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Alumina thin coatings were grown on Germanium (Ge) coated black polyimide (GBP) or Kapton which has been used as a sunshield membrane on communication satellite antennas to protect it from environmental degradation during ground storage and implementation. The deposited nanoalumina coatings were found to be optically transparent in solar regime in spectral window while RF characteristic revealed negligible losses. Space worthiness of the coating was examined by simulated environments, e.g. humidity, thermal cycling and thermovacuum tests. No degradation was observed in its microstructural, thermo-optical, electrical, chemical state and RF characteristic in particular Ku and Ka bands. The aforesaid study indicates that the alumina thin coating is able to prevent surface degradation of GBP retaining the thermo-optical properties of the Ge coated Kapton and RF transparency which are functional requirements for communication antenna. The thickness of the optimized alumina coating was ~60 nm.

Protective alumina thin films of different thicknesses (35–95 nm) were grown by pulsed RF magnetron sputtering technique at room temperature on germanium (Ge) coated black polyimide or Kapton® substrate which is often employed as sunshield membrane on communications satellite antennas. The thin alumina top layer provides shielding of Ge coating from degradation during storage. The alumina thin film was characterized by X-ray diffraction, field emission scanning electron microscopy and X-ray photoelectron spectroscopy (XPS) techniques to investigate microstructural and electronic characteristics. Thermo-optical properties such as IR emittance, solar absorptance, reflectance and transmittance and electrical property e.g. sheet resistance of the deposited alumina films were measured. The RF losses e.g. insertion loss and return loss were measured in both Ku band (10.5–14.5 GHz) and Ka band (27–40 GHz). Finally, to prove anti-degradation behavior of alumina thin film, water droplet spreading experiments were carried out and evaluated its chemical degradation by XPS.

Laser spectroscopy measurements have been performed on neutron deficient iridium isotopes. The hyperfine structure and isotope shift of the optical Ir I transition 5d76s24F9/2 → 5d76s6p 6F11/2 at 351.5 nm have been studied for the 182–189Ir, \(^{186} {\text{Ir}}^\user1{m} \) and 191,193Ir isotopes. The nuclear magnetic and quadrupole moments were obtained from the HFS measurements and the changes of the mean square charge radii from the IS measurements. A large mean square charge radius change between 187Ir and 186Ir and between \(^{186} {\text{Ir}}^\user1{m} \) and \(^{186} {\text{Ir}}^\user1{g} \) has been observed.

Laser spectroscopy measurements have been carried out on very neutron-deficient isotopes of Au, Pt and Ir, produced as daughter elements from a Hg ISOLDE beam. For these transitional region nuclides, the hyperfine structure (HFS) and isotope shift (IS) were measured by Resonance Ionization Spectroscopy (RIS). Magnetic moments μ, spectroscopic quadrupole moments Qs and changes of the nuclear mean square charge radius δ〈rc 2〉along isotopic series have been extracted. For some results, a detailed comparison with theoretical predictions is presented.

Resonance ionization laser ion source (RILIS) technique has been used in the β-decay studies of 59Mn and 58Zn. The importance of the RILIS for production of these elements is discussed. The properties of the low-lying levels of the studied nuclei are discussed.

At the ISOLDE on line mass separator a system of copper vapor lasers and dye lasers serves for resonant ionization of atoms inside a hot cavity attached to the target. Radioactive ion beams of Yb, Ag, Mn, Ni, Zn, Be, Cu, Cd and Sn were produced with the Resonance Ionization Laser Ion Source (RILIS). Two and three step excitation schemes are used, providing an ionization efficiency of about 10%. Thanks to the use of the RILIS it became possible to ionize beryllium efficiently at ISOLDE, and all particle stable Be isotopes could be separated for the first time. Separation of Ag and Cu nuclear isomers was achieved in the ion source by appropriate tuning of the laser wavelength. New isotopes of Ag, Mn, Zn, Cd and Sn were found, including the r process “waiting point” nucleus 129Ag.

Isotope shift and hyperfine structure measurements have been performed on the short lived184Au nucleus using the COMPLIS apparatus installed at ISOLDE. The charge radius change and the magnetic and quadrupole moments of both isomeric and ground states have been deduced. The184Au ground state appears to be slightly more deformed than the isomeric state.

A preparation scheme for a 7Li+ ion beam in a storage ring is presented which provides ions in the metastable triplet states with well controlled longitudinal phase space properties. For both state selective preparation and beam cooling, laser- and electron-cooler forces are applied. The spatial- and momentum distributions of the ions are directly detected by a time resolved measurement of the fluorescence light. At low beam intensities, the remaining heating rate of such a beam is completely determined by residual gas scattering.

Radioactive copper isotopes were ionized with the resonance ionization laser ion source (RILIS) at the on-line isotope separator ISOLDE (CERN). Using the different hyperfine structure in the 3d10 4s 2 S1/2 – 3d10 4p 2 P01/2 transition the low- and high-spin isomers of 70 Cu were selectively enhanced by tuning the laser wavelength. The light was provided by a narrow-bandwidth dye laser pumped by copper vapor lasers (CVL) and frequency doubled in a BBO crystal. The ground state to isomeric state intensity ratio could be varied by a factor of 30, allowing to assign gamma transitions unambiguously to the decay of the individual isomers. It is shown that the method can also be used to determine magnetic moments. In a first experiment for the 1+ ground state of 70 Cu a magnetic moment of (+)1.8(3) μN and for the high-spin isomer of 70 Cu a magnetic moment of (±)1.2(3) μN could be deduced.

13C-NMR spectroscopy (22.5 MHz) was used to characterize poly(butadiene (B)–acrylonitrile (A)–methacrylic acid (M)) liquid terpolymers prepared by emulsion polymerization. The sequence distribution of the monomers in the terpolymers was described in terms of triads BBB, ABA, ABB, BBA, MBB, and AMB and was found to vary with the mode of addition of methacrylic acid monomer. The NMR data was found to be in good agreement with a mechanism of polymerization in which methacrylic acid is preferentially involved in initiation reactions by a thiyl radical arising from the reaction of the chain modifier, 1-dodecanethiol, and cyanoisopropyl radical generated from AIBN initiator. Binders obtained by curing the liquid terpolymers with an epoxy resin showed widely varying mechanical properties with tensile strength varying from 4.3 to 0.6 kg/cm2 and elongation at break from 130 to 450%. It was found that tensile strength increases and elongation decreases with the number of acrylonitrile units between the methacrylic acid crosslinks. Good correlation was obtained between triad population ratio [ABB + BBA] [BBvB]/[ABA][MBB] and the mechanical properties of the binders. Pyrolysis-GC data at 550 and 600°C confirmed the results obtained from 13C-NMR, and the mole ratio of butadiene to arylonitrile in the pyrolyzates showed correlation with the properties of binders.

This paper is divided in three parts: (i) the measurement of yields and decay losses of Li and Be isotopes released from a thin foil tantalum target at the CERN/ISOLDE PS-Booster; (ii) results from beta-decay experiments on Be-12 and Be-14, an improved half-life of 21.49(3) ms has been obtained for Be-12; (iii) the beta-decay of C-9. An outline of the analysis procedure to determine the branching at high excitation energies is given. The ground-state branch has been determined to 54.1(15)%.

The Pseudomonas aeruginosa PA1 strain, isolated from the water of oil production in Sergipe, Northeast Brazil, was evaluated as a potential rhamnolipid type of biosurfactant producer. The production of biosurfactants was investigated using different carbon sources (n-hexadecane, paraffin oil, glycerol, and babassu oil) and inoculum concentrations (0.0016–0.008 g/L). The best results were obtained with glycerol as the substrate and an initial cell concentration of 0.004 g/L. A C:N ratio of 22.8 led to the greatest production of rhamnolipids (1700 mg/L) and efficiency (1.18 g of rhamnolipid/g of dry wt).

Laser spectroscopy measurements have been carried out on very-neutron-deficient platinum isotopes with the COMPLIS experimental setup. Using the ${5d}^{9}{6s}^{3}{D}_{3}\ensuremath{\rightarrow}{5d}^{9}{6p}^{3}{P}_{2}$ optical transition, hyperfine spectra of ${}^{182,181,180,179,178}\mathrm{Pt}$ and ${}^{183}{\mathrm{Pt}}^{m}$ were recorded for the first time. The variation of the mean square charge radius between these nuclei, the magnetic moments of the odd isotopes, and the quadrupole moment of ${}^{183}{\mathrm{Pt}}^{m}$ were thus measured. A large deformation change between ${}^{183}{\mathrm{Pt}}^{g}$ and ${}^{183}{\mathrm{Pt}}^{m},$ an odd-even staggering of the charge radius, and a deformation drop from $A=179$ are clearly observed. Comparisons are made with microscopic theoretical predictions, in particular Hartree-Fock-Bogoliubov calculations using the Gogny force.

Laser spectroscopy measurements have been performed on neutron-deficient iridium isotopes. The hyperfine structure and isotope shift of the optical Ir I transition 5d76s2 4F9/2→5d76s6p 6F11/2 have been studied for the 182–189Ir, 180Irm and 191,193Ir isotopes. The nuclear magnetic and quadrupole moments were obtained from the hyperfine splitting measurements and the changes of the mean square charge radii from the isotope shift measurements. A large deformation change between 187Ir and 186Ir and between 186Irm and 186Irg has been observed.

International audience; COMPLIS is an experimental facility designed to carry out spectroscopic studieson radioisotopes produced by disintegration of elements available at CERN's Booster-ISOLDEon-line isotope separator. During recent series of experimental runs, hyperfine structuremeasurements have yielded information on nuclear moments and deformations of platinum andiridium isotopes. For the first time, population by a-decay from Hg was exploited toinvestigate 178-18lpt - the most neutron-deficient Pt isotopes yet studied. Successfulmeasurements have recently been carried out on 182-189lr

Deformation changes δβ have been found out between isomeric and ground states of the 183Pt and 184Au isotones. Atomic spectroscopy measurements by laser were carried out using the COMPLIS setup. Hyperfine structure (HFS) spectra and isotope shift (IS) were obtained for the 5d96s 3D3→5d96p 3P2 and 5d106s 2S1/2→5d106p 2P3/2 optical transitions in Pt and Au atoms respectively, providing deformation parameters β and nuclear moments μ and Qs. The influence of the proton-neutron coupling on the δβ value in 184Au relatively to its isotone 183Pt has been determined. Besides, the h9/2 proton state that is decoupled from the core in 183,185Au, becomes the 3/2[532] state (h9/2 parentage) strongly coupled in the doubly-odd 184Au nucleus.

The use of chemically selective laser ionization combined with beta-delayed neutron counting at ISOLDE has permitted identification and half-life measurements for 61Mn up through 69Mn. The 14(4)-ms half life for 69Mn is one of the shortest determined for any nuclide beyond the sd shell. Gamma-ray singles and coincidence spectra have been determined for the decays of 64,66Mn to levels of 64,66Fe, revealing strong deformation and vanishing of the N=40 subshell in the Fe isotopes.

At the ISOLDE facility radioactive ion beams are produced via proton induced reactions in a target which is connected to a laser ion source. For beryllium a two step excitation scheme with laser light at wavelengths of λ=235 nm and λ=297 nm has been developed. Efficient laser ionization of beryllium was achieved with a new optical set-up using frequency tripling with two non-linear BBO crystals to generate laser light in the ultraviolet for the first excitation step. The second step was optimized to reach the 2p2 1S0 autoionizing state for high ionization efficiency. The isotope shift of 7,9,10,11,12,14Be could be measured by tuning the wavelength of the first step. The laser ion source has also been used for the preparation of neutron-rich silver ion beams. Tuning the laser frequency of the first step it was possible to ionize selectively low-and high spin isomers of silver isotopes via the hyperfine structure. In both cases it was demonstrated that laser spectroscopy of exotic isotopes can be performed ...

The proton noise-decoupled 13C NMR spectra were used to characterize the terpolymer of butadiene (BD), acrylonitrile (AN), and methacrylic acid (MMA) prepared by emulsion polymerisation. Assignments for the various triads of butadiene units adjacent to acrylonitrile in the terpolymer were made by comparing the olefinic and aliphatic carbon resonances of a butadiene (B)-acrylonitrile (A) copolymer. Measurement of intensities of olefinic resonances in the nitrile environment for the terpolymer gives information about the BBB, BBA, ABB and ABA triads distribution, BBA and ABA being predominant. The intensities of methylene carbon resonances of the various triads for BD units connected to AN show a similar trend. The relative populations of various triads calculated from the peak intensities show that the terpolymer has a random structure. The assignments pertaining to BD units were made by comparison with 13C resonances of polybutadiene. The distribution of trans-1,4-, cis-1,4- and 1,2-units in the terpolymer indicates that the terpolymer has a random structure.

Synthese et polymerisation de monomeres bases sur le bisitaconimide et le bisnadimide de deux diaminobenzooxazoles isomeres, l'amino-5 (amino-4' phenyl)-2 benzooxazole et l'amino-5(amino-3' phenyl)-2 benzooxazole. Proprietes thermiques des polymeres comparees a celles de polyimides similaires bases sur le diamino-4,4' diphenyl ether

Four structurally different bisimidobenzoxazole monomers were synthesized, based on the reaction of two isomeric diaminobenzoxazoles, viz., 5-amino-2-(p-aminophenyl) benzoxazole and 5-amino-2-(m-aminophenyl) benzoxazole with maleic and citraconic anhydrides. The diamines were synthesized by a new route. The imides and the amic intermediates were characterized by elemental analysis, IR, NMR, and mass spectra. The imides could be thermally polymerized to crosslinked brittle polybisimidobenzoxazoles. The citraconimides polymerized at a lower temperature than the maleimide. Thermal stability of the cured resins was evaluated by TGA and was correlated to the structure of the polyimide. The polybismaleimidobenzoxazoles were stable up to about 500°C in N2, leaving 50–60% anaerobic char yield at 800°C, whereas polybiscitraconimidobenzoxazoles were stable up to 420°C. Comparison of the thermal behavior of similar polyimides based on oxydianiline revealed that incorporation of benzoxazole structure enhances the decomposition temperature, lowers the rate of decomposition, and enhances the anaerobic char yield at high temperature. Addition of diamines as chain-extending agents decreased the thermal stability of the resins without any change in the anaerobic char yield.