A battery-operated, stabilized, high-energy pulsed electron gun for the production of rare gas excimers

We report on the design of a new type of electron gun to be used for experiments of infrared emission spectroscopy of rare gas excimers. It is based on a filament heated by means of a pack of rechargeable batteries floated atop the high-voltage power supply. The filament current is controlled by a feedback circuit including a superluminescent diode decoupled from the high voltage by means of an optical fiber. Our experiment requires that the charge injection is pulsed and constant and stable in time. This electron gun can deliver several tens of nC per pulse of electrons of energy up to $100\,$keV into the sample cell. This new design eliminates ripples in the emission current and ensures up to 12 hrs of stable performance.Comment: 1o pages, 8 figures, to be submitted to Review of Scientific Instrument

Оптический метод исследования влияния давления на фазовый переход высокий спин−низкий спин в железосодержащих координационных соединениях

На основе анализа спектров поглощения разработан оптический метод исследования переходов высокий спин (HS)−низкий спин (LS) под давлением. Изучено влияние давления на превращение HS−LS в соединении Fe(BF₄)₂[pmd]{Ag(CN)₂}₂·H₂O при комнатной температуре и показано, что в нем наблюдается полный переход из HS- в LS-состояние при увеличении давления до 1 GPa. При сбросе давления наблюдается гистерезис с шириной петли 0.2 GPa.An optical method for the high spin (HS)−low spin (LS) transition investigation under pressure has been developed basing on the analysis of absorption spectra. Pressure effect on the HS−LS transformation in Fe(BF₄)₂[pmd]{Ag(CN)₂}₂·H2O has been investigated at room temperature. It is shown that in this compound there is a complete transition from HS to LS state with pressure increase to 1GPa. Pressure relief gives a hysteresis with loop width of 0.2 GPa

Влияние давления на фазовый переход высокий спин–низкий спин в изоструктурных полимерных соединениях

Исследовано влияние давления на переход высокий спин (HS)–низкий спин (LS) (для краткости обозначим HL) в двух изоморфных соединениях [Fe(pmd)(H₂O){M(CN)₂}₂]·H₂O (где M = Ag или Au). Изучено поведение температуры перехода Т₁/₂ и ширины гистерезиса ΔT при разных давлениях. Установлено, что для соединения Fe−Ag с ростом давления Т₁/₂ увеличивается монотонно, в то время как для Fe−Au – немонотонно. У обоих соединений при малых давлениях рост ширины гистерезиса незначителен, в диапазоне средних давлений наблюдается резкое увеличение ΔT, а при высоких давлениях ширина гистерезиса уменьшается. На основе феноменологической модели в приближении молекулярного поля проведен анализ экспериментальных результатов. Выяснено, что расчетные значения энергии PΔVHL не совпадают с энергией, соответствующей экспериментально наблюдаемым значениям T₁/₂.Pressure effect on high spin (HS)−low spin (LS) transition in two isomorphic compounds [Fe(pmd)(H₂O){M(CN)₂}₂]·H₂O (M = Ag or Au) has been investigated. The behavior of transition temperature T₁/₂ and hysteresis width ΔT has been studied for various pressures. It has been revealed that with pressure growth there is a monotonic increase of T₁/₂ for Fe−Ag and nonmonotonic one for Fe−Au. The both compounds show a negligible growth of the hysteresis width at low pressures, in the range of medium pressures the ΔT increases sharply and decreases at high pressures. The experimental results have been analysed basing on phenomenological model within the molecular field approximation. It has been determined that the calculated values of energy PΔVHL are inconsistent with the energy corresponding to experimentally observed values of T₁/₂

Radiation Hardness Tests Of Piezoelectric Actuators With Fast Neutrons At Liquid Helium Temperature

Piezoelectric actuators, which are integrated into the cold tuning system and used to compensate the small mechanical deformations of the cavity wall induced by Lorentz forces due to the high electromagnetic surface field, may be located in the radiation environment during particle accelerator operation. In order to provide for a reliable operation of the accelerator, the performance and life time of piezoelectric actuators (~24.000 units for ILC) should not show any significant degradation for long periods (i.e. machine life duration: ~20 years), even when subjected to intense radiation (i.e. gamma rays and fast neutrons). An experimental program, aimed at investigating the effect of fast neutrons radiation on the characteristics of piezoelectric actuators at liquid helium temperature (i.e. T~4.2 K), was proposed for the working package WP#8 devoted to tuners development in the frame of CARE project. A neutrons irradiation facility, already installed at the CERI cyclotron located at Orléans (France), was upgraded and adapted for actuators irradiations tests purpose. A deuterons beam (maximum energy and beam current: 25 MeV and 35µA) collides with a thin (thickness: 3 mm) beryllium target producing a high neutrons flux with low gamma dose (~20%): a neutrons fluence of more than 1014 n/cm2 is achieved in ~20 hours of exposure. A dedicated cryostat was developed at IPN Orsay and used previously for radiation hardness test of calibrated cryogenic thermometers and pressure transducers used in LHC superconducting magnets. This cryostat could be operated either with liquid helium or liquid argon. This irradiation facility was upgraded for allowing fast turn-over of experiments and a dedicated experimental set-up was designed, fabricated, installed at CERI and successfully operated for radiation hardness tests of several piezoelectric actuators at T~4.2 K. This new apparatus allows on-line automatic measurements of actuators characteristics and the cryogenic parameters. Further, the test-cell and actuators are equipped with high purity Ni foils for measuring the total neutrons dose by an activation method. In this report, the details of the irradiation test facility will be described then the experimental data will be analyzed and discussed

ETUDE MORPHO-GRANULOMETRIQUE ET STRUCTURALE DES SEMOULES DE BLE DUR PROPRIETES D'HYDRATATION ET D'AGGLOMERATION

International audienceLes propriétés d'hydratation et d'agglomération de la semoule de blé dur dépendent des caractéristiques de la matière à granuler, du liquide de granulation et de l'outil de granulation. Dans le procédé de fabrication des graines de couscous, la formation, la croissance et la densification des grains de semoule sont effectuées par addition d'eau, mélange et roulage. Une étude de caractérisation de la semoule de blé dur a été entreprise à différentes échelles d'observation : macroscopique, mésoscopique et moléculaire afin de comprendre les mécanismes d'hydratation et d'agglomération. La semoule de blé dur constitue une population de particules hétérogènes en granulométrie et en composition biochimique. Si cette hétérogénéité se traduit par des modifications des propriétés d'hydratation, d'autres études sont nécessaires pour mieux appréhender son influence sur les propriétés d'agglomération

Modifications of powders properties by dry-coating: some examples of processes and products characteristics

International audienceDry-coating appears to be an interesting way to create new composite materials in various application areas, avoiding the use of solvents involved in traditional processes, like granulation. Moreover, dry coating processes can be performed on smaller particles sizes. Typical applications include, but are not limited to, altering flowability, solubility, dispersibility, wettability (hydrophilic/hydrophobic properties), electric, electrostatic, magnetic, optical, color, flavor, shape, etc. Particles with relatively large particle size (host particles, 1-500 µm) can be mechanically coated with fine particles (guest particles, 0,1-50 µm) in order to create new functionality or to improve their initial characteristics. In this study we present results obtained with various products and in particular more accurately in the case of silica host particles coated by magnesium stearate using two processes: the Hybridizer NSH0 of the Nara Machinery company and the Cyclomix of Hosokawa company. In this paper we describe the experimental investigation of an application of dry coating technique to change the surface properties of silica gel particles (d50 = 55 µm) coated with different mass ratio of magnesium stearate (MgSt; d50 = 4,6 µm): 1%, 5% and 15%. The products properties were characterised though different methods: particles size distribution (in order to examine the adhesion quality of the fine particles on host particles), flowability, wettability, Atomic Force Microscopy (AFM), and Electron Microscopy (ESEM). The flowability of the samples was characterized by measurements of the tapped and aerated densities. It has been shown in particular that the flowability of silica gel treated with and without MgSt in Hybridizer was not significantly affected and remained good. The wettability of silica gel was determined by measurements of the contact angle between the water drop and the powder bed prepared for each sample. The results obtained have shown that the coating of silica gel powder by hydrophobic magnesium stearate, can improve its hydrophobic properties

Antimicrobial Properties of Ethylene Vinyl Alcohol/Epsilon-Polylysine Films and Their Application in Surimi Preservation

[EN] Polymer films based on ethylene vinyl copolymers (EVOH) containing a 29 % (EVOH 29) and a 44 % molar percentage of ethylene (EVOH 44), and incorporating epsilon-polylysine (EPL) at 0 %, 1 %, 5 % and 10 % were successfully made by casting. The optical properties and the amount of EPL released from the films to phosphate buffer at pH 7.5 were evaluated, films showing great transparency and those of EVOH 29 copolymer releasing a greater amount of EPL. The antimicrobial properties of the resulting films were tested in vitro against different foodborne microorganisms and in vivo in surimi sticks. With regard to the antimicrobial capacity tested in vitro in liquid medium at 37 A degrees C and 4 A degrees C against Listeria monocytogenes and Escherichia coli over a period of 72 h, films showed a considerable growth inhibitory effect against both pathogens, more notably against L. monocytogenes, and being EVOH 29 more effective than EVOH 44 films. At 37 A degrees C, total growth inhibition was observed for EVOH 29 films incorporating 10 % EPL against both microorganisms whereas the copolymer EVOH 44 did show total inhibition against L. monocytogenes and the growth of E. coli was reduced by 6.64 log units. At 4 A degrees C, no film was able to inhibit completely bacterial growth. Scanning electron microscopy micrographs showed corrugated cell surfaces with blisters and bubbles, and collapse of the cells appearing shorter and more compact after treatment with EPL. Finally, the films were successfully used to increase the shelf life of surimi sticks. The results show the films developed have a great potential for active food packaging applications.The authors acknowledge the financial support of the Spanish Ministry of Economy and Competitiveness, projects AGL2012-39920-C03-01, and fellowship funding for V. M.-G.Muriel-Galet, V.; Lopez-Carballo, G.; Gavara Clemente, R.; Hernández-Muñoz, P. (2014). Antimicrobial Properties of Ethylene Vinyl Alcohol/Epsilon-Polylysine Films and Their Application in Surimi Preservation. Food and Bioprocess Technology. 7(12):3548-3559. https://doi.org/10.1007/s11947-014-1363-1S35483559712Adams, M. R., & Moss, M. O. (2008). Food microbiology. UK: The Royal Society of Chemistry Cambridge.Aucejo, S., Catala, R., & Gavara, R. (2000). Interactions between water and EVOH food packaging films. Food Science and Technology International, 6(2), 159–164.Brandt, A. L., Castillo, A., Harris, K. B., Keeton, J. T., Hardin, M. D., & Taylor, T. M. (2010). Inhibition of Listeria monocytogenes by food antimicrobials applied singly and in combination. Journal of Food Science, 75(9), 557–563.Buchanan, R. L., & Doyle, M. P. (1997). Foodborne disease significance of Escherichia coli O157:H7 and other enterohemorrhagic E-coli. Food Technology, 51(10), 69–76.Chang, S.-S., Lu, W.-Y. W., Park, S.-H., & Kang, D.-H. (2010). Control of foodborne pathogens on ready-to-eat roast beef slurry by epsilon-polylysine. International Journal of Food Microbiology, 141(3), 236–241.Chang, Y., McLandsborough, L., & McClements, D. J. (2012). Cationic antimicrobial (epsilon-polylysine)-anionic polysaccharide (Pectin) interactions: influence of polymer charge on physical stability and antimicrobial efficacy. Journal of Agricultural and Food Chemistry, 60(7), 1837–1844.Chi-Zhang, Y. D., Yam, K. L., & Chikindas, M. L. (2004). Effective control of Listeria monocytogenes by combination of nisin formulated and slowly released into a broth system. International Journal of Food Microbiology, 90(1), 15–22.Coton, M., Denis, C., Cadot, P., & Coton, E. (2011). Biodiversity and characterization of aerobic spore-forming bacteria in surimi seafood products. Food Microbiology, 28(2), 252–260.FAO (2005) Further processing of fish Fisheries and Aquaculture Department, Rome. Updated 27 May 2005 Retrieved 14 March 2011.FDA (2004) Agency reponse letter GRAS Notice No. GRN 00135.Gambarin, P., Magnabosco, C., Losio, M. N., Pavoni, E., Gattuso, A., Arcangeli, G., et al. (2012). Listeria monocytogenes in ready-to-rat seafood and potential hazards for the consumers. International Journal of Microbiology, 2012, 497–635.Geornaras I, Yoon Y., Belk K. E., Smith G. C., Sofos J. N. (2007). Antimicrobial activity of epsilonpolylysine against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in various food extracts. Journal of Food Science, 72(8), M330–4.Gunlu, A., & Koyun, E. (2013). Effects of vacuum packaging and wrapping with chitosan-based edible film on the extension of the shelf life of sea bass (Dicentrarchus labrax) fillets in cold storage (4 A degrees C). Food and Bioprocess Technology, 6(7), 1713–1719.Hiraki, J. (1995). Basic and applied studies on ε-polylysine. Journal of Antibacterial Antifungal Agents Japan, 23, 349–493.Hiraki, J. (2000). ε-Polylysine, its development and utilization. Fine Chemistry, 29, 18–25.Hiraki, J., Ichikawa, T., Ninomiya, S., Seki, H., Uohama, K., Kimura, S., et al. (2003). Use of ADME studies to confirm the safety of epsilon-polylysine as a preservative in food. Regulatory Toxicology and Pharmacology, 37(2), 328–340.Ho, Y. T., Ishizaki, S., & Tanaka, M. (2000). Improving emulsifying activity of epsilon-polylysine by conjugation with dextran through the Maillard reaction. Food Chemistry, 68(4), 449–455.Huss, H. H., Jorgensen, L. V., & Vogel, B. F. (2000). Control options for Listeria monocytogenes in seafoods. International Journal of Food Microbiology, 62(3), 267–274.Kaneko, K., Hayashidani, H., Ohtomo, Y., Kosuge, J., Kato, M., Takahashi, K., et al. (1999). Bacterial contamination of ready-to-eat foods and fresh products in retail shops and food factories. Journal of Food Protection, 62(6), 644–649.Kang, E. T., Tan, K. L., Kato, K., Uyama, Y., & Ikada, Y. (1996). Surface modification and functionalization of polytetrafluoroethylene films. Macromolecules, 29(21), 6872–6879.Li, J., Han, Q., Chen, W., & Ye, L. (2012). Antimicrobial activity of Chinese bayberry extract for the preservation of surimi. Journal of the Science of Food and Agriculture, 92(11), 2358–2365.Lopez de Dicastillo, C., Nerin, C., Alfaro, P., Catala, R., Gavara, R., & Hernandez-Munoz, P. (2011). Development of new antioxidant active packaging films based on ethylene vinyl alcohol copolymer (EVOH) and green tea extract. Journal of Agricultural and Food Chemistry, 59(14), 7832–7840.Lopez-de-Dicastillo, C., Alonso, J. M., Catala, R., Gavara, R., & Hernandez-Munoz, P. (2010). Improving the antioxidant protection of packaged food by incorporating natural flavonoids into ethylene-vinyl alcohol copolymer (EVOH) dilms. Journal of Agricultural and Food Chemistry, 58(20), 10958–10964.Lopez-de-Dicastillo, C., Pezo, D., Nerin, C., Lopez-Carballo, G., Catala, R., Gavara, R., et al. (2012). Reducing oxidation of foods through antioxidant active packaging based on ethyl vinyl alcohol and natural flavonoids. Packaging Technology and Science, 25(8), 457–466.M100-S22 (2012) Performance Standards for Antimicrobial Susceptibility Testing: Eighteenth Informational Supplement. Clinical and Laboratory Standards Institute. Advancing Quality in Health Care Testing. Vol. 32 No. 3. Replaces M100-S21 . Vol. 31 No. 1Mead, P. S., & Griffin, P. M. (1998). Escherichia coli O157:H7. Lancet, 352(9135), 1207–1212.Miya, S., Takahashi, H., Ishikawa, T., Fujii, T., & Kimura, B. (2010). Risk of Listeria monocytogenes xontamination of raw ready-to-eat seafood products available at retail outlets in Japan. Applied and Environmental Microbiology, 76(10), 3383–3386.Muriel-Galet, V., Cerisuelo, J. P., Lopez-Carballo, G., Lara, M., Gavara, R., & Hernandez-Munoz, P. (2012a). Development of antimicrobial films for microbiological control of packaged salad. International Journal of Food Microbiology, 157(2), 195–201.Muriel-Galet, V., Lopez-Carballo, G., Gavara, R., & Hernandez-Munoz, P. (2012b). Antimicrobial food packaging film based on the release of LAE from EVOH. International Journal of Food Microbiology, 157(2), 239–244.Muriel-Galet, V., Cerisuelo, J. P., Lopez-Carballo, G., Aucejo, S., Gavara, R., & Hernandez-Munoz, P. (2013a). Evaluation of EVOH-coated PP films with oregano essential oil and citral to improve the shelf-life of packaged salad. Food Control, 30(1), 137–143.Muriel-Galet, V., López-Carballo, G., Hernández-Muñoz, P., & Gavara, R. (2013b). Characterization of ethylene–vinyl alcohol copolymer containing lauril arginate (LAE) as material for active antimicrobial food packaging. Food Packaging and Shelf Life, 1, 10–17.Park, J. W. (2014). Surimi and surimi seafood. Boca Raton: CRC Press.Shima, S., & Sakai, H. (1977). Polylysine produced by Streptomyces. Agricultural and Biological Chemistry, 41(9), 1807–1809.Shima, S., Matsuoka, H., Iwamoto, T., & Sakai, H. (1984). Antimicrobial action of epsilon-poly-l-lysine. Journal of Antibiotics, 37(11), 1449–1455.Singh, R. K., & Balange, A. K. (2005). Characteristics of pink perch (Nemipterus japonicus) surimi at frozen temperature. Journal of Food Processing and Preservation, 29(1), 75–83.Suppakul, P., Miltz, J., Sonneveld, K., & Bigger, S. W. (2003). Active packaging technologies with an emphasis on antimicrobial packaging and its applications. Journal of Food Science, 68(2), 408–420.Ting, H. Y., Ishizaki, S., & Tanaka, M. (1999). Epsilon-polylysine improves the quality of surimi products. Journal of Muscle Foods, 10(4), 279–294.Tzschoppe, M., Martin, A., & Beutin, L. (2012). A rapid procedure for the detection and isolation of enterohaemorrhagic Escherichia coli (EHEC) serogroup O26, O103, O111, O118, O121, O145 and O157 strains and the aggregative EHEC O104:H4 strain from ready-to-eat vegetables. International Journal of Food Microbiology, 152(1–2), 19–30.Uchida, E., Uyama, Y., & Ikada, Y. (1993). Sorption of low-molecular-weight anions into thin polycation layers grafted onto a film. Langmuir, 9(4), 1121–1124.Unalan, I. U., Ucar, K. D. A., Arcan, I., Korel, F., & Yemenicioglu, A. (2011). Antimicrobial potential of polylysine in edible films. Food Science and Technology Research, 17(4), 375–380.Venugopal, V., & Shahidi, F. (1995). Value-added products from underutilized fish species. Critical Reviews in Food Science and Nutrition, 35(5), 431–453.Zambuchini, B., Fiorini, D., Verdenelli, M. C., Orpianesi, C., & Ballini, R. (2008). Inhibition of microbiological activity during sole (Solea solea L.) chilled storage by applying ellagic and ascorbic acids. LWT--Food Science and Technology, 41(9), 1733–1738.Zinoviadou, K. G., Koutsoumanis, K. P., & Biliaderis, C. G. (2010). Physical and thermo-mechanical properties of whey protein isolate films containing antimicrobials, and their effect against spoilage flora of fresh beef. Food Hydrocolloids, 24(1), 49–59

Cooperative thermal and optical switching of spin states in a new two-dimensional coordination polymer

{Fe(pmd)2[Cu(CN)2]2} (pmd = pyrimidine) displays a rigid two-dimensional structure and undergoes thermal- and optical-driven spin crossover behaviour; cooperative elastic coupling between iron(II) ions in the framework induces thermal hysteresis in the HS↔LS conversion and sigmoidal HS→LS relaxation of the photo-induced HS state at low temperatures.Niel, Virginie, [email protected] ; Galet Domingo, Ana Guadalupe, [email protected] ; Gaspar Pedros, Ana Belen, [email protected] ; Real Cabezos, Jose Antonio, [email protected]

Grape yield and must composition of "Cabernet Sauvignon" grapevines with organic compost and urea fertilization.

Urea and organic compost are applied as a nitrogen (N) source in vineyards. The aim of this study was to evaluate the yield, total N content in the leaves and the must composition in grapevines with the application of organic compost and urea. ?Cabernet Sauvignon? grapevines, in the 2008/2009 and 2009/2010 crop seasons were subjected to the application of 40 kg N ha-1 in the form of organic compost and urea; but there were also unfertilized grapevines. In both crop seasons, leaves were collected at the stages of full flowering and at the change in color of the berries, and the total N content were analyzed; grape yield was evaluated and enological attributes were determined in the must. The application of organic compost and urea did not affect the N content in the leaf nor the grape yield in the second crop season evaluated. However, in the first crop season, grape yield was greater in the grapevines with application of organic compost to the soil. The addition of N sources did not affect the total nutrient content in the must but, in the second crop season, the grape must from the grapevines with the addition of organic compost had a lower soluble solids concentration and a higher total acidity value, as well as tartaric and malic acid values. KEYWORDS: nitrogen, leaf analysis, Vitis vinifera L

Modification des propriétés des poudres par enrobage à sec dans un mélangeur Cyclomix

International audienceNous présentons ici une étude de la modification de certaines propriétés de poudres après enrobage de fines particules sur des particules hôtes dans un mélangeur de laboratoire modèle « Cyclomix », d'une contenance de 1 litre. Ce type d'appareil présente des effets de cisaillement et d'impact, permettant de réaliser rapidement des enrobages à sec avec des volumes significatifs de poudre. De plus des possibilités d'extrapolation à des échelles supérieures (jusqu'à 500 L) existent pour préparer des quantités industrielles de poudres à surface modifiée. Plusieurs systèmes particulaires sont utilisés, avec des particules hôtes différentes : des poudres de gel de silice et d'amidon de maïs. Différents types de particules invitées ont été également examinées : stéarate de magnésium, silice hydrophile ou hydrophobe. Les caractéristiques morphologiques des poudres, et les densités du solide (mesurées par pycnomètre à hélium) ont été déterminées. Les modifications apportées aux particules hôtes par les particules invitées sont caractérisées par des tests de cinétique d'adsorption de vapeur d'eau, de mesure d'angle de contact par goutte posée, et d'évaluation de la coulabilité par mesures de densités tassées ou non tassées. Les résultats obtenus montrent que le mélangeur Cyclomix permet de réaliser des enrobages de poudres modifiant les propriétés de façon sensible