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Sample records for dysprosium compounds

  1. Tuning Slow Magnetic Relaxation in a Two-Dimensional Dysprosium Layer Compound through Guest Molecules.

    Science.gov (United States)

    Chen, Qi; Li, Jian; Meng, Yin-Shan; Sun, Hao-Ling; Zhang, Yi-Quan; Sun, Jun-Liang; Gao, Song

    2016-08-15

    A novel two-dimensional dysprosium(III) complex, [Dy(L)(CH3COO)]·0.5DMF·H2O·2CH3OH (1), has been successfully synthesized from a new pyridine-N-oxide (PNO)-containing ligand, namely, N'-(2-hydroxy-3-methoxybenzylidene)pyridine-N-oxidecarbohydrazide (H2L). Single-crystal X-ray diffraction studies reveal that complex 1 is composed of a dinuclear dysprosium subunit, which is further extended by the PNO part of the ligand to form a two-dimensional layer. Magnetic studies indicate that complex 1 shows well-defined temperature- and frequency-dependent signals under a zero direct-current (dc) field, typical of slow magnetic relaxation with an effective energy barrier Ueff of 33.6 K under a zero dc field. Interestingly, powder X-ray diffraction and thermogravimetric analysis reveal that compound 1 undergoes a reversible phase transition that is induced by the desorption and absorption of methanol and water molecules. Moreover, the desolvated sample [Dy(L)(CH3COO)]·0.5DMF (1a) also exhibits slow magnetic relaxation but with a higher anisotropic barrier of 42.0 K, indicating the tuning effect of solvent molecules on slow magnetic relaxation.

  2. A Linear Tetranuclear Dysprosium(III) Compound Showing Single-Molecule Magnet Behavior

    Energy Technology Data Exchange (ETDEWEB)

    Ke, Hongshan; Xu, Gong Feng; Guo, Yun-Nan; Gamez, Patrick; Beavers, Christine M; Teat, Simon J; Tang, Jinkui

    2010-04-20

    Although magnetic measurements reveal a single-relaxation time for a linear tetranuclear Dy(III) compound, the wide distribution of the relaxation time observed clearly suggests the presence of two slightly different anisotropic centres, therefore opening new avenues for investigating the relaxation dynamics of lanthanide aggregates.

  3. Magnetic Properties of Some Gadolinium, Erbium, Dysprosium, Manganese Substituted Samarium-2 Cobalt-17 Intermetallic Compounds.

    Science.gov (United States)

    1979-08-01

    S K AREA B WORK UNIT NUMBERSElect ronic Materials Research Division 61102AUS Army Electronics Technology & Devices Laborator) 1-rrr~ -rrd2An47 02 031...permanent magnet materials having intrinsically temperature compensated magneti- zations. The properties investigated were saturation magnetization...that excellent temperature compensation could be achieved in these compounds in the teinper~ture (cont’d) ~‘ DD I ? ) 1Q3 L°’TI°M °’ INOV BI

  4. The dysprosium-tin phase diagram

    Energy Technology Data Exchange (ETDEWEB)

    Eremenko, V.N.; Bulanova, M.V.; Martsenjuk, P.S. (I.N. Frantsevich Inst. for Problems of Materials Science, Kiev (Ukraine))

    1992-12-07

    The dysprosium-tin phase diagram was established by means of differential thermal, X-ray and microscopic analyses of 22 alloys. Seven intermetallic compounds were found to exist in the system. Dy[sub 5]Sn[sub 3] melts congruently at 1870 degC, and undergoes a polymorphous transformation at 1823 [+-] 6 degC. The intermetallics Dy[sub 5]Sn[sub 4], Dy[sub 11]Sn[sub 10], DySn, Dy[sub 4]Sn[sub 5], DySn[sub 2], DySn[sub 3] are formed peritectically at 1712 [+-]11, 1605 [+-]12, 1208 [+-]3, 1166 [+-]7, 1138 [+-]3 and 747 [+-]6 degC respectively. DySn[sub 3] exists in a narrow temperature range, in two polymorphous modifications. The transformation [beta]-DySn[sub 3] [yields] [alpha]-DySn[sub 3] occurs at 608 [+-] 12 degC, and at 499 [+-]2 degC [alpha]-DySn[sub 3] decomposes to DySn[sub 2] and the tin-rich melt. The dysprosium-rich eutectic crystallizes at 1204 [+-]10 degC and contains 13 at.% tin. The solid-state solubility of tin in dysprosium is about 3 at.%, and that of dysprosium in tin is negligible.

  5. Slow Magnetic Relaxation Observed in Dysprosium Compounds Containing Unsupported Near-Linear Hydroxo- and Fluoro-Bridges.

    Science.gov (United States)

    Brunet, Gabriel; Habib, Fatemah; Korobkov, Ilia; Murugesu, Muralee

    2015-07-06

    The encapsulating N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) ligand was employed to isolate two novel Dy(III) compounds which contain rare bridging pathways for lanthanide systems. Compound 1, [Na2Dy(III)2(valdien)2(μ-OH)(dbm)2(H2O)2][Na2Dy(III)2(valdien)2(μ-OH)(NO3)2(dbm)2], where dbm(-) is dibenzoylmethanido, and compound 2, [Na3Dy(III)2(valdien)2(μ-F)(μ3-F)2(Cl)2(MeOH)2]n·0.5(MeOH)·(H2O), both exhibit linear lone hydroxo- and fluoro-bridges, respectively, between the metal centers. The unit cell of 1 comprises two discrete dinuclear molecules, which differ slightly, forming a cation-anion pair, while 2 forms a coordination polymer. The magnetic investigations indicate that both compounds display ferromagnetic coupling between the Dy(III) ions. Magnetic susceptibility measurements in the temperature range 1.8-300 K reveal that the Dy(III) ions in 1 are weakly coupled, resulting in a mononuclear single-molecule magnet-like behavior under an applied field. In the case of 2, the stronger coupling arising from the fluoride-bridge, leads to zero-field single-molecule magnet (SMM) behavior with a non-negligible anisotropy barrier (Ueff) of 42 K.

  6. Phenalenyl-based mononuclear dysprosium complexes

    Directory of Open Access Journals (Sweden)

    Yanhua Lan

    2016-07-01

    Full Text Available The phenalenyl-based dysprosium complexes [Dy(PLN2(HPLNCl(EtOH] (1, [Dy(PLN3(HPLN]·[Dy(PLN3(EtOH]·2EtOH (2 and [Dy(PLN3(H2O2]·H2O (3, HPLN being 9-hydroxy-1H-phenalen-1-one, have been synthesized. All compounds were fully characterized by means of single crystal X-ray analysis, paramagnetic 1H NMR, MALDI-TOF mass spectrometry, UV–vis spectrophotometry and magnetic measurements. Both static (dc and dynamic (ac magnetic properties of these complexes have been investigated, showing slow relaxation of magnetization, indicative of single molecule magnet (SMM behavior. Attempts to synthesize sublimable phenalenyl-based dysprosium complexes have been made by implementing a synthetic strategy under anhydrous conditions. The sublimed species were characterized and their thermal stability was confirmed. This opens up the possibility to deposit phenalenyl-based lanthanides complexes by sublimation onto surfaces, an important prerequisite for ongoing studies in molecular spintronics.

  7. Dysprosium magneto-optical traps

    CERN Document Server

    Youn, Seo Ho; Ray, Ushnish; Lev, Benjamin L

    2010-01-01

    Magneto-optical traps (MOTs) of highly magnetic lanthanides open the door to explorations of novel phases of strongly correlated matter such as lattice supersolids and quantum liquid crystals. We recently reported the first MOTs of the five high abundance isotopes of the most magnetic atom, dysprosium. Described here are details of the experimental technique employed for repumper-free Dy MOTs containing up to half a billion atoms. Extensive characterization of the MOTs' properties---population, temperature, loading, metastable decay dynamics, trap dynamics---is provided.

  8. Sandwich-type tetrakis(phthalocyaninato) dysprosium-cadmium quadruple-decker SMM.

    Science.gov (United States)

    Wang, Hailong; Qian, Kang; Wang, Kang; Bian, Yongzhong; Jiang, Jianzhuang; Gao, Song

    2011-09-14

    Homoleptic tetrakis[2,3,9,10,16,17,23,24-octa(butyloxy)phthalocyaninato] dysprosium-cadmium quadruple-decker complex 1 was isolated in relatively good yield of 43% from a simple one-pot reaction. This compound represents the first sandwich-type tetrakis(phthalocyaninato) rare earth-cadmium quadruple-decker SMM that has been structurally characterized.

  9. On polymorphism of dysprosium trichloride

    Energy Technology Data Exchange (ETDEWEB)

    Zakiryanova, Irina D.; Khokhlov, Vladimir A.; Salyulev, Alexander B.; Korzun, Iraida V. [RAS Ural Branch, Ekaterinburg (Russian Federation). Institute of High-Temperature Electrochemistry

    2015-07-01

    For the first time, the structure of crystalline DyCl{sub 3} over a wide temperature range from room temperature to melting point was studied by Raman spectroscopy. The phonon modes (cm{sup -1}) of dysprosium trichloride (monoclinic crystal lattice of AlCl{sub 3} type, Z = 4, CN = 6) at room temperature are 257 (A{sub 1g}), 201 (E{sub g}), 112 (E{sub g}), 88 (A{sub 1g}), and 63 (E{sub g}). The monoclinic structure of the crystalline DyCl{sub 3} C{sub 2h}{sup 3} symmetry was found to remain constant over the studied temperature range. No polymorphic transformation in the solid state was detected. Gravimetry, calorimetry, and mass spectrometry have been used in addition to support the conclusions made on the basis of Raman spectroscopic data.

  10. Resonance ionization spectroscopy in dysprosium

    Energy Technology Data Exchange (ETDEWEB)

    Studer, D., E-mail: dstuder@uni-mainz.de; Dyrauf, P.; Naubereit, P.; Heinke, R.; Wendt, K. [Johannes Gutenberg-Universität Mainz, Institut für Physik (Germany)

    2017-11-15

    We report on resonance ionization spectroscopy (RIS) of high-lying energy levels in dysprosium. We developed efficient excitation schemes and re-determined the first ionization potential (IP) via analysis of Rydberg convergences. For this purpose both two- and three-step excitation ladders were investigated. An overall ionization efficiency of 25(4) % could be demonstrated in the RISIKO mass separator of Mainz University, using a three-step resonance ionization scheme. Moreover, an extensive analysis of the even-parity 6sns- and 6snd-Rydberg-series convergences, measured via two-step excitation was performed. To account for strong perturbations in the observed s-series, the approach of multichannel quantum defect theory (MQDT) was applied. Considering all individual series limits we extracted an IP-value of 47901.76(5) cm{sup −1}, which agrees with the current literature value of 47901.7(6) cm{sup −1}, but is one order of magnitude more precise.

  11. Dysprosium complexes with the tetraphenylporphyrin macrocyclic ligand; Complejos de disprosio con el ligante macrociclico tetrafenilporfirina

    Energy Technology Data Exchange (ETDEWEB)

    Martinez M, V.; Padilla, J.; Ramirez, F.M

    1992-04-15

    In this report, the results obtained on the synthesis, characterization and study of the chemical behavior of dysprosium complex with the acetylacetone chelating agent (Hacac) and the tetraphenylporphyrin macrocyclic ligand (H{sub 2}TFP) are given. Based on the literature but according to our necessities and interest, the appropriate methodology settled down from the synthesis of prime matters until the obtaining and characterization of the products. The acetyl acetonate complex was obtained of mono hydrated dysprosium [Dy(acac){sub 3}. H{sub 2}0] and trihydrated [Dy(acac){sub 3} .3 H{sub 2}0], the mono tetra phenyl porphyrinate [Dy(TFP)(acac). 2 ac] the double sandwich of the dysprosium porphyrinate [Dy(TFP){sub 2}] and the triple sandwich of the dysprosium porphyrinate [Dy(TFP){sub 3}. 2 TCB] (TCB = trichlorobenzene). Its were characterized by their melting points, solubility, IR, UV, TGA and DTA both first and besides the techniques already mentioned for NMR'H, RPE and Magnetic susceptibility the three last complexes. From the spectroscopic point of view, IR and RPE its suggested the existence of a complex of inverse mixed valence [Dy(TFP){sup 2-} (TFP) {sup 1-}] for the Dy(TFP){sub 2} as a result of the existence of the free radical (TFP' {sup 1-} and that it was not in none of the other porphyrin compounds. In the NMR'H spectra of the compounds were not observed signals in the region from 0 to 10 ppm that which shows that the dysprosium complexes in special those of the porphyrin type are highly paramagnetic and its could be used as displacement reagents, creators of images and contrast agents of great utility in these days in studies of NMR, technique today by today used in medical diagnoses. (Author)

  12. Towards a new measurement of parity violation in dysprosium

    CERN Document Server

    Leefer, N; Antypas, D; Budker, D

    2014-01-01

    The dysprosium parity violation experiment concluded nearly 17 years ago with an upper limit on weak interaction induced mixing of nearly degenerate, opposite parity states in atomic dysprosium. While that experiment was limited in sensitivity by statistics, a new apparatus constructed in the interim for radio-frequency spectroscopy is expected to provide significant improvements to the statistical sensitivity. Preliminary work from the new PV experiment in dysprosium is presented with a discussion of the current statistical sensitivity and outlook.

  13. A comparison of the effects of symmetry and magnetoanisotropy on paramagnetic relaxation in related dysprosium single ion magnets.

    Science.gov (United States)

    Williams, Ursula J; Mahoney, Brian D; DeGregorio, Patrick T; Carroll, Patrick J; Nakamaru-Ogiso, Eiko; Kikkawa, James M; Schelter, Eric J

    2012-06-07

    Dysprosium complexes of the tmtaa(2-) ligand were synthesized and characterized by X-band EPR and magnetism studies. Both complexes demonstrate magnetoanisotropy and slow paramagnetic relaxation. Comparison of these compounds with the seminal phthalocyanine complex [Dy(Pc)(2)](-) shows the azaannulide complexes are more susceptible to relaxation through non-thermal pathways.

  14. Dysprosium Modification of Cobalt Ferrite Ionic Magnetic Fluids

    Institute of Scientific and Technical Information of China (English)

    JIANG Rong-li; LIU Yong-chao; GENG Quan-rong; ZHAO Wen-tao

    2005-01-01

    Dysprosium composite cobalt ferrite ionic magnetic fluids were prepared by precipitation in the presence of Tri-sodium citrate. Influence of dysprosium modification on magnetic property is studied. The result shows that magnetic response toward exterior magnetic field can be improved by adding Dy3+. Studies also show that the increase of reaction temperature may improve the modification effect of dysprosium. By adding dysprosium ions, the average diameter of the magnetic nanoparticles will be decreased evidently. It is clear that the particles appear as balls, Cobalt ferrite with sizes of 12-15 nm, rare earth composite cobalt ferrite with sizes of 6-8 nm.

  15. Can a dysprosium shortage threaten green energy technologies?

    NARCIS (Netherlands)

    Hoenderdaal, S.; Tercero Espinoza, L.; Marschneider-Weidemann, F.; Crijns - Graus, Wina

    2013-01-01

    Dysprosium, one of the various rare earth elements, is currently for more than 99% mined in China. As China is reducing its exports, new mining projects outside of China are needed to sustain supply and meet future demands. Dysprosium is mainly used in permanent magnets to retain the magnet's streng

  16. Anisotropy in the Interaction of Ultracold Dysprosium

    CERN Document Server

    Kotochigova, Svetlana

    2011-01-01

    The nature of the interaction between ultracold atoms with a large orbital and spin angular momentum has attracted considerable attention. It was suggested that such interactions can lead to the realization of exotic states of highly correlated matter. Here, we report on a theoretical study of the competing anisotropic dispersion, magnetic dipole-dipole, and electric quadrupole-quadrupole forces between two dysprosium atoms. Each dysprosium atom has an orbital angular momentum L=6 and magnetic moment $\\mu=10\\mu_B$. We show that the dispersion coefficients of the ground state adiabatic potentials lie between 1865 a.u. and 1890 a.u., creating a non-negligible anisotropy with a spread of 25 a.u. and that the electric quadrupole-quadrupole interaction is weak compared to the other interactions. We also find that for interatomic separations $R< 50\\,a_0$ both the anisotropic dispersion and magnetic dipole-dipole potential are larger than the atomic Zeeman splittings for external magnetic fields of order 10 G to ...

  17. Dysprosium selective potentiometric membrane sensor

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Faridbod, Farnoush; Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of)

    2013-03-01

    A novel Dy(III) ion-selective PVC membrane sensor was made using a new synthesized organic compound, 3,4-diamino-N Prime -((pyridin-2-yl)methylene)benzohydrazide (L) as an excellent sensing element. The electrode showed a Nernstian slope of 19.8 {+-} 0.6 mV per decade in a wide concentration range of 1.0 Multiplication-Sign 10{sup -6}-1.0 Multiplication-Sign 10{sup -2} mol L{sup -1}, a detection limit of 5.5 Multiplication-Sign 10{sup -7} mol L{sup -1}, a short conditioning time, a fast response time (< 10 s), and high selectivity towards Dy(III) ion in contrast to other cations. The proposed sensor was successfully used as an indicator electrode in the potentiometric titration of Dy(III) ions with EDTA. The membrane sensor was also applied to the F{sup -} ion indirect determination of some mouth washing solutions and to the Dy{sup 3+} determination in binary mixtures. Highlights: Black-Right-Pointing-Pointer The novelty of this work is based on the high affinity of the ionophore toward the Dy{sup 3+} ions. Black-Right-Pointing-Pointer This technique is very simple, fast and inexpensive and it is not necessary to use sophisticated equipment. Black-Right-Pointing-Pointer The newly developed sensor is superior to the formerly reported Dy{sup 3+} sensors in terms of selectivity.

  18. Mixed (phthalocyaninato)(Schiff-base) di-dysprosium sandwich complexes. Effect of magnetic coupling on the SMM behavior.

    Science.gov (United States)

    Wang, Hailong; Liu, Chenxi; Liu, Tao; Zeng, Suyuan; Cao, Wei; Ma, Qi; Duan, Chunying; Dou, Jianmin; Jiang, Jianzhuang

    2013-11-21

    Reaction between Schiff-base ligand and half-sandwich complex M(Pc)(acac) led to the isolation of new sandwich-type mixed (phthalocyaninato)(Schiff-base) di-lanthanide compounds M2(Pc)2(L)H2O (M = Dy, Gd) (1, 2) [H2Pc = metal free phthalocyanine, Hacac = acetylacetone, H2L = N,N'-bis(3-methyloxysalicylidene)benzene-1,2-diamine] with the triple-decker molecular structure clearly revealed by single crystal X-ray diffraction analysis. For the comparative studies, sandwich triple-decker analogues with pure Schiff-base ligand M2(L)3H2O (M = Dy, Gd) (3, 4) were also prepared. Dynamic magnetic measurement result reveals the single-molecule magnet (SMM) nature of the di-dysprosium derivative 1, while the static magnetic investigation over both pure and the diamagnetic diluted samples of this compound discloses the interionic ferromagnetic coupling between the two dysprosium ions, which in turn effectively suppresses the QTM and enhances the energy barrier of this SMM. Nevertheless, comparative studies over the static magnetic properties of the di-dysprosium triple-decker complexes 1 and 3 indicate the stronger magnetic coupling between the two lanthanide ions in mixed (phthalocyaninato)(Schiff-base) species than in the pure Schiff-base triple-decker analogue, suggesting the special coordination sphere around the dysprosium ions in the former compound over the latter one on the more intense inter-ionic ferromagnetic coupling. As a very small step towards understanding the structure-property relationship, the present result will be surely helpful for the design and synthesis of the multinuclear lanthanide-based SMMs with good properties.

  19. First search for double $\\beta$ decay of dysprosium

    CERN Document Server

    Belli, P; Cappella, F; Cerulli, R; Danevich, F A; d'Angelo, S; Di Vacri, M L; Incicchitti, A; Laubenstein, M; Nagorny, S S; Nisi, S; Tolmachev, A V; Tretyak, V I; Yavetskiy, R P

    2011-01-01

    A search for double $\\beta$ decay of dysprosium was realized for the first time with the help of an ultra low-background HP Ge $\\gamma$ detector. After 2512 h of data taking with a 322 g sample of dysprosium oxide limits on double beta processes in $^{156}$Dy and $^{158}$Dy have been established on the level of $T_{1/2}\\geq 10^{14}-10^{16}$ yr. Possible resonant double electron captures in $^{156}$Dy and $^{158}$Dy were restricted on a similar level. As a by-product of the experiment we have measured the radioactive contamination of the Dy$_2$O$_3$ sample and set limits on the $\\alpha$ decay of dysprosium isotopes to the excited levels of daughter nuclei as $T_{1/2}\\geq 10^{15} - 10^{17}$ yr.

  20. Neutron resonance parameters of dysprosium isotopes using neutron capture yields

    Energy Technology Data Exchange (ETDEWEB)

    Shin, S. G.; Kye, Y. U.; Cho, M. H. [POSTECH, Pohang (Korea, Republic of); Namkung, W. [Pohang Accelerator Laboratory, Pohang (Korea, Republic of); Kim, G. N. [Kyungpook National University, Daegu (Korea, Republic of); Lee, M. W.; Kang, Y. R. [Dongnam Inst. Of Radiological and Medical Science, Busan (Korea, Republic of)

    2015-10-15

    Dysprosium is used in the field of nuclear reactor system because it has a very large thermal neutron absorption cross-section. The dysprosium alloyed with special stainless steels is attractive for control in nuclear reactor because of the ability to absorb neutrons readily without swelling or contracting over time and its high melting point. Dysprosium is also one of fission products from the thermal fission of {sup 234}U, {sup 233}U, and {sup 239}Pu. The fission products are accumulated in the reactor core by the burn-up of the nuclear fuel and the poison effect is increased. Therefore, it is required to understand how Dysprosium as both a poison and an absorbing material in the control rod has an effect on the neutron population in a nuclear reactor system over all energy regions. Neutron Capture experiments on Dy isotopes were performed at the electron linear accelerator (LINAC) facility of the Rensselear Polytechnic Institute (RPI) in the neutron energy region from 10 eV to 1 keV. Resonance parameters were extracted by fitting the neutron capture data using the SAMMY multilevel R-matrix Bayesian code.

  1. Properties of Polydisperse Tin-doped Dysprosium and Indium Oxides

    Directory of Open Access Journals (Sweden)

    Malinovskaya Tatyana

    2017-01-01

    Full Text Available The results of investigations of the complex permittivity, diffuse-reflectance, and characteristics of crystal lattices of tin-doped indium and dysprosium oxides are presented. Using the methods of spectroscopy and X-ray diffraction analysis, it is shown that doping of indium oxide with tin results in a significant increase of the components of the indium oxide complex permittivity and an appearance of the plasma resonance in its diffuse-reflectance spectra. This indicates the appearance of charge carriers with the concentration of more than 1021 cm−3 in the materials. On the other hand, doping of the dysprosium oxide with the same amount of tin has no effect on its optical and electromagnetic properties.

  2. Dysprosium titanate as an absorber material for control rods

    Science.gov (United States)

    Risovany, V. D.; Varlashova, E. E.; Suslov, D. N.

    2000-09-01

    Disprosium titanate is an attractive control rod material for the thermal neutron reactors. Its main advantages are: insignificant swelling, no out-gassing under neutron irradiation, rather high neutron efficiency, a high melting point (˜1870°C), non-interaction with the cladding at temperatures above 1000°C, simple fabrication and easily reprocessed non-radioactive waste. It can be used in control rods as pellets and powder. The disprosium titanate control rods have worked off in the MIR reactor for 17 years, in VVER-1000 - for 4 years without any operating problems. After post-irradiation examinations this type of control rod having high lifetime was recommended for the VVER and RBMK. The paper presents the examination results of absorber element dummies containing dysprosium titanate, irradiated in the SM reactor to the neutron fluence of 3.4×10 22 cm -2 ( E>0.1 MeV) and, also, the data on structure, thermal-physical properties of dysprosium titanate, efficiency of dysprosium titanate control rods.

  3. Electrochemical behaviour of dysprosium in the eutectic LiCl-KCl at W and Al electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Castrillejo, Y. [Dpto de Quimica Analitica, Facultad de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain)]. E-mail: ycastril@qa.uva.es; Bermejo, M.R. [Dpto de Quimica Analitica, Facultad de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Barrado, A.I. [Dpto de Quimica Analitica, Facultad de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Pardo, R. [Dpto de Quimica Analitica, Facultad de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Barrado, E. [Dpto de Quimica Analitica, Facultad de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Martinez, A.M. [Department of Materials Technology, Sem Saelands vei 6, 7491 Trondheim (Norway)

    2005-03-15

    The electrochemical behaviour of DyCl{sub 3} was studied in the eutectic LiCl-KCl at different temperatures. The cathodic reaction can be written:Dy(III)+3e-bar Dy(0)which can be divided in two very close cathodic steps:Dy(III)+1e-bar Dy(II)andDy(II)+2e-bar Dy(0)Transient electrochemical techniques, such as cyclic voltammetry, chronopotentiometry, and chronoamperometry were used in order to study the reaction mechanism and the transport parameters of electroactive species at a tungsten electrode. The results showed that in the eutectic LiCl-KCl, electrocrystallization of dysprosium seems to be the controlling electrochemical step. Chronoamperometric studies indicated instantaneous nucleation of dysprosium with three dimensional growth of the nuclei whatever the applied overpotential.Mass transport towards the electrode is a simple diffusion process, and the diffusion coefficient of the electroactive species, i.e. Dy(III), has been calculated. The validity of the Arrhenius law was also verified by plotting the variation of the logarithm of the diffusion coefficient versus 1/T.In addition, the electrode reactions of the LiCl-KCl-DyCl{sub 3} solutions at an Al wire were also investigated by cyclic voltammetry and open circuit chronopotentiometry. The redox potential of the Dy(III)/Dy couple at the Al electrode was observed at more positive potentials values than those at the inert electrode. This potential shift was thermodynamically analyzed by a lowering of activity of Dy in the metal phase due to the formation of intermetallic compounds.

  4. Dysprosium electrodeposition from a hexaalkylguanidinium-based ionic liquid

    Science.gov (United States)

    Berger, Claudia A.; Arkhipova, Maria; Maas, Gerhard; Jacob, Timo

    2016-07-01

    The rare-earth element dysprosium (Dy) is an important additive that increases the magnetocrystalline anisotropy of neodymium magnets and additionally prevents from demagnetizing at high temperatures. Therefore, it is one of the most important elements for high-tech industries and is mainly used in permanent magnetic applications, for example in electric vehicles, industrial motors and direct-drive wind turbines. In an effort to develop a more efficient electrochemical technique for depositing Dy on Nd-magnets in contrast to commonly used costly physical vapor deposition, we investigated the electrochemical behavior of dysprosium(iii) trifluoromethanesulfonate in a custom-made guanidinium-based room-temperature ionic liquid (RTIL). We first examined the electrodeposition of Dy on an Au(111) model electrode. The investigation was carried out by means of cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS). The initial stages of metal deposition were followed by in situ scanning tunneling microscopy (STM). CV measurements revealed a large cathodic reduction peak, which corresponds to the growth of monoatomic high islands, based on STM images taken during the initial stages of deposition. XPS identified these deposited islands as dysprosium. A similar reduction peak was also observed on an Nd-Fe-B substrate, and positively identified as deposited Dy using XPS. Finally, we varied the concentration of the Dy precursor, electrolyte flow and temperature during Dy deposition and demonstrated that each of these parameters could be used to increase the thickness of the Dy deposit, suggesting that these parameters could be tuned simultaneously in a temperature-controlled flow cell to enhance the thickness of the Dy layer.The rare-earth element dysprosium (Dy) is an important additive that increases the magnetocrystalline anisotropy of neodymium magnets and additionally prevents from demagnetizing at high temperatures. Therefore, it is one of the most important

  5. Dysprosium detector for neutron dosimetry in external beam radiotherapy

    Science.gov (United States)

    Ostinelli, A.; Berlusconi, C.; Conti, V.; Duchini, M.; Gelosa, S.; Guallini, F.; Vallazza, E.; Prest, M.

    2014-09-01

    Radiotherapy treatments with high-energy (>8 MeV) photon beams are a standard procedure in clinical practice, given the skin and near-target volumes sparing effect, the accurate penetration and the uniform spatial dose distribution. On the other hand, despite these advantages, neutrons may be produced via the photo-nuclear (γ,n) reactions of the high-energy photons with the high-Z materials in the accelerator head, in the treatment room and in the patient, resulting in an unwanted dose contribution which is of concern, given its potential to induce secondary cancers, and which has to be monitored. This work presents the design and the test of a portable Dysprosium dosimeter to be used during clinical treatments to estimate the "in vivo" dose to the patient. The dosimeter has been characterized and validated with tissue-equivalent phantom studies with a Varian Clinical iX 18 MV photon beam, before using it with a group of patients treated at the S. Anna Hospital in Como. The working principle of the dosimeter together with the readout chain and the results in terms of delivered dose are presented.

  6. Dysprosium detector for neutron dosimetry in external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ostinelli, A.; Berlusconi, C.; Conti, V.; Duchini, M.; Gelosa, S. [Medical Physics - Sant' Anna Hospital, Como (Italy); Guallini, F. [EL.SE s.r.l. (Italy); Vallazza, E. [INFN, Trieste (Italy); Prest, M. [University of Insubria, Como (Italy)

    2014-09-21

    Radiotherapy treatments with high-energy (>8MeV) photon beams are a standard procedure in clinical practice, given the skin and near-target volumes sparing effect, the accurate penetration and the uniform spatial dose distribution. On the other hand, despite these advantages, neutrons may be produced via the photo-nuclear (γ,n) reactions of the high-energy photons with the high-Z materials in the accelerator head, in the treatment room and in the patient, resulting in an unwanted dose contribution which is of concern, given its potential to induce secondary cancers, and which has to be monitored. This work presents the design and the test of a portable Dysprosium dosimeter to be used during clinical treatments to estimate the “in vivo” dose to the patient. The dosimeter has been characterized and validated with tissue-equivalent phantom studies with a Varian Clinical iX 18 MV photon beam, before using it with a group of patients treated at the S. Anna Hospital in Como. The working principle of the dosimeter together with the readout chain and the results in terms of delivered dose are presented.

  7. Low Field Magnetic and Thermal Hysteresis in Antiferromagnetic Dysprosium

    Directory of Open Access Journals (Sweden)

    Iuliia Liubimova

    2017-06-01

    Full Text Available Magnetic and thermal hysteresis (difference in magnetic properties on cooling and heating have been studied in polycrystalline Dy (dysprosium between 80 and 250 K using measurements of the reversible Villari effect and alternating current (AC susceptibility. We argue that measurement of the reversible Villari effect in the antiferromagnetic phase is a more sensitive method to detect magnetic hysteresis than the registration of conventional B(H loops. We found that the Villari point, recently reported in the antiferromagnetic phase of Dy at 166 K, controls the essential features of magnetic hysteresis and AC susceptibility on heating from the ferromagnetic state: (i thermal hysteresis in AC susceptibility and in the reversible Villari effect disappears abruptly at the temperature of the Villari point; (ii the imaginary part of AC susceptibility is strongly frequency dependent, but only up to the temperature of the Villari point; (iii the imaginary part of the susceptibility drops sharply also at the Villari point. We attribute these effects observed at the Villari point to the disappearance of the residual ferromagnetic phase. The strong influence of the Villari point on several magnetic properties allows this temperature to be ranked almost as important as the Curie and Néel temperatures in Dy and likely also for other rare earth elements and their alloys.

  8. A Low-Symmetry Dysprosium Metallocene Single-Molecule Magnet with a High Anisotropy Barrier.

    Science.gov (United States)

    Pugh, Thomas; Chilton, Nicholas F; Layfield, Richard A

    2016-09-05

    The single-molecule magnet (SMM) properties of the isocarbonyl-ligated dysprosium metallocene [Cp*2 Dy{μ-(OC)2 FeCp}]2 (1Dy ), which contains a rhombus-shaped Dy2 Fe2 core, are described. Combining a strong axial [Cp*](-) ligand field with a weak equatorial field consisting of the isocarbonyl ligands leads to an anisotropy barrier of 662 cm(-1) in zero applied field. The dominant thermal relaxation pathways in 1Dy involves at least the fourth-excited Kramers doublet, thus demonstrating that prominent SMM behavior can be observed for dysprosium in low-symmetry environments.

  9. Malonate complexes of dysprosium: synthesis, characterization and application for LI-MOCVD of dysprosium containing thin films.

    Science.gov (United States)

    Milanov, Andrian P; Seidel, Rüdiger W; Barreca, Davide; Gasparotto, Alberto; Winter, Manuela; Feydt, Jürgen; Irsen, Stephan; Becker, Hans-Werner; Devi, Anjana

    2011-01-07

    A series of malonate complexes of dysprosium were synthesized as potential metalorganic precursors for Dy containing oxide thin films using chemical vapor deposition (CVD) related techniques. The steric bulkiness of the dialkylmalonato ligand employed was systematically varied and its influence on the resulting structural and physico-chemical properties that is relevant for MOCVD was studied. Single crystal X-ray diffraction analysis revealed that the five homoleptic tris-malonato Dy complexes (1-5) are dimers with distorted square-face bicapped trigonal-prismatic geometry and a coordination number of eight. In an attempt to decrease the nuclearity and increase the solubility of the complexes in various solvents, the focus was to react these dimeric complexes with Lewis bases such as 2,2'-biypridyl and pyridine (6-9). This resulted in monomeric tris-malonato mono Lewis base adduct complexes with improved thermal properties. Finally considering the ease of synthesis, the monomeric nature and promising thermal characteristics, the silymalonate adduct complex [Dy(dsml)(3)bipy] (8) was selected as single source precursor for growing DySi(x)O(y) thin films by liquid injection metalorganic chemical vapor deposition (LI-MOCVD) process. The as-deposited films were analyzed for their morphology and composition by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, Rutherford backscattering (RBS) analysis and X-ray photoelectron spectroscopy.

  10. Exploration of dysprosium: the most critical element for Japan

    Science.gov (United States)

    Watanabe, Y.

    2012-04-01

    Dysprosium (Dy), one of the heavy rare earth elements, is used mainly as an additive for NdFeB permanent magnets which are installed in various modern industrial products such as voice coil motors in computers, factory automation machinery, hybrid and electric vehicles, home electronics, and wind turbine, to improve heat resistance of the magnets. Dy has been produced about 2,000t per year from the ores from ion adsorption type deposits in southern China. However, the produced amount of Dy was significantly reduced in 2011 in China due to reservation of heavy rare earth resources and protection of natural environment, resulting in soaring of Dy price in the world. In order to respond the increasing demand of Dy, unconventional supply sources are inevitably developed, in addition to heavy rare earth enriched ion adsorption type deposits outside China. Heavy rare earth elements including Dy are dominantly hosted in xenotime, fergusonite, zircon, eudialyte, keiviite, kainosite, iimoriite, etc. Concentration of xenotime is found in placer deposits in Malaysia and India, hydrothermal deposits associated with unconformity-type uranium mineralization (Athabasca basin in Canada, Western Australia), iron-oxide fluorite mineralization (South Africa) and Sn-bearing alkaline granite (Brazil). Zircon and fergusontie concentration is found as igneous and hydrothermal products in peralkaline syenite, alkaline granite and pegmatite (e.g., Nechalacho in Canada). Eudialyte concentration is found in some peralkaline syenite bodies in Greenland, Canada, Sweden and Russia. Among these sources, large Dy resources are estimated in the deposits hosted in peralkaline rocks (Nechalacho: 79,000t, Kvanefjeld: 49,000t, Norra Karr: 15,700t, etc.) compared to the present demand of Dy. Thus, Dy will be supplied from the deposits associated with peralkaline and alkaline deposits in future instead of ion adsorption type deposits in southern China.

  11. Long afterglow of trivalent dysprosium doped strontium aluminate

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yuan Ming, E-mail: dongshanisland@126.com [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China); Ma, Qing-lan [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China); School of Electronics and Information, Nantong University, Jiangsu 226019 (China)

    2015-04-15

    Trivalent dysprosium doped strontium aluminate (SrA1{sub 2}O{sub 4}:Dy{sup 3+}) was synthesized via the sol–gel combustion method to realize green afterglow in the absence of Eu{sup 2+} luminescent centers. The morphology, crystal structure, photoluminescence and long afterglow of the SrAl{sub 2}O{sub 4}:Dy{sup 3+} were characterized with scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and photoluminescence spectroscopy, respectively. The bluish-green photoluminescence of SrAl{sub 2}O{sub 4}:Dy{sup 3+} consists of a broad emission band centered at about 520 nm and two characteristic emissions of Dy{sup 3+} ions centered at 480 and 575 nm, respectively. The green afterglow of SrAl{sub 2}O{sub 4}:Dy{sup 3+} is a broad emission band centered at around 520 nm, and the lifetime extracted from afterglow decay is found to be 53 s. The mechanism on the green afterglow from SrAl{sub 2}O{sub 4}:Dy{sup 3+} is discussed in terms of the possible defect levels in the host. - Highlights: • Broad band long-lasting afterglow is observed in SrAl{sub 2}O{sub 4}:Dy{sup 3+} phosphors. • Characteristic emissions of Dy{sup 3+} ions are superimposed on the broad PL of phosphors. • Dy{sup 3+} ions can also act as luminescent centers in addition to electron traps. • A mechanism on long afterglow of SrAl{sub 2}O{sub 4}:Dy{sup 3+} is proposed without Eu{sup 2+} activator.

  12. Low temperature spin reorientation in dysprosium iron garnet

    Energy Technology Data Exchange (ETDEWEB)

    Lahoubi, M; Younsi, W; Soltani, M L [Department of Physics, Badji-Mokhtar University, BP-12 Annaba, 23000 (Algeria); Voiron, J; Schmitt, D, E-mail: mlahoubi@gmail.co [Louis Neel Laboratory, CNRS-UJF, BP-166, 38042 Grenoble Cedex 9 (France)

    2009-03-01

    The spin reorientation (SR) phase transition in dysprosium iron garnet (Dy{sub 3}Fe{sub 5}O{sub 12} or DyIG) have been studied by specific heat C{sub p}(T) and high field magnetisation measurements M{sub T}(H) and M{sub H}(T) on single crystals at low temperature. A first order SR is observed with a sharp jump at T{sub SR} = 14.5+-0.5 K in the C{sub p}(T) curve which corresponds to a spontaneous change from the high temperature (HT) easy direction (111) to an (uuw) angular low temperature (LT) phases. Above T{sub SR}, the magnetic structure is described by the irreducible representation (IR) A{sub 2g} of the rhombohedral space group R 3 c. Below T{sub SR}, the magnetic structure changes in the monoclinic the space group C2/c with the IR A{sub g}. When the field H is kept aligned along the hard symmetry directions (100) and (110), we obtain respectively the variation of the angular positions theta(T) and theta'(T) from the total spontaneous magnetisation down to 1.5 K (theta = 39.23 deg. and theta' = 30.14 deg.) and the results are in good agreement with the previous observations in low fields. When the sample is allowed to rotate freely on itself, the critical field H{sub c}(T) between the HT(111) and the LT(uuw) angular phases permits us to precise the transition line up to 15 T and 40 K between the so called canted field induced (FI) and the associated collinear magnetic phases. The experimental magnetic phase diagram (MPD) is precisely determined in the (H{sub c}-T) plane and the domains of the existence and the stability of the two magnetic phases are specified.

  13. Anisotropic magnetic properties of dysprosium iron garnet (DyIG)

    Energy Technology Data Exchange (ETDEWEB)

    Lahoubi, M; Younsi, W; Soltani, M-L [Department of Physics, Badji-Mokhtar University, BP 12 - 23000 Annaba (Algeria); Ouladdiaf, B, E-mail: mlahoubi@gmail.co [Institut Laue Langevin, BP 156 - 38042 Grenoble Cedex 9 (France)

    2010-01-01

    The magnetic properties of dysprosium iron garnet (DyIG) have been studied by performing high resolution powder neutron diffraction experiments and high dc fields magnetizations on single crystals. Among all the reflections (hkl) indexed in the nuclear cubic space group (CSG) Ia 3-bar d with h+k+l=2n and k=[000], the superstructure lines (hkl)* forbidden by the symmetry (222)* and (622)* are not observed in the patterns at all temperatures. The pattern at 130 K is well interpreted within the magnetic modes F belonging to the irreducible representation (IR) T{sub 1g} of the CSG and identified to the room temperature ferrimagnetic Neel model. The high magnetic field behavior of the spontaneous collinear magnetic structure (MS) along the easy axis (EA) <111> is isotropic. Below 130 K, the patterns exhibit additional magnetic superstructure lines. They are associated to the appearance of the spontaneous non collinear MS which is described in the subgroup of the CSG, R 3-bar c within the IR A{sub 2g}. A strong magnetization anisotropy (MA) is observed at 1.5 K in the low symmetry phases were the spin reorientation transition (SR) occur at T{sub RS}=14.5 K. The onset of MA is detected below two characteristic temperatures, Ta{sub 1}=125 K and Ta{sub 2}=75 K respectively to the hard axis (HA) <100> and <110>. Symmetry arguments are used in the framework of the theory of representation analysis (RA) applied to the subgroup of R 3-bar c, C2/c within the IR A{sub g}. It seems that this MA results essentially from the difference between the spontaneous non collinear MS and the field induced (FI) configurations. All results are discussed with previous neutrons studies.

  14. Dysprosium-containing layered double hydroxides nanoparticles intercalated with biologically active species as an approach for theranostic systems

    KAUST Repository

    Arratia-Quijada, Jenny

    2015-10-23

    A layered double hydroxide structure including dysprosium cations was prepared by co-precipitation. The nanoparticles showed a linear relationship with the reciprocal relaxation spin-lattice (T1) time of water protons which is reflected as contrast in aqueous suspensions analyzed by magnetic resonance imaging. The interlayer space of dysprosium containing LDH was successfully intercalated with folate, ibuprofen and gallate ions, which are key molecules for recognition of some cancer cells and treatment of diseases. The paramagnetic property of the dysprosium-containing LDH detected in this work beside the ability to transport drugs open up the opportunity to design theranostic materials in a single crystal phase with nanometric dimensions.

  15. Effects of Dysprosium Oxide Doping on Microstructure and Properties of Barium Titanate Ceramic

    Institute of Scientific and Technical Information of China (English)

    Pu Yongping; Ren Huijun; Chen Wei; Chen Shoutian

    2005-01-01

    Different amounts of dysprosium oxide were incorporated into barium titanate powders synthesized by hydrothermal method. Relations of substitution behaviors and lattice parameters with solid-solubility were studied. Furthermore, the influences of dysprosium oxide doping fraction on grain size and dielectric properties of barium titanate ceramic, including dielectric constant and breakdown electric field strength, were investigated via scanning electron microscope, X-ray diffraction and electric property tester. The results show that dysprosium oxide can restrain abnormal grain growth during sintering and that fine-grained and high density of barium titanate ceramic can result in excellent dielectric properties. As mass fraction of dysprosium oxide is 0.6%, the lattice parameters of grain increase to the maximum because of the lowest vacancy concentration. The electric property parameters are cited as following: dielectric constant (25 ℃) reaches 4100, the change in relative dielectric constant with temperature is -10% to 10% within the range of -15~100 ℃, breakdown electric field strength (alternating current) achieves 3.2 kV·mm-1, which can be used in manufacturing high voltage ceramic capacitors.

  16. In situ characterization of the nitridation of dysprosium during mechanochemical processing

    Energy Technology Data Exchange (ETDEWEB)

    Jaques, Brian J.; Osterberg, Daniel D.; Alanko, Gordon A.; Tamrakar, Sumit; Smith, Cole R.; Hurley, Michael F.; Butt, Darryl P., E-mail: DarrylButt@BoiseState.edu

    2015-01-15

    Highlights: • A nitridation reaction in a high energy planetary ball mill was monitored in situ. • Dysprosium mononitride was synthesized from Dy at low temperatures in short times. • Ideal gas law and in situ temperature and pressure used to assess reaction extent. • It is proposed that reaction rate is proportional to the creation of new surface. - Abstract: Processing of advanced nitride ceramics traditionally requires long durations at high temperatures and, in some cases, in hazardous atmospheres. In this study, dysprosium mononitride (DyN) was rapidly formed from elemental dysprosium in a closed system at ambient temperatures. An experimental procedure was developed to quantify the progress of the nitridation reaction during mechanochemical processing in a high energy planetary ball mill (HEBM) as a function of milling time and intensity using in situ temperature and pressure measurements, SEM, XRD, and particle size analysis. No intermediate phases were formed. It was found that the creation of fresh dysprosium surfaces dictates the rate of the nitridation reaction, which is a function of milling intensity and the number of milling media. These results show clearly that high purity nitrides can be synthesized with short processing times at low temperatures in a closed system requiring a relatively small processing footprint.

  17. Synthesis, structural characterization and in vitro testing of dysprosium containing silica particles as potential MRI contrast enhancing agents

    Science.gov (United States)

    Chiriac, L. B.; Trandafir, D. L.; Turcu, R. V. F.; Todea, M.; Simon, S.

    2016-11-01

    The work is focused on synthesis and structural characterization of novel dysprosium-doped silica particles which could be considered as MRI contrast agents. Sol-gel derived silica rich particles obtained via freeze-drying and spray-drying processing methods were structurally characterized by XRD, 29Si MAS-NMR and XPS methods. The occurrence of dysprosium on the outermost layer of dysprosium containing silica particles was investigated by XPS analysis. The MRI contrast agent characteristics have been tested using RARE-T1 and RARE-T2 protocols. The contrast of MRI images delivered by the investigated samples was correlated with their local structure. Dysprosium disposal on microparticles with surface structure characterised by decreased connectivity of the silicate network units favours dark T2-weighted MRI contrast properties.

  18. Dysprosium-containing layered double hydroxides nanoparticles intercalated with biologically active species as an approach for theranostic systems

    Energy Technology Data Exchange (ETDEWEB)

    Arratia-Quijada, Jenny [Departamento de Ciencias de la Salud, Centro Universitario Tonalá, Universidad de Guadalajara, Av. Nuevo Periférico No. 555, C.P. 48525, Tonalá, Jalisco (Mexico); Sánchez Jiménez, Cecilia [Departamento de Química, Universidad de Guadalajara, Boulevard Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico); Gurinov, Andrey [Research Resources Center for Magnetic Resonance, St. Petersburg State University, Universitetskiy pr. 26, 198504 St. Petersburg (Russian Federation); NMR Core Lab, King Abdullah University of Science and Technology, Thuwal 23955-6900 (Saudi Arabia); Pérez Centeno, Armando; Ceja Andrade, Israel [Departamento de Física, Universidad de Guadalajara, Boulevard Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico); Carbajal Arízaga, Gregorio Guadalupe, E-mail: gregoriocarbajal@yahoo.com.mx [Departamento de Química, Universidad de Guadalajara, Boulevard Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico)

    2016-01-15

    Graphical abstract: - Highlights: • LDH structure including dysprosium was prepared by co-precipitation. • LDH was capable to produce contrast in the T1 mode of MRI. • LDH were intercalated with folate, ibuprofen and gallate ions. - Abstract: A layered double hydroxide structure including dysprosium cations was prepared by co-precipitation. The nanoparticles showed a linear relationship with the reciprocal relaxation spin-lattice (T1) time of water protons which is reflected as contrast in aqueous suspensions analyzed by magnetic resonance imaging. The interlayer space of dysprosium containing LDH was successfully intercalated with folate, ibuprofen and gallate ions, which are key molecules for recognition of some cancer cells and treatment of diseases. The paramagnetic property of the dysprosium-containing LDH detected in this work beside the ability to transport drugs open up the opportunity to design theranostic materials in a single crystal phase with nanometric dimensions.

  19. Slow magnetic relaxation in a hydrogen-bonded 2D array of mononuclear dysprosium(III) oxamates.

    Science.gov (United States)

    Fortea-Pérez, Francisco R; Vallejo, Julia; Julve, Miguel; Lloret, Francesc; De Munno, Giovanni; Armentano, Donatella; Pardo, Emilio

    2013-05-01

    The reaction of N-(2,6-dimethylphenyl)oxamic acid with dysprosium(III) ions in a controlled basic media afforded the first example of a mononuclear lanthanide oxamate complex exhibiting a field-induced slow magnetic relaxation behavior typical of single-ion magnets (SIMs). The hydrogen-bond-mediated self-assembly of this new bifunctional dysprosium(III) SIM in the solid state provides a unique example of 2D hydrogen-bonded polymer with a herringbone net topology.

  20. Dysprosium-Catalyzed Growth of Single-Walled Carbon Nanotube Arrays on Substrates

    Directory of Open Access Journals (Sweden)

    Qian Yong

    2009-01-01

    Full Text Available Abstract In this letter, we report that dysprosium is an effective catalyst for single-walled carbon nanotubes (SWNTs growth via a chemical vapor deposition (CVD process for the first time. Horizontally superlong well-oriented SWNT arrays on SiO2/Si wafer can be fabricated by EtOH-CVD under suitable conditions. The structure and properties are characterized by scanning electron microscopy, transition electron microscopy, Raman spectroscopy and atomic force microscopy. The results show that the SWNTs from dysprosium have better structural uniformity and better conductivity with fewer defects. This rare earth metal provides not only an alternative catalyst for SWNTs growth, but also a possible method to generate high percentage of superlong semiconducting SWNT arrays for various applications of nanoelectronic device.

  1. Direct Search for keV Sterile Neutrino Dark Matter with a Stable Dysprosium Target

    CERN Document Server

    Lasserre, T; Cribier, M; Merle, A; Mertens, S; Vivier, M

    2016-01-01

    We investigate a new method to search for keV-scale sterile neutrinos that could account for Dark Matter. Neutrinos trapped in our galaxy could be captured on stable $^{163}$Dy if their mass is greater than 2.83~keV. Two experimental realizations are studied, an integral counting of $^{163}$Ho atoms in dysprosium-rich ores and a real-time measurement of the emerging electron spectrum in a dysprosium-based detector. The capture rates are compared to the solar neutrino and radioactive backgrounds. An integral counting experiment using several kilograms of $^{163}$Dy could reach a sensitivity for the sterile-to-active mixing angle $\\sin^2\\theta_{e4}$ of $10^{-5}$ significantly exceeding current laboratory limits. Mixing angles as low as $\\sin^2\\theta_{e4} \\sim 10^{-7}$ / $\\rm m_{^{163}\\rm Dy}\\rm{(ton)}$ could possibly be explored with a real-time experiment.

  2. Preparation of Dysprosium Ferrite/Polyacrylamide Magnetic Composite Microsphere and Its Characterization

    Institute of Scientific and Technical Information of China (English)

    Hidehiro Kumazawa; Wang Zhifeng; Zhou Lanxiang; Zhang Hong; Li Yourong; Zhang Ming

    2005-01-01

    Using the technique of microemulsion polymerization with nano-reactor, dysprosium ferrite/polyacrylamide magnetic composite microsphere was prepared by one-step method in a single inverse microemulsion. The structure, average particle size, morphology of composite microsphere were characterized by FTIR, XRD, TEM and TGA. The magnetic responsibility of composite microsphere was also investigated. The results indicate that the magnetic composite microsphere possess high magnetic responsibility and suspension stability.

  3. {Delta}I = 2 energy staggering in normal deformed dysprosium nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Riley, M.A.; Brown, T.B.; Archer, D.E. [Florida State Univ., Tallahassee, FL (United States)] [and others

    1996-12-31

    Very high spin states (I{ge}50{Dirac_h}) have been observed in {sup 155,156,157}Dy. The long regular band sequences, free from sharp backbending effects, observed in these dysprosium nuclei offer the possibility of investigating the occurence of any {Delta}I = 2 staggering in normal deformed nuclei. Employing the same analysis techniques as used in superdeformed nuclei, certain bands do indeed demonstrate an apparent staggering and this is discussed.

  4. Poly[[[μ3-N′-(carboxymethylethylenediamine-N,N,N′-triacetato]dysprosium(III] trihydrate

    Directory of Open Access Journals (Sweden)

    Xiaomei Zhuang

    2010-11-01

    Full Text Available In the title coordination polymer, {[Dy(C10H13N2O8]·3H2O}n, the dysprosium(III ion is coordinated by two N atoms and six O atoms from three different (carboxymethylethylenediaminetriacetate ligands in a distorted square-antiprismatic geometry. The ligands connect the metal atoms, forming layers parallel to the ab plane. O—H...O hydrogen bonds further assemble adjacent layers into a three-dimensional supramolecular network.

  5. Making two dysprosium atoms rotate - Einstein-de Haas effect revisited

    OpenAIRE

    Górecki, Wojciech; Rzążewski, Kazimierz

    2016-01-01

    We present a numerical study of the behaviour of two magnetic dipolar atoms trapped in a harmonic potential and exhibiting the standard Einstein-de Haas effect while subject to a time dependent homogeneous magnetic field. Using a simplified description of the short range interaction and the full expression for the dipole-dipole forces we show, that under experimentally realisable conditions two dysprosium atoms may be pumped to a high ($l>20$) value of the relative orbital angular momentum.

  6. Phosphor Dysprosium-Doped Layered Double Hydroxides Exchanged with Different Organic Functional Groups

    Directory of Open Access Journals (Sweden)

    David Ricardo Martínez Vargas

    2013-01-01

    Full Text Available The layers of a Zn/Al layered double hydroxide (LDH were doped with Dy3+ cations. Among some compositions, the Zn2+ : Al3+ : Dy3+ molar ratio equal to 30 : 9 : 1 presented a single crystalline phase. Organic anions with carboxylic, amino, sulfate, or phosphate functional groups were intercalated as single layers between LDH layers as confirmed by X-ray diffraction and infrared spectroscopy. Photoluminescence spectra of the nitrate intercalated LDH showed a wide emission band with strong intensity in the yellow region (around 574 nm, originated due to symmetry distortion of the octahedral coordination in dysprosium centers. Moreover, a broad red band emission was also detected apparently due to the presence of zinc oxide. The distorted symmetry of the dysprosium coordination environment, also confirmed by X-ray photoelectron spectroscopy analysis, was modified after the intercalation with phenyl phosphonate (PP, aspartate (Asp, adipate (Adip, and serinate (Ser anions; the emission as measured from PL spectra of these LDH was more intense in the blue region (ca. 486 nm, thus indicating an increase in symmetry of dysprosium octahedrons. The red emission band from zinc oxide kept the same intensity after intercalation of dodecyl sulfate (DDS. An additional emission of unknown origin at λ = 767 nm was present in all LDHs.

  7. Systematic study on surface and magnetostructural changes in Mn-substituted dysprosium ferrite by hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Rekha, G. [Department of Physics, College of Engineering Guindy, Anna University, Sardar Patel Road, Chennai 600025 (India); Tholkappiyan, R. [Department of Physics, College of Engineering Guindy, Anna University, Sardar Patel Road, Chennai 600025 (India); Department of Physics, College of Science, UAE University, Al-Ain 15551 (United Arab Emirates); Vishista, K., E-mail: raovishista@gmail.com [Department of Physics, College of Engineering Guindy, Anna University, Sardar Patel Road, Chennai 600025 (India); Hamed, Fathalla [Department of Physics, College of Science, UAE University, Al-Ain 15551 (United Arab Emirates)

    2016-11-01

    Highlights: • Garnet type Dy{sub 3}Fe{sub 5-x}Mn{sub x}O{sub 12} (x = 0–0.06) nanoparticles of 88.4–86.8 nm were synthesized by hydrothermal method. • The Dy, Mn, Fe and O elements in the ferrites were confirmed from XPS. • The multiple oxidation states of Fe and Mn ions, bonding energy and cationic distributions of the samples were examined by XPS. • The magnetic property shows ferromagnetic behavior from VSM technique. • The results from these studies are correlated with respect to Mn dopant. - Abstract: Dysprosium iron garnets are of scientific importance because of the wide range of magnetic properties that can be obtained in substituting dysprosium by a rare earth metal. In the present work, the effect of Mn substitution on magnetostructural changes in dysprosium ferrite nanoparticles is studied. Highly crystalline pure and Mn doped dysprosium ferrite nanoparticles were synthesized by hydrothermal method. The samples were calcined at 1100 °C for 2 h in air atmosphere which is followed by characterization using XRD, FT-IR analysis, SEM, XPS and VSM. The average crystallite size of synthesized samples were calculated by X-ray diffraction falls in the range of 88.4–86.8 nm and was found to be in cubic garnet structure. For further investigation of the structure and corresponding changes in the tetrahedral and octahedral stretching vibrational bonds, FT-IR was used. The synthesized samples consist of multiple oxidation (Fe{sup 3+} and Fe{sup 2+}) states for Fe ions and (Mn{sup 3+} and Mn{sup 2+}) Mn ions analyzed in three ways of Fe 2p and Mn 2p spectra from the XPS analysis. With respect to Mn dopant in Dy{sub 3}Fe{sub 5}O{sub 12}, the cationic distributions of elements were discussed from high resolution XPS spectra by peak position and shift, area, width. To find out the porous/void surface morphology of the sample, scanning electron microscopy was used. From XPS analysis, the presence of elements (Dy, Mn, Fe and O) and their composition in the

  8. Synthesis, structural characterization and in vitro testing of dysprosium containing silica particles as potential MRI contrast enhancing agents

    Energy Technology Data Exchange (ETDEWEB)

    Chiriac, L.B.; Trandafir, D.L. [Faculty of Physics & National Magnetic Resonance Center, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Interdisciplinary Research Institute on Bio-Nano-Sciences & Faculty of Physics, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Turcu, R.V.F. [Faculty of Physics & National Magnetic Resonance Center, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Todea, M. [Interdisciplinary Research Institute on Bio-Nano-Sciences & Faculty of Physics, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Simon, S., E-mail: simons@phys.ubbcluj.ro [Faculty of Physics & National Magnetic Resonance Center, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Interdisciplinary Research Institute on Bio-Nano-Sciences & Faculty of Physics, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania)

    2016-11-01

    Highlights: • Dysprosium containing silica microparticles obtained by freeze and spray drying. • Higher structural units interconnection achieved in freeze vs. spray dried samples. • Dy occurance on the outermost layer of the microparticles evidenced by XPS. • Enhanced MRI contrast observed for freeze dried samples with 5% mol Dy{sub 2}O{sub 3}. - Abstract: The work is focused on synthesis and structural characterization of novel dysprosium-doped silica particles which could be considered as MRI contrast agents. Sol-gel derived silica rich particles obtained via freeze-drying and spray-drying processing methods were structurally characterized by XRD, {sup 29}Si MAS-NMR and XPS methods. The occurrence of dysprosium on the outermost layer of dysprosium containing silica particles was investigated by XPS analysis. The MRI contrast agent characteristics have been tested using RARE-T{sub 1} and RARE-T{sub 2} protocols. The contrast of MRI images delivered by the investigated samples was correlated with their local structure. Dysprosium disposal on microparticles with surface structure characterised by decreased connectivity of the silicate network units favours dark T{sub 2}-weighted MRI contrast properties.

  9. Influence of exchange splitting on optical properties in gadolinium and dysprosium single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, Yu.V.; Bolotin, G.A. (AN SSSR, Sverdlovsk. Inst. Fiziki Metallov)

    1984-12-01

    The temperature dependences of optical conductivity in gadolinium and dysprosium single crystals at the light wave vector polarization along a hexagonal axis and in the basis plane are considered. A substantial anisotropy of interzonal absorption has been found. The sample transition into magnetically ordered state is shown to be accompanied by the emergence of resonance absorption peaks in the near infrared spectral region. The manifestation of these peculiarities is associated with quantum electron transitions between the s-, d-f- interaction-split energy bands near the Fermi level. Main peculiarities of the experimental spectrum of gadolinium optical conductivity found their reflection in theoretically calculated dispersion dependence.

  10. Therapeutic application of dysprosium-165-FHMA in the treatment of rheumatoid knee effusions

    Energy Technology Data Exchange (ETDEWEB)

    English, R.J.; Zalutsky, M.; Venkatesan, P.; Sledge, C.B.

    1986-03-01

    Radiation synovectomy utilizing a variety of radionuclides has proven to be an effective technique in the treatment of rheumatoid arthritis. The recent introduction of the short-lived radionuclide, Dysprosium-165 (/sup 165/Dy), as a replacement for the longer-lived radiocolloids has reduced nontarget dosimetry caused by leakage of the agent from the articular cavity. A review of the methods and status of radiation synovectomy, and the application of /sup 165/Dy-ferric hydroxide macroaggregates (FHMA) as an alternative therapeutic agent is described.

  11. Properties of dysprosium-doped gallium lanthanum sulfide fiber amplifiers operating at 1.3 microm.

    Science.gov (United States)

    Samson, B N; Schweizer, T; Hewak, D W; Laming, R I

    1997-05-15

    In light of recent progress in the fabrication of gallium lanthanum sulfide (GaLaS) fibers, we have modeled the performance of dysprosium-doped GaLaS fiber amplifiers operating at 1.3 microm . Based on experimental data, we find that the incorporation of a codopant (terbium) in the fiber core significantly shortens the optimum amplifier length from >30 m to approximately 3 m . Such a device may be practical, given the fiber losses currently achieved in GaLaS fibers.

  12. Effect of dysprosium on the kinetics and structural transformations during the decomposition of the supersaturated solid solution in magnesium-samarium alloys

    Science.gov (United States)

    Rokhlin, L. L.; Luk'yanova, E. A.; Tabachkova, N. Yu.; Dobatkina, T. V.; Tarytina, I. E.; Korol'kova, I. G.

    2017-03-01

    The effect of dysprosium added in the amounts such that it does not form an individual phase in equilibrium with solid magnesium on the decomposition of the supersaturated magnesium solid solution in Mg-Sm alloys is studied. The presence of dysprosium in Mg-Sm alloys is found to retard the decomposition of the supersaturated magnesium solid solution and to increase the hardening effect upon aging. When these alloys are aged, dysprosium is partly retained in the magnesium solid solution and partly enters into the compositions of the phases that form during the decomposition of the solid solution and are characteristic of Mg-Sm alloys.

  13. Cyclic single-molecule magnets: from the odd-numbered heptanuclear to a dimer of heptanuclear dysprosium clusters.

    Science.gov (United States)

    Tian, Haiquan; Bao, Song-Song; Zheng, Li-Min

    2016-02-01

    A heptanuclear and a dimer of heptanuclear dysprosium clusters (Dy7 and Dy14) have been successfully synthesized by ingenious coalescence of the single and double pyrazinyl hydrazone as well as phosphonate ligands. The complexes feature the largest odd-numbered cyclic lanthanide clusters reported thus far. Both exhibit single molecule magnet behaviors at low temperature.

  14. Dual responsive dysprosium-doped hydroxyapatite particles and toxicity reduction after functionalization with folic and glucuronic acids

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez Lafarga, Ana Karen; Pacheco Moisés, Fermín P. [Departamento de Química, Universidad de Guadalajara, Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico); Gurinov, Andrey [Research Resources Center for Magnetic Resonance, Saint Petersburg State University, Universitetskij pr. 26, 198504 St. Petersburg (Russian Federation); Ortiz, Genaro Gabriel [Laboratorio Desarrollo-Envejecimiento, Enfermedades Neurodegenerativas, Centro de Investigación Biomédica de Occidente (CIBO), Instituto Mexicano de Seguro Social (IMSS), Guadalajara, Jalisco (Mexico); Carbajal Arízaga, Gregorio Guadalupe, E-mail: gregoriocarbajal@yahoo.com.mx [Departamento de Química, Universidad de Guadalajara, Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico)

    2015-03-01

    The development of probes for biomedical applications demands materials with low toxicity levels besides fluorescence or magnetic properties to be detected by confocal microscopes or MRI resonators. Several drug delivery systems or other biomedical materials prepared with hydroxyapatite have been proposed, however, toxicity effects might arise when the size of particles is nanometric. In this study, hydroxyapatite functionalized with glucuronic or folic acids presented lower oxidative stress, measured from lipoperoxides and nitric oxide indicators in rats than pure hydroxyapatite. In separated experiments, hydroxyapatite was doped with dysprosium cations by coprecipitation producing a single crystal phase with fluorescent properties easily visualized by confocal microscopy when excited at 488 nm. These particles also presented the ability to modify the proton relaxation time in T1 maps collected by magnetic resonance imaging. These modified hydroxyapatite nanoparticles could be candidates to design bimodal probes with low toxicity. - Highlights: • Hydroxyapatite functionalized with glucuronic acid reduced oxidative stress in rats. • Functionalization with folic acid reduced oxidative stress in rats. • Dysprosium doping does not affect the crystalline structure of hydroxyapatite. • Dysprosium doped particles are visible in fluorescent microscope. • Dysprosium doped particles act as MRI contrast agents.

  15. Dosimetric properties of dysprosium doped calcium magnesium borate glass subjected to Co-60 gamma ray

    Energy Technology Data Exchange (ETDEWEB)

    Omar, R. S., E-mail: ratnasuffhiyanni@gmail.com; Wagiran, H., E-mail: husin@utm.my; Saeed, M. A. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru (Malaysia)

    2016-01-22

    Thermoluminescence (TL) dosimetric properties of dysprosium doped calcium magnesium borate (CMB:Dy) glass are presented. This study is deemed to understand the application of calcium as the modifier in magnesium borate glass with the presence of dysprosium as the activator to be performed as TL dosimeter (TLD). The study provides fundamental knowledge of a glass system that may lead to perform new TL glass dosimetry application in future research. Calcium magnesium borate glass systems of (70-y) B{sub 2}O{sub 3} − 20 CaO – 10 MgO-(y) Dy{sub 2}O{sub 3} with 0.05  mol % ≤ y ≤ 0.7  mol % of dyprosium were prepared by melt-quenching technique. The amorphous structure and TL properties of the prepared samples were determined using powder X-ray diffraction (XRD) and TL reader; model Harshaw 4500 respectively. The samples were irradiated to Co-60 gamma source at a dose of 50 Gy. Dosimetric properties such as annealing procedure, time temperature profile (TTP) setting, optimization of Dy{sub 2}O{sub 3} concentration of 0.5 mol % were determined for thermoluminescence dosimeter (TLD) reader used.

  16. Luminescent properties of dysprosium(Ⅲ) ions in LaAlO3 nanocrystallites

    Institute of Scientific and Technical Information of China (English)

    K. Lema(n)ski; P.J. Dere(n)

    2011-01-01

    The absorption and emission spectra as well as decay time profile of Dy3+ ions in LaAlO3 nanocrystals were analyzed.The crystal structure of LaAlO3 was confirmed from XRD measurement.The emission peaks from blue to red came from main emitting level of dysprosium 4F9/2 to the ground and other excited levels of Dy3+ ions.Cross relaxation process led to non-radiative quenching of luminescence,so that the lifetime of the 4F9/2 energy level ions decreased with increasing amount of doped Dy3+ ions.The cross relaxation transfer rates were experimentally determined as a function of Dy3+ concentration.

  17. Magnetic ordering temperatures in rare earth metal dysprosium under ultrahigh pressures

    Science.gov (United States)

    Samudrala, Gopi K.; Tsoi, Georgiy M.; Weir, Samuel T.; Vohra, Yogesh K.

    2014-04-01

    Magnetic ordering temperatures in heavy rare earth metal dysprosium (Dy) have been studied using an ultrasensitive electrical transport measurement technique in a designer diamond anvil cell to a pressure of 69 GPa and a temperature of 10 K. Previous studies using magnetic susceptibility measurements at high pressures were able to track magnetic ordering temperature only till 7 GPa in the hexagonal close packed (hcp) phase of Dy. Our studies indicate that the magnetic ordering temperature shows an abrupt drop of 80 K at the hcp-Sm phase transition followed by a gradual decrease that continues till 17 GPa. This is followed by a rapid increase in the magnetic ordering temperatures in the double hcp phase and finally leveling off in the distorted face centered cubic phase of Dy. Our studies reaffirm that 4f-shell remains localized in Dy and there is no loss of magnetic moment or 4f-shell delocalization for pressures up to 69 GPa.

  18. Structural, optical, thermal, mechanical and dielectric studies of Sulfamic acid single crystals: An influence of dysprosium (Dy3+) doping

    Science.gov (United States)

    Singh, Budhendra; Shkir, Mohd.; AlFaify, S.; Kaushal, Ajay; Nasani, Narendar; Bdikin, Igor; Shoukry, H.; Yahia, I. S.; Algarni, H.

    2016-09-01

    Sulfamic acid is a potential material that exhibits excellent optical properties. A good quality, pure and dysprosium (Dy3+) doped (2.5 and 5 mol %) Sulfamic acid (SA) single crystals were grown successfully by slow cooling method. Structural study revealed a slight change in its lattice parameters and volume, suggesting the successful incorporation of Dy3+ in crystal system. The existence of dysprosium in the system was also confirmed. Presence of various vibrational modes was confirmed. Optical transparency was found to have a significant effect with variation in the doping concentration. Furthermore, a marked enhancement in its mechanical parameters with doping was also identified by nanoindentation technique. Etching study was also performed on the grown crystals to study the etch-pit formation and growth mechanism. Effect of doping on the thermal stability was analysed. All the results were compared and discussed in detail to get insight of the effect of doping concentration on Sulfamic acid crystal.

  19. Optical trapping of ultracold dysprosium atoms: transition probabilities, dynamic dipole polarizabilities and van der Waals $C_6$ coefficients

    CERN Document Server

    Li, Hui; Dulieu, Olivier; Nascimbene, Sylvain; Lepers, Maxence

    2016-01-01

    The efficiency of optical trapping of ultracold atoms depend on the atomic dynamic dipole polarizability governing the atom-field interaction. In this article, we have calculated the real and imaginary parts of the dynamic dipole polarizability of dysprosium in the ground and first excited level. Due to the high electronic angular momentum of those two states, the polarizabilities possess scalar, vector and tensor contributions that we have computed, on a wide range of trapping wavelengths, using the sum-over-state formula. Using the same formalism, we have also calculated the $C_6$ coefficients characterizing the van der Waals interaction between two dysprosium atoms in the two lowest levels. We have computed the energies of excited states and the transition probabilities appearing in the sums, using a combination of \\textit{ab initio} and least-square-fitting techniques provided by the Cowan codes and extended in our group. Regarding the real part of the polarizability, for field frequencies far from atomic...

  20. Evaluating United States and world consumption of neodymium, dysprosium, terbium, and praseodymium in final products

    Science.gov (United States)

    Hart, Matthew

    This paper develops scenarios of future rare-earth-magnet metal (neodymium, dysprosium, terbium, and praseodymium) consumption in the permanent magnets used in wind turbines and hybrid electric vehicles. The scenarios start with naive base-case scenarios for growth in wind-turbine and hybrid-electric-vehicle sales over the period 2011 to 2020, using historical data for each good. These naive scenarios assume that future growth follows time trends in historical data and does not depend on any exogenous variable. Specifically, growth of each technological market follows historical time trends, and the amount of rare earths used per unit of technology remains fixed. The chosen reference year is 2010. Implied consumptions of the rare earth magnet metals are calculated from these scenarios. Assumptions are made for the material composition of permanent magnets, the market share of permanent-magnet wind turbines and vehicles, and magnet weight per unit of technology. Different scenarios estimate how changes in factors like the material composition of magnets, growth of the economy, and the price of a substitute could affect future consumption. Each scenario presents a different method for reducing rare earth consumption and could be interpreted as potential policy choices. In 2010, the consumption (metric tons, rare-earth-oxide equivalent) of each rare-earth-magnet metal was as follows. Total neodymium consumption in the world for both technologies was 995 tons; dysprosium consumption was 133 tons; terbium consumption was 50 tons; praseodymium consumption was zero tons. The base scenario for wind turbines shows there could be strong, exponential growth in the global wind turbine market. New U.S. sales of hybrid vehicles would decline (in line with the current economic recession) while non-U.S. sales increase through 2020. There would be an overall increase in the total amount of magnetic rare earths consumed in the world. Total consumption of each rare earth in the short

  1. Luminescence features of dysprosium and phosphorus oxide co-doped lithium magnesium borate glass

    Science.gov (United States)

    Hashim, S.; Mhareb, M. H. A.; Ghoshal, S. K.; Alajerami, Y. S. M.; Saripan, M. I.; Bradley, D. A.

    2017-08-01

    Lithium magnesium borate (LMB) glass system co-doped with the oxides of dysprosium (Dy2O3) and phosphorus (P2O5) were synthesized using melt-quenching method. Prepared samples were characterized using various techniques to determine the effects of co-dopants concentration variation on their thermoluminescence (TL) and photoluminescence (PL) properties. TL glow curves of LMB:0.5Dy sample revealed a single prominent peak at Tm=190 °C, where TL intensity was enhanced by a factor of 2.5 with the increase of P2O5 concentration up to 1 mol%. This enhancement was accompanied by a shift in Tm towards higher temperature. Good linearity in the range of 1-100 Gy with linear correlation coefficient of 0.998 was achieved. PL spectra displayed two significant peaks centred at 481 nm and 573 nm. These attractive luminescence features of the proposed glass system may be useful for the development of radiation dosimetry.

  2. Single-molecule magnet behavior for an antiferromagnetically superexchange-coupled dinuclear dysprosium(III) complex.

    Science.gov (United States)

    Long, Jérôme; Habib, Fatemah; Lin, Po-Heng; Korobkov, Ilia; Enright, Gary; Ungur, Liviu; Wernsdorfer, Wolfgang; Chibotaru, Liviu F; Murugesu, Muralee

    2011-04-13

    A family of five dinuclear lanthanide complexes has been synthesized with general formula [Ln(III)(2)(valdien)(2)(NO(3))(2)] where (H(2)valdien = N1,N3-bis(3-methoxysalicylidene)diethylenetriamine) and Ln(III) = Eu(III)1, Gd(III)2, Tb(III)3, Dy(III)4, and Ho(III)5. The magnetic investigations reveal that 4 exhibits single-molecule magnet (SMM) behavior with an anisotropic barrier U(eff) = 76 K. The step-like features in the hysteresis loops observed for 4 reveal an antiferromagnetic exchange coupling between the two dysprosium ions. Ab initio calculations confirm the weak antiferromagnetic interaction with an exchange constant J(Dy-Dy) = -0.21 cm(-1). The observed steps in the hysteresis loops correspond to a weakly coupled system similar to exchange-biased SMMs. The Dy(2) complex is an ideal candidate for the elucidation of slow relaxation of the magnetization mechanism seen in lanthanide systems.

  3. A comparative study of donor formation in dysprosium, holmium, and erbium implanted silicon

    Energy Technology Data Exchange (ETDEWEB)

    Emtsev, V.V.; Emtsev, V.V. Jr.; Poloskin, D.S.; Shek, E.I.; Sobolev, N.A. [Division of Solid State Electronics, Ioffe Physicotechnical Institute, Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation)

    1998-12-01

    Formation of donor centers in Czochralski grown silicon doped with dysprosium, holmium, and erbium is discussed. Donor states of three kinds are introduced in the implanted layers after annealing at T=700C. Shallow donor states with ionization energies between 20 and 40 meV are attributed to oxygen -related thermal donors. Other donor centers in the energy range of E{sub C}-(60...70) meV and E{sub C}-(100...120) meV appear to be dependent on dopants. After a 900C anneal strong changes in the donor formation are observed only in silicon doped with erbium. Instead of donors at E{sub C}-(118{+-}5) meV, new donor centres at E{sub C}-(145{+-}5) meV are formed. Reportedly, the latter ones are involved in the excitation process of the Er{sup 3+} ions with a characteristic luminescence line at {approx}1.54 {mu}m. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  4. Thermoluminescence properties of lithium magnesium borate glasses system doped with dysprosium oxide.

    Science.gov (United States)

    Mhareb, M H A; Hashim, S; Ghoshal, S K; Alajerami, Y S M; Saleh, M A; Razak, N A B; Azizan, S A B

    2015-12-01

    We report the impact of dysprosium (Dy(3+)) dopant and magnesium oxide (MgO) modifier on the thermoluminescent properties of lithium borate (LB) glass via two procedures. The thermoluminescence (TL) glow curves reveal a single prominent peak at 190 °C for 0.5 mol% of Dy(3+). An increase in MgO contents by 10 mol% enhances the TL intensity by a factor of 1.5 times without causing any shift in the maximum temperature. This enhancement is attributed to the occurrence of extra electron traps created via magnesium and the energy transfer to trivalent Dy(3+) ions. Good linearity in the range of 0.01-4 Gy with a linear correlation coefficient of 0.998, fading as low as 21% over a period of 3 months, excellent reproducibility without oven annealing and tissue equivalent effective atomic numbers ~8.71 are achieved. The trap parameters, including geometric factor (μg), activation energy (E) and frequency factor (s) associated with LMB:Dy are also determined. These favorable TL characteristics of prepared glasses may contribute towards the development of Li2O-MgO-B2O3 radiation dosimeters.

  5. Optical properties of zinc borotellurite glass doped with trivalent dysprosium ion

    Science.gov (United States)

    Ami Hazlin, M. N.; Halimah, M. K.; Muhammad, F. D.; Faznny, M. F.

    2017-04-01

    The zinc borotellurite doped with dysprosium oxide glass samples with chemical formula {[(TeO2) 0 . 7(B2O3) 0 . 3 ] 0 . 7(ZnO) 0 . 3 } 1 - x(Dy2O3)x (where x=0.01, 0.02, 0.03, 0.04 and 0.05 M fraction) were prepared by using conventional melt quenching technique. The structural and optical properties of the proposed glass systems were characterized by using X-ray diffraction (XRD) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and UV-VIS spectroscopy. The amorphous nature of the glass systems is confirmed by using XRD technique. The infrared spectra of the glass systems indicate three obvious absorption bands which are assigned to BO3 and TeO4 vibrational groups. Based on the absorption spectra obtained, the direct and indirect optical band gaps, as well as the Urbach energy were calculated. It is observed that both the direct and indirect optical band gaps increase with the concentration of Dy3+ ions. On the other hand, the Urbach energy is observed to decrease as the concentration of Dy3+ ions increases.

  6. Isolation of {sup 163}Ho from dysprosium target material by HPLC for neutrino mass measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mocko, Veronika; Taylor, Wayne A.; Nortier, Francois M.; Engle, Jonathan W.; Pollington, Anthony D.; Kunde, Gerd J.; Rabin, Michael W.; Birnbaum, Eva R. [Los Alamos National Laboratory, Los Alamos, NM (United States). Chemistry Div.; Barnhart, Todd E.; Nickles, Robert J. [Univ. Wisconsinn, Madison, WI (United States). Dept. of Medical Physics

    2015-07-01

    The rare earth isotope {sup 163}Ho is of interest for neutrino mass measurements. This report describes the isolation of {sup 163}Ho from a proton-irradiated dysprosium target and its purification. A Dy metal target was irradiated with 16 MeV protons for 10 h. After target dissolution, {sup 163}Ho was separated from the bulk Dy via cation-exchange high performance liquid chromatography using 70 mmol dm{sup -3} α-hydroxyisobutyric acid as the mobile phase. Subsequent purification of the collected Ho fraction was performed to remove the α-hydroxyisobutyrate chelating agent and to concentrate the Ho in a low ionic strength aqueous matrix. The final solution was characterized by MC-ICP-MS to determine the {sup 163}Ho/{sup 165}Ho ratio, {sup 163}Ho and the residual Dy content. The HPLC purification process resulted in a decontamination factor 1.4 x 10{sup 5} for Dy. The isolated Ho fraction contained 24.8 ± 1.3 ng of {sup 163}Ho corresponding to holmium recovery of 72 ± 3%.

  7. Acute dysprosium toxicity to Daphnia pulex and Hyalella azteca and development of the biotic ligand approach.

    Science.gov (United States)

    Vukov, Oliver; Smith, D Scott; McGeer, James C

    2016-01-01

    The toxicological understanding of rare earth elements (REEs) in the aquatic environment is very limited but of increasing concern. The objective of this research is to compare the toxicological effect of the REE dysprosium to the freshwater invertebrates Daphnia pulex and Hyalella azteca and in the more sensitive organism, understand the toxicity modifying influence of Ca, Na, Mg, pH and dissolved organic matter (DOM). Standard methods (Environment Canada) were followed for testing and culture in media of intermediate hardness (60mg CaCO3 mg/L) at pH 7.8 with Ca at 0.5, Na 0.5, Mg 0.125 (mM) and 23°C. Acute toxicity tests were done with azteca and D. pulex revealed Hyalella to be 1.4 times more sensitive than Daphnia. Additions of Ca and Na but not Mg provided significant protection against Dy toxicity to Hyalella. Similarly, low pH was associated with reduction in toxicity. Exposures which were pH buffered with and without MOPS were significantly different and indicated that MOPS enhanced Dy toxicity. DOM also mitigated Dy toxicity. Biotic ligand based parameters (LogK values) were calculated based on free ion relationships as determined by geochemical equilibrium modeling software (WHAM ver. 7.02). The logK value for Dy(3+) toxicity to Hyalella was 7.75 while the protective influence of Ca and Na were 3.95 and 4.10, respectively. This study contributes data towards the development of site specific water quality guidelines and criteria for Dy and possibly REEs in general and offers insight into the complex bio-geochemical nature of this element.

  8. Optical trapping of ultracold dysprosium atoms: transition probabilities, dynamic dipole polarizabilities and van der Waals C 6 coefficients

    Science.gov (United States)

    Li, H.; Wyart, J.-F.; Dulieu, O.; Nascimbène, S.; Lepers, M.

    2017-01-01

    The efficiency of the optical trapping of ultracold atoms depends on the atomic dynamic dipole polarizability governing the atom-field interaction. In this article, we have calculated the real and imaginary parts of the dynamic dipole polarizability of dysprosium in the ground and first excited levels. Due to the high electronic angular momentum of those two states, the polarizabilities possess scalar, vector and tensor contributions that we have computed, on a wide range of trapping wavelengths, using the sum-over-state formula. Using the same formalism, we have also calculated the C 6 coefficients characterizing the van der Waals interaction between two dysprosium atoms in the two lowest levels. We have computed the energies of excited states and the transition probabilities appearing in the sums, using a combination of ab initio and least-square-fitting techniques provided by the Cowan codes and extended in our group. Regarding the real part of the polarizability, for field frequencies far from atomic resonances, the vector and tensor contributions are two-orders-of-magnitude smaller than the scalar contribution, whereas for the imaginary part, the vector and tensor contributions represent a noticeable fraction of the scalar contribution. Finally, our anisotropic C 6 coefficients are much smaller than those published in the literature.

  9. Acute dysprosium toxicity to Daphnia pulex and Hyalella azteca and development of the biotic ligand approach

    Energy Technology Data Exchange (ETDEWEB)

    Vukov, Oliver, E-mail: vuko3930@mylaurier.ca [Biology Department, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada); Smith, D. Scott [Chemistry Department, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada); McGeer, James C. [Biology Department, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada)

    2016-01-15

    The toxicological understanding of rare earth elements (REEs) in the aquatic environment is very limited but of increasing concern. The objective of this research is to compare the toxicological effect of the REE dysprosium to the freshwater invertebrates Daphnia pulex and Hyalella azteca and in the more sensitive organism, understand the toxicity modifying influence of Ca, Na, Mg, pH and dissolved organic matter (DOM). Standard methods (Environment Canada) were followed for testing and culture in media of intermediate hardness (60 mg CaCO{sub 3} mg/L) at pH 7.8 with Ca at 0.5, Na 0.5, Mg 0.125 (mM) and 23 °C. Acute toxicity tests were done with <24 h old neonates for 48 h in the case of D. pulex and with 2–9 days old offspring for 96 h tests with Hyalella. The potential protective effect of cationic competition was tested with Ca (0.5–2.0 mM), Na (0.5–2.0 mM) and Mg (0.125–0.5 mM). The effect of pH (6.5–8.0) and Suwannee River DOM complexation (at dissolved organic carbon (DOC) concentrations of 9 and 13 mg C/L) were evaluated. Dissolved Dy concentrations were lower than total (unfiltered) indicating precipitation, particularly at higher concentrations. Acute toxicity of Dy to H. azteca and D. pulex revealed Hyalella to be 1.4 times more sensitive than Daphnia. Additions of Ca and Na but not Mg provided significant protection against Dy toxicity to Hyalella. Similarly, low pH was associated with reduction in toxicity. Exposures which were pH buffered with and without MOPS were significantly different and indicated that MOPS enhanced Dy toxicity. DOM also mitigated Dy toxicity. Biotic ligand based parameters (Log K values) were calculated based on free ion relationships as determined by geochemical equilibrium modeling software (WHAM ver. 7.02). The log K value for Dy{sup 3+} toxicity to Hyalella was 7.75 while the protective influence of Ca and Na were 3.95 and 4.10, respectively. This study contributes data towards the development of site specific

  10. White light emission of dysprosium doped lanthanum calcium phosphate oxide and oxyfluoride glasses

    Science.gov (United States)

    Luewarasirikul, N.; Kim, H. J.; Meejitpaisan, P.; Kaewkhao, J.

    2017-04-01

    Lanthanum calcium phosphate oxide and oxyfluoride glasses doped with dysprosium oxide were prepared by melt-quenching technique with chemical composition 20La2O3:10CaO:69P2O5:1Dy2O3 and 20La2O3:10CaF2:69P2O5:1Dy2O3. The physical, optical and luminescence properties of the glass samples were studied to evaluate their potential to using as luminescence materials for solid-state lighting applications. The density, molar volume and refractive index of the glass samples were carried out. The optical and luminescence properties were studied by investigating absorption, excitation, and emission spectra of the glass samples. The absorption spectra were investigated in the UV-Vis-NIR region from 300 to 2000 nm. The excitation spectra observed under 574 nm emission wavelength showed the highest peak centered at 349 nm (6H15/2 → 6P7/2). The emission spectra, excited with 349 nm excitation wavelength showed two major peaks corresponding to 482 nm blue emission (4F9/2 → 6H15/2) and 574 nm yellow emission (4F9/2 → 6H13/2). The experimental lifetime were found to be 0.539 and 0.540 for oxide and oxyfluoride glass sample, respectively. The x,y color coordinates under 349 nm excitation wavelength were (0.38, 0.43) for both glass samples, that be plotted in white region of CIE 1931 chromaticity diagram. The CCT values obtained from the glass samples are 4204 K for oxide glass and 4228 K for oxyfluoride glass corresponding to the commercial cool white light (3100-4500 K). Judd-Ofelt theory had also been employed to obtain the J-O parameters (Ω2, Ω4 and Ω6), oscillator strength, radiative transition possibility, stimulated emission cross section and branching ratio. The Ω2 > Ω4 > Ω6 trend of J-O parameters of both glass samples may indicate the good quality of a glass host for using as optical device application. Temperature dependence of emission spectra was studied from 300 K to 10 K and found that the intensity of the emission peak was found to be increased with

  11. Limits on violations of Lorentz symmetry and the Einstein equivalence principle using radio-frequency spectroscopy of atomic dysprosium.

    Science.gov (United States)

    Hohensee, M A; Leefer, N; Budker, D; Harabati, C; Dzuba, V A; Flambaum, V V

    2013-08-02

    We report a joint test of local Lorentz invariance and the Einstein equivalence principle for electrons, using long-term measurements of the transition frequency between two nearly degenerate states of atomic dysprosium. We present many-body calculations which demonstrate that the energy splitting of these states is particularly sensitive to violations of both special and general relativity. We limit Lorentz violation for electrons at the level of 10(-17), matching or improving the best laboratory and astrophysical limits by up to a factor of 10, and improve bounds on gravitational redshift anomalies for electrons by 2 orders of magnitude, to 10(-8). With some enhancements, our experiment may be sensitive to Lorentz violation at the level of 9 × 10(-20).

  12. Nonlinear optical properties of lutetium and dysprosium bisphthalocyanines at 1550 nm with femto- and nanosecond pulse excitation

    Science.gov (United States)

    Plekhanov, A. I.; Basova, T. V.; Parkhomenko, R. G.; Gürek, A. G.

    2017-02-01

    In this work, the nonlinear optical properties of unsubstituted lutetium (LuPc2) and dysprosium (DyPc2) bisphthalocyanines as well as octasubstituted Lu(PcR8)2 derivative with R=-S(C6H13) were studied at a wavelength of 1550 nm with 10 ns and 300 fs pulses. Based on Z-scan measurements the nonlinear absorption and refraction coefficient as well as the nature of nonlinear optical properties were analyzed for these materials. Open aperture Z-scan indicates strong two-photon absorption in all three bisphthalocyanines in nano- and femtosecond regimes. With good nonlinear optical coefficients, bisphthalocyanines of rare earth elements are expected to be promising materials for the creation of optical limiters.

  13. Spectroscopic data of the 1.8-, 2.9-, and 4.3- mu m transitions in dysprosium-doped gallium lanthanum sulfide glass

    Science.gov (United States)

    Schweizer, T.; Hewak, D. W.; Samson, B. N.; Payne, D. N.

    1996-10-01

    Infrared emission at 1.8, 2.9, and 4.3 mu m is measured in dysprosium-doped gallium lanthanum sulfide (Ga:La:S) glass excited at 815 nm. Emission cross sections were calculated by Judd-Ofelt analysis, the Fuchtbauer-Ladenburg equation, and the theory of McCumber. The sigma tau value for the 4.3- mu m transition is \\similar 4000 times larger in the Ga:La:S glass than in a dysprosium-doped LiYF4 crystal, which has lased on this transition. The large sigma tau value and the recently reported ability of Ga:La:S glass to be fabricated into fiber form show the potential for an efficient, low-threshold mid-infrared fiber laser. The fluorescence peak at 4.3 mu m coincides with the fundamental absorption of atmospheric carbon dioxide, making the glass a potential laser source for gas-sensing applications.

  14. Spectroscopic data of the 1.8-, 2.9-, and 4.3-microm transitions in dysprosium-doped gallium lanthanum sulfide glass.

    Science.gov (United States)

    Schweizer, T; Hewak, D W; Samson, B N; Payne, D N

    1996-10-01

    Infrared emission at 1.8, 2.9, and 4.3 microm is measured in dysprosium-doped gallium lanthanum sulfide (Ga:La:S) glass excited at 815 nm. Emission cross sections were calculated by Judd-Ofelt analysis, the Füchtbauer- Ladenburg equation, and the theory of McCumber. The sigmatau value for the 4.3-microm transition is ~4000 times larger in the Ga:La:S glass than in a dysprosium-doped LiYF(4) crystal, which has lased on this transition. The large sigmatau value and the recently reported ability of Ga:La:S glass to be fabricated into fiber form show the potential for an efficient, low-threshold mid-infrared fiber laser. The f luorescence peak at 4.3 microm coincides with the fundamental absorption of atmospheric carbon dioxide, making the glass a potential laser source for gas-sensing applications.

  15. On-line complexation/cloud point preconcentration for the sensitive determination of dysprosium in urine by flow injection inductively coupled plasma-optical emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, Claudia; Cerutti, Soledad; Silva, Maria F. [Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700, San Luis (Argentina); Olsina, Roberto A.; Martinez, Luis D. [Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700, San Luis (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Avda. Rivadavia 1917, CP C1033AAJJ, Buenos Aires (Argentina)

    2003-01-01

    An on-line dysprosium preconcentration and determination system based on the hyphenation of cloud point extraction (CPE) to flow injection analysis (FIA) associated with ICP-OES was studied. For the preconcentration of dysprosium, a Dy(III)-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complex was formed on-line at pH 9.22 in the presence of nonionic micelles of PONPE-7.5. The micellar system containing the complex was thermostated at 30 C in order to promote phase separation, and the surfactant-rich phase was retained in a microcolumn packed with cotton at pH 9.2. The surfactant-rich phase was eluted with 4 mol L{sup -1} nitric acid at a flow rate of 1.5 mL min{sup -1}, directly in the nebulizer of the plasma. An enhancement factor of 50 was obtained for the preconcentration of 50 mL of sample solution. The detection limit value for the preconcentration of 50 mL of aqueous solution of Dy was 0.03 {mu}g L{sup -1}. The precision for 10 replicate determinations at the 2.0 {mu}g L{sup -1}Dy level was 2.2% relative standard deviation (RSD), calculated from the peak heights obtained. The calibration graph using the preconcentration system for dysprosium was linear with a correlation coefficient of 0.9994 at levels near the detection limits up to at least 100 {mu}g L {sup -1}. The method was successfully applied to the determination of dysprosium in urine. (orig.)

  16. Synthesis and Crystal Structure of Tri-(2-mercaptopyridine N-oxide)bis(dimethyl sulfoxide) Dysprosium(Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A range of rare earth metal complexes of 2-mercaptopyridine N-oxide (Hmpo) have been synthesized, and studied by elemental analysis and IR spectroscopic technique. Crystal structure of Dy(mpo)3(DMSO)2 (DMSO = dimethyl sulfoxide) has been determined. The complex crystallizes in the triclinic system, space group Pī with lattice parameters: a = 9.602(3), b = 9.803(3), c = 15.498(5)A, α= 89.51(1), β= 85.73(1), γ= 62.99(1)°, Dc = 1.787 g/cm3, C19H24N3O5S5Dy, Mr = 697.21, Z = 2, F(000) = 690, μ = 3.321mm-1, the final R = 0.0237 and wR = 0.0587 for 4116 reflections with I>σ2(I). The coordination number of dysprosium Ⅲ is eight, and its coordination geometry is a somewhat distorted square antiprism with O(3), O(4), O(5), S(3) and O(1), O(2), S(1), S(2) at the tetragonal bases (dihedral angle between their mean planes is 2.9(1)0). Around the Dy atom, three five-membered ring planes (Dy, O, N, C, S) make the dihedral angles of 74.42, 11.31 and 83.72, respectively.

  17. Photo-, cathodo- and thermoluminescent properties of dysprosium-doped HfO2 films deposited by ultrasonic spray pyrolysis.

    Science.gov (United States)

    Manríquez, R Reynoso; Góngora, J A I Díaz; Guzmán-Mendoza, J; Montalvo, T Rivera; Olguín, J C Guzmán; Ramírez, P V Cerón; García-Hipólito, M; Falcony, C

    2014-09-01

    In this work, the photoluminescent (PL), cathodoluminescent (CL) and thermoluminescent (TL) properties of hafnium oxide films doped with trivalent dysprosium ions are reported. The films were deposited on glass substrates at temperatures ranging from 300 to 600°C, using chlorides as precursor reagents. The surface morphology of films showed a veins shaped microstructure at low deposition temperatures, while at higher temperatures the formation of spherical particles was observed on the surface. X-ray diffraction showed the presence of HfO2 monoclinic phase in the films deposited at temperatures greater than 400°C. The PL and CL spectra of the doped films showed the highest emission band centered at 575nm corresponding to the transitions (4)F9/2→(6)H13/2, which is a characteristic transition of Dy(3+) ion. The greatest emission intensities were observed in samples doped with 1 atomic percent (at%) of DyCl3 in the precursor solution. Regarding the TL behavior, the glow curve of HfO2:Dy(+3) films exhibited spectrum with one broad band centered at about 150°C. The highest intensity TL response was observed on the films deposited at 500°C. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Workplace testing of the new single sphere neutron spectrometer based on Dysprosium activation foils (Dy-SSS)

    Science.gov (United States)

    Bedogni, R.; Gómez-Ros, J. M.; Esposito, A.; Gentile, A.; Chiti, M.; Palacios-Pérez, L.; Angelone, M.; Tana, L.

    2012-08-01

    A photon insensitive passive neutron spectrometer consisting of a single moderating polyethylene sphere with Dysprosium activation foils arranged along three perpendicular axes was designed by CIEMAT and INFN. The device is called Dy-SSS (Dy foil-based Single Sphere Spectrometer). It shows nearly isotropic response in terms of neutron fluence up to 20 MeV. The first prototype, previously calibrated with 14 MeV neutrons, has been recently tested in workplaces having different energy and directional distributions. These are a 2.5 MeV nearly mono-chromatic and mono-directional beam available at the ENEA Frascati Neutron Generator (FNG) and the photo-neutron field produced in a 15 MV Varian CLINAC DHX medical accelerator, located in the Ospedale S. Chiara (Pisa). Both neutron spectra are known through measurements with a Bonner Sphere Spectrometer. In both cases the experimental response of the Dy-SSS agrees with the reference data. Moreover, it is demonstrated that the spectrometric capability of the new device are independent from the directional distribution of the neutron field. This opens the way to a new generation of moderation-based neutron instruments, presenting all advantages of the Bonner sphere spectrometer without the disadvantage of the repeated exposures. This concept is being developed within the NESCOFI@BTF project of INFN (Commissione Scientifica Nazionale 5).

  19. Ferroelectric properties of dysprosium-doped Bi4Ti3O12 thin films crystallized in various atmospheres

    Institute of Scientific and Technical Information of China (English)

    CHENG Chuan-pin; TANG Ming-hua; YE Zhi; ZHOU Yic-hun; ZHENG Xue-jun; ZHONG Xiang-li; HU Zeng-shun

    2006-01-01

    Dysprosium-doped Bi4Ti3O12 (Bi3.4Dy0.6Ti3O12,BDT) ferroelectric thin films were deposited on Pt(111)/Ti/SiO2/Si(111) substrates by chemical solution deposition (CSD) and crystallized in nitrogen,air and oxygen atmospheres,respectively. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to identify the crystal structure,the surface and cross-section morphology of the deposited ferroelectric films. The results show that the crystallization atmosphere has significant effect on determining the crystallization and ferroelectric properties of the BDT films. The film crystallized in nitrogen at a relatively low temperature of 650 ℃,exhibits excellent crystallinity and ferroelectricity with a remanent polarization of 2Pr = 24.9 μC/cm2 and a coercive field of 144.5 kV/cm. While the films annealed in air and oxygen at 650 ℃ do not show good crystallinity and ferroelectricity until they are annealed at 700 ℃. The structure evolution and ferroelectric properties of BDT thin films annealed under different temperatures (600-750 ℃) were also investigated. The crystallinity of the BDT films is improved and the average grain size increases when the annealing temperature increases from 600 ℃ to 750 ℃ at an interval of 50 ℃. However,the polarization of the films is not monotonous function of the annealing temperature.

  20. Sensitive search for the temporal variation of the fine structure constant using radio-frequency E1 transitions in atomic dysprosium

    CERN Document Server

    Nguyen, A T; Lamoreaux, S K; Torgerson, J R

    2003-01-01

    It has been proposed that the radio-frequency electric-dipole (E1) transition between two nearly degenerate opposite-parity states in atomic dysprosium should be highly sensitive to possible temporal variation of the fine structure constant ($\\alpha$) [V. A. Dzuba, V. V. Flambaum, and J. K. Webb, Phys. Rev. A {\\bf 59}, 230 (1999)]. We discuss here an experimental realization of the proposed search, which involves monitoring the E1 transition frequency over a period of time using direct frequency counting techniques. We estimate that a statistical sensitivity of $|\\adota| \\sim 10^{-18}$/yr may be achieved and discuss possible systematic effects in such a measurement.

  1. Thermal expansion in dysprosium tungstate Dy10W2O21

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The complex oxide Dy10W2O21 was synthesized by a solid-state reaction and isolated in cubic symmetry by an X-ray diffractometry (XRD) method. Differential scanning calorimetry (DSC) measurements show that the compound is thermodynamically stable. The intrinsic thermal expansion coefficients were determined by extra-power powder Xray diffractometry from room temperature to 1000 ℃: linear coefficient α = 1.07 × 10-5 ℃-1 and bulk coefficient β=3.20 × 10-5℃-1. Dilatometry was used to measure the extrinsic thermal expansion coefficient (9.2 × 10-6℃-1).

  2. Neodymium Dysprosium Modified Starch- coated Magnetic Fluid Preparation of Ferrite%淀粉包覆镝钕改性铁氧体磁性液体的制备

    Institute of Scientific and Technical Information of China (English)

    林穗云; 周育辉

    2011-01-01

    In this paper, in order to obtain the ferrite magnetic fluids of higher saturation magnetic intensity with simple technology, nanometer magnetite ( Fe3O4 ) particles ware prepared by chemical co - precipitation. And to a certain proportion of Dysprosium Neodymium ferrite magnetic fluids on the modification, we selected starch prepara- tion for the relief of water - based coating of rare earth iron oxide magnetic fluid composites. We also investigated the amount of Nd - Dy, the amount of coating agent, reaction temperature, coating temperature on the performance of the products and the effects of particle size, and its preliminary characterization was also performed . Through experiment,we summed up, under n (Fe) : [ n ( Nd3+ ) + n ( Dy3+ ) ] = 30:1 and n ( Fe3 + ) : n ( Fe2 + ) = 1.70 ~ 1. 75, the ratio for use of dysprosium and neodymium is n(Dy3+ ) : n(Nd3+ ) =4:1, 25%NH3 · H2O(A. R. ) as precipitating agent and pH value conditioner; the reacting system temperature was controlled in 35 ℃, and the pH value was adjusted to 9 ~ 11 ; the best dosage of starch as the relief is O. 0050g each 6OraL magnetic fluids, the temperature of surfactant was controlled in 50℃ and the pH value was adjusted to 2 ~ 3. In such system under the conditions of a water - based rare - earth compound Nd Dy Fe Magnetic, fluid magnetic oxygen was higher than or- dinary water- based ferrite.%为制备工艺简单且饱和磁化强度高的磁流体,本文采用化学共沉淀法制得了纳米磁性Fe304粒子.然后以一定比例的镝钕对铁氧体磁流体改性,选择淀粉为包覆剂制备水基稀土复合铁氧磁流体.考察了镝钕的用量、包覆剂的用量、反应温度、包覆温度等因素对产物粒径及性能的影响,并对其进行了初步的性能表征.实验总结出适宜的条件:在n(Fe):[n(Nd3+)+n(Dy3+)]=30:1,n(Fe3+):n(Fe2+)=1.70~1.75

  3. Dysprosium doping induced shape and magnetic anisotropy of Fe3-xDyxO4 (x=0.01-0.1) nanoparticles

    Science.gov (United States)

    Jain, Richa; Luthra, Vandna; Gokhale, Shubha

    2016-09-01

    The effect of dysprosium doping on evolution of structural and magnetic properties of magnetite (Fe3O4) nanoparticles is reported. A standard route of co-precipitation was used for the synthesis of undoped and doped magnetite nanoparticles Fe3-xDyxO4 (x=0.0-0.1). Transmission electron microscopy (TEM) shows formation of round shaped particles with diameter in the range of 8-14 nm for undoped sample. On doping beyond x=0.01, the formation of rod like structures is initiated along with the round shaped particles. The number of rods is found to increase with increasing doping concentration. Magnetic characterization using Vibrating Sample Magnetometer (VSM) revealed doping dependent magnetic properties which can be correlated with the crystallite size as determined from X-ray diffraction (XRD). Enhancement in the saturation magnetization in the initial stages of doping can be explained on the basis of incorporation of Dy3+ ions in the inverse spinel structure at the octahedral site in place of Fe3+ ions. Subsequent decrease in saturation magnetization observed beyond x=0.03 could be attributed to precipitation of excess Dy in form of dysprosium ferrite phase.

  4. Dysprosium(III)-diethylenetriaminepentaacetate complexes of aminocyclodextrins as chiral NMR shift reagents.

    Science.gov (United States)

    Wenzel, T J; Miles, R D; Zomlefer, K; Frederique, D E; Roan, M A; Troughton, J S; Pond, B V; Colby, A L

    2000-01-01

    A metal chelating ligand is bonded to alpha-, beta-, and gamma-cyclodextrin by the reaction of diethylenetraminepentaacetic dianhydride with the corresponding 6-mono- and 2-mono(amine)cyclodextrin. Adding Dy(III) to the cyclodextrin derivatives causes shifts in the (1)H-NMR spectra of substrates such as propranolol, tryptophan, aspartame, carbinoxamine, pheniramine, doxylamine, and 1-anilino-8-naphthalenesulfonate. The Dy(III)-induced shifts enhance the enantiomeric resolution in the NMR spectra of several substrates. Enhancements in enantiomeric resolution using cyclodextrin derivatives with the amine tether are compared to previously described compounds in which the chelating ligand is attached through an ethylenediamine tether. In general, the Dy(III) complex of the 6-beta-derivative with the amine tether is a more effective chiral resolving agent than the complex with the ethylenediamine tether. The opposite trend is observed with the 2-beta-derivatives. The presence of the chelating ligand in the 2-beta-derivative hinders certain substrates from entering the cavity. For cationic substrates, evidence suggests that a cooperative association involving inclusion in the cavity and association with the Dy(III) unit occurs. Enhancements in enantiomeric resolution in the spectrum of tryptophan are greater for the secondary alpha- and gamma-derivatives than the beta-derivative.

  5. Single-molecule magnet behavior in an octanuclear dysprosium(iii) aggregate inherited from helical triangular Dy3 SMM-building blocks.

    Science.gov (United States)

    Zhang, Li; Zhang, Peng; Zhao, Lang; Wu, Jianfeng; Guo, Mei; Tang, Jinkui

    2016-06-28

    An unprecedented octanuclear dysprosium(iii) cluster with the formula [Dy8L6(μ3-OH)4(μ2-CH3O)2(CH3OH)6(H2O)2]·6H2O·10CH3OH·2CH3CN () based on a nonlinearly tritopic aroylhydrazone ligand H3L has been isolated, realizing the successful linking of pairwise interesting triangular Dy3 SMMs. It is noteworthy that two enantiomers (Λ and Δ configurations) individually behaving as a coordination-induced chirality presented in the Dy3 helicate are connected in the meso Dy8 cluster. Remarkably, alternating-current magnetic susceptibility measurements revealed that the Dy8 cluster shows typical SMM behavior inherited from its Dy3 helical precursor. It is one of the rare polynuclear Lnn SMMs (n > 7) under zero dc field.

  6. Another challenge to paramagnetic relaxation theory: a study of paramagnetic proton NMR relaxation in closely related series of pyridine-derivatised dysprosium complexes.

    Science.gov (United States)

    Rogers, Nicola J; Finney, Katie-Louise N A; Senanayake, P Kanthi; Parker, David

    2016-02-14

    Measurements of the relaxation rate behaviour of two series of dysprosium complexes have been performed in solution, over the field range 1.0 to 16.5 Tesla. The field dependence has been modelled using Bloch-Redfield-Wangsness theory, allowing estimates of the electronic relaxation time, T1e, and the size of the magnetic susceptibility, μeff, to be made. Changes in relaxation rate of the order of 50% at higher fields were measured, following variation of the para-substituent in the single pyridine donor. The magnetic susceptibilities deviated unexpectedly from the free-ion values for certain derivatives in each series examined, in a manner that was independent of the electron-releasing/withdrawing ability of the pyridine substituent, suggesting that the polarisability of just one pyridine donor in octadenate ligands can play a significant role in defining the magnetic susceptibility anisotropy.

  7. Tuning the composition and magnetostructure of dysprosium iron garnets by Co-substitution: An XRD, FT-IR, XPS and VSM study

    Energy Technology Data Exchange (ETDEWEB)

    Tholkappiyan, R.; Vishista, K., E-mail: raovishista@gmail.com

    2015-10-01

    Graphical abstract: - Highlights: • Garnet type Dy{sub 3}Fe{sub 5−x}Co{sub x}O{sub 12} (x = 0–0.06) nanoparticles were synthesized by glycine assisted combustion method. • To investigate and confirm the phases in the synthesized ferrite nanoparticles by FT-IR and XRD analysis. • To investigate the compositional and oxidation state of the samples by X-ray photoelectron spectroscopy. • The detailed core level spectra of Dy 4d, Fe 2p, Co 2p and O 1s were analyzed using XPS. • The magnetic property was studied by VSM technique. - Abstract: We report the Co-substituting on the synthesis and properties of garnet type dysprosium ferrite nanoparticles by basic composition Dy{sub 3}Fe{sub 5−x}Co{sub x}O{sub 12} (x = 0–0.06) synthesized through glycine assisted combustion method. A possible formation mechanism of synthesized Dy{sub 3}Fe{sub 5−x}Co{sub x}O{sub 12} samples by controlling the synthesis process has been proposed. XRD, FT-IR, XPS and VSM studies were used to investigate the compositional and magnetostructural properties of the prepared nanoparticles. XRD results confirm that all the samples are single-phase cubic garnet structure with mean crystallite size of 97–105 nm obtained from Scherrer method and 95–102 nm from W–H method. FT-IR analysis shows the presence of three expected bands in the frequency limit of 450–600 cm{sup −1} attributed to metal–O stretching vibration in tetrahedral site of garnet structure. A typical survey spectrum from XPS results confirmed the presence of Dy, Fe, Co and O elements in the samples. This study also to characterize the different oxidation states of the samples by fitting the parameters of high resolution Dy 4d, Fe 2p, Co 2p and O 1s XPS spectra. The XPS data of Dy 4d spectrum show that Dy{sup 3+} ion occupy in dodecahedral (D) site. The XPS analysis of Fe 2p and Co 2p data suggests that (Fe{sup 3+} and Fe{sup 2+}), (Co{sup 3+} and Co{sup 2+}) are distributed in tetrahedral and octahedral sites

  8. A dysprosium-based metal-organic framework: Synthesis, characterization, crystal structure and interaction with calf thymus-DNA and bovine serum albumin

    Indian Academy of Sciences (India)

    Biplab Mondal; Buddhadeb Sen; Ennio Zangrando; Pabitra Chattopadhyay

    2014-07-01

    A dysprosium-based metallo-organic framework (MOF) containing calcium ions formulated as {Dy(pyda)3Ca1.5(H2O)6} · 5.5H2O (1) (H2pyda = pyridine-2,6-dicarboxylic acid) was solvothermally synthesized in ethanolic medium and characterized by physico-chemical and spectroscopic tools. A detailed structural analysis of the solid state structure of 1 by single crystal X-ray diffraction study showed a tricapped trigonal prism geometry for lanthanide in the [Dy(pyda)3]3− fragment. The mode of interaction of 1 with calf thymus- DNA and with protein bovine serum albumin (BSA) was investigated by using absorption and emission spectroscopic tools. The apparent association constant of complex 1 with CT-DNA was deduced from an absorption spectral study (b = 4.08 × 104 M-1). Spectral and viscosity measurements indicated a groove-binding mode of 1 with CT-DNA, and from spectroscopic study the formation of a metal complex-BSA adduct was assumed to be the result of the interaction of 1 with BSA.

  9. Dual-mode T1 and T2 magnetic resonance imaging contrast agent based on ultrasmall mixed gadolinium-dysprosium oxide nanoparticles: synthesis, characterization, and in vivo application

    Science.gov (United States)

    Tegafaw, Tirusew; Xu, Wenlong; Wasi Ahmad, Md; Baeck, Jong Su; Chang, Yongmin; Bae, Ji Eun; Chae, Kwon Seok; Kim, Tae Jeong; Lee, Gang Ho

    2015-09-01

    A new type of dual-mode T1 and T2 magnetic resonance imaging (MRI) contrast agent based on mixed lanthanide oxide nanoparticles was synthesized. Gd3+ (8S7/2) plays an important role in T1 MRI contrast agents because of its large electron spin magnetic moment resulting from its seven unpaired 4f-electrons, and Dy3+ (6H15/2) has the potential to be used in T2 MRI contrast agents because of its very large total electron magnetic moment: among lanthanide oxide nanoparticles, Dy2O3 nanoparticles have the largest magnetic moments at room temperature. Using these properties of Gd3+ and Dy3+ and their oxide nanoparticles, ultrasmall mixed gadolinium-dysprosium oxide (GDO) nanoparticles were synthesized and their potential to act as a dual-mode T1 and T2 MRI contrast agent was investigated in vitro and in vivo. The D-glucuronic acid coated GDO nanoparticles (davg = 1.0 nm) showed large r1 and r2 values (r2/r1 ≈ 6.6) and as a result clear dose-dependent contrast enhancements in R1 and R2 map images. Finally, the dual-mode imaging capability of the nanoparticles was confirmed by obtaining in vivo T1 and T2 MR images.

  10. Experimental and molecular dynamics studies of dysprosium(III) salt solutions for a better representation of the microscopic features used within the binding mean spherical approximation theory.

    Science.gov (United States)

    Ruas, Alexandre; Guilbaud, Philippe; Den Auwer, Christophe; Moulin, Christophe; Simonin, Jean-Pierre; Turq, Pierre; Moisy, Philippe

    2006-10-19

    This work is aimed at a predictive description of the thermodynamic properties of actinide(III) salt solutions at high concentration and 25 degrees C. A new solution of the binding mean spherical approximation (BIMSA) theory, based on the Wertheim formalism, for taking into account 1:1 and also 1:2 complex formation, is used to reproduce, from a simple procedure, experimental osmotic coefficient variation with concentration for three binary salt solutions of the same lanthanide(III) cation: dysprosium(III) perchlorate, nitrate, and chloride. The relevance of the fitted parameters is discussed, and their values are compared with available literature values. UV-vis/near-IR, time-resolved laser-induced fluorescence spectroscopy experiments, and molecular dynamics (MD) calculations were conducted for dilute to concentrated solutions (ca. 3 mol.kg-1) for a study of the microscopic behavior of DyCl3 binary solutions. Coupling MD calculations and extended X-ray absorption fine structure led to the determination of reliable distances. The MD results were used for a discussion of the parameters used in the BIMSA.

  11. Experimental and molecular dynamics studies of dysprosium(III) salt solutions for a better representation of the microscopic features used within the binding mean spherical approximation theory

    Energy Technology Data Exchange (ETDEWEB)

    Ruas, Alexandre; Guilbaud, Philippe; Den Auwer, Christophe; Moulin, Christophe; Simonin, Jean-Pierre; Turq, Pierre; Moisy, Philippe [DEN/DRCP/SCPS, CEA-Valrho Marcoule, BP 17171, 30207 Bagnols-sur-Ceze Cedex, DEN/DPC/SECR/LSRM, CEA-Saclay, Bat 391, BP 91191 Gif sur Yvette, Cedex (France); Laboratoire LI2C (UMR 7612), Universite Pierre et Marie Curie-Paris 6, Boite No. 51, 4 Place Jussieu, 75252 Paris Cedex 05 (France)

    2006-07-01

    This work is aimed at a predictive description of the thermodynamic properties of actinide (III) salt solutions at high concentration and 25 deg. C. A new solution of the binding mean spherical approximation (BIMSA) theory, based on the Wertheim formalism, for taking into account 1: 1 and also 1: 2 complex formation, is used to reproduce, from a simple procedure, experimental osmotic coefficient variation with concentration for three binary salt solutions of the same lanthanide (III) cation: dysprosium (III) perchlorate, nitrate, and chloride. The relevance of the fitted parameters is discussed, and their values are compared with available literature values. UV-vis/near-IR, time-resolved laser-induced fluorescence spectroscopy experiments, and molecular dynamics (MD) calculations were conducted for dilute to concentrated solutions (ca. 3 mol, kg{sup -1}) for a study of the microscopic behavior of DyCl{sub 3} binary solutions. Coupling MD calculations and extended X-ray absorption fine structure led to the determination of reliable distances. The MD results were used for a discussion of the parameters used in the BIMSA. (authors)

  12. Elucidation of Dual Magnetic Relaxation Processes in Dinuclear Dysprosium(III) Phthalocyaninato Triple-Decker Single-Molecule Magnets Depending on the Octacoordination Geometry.

    Science.gov (United States)

    Katoh, Keiichi; Aizawa, Yu; Morita, Takaumi; Breedlove, Brian K; Yamashita, Masahiro

    2017-08-07

    When applying single-molecule magnets (SMMs) to spintronic devices, control of the quantum tunneling of the magnetization (QTM) as well as a spin-lattice interactions are important. Attempts have been made to use not only coordination geometry but also magnetic interactions between SMMs as an exchange bias. In this manuscript, dinuclear dysprosium(III) (Dy(III) ) SMMs with the same octacoordination geometry undergo dual magnetic relaxation processes at low temperature. In the dinuclear Dy(III) phthalocyaninato (Pc(2-) ) triple-decker type complex [(Pc)Dy(ooPc)Dy(Pc)] (1) (ooPc(2-) =2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato) with a square-antiprismatic (SAP) geometry, the ground state is divided by the Zeeman effect, and level intersection occurs when a magnetic field is applied. Due to the ground state properties of 1, since the Zeeman diagram where the levels intersect in an Hdc of 2500 Oe, two kinds of QTM and direct processes occur. However, dinuclear Dy(III) -Pc systems with C4 geometry, which have a twist angle (ϕ) of less than 45° do not undergo dual magnetic relaxation processes. From magnetic field and temperature dependences, the dual magnetic relaxation processes were clarified. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Annealing behaviour and crystal structure of RF-sputtered Bi-substituted dysprosium iron-garnet films having excess co-sputtered Bi-oxide content

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, M; Nur-E-Alam, M; Alameh, K [Electron Science Research Institute, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027 (Australia); Premchander, P; Lee, Y T [Department of Information and Communications, Gwangju Institute of Science and Technology (GIST), Gwangju, 500-712 (Korea, Republic of); Kotov, V A [Institute of Radio Engineering and Electronics, Russian Academy of Sciences, 11 Mohovaya St, Moscow, 125009 (Russian Federation); Lee, Y P, E-mail: m.vasiliev@ecu.edu.au [Quantum Photonic Science Research Center, Department of Physics, Hanyang University, 133-791 (Korea, Republic of)

    2011-02-23

    We investigate the magneto-optic properties, crystal structure and annealing behaviour of nano-composite media with record-high magneto-optic quality exceeding the levels reported so far in sputtered iron-garnet films. Bi-substituted dysprosium-gallium iron-garnet films having excess bismuth oxide content are deposited using RF co-sputtering, and a range of garnet materials are crystallized using conventional oven-annealing processes. We report, for the first time ever, the results of optimization of thermal processing regimes for various high-performance magneto-optic iron-garnet compositions synthesized and describe the evolution of the optical and magneto-optical properties of garnet-Bi-oxide composite-material films occurring during the annealing processes. The crystallization temperature boundaries of the system (BiDy){sub 3}(FeGa){sub 5}O{sub 12} : Bi{sub 2}O{sub 3} are presented. We also report the results of x-ray diffraction and energy-dispersive x-ray spectroscopy studies of this recently developed class of high-performance magneto-optic composites. Our hypothesis of iron oxides being the cause of excess optical absorption in sputtered Bi-iron-garnet films is confirmed experimentally.

  14. Effect of Ligand Field Tuning on the SMM Behavior for Three Related Alkoxide-Bridged Dysprosium Dimers.

    Science.gov (United States)

    Peng, Yan; Mereacre, Valeriu; Baniodeh, Amer; Lan, Yanhua; Schlageter, Martin; Kostakis, George E; Powell, Annie K

    2016-01-04

    The synthesis and characterization of three Dy2 compounds, [Dy2(HL1)2(NO3)4] (1), [Dy2(L2)2(NO3)4] (2), and [Dy2(HL3)2(NO3)4] (3), formed using related tripodal ligands with a central tertiary amine bearing picolyl and alkoxy arms, 2-[(2-hydroxy-ethyl)-pyridin-2-ylmethylamino]-ethanol (H2L1), 2-(bis-pyridin-2-ylmethylamino)-ethanol (HL2), and 2-(bis-pyridin-2-ylmethylamino)-propane-1,3-diol (H2L3), are reported. The compounds are rare examples of alkoxide-bridged {Dy2} complexes and display capped square antiprism coordination geometry around each Dy(III) ion. Changes in the ligand field environment around the Dy(III) ions brought about through variations in the ligand donors can be gauged from the magnetic properties, with compounds 1 and 2 showing antiparallel coupling between the Dy(III) ions and 3 showing parallel coupling. Furthermore, slow relaxation of the magnetization typical of SMM behavior could be observed for compounds 2 and 3, suggesting that small variations in the ligand field can have a significant influence on the slow relaxation processes responsible for SMM behavior of Dy(III)-based systems.

  15. Polybenzimidazole compounds

    Science.gov (United States)

    Klaehn, John R.; Peterson, Eric S.; Wertsching, Alan K.; Orme, Christopher J.; Luther, Thomas A.; Jones, Michael G.

    2010-08-10

    A PBI compound that includes imidazole nitrogens, at least a portion of which are substituted with an organic-inorganic hybrid moiety. At least 85% of the imidazole nitrogens may be substituted. The organic-inorganic hybrid moiety may be an organosilane moiety, for example, (R)Me.sub.2SiCH.sub.2--, where R is selected from among methyl, phenyl, vinyl, and allyl. The PBI compound may exhibit similar thermal properties in comparison to the unsubstituted PBI. The PBI compound may exhibit a solubility in an organic solvent greater than the solubility of the unsubstituted PBI. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may occur at about room temperature and/or at about atmospheric pressure. Substituting may use at least five equivalents in relation to the imidazole nitrogens to be substituted or, preferably, about fifteen equivalents.

  16. Global use structures of the magnetic materials neodymium and dysprosium. A scenario-based analysis of the effect of the diffusion of electromobility on the demand for rare earths; Globale Verwendungsstrukturen der Magnetwerkstoffe Neodym und Dysprosium. Eine szenariobasierte Analyse der Auswirkung der Diffusion der Elektromobilitaet auf den Bedarf an Seltenen Erden

    Energy Technology Data Exchange (ETDEWEB)

    Gloeser-Chahoud, Simon; Kuehn, Andre; Tercero Espinoza, Luis

    2016-06-15

    Neodymium-iron-boron magnets (NdFeB) have experienced a significant demand as the most powerful permanent magnet in recent years, especially for the manufacture of compact electric servomotors with high efficiency and high power density, especially for mobile applications in hybrid traction motors and electric vehicles or for electric bikes. However, NdFeB magnets are also increasingly being used in general mechanical engineering (conveying and pumping systems, tools, air conditioning systems, lift motors, etc.), in the small electric motors of conventional passenger cars or in the generators of large wind power plants with permanent magnetic direct drive. Nevertheless, there is still high uncertainty in the use structures of NdFeB magnets and the contained rare earth elements neodymium and dysprosium. An effective instrument for increasing the market transparency and the understanding of complex anthropogenic material cycles is the dynamic material flow modeling. In the present work paper, this instrument is used for an in-depth analysis of the use structures of NdFeB magnets and the contained rare earths on a global scale. The dynamic modeling of product usage cycles reveals today's usage structures and quantifies future magnetic quantities in obsolete product flows. It could be shown that the magnets in today's scrap volume are mainly contained in obsolete electronics applications such as hard disks (HDD), CD and DVD drives, which makes the recycling hardly seem to be economical due to the small magnets and the high material spread, but in the foreseeable future with larger magnetic quantities from synchronous servomotors and generators can be expected, which significantly increases the recycling potential. In a further step, the effect of the diffusion of alternative drives in the automotive market on the dysprosium requirement is analyzed using a system dynamics model and possible adaptation mechanisms in the form of different substitution effects in

  17. The role of dysprosium on the structural and magnetic properties of (Nd1-xDyx)2Fe14B nanoparticles

    Science.gov (United States)

    Rahimi, Hamed; Ghasemi, Ali; Mozaffarinia, Reza; Tavoosi, Majid

    2017-02-01

    In current work, Nd2Fe14B nanoparticles was synthesized by sol-gel method. Dysprosium powders were added into Nd2Fe14B nanoparticles by mechanical alloying process in order to enhancement of coercivity. The phase analysis, structure, and magnetic properties of annealed (Nd1-xDyx)2Fe14B nanoparticles with different Dy-content (x=0.1, 0.2, 0.3, 0.4, 0.5, 0.6) were investigated by employing X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive spectroscopy, field emission scanning electron microscope, transmission electron microscope and vibrating sample magnetometer techniques. The results showed that with an increase in Dy amounts, the coercivity of particles increased from 2.9 kOe to 13.4 kOe and then decreased to 5.6 kOe. By adding an optimum amount of Dy (x=0.4), the coercivity was significantly increased from 2.9 kOe to 13.4 kOe. The average particle size of annealed (Nd1-xDyx)2Fe14B nanoparticles was below 10 nm. Magnetization reversal studies indicate that the coercivity of milled and annealed (Nd1-xDyx)2Fe14B nanoparticles is controlled by the nucleation of reversed magnetic domains. The experimental results in the angular dependence of coercivity for (Nd1-xDyx)2Fe14B permanent magnets showed that the normalized coercivity of the permanent magnets Hc(θ)/Hc(0) increases from 1 to about 1.2-1.5 with increasing θ from 0 to about π/3, for x=0.4-0.6.

  18. Multipurpose Compound

    Science.gov (United States)

    1983-01-01

    Specially formulated derivatives of an unusual basic compound known as Alcide may be the answer to effective treatment and prevention of the disease bovine mastitis, a bacterial inflammation of a cow's mammary gland that results in loss of milk production and in extreme cases, death. Manufactured by Alcide Corporation the Alcide compound has killed all tested bacteria, virus and fungi, shortly after contact, with minimal toxic effects on humans or animals. Alcide Corporation credits the existence of the mastitis treatment/prevention products to assistance provided the company by NERAC, Inc.

  19. Intermetallic Compounds

    Science.gov (United States)

    Takagiwa, Y.; Matsuura, Y.; Kimura, K.

    2014-06-01

    We have focused on the binary narrow-bandgap intermetallic compounds FeGa3 and RuGa3 as thermoelectric materials. Their crystal structure is FeGa3-type (tetragonal, P42/ mnm) with 16 atoms per unit cell. Despite their simple crystal structure, their room temperature thermal conductivity is in the range 4-5-W-m-1-K-1. Both compounds have narrow-bandgaps of approximately 0.3-eV near the Fermi level. Because their Seebeck coefficients are quite large negative values in the range 350-FeGa3 and RuGa3 as n and p-type materials. The dimensionless figure of merit, ZT, was significantly improved by substitution of Sn for Ga in FeGa3 (electron-doping) and by substitution of Zn for Ga in RuGa3 (hole-doping), mainly as a result of optimization of the electronic part, S 2 σ.

  20. Organic Compounds

    Science.gov (United States)

    Shankland, Kenneth

    For many years, powder X-ray diffraction was used primarily as a fingerprinting method for phase identification in the context of molecular organic materials. In the early 1990s, with only a few notable exceptions, structures of even moderate complexity were not solvable from PXRD data alone. Global optimisation methods and highly-modified direct methods have transformed this situation by specifically exploiting some well-known properties of molecular compounds. This chapter will consider some of these properties.

  1. Compound odontoma

    Directory of Open Access Journals (Sweden)

    Monica Yadav

    2012-01-01

    Full Text Available Odontomas have been extensively reported in the dental literature, and the term refers to tumors of odontogenic origin. Though the exact etiology is still unknown, the postulated causes include: local trauma, infection, inheritance and genetic mutation. The majority of the lesions are asymptomatic; however, may be accompanied with pain and swelling as secondary complaints in some cases. Here, we report a case of a compound odontome in a 14 year old patient.

  2. Dysprosium(III) complexes with a square-antiprism configuration featuring mononuclear single-molecule magnetic behaviours based on different β-diketonate ligands and auxiliary ligands.

    Science.gov (United States)

    Zhang, Sheng; Ke, Hongshan; Shi, Quan; Zhang, Jangwei; Yang, Qi; Wei, Qing; Xie, Gang; Wang, Wenyuan; Yang, Desuo; Chen, Sanping

    2016-03-28

    Three mononuclear dysprosium(III) complexes derived from three β-diketonate ligands, 4,4,4-trifluoro-1-(4-methylphenyl)-1,3-butanedione (tfmb), 4,4,4-trifluoro-1-(4-fluorophenyl)-1,3-butanedione (tffb) and 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (tfnb) as well as auxiliary ligands, 5-nitro-1,10-phenanthroline (5-NO2-Phen), DMF and 2,2'-bipyridine (bpy) have been synthesized and structurally characterized, namely [Dy(5-NO2-Phen)(tfmb)3] (1), [Dy(DMF)2(tffb)3] (2) and [Dy(bpy)2(tfnb)3]·0.5(1,4-dioxane) (3). The metal ions in 1-3 adopt an approximately square-antiprismatic (SAP) coordination environment with D4d axial symmetry. The magnetic properties of 1-3 have been investigated, displaying weak out-of-phase AC signals under a zero-DC field. With an applied DC field of 1200 Oe, the quantum tunnelling of the magnetization was suppressed in 1-3 with the pre-exponential factor τ0 = 5.3 × 10(-7) s and the effective barrier ΔE/kB = 83 K for 1 as well as the pre-exponential factor τ0 = 3.09 × 10(-7) s and the effective barrier ΔE/kB = 39 K for 3. Interestingly, for the frequency dependence of the out-of-phase (χ'') of the AC susceptibility of 2, two slow relaxation of the magnetization processes occurred under the applied magnetic field of 1200 Oe, corresponding to the fast relaxation (FR) phase and slow relaxation (SR) phase, respectively. Arrhenius analysis gave the effective energy barrier (ΔE/kB) of 55 K and the pre-exponential factor (τ0) of 8.23 × 10(-12) for the SR. It is thus very likely that the FR process in complex 2 results from QTM enhanced by dipolar interactions between the Dy ions or the presence of the applied field. The structure-property relationship of some Dy(III) based mononuclear SMMs with the SAP configuration was further discussed.

  3. Magnetic Phase Transition of Nanocrystalline Bulk Metal Gadolinium and Dysprosium%纳米块体金属钆和镝的磁性相变分析

    Institute of Scientific and Technical Information of China (English)

    刘凤艳; 侯碧辉; 岳明; 王克军

    2011-01-01

    The magnetic properties of bulk nanocrystalline metal gadolinium (Gd) and dysprosium (Dy)samples were studied.The magnetization and Curie temperature TC of nanocrystalline Gd and Dy decreased usually as compared with the polycrystal.However,when the mean grain size was 10 nm, the Curie temperature Tc of nanocrystalline Dy increased to 100 K instead and there was an antiferromagnetic phase in nanocrystalline Gd.According to the calculation based on Ruderman-Kittel-Kasuya-Yosida exchange interaction, the exchange integral of the grain boundary atoms and crystalline surface atoms had its sign changed from plus to minus or vice versa, and there were three orderly phases in the steady state with the lowest energy, ferromagnetic phase, antiferromagnetic phase and fan phase.For the nanocrystals with mean grain size of 10 nm, the proportion of grain boundary to crystalline surface atoms was high, and as the result of superposition of the three phases, and there appeared a peak near the phase transition temperature for the nanocrystalline Gd.While for the Dy, the magnetization decreased gently with temperature, and showing a higher Curie temperature than in the case of the polycrystal.%对纳米晶钆(Gd)和镝(Dy)块体材料的磁性进行了研究.与多晶比较,通常纳米晶的磁化强度减小,居里温度TC降低,但平均粒径为10 nm的纳米晶Dy的居里温度TC反而升高到100 K,平均粒径为10 nm的纳米晶Gd中还存在明显的反铁磁相.通过RKKY交换作用的计算知道,晶面晶界处原子的交换积分会发生正负号的变化,能量最低的稳定状态对应三种有序相:铁磁相、反铁磁相和扇相,晶粒中在一定条件下出现三相共存.对于平均粒径为10 nm的纳米晶,晶面晶界处原子所占比例很大,三相叠加的结果,对于Gd,即是在相变点附近出现磁化强度尖峰;对于Dy,则是磁化强度随温度升高下降缓慢,表现为居里温度TC比多晶升高.

  4. Magnesium compounds

    Science.gov (United States)

    Kramer, D.A.

    2012-01-01

    Seawater and natural brines accounted for about 57 percent of magnesium compounds produced in the United States in 2011. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties LLC from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia LLC in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash Wendover LLC and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma Inc. in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its brine operation in Michigan.

  5. Extension of the energy range of the experimental activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium up to 65 MeV

    CERN Document Server

    Tárkányi, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2016-01-01

    Activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium were extended up to 65 MeV by using stacked foil irradiation and gamma spectrometry experimental methods. Experimental cross-sections data for the formation of the radionuclides $^{159}$Dy, $^{157}$Dy, $^{155}$Dy, $^{161}$Tb, $^{160}$Tb, $^{156}$Tb, $^{155}$Tb, $^{154m2}$Tb, $^{154m1}$Tb, $^{154g}$Tb, $^{153}$Tb, $^{152}$Tb and $^{151}$Tb are reported in the 36-65 MeV energy range, and compared with an old dataset from 1964. The experimental data were also compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS nuclear reaction model code as listed in the latest on-line libraries TENDL 2013.

  6. Extension of the energy range of the experimental activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium up to 65MeV.

    Science.gov (United States)

    Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2015-04-01

    Activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium were extended up to 65MeV by using stacked foil irradiation and gamma spectrometry experimental methods. Experimental cross-sections data for the formation of the radionuclides (159)Dy, (157)Dy, (155)Dy, (161)Tb, (160)Tb, (156)Tb, (155)Tb, (154m2)Tb, (154m1)Tb, (154g)Tb, (153)Tb, (152)Tb and (151)Tb are reported in the 36-65MeV energy range, and compared with an old dataset from 1964. The experimental data were also compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS nuclear reaction model code as listed in the latest on-line libraries TENDL 2013. Copyright © 2015. Published by Elsevier Ltd.

  7. The magnetocaloric effect in dysprosium

    Science.gov (United States)

    Benford, S. M.

    1979-01-01

    The magnetocaloric effect in polycrystalline Dy was measured in the 84-280-K range in measuring fields from 1 to 7 T. These adiabatic temperature changes reflect structural changes in Dy with applied field and temperature, and include the first magnetocaloric data for a helical antiferromagnet. Above the Neel point (179 K) a field increase always caused heating; below the Neel point fields less than about 2 T cause cooling for some values of initial temperature. The largest temperature increase with a 7 T field occurs at the Neel point and at fields below 2 T near the Curie point. For refrigeration purposes the optimal working region for a Dy cooling element is field dependent.

  8. Volatile Organic Compounds (VOCs)

    Science.gov (United States)

    ... Contact Us Share Volatile Organic Compounds' Impact on Indoor Air Quality On this page: Introduction Sources Health Effects Levels in Homes Steps to Reduce Exposure Standards or Guidelines Additional Resources Introduction Volatile organic compounds ( ...

  9. Reissert compound of bisbenzimidazole

    OpenAIRE

    1989-01-01

    A Reissert compound of bisbenzimidazole can be formed by first reacting benzimidazole with an aliphatic diacid chloride to form bisbenzimidazole and then reacting the bisbenzimidazole with an aliphatic acid chloride and cyanide to form the Reissert compound thereof.

  10. Microstructure and dielectric properties of dysprosium-doped barium titanate ceramics Microestrutura e propriedades dielétricas de cerâmicas de titanato de bário dopado com disprósio

    Directory of Open Access Journals (Sweden)

    Y. Pu

    2005-09-01

    Full Text Available The substitution behavior and lattice parameter of barium titanate between solid_solubility with a dopant concentration in the range of 0.25 to 1.5 mol% are studied. The influences of dysprosium-doped fraction on the grain size and dielectric properties of barium titanate ceramic, including dielectric constant and breakdown electric field strength, are investigated via scanning electronic microscopy, X-ray diffraction and electric property tester. The results show that, at a dysprosium concentration of 0.75 mol%, the abnormal grain growth is inhibited and the lattice parameters of grain rise up to the maximum because of the lowest vacancy concentration. In addition, the finegrain and high density of barium titanate ceramic result in its excellent dielectric properties. The relative dielectric constant (25 °C reaches to 4100. The temperature coefficient of the capacitance varies from -10 to 10% within the temperature range of -15 °C -100 °C, and the breakdown electric field strength (alternating current achieves 3.2 kV/mm. These data suggest that our barium titanate could be used in the manufacture of high voltage ceramic capacitors.Foram estudados o comportamento da substituição e o parâmetro de rede de titanato de bário da solubilidade sólida com uma concentração de dopante na faixa 0,25-1,5 mol%. As influências da fração do dopante disprósio no tamanho de grão e nas propriedades dielétricas da cerâmica de titanato de bário, incluindo constante dielétrica e rigidez dielétrica foram investigadas por meio de microscopia eletrônica de varredura, difração de raios X e teste de propriedades elétricas. Os resultados mostram que a uma concentração de disprósio de 0,75 mol% o crescimento anormal de grão é inibido e os parâmetros de rede aumentam até um máximo devido a menor concentração de vacâncias. Além disso, as cerâmicas de grãos pequenos e alta densidade resultam em excelentes propriedades dielétricas. A

  11. Ecotoxicology of organofluorous compounds.

    Science.gov (United States)

    Murphy, Margaret B; Loi, Eva I H; Kwok, Karen Y; Lam, Paul K S

    2012-01-01

    Organofluorous compounds have been developed for myriad purposes in a variety of fields, including manufacturing, industry, agriculture, and medicine. The widespread use and application of these compounds has led to increasing concern about their potential ecological toxicity, particularly because of the stability of the C-F bond, which can result in chemical persistence in the environment. This chapter reviews the chemical properties and ecotoxicology of four groups of organofluorous compounds: fluorinated refrigerants and propellants, per- and polyfluorinated compounds (PFCs), fluorinated pesticides, and fluoroquinolone antibiotics. These groups vary in their environmental fate and partitioning, but each raises concern in terms of ecological risk on both the regional and global scale, particularly those compounds with long environmental half-lives. Further research on the occurrence and toxicities of many of these compounds is needed for a more comprehensive understanding of their ecological effects.

  12. Two-dimensional dysprosium(III triiodate(V dihydrate, Dy(IO33(H2O·H2O

    Directory of Open Access Journals (Sweden)

    Laishun Qin

    2009-08-01

    Full Text Available During our research into novel nonlinear optical materials using 1,10-phenanthroline as an appending ligand on lanthanide iodates, crystals of an infinite layered DyIII iodate compound, Dy(IO33(H2O·H2O, were obtained under hydrothermal conditions. The DyIII cation has a dicapped trigonal prismatic coordination environment consisting of one water O atom and seven other O atoms from seven iodate anions. These iodate anions bridge the DyIII cations into a two-dimensional structure. Through O—H...O hydrogen bonds, all of these layers stack along [111], giving a supramolecular channel, with the solvent water molecules filling the voids.

  13. Two-dimensional dysprosium(III) triiodate(V) dihydrate, Dy(IO3)3(H2O)·H2O

    Science.gov (United States)

    Chai, Wenxiang; Song, Li; Shi, Hongsheng; Qin, Laishun; Shu, Kangying

    2009-01-01

    During our research into novel nonlinear optical materials using 1,10-phenanthroline as an appending ligand on lanthanide iodates, crystals of an infinite layered DyIII iodate compound, Dy(IO3)3(H2O)·H2O, were obtained under hydro­thermal conditions. The DyIII cation has a dicapped trigonal prismatic coordination environment consisting of one water O atom and seven other O atoms from seven iodate anions. These iodate anions bridge the DyIII cations into a two-dimensional structure. Through O—H⋯O hydrogen bonds, all of these layers stack along [111], giving a supra­molecular channel, with the solvent water mol­ecules filling the voids. PMID:21583297

  14. Hexanuclear, heterometallic, Ni₃Ln₃ complexes possessing O-capped homo- and heterometallic structural subunits: SMM behavior of the dysprosium analogue.

    Science.gov (United States)

    Goura, Joydeb; Guillaume, Rogez; Rivière, Eric; Chandrasekhar, Vadapalli

    2014-08-04

    The reaction of hetero donor chelating mannich base ligand 6,6'-{(2-(dimethylamino)ethylazanediyl)bis(methylene)}bis(2-methoxy-4-methylphenol) with Ni(ClO4)2·6H2O and lanthanide(III) salts [Dy(III) (1); Tb(III) (2); Gd (III) (3); Ho(III) (4); and Er(III) (5)] in the presence of triethylamine and pivalic acid afforded a series of heterometallic hexanuclear Ni(II)-Ln(III) coordination compounds, [Ni3Ln3(μ3-O)(μ3-OH)3(L)3(μ-OOCCMe3)3]·(ClO4)·wCH3CN·xCH2Cl2·yCH3OH·zH2O [for 1, w = 8, x = 3, y = 0, z = 5.5; for 2, w = 0, x = 5, y = 0, z = 6.5; for 3, w = 15, x = 18, y = 3, z = 7.5; for 4, w = 15, x = 20, y = 6, z = 9.5; and for 5, w = 0, x = 3, y = 2, z = 3]. The molecular structure of these complexes reveals the presence of a monocationic hexanuclear derivative containing one perchlorate counteranion. The asymmetric unit of each of the hexanuclear derivatives comprises the dinuclear motif [NiLn(L)(μ3-O)(μ3-OH)(μ-Piv)]. The cation contains three interlinked O-capped clusters: one Ln(III)3O and three Ni(II)Ln(III)2O. Each of the lanthanide centers is eight- coordinated (distorted trigonal-dodecahedron), while the nickel centers are hexacoordinate (distorted octahedral). The study of the magnetic properties of all compounds are reported and suggests single molecule magnet behavior for the Dy(III) derivative (1).

  15. NATURAL POLYACETYLENE COMPOUNDS

    Directory of Open Access Journals (Sweden)

    D. A. Konovalov

    2014-01-01

    Full Text Available Polyacetylenes (polyynes are compounds which contain two or more triple bonds in its structure. About 2 000 different polyacetylenes and biogenetically related substances were identified in 24 families of higher plants. However, most of these compounds were found in seven families of flowering plants: Apiaceae (Umbelliferae, Araliaceae, Asteraceae (Compositae, Campanulaceae, Olacaceae, Pittosporaceae and Santalaceae. Polyacetylenes are relatively unstable, chemically and biologically active compounds, and present in fungi, microorganisms, marine invertebrates and other organisms except for plants. Acetylenes form distinct specialized group of chemically active natural compounds, which are biosynthesized in plants of unsaturated fatty acids. In addition to widespread aliphatic polyacetylenes thiophenes dithiacyclohexadienes (thiarubrines, thioethers, sulphoxides, sulphones, alkamides, chlorohydrins, lactones, spiroacetal enol ethers, furans, pyrans, tetrahydropyrans, isocoumarins, aromatic acetylenes were also found in plant species. Polyacetylenes are localized in different plant organs, and can be found both individually and as a compound with carbohydrates, terpene, phenolic and other compounds. Many polyacetylenes are found in the composition of the essential oils of plants and it confirms their strongly marked ecological functions. From biological point of view these compounds are often synthesized by plants as toxic or bitter antifeedants, allelopathic compounds, phytoalexins or broadly antibiotic components. Polyynes are strong photosensitizers. They exhibit anti-inflammatory, anti-coagulant, anti-bacterial, antituberculosis, anti-fungal, anti-viral, neuroprotective and neurotoxic activity. Immunostimulatory influence associated with certain allergenicity of some of these substances was established. Therefore, without a doubt polyacetylenes are of interest for the modern pharmacy and medicine.

  16. Determination of phenolic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Chao, G.K.J.; Suatoni, J.C.

    1982-01-01

    Details are given of a procedure for separation and identification of phenolic compounds in aqueous solution by high-performance liquid chromatography. It can also be applied to non-aqueous samples after preliminary isolation of a polar fraction containing the phenolic compounds.

  17. Effect of dysprosium substitution on electrical properties of SrBi{sub 4}Ti{sub 4}O{sub 15}

    Energy Technology Data Exchange (ETDEWEB)

    Mamatha, B., E-mail: boinanemamatha@gmail.com; Sarah, P.

    2014-10-15

    SrBi{sub 4−x}Dy{sub x}Ti{sub 4}O{sub 15} (with x = 0.02, 0.04, 0.06 and 0.08) powders have been synthesized using the stoichiometric amounts of nitrates and oxides of the constituent materials through sol–gel method. The compound so formed is characterized using X-ray diffraction. The density and lattice parameters are calculated. The impedance and electrical conductivity properties are investigated. The imaginary part of impedance as a function of frequency shows Debye like relaxation. Impedance data presented in the Nyquist plot which is used to identify an equivalent circuit and the fundamental circuit parameters are determined at different temperatures. The results of bulk a.c. conductivity as a function of frequency at different temperatures are presented. The dielectric behavior was investigated. Permittivity was calculated based on the relaxation frequency using an alternative approach based on the variation of the imaginary impedance component as a function of reciprocal angular frequency. The frequency dependence of real and imaginary permittivities was also investigated. - Highlights: • SrBi{sub 4−x}Dy{sub x}Ti{sub 4}O{sub 15} (x = 0.02, 0.04, 0.06 and 0.08) powders are produced by sol–gel method. Phase formation is confirmed by XRD analysis. • Frequency dependent imaginary part of impedance shows distribution of relaxation in system. • Broadness of Z″ peak shows distribution of relaxation frequency. • Increase in peak width at ½ maxima of Z″ with increase of temperature shows increase of relaxation frequency distribution. • Cole–Cole plots are resolved into two different circles, ascribed to different mechanisms of polarization and relaxation phenomena.

  18. 表面修饰对镝铁氧体纳米磁粒子的合成及其磁性能的影响%Effect of Surface Modification on Formation and Magnetic Property of Dysprosium Ferrite Nanomagnetic Particles

    Institute of Scientific and Technical Information of China (English)

    陈静; 张茂润; 邓真娟

    2011-01-01

    利用湿化学法制备镝铁氧体纳米磁粒子时,用适量的阴离子表面活性剂进行表面修饰,能够有效地控制磁粒子的粒径,同时避免干燥时产生硬团聚.文章介绍了用月桂酸、月桂酸钠、正十二烷基硫酸钠对磁粒子进行表面修饰的研究结果,探讨了三者及其用量对磁粒子的形成及磁性能的影响.借助X射线衍射仪(XRD)、透射电镜(TEM)、振动样品磁强计(VSM)、红外光谱仪(IR)对产物的性能进行了表征.结果表明,用月桂酸修饰后的产物具有Fe3O4磁粒子的晶型结构且结晶度高、磁性能优异、平均粒径约16nm;用月桂酸钠、正十二烷基硫酸钠修饰后的产物不具有Fe3O4磁粒子的晶型结构,结晶度低且磁性能差.%When wet chemical method are use to prepare dysprosium-doped ferrite magnetic nanoparticles, right a-mount of anionic surfactant were doped as surface modification, which can effectively control the size of magnetic particles, and avoid producing hard reunion when dry out. This paper introduces the research results of magnetic particle surface modification by using lauric acid, laurel acid sodium and lauryl sodium sulfate, discusses the effect of lauric acid, laurel acid sodium and lauryl sodium sulfate and their dosages on the formation of magnetic and its magnetic property. The properties of the product can be characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), infrared spectrometer (IR). The results showed that the product modified with lauric acid have a crystalline structure of Fe3O4 magnetic particles and high crystallin-ity, excellent magnetic properties. The average particle size is about 16 nm; the product modified with laurel acid sodium and lauryl sodium sulfate does not have the crystalline structure of Fe3O4 magnetic particles, with low crystal-linity and low magnetic property.

  19. MEA 86 Compound data

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data file contains the full raw parameter data for the 86 compounds tested in the developmental MEA assay, as well as Area Under the Curve (AUC) calculations...

  20. Compound Semiconductor Radiation Detectors

    CERN Document Server

    Owens, Alan

    2012-01-01

    Although elemental semiconductors such as silicon and germanium are standard for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by their physical limitations, namely the need for ancillary cooling, their modest stopping powers, and radiation intolerance. Compound semiconductors, on the other hand, encompass such a wide range of physical and electronic properties that they have become viable competitors in a number of applications. Compound Semiconductor Radiation Detectors is a consolidated source of information on all aspects of the use of compound semiconductors for radiation detection and measurement. Serious Competitors to Germanium and Silicon Radiation Detectors Wide-gap compound semiconductors offer the ability to operate in a range of hostile thermal and radiation environments while still maintaining sub-keV spectral resolution at X-ray wavelengths. Narrow-gap materials offer the potential of exceeding the spectral resolutio...

  1. Heart testing compound

    Science.gov (United States)

    Knapp, F.F. Jr.; Goodman, M.M.

    1983-06-29

    The compound 15-(p-(/sup 125/I)-iodophenyl)-6-tellurapentadecanoic acid is disclosed as a myocardial imaging agent having rapid and pronounced uptake, prolonged myocardial retention, and low in vivo deiodination.

  2. Polynitramino compounds outperform PETN.

    Science.gov (United States)

    Joo, Young-Hyuk; Shreeve, Jean'ne M

    2010-01-07

    New polynitramino compounds were synthesized and fully characterized using IR and multinuclear ((1)H, (13)C, (15)N) NMR spectroscopy, and elemental analysis as well as single-crystal X-ray diffraction.

  3. Thermodynamics of Organic Compounds

    Science.gov (United States)

    1979-01-01

    General Techniques for Combustion of Liquid/Soli. Organic Compounds by Oxygen Bomb Calorimetry by Arthur J. Head, William D. Good, and Ccrnelius...Mosselman, Chap. 8; Combustion of Liquid/Solid Organic Compounds with Non-Metallic Hetero-Atoms by Arthur J. Head and William D. Good, Chap. 9; in...0 Box 95085 Washington, DC 20234 Los Angeles, CA 90045 National Bureau of Standards CINDAS Chemical Thermodynamics Division Purdue University

  4. Compound composite odontoma.

    Science.gov (United States)

    Girish, G; Bavle, Radhika M; Singh, Manish Kumar; Prasad, Sahana N

    2016-01-01

    The term odontoma has been used as a descriptor for any tumor of odontogenic origin. It is a growth in which both epithelial and mesenchymal cells exhibits complete differentiation. Odontomas are considered as hamartomas rather than true neoplasm. They are usually discovered on routine radiographic examination. Odontomas, according to the World Health Organization, are classified into complex odontoma and compound odontomas. The present paper reports a case of compound composite odontomas.

  5. Compound composite odontoma

    Directory of Open Access Journals (Sweden)

    G Girish

    2016-01-01

    Full Text Available The term odontoma has been used as a descriptor for any tumor of odontogenic origin. It is a growth in which both epithelial and mesenchymal cells exhibits complete differentiation. Odontomas are considered as hamartomas rather than true neoplasm. They are usually discovered on routine radiographic examination. Odontomas, according to the World Health Organization, are classified into complex odontoma and compound odontomas. The present paper reports a case of compound composite odontomas.

  6. Chemistry of peroxide compounds

    Science.gov (United States)

    Volnov, I. I.

    1981-01-01

    The history of Soviet research from 1866 to 1967 on peroxide compounds is reviewed. This research dealt mainly with peroxide kinetics, reactivity and characteristics, peroxide production processes, and more recently with superoxides and ozonides and emphasis on the higher oxides of group 1 and 2 elements. Solid state fluidized bed synthesis and production of high purity products based on the relative solubilities of the initial, intermediate, and final compounds and elements in liquid ammonia are discussed.

  7. Phenolic Molding Compounds

    Science.gov (United States)

    Koizumi, Koji; Charles, Ted; de Keyser, Hendrik

    Phenolic Molding Compounds continue to exhibit well balanced properties such as heat resistance, chemical resistance, dimensional stability, and creep resistance. They are widely applied in electrical, appliance, small engine, commutator, and automotive applications. As the focus of the automotive industry is weight reduction for greater fuel efficiency, phenolic molding compounds become appealing alternatives to metals. Current market volumes and trends, formulation components and its impact on properties, and a review of common manufacturing methods are presented. Molding processes as well as unique advanced techniques such as high temperature molding, live sprue, and injection/compression technique provide additional benefits in improving the performance characterisitics of phenolic molding compounds. Of special interest are descriptions of some of the latest innovations in automotive components, such as the phenolic intake manifold and valve block for dual clutch transmissions. The chapter also characterizes the most recent developments in new materials, including long glass phenolic molding compounds and carbon fiber reinforced phenolic molding compounds exhibiting a 10-20-fold increase in Charpy impact strength when compared to short fiber filled materials. The role of fatigue testing and fatigue fracture behavior presents some insight into long-term reliability and durability of glass-filled phenolic molding compounds. A section on new technology outlines the important factors to consider in modeling phenolic parts by finite element analysis and flow simulation.

  8. Highly trifluoromethylated platinum compounds.

    Science.gov (United States)

    Martínez-Salvador, Sonia; Forniés, Juan; Martín, Antonio; Menjón, Babil

    2011-07-11

    The homoleptic, square-planar organoplatinum(II) compound [NBu(4)](2) [Pt(CF(3))(4)] (1) undergoes oxidative addition of CF(3) I under mild conditions to give rise to the octahedral organoplatinum(IV) complex [NBu(4)](2) [Pt(CF(3))(5)I] (2). This highly trifluoromethylated species reacts with Ag(+) salts of weakly coordinating anions in Me(2)CO under a wet-air stream to afford the aquo derivative [NBu(4)][Pt(CF(3))(5) (OH(2))] (4) in around 75% yield. When the reaction of 2 with the same Ag(+) salts is carried out in MeCN, the solvento compound [NBu(4) ][Pt(CF(3))(5)(NCMe)] (5) is obtained in around 80% yield. The aquo ligand in 4 as well as the MeCN ligand in 5 are labile and can be cleanly replaced by neutral and anionic ligands to furnish a series of pentakis(trifluoromethyl)platinate(IV) compounds with formulae [NBu(4)][Pt(CF(3))(5) (L)] (L=CO (6), pyridine (py; 7), tetrahydrothiophene (tht; 8)) and [NBu(4)](2) [Pt(CF(3))(5)X] (X=Cl (9), Br (10)). The unusual carbonyl-platinum(IV) derivative [NBu(4)][Pt(CF(3))(5) (CO)] (6) is thermally stable and has a ν(CO) of 2194 cm(-1). The crystal structures of 2⋅CH(2)Cl(2), 5, [PPh(4) ][Pt(CF(3))(5)(CO)] (6'), and 7 have been established by X-ray diffraction methods. Compound 2 has shown itself to be a convenient entry to the chemistry of highly trifluoromethylated platinum compounds. To the best of our knowledge, compounds 2 and 4-10 are the organoelement compounds with the highest CF(3) content to have been isolated and adequately characterized to date.

  9. Nomenclature of chemical compounds

    Directory of Open Access Journals (Sweden)

    Karolina Kaczmarek

    2009-01-01

    Full Text Available This article presents the mechanisms of the inorganic chemistry nomenclature formation in French language. It shows the structure and the way of presenting the names of chemical compounds either descriptively or by giving the structural formulas’ characteristics, their transcription and order of reading the letters. The text specifies the rules of naming a chemical compound, according to the criteria of IUPAC (Union of Pure and Applied Chemistry, the organisation responsible for digesting the chemical nomenclature. The article contains the transcription chart and the manner of reading the structural formula, also called latero-numerical. Additionally, there is information conceming the usage of the common names given, still remaining in use next to the names compatible with those of IUPAC. Particular types of chemical compounds have served as models for description of other nomenclature formation rules from the simplest structures to the complicated compound ones. A short summary presents the relations and similarities between the names of particular types of chemical compounds.

  10. Flavour Compounds in Fungi

    DEFF Research Database (Denmark)

    Ravasio, Davide Antonio

    Fungi produce a variety of volatile organic compounds (VOCs) during their primary or secondary metabolism and with a wide range of functions. The main focus of this research work has been put on flavour molecules that are produced during fermentation processes, mainly esters and alcohols derived...... region is directly regulated by the ScAro80 transcription factor. This interaction has been used to create a lacZ-reporter system to correlate the formation of two volatile compounds, 2- phenylethanol and 2-phenylethyl acetate in yeast with ARO9 expression levels. This indirect genetic assay also....... This resulted in the identification of Wickerhamomyces anomalus and Pichia kluyveri as high producers of esters fruity compounds, which contribute to enhance the complexity of wine and beer product. In addition the strain Debaromyces subglobosus showed high yields of aldehydes and fruity ketones, which...

  11. Compound semiconductor device physics

    CERN Document Server

    Tiwari, Sandip

    2013-01-01

    This book provides one of the most rigorous treatments of compound semiconductor device physics yet published. A complete understanding of modern devices requires a working knowledge of low-dimensional physics, the use of statistical methods, and the use of one-, two-, and three-dimensional analytical and numerical analysis techniques. With its systematic and detailed**discussion of these topics, this book is ideal for both the researcher and the student. Although the emphasis of this text is on compound semiconductor devices, many of the principles discussed will also be useful to those inter

  12. Aminopropyl thiophene compounds

    Science.gov (United States)

    Goodman, Mark M.; Knapp, Jr., Furn F.

    1990-01-01

    Radiopharmaceuticals useful in brain imaging comprising radiohalogenated thienylethylamine derivatives. The compounds are 5-halo-thiophene-2-isopropyl amines able to cross the blood-brain barrier and be retained for a sufficient length of time to allow the evaluation of regional blood flow by radioimaging of the brain.

  13. Toxicology of perfluorinated compounds

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, Thorsten [Hessian State Laboratory, Wiesbaden (Germany); Mattern, Daniela; Brunn, Hubertus [Hessian State Laboratory, Giessen (Germany)

    2011-12-15

    Perfluorinated compounds [PFCs] have found a wide use in industrial products and processes and in a vast array of consumer products. PFCs are molecules made up of carbon chains to which fluorine atoms are bound. Due to the strength of the carbon/fluorine bond, the molecules are chemically very stable and are highly resistant to biological degradation; therefore, they belong to a class of compounds that tend to persist in the environment. These compounds can bioaccumulate and also undergo biomagnification. Within the class of PFC chemicals, perfluorooctanoic acid and perfluorosulphonic acid are generally considered reference substances. Meanwhile, PFCs can be detected almost ubiquitously, e.g., in water, plants, different kinds of foodstuffs, in animals such as fish, birds, in mammals, as well as in human breast milk and blood. PFCs are proposed as a new class of 'persistent organic pollutants'. Numerous publications allude to the negative effects of PFCs on human health. The following review describes both external and internal exposures to PFCs, the toxicokinetics (uptake, distribution, metabolism, excretion), and the toxicodynamics (acute toxicity, subacute and subchronic toxicities, chronic toxicity including carcinogenesis, genotoxicity and epigenetic effects, reproductive and developmental toxicities, neurotoxicity, effects on the endocrine system, immunotoxicity and potential modes of action, combinational effects, and epidemiological studies on perfluorinated compounds). (orig.)

  14. NATURAL POLYACETYLENE COMPOUNDS

    Directory of Open Access Journals (Sweden)

    A. M. Nasukhova

    2014-01-01

    Full Text Available In article the review of the initial stage of researches of natural polyacetylene compounds is resulted. The high reactionary ability leading to fast oxidation and degradation of these compounds, especially at influence of Uf-light, oxygen of air, pH and other factors, has caused the serious difficulties connected with an establishment of structure and studying of their physical and chemical properties. Therefore the greatest quantity of works of this stage is connected with studying of essential oils of plants from families Apiaceae, Araliaceae, Asteraceae, Campanulaceae, Olacaceae, Pittosporaceae and Santalaceae where have been found out, basically, diacetylene compounds. About development of physical and chemical methods of the analysis of possibility of similar researches have considerably extended. More than 2000 polyacetylenes are known today, from them more than 1100 are found out in plants fam. Asteraceae. Revolution in the field of molecular biology has allowed to study processes of biosynthesis of these compounds intensively.

  15. Computing compound distributions faster

    NARCIS (Netherlands)

    P. den Iseger; M.A.J. Smith; R. Dekker (Rommert)

    1997-01-01

    textabstractThe use of Panjer's algorithm has meanwhile become a widespread standard technique for actuaries (Kuon et al., 1955). Panjer's recursion formula is used for the evaluation of compound distributions and can be applied to life and general insurance problems. The discrete version of Panjer'

  16. Flavour Compounds in Fungi

    DEFF Research Database (Denmark)

    Ravasio, Davide Antonio

    Fungi produce a variety of volatile organic compounds (VOCs) during their primary or secondary metabolism and with a wide range of functions. The main focus of this research work has been put on flavour molecules that are produced during fermentation processes, mainly esters and alcohols derived...

  17. Fun with Ionic Compounds

    Science.gov (United States)

    Logerwell, Mollianne G.; Sterling, Donna R.

    2007-01-01

    Ionic bonding is a fundamental topic in high school chemistry, yet it continues to be a concept that students struggle to understand. Even if they understand atomic structure and ion formation, it can be difficult for students to visualize how ions fit together to form compounds. This article describes several engaging activities that help…

  18. Toxicity of dipyridyl compounds and related compounds.

    Science.gov (United States)

    Li, Shenggang; Crooks, Peter A; Wei, Xiaochen; de Leon, Jose

    2004-01-01

    Five dipyridyl isomers, 2,2'-, 2,3'-, 2,4'-, 3,3'-, and 4,4'-dipyridyl, are products resulting from the pyrolytic degradation of tobacco products and degradation of the herbicide paraquat, and therefore may be present in the environment. In this article, the toxicological properties of these dipyridyl isomers in humans and animals are reviewed. Epidemiological studies suggest that cancerous skin lesions in workers involved in the manufacturing of paraquat may be associated with exposure to dipyridyl compounds. Experimental animal studies suggest that dipyridyl isomers may have several toxicological effects. Three of the dipyridyl isomers (the 2,2', 2,4', and 4,4' isomers) appear to be inducers of some metabolic enzymes. The 2,2'-dipyridyl isomer, an iron chelator, appears to influence vasospasm in primate models of stroke. The cytotoxic effects of 2,2'-dipyridyl on several leukemia cell lines have been reported, and a potent teratogenic effect of 2,2'-dipyridyl has been observed in rats. Based on the results of paraquat studies in experimental animal models, it has been proposed that paraquat may have deleterious effects on dopaminergic neurons. These findings support the epidemiological evidence that paraquat exposure may be associated with the development of Parkinson's disease. Studies designed to determine an association between paraquat exposure and Parkinson's disease are complicated by the possibility that metabolic changes may influence the neurotoxicity of paraquat and/or its metabolites. Preliminary unpublished data in mice show that 300-mg/kg doses of 2,2'-dipyridyl are neurotoxic, and 300-mg/kg doses of 2,4'- and 4,4'-dipyridyls are lethal. These results are consistent with earlier studies in Sherman rats using high 2,2'- and 4,4'-dipyridyl doses. New studies are needed to further explore the toxicological properties of dipyridyls and their potential public health impact.

  19. Erupted compound odontome

    Directory of Open Access Journals (Sweden)

    Shekar S

    2009-01-01

    Full Text Available Odontomas are considered to be hamartomas rather than a true neoplasm. They consist chiefly of enamel and dentin, with variable amount of pulp and cementum when fully developed. They are generally asymptomatic and are included under the benign calcified odontogenic tumors. They are usually discovered on routine radiographic examination. Eruption of an odontoma in the oral cavity is rare. Peripheral compound odontomas arise extraosseously and have a tendency to exfoliate. In this article we are reporting a case of a 15-year-old girl with peripheral compound odontoma, with a single rudimentary tooth-like structure in the mandibular right second molar region, which is about to be exfoliated. Its eruption in the oral cavity and location in the mandibular posterior region is associated with aplasia of the mandibular right second molar, making it an interesting case for reporting.

  20. Compound semiconductor device modelling

    CERN Document Server

    Miles, Robert

    1993-01-01

    Compound semiconductor devices form the foundation of solid-state microwave and optoelectronic technologies used in many modern communication systems. In common with their low frequency counterparts, these devices are often represented using equivalent circuit models, but it is often necessary to resort to physical models in order to gain insight into the detailed operation of compound semiconductor devices. Many of the earliest physical models were indeed developed to understand the 'unusual' phenomena which occur at high frequencies. Such was the case with the Gunn and IMPATI diodes, which led to an increased interest in using numerical simulation methods. Contemporary devices often have feature sizes so small that they no longer operate within the familiar traditional framework, and hot electron or even quantum­ mechanical models are required. The need for accurate and efficient models suitable for computer aided design has increased with the demand for a wider range of integrated devices for operation at...

  1. Process for compound transformation

    KAUST Repository

    Basset, Jean-Marie

    2016-12-29

    Embodiments of the present disclosure provide for methods of using a catalytic system to chemically transform a compound (e.g., a hydrocarbon). In an embodiment, the method does not employ grafting the catalyst prior to catalysis. In particular, embodiments of the present disclosure provide for a process of hydrocarbon (e.g., C1 to C20 hydrocarbon) metathesis (e.g., alkane, olefin, or alkyne metathesis) transformation, where the process can be conducted without employing grafting prior to catalysis.

  2. Biodegradation of Organofluorine Compounds

    Science.gov (United States)

    2016-02-01

    RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) XX-02-2016 2. REPORT TYPE Final 3. DATES COVERED (From - To) Mar 2011 – Sep...compounds as sole carbon sources for growth, which was confirmed on two substrates: benzoyl fluoride and 1H,1H,2H,2H-perfluorooctyltriethoxysilane...Subsequent measurements of defluorination rates showed that benzoyl fluoride defluorinated very rapidly; therefore, the growth observed was probably

  3. Toxicity of platinum compounds.

    Science.gov (United States)

    Hartmann, Jörg Thomas; Lipp, Hans-Peter

    2003-06-01

    Since the introduction of platinum-based combination chemotherapy, particularly cisplatin, the outcome of the treatment of many solid tumours has changed. The leading platinum compounds in cancer chemotherapy are cisplatin, carboplatin and oxaliplatin. They share some structural similarities; however, there are marked differences between them in therapeutic use, pharmacokinetics and adverse effects profiles [1-4]. Compared to cisplatin, carboplatin has inferior efficacy in germ-cell tumour, head and neck cancer and bladder and oesophageal carcinoma, whereas both drugs seem to have comparable efficacy in advanced non-small cell and small cell lung cancer as well as ovarian cancer [5-7]. Oxaliplatin belongs to the group of diaminocyclohexane platinum compounds. It is the first platinum-based drug that has marked efficacy in colorectal cancer when given in combination with 5-fluorouracil and folinic acid [8,9]. Other platinum compounds such as oral JM216, ZD0473, BBR3464 and SPI-77, which is a pegylated liposomal formulation of cisplatin, are still under investigation [10-13], whereas nedaplatin has been approved in Japan for the treatment of non-small cell lung cancer and other solid tumours. This review focuses on cisplatin, carboplatin and oxaliplatin.

  4. Toxic compounds in honey.

    Science.gov (United States)

    Islam, Md Nazmul; Khalil, Md Ibrahim; Islam, Md Asiful; Gan, Siew Hua

    2014-07-01

    There is a wealth of information about the nutritional and medicinal properties of honey. However, honey may contain compounds that may lead to toxicity. A compound not naturally present in honey, named 5-hydroxymethylfurfural (HMF), may be formed during the heating or preservation processes of honey. HMF has gained much interest, as it is commonly detected in honey samples, especially samples that have been stored for a long time. HMF is a compound that may be mutagenic, carcinogenic and cytotoxic. It has also been reported that honey can be contaminated with heavy metals such as lead, arsenic, mercury and cadmium. Honey produced from the nectar of Rhododendron ponticum contains alkaloids that can be poisonous to humans, while honey collected from Andromeda flowers contains grayanotoxins, which can cause paralysis of limbs in humans and eventually leads to death. In addition, Melicope ternata and Coriaria arborea from New Zealand produce toxic honey that can be fatal. There are reports that honey is not safe to be consumed when it is collected from Datura plants (from Mexico and Hungary), belladonna flowers and Hyoscamus niger plants (from Hungary), Serjania lethalis (from Brazil), Gelsemium sempervirens (from the American Southwest), Kalmia latifolia, Tripetalia paniculata and Ledum palustre. Although the symptoms of poisoning due to honey consumption may differ depending on the source of toxins, most common symptoms generally include dizziness, nausea, vomiting, convulsions, headache, palpitations or even death. It has been suggested that honey should not be considered a completely safe food.

  5. Light metal compound casting

    Institute of Scientific and Technical Information of China (English)

    Konrad; J.; M.; PAPIS; Joerg; F.; LOEFFLER; Peter; J.; UGGOWITZER

    2009-01-01

    Compound casting’simplifies joining processes by directly casting a metallic melt onto a solid metal substrate. A continuously metallurgic transition is very important for industrial applications, such as joint structures of spaceframe constructions in transport industry. In this project, ‘compound casting’ of light metals is investigated, aiming at weight-saving. The substrate used is a wrought aluminium alloy of type AA5xxx, containing magnesium as main alloying element. The melts are aluminium alloys, containing various alloying elements (Cu, Si, Zn), and magnesium. By replacing the natural oxygen layer with a zinc layer, the inherent wetting difficulties were avoided, and compounds with flawless interfaces were successfully produced (no contraction defects, cracks or oxides). Electron microscopy and EDX investigations as well as optical micrographs of the interfacial areas revealed their continu- ously metallic constitution. Diffusion of alloying elements leads to heat-treatable microstructures in the vicinity of the joining interfaces in Al-Al couples. This permits significant variability of mechanical properties. Without significantly cutting down on wettability, the formation of low-melting intermetallic phases (Al3Mg2 and Al12Mg17 IMPs) at the interface of Al-Mg couples was avoided by applying a protective coating to the substrate.

  6. Light metal compound casting

    Institute of Scientific and Technical Information of China (English)

    Konrad J.M.PAPIS; Joerg F.LOEFFLER; Peter J.UGGOWITZER

    2009-01-01

    'Compound casting'simplifies joining processes by directly casting a metallic melt onto a solid metal substrate. A continuously metallurgic transition is very important for industrial applications, such as joint structures of spaceframe constructions in transport industry. In this project, 'compound casting' of light metals is investigated, aiming at weight-saving. The substrate used is a wrought aluminium alloy of type AA5xxx, containing magnesium as main alloying element. The melts are aluminium alloys, containing various alloying elements (Cu, Si, Zn), and magnesium. By replacing the natural oxygen layer with a zinc layer, the inherent wetting difficulties were avoided, and compounds with flawless interfaces were successfully produced (no contraction defects, cracks or oxides). Electron microscopy and EDX investigations as well as optical micrographs of the interfacial areas revealed their continu-ously metallic constitution. Diffusion of alloying elements leads to heat-treatable microstructures in the vicinity of the joining interfaces in Al-Al couples. This permits significant variability of mechanical properties. Without significantly cutting down on wettability, the formation of low-melting intermetallic phases (Al3Mg2 and AI12Mg17 IMPs) at the interface of Al-Mg couples was avoided by applying a protec-tive coating to the substrate.

  7. Antifungal Compounds from Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Tânia K. Shishido

    2015-04-01

    Full Text Available Cyanobacteria are photosynthetic prokaryotes found in a range of environments. They are infamous for the production of toxins, as well as bioactive compounds, which exhibit anticancer, antimicrobial and protease inhibition activities. Cyanobacteria produce a broad range of antifungals belonging to structural classes, such as peptides, polyketides and alkaloids. Here, we tested cyanobacteria from a wide variety of environments for antifungal activity. The potent antifungal macrolide scytophycin was detected in Anabaena sp. HAN21/1, Anabaena cf. cylindrica PH133, Nostoc sp. HAN11/1 and Scytonema sp. HAN3/2. To our knowledge, this is the first description of Anabaena strains that produce scytophycins. We detected antifungal glycolipopeptide hassallidin production in Anabaena spp. BIR JV1 and HAN7/1 and in Nostoc spp. 6sf Calc and CENA 219. These strains were isolated from brackish and freshwater samples collected in Brazil, the Czech Republic and Finland. In addition, three cyanobacterial strains, Fischerella sp. CENA 298, Scytonema hofmanni PCC 7110 and Nostoc sp. N107.3, produced unidentified antifungal compounds that warrant further characterization. Interestingly, all of the strains shown to produce antifungal compounds in this study belong to Nostocales or Stigonematales cyanobacterial orders.

  8. atmospheric volatile organic compounds

    Directory of Open Access Journals (Sweden)

    A. R. Koss

    2016-07-01

    organic compounds (VOCs that cannot be ionized with H3O+ ions (e.g., in a PTR-MS or H3O+ CIMS instrument. Here we describe the adaptation of a high-resolution time-of-flight H3O+ CIMS instrument to use NO+ primary ion chemistry. We evaluate the NO+ technique with respect to compound specificity, sensitivity, and VOC species measured compared to H3O+. The evaluation is established by a series of experiments including laboratory investigation using a gas-chromatography (GC interface, in situ measurement of urban air using a GC interface, and direct in situ measurement of urban air. The main findings are that (1 NO+ is useful for isomerically resolved measurements of carbonyl species; (2 NO+ can achieve sensitive detection of small (C4–C8 branched alkanes but is not unambiguous for most; and (3 compound-specific measurement of some alkanes, especially isopentane, methylpentane, and high-mass (C12–C15 n-alkanes, is possible with NO+. We also demonstrate fast in situ chemically specific measurements of C12 to C15 alkanes in ambient air.

  9. Antifungal compounds from cyanobacteria.

    Science.gov (United States)

    Shishido, Tânia K; Humisto, Anu; Jokela, Jouni; Liu, Liwei; Wahlsten, Matti; Tamrakar, Anisha; Fewer, David P; Permi, Perttu; Andreote, Ana P D; Fiore, Marli F; Sivonen, Kaarina

    2015-04-13

    Cyanobacteria are photosynthetic prokaryotes found in a range of environments. They are infamous for the production of toxins, as well as bioactive compounds, which exhibit anticancer, antimicrobial and protease inhibition activities. Cyanobacteria produce a broad range of antifungals belonging to structural classes, such as peptides, polyketides and alkaloids. Here, we tested cyanobacteria from a wide variety of environments for antifungal activity. The potent antifungal macrolide scytophycin was detected in Anabaena sp. HAN21/1, Anabaena cf. cylindrica PH133, Nostoc sp. HAN11/1 and Scytonema sp. HAN3/2. To our knowledge, this is the first description of Anabaena strains that produce scytophycins. We detected antifungal glycolipopeptide hassallidin production in Anabaena spp. BIR JV1 and HAN7/1 and in Nostoc spp. 6sf Calc and CENA 219. These strains were isolated from brackish and freshwater samples collected in Brazil, the Czech Republic and Finland. In addition, three cyanobacterial strains, Fischerella sp. CENA 298, Scytonema hofmanni PCC 7110 and Nostoc sp. N107.3, produced unidentified antifungal compounds that warrant further characterization. Interestingly, all of the strains shown to produce antifungal compounds in this study belong to Nostocales or Stigonematales cyanobacterial orders.

  10. Xenobiotic organic compounds in wastewater

    DEFF Research Database (Denmark)

    Eriksson, Eva; Baun, Anders; Henze, Mogens

    2002-01-01

    Information regarding the contents of xenobiotic organic compounds (XOCs) in wastewater is limited, but it has been shown that at least 900 different compounds / compound groups could potentially be present in grey wastewater. Analyses of Danish grey wastewater revealed the presence of several...... hundred of XOCs, among them mainly originating from hygiene products: chlorophenols, detergents and phthalates. Several compounds not deriving from hygiene products were also identified e.g. flame-retardants and drugs. A environmental hazard identification showed that a large number of compounds with high...... aquatic toxicity were present and that data for environmental fate could only be retrieved for about half of the compounds....

  11. R5T4 compounds - unique multifunctional intermetallics for basic research and applications

    Energy Technology Data Exchange (ETDEWEB)

    Mudryk, Yaroslav

    2016-10-01

    The unique properties of the rare-earth elements and their alloys have brought them from relative obscurity to high profile use in common high-tech applications. The broad technological impact of these remarkable materials may have never been known by the general public if not for the supply concerns that placed the rare-earth materials on the front page of newspapers and magazines. Neodymium and dysprosium, two essential components of Nd2Fe14B-based high-performance permanent magnets, have drawn much attention and have been deemed critical materials for many energy-related applications. Ironically, the notoriety of rare-earth elements and their alloys is the result of a global movement to reduce their use in industrial applications and, thus, ease concerns about their supply and ultimately to reduce their position in high-tech supply chains. Research into the applications of lanthanide alloys has been de-emphasized recently due to the perception that industry is moving away from the use of rare-earth elements in new products. While lanthanide supply challenges justify efforts to diversify the supply chain, a strategy to completely replace the materials overlooks the reasons rare earths became important in the first place -- their unique properties are too beneficial to ignore. Rare-earth alloys and compounds possess truly exciting potential for basic science exploration and application development such as solid-state caloric cooling. In this brief review, we touch upon several promising systems containing lanthanide elements that show important and interesting magnetism-related phenomena.

  12. Offset Compound Gear Drive

    Science.gov (United States)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  13. Rubber compounding and processing

    CSIR Research Space (South Africa)

    John

    2014-06-01

    Full Text Available stream_source_info John_2014_ABSTRACT ONLY.pdf.txt stream_content_type text/plain stream_size 886 Content-Encoding ISO-8859-1 stream_name John_2014_ABSTRACT ONLY.pdf.txt Content-Type text/plain; charset=ISO-8859...-1 Handbook of Green Materials Processing Technologies, Properties and Applications Chapter 15 RUBBER COMPOUNDING AND PROCESSING MAYA JACOB JOHN1,2 1CSIR Materials Science and Manufacturing, Polymers and Composites Competence Area, P.O. Box 1124...

  14. Oligosilanylated Antimony Compounds

    Science.gov (United States)

    2015-01-01

    By reactions of magnesium oligosilanides with SbCl3, a number of oligosilanylated antimony compounds were obtained. When oligosilanyl dianions were used, either the expected cyclic disilylated halostibine was obtained or alternatively the formation of a distibine was observed. Deliberate formation of the distibine from the disilylated halostibine was achieved by reductive coupling with C8K. Computational studies of Sb–Sb bond energies, barriers of pyramidal inversion at Sb, and the conformational behavior of distibines provided insight for the understanding of the spectroscopic properties. PMID:25937691

  15. Special Risks of Pharmacy Compounding

    Science.gov (United States)

    ... Consumer Updates RSS Feed The Special Risks of Pharmacy Compounding Get Consumer Updates by E-mail Consumer ... page: A Troubling Trend What You Can Do Pharmacy compounding is a practice in which a licensed ...

  16. High temperature superconducting compounds

    Science.gov (United States)

    Goldman, Allen M.

    1992-11-01

    The major accomplishment of this grant has been to develop techniques for the in situ preparation of high-Tc superconducting films involving the use of ozone-assisted molecular beam epitaxy. The techniques are generalizable to the growth of trilayer and multilayer structures. Films of both the DyBa2Cu3O(7-x) and YBa2Cu3O(7-x) compounds as well as the La(2-x)Sr(x)CuO4 compound have been grown on the usual substrates, SrTiO3, YSZ, MgO, and LaAlO3, as well as on Si substrates without any buffer layer. A bolometer has been fabricated on a thermally isolated SiN substrate coated with YSZ, an effort carried out in collaboration with Honeywell Inc. The deposition process facilitates the fabrication of very thin and transparent films creating new opportunities for the study of superconductor-insulator transitions and the investigation of photo-doping with carriers of high temperature superconductors. In addition to a thin film technology, a patterning technology has been developed. Trilayer structures have been developed for FET devices and tunneling junctions. Other work includes the measurement of the magnetic properties of bulk single crystal high temperature superconductors, and in collaboration with Argonne National Laboratory, measurement of electric transport properties of T1-based high-Tc films.

  17. Optimizing Synthetic Aperture Compound Imaging

    DEFF Research Database (Denmark)

    Hansen, Jens Munk; Jensen, Jørgen Arendt

    2012-01-01

    Spatial compound images are constructed from synthetic aperture data acquired using a linear phased-array transducer. Compound images of wires, tissue, and cysts are created using a method, which allows both transmit and receive compounding without any loss in temporal resolution. Similarly to co...

  18. Semiconducting III-V compounds

    CERN Document Server

    Hilsum, C; Henisch, Heinz R

    1961-01-01

    Semiconducting III-V Compounds deals with the properties of III-V compounds as a family of semiconducting crystals and relates these compounds to the monatomic semiconductors silicon and germanium. Emphasis is placed on physical processes that are peculiar to III-V compounds, particularly those that combine boron, aluminum, gallium, and indium with phosphorus, arsenic, and antimony (for example, indium antimonide, indium arsenide, gallium antimonide, and gallium arsenide).Comprised of eight chapters, this book begins with an assessment of the crystal structure and binding of III-V compounds, f

  19. Nanocrystalline semiconductor doped rare earth oxide for the photocatalytic degradation studies on Acid Blue 113: A di-azo compound under UV slurry photoreactor.

    Science.gov (United States)

    Suganya Josephine, G A; Mary Nisha, U; Meenakshi, G; Sivasamy, A

    2015-11-01

    Preventive measures for the control of environmental pollution and its remediation has received much interest in recent years due to the world-wide increase in the contamination of water bodies. Contributions of these harmful effluents are caused by the leather processing, pharmaceutical, cosmetic, textile, agricultural and other chemical industries. Nowadays, advanced oxidation processes considered to be better option for the complete destruction of organic contaminants in water and wastewater. Acid Blue 113 is a most widely used di-azo compound in leather, textile, dying and food industry as a color rending compound. In the present study, we have reported the photo catalytic degradation of Acid Blue 113 using a nanocrystalline semiconductor doped rare earth oxide as a photo catalyst under UV light irradiation. The photocatalyst was prepared by a simple precipitation technique and were characterized by XRD, FT-IR, UV-DRS and FE-SEM analysis. The experimental results proved that the prepared photo catalyst was nanocrystalline and highly active in the UV region. The UV-DRS results showed the band gap energy was 3.15eV for the prepared photo catalyst. The photodegradation efficiency was analyzed by various experimental parameters such as pH, catalyst dosage, variation of substrate concentration and effect of electrolyte addition. The photo degradation process followed a pseudo first order kinetics and was continuously monitored by UV-visible spectrophotometer. The experimental results proved the efficacy of the nanocrystalline zinc oxide doped dysprosium oxide which are highly active under UV light irradiations. It is also suggested that the prepared material would find wider applications in environmental remediation technologies to remove the carcinogenic and toxic moieties present in the industrial effluents.

  20. Synthetic Aperture Compound Imaging

    DEFF Research Database (Denmark)

    Hansen, Jens Munk

    Medical ultrasound imaging is used for many purposes, e.g. for localizing and classifying cysts, lesions, and other processes. Almost any mass is first observed using B-mode imaging and later classified using e.g. color flow, strain, or attenuation imaging. It is therefore important that the B....... The method is investigated using simulations and through measurements using both phased array and convex array transducers. The images all show an improved contrast compared to images without compounding, and by construction, imaging using an improved frame rate is possible. Using a phased array transducer...... and the limiting factor is the amount of memory IO resources available. An equally high demand for memory throughput is found in the computer gaming industry, where a large part of the processing takes place on the graphics processing unit (GPU). Using the GPU, a framework for synthetic aperture imaging...

  1. Public chemical compound databases.

    Science.gov (United States)

    Williams, Anthony J

    2008-05-01

    The internet has rapidly become the first port of call for all information searches. The increasing array of chemistry-related resources that are now available provides chemists with a direct path to the information that was previously accessed via library services and was limited by commercial and costly resources. The diversity of the information that can be accessed online is expanding at a dramatic rate, and the support for publicly available resources offers significant opportunities in terms of the benefits to science and society. While the data online do not generally meet the quality standards of manually curated sources, there are efforts underway to gather scientists together and 'crowdsource' an improvement in the quality of the available data. This review discusses the types of public compound databases that are available online and provides a series of examples. Focus is also given to the benefits and disruptions associated with the increased availability of such data and the integration of technologies to data mine this information.

  2. Tin compounds and insect fauna

    Energy Technology Data Exchange (ETDEWEB)

    Butovskiy, R.O.

    1985-03-01

    A review of the literature of tin compounds serving as pesticides has resulted in the identification of 11 widely used compounds, both organic and inorganic, with largely fungicidal activity. Organotin compounds seem to be limited in use to the control of insect pests, with the majority of the compounds consisting of Sn(IV) and falling into the following four categories: R/sub 4/Sn, R/sub 3/SNX, R/sub 2/SnX/sub 2/, and RSnX/sub 3/, where R = aliphatic or aromatic hydrocarbon radicals, and X = organic or inorganic substituent. The insecticidal activity of these compounds appears to rest on inhibition of ATPase and uncoupling of oxidative phosphorylation. As a result, these compounds act as larvicides, ovicides and imagocides. 77 references.

  3. Sesquiterpene compounds from Inula viscosa.

    Science.gov (United States)

    Fontana, Gianfranco; La Rocca, Salvatore; Passannanti, Salvatore; Paternostro, Maria Pia

    2007-07-20

    Two new compounds, 2,5-dihydroxyisocostic acid and 2,3-dihydroxycostic acid together with three known sesquiterpene compounds, Isocostic acid, Carabrone and Tomentosin, have been isolated from the acetone extract of Inula viscosa (L.) Aiton. The structures of all new compounds were determined by spectroscopic methods, in particular 1D and 2D (1)H- and (13)C-NMR. The (13)C-NMR spectra of Isocostic acid and of Tomentosin are reported here for the first time.

  4. Potential Risks of Pharmacy Compounding

    OpenAIRE

    Gudeman, Jennifer; Jozwiakowski, Michael; Chollet, John; Randell, Michael

    2013-01-01

    Pharmacy compounding involves the preparation of customized medications that are not commercially available for individual patients with specialized medical needs. Traditional pharmacy compounding is appropriate when done on a small scale by pharmacists who prepare the medication based on an individual prescription. However, the regulatory oversight of pharmacy compounding is significantly less rigorous than that required for Food and Drug Administration (FDA)-approved drugs; as such, compoun...

  5. Natural compounds with herbicidal activity

    Directory of Open Access Journals (Sweden)

    Pasquale Montemurro

    2011-02-01

    Full Text Available Research about phytotoxic activity of natural compounds could lead both to find new herbicidal active ingredients and to plan environmental friendly weed control strategies. Particularly, living organisms could be a source of compounds that are impossible, for their complexity, to synthesize artificially. More over, they could have alternative sites of action respect to the known chemical herbicides and, due to their origin, they should be more environmental safe. Many living organism, such as bacteria, fungi, insects, lichens and plants, are able to produce bioactive compounds. They generally are secondary metabolites or simply waste molecules. In this paper we make a review about these compounds, highlighting potential and constraints.

  6. Transition Metal Compounds Towards Holography

    Directory of Open Access Journals (Sweden)

    Volker Dieckmann

    2012-06-01

    Full Text Available We have successfully proposed the application of transition metal compounds in holographic recording media. Such compounds feature an ultra-fast light-induced linkage isomerization of the transition-metal–ligand bond with switching times in the sub-picosecond regime and lifetimes from microseconds up to hours at room temperature. This article highlights the photofunctionality of two of the most promising transition metal compounds and the photophysical mechanisms that are underlying the hologram recording. We present the latest progress with respect to the key measures of holographic media assembled from transition metal compounds, the molecular embedding in a dielectric matrix and their impressive potential for modern holographic applications.

  7. Saturn's Stratospheric Oxygen Compounds

    Science.gov (United States)

    Romani, Paul N.; Delgado Díaz, Héctor E.; Bjoraker, Gordon; Hesman, Brigette; Achterberg, Richard

    2016-10-01

    There are three known oxygenated species present in Saturn's upper atmosphere: H2O, CO and CO2. The ultimate source of the water must be external to Saturn as Saturn's cold tropopause effectively prevents any internal water from reaching the upper atmosphere. The carbon monoxide and dioxide source(s) could be internal, external, produced by the photochemical interaction of water with Saturn's stratospheric hydrocarbons or some combination of all of these. At this point it is not clear what the external source(s) are.Cassini's Composite InfraRed Spectrometer (CIRS) has detected emission lines of H2O and CO2 (Hesman et al., DPS 2015, 311.16 & Abbas et al. 2013, Ap. J. doi:10.1088/0004-637X/776/2/73) on Saturn. CIRS also retrieves the temperature of the stratosphere using CH4 lines at 7.7 microns. Using CIRS retrieved temperatures, the mole fraction of H2O at the 0.5-5 mbar level can be retrieved and the CO2 mole fraction at ~1-10 mbar. Coupled with ground based observations of CO (Cavalié et al., 2010, A&A, DOI: 10.1051/0004-6361/200912909) these observations provide a complete oxygen compound data set to test photochemical models.Preliminary results will be presented with an emphasis on upper limit analysis to determine the percentage of stratospheric CO and CO2 that can be produced photochemically from CIRS observational constraints on the H2O profile.

  8. Antimicrobial compounds in tears.

    Science.gov (United States)

    McDermott, Alison M

    2013-12-01

    The tear film coats the cornea and conjunctiva and serves several important functions. It provides lubrication, prevents drying of the ocular surface epithelia, helps provide a smooth surface for refracting light, supplies oxygen and is an important component of the innate defense system of the eye providing protection against a range of potential pathogens. This review describes both classic antimicrobial compounds found in tears such as lysozyme and some more recently identified such as members of the cationic antimicrobial peptide family and surfactant protein-D as well as potential new candidate molecules that may contribute to antimicrobial protection. As is readily evident from the literature review herein, tears, like all mucosal fluids, contain a plethora of molecules with known antimicrobial effects. That all of these are active in vivo is debatable as many are present in low concentrations, may be influenced by other tear components such as the ionic environment, and antimicrobial action may be only one of several activities ascribed to the molecule. However, there are many studies showing synergistic/additive interactions between several of the tear antimicrobials and it is highly likely that cooperativity between molecules is the primary way tears are able to afford significant antimicrobial protection to the ocular surface in vivo. In addition to effects on pathogen growth and survival some tear components prevent epithelial cell invasion and promote the epithelial expression of innate defense molecules. Given the protective role of tears a number of scenarios can be envisaged that may affect the amount and/or activity of tear antimicrobials and hence compromise tear immunity. Two such situations, dry eye disease and contact lens wear, are discussed here.

  9. II-VI semiconductor compounds

    CERN Document Server

    1993-01-01

    For condensed matter physicists and electronic engineers, this volume deals with aspects of II-VI semiconductor compounds. Areas covered include devices and applications of II-VI compounds; Co-based II-IV semi-magnetic semiconductors; and electronic structure of strained II-VI superlattices.

  10. Electrochemical reactions of organosilicon compounds

    Science.gov (United States)

    Jouikov, Vyacheslav V.

    1997-06-01

    Data on the processes of electrochemical reduction and oxidation of organosilicon compounds of various classes as well as on the interaction of these compounds with electrically generated reagents are generalised and surveyed systematically. The electrochemical reactivity of organic derivatives of silicon is considered taking into account their structures and reaction conditions. The bibliography includes 245 references.

  11. Testing of Experimental Antileishmanial Compounds.

    Science.gov (United States)

    1994-10-19

    administrative and clerical assistance and Ms. Barbara L. Harris, Laboratory Technician II, for technical assistance with this study. Their efforts are appreciated...braziliensis) leishmaniasis . Although several new compounds have been identified with activity against L. (V.) braziliensis, none have shown adequate promise...to warrant initiation of clinical trials. However, among the most promising active compounds found against visceral leishmaniasis during these

  12. Cytotoxic Compounds from Zanthoxylum Americanum

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Four pyranocoumarins: dipetaline, alloxanthoxyletin, xanthoxyletin, and xanthyletin, and two lignans: sesamin and asarinin were isolated from the northern prickly ash, Zanthoxylum americanum. To varying degrees, all six compounds inhibited the incorporation of tritiated thymidine into human leukemia (HL-60) cells and the inhibitory effect was dependent on the structures of the isolated compounds.

  13. Process for demethylating dimethylsulfonium compounds

    NARCIS (Netherlands)

    Hansen, Theo; van der Maarel, Marc

    1998-01-01

    PCT No. PCT/EP94/01640 Sec. 371 Date Nov. 14, 1995 Sec. 102(e) Date Nov. 14, 1995 PCT Filed May 16, 1994 PCT Pub. No. WO94/26918 PCT Pub. Date Nov. 24, 1994Process for preparing S-methylmercapto and mercapto compounds comprising the step of demethylating a dimethylsulfonium compound of formula I to

  14. Assimilation of Unusual Carbon Compounds

    Science.gov (United States)

    Middelhoven, Wouter J.

    Yeast taxa traditionally are distinguished by growth tests on several sugars and organic acids. During the last decades it became apparent that many yeast species assimilate a much greater variety of naturally occurring carbon compounds as sole source of carbon and energy. These abilities are indicative of a greater role of yeasts in the carbon cycle than previously assumed. Especially in acidic soils and other habitats, yeasts may play a role in the degradation of carbon compounds. Such compounds include purines like uric acid and adenine, aliphatic amines, diamines and hydroxyamines, phenolics and other benzene compounds and polysaccharides. Assimilation of purines and amines is a feature of many ascomycetes and basidiomycetes. However, benzene compounds are degraded by only a few ascomycetous yeasts (e.g. the Stephanoascus/ Blastobotrys clade and black yeastlike fungi) but by many basidiomycetes, e.g. Filobasidiales, Trichosporonales, red yeasts producing ballistoconidia and related species, but not by Tremellales. Assimilation of polysaccharides is wide-spread among basidiomycetes

  15. Bilayer Effects of Antimalarial Compounds.

    Directory of Open Access Journals (Sweden)

    Nicole B Ramsey

    Full Text Available Because of the perpetual development of resistance to current therapies for malaria, the Medicines for Malaria Venture developed the Malaria Box to facilitate the drug development process. We tested the 80 most potent compounds from the box for bilayer-mediated effects on membrane protein conformational changes (a measure of likely toxicity in a gramicidin-based stopped flow fluorescence assay. Among the Malaria Box compounds tested, four compounds altered membrane properties (p< 0.05; MMV007384 stood out as a potent bilayer-perturbing compound that is toxic in many cell-based assays, suggesting that testing for membrane perturbation could help identify toxic compounds. In any case, MMV007384 should be approached with caution, if at all.

  16. Complex chemistry with complex compounds

    Directory of Open Access Journals (Sweden)

    Eichler Robert

    2016-01-01

    Full Text Available In recent years gas-phase chemical studies assisted by physical pre-separation allowed for the investigation of fragile single molecular species by gas-phase chromatography. The latest success with the heaviest group 6 transactinide seaborgium is highlighted. The formation of a very volatile hexacarbonyl compound Sg(CO6 was observed similarly to its lighter homologues molybdenum and tungsten. The interactions of these gaseous carbonyl complex compounds with quartz surfaces were investigated by thermochromatography. Second-generation experiments are under way to investigate the intramolecular bond between the central metal atom of the complexes and the ligands addressing the influence of relativistic effects in the heaviest compounds. Our contribution comprises some aspects of the ongoing challenging experiments as well as an outlook towards other interesting compounds related to volatile complex compounds in the gas phase.

  17. Membrane rejection of nitrogen compounds

    Science.gov (United States)

    Lee, S.; Lueptow, R. M.

    2001-01-01

    Rejection characteristics of nitrogen compounds were examined for reverse osmosis, nanofiltration, and low-pressure reverse osmosis membranes. The rejection of nitrogen compounds is explained by integrating experimental results with calculations using the extended Nernst-Planck model coupled with a steric hindrance model. The molecular weight and chemical structure of nitrogen compounds appear to be less important in determining rejection than electrostatic properties. The rejection is greatest when the Donnan potential exceeds 0.05 V or when the ratio of the solute radius to the pore radius is greater than 0.8. The transport of solute in the pore is dominated by diffusion, although convective transport is significant for organic nitrogen compounds. Electromigration contributes negligibly to the overall solute transport in the membrane. Urea, a small organic compound, has lower rejection than ionic compounds such as ammonium, nitrate, and nitrite, indicating the critical role of electrostatic interaction in rejection. This suggests that better treatment efficiency for organic nitrogen compounds can be obtained after ammonification of urea.

  18. The demise of compound houses

    DEFF Research Database (Denmark)

    Andreasen, Jørgen; Eskemose Andersen, Jørgen

    2006-01-01

    and the neighbourhood unity is a challenge for urban planners. However they represent good value for money, cost little to build, suit traditional inheritence patterns, allow independent life at low cost and allow sharing of services with a finite and known group (albeit within a potential conflictive domain). Compound...... of compound housing and analyses the advantages and disadvantages of life within such housing in Kumasi. Issues of privacy, image and communal life are usually cited by occupants dissatiesfied with life in compound houses, and the difficulty of extending them without spoiling the open spaces...

  19. Polishing compound for plastic surfaces

    Science.gov (United States)

    Stowell, Michael S.

    1995-01-01

    A polishing compound for plastic surfaces. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains fine particles silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS.TM., LEXAN.TM., LUCITE.TM., polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired.

  20. Polishing compound for plastic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Stowell, M.S.

    1993-01-01

    A polishing compound for plastic surfaces is disclosed. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains colloidal silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS{sup TM}, LEXAN{sup TM}, LUCITE{sup TM}, polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired.

  1. First flush of dissolved compounds

    DEFF Research Database (Denmark)

    Krebs, P.; Holzer, P.; Huisman, J.L.

    1999-01-01

    In a crude conceptual approach it is commonly assumed that in a combined sewer system the concentration of dissolved compounds is diluted by an increasing flow rate due to rainwater inflow. However, theory of hydraulics suggests that these compounds are influenced by hydrodynamic effects....... It is known that since the wave celerity is higher than the flow velocity of the water, the increase of flow rate induced through rain runoff is recognised earlier at a certain downstream section of the combined sewer than the concentration increase of typical rain-water compounds originating from surface...... wash-off. This description implies that the wave front is formed from the fluid that was present in the sewer before the Bow rare increased, that is the sewage! By means of measurements and numerical simulations, it is shown that this effect may cause a significant impact of dissolved compounds...

  2. Optimization of compound gear pump

    Institute of Scientific and Technical Information of China (English)

    栾振辉

    2002-01-01

    This paper introduces the performances of compound gear pump. Based on the target of having the smallest mass per unit volume, the paper established a mathematical model of optimization, and obtained the results of optimization of the pump.

  3. Multi-angle compound imaging

    DEFF Research Database (Denmark)

    Jespersen, Søren Kragh; Wilhjelm, Jens Erik; Sillesen, Henrik

    1998-01-01

    to conventional B-mode imaging MACI offers better defined tissue boundaries and lower variance of the speckle pattern, resulting in an image with reduced random variations. Design and implementation of a compound imaging system is described, images of rubber tubes and porcine aorta are shown and effects......This paper reports on a scanning technique, denoted multi-angle compound imaging (MACI), using spatial compounding. The MACI method also contains elements of frequency compounding, as the transmit frequency is lowered for the highest beam angles in order to reduce grating lobes. Compared...... on visualization are discussed. The speckle reduction is analyzed numerically and the results are found to be in excellent agreement with existing theory. An investigation of detectability of low-contrast lesions shows significant improvements compared to conventional imaging. Finally, possibilities for improving...

  4. Polishing compound for plastic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Stowell, M.S.

    1991-01-01

    This invention is comprised of a polishing compound for plastic materials. The compound includes approximately by approximately by weight 25 to 80 parts at least one petroleum distillate lubricant, 1 to 12 parts mineral spirits, 50 to 155 parts abrasive paste, and 15 to 60 parts water. Preferably, the compound includes approximately 37 to 42 parts at least one petroleum distillate lubricant, up to 8 parts mineral spirits, 95 to 110 parts abrasive paste, and 50 to 55 parts water. The proportions of the ingredients are varied in accordance with the particular application. The compound is used on PLEXIGLAS{trademark}, LEXAN{trademark}, LUCITE{trademark}, polyvinyl chloride (PVC), and similar plastic materials whenever a smooth, clear polished surface is desired.

  5. Fourth symposium on macrocyclic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, J. J.; Izatt, R. M.

    1980-01-01

    Both theoretical and experimental aspects of the properties and behavior of synthetic and naturally occurring macrocyclic compounds are covered in this symposium. This document contains abstracts of the papers. (DLC)

  6. Crystallographic properties of fertilizer compounds

    Energy Technology Data Exchange (ETDEWEB)

    Frazier, A.W.; Dillard, E.F.; Thrasher, R.D.; Waerstad, K.R.; Hunter, S.R.; Kohler, J.J.; Scheib, R.M.

    1991-02-01

    This bulletin is a compilation of crystallographic data collected at NFERC on 450 fertilizer-related compounds. In TVA's fertilizer R and D program, petrographic examination, XRD, and infrared spectroscopy are combined with conventional chemical analysis methods in identifying the individual compounds that occur in fertilizer materials. This handbook brings together the results of these characterization studies and supplemental crystallographic data from the literature. It is in one-compound-per-page, loose-leaf format, ordered alphabetically by IUPAC name. Indexes provided include IUPAC name, formula, group, alternate formula, synonyms, x-ray data, optical data. Tables are given for solids, compounds in commercial MAP and DAP, and matrix materials in phosphate rock.

  7. Cytotoxic Compounds from Brucea mollis

    OpenAIRE

    Tung, Mai Hung Thanh; Đuc, Ho Viet; Huong, Tran Thu; Nguyen Thanh DUONG; Do Thi PHUONG; Thao, Do Thi; Tai, Bui Huu; Kim, Young Ho; Bach, Tran The; Cuong, Nguyen Manh

    2012-01-01

    Ten compounds, including soulameanone (1), isobruceine B (2), 9-methoxy-canthin-6-one (3), bruceolline F (4), niloticine (5), octatriacontan-1-ol (6), bombiprenone (7), α-tocopherol (8), inosine (9), and apigenin 7-O-β-D-glucopyranoside (10), were isolated from the leaves, stems, and roots of Brucea mollis Wall. ex Kurz. Their structures were determined using one- and two-dimensional NMR spectroscopy and mass spectrometry. All compounds were evaluated for their cytotoxic activity against KB (...

  8. Miniature curved artificial compound eyes.

    Science.gov (United States)

    Floreano, Dario; Pericet-Camara, Ramon; Viollet, Stéphane; Ruffier, Franck; Brückner, Andreas; Leitel, Robert; Buss, Wolfgang; Menouni, Mohsine; Expert, Fabien; Juston, Raphaël; Dobrzynski, Michal Karol; L'Eplattenier, Geraud; Recktenwald, Fabian; Mallot, Hanspeter A; Franceschini, Nicolas

    2013-06-04

    In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories.

  9. Bioaccessibility testing of cobalt compounds.

    Science.gov (United States)

    Stopford, Woodhall; Turner, John; Cappellini, Danielle; Brock, Tom

    2003-08-01

    Testing of metal compounds for solubility in artificial fluids has been used for many years to assist determining human health risk from exposure to specific compounds of concern. In lieu of obtaining bioavailability data from samples of urine, blood, or other tissues, these studies measured solubility of compounds in various artificial fluids as a surrogate for bioavailability. In this context, the measurement of metal "bioaccessibility" can be used as an in vitro substitute for measuring metal bioavailability. Bioaccessibility can be defined as a value representing the availability of metal for absorption when dissolved in in vitro surrogates of body fluids or juices. The aim of this study was to measure and compare the bioaccessibility of selected cobalt compounds in artificial human tissue fluids and human serum. A second aim was to initiate studies to experimentally validate an in vitro methodology that would provide a conservative estimate of cobalt bioavailability in the assessment of dose from human exposure to various species of cobalt compounds. This study evaluated the bioaccessibility of cobalt(II) from 11 selected cobalt compounds and an alloy in 2 physical forms in 5 surrogate human tissue fluids and human serum. Four (4) separate extraction times were used up to 72 hours. The effect of variables such as pH, dissolution time, and mass-ion effect on cobalt bioaccessibility were assessed as well. We found that the species of cobalt compound as well as the physico-chemical properties of the surrogate fluids, especially pH, had a major impact on cobalt solubility. Cobalt salts such as cobalt(II) sulfate heptahydrate were highly soluble, whereas cobalt alloys used in medical implants and cobalt aluminate spinels used as pigments, showed minimal dissolution over the period of the assay.

  10. Cytotoxic Compounds from Brucea mollis

    Directory of Open Access Journals (Sweden)

    Mai Hung Thanh TUNG

    2016-09-01

    Full Text Available Ten compounds, including soulameanone (1, isobruceine B (2, 9-methoxy-canthin-6-one (3, bruceolline F (4, niloticine (5, octatriacontan-1-ol (6, bombiprenone (7, α-tocopherol (8, inosine (9, and apigenin 7-O-β-D-glucopyranoside (10, were isolated from the leaves, stems, and roots of Brucea mollis Wall. ex Kurz. Their structures were determined using one- and two-dimensional NMR spectroscopy and mass spectrometry. All compounds were evaluated for their cytotoxic activity against KB (human carcinoma of the mouth, LU-1 (human lung adenocarcinoma, LNCaP (human prostate adeno-carcinoma, and HL-60 (human promyelocytic leukemia cancer cell lines. Compound 2 showed significant cytotoxic activity against KB, LU-1, LNCaP, and HL-60 cancer cells with IC50 values of 0.39, 0.40, 0.34, and 0.23 μg/mL, respectively. In addition, compounds 3 and 5 showed significant cytotoxic activity against KB, LU-1, LNCaP, and HL-60 cancer cells with IC50 values around 1–4 μg/mL. Compounds 9-methoxycanthin-6-one (3 and niloticine (5 have been discovered for the first time from the Brucea genus.

  11. Current Research on Antiepileptic Compounds

    Directory of Open Access Journals (Sweden)

    Cheng-Xi Wei

    2015-11-01

    Full Text Available Epilepsy affects about 1% of the world’s population. Due to the fact all antiepileptic drugs (AEDs have some undesirable side effects and about 30% of epileptic patients are not seizure-free with the existing AEDs, there is still an urgent need for the development of more effective and safer AEDs. Based on our research work on antiepileptic compounds and other references in recent years, this review covers the reported work on antiepileptic compounds which are classified according to their structures. This review summarized 244 significant anticonvulsant compounds which are classified by functional groups according to the animal model data, although there are some limitations in the data. This review highlights the properties of new compounds endowed with promising antiepileptic properties, which may be proven to be more effective and selective, and possibly free of unwanted side effects. The reviewed compounds represent an interesting possibility to overcome refractory seizures and to reduce the percentage of patients with a poor response to drug therapy.

  12. Associative asymmetry of compound words.

    Science.gov (United States)

    Caplan, Jeremy B; Boulton, Kathy L; Gagné, Christina L

    2014-07-01

    Early verbal-memory researchers assumed participants represent memory of a pair of unrelated items with 2 independent, separately modifiable, directional associations. However, memory for pairs of unrelated words (A-B) exhibits associative symmetry: a near-perfect correlation between accuracy on forward (A →?) and backward (?← B) cued recall. This was viewed as arguing against the independent-associations hypothesis and in favor of the hypothesis that associations are remembered as holistic units. Here we test the Holistic Representation hypothesis further by examining cued recall of compound words. If we suppose preexisting words are more unitized than novel associations, the Holistic Representation hypothesis predicts compound words (e.g., ROSE BUD) will have a higher forward-backward correlation than novel compounds (e.g., BRIEF TAX). We report the opposite finding: Compound words, as well as noncompound words, exhibited less associative symmetry than novel compounds. This challenges the Holistic Representation account of associative symmetry. Moreover, preexperimental associates (positional family size) influenced associative symmetry-but asymmetrically: Increasing family size of the last constituent increasing decoupled forward and backward recall, but family size of the 1st constituent had no such effect. In short, highly practiced, meaningful associations exhibit associative asymmetry, suggesting associative symmetry is not diagnostic of holistic representations but, rather, is a characteristic of ad hoc associations. With additional learning, symmetric associations may be replaced by directional, independently modifiable associations as verbal associations become embedded within a rich knowledge structure.

  13. Heterometallic octanuclear RE(III)3Ni(II)5 (RE = Dy(III), Gd(III) and Y(III)) clusters with slow magnetic relaxation for the dysprosium derivative.

    Science.gov (United States)

    Wang, Huiyu; Ke, Hongshan; Lin, Shuang-Yan; Guo, Yang; Zhao, Lang; Tang, Jinkui; Li, Yun-Hui

    2013-04-21

    Reactions of rare earth benzoate and nickel perchlorate with a Schiff-base ligand, 2-([(2-hydroxyphenyl)imino]methyl) phenol (H2L), in the presence of triethylamine yielded three heterobimetallic octanuclear clusters of general formula [RE3Ni5L5(PhCOO)3(μ3-OH)5(μ3-OCH3)(CH3OH)4(H2O)]·xCH3OH·yH2O (RE = Dy(III), x = 4, y = 4 (1), RE = Gd(III), x = 5, y = 4 (2), RE = Y(III), x = 5, y = 3 (3)). Single-crystal X-ray diffraction reveals that the metal core of each cluster consists of two distorted [RE2Ni2O4] cubane-like moieties and a heterobimetallic triangular [RE2NiO2] unit, with RE ions arranged in a typical triangular fashion. Variable-temperature solid state magnetic susceptibilities of these complexes were measured in the temperature range 2-300 K and the results indicate that an overall ferromagnetic interaction among the metal ions is operative for compounds 2 and 3. Under zero external field, the Dy3Ni5 compound shows a frequency dependence of the out-of-phase (χ'') signals, which indicates slow relaxation of the magnetization.

  14. Antitumor Compounds from Marine Actinomycetes

    Directory of Open Access Journals (Sweden)

    José A. Salas

    2009-06-01

    Full Text Available Chemotherapy is one of the main treatments used to combat cancer. A great number of antitumor compounds are natural products or their derivatives, mainly produced by microorganisms. In particular, actinomycetes are the producers of a large number of natural products with different biological activities, including antitumor properties. These antitumor compounds belong to several structural classes such as anthracyclines, enediynes, indolocarbazoles, isoprenoides, macrolides, non-ribosomal peptides and others, and they exert antitumor activity by inducing apoptosis through DNA cleavage mediated by topoisomerase I or II inhibition, mitochondria permeabilization, inhibition of key enzymes involved in signal transduction like proteases, or cellular metabolism and in some cases by inhibiting tumor-induced angiogenesis. Marine organisms have attracted special attention in the last years for their ability to produce interesting pharmacological lead compounds.

  15. [Triterpene compounds from Cirsium setosum].

    Science.gov (United States)

    Li, Lingling; Sun, Zheng; Shang, Xiaoya; Li, Jinjie; Wang, Rong; Zhu, Jie

    2012-04-01

    To investigate chemical constituents contained in cytotoxic petroleum ether extractive fractions from ethanol extracts of Cirsium setosum. The constituents were separated and purified by a combination of various chromatographic methods including silica gel, Sephadex LH-20, and preparative HPLC. Structures of the isolates were elucidated by spectroscopic methods including 1D, 2D NMR and MS methods. The compound structures were also determined by reference to literature. Twelve compounds were separated from the petroleum ether fraction of ethanolic extract and elucidated as lupenyl acetate (1), lupeol (2), lupenone (3), beta-amyrin (4), psi-taraxasterol (5), psi-taraxasteryl acetate (6), taraxasteryl acetate (7), marsformoxide B (8), alpha-amyrenone (9), beta-amyrenone (10), taraxasterone (11) and psi-taraxasterone (12). Of them, compounds 3, 5, 7-12 were separated from this genus for the first time.

  16. Electronic Configuration of Yb Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Temmerman, W.M.; Szotek, Z. [Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, Cheshire (United Kingdom); Svane, A. [Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Strange, P. [Physics Department, Keele University, Keele, Staffordshire, ST5 5BG (United Kingdom); Winter, H. [INFP, Forschungszentrum Karlsruhe GmbH, Postfach 3640, D-76021 Karlsruhe (Germany); Delin, A.; Johansson, B.; Eriksson, O.; Fast, L. [Condensed Matter Theory Group, Department of Physics, University of Uppsala, Box 530, 75121 Uppsala (Sweden); Wills, J.M. [Center of Materials Science and Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

    1999-11-01

    The total energy differences between divalent and trivalent configurations of Yb ions in a number of Yb compounds are studied. Two different band theoretical methods, which differ in the treatment of the localized f electrons, are used. The results show that in all Yb compounds the valence energy differences are equal to the energy needed to localize an f electron. These valence energy differences correlate with the number of f electrons hybridizing with the conduction bands in the trivalent configuration. For divalent YbS, the pressure induced f -electron delocalization implies an intermediate valency, as also indicated by experiment. {copyright} {ital 1999} {ital The American Physical Society }

  17. Antiprotozoal compounds from Asparagus africanus

    DEFF Research Database (Denmark)

    Oketch-Rabah, H A; Dossaji, S F; Christensen, S B

    1997-01-01

    Two antiprotozoal compounds have been isolated from the roots of Asparagus africanus Lam. (Liliaceae), a new sapogenin, 2 beta, 12 alpha-dihydroxy-(25R)-spirosta-4,7-dien-3-one (1), which was named muzanzagenin, and the lignan (+)-nyasol (2), (Z)-(+)-4,4'-(3-ethenyl-1-propene-1,3-diyl)-bisphenol.......Two antiprotozoal compounds have been isolated from the roots of Asparagus africanus Lam. (Liliaceae), a new sapogenin, 2 beta, 12 alpha-dihydroxy-(25R)-spirosta-4,7-dien-3-one (1), which was named muzanzagenin, and the lignan (+)-nyasol (2), (Z)-(+)-4,4'-(3-ethenyl-1-propene-1,3-diyl...

  18. The structures of binary compounds

    CERN Document Server

    Hafner, J; Jensen, WB; Majewski, JA; Mathis, K; Villars, P; Vogl, P; de Boer, FR

    1990-01-01

    - Up-to-date compilation of the experimental data on the structures of binary compounds by Villars and colleagues. - Coloured structure maps which order the compounds into their respective structural domains and present for the first time the local co-ordination polyhedra for the 150 most frequently occurring structure types, pedagogically very helpful and useful in the search for new materials with a required crystal structure. - Crystal co-ordination formulas: a flexible notation for the interpretation of solid-state structures by chemist Bill Jensen. - Recent important advances in unders

  19. Organophosphorus Compounds in Organic Electronics.

    Science.gov (United States)

    Shameem, Muhammad Anwar; Orthaber, Andreas

    2016-07-25

    This Minireview describes recent advances of organophosphorus compounds as opto-electronic materials in the field of organic electronics. The progress of (hetero-) phospholes, unsaturated phosphanes, and trivalent and pentavalent phosphanes since 2010 is covered. The described applications of organophosphorus materials range from single molecule sensors, field effect transistors, organic light emitting diodes, to polymeric materials for organic photovoltaic applications.

  20. Students' Categorizations of Organic Compounds

    Science.gov (United States)

    Domin, Daniel S.; Al-Masum, Mohammad; Mensah, John

    2008-01-01

    Categorization is a fundamental psychological ability necessary for problem solving and many other higher-level cognitive tasks. In organic chemistry, students must establish groupings of different chemical compounds in order not only to solve problems, but also to understand course content. Classic models of categorization emphasize similarity as…

  1. Halogenated compounds from marine algae.

    Science.gov (United States)

    Cabrita, Maria Teresa; Vale, Carlos; Rauter, Amélia Pilar

    2010-08-09

    Marine algae produce a cocktail of halogenated metabolites with potential commercial value. Structures exhibited by these compounds go from acyclic entities with a linear chain to complex polycyclic molecules. Their medical and pharmaceutical application has been investigated for a few decades, however other properties, such as antifouling, are not to be discarded. Many compounds were discovered in the last years, although the need for new drugs keeps this field open as many algal species are poorly screened. The ecological role of marine algal halogenated metabolites has somehow been overlooked. This new research field will provide valuable and novel insight into the marine ecosystem dynamics as well as a new approach to comprehending biodiversity. Furthermore, understanding interactions between halogenated compound production by algae and the environment, including anthropogenic or global climate changes, is a challenging target for the coming years. Research of halogenated metabolites has been more focused on macroalgae than on phytoplankton. However, phytoplankton could be a very promising material since it is the base of the marine food chain with quick adaptation to environmental changes, which undoubtedly has consequences on secondary metabolism. This paper reviews recent progress on this field and presents trends on the role of marine algae as producers of halogenated compounds.

  2. Compound Cuing in Free Recall

    Science.gov (United States)

    Lohnas, Lynn J.; Kahana, Michael J.

    2014-01-01

    According to the retrieved context theory of episodic memory, the cue for recall of an item is a weighted sum of recently activated cognitive states, including previously recalled and studied items as well as their associations. We show that this theory predicts there should be compound cuing in free recall. Specifically, the temporal contiguity…

  3. Moessbauer spectroscopy in neptunium compounds

    Energy Technology Data Exchange (ETDEWEB)

    Nakamoto, Tadahiro; Nakada, Masami; Masaki, Nobuyuki; Saeki, Masakatsu [Japan Atomic Energy Research Inst., Tokyo (Japan)

    1997-03-01

    Moessbauer effects are observable in seven elements of actinides from {sup 232}Th to {sup 247}Cm and Moesbauer spectra have been investigated mainly with {sup 237}Np and {sup 238}U for the reasons of availability and cost of materials. This report describes the fundamental characteristics of Moessbauer spectra of {sup 237}Np and the correlation between the isomer shift and the coordination number of Np(V) compounds. The isomer shifts of Np(V) compounds had a tendency to increase as an increase of coordination number and the isomer shifts of Np(V) compounds showed broad distribution as well as those of Np(VI) but {delta} values of the compounds with the same coordination number were distributed in a narrow range. The {delta} values of Np(VI) complexes with O{sub x} donor set suggest that the Np atom in its hydroxide (NpO{sub 2}(OH){center_dot}4H{sub 2}O)might have pentagonal bipyramidal structure and at least, pentagonal and hexagonal bipyramidal structures might coexist in its acetate and benzoate. Really, such coexistence has been demonstrated in its nitrate, (NpO{sub 2}){sub 2}(NO{sub 3}){sub 2}{center_dot}5H{sub 2}O. (M.N.)

  4. Bacterial degradation of fluorinated compounds

    NARCIS (Netherlands)

    Ferreira, Maria Isabel Martins

    2007-01-01

    Fluorine was produced for the first time by Henri Moissan in 1886, for which he received the Nobel Prize in chemistry in 1906. The unique properties of fluorine have led to the development of fluorine chemistry and numerous synthetic fluorinated compounds have been prepared and tested for different

  5. Assimilation of Unusual Carbon Compounds

    NARCIS (Netherlands)

    Middelhoven, W.J.

    2009-01-01

    Yeast taxa traditionally are distinguished by growth tests on several sugars and organic acids. During the last decades it became apparent that many yeast species assimilate a much greater variety of naturally occurring carbon compounds as sole source of carbon and energy. These abilities are indica

  6. Thermal Decomposition of Dicyclopentadienylarylvanadium Compounds

    NARCIS (Netherlands)

    Boekel, C.P.; Jelsma, A.; Teuben, J.H.; Liefde Meijer, H.J. de

    1977-01-01

    The thermolysis of compounds of the type Cp2VR (R = aryl) in the solid state has been studied. A distinct increase in thermal stability is observed upon substitution of the ortho-position of the aryl group. Thermal decomposition occurs with formation of RH, Cp2V, a vanadocene homologue with the

  7. Unpacking Noun-Noun Compounds

    DEFF Research Database (Denmark)

    Smith, Viktor; Barratt, Daniel; Zlatev, Jordan

    2014-01-01

    In two complementary experiments we took an integrated approach to a set of tightly interwoven, yet rarely combined questions concerning the spontaneous interpretation of novel (unfamiliar) noun-noun compounds (NNCs) when encountered in isolation, and possible (re)interpretations of novel as well...

  8. Compounding errors in 2 dogs receiving anticonvulsants.

    Science.gov (United States)

    McConkey, Sandra E; Walker, Susan; Adams, Cathy

    2012-04-01

    Two cases that involve drug compounding errors are described. One dog exhibited increased seizure activity due to a compounded, flavored phenobarbital solution that deteriorated before the expiration date provided by the compounder. The other dog developed clinical signs of hyperkalemia and bromine toxicity following a 5-fold compounding error in the concentration of potassium bromide (KBr).

  9. Alkylation of organic aromatic compounds

    Science.gov (United States)

    Smith, L.A. Jr.

    1989-07-18

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  10. Bacterial Degradation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Qing X. Li

    2009-01-01

    Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

  11. Microstructural degradation in compound tubes

    Energy Technology Data Exchange (ETDEWEB)

    Salonen, J.; Auerkari, P. [VTT Manufacturing Technology, Espoo (Finland)

    1996-12-31

    In order to quantify microstructural degradation at high temperatures, samples of SA 210 / AISI 304 L compound tube material were annealed in the temperature range 540-720 deg C for 1 to 1 000 hours. The hardness of the annealed material was measured and the micro structure of the samples was investigated with optical and scanning electron microscopy. Microstructural degradation was characterised by the carbide structure in the ferritic-pearlitic base material and by the depth of decarburised and carburised zones of the compound tube interface. The observed changes were quantified in terms of their time and temperature dependence and diffusion coefficients of the process. The results can be used in estimating the extent of thermal exposure of high-temperature components after long-term service or after incidences of overheating. (orig.) (4 refs.)

  12. Polymer-solvent molecular compounds

    CERN Document Server

    Guenet, Jean-Michel

    2010-01-01

    Crystallisable polymers represent a large share of the polymers used for manufacturing a wide variety of objects, and consequently have received continuous attention from scientists these past 60 years. Molecular compounds from crystallisable polymers, particularly from synthetic polymers, are receiving growing interest due to their potential application in the making of new materials such as multiporous membranes capable of capturing large particles as well as small pollutant molecules. The present book gives a detailed description of these promising systems. The first chapter

  13. Neoclassical compounds and language registers

    OpenAIRE

    Lasserre, Marine

    2013-01-01

    International audience; Neoclassical compounds are special in French morphology. With regard to their final elements, they are at the border of composition and derivation. If originally they were used to designate scientific or technical concepts, today they are commonly used in everyday language. In this paper, we will see how these different language registers come into play in the construction of these words containing neoclassical elements, both from a formal and from a semantic point of ...

  14. Triterpenes as potentially cytotoxic compounds.

    Science.gov (United States)

    Chudzik, Malwina; Korzonek-Szlacheta, Ilona; Król, Wojciech

    2015-01-19

    Triterpenes are compounds of natural origin, which have numerously biological activities: anti-cancer properties, anti-inflammatory, anti-oxidative, anti-viral, anti-bacterial and anti-fungal. These substances can be isolated from plants, animals or fungi. Nowadays, when neoplasms are main cause of death, triterpenes can become an alternative method for treating cancer because of their cytotoxic properties and chemopreventive activities.

  15. Compound facial expressions of emotion.

    Science.gov (United States)

    Du, Shichuan; Tao, Yong; Martinez, Aleix M

    2014-04-15

    Understanding the different categories of facial expressions of emotion regularly used by us is essential to gain insights into human cognition and affect as well as for the design of computational models and perceptual interfaces. Past research on facial expressions of emotion has focused on the study of six basic categories--happiness, surprise, anger, sadness, fear, and disgust. However, many more facial expressions of emotion exist and are used regularly by humans. This paper describes an important group of expressions, which we call compound emotion categories. Compound emotions are those that can be constructed by combining basic component categories to create new ones. For instance, happily surprised and angrily surprised are two distinct compound emotion categories. The present work defines 21 distinct emotion categories. Sample images of their facial expressions were collected from 230 human subjects. A Facial Action Coding System analysis shows the production of these 21 categories is different but consistent with the subordinate categories they represent (e.g., a happily surprised expression combines muscle movements observed in happiness and surprised). We show that these differences are sufficient to distinguish between the 21 defined categories. We then use a computational model of face perception to demonstrate that most of these categories are also visually discriminable from one another.

  16. Studying the Propensity of Compounds to Supersaturate

    DEFF Research Database (Denmark)

    Palmelund, Henrik; Madsen, Cecilie Maria; Plum, Jakob;

    2016-01-01

    Supersaturating drug delivery systems can enhance the oral bioavailability of poorly soluble drug compounds. Supersaturation of such compounds has been studied in many different ways; however, a more standardized method is required. The rationale of choosing suitable concentrations of supersatura......Supersaturating drug delivery systems can enhance the oral bioavailability of poorly soluble drug compounds. Supersaturation of such compounds has been studied in many different ways; however, a more standardized method is required. The rationale of choosing suitable concentrations...... of supersaturation to study has previously been very inconsistent. This makes comparisons between studies and compounds difficult, as the propensity of compounds to supersaturate varies greatly. This study presents a standardized method to study the supersaturation of drug compounds. The method allows, both......, for a ranking of compounds according to their supersaturation propensity and the effectiveness of precipitation inhibitors. The time-concentration profile of supersaturation and precipitation was studied in situ for 4 different concentrations for 6 model compounds (albendazole, aprepitant, danazol, felodipine...

  17. Investigations on organogermanium compounds XII. Reactions of trialkylgermylalkalimetal compounds in hexamethylphosphoric triamide (HMPT) with some inorganic and organic compounds

    NARCIS (Netherlands)

    Bulten, E.J.; Noltes, J.G.

    1971-01-01

    Trialkylgermyl alkali metal compounds in HMPT have been found to be highly reactive nucleophiles. Reactions with some inorganic and organic compounds, such as oxygen, carbon dioxide, inorganic and orgaanic halides, aldehydes, ketones, epoxides and lactones are described. Several new

  18. Volatile flavor compounds in yogurt: a review.

    Science.gov (United States)

    Cheng, Hefa

    2010-11-01

    Considerable knowledge has been accumulated on the volatile compounds contributing to the aroma and flavor of yogurt. This review outlines the production of the major flavor compounds in yogurt fermentation and the analysis techniques, both instrumental and sensory, for quantifying the volatile compounds in yogurt. The volatile compounds that have been identified in plain yogurt are summarized, with the few key aroma compounds described in detail. Most flavor compounds in yogurt are produced from lipolysis of milkfat and microbiological transformations of lactose and citrate. More than 100 volatiles, including carbonyl compounds, alcohols, acids, esters, hydrocarbons, aromatic compounds, sulfur-containing compounds, and heterocyclic compounds, are found in yogurt at low to trace concentrations. Besides lactic acid, acetaldehyde, diacetyl, acetoin, acetone, and 2-butanone contribute most to the typical aroma and flavor of yogurt. Extended storage of yogurt causes off-flavor development, which is mainly attributed to the production of undesired aldehydes and fatty acids during lipid oxidation. Further work on studying the volatile flavor compounds-matrix interactions, flavor release mechanisms, and the synergistic effect of flavor compounds, and on correlating the sensory properties of yogurt with the compositions of volatile flavor compounds are needed to fully elucidate yogurt aroma and flavor.

  19. Nitrogen Compounds in Radiation Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Sims, H.E. [NNL Sellafield (United Kingdom); Dey, G.R. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Vaudey, C.E.; Peaucelle, C. [Institut de Physique Nucleaire de Lyon - IPNL, 69 - Lyon (France); Boucher, J.L. [Lab. de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR 8601 CNRS 45 rue des Saints Peres, 75270 Paris cedex 06, Univ Paris 5, 75 (France); Toulhoat, N. [Institut de Physique Nucleaire de Lyon (France); Commissariat a l' Energie Atomique CEA/DEN, Centre de Saclay (France); Bererd, N. [Institut de Physique Nucleaire de Lyon (France); IUT Departement Chimie, Universite Claude Bernard Lyon 1 (France); Koppenol, W.H. [Department of Chemistry and Applied Biosciences, ETH Zurich (Switzerland); Janata, E. [Helmholtz-Zentrum fuer Materialien und Energie, Solar Energy Research, Berlin (Germany); Dauvois, V.; Durand, D.; Legand, S.; Roujou, J.L.; Doizi, D.; Dannoux, A.; Lamouroux, C. [Laboratoire de Speciation des Radionucleides et des Molecules, DEN/DPC/Service d' Etude du Comportement des Radionucleides, CEA Saclay, 91 - Gif sur yvette (France)

    2009-07-01

    Water radiolysis in presence of N{sub 2} is probably the topic the most controversy in the field of water radiolysis. It still exists a strong discrepancy between the different reports of ammonia formation by water radiolysis in presence of N{sub 2} and moreover in absence of oxygen there is no agreement on the formation or not of nitrogen oxide like NO{sub 2}- and NO{sub 3}-. These discrepancies come from multiple sources: - the complexity of the reaction mechanisms where nitrogen is involved - the experimental difficulties - and, the irradiation conditions. The aim of the workshop is to capitalize the knowledge needed to go further in simulations and understanding the problems caused (or not) by the presence of nitrogen / water in the environment of radioactive materials. Implications are evident in terms of corrosion, understanding of biological systems and atmospheric chemistry under radiation. Topics covered include experimental and theoretical approaches, application and fundamental researches: - Nitrate and Ammonia in radiation chemistry in nuclear cycle; - NOx in biological systems and atmospheric chemistry; - Formation of Nitrogen compounds in Nuclear installations; - Nitrogen in future power plant projects (Gen4, ITER...) and large particle accelerators. This document gathers the transparencies available for 7 of the presentations given at this workshop. These are: - H.E SIMS: 'Radiation Chemistry of Nitrogen Compounds in Nuclear Power Plant'; - G.R. DEY: 'Nitrogen Compounds Formation in the Radiolysis of Aqueous Solutions'; - C.E. VAUDEY et al.: 'Radiolytic corrosion of nuclear graphite studied with the dedicated gas irradiation cell of IPNL'; - J.L. BOUCHER: 'Roles and biosynthesis of NO in eukaryotes and prokaryotes'; - W.H. KOPPENOL: 'Chemistry of NOx'; - E. JANATA: 'Yield of OH in N{sub 2}O saturated aqueous solution'; - V. DAUVOIS: 'Analytical strategy for the study of radiolysis gases'

  20. Bacterial degradation of detergent compounds.

    Science.gov (United States)

    Goodnow, R A; Harrison, A P

    1972-10-01

    A survey for surfactant degradation among aerobic bacteria has been undertaken. Tests have been made in peptone medium where such a degradation, if it occurs, will be gratuitous. Tallow-alkyl-sulfate, alkyl-ethoxylate-sulfate, and linear-alkyl-benzene-sulfonate were used. Forty-five strains of 34 species in 19 genera degrade one or more of these detergent compounds. With some species, the surfactant inhibits degradation without inhibiting growth, whereas with one species slight degradation took place even at a toxic concentration of surfactant.

  1. Aroma compounds in fresh cut pomegranate arils.

    Science.gov (United States)

    Little published information exists regarding flavor and aroma compounds in pomegranate (Punica granatum). Although arils have fruity and sweet characteristics, we found no publications describing actual compounds responsible for their typical flavor. Since most commercial usage of pomegranates in...

  2. Lipid encapsulated phenolic compounds by fluidization

    Science.gov (United States)

    Phenolic compounds exhibit antioxidant and antimicrobial activities with applications as functional food and feed additives. Ferulic acid, a phenolic compound present in grain crops and lignocellulose biomass, was encapsulated with saturated triglycerides using a laboratory fluidizer. Stability of t...

  3. Therapeutic Phytogenic Compounds for Obesity and Diabetes

    Directory of Open Access Journals (Sweden)

    Hee Soong Jung

    2014-11-01

    Full Text Available Natural compounds have been used to develop drugs for many decades. Vast diversities and minimum side effects make natural compounds a good source for drug development. However, the composition and concentrations of natural compounds can vary. Despite this inconsistency, half of the Food and Drug Administration (FDA-approved pharmaceuticals are natural compounds or their derivatives. Therefore, it is essential to continuously investigate natural compounds as sources of new pharmaceuticals. This review provides comprehensive information and analysis on natural compounds from plants (phytogenic compounds that may serve as anti-obesity and/or anti-diabetes therapeutics. Our growing understanding and further exploration of the mechanisms of action of the phytogenic compounds may afford opportunities for development of therapeutic interventions in metabolic diseases.

  4. Formation of Reissert compound of bisbenzimidazole

    OpenAIRE

    1990-01-01

    A Reissert compound of bisbenzimidazole can be formed by first reacting benzimidazole with an aliphatic diacid chloride to form bisbenzimidazole and then reacting the bisbenzimidazole with an aliphatic acid chloride and cyanide to form the Reissert compound thereof.

  5. SELKIRK'S THEORY OF VERBAL COMPOUNDING: A CRITICAL ...

    African Journals Online (AJOL)

    English verbal compounds are "endocentric adjective or noun compounds whose head ... from phrase structure and does not simply constitute the "lower" portion ..... to V-ing' can, pragmatically, be made somewhat more specific, and approach.

  6. Two new acetylenic compounds from Asparagus officinalis.

    Science.gov (United States)

    Li, Xue-Mei; Cai, Jin-Long; Wang, Wen-Xiang; Ai, Hong-Lian; Mao, Zi-Chao

    2016-01-01

    Two new acetylenic compounds, asparoffins A (1) and B (2), together with two known compounds, nyasol (3) and 3″-methoxynyasol (4), were isolated from stems of Asparagus officinalis. The structures of two new compounds were elucidated on the basis of detailed spectroscopic analyses (UV, IR, MS, 1D, and 2D NMR). All compounds were evaluated for their cytotoxicities against three human cancer cell lines.

  7. Bioavailability of dietary phenolic compounds: Review

    OpenAIRE

    Erick Gutiérrez-Grijalva Paul Gutiérrez-Grijalva; Dulce Libna Ambriz-Pérez; Nayely Leyva-López; Ramón Ignacio Castillo-López; José Basilio Heredia

    2015-01-01

    Phenolic compounds are ubiquitous in plant-based foods. High dietary intake of fruits, vegetables and cereals is related to a decreased rate in chronic diseases. Phenolic compounds are thought to be responsible, at least in part, for those health effects. Nonetheless, phenolic compounds bioaccessibility and biotransformation is often not considered in these studies; thus, a precise mechanism of action of phenolic compounds is not known. In this review we aim to present a comprehensive knowled...

  8. Corrosion Preventive Compounds Lifetime Testing

    Science.gov (United States)

    Hale, Stephanie M.; Kammerer, Catherine C.; Copp, Tracy L.

    2007-01-01

    Lifetime Testing of Corrosion Preventive Compounds (CPCs) was performed to quantify performance in the various environments to which the Space Shuttle Orbiter is exposed during a flight cycle. Three CPCs are approved for use on the Orbiter: RD Calcium Grease, Dinitrol AV-30, and Braycote 601 EF. These CPCs have been rigorously tested to prove that they mitigate corrosion in typical environments, but little information is available on how they perform in the unique combination of the coastal environment at the launch pad, the vacuum of low-earth orbit, and the extreme heat of reentry. Currently, there is no lifetime or reapplication schedule established for these compounds that is based on this combination of environmental conditions. Aluminum 2024 coupons were coated with the three CPCs and exposed to conditions that simulate the environments to which the Orbiter is exposed. Uncoated Aluminum 2024 coupons were exposed to the environmental conditions as a control. Visual inspection and Electro- Impedance Spectroscopy (EIS) were performed on the samples in order to determine the effectiveness of the CPCs. The samples were processed through five mission life cycles or until the visual inspection revealed the initiation of corrosion and EIS indicated severe degradation of the coating.

  9. Prebiotic Evolution of Nitrogen Compounds

    Science.gov (United States)

    Arrhenius, G.

    1999-01-01

    Support from this four year grant has funded our research on two general problems. One involves attempts to model the abiotic formation of simple source compounds for functional biomolecules, their concentration from dilute state in the hydrosphere and, in several cases, surface induced reactions to form precursor monomers for bioactive end products (refs. 1-5). Because of the pervasiveness and antiquity of phosphate based biochemistry and the catalytic activity of RNA we have exploring the hypothesis of an RNA World as an early stage in the emergence of life. This concept is now rather generally considered, but has been questioned due to the earlier lack of an experimentally demonstrated successful scheme for the spontaneous formation of ribose phosphate, the key backbone molecule in RNA. That impediment has now been removed. This has been achieved by demonstrating probable sources of activated (condensed) highly soluble and strongly sorbed phosphates in nature (Refs. 1,2) and effective condensation of aldehyde phosphates to form ribose phosphate in high yield (ref.6), thereby placing the RNA World concept on a somewhat safer experimental footing. Like all work in this field these experiments are oversimplifications that largely ignore competing side reactions with other compounds expected to be present. None the less our choice of experimental conditions aim at selective processes that eliminate interfering reactions. We have also sought to narrow the credibility gap by simulating geophysically and geochemically plausible conditions surrounding the putative prebiotic reactions.

  10. Superconductivity in graphite intercalation compounds

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Robert P. [Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Weller, Thomas E.; Howard, Christopher A. [Department of Physics & Astronomy, University College of London, Gower Street, London WCIE 6BT (United Kingdom); Dean, Mark P.M. [Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY 11973 (United States); Rahnejat, Kaveh C. [Department of Physics & Astronomy, University College of London, Gower Street, London WCIE 6BT (United Kingdom); Saxena, Siddharth S. [Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Ellerby, Mark, E-mail: mark.ellerby@ucl.ac.uk [Department of Physics & Astronomy, University College of London, Gower Street, London WCIE 6BT (United Kingdom)

    2015-07-15

    Highlights: • Historical background of graphite intercalates. • Superconductivity in graphite intercalates and its place in the field of superconductivity. • Recent developments. • Relevant modeling of superconductivity in graphite intercalates. • Interpretations that pertain and questions that remain. - Abstract: The field of superconductivity in the class of materials known as graphite intercalation compounds has a history dating back to the 1960s (Dresselhaus and Dresselhaus, 1981; Enoki et al., 2003). This paper recontextualizes the field in light of the discovery of superconductivity in CaC{sub 6} and YbC{sub 6} in 2005. In what follows, we outline the crystal structure and electronic structure of these and related compounds. We go on to experiments addressing the superconducting energy gap, lattice dynamics, pressure dependence, and how these relate to theoretical studies. The bulk of the evidence strongly supports a BCS superconducting state. However, important questions remain regarding which electronic states and phonon modes are most important for superconductivity, and whether current theoretical techniques can fully describe the dependence of the superconducting transition temperature on pressure and chemical composition.

  11. When to Compound Medications for Veterinary Patients.

    Science.gov (United States)

    Forsythe, Lauren Eichstadt

    2017-01-01

    This article serves as a brief discussion about some of the restrictions applicable to compounding medications for veterinary patients based on U. S. Food and Drug Administration compliance policy guidelines and provides a brief summary of when it is appropriate to compound medications for veterinary patients. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

  12. Five new bioactive compounds from Chenopodium ambrosioides.

    Science.gov (United States)

    Song, Kun; Zhang, Jian; Zhang, Peng; Wang, Hong-Qing; Liu, Chao; Li, Bao-Ming; Kang, Jie; Chen, Ruo-Yun

    2015-05-01

    Five new bioactive compounds, chenopodiumamines A-D (1-4) and chenopodiumoside A (5), were isolated from the ethanol extract of Chenopodium ambrosioides. The structures of these compounds were elucidated by various spectroscopic means (UV, IR, HR-ESI-MS, 1D and 2D NMR). Compounds 1-3 had moderate antioxidant and anti-inflammatory activities.

  13. Semiconducting compounds and devices incorporating same

    Energy Technology Data Exchange (ETDEWEB)

    Marks, Tobin J; Facchetti, Antonio; Boudreault, Pierre-Luc; Miyauchi, Hiroyuki

    2014-06-17

    Disclosed are molecular and polymeric compounds having desirable properties as semiconducting materials. Such compounds can exhibit desirable electronic properties and possess processing advantages including solution-processability and/or good stability. Organic transistor and photovoltaic devices incorporating the present compounds as the active layer exhibit good device performance.

  14. Semiconducting compounds and devices incorporating same

    Energy Technology Data Exchange (ETDEWEB)

    Marks, Tobin J.; Facchetti, Antonio; Boudreault, Pierre-Luc; Miyauchi, Hiroyuki

    2016-01-19

    Disclosed are molecular and polymeric compounds having desirable properties as semiconducting materials. Such compounds can exhibit desirable electronic properties and possess processing advantages including solution-processability and/or good stability. Organic transistor and photovoltaic devices incorporating the present compounds as the active layer exhibit good device performance.

  15. Low-molecular compounds of erythrocytes

    Directory of Open Access Journals (Sweden)

    O. O. Sorochan

    2006-01-01

    Full Text Available Glucose and free amino acids levels in rats’ blood plasma and erythrocytes hemolysate under carcinoma Geuren Т8 development as well as after introduction of Rhenium (III and сys-Platinum compounds were studied. The complex Rhenium (III compounds with organic ligands act as antioxidant and normalize the concentration of low-molecular compounds in erythrocytes under the carcinogenesis.

  16. A New Compound from Swertia cincta

    Institute of Scientific and Technical Information of China (English)

    Wen-xing Liu; Qian Tian; Cui Yang; Hai-yan Wu; Shang-xiu Li; Gan-peng Li

    2016-01-01

    Objective To study the chemical constituents from the whole plant of Swertia cincta.Methods The chemical constituents were purified by chromatographic methods such as silica gel column and Sephadex LH-20.The structures of these compounds were elucidated by MS,IR,and NMR analyses.Results Two compounds were isolated from S.cincta.Conclusion Compound 1 is a new compound named swercinctlactone A.Compound 2 is identified as (±)-gentiolactone and its configuration is confirmed by single crystal X-ray diffraction and optical specific rotation.

  17. Highly sweet compounds of plant origin.

    Science.gov (United States)

    Kim, Nam-Cheol; Kinghorn, A Douglas

    2002-12-01

    The demand for new alternative "low calorie" sweeteners for dietetic and diabetic purposes has increased worldwide. Although the currently developed and commercially used highly sweet sucrose substitutes are mostly synthetic compounds, the search for such compounds from natural sources is continuing. As of mid-2002, over 100 plant-derived sweet compounds of 20 major structural types had been reported, and were isolated from more than 25 different families of green plants. Several of these highly sweet natural products are marketed as sweeteners or flavoring agents in some countries as pure compounds, compound mixtures, or refined extracts. These highly sweet natural substances are reviewed herein.

  18. Use of a compound of formula (I) to manufacture a medicament for treating gaucher's disease, pharmaceutical composition, a compound of formula (IB) and method for obtaining said compound

    OpenAIRE

    Alfonso Palacin, Pilar; Moya García, Aurelio; Sánchez-Jiménez, Francisca; Pocovi Mieras, Miguel; Giraldo, Pilar; Ortiz-Mellet, Carmen; García Fernández, José Manuel

    2013-01-01

    [EN] Use of a compound of formula (I) to manufacture a medicament for treating Gaucher's disease in a human subject, a pharmaceutical composition comprising a compound of formula (I), compounds of formula (Ib) and method for obtaining said compounds.

  19. Veterinary Compounding: Regulation, Challenges, and Resources.

    Science.gov (United States)

    Davidson, Gigi

    2017-01-10

    The spectrum of therapeutic need in veterinary medicine is large, and the availability of approved drug products for all veterinary species and indications is relatively small. For this reason, extemporaneous preparation, or compounding, of drugs is commonly employed to provide veterinary medical therapies. The scope of veterinary compounding is broad and focused primarily on meeting the therapeutic needs of companion animals and not food-producing animals in order to avoid human exposure to drug residues. As beneficial as compounded medical therapies may be to animal patients, these therapies are not without risks, and serious adverse events may occur from poor quality compounds or excipients that are uniquely toxic when administered to a given species. Other challenges in extemporaneous compounding for animals include significant regulatory variation across the global veterinary community, a relative lack of validated compounding formulas for use in animals, and poor adherence by compounders to established compounding standards. The information presented in this article is intended to provide an overview of the current landscape of compounding for animals; a discussion on associated benefits, risks, and challenges; and resources to aid compounders in preparing animal compounds of the highest possible quality.

  20. Promiscuity progression of bioactive compounds over time.

    Science.gov (United States)

    Hu, Ye; Jasial, Swarit; Bajorath, Jürgen

    2015-01-01

    In the context of polypharmacology, compound promiscuity is rationalized as the ability of small molecules to specifically interact with multiple targets. To study promiscuity progression of bioactive compounds in detail, nearly 1 million compounds and more than 5.2 million activity records were analyzed. Compound sets were assembled by applying different data confidence criteria and selecting compounds with activity histories over many years. On the basis of release dates, compounds and activity records were organized on a time course, which ultimately enabled monitoring data growth and promiscuity progression over nearly 40 years, beginning in 1976. Surprisingly low degrees of promiscuity were consistently detected for all compound sets and there were only small increases in promiscuity over time. In fact, most compounds had a constant degree of promiscuity, including compounds with an activity history of 10 or 20 years. Moreover, during periods of massive data growth, beginning in 2007, promiscuity degrees also remained constant or displayed only minor increases, depending on the activity data confidence levels. Considering high-confidence data, bioactive compounds currently interact with 1.5 targets on average, regardless of their origins, and display essentially constant degrees of promiscuity over time. Taken together, our findings provide expectation values for promiscuity progression and magnitudes among bioactive compounds as activity data further grow.

  1. New permanent magnets; manganese compounds.

    Science.gov (United States)

    Coey, J M D

    2014-02-12

    The exponential growth of maximum energy product that prevailed in the 20th century has stalled, leaving a market dominated by two permanent magnet materials, Nd2Fe14B and Ba(Sr)Fe12O19, for which the maximum theoretical energy products differ by an order of magnitude (515 kJ m(-3) and 45 kJ m(-3), respectively). Rather than seeking to improve on optimized Nd-Fe-B, it is suggested that some research efforts should be devoted to developing appropriately priced alternatives with energy products in the range 100-300 kJ m(-3). The prospects for Mn-based hard magnetic materials are discussed, based on known Mn-based compounds with the tetragonal L10 or D022 structure or the hexagonal B81 structure.

  2. Antimicrobial compounds from Alpinia conchigera.

    Science.gov (United States)

    Aziz, Ahmad Nazif; Ibrahim, Halijah; Rosmy Syamsir, Devi; Mohtar, Mastura; Vejayan, Jaya; Awang, Khalijah

    2013-02-13

    The rhizome of Alpinia conchigerahas been used as a condiment in the northern states of Peninsular Malaysia and occasionally in folk medicine in the east coast to treat fungal infections. In some states of Peninsular Malaysia, the rhizomes are consumed as a post-partum medicine and the young shoots are prepared into a vegetable dish. This study aimed to investigate the chemical constituents of the pseudostems and rhizomes of Malaysian Alpinia conchigera and to evaluate the antimicrobial activity of the dichloromethane (DCM) extracts of the pseudostems, rhizomes and the isolated compounds against three selected fungi and five strains of Staphylococcus aureus. The dried and ground pseudostems (0.8kg) and rhizomes (1.0kg) were successively extracted in Soxhlet extractor using n-hexane, dichloromethane (DCM) and methanol. The n-hexane and DCM extracts of the pseudostem and rhizome were subjected to isolation and purification using column chromatography on silica gel using a stepwise gradient system (n-hexane to methanol). Briefly, a serial two fold dilutions of the test materials dissolved in DMSO were prepared prior to addition of 100μl overnight microbial suspension (108 cfu/ml) followed by incubation at 37°C (bacteria) or 26°C (dermatophytes and candida) for 24h. The highest concentration of DMSO remaining after dilution (5%, v/v) caused no inhibition to bacterial/candida/dermatophytes' growth. Antibiotic cycloheximide was used as reference for anticandidal and antidermatophyte comparison while oxacilin was used as reference for antibacterial testing. DMSO served as negative control. Turbidity was taken as indication of growth, thus the lowest concentration which remains clear after macroscopic evaluation was taken as the minimum inhibitory concentration (MIC). The isolation of n-hexane and DCM extracts of the rhizomes and pseudostems of Alpinia conchigera via column chromatography yielded two triterpenes isolated as a mixture of stigmasterol and

  3. Zirconium Compound with Boundless Prospects

    Institute of Scientific and Technical Information of China (English)

    LUO FangCheng; ZHENG JingYi; LV WenGuang; CHEN ZhongXi; WU FengFeng

    2001-01-01

    @@ Zirconium compound has a wide-ranging use in the field of high and new technology. It is published in 2000'CHINA HIGH AND NEW TECHNOLOGY PRODUCT CATALOGUE , CHINA HIGH and NEW TECHNOLOGY PRODUCT EXPORT CATALOGUE, and INTERNATIONAL KEY AND URGING DEVELOPMENT CATALOGUE OF PROPERTY, COMMODITY AND TECHNOLNGY Zirconia with the characteristic of electricity, magnetism, optics and mechanies, has good advantageous in making configurable ceramic and functional ceramic, such as band filter, resonator, buzzer and other electronic elements; optical lens, upholster crystallize glasses and other glass; synthetic tooth, synthetic bones and other biological ceramic products; new type axletree, engine, valve, airproof loop and other components of internal-combustion engine and steamship; ferrozirconium and other high temperature ceramic paint. It become a new material which has a wide-ranging use in the field of electron, spaceflight, aerospace, metallurgy, chemistry, biology, medicine and etc.

  4. Zirconium Compound with Boundless Prospects

    Institute of Scientific and Technical Information of China (English)

    LUO; FangCheng

    2001-01-01

    Zirconium compound has a wide-ranging use in the field of high and new technology. It is published in 2000'CHINA HIGH AND NEW TECHNOLOGY PRODUCT CATALOGUE , CHINA HIGH and NEW TECHNOLOGY PRODUCT EXPORT CATALOGUE, and INTERNATIONAL KEY AND URGING DEVELOPMENT CATALOGUE OF PROPERTY, COMMODITY AND TECHNOLNGY Zirconia with the characteristic of electricity, magnetism, optics and mechanies, has good advantageous in making configurable ceramic and functional ceramic, such as band filter, resonator, buzzer and other electronic elements; optical lens, upholster crystallize glasses and other glass; synthetic tooth, synthetic bones and other biological ceramic products; new type axletree, engine, valve, airproof loop and other components of internal-combustion engine and steamship; ferrozirconium and other high temperature ceramic paint. It become a new material which has a wide-ranging use in the field of electron, spaceflight, aerospace, metallurgy, chemistry, biology, medicine and etc.  ……

  5. Organic compounds in carbonaceous meteorites.

    Science.gov (United States)

    Sephton, Mark A

    2002-06-01

    The carbonaceous chondrite meteorites are fragments of asteroids that have remained relatively unprocessed since the formation of the solar system 4.6 billion years ago. These carbon-rich objects contain a variety of extraterrestrial organic molecules that constitute a record of chemical evolution prior to the origin of life. Compound classes include aliphatic hydrocarbons, aromatic hydrocarbons, amino acids, carboxylic acids, sulfonic acids, phosphonic acids, alcohols, aldehydes, ketones, sugars, amines, amides, nitrogen heterocycles, sulfur heterocycles and a relatively abundant high molecular weight macromolecular material. Structural and stable isotopic characteristics suggest that a number of environments may have contributed to the organic inventory, including interstellar space, the solar nebula and the asteroidal meteorite parent body. This review covers work published between 1950 and the present day and cites 193 references.

  6. The formation of lithium diarylargentates from arylsilver compounds and the corresponding aryllithium compounds

    NARCIS (Netherlands)

    Blenkers, J.; Hofstee, H.K.; Boersma, J.; Kerk, G.J.M. van der

    1979-01-01

    Diarylsilverlithium compounds of the type Ar2AgLi are formed by treating arylsilver compounds with the corresponding aryllithium compounds. Cryoscopy in benzene shows that the Ar2AgLi compounds are associated into dimers. NMR spectroscopic data indicate that only one type of aryl group is present in

  7. High-Strength, Superelastic Compounds

    Science.gov (United States)

    Stanford, Malcolm; Noebe, Ronald; Dellacorte, Christopher; Bigelow, Glen; Thomas, Fransua

    2013-01-01

    In a previous disclosure, the use of 60- NiTiNOL, an ordered intermetallic compound composed of 60 weight percent nickel and 40 weight percent titanium, was investigated as a material for advanced aerospace bearings due to its unique combination of physical properties. Lessons learned during the development of applications for this material have led to the discovery that, with the addition of a ternary element, the resulting material can be thermally processed at a lower temperature to attain the same desirable hardness level as the original material. Processing at a lower temperature is beneficial, not only because it reduces processing costs from energy consumption, but because it also significantly reduces the possibility of quench cracking and thermal distortion, which have been problematic with the original material. A family of ternary substitutions has been identified, including Hf and Zr in various atomic percentages with varying concentrations of Ni and Ti. In the present innovation, a ternary intermetallic compound consisting of 57.6 weight percent Ni, 39.2 weight percent Ti, and 3.2 weight percent Hf (54Ni-45Ti-1Hf atomic percent) was prepared by casting. In this material, Hf substitutes for some of the Ti atoms in the material. In an alternate embodiment of the innovation, Zr, which is close in chemical behavior to Hf, is used as the substitutional element. With either substitution, the solvus temperature of the material is reduced, and lower temperatures can be used to obtain the necessary hardness values. The advantages of this innovation include the ability to solution-treat the material at a lower temperature and still achieve the required hardness for bearings (at least 50 Rockwell C) and superelastic behavior with recoverable strains greater than 2%. Most structural alloys will not return to their original shape after being deformed as little as 0.2% (a tenth of that possible with superelastic materials like 60 NiTiNOL). Because lower temperatures

  8. Compound cryopump for fusion reactors

    CERN Document Server

    Kovari, M; Shephard, T

    2013-01-01

    We reconsider an old idea: a three-stage compound cryopump for use in fusion reactors such as DEMO. The helium "ash" is adsorbed on a 4.5 K charcoal-coated surface, while deuterium and tritium are adsorbed at 15-22 K on a second charcoal-coated surface. The helium is released by raising the first surface to ~30 K. In a separate regeneration step, deuterium and tritium are released at ~110 K. In this way, the helium can be pre-separated from other species. In the simplest design, all three stages are in the same vessel, with a single valve to close the pump off from the tokamak during regeneration. In an alternative design, the three stages are in separate vessels, connected by valves, allowing the stages to regenerate without interfering with each other. The inclusion of the intermediate stage would not affect the overall pumping speed significantly. The downstream exhaust processing system could be scaled down, as much of the deuterium and tritium could be returned directly to the reactor. This could reduce ...

  9. Insecticidal Activity of Cyanohydrin and Monoterpenoid Compounds

    Directory of Open Access Journals (Sweden)

    Joel R. Coats

    2000-04-01

    Full Text Available The insecticidal activities of several cyanohydrins, cyanohydrin esters and monoterpenoid esters (including three monoterpenoid esters of a cyanohydrin were evaluated. Topical toxicity to Musca domestica L. adults was examined, and testing of many compounds at 100 mg/fly resulted in 100% mortality. Topical LD50 values of four compounds for M. domestica were calculated. Testing of many of the reported compounds to brine shrimp (Artemia franciscana Kellog resulted in 100% mortality at 10 ppm, and two compounds caused 100% mortality at 1 ppm. Aquatic LC50 values were calculated for five compounds for larvae of the yellow fever mosquito (Aedes aegypti (L.. Monoterpenoid esters were among the most toxic compounds tested in topical and aquatic bioassays.

  10. Organic electronic devices using phthalimide compounds

    Science.gov (United States)

    Hassan, Azad M.; Thompson, Mark E.

    2010-09-07

    Organic electronic devices comprising a phthalimide compound. The phthalimide compounds disclosed herein are electron transporters with large HOMO-LUMO gaps, high triplet energies, large reduction potentials, and/or thermal and chemical stability. As such, these phthalimide compounds are suitable for use in any of various organic electronic devices, such as OLEDs and solar cells. In an OLED, the phthalimide compounds may serve various functions, such as a host in the emissive layer, as a hole blocking material, or as an electron transport material. In a solar cell, the phthalimide compounds may serve various functions, such as an exciton blocking material. Various examples of phthalimide compounds which may be suitable for use in the present invention are disclosed.

  11. Antibacterial and antifungal compounds from marine fungi.

    Science.gov (United States)

    Xu, Lijian; Meng, Wei; Cao, Cong; Wang, Jian; Shan, Wenjun; Wang, Qinggui

    2015-06-02

    This paper reviews 116 new compounds with antifungal or antibacterial activities as well as 169 other known antimicrobial compounds, with a specific focus on January 2010 through March 2015. Furthermore, the phylogeny of the fungi producing these antibacterial or antifungal compounds was analyzed. The new methods used to isolate marine fungi that possess antibacterial or antifungal activities as well as the relationship between structure and activity are shown in this review.

  12. Antibacterial and Antifungal Compounds from Marine Fungi

    OpenAIRE

    Lijian Xu; Wei Meng; Cong Cao; Jian Wang; Wenjun Shan; Qinggui Wang

    2015-01-01

    This paper reviews 116 new compounds with antifungal or antibacterial activities as well as 169 other known antimicrobial compounds, with a specific focus on January 2010 through March 2015. Furthermore, the phylogeny of the fungi producing these antibacterial or antifungal compounds was analyzed. The new methods used to isolate marine fungi that possess antibacterial or antifungal activities as well as the relationship between structure and activity are shown in this review.

  13. High performance compound semiconductor SPAD arrays

    Science.gov (United States)

    Harmon, Eric S.; Naydenkov, Mikhail; Bowling, Jared

    2016-05-01

    Aggregated compound semiconductor single photon avalanche diode (SPAD) arrays are emerging as a viable alternative to the silicon photomultiplier (SiPM). Compound semiconductors have the potential to surpass SiPM performance, potentially achieving orders of magnitude lower dark count rates and improved radiation hardness. New planar processing techniques have been developed to enable compound semiconductor SPAD devices to be produced with pixel pitches of 11 - 25 microns, with thousands of SPADs per array.

  14. Automated compound classification using a chemical ontology

    Directory of Open Access Journals (Sweden)

    Bobach Claudia

    2012-12-01

    Full Text Available Abstract Background Classification of chemical compounds into compound classes by using structure derived descriptors is a well-established method to aid the evaluation and abstraction of compound properties in chemical compound databases. MeSH and recently ChEBI are examples of chemical ontologies that provide a hierarchical classification of compounds into general compound classes of biological interest based on their structural as well as property or use features. In these ontologies, compounds have been assigned manually to their respective classes. However, with the ever increasing possibilities to extract new compounds from text documents using name-to-structure tools and considering the large number of compounds deposited in databases, automated and comprehensive chemical classification methods are needed to avoid the error prone and time consuming manual classification of compounds. Results In the present work we implement principles and methods to construct a chemical ontology of classes that shall support the automated, high-quality compound classification in chemical databases or text documents. While SMARTS expressions have already been used to define chemical structure class concepts, in the present work we have extended the expressive power of such class definitions by expanding their structure-based reasoning logic. Thus, to achieve the required precision and granularity of chemical class definitions, sets of SMARTS class definitions are connected by OR and NOT logical operators. In addition, AND logic has been implemented to allow the concomitant use of flexible atom lists and stereochemistry definitions. The resulting chemical ontology is a multi-hierarchical taxonomy of concept nodes connected by directed, transitive relationships. Conclusions A proposal for a rule based definition of chemical classes has been made that allows to define chemical compound classes more precisely than before. The proposed structure-based reasoning

  15. Integrated modelling of two xenobiotic organic compounds

    DEFF Research Database (Denmark)

    Lindblom, Erik Ulfson; Gernaey, K.V.; Henze, Mogens

    2006-01-01

    compounds, is carried out. Sorption and specific biological degradation processes are integrated with standardised water process models to model the fate of both compounds. Simulated mass flows of the two compounds during one dry weather day and one wet weather day are compared for realistic influent flow...... rate and concentration profiles. The wet weather day induces resuspension of stored sediments, which increases the pollutant load on the downstream system. The potential of the model to elucidate important phenomena related to origin and fate of the model compounds is demonstrated....

  16. Hydrodesulfurization catalysis by Chevrel phase compounds

    Science.gov (United States)

    McCarty, Kevin F.; Schrader, Glenn L.

    1985-12-24

    A process is disclosed for the hydrodesulfurization of sulfur-containing hydrocarbon fuel with reduced ternary molybdenum sulfides, known as Chevrel phase compounds. Chevrel phase compounds of the general composition M.sub.x Mo.sub.6 S.sub.8, with M being Ho, Pb, Sn, Ag, In, Cu, Fe, Ni, or Co, were found to have hydrodesulfurization activities comparable to model unpromoted and cobalt-promoted MoS.sub.2 catalysts. The most active catalysts were the "large" cation compounds (Ho, Pb, Sn), and the least active catalysts were the "small" cation compounds (Cu, Fe, Ni, Co.).

  17. Electronic structure and magnetism in actinide compounds

    Energy Technology Data Exchange (ETDEWEB)

    Durakiewicz, T. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)]. E-mail: tomasz@lanl.gov; Joyce, J.J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Lander, G.H. [JRC, Institute of Transuranium Elements, Postfach 2340, 76125 Karlsruhe (Germany); Olson, C.G. [Ames Laboratory, Iowa State University, Ames, Iowa 5011 (United States); Butterfield, M.T. [Lawrence Livermoore National Laboratory, Livermoore, CA 94550 (United States); Guziewicz, E. [Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw (Poland); Batista, C.D. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Arko, A.J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Morales, L. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Mattenberger, K. [Laboratorium fur Festkorperphysik, ETH, CH-8093, Zurich (Switzerland); Vogt, O. [Laboratorium fur Festkorperphysik, ETH, CH-8093, Zurich (Switzerland)

    2006-05-01

    A close relationship between electronic structure and magnetic properties is observed in actinide compounds. The exact nature of this relationship is under investigation. We present examples of a direct link between electronic structure and ordered magnetic moment and/or magnetization. Specifically, results obtained for cubic U, Np and Pu compounds and quasi-2D U compounds are be presented. In the case of cubic compounds, a direct relationship between binding energy of valence band features and magnetic moment will be discussed. A Stoner-like mechanism and simple mean-field explanation is proposed for ferromagnetic UTe.

  18. Antimicrobial Action of Compounds from Marine Seaweed

    Directory of Open Access Journals (Sweden)

    María José Pérez

    2016-03-01

    Full Text Available Seaweed produces metabolites aiding in the protection against different environmental stresses. These compounds show antiviral, antiprotozoal, antifungal, and antibacterial properties. Macroalgae can be cultured in high volumes and would represent an attractive source of potential compounds useful for unconventional drugs able to control new diseases or multiresistant strains of pathogenic microorganisms. The substances isolated from green, brown and red algae showing potent antimicrobial activity belong to polysaccharides, fatty acids, phlorotannins, pigments, lectins, alkaloids, terpenoids and halogenated compounds. This review presents the major compounds found in macroalga showing antimicrobial activities and their most promising applications.

  19. CHARACTERIZATION OF RUTIN-CYCLODEXTRIN INCLUSION COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Andreia Corciovă

    2011-12-01

    Full Text Available The objectives of this study were to examine the potential of beta-cyclodextrin to improve the solubility of rutin and obtain inclusion compounds that were analyzed by different techniques: UV-Vis, IR spectroscopy, thermal analysis. The presence of β-cyclodextrin raises the content of rutin in water. The inclusion compounds were prepared by dry mixing, complexation in semisolid and liquid medium in 1:2 molar ratio rutin - β-cyclodextrin. The UV-Vis and IR analysis demonstrated the obtaining of inclusion compounds and the thermal analysis show that these compounds are more stable than the parent substance.

  20. Potent antifouling compounds produced by marine Streptomyces

    KAUST Repository

    Xu, Ying

    2010-02-01

    Biofouling causes huge economic loss and a recent global ban on organotin compounds as antifouling agents has increased the need for safe and effective antifouling compounds. Five structurally similar compounds were isolated from the crude extract of a marine Streptomyces strain obtained from deep-sea sediments. Antifouling activities of these five compounds and four other structurally-related compounds isolated from a North Sea Streptomyces strain against major fouling organisms were compared to probe structure-activity relationships of compounds. The functional moiety responsible for antifouling activity lies in the 2-furanone ring and that the lipophilicity of compounds substantially affects their antifouling activities. Based on these findings, a compound with a straight alkyl side-chain was synthesized and proved itself as a very effective non-toxic, anti-larval settlement agent against three major fouling organisms. The strong antifouling activity, relatively low toxicity, and simple structures of these compounds make them promising candidates for new antifouling additives. © 2009 Elsevier Ltd. All rights reserved.

  1. Investigations on organogermanium compounds XII. Reactions of trialkylgermylalkalimetal compounds in hexamethylphosphoric triamide (HMPT) with some inorganic and organic compounds

    NARCIS (Netherlands)

    Bulten, E.J.; Noltes, J.G.

    1971-01-01

    Trialkylgermyl alkali metal compounds in HMPT have been found to be highly reactive nucleophiles. Reactions with some inorganic and organic compounds, such as oxygen, carbon dioxide, inorganic and orgaanic halides, aldehydes, ketones, epoxides and lactones are described. Several new carbon-functiona

  2. Prioritizing pesticide compounds for analytical methods development

    Science.gov (United States)

    Norman, Julia E.; Kuivila, Kathryn; Nowell, Lisa H.

    2012-01-01

    The U.S. Geological Survey (USGS) has a periodic need to re-evaluate pesticide compounds in terms of priorities for inclusion in monitoring and studies and, thus, must also assess the current analytical capabilities for pesticide detection. To meet this need, a strategy has been developed to prioritize pesticides and degradates for analytical methods development. Screening procedures were developed to separately prioritize pesticide compounds in water and sediment. The procedures evaluate pesticide compounds in existing USGS analytical methods for water and sediment and compounds for which recent agricultural-use information was available. Measured occurrence (detection frequency and concentrations) in water and sediment, predicted concentrations in water and predicted likelihood of occurrence in sediment, potential toxicity to aquatic life or humans, and priorities of other agencies or organizations, regulatory or otherwise, were considered. Several existing strategies for prioritizing chemicals for various purposes were reviewed, including those that identify and prioritize persistent, bioaccumulative, and toxic compounds, and those that determine candidates for future regulation of drinking-water contaminants. The systematic procedures developed and used in this study rely on concepts common to many previously established strategies. The evaluation of pesticide compounds resulted in the classification of compounds into three groups: Tier 1 for high priority compounds, Tier 2 for moderate priority compounds, and Tier 3 for low priority compounds. For water, a total of 247 pesticide compounds were classified as Tier 1 and, thus, are high priority for inclusion in analytical methods for monitoring and studies. Of these, about three-quarters are included in some USGS analytical method; however, many of these compounds are included on research methods that are expensive and for which there are few data on environmental samples. The remaining quarter of Tier 1

  3. Dysprosium-free melt-spun permanent magnets.

    Science.gov (United States)

    Brown, D N; Wu, Z; He, F; Miller, D J; Herchenroeder, J W

    2014-02-12

    Melt-spun NdFeB powders can be formed into a number of different types of permanent magnet for a variety of applications in electronics, automotive and clean technology industries. The melt-spinning process produces flake powder with a fine uniform array of nanoscale Nd2Fe14B grains. These powders can be net-shape formed into isotropic polymer-bonded magnets or hot formed into fully dense magnets. This paper discusses the influence of heavy rare earth elements and microstructure on the magnetic performance, thermal stability and material cost of NdFeB magnets. Evidence indicates that melt-spun nanocrystalline NdFeB magnets are less dependent on heavy rare earth elements for high-temperature performance than the alternative coarser-grained sintered NdFeB magnets. In particular, hot-pressed melt-spun magnets are an attractive low-cost solution for applications that require thermal stability up to 175-200 °C.

  4. Structural and magnetic study of dysprosium substituted cobalt ferrite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Hemaunt, E-mail: hvatsal@gmail.com [Department of Physics, Govind Ballabh Pant University of Agr. & Technology, Pantnagar, Uttarakhand 263145 (India); Srivastava, R.C. [Department of Physics, Govind Ballabh Pant University of Agr. & Technology, Pantnagar, Uttarakhand 263145 (India); Pal Singh, Jitendra [Advanced Analysis Centre, Korea Institute of Science and Technology, Seoul 02792 (Korea, Republic of); Negi, P. [Department of Physics, Govind Ballabh Pant University of Agr. & Technology, Pantnagar, Uttarakhand 263145 (India); Agrawal, H.M. [Advanced Analysis Centre, Korea Institute of Science and Technology, Seoul 02792 (Korea, Republic of); Das, D. [UGC-DAE CSR Kolkata Centre, Kolkata 700098 (India); Hwa Chae, Keun [Advanced Analysis Centre, Korea Institute of Science and Technology, Seoul 02792 (Korea, Republic of)

    2016-03-01

    The present work investigates the magnetic behavior of Dy{sup 3+} substituted cobalt ferrite nanoparticles. X-ray diffraction studies reveal presence of cubic spinel phases in these nanoparticles. Raman spectra of these nanoparticles show change in intensity of Raman bands, which reflects cation redistribution in cubic spinel lattice. Saturation magnetization and coercivity decrease with increase of Dy{sup 3+}concentration in these nanoparticles. Room temperature Mössbauer measurements show the cation redistribution in these nanoparticles and corroborates the results obtained from Raman Spectroscopic measurements. Decrease in magnetization of Dy{sup 3+} substituted cobalt ferrite is attributed to the reduction in the magnetic interaction and cation redistribution. - Highlights: • Slight decrease in crystallite size after Dy{sup 3+} doping. • Saturation magnetization and coercivity decrease after Dy{sup 3+} doping. • Mössbauer measurements show the cation redistribution in the samples.

  5. Dysprosium Acetylacetonato Single-Molecule Magnet Encapsulated in Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Ryo Nakanishi

    2016-12-01

    Full Text Available Dy single-molecule magnets (SMMs, which have several potential uses in a variety of applications, such as quantum computing, were encapsulated in multi-walled carbon nanotubes (MWCNTs by using a capillary method. Encapsulation was confirmed by using transmission electron microscopy (TEM. In alternating current magnetic measurements, the magnetic susceptibilities of the Dy acetylacetonato complexes showed clear frequency dependence even inside the MWCNTs, meaning that this hybrid can be used as magnetic materials in devices.

  6. Microscopic study of neutron-rich dysprosium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, Carlos E. [Universidad Veracruzana, Facultad de Fisica e Inteligencia Artificial, Xalapa (Mexico); Universidad Nacional Autonoma de Mexico, Facultad de Ciencias, Apartado Postal 70-542, Mexico D.F. (Mexico); Velazquez, Victor [Universidad Nacional Autonoma de Mexico, Facultad de Ciencias, Apartado Postal 70-542, Mexico D.F. (Mexico); Lerma, Sergio [Universidad Veracruzana, Facultad de Fisica e Inteligencia Artificial, Xalapa (Mexico)

    2013-01-15

    Microscopic studies in heavy nuclei are very scarce due to large valence spaces involved. This computational problem can be avoided by means of the use of symmetry-based models. Ground-state, {gamma} and {beta} bands, and their B(E2) transition strengths in {sup 160-168}Dy isotopes, are studied in the framework of the pseudo-SU(3) model which includes the preserving symmetry Q . Q term and the symmetry-breaking Nilsson and pairing terms, systematically parametrized. Additionally, three rotor-like terms are considered, whose free parameters, fixed for all members of the chain, are used to fine tune the moment of inertia of rotational bands and the band head of {gamma} and {beta} bands. The model succesfully describes in a systematic way rotational features in these nuclei and allows to extrapolate toward the midshell nucleus {sup 170}Dy. The results presented show that it is possible to study a full chain of isotopes or isotones in the region with the present model. (orig.)

  7. Photodissociation spectroscopy of the dysprosium monochloride molecular ion

    CERN Document Server

    Dunning, Alexander; Showalter, Steven J; Puri, Prateek; Kotochigova, Svetlana; Hudson, Eric R

    2015-01-01

    We have performed a combined experimental and theoretical study of the photodissociation cross section of the molecular ion DyCl$^+$. The cross section for the photon energy range 35,500 cm$^{-1}$ to 47,500 cm$^{-1}$ is measured using an integrated ion trap and time-of-flight mass spectrometer, and we observe a broad, asymmetric profile that is peaked near 43,000 cm$^{-1}$. The theoretical cross section is determined from electronic potentials and transition dipole moments calculated using the relativistic configuration-interaction valence-bond and coupled-cluster methods. The electronic structure of DyCl$^+$ is unprecedentedly complex due to the presence of multiple open electronic shells, including 4f$^{10}$ orbitals. The molecule has nine attractive potentials with ionically-bonded electrons and 99 repulsive potentials dissociating to a ground state Dy$^+$ ion and Cl atom. We explain the lack of symmetry in the cross section as due to multiple contributions from one-electron-dominated transitions between t...

  8. FTIR and Electrical Study of Dysprosium Doped Cobalt Ferrite Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hemaunt Kumar

    2014-01-01

    Full Text Available We have studied the role of Dy3+ doping on the XRD, TEM, FTIR, and dielectric and electrical properties of CoFe2O4 at room temperature. Cubic spinel phase of CoFe2−xDyxO4 (x = 0.00, 0.05, 0.10, and 0.15 was synthesized by using different sintering temperatures (300, 500, 700, and 900°C. The two absorption bands ν1 and ν2 are observed in Fourier transform infrared spectroscopy (FTIR spectra corresponding to the tetrahedral and octahedral sites, which show signature of spinel structure of the sample. For the sample sintered at 300°C, the dielectric constant is almost unchanged with the frequency at the particular concentrations of x = 0.00 and 0.05. Similar result is obtained for the sample sintered at 500°C (x = 0.10, 0.15, 700°C (x = 0.05, 0.10, and 0.15, and 900°C (x = 0.05, 0.10. An increase in the dielectric constant was observed for the undoped cobalt ferrite sintered at 500, 700, and 900°C. The values of electrical resistivity of the materials vary from ~105 to 109 Ω-cm.

  9. Adsorption of D113 Resin for Dysprosium(Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The adsorption behavior and mechanism of D113 resin for Dy(Ⅲ) was investigated by using the method of resin adsorption. Experimental results show that the optimum medium pH of adsorption of D113 resin for Dy3+ is pH=6.00 in the HAc-NaAc medium. The static adsorption capacity of D113 resin for Dy3+chemical analysis and IR spectra.

  10. 1300-nm gain obtained with dysprosium-doped chloride crystals

    Energy Technology Data Exchange (ETDEWEB)

    Page, R.H.; Schaffers, K.I.; Beach, R.J.; Payne, S.A.; Krupke, W.F.

    1996-03-01

    Dy{sup 3+} - doped chloride crystals have high 1300-nm emission quantum yields. Pump - probe experiments on La Cl{sub 3}:Dy{sup 3+} demonstrate optical gain consistent with predictions based on spectroscopic cross sections and lifetimes.

  11. Microscopic study of neutron-rich Dysprosium isotopes

    CERN Document Server

    Vargas, Carlos E; Lerma, Sergio; 10.1140/epja/i2013-13004-1

    2013-01-01

    Microscopic studies in heavy nuclei are very scarce due to large valence spaces involved. This computational problem can be avoided by means of the use of symmetry based models. Ground-state, gamma and beta-bands, and their B(E2) transition strengths in 160-168Dy isotopes, are studied in the framework of the pseudo-SU(3) model which includes the preserving symmetry Q.Q term and the symmetry-breaking Nilsson and pairing terms, systematically parametrized. Additionally, three rotor-like terms are considered whose free parameters, fixed for all members of the chain are used to fine tune the moment of inertia of rotational bands and the band-head of gamma and beta-bands. The model succesfully describes in a systematic way rotational features in these nuclei and allows to extrapolate toward the midshell nucleus 170Dy. The results presented show that it is possible to study full chain of isotopes or isotones in the region with the present model.

  12. Visible luminescence of dysprosium ions in oxyhalide lead borate glasses

    Science.gov (United States)

    Pisarska, Joanna; Żur, Lidia; Pisarski, Wojciech A.

    2011-08-01

    Visible luminescence of Dy 3+ ions in oxyhalide lead borate glasses was examined. Luminescence spectra show two intense bands at 480 nm and 573 nm due to 4F 9/2 → 6H 15/2 (blue) and 4F 9/2 → 6H 13/2 (yellow) transitions of Dy 3+. Luminescence decays from 4F 9/2 state and yellow-to-blue luminescence intensity ratios (Y/B) were analysed with PbX 2 (X = F, Cl) content. An introduction of PbX 2 to the borate glass results in the increasing of 4F 9/2 lifetime and the decreasing of yellow-to-blue luminescence intensity ratio, which is due to reduction of covalency between Dy 3+ and O 2-/X - ions.

  13. MAGNETIC FIELD INDUCED FIRST-ORDER TRANSITIONS IN DYSPROSIUM ORTHOFERRITE

    OpenAIRE

    Eremenko, V.; Gnatchenko, S.; Kharchenko, N.; Lebedev, P.; Piotrowski, K; Szymczak, H.; Szymczak, R.

    1988-01-01

    New type of magnetic first-order phase transition induced by external magnetic field applied in the ab-plane in DyFeO3 is investigated using different magnetooptic techniques. The phenomenological model of this transition is proposed. The phase diagram in H-T plane has been obtained for various H orientation in the ab-plane.

  14. Platinum compounds with anti-tumour activity

    NARCIS (Netherlands)

    Plooy, A.C.M.; Lohman, P.H.M.

    1980-01-01

    Ten platinum (Pt) coordination complexes with different ligands, comprising both Pt(II) and Pt(IV) complexes of which the cis-compounds all possessed at least some anti-tumour activity and the trans-compounds were inactive, were tested as to their effect on cell survival and the induction and repair

  15. Ambient Air Monitoring for Sulfur Compounds

    Science.gov (United States)

    Forrest, Joseph; Newman, Leonard

    1973-01-01

    A literature review of analytical techniques available for the study of compounds at low concentrations points up some of the areas where further research is needed. Compounds reviewed are sulfur dioxide, sulfuric acid, ammonium sulfate and bisulfate, metal sulfates, hydrogen sulfide, and organic sulfides. (BL)

  16. Two new compounds from Ganoderma lucidum.

    Science.gov (United States)

    Wang, Xin-Fang; Yan, Yong-Ming; Wang, Xin-Long; Ma, Xiu-Jing; Fu, Xue-Yan; Cheng, Yong-Xian

    2015-01-01

    Two pairs of new enantiomers, lucidulactones A and B (1 and 2), and two known compounds were isolated from Ganoderma lucidum. Their structures were determined by means of spectroscopic methods. The chiral HPLC was used to separate the ( - )- and (+)-antipodes of the new compounds.

  17. Volatile organic compound emissions from silage systems

    Science.gov (United States)

    As a precursor to smog, emission of volatile organic compounds (VOCs) to the atmosphere is an environmental concern in some regions. The major source from farms is silage, with emissions coming from the silo face, mixing wagon, and feed bunk. The major compounds emitted are alcohols with other impor...

  18. The mechanocaloric potential of spin crossover compounds

    OpenAIRE

    Sandeman, K. G.

    2016-01-01

    We present a first evaluation of the potential for spin crossover (SCO) compounds to be considered as a new class of giant mechanocaloric effect material. From literature data on the variation of the spin crossover temperature with pressure, we estimate the maximum available adiabatic temperature change for several compounds and the relatively low pressures that may be required to observe these effects.

  19. Hybrid Compounding in New Zealand English

    Science.gov (United States)

    Degani, Marta; Onysko, Alexander

    2010-01-01

    This study investigates hybrid compound formation of Maori and English terms in present day New Zealand English (NZE). On the background of Maori and English language contact, the phenomenon of hybrid compounding emerges as a process that, on the one hand, symbolizes the vitality of the Maori element in NZE and, on the other hand, marks the…

  20. Compounds from the roots of Jasminum sambac.

    Science.gov (United States)

    Zeng, Lin-Hong; Hu, Min; Yan, Yong-Ming; Lu, Qing; Cheng, Yong-Xian

    2012-01-01

    Four new compounds (+)-jasminoids A, B, C, and D, together with seven known compounds, were isolated from the roots of Jasminum sambac. Their structures were identified using spectroscopic methods. This study provides a better understanding to the chemical composition of J. sambac roots that have been thought to be one ingredient of an ancient prescription 'Ma-Fei-San'.

  1. Bioactive compounds in whole grain wheat

    NARCIS (Netherlands)

    Mateo Anson, N.

    2010-01-01

    Bread can be healthier! Consuming whole-grain foods can prevent cardiovascular diseases, type-2 diabetes and metabolic syndrome. This is due to bioactive compounds in whole grain, such as antioxidants and anti-inflammatory compounds. We found that the different fractions of a wheat grain vary much

  2. Heterogeneous photocatalytic reactions of sulfur aromatic compounds.

    Science.gov (United States)

    Samokhvalov, Alexander

    2011-11-18

    Sulfur aromatic compounds, such as mono-, di-, tri-, and tetraalkyl-substituted thiophene, benzothiophenes, dibenzothiophenes, are the molecular components of many fossils (petroleum, oil shale, tar sands, bitumen). Structural units of natural, cross-linked heteroaromatic polymers present in brown coals, turf, and soil are similar to those of sulfur aromatic compounds. Many sulfur aromatic compounds are found in the streams of petroleum refining and upgrading (naphthas, gas oils) and in the consumer products (gasoline, diesel, jet fuels, heating fuels). Besides fossils, the structural fragments of sulfur aromatic compounds are present in molecules of certain organic semiconductors, pesticides, small molecule drugs, and in certain biomolecules present in human body (pheomelanin pigments). Photocatalysis is the frontier area of physical chemistry that studies chemical reactions initiated by absorption of photons by photocatalysts, that is, upon electronic rather than thermal activation, under "green" ambient conditions. This review provides systematization and critical review of the fundamental chemical and physicochemical information on heterogeneous photocatalysis of sulfur aromatic compounds accumulated in the last 20-30 years. Specifically, the following topics are covered: physicochemical properties of sulfur aromatic compounds, major classes of heterogeneous photocatalysts, mechanisms and reactive intermediates of photocatalytic reactions of sulfur aromatic compounds, and the selectivity of these reactions. Quantum chemical calculations of properties and structures of sulfur aromatic compounds, their reactive intermediates, and the structure of adsorption complexes formed on the surface of the photocatalysts are also discussed.

  3. Bioactive compounds in whole grain wheat

    NARCIS (Netherlands)

    Mateo Anson, N.

    2010-01-01

    Bread can be healthier! Consuming whole-grain foods can prevent cardiovascular diseases, type-2 diabetes and metabolic syndrome. This is due to bioactive compounds in whole grain, such as antioxidants and anti-inflammatory compounds. We found that the different fractions of a wheat grain vary much i

  4. Exploring marine resources for bioactive compounds.

    Science.gov (United States)

    Kiuru, Paula; DʼAuria, M Valeria; Muller, Christian D; Tammela, Päivi; Vuorela, Heikki; Yli-Kauhaluoma, Jari

    2014-09-01

    Biodiversity in the seas is only partly explored, although marine organisms are excellent sources for many industrial products. Through close co-operation between industrial and academic partners, it is possible to successfully collect, isolate and classify marine organisms, such as bacteria, fungi, micro- and macroalgae, cyanobacteria, and marine invertebrates from the oceans and seas globally. Extracts and purified compounds of these organisms can be studied for several therapeutically and industrially significant biological activities, including anticancer, anti-inflammatory, antiviral, antibacterial, and anticoagulant activities by applying a wide variety of screening tools, as well as for ion channel/receptor modulation and plant growth regulation. Chromatographic isolation of bioactive compounds will be followed by structural determination. Sustainable cultivation methods for promising organisms and biotechnological processes for selected compounds can be developed, as well as biosensors for monitoring the target compounds. The (semi)synthetic modification of marine-based bioactive compounds produces their new derivatives, structural analogs and mimetics that could serve as hit or lead compounds and be used to expand compound libraries based on marine natural products. The research innovations can be targeted for industrial product development in order to improve the growth and productivity of marine biotechnology. Marine research aims at a better understanding of environmentally conscious sourcing of marine biotechnology products and increased public awareness of marine biodiversity. Marine research is expected to offer novel marine-based lead compounds for industries and strengthen their product portfolios related to pharmaceutical, nutraceutical, cosmetic, agrochemical, food processing, material and biosensor applications.

  5. Bioactive compounds in whole grain wheat

    NARCIS (Netherlands)

    Mateo Anson, N.

    2010-01-01

    Bread can be healthier! Consuming whole-grain foods can prevent cardiovascular diseases, type-2 diabetes and metabolic syndrome. This is due to bioactive compounds in whole grain, such as antioxidants and anti-inflammatory compounds. We found that the different fractions of a wheat grain vary much i

  6. Pickpocket compounds from Latin to Romance

    NARCIS (Netherlands)

    Nielsen Whitehead, Benedicte

    2012-01-01

    This thesis discusses the development in Proto–Indo–European, Latin and Romance of a word–formation pattern which the most adequate terminology in use dubs ‘verbal government compounds with a governing first member’; I use the shorthand ‘pickpocket compounds’. The first member of such compounds deri

  7. Preparation of Several Tritiated Macromolecular Compounds

    Institute of Scientific and Technical Information of China (English)

    CHEN; Bao-jun; YU; Ning-wen; FAN; Cai-yun

    2015-01-01

    Tritiated compounds are widely used in drug metabolism and pharmacokinetic studies.They play an important role in new drug research.Isotope exchange method is a very effective method for the preparation of tritiated compounds.It is particularly suitable for labeling macromolecule

  8. Bacterial formation of hydroxylated aromatic compounds.

    NARCIS (Netherlands)

    Tweel, van den W.J.J.

    1988-01-01

    As stated in the introduction of this thesis, hydroxylated aromatic compounds in general are of great importance for various industries as for instance pharmaceutical, agrochemical and petrochemical industries. Since these compounds can not be isolated in sufficient amounts from natural resources, t

  9. Crystal structure analysis of intermetallic compounds

    Science.gov (United States)

    Conner, R. A., Jr.; Downey, J. W.; Dwight, A. E.

    1968-01-01

    Study concerns crystal structures and lattice parameters for a number of new intermetallic compounds. Crystal structure data have been collected on equiatomic compounds, formed between an element of the Sc, Ti, V, or Cr group and an element of the Co or Ni group. The data, obtained by conventional methods, are presented in an easily usable tabular form.

  10. Analysis of phenolic compounds for poultry feeds

    Science.gov (United States)

    Phenolic compounds have generated significant interest recently as feed additives that can impart bioactive characteristics such as anti-oxidant, anti-microbial, and anti-fungal properties to a feed formulation [1-2]. Such natural compounds may offer some preventive benefit to the routine administra...

  11. Amino acid modifiers in guayule rubber compounds

    Science.gov (United States)

    Tire producers are increasingly interested in biobased materials, including rubber but also as compounding chemicals. An alternative natural rubber for tire use is produced by guayule, a woody desert shrub native to North America. Alternative compounding chemicals include naturally-occurring amino a...

  12. Lattice anisotropy in uranium ternary compounds

    DEFF Research Database (Denmark)

    Maskova, S.; Adamska, A.M.; Havela, L.

    2012-01-01

    Several U-based intermetallic compounds (UCoGe, UNiGe with the TiNiSi structure type and UNiAl with the ZrNiAl structure type) and their hydrides were studied from the point of view of compressibility and thermal expansion. Confronted with existing data for the compounds with the ZrNiAl structure...

  13. Semantics vs Pragmatics of a Compound Word

    Science.gov (United States)

    Smirnova, Elena A.; Biktemirova, Ella I.; Davletbaeva, Diana N.

    2016-01-01

    This paper is devoted to the study of correlation between semantic and pragmatic potential of a compound word, which functions in informal speech, and the mechanisms of secondary nomination, which realizes the potential of semantic-pragmatic features of colloquial compounds. The relevance and the choice of the research question is based on the…

  14. Chalcones: compounds possessing a diversity in applications

    OpenAIRE

    2012-01-01

    Chalcones are a class of α, β- unsaturated carbonyl compounds that form the central core for a variety of naturally occurring biologically active compounds. They exhibit tremendous potential to act as a pharmacological agent. Besides their various pharmacological activities, chalcones have been explored for different optical applications including second harmonic generation materials in non- linear optics, fluorescent probe for sensing different molecules.

  15. Bis(1,3-dithiole) Compounds

    DEFF Research Database (Denmark)

    Andersen, Jan Rud; Engler, E. M.; Green, D. C.;

    1977-01-01

    There is described the preparation of bis-1,3-dithiole compounds (I) which are key synthetic precursors for the preparation of new polymeric metal bis(dithiolene) (i.e., II) and tetrathiafulvalene compounds (i.e., III): (Image Omitted)...

  16. Method for the detection of aquaretic compounds

    DEFF Research Database (Denmark)

    2003-01-01

    Disclosed is a method for detecting an aquaretic compound. In one embodiment, the method includes administering to a mammal a candidate compound that modulates a nociceptin receptor. Biological material is isolated from the mammal and expression of aquaporin-2 is measured. Modulation of the aquap......Disclosed is a method for detecting an aquaretic compound. In one embodiment, the method includes administering to a mammal a candidate compound that modulates a nociceptin receptor. Biological material is isolated from the mammal and expression of aquaporin-2 is measured. Modulation...... of the aquaporin-2 is taken to be indicative of a candidate compound having aquaretic activity. The invention has a wide spectrum of uses including helping to identify new diuretics that spare unwanted loss of sodium and potassium ions....

  17. Potent acetylcholinesterase inhibitory compounds from Myristica fragrans.

    Science.gov (United States)

    Cuong, To Dao; Hung, Tran Manh; Han, Hyoung Yun; Roh, Hang Sik; Seok, Ji-Hyeon; Lee, Jong Kwon; Jeong, Ja Young; Choi, Jae Sue; Kim, Jeong Ah; Min, Byung Sun

    2014-04-01

    The anti-cholinesterase activity was evaluated of the ethyl acetate fraction of the methanol extract of Myristica fragrans Houtt (Myristicaceae) seeds and of compounds isolated from it by various chromatographic techniques. The chemical structures of the compounds were determined from spectroscopic analyses (NMR data). Thirteen compounds (1-13) were isolated and identified. Compound 8 { [(7S)-8'-(4'-hydroxy-3'-methoxyphenyl)-7-hydroxypropyl]benzene-2,4-diol) showed the most effective activity with an IC50 value of 35.1 microM, followed by compounds 2 [(8R,8'S)-7'-(3',4'-methylenedioxyphenyl)-8,8'-dimethyl-7-(3,4-dihydroxyphenyl)-butane] and 11 (malabaricone C) with IC50 values of 42.1 and 44.0 pM, respectively. This is the first report of significant anticholinesterase properties of M. fragrans seeds. The findings demonstrate that M. fragrans could be used beneficially in the treatment of Alzheimer's disease.

  18. Depyrogenation options for the compounding cleanroom.

    Science.gov (United States)

    Weller, Tom; Bell, Jeff; Dullinger, Roger; Allen, Vern; Anthenat, Bruce

    2014-01-01

    Compounding pharmacies, especially those awarded 503B status under the U.S. Federal Food, Drug, and Cosmetic Act that resulted from the Drug Quality and Security Act, must meet increasingly strict standards for the preparation of sterile formulations. Depyrogenating the containers and tools used in such compounding is essential to meeting those standards and ensuring patient safety. Although pyrogens are relatively thermally stable, treating aseptic-compounding glassware and implements in a dry-heat oven or tunnel is the most common method of depyrogenation. Depyrogenation tunnels are used at larger facilities in which automation and a higher throughput can justify the cost of that equipment, but a small batch oven is an inexpensive and appropriate solution to meeting sterilization and depyrogenation requirements in a smaller compounding pharmacy. In this article, we discuss the appropriate use of depyrogenation ovens and tunnels, compare those types of equipment, and describe the selection and use of a cleanroom oven in a compounding pharmacy.

  19. Methods of making organic compounds by metathesis

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, Timothy W.; Kaido, Hiroki; Lee, Choon Woo; Pederson, Richard L.; Schrodi, Yann; Tupy, Michael John

    2015-09-01

    Described are methods of making organic compounds by metathesis chemistry. The methods of the invention are particularly useful for making industrially-important organic compounds beginning with starting compositions derived from renewable feedstocks, such as natural oils. The methods make use of a cross-metathesis step with an olefin compound to produce functionalized alkene intermediates having a pre-determined double bond position. Once isolated, the functionalized alkene intermediate can be self-metathesized or cross-metathesized (e.g., with a second functionalized alkene) to produce the desired organic compound or a precursor thereto. The method may be used to make bifunctional organic compounds, such as diacids, diesters, dicarboxylate salts, acid/esters, acid/amines, acid/alcohols, acid/aldehydes, acid/ketones, acid/halides, acid/nitriles, ester/amines, ester/alcohols, ester/aldehydes, ester/ketones, ester/halides, ester/nitriles, and the like.

  20. Odor-active compounds in cardboard.

    Science.gov (United States)

    Czerny, Michael; Buettner, Andrea

    2009-11-11

    The odor-active compounds of cardboard were identified by aroma extract dilution analysis and HRGC-MS analysis. In total, 36 compounds were detected with medium to high intensities during HRGC-olfactometry. The highest odor intensities were evaluated for vanillin, (E)-non-2-enal, (R/S)-gamma-nonalactone, 2-methoxyphenol, (R/S)-delta-decalactone, p-anisaldehyde, 3-propylphenol, and a woody-smelling unknown compound. Most of the identified compounds were described as odor-active cardboard constituents for the first time. Sensory experiments demonstrated that extensive release of odor-active compounds occurred upon moistening of the cardboard. Accordingly, data indicated that the odorants are present in cardboard in relatively high amounts. In a further sensory study, a transfer of the released odor to food was demonstrated in a model experiment showing that cardboards with high odor potential can cause unwanted flavor changes in foods.

  1. Methods of making organic compounds by metathesis

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, Timothy W.; Kaido, Hiroki; Lee, Choon Woo; Pederson, Richard L.; Schrodi, Yann; Tupy, Michael John

    2015-09-01

    Described are methods of making organic compounds by metathesis chemistry. The methods of the invention are particularly useful for making industrially-important organic compounds beginning with starting compositions derived from renewable feedstocks, such as natural oils. The methods make use of a cross-metathesis step with an olefin compound to produce functionalized alkene intermediates having a pre-determined double bond position. Once isolated, the functionalized alkene intermediate can be self-metathesized or cross-metathesized (e.g., with a second functionalized alkene) to produce the desired organic compound or a precursor thereto. The method may be used to make bifunctional organic compounds, such as diacids, diesters, dicarboxylate salts, acid/esters, acid/amines, acid/alcohols, acid/aldehydes, acid/ketones, acid/halides, acid/nitriles, ester/amines, ester/alcohols, ester/aldehydes, ester/ketones, ester/halides, ester/nitriles, and the like.

  2. Biochemical and medical importance of vanadium compounds.

    Science.gov (United States)

    Korbecki, Jan; Baranowska-Bosiacka, Irena; Gutowska, Izabela; Chlubek, Dariusz

    2012-01-01

    Vanadium belongs to the group of transition metals and is present in the air and soil contaminants in large urban agglomerations due to combustion of fossil fuels. It forms numerous inorganic compounds (vanadyl sulfate, sodium metavanadate, sodium orthovanadate, vanadium pentoxide) as well as complexes with organic compounds (BMOV, BEOV, METVAN). Depending on the research model, vanadium compounds exhibit antitumor or carcinogenic properties. Vanadium compounds generate ROS as a result of Fenton's reaction or of the reaction with atmospheric oxygen. They inactivate the Cdc25B(2) phosphatase and lead to degradation of Cdc25C, which induces G(2)/M phase arrest. In cells, vanadium compounds activate numerous signaling pathways and transcription factors, including PI3K-PKB/Akt-mTOR, NF-κB, MEK1/2-ERK, that cause cell survival or increased expression and release of VEGF. Vanadium compounds inhibit p53-dependent apoptosis and promote entry into the S phase of cells containing functional p53 protein. In addition, vanadium compounds, in particular organic derivatives, have insulin-mimetic and antidiabetic properties. Vanadium compounds lower blood glucose levels in animals and in clinical trials. They also inhibit the activity of protein tyrosine phosphatase 1B. By activating the PI3K-PKB/Akt pathway, vanadium compaunds increase the cellular uptake of glucose by the GLUT4 transporter. The PKB/Akt pathway is also used to inactivate glycogen synthase kinase-3. The impact of vanadium compounds on inflammatory reactions has not been fully studied. Vanadium pentoxide causes expression of COX-2 and the release of proinflammatory cytokines in a human lung fibroblast model. Other vanadium compounds activate NF-κB in macrophages by activating IKKβ.

  3. Thiophenic Sulfur Compounds Released During Coal Pyrolysis

    Science.gov (United States)

    Xing, Mengwen; Kong, Jiao; Dong, Jie; Jiao, Haili; Li, Fan

    2013-01-01

    Abstract Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography–mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis. PMID:23781126

  4. The reaction of diarylzinc compounds with silver salts : Synthesis and characterization of arylsilver(I) compounds

    NARCIS (Netherlands)

    Hofstee, H.K.; Boersma, J.; Kerk, G.J.M. van der

    1979-01-01

    The reaction of diarylzinc compounds with silver(I) salts is an excellent method of preparing stable arylsilver compounds in quantitative yields. These compounds have been characterized by IR and 1H and 13C NMR spectroscopy Cryoscopy in benzene shows phenylsilver to be polymeric, and the

  5. Water-soluble constituents of caraway: aromatic compound, aromatic compound glucoside and glucides.

    Science.gov (United States)

    Matsumura, Tetsuko; Ishikawa, Toru; Kitajima, Junichi

    2002-10-01

    From the water-soluble portion of the methanolic extract of caraway (fruit of Carum carvi L.), an aromatic compound, an aromatic compound glucoside and a glucide were isolated together with 16 known compounds. Their structures were clarified as 2-methoxy-2-(4'-hydroxyphenyl)ethanol, junipediol A 2-O-beta-D-glucopyranoside and L-fucitol, respectively.

  6. Poly[hexaaquatri-μ-malonato-didysprosium(III

    Directory of Open Access Journals (Sweden)

    Mei Yang

    2008-07-01

    Full Text Available The title compound, [Dy2(C3H2O43(H2O6]n, forms a coordination polymeric structure comprising hydrated dysprosium ions and malonate ligands. In the asymmetric unit, there are one dysprosium ion, one and a half malonate ligands, and three water molecules. Each DyIII atom is coordinated by six O atoms from four malonate ligands and by three water molecules, and displays a tricapped trigonal–prismatic coordination geometry. The malonate ligands adopt two types of coordination mode, linking dysprosium centres to form a three-dimensional coordination polymer. The extensive network of hydrogen bonds in this polymer enhances the structural stability.

  7. Phenolic compounds in Ross Sea water

    Science.gov (United States)

    Zangrando, Roberta; Barbaro, Elena; Gambaro, Andrea; Barbante, Carlo; Corami, Fabiana; Kehrwald, Natalie; Capodaglio, Gabriele

    2016-04-01

    Phenolic compounds are semi-volatile organic compounds produced during biomass burning and lignin degradation in water. In atmospheric and paleoclimatic ice cores studies, these compounds are used as biomarkers of wood combustion and supply information on the type of combusted biomass. Phenolic compounds are therefore indicators of paleoclimatic interest. Recent studies of Antarctic aerosols highlighted that phenolic compounds in Antarctica are not exclusively attributable to biomass burning but also derive from marine sources. In order to study the marine contribution to aerosols we developed an analytical method to determine the concentration of vanillic acid, vanillin, p-coumaric acid, syringic acid, isovanillic acid, homovanillic acid, syringaldehyde, acetosyringone and acetovanillone present in dissolved and particle phases in Sea Ross waters using HPLC-MS/MS. The analytical method was validated and used to quantify phenolic compounds in 28 sea water samples collected during a 2012 Ross Sea R/V cruise. The observed compounds were vanillic acid, vanillin, acetovanillone and p-coumaric acid with concentrations in the ng/L range. Higher concentrations of analytes were present in the dissolved phase than in the particle phase. Sample concentrations were greatest in the coastal, surficial and less saline Ross Sea waters near Victoria Land.

  8. Biodegradable compounds: Rheological, mechanical and thermal properties

    Science.gov (United States)

    Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

    2015-12-01

    Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

  9. [Functional analysis of bioactive natural compounds using monoclonal antibodies against natural compounds].

    Science.gov (United States)

    Uto, Takuhiro

    2014-01-01

    Herbal medicines have recently attracted much importance owing to the rising interest in their health benefits. Hence, further elucidation of the functions and mechanisms of these natural compounds is necessary. Our laboratory has established more than 30 kinds of monoclonal antibodies (MAbs) against bioactive natural compounds. Moreover, we have developed highly sensitive measurement systems for natural compounds, such as enzyme-linked immunosorbent assay (ELISA) and eastern blotting using MAbs. To expand the application of these MAbs to the functional analysis of natural compounds, we established a new approach for the isolation of the target compound from plant extracts using an immunoaffinity column conjugated with an anti-natural compound MAb. Through one-step purification using a MAb-conjugated immunoaffinity column, we have succeeded in preparing a knockout (KO) extract containing all components except the target compound, used as a hapten. Furthermore, we examined the pharmacological effects of the KO extract to identify the precise roles of the bioactive compound in the plant extract. To confirm another beneficial use of MAbs, we investigated the cellular localization and target molecules of natural compounds by immunocytochemistry (ICC) and Western blotting using MAbs. Our results demonstrated that MAbs clearly determined the cellular localization and target molecules of the natural compounds. These approaches may make it possible to determine the potential functions and target molecules of bioactive natural compounds in herbal medicines.

  10. Synthesis of Novel Antifungal Triazole Compounds

    Institute of Scientific and Technical Information of China (English)

    Yong CHU; Ming Xia XU; Ding LU

    2004-01-01

    Based on our previous studies of 3D-QSAR, 38 novel objective compounds belonging to 4 series were designed and successfully synthesized directed by the idea of reconstructing the structure of non-pharmacophores while reserving essential ones in triazoles. In vitro pilot studies on their antifungal activities showed that most compounds have inhibitory effects on C.albicans and some inhibit S.cerevisiae also. The effects on C.albicans of 5 compounds are more potent than or equal to that of fluconazole or itraconazole.

  11. Pickpocket compounds from Latin to Romance

    DEFF Research Database (Denmark)

    Whitehead, Benedicte Nielsen

    This thesis discusses the development in Proto–Indo–European, Latin and Romance of a word–formation pattern which the most adequate terminology in use dubs ‘verbal government compounds with a governing first member’; I use the shorthand ‘pickpocket compounds’. The first member of such compounds......–noun, represented by truck–driver, has the deverbal member second and carries an agentive suffix, -er. Pickpocket compounds are attested in early strata of Greek and Indo–Iranian and in medieval strata of Germanic, Slavic and Romance. Latin has around a dozen examples. The scholarly debate, continued in this thesis...

  12. Periodicity effects on compound guided waves

    Science.gov (United States)

    Chiadini, Francesco; Fiumara, Vincenzo; Scaglione, Antonio; Lakhtakia, Akhlesh

    2016-09-01

    Surface waves of different types can be compounded when a homogeneous layer is sandwiched between two half spaces filled with dissimilar periodically non-homogeneous dielectric materials and the intermediate layer is sufficiently thin. We solved the boundary-value problem for compound waves guided by a layer of a homogeneous and isotropic (metal or dielectric) material sandwiched between a structurally chiral material (SCM) and a periodically multi-layered isotropic dielectric material. We found that the periodicity of the SCM is crucial to excite a multiplicity of compound guided waves with strong coupling between the two interfaces.

  13. A new caffeate compound from Nardostachys chinensis.

    Science.gov (United States)

    Chen, Ying-peng; Wang, Zhong-ping; Zheng, Hong-hong; Xu, Yan-tong; Zhu, Yani; Zhang, Peng; Wu, Hong-hua

    2016-01-01

    A new caffeate compound, (E)-erythro-syringylglyceryl caffeate (1), was isolated from the roots and rhizomes of Nardostachys chinensis Batal., together with nine known phenolic compounds, including (+)-licarin A (2), naringenin 4', 7-dimethyl ether (3), pinoresinol-4-O-β-D-glucoside (4), caraphenol A (5), Z-miyabenol C (6), protocatechuic acid (7), caffeic acid (8), gallic acid (9) and vanillic acid (10). Their chemical structures were elucidated on the basis of spectroscopic data and physicochemical properties. Furthermore, this is the first report of compounds 2, 5 and 6 from Nardostachys genus.

  14. Microbial production of scent and flavor compounds.

    Science.gov (United States)

    Carroll, Austin L; Desai, Shuchi H; Atsumi, Shota

    2016-02-01

    Scents and flavors like those of fresh oranges are no longer limited to just the natural product. Fruit, flower, and essential oil scents have found place in cosmetics, soaps, candles, and food amongst many common household products. With their increasing global demand and difficulty in extractation from the natural source, alternative methods of their production are being sought. One sustainable method is to employ microorganisms for the production of these high value compounds. With the tools of metabolic engineering, microorganisms can be modified to produce compounds such as esters, terpenoids, aldehydes, and methyl ketones. Approaches and challenges for the production of these compounds from microbial hosts are discussed in this review.

  15. A growing codependency: compounding pharmacy and safety.

    Science.gov (United States)

    Prince, Bryan; Lundevall, Jeremy

    2013-01-01

    Pharmacists and pharmacy technicians are in constant contact with potent compounds. When compounding with powders, there is a susceptibility to environmental conditions such that proper containment be in place to keep the employees safe, the medicine free from cross contamination or the introduction of outside contaminants, and the workplace free from floating active pharmaceutical ingredient particles. Adapting powder hoods as safety devices that work in direct relation to clearly defined standard operating procedures and good lab practices will facilitate a safer lab environment for employees and ensure good-quality prescriptions. This article discusses the safety concerns of compounding with powders and the safety measures to consider when purchasing powder hoods.

  16. Compound leaf development in model plant species.

    Science.gov (United States)

    Bar, Maya; Ori, Naomi

    2015-02-01

    Plant leaves develop in accordance with a common basic program, which is flexibly adjusted to the species, developmental stage and environment. Two key stages of leaf development are morphogenesis and differentiation. In the case of compound leaves, the morphogenesis stage is prolonged as compared to simple leaves, allowing for the initiation of leaflets. Here, we review recent advances in the understanding of how plant hormones and transcriptional regulators modulate compound leaf development, yielding a substantial diversity of leaf forms, focusing on four model compound leaf organisms: cardamine (Cardamine hirsuta), tomato (Solanum lycopersicum), medicago (Medicago truncatula) and pea (Pisum sativum).

  17. Two novel compounds from Paeonia suffructicosa.

    Science.gov (United States)

    Lin, H C; Ding, H Y; Wu, Y C

    1998-03-01

    A new hexacyclic triterpenoid, mudanpinoic acid A (1), and a new gallic acid glycoside, mudanoside B (2), along with nine known compounds--benzoic acid, resacetophenone, paeoniflorigenone, beta-sitosterol, betulinic acid, oleanoic acid, quercetin, beta-sitosterol-beta-D-glucoside, and trans-caffeic acid stearyl ester-were isolated from the dried root cortex of Paeonia suffruticosa. The structures of the novel compounds were elucidated on the basis of spectral methods, and that of compound 1 was confirmed by X-ray crystallographic analysis.

  18. Endocannabinoids, Related Compounds and Their Metabolic Routes

    Directory of Open Access Journals (Sweden)

    Filomena Fezza

    2014-10-01

    Full Text Available Endocannabinoids are lipid mediators able to bind to and activate cannabinoid receptors, the primary molecular targets responsible for the pharmacological effects of the Δ9-tetrahydrocannabinol. These bioactive lipids belong mainly to two classes of compounds: N-acylethanolamines and acylesters, being N-arachidonoylethanolamine (AEA and 2-arachidonoylglycerol (2-AG, respectively, their main representatives. During the last twenty years, an ever growing number of fatty acid derivatives (endocannabinoids and endocannabinoid-like compounds have been discovered and their activities biological is the subject of intense investigations. Here, the most recent advances, from a therapeutic point of view, on endocannabinoids, related compounds, and their metabolic routes will be reviewed.

  19. Endocannabinoids, related compounds and their metabolic routes.

    Science.gov (United States)

    Fezza, Filomena; Bari, Monica; Florio, Rita; Talamonti, Emanuela; Feole, Monica; Maccarrone, Mauro

    2014-10-24

    Endocannabinoids are lipid mediators able to bind to and activate cannabinoid receptors, the primary molecular targets responsible for the pharmacological effects of the Δ9-tetrahydrocannabinol. These bioactive lipids belong mainly to two classes of compounds: N-acylethanolamines and acylesters, being N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG), respectively, their main representatives. During the last twenty years, an ever growing number of fatty acid derivatives (endocannabinoids and endocannabinoid-like compounds) have been discovered and their activities biological is the subject of intense investigations. Here, the most recent advances, from a therapeutic point of view, on endocannabinoids, related compounds, and their metabolic routes will be reviewed.

  20. Nonlinear system compound inverse control method

    Institute of Scientific and Technical Information of China (English)

    Yan ZHANG; Zengqiang CHEN; Peng YANG; Zhuzhi YUAN

    2005-01-01

    A compound neural network is utilized to identify the dynamic nonlinear system.This network is composed of two parts: one is a linear neural network,and the other is a recurrent neural network.Based on the inverse theory a compound inverse control method is proposed.The controller has also two parts:a linear controller and a nonlinear neural network controller.The stability condition of the closed-loop neural network-based compound inverse control system is demonstrated based on the Lyapunov theory.Simulation studies have shown that this scheme is simple and has good control accuracy and robustness.

  1. Botanical Compounds: Effects on Major Eye Diseases

    Directory of Open Access Journals (Sweden)

    Tuan-Phat Huynh

    2013-01-01

    Full Text Available Botanical compounds have been widely used throughout history as cures for various diseases and ailments. Many of these compounds exhibit strong antioxidative, anti-inflammatory, and antiapoptotic properties. These are also common damaging mechanisms apparent in several ocular diseases, including age-related macular degeneration (AMD, glaucoma, diabetic retinopathy, cataract, and retinitis pigmentosa. In recent years, there have been many epidemiological and clinical studies that have demonstrated the beneficial effects of plant-derived compounds, such as curcumin, lutein and zeaxanthin, danshen, ginseng, and many more, on these ocular pathologies. Studies in cell cultures and animal models showed promising results for their uses in eye diseases. While there are many apparent significant correlations, further investigation is needed to uncover the mechanistic pathways of these botanical compounds in order to reach widespread pharmaceutical use and provide noninvasive alternatives for prevention and treatments of the major eye diseases.

  2. DNA Modification with Photochromic Spiro Compounds

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The photochromic spiropyrans and spirooxazine having a succinimidyl ester or isothiocyanate pendant group can form covalent products with transaminated DNA.The absorption spectra and solid reflection spectra of modified DNA with these photochromic spiro compounds were investigated.

  3. Compositional differences in the phenolics compounds of ...

    African Journals Online (AJOL)

    Administrator

    This study evaluates phenolic composition of commercial and experimental ... white wines, some contained large number of phenolic compounds while the others showed smaller number of ..... Synthesis, Properties, and Significance. Plenum ...

  4. Security evaluation of compounded microbial flocculant

    Institute of Scientific and Technical Information of China (English)

    马放; 王博; 范春; 杨基先; 李百祥; 刘艳滨

    2004-01-01

    A new kind of compounded microbial flocculant (CMBF) for water and wastewater treatment has been developed through biological technology. In order to discuss its biological security, four groups of experiments, rat acute toxicity test via mouth, salmonella assay in vitro, mouse micronucleus in vivo test and teratogenesis test were conducted to evaluate its general toxicity, genotoxicity and generative toxicity. The experimental results showed that this type of compounded microbial fiocculant was a substantial non-toxic substance based on the fact that LD50 value was over 10 mg/kg. The results from salmonella in vivo test and mouse micronucleus in vivo test revealed that the compounded microbial flocculant is a genetically non-toxic substance. Furthermore, compounded microbial flocculant has little effect on the growth of all the rats, and any morphologic abnormal phenomenon hasnt appeared.

  5. Mechanochemical reactions on copper-based compounds

    NARCIS (Netherlands)

    Castricum, H.L.; Bakker, H.; Poels, E.K.

    1999-01-01

    Mechanochemical reactions of copper and copper oxides with oxygen and carbon dioxide are discussed, as well as decomposition and reduction of copper compounds by mechanical milling under high-vacuum conditions.

  6. Atmospheric Chemistry of Micrometeoritic Organic Compounds

    Science.gov (United States)

    Kress, M. E.; Belle, C. L.; Pevyhouse, A. R.; Iraci, L. T.

    2011-01-01

    Micrometeorites approx.100 m in diameter deliver most of the Earth s annual accumulation of extraterrestrial material. These small particles are so strongly heated upon atmospheric entry that most of their volatile content is vaporized. Here we present preliminary results from two sets of experiments to investigate the fate of the organic fraction of micrometeorites. In the first set of experiments, 300 m particles of a CM carbonaceous chondrite were subject to flash pyrolysis, simulating atmospheric entry. In addition to CO and CO2, many organic compounds were released, including functionalized benzenes, hydrocarbons, and small polycyclic aromatic hydrocarbons. In the second set of experiments, we subjected two of these compounds to conditions that simulate the heterogeneous chemistry of Earth s upper atmosphere. We find evidence that meteor-derived compounds can follow reaction pathways leading to the formation of more complex organic compounds.

  7. Negative thermal expansion in framework compounds

    Indian Academy of Sciences (India)

    R Mittal

    2008-10-01

    We have studied negative thermal expansion (NTE) compounds with chemi- cal compositions of NX2O8 and NX2O7 (N=Zr, Hf and X=W, Mo, V) and M2O (M=Cu, Ag) using the techniques of inelastic neutron scattering and lattice dynamics. There is a large variation in the negative thermal expansion coefficients of these compounds. The inelastic neutron scattering experiments have been carried out using polycrystalline and single crystal samples at ambient pressure as well as at high pressures. Experimental data are useful to confirm the predictions made from our lattice dynamical calculations as well as to check the quality of the interatomic potentials developed by us. We have been able to successfully model the NTE behaviour of these compounds. Our studies show that unusual phonon softening of low energy modes is able to account for NTE in these compounds.

  8. Compound Option Pricing under Fuzzy Environment

    Directory of Open Access Journals (Sweden)

    Xiandong Wang

    2014-01-01

    Full Text Available Considering the uncertainty of a financial market includes two aspects: risk and vagueness; in this paper, fuzzy sets theory is applied to model the imprecise input parameters (interest rate and volatility. We present the fuzzy price of compound option by fuzzing the interest and volatility in Geske’s compound option pricing formula. For each α, the α-level set of fuzzy prices is obtained according to the fuzzy arithmetics and the definition of fuzzy-valued function. We apply a defuzzification method based on crisp possibilistic mean values of the fuzzy interest rate and fuzzy volatility to obtain the crisp possibilistic mean value of compound option price. Finally, we present a numerical analysis to illustrate the compound option pricing under fuzzy environment.

  9. The Industrial Reduction of Aromatic Nitro Compounds.

    Science.gov (United States)

    Gilbert, G.

    1980-01-01

    Describes methods for enriching an A-level chemistry course with a series of chemical company visits. The rationale is discussed for an emphasis of the visits on the industrial reduction of aromatic nitro compounds. (CS)

  10. Thermodynamic Analysis of Ionic Compounds: Synthetic Applications.

    Science.gov (United States)

    Yoder, Claude H.

    1986-01-01

    Shows how thermodynamic cycles can be used to understand trends in heats of formation and aqueous solubilities and, most importantly, how they may be used to choose synthetic routes to new ionic compounds. (JN)

  11. New approach for screeninganti-tumor compounds

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new screening approach for anticancer active compounds is presented. In this method, a target enzyme is incubated with a mixture of compounds, and then the complex formed by the target and small molecules is separated from the rest of the mixture by ultra-filtration. The complex that is retained on the membrane is subsequently washed with acid and small molecules that are specifically bound to the target are released and collected, then analyzed by high-performance liquid chromatograph combined with electrospray ionization mass spectrometry (HPLC/ESI-MS) analysis. We have successfully applied this method to screen anti-cancer compounds. DNA topoisomeraseⅡ is used as a target to capture anti-tumor candidates from a mixture of combinatorial compounds, such as doxorubicin, daunorubicin and pravastain.

  12. Trifluoromethylation of Carbonyl Compounds with Sodium Trifluoroacetate

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In the presence of copper (Ⅰ) halide as catalyst, a variety of carbonyl compounds could be trifluoromethylated with sodium trifluoroacetate to give the corresponding alcohols in moderate to high yields.

  13. Phytoestrogens: Plant-derived Estrogenic Compounds

    Directory of Open Access Journals (Sweden)

    Nevzat Konar

    2011-12-01

    Full Text Available Estrogen is a hormone, which is produced in ovary and testis; however, it has many biological effects besides the reproductive system. Phytoestrogens are the compounds, which have estrogen-like structure and activities, taking place in structure of various edible plants at different levels and in different compositions. These compounds attracted notice after the first quarter of 20th century upon they had been associated with infertility seen in some of animals fed with alfalfa, and these compounds have been identified in human-derived biological samples and its effects on health have been taken under study in the recent 30 years. These materials have especially antioxidant role in plants while they have activities in animals and humans as estrogen agonist and antagonists. Based on their chemical structure, they may be gathered under especially isoflavon and lignan groups while some of members of coumestan and stilbene groups are also identified as phytoestrogenic compound.

  14. Food applications of natural antimicrobial compounds

    Directory of Open Access Journals (Sweden)

    Matteo Alessandro eDel Nobile

    2012-08-01

    Full Text Available In agreement with the current trend of giving value to natural and renewable resources, the use of natural antimicrobial compounds, particularly in food and biomedical applications, becomes very frequent. The direct addition of natural compounds to food is the most common method of application, even if numerous efforts have been made to find alternative solutions to the aim of avoiding undesirable inactivation. Dipping, spraying and coating treatment of food with active solutions are currently applied to product prior to packaging as valid options. The aim of the current work is to give an overview on the use of natural compounds in food sector. In particular, the review will gather numerous case-studies of meat, fish, dairy products, minimally processed fruit and vegetables and cereal-based products where these compounds found application.

  15. Organolead compounds shown to be genetically active

    Energy Technology Data Exchange (ETDEWEB)

    Ahlberg, J.; Ramel, C.; Wachtmeister, C.A.

    1972-01-01

    The purpose of the present investigation was to determine whether alkyllead compounds would cause a genetic effect similar to that caused by alkyl mercury compounds. Experiments were conducted on Allium cepa (onion) in order to determine the effect of lead compounds on the spindle fiber mechanism. Results indicate that disturbances of the spindle fiber mechanism occur even at very low concentrations. The lowest concentration at which such effects are observed seems to be between 10/sup -6/ and 10/sup -7/ M for the organic compounds. Although no effect can be observed on the spindle fibers at lower dosages, the mitotic index is changed even at a dose of 10/sup -7/ M with dimethyllead. A preliminary experiment was made on Drosophila with triethyllead in order to investigate whether the effects which were observed on mitoses in Allium would also be observed in a meiotic cell system in an animal.

  16. Perfluorinated Compounds In The Ohio River Basin

    Science.gov (United States)

    Contaminants of emerging concern (CECs) in waterways include pharmaceuticals and personal care products (PPCPs), alkylphenols, endocrine disrupting chemicals (EDCs) and perfluorinated alkyl compounds (PFCs). Their distributions and persistence in the aquatic environment remain p...

  17. Electrode reactions and electroanalysis of organomercury compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kurmaz, Vladimir A [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation); Gul' tyai, Vadim P [N.D.Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

    2010-06-09

    Characteristic features of mechanisms and kinetics of electrode reactions of organomercury compounds (symmetrical, non-symmetrical) and organomercury salts on a mercury electrode are analyzed. Attention is focused on the effect of coordination, adsorption and the nature and properties of intermediates on these processes as well as on the formation of organomercury derivatives in the adsorption of organic and hetero-organic compounds on a mercury electrode. The kinetics of heterogeneous chemical equilibrium {sup o}rganic calomel{sup -}symmetrical organomercury compound in the adsorption layer and the relative stability of intermediates in the one-electron reduction of organomercury salts are discussed as well as the electrolytic hydrogen evolution catalyzed by organomercury intermediates. The problems of combined and separate electrochemical quantitation of organic and inorganic mercury compounds in natural objects are considered.

  18. Techniques for Analysis of Plant Phenolic Compounds

    Directory of Open Access Journals (Sweden)

    Thomas H. Roberts

    2013-02-01

    Full Text Available Phenolic compounds are well-known phytochemicals found in all plants. They consist of simple phenols, benzoic and cinnamic acid, coumarins, tannins, lignins, lignans and flavonoids. Substantial developments in research focused on the extraction, identification and quantification of phenolic compounds as medicinal and/or dietary molecules have occurred over the last 25 years. Organic solvent extraction is the main method used to extract phenolics. Chemical procedures are used to detect the presence of total phenolics, while spectrophotometric and chromatographic techniques are utilized to identify and quantify individual phenolic compounds. This review addresses the application of different methodologies utilized in the analysis of phenolic compounds in plant-based products, including recent technical developments in the quantification of phenolics.

  19. Separation and characterization of phenolic compounds from ...

    African Journals Online (AJOL)

    Attioua

    2013-07-03

    Jul 3, 2013 ... natural habitat in Ivory Coast, in the forest region near Abidjan .... Structure of the isolated compounds from T. ivoiriensis: 1, .... Complex tannins are generally considered to have .... Forest production for tropical America.

  20. Characterisation of selected volatile organic compounds in ...

    African Journals Online (AJOL)

    kshale

    2013-05-15

    May 15, 2013 ... spectrometry. K. Shale1*, J. Mukamugema2, R. J. Lues1, P. Venter3 and K. K. Mokoena1 ..... Cajka T, Riddellova K, Tomaniova M, Hajslova J (2010). Recognition of ... volatile organic compounds of coniferous needle litter.

  1. Carbonyl compounds generated from electronic cigarettes

    National Research Council Canada - National Science Library

    Bekki, Kanae; Uchiyama, Shigehisa; Ohta, Kazushi; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki

    2014-01-01

    Electronic cigarettes (e-cigarettes) are advertised as being safer than tobacco cigarettes products as the chemical compounds inhaled from e-cigarettes are believed to be fewer and less toxic than those from tobacco cigarettes...

  2. Expatriate Compound Living: An Ethnographic Field Study

    DEFF Research Database (Denmark)

    Lauring, Jakob; Selmer, Jan

    2009-01-01

    ethnographic field-work methodology, including interviews and participant observation during a period of three months, this exploratory study investigated 16 Danish business expatriates of a large Danish corporation and their families living in the same compound in Saudi Arabia. They shared their spare time...... and the expatriates had the same working hours in the same subsidiary. Results show that a Danish national group was established and maintained. This in-group dominated life in the compound and at work it may have contributed to the perceptual bias and discriminatory behaviour demonstrated by the Danish expatriates......In certain countries, closed expatriate compounds have developed.  They serve to provide resident expatriates and accompanying family members with a comfortable and safe environment. Unfortunately, not much is known about compound life since associated empirical research is scarce. Through...

  3. Medical Applications and Toxicities of Gallium Compounds

    Directory of Open Access Journals (Sweden)

    Christopher R. Chitambar

    2010-05-01

    Full Text Available Over the past two to three decades, gallium compounds have gained importance in the fields of medicine and electronics. In clinical medicine, radioactive gallium and stable gallium nitrate are used as diagnostic and therapeutic agents in cancer and disorders of calcium and bone metabolism. In addition, gallium compounds have displayed anti-inflammatory and immunosuppressive activity in animal models of human disease while more recent studies have shown that gallium compounds may function as antimicrobial agents against certain pathogens. In a totally different realm, the chemical properties of gallium arsenide have led to its use in the semiconductor industry. Gallium compounds, whether used medically or in the electronics field, have toxicities. Patients receiving gallium nitrate for the treatment of various diseases may benefit from such therapy, but knowledge of the therapeutic index of this drug is necessary to avoid clinical toxicities. Animals exposed to gallium arsenide display toxicities in certain organ systems suggesting that environmental risks may exist for individuals exposed to this compound in the workplace. Although the arsenic moiety of gallium arsenide appears to be mainly responsible for its pulmonary toxicity, gallium may contribute to some of the detrimental effects in other organs. The use of older and newer gallium compounds in clinical medicine may be advanced by a better understanding of their mechanisms of action, drug resistance, pharmacology, and side-effects. This review will discuss the medical applications of gallium and its mechanisms of action, the newer gallium compounds and future directions for development, and the toxicities of gallium compounds in current use.

  4. Bioactive compounds in whole grain wheat

    OpenAIRE

    Mateo Anson, N.

    2010-01-01

    Bread can be healthier! Consuming whole-grain foods can prevent cardiovascular diseases, type-2 diabetes and metabolic syndrome. This is due to bioactive compounds in whole grain, such as antioxidants and anti-inflammatory compounds. We found that the different fractions of a wheat grain vary much in their content. The external fractions of the grain, the bran and specially the aleurone, are the richest. We observed that processing the bran in whole-grain breads increased three times the leve...

  5. BASF Launches New Compounding Plant in China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ BASF, a leading international chemical company,kicked off construction of an engineering plastics compounding plant Pudong Area in Shanghai in midMay. The new facility is a world-scale plant with annual capacity of 45,000 tons. It is one of the most modern compounding plants in the world today, with "the highest environmental standards and the most efficient production capabilities available," according to a BASF official.

  6. Two new compounds from Zingiber officinale

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new cyclic diarylheptanoid, 1,5-epoxy-3-hydroxy-1-(3-methoxy-4,5-dihydroxyphenyl)-7-(4-hydroxyphenyl)-heptane (1), as well as a new monoterpene, 10-O-β-D-glucopyranosyl-hydroxy cineole (2) were isolated from the rhizomes of Zingiber officinale.The structures of compounds 1 and 2 were established based on their spectral data. In addition, the antioxidant activities of these compounds were also measured.

  7. Microwave Resonant Absorption of Potential Exothermic Compounds

    Science.gov (United States)

    1989-12-22

    exothermic materials: lead azide, lead styphnate , PETN, composition B, black powder, nitrocellulose, boron barium Chromate, and M-30 exhibit sharp...the exothermic materials. Table 1. Compounds Tested Compound Source 1 Lead Azide Broco Inc, Rialto CA 2 Lead Styphnate 3 PETN 4 Comp B 5 Black Powder 6...Nitrocellulose (12.6% Nitration) 7 Boron Barium Chromate ICI America, Valley Forge, PA 8 M30 (Gun Propellent) Radford Army Ammunition Plant, Radford

  8. Health promoting compounds in vegetables and fruits:

    DEFF Research Database (Denmark)

    Brandt, K.; Christensen, L.P.; Hansen-Møller, J.

    2004-01-01

    Vegetables contain unknown compounds with important health promoting effect. The described project defined and tested a two-step screening procedure for identification of such compounds. Step 1 is initial screening according to three criteria: 1.1, chemically reactive functional groups; 1.2, toxi...... in bioassay; and 2.3, possibility to control content in food. Falcarinol from carrots fulfilled all 6 criteria and subsequently showed anticancer effect in rats....

  9. Techniques for Analysis of Plant Phenolic Compounds

    OpenAIRE

    Roberts, Thomas H.; Meredith A. Wilkes; Ali Khoddami

    2013-01-01

    Phenolic compounds are well-known phytochemicals found in all plants. They consist of simple phenols, benzoic and cinnamic acid, coumarins, tannins, lignins, lignans and flavonoids. Substantial developments in research focused on the extraction, identification and quantification of phenolic compounds as medicinal and/or dietary molecules have occurred over the last 25 years. Organic solvent extraction is the main method used to extract phenolics. Chemical procedures are used to detect the pre...

  10. Chalcones: compounds possessing a diversity in applications

    Directory of Open Access Journals (Sweden)

    Urmila Berar

    2012-10-01

    Full Text Available Chalcones are a class of α, β- unsaturated carbonyl compounds that form the central core for a variety of naturally occurring biologically active compounds. They exhibit tremendous potential to act as a pharmacological agent. Besides their various pharmacological activities, chalcones have been explored for different optical applications including second harmonic generation materials in non- linear optics, fluorescent probe for sensing different molecules.

  11. Carbonyl Compounds Generated from Electronic Cigarettes

    Directory of Open Access Journals (Sweden)

    Kanae Bekki

    2014-10-01

    Full Text Available Electronic cigarettes (e-cigarettes are advertised as being safer than tobacco cigarettes products as the chemical compounds inhaled from e-cigarettes are believed to be fewer and less toxic than those from tobacco cigarettes. Therefore, continuous careful monitoring and risk management of e-cigarettes should be implemented, with the aim of protecting and promoting public health worldwide. Moreover, basic scientific data are required for the regulation of e-cigarette. To date, there have been reports of many hazardous chemical compounds generated from e-cigarettes, particularly carbonyl compounds such as formaldehyde, acetaldehyde, acrolein, and glyoxal, which are often found in e-cigarette aerosols. These carbonyl compounds are incidentally generated by the oxidation of e-liquid (liquid in e-cigarette; glycerol and glycols when the liquid comes in contact with the heated nichrome wire. The compositions and concentrations of these compounds vary depending on the type of e-liquid and the battery voltage. In some cases, extremely high concentrations of these carbonyl compounds are generated, and may contribute to various health effects. Suppliers, risk management organizations, and users of e-cigarettes should be aware of this phenomenon.

  12. Carbonyl compounds generated from electronic cigarettes.

    Science.gov (United States)

    Bekki, Kanae; Uchiyama, Shigehisa; Ohta, Kazushi; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki

    2014-10-28

    Electronic cigarettes (e-cigarettes) are advertised as being safer than tobacco cigarettes products as the chemical compounds inhaled from e-cigarettes are believed to be fewer and less toxic than those from tobacco cigarettes. Therefore, continuous careful monitoring and risk management of e-cigarettes should be implemented, with the aim of protecting and promoting public health worldwide. Moreover, basic scientific data are required for the regulation of e-cigarette. To date, there have been reports of many hazardous chemical compounds generated from e-cigarettes, particularly carbonyl compounds such as formaldehyde, acetaldehyde, acrolein, and glyoxal, which are often found in e-cigarette aerosols. These carbonyl compounds are incidentally generated by the oxidation of e-liquid (liquid in e-cigarette; glycerol and glycols) when the liquid comes in contact with the heated nichrome wire. The compositions and concentrations of these compounds vary depending on the type of e-liquid and the battery voltage. In some cases, extremely high concentrations of these carbonyl compounds are generated, and may contribute to various health effects. Suppliers, risk management organizations, and users of e-cigarettes should be aware of this phenomenon.

  13. Semantic Analysis of Compound Verbs: A Cognitive Perspective

    Institute of Scientific and Technical Information of China (English)

    王兴龙

    2015-01-01

    In compounding studies,NN compounds have caught great attention,while compound verbs are always kept outside of the main focus.Therefore much more efforts should be put on the study of compound verbs to balance this disproportion as well as to complete the research of compounding.

  14. Synthesis of a new series of anti-rhinovirus compounds

    Institute of Scientific and Technical Information of China (English)

    Shi Yong Fan; Chun Lai Mi; Jun Yang; Song Li; Zhi Bing Zheng

    2007-01-01

    The synthesis of a series of 3,6-dichloropyridazine derivatives was described. In vitro experiment, all compounds exhibited an anti-rhinovirus activity, and one of the compounds 6g showed the comparable activity as our lead compound pirodavir.

  15. High Resolution Screening of biologically active compounds and metabolites

    NARCIS (Netherlands)

    Kool, J.

    2007-01-01

    High Resolution Screening of biologically active compounds and metabolites Jeroen Kool Biotransformation enzymes play a crucial role in the metabolism of both endogenous compounds and xenobiotics. Usually, the detoxication of these compounds by biotransformation enzymes results in harmless metab

  16. Chemical effect on diffusion in intermetallic compounds

    Science.gov (United States)

    Chen, Yi-Ting

    With the trend of big data and the Internet of things, we live in a world full of personal electronic devices and small electronic devices. In order to make the devices more powerful, advanced electronic packaging such as wafer level packaging or 3D IC packaging play an important role. Furthermore, ?-bumps, which connect silicon dies together with dimension less than 10 ?m, are crucial parts in advanced packaging. Owing to the dimension of ?-bumps, they transform into intermetallic compound from tin based solder after the liquid state bonding process. Moreover, many new reliability issues will occur in electronic packaging when the bonding materials change; in this case, we no longer have tin based solder joint, instead, we have intermetallic compound ?-bumps. Most of the potential reliability issues in intermetallic compounds are caused by the chemical reactions driven by atomic diffusion in the material; thus, to know the diffusivities of atoms inside a material is significant and can help us to further analyze the reliability issues. However, we are lacking these kinds of data in intermetallic compound because there are some problems if used traditional Darken's analysis. Therefore, we considered Wagner diffusivity in our system to solve the problems and applied the concept of chemical effect on diffusion by taking the advantage that large amount of energy will release when compounds formed. Moreover, by inventing the holes markers made by Focus ion beam (FIB), we can conduct the diffusion experiment and obtain the tracer diffusivities of atoms inside the intermetallic compound. We applied the technique on Ni3Sn4 and Cu3Sn, which are two of the most common materials in electronic packaging, and the tracer diffusivities are measured under several different temperatures; moreover, microstructure of the intermetallic compounds are investigated to ensure the diffusion environment. Additionally, the detail diffusion mechanism was also discussed in aspect of diffusion

  17. Phenolic compounds in Rosaceae fruits from Ecuador.

    Science.gov (United States)

    Vasco, Catalina; Riihinen, Kaisu; Ruales, Jenny; Kamal-Eldin, Afaf

    2009-02-25

    RP-HPLC-DAD was used to study the content of phenolic compounds in four Ecuadorian fruits (strawberry, Andean blackberry, plum, and capuli cherry). Compounds were identified using spectral characteristics of representative standards and reference samples. Further, LC-MS with MS/MS was used to confirm molecular assignments in previously unstudied capuli cherry. Gallic acid was detected in Andean blackberry, and galloyl esters were detected in strawberries. Both these berries contained ellagic acid derivatives as major compounds, followed by anthocyanins, cyanidin, and pelargonidin glycosides. Plums and capuli cherry showed similar profiles of phenolic compounds, with chlorogenic and neochlorogenic acids being the most important hydroxycinnamates. (-)-Epicatechin was found in high amounts in Andean blackberry, plums, and capuli cherry, while (+)-catechin was only found in capuli cherry. Proanthocyanidins were major compounds in all fruits, and all contained considerable amounts of quercetin derivatives and smaller amounts of kaempferol derivatives. LC-MS analysis of capuli cherry revealed dimeric and trimeric procyanidins, quercetin and kaempferol hexosides and pentosides, and a kaempferol-O,C-dipentoside.

  18. Excretion of biliary compounds during intrauterine life

    Science.gov (United States)

    Macias, Rocio IR; Marin, Jose JG; Serrano, Maria A

    2009-01-01

    In adults, the hepatobiliary system, together with the kidney, constitute the main routes for the elimination of several endogenous and xenobiotic compounds into bile and urine, respectively. However, during intrauterine life the biliary route of excretion for cholephilic compounds, such as bile acids and biliary pigments, is very poor. Although very early in pregnancy the fetal liver produces bile acids, bilirubin and biliverdin, these compounds cannot be efficiently eliminated by the fetal hepatobiliary system, owing to the immaturity of the excretory machinery in the fetal liver. Therefore, the potentially harmful accumulation of cholephilic compounds in the fetus is prevented by their elimination across the placenta. Owing to the presence of detoxifying enzymes and specific transport systems at different locations of the placental barrier, such as the endothelial cells of chorionic vessels and trophoblast cells, this organ plays an important role in the hepatobiliary-like function during intrauterine life. The relevance of this excretory function in normal fetal physiology is evident in situations where high concentrations of biliary compounds are accumulated in the mother. This may result in oxidative stress and apoptosis, mainly in the placenta and fetal liver, which might affect normal fetal development and challenge the fate of the pregnancy. The present article reviews current knowledge of the mechanisms underlying the hepatobiliary function of the fetal-placental unit and the repercussions of several pathological conditions on this tandem. PMID:19230042

  19. Reflectance spectroscopy of organic compounds: 1. Alkanes

    Science.gov (United States)

    Clark, R.N.; Curchin, J.M.; Hoefen, T.M.; Swayze, G.A.

    2009-01-01

    Reflectance spectra of the organic compounds comprising the alkane series are presented from the ultraviolet to midinfrared, 0.35 to 15.5 /??m. Alkanes are hydrocarbon molecules containing only single carbon-carbon bonds, and are found naturally on the Earth and in the atmospheres of the giant planets and Saturn's moon, Titan. This paper presents the spectral properties of the alkanes as the first in a series of papers to build a spectral database of organic compounds for use in remote sensing studies. Applications range from mapping the environment on the Earth, to the search for organic molecules and life in the solar system and throughout the. universe. We show that the spectral reflectance properties of organic compounds are rich, with major diagnostic spectral features throughout the spectral range studied. Little to no spectral change was observed as a function of temperature and only small shifts and changes in the width of absorption bands were observed between liquids and solids, making remote detection of spectral properties throughout the solar system simpler. Some high molecular weight organic compounds contain single-bonded carbon chains and have spectra similar to alkanes even ' when they fall into other families. Small spectral differences are often present allowing discrimination among some compounds, further illustrating the need to catalog spectral properties for accurate remote sensing identification with spectroscopy.

  20. Cerium-iron-based magnetic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Chen; Pinkerton, Frederick E.; Herbst, Jan F.

    2017-01-17

    New magnetic materials containing cerium, iron, and small additions of a third element are disclosed. These materials comprise compounds Ce(Fe.sub.12-xM.sub.x) where x=1-4, having the ThMn.sub.12 tetragonal crystal structure (space group I4/mmm, #139). Compounds with M=B, Al, Si, P, S, Sc, Co, Ni, Zn, Ga, Ge, Zr, Nb, Hf, Ta, and W are identified theoretically, and one class of compounds based on M=Si has been synthesized. The Si cognates are characterized by large magnetic moments (4.pi.M.sub.s greater than 1.27 Tesla) and high Curie temperatures (264.ltoreq.T.sub.c.ltoreq.305.degree. C.). The Ce(Fe.sub.12-xM.sub.x) compound may contain one or more of Ti, V, Cr, and Mo in combination with an M element. Further enhancement in T.sub.c is obtained by nitriding the Ce compounds through heat treatment in N.sub.2 gas while retaining the ThMn.sub.12 tetragonal crystal structure; for example CeFe.sub.10Si.sub.2N.sub.1.29 has T.sub.c=426.degree. C.

  1. Macrocyclic trichothecenes as antifungal and anticancer compounds.

    Science.gov (United States)

    de Carvalho, Maira Peres; Weich, Herbert; Abraham, Wolf-Rainer

    2016-01-01

    Trichothecenes are sesquiterpenoid metabolites produced by fungi and species of the plant genus Baccharis, family Asteraceae. They comprise a tricyclic core with an epoxide at C-12 and C-13 and can be grouped into non-macrocyclic and macrocyclic compounds. While many of these compounds are of concern in agriculture, the macrocyclic metabolites have been evaluated as antiviral, anti-cancer, antimalarial and antifungal compounds. Some known cytotoxic responses on eukaryotic cells include inhibition of protein, DNA and RNA syntheses, interference with mitochondrial function, effects on cell division and membranes. These targets however have been elucidated essentially employing non-macrocyclic trichothecenes and only one or two closely related macrocyclic compounds. For several macrocyclic trichothecenes high selectivity against fungal species and against cancer cell lines have been reported suggesting that the macrocycle and its stereochemistry are of crucial importance regarding biological activity and selectivity. This review is focused on compounds belonging to the macrocyclic type, where a cyclic diester or triester ring binds to the trichothecane moiety at C-4 and C- 15 leading to natural products belonging to the groups of satratoxins, verrucarins, roridins, myrotoxins and baccharinoids. Their biological activities, cytotoxic mechanisms and structure-activity relationships (SAR) are discussed. From the reported data it becomes evident that even small changes in the molecules can lead to pronounced effects on biological activity or selectivity against cancer cells lines. Understanding the underlying mechanisms may help to design highly specific drugs for cancer therapy.

  2. Nature of phenolic compounds in coffee melanoidins.

    Science.gov (United States)

    Coelho, Carina; Ribeiro, Miguel; Cruz, Ana C S; Domingues, M Rosário M; Coimbra, Manuel A; Bunzel, Mirko; Nunes, Fernando M

    2014-08-06

    Phenolic compounds are incorporated into coffee melanoidins during roasting mainly in condensed form (42-62 mmol/100 g) and also in ester-linked form (1.1-1.6 mmol/100 g), with incorporation levels depending on the green coffee chlorogenic acid content. The phenolic compounds are incorporated in different coffee melanoidin populations, but mainly in those soluble in 75% ethanol (82%), a significant correlation between the amount of phenolic compounds and the amount of protein and color characteristics of the different melanoidin populations being observed. The incorporation of phenolic compounds into coffee melanoidins is a significant pathway of chlorogenic acid degradation during roasting, representing 23% of the chlorogenic acids lost. These account for the nearly 26% of the material not accounted for by polysaccharides and proteins present in coffee melanodins. The cleavage mechanism and the efficiency of alkaline fusion used to release condensed phenolics from coffee melanoidins suggest that the phenolic compounds can be linked to the polymeric material by aryl-ether, stilbene type, and/or biphenyl linkages.

  3. Basics and prospective of magnetic Heusler compounds

    Directory of Open Access Journals (Sweden)

    Claudia Felser

    2015-04-01

    Full Text Available Heusler compounds are a remarkable class of materials with more than 1000 members and a wide range of extraordinary multi-functionalities including halfmetallic high-temperature ferri- and ferromagnets, multi-ferroics, shape memory alloys, and tunable topological insulators with a high potential for spintronics, energy technologies, and magneto-caloric applications. The tunability of this class of materials is exceptional and nearly every functionality can be designed. Co2-Heusler compounds show high spin polarization in tunnel junction devices and spin-resolved photoemission. Manganese-rich Heusler compounds attract much interest in the context of spin transfer torque, spin Hall effect, and rare earth free hard magnets. Most Mn2-Heusler compounds crystallize in the inverse structure and are characterized by antiparallel coupling of magnetic moments on Mn atoms; the ferrimagnetic order and the lack of inversion symmetry lead to the emergence of new properties that are absent in ferromagnetic centrosymmetric Heusler structures, such as non-collinear magnetism, topological Hall effect, and skyrmions. Tetragonal Heusler compounds with large magneto crystalline anisotropy can be easily designed by positioning the Fermi energy at the van Hove singularity in one of the spin channels. Here, we give a comprehensive overview and a prospective on the magnetic properties of Heusler materials.

  4. Polymers containing borane or carborane cage compounds and related applications

    Science.gov (United States)

    Bowen, III, Daniel E; Eastwood, Eric A

    2013-04-23

    Polymers comprising residues of cage compound monomers having at least one polyalkoxy silyl substituent are provided. The cage compound monomers are selected from borane cage compound monomers comprising at least 7 cage atoms and/or carborane cage compound monomers comprising 7 to 11 cage compound monomers. Such polymers can further comprise one or more reactive matrices and/or co-monomers covalently bound with the cage compound monomer residues. Articles of manufacture comprising such polymers are also disclosed.

  5. Optimizing the extraction of antibacterial compounds from pineapple leaf fiber

    National Research Council Canada - National Science Library

    Zhikai Zhuang; Jin Zhang; Mingfu Li; Ganran Deng; Zhongqing Ou; Wenwei Lian; Junyan He; Tao Huang

    2016-01-01

    ...) were used to extract antibacterial compounds from pineapple leaf fiber. Compounds extracted using acetone showed the greatest antibacterial effect against , measured by inhibition zone diameter...

  6. [Platinum compounds: metabolism, toxicity and supportive strategies].

    Science.gov (United States)

    Lipp, H P; Hartmann, J T

    2005-02-09

    Although the leading platinum compounds, cisplatin, carboplatin, and oxaliplatin, share some structural similarities, there are marked differences between them in therapeutic uses, pharmacokinetics, and adverse effects profiles. Compared with cisplatin, carboplatin has inferior efficacy in germ-cell tumors, head and neck cancers, and bladder and esophageal carcinomas, whereas the two drugs appear to have comparable efficacy in ovarian cancer, extensive small-cell lung cancers (SCLC), and advanced non-small-cell lung cancers (NSCLC). Oxaliplatin belongs to the group of diaminocyclohexane (DACH) platinum compounds. It is the first platinum-based drug that has marked efficacy in colorectal cancer when given in combination with 5-fluorouracil and folinic acid. Nedaplatin has been registered in Japan, whereas other derivatives, like JM216 (which is the only orally available platinum derivative), ZD0473, BBR3464, and SPI-77 (a liposomal formulation of cisplatin), are still under investigation. The adverse effects of platinum compounds are reviewed together with possible prevention strategies.

  7. Magnetic phase transitions in layered intermetallic compounds

    Science.gov (United States)

    Mushnikov, N. V.; Gerasimov, E. G.; Rosenfeld, E. V.; Terent'ev, P. B.; Gaviko, V. S.

    2012-10-01

    Magnetic, magnetoelastic, and magnetotransport properties have been studied for the RMn2Si2 and RMn6Sn6 (R is a rare earth metal) intermetallic compounds with natural layered structure. The compounds exhibit wide variety of magnetic structures and magnetic phase transitions. Substitution of different R atoms allows us to modify the interatomic distances and interlayer exchange interactions thus providing the transition from antiferromagnetic to ferromagnetic state. Near the boundary of this transition the magnetic structures are very sensitive to the external field, temperature and pressure. The field-induced transitions are accompanied by considerable change in the sample size and resistivity. It has been shown that various magnetic structures and magnetic phase transitions observed in the layered compounds arise as a result of competition of the Mn-Mn and Mn-R exchange interactions.

  8. Volatile Sulfur Compounds from Livestock Production

    DEFF Research Database (Denmark)

    Kasper, Pernille

    2017-01-01

    Volatile sulfur compounds, i.e. hydrogen sulfide, methanethiol and dimethyl sulfide have been identified as key odorants in livestock production due to their high concentration levels and low odor threshold values. At the same time their removal with abatement technologies based on mass transfer...... and, thus, odor removal in these systems. In this context, two processes based on the absorptive oxidation of sulfur compounds in trickling filters containing metal catalysts were examined. One process with iron chelated by ethylenediaminetetraacetic acid (EDTA) was shown to remove hydrogen sulfide...... that the original sample composition was significantly impaired due to adsorption and diffusion at the walls of the measuring equipment. Generally, sulfur compounds were best preserved in both olfactometers and sample bags, while carboxylic acids, 4-methylphenol and trimethylamine were found to undergo substantial...

  9. Three new compounds from Morus nigra L.

    Science.gov (United States)

    Wang, Lei; Yang, Yan; Liu, Chao; Chen, Ruo-Yun

    2010-06-01

    A new 2-arylbenzofuran derivative, mornigrol D (1), along with two new flavones, mornigrol G (2) and mornigrol H (3), and six known compounds, norartocarpetin (4), dihydrokaempferol (5), albanin A (6), albanin E (7), moracin M (8), and albafuran C (9), were isolated from the barks of Morus nigra. Their structures were elucidated by spectroscopic analysis. Compounds 1 and 9 showed antioxidative activities in vitro with inhibition ratios of 98 and 99% at the concentration of 10(-4) mol/l, and of 74 and 75% at the concentration of 10(-5) mol/l. In addition, compounds 1 and 4 showed potent anti-inflammatory activities (inhibition of release of beta-glucuronidase from rat polymorphonuclear leucocytes induced by platelet activating factor) with inhibitory ratios of 65.9% (P < 0.01) and 67.7% (P < 0.01) at a concentration of 10(-5) mol/l.

  10. Compound control methodology for flight vehicles

    CERN Document Server

    Xia, Yuanqing

    2013-01-01

    Compound Control Methodology for Flight Vehicles” focuses on new control methods for flight vehicles. In this monograph the concept of compound control is introduced. It is demonstrated that both Sliding Mode Control (SMC) and Active Disturbance Rejection Control (ADRC) have their own advantages and limitations, i.e., chattering of SMC and the observability of extended state observer (ESO), respectively. It is shown that compound control combines their advantages and improves the performance of the closed-loop systems. The book is self-contained, providing sufficient mathematical foundations for understanding the contents of each chapter. It will be of significant interest to scientists and engineers engaged in the field of flight vehicle control.

  11. Volatile compounds in meat and meat products

    Directory of Open Access Journals (Sweden)

    Monika KOSOWSKA

    Full Text Available Abstract Meaty flavor is composed of a few hundreds of volatile compounds, only minor part of which are responsible for the characteristic odor. It is developed as a result of multi-directional reactions proceeding between non-volatile precursors contained in raw meat under the influence of temperature. The volatile compounds are generated upon: Maillard reactions, lipid oxidation, interactions between Maillard reaction products and lipid oxidation products as well as upon thiamine degradation. The developed flavor is determined by many factors associated with: raw material (breed, sex, diet and age of animal, conditions and process of slaughter, duration and conditions of meat storage, type of muscle, additives applied and the course of the technological process. The objective of this review article is to draw attention to the issue of volatile compounds characteristic for meat products and factors that affect their synthesis.

  12. Bioactive Compounds Found in Brazilian Cerrado Fruits

    Directory of Open Access Journals (Sweden)

    Elisa Flávia Luiz Cardoso Bailão

    2015-10-01

    Full Text Available Functional foods include any natural product that presents health-promoting effects, thereby reducing the risk of chronic diseases. Cerrado fruits are considered a source of bioactive substances, mainly phenolic compounds, making them important functional foods. Despite this, the losses of natural vegetation in the Cerrado are progressive. Hence, the knowledge propagation about the importance of the species found in Cerrado could contribute to the preservation of this biome. This review provides information about Cerrado fruits and highlights the structures and pharmacologic potential of functional compounds found in these fruits. Compounds detected in Caryocar brasiliense Camb. (pequi, Dipteryx alata Vog. (baru, Eugenia dysenterica DC. (cagaita, Eugenia uniflora L. (pitanga, Genipa americana L. (jenipapo, Hancornia speciosa Gomes (mangaba, Mauritia flexuosa L.f. (buriti, Myrciaria cauliflora (DC Berg (jabuticaba, Psidium guajava L. (goiaba, Psidium spp. (araçá, Solanum lycocarpum St. Hill (lobeira, Spondias mombin L. (cajá, Annona crassiflora Mart. (araticum, among others are reported here.

  13. Bioactive Compounds Found in Brazilian Cerrado Fruits.

    Science.gov (United States)

    Bailão, Elisa Flávia Luiz Cardoso; Devilla, Ivano Alessandro; da Conceição, Edemilson Cardoso; Borges, Leonardo Luiz

    2015-10-09

    Functional foods include any natural product that presents health-promoting effects, thereby reducing the risk of chronic diseases. Cerrado fruits are considered a source of bioactive substances, mainly phenolic compounds, making them important functional foods. Despite this, the losses of natural vegetation in the Cerrado are progressive. Hence, the knowledge propagation about the importance of the species found in Cerrado could contribute to the preservation of this biome. This review provides information about Cerrado fruits and highlights the structures and pharmacologic potential of functional compounds found in these fruits. Compounds detected in Caryocar brasiliense Camb. (pequi), Dipteryx alata Vog. (baru), Eugenia dysenterica DC. (cagaita), Eugenia uniflora L. (pitanga), Genipa americana L. (jenipapo), Hancornia speciosa Gomes (mangaba), Mauritia flexuosa L.f. (buriti), Myrciaria cauliflora (DC) Berg (jabuticaba), Psidium guajava L. (goiaba), Psidium spp. (araçá), Solanum lycocarpum St. Hill (lobeira), Spondias mombin L. (cajá), Annona crassiflora Mart. (araticum), among others are reported here.

  14. Compound imaging using Synthetic Aperture Sequential Beamformation

    DEFF Research Database (Denmark)

    Jensen, Casper Bo; Jensen, Jonas; Hemmsen, Martin Christian

    2011-01-01

    Synthetic Aperture Sequential Beamforming (SASB) is a technique with low complexity and the ability to yield a more uniform lateral resolution with range. However, the presence of speckle artifacts in ultrasound images degrades the contrast. In conventional imaging speckle is reduced by using...... spatial compounding at the cost of a reduced frame rate. The objective is to apply spatial compounding to SASB and evaluate if the images have a reduced speckle appearance and thereby an improved image quality in terms of contrast compared to ordinary SASB. Using the simulation software Field II, RF data...... detection the five second stage images are added to form the compounded image. Using a ProFocus scanner and the 8804 linear array transducer (BK Medical, Herlev, Denmark) measurements of a phantom containing water filled cysts are obtained to validate the simulation results. The setup is the same...

  15. Feasibility of a complex compound heat pump

    Science.gov (United States)

    Rockenfeller, Uwe

    1987-07-01

    A feasibility study is described of a double effect gas fired heat pump using ammoniated solid vapor complex compounds as the working media. The cycle takes advantage of the coordinative characteristics of complex compound ligand bonds resulting in large coordination spheres with only one degree of freedom. The cycle has high efficiency, no moving parts, and minimum electrical parasitic requirements. Fluid properties of candidate materials were measured with respect to vapor pressure equilibria, coordination properties and thermal stability. Preliminary reaction rate measurements were performed in adsorption and desorption processes. A computer model of double effect cycle was developed in order to predict the operating performance of the candidate complex compound media. The computer model was used to determine preliminary heat balances and coefficients of performance.

  16. Chemical compounds from Chenopodium album Linn.

    Science.gov (United States)

    Zheng, Wei

    2017-06-01

    Bioactive components from Chenopodium album Linn. were isolated and identified in this research. Light petroleum, dichloromethane and n-BuOH were firstly applied to partition the 75% EtOH extract of Chenopodium album Linn. which were then subjected to normal-phase silica, ODS silica gel column chromatography and semi-preparative HPLC chromatography. By the employment of NMR method in this study, chemical structures of the compounds were elucidated. Three known compounds were isolated from Chenopodium album Linn., and identified as Isolariciresinol 4-O-β-D-glucopyranoside (1), (7’S, 8R, 8’R)-Isolariciresinol (2) and (7’S, 8R, 8’S)-Isolariciresinol (3) by comparison of their spectral data with references. This is the first time that isolation of the compounds mentioned above from Chenopodium album Linn. was achieved.

  17. Magnetic anisotropies of rare-earth compounds

    Science.gov (United States)

    Loewenhaupt, M.; Rotter, M.; Kramp, S.

    2000-03-01

    There are two kinds of magnetic anisotropy in rare-earth compounds: the single-ion anisotropy caused by the crystal field (CF) and the anisotropy of the two-ion interactions. Both types of anisotropy have to be considered to arrive at a consistent description of the magnetic properties of the orthorhombic intermetallic compound NdCu 2. From the analysis of NdCu 2 we can derive predictions for the type of ordering in other isostructural RCu 2 compounds, that agree well with experimental results: If the magnetic moments point into the crystallographic b-direction, an ordering wave vector of (2/3 0 0) is expected. If the moments are oriented perpendicular to b then the ordering wave vector is (2/3 1 0) .

  18. Reliability and radiation effects in compound semiconductors

    CERN Document Server

    Johnston, Allan

    2010-01-01

    This book discusses reliability and radiation effects in compound semiconductors, which have evolved rapidly during the last 15 years. Johnston's perspective in the book focuses on high-reliability applications in space, but his discussion of reliability is applicable to high reliability terrestrial applications as well. The book is important because there are new reliability mechanisms present in compound semiconductors that have produced a great deal of confusion. They are complex, and appear to be major stumbling blocks in the application of these types of devices. Many of the reliability problems that were prominent research topics five to ten years ago have been solved, and the reliability of many of these devices has been improved to the level where they can be used for ten years or more with low failure rates. There is also considerable confusion about the way that space radiation affects compound semiconductors. Some optoelectronic devices are so sensitive to damage in space that they are very difficu...

  19. Radiation synthesis of materials and compounds

    CERN Document Server

    Kharisov, Boris Ildusovich; Ortiz Méndez, Ubaldo

    2013-01-01

    Researchers and engineers working in nuclear laboratories, nuclear electric plants, and elsewhere in the radiochemical industries need a comprehensive handbook describing all possible radiation-chemistry interactions between irradiation and materials, the preparation of materials under distinct radiation types, the possibility of damage of materials under irradiation, and more. Radiation nanotechnology is still practically an undeveloped field, except for some achievements in the fabrication of metallic nanoparticles under ionizing flows. Radiation Synthesis of Materials and Compounds presents the state of the art of the synthesis of materials, composites, and chemical compounds, and describes methods based on the use of ionizing radiation. It is devoted to the preparation of various types of materials (including nanomaterials) and chemical compounds using ionizing radiation (alpha particles, beta particles, gamma rays, x-rays, and neutron, proton, and ion beams). The book presents contributions from leaders ...

  20. Antiviral effect of cationic compounds on bacteriophages

    Directory of Open Access Journals (Sweden)

    Mai Huong eChatain-Ly

    2013-03-01

    Full Text Available The antiviral activity of several cationic compounds - cetytrimethylammonium (CTAB, chitosan, nisin and lysozyme - was investigated on the bacteriophage c2 (DNA head and non-contractile tail infecting Lactococcus strains and the bacteriophage MS2 (F-specific RNA infecting E.coli. Firstly, these activities were evaluated in a phosphate buffer pH 7- 10 mM. The CTAB had a virucidal effect on the Lactococcus bacteriophages, but not on the MS2. After 1 min of contact with 0.125 mM CTAB, the c2 population was reduced from 6 log(pfu/mL to 1,5 log(pfu/mL and completely deactivated at 1 mM. On the contrary, chitosan inhibited the MS2 more than it did the bacteriophages c2. No antiviral effect was observed for the nisin or the lysozyme on bacteriophages after 1 min of treatment. A 1 and 2.5 log reduction was respectively observed for nisin and lysozyme when the treatment time increased (5 or 10 min. These results showed that the antiviral effect depended both on the virus and structure of the antimicrobial compounds. The antiviral activity of these compounds was also evaluated in different physico-chemical conditions and in complex matrices. The antiviral activity of CTAB was impaired in acid pH and with an increase of the ionic strength. These results might be explained by the electrostatic interactions between cationic compounds and negatively charged particles such as bacteriophages or other compounds in a matrix. Milk proved to be protective suggesting the components of food could interfere with antimicrobial compounds.

  1. Antiviral Lead Compounds from Marine Sponges

    Directory of Open Access Journals (Sweden)

    Kenneth P. Minneman

    2010-10-01

    Full Text Available Marine sponges are currently one of the richest sources of pharmacologically active compounds found in the marine environment. These bioactive molecules are often secondary metabolites, whose main function is to enable and/or modulate cellular communication and defense. They are usually produced by functional enzyme clusters in sponges and/or their associated symbiotic microorganisms. Natural product lead compounds from sponges have often been found to be promising pharmaceutical agents. Several of them have successfully been approved as antiviral agents for clinical use or have been advanced to the late stages of clinical trials. Most of these drugs are used for the treatment of human immunodeficiency virus (HIV and herpes simplex virus (HSV. The most important antiviral lead of marine origin reported thus far is nucleoside Ara-A (vidarabine isolated from sponge Tethya crypta. It inhibits viral DNA polymerase and DNA synthesis of herpes, vaccinica and varicella zoster viruses. However due to the discovery of new types of viruses and emergence of drug resistant strains, it is necessary to develop new antiviral lead compounds continuously. Several sponge derived antiviral lead compounds which are hopedto be developed as future drugs are discussed in this review. Supply problems are usually the major bottleneck to the development of these compounds as drugs during clinical trials. However advances in the field of metagenomics and high throughput microbial cultivation has raised the possibility that these techniques could lead to the cost-effective large scale production of such compounds. Perspectives on biotechnological methods with respect to marine drug development are also discussed.

  2. Antiviral lead compounds from marine sponges

    KAUST Repository

    Sagar, Sunil

    2010-10-11

    Marine sponges are currently one of the richest sources of pharmacologically active compounds found in the marine environment. These bioactive molecules are often secondary metabolites, whose main function is to enable and/or modulate cellular communication and defense. They are usually produced by functional enzyme clusters in sponges and/or their associated symbiotic microorganisms. Natural product lead compounds from sponges have often been found to be promising pharmaceutical agents. Several of them have successfully been approved as antiviral agents for clinical use or have been advanced to the late stages of clinical trials. Most of these drugs are used for the treatment of human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The most important antiviral lead of marine origin reported thus far is nucleoside Ara-A (vidarabine) isolated from sponge Tethya crypta. It inhibits viral DNA polymerase and DNA synthesis of herpes, vaccinica and varicella zoster viruses. However due to the discovery of new types of viruses and emergence of drug resistant strains, it is necessary to develop new antiviral lead compounds continuously. Several sponge derived antiviral lead compounds which are hopedto be developed as future drugs are discussed in this review. Supply problems are usually the major bottleneck to the development of these compounds as drugs during clinical trials. However advances in the field of metagenomics and high throughput microbial cultivation has raised the possibility that these techniques could lead to the cost-effective large scale production of such compounds. Perspectives on biotechnological methods with respect to marine drug development are also discussed. 2010 by the authors; licensee MDPI.

  3. Web-accessible Chemical Compound Information

    OpenAIRE

    Roth, Dana L

    2008-01-01

    Web-accessible chemical compound information resources are widely available. In addition to fee-based resources, such as SciFinder Scholar and Beilstein, there is a wide variety of freely accessible resources such as ChemSpider and PubChem. The author provides a general description of various fee-based and free chemical compound resources. The free resources generally offer an acceptable alternative to fee-based resources for quick retrieval. It is assumed that readers will be familiar with ...

  4. Validation of EXAFS Analysis of Iridium Compounds

    Science.gov (United States)

    Feiters, M. C.; Longo, A.; Banerjee, D.; van der Ham, C. J. M.; Hetterscheid, D. G. H.

    2016-05-01

    Results of iridium L3 edge EXAFS measurements of compounds relevant for water oxidation catalysis are compared to those of other structural techniques. The structural results from EXAFS for the Ir compounds investigated here compare well to those of other structural techniques. Multiple scattering contributions are important in the coordinated Cp* and NHC ligands as well as in the IrCl6 unit and the IrO2 rutile structure. NHC is relatively weak compared to Ir, Cl, and even Cp* and O, and often out of phase with the other contributions.

  5. Broad spectrum antibiotic compounds and use thereof

    Energy Technology Data Exchange (ETDEWEB)

    Koglin, Alexander; Strieker, Matthias

    2016-07-05

    The discovery of a non-ribosomal peptide synthetase (NRPS) gene cluster in the genome of Clostridium thermocellum that produces a secondary metabolite that is assembled outside of the host membrane is described. Also described is the identification of homologous NRPS gene clusters from several additional microorganisms. The secondary metabolites produced by the NRPS gene clusters exhibit broad spectrum antibiotic activity. Thus, antibiotic compounds produced by the NRPS gene clusters, and analogs thereof, their use for inhibiting bacterial growth, and methods of making the antibiotic compounds are described.

  6. Web-accessible Chemical Compound Information

    OpenAIRE

    Roth, Dana L

    2008-01-01

    Web-accessible chemical compound information resources are widely available. In addition to fee-based resources, such as SciFinder Scholar and Beilstein, there is a wide variety of freely accessible resources such as ChemSpider and PubChem. The author provides a general description of various fee-based and free chemical compound resources. The free resources generally offer an acceptable alternative to fee-based resources for quick retrieval. It is assumed that readers will be familiar with ...

  7. Reduction of Compound Lotteries with Objective Probabilities

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    2015-01-01

    The reduction of compound lotteries axiom (ROCL) has assumed a central role in the evaluation of behavior toward risk and uncertainty. We present experimental evidence on its validity in the domain of objective probabilities. Our battery of lottery pairs includes simple one-stage lotteries, two....... Therefore, we provide a word of caution for experimenters interested in studying ROCL for other purposes, such as the relationship between ambiguity attitudes and attitudes toward compound lotteries, to carefully think about the design to study ROCL, payment protocols and their interaction...

  8. Exchange bias effect in alloys and compounds.

    Science.gov (United States)

    Giri, S; Patra, M; Majumdar, S

    2011-02-23

    The phenomenology of exchange bias effects observed in structurally single-phase alloys and compounds but composed of a variety of coexisting magnetic phases such as ferromagnetic, antiferromagnetic, ferrimagnetic, spin-glass, cluster-glass and disordered magnetic states are reviewed. The investigations on exchange bias effects are discussed in diverse types of alloys and compounds where qualitative and quantitative aspects of magnetism are focused based on macroscopic experimental tools such as magnetization and magnetoresistance measurements. Here, we focus on improvement of fundamental issues of the exchange bias effects rather than on their technological importance.

  9. Basics of sterile compounding: bubble point testing.

    Science.gov (United States)

    Thoma, Laura

    2014-01-01

    Compounding pharmacies that compound sterile preparations must choose sterile filters that are approved for human use. They may rely on the filter manufacturer's Certificate of Quality to ensure the sterile filter is pyrogen free and has been tested for bacterial retention. The Certificate of Quality from the filter manufacturer also contains other useful information about the filter such as: flow rate and maximum pressure drop, thermal and hydraulic stress, and membrane results of the initial integrity test performed on the filter membrane with water, if a hydrophilic membrane. This article discusses the integrity test, which is often called the water bubble point test.

  10. NUMERICAL MODELING OF COMPOUND CHANNEL FLOWS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A numerical model capable of predicting flow characteristics in a compound channel was established with the 3-D steady continuity and momentum equations along with the transport equations for turbulence kinetic energy and dissipation rate. Closure was achieved with the aid of algebraic relations for turbulent shear stresses. The above equations were discretized with implicit difference approach and solved with a step method along the flow direction. The computational results showing the lateral distribution of vertical average velocities and the latio of total flow in the compound channel agree well with the available experimental data.

  11. Volatile compound formation during argan kernel roasting.

    Science.gov (United States)

    El Monfalouti, Hanae; Charrouf, Zoubida; Giordano, Manuela; Guillaume, Dominique; Kartah, Badreddine; Harhar, Hicham; Gharby, Saïd; Denhez, Clément; Zeppa, Giuseppe

    2013-01-01

    Virgin edible argan oil is prepared by cold-pressing argan kernels previously roasted at 110 degrees C for up to 25 minutes. The concentration of 40 volatile compounds in virgin edible argan oil was determined as a function of argan kernel roasting time. Most of the volatile compounds begin to be formed after 15 to 25 minutes of roasting. This suggests that a strictly controlled roasting time should allow the modulation of argan oil taste and thus satisfy different types of consumers. This could be of major importance considering the present booming use of edible argan oil.

  12. Synthesis of Dibenzylidene Sorbitol Series Compound

    Institute of Scientific and Technical Information of China (English)

    FENG Rongxiu; CHEN Ligong; HOU Zhongke; SONG Jian

    2007-01-01

    A series of alditol derivatives were designed and synthesized with relatively high yield. On the basis of reaction between sorbitol and a series of substituted benzaldehyde in the presence of an acid catalyst, a series of acetal derivatives were synthesized through free hydroxyl esterification. D-sorbitol acetal amido derivatives were prepared by reduction of nitryl and acylation of amino. Dsorbitol acetal carboxyl esterification derivatives were prepared through esterification and hydrolysis. By high performance liquid chromatography-mass spectra (HPLC-MS) and H nuclear magneticresonance spectra (1 H-NMR), 36 compounds prepared were identified. Among these derivatives prepared, 26 compounds have not been reported in the previous literatures.

  13. Bioactive compounds from Iostephane heterophylla (Asteraceae).

    Science.gov (United States)

    Aguilar, M I; Delgado, G; Hernández, M L; Villarreal, M L

    2001-01-01

    The novel bisabolene sesquiterpenes 3-6, were isolated from Iostephane heterophylla, using bioguided fractionation. The new compounds were determined to be (12R/12S)-12,13-epoxy-xanthorrhizols (3,4) and (12R/12S)-12,13-dihydro-12,13-dihydroxy-xanthorrizols (5,6) and their structures were characterized by analysis of spectroscopic data and by chemical correlation from xanthorrhizol (2). The stereochemistry at C-12 of 5 was deduced using the modified Mosher experiment. Some of the isolated compounds elicited activity against gram positive and gram negative bacteria, levadura and dermatophytes.

  14. Magnetic moment densities in selected UTX compounds

    Energy Technology Data Exchange (ETDEWEB)

    Javorsky, P.; Schweizer, J.; Givord, F.; Boucherle, J.-X.; Andreev, A.V.; Divis, M.; Lelievre-Berna, E.; Sechovsky, V

    2004-07-15

    We present results of polarized neutron-diffraction studies of magnetization distribution in several isostructural UTX compounds. Besides the uranium magnetic moment, we observe a significant magnetization also on the transition-metal sites and in the interstitial region, close to the X-atom site. The values of the moments induced on the T-atoms in the U-T and T-X basal planes are rather similar for compounds with 3d-metals, UNiGa, UNiAl, and UCoAl, while a difference occurs in UPtAl. Our results are compared with literature data for URhAl and URuAl.

  15. Phonological Processes in Complex and Compound Words

    Directory of Open Access Journals (Sweden)

    Alieh Kord Zaferanlu Kambuziya

    2016-01-01

    Full Text Available Abstract This research at making a comparison between phonological processes in complex and compound Persian words. Data are gathered from a 40,000-word Persian dictionary. To catch some results, 4,034 complex words and 1,464 compound ones are chosen. To count the data, "excel" software is used. Some results of the research are: 1- "Insertion" is the usual phonological process in complex words. More than half of different insertions belongs to the consonant /g/. Then /y/ and // are in the second and the third order. The consonant /v/ has the least percentage of all. The most percentage of vowel insertion belongs to /e/. The vowels /a/ and /o/ are in the second and third order. Deletion in complex words can only be seen in consonant /t/ and vowel /e/. 2- The most frequent phonological processes in compounds is consonant deletion. In this process, seven different consonants including /t/, //, /m/, /r/, / ǰ/, /d, and /c/. The only deleted vowel is /e/. In both groups of complex and compound, /t/ deletion can be observed. A sequence of three consonants paves the way for the deletion of one of the consonants, if one of the sequences is a sonorant one like /n/, the deletion process rarely happens. 3- In complex words, consonant deletion causes a lighter syllable weight, whereas vowel deletion causes a heavier syllable weight. So, both of the processes lead to bi-moraic weight. 4- The production of bi-moraic syllable in Persian is preferable to Syllable Contact Law. So, Specific Rules have precedence to Universals. 5- Vowel insertion can be seen in both groups of complex and compound words. In complex words, /e/ insertion has the most fundamental part. The vowels /a/ and /o/ are in the second and third place. Whenever there are two sequences of ultra-heavy syllables. By vowel insertion, the first syllable is broken into two light syllables. The compounds that are influenced by vowel insertion, can be and are pronounced without any

  16. Phonological Processes in Complex and Compound Words

    Directory of Open Access Journals (Sweden)

    Alieh Kord Zaferanlu Kambuziya

    2016-02-01

    Full Text Available Abstract This research at making a comparison between phonological processes in complex and compound Persian words. Data are gathered from a 40,000-word Persian dictionary. To catch some results, 4,034 complex words and 1,464 compound ones are chosen. To count the data, "excel" software is used. Some results of the research are: 1- "Insertion" is the usual phonological process in complex words. More than half of different insertions belongs to the consonant /g/. Then /y/ and // are in the second and the third order. The consonant /v/ has the least percentage of all. The most percentage of vowel insertion belongs to /e/. The vowels /a/ and /o/ are in the second and third order. Deletion in complex words can only be seen in consonant /t/ and vowel /e/. 2- The most frequent phonological processes in compounds is consonant deletion. In this process, seven different consonants including /t/, //, /m/, /r/, / ǰ/, /d, and /c/. The only deleted vowel is /e/. In both groups of complex and compound, /t/ deletion can be observed. A sequence of three consonants paves the way for the deletion of one of the consonants, if one of the sequences is a sonorant one like /n/, the deletion process rarely happens. 3- In complex words, consonant deletion causes a lighter syllable weight, whereas vowel deletion causes a heavier syllable weight. So, both of the processes lead to bi-moraic weight. 4- The production of bi-moraic syllable in Persian is preferable to Syllable Contact Law. So, Specific Rules have precedence to Universals. 5- Vowel insertion can be seen in both groups of complex and compound words. In complex words, /e/ insertion has the most fundamental part. The vowels /a/ and /o/ are in the second and third place. Whenever there are two sequences of ultra-heavy syllables. By vowel insertion, the first syllable is broken into two light syllables. The compounds that are influenced by vowel insertion, can be and are pronounced without any insertion

  17. Dissolution behavior of lithium compounds in ethanol

    Directory of Open Access Journals (Sweden)

    Tomohiro Furukawa

    2016-12-01

    Full Text Available In order to exchange the components which received irradiation damage during the operation at the International Fusion Materials Irradiation Facility, the adhered lithium, which is partially converted to lithium compounds such as lithium oxide and lithium hydroxide, should be removed from the components. In this study, the dissolution experiments of lithium compounds (lithium nitride, lithium hydroxide, and lithium oxide were performed in a candidate solvent, allowing the clarification of time and temperature dependence. Based on the results, a cleaning procedure for adhered lithium on the inner surface of the components was proposed.

  18. Independent Community Pharmacists' Perspectives on Compounding in Contemporary Pharmacy Education

    Science.gov (United States)

    McPherson, Timothy B.; Fontane, Patrick E.; Berry, Tricia; Chereson, Rasma; Bilger, Rhonda

    2009-01-01

    Objectives To identify compounding practices of independent community pharmacy practitioners in order to make recommendations for the development of curricular objectives for doctor of pharmacy (PharmD) programs. Methods Independent community practitioners were asked about compounding regarding their motivations, common activities, educational exposures, and recommendations for PharmD education. Results Most respondents (69%) accepted compounding as a component of pharmaceutical care and compounded dermatological preparations for local effects, oral solutions, and suspensions at least once a week. Ninety-five percent were exposed to compounding in required pharmacy school courses and most (98%) who identified compounding as a professional service offered in their pharmacy sought additional postgraduate compounding education. Regardless of the extent of compounding emphasis in the practices surveyed, 84% stated that PharmD curricula should include compounding. Conclusions Pharmacy schools should define compounding curricular objectives and develop compounding abilities in a required laboratory course to prepare graduates for pharmaceutical care practice. PMID:19564997

  19. Study on Compound Effect of Bonded Magnets

    Institute of Scientific and Technical Information of China (English)

    Chang Ying; Ma Nuo; Yu xiaojun; Li Wei; Liu Changsheng; Lian Fazeng

    2004-01-01

    The compound effect of Nd2Fe14B/Fe3B-Ferrite bonded magnets was studied.The result shows that the value ofβjHC obviously decreases with the ferrite content increasing.In addition, a functional relation between magnetic properties and ferrite content was clearly revealed by the physical relation in the magnetic powders.

  20. Spatial Information Capacity of Compound Eyes

    NARCIS (Netherlands)

    Snyder, Allan W.; Stavenga, Doekele G.; Laughlin, Simon B.

    1977-01-01

    The capacity of the compound eye to perceive its spatial environment is quantified by determining the number of different pictures that can be reconstructed by its array of retinula cells. We can then decide on the best compromise between an animal's capacity for fine detail and contrast sensitivity

  1. Mutagenic compounds from chlorination of humic substances

    Science.gov (United States)

    Holmbom, Bjarne

    Chlorination of natural humic substances, as well as of lignin, produces a myriad of non-chlorinated and chlorinated compounds. The identification of an important class of strongly mutagenic compounds is reviewed. The most important Ames mutagen in chlorinated drinking waters of various origin is the compound 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone ("MX"). This compound occurs at neutral pH in the acyclic form, i.e. in the form of Z-2-chloro-3-(dichloromethyl)-4-oxobutenoic acid. Its E-isomer (E-MX) is present in chlorinated drinking waters at a similar concentration, but is less mutagenic in Ames test. Both oxidised and reduced forms of MX and E-MX are also present in chlorinated waters. The present knowledge of the chemistry and toxicology of these mutagens is examined. The formation and possible elimination of the chlorination mutagens is discussed. The need of understanding the mechanisms of formation of these mutagens from humic substances during drinking water chlorination is emphasized.

  2. Effects of polycationic compounds on mitogen stimulation

    DEFF Research Database (Denmark)

    Heron, I; Larsen, B; Hokland, M

    1981-01-01

    and cell density experiments. The direct effect on cells was found not to be due to monocyte bypass or to activation of non-T cells by the mitogen. It is pointed out that effect of chemicals on in vitro immunresponses have to be considered in relation to the charge properties of the compound...

  3. Alkylcobalt(III) compounds with ammine ligands

    DEFF Research Database (Denmark)

    Kofod, Pauli

    2005-01-01

    Amminecobalt(III) compounds with a coordinated primary alkyl group (ethyl, n-propyl, n-butyl, 2-phenylethyl, 3-aminopropyl) have been prepared using monoalkylhydrazines as alkylating agents. The identities have been established using solution 1H and 13C NMR spectroscopy and elemental analysis...

  4. Two new compounds from Trollius chinensis Bunge.

    Science.gov (United States)

    Jie-Shi, Ya; Wei-Sang, Lin; Yan, Rui; Zhao, Qiang; Zhang, Yang; Yun-Zhao, Gui; Cong-Li, Yun; Chen, Xue; Yu-Zhang, Chong; Qiao, Hua; Gang-Zhang, Guo

    2017-01-01

    Two new compounds, 2″-O-feruloylisoswertiajaponin (1) and (2E)-2-methyl-1-O-vaniloyl-4-β-D-glucopyranoside-2-butene (2), along with one indole alkaloid and five known flavonoids, were isolated from the flowers of Trollius chinensis Bunge. Their structures were elucidated on the basis of spectroscopic evidence (UV, IR, HR-ESI-MS, NMR).

  5. Soil science: Heat-proof carbon compound

    Science.gov (United States)

    Prescott, Cindy

    2008-12-01

    Two-thirds of terrestrial carbon is stored as organic matter in soils, but its response to warming has yet to be resolved. A soil warming experiment in a Canadian forest has revealed that the leaf-derived compound cutin is resistant to decomposition under elevated temperatures.

  6. Process for the preparation of aromatic compounds

    NARCIS (Netherlands)

    Schenk, N.J.; Biesbroek, Arnold; Heeres, André; Heeres, Hero

    2015-01-01

    Aromatic compounds are prepared from a feed stream comprising biomass or a mixture of biomass and synthetic polymer in a process, comprising: a) subjecting the feed stream to a pyrolysis treatment in the presence of a cracking catalyst to yield a vaporous fraction comprising hydrocarbons with

  7. Study on resistance coefficient in compound channels

    Institute of Scientific and Technical Information of China (English)

    Kejun Yang; Shuyou Cao; Xingnian Liu; Ron Marshall

    2005-01-01

    This paper presents a further study of the Manning and Darcy-Weisbach resistance coefficients, as they play a significant role in assessing the cross-sectional mean velocity, conveyance capacity and determining the lateral distribution of depth mean velocity and local boundary shear stress in compound channels. The relationships between the local, zonal and overall resistance coefficients, and a wide range of geometries and different roughness between the main channel and the flood plain are established by analyzing a vast amount of experimental data from a British Science and Engineering Research Council Flood Channel Facility (SERC-FCF). And the experimental results also show that the overall Darcy-Weisbach resistance coefficient for a compound channel is the function of Reynolds number, but the function relationship is different from that for a single channel. By comparing and analyzing the conventional methods with the experimental data to predict composite roughness in compound channels, it is found that these methods are not suitable for compound channels. Moreover, the reason why the conventional methods cannot assess correctly the conveyance capacity of com pound channels is also analyzed in this paper.

  8. Atmospheric degradation mechanism of organic sulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Benter, T.; Arsene, C.

    2002-02-01

    In the present work a detailed product study has been performed on the OH radical initiated oxidation of dimethyl sulphide and dimethyl sulphoxide, under different conditions of temperature, partial pressure of oxygen and NO{sub x} concentration, in order to better define the degradation mechanism of the above compounds under conditions which prevail in the atmosphere. (orig.)

  9. Testing of Compounds for Efficacy against Schistosomiasis.

    Science.gov (United States)

    1987-08-25

    n the snail intermediate host is Oncomelani " hnsi q u ada from the Philippine Islands. Protocol WRHN:-IIa and WRHN-IIb. A total of 31 compounds were...1978. Linhagem humana, de S fanm. resistente a esquistossomicidas. Revista de Saude Publica de Sao Paulo, 12:110. 3. Dias, L.C.S., Pedro, R.J., and

  10. Excretion of biliary compounds during intrauterine life

    Institute of Scientific and Technical Information of China (English)

    Rocio IR Macias; Jose JG Marin; Maria A Serrano

    2009-01-01

    In adults, the hepatobiliary system, together with thekidney, constitute the main routes for the eliminationof several endogenous and xenobiotic compounds intobile and urine, respectively. However, during intrauterinelife the biliary route of excretion for cholephiliccompounds, such as bile acids and biliary pigments, isvery poor. Although very early in pregnancy the fetal liver produces bile acids, bilirubin and biliverdin, these compounds cannot be efficiently eliminated by the fetal hepatobiliary system, owing to the immaturity of the excretory machinery in the fetal liver. Therefore, the potentially harmful accumulation of cholephilic compounds in the fetus is prevented by their elimination across the placenta. Owing to the presence of detoxifying enzymes and specific transport systems at different locations of the placental barrier, such as the endothelial cells of chorionic vessels and trophoblast cells, this organ plays an important role in the hepatobiliary-like function during intrauterine life. The relevance of this excretory function in normal fetal physiology is evident in situations where high concentrations of biliary compounds are accumulated in the mother. This may result in oxidative stress and apoptosis, mainly in the placenta and fetal liver, which might affect normal fetal development and challenge the fate of the pregnancy. The present article reviews current knowledge of the mechanisms underlying the hepatobiliary function of the fetal-placental unit and the repercussions of several pathological conditions on this tandem.

  11. A view on organocopper compounds an cuprates

    NARCIS (Netherlands)

    Koten, G. van

    1990-01-01

    Research on the chemistry and structural aspects of ortho-substituted-arylcopper and -cuprate compounds in which the ortho-substituents either interfere sterically with the C{i}{p}{s}{o}-to-copper bonding or have a potentially coordinating heteroatom, is described. Concluded is that the simple arylc

  12. Teachers’ knowledge for teaching compound interest

    Directory of Open Access Journals (Sweden)

    Craig Pournara

    2013-09-01

    Full Text Available There is increasing acknowledgement that teachers’ knowledge for teaching mathematics is multifaceted and topic specific. Given the paucity of research on the teaching and learning of financial mathematics in general, little can be known about teachers’ knowledge for teaching compound interest. However, since financial mathematics is a component of the school curriculum in South Africa, and an important element of financial literacy more broadly, attention needs to be given to knowledge for teaching financial mathematics, and compound interest in particular. Drawing from a larger study in which the author taught a financial mathematics course to pre-service secondary mathematics teachers, a theoretical elaboration is provided of the underlying mathematics of compound interest, and connections with the world of banking. Based on findings from the study, two key student errors are identified: the over-generalisation of linear thinking in multiplicative scenarios, and the over-generalisation of reversible operations in percentage-change scenarios. Taken together, teachers’ knowledge of relevant mathematics, of the banking context and of learners’ conceptions will contribute to building a knowledge-base for teachers’ knowledge for teaching compound interest.

  13. Antibacterial compounds from Salvia adenophora Fernald (Lamiaceae).

    Science.gov (United States)

    Bisio, Angela; Schito, Anna Maria; Ebrahimi, Samad Nejad; Hamburger, Matthias; Mele, Giacomo; Piatti, Gabriella; Romussi, Giovanni; Dal Piaz, Fabrizio; De Tommasi, Nunziatina

    2015-02-01

    From the aerial parts of Salvia adenophora Fernald four derivatives of 12-oxo-phytodienoic acid (1-4) together with five clerodane diterpenoids (5, 6, 8-10), and one known diterpene (7) have been isolated. Compounds 1-6 and 8-10 are described for the first time. The structures were established by extensive 1D, 2D NMR and HRESI-TOFMS spectroscopic methods. Finally, the absolute configuration has been established by comparing of experimental and quantum chemical calculation of ECD spectra. Despite a total lack of antimicrobial activity of the plant extract, hinting to the existence of antagonistic interactions in the crude material, three oxylipins (2-4) displayed a promising inhibition on Gram-positive multidrug-resistant clinical strains including Staphylococcus aureus, Streptococcus agalactiae and, particularly, Staphylococcus epidermidis, while the compounds 9 and 10 revealed a specific and strain-dependent activity against S. epidermidis. Interestingly, the inhibition provided by these compounds was independent of the resistance patterns of these pathogens to classic antibiotics. No action was reported on Gram-negative strains nor on Candida albicans. These results confirm that clerodanes and, particularly, prostaglandin-like compounds can be considered as interesting antimicrobial agents deserving further study.

  14. Iron(III) spin crossover compounds

    NARCIS (Netherlands)

    van Koningsbruggen, PJ; Maeda, Y; Oshio, H

    2004-01-01

    In this chapter, selected results obtained so far on Fe(III) spin crossover compounds are summarized and discussed. Fe(III) spin transition materials of ligands containing chalcogen donor atoms are considered with emphasis on those of N,N-disubstituted-dithiocarbamates, N,N-disubstituted-XY-carbamat

  15. Analyzing volatile compounds in dairy products

    Science.gov (United States)

    Volatile compounds give the first indication of the flavor in a dairy product. Volatiles are isolated from the sample matrix and then analyzed by chromatography, sensory methods, or an electronic nose. Isolation may be performed by solvent extraction or headspace analysis, and gas chromatography i...

  16. Baseline isotopic data of polyhalogenated compounds

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, Walter [University of Hohenheim, Institute of Food Chemistry, Garbenstr. 28, D-70593 Stuttgart (Germany)]. E-mail: w-vetter@uni-hohenheim.de; Armbruster, Wolfgang [University of Hohenheim, Institute of Food Chemistry, Garbenstr. 28, D-70593 Stuttgart (Germany); Betson, Tatiana R. [Medical Biochemistry and Biophysics, Umea University, SE-901 87 Umea (Sweden); Schleucher, Juergen [Medical Biochemistry and Biophysics, Umea University, SE-901 87 Umea (Sweden); Kapp, Thomas [University of Hohenheim, Institute of Food Chemistry, Garbenstr. 28, D-70593 Stuttgart (Germany); Lehnert, Katja [University of Hohenheim, Institute of Food Chemistry, Garbenstr. 28, D-70593 Stuttgart (Germany)

    2006-09-08

    The {delta} {sup 2}H- and {delta} {sup 13}C-values of polyhalogenated compounds were determined by EA-IRMS. Most of the compounds were related to the chloropesticides DDT and its metabolites, hexachlorocyclohexanes, and toxaphene, as well as several polybrominated compounds such as bromophenols and -anisoles. {delta} {sup 2}H-values ranged between -235 per mille and +75 per mille whereas {delta} {sup 13}C-values were found in the range -22 per mille to -38 per mille . No correlation between {delta} {sup 2}H- and {delta} {sup 13}C-values could be identified. Comparative analysis clarified that bromophenols and the corresponding bromoanisoles may vary in their isotopic distribution. {sup 2}H NMR was used to quantify abundances of {sup 2}H isotopomers. Quantification of isotopomers of 2,4-dibromophenol and 2,4-dibromoanisole proved that both compounds from different suppliers do not originate from the same source. Differences in the {delta} {sup 2}H-values of two toxaphene products were further investigated by the synthesis of products of different degree of chlorination from camphene. It was shown that the {delta} {sup 13}C-values remained mostly unaltered as was expected since no carbon is lost in this procedure. However, the reaction products became enriched in {sup 2}H with increasing degree of chlorination. Different {delta} {sup 2}H-values of the starting material will also impact the {delta} {sup 2}H-values of the chlorination products.

  17. Visualizing Compound Rotations with Virtual Reality

    Science.gov (United States)

    Flanders, Megan; Kavanagh, Richard C.

    2013-01-01

    Mental rotations are among the most difficult of all spatial tasks to perform, and even those with high levels of spatial ability can struggle to visualize the result of compound rotations. This pilot study investigates the use of the virtual reality-based Rotation Tool, created using the Virtual Reality Modeling Language (VRML) together with…

  18. Photoelectron spectroscopy of strongly correlated Yb compounds

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, J.J.; Andrews, A.B.; Arko, A.J.; Bartlett, R.J.; Blythe, R.I. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Olson, C.G.; Benning, P.J.; Canfield, P.C. [Ames Laboratory, U. S. Department of Energy, Ames, Iowa 50011 (United States); Poirier, D.M. [Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    1996-12-01

    The electronic properties of the Yb compounds YBCu{sub 2}Si{sub 2}, YBAgCu{sub 4}, and YbAl{sub 3} along with purely divalent Yb metal, have been investigated by means of high-resolution ultraviolet and x-ray photoelectron spectroscopy. We present the intrinsic characteristic features of the 4{ital f} levels of Yb while accounting for lattice vibrations and the manifestation of corelike energy levels degenerate with the valence states and modified by the temperature-dependent Fermi function. For these strongly correlated Yb-based compounds, the hole occupancy values ({ital n}{sub {ital f}}{approximately}0.6) directly obtained from integration of the divalent and trivalent portions of the 4{ital f} photoemission features indicate that these compounds are strongly mixed valent. The small intensity modulation with temperature in the divalent Yb 4{ital f} levels (0{endash}10{percent} over a {ital T}=20{minus}300 K range) is discussed within the conventional framework of the photoemission process and nominal allowances for lattice variations with temperature. Results from photoemission experiments on the divalent 4{ital f} levels of strongly correlated Yb compounds are remarkably similar to the 4{ital f} levels of purely divalent Yb metal. {copyright} {ital 1996 The American Physical Society.}

  19. A Novel Route of Furan Compounds Syntheses

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A series of compounds that contained furan skeletons were synthesized using 3,4-bis(trimethylsilyl)furan as staring material. 1H NMR, 13C NMR, MS and EA had identified these new molecules. The important factors that influenced reactions were discussed, and the new furan intermediates could be used in various organic syntheses.

  20. Quantum chemical studies of estrogenic compounds

    Science.gov (United States)

    Quantum chemical methods are potent tools to provide information on the chemical structure and electronic properties of organic molecules. Modern computational chemistry methods have provided a great deal of insight into the binding of estrogenic compounds to estrogenic receptors (ER), an important ...

  1. Adsorption of Organic Compounds to Building Products

    DEFF Research Database (Denmark)

    Kjær, Ulla Dorte

    The presence of VOCs (Volatile Organic Compounds) in the indoor air may be a contributory cause of complaints about irritation of mucous membranes in eyes, nose and throat, difficulty in breathing, frequent airway inflammation, skin irritation, fatigue, concentration difficulty, dizziness and hea...

  2. Screening for bioactive compounds from algae.

    Science.gov (United States)

    Plaza, M; Santoyo, S; Jaime, L; García-Blairsy Reina, G; Herrero, M; Señoráns, F J; Ibáñez, E

    2010-01-20

    In the present work, a comprehensive methodology to carry out the screening for novel natural functional compounds is presented. To do that, a new strategy has been developed including the use of unexplored natural sources (i.e., algae and microalgae) together with environmentally clean extraction techniques and advanced analytical tools. The developed procedure allows also estimating the functional activities of the different extracts obtained and even more important, to correlate these activities with their particular chemical composition. By applying this methodology it has been possible to carry out the screening for bioactive compounds in the algae Himanthalia elongata and the microalgae Synechocystis sp. Both algae produced active extracts in terms of both antioxidant and antimicrobial activity. The obtained pressurized liquid extracts were chemically characterized by GC-MS and HPLC-DAD. Different fatty acids and volatile compounds with antimicrobial activity were identified, such as phytol, fucosterol, neophytadiene or palmitic, palmitoleic and oleic acids. Based on the results obtained, ethanol was selected as the most appropriate solvent to extract this kind of compounds from the natural sources studied.

  3. Exit problems for oscillating compound Poisson process

    CERN Document Server

    Kadankova, Tetyana

    2011-01-01

    In this article we determine the Laplace transforms of the main boundary functionals of the oscillating compound Poisson process. These are the first passage time of the level, the joint distribution of the first exit time from the interval and the value of the overshoot through the boundary. Under certain conditions we establish the asymptotic behaviour of the mentioned functionals.

  4. Fluorescent compounds for plastic scintillation applications

    Energy Technology Data Exchange (ETDEWEB)

    Pla-Dalmau, A.; Bross, A.D.

    1994-04-01

    Several 2-(2{prime}-hydroxyphenyl)benzothiazole, -benzoxazole, and -benzimidazole derivatives have been prepared. Transmittance, fluorescence, light yield, and decay time characteristics of these compounds have been studied in a polystyrene matrix and evaluated for use in plastic scintillation detectors. Radiation damage studies utilizing a {sup 60}C source have also been performed.

  5. Self injection of Dichlorvos, an Organophosphorus Compound

    Directory of Open Access Journals (Sweden)

    Sujeet Raina

    2008-07-01

    Full Text Available We report two patients who injected themselves a strong organophosphate compound, dichlorvas, and showed the typical clinical picture of organophosphate intoxication. There are very few case reports of parenteral organophosphorous poisoning. With the appropriate therapy, their symptoms disappeared in a few days. The cases are reported because of unusual and interesting way of intoxication.

  6. Analysis of cell death inducing compounds

    DEFF Research Database (Denmark)

    Spicker, Jeppe; Pedersen, Henrik Toft; Nielsen, Henrik Bjørn

    2007-01-01

    Biomarkers for early detection of toxicity hold the promise of improving the failure rates in drug development. In the present study, gene expression levels were measured using full-genome RAE230 version 2 Affymetrix GeneChips on rat liver tissue 48 h after administration of six different compounds...... in the literature and the novel finding represents a putative hepatotoxicity biomarker....

  7. Microscale Group Test for Carbonyl Compounds.

    Science.gov (United States)

    Horak, V.; Klein, R. F. X.

    1985-01-01

    Procedures are provided for a test that (1) demonstrates principles of derivatization with 2,4-dinitrophenylhydrazine; (2) is a thin layer chromatography experiment that visually demonstrates separation of colored compounds of different polarities; and (3) introduces microscale experimentation to students in sophomore organic chemistry…

  8. XANES spectra of transition metal compounds

    NARCIS (Netherlands)

    de Groot, F.M.F.|info:eu-repo/dai/nl/08747610X

    2009-01-01

    An overview is given of the interactions that determine the XANES spectral shapes of transition metal compounds. The interactions are divided into ground state effects, final state effects and transition effects. The metal L edges, metal K edges and ligand K edges are analysed with respect to these

  9. Storage compound production by phototrophic diatoms

    NARCIS (Netherlands)

    Mooij, P.R.; Van Loosdrecht, M.C.M.; Kleerebezem, R.

    2015-01-01

    The invention is directed to a method for producing an enriched diatom culture, comprising subjecting a starting culture comprising one or more diatom species to selective pressure, thus giving a competitive advantage to storage compound producing species of diatoms, by subjecting said starting cult

  10. Targeting Platinum Compounds: synthesis and biological activity

    OpenAIRE

    VAN ZUTPHEN, Steven

    2005-01-01

    Inspired by cisplatin, the inorganic drug discovered by Barnett Rosenberg in 1965, the research described in this thesis uses targeting ligands, or ligands varied in a combinatorial fashion, to find platinum complexes with more specific modes of action. These studies have lead to the development of novel (solid-phase) synthetic methods and to the discovery of several compounds with promising biological properties.

  11. Aryldicyclopentadienyltitanium compounds and their dinitrogen complexes

    NARCIS (Netherlands)

    Teuben, Jan Harmannus

    1973-01-01

    This thesis describes the synthesis and some characteristic properties of organotitanium compounds of the type Cp2TiR and the dinitrogen complexes (Cp2TiR)2N2 (R= aryl, benzyl; Cp = n-cyclopentadienyl). ... Zie: Summary

  12. The Compoundness and Sequentiality of Digital Inequality

    NARCIS (Netherlands)

    Deursen, van Alexander; Helsper, Ellen; Eynon, Rebecca; Dijk, van Jan

    2017-01-01

    Through a survey with a representative sample of Dutch Internet users, this article examines compound digital exclusion: whether a person who lacks a particular digital skill also lacks another kind of skill, whether a person who does not engage in a particular way online is also less likely to enga

  13. Two new phenolic compounds from Artemisia sphaerocephala

    Institute of Scientific and Technical Information of China (English)

    Dong Bao Zhao; Lin Xi Li; Xiu Hua Liu; Ming Jing Li; Wen Ling Wang

    2007-01-01

    Two new phenolic compounds were isolated from whole plant of Artemisia sphaerocephala. The structures were elucidated on the basis of spectroscopic methods as 4-(1-hydroxylethyl)-phenol-1-O-β-D-glucopyranoside and 4-O-acetophenone-β-D-glucopyranosyl-(1-3)-β-D-glucopyranoside.

  14. Xeno-estrogenic compounds in precipitation

    NARCIS (Netherlands)

    Peters, R.J.B.; Beeltje, H.; Delft, R.J.

    2008-01-01

    The exposure to some chemicals can lead to hormone disrupting effects. Presently, much attention is focused on so-called xeno-estrogens, synthetic compounds that interact with hormone receptors causing a number of reactions that eventually lead to effects related to reproduction and development. The

  15. Two new phenolic compounds from Ardisia gigantifolia

    Institute of Scientific and Technical Information of China (English)

    Zhu Yang; Ping Wen; Nai Li Wang; Xin Sheng Yao

    2008-01-01

    Two new compounds were isolated from the 60% ethanol extract of the dried rhizome of Ardisia gigantifolia Stapf. The structures were elucidated on the basis of spectroscopic methods as (+)-5-(1,2-dihydroxypentyl)-benzene-1,3-diol and (-)-5-(1,2-dihydroxypentyl) benzene-1,3-diol.

  16. Flavor compounds of popped amaranth seeds

    NARCIS (Netherlands)

    Gamel, T.H.; Linssen, J.P.H.

    2008-01-01

    Amaranth caudatus seeds were popped and studied for optimal popping conditions and flavor compounds. The optimum popping temperature for the seeds was 180C. At this temperature, the expansion volume, flake size and unpopped kernel proportion were 9.4¿11.3 cm3/g, 0.010¿0.012 cm/g and 10¿2%, respectiv

  17. Atmospheric nitrogen compounds: Occurrence, composition and deposition

    DEFF Research Database (Denmark)

    Nielsen, T.; Pilegaard, K.; Egeløv, A.H.;

    1996-01-01

    Traffic in cities and on highways is an important contributor to NOy atmospheric pollution in open areas. In this situation both the concentration and composition of NOy compounds show a wide variation and are dependent on meteorological and atmospheric chemical conditions. The proportion of NOz...

  18. Visualizing Compound Rotations with Virtual Reality

    Science.gov (United States)

    Flanders, Megan; Kavanagh, Richard C.

    2013-01-01

    Mental rotations are among the most difficult of all spatial tasks to perform, and even those with high levels of spatial ability can struggle to visualize the result of compound rotations. This pilot study investigates the use of the virtual reality-based Rotation Tool, created using the Virtual Reality Modeling Language (VRML) together with…

  19. Distribution of antiherbivory compounds in Flourensia cernua

    Science.gov (United States)

    Flourensia cernua is serving as a shrub model to study the influence of terpenes on intake by livestock at this location. Two studies (n=20 plants per study) were conducted to examine within plant distribution of volatile compounds to improve sampling protocol. Leaves from 3 positions (outer canopy,...

  20. Fast Screening of Antibacterial Compounds from Fusaria

    DEFF Research Database (Denmark)

    Sondergaard, Teis Esben; Fredborg, Marlene; Christensen, Ann-Maria Oppenhagen

    2016-01-01

    Bio-guided screening is an important method to identify bioactive compounds from fungi. In this study we applied a fast digital time-lapse microscopic method for assessment of the antibacterial properties of secondary metabolites from the fungal genus Fusarium. Here antibacterial effects could be...

  1. Determination of Phytochemical Compounds, and Tyrosinase ...

    African Journals Online (AJOL)

    compounds, namely, (E)-2,4-dihydroxy-3-(3,7-dimethyl-2,6-octadienyl) benzaldehyde ... natural whitening agents. ... yield a petroleum ether extract. ... carrier gas was helium 5.6 at a flow rate 1.2 .... needles, soluble in methanol and dimethyl.

  2. Biogenic volatile organic compounds - small is beautiful

    Science.gov (United States)

    Owen, S. M.; Asensio, D.; Li, Q.; Penuelas, J.

    2012-12-01

    While canopy and regional scale flux measurements of biogenic volatile organic compounds (bVOCs) are essential to obtain an integrated picture of total compound reaching the atmosphere, many fascinating and important emission details are waiting to be discovered at smaller scales, in different ecological and functional compartments. We concentrate on bVOCs below ground to allelopathy. A gradient of monoterpene concentration was found in soil around Pinus sylvestris and Pinus halepensis, decreasing with distance from the tree. Some compounds (α-pinene, sabinene, humulene and caryophyllene) in mineral soil were linearly correlated with the total amount of each compound in the overlying litter, indicating that litter might be the dominant source of these compounds. However, α-pinene did not fall within the correlation, indicating a source other than litter, probably root exudates. We also show that rhizosphere bVOCs can be a carbon source for soil microbes. In a horizontal gradient from Populus tremula trees, microbes closest to the tree trunk were better enzymatically equipped to metabolise labeled monoterpene substrate. Monoterpenes can also increase the degradation rate in soil of the persistant organic pollutants, likely acting as analogues for the cometabo-lism of polychlorinated biphenyls (PCBs) Flowers of a ginger species (Alpinia kwangsiensis) and a fig species (Ficus hispida) showed different bVOC signals pre- and post pollination. For Ficus hispida, there are three floral stages of a fig-wasp dependency mechanism: receptive, post pollinator and interfloral. Of 28 compounds detected, transcaryophyllene with trans-β-farnesene were the most important at the receptor stage, trans-caryophyllene was the most abundant at the post-pollinator stage, and isoprene was the most abundant in the interfloral stage. Alpinia kwangsiensis presents two morphologies for the reproductive parts of the flower. The "anaflexistyle" morphology has the flower style lowered in the

  3. Special Heusler compounds for spintronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Balke, B.

    2007-07-01

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

  4. Comparative angioprotective effects of magnesium compounds.

    Science.gov (United States)

    Kharitonova, Maria; Iezhitsa, Igor; Zheltova, Anastasia; Ozerov, Alexander; Spasov, Alexander; Skalny, Anatoly

    2015-01-01

    Magnesium (Mg) deficiency is implicated in the development of numerous disorders of the cardiovascular system. Moreover, the data regarding the efficacy of different magnesium compounds in the correction of impaired functions due to low magnesium intake are often fragmentary and inconsistent. The aim of this study was to compare the effects of the most bioavailable Mg compounds (Mg l-aspartate, Mg N-acetyltaurate, Mg chloride, Mg sulphate and Mg oxybutyrate) on systemic inflammation and endothelial dysfunction in rats fed a low Mg diet for 74 days. A low Mg diet decreased the Mg concentration in the plasma and erythrocytes, which was accompanied by a reduced concentration of eNOs and increased levels of endothelin-1 level in the serum and impaired endothelium-dependent vasodilatation. These effects increased the concentration of proinflammatory molecules, such as VCAM-1, TNF-α, IL-6 and CRP, indicating the development of systemic inflammation and endothelial dysfunction. The increased total NO level, which estimated from the sum of the nitrate and nitrite concentrations in the serum, may also be considered to be a proinflammatory marker. Two weeks of Mg supplementation partially or fully normalised the ability of the vascular wall to effect adequate endothelium-dependent vasodilatation and reversed the levels of most endothelial dysfunction and inflammatory markers (except CRP) to the mean values of the control group. Mg sulphate had the smallest effect on the endothelin-1, TNF-α and VCAM-1 levels. Mg N-acetyltaurate was significantly more effective in restoring the level of eNOS compared to all other studied compounds, except for Mg oxybutyrate. Taken together, the present findings demonstrate that all Mg compounds equally alleviate endothelial dysfunction and inflammation caused by Mg deficiency. Mg sulphate tended to be the least effective compound.

  5. Student Evaluation of Online Pharmaceutical Compounding Videos.

    Science.gov (United States)

    Park, Hanna L; Shrewsbury, Robert P

    2016-03-25

    Objective. To describe pharmacy students' views on the effectiveness of an expansion of the compounding laboratory website at the UNC Eshelman School of Pharmacy. Methods. Originally, there were 39 videos and three animations available. In 2011, an additional 59 videos and two animations were added. Concurrently, all of the interactive questions were updated to fully integrate with the expanded video library. Students were surveyed about the expanded video library regarding accessibility, functionality, and usefulness, and how using the library impacted their learning of compounding. Surveys were analyzed with descriptive statistics. Means and SDs were calculated for the rating scale questions; independent t tests and Wilcoxon nonparametric tests were used to find differences between professional classes and campuses. Analytical results were evaluated with a one-way analysis of variance (ANOVA), z test, and a homogeneity of variance (Levene's) test. Results. The response rate to the survey was 85%. Compounding videos were used by 386/391 students. Thirty-four percent of students used the videos an average of 30 minutes or less per week; 56% used the videos 1-2 hours per week. Approximately 80% of students were satisfied with the functionality and accessibility of the videos. All students, regardless of professional year or campus affiliation, put their confidence/competence at about 70% of the rating scale. Conclusions. As no standardized compounding curriculum was found in US schools of pharmacy and students reported being satisfied with the website, it could be an accessible, functional, and useful resource for pharmaceutical compounding in schools of pharmacy.

  6. Spin state switching in iron coordination compounds

    Directory of Open Access Journals (Sweden)

    Philipp Gütlich

    2013-02-01

    Full Text Available The article deals with coordination compounds of iron(II that may exhibit thermally induced spin transition, known as spin crossover, depending on the nature of the coordinating ligand sphere. Spin transition in such compounds also occurs under pressure and irradiation with light. The spin states involved have different magnetic and optical properties suitable for their detection and characterization. Spin crossover compounds, though known for more than eight decades, have become most attractive in recent years and are extensively studied by chemists and physicists. The switching properties make such materials potential candidates for practical applications in thermal and pressure sensors as well as optical devices.The article begins with a brief description of the principle of molecular spin state switching using simple concepts of ligand field theory. Conditions to be fulfilled in order to observe spin crossover will be explained and general remarks regarding the chemical nature that is important for the occurrence of spin crossover will be made. A subsequent section describes the molecular consequences of spin crossover and the variety of physical techniques usually applied for their characterization. The effects of light irradiation (LIESST and application of pressure are subjects of two separate sections. The major part of this account concentrates on selected spin crossover compounds of iron(II, with particular emphasis on the chemical and physical influences on the spin crossover behavior. The vast variety of compounds exhibiting this fascinating switching phenomenon encompasses mono-, oligo- and polynuclear iron(II complexes and cages, polymeric 1D, 2D and 3D systems, nanomaterials, and polyfunctional materials that combine spin crossover with another physical or chemical property.

  7. Production of the rare ginsenosides compound K, compound Y, and compound Mc by a thermostable beta-glycosidase from Sulfolobus acidocaldarius.

    Science.gov (United States)

    Noh, Kyeong-Hwan; Oh, Deok-Kun

    2009-11-01

    The rare ginsenosides compound K, compound Y, and compound Mc were produced from the major ginsenosides Rb(1), Rb(2), Rc, and Rd by a thermostable beta-glycosidase from Sulfolobus acidocaldarius via three pathways: Rb(1)-->Rd-->compound K, Rb(2)-->compound Y-->compound K, and Rc-->compound Mc. Each of the ginsenosides was identified by high-performance liquid chromatography using standards and liquid chromatography-mass spectrometry based on their molecular weights. The catalytic efficiency of the enzyme for ginsenosides followed the order Rb(1) (4.8)>Rc (4.5)>Rd (1.0)>Rb(2) (0.77 mM(-1) min(-1)). The enzyme converted 1 mg/ml reagent-grade Rb(1), Rb(2), and Rc to 0.53 mg/ml compound K, 0.56 mg/ml compound Y, and 0.70 mg/ml compound Mc, respectively, at pH 5.5 and 85 degrees C after 180 min, corresponding to mole conversion yields of 94, 80, and 100% (mol/mol), respectively. The enzyme converted the major ginsenosides Rb(1), Rb(2), Rc, and Rd in 10% (w/v) ginseng root extract to the rare ginsenosides with a mole yield of 99% after 24 h. These results suggest that beta-glycosidase from S. acidocaldarius can be used to produce compound K, compound Y, and compound Mc.

  8. Synthesis of a naphthalene-hydroxynaphthalene polymer model compound

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-02

    The objective of this project was the synthesis of one pound of a new naphthalene-hydroxynaphthalene polymer model compound for use in coal combustion studies. Since this compound was an unreported compound, this effort also required the development of a synthetic route to this compound (including routes to the unique and unreported intermediates leading to its synthesis).

  9. Human biological monitoring of suspected endocrine-disrupting compounds

    OpenAIRE

    Moosa Faniband; Lindh, Christian H; Bo AG Jönsson

    2014-01-01

    Endocrine-disrupting compounds are exogenous agents that interfere with the natural hormones of the body. Human biological monitoring is a powerful method for monitoring exposure to endocrine disrupting compounds. In this review, we describe human biological monitoring systems for different groups of endocrine disrupting compounds, polychlorinated biphenyls, brominated flame retardants, phthalates, alkylphenols, pesticides, metals, perfluronated compounds, parabens, ultraviolet filters, and o...

  10. Tritium labeling of organic compounds deposited on porous structures

    Science.gov (United States)

    Ehrenkaufer, Richard L. E.; Wolf, Alfred P.; Hembree, Wylie C.

    1979-01-01

    An improved process for labeling organic compounds with tritium is carried out by depositing the selected compound on the extensive surface of a porous structure such as a membrane filter and exposing the membrane containing the compound to tritium gas activated by the microwave discharge technique. The labeled compound is then recovered from the porous structure.

  11. A New Nonlinear Compound Forecasting Method Based on ANN

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper the compound-forecasting method is discussed. The compound-forecasting method is one of the hotspots in the current predication. Firstly, the compound-forecasting method is introduced and various existing compound-forecasting methods arediscussed. Secondly, the Artificial Neural Network (ANN) is brought in compound-prediction research and a nonlinear compound-prediction model based on ANN is presented. Finally, inorder to avoid irregular weight, a new method is presented which uses principal component analyses to increase the availability of compound-forecasting information. Higherforecasting precision is achieved in practice.

  12. Synthesis, Chemistry, and Applications of Heterocyclic Cage Compounds (V)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ The synthesis and chemistry of polycyclic of cage compounds have attracted considerable attention in recent years. The vast majority of the work reported in this area has dealt with carbocylic cage compounds. On the other hand, the synthesis and chemistry of heterocyclic cage compounds have received less attention. Recently, we envisioned that studies on the synthesis and chemistry of heterocyclic cage compounds can greatly expand the scopes and utilities of cage compounds.1 As part of a program that involves the synthesis, chemistry, and application of heterocyclic cage compounds, we report here the synthesis of new thia-oxa-cage compounds and the chemical nature of these thia-cages.

  13. THE COMPOUND NOUNS BETWEEN ENGLISH AND ALBANIAN LANGUAGE

    OpenAIRE

    Shkelqim Millaku; Xhevahire Topanica

    2016-01-01

    The compound words are all the words that are compound from two or more words and both of them creative the new words with the new meaning. In linguistics, a compound is a lexeme (less precisely, a word) that consists of more than one stem. Compounding or composition is the word-formation that creates compound lexemes (the other word-formation process being derivation). Compounding or Word-compounding refers to the faculty and device of language to form new words by combining or putting toget...

  14. Luminescence investigation of Dy2O2S and Dy2O2SO4 obtained by thermal decomposition of sulfate hydrate

    Institute of Scientific and Technical Information of China (English)

    RV Rodrigues; L Marciniak; LU Khan; JR Matos; HF Brito; W Strk

    2016-01-01

    The yellow emitting dysprosium oxysulfide (Dy2O2S) and dysprosium oxysulfate (Dy2O2SO4) compounds were prepared from the thermal decomposition of hydrated dysprosium sulphate. The materials were characterized by using thermogravimetry (TG/DTG), X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopies. The thermal stability temperatures at around 1151 and 1313 K were determined for the Dy2O2S and Dy2O2SO4 materials, respectively. The photolumines-cence properties of the dysprosium oxysulfide were investigated, showing narrow emission bands assigned to the 4F9/2→6HJ intracon-figurational transitions of the Dy3+ion. The yellow emission color of this phosphor suggests that the Dy2O2S is a promising material for applications in LEDs.

  15. Raman scattering in transition metal compounds: Titanium and compounds of titanium

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, J.; Ederer, D.L.; Shu, T. [Tulane Univ., New Orleans, LA (United States)] [and others

    1997-04-01

    The transition metal compounds form a very interesting and important set of materials. The diversity arises from the many states of ionization the transition elements may take when forming compounds. This variety provides ample opportunity for a large class of materials to have a vast range of electronic and magnetic properties. The x-ray spectroscopy of the transition elements is especially interesting because they have unfilled d bands that are at the bottom of the conduction band with atomic like structure. This group embarked on the systematic study of transition metal sulfides and oxides. As an example of the type of spectra observed in some of these compounds they have chosen to showcase the L{sub II, III} emission and Raman scattering in some titanium compounds obtained by photon excitation.

  16. Volatile compounds of commercial Milano salami.

    Science.gov (United States)

    Meynier, A; Novelli, E; Chizzolini, R; Zanardi, E; Gandemer, G

    1999-02-01

    The relationship between extracted volatiles of Milano salami, one of the main dry-cured sausages produced in Italy, and their olfactory properties was studied. Volatile compounds were extracted by a purge-and-trap method, quantified using a flame ionisation detector and identified by mass spectrometry. Olfactory analysis was performed by sniffing the gas chromatographic effluent. Nearly 80 compounds were identified and quantified: most came from spices (60.5%), 18.9% from lipid oxidation, 11.8% from amino acid catabolism and 4.9% from fermentation processes. Panellists detected 19 odours by sniffing. These odours were associated with spices, lipid oxidation or fermentation and were in agreement with the contributions of each reaction to the overall aroma of the product.

  17. Screening Some Plants for their Antiproliferative Compounds

    Directory of Open Access Journals (Sweden)

    Ufuk Kolak

    2012-03-01

    Full Text Available This paper covers the screening of the secondary plant products to find a cure against cancer which were piled up during the years. In early stages of these studies highly active antitumor glycoproteins were obtained from native Arizona (USA plants. Later smaller molecules were isolated showing antitumor activity in different test systems. Among these compounds sesquiterpene lactones with an exo-methylene group in the lactone ring, unsaturated diterpenoids and some triterpenoids exhibited activity in vivo and in vitro test systems. A few Colchicum alkaloids showed high activity against murine lymphocytic leukemia (P388. Activity also established in some flavonoidal compounds. Today all around the world research on Natural Products is still going on.

  18. Synthesis and properties of trifluoromethylating steroid compounds

    Institute of Scientific and Technical Information of China (English)

    王钟麒; 卢寿福; 张建蓉

    1997-01-01

    Trifluoromethyl steroids la,b; 2a,b; 3a,b have been synthesized by starting from estren 3,17-dicarbonyl-3,3-dimethyl ether (4) and dl-18-methyl-2(3)l5(10)-estra-diene-17-carbonyl-3-methyl ether (5),and by using trimthyltrifluoromethylsilane as the trifluoromethylating agent under the catalysis of tetrarnethylam-monium fluoride.The overall yields were 82%,76%; 54%,62%; and 27%,25%,respectively The α-configura tion of trifluoromethyl group of 17-position was determined by X-ray crystal diffraction method Compounds 1a,2a and 3a showed high affinity for rat uterus PRc.The test of biological activities of compounds 1b,2b and 3b is proceeding.

  19. Intercalation compounds involving inorganic layered structures

    Directory of Open Access Journals (Sweden)

    CONSTANTINO VERA R. L.

    2000-01-01

    Full Text Available Two-dimensional inorganic networks can shown intracrystalline reactivity, i.e., simple ions, large species as Keggin ions, organic species, coordination compounds or organometallics can be incorporated in the interlayer region. The host-guest interaction usually causes changes in their chemical, catalytic, electronic and optical properties. The isolation of materials with interesting properties and making use of soft chemistry routes have given rise the possibility of industrial and technological applications of these compounds. We have been using several synthetic approaches to intercalate porphyrins and phthalocyanines into inorganic materials: smectite clays, layered double hydroxides and layered niobates. The isolated materials have been characterized by elemental and thermal analysis, X-ray diffraction, surface area measurements, scanning electronic microscopy, electronic and resonance Raman spectroscopies and EPR. The degree of layer stacking and the charge density of the matrices as well their acid-base nature were considered in our studies on the interaction between the macrocycles and inorganic hosts.

  20. [Today's threat of use of organophosphorus compounds].

    Science.gov (United States)

    Sokołowski, Rafał; Płusa, Tadeusz

    2015-09-01

    Organophosphates are stable cholinesterases inhibitors (AChE). Inhibition of AChE activity leads to the accumulation of large amounts of acetylcholine and hyperactivity of the cholinergic system by stimulating acetylcholine receptors - muscarinic and nicotinic. This group included tabun, sarin, soman and VX gases. Exposure to gaseous form causes symptoms within a few seconds of exposure. This depends on the gas concentration in the atmosphere. The most sensitive organ is the eyes and the respiratory system. Severe poisoning are characterized by the immediate loss of consciousness with convulsions. Therapeutic management of acute poisoning organophosphorus compounds boils down to treating symptomatic and supportive vital functions. Monitoring of cardiovascular, respiratory and renal failure in intensive care gives only guarantee the effective treatment of poisoning. Properties toxic organophosphorus compounds also are of interest to terrorist groups.

  1. Quaternary ammonium compounds – New occupational hazards

    Directory of Open Access Journals (Sweden)

    Agnieszka Lipińska-Ojrzanowska

    2014-10-01

    Full Text Available Quaternary ammonium compounds (QACs, quats belong to organic ionic chemical agents which display unique properties of both surfactants and disinfectants. Their wide distribution in the work environment and also in private households brings about new occupational hazards. This paper reviews reports about the health effects of QACs. QACs could play a role of sensitizers and irritants to the skin and mucous membranes. It is suspected that particular QACs can display an immunologic crossreactivity between each other and with other chemical compounds containing ammonium ion, such as muscle relaxants widely used in anesthesia. They may promote the development of airway allergy, however, the background mechanisms are still unclear and need to be further investigated. Until now, a few cases of occupational asthma induced by QACs have been described and their involvement in contact dermatitis has been documented. The possibility of anaphylaxis due to QACs cannot be excluded as well. Med Pr 2014;65(5:675–682

  2. Pickpocket compounds from Latin to Romance

    DEFF Research Database (Denmark)

    Whitehead, Benedicte Nielsen

    –noun, represented by truck–driver, has the deverbal member second and carries an agentive suffix, -er. Pickpocket compounds are attested in early strata of Greek and Indo–Iranian and in medieval strata of Germanic, Slavic and Romance. Latin has around a dozen examples. The scholarly debate, continued in this thesis....... It contains a cursory discussion of Homeric Greek, Indo–Iranian and Germanic representatives. This comparative perspective on the morphology of the type is continued in chapters 3–5 on Latin and Romance. An important conclusion, and an answer to one of the most–discussed questions in the debate......, is that these compounds cannot be considered univerbated imperative clauses. (2) is likewise assessed preliminarily in chapter 2, offering an outline of the history of the Greek and Indo–Aryan material. Taking the history of the Latin/Romance material up for revision, chapters 3–5 conclude that Latin offers no evidence...

  3. Reactive spreading: Adsorption, ridging and compound formation

    Energy Technology Data Exchange (ETDEWEB)

    Saiz, E.; Cannon, R.M.; Tomsia, A.P.

    2000-09-11

    Reactive spreading, in which a chemically active element is added to promote wetting of noble metals on nonmetallic materials, is evaluated. Theories for the energetics and kinetics of the necessary steps involved in spreading are outlined and compared to the steps in compound formation that typically accompany reactive wetting. These include: fluid flow, active metal adsorption, including nonequilibrium effects, and triple line ridging. All of these can be faster than compound nucleation under certain conditions. Analysis and assessment of recently reported experiments on metal/ceramic systems lead to a focus on those conditions under which spreading proceeds ahead of the actual formation of a new phase at the interface. This scenario may be more typical than believed, and perhaps the most effective situation leading to enhanced spreading. A rationale for the pervasive variability and hysteresis observed during high temperature wetting also emerges.

  4. Adsorption of lignosulfonate compounds using powdered eggshell

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Zulfikar

    2012-07-01

    Full Text Available Batch adsorption of lignosulfonates using untreated powdered eggshell under the influences of mixing time, pH,particle size and dose of powdered eggshell was investigated. Adsorption isotherms of lignosulfonates onto powder eggshellwere also studied. Eggshells were collected from the Balubur traditional market in Bandung, Indonesia, washed with distilledwater, air dried, and then ground into powder of different particle sizes. Kinetic studies found that equilibrium time was ashigh as 90 minutes. From experiments carried out at different pH, it was observed that pH plays an important role in theadsorption of lignosulfonate compounds. It was also observed that particles size has no significant effect on the adsorptionof lignosulfonate compounds. The optimum dosage of powdered eggshell was 30 g/100 mL of 500 mg/L lignosulfonatesolution. Adsorption isotherms studied through the use of graphical methods revealed that the adsorption of lignosulfonatesonto powdered eggshell follows the Langmuir model.

  5. NOVEL BIOACTIVE COMPOUNDS FROM MANGROVE DERIVED ACTINOMYCETES

    Directory of Open Access Journals (Sweden)

    Kumari Amrita

    2012-09-01

    Full Text Available Mangrove is most productive and unexplored ecosystem that approximately covers one fourth of world coastline with high diversity of thriving organism. Recently the rate of isolation of novel bioactive compounds from microorganism living in mangrove forest has tremendously increased which is reflected in significant hasten for exploration of mangrove actinomycetes. Actinomycetes are group of bacteria which are extremely interesting as active producers of many primary and secondary metabolites. Many survey reports has depicted that the biologically active compounds which have been obtained so far from microbes, 45 percent are produced by actinomycetes, 38 percent by fungi and 17 percent by unicellular bacteria. Actinomycetes from mangrove environment provide diverse and are potential rich source of antibiotics, anticancer, antifungal and antiviral agent, enzyme and enzyme inhibitor. Mangrove actinomycetes are a prolific but underexploited source for the discovery of novel secondary metabolites.

  6. Compound Composite Odontoma and Its Management

    Directory of Open Access Journals (Sweden)

    Morawala Abdul

    2014-01-01

    Full Text Available Odontomas are odontogenic benign tumors composed of dental tissue. Majority of these lesions are asymptomatic and are often detected on routine radiographs. They can be thought of as “tooth hamartomas" with the lesion consisting of various tooth components. They are divided histologically into complex odontomas and compound odontomas. This paper describes the case of a compound odontoma in a 13-year-old girl diagnosed due to the retention of the primary right mandibular second molar. A surgical excision was performed without disturbing the unerupted premolar. The results achieved indicate that early diagnosis of odontomas enables adoption of less complex treatment, a better prognosis, and displacement or devitalisation of adjacent tooth.

  7. Oxyfluoride Chemistry of Layered Perovskite Compounds

    Directory of Open Access Journals (Sweden)

    Yoshihiro Tsujimoto

    2012-03-01

    Full Text Available In this paper, we review recent progress and new challenges in the area of oxyfluoride perovskite, especially layered systems including Ruddlesden-Popper (RP, Dion-Jacobson (DJ and Aurivillius (AV type perovskite families. It is difficult to synthesize oxyfluoride perovskite using a conventional solid-state reaction because of the high chemical stability of the simple fluoride starting materials. Nevertheless, persistent efforts made by solid-state chemists have led to a major breakthrough in stabilizing such a mixed anion system. In particular, it is known that layered perovskite compounds exhibit a rich variety of O/F site occupation according to the synthesis used. We also present the synthetic strategies to further extend RP type perovskite compounds, with particular reference to newly synthesized oxyfluorides, Sr2CoO3F and Sr3Fe2O5+xF2−x (x ~ 0.44.

  8. A New Compound Along With Seven Known Compounds from an Endophytic Fungus Aspergillus sp. HS-05

    Directory of Open Access Journals (Sweden)

    Gang Chen

    2013-08-01

    Full Text Available Investigation of EtOAc extract from the fermentation broth of the endophytic fungus Asperilligus sp. HS-05 led to the isolation of a new compound (1 of spiro moiety named aspergispiroketal and seven known compounds (2-8. Their structures were elucidated mainly by NMR and HR-TOF-MS, as well as on comparison with the reported data. The absolute configuration of 1 was defined by comparison of quantum chemical TDDFT calculated and experimental ECD spectra.

  9. Metals and metal compounds in cancer treatment.

    Science.gov (United States)

    Desoize, Bernard

    2004-01-01

    Metals and metal compounds have been used in medicine for several thousands of years. In this review we summarized the anti-cancer activities of the ten most active metals: arsenic, antimony, bismuth, gold, vanadium, iron, rhodium, titanium, gallium and platinum. The first reviewed metal, arsenic, presents the anomaly of displaying anti-cancer and oncogenic properties simultaneously. Some antimony derivatives, such as Sb2O3, salt (tartrate) and organic compounds, show interesting results. Bismuth directly affects Helicobacter pylori and gastric lymphoma; the effects of bismuth complexes of 6-mercaptopurine are promising. Gold(I) and (III) compounds show anti-tumour activities, although toxicity remains high. Research into the potential use of gold derivatives is still ongoing. Several derivatives of vanadium show anti-proliferative activity, but their toxicity must be overcome. Several pieces of evidence indicate that iron deprivation could be an excellent therapeutic approach; furthermore, it is synergistic with classic anti-cancer drugs. Rhodium belongs to the same group as platinum and it also presents interesting activity, but with the same nephrotoxicity. Several rhodium compounds have entered phase I clinical trials. In contrast to the platinum complexes, titanium derivatives showed no evidence of nephrotoxicity or myelotoxicity; titanocene dichloride is undergoing clinical trial. The anti-proliferative effect of gallium could be related to its competition with the iron atom; in addition a derivative appears to reverse the multidrug resistance. The last metal reviewed, platinum, has given some of the very best anti-cancer drugs. Four derivatives are used today in the clinic; their mechanism of action and of resistance are described.

  10. Characterization of A New Organic Photochromic Compound

    Institute of Scientific and Technical Information of China (English)

    LIU,Guang-Fei; LIU,Lang; JIA,Dian-Zeng; HU,Xin; YU,Kai-Bei

    2004-01-01

    @@ A new organic photochromic compound, 1-phenyl-3-methyl-4-(4-fluoro)-benzal-5-pyrazolone ethanyl-thiosemicarbazone (PM4FBP-ETSC) was found to undergo photochromic reactions in the solid state. Upon irradiation with 365nm light the white powder sample turned light yellow. The photochromic properties were characterized by the time-dependent UV-vis reflective spectra. The structure of PM4FBP-ETSC was determined by single crystal X-ray diffraction.

  11. Fungal Endophthalmitis Associated with Compounded Products

    OpenAIRE

    Mikosz, Christina A.; Rachel M. Smith; Kim, Moon; Tyson, Clara; Lee, Ellen H.; Adams, Eleanor; Straif-Bourgeois, Susanne; Sowadsky, Rick; Arroyo, Shannon; Grant-Greene, Yoran; Duran, Julie; Vasquez, Yvonne; Robinson, Byron F.; Harris, Julie R.; Lockhart, Shawn R.

    2014-01-01

    Fungal endophthalmitis is a rare but serious infection. In March 2012, several cases of probable and laboratory-confirmed fungal endophthalmitis occurring after invasive ocular procedures were reported nationwide. We identified 47 cases in 9 states: 21 patients had been exposed to the intraocular dye Brilliant Blue G (BBG) during retinal surgery, and the other 26 had received an intravitreal injection containing triamcinolone acetonide. Both drugs were produced by Franck’s Compounding Lab (Oc...

  12. Novel ocular antihypertensive compounds in clinical trials

    Directory of Open Access Journals (Sweden)

    Chen J

    2011-05-01

    Full Text Available June Chen1, Stephen A Runyan1, Michael R Robinson21Department of Biological Sciences, 2Ophthalmology Clinical Research, Allergan, Inc, Irvine, CA, USAIntroduction: Glaucoma is a multifactorial disease characterized by progressive optic nerve injury and visual field defects. Elevated intraocular pressure (IOP is the most widely recognized risk factor for the onset and progression of open-angle glaucoma, and IOP-lowering medications comprise the primary treatment strategy. IOP elevation in glaucoma is associated with diminished or obstructed aqueous humor outflow. Pharmacotherapy reduces IOP by suppressing aqueous inflow and/or increasing aqueous outflow.Purpose: This review focuses on novel non-FDA approved ocular antihypertensive compounds being investigated for IOP reduction in ocular hypertensive and glaucoma patients in active clinical trials within approximately the past 2 years.Methods: The mode of IOP reduction, pharmacology, efficacy, and safety of these new agents were assessed. Relevant drug efficacy and safety trials were identified from searches of various scientific literature databases and clinical trial registries. Compounds with no specified drug class, insufficient background information, reformulations, and fixed-combinations of marketed drugs were not considered.Results: The investigational agents identified comprise those that act on the same targets of established drug classes approved by the FDA (ie, prostaglandin analogs and β-adrenergic blockers as well as agents belonging to novel drug classes with unique mechanisms of action. Novel targets and compounds evaluated in clinical trials include an actin polymerization inhibitor (ie, latrunculin, Rho-associated protein kinase inhibitors, adenosine receptor analogs, an angiotensin II type 1 receptor antagonist, cannabinoid receptor agonists, and a serotonin receptor antagonist.Conclusion: The clinical value of novel compounds for the treatment of glaucoma will depend

  13. Basics of compounding foam dosage forms.

    Science.gov (United States)

    Allen, Loyd V

    2013-01-01

    The purpose of this article is to provide information on the use of foam dosage forms and pharmacists' ability to extemporaneously compound them. The article provides: (1) a discussion on the rationale and advantages of using foams, (2) a differentiation between the various types and structures of foams, (3) a list of the various types of ingredients and examples of each, and (4) a description of the preparation of pharmaceutical foams.

  14. Photocatalytic oxidation of organic compounds on Mars

    Science.gov (United States)

    Chun, S. F. S.; Pang, K. D.; Cutts, J. A.; Ajello, J. M.

    1978-01-01

    Ultraviolet-stimulated catalytic oxidation is proposed as a mechanism for the destruction of organic compounds on Mars. The process involves the presence of gaseous oxygen, UV radiation, and a catalyst (titanium dioxide), and all three of these have been found to be present in the Martian environment. Therefore it seems plausible that UV-stimulated oxidation of organics is responsible for degrading organic molecules into inorganic end products.

  15. Fipronil Compound Consumption Presenting as Status Epilepticus

    OpenAIRE

    Bharathraj, M.Y; Venugopal, K; Jaligidad, Kadappa; Karibasappa, Halli; Kumar, Hemantha

    2015-01-01

    Fipronil is a broadspectrum N-phenylpyrazole insecticide with gamma-aminobutyric acid type A receptor inhibitory action causing hyperexcitability of central nervous system. There is no literature reported in the past concerning its acute toxicity in human beings. A case report is useful for workers in medical and veterinary field. Hence, we are reporting a case in which young male intoxicated with fipronil compound was presented to the emergency department for having generalized tonic-clonic ...

  16. Cometary micrometeorites and input of prebiotic compounds

    OpenAIRE

    2014-01-01

    The apparition of life on the early Earth was probably favored by inputs of extraterrestrial matter brought by carbonaceous chondrite-like objects or cometary material. Interplanetary dust collected nowadays on Earth is related to carbonaceous chondrites and to cometary material. They contain in particular at least a few percent of organic matter, organic compounds (amino-acids, PAHs,…), hydrous silicates, and could have largely contributed to the budget of prebiotic matter on Earth, about 4 ...

  17. Tetrazolium Compounds: Synthesis and Applications in Medicine

    Directory of Open Access Journals (Sweden)

    Cheng-Xi Wei

    2015-03-01

    Full Text Available Tetrazoles represent a class of five-membered heterocyclic compounds with polynitrogen electron-rich planar structural features. This special structure makes tetrazole derivatives useful drugs, explosives, and other functional materials with a wide range of applications in many fields of medicine, agriculture, material science, etc. Based on our research works on azoles and other references in recent years, this review covers reported work on the synthesis and biological activities of tetrazole derivatives.

  18. Expatriate Compound Living: An Ethnographic Field Study

    DEFF Research Database (Denmark)

    Lauring, Jakob; Selmer, Jan

    2009-01-01

    and the expatriates had the same working hours in the same subsidiary. Results show that a Danish national group was established and maintained. This in-group dominated life in the compound and at work it may have contributed to the perceptual bias and discriminatory behaviour demonstrated by the Danish expatriates...... in their management of the foreign national employees. Implications of these findings are discussed in detail....

  19. Aromatic compounds from three Brazilian Lauraceae species

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Andrea Nastri de Luca; Batista Junior, Joao Marcos; Lopez, Silvia Noeli; Furlan, Maysa; Cavalheiro, Alberto Jose; Silva, Dulce Helena Siqueira; Bolzani, Vanderlan da Silva [UNESP, Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Quimica Organica; Nunomura, Sergio Massayoshi [Instituto Nacional de Pesquisa da Amazonia (INPA), Manaus, AM (Brazil). Dept. de Produtos Naturais; Yoshida, Massayoshi [Centro de Biotecnologia da Amazonia, Manaus, AM (Brazil)

    2010-07-01

    Phytochemical investigations on three Brazilian Lauraceae species from the Cerrado region of Sao Paulo State, Ocotea corymbosa (Meins) Mez., O. elegans Mez. and Persea pyrifolia Nees and Mart. ex Nees resulted in the isolation of flavonoids, an ester of the 4-O-E-caffeoylquinic acid, an aromatic sesquiterpene besides furofuran lignans. This is the first chemical study on the leaves of Ocotea elegans and O. corymbosa as well as the first report of non-volatile compounds from Persea pyrifolia. (author)

  20. Growing Single Crystals of Compound Semiconductors

    Science.gov (United States)

    Naumann, Robert J.; Lehoczky, Sandor L.; Frazier, Donald O.

    1987-01-01

    Defect reduced by preventing melt/furnace contact and suppressing convention. Large crystals of compound semiconductors with few defects grown by proposed new method. Such materials as gallium arsenide and cadmium telluride produced, with quality suitable for very-large-scale integrated circuits or for large focal-plane arrays of photodetectors. Method used on small scale in Earth gravity, but needs microgravity to provide crystals large enough for industrial use.

  1. Antimalarial compounds from Kniphofia foliosa roots.

    Science.gov (United States)

    Wube, Abraham Abebe; Bucar, Franz; Asres, Kaleab; Gibbons, Simon; Rattray, Lauren; Croft, Simon L

    2005-06-01

    During the course of screening Ethiopian medicinal plants for their antimalarial properties, it was found that the dichloromethane extract of the roots of Kniphofia foliosa Hochst. (Asphodelaceae), which have long been used in the traditional medicine of Ethiopia for the treatment of abdominal cramps and wound healing, displayed strong in vitro antiplasmodial activity against the chloroquine-sensitive 3D7 strain of Plasmodium falciparum with an ED50 value of 3.8 microg/mL and weak cytotoxic activity against KB cells with an ED50 value of 35.2 microg/mL. Five compounds were isolated from the roots and evaluated for their in vitro antimalarial activity. Among the compounds tested, 10-(chrysophanol-7'-yl)-10-(xi)-hydroxychrysopanol-9-anthrone and chryslandicin, showed a high inhibition of the growth of the malaria parasite, P. falciparum with ED50 values of 0.260 and 0.537 microg/mL, respectively, while the naphthalene derivative, 2-acetyl-1-hydroxy-8-methoxy-3-methylnaphthalene, exhibited a less significant antimalarial activity with an ED50 value of 15.4 microg/mL. To compare the effect on the parasite with toxicity to mammalian cells, the cytotoxic activities of the isolated compounds against the KB cell line were evaluated and 10-(chrysophanol-7'-yl)-10-(xi)-hydroxychrysopanol-9-anthrone and chryslandicin displayed very low toxicity with ED50 values of 104 and 90 microg/mL, respectively. This is the first report of the inhibition of the growth of P. falciparum by anthraquinone-anthrone dimers and establishes them as a new class of potential antimalarial compounds with very little host cell toxicity.

  2. Measurement of volatile organic compounds inside automobiles.

    Science.gov (United States)

    Fedoruk, Marion J; Kerger, Brent D

    2003-01-01

    The objective of the current study was to evaluate the types and concentrations of volatile organic compounds (VOCs) in the passenger cabin of selected sedan automobiles under static (parked, unventilated) and specified conditions of operation (i.e., driving the vehicle using air conditioning alone, vent mode alone, or driver's window half open). Data were collected on five different passenger sedan vehicles from three major automobile manufacturers. Airborne concentrations were assessed using 90-min time-weighted average (TWA) samples under U.S. Environmental Protection Agency (USEPA) Method IP-1B to assess individual VOC compounds and total VOCs (TVOCs) calibrated to toluene. Static vehicle testing demonstrated TVOC levels of approximately 400-800 microg/m(3) at warm interior vehicle temperatures (approximately 80 degrees F), whereas TVOCs at least fivefold higher were observed under extreme heat conditions (e.g., up to 145 degrees F). The profile of most prevalent individual VOC compounds varied considerably according to vehicle brand, age, and interior temperature tested, with predominant compounds including styrene, toluene, and 8- to 12-carbon VOCs. TVOC levels under varied operating conditions (and ventilation) were generally four- to eightfold lower (at approximately 50-160 microg/m(3)) than the static vehicle measurements under warm conditions, with the lowest measured levels generally observed in the trials with the driver's window half open. These data indicate that while relatively high concentrations of certain VOCs can be measured inside static vehicles under extreme heat conditions, normal modes of operation rapidly reduce the inside-vehicle VOC concentrations even when the air conditioning is set on recirculation mode.

  3. Effect of intermediate compounds and products on wet oxidation and biodegradation rates of pharmaceutical compounds.

    Science.gov (United States)

    Collado, Sergio; Laca, Adriana; Diaz, Mario

    2013-06-01

    Kinetics of pure compounds in batch agitated reactors are useful data to clarify the characteristics of a given reaction, but they frequently do not provide the required information to design industrial mixed continuous processes because in this case the final and intermediate products interact with the reaction of interest, due to backmixing effects. Simultaneously, the presence and transformations of other compounds, frequent in industrial wastewater treatments, adds more complexity to these types of interactions, whose effect can be different, favorable or unfavorable, for chemical or biological reactions. In this work, batch laboratory reactor data were obtained for the wet oxidation and biodegradation of four phenolic compounds present in a pharmaceutical wastewater and then compared with those collected from industrial continuous stirred tank reactors. For wet oxidation, batch laboratory degradation rates were significantly lower than those found in industrial continuous stirred operation. This behavior was explained by a different distribution of intermediate compounds in lab and industrial treatments, caused by the degree of backmixing and the synergistic effects between phenolic compounds (matrix effects). On the other hand, the specific utilization rates during aerobic biodegradation in the continuous industrial operation were lower than those measured in the laboratory, due to the simultaneous presence of the four pollutants in the industrial process (matrix effects) increasing the inhibitory effects of these compounds and its intermediates.

  4. Guanidino compounds as uremic (neuro)toxins.

    Science.gov (United States)

    De Deyn, Peter Paul; Vanholder, Raymond; Eloot, Sunny; Glorieux, Griet

    2009-01-01

    Neurological and vascular impairment are important sources of morbidity in patients with renal failure. A portion of patients still suffers from uremic encephalopathy or other signs of nervous system impairment. Several reports demonstrate increased incidence of cardiac infarction and cerebrovascular accidents in chronic renal failure patients, even in those otherwise adequately dialyzed. Epileptic and cognitive symptoms are among the most typical manifestations of uremic encephalopathy. Several guanidino compounds (GCs) may play an important role in the etiology of uremic encephalopathy. Four GCs appeared to be substantially increased as well in serum, cerebrospinal fluid, and brain of uremic patients. These compounds, "uremic" GCs, are creatinine, guanidine (G), guanidinosuccinic acid (GSA), and methylguanidine. All four compounds are experimental convulsants in concentrations similar to those found in uremic brain. We described a possible mechanism for the contribution of GCs to uremic hyperexcitability, referring to the in vitro effects of uremic GCs on inhibitory and excitatory amino acid receptors. It was demonstrated that the excitatory effects of uremic GCs on the central nervous system can be explained by the activation of N-methyl-d-aspartate receptors by GSA, concomitant inhibition of gamma-aminobutyric acid type A receptors by uremic GCs, and other depolarizing effects. These effects might also indicate the putative contribution of uremic GCs to the etiology of uremic encephalopathy. In this article, we review the uremic GCs with particular attention to their neurotoxicity. We elaborate in detail on the mechanisms of action of the neurotoxic uremic GCs and summarize the kinetics of these toxins.

  5. Endogenous guanidino compounds as uremic neurotoxins.

    Science.gov (United States)

    De Deyn, P P; D'Hooge, R; Van Bogaert, P P; Marescau, B

    2001-02-01

    Epileptic and cognitive symptomatologies are among the most typical manifestations of uremic encephalopathy. Several guanidino compounds (GCs) may play an important role in the etiology of uremic encephalopathy. Four GCs appeared to be highly increased as well in serum, cerebrospinal fluid, and brain of uremic patients, whereas the levels of other metabolically relevant GCs were not or only moderately increased and others were even decreased. These highly increased compounds or "uremic" GCs are creatinine (CTN), guanidine (G), guanidinosuccinic acid (GSA), and methylguanidine (MG). All four compounds were shown to be experimental convulsants in brain concentrations similar to those found in uremic brain. We have described a possible mechanism for the contribution of GCs to uremic hyperexcitability, referring to the in vitro effects of uremic GCs on inhibitory and excitatory amino acid receptors. The excitatory effects of uremic GCs on the central nervous system may be explained by the activation of N-methyl-D-aspartate (NMDA) receptors by GSA, concomitant inhibition of GABA(A) receptors by uremic GCs, and other depolarizing effects. These effects might also indicate the putative contribution of uremic GCs to the etiology of uremic encephalopathy.

  6. A Novel Antibacterial Compound from Siegesbeckia glabrescens

    Directory of Open Access Journals (Sweden)

    Deokhoon Park

    2012-10-01

    Full Text Available The crude methanol extract of the dried aerial parts of Siegesbeckia glabrescens (Compositae showed antibacterial activity against the foodborne pathogen Staphylococcus aureus. Bioactivity-guided separation led to the isolation of 3-(dodecanoyloxy-2-(isobutyryloxy-4-methylpentanoic acid from nature for the first time. The structure was determined by spectroscopic data analysis (UV, MS, and NMR. The minimal inhibitory concentration (MIC of 3-(dodecanoyloxy-2-(isobutyryloxy-4-methylpentanoic acid against S. aureus was found to be 3.12 μg/mL. In addition, in a further antimicrobial activity assay against Gram-positive (B. subtilis, E. faecalis, P. acnes, S. epidermidis, S. schleiferi subsp. coagulans, S. agalactiae and S. pyrogens, and Gram-negative bacteria (E. coli and P. aeruginosa, and yeast strains (C. alibicans and F. neoformans, the antimicrobial activity of the compound was found to be specific for Gram-positive bacteria. The MIC values of the compound for Gram-positive bacteria ranged from 3.12 to 25 mg/mL. Furthermore, it was found that the 2-(isobutyryloxy-4-methylpentanoic acid substituent may operate as a key factor in the antibacterial activity of the compound, together with the laurate group.

  7. Water encapsulation in a polyoxapolyaza macrobicyclic compound.

    Science.gov (United States)

    Mateus, Pedro; Delgado, Rita; Groves, Patrick; Campos, Sara R R; Baptista, António M; Brandão, Paula; Félix, Vítor

    2012-08-17

    A new heteroditopic macrobicyclic compound (t(2)pN(5)O(3)) containing two separate polyoxa and polyaza compartments was synthesized in good yield through a [1 + 1] "tripod-tripod coupling" strategy. The X-ray crystal structure of H(3)t(2)pN(5)O(3)(3+) revealed the presence of one encapsulated water molecule accepting two hydrogen bonds from two protonated secondary amines and donating a hydrogen bond to one amino group. The acid-base behavior of the compound was studied by potentiometry at 298.2 K in aqueous solution and at ionic strength 0.10 M in KCl. The results revealed unusual protonation behavior, namely a surprisingly low fourth protonation constant contrary to what was expected for the compound. (1)H NMR and DOSY experiments, as well as molecular modeling studies, showed that the water encapsulation and the conformation observed in the solid state are retained in solution. The strong binding of the encapsulated water molecule, reinforced by the cooperative occurrence of a trifurcated hydrogen bond at the polyether compartment of the macrobicycle, account for the very low log K(4)(H) value obtained.

  8. Antitumor activity of chemical modified natural compounds

    Directory of Open Access Journals (Sweden)

    Marilda Meirelles de Oliveira

    1991-01-01

    Full Text Available Search of new activity substances starting from chemotherapeutic agents, continously appears in international literature. Perhaps this search has been done more frequently in the field of anti-tumor chemotherapy on account of the unsuccess in saving advanced stage patients. The new point in this matter during the last decade was computer aid in planning more rational drugs. In near future "the accessibility of supercomputers and emergence of computer net systems, willopen new avenues to rational drug design" (Portoghese, P. S. J. Med. Chem. 1989, 32, 1. Unknown pharmacological active compounds synthetized by plants can be found even without this eletronic devices, as tradicional medicine has pointed out in many contries, and give rise to a new drug. These compounds used as found in nature or after chemical modifications have produced successful experimental medicaments as FAA, "flavone acetic acid" with good results as inibitors of slow growing animal tumors currently in preclinical evaluation for human treatment. In this lecture some international contributions in the field of chemical modified compounds as antineoplasic drugs will be examined, particularly those done by Brazilian researches.

  9. Heavy metal screening in compounds feeds

    Directory of Open Access Journals (Sweden)

    Tomas Toth

    2015-05-01

    Full Text Available Heavy metals are generally classified as basic groups of pollutants that are now a days found in different environmental compartments. This is quite a large group of contaminants, which have different characteristics, effects on the environment and sources of origin. For environment pose the greatest risks, especially heavy metals produced by anthropogenic activities that adversely affect the health and vitality of organisms and natural environmental conditions. Livestock nutrition is among the main factors which affect not only the deficiency of livestock production and quality of food of animal origin, but they are also a factor affecting the safety and wholesomeness and the animal health. Compound feeds is characterized as a mixture of two or more feed grain. Containing organic, inorganic nutrients and specifically active compound feed meet the nutritional requirements of a given kind and age category of animals. They are used mainly in the diet of pigs, poultry, but also the nutrition of cattle, sheep, horses and other animal categories. The basic ingredients are cereals in proportion of 60-70 %. The aim of this thesis was to analyze the content of hazardous elements (copper, zinc, iron, manganese, cobalt, nickel, chromium, lead, cadmium, mercury in 15 samples of compound feeds and then evaluating their content in comparison with maximum limits laid down by Regulation of the Government of the Slovak Republic and Regulation Commission (EC.

  10. Bismuth nanoparticles for phenolic compounds biosensing application.

    Science.gov (United States)

    Mayorga-Martinez, Carmen C; Cadevall, Miquel; Guix, Maria; Ros, Josep; Merkoçi, Arben

    2013-02-15

    The rapid determination of trace phenolic compounds is of great importance for evaluating the total toxicity of contaminated water samples. Nowadays, electrochemical tyrosinase (Tyr) based biosensors constitute a promising technology for the in situ monitoring of phenolic compounds because of their advantages such as high selectivity, low production cost, promising response speed, potential for miniaturization, simple instrumentation and easy automatization. A mediator-free amperometric biosensor for phenolic compounds detection based on the combination of bismuth nanoparticles (BiNPs) and Tyr for phenol detections will be hereby reported. This is achieved through the integration of BiNPs/Tyr onto the working electrode of a screen printed electrode (SPE) by using glutaraldehyde as a cross-linking agent. BiNPs/Tyr biosensor is evaluated by amperometric measurements at -200 mV DC and a linear range of up to 71 μM and 100 μM and a correlation coefficient of 0.995 and 0.996 for phenol and catechol, respectively. The very low DC working potential ensures the avoidance of interferences making this biosensor an advantageous device for real sample applications. In addition, the response mechanism including the effect of BiNPs based on electrochemical studies and optical characterizations will be also discussed. The obtained results may open the way to many other BiNPs applications in the biosensing field.

  11. Chlorinated organic compounds in urban river sediments

    Energy Technology Data Exchange (ETDEWEB)

    Soma, Y.; Shiraishi, H.; Inaba, K. [National Inst. of Environmental Studies, Tsukuba, Ibaraki (Japan)

    1995-12-31

    Among anthropogenic chemicals, many chlorinated organic compounds have been used as insecticides and detected frequently as contaminants in urban river sediments so far. However, the number and total amount of chemicals produced commercially and used are increasing year by year, though each amount of chemicals is not so high. New types of contaminants in the environment may be detected by the use of newly developed chemicals. Chlorinated organic compounds in the urban river sediments around Tokyo and Kyoto, large cities in Japan, were surveyed and recent trends of contaminants were studied. Contaminants of the river sediments in industrial areas had a variety, but PCB (polychlorinated biphenyls) was detected in common in industrial areas. Concentration of PCB related well to the number of factories on both sides of rivers, although the use of PCB was stopped 20 years ago. In domestic areas, Triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol) and Triclocarban (3,4,4{prime}-trichlorocarbanilide)(both are contained in soap or shampoo for fungicides), p-dichlorobenzene (insecticides for wears) and TCEP(tris-chloroethyl phosphate) were detected. EOX(extracted organic halogen) in the sediments was 5 to 10 times of chlorinated organic compounds detected by GC/MS. Major part of organic halogen was suggested to be included in chlorinated organics formed by bleaching or sterilization.

  12. Antimicrobial compounds from Coleonema album (Rutaceae).

    Science.gov (United States)

    Esterhuizen, Lindy L; Meyer, Riaan; Dubery, Ian A

    2006-01-01

    Coleonema album, a member of the South African fynbos biome, was evaluated for its antimicrobial activity associated with its secondary metabolites. Ethanol- and acetone-based extracts obtained from plants from two different geographical areas were analyzed. A bioassay-guided fractionation methodology was followed for rapid and effective screening for the presence of bioactive compounds. The TLC-bioautographic method, used to screen the plant extracts for antimicrobial activity and localization of the active compounds, indicated the presence of a number of inhibitory compounds with activity against the microorganisms (E. coli, B. subtilis, E. faecalis, P. aeruginosa, S. aureus, M. smegmatis, M. tuberculosis, C. albicans, C. cucumerinum) tested. Evaluation of the inhibitory strength of each extract by the serial microdilution assay indicated that the C. album extracts inhibited effectively all the microorganisms, with the minimum inhibitory concentrations in the low mg ml(-1) range. Identification and structural information of the bioactive components were obtained by a combination of preparative TLC and LC-MS. It revealed the presence of coumarin aglycones which were responsible for the observed antimicrobial activities. The results of this study indicate that C. album possesses strong antimicrobial activity against a wide range of microorganisms that warrants further investigation into the use of the extracts or their active constituents as a potential source for novel drugs.

  13. Raman spectroscopy for analysis of thorium compounds

    Science.gov (United States)

    Su, Yin-Fong; Johnson, Timothy J.; Olsen, Khris B.

    2016-05-01

    The thorium fuel cycle is an alternative to the uranium fuel cycle in that when 232Th is irradiated with neutrons it is converted to 233U, another fissile isotope. There are several chemical forms of thorium which are used in the Th fuel cycle. Recently, Raman spectroscopy has become a very portable and facile analytical technique useful for many applications, including e.g. determining the chemical composition of different materials such as for thorium compounds. The technique continues to improve with the development of ever-more sensitive instrumentation and better software. Using a laboratory Fourier-transform (FT)-Raman spectrometer with a 785 nm wavelength laser, we were able to obtain Raman spectra from a series of thorium-bearing compounds of unknown origin. These spectra were compared to the spectra of in-stock-laboratory thorium compounds including e.g. ThO2, ThF4, Th(CO3)2 and Th(C2O4)2. The unknown spectra showed very good agreement to the known standards, demonstrating the applicability of Raman spectroscopy for detection and identification of these nuclear materials.

  14. Cytotoxicity of Odorous Compounds from Poultry Manure

    Directory of Open Access Journals (Sweden)

    Adriana Nowak

    2016-10-01

    Full Text Available Long-term exposure and inhalation of odorous compounds from poultry manure can be harmful to farm workers and the surrounding residents as well as animals. The aim of the present study was to determine the cytotoxicity and IC50 values of common odorous compounds such as ammonium, dimethylamine, trimethylamine, butyric acid, phenol, and indole in the chick liver hepatocellular carcinoma cell line LMH (Leghorn Male Hepatoma, in vitro, using MTT (3-(4,5-dimethylthiazolyl-2-2,5-diphenyltetrazolium bromide and PrestoBlue cytotoxicity assays. The cells were microscopically examined for any morphological changes post treatment. Dimethylamine exhibited the strongest cytotoxic effect on LMH cells with an IC50 value of 0.06% and 0.04% after an exposure of 24 h and 48 h, respectively. Both ammonium and trimethylamine had comparable cytotoxicity and their IC50 values were 0.08% and 0.04% after 24 h and 48 h, respectively. Of note, indole had the lowest cytotoxicity as the majority of cells were viable even after 72 h exposure. Thus, the IC50 for indole was not calculated. Results achieved from both MTT and PrestoBlue assays were comparable. Moreover, the morphological changes induced by the tested odours in LMH cells resulted in monolayer destruction, cytoplasm vacuolisation, chromatin condensation, and changes in nucleus and cell shape. Our study showed harmful effects of odorous compounds in chick tissues.

  15. Natural Biodegradation of Phenolic Compounds in Groundwater

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A combination of field data and theoretical approaches is used to assess the natural attenuation and status of a complex plume of phenolic compounds (phenol, cresols, xylenols) in a deep, consolidated, UK Permo-Triassic sandstone aquifer. Biodegradation of the phenolic compounds at concentrations up to 12500mg·L-1 is occurring under aerobic, NO-3-reducing, Mn/Fe-reducing, SO2-4-reducing and methanogenic conditions in the aquifer, with the accumulation of inorganic and organic metabolites in the plume. An electron and carbon balance for the plume suggests that only 6% of the source term has been degraded in 50 years. The residual contaminant mass in the plume significantly exceeds estimates of electron acceptor inputs, indicating that the plume will grow. Two detailed vertical profiles through the plume show that contaminant distributions are controlled more by source history than by biodegradation processes. Microbiological and mass balance studies show that biodegradation is greatest at the plume fringe where contaminant concentrations are diluted by transverse mixing. Active bacterial populations exist throughout the plume but biodegradation is inhibited in the plume core by high contaminant concentrations. Stable isotope studies show that SO2-4-reduction is particularly sensitive to contaminant concentration. The aquifer is not oxidant-deficient but natural attenuation of the phenolic compounds in this system is limited by toxicity from the pollutant load and the bioavailability of electron acceptors. Natural attenuation of these contaminants will increase only after increased dilution of the plume.

  16. Activity of Polyphenolic Compounds against Candida glabrata

    Directory of Open Access Journals (Sweden)

    Ricardo Salazar-Aranda

    2015-09-01

    Full Text Available Opportunistic mycoses increase the morbidity and mortality of immuno-compromised patients. Five Candida species have been shown to be responsible for 97% of worldwide cases of invasive candidiasis. Resistance of C. glabrata and C. krusei to azoles has been reported, and new, improved antifungal agents are needed. The current study was designed to evaluatethe activity of various polyphenolic compounds against Candida species. Antifungal activity was evaluated following the M27-A3 protocol of the Clinical and Laboratory Standards Institute, and antioxidant activity was determined using the DPPH assay. Myricetin and baicalein inhibited the growth of all species tested. This effect was strongest against C. glabrata, for which the minimum inhibitory concentration (MIC value was lower than that of fluconazole. The MIC values against C. glabrata for myricitrin, luteolin, quercetin, 3-hydroxyflavone, and fisetin were similar to that of fluconazole. The antioxidant activity of all compounds was confirmed, and polyphenolic compounds with antioxidant activity had the greatest activity against C. glabrata. The structure and position of their hydroxyl groups appear to influence their activity against C. glabrata.

  17. of polyphenolic compounds in Ilex Sp.

    Directory of Open Access Journals (Sweden)

    Zwyrzykowska Anna

    2015-11-01

    Full Text Available Natural compounds are an important source of desired biological activity which help to improve nutritional status, enhance productivity and bring many health benefits. The leaves of the Ilex paraguariensis (Aquifoliaceae are used for preparing a beverage known as yerba mate and represent a proven source of natural polyphenols which are known to foster biological activity with the emphasis on antioxidant properties. In present work we focused on the polyphenolic content of air-dried leaves of Ilex aquifolium L., Ilex aquifolium ‘Argentea Mariginata’, Ilex meserveae ‘Blue Angel’, and a commercially available mate as the reference product. Liquid chromatography combined with mass spectrometry (HPLC and LC-MS and thin layer chromatography (TLC, were used to establish polyphenolic substances content in aqueous methanolic extracts obtained from the biological matter. Up to 20 polyphenolic compounds were identified in the extracts, including rutin, quinic acid and its caffeoyl esters, i.e. chlorogenic acid and its isomers as well as dicaffeoyl derivatives. We took chlorogenic acid and rutin as reference compounds to quantify their levels in the extracts. It was determined that in all tested plants, high levels of these antioxidants were present. This led us to the conclusion that their leaves might serve as valuable food additives.

  18. Cytotoxicity of Odorous Compounds from Poultry Manure.

    Science.gov (United States)

    Nowak, Adriana; Matusiak, Katarzyna; Borowski, Sebastian; Bakuła, Tadeusz; Opaliński, Sebastian; Kołacz, Roman; Gutarowska, Beata

    2016-10-26

    Long-term exposure and inhalation of odorous compounds from poultry manure can be harmful to farm workers and the surrounding residents as well as animals. The aim of the present study was to determine the cytotoxicity and IC50 values of common odorous compounds such as ammonium, dimethylamine, trimethylamine, butyric acid, phenol, and indole in the chick liver hepatocellular carcinoma cell line LMH (Leghorn Male Hepatoma), in vitro, using MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) and PrestoBlue cytotoxicity assays. The cells were microscopically examined for any morphological changes post treatment. Dimethylamine exhibited the strongest cytotoxic effect on LMH cells with an IC50 value of 0.06% and 0.04% after an exposure of 24 h and 48 h, respectively. Both ammonium and trimethylamine had comparable cytotoxicity and their IC50 values were 0.08% and 0.04% after 24 h and 48 h, respectively. Of note, indole had the lowest cytotoxicity as the majority of cells were viable even after 72 h exposure. Thus, the IC50 for indole was not calculated. Results achieved from both MTT and PrestoBlue assays were comparable. Moreover, the morphological changes induced by the tested odours in LMH cells resulted in monolayer destruction, cytoplasm vacuolisation, chromatin condensation, and changes in nucleus and cell shape. Our study showed harmful effects of odorous compounds in chick tissues.

  19. Raman Spectroscopy for Analysis of Thorium Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Su, Yin-Fong; Johnson, Timothy J.; Olsen, Khris B.

    2016-05-12

    The thorium fuel cycle is an alternative to the uranium fuel cycle in that when 232Th is irradiated with neutrons it is converted to 233U, another fissile isotope. There are several chemical forms of thorium which are used in the Th fuel cycle. Recently, Raman spectroscopy has become a very portable and facile analytical technique useful for many applications, including e.g. determining the chemical composition of different materials such as for thorium compounds. The technique continues to improve with the development of ever-more sensitive instrumentation and better software. Using a laboratory Fourier-transform (FT)-Raman spectrometer with a 785 nm wavelength laser, we were able to obtain Raman spectra from a series of thorium-bearing compounds of unknown origin. These spectra were compared to the spectra of in-stock-laboratory thorium compounds including ThO2, ThF4, Th(CO3)2 and Th(C2O4)2. The unknown spectra showed very good agreement to the known standards, demonstrating the applicability of Raman spectroscopy for detection and identification of these nuclear materials.

  20. Volatile Organic Compound Analysis in Istanbul

    Science.gov (United States)

    Ćapraz, Ö.; Deniz, A.; Öztürk, A.; Incecik, S.; Toros, H.; Coşkun, M.

    2012-04-01

    Volatile Organic Compound Analysis in Istanbul Ö. Çapraz1, A. Deniz1,3, A. Ozturk2, S. Incecik1, H. Toros1 and, M. Coskun1 (1) Istanbul Technical University, Faculty of Aeronautics and Astronautics, Department of Meteorology, 34469, Maslak, Istanbul, Turkey. (2) Istanbul Technical University, Faculty of Chemical and Metallurgical, Chemical Engineering, 34469, Maslak, Istanbul, Turkey. (3) Marmara Clean Air Center, Ministry of Environment and Urbanization, Nişantaşı, 34365, İstanbul, Turkey. One of the major problems of megacities is air pollution. Therefore, investigations of air quality are increasing and supported by many institutions in recent years. Air pollution in Istanbul contains many components that originate from a wide range of industrial, heating, motor vehicle, and natural emissions sources. VOC, originating mainly from automobile exhaust, secondhand smoke and building materials, are one of these compounds containing some thousands of chemicals. In spite of the risks to human health, relatively little is known about the levels of VOC in Istanbul. In this study, ambient air quality measurements of 32 VOCs including hydrocarbons, halogenated hydrocarbons and carbonyls were conducted in Kağıthane (Golden Horn) region in Istanbul during the winter season of 2011 in order to develop the necessary scientific framework for the subsequent developments. Kağıthane creek valley is the source part of the Golden Horn and one of the most polluted locations in Istanbul due to its topographical form and pollutant sources in the region. In this valley, horizontal and vertical atmospheric motions are very weak. The target compounds most commonly found were benzene, toluene, xylene and ethyl benzene. Concentrations of total hydrocarbons ranged between 1.0 and 10.0 parts per billion, by volume (ppbv). Ambient air levels of halogenated hydrocarbons appeared to exhibit unique spatial variations and no single factor seemed to explain trends for this group of