on N-linked glycans. Fragmentation of high-mannose glycans released from several glycoproteins, including those from viral sources, provided over 50 fragments, many of which gave unique collisional cross-sections and provided additional information used to assign structural isomers. For example, cross-ring fragments arising from cleavage of the reducing terminal GlcNAc residue on Man 8 GlcNAc 2 isomers have unique collision cross-sections enabling isomers to be differentiated in mixtures. Specific fragment collision cross-sections enabled identification of glycans, the antennae of which terminated in the antigenic α-galactose residue, and ions defining the composition of the 6-antenna of several of the glycans were also found to have different cross-sections from isomeric ions produced in the same spectra. Potential mechanisms for the formation of the various ions are discussed and the estimated collisional cross-sections are tabulated. Graphical Abstract ᅟ.

  9. Infrared Spectroscopy of Two Isomers of the OCS-CS_{2} Complex

    Science.gov (United States)

    Oliaee, J. N.; Dehghany, M.; Afshari, Mahin; Moazzen-Ahmadi, N.; McKellar, A. R. W.

    2009-06-01

    A second isomer of OCS-CS_{2} complex, with a nonplanar cross-shaped structure, has been studied for the first time by analysing an infrared band in the region of the OCS stretching vibration (2062 cm^{-1}). This isomer has C_{s} symmetry and the observed band consists of purely c-type rotational transitions. The ground state rotational parameters are found to be A=0.07306 cm^{-1}, B=0.03325 cm^{-1} and C=0.02879 cm^{-1}, in good agreement with a previous semi-empirical calculation. In addition, a hybrid band with a- and b-type rotational transitions has been assigned to be due to the known planar form of OCS-CS_{2}, as previously studied by microwave spectroscopy. The spectra were recorded using a rapid-scan tunable diode laser spectrometer to probe a pulsed supersonic jet expansion. Calculations indicate that the planar isomer of OCS-CS_{2} is the lowest in energy, in contrast to CO_{2}-CS_{2} where the crossed form is believed to be the lowest. J. J. Newby, M. M. Serafin, R. A. Peebles and S. A. Peebles, Phys. Chem. Chem. Phys. 7, 487 (2005). C. C. Dutton, D. A. Dows, R. Eikey, S. Evans and R. A. Beaudet, J. Phys. Chem. A 102, 6904 (1998).

  10. Production of isomers in compound and transfer reactions with 4He ions

    International Nuclear Information System (INIS)

    Karamyan, S.A.; Aksenov, N.V.; Albin, Yu.A.; Bozhikov, G.A.; Dmitriev, S.N.; Starodub, G.Ya.; Vostokin, G.K.; Carroll, J.J.

    2011-01-01

    A well-known island of nuclear isomerism appears near A = 175-180 due to the deformation alignment of single-particle orbits at high angular momentum. This sometimes results in the formation of multi-quasiparticle states with record spin that are long-lived because of 'K-hindrance', i.e., symmetry rearrangement. Production methods and spectroscopic studies of these isomers remain a challenge for modern nuclear reaction and nuclear structure physics. Activities were produced by irradiation of 176 Yb(97.6%) enriched and nat Lu targets with 35-MeV 4 He ions from the internal beam of the U200 cyclotron. Induced activities were analyzed applying methods of radiochemistry and gamma spectroscopy. Yields of compound and nucleon-transfer reactions were measured and the isomer-to-ground state ratios were deduced. Calculated results were obtained using standard procedures to reproduce the (α, xn) cross sections, and the systematic behavior of the nucleon-transfer yields was established. The isomer-to-ground state ratios for direct reactions with 4 He ions were examined, resulting in a new characterization of the reaction mechanism

  11. Configuration changes and hindered decays in four- and six-quasiparticle isomers in 178Ta

    International Nuclear Information System (INIS)

    Kondev, F.G.; Dracoulis, G.D.; Byrne, A.P.; Kibedi, T.; Bayer, S.; Lane, G.J.

    1996-01-01

    A six-quasiparticle isomer with K π =21 - , a half-life of 290(12) ms, and the π 3 ν 3 configuration has been identified in the odd-odd nucleus 178 Ta, at an excitation energy of 2902 keV. The rotational bands built on the known K π =15 - isomer and on the newly found 16 + four-quasiparticle and 22 + six-quasiparticle states, have also been identified, allowing characterization of the configurations. The 15 - band is predominantly of πν 3 character with a π 3 ν admixture. When the mixing is taken into account the excitation energies of the main yrast multi-quasiparticle states can be reproduced. The multi-quasiparticle states observed are related essentially through the addition of the two-quasiparticle component ν 2 [6 + ] or π 2 [6 + ]. Depending on whether the transition between the states involves the change ν 2 [6 + ] → [0] or π 2 [6 + ] → [0], the E2 hindrance factors for decays between the six- and four-quasiparticle states are relatively large or small. This dependence mimics the pattern observed in the two-quasiparticle core transitions and, because the 15 - isomer is mainly πν 3 , the magnitude sequence is inverted compared to that observed in 176 Ta. copyright 1996 The American Physical Society

  12. Profiling of the Molecular Weight and Structural Isomer Abundance of Macroalgae-Derived Phlorotannins

    Directory of Open Access Journals (Sweden)

    Natalie Heffernan

    2015-01-01

    Full Text Available Phlorotannins are a group of complex polymers of phloroglucinol (1,3,5-trihydroxybenzene unique to macroalgae. These phenolic compounds are integral structural components of the cell wall in brown algae, but also play many secondary ecological roles such as protection from UV radiation and defense against grazing. This study employed Ultra Performance Liquid Chromatography (UPLC with tandem mass spectrometry to investigate isomeric complexity and observed differences in phlorotannins derived from macroalgae harvested off the Irish coast (Fucus serratus, Fucus vesiculosus, Himanthalia elongata and Cystoseira nodicaulis. Antioxidant activity and total phenolic content assays were used as an index for producing phlorotannin fractions, enriched using molecular weight cut-off dialysis with subsequent flash chromatography to profile phlorotannin isomers in these macroalgae. These fractions were profiled using UPLC-MS with multiple reaction monitoring (MRM and the level of isomerization for specific molecular weight phlorotannins between 3 and 16 monomers were determined. The majority of the low molecular weight (LMW phlorotannins were found to have a molecular weight range equivalent to 4–12 monomers of phloroglucinol. The level of isomerization within the individual macroalgal species differed, resulting in substantially different numbers of phlorotannin isomers for particular molecular weights. F. vesiculosus had the highest number of isomers of 61 at one specific molecular mass, corresponding to 12 phloroglucinol units (PGUs. These results highlight the complex nature of these extracts and emphasize the challenges involved in structural elucidation of these compounds.

  13. Decay spectroscopy of 160Sm: The lightest four-quasiparticle K isomer

    Directory of Open Access Journals (Sweden)

    Z. Patel

    2016-02-01

    Full Text Available The decay of a new four-quasiparticle isomeric state in 160Sm has been observed using γ-ray spectroscopy at the RIBF, RIKEN. The four-quasiparticle state is assigned a 2π⊗2ν π52−[532], π52+[413], ν52−[523], ν72+[633] configuration. The half-life of this (11+ state is measured to be 1.8(4 μs. The (11+ isomer decays into a rotational band structure, based on a (6− ν52−[523]⊗ν72+[633] bandhead, consistent with the gK−gR values. This decays to a (5− two-proton quasiparticle state, which in turn decays to the ground state band. Potential energy surface and blocked-BCS calculations were performed in the deformed midshell region around 160Sm. They reveal a significant influence from β6 deformation and that 160Sm is the best candidate for the lightest four-quasiparticle K isomer to exist in this region. The relationship between reduced hindrance and isomer excitation energy for E1 transitions from multiquasiparticle states is considered with the new data from 160Sm. The E1 data are found to agree with the existing relationship for E2 transitions.

  14. Fundamental Issues Related to the Origin of Melatonin and Melatonin Isomers during Evolution: Relation to Their Biological Functions

    Directory of Open Access Journals (Sweden)

    Dun-Xian Tan

    2014-09-01

    Full Text Available Melatonin and melatonin isomers exist and/or coexist in living organisms including yeasts, bacteria and plants. The levels of melatonin isomers are significantly higher than that of melatonin in some plants and in several fermented products such as in wine and bread. Currently, there are no reports documenting the presence of melatonin isomers in vertebrates. From an evolutionary point of view, it is unlikely that melatonin isomers do not exist in vertebrates. On the other hand, large quantities of the microbial flora exist in the gut of the vertebrates. These microorganisms frequently exchange materials with the host. Melatonin isomers, which are produced by these organisms inevitably enter the host’s system. The origins of melatonin and its isomers can be traced back to photosynthetic bacteria and other primitive unicellular organisms. Since some of these bacteria are believed to be the precursors of mitochondria and chloroplasts these cellular organelles may be the primary sites of melatonin production in animals or in plants, respectively. Phylogenic analysis based on its rate-limiting synthetic enzyme, serotonin N-acetyltransferase (SNAT, indicates its multiple origins during evolution. Therefore, it is likely that melatonin and its isomer are also present in the domain of archaea, which perhaps require these molecules to protect them against hostile environments including extremely high or low temperature. Evidence indicates that the initial and primary function of melatonin and its isomers was to serve as the first-line of defence against oxidative stress and all other functions were acquired during evolution either by the process of adoption or by the extension of its antioxidative capacity.

  15. The unusual high-spin isomer in 182Os and the proton-neutron interaction in high-j orbitals

    International Nuclear Information System (INIS)

    Tajima, Naoki; Onishi, Naoki

    1986-01-01

    An intermediate-coupling model of particle-plus-γ-soft-rotor is applied to a qualitative interpretation of the recently observed isomer of 182 Os and the characteristic decay pattern. In the model h 11/2 protons and i 13/2 neutrons are incorporated at the same time. The isomer is realized as the bandhead of a two-proton - two-neutron-aligned band from the present calculation. (orig.)

  16. Recursive Advice for Coordination

    DEFF Research Database (Denmark)

    Terepeta, Michal Tomasz; Nielson, Hanne Riis; Nielson, Flemming

    2012-01-01

    Aspect-oriented programming is a programming paradigm that is often praised for the ability to create modular software and separate cross-cutting concerns. Recently aspects have been also considered in the context of coordination languages, offering similar advantages. However, introducing aspects...... challenging. This is important since ensuring that a system does not contain errors is often equivalent to proving that some states are not reachable. In this paper we show how to solve these challenges by applying a successful technique from the area of software model checking, namely communicating pushdown...

  17. Theoretical study of γ-hexachlorocyclohexane and β-hexachlorocyclohexane isomers interaction with surface groups of activated carbon model.

    Science.gov (United States)

    Enriquez-Victorero, Carlos; Hernández-Valdés, Daniel; Montero-Alejo, Ana Lilian; Durimel, Axelle; Gaspard, Sarra; Jáuregui-Haza, Ulises

    2014-06-01

    Activated carbon (AC) is employed in drinking water purification without almost any knowledge about the adsorption mechanism of persistent organic pollutants (POPs) onto it. Hexachlorocyclohexane (HCH) is an organochlorinated contaminant present in water and soils of banana crops production zones of the Caribbean. The most relevant isomers of HCH are γ-HCH and β-HCH, both with great environmental persistence. A theoretical study of the influence of AC surface groups (SGs) on HCH adsorption is done in order to help to understand the process and may lead to improve the AC selection process. A simplified AC model consisting of naphthalene with a functional group was used to assess the influence of SGs over the adsorption process. The Multiple Minima Hypersurface (MMH) methodology was employed to study γ-HCH and β-HCH interactions with different AC SGs (hydroxyl and carboxyl) under different hydration and pH conditions. The results obtained showed that association of HCH with SGs preferentially occurs between the axial protons of HCH and SG's oxygen atom, and the most favorable interactions occurring with charged SGs. An increase in carboxylic SGs content is proposed to enhance HCH adsorption onto AC under neutral pH conditions. Finally, this work presents an inexpensive computer aided methodology for preselecting activated carbon SGs content for the removal of a given compound. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. A case of Z/E-isomers elution order inversion caused by cosolvent percentage change in supercritical fluid chromatography.

    Science.gov (United States)

    Pokrovskiy, Oleg I; Ustinovich, Konstantin B; Usovich, Oleg I; Parenago, Olga O; Lunin, Valeriy V; Ovchinnikov, Denis V; Kosyakov, Dmitry S

    2017-01-06

    A case of elution order inversion caused by cosolvent percentage change in supercritical fluid chromatography was observed and investigated in some detail. Z- and E-isomers of phenylisobutylketone oxime experience an elution order reversal on most columns if the mobile phase consists of CO 2 and alcohol. At lower percentages of alcohol Z-oxime is retained less, somewhere at 2-5% coelution occurs and at larger cosolvent volume elution order reverses - Z-oxime is eluted later than E-oxime. We suppose inversion with CO 2 -ROH phases happens due to a shift in balance between two main interactions governing retention. At low ROH percentages stationary phase surface is only slightly covered by ROH molecules so oximes primarily interact with adsorption sites via hydrogen bond formation. Due to intramolecular sterical hindrance Z-oxime is less able to form hydrogen bonds and consequently is eluted first. At higher percentages alcohols occupy most of strong hydrogen bonding sites on silica surface thus leaving non-specific electrostatic interactions predominantly responsible for Z/E selectivity. Z-oxime has a much larger dipole moment than E-oxime and at these conditions it is eluted later. Additional experimental data with CO 2 -CH 3 CN, hexane-iPrOH and CHF 3 -ROH mobile phases supporting this explanation are presented. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Investigation of cis-trans isomer dependent dermatotoxicokinetics of UV filter ethylhexyl methoxycinnamate through stratum corneum in vivo.

    Science.gov (United States)

    Sharma, Anežka; Bányiová, Katarína; Vrana, Branislav; Justan, Ivan; Čupr, Pavel

    2017-11-01

    2-Ethylhexyl methoxycinnamate (EHMC) is one of the most used ultraviolet filters in personal care products. It undergoes cis/trans isomerization in sunlight, and there is limited toxicological understanding of the effects of the cis-isomer. It is known that two geometric isomers of one compound can have different physico-chemical properties and effects. However, there are no studies focusing on toxicokinetics of EHMC isomerization products to compare their potential difference in dermal exposure to cis-EHMC and trans-EHMC due to the difference in their dermatotoxicokinetics. In this study, dermal absorption of the parental trans-EHMC and its cis isomer was studied. A commercially available sunscreen lotion containing trans-EHMC and spiked with laboratory-prepared cis-EHMC was locally applied on the forearm skin of two volunteers. After 8 h of skin exposure, the stratum corneum (SC) layer was removed by tape stripping. The removed thickness of the SC was determined spectrophotometrically using a total protein assay. The concentration of both isomers in the removed SC was measured by HPLC-DAD. A new diffusion and permeability coefficient of both EHMC isomers in SC were determined by Fick's second law of diffusion in vivo. The difference in dermatotoxicokinetic parameters between the two isomers was not statistically significant. However, separate toxicological studies of isomeric forms and the determination of their dermatotoxicokinetic parameters are crucial for refinement of human risk assessment.

  20. Absorption Kinetics of the Main Conjugated Linoleic Acid Isomers in Commercial-Rich Oil after Oral Administration in Rats.

    Science.gov (United States)

    Rodríguez-Alcalá, Luís M; Ares, Irma; Fontecha, Javier; Martínez-Larrañaga, María-Rosa; Anadón, Arturo; Martínez, María-Aránzazu

    2017-09-06

    This study aimed to assess the oral absorption and plasma kinetics of two main isomers contained in commercial conjugated linoleic acid (CLA)-rich oil (Tonalin TG-80), rumenic acid (RA), and C18:2 trans-10, cis-12. The isomer plasma disposition after the single oral dose of 3000 mg of Tonalin TG-80/kg, containing 1200 mg/kg of each isomer, was studied in rats. The isomer plasma concentrations were determined by gas chromatography with flame ionization detection. The plasma kinetics showed rapid oral absorption of RA and C18:2 trans-10, cis-12 (t 1/2a 0.34 ± 0.09 and 0.53 ± 0.01 h) and slow elimination (t 1/2β 25.68 ± 3.29 and 18.12 ± 1.71 h); the maximal isomer plasma concentrations (C max ) of 8.48 ± 0.98 and 7.67 ± 0.80 μg mL -1 , respectively, were estimated at 2.08 ± 0.14 and 2.26 ± 0.11 h. Our results from a preclinical kinetic study in rats help to design future studies in humans for evaluating the CLA isomer dose-response.

  1. Lifetime and g-factor of a new isomer in 130 La

    International Nuclear Information System (INIS)

    Ionescu-Bujor, M.; Iordachescu, A.; Brandolini, F.; Pavan, P.; Rossi Alvarez, C.; De Poli, M.; Medina, N.H.; Rao, M.N.

    1999-01-01

    Pulsed-beam measurements have been recently performed at the XTU-tandem of the National Laboratory of Legnaro with the aim to investigate short-lived isomeric states in neutron-deficient nuclei of the A∼130 region. Isotopically enriched tin targets were irradiated with a 70 MeV 16 O beam (pulse width of 3 ns at a repetition rate of 800 ns) and the γ-ray angular distributions perturbed in magnetic or electric interaction were observed time-differentially. Static electromagnetic moments were thus determined for several known short-lived isomers in 129,130,131 Ce and 129 Ba. In these experiments a new isomeric decay has been also identified and its properties are reported in the present work. The isomer has been observed on a target containing 116 Sn (87%), 117 Sn (8%) and 118 Sn (5%). The tin target of 0.6 mg/cm 2 thickness evaporated on a Pb foil was placed in an external magnetic field of 32 kG whose orientation was periodically reversed. Two planar HPGe detectors positioned at ±135 deg. with respect to the beam direction were used for the γ-ray detection. In the delayed spectra a γ-ray of 105.2 keV has been observed and a half-life of 32(5)ns has been determined for it. The experimental and calculated R(t) modulation ratios of the 105.2 keV γ-ray in the external magnetic field are given. From the derived Larmor frequency a value g = + 0.48(3) has been determined for the isomeric state g-factor. A dipole character has been established for the delayed 105.2 keV γ-transition based on the determined negative A 2 coefficient. The new isomer was tentatively assigned to the odd-odd 130 La populated in the 116,117,118 Sn ( 16 O,pxn) reaction. In this nucleus a state at (150.3 + x) keV de-excited by a 105.2 keV transition is known and it was identified with the isomer. Further experiments are in progress for the definite assignment and the elucidation of the isomer configuration. (authors)

  2. Coordinating towards a Common Good

    Science.gov (United States)

    Santos, Francisco C.; Pacheco, Jorge M.

    2010-09-01

    Throughout their life, humans often engage in collective endeavors ranging from family related issues to global warming. In all cases, the tragedy of the commons threatens the possibility of reaching the optimal solution associated with global cooperation, a scenario predicted by theory and demonstrated by many experiments. Using the toolbox of evolutionary game theory, I will address two important aspects of evolutionary dynamics that have been neglected so far in the context of public goods games and evolution of cooperation. On one hand, the fact that often there is a threshold above which a public good is reached [1, 2]. On the other hand, the fact that individuals often participate in several games, related to the their social context and pattern of social ties, defined by a social network [3, 4, 5]. In the first case, the existence of a threshold above which collective action is materialized dictates a rich pattern of evolutionary dynamics where the direction of natural selection can be inverted compared to standard expectations. Scenarios of defector dominance, pure coordination or coexistence may arise simultaneously. Both finite and infinite population models are analyzed. In networked games, cooperation blooms whenever the act of contributing is more important than the effort contributed. In particular, the heterogeneous nature of social networks naturally induces a symmetry breaking of the dilemmas of cooperation, as contributions made by cooperators may become contingent on the social context in which the individual is embedded. This diversity in context provides an advantage to cooperators, which is particularly strong when both wealth and social ties follow a power-law distribution, providing clues on the self-organization of social communities. Finally, in both situations, it can be shown that individuals no longer play a defection dominance dilemma, but effectively engage in a general N-person coordination game. Even if locally defection may seem

  3. Comparative evaluation of capillary electrophoresis and high-performance liquid chromatography for the separation of cis-cis, cis-trans, and trans-trans isomers of atracurium besylate.

    Science.gov (United States)

    de Moraes, M de L; Polakiewicz, B; Mattua, M F; Tavares, M F

    1998-01-01

    Atracurium besylate is a highly selective nondepolarizing neuromuscular blocking agent routinely used during anesthetic procedures. The commercial presentation of this drug is a mixture of positional isomers, cis-cis, cis-trans, and trans-trans. Reversed-phase high-performance liquid chromatography has been the technique of choice for the analysis of atracurium besylate formulations at the quality control laboratory of Núcleo de Desenvolvimento Cristália (São Paulo, Brazil), a local pharmaceutical company. HPLC analysis is usually conducted under gradient elution using acetonitrile/0.1 M phosphate buffer eluent mixture as mobile phase and an octadecyl silica (ODS)-packed column. The complete elution of the three isomers takes about 1 hr. In this work, an alternative capillary electrophoresis methodology was developed. The complete resolution of all three isomers was accomplished in about 13 min (+20 kV/72 cm, 211 nm direct detection) using a 60-mM phosphate buffer solution (pH 4) containing 20 mM beta-cyclodextrin and 4 M urea. The isomer ratio was found to be 59.1% cis-cis, 35.9% cis-trans, and 5.02% trans-trans (expected ratio: 59:35:6). Laudanosine, a major metabolite of atracurium besylate, was identified in two commercially available formulations, Tracur (Núcleo de Desenvolvimento Cristália) and Tracrium (Glaxo Wellcome, S.A., Rio de Janeiro, Brazil). Its concentration increases considerably during storage of the product, even if the product is stored at low temperatures.

  4. Network Coordinator Report

    Science.gov (United States)

    Himwich, Ed; Strand, Richard

    2013-01-01

    This report includes an assessment of the network performance in terms of lost observing time for the 2012 calendar year. Overall, the observing time loss was about 12.3%, which is in-line with previous years. A table of relative incidence of problems with various subsystems is presented. The most significant identified causes of loss were electronics rack problems (accounting for about 21.8% of losses), antenna reliability (18.1%), RFI (11.8%), and receiver problems (11.7%). About 14.2% of the losses occurred for unknown reasons. New antennas are under development in the USA, Germany, and Spain. There are plans for new telescopes in Norway and Sweden. Other activities of the Network Coordinator are summarized.

  5. Accuracy increase of the coordinate measurement based on the model production of geometrical parts specifications

    Science.gov (United States)

    Zlatkina, O. Yu

    2018-04-01

    There is a relationship between the service properties of component parts and their geometry; therefore, to predict and control the operational characteristics of parts and machines, it is necessary to measure their geometrical specifications. In modern production, a coordinate measuring machine is the advanced measuring instrument of the products geometrical specifications. The analysis of publications has shown that during the coordinate measurements the problems of choosing locating chart of parts and coordination have not been sufficiently studied. A special role in the coordination of the part is played by the coordinate axes informational content. Informational content is the sum of the degrees of freedom limited by the elementary item of a part. The coordinate planes of a rectangular coordinate system have different informational content (three, two, and one). The coordinate axes have informational content of four, two and zero. The higher the informational content of the coordinate plane or axis, the higher its priority for reading angular and linear coordinates is. The geometrical model production of the coordinate measurements object taking into account the information content of coordinate planes and coordinate axes allows us to clearly reveal the interrelationship of the coordinates of the deviations in location, sizes and deviations of their surfaces shape. The geometrical model helps to select the optimal locating chart of parts for bringing the machine coordinate system to the part coordinate system. The article presents an algorithm the model production of geometrical specifications using the example of the piston rod of a compressor.

  6. Analysis of carboxylate coordination function of the isomeric lanthanide pyridinedicarboxylates by means of vibration spectroscopy

    International Nuclear Information System (INIS)

    Puntus, L.; Zolin, V.; Kudryashova, V.

    2004-01-01

    The investigation of IR spectra of salts of six isomers of pyridinedicarboxylic acid (PDA): 2,3-, 2,4-, 2,5-, 2,6-, 3,4- and 3,5-pyridinedicarboxylic acids, have demonstrated that properties of these salts are dependent on the bonding manner of carboxylate groups and on coordination of heterocyclic nitrogen atom. The most prominent differences in properties and spectra of 2,6- and 3,4-PDA salts are conditioned correspondingly by monodentate and bidentate coordination functions of the carboxylate groups in these compounds. The correlation of the breathing vibration frequency, reflecting the rigidity of the heterocyclic ring, with position of the carboxylate substituents, conditioning intramolecular charge transfer (CT), was postulated and proved by shifts of the breathing vibration frequency dependent on the structure of isomeric ligand

  7. Ionic liquid-based single-drop microextraction/gas chromatographic/mass spectrometric determination of benzene, toluene, ethylbenzene and xylene isomers in waters.

    Science.gov (United States)

    Aguilera-Herrador, Eva; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel

    2008-08-01

    The direct coupling between ionic liquid-based single-drop microextraction and gas chromatography/mass spectrometry is proposed for the rapid and simple determination of benzene, toluene, ethylbenzene and xylenes isomers (BTEX) in water samples. The extraction procedure exploits not only the high affinity of the selected ionic liquid (1-methyl-3-octyl-imidazolium hexaflourophosphate) to these aromatic compounds but also its special properties like viscosity, low vapour pressure and immiscibility with water. All the variables involved in the extraction process have been studied in depth. The developed method allows the determination of these single-ring compounds in water under the reference concentration level fixed by the international legislation. In this case, limits of detection were in the range 20 ng L(-1) (obtained for benzene) and 91 ng L(-1) (for o-xylene). The repeatability of the proposed method, expressed as RSD (n=5), varied between 3.0% (o-xylene) and 5.2% (toluene).

  8. A comparison of hydrogen-bonded and van der Waals isomers of phenolṡṡnitrogen and phenolṡṡcarbon monoxide: An ab initio study

    Science.gov (United States)

    Chapman, Darren M.; Müller-Dethlefs, Klaus; Peel, J. Barrie

    1999-08-01

    The hydrogen-bonded and van der Waals isomers of phenolṡṡnitrogen and phenolṡṡcarbon monoxide in their neutral electronic (S0) and cation ground state (D0) were studied using ab initio HF/6-31G*, MP2/6-31G*, and B3LYP/6-31G* methods. The hydrogen-bonded isomers have the ligand bound via the hydroxyl group of the phenol ring, while the van der Waals isomers studied have the ligand located above the aromatic ring. For both complexes, the hydrogen-bonded isomer was found to be the most stable form for both the S0 and the D0 states. For phenolṡṡcarbon monoxide, twice as many isomers as compared to phenolṡṡnitrogen were found. The hydrogen-bonded isomer with the carbon end bonded to the hydroxyl group was the most stable structure for both the S0 and the D0 states.

  9. Feeding of the 1 1/2- isomers in stable Ir and Au isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Fotiadis, Nikolaos [Los Alamos National Laboratory; Nelson, Ronald O [Los Alamos National Laboratory; Devlin, Matthew [Los Alamos National Laboratory; Holloway, Shannon T [Los Alamos National Laboratory; Kawano, Toshihiko [Los Alamos National Laboratory; Talou, Patrick [Los Alamos National Laboratory; Chadwick, Mark B [Los Alamos National Laboratory; Becker, John A [LLNL; Garrett, Paul E [U GUELPH, CANADA

    2008-01-01

    Excited states were studied and absolute partial {gamma}-ray cross sections were measured using the ({eta}, {eta}'{gamma}) reaction in {sup 191}Ir, {sup 193}Ir and {sup 197}Au. A Compton-suppressed germanium-detector array (GEANIE) for {gamma}-ray spectroscopy and the broad-spectrum pulsed neutron source of the Los Alamos Neutron Science Center's WNR facility were used for the measurement. The energy of the incident neutrons was determined using the time-of-flight technique. Absolute partial {gamma}-ray cross sections were measured up to incident neutron energy of 20 MeV for several transitions feeding directly the 1 1/2- isomers and ground states in {sup 191}Ir, {sup 193}Ir and {sup 197}Au. The feeding of the 1 1/2- isomers, which originate from the odd proton occupying the h{sub 1 1/2} orbital, was found for the three targets to be very similar and increasing relative to the feeding of the corresponding ground state with increasing neutron energy up to E{sub n} {approx} 10 MeV. Above this neutron energy the opening of the (n, 2{sub n}) reaction channel strongly affects the population of the isomers and leads to a decrease of their relative population compared to the population of the ground states. The experimental results are compared with theoretical predictions from the GNASH reaction model calculation implementing a version of the spin distribution for the pre-equilibrium reaction piece with either a compound nucleus spin distribution (CN-GNASH) or a Feshbach-Kerman-Koonin (FKK-GNASH) quantum mechanical spin distribution. The effects of the spin cutoff parameter values on the population of states are examined. Evidence is presented that FKK-GNASH provides a description of the experimental data that mitigates the need for adjustment of the level density parameter to fit the data.

  10. Toward the laboratory identification of the not-so-simple NS2 neutral and anion isomers

    Science.gov (United States)

    Fortenberry, Ryan C.; Thackston, Russell; Francisco, Joseph S.; Lee, Timothy J.

    2017-08-01

    The NS2 radical is a simple arrangement of atoms with a complex electronic structure. This molecule was first reported by Hassanzadeh and Andrew's group [J. Am. Chem. Soc. 114, 83 (1992)] through Ar matrix isolation experiments. In the quarter century since this seminal work was published, almost nothing has been reported about nitrogen disulfide even though NS2 is isovalent with the common NO2. The present study aims to shed new insight into possible challenges with the characterization of this radical. No less than three potential energy surfaces all intersect in the C2v region of the SNS radical isomer. A type-C Renner-Teller molecule is present for the linear 2Πu state where the potential energy surface is fully contained within the 2.05 kcal/mol lower energy X ˜ 2A1 state. A C2v, 1 2B1 state is present in this same region, but a double excitation is required to access this state from the X ˜ 2A1 state of SNS. Additionally, a 1 2A' NSS isomer is also present but with notable differences in the geometry from the global minimum. Consequently, the rovibronic spectrum of these NS2 isomers is quite complicated. While the present theory and previous Ar matrix experiments agree well on isotopic shifts, they differ notably for the absolute fundamental vibrational frequency transitions. These differences are likely a combination of matrix shifts and issues associated with the neglect of non-adiabatic coupling in the computations. In either case, it is clear that high-resolution gas phase experimental observations will be complicated to sort. The present computations should aid in their analysis.

  11. Occurrence, fluxes and sources of perfluoroalkyl substances with isomer analysis in the snow of northern China

    International Nuclear Information System (INIS)

    Shan, Guoqiang; Chen, Xinwei; Zhu, Lingyan

    2015-01-01

    Highlights: • Relatively high levels of PFASs were present in the snow in northern China in 2013. • Particulate bound PFASs contributed 21.5–56.2% to the total PFASs in snow. • Particulate matters are vital for PFASs transport and deposition in urban atmosphere. • Partitioning of PFASs between particulate and dissolved phase was related to carbon chain length. • Isomer profiles in snow suggested that airborne PFASs were mainly from direct release. - Abstract: In this study, perfluoroalkyl substances (PFASs) and the isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were analyzed in fresh snow samples collected from 19 cities in northern China, 2013. The levels of total PFASs in the snow samples were 33.5–229 ng/L, suggesting heavy atmospheric pollution of PFASs in northern China. PFOA (9.08–107 ng/L), PFOS (3.52–54.3 ng/L), perfluoroheptanoate (PFHpA) (3.66–44.8 ng/L), and perfluorohexanoate (PFHxA) (3.21–23.6 ng/L) were predominant with a summed contribution of 82% to the total PFASs. The particulate matters (PMs) associated PFASs contributed 21.5–56.2% to the total PFASs in the snow, suggesting PMs are vital for the transport and deposition of airborne PFASs. Partitioning of PFASs between PM and dissolved phases was dependent on the carbon chain length and end functional groups. Isomer profiles of PFOA and PFOS in the snow were in agreement with the signature of the historical 3 M electrochemical fluorination (ECF) products, suggesting that the ECF products were still produced and used in China. Further source analysis showed that the airborne PFASs in urban area were mainly due to direct release rather than degradation of their precursors.

  12. Occurrence, fluxes and sources of perfluoroalkyl substances with isomer analysis in the snow of northern China

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Guoqiang; Chen, Xinwei; Zhu, Lingyan, E-mail: zhuly@nankai.edu.cn

    2015-12-15

    Highlights: • Relatively high levels of PFASs were present in the snow in northern China in 2013. • Particulate bound PFASs contributed 21.5–56.2% to the total PFASs in snow. • Particulate matters are vital for PFASs transport and deposition in urban atmosphere. • Partitioning of PFASs between particulate and dissolved phase was related to carbon chain length. • Isomer profiles in snow suggested that airborne PFASs were mainly from direct release. - Abstract: In this study, perfluoroalkyl substances (PFASs) and the isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were analyzed in fresh snow samples collected from 19 cities in northern China, 2013. The levels of total PFASs in the snow samples were 33.5–229 ng/L, suggesting heavy atmospheric pollution of PFASs in northern China. PFOA (9.08–107 ng/L), PFOS (3.52–54.3 ng/L), perfluoroheptanoate (PFHpA) (3.66–44.8 ng/L), and perfluorohexanoate (PFHxA) (3.21–23.6 ng/L) were predominant with a summed contribution of 82% to the total PFASs. The particulate matters (PMs) associated PFASs contributed 21.5–56.2% to the total PFASs in the snow, suggesting PMs are vital for the transport and deposition of airborne PFASs. Partitioning of PFASs between PM and dissolved phases was dependent on the carbon chain length and end functional groups. Isomer profiles of PFOA and PFOS in the snow were in agreement with the signature of the historical 3 M electrochemical fluorination (ECF) products, suggesting that the ECF products were still produced and used in China. Further source analysis showed that the airborne PFASs in urban area were mainly due to direct release rather than degradation of their precursors.

  13. Coordinates in relativistic Hamiltonian mechanics

    International Nuclear Information System (INIS)

    Sokolov, S.N.

    1984-01-01

    The physical (covariant and measurable) coordinates of free particles and covariant coordinates of the center of inertia are found for three main forms of relativistic dynamics. In the point form of dynamics, the covariant coordinates of two directly interacting particles are found, and the equations of motion are brought to the explicitly covariant form. These equations are generalized to the case of interaction with an external electromagnetic field

  14. Proton radioactivity: the case for 53m Co proton-emitter isomer

    International Nuclear Information System (INIS)

    Tavares, O.A.P.; Medeiros, E.L.

    2010-01-01

    The partial proton emission half-life for 53m Co unstable isomer is re-examined in the framework of a semiempirical model based on tunneling through a Coulomb-plus centrifugal- plus-overlapping potential barrier within the spherical nucleus approximation. It is shown that the known measured half-life value of 17 s is compatible with a large prolate shape for 53m Co proton emitter and a high angular momentum ι = 11 assigned to the proton transition to the ground-state of 52 Fe. (author)

  15. Yrast spectroscopy: status of yrast isomers, oblate shapes and feeding of yrast states

    International Nuclear Information System (INIS)

    Khoo, T.L.

    1980-01-01

    The properties of very-high-spin states at the yrast line are addressed. Three different but related topics are discussed: the status of yrast isomers (mainly in the A approx. 150 region); the nuclear shape along the yrast line; and the feeding of the yrast states as a function of spin. A recurrent theme is the response of the core to the polarizing effects of a successively increasing number of valence particles and how the investigation of very-high-spin states bears on this problem. 10 figures, 1 table

  16. Proton radioactivity: the case for {sup 53m} Co proton-emitter isomer

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, O.A.P.; Medeiros, E.L., E-mail: emil@cbpf.b

    2010-07-01

    The partial proton emission half-life for {sup 53m}Co unstable isomer is re-examined in the framework of a semiempirical model based on tunneling through a Coulomb-plus centrifugal- plus-overlapping potential barrier within the spherical nucleus approximation. It is shown that the known measured half-life value of 17 s is compatible with a large prolate shape for {sup 53m}Co proton emitter and a high angular momentum {iota} = 11 assigned to the proton transition to the ground-state of {sup 52}Fe. (author)

  17. Microscopical study of K isomers in the nuclear region A ∼ 180

    International Nuclear Information System (INIS)

    Libert, J.; Quentin, P.; Pillet, N.; Ponsa, A.

    1997-01-01

    At present the K isomers are the best candidates for high density energy storage, although one of the major problems resides in the availability of simple and fast storage mechanisms. To respond to this question it is necessary to know thoroughly the structure of the concerned isomers and low energy modes of excitation. Particularly, proper to this type of studies is the region of A ∼ 180, where a large number of K isomers are known at present ( 178 Hf, 179 Hf and 180 Ta). Microscopic calculations using Skyrme SIII plus a simple pairing interaction lead to a good reproduction of certain single particle and collective spectroscopic properties of 178 Hf. In this region the spectroscopic properties are governed by three single proton states (5/2 - , 7/2 - and 9/2 + ) and by two single neutron states (7/2 + , 9/2 - ). The computed quasi-particle spectrum reproduces within 100 keV the energies of the isomeric states 16 + , 14 - , 25/2 - and 9 - . Based on this agreement one can predict a band spectroscopy rich in high K values due to a plenty of possible single particle combinations which have themselves high K value. Particularly, one have to stress the quasi-degeneracy of a K π = 15 + with the 16 + configuration in 178 Hf. Should this prediction experimentally be confirmed interesting consequences have to be expected on the spectroscopy above the 16 + isomer of 178 Hf as well as on the states implied in the decay of this storage state. Actually, 1 MeV above the 16 + state one can note isolated states reachable by parity breaking (or not breaking) transitions which could be mixture of K = 15, 14, 13, etc structures due to Coriolis interaction. The calculation reported are although simple (the approximation of the free quasi-particles on the BCS vacuum of 178 Hf). Under current study are the quantitative consequences of the Coriolis coupling, the decrease of pairing gaps with increasing quasi-particle number, the Hartree-Fock polarization (even and odd under time

  18. Isomer shifts and chemical bonding in crystalline Sn(II) and Sn(IV) compounds

    International Nuclear Information System (INIS)

    Terra, J.; Guenzburger, D.

    1991-01-01

    First-principles self-consistent Local Density calculations of the electronic structure of clusters representing Sn(II) (SnO, SnF 2 , SnS, SnSe) and Sn(IV) (SnO 2 , SnF 4 ) crystalline compounds were performed. Values of the electron density at the Sn nucleus were obtained and related to measured values of the Moessbauer Isomer Shifts reported in the literature. The nuclear parameter of 119 Sn derived was ΔR/R=(1.58±0.14)x10 -4 . The chemical bonding in the solids was analysed and related to the electron densities obtained. (author)

  19. Radioactive isotope and isomer separation with using light induced drift effect

    International Nuclear Information System (INIS)

    Hradecny, C.; Slovak, J.; Tethal, T.; Ermolaev, I.M.; Shalagin, A.M.

    1991-01-01

    The isotope separation with using light induced drift (LID) is discussed. The basic theoretical characteristics of the method are deduced: separation simultaneously with an arbitrary high enrichment and without significant losses; separation productivity up to 100 μg/h. These characteristics are sufficient and very convenient for separation of expensive radioactive isotopes and isomers which are applied in medicine and science. The first experimental separation of the radioactive isotopes ( 22,24 Na) by using the LID effect is reported. 13 refs.; 5 figs

  20. Structure of high-spin isomers in trans-lead nuclei

    International Nuclear Information System (INIS)

    Dracoulis, G.D.

    1990-01-01

    The structure of core-excited high-spin isomers in the N ≤ 126 isotopes of At, Rn and Fr is reviewed. New results for high-spin states in 211 Rn and 212 Rn, approaching the limit of the available angular momentum from the valence particles, are presented. The recurring experimental feature is decay by very enhanced E3 transitions. These, and other properties are explained in a natural way by inclusion of particle-octupole vibration coupling, in a semi-empirical shell model. The deformed independent particle model is not successful in explaining these features. 40 refs., 4 tabs., 11 figs

  1. Decay of a three-quasiparticle isomer in the neutron-rich nucleus 183Ta

    Directory of Open Access Journals (Sweden)

    Zhu S.

    2012-10-01

    Full Text Available Excited states in neutron-rich tantalum isotopes have been studied with deep-inelastic reactions using 136Xe ions incident on a 186W target. New transitions observed below the τ=1.3 μs isomer in 183Ta have enabled the establishment of its energy and put limits on the spin and parity. On the basis of the reduced hindrances for the depopulating transitions, a 3-quasiparticle configuration of ν1/2−[510]11/2+[615] ⊗ π9/2−[514] is suggested.

  2. Quadrupole moments of the 12+ isomers in 188Hg and 190Hg

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Lonnroth, T.; Vajda, S.; Dafni, E.; Schatz, G.

    1984-01-01

    The electric quadrupole interaction of the 12 + isomers in 188 Hg and 190 Hg has been measured in solid Hg. The quadrupole moments deduced, vertical strokeQ[ 188 Hg(12 + )]vertical stroke = 91(11) e fm 2 and vertical strokeQ[ 190 Hg(12 + )]vertical stroke = 117(14) e fm 2 suggest a possible change in γ-deformation due to the rotation alignment of the isub(13/2) quasi-neutrons. The temperature dependence of the electric field gradient tensor in Hg was also determined. (orig.)

  3. High-spin yrast isomers in 211Rn and 212Rn with enhanced E3 decays

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Byrne, A.P.; Fabricius, B.

    1990-01-01

    New isomeric states with J π =69/2 + ,τ m = 13 (1) ns in 211 Rn and J π =33 - ,τ m = 7(1) ns in 212 Rn have been identified. They decay by enchanced E3 transitions with strengths of 33(3) and 43(6) single particle units to the known 63/2 - and 30 + isomers 211 Rn and 212 Rn, respectively. The excitation energies and transition strengths agree well with predictions of the multi-particle, octupole-vibration coupled model. 13 refs., 2 tabs., 3 figs

  4. Computer-assisted structure elucidation from 13C-NMR-Spectra. I. The development of a three-dimensional structure code. II. The development of an isomer generating program

    International Nuclear Information System (INIS)

    Schuetz, V.

    1999-05-01

    The presented thesis consists of two separate programs which both aid the automated structure elucidation in the CSEARCH database system. A successful utilization of a large collection of NMR reference spectra for the prediction of chemical shift values is dependent on a strong correlation between the spectral data and the structural information via unique coding. By now, this was done using the two-dimensional HOSE code, which turned out to be insufficient whenever stereochemical effects other than cis/trans-isomerism contribute to the chemical shift values. Therefore, this new algorithm has been developed to derive the demanded three-dimensional descriptors. The calculation is performed by matching the query structures against pattern molecules taken from a carefully selected library of ring skeletons. No three-dimensional coordinates are necessary, since the algorithm elucidates the descriptors on base of two-dimensional structures having their stereocenters specified using 'up/down' bonds. The descriptors are defined as number of interactions over 3 to 5 bonds, number of cis-substituents over 1 to 2 ringbonds and markers for axial substituents. This approach of deriving descriptors for steric interactions has successfully extended the HOSE coding scheme and has been implemented into a neural network; both methods allow for high-quality prediction of 13 C-NMR chemical shift values. The second algorithm is an isomer generating program named GENERAL, which efficiently supports the structure elucidation process by calculating all mathematically possible structures to a given molecular formula. The resulting list of structures is exhaustive and free of redundancy. Besides the basic input information - like the molecular formula and the specification of structural fragments, constraints can be defined to restrict the number of resulting structures. The most valuable information is provided by state-of-the-art 2D-NMR experiments and can be easily incorporated into

  5. Clomiphene and Its Isomers Block Ebola Virus Particle Entry and Infection with Similar Potency: Potential Therapeutic Implications.

    Science.gov (United States)

    Nelson, Elizabeth A; Barnes, Alyson B; Wiehle, Ronald D; Fontenot, Gregory K; Hoenen, Thomas; White, Judith M

    2016-08-02

    The 2014 outbreak of Ebola virus (EBOV) in Western Africa highlighted the need for anti-EBOV therapeutics. Clomiphene is a U.S. Food and Drug Administration (FDA)-approved drug that blocks EBOV entry and infection in cells and significantly protects EBOV-challenged mice. As provided, clomiphene is, approximately, a 60:40 mixture of two stereoisomers, enclomiphene and zuclomiphene. The pharmacokinetic properties of the two isomers vary, but both accumulate in the eye and male reproductive tract, tissues in which EBOV can persist. Here we compared the ability of clomiphene and its isomers to inhibit EBOV using viral-like particle (VLP) entry and transcription/replication-competent VLP (trVLP) assays. Clomiphene and its isomers inhibited the entry and infection of VLPs and trVLPs with similar potencies. This was demonstrated with VLPs bearing the glycoproteins from three filoviruses (EBOV Mayinga, EBOV Makona, and Marburg virus) and in two cell lines (293T/17 and Vero E6). Visual problems have been noted in EBOV survivors, and viral RNA has been isolated from semen up to nine months post-infection. Since the clomiphene isomers accumulate in these affected tissues, clomiphene or one of its isomers warrants consideration as an anti-EBOV agent, for example, to potentially help ameliorate symptoms in EBOV survivors.

  6. Clomiphene and Its Isomers Block Ebola Virus Particle Entry and Infection with Similar Potency: Potential Therapeutic Implications

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Nelson

    2016-08-01

    Full Text Available The 2014 outbreak of Ebola virus (EBOV in Western Africa highlighted the need for anti-EBOV therapeutics. Clomiphene is a U.S. Food and Drug Administration (FDA-approved drug that blocks EBOV entry and infection in cells and significantly protects EBOV-challenged mice. As provided, clomiphene is, approximately, a 60:40 mixture of two stereoisomers, enclomiphene and zuclomiphene. The pharmacokinetic properties of the two isomers vary, but both accumulate in the eye and male reproductive tract, tissues in which EBOV can persist. Here we compared the ability of clomiphene and its isomers to inhibit EBOV using viral-like particle (VLP entry and transcription/replication-competent VLP (trVLP assays. Clomiphene and its isomers inhibited the entry and infection of VLPs and trVLPs with similar potencies. This was demonstrated with VLPs bearing the glycoproteins from three filoviruses (EBOV Mayinga, EBOV Makona, and Marburg virus and in two cell lines (293T/17 and Vero E6. Visual problems have been noted in EBOV survivors, and viral RNA has been isolated from semen up to nine months post-infection. Since the clomiphene isomers accumulate in these affected tissues, clomiphene or one of its isomers warrants consideration as an anti-EBOV agent, for example, to potentially help ameliorate symptoms in EBOV survivors.

  7. Single-molecule imaging reveals topological isomer-dependent diffusion by 4-armed star and dicyclic 8-shaped polymers

    KAUST Repository

    Habuchi, Satoshi

    2015-04-21

    Diffusion dynamics of topological isomers of polymer molecules was investigated at the single-molecule level in a melt state by employing the fluorophore-incorporated 4-armed star and the corresponding doubly-cyclized, 8-shaped poly(THF) chains. While the single-molecule fluorescence imaging experiment revealed that the diffusion of the 4-armed star polymer was described by a single Gaussian distribution, the diffusion of the 8-shaped polymer exhibited a double Gaussian distribution behaviour. We reasoned that the two 8-shaped polymeric isomers have distinct diffusion modes in the melt state, although ensemble-averaged experimental methods cannot detect differences in overall conformational state of the isomers. The single-molecule experiments suggested that one of the 8-shaped polymeric isomer, having the horizontally oriented form, causes an efficient threading with the linear matrix chains which leads to the slower diffusion compared with the corresponding 4-armed star polymer, while the other 8-shaped polymeric isomer, having the vertically oriented form, displayed faster diffusion by the suppression of effective threading with the linear matrix chains due to its contracted chain conformation.

  8. Chaotic coordinates for the Large Helical Device

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, S. R., E-mail: shudson@pppl.gov [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 (United States); Suzuki, Y. [National Institute for Natural Sciences, National Institute for Fusion Sciences, 322-6 Oroshi, Toki, 509-5292 (Japan)

    2014-10-15

    The theory of quadratic-flux-minimizing (QFM) surfaces is reviewed, and numerical techniques that allow high-order QFM surfaces to be efficiently constructed for experimentally relevant, non-integrable magnetic fields are described. As a practical example, the chaotic edge of the magnetic field in the Large Helical Device (LHD) is examined. A precise technique for finding the boundary surface is implemented, the hierarchy of partial barriers associated with the near-critical cantori is constructed, and a coordinate system, which we call chaotic coordinates, that is based on a selection of QFM surfaces is constructed that simplifies the description of the magnetic field, so that flux surfaces become “straight” and islands become “square.”.

  9. Team reasoning: Solving the puzzle of coordination.

    Science.gov (United States)

    Colman, Andrew M; Gold, Natalie

    2017-11-03

    In many everyday activities, individuals have a common interest in coordinating their actions. Orthodox game theory cannot explain such intuitively obvious forms of coordination as the selection of an outcome that is best for all in a common-interest game. Theories of team reasoning provide a convincing solution by proposing that people are sometimes motivated to maximize the collective payoff of a group and that they adopt a distinctive mode of reasoning from preferences to decisions. This also offers a compelling explanation of cooperation in social dilemmas. A review of team reasoning and related theories suggests how team reasoning could be incorporated into psychological theories of group identification and social value orientation theory to provide a deeper understanding of these phenomena.

  10. Accessible silanol sites - beneficial for the RP-HPLC separation of constitutional and diastereomeric azaspirovesamicol isomers.

    Science.gov (United States)

    Wenzel, Barbara; Fischer, Steffen; Brust, Peter; Steinbach, Jörg

    2010-12-10

    Different RP-HPLC columns (phenyl, conventional ODS, cross-linked C(18) and special end-capped C(8) and C(18) phases) were used to investigate the separation of four basic ionizable isomers. Using ACN/20mM NH(4)OAc aq., a separation was observed exclusively on RP columns with higher silanol activity at unusual high ACN concentration, indicating cation-exchange as main retention mechanism. Using MeOH/20mM NH(4)OAc aq., another separation at low MeOH concentrations was observed on both, RP columns with higher as well as RP columns with lower silanol activity, which is mainly based on hydrophobic interactions. The isomers were also separated on a bare silica column at higher MeOH content using NH(4)OAc. Since cation-exchange governs this retention, the elution order was different compared to the RP phases. A strong retention on the silica column was observed in ACN, which could be attributed to partition processes as additional retention mechanism. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Photo-Induced depopulation of the 180mTa isomer

    Science.gov (United States)

    Bhike, Megha; Krishichayan, Fnu; Tornow, W.

    2015-10-01

    The 180mTa nucleus is the rarest isotope in the universe, existing only in an isomeric state at 77.2 keV (Jπ = 9-) with half-life of greater than 7.1 ×1015 years. The stellar production of this high-spin isomer has been a challenging astrophysical problem. Cross-section measurements for the depopulation of the 180mTa isomer with monoenergetic photon beams of energies 2.5 and 3.1 MeV have been carried out at the HI γS facility. The activated Ta foils of natural abundance and containing 14.4 mg of 180mTa were γ-ray counted at TUNL's low background facility using a 13% planar HPGe detector. A 8'' ×12'' NaI detector in combination with the standard HI γS scintillator paddle system was employed for absolute photon-flux determination. Preliminary results will be discussed, and measurements at lower energies are planned. This work was supported by the U.S. DOE under Grant NO. DE-FG02-97ER41033.

  12. Multiparticle octupole coupling and magnetic moments of hn9/2 isomers in N=126 isotones

    International Nuclear Information System (INIS)

    Stuchbery, A.E.; Byrne, A.P.; Dracoulis, G.D.; Fabricius, B.; Kibedi, T.

    1992-12-01

    The influence of particle-vibration coupling on the g-factors of the (h 9/2 ) n > isomers in the N = 126 isotones is assessed using the multiparticle octupole coupling model. According to the model, admixtures of the configuration (h 9/2 ) n-1 f 7/2 > in the yrast 8 + and 21/2 - states, nominally associated with the configuration (h 9/2 ) n >, increase with n. On its own, the octupole mixing mechanism therefore predicts g-factors for these states that increase with the number of valence protons. This trend is the opposite of that predicted by core-polarization blocking. Combining multiparticle octupole coupling and first order core-polarization blocking significantly reduces the discrepancy between the experimental and theoretical g-factors of these states. It is concluded that the observed breakdown in additivity for the g-factors of the (h 9/2 ) n > isomers in the N = 126 isotones arises primarily from first order core-polarization blocking and the combination of configuration mixing due to multiparticle octupole coupling and shell model residual interactions. 40 refs., 5 tabs., 3 figs

  13. Formation of tyrosine isomers in aqueous phenylalanine solutions by gamma irradiation

    International Nuclear Information System (INIS)

    Aflaki, F.; Salahinejad, M.; Roozbehani, A.

    2009-01-01

    Ortho-tyrosine detection method can be used for detection of irradiated protein rich foods. Tyrosine isomers produced by gamma radiation of aqueous phenylalanine solutions at wide dose levels (0.1-50 k Gy) were examined to obtain basic information for o-tyrosine detection method of irradiated foods. Determination of tyrosines produced in aqueous phenylalanine solutions were carried out by high performance liquid chromatography and fluorescence detection. The detection limit of o-tyrosine was 0.01 ppm and the linear range of calibration and the relative standard deviation of analysis was 50 ng and 4-13%, respectively. The amounts of the tyrosines increased with the irradiation level up to 10 k Gy and no further tyrosine formation was observed when the dose level was increased. At a constant dose level, the yield of tyrosines initially increased with the phenylalanine concentration, while with further increase of phenylalanine concentration no effect on increase of tyrosine yield was observed. When the dose rate was varying from 2.3 k Gy/h to 1.2 k Gy/h with a total amount of 10 k Gy in each case, there was no significant effect on tyrosine isomers formation was observed. Also the results showed that tyrosine yield was affected by temperature, p H and the presence of oxygen

  14. Quasi-particle and collective magnetism: Rotation, pairing and blocking in high-K isomers

    International Nuclear Information System (INIS)

    Stone, N.J.; Stone, J.R.; Walker, P.M.; Bingham, C.R.

    2013-01-01

    For the first time, a wide range of collective magnetic g-factors g R , obtained from a novel analysis of experimental data for multi-quasi-particle configurations in high-K isomers, is shown to exhibit a striking systematic variation with the relative number of proton and neutron quasi-particles, N p −N n . Using the principle of additivity, the quasi-particle contribution to magnetism in high-K isomers of Lu–Re, Z=71–75, has been estimated. Based on these estimates, band-structure branching ratio data are used to explore the behavior of the collective contribution as the number and proton/neutron nature (N p , N n ), of the quasi-particle excitations, change. Basic ideas of pairing, its quenching by quasi-particle excitation and the consequent changes to moment of inertia and collective magnetism are discussed. Existing model calculations do not reproduce the observed g R variation adequately. The paired superfluid system of nucleons in these nuclei, and their excitations, present properties of general physics interest. The new-found systematic behavior of g R in multi-quasi-particle excitations of this unique system, showing variation from close to zero for multi-neutron states to above 0.5 for multi-proton states, opens a fresh window on these effects and raises the important question of just which nucleons contribute to the ‘collective’ properties of these nuclei

  15. Isomer pattern and elimination of dioxins in workers exposed at a municipal waste incineration plant

    Science.gov (United States)

    YAMAMOTO, Kenya; KUDO, Mitsuhiro; ARITO, Heihachiro; OGAWA, Yasutaka; TAKATA, Tsutomu

    2015-01-01

    The aim of this study was to clarify patterns of serum concentrations of dioxins in the employees of a waste incineration plant and to estimate elimination rates and half-lives of serum dioxin isomers, and the maximum serum concentrations of dioxin isomers at the time of plant shutdown. Sixteen subjects participating 3 times or more in annual health examinations during an 8-yr period from 2000 to 2007 were recruited for this study. Serum concentrations of dioxins expressed as TEQ/g lipid decreased gradually after plant shutdown with the highest decrease observed in polychlorinated dibenzofurans (PCDFs) followed by polychlorinated deibenzo-p-dioxins (PCDDs) and then coplanar PCBs. The serum toxic equivalency (TEQ) concentrations of PCDF and PCDD congeners in the employees were higher than those in the general population survey by the Ministry of the Environment, Japan, whereas the serum concentrations of coplanar PCBs were similar to those in the general population. The estimated half-lives and elimination rates of PCDDs and PCDFs in the highly exposed workers increased compared with the moderately exposed workers. The estimated geometric mean serum concentrations of PCDDs, PCDFs and total dioxins at the time of plant shutdown were 35, 53 and 107 pg TEQ/g lipid, respectively. PMID:26118856

  16. Determination of melatonin and its isomer in foods by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Kocadağlı, Tolgahan; Yılmaz, Cemile; Gökmen, Vural

    2014-06-15

    This study aimed to develop a reliable analytical method for the determination of melatonin and its isomers in various food products. The method entails ethanol extraction of solid samples (or dilution of liquid samples) prior to liquid chromatography coupled to triple quadruple mass spectrometry (LC-MS/MS) analysis of target analytes. The method was in-house validated and successfully applied to various food matrices. Recovery of melatonin from different matrices were found to be 86.0 ± 3.6%, 76.9 ± 5.4%, 98.6 ± 6.4%, and 67.0 ± 4.5% for beer, walnut, tomato and sour cherry samples, respectively. No melatonin could be detected in black and green tea, sour cherry, sour cherry concentrate, kefir (a fermented milk drink) and red wine while the highest amount of melatonin (341.7 ± 29.3 pg/g) was detected in crumb. The highest amounts of melatonin isomer were detected in yeast-fermented foods such as 170.7 ± 29.9 ng/ml in red wine, 14.3 ± 0.48 ng/ml in beer, and 15.7 ± 1.4 ng/g in bread crumb. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Polyelectrolyte functionalized gold nanoparticles-reduced graphene oxide nanohybrid for electrochemical determination of aminophenol isomers

    International Nuclear Information System (INIS)

    Li, Xinchun; Zhong, Anni; Wei, Shanshan; Luo, Xiaoli; Liang, Yanjin; Zhu, Qiao

    2015-01-01

    A green chemical method for preparation of gold nanoparticles-reduced graphene oxide nanocomposite is described. This can be readily accomplished through a two-step chemical reduction scheme by using poly(diallyldimethylammonium chloride), a cationic polyelectrolyte as a common reducer. Polyelectrolyte here also serves to stabilize gold nanoparticles and is beneficial to electrical communication, leading to the formation of well-characteristic nanohybrid. The prepared nanomaterial showed remarkable electrocatalytic ability as a result of the rational conjunction of graphene and gold nanoparticles, which was demonstrated by direct electrochemical determination of three aminophenol isomers on a modified glassy carbon electrode. Effective peak separation of three isomers was achieved due to the favorable electron-transfer network perfectly assembled on the electrode surface, thus enabling the simultaneous assay of multiple components featuring analogous chemical structure without chromatographic separation. The modified electrode was further used to detect para-aminophenol in paracetamol tablets. The present method is simple, eco-friendly and holds potential for electroanalytical and biosensing applications

  18. Anti-Leishmania and cytotoxic activities of perillaldehyde epoxide synthetic positional isomers.

    Science.gov (United States)

    Keesen, Tatjana Souza Lima; da Silva, Larisse Virgolino; da Câmara Rocha, Juliana; Andrade, Luciana Nalone; Lima, Tamires Cardoso; de Sousa, Damião Pergentino

    2018-03-13

    Leishmaniasis belongs to a complex of zoonotic disease caused by protozoa of the genus Leishmania and is considered a major public health problem. Several essential oil chemical components have inhibitory effect against protozoa, including Leishmania donovani. Thus, the aim of this study was to evaluate for the first time the anti-Leishmania activity of two p-menthane monoterpene isomers (EPER-1: perillaldehyde 1,2-epoxide and EPER-2: perillaldehyde 8,9-epoxide) against L. donovani promastigotes as well as evaluating cytotoxic effect on mononuclear peripheral blood cells. Results of anti-Leishmania assay revealed that EPER-2 (IC 50  = 3.8 μg.mL -1 ) was 16-fold more potent than its isomer EPER-1 (IC 50  = 64.6 μg.mL -1 ). In contrast to PBMC cells, EPER-2 was not cytotoxic (IC 50  > 400 μg.mL -1 ) when compared to positive control. These data suggest that the disposition of epoxide group into the p-menthane skeleton affects the anti-Leishmania activity, being that the presence of the exocyclic epoxide group considerably increased potency. Thus, it was possible to observe that the location of the epoxide group into the p-menthane skeleton resulted in different potencies.

  19. Occurrence, fluxes and sources of perfluoroalkyl substances with isomer analysis in the snow of northern China.

    Science.gov (United States)

    Shan, Guoqiang; Chen, Xinwei; Zhu, Lingyan

    2015-12-15

    In this study, perfluoroalkyl substances (PFASs) and the isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were analyzed in fresh snow samples collected from 19 cities in northern China, 2013. The levels of total PFASs in the snow samples were 33.5-229 ng/L, suggesting heavy atmospheric pollution of PFASs in northern China. PFOA (9.08-107 ng/L), PFOS (3.52-54.3 ng/L), perfluoroheptanoate (PFHpA) (3.66-44.8 ng/L), and perfluorohexanoate (PFHxA) (3.21-23.6 ng/L) were predominant with a summed contribution of 82% to the total PFASs. The particulate matters (PMs) associated PFASs contributed 21.5-56.2% to the total PFASs in the snow, suggesting PMs are vital for the transport and deposition of airborne PFASs. Partitioning of PFASs between PM and dissolved phases was dependent on the carbon chain length and end functional groups. Isomer profiles of PFOA and PFOS in the snow were in agreement with the signature of the historical 3M electrochemical fluorination (ECF) products, suggesting that the ECF products were still produced and used in China. Further source analysis showed that the airborne PFASs in urban area were mainly due to direct release rather than degradation of their precursors. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Association between Human Plasma Chondroitin Sulfate Isomers and Carotid Atherosclerotic Plaques

    Directory of Open Access Journals (Sweden)

    Elisabetta Zinellu

    2012-01-01

    Full Text Available Several studies have evidenced variations in plasma glycosaminoglycans content in physiological and pathological conditions. In normal human plasma GAGs are present mainly as undersulfated chondroitin sulfate (CS. The aim of the present study was to evaluate possible correlations between plasma CS level/structure and the presence/typology of carotid atherosclerotic lesion. Plasma CS was purified from 46 control subjects and 47 patients undergoing carotid endarterectomy showing either a soft or a hard plaque. The concentration and structural characteristics of plasma CS were assessed by capillary electrophoresis of constituent unsaturated fluorophore-labeled disaccharides. Results showed that the concentration of total CS isomers was increased by 21.4% (P<0.01 in plasma of patients, due to a significant increase of undersulfated CS. Consequently, in patients the plasma CS charge density was significantly reduced with respect to that of controls. After sorting for plaque typology, we found that patients with soft plaques and those with hard ones differently contribute to the observed changes. In plasma from patients with soft plaques, the increase in CS content was not associated with modifications of its sulfation pattern. On the contrary, the presence of hard plaques was associated with CS sulfation pattern modifications in presence of quite normal total CS isomers levels. These results suggest that the plasma CS content and structure could be related to the presence and the typology of atherosclerotic plaque and could provide a useful diagnostic tool, as well as information on the molecular mechanisms responsible for plaque instability.

  1. [Formation of protodioscin and deltoside isomers in suspension cultures of Nepal yam (Dioscorea deltoidea Wall.) cells].

    Science.gov (United States)

    Khandy, M T; Titova, M V; Konstantinova, S V; Kochkin, D V; Ivanov, I M; Nosov, A M

    2016-01-01

    Changes in the content of the furostanol glycosides protodioscin and deltoside, particularly that of the (25S)-isomers of the glycosides, during suspension cultivation of different lines of Nepal yam (Dioscorea deltoidea Wall.) cells of the strain IFR-DM-0.5 has been investigated. The composition of furostanol glycosides has been characterized, and the dynamics of the accumulation of individual glycosides during lengthy subcultivation of cells maintained in flasks or in a barbotage bioreactor has been analyzed. A positive correlation between the growth and accumulation of substances that belonged to the class of furostanol glycosides has been demonstrated for cultured dioscorea cells, whereas the content of some of the individual glycosides varied considerably between the lines of the strain, cultures maintained under different conditions, and even between cells in different phases of the growth cycle. The increased content of (25R)-forms of the glycosides (protodioscin and deltoside) was correlated with a decrease in the cellular growth rate, whereas an increase in culture growth intensity occurred concomitantly to an increase of the amount of (25S)-isomers. This may be indicative of the specific stimulatory effect of (25S)-glycosides, but not the (25R)-forms, on cell proliferation in vitro. Thus, the concentration of (25S)-forms may increase due to the autoselection of cells capable of intensive division during prolonged cultivation.

  2. Isomer beam elastic scattering: 26mAl(p, p) for astrophysics

    Science.gov (United States)

    Kahl, D.; Shimizu, H.; Yamaguchi, H.; Abe, K.; Beliuskina, O.; Cha, S. M.; Chae, K. Y.; Chen, A. A.; Ge, Z.; Hayakawa, S.; Imai, N.; Iwasa, N.; Kim, A.; Kim, D. H.; Kim, M. J.; Kubono, S.; Kwag, M. S.; Liang, J.; Moon, J. Y.; Nishimura, S.; Oka, S.; Park, S. Y.; Psaltis, A.; Teranishi, T.; Ueno, Y.; Yang, L.

    2018-01-01

    The advent of radioactive ground-state beams some three decades ago ultimately sparked a revolution in our understanding of nuclear physics. However, studies with radioactive isomer beams are sparse and have often required sophisticated apparatuses coupled with the technologies of ground-state beams due to typical mass differences on the order of hundreds of keV and vastly different lifetimes for isomers. We present an application of a isomeric beam of 26mAl to one of the most famous observables in nuclear astrophysics: galactic 26Al. The characteristic decay of 26Al in the Galaxy was the first such specific radioactivity to be observed originating from outside the Earth some four decades ago. We present a newly-developed, novel technique to probe the structure of low-spin states in 27Si. Using the Center for Nuclear Study low-energy radioisotope beam separator (CRIB), we report on the measurement of 26mAl proton resonant elastic scattering conducted with a thick target in inverse kinematics. The preliminary results of this on-going study are presented.

  3. New information on the T1/2=47 s isomer in the 136I nucleus

    International Nuclear Information System (INIS)

    Urban, W.; Rzaca-Urban, T.; Saha Sarkar, M.; Sarkar, S.; Durell, J.L.; Smith, A.G.; Genevey, J.A.; Pinston, J.A.; Simpson, G.S.; Ahmad, I.

    2006-01-01

    The 136 I nucleus, populated in the spontaneous fission of 248 Cm, was studied by means of prompt γ-ray spectroscopy using the EUROGAM2 array. The observation in this work of the 42.6 keV prompt-γ, M1+E2 transition de-exciting the 7 - level in 136 I indicates that this level, interpreted as the (πg 7/2 3 νf 7/2 ) 7- configuration, does not correspond to the T=47 s, β-decaying isomer in 136 I. The isomer is placed 42.6 keV below the 7 - level. It has spin 6 - and is interpreted as the (πg 7/2 2 d 5/2 νf 7/2 ) 6- configuration. This and other members of both multiplets can be reproduced properly only if one assumes that the πd 5/2 orbital in 136 I is located 400keV lower than in 133 Sb. Possible mechanisms causing this effect are discussed. (orig.)

  4. Conformational inversion-topomerization mechanism of ethylcyclohexyl isomers and its role in combustion kinetics

    KAUST Repository

    Bian, Huiting

    2016-07-26

    With the "strain-free" cyclic structure, cyclohexane and alkyl cyclohexanes (and their radicals) have various conformers (e.g. chair, boat, and twist etc.) by pseudorotation of the alkyl ring. Noting that different conformers will undergo different types of H-migration reactions, the mechanism of conformational change may impact the distribution of cyclohexyl and the branched cyclohexyl radical isomers during cyclohexane and alkyl cyclohexanes combustion. Consequently, it will influence the formation of subsequent decomposition products. In this work, the conformational inversion-topomerization mechanism and H-migration reactions for six ethylcyclohexyl radical isomers were systematically studied by ab initio calculations and the transition state theory. The updated sub-mechanism of these conformational changes is incorporated into an ethylcyclohexane pyrolysis model. By comparing the simulated results of the "complete" model including the sub-mechanism of conformational changes and the simplified model ignoring these processes, the effect of inversion-topomerization mechanism on the relative concentrations of various ethylcyclohexyl radicals and the formation of subsequent decomposition products were revealed. © 2016.

  5. Coordination in continuously repeated games

    NARCIS (Netherlands)

    Weeren, A.J.T.M.; Schumacher, J.M.; Engwerda, J.C.

    1995-01-01

    In this paper we propose a model to describe the effectiveness of coordination in a continuously repeated two-player game. We study how the choice of a decision rule by a coordinator affects the strategic behavior of the players, resulting in more or less cooperation. Our model requires the analysis

  6. Coordinated Transportation: Problems and Promise?

    Science.gov (United States)

    Fickes, Michael

    1998-01-01

    Examines the legal, administrative, and logistical barriers that have prevented the wide acceptance of coordinating community and school transportation services and why these barriers may be breaking down. Two examples of successful implementation of coordinated transportation are examined: employing a single system to serve all transportation…

  7. Bare coordination: the semantic shift

    NARCIS (Netherlands)

    de Swart, Henriette; Le Bruyn, Bert

    2014-01-01

    This paper develops an analysis of the syntax-semantics interface of two types of split coordination structures. In the first type, two bare singular count nouns appear as arguments in a coordinated structure, as in bride and groom were happy. We call this the N&N construction. In the second type,

  8. [Simultaneous separation and detection of principal component isomer and related substances of raw material drug of ammonium glycyrrhizinate by RP-HPLC and structure confirmation].

    Science.gov (United States)

    Zhao, Yan-Yan; Liu, Li-Yan; Han, Yuan-Yuan; Li, Yue-Qiu; Wang, Yan; Shi, Min-Jian

    2013-08-01

    A simple, fast and sensitive analytical method for the simultaneous separation and detection of 18alpha-glycyrrhizinic acid, 18beta-glycyrrhizinic acid, related substance A and related substance B by RP-HPLC and drug quality standard was established. The structures of principal component isomer and related substances of raw material drug of ammonium glycyrrhizinate have been confirmed. Reference European Pharmacopoeia EP7.0 version, British Pharmacopoeia 2012 version, National Drug Standards of China (WS 1-XG-2002), domestic and international interrelated literature were referred to select the composition of mobile phase. The experimental parameters including salt concentration, pH, addition quantities of organic solvent, column temperature and flow rate were optimized. Finally, the assay was conducted on a Durashell-C18 column (250 mm x 4.6 mm, 5 microm) with 0.01 mol x mL(-1) ammonium perchlorate (add ammonia to adjust the pH value to 8.2) -methanol (48 : 52) as mobile phase at the flow rate of 0.8 mL x min(-1), and the detection wavelength was set at 254 nm. The column temperature was 50 degrees C and the injection volume was 10 microL. The MS, NMR, UV and RP-HPLC were used to confirm the structures of principal component isomer and related substances of raw material drug of ammonium glycyrrhizinate. Under the optimized separation conditions, the calibration curves of 18 alpha-glycyrrhizinic acid, 18beta-glycyrrhizinic acid, related substance A and related substance B showed good linearity within the concentration of 0.50-100 microg x mL(-1) (r = 0.999 9). The detection limits for 18alpha-glycyrrhizinic acid, 18beta-glycyrrhizinic acid, related substance A and related substance B were 0.15, 0.10, 0.10, 0.15 microg x mL(-1) respectively. The method is sensitive, reproducible and the results are accurate and reliable. It can be used for chiral resolution of 18alpha-glycyrrhizinic acid, 18Pbeta-glycyrrhizinic acid, and detection content of principal component and

  9. Directional Overcurrent Relays Coordination Problems in Distributed Generation Systems

    OpenAIRE

    Jakub Ehrenberger; Jan Švec

    2017-01-01

    This paper proposes a new approach to the distributed generation system protection coordination based on directional overcurrent protections with inverse-time characteristics. The key question of protection coordination is the determination of correct values of all inverse-time characteristics coefficients. The coefficients must be correctly chosen considering the sufficiently short tripping times and the sufficiently long selectivity times. In the paper a new approach to protection coordinat...

  10. Study of the odd-${A}$, high-spin isomers in neutron-deficient trans-lead nuclei with ISOLTRAP

    CERN Multimedia

    Herfurth, F; Blaum, K; Beck, D; Kowalska, M; Schwarz, S; Stanja, J; Huyse, M L; Wienholtz, F

    We propose to measure the excitation energy of the $\\frac{13^{+}}{2}$ isomers in the neutron-deficient isotopes $^{193,195,197}$Po with the ISOLTRAP mass spectrometer. The assignment of the low- and high-spin isomers will be made by measuring the energy of the $\\alpha$- particles emitted in the decay of purified beams implanted in a windmill system. Using $\\alpha$-decay information, it is then also possible to determine the excitation energy of the similar isomers in the $\\alpha$-daughter nuclei $^{189,191,193}$Pb, $\\alpha$-parent nuclei $^{197,199,201}$Rn, and $\\alpha$-grand-parent nuclei $^{201,203,205}$Ra. The polonium beams are produced with a UC$_{\\textrm{x}}$ target and using the RILIS.

  11. Isomeric and high-spin states of 94Tc and the search for yrast isomers near N~50

    Science.gov (United States)

    Lee, I. Y.; Johnson, N. R.; McGowan, F. K.; Young, G. R.; Guidry, M. W.; Yates, S. W.

    1981-07-01

    A search for isomers in the N~50 region has produced no evidence of high-spin yrast isomerism. A new 4.5-ns low-multiplicity isomer has been identified and assigned to 94Tc, while the yrast sequence of 94Tc has been established to more than 5 MeV in excitation energy. [NUCLEAR REACTIONS 76Ge, 78Se(20Ne,xnypγ), E=80.9 MeV, 89Y, 93Nb(10B,xnypγ), E=52.0,58.4,62.8 MeV; measured Eγ, Iγ, γ-γ prompt and delayed coin, γ-X coin; deduced levels, t12 of 94Tc isomer, yrast states.

  12. Measurements of quadrupole interaction frequencies of long-lived isomers with the level mixing spectroscopy (LEMS) method

    International Nuclear Information System (INIS)

    Neyens, G.; Nouwen, R.; S'heeren, G.; Bergh, M. van den; Coussement, R.

    1993-01-01

    The level mixing spectroscopy (LEMS) method has proven to be a very useful method to determine the quadrupole interaction frequency of an isomer in a solid host. Especially in the 'difficult' cases, e.g. when the isomeric lifetime is very long or its spin is very high, the method yields valuable information which is not accessible with other methods (such as TDPAD). Since the development of the method some years ago, many experiments have been performed on high spin isomers in the lead region. The static quadrupole moment of isomers with lifetimes ranging from 20 ns up to 13 ms and spins up to 65/2h have been determined in neutron deficient isotopes of Bi, At, Fr and Ra. (orig.)

  13. Even-odd alternation of the formation of dimer isomers in irradiated polycrystalline alkanes: evidence from product analysis

    International Nuclear Information System (INIS)

    Baudson, T.; Tilquin, B.

    1984-01-01

    Recent ESR studies on n-alkanes from n-C 11 to n-C 25 have shown that a prominent chain end (-CH 2 -CH 2 ) alkyl radical is formed in odd members of the series. In this preliminary discussion of our study, we shall report the capillary chromatogram in the dimer isomers range for n-alkanes ranging from n-C 11 to n-C 17 irradiated at 80 kGy. Dimer isomers, produced in part by the combination of chain end radicals, are eluted at the end chromatogram. The combination of two chain end radicals gives the dimer (D 11 ) isomer eluted at the last place. It is shown that dimers produced by the combination of chain end alkyl radicals are more important for the odd members of the series than for the even members. (author)

  14. UV-induced bond modifications in thymine and thymine dideoxynucleotide: structural elucidation of isomers by differential mobility mass spectrometry.

    Science.gov (United States)

    St-Jacques, Antony; Anichina, Janna; Schneider, Bradley B; Covey, Thomas R; Bohme, Diethard K

    2010-07-15

    Differential mobility spectrometry has been applied to reveal the occurrence of isomerization of thymine nucleobase and of thymine dideoxynucleotide d(5'-TT-3') due to bond redisposition induced by UV irradiation at 254 nm of frozen aqueous solutions of these molecules. Collision-induced dissociation (CID) spectra of electrosprayed photoproducts of the thymine solution suggest the presence of two isomers (the so-called cyclobutane and 6,4-photoproducts) in addition to the proton-bound thymine dimer, and these were separated using differential mobility spectrometry/mass spectrometry (DMS/MS) techniques with water as the modifier. Similar experiments with d(5'-TT-3') revealed the formation of a new isomer of deprotonated thymine dideoxynucleotide upon UV irradiation that was easily distinguished using DMS/MS with isopropanol as the modifier. The results reinforce the usefulness of DMS/MS in isomer separation.

  15. Static quadrupole moment of the Kπ = 14+ isomer in 176W

    International Nuclear Information System (INIS)

    Ionescu-Bujor, M.; Iordachescu, A.; Bucurescu, D.; Brandolini, F.; Lenzi, S. M.; Pavan, P.; Rossi Alvarez, C.; Marginean, N.; Medina, N.H.; Ribas, R.V.; De Poli, M.; Napoli, D. R.; Podolyak, Zs.; Ur, C. A.

    2001-01-01

    The investigation of high-K isomeric states in the deformed nuclei of the A∼180 region has found renewed interest in recent years. Much experimental and theoretical work was devoted to understand the mechanisms which govern their decay to lower-lying states, particularly the anomalous strong decays to low-K states. Other questions of great importance are the quenching of the pairing correlations and the shape polarization effects in the high-seniority multi-quasiparticle excitations. Our interest focused on the 41 ns K π =14 + 3746 keV isomeric state with anomalous decay in 176 W. On the basis of a precise g-factor measurement we assigned to this isomer a pure four-quasiparticle configuration, composed by two protons in the 7/2 + [404] and 9/2 - [514] orbitals and two neutrons in the 7/2 + [633] and 5/2 - [512] orbitals. In the present work the measurement of its static quadrupole moment has been performed. Prior to our experiment, static quadrupole moments have been measured only for three high-K isomeric states of seniority ≥ 4 in the A∼180 region: 16 + in 178 Hf, 35/2 - in 179 W and 25 + in 182 Os. A deformation very similar to that of the ground state has been deduced for the 16 + isomer in 178 Hf, while for the high-K isomers in 179 W and 182 Os significantly smaller deformations were reported. The quadrupole interaction of the 14 + isomeric state in 176 W has been investigated in the electric field gradient (EFG) of the polycrystalline lattice of metallic Tl by applying the time-differential perturbed angular distribution method. For W impurities in Tl host the EFG strength and its temperature dependence have been recently reported. The isomer was populated in the 164 Dy( 16 O,4n) 176 W reaction using a 83 MeV 16 O pulsed beam (pulse width 1.5 ns, repetition period 800 ns) delivered by the XTU-Tandem of Laboratori Nazionali di Legnaro. The target consisted of 0.5 mg/cm 2 metallic 164 Dy on thick Tl backing in which both the recoiling 176 W nuclei and

  16. Multipole structure and coordinate systems

    International Nuclear Information System (INIS)

    Burko, Lior M

    2007-01-01

    Multipole expansions depend on the coordinate system, so that coefficients of multipole moments can be set equal to zero by an appropriate choice of coordinates. Therefore, it is meaningless to say that a physical system has a nonvanishing quadrupole moment, say, without specifying which coordinate system is used. (Except if this moment is the lowest non-vanishing one.) This result is demonstrated for the case of two equal like electric charges. Specifically, an adapted coordinate system in which the potential is given by a monopole term only is explicitly found, the coefficients of all higher multipoles vanish identically. It is suggested that this result can be generalized to other potential problems, by making equal coordinate surfaces adapt to the potential problem's equipotential surfaces

  17. Application of the high-spin isomer beams to the secondary fusion reaction and the measurement of g-factor

    International Nuclear Information System (INIS)

    Watanabe, H.; Asahi, K.; Kishida, T.; Ueno, H.; Sato, W.; Yoshimi, A.; Kobayashi, Y.; Kameda, D.; Miyoshi, H.; Fukuchi, T.; Wakabayashi, Y.; Sasaki, T.; Kibe, M.; Hokoiwa, N.; Odahara, A.; Cederwall, B.; Lagergren, K.; Podolyak, Zs.; Ishihara, M.; Gono, Y.

    2004-01-01

    A technique for providing high-spin isomers as probes of the fusion reaction and the measurement of g-factor has been worked out at RIKEN. In the study of the fusion reaction 12 C( 145m Sm,xn) 157-x Er, the γ rays emitted from the fusion-evaporation residue 154 Er have been successfully observed. The nuclear g-factor of the T 1/2 = 28 ns high-spin isomer in 149 Dy has been measured with the γ-ray TDPAD method

  18. Initial studies of the gamma resonance of the 109mAg isomer with a gravitational gamma spectrometer

    International Nuclear Information System (INIS)

    Alpatov, V. G.; Bayukov, Yu. D.; Davydov, A. V.; Isaev, Yu. N.; Kartashov, G. R.; Korotkov, M. M.; Migachev, V. V.

    2008-01-01

    The problem of observing the Moessbauer resonance absorption of gamma rays from long-lived isomers is briefly outlined, first and foremost for 109m Ag taken as an example. Experiments indicative of a small broadening of the Moessbauer gamma line of this isomer in metallic silver are described. This circumstance made it possible to develop and manufacture a gravitational gamma spectrometer and to perform the first experiments with it, which confirm once again the previous data on a small width of the gamma line in question. The broadening factor obtained from these data proved to be 6.3 -1.9 +5.2 .

  19. Determination of Isotopic Abundance of 2H, 13C, 18O, and 37Cl in Biofield Energy Treated Dichlorophenol Isomers

    OpenAIRE

    Branton, Alice; Trivedi, Dahryn; Nayak, Gopal; Trivedi, Mahendra; Saikia, Gunin; Jana, Snehasis

    2016-01-01

    2,4-Dichlorophenol (2,4-DCP) and 2,6-dichlorophenol (2,6-DCP) are two isomers of dichlorophenols, have been used as preservative agents for wood, paints, vegetable fibers and as intermediates in the production of pharmaceuticals and dyes. The aim of the study was to evaluate the impact of biofield energy treatment on the isotopic abundance ratios of 2H/1H or 13C/12C, and 18O/16O or 37Cl/35Cl, in dichlorophenol isomers using gas chromatography-mass spectrometry (GC-MS). The 2,4-DCP and 2,6-DCP...

  20. Nuclear structure around doubly-magic nuclei: lifetime measurements in the vicinity of 68Ni and search for isomers around 100Sn

    International Nuclear Information System (INIS)

    Celikovic, Igor

    2013-01-01

    In this thesis we investigated the structure of nuclei around 68 Ni as well as the production, separation and identification of proton-rich isotopes lying in the vicinity of the doubly-magic 100 Sn nucleus.In the first part, we discuss the evolution of collectivity and the interplay between collective and single-particle degrees of freedom in nuclei around 68 Ni. We measured lifetimes in Zn isotopes around N = 40 produced in 238 U + 70 Zn deep-inelastic collisions at GANIL. We used a plunger device and the recoil-distance Doppler-shift method. The nuclei of interest were identified by the VAMOS spectrometer and the γ-rays with the EXOGAM array. The reduced electromagnetic transitions probabilities were extracted from the lifetimes. Several transitions and lifetimes are reported for the first time. The experimental results are discussed in the framework of shell model calculations. In the second part, the partial conservation of seniority in the g 9/2 shell and its influence on one-particle transfer is discussed. The third part presents the analysis of an in-beam test performed at RIKEN (Japan) to evaluate two settings of the BigRIPS separator for optimizing the production and selection of 100 Sn. This study has been used to setup our subsequent experiment, dedicated to the measurement of the Gamow-Teller strength in the decay of 100 Sn, to the mapping of the proton drip-line and the study of short-lived isomers in this mass region. Nuclei around 100 Sn were produced by fragmentation of a 345 MeV/u 124 Xe beam on a Be target. The production cross-sections of nuclei around 100 Sn were measured. The search for new isotopes and new isomers in all identified nuclei is presented. (author) [fr

  1. Keep Meaning in Conversational Coordination

    Directory of Open Access Journals (Sweden)

    Elena Clare Cuffari

    2014-12-01

    Full Text Available Coordination is a widely employed term across recent quantitative and qualitative approaches to intersubjectivity, particularly approaches that give embodiment and enaction central explanatory roles. With a focus on linguistic and bodily coordination in conversational contexts, I review the operational meaning of coordination in recent empirical research and related theorizing of embodied intersubjectivity. This discussion articulates what must be involved in treating linguistic meaning as dynamic processes of coordination. The coordination approach presents languaging as a set of dynamic self-organizing processes and actions on multiple timescales and across multiple modalities that come about and work in certain domains (those jointly constructed in social, interactive, high-order sense-making. These processes go beyond meaning at the level that is available to first-person experience. I take one crucial consequence of this to be the ubiquitously moral nature of languaging with others. Languaging coordinates experience, among other levels of behavior and event. Ethical effort is called for by the automatic autonomy-influencing forces of languaging as coordination.

  2. Coordinating distributed work : Exploring situated coordination with gaming-simulation

    NARCIS (Netherlands)

    van Laere, J.

    2003-01-01

    Organizational work has become more and more distributed nowadays. Information and communication technologies (ICT) provide opportunities to improve coordination of distributed work, but in practice many organizations struggle with integrating new organizational structures, new work practices and

  3. Trans fatty acid isomers and the trans-9/trans-11 index in fat containing foods

    Science.gov (United States)

    Kuhnt, Katrin; Baehr, Melanie; Rohrer, Carsten; Jahreis, Gerhard

    2011-01-01

    To determine trans fatty acid (TFA) distribution of contemporary foods, especially regarding individual trans octadecenoic acids (trans C18:1), 339 German foods of six categories (semi-solid fats, deep-fried potato products, bakery products, confectioneries, instant products and butter) were analysed using two GC methods. Results showed a high variation of TFA content between and within the categories containing between 0 and 40.5% of FAME except in butter, which is a source of natural TFA. The mean TFA values were below 2.0% of FAME, however, bakery products contained 4.5% and butter fat 3.2%, respectively. In addition, the distribution of individual trans C18:1 differed. In samples containing ruminant fat (butter and various confectioneries), vaccenic acid (t11-C18:1, t11) predominated, while in foods containing industrially hydrogenated fats, elaidic acid (trans-9, t9-) and t10-C18:1 were the major trans isomers.. This was reflected by a low t9/t11 index of 0.3 and 0.5 in butter and ruminant fat containing confectioneries, respectively, whilst the highest index was observed in shortenings and deep-fried potato products at 5.2 and 6.8, respectively. In conclusion, the TFA content of foods available on the German market is generally declining, but substantial variations are present. The t9/t11 index could be used as an indicator to determine ruminant fat. Practical applications: A number of studies provide evidence that a high TFA intake, particularly of industrial origin, adversely affects human health. The TFA content of foods could be reduced due to the introduction of several mandatory regulations and modifications regarding the hydrogenation process of oils. The most abundant dietary TFA are the isomers of trans C18:1. Unfortunately, the differentiation of these isomers is not yet very common, though the trans C18:1 profile differs depending on its origin (bacterial hydrogenation in the rumen or industrial hydrogenation). To date, data for TFA content

  4. Hydrogen atom transfer reactions in thiophenol: photogeneration of two new thione isomers.

    Science.gov (United States)

    Reva, Igor; Nowak, Maciej J; Lapinski, Leszek; Fausto, Rui

    2015-02-21

    Photoisomerization reactions of monomeric thiophenol have been investigated for the compound isolated in low-temperature argon matrices. The initial thiophenol population consists exclusively of the thermodynamically most stable thiol form. Phototransformations were induced by irradiation of the matrices with narrowband tunable UV light. Irradiation at λ > 290 nm did not induce any changes in isolated thiophenol molecules. Upon irradiation at 290-285 nm, the initial thiol form of thiophenol converted into its thione isomer, cyclohexa-2,4-diene-1-thione. This conversion occurs by transfer of an H atom from the SH group to a carbon atom at the ortho position of the ring. Subsequent irradiation at longer wavelengths (300-427 nm) demonstrated that this UV-induced hydrogen-atom transfer is photoreversible. Moreover, upon irradiation at 400-425 nm, the cyclohexa-2,4-diene-1-thione product converts, by transfer of a hydrogen atom from the ortho to para position, into another thione isomer, cyclohexa-2,5-diene-1-thione. The latter thione isomer is also photoreactive and is consumed if irradiated at λ atom-transfer isomerization reactions dominate the unimolecular photochemistry of thiophenol confined in a solid argon matrix. A set of low-intensity infrared bands, observed in the spectra of UV irradiated thiophenol, indicates the presence of a phenylthiyl radical with an H- atom detached from the SH group. Alongside the H-atom-transfer and H-atom-detachment processes, the ring-opening photoreaction occurred in cyclohexa-2,4-diene-1-thione by the cleavage of the C-C bond at the alpha position with respect to the thiocarbonyl C[double bond, length as m-dash]S group. The resulting open-ring conjugated thioketene adopts several isomeric forms, differing by orientations around single and double bonds. The species photogenerated upon UV irradiation of thiophenol were identified by comparison of their experimental infrared spectra with the spectra theoretically calculated for

  5. Carborane-stilbene dyads: the influence of substituents and cluster isomers on photoluminescence properties.

    Science.gov (United States)

    Ferrer-Ugalde, A; Cabrera-González, J; Juárez-Pérez, E J; Teixidor, F; Pérez-Inestrosa, E; Montenegro, J M; Sillanpää, R; Haukka, M; Núñez, R

    2017-02-14

    Two novel styrene-containing meta-carborane derivatives substituted at the second carbon cluster atom (C c ) with either a methyl (Me) or a phenyl (Ph) group are introduced herein along with a new set of stilbene-containing ortho- (o-) and meta- (m-) carborane dyads. The latter set of compounds have been prepared from styrene-containing carborane derivatives via a Heck coupling reaction. High regioselectivity has been achieved for these compounds by using a combination of palladium complexes [Pd 2 (dba) 3 ]/[Pd(t-Bu 3 P) 2 ] as a catalytic system, yielding exclusively E isomers. All compounds have been fully characterised and the crystal structures of seven of them were analysed by X-ray diffraction. The absorption spectra of these compounds are similar to those of their respective fluorophore groups (styrene or stilbene), showing a very small influence of the substituent (Me or Ph) linked to the second C c atom or the cluster isomer (o- or m-). On the other hand, fluorescence spectroscopy revealed high emission intensities for Me-o-carborane derivatives, whereas their Ph-o-carborane analogues evidenced an almost total lack of fluorescence, confirming the significant role of the substituent bound to the adjacent C c in o-carboranes. In contrast, all the m-carborane derivatives display similar photoluminescence (PL) behavior regardless of the substituent attached to the second C c , demonstrating its small influence on emission properties. Additionally, m-carborane derivatives are significantly more fluorescent than their o-counterparts, reaching quantum yield values as high as 30.2%. Regarding solid state emission, only stilbene-containing Ph-o-carborane derivatives, which showed very low fluorescence in solution, exhibited notable PL emission in films attributed to aggregation-induced emission. DFT calculations were performed to successfully complement the photoluminescence studies, supporting the experimentally observed photophysical behavior of the styrene and

  6. Detection of biologically active isomers of conjugated linoleic acid in kaymak

    Directory of Open Access Journals (Sweden)

    Ökten, Sevtap

    2005-12-01

    Full Text Available Numerous physiological effects are attributed to conjugated linoleic acids (CLA. Biologically active isomers of CLA ( cis -9, trans -11 (C18:2 and trans- 10, cis- 12 (C18:2 have been reported to have anticarcinogenic, antioxidative and antiatherosclerotic properties. Relatively rich sources of CLA include milk fat-containing foods such as kaymak. Kaymak is a kind of concentrated cream which is traditionally manufactured from buffalo or cow's milk mainly in Turkey . The objective of this study was to determine CLA concentrations during kaymak production. Kaymak was manufactured from cow's milk which was enriched with unfermented cream. Biologically active isomers of CLA in raw milk, cream and kaymak were analyzed using gas chromatography. The method was quick, repeatable and sensitive for the CLA determination of samples. Significant differences were found among the concentrations of both isomer and total CLA during the production process (pNumerosos efectos fisiológicos se atribuyen a los ácidos linoleico conjugados (CLA. Así los isómeros biológicamente activos ( cis -9, trans -11 (C18:2 y trans- 10, cis del ácido linoleico han sido descritos con propiedades anticarcinogénicas, antioxidantes y antiarterioscleróticas. Fuentes relativamente ricas de CLA incluyen alimentos con grasas lácteas tales como el kaymak. El kaymak es una crema concentrada elaborada de leche de búfalo o vaca principalmente en Turquía. El objetivo de este estudio fue la determinación de la concentración de CLA durante la producción de kaymak. El kaymak objeto de estudio fue elaborado a partir de leche de vaca que fue enriquecida con crema no fermentada. Los isómeros biológicamente activos del CLA fueron analizados por cromatografía gaseosa en leche cruda, crema y kaymak. El método empleado fue rápido, reproducible y sensible. Se encontraron diferencias significativas en las concentraciones de ambos isómeros y de CLA total durante el proceso de producci

  7. LC-H-1 NMR used for determination of the elution order of S-naproxen glucuronide isomers in two isocratic reversed-phase LC-systems

    DEFF Research Database (Denmark)

    Mortensen, R. W.; Corcoran, O.; Cornett, Claus

    2001-01-01

    . In both systems the elution order for the 2-, 3- and 4-O-acyl isomers corresponded with previously published results for 2-, 3-, and 4-fluorobenzoic acid glucuronide isomers determined by reversed phase HPLC-H-1 NMR [U.G. Sidelmann, S.H. Hansen, C. Gavaghan, A.W. Nicholls, H.A.J. Carless, J.C. Lindon, I...

  8. Gamma-ray Spectroscopy of Nano-second Isomers in Neutron-rich Ni Region Produced by Deep-inelastic Collisions

    Science.gov (United States)

    Ishii, Tetsuro; Asai, Masato; Kleinheinz, Peter; Matsuda, Makoto; Ichikawa, Shinichi; Makishima, Akiyasu; Ogawa, Masao

    2001-10-01

    We have been studying nuclear structure of neutron-rich nuclei produced by heavy-ion deep-inelastic collisions at the JAERI Tandem Booster facility. In our method using an `isomer-scope', γ-rays only from isomers with T_1/2 > 1ns are measured by shielding Ge detectors from prompt γ rays emitted at the target position. Atomic numbers of isomers can be also identified by detecting projectile-like fragments with Si Δ E-E detectors. Until now, we have found several new isomers in neutron-rich Ni region using about 8 MeV/nucleon ^70Zn, ^76Ge and ^82Se beams and a ^198Pt target of 4.3 mg/cm^2 thickness. In the doubly magic ^68_28Ni_40, the (ν g_9/2^2 ν p_1/2-2)8^+ isomer with T_1/2=23(1) ns was found. In its neighbor nuclei ^69,71Cu, the 19/2^- isomers were found and the energy levels decaying from the isomers can be calculated very accurately by a parameter-free shell model calculation using experimental energy levels as two-body residual interactions. I will also briefly discuss nano-second isomers in ^32,33Si and ^34P produced by 9 MeV/nucleon ^37Cl beams.

  9. The coordinate transforming in geography information system

    International Nuclear Information System (INIS)

    Zhao Xiang; Chen Gang

    2003-01-01

    The coordinate transforming of geography information system includes two kinds of transforming, map projection and coordinate-transforming. This paper proposed a arithmetic of coordinate-transforming, it implement the transforming between the longitude-latitude coordinate and the screen coordinate and apply it in the GIS. The preferable effect was made. (authors)

  10. Who matters in coordination problems?

    Czech Academy of Sciences Publication Activity Database

    Sákovics, J.; Steiner, Jakub

    2012-01-01

    Roč. 102, č. 7 (2012), s. 3439-3461 ISSN 0002-8282 Institutional support: RVO:67985998 Keywords : coordination problem s * heterogeneous agents Subject RIV: AH - Economics Impact factor: 2.792, year: 2012

  11. Coordination Processes in International Organisations

    DEFF Research Database (Denmark)

    Nedergaard, Peter

    2008-01-01

    The EU is not a member of the International Labour Organisation (ILO), but relatively elaborate EU coordination takes place anyway. This paper addresses two research questions: 1) How is it possible to evaluate the coordination of the EU in its specific observable configuration in the ILO?, and 2......-à-vis their principals, the Member States. The Commission is the leading agent in the phase leading up to the Conference; the Presidency then takes over. On the one hand, due to the Treaty obligations and their interpretations by the Court of Justice, both the Presidency and the Commission are kept within tight limits...... by the principals. On the other hand, both before and during the Conference, the Member States accept the so-called discursive coordination of the Commission, which seems to be of great (but often neglected) importance. Owing to the organisational set-up in which coordination takes place, the EU is able...

  12. Hall effect in noncommutative coordinates

    International Nuclear Information System (INIS)

    Dayi, Oemer F.; Jellal, Ahmed

    2002-01-01

    We consider electrons in uniform external magnetic and electric fields which move on a plane whose coordinates are noncommuting. Spectrum and eigenfunctions of the related Hamiltonian are obtained. We derive the electric current whose expectation value gives the Hall effect in terms of an effective magnetic field. We present a receipt to find the action which can be utilized in path integrals for noncommuting coordinates. In terms of this action we calculate the related Aharonov-Bohm phase and show that it also yields the same effective magnetic field. When magnetic field is strong enough this phase becomes independent of magnetic field. Measurement of it may give some hints on spatial noncommutativity. The noncommutativity parameter θ can be tuned such that electrons moving in noncommutative coordinates are interpreted as either leading to the fractional quantum Hall effect or composite fermions in the usual coordinates

  13. Future in actinoids coordination chemistry

    International Nuclear Information System (INIS)

    Kitazawa, Takafumi

    2006-01-01

    Actinoids coordination chemistry is concerned with spent nuclear fuel reprocessing, specifically with solid-state chemistry of nuclear fuels, separation process with radioactive substances, and geological disposal of high-level radioactive substances. In the 21st century, accumulation of minor actinides, Np, Am, Cm, and others will be realized according with the present program of nuclear energy development. The present article briefly introduces general properties of actinide elements, followed by their coordination chemistry compared with rare earths coordination chemistry. Special facility needed to treat actinoids as well as their chemistry is briefly explained, together with the specific experimental apparatus such as X-ray Absorption Fine Structure (XAFS) and time-resolved laser-induced fluorescence spectrometry (TRLFS) with synchrotron radiation facilities. The effect of coordination with actinoids in the environment chemistry is important in underground disposal of high-level radioactive wastes. For theoretical analysis of the results with actinoids chemistry, relativistic calculation is needed. (S. Ohno)

  14. Identification of isomers in the gas phase and as adsorbates by near-edge X-ray absorption fine structure spectroscopy: Cis- and trans-stilbene

    International Nuclear Information System (INIS)

    Püttner, Ralph; Schmidt-Weber, Philipp; Kampen, Thorsten; Kolczewski, Christine; Hermann, Klaus; Horn, Karsten

    2017-01-01

    Highlights: • NEXAFS spectra of the cis- and trans-isomer of stilbene reveal distinct differences by which the isomers can be distinguished. • DFT calculations using the transition potential approach assign specific transitions that are different in the two isomers. • On Si(100), these differences in NEXAFS are also observed, suggesting that their conformations survive in the bonding situation. • NEXAFS is thus shown to be a sensitive tool to distinguish isomers in adsorbed species. - Abstract: Near-edge x-ray absorption fine structure spectra of the cis- and trans-isomers of stilbene in the gas phase reveal clear differences, which are analyzed by results from density-functional theory calculations using the transition potential approach. The differences between the two species also occur in stilbene adsorbed on Si(100), opening the way towards studying structural changes in molecules in different surface environments, and configurational switching in organic molecules on surfaces in particular.

  15. Structures, stabilities, aromaticity, and electronic properties of C66 fullerene isomers, anions (C662-, C664-, C666-), and metallofullerenes (Sc2-C66)

    International Nuclear Information System (INIS)

    Cui Yanhong; Tian, Wei Quan; Feng Jikang; Chen Deli

    2010-01-01

    Among all the 4478 classical isomers of C 66 , C 66 (C s :0060) with the lowest number of pentagon-pentagon fusions was predicted to be the most stable isomer, followed by isomers C 66 (C 2v :0011) and C 66 (C 2 :0083). The infrared spectra and aromaticity of the most stable isomers were predicted. The relative stabilities of C 66 isomers change with charges or doping of metals. The structures and relative stabilities of the most stable metallofullerenes were delineated and compared with experiment. Sc 2 -C 66 (C 2 :0083) was predicted to be the most stable metallofullerene, although Sc 2 -C 66 (C 2v :0011) was observed. Charge-transfer from Sc 2 to the fused pentagons and the bonding between these two moieties significantly decrease the strain energies caused by the pair of fused pentagons thereby stabilizing the fullerene cage.

  16. Identification of isomers in the gas phase and as adsorbates by near-edge X-ray absorption fine structure spectroscopy: Cis- and trans-stilbene

    Energy Technology Data Exchange (ETDEWEB)

    Püttner, Ralph [Department of Physics, Freie Universität Berlin, 14195 Berlin (Germany); Schmidt-Weber, Philipp [Fritz Haber Institute of the Max Planck Society, 14195 Berlin (Germany); Kampen, Thorsten [SPECS Surface Nano Analysis GmbH, 13355 Berlin (Germany); Kolczewski, Christine [Deutsches Museum München, 80538 Munich (Germany); Hermann, Klaus [Fritz Haber Institute of the Max Planck Society, 14195 Berlin (Germany); Horn, Karsten, E-mail: horn@fhi-berlin.mpg.de [Fritz Haber Institute of the Max Planck Society, 14195 Berlin (Germany)

    2017-02-15

    Highlights: • NEXAFS spectra of the cis- and trans-isomer of stilbene reveal distinct differences by which the isomers can be distinguished. • DFT calculations using the transition potential approach assign specific transitions that are different in the two isomers. • On Si(100), these differences in NEXAFS are also observed, suggesting that their conformations survive in the bonding situation. • NEXAFS is thus shown to be a sensitive tool to distinguish isomers in adsorbed species. - Abstract: Near-edge x-ray absorption fine structure spectra of the cis- and trans-isomers of stilbene in the gas phase reveal clear differences, which are analyzed by results from density-functional theory calculations using the transition potential approach. The differences between the two species also occur in stilbene adsorbed on Si(100), opening the way towards studying structural changes in molecules in different surface environments, and configurational switching in organic molecules on surfaces in particular.

  17. Directional Overcurrent Relays Coordination Problems in Distributed Generation Systems

    Directory of Open Access Journals (Sweden)

    Jakub Ehrenberger

    2017-09-01

    Full Text Available This paper proposes a new approach to the distributed generation system protection coordination based on directional overcurrent protections with inverse-time characteristics. The key question of protection coordination is the determination of correct values of all inverse-time characteristics coefficients. The coefficients must be correctly chosen considering the sufficiently short tripping times and the sufficiently long selectivity times. In the paper a new approach to protection coordination is designed, in which not only some, but all the required types of short-circuit contributions are taken into account. In radial systems, if the pickup currents are correctly chosen, protection coordination for maximum contributions is enough to ensure selectivity times for all the required short-circuit types. In distributed generation systems, due to different contributions flowing through the primary and selective protections, coordination for maximum contributions is not enough, but all the short-circuit types must be taken into account, and the protection coordination becomes a complex problem. A possible solution to the problem, based on an appropriately designed optimization, has been proposed in the paper. By repeating a simple optimization considering only one short-circuit type, the protection coordination considering all the required short-circuit types has been achieved. To show the importance of considering all the types of short-circuit contributions, setting optimizations with one (the highest and all the types of short-circuit contributions have been performed. Finally, selectivity time values are explored throughout the entire protected section, and both the settings are compared.

  18. Uncovering biologically significant lipid isomers with liquid chromatography, ion mobility spectrometry and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kyle, Jennifer E.; Zhang, Xing; Weitz, Karl K.; Monroe, Matthew E.; Ibrahim, Yehia M.; Moore, Ronald J.; Cha, Jeeyeon; Sun, Xiaofei; Lovelace, Erica S.; Wagoner, Jessica; Polyak, Steve; Metz, Thomas O.; Dey, Sudhansu K.; Smith, Richard D.; Burnum-Johnson, Kristin E.; Baker, Erin Shammel

    2016-01-01

    Understanding how biological molecules are generated, metabolized and eliminated in living systems is important for interpreting processes such as immune response and disease pathology. While genomic and proteomic studies have provided vast amounts of information over the last several decades, interest in lipidomics has also grown due to improved analytical technologies revealing altered lipid metabolism in type 2 diabetes, cancer, and lipid storage disease. Liquid chromatography and mass spectrometry (LC-MS) measurements are currently the dominant approach for characterizing the lipidome by providing detailed information on the spatial and temporal composition of lipids. However, interpreting lipids’ biological roles is challenging due to the existence of numerous structural and stereoisomers (i.e. distinct acyl chain and double-bond positions), which are unresolvable using present LC-MS approaches. Here we show that combining structurally-based ion mobility spectrometry (IMS) with LC-MS measurements distinguishes lipid isomers and allows insight into biological and disease processes.

  19. Differential behavior of amino-imino constitutional isomers in nonlinear optical processes.

    Science.gov (United States)

    Latorre, Sonia; Moreira, Ibério de P R; Villacampa, Belén; Julià, Lluís; Velasco, Dolores; Bofill, Josep Maria; López-Calahorra, Francisco

    2010-03-15

    A detailed study of the "blocked" amino-imino tautomers derived from N-acridine-substituted 2-aminobenzothiazole--and their effect on the nonlinear optical response--is presented. The synthesis, characterization, and nonlinear optical properties of these frozen tautomers, namely, N-methyl-N-(2-nitroacridin-6-yl)-2-aminobenzothia-zole and 3-methyl-N-(7-nitroacridin-3-yl)-2-iminobenzothiazole, are reported. A theoretical model based on valence-bond theory is also proposed and used to analyze the effects of the nuclear configuration corresponding to each frozen tautomer structure. In the present case, the aromatic form and the allylic-anion-like system of the -N-C-N- group inherent to each isomer are crucial for understanding and analyzing the different responses of each "blocked" tautomer.

  20. Separation of multiphosphorylated peptide isomers by hydrophilic interaction chromatography on an aminopropyl phase.

    Science.gov (United States)

    Singer, David; Kuhlmann, Julia; Muschket, Matthias; Hoffmann, Ralf

    2010-08-01

    The separation of isomeric phosphorylated peptides is challenging and often impossible for multiphosphorylated isomers using chromatographic and capillary electrophoretic methods. In this study we investigated the separation of a set of single-, double-, and triple-phosphorylated peptides (corresponding to the human tau protein) by ion-pair reversed-phase chromatography (IP-RPC) and hydrophilic interaction chromatography (HILIC). In HILIC both hydroxyl and aminopropyl stationary phases were tested with aqueous acetonitrile in order to assess their separation efficiency. The hydroxyl phase separated the phosphopeptides very well from the unphosphorylated analogue, while on the aminopropyl phase even isomeric phosphopeptides attained baseline separation. Thus, up to seven phosphorylated versions of a given tau domain were separated. Furthermore, the low concentration of an acidic ammonium formate buffer allowed an online analysis with electrospray ionization tandem mass spectrometry (ESI-MS/MS) to be conducted, enabling peptide sequencing and identification of phosphorylation sites.