49 research outputs found
Planktonic bacterial community composition of an extremely shallow soda pond during a phytoplankton bloom revealed by cultivation and molecular cloning
Different Neutralization Profiles After Primary SARS-CoV-2 Omicron BA.1 and BA.2 Infections
Background and MethodsThe SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) Omicron (B.1.1.529) variant is the antigenically most distinct variant to date. As the heavily mutated spike protein enables neutralization escape, we studied serum-neutralizing activities of naïve and vaccinated individuals after Omicron BA.1 or BA.2 sub-lineage infections in live virus neutralization tests with Omicron BA.1, Omicron BA.2, wildtype (WT, B1.1), and Delta (B.1.617.2) strains. Serum samples obtained after WT infections and three-dose mRNA vaccinations with and without prior infection were included as controls.ResultsPrimary BA.1 infections yielded reduced neutralizing antibody levels against WT, Delta, and Omicron BA.2, while samples from BA.2-infected individuals showed almost no cross-neutralization against the other variants. Serum neutralization of Omicron BA.1 and BA.2 variants was detectable after three-dose mRNA vaccinations, but with reduced titers. Vaccination-breakthrough infections with either Omicron BA.1 or BA.2, however, generated equal cross-neutralizing antibody levels against all SARS-CoV-2 variants tested.ConclusionsOur study demonstrates that although Omicron variants are able to enhance cross-neutralizing antibody levels in pre-immune individuals, primary infections with BA.1 or BA.2 induced mostly variant-specific neutralizing antibodies, emphasizing the differently shaped humoral immunity induced by the two Omicron variants. These data thus contribute substantially to the understanding of antibody responses induced by primary Omicron infections or multiple exposures to different SARS-CoV-2 variants and are of particular importance for developing vaccination strategies in the light of future emerging variants
Dark Matter Search Results from the PICO-60C(3)F(8) Bubble Chamber
[EN] New results are reported from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 52 kg of C3F8 located in the SNOLAB underground laboratory. As in previous PICO bubble chambers, PICO-60 C3F8 exhibits excellent electron recoil and alpha decay rejection, and the observed multiple-scattering neutron rate indicates a single-scatter neutron background of less than one event per month. A blind analysis of an efficiency-corrected 1167-kg day exposure at a 3.3-keV thermodynamic threshold reveals no single-scattering nuclear recoil candidates, consistent with the predicted background. These results set the most stringent direct-detection constraint to date on the weakly interacting massive particle (WIMP)-proton spin-dependent cross section at 3.4 x 10(-41) cm(2) for a 30-GeVc(-2) WIMP, more than 1 order of magnitude improvement from previous PICO results.The PICO Collaboration wishes to thank SNOLAB and its staff for support through underground space, logistical, and technical services. SNOLAB operations are supported by the Canada Foundation for Innovation and the Province of Ontario Ministry of Research and Innovation, with underground access provided by Vale at the Creighton mine site. We are grateful to Kristian Hahn and Stanislava Sevova of Northwestern University and Bjorn Penning of the University of Bristol for their assistance and useful discussion. We wish to acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI) for funding. We acknowledge the support from National Science Foundation (NSF) (Grants No. 0919526, No. 1506337, No. 1242637, and No. 1205987). We acknowledge that this work is supported by the U.S. Department of Energy (DOE) Office of Science, Office of High Energy Physics (under Award No. DE-SC-0012161), by a DOE Office of Science Graduate Student Research (SCGSR) award, by Direccion General Asuntos del Personal Academico, Universidad Nacional Autonoma de Mexico (DGAPA-UNAM) through the grant Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT) No. IA100316 and by Consejo Nacional de Ciencia y Tecnologia (CONACyT) (Mexico) through Grant No. 252167, by the Department of Atomic Energy (DAE), the Government of India, under the Center of AstroParticle Physics II project (CAPP-II) at Saha Institute of Nuclear Physics (SINP), by the Czech Ministry of Education, Youth and Sports (Grant No. LM2015072), and by the Spanish Ministerio de Economia y Competitividad, Consolider MultiDark (Grant No. CSD2009-00064). This work is partially supported by the Kavli Institute for Cosmological Physics at the University of Chicago through NSF Grant No. 1125897, and an endowment from the Kavli Foundation and its founder Fred Kavli. We also wish to acknowledge the support from Fermi National Accelerator Laboratory under Contract No. De-AC02-07CH11359, and Pacific Northwest National Laboratory, which is operated by Battelle for the U.S. Department of Energy under Contract No. DE-AC05-76RL01830. We also thank Compute Canada and the Center for Advanced Computing, ACENET, Calcul Quebec, Compute Ontario, and WestGrid for the computational support.Amole, C.; Ardid RamÃrez, M.; Arnquist, I.; Asner, DM.; Baxter, D.; Behnke, E.; Bhattacharjee, P.... (2017). Dark Matter Search Results from the PICO-60C(3)F(8) Bubble Chamber. Physical Review Letters. 118(25). https://doi.org/10.1103/PhysRevLett.118.251301S11825Olive, K. A. (2014). Review of Particle Physics. Chinese Physics C, 38(9), 090001. doi:10.1088/1674-1137/38/9/090001Komatsu, E., Dunkley, J., Nolta, M. R., Bennett, C. L., Gold, B., Hinshaw, G., … Wright, E. L. (2009). FIVE-YEAR
WILKINSON MICROWAVE ANISOTROPY PROBE
OBSERVATIONS: COSMOLOGICAL INTERPRETATION. The Astrophysical Journal Supplement Series, 180(2), 330-376. doi:10.1088/0067-0049/180/2/330Jungman, G., Kamionkowski, M., & Griest, K. (1996). Supersymmetric dark matter. Physics Reports, 267(5-6), 195-373. doi:10.1016/0370-1573(95)00058-5Goodman, M. W., & Witten, E. (1985). Detectability of certain dark-matter candidates. Physical Review D, 31(12), 3059-3063. doi:10.1103/physrevd.31.3059Bertone, G., Hooper, D., & Silk, J. (2005). Particle dark matter: evidence, candidates and constraints. Physics Reports, 405(5-6), 279-390. doi:10.1016/j.physrep.2004.08.031Feng, J. L. (2010). Dark Matter Candidates from Particle Physics and Methods of Detection. Annual Review of Astronomy and Astrophysics, 48(1), 495-545. doi:10.1146/annurev-astro-082708-101659Aubin, F., Auger, M., Genest, M.-H., Giroux, G., Gornea, R., Faust, R., … Storey, C. (2008). Discrimination of nuclear recoils from alpha particles with superheated liquids. New Journal of Physics, 10(10), 103017. doi:10.1088/1367-2630/10/10/103017Amole, C., Ardid, M., Asner, D. M., Baxter, D., Behnke, E., Bhattacharjee, P., … Broemmelsiek, D. (2015). Dark Matter Search Results from the PICO-2LC3F8Bubble Chamber. Physical Review Letters, 114(23). doi:10.1103/physrevlett.114.231302Amole, C., Ardid, M., Arnquist, I. J., Asner, D. M., Baxter, D., Behnke, E., … Brice, S. J. (2016). Improved dark matter search results from PICO-2L Run 2. Physical Review D, 93(6). doi:10.1103/physrevd.93.061101Amole, C., Ardid, M., Asner, D. M., Baxter, D., Behnke, E., Bhattacharjee, P., … Broemmelsiek, D. (2016). Dark matter search results from the PICO-60CF3Ibubble chamber. Physical Review D, 93(5). doi:10.1103/physrevd.93.052014Behnke, E., Behnke, J., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Conner, A. (2012). First dark matter search results from a 4-kgCF3Ibubble chamber operated in a deep underground site. Physical Review D, 86(5). doi:10.1103/physrevd.86.052001Behnke, E., Behnke, J., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Cooper, P. S. (2011). Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two LiterCF3IBubble Chamber. Physical Review Letters, 106(2). doi:10.1103/physrevlett.106.021303Archambault, S., Behnke, E., Bhattacharjee, P., Bhattacharya, S., Dai, X., Das, M., … Zacek, V. (2012). Constraints on low-mass WIMP interactions on 19F from PICASSO. Physics Letters B, 711(2), 153-161. doi:10.1016/j.physletb.2012.03.078Behnke, E., Besnier, M., Bhattacharjee, P., Dai, X., Das, M., Davour, A., … Zacek, V. (2017). Final results of the PICASSO dark matter search experiment. Astroparticle Physics, 90, 85-92. doi:10.1016/j.astropartphys.2017.02.005Felizardo, M., Girard, T. A., Morlat, T., Fernandes, A. C., Ramos, A. R., Marques, J. G., … Marques, R. (2014). The SIMPLE Phase II dark matter search. Physical Review D, 89(7). doi:10.1103/physrevd.89.072013Agostinelli, S., Allison, J., Amako, K., Apostolakis, J., Araujo, H., Arce, P., … Barrand, G. (2003). Geant4—a simulation toolkit. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 506(3), 250-303. doi:10.1016/s0168-9002(03)01368-8Allison, J., Amako, K., Apostolakis, J., Araujo, H., Arce Dubois, P., Asai, M., … Chytracek, R. (2006). Geant4 developments and applications. IEEE Transactions on Nuclear Science, 53(1), 270-278. doi:10.1109/tns.2006.869826Lewin, J. D., & Smith, P. F. (1996). Review of mathematics, numerical factors, and corrections for dark matter experiments based on elastic nuclear recoil. Astroparticle Physics, 6(1), 87-112. doi:10.1016/s0927-6505(96)00047-3Fitzpatrick, A. L., Haxton, W., Katz, E., Lubbers, N., & Xu, Y. (2013). The effective field theory of dark matter direct detection. Journal of Cosmology and Astroparticle Physics, 2013(02), 004-004. doi:10.1088/1475-7516/2013/02/004Anand, N., Fitzpatrick, A. L., & Haxton, W. C. (2014). Weakly interacting massive particle-nucleus elastic scattering response. Physical Review C, 89(6). doi:10.1103/physrevc.89.065501Gresham, M. I., & Zurek, K. M. (2014). Effect of nuclear response functions in dark matter direct detection. Physical Review D, 89(12). doi:10.1103/physrevd.89.123521Gluscevic, V., Gresham, M. I., McDermott, S. D., Peter, A. H. G., & Zurek, K. M. (2015). Identifying the theory of dark matter with direct detection. Journal of Cosmology and Astroparticle Physics, 2015(12), 057-057. doi:10.1088/1475-7516/2015/12/057Fu, C., Cui, X., Zhou, X., Chen, X., Chen, Y., … Fang, D. (2017). Spin-Dependent Weakly-Interacting-Massive-Particle–Nucleon Cross Section Limits from First Data of PandaX-II Experiment. Physical Review Letters, 118(7). doi:10.1103/physrevlett.118.071301Aartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., … Ansseau, I. (2017). Search for annihilating dark matter in the Sun with 3 years of IceCube data. The European Physical Journal C, 77(3). doi:10.1140/epjc/s10052-017-4689-9Tanaka, T., Abe, K., Hayato, Y., Iida, T., Kameda, J., Koshio, Y., … Nakahata, M. (2011). AN INDIRECT SEARCH FOR WEAKLY INTERACTING MASSIVE PARTICLES IN THE SUN USING 3109.6 DAYS OF UPWARD-GOING MUONS IN SUPER-KAMIOKANDE. The Astrophysical Journal, 742(2), 78. doi:10.1088/0004-637x/742/2/78Choi, K., Abe, K., Haga, Y., Hayato, Y., Iyogi, K., Kameda, J., … Nakahata, M. (2015). Search for Neutrinos from Annihilation of Captured Low-Mass Dark Matter Particles in the Sun by Super-Kamiokande. Physical Review Letters, 114(14). doi:10.1103/physrevlett.114.141301Roszkowski, L., Austri, R. R. de, & Trotta, R. (2007). Implications for the Constrained MSSM from a new prediction forb→sγ. Journal of High Energy Physics, 2007(07), 075-075. doi:10.1088/1126-6708/2007/07/075Akerib, D. S., Araújo, H. M., Bai, X., Bailey, A. J., Balajthy, J., Beltrame, P., … Boulton, E. M. (2016). Results on the Spin-Dependent Scattering of Weakly Interacting Massive Particles on Nucleons from the Run 3 Data of the LUX Experiment. Physical Review Letters, 116(16). doi:10.1103/physrevlett.116.161302Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Amaro, F. D., Anthony, M., … Bauermeister, B. (2016). XENON100 dark matter results from a combination of 477 live days. Physical Review D, 94(12). doi:10.1103/physrevd.94.122001Adrián-MartÃnez, S., Albert, A., André, M., Anton, G., Ardid, M., Aubert, J.-J., … Basa, S. (2016). Limits on dark matter annihilation in the sun using the ANTARES neutrino telescope. Physics Letters B, 759, 69-74. doi:10.1016/j.physletb.2016.05.019Adrián-MartÃnez, S., Albert, A., André, M., Anton, G., Ardid, M., Aubert, J.-J., … Basa, S. (2016). A search for Secluded Dark Matter in the Sun with the ANTARES neutrino telescope. Journal of Cosmology and Astroparticle Physics, 2016(05), 016-016. doi:10.1088/1475-7516/2016/05/016Akerib, D. S., Alsum, S., Araújo, H. M., Bai, X., Bailey, A. J., Balajthy, J., … Biesiadzinski, T. P. (2017). Results from a Search for Dark Matter in the Complete LUX Exposure. Physical Review Letters, 118(2). doi:10.1103/physrevlett.118.021303Tan, A., Xiao, M., Cui, X., Chen, X., Chen, Y., Fang, D., … Gong, H. (2016). Dark Matter Results from First 98.7 Days of Data from the PandaX-II Experiment. Physical Review Letters, 117(12). doi:10.1103/physrevlett.117.121303Angloher, G., Bento, A., Bucci, C., Canonica, L., Defay, X., Erb, A., … Zöller, A. (2016). Results on light dark matter particles with a low-threshold CRESST-II detector. The European Physical Journal C, 76(1). doi:10.1140/epjc/s10052-016-3877-3Agnese, R., Anderson, A. J., Aramaki, T., Asai, M., Baker, W., Balakishiyeva, D., … Billard, J. (2016). New Results from the Search for Low-Mass Weakly Interacting Massive Particles with the CDMS Low Ionization Threshold Experiment. Physical Review Letters, 116(7). doi:10.1103/physrevlett.116.071301Agnes, P., Agostino, L., Albuquerque, I. F. M., Alexander, T., Alton, A. K., Arisaka, K., … Bonfini, G. (2016). Results from the first use of low radioactivity argon in a dark matter search. Physical Review D, 93(8). doi:10.1103/physrevd.93.081101Agnese, R., Anderson, A. J., Asai, M., Balakishiyeva, D., Basu Thakur, R., Bauer, D. A., … Bowles, M. A. (2014). Search for Low-Mass Weakly Interacting Massive Particles with SuperCDMS. Physical Review Letters, 112(24). doi:10.1103/physrevlett.112.241302Agnese, R., Anderson, A. J., Asai, M., Balakishiyeva, D., Barker, D., Basu Thakur, R., … Bowles, M. A. (2015). Improved WIMP-search reach of the CDMS II germanium data. Physical Review D, 92(7). doi:10.1103/physrevd.92.072003Hehn, L., Armengaud, E., Arnaud, Q., Augier, C., Benoît, A., Bergé, L., … Yakushev, E. (2016). Improved EDELWEISS-III sensitivity for low-mass WIMPs using a profile likelihood approach. The European Physical Journal C, 76(10). doi:10.1140/epjc/s10052-016-4388-yTovey, D. R., Gaitskell, R. J., Gondolo, P., Ramachers, Y., & Roszkowski, L. (2000). A new model-independent method for extracting spin-dependent cross section limits from dark matter searches. Physics Letters B, 488(1), 17-26. doi:10.1016/s0370-2693(00)00846-7Buchmueller, O., Dolan, M. J., Malik, S. A., & McCabe, C. (2015). Characterising dark matter searches at colliders and direct detection experiments: vector mediators. Journal of High Energy Physics, 2015(1). doi:10.1007/jhep01(2015)037Aaboud, M., Aad, G., Abbott, B., Abdallah, J., Abdinov, O., Abeloos, B., … Abramowicz, H. (2016). Search for new phenomena in final states with an energetic jet and large missing transverse momentum inppcollisions ats=13  TeVusing the ATLAS detector. Physical Review D, 94(3). doi:10.1103/physrevd.94.03200
Hydrogen and Carbon Nanotubes from Pyrolysis-Catalysis of Waste Plastics: A Review
More than 27 million tonnes of waste plastics are generated in Europe each year representing a considerable potential resource. There has been extensive research into the production of liquid fuels and aromatic chemicals from pyrolysis-catalysis of waste plastics. However, there is less work on the production of hydrogen from waste plastics via pyrolysis coupled with catalytic steam reforming. In this paper, the different reactor designs used for hydrogen production from waste plastics are considered and the influence of different catalysts and process parameters on the yield of hydrogen from different types of waste plastics are reviewed. Waste plastics have also been investigated as a source of hydrocarbons for the generation of carbon nanotubes via the chemical vapour deposition route. The influences on the yield and quality of carbon nanotubes derived from waste plastics are reviewed in relation to the reactor designs used for production, catalyst type used for carbon nanotube growth and the influence of operational parameters
Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber
New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of 98.2%. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.The PICO Collaboration would like to thank SNOLAB and its staff for providing an exceptional underground laboratory space and invaluable technical support. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under award DE-SC-0012161. Fermi National Accelerator Laboratory is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359. Part of the research described in this paper was conducted under the Ultra Sensitive Nuclear Measurements Initiative at Pacific Northwest National Laboratory, a multiprogram national laboratory operated by Battelle for the U.S. Department of Energy. We acknowledge the National Science Foundation for their support including Grants No. PHY-1242637, No. PHY-0919526, and No. PHY-1205987. We acknowledge the support of the National Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI). We also acknowledge support from the Kavli Institute for Cosmological Physics at the University of Chicago. We acknowledge the financial support of the Spanish Ministerio de Economia y Competitividad, Consolider MultiDark CSD2009-00064 Grant. We acknowledge support from the Department of Atomic Energy (DAE), Government of India, under the Center for AstroParticle Physics II project (CAPP-II) at Saha Insititute of Nuclear Physics (SINP), Kolkata. We acknowledge the Czech Ministry of Education, Youth and Sports, Grant No. LM2011027. We acknowledge technical assistance from Fermilab's Computing, Particle Physics, and Accelerator Divisions, and from A. Behnke at IUSB.Amole, C.; Ardid RamÃrez, M.; Asner, DM.; Baxter, D.; Behnke, E.; Bhattacharjee, P.; Borsodi, H.... (2015). Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber. Physical Review Letters. 114(2313):1-6. https://doi.org/10.1103/PhysRevLett.114.231302S161142313Komatsu, E., Dunkley, J., Nolta, M. R., Bennett, C. L., Gold, B., Hinshaw, G., … Wright, E. L. (2009). FIVE-YEARWILKINSON MICROWAVE ANISOTROPY PROBEOBSERVATIONS: COSMOLOGICAL INTERPRETATION. The Astrophysical Journal Supplement Series, 180(2), 330-376. doi:10.1088/0067-0049/180/2/330Jungman, G., Kamionkowski, M., & Griest, K. (1996). Supersymmetric dark matter. Physics Reports, 267(5-6), 195-373. doi:10.1016/0370-1573(95)00058-5Bertone, G., Hooper, D., & Silk, J. (2005). Particle dark matter: evidence, candidates and constraints. Physics Reports, 405(5-6), 279-390. doi:10.1016/j.physrep.2004.08.031Feng, J. L. (2010). Dark Matter Candidates from Particle Physics and Methods of Detection. Annual Review of Astronomy and Astrophysics, 48(1), 495-545. doi:10.1146/annurev-astro-082708-101659Goodman, M. W., & Witten, E. (1985). Detectability of certain dark-matter candidates. Physical Review D, 31(12), 3059-3063. doi:10.1103/physrevd.31.3059Behnke, E., Behnke, J., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Conner, A. (2012). First dark matter search results from a 4-kgCF3Ibubble chamber operated in a deep underground site. Physical Review D, 86(5). doi:10.1103/physrevd.86.052001Behnke, E., Behnke, J., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Cooper, P. S. (2011). Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two LiterCF3IBubble Chamber. Physical Review Letters, 106(2). doi:10.1103/physrevlett.106.021303Archambault, S., Behnke, E., Bhattacharjee, P., Bhattacharya, S., Dai, X., Das, M., … Zacek, V. (2012). Constraints on low-mass WIMP interactions on 19F from PICASSO. Physics Letters B, 711(2), 153-161. doi:10.1016/j.physletb.2012.03.078Felizardo, M., Girard, T. A., Morlat, T., Fernandes, A. C., Ramos, A. R., Marques, J. G., … Marques, R. (2014). The SIMPLE Phase II dark matter search. Physical Review D, 89(7). doi:10.1103/physrevd.89.072013Glaser, D. A., & Rahm, D. C. (1955). Characteristics of Bubble Chambers. Physical Review, 97(2), 474-479. doi:10.1103/physrev.97.474Seitz, F. (1958). On the Theory of the Bubble Chamber. Physics of Fluids, 1(1), 2. doi:10.1063/1.1724333Behnke, E., Benjamin, T., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Cooper, P. S. (2013). Direct measurement of the bubble-nucleation energy threshold in aCF3Ibubble chamber. Physical Review D, 88(2). doi:10.1103/physrevd.88.021101Agostinelli, S., Allison, J., Amako, K., Apostolakis, J., Araujo, H., Arce, P., … Barrand, G. (2003). Geant4—a simulation toolkit. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 506(3), 250-303. doi:10.1016/s0168-9002(03)01368-8Allison, J., Amako, K., Apostolakis, J., Araujo, H., Arce Dubois, P., Asai, M., … Chytracek, R. (2006). Geant4 developments and applications. IEEE Transactions on Nuclear Science, 53(1), 270-278. doi:10.1109/tns.2006.869826Aubin, F., Auger, M., Genest, M.-H., Giroux, G., Gornea, R., Faust, R., … Storey, C. (2008). Discrimination of nuclear recoils from alpha particles with superheated liquids. New Journal of Physics, 10(10), 103017. doi:10.1088/1367-2630/10/10/103017Archambault, S., Aubin, F., Auger, M., Beleshi, M., Behnke, E., … Behnke, J. (2011). New insights into particle detection with superheated liquids. New Journal of Physics, 13(4), 043006. doi:10.1088/1367-2630/13/4/043006Pozzi, S. A., Padovani, E., & Marseguerra, M. (2003). MCNP-PoliMi: a Monte-Carlo code for correlation measurements. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 513(3), 550-558. doi:10.1016/j.nima.2003.06.012Robinson, A. E. (2014). New libraries for simulating neutron scattering in dark matter detector calibrations. Physical Review C, 89(3). doi:10.1103/physrevc.89.032801Yellin, S. (2002). Finding an upper limit in the presence of an unknown background. Physical Review D, 66(3). doi:10.1103/physrevd.66.032005Lewin, J. D., & Smith, P. F. (1996). Review of mathematics, numerical factors, and corrections for dark matter experiments based on elastic nuclear recoil. Astroparticle Physics, 6(1), 87-112. doi:10.1016/s0927-6505(96)00047-3Tovey, D. R., Gaitskell, R. J., Gondolo, P., Ramachers, Y., & Roszkowski, L. (2000). A new model-independent method for extracting spin-dependent cross section limits from dark matter searches. Physics Letters B, 488(1), 17-26. doi:10.1016/s0370-2693(00)00846-7Roszkowski, L., Austri, R. R. de, & Trotta, R. (2007). Implications for the Constrained MSSM from a new prediction forb→sγ. Journal of High Energy Physics, 2007(07), 075-075. doi:10.1088/1126-6708/2007/07/075Aprile, E., Alfonsi, M., Arisaka, K., Arneodo, F., Balan, C., Baudis, L., … Bokeloh, K. (2013). Limits on Spin-Dependent WIMP-Nucleon Cross Sections from 225 Live Days of XENON100 Data. Physical Review Letters, 111(2). doi:10.1103/physrevlett.111.021301Aartsen, M. G., Abbasi, R., Abdou, Y., Ackermann, M., Adams, J., Aguilar, J. A., … Bai, X. (2013). Search for Dark Matter Annihilations in the Sun with the 79-String IceCube Detector. Physical Review Letters, 110(13). doi:10.1103/physrevlett.110.131302Tanaka, T., Abe, K., Hayato, Y., Iida, T., Kameda, J., Koshio, Y., … Nakahata, M. (2011). AN INDIRECT SEARCH FOR WEAKLY INTERACTING MASSIVE PARTICLES IN THE SUN USING 3109.6 DAYS OF UPWARD-GOING MUONS IN SUPER-KAMIOKANDE. The Astrophysical Journal, 742(2), 78. doi:10.1088/0004-637x/742/2/78Chatrchyan, S., Khachatryan, V., Sirunyan, A. M., Tumasyan, A., Adam, W., Bergauer, T., … Friedl, M. (2012). Search for Dark Matter and Large Extra Dimensions inppCollisions Yielding a Photon and Missing Transverse Energy. Physical Review Letters, 108(26). doi:10.1103/physrevlett.108.261803First results on dark matter annihilation in the Sun using the ANTARES neutrino telescope. (2013). Journal of Cosmology and Astroparticle Physics, 2013(11), 032-032. doi:10.1088/1475-7516/2013/11/032Demidov, S., & Suvorova, O. (2010). Annihilation of NMSSM neutralinos in the Sun and neutrino telescope limits. Journal of Cosmology and Astroparticle Physics, 2010(06), 018-018. doi:10.1088/1475-7516/2010/06/018Avrorin, A. D., Avrorin, A. V., Aynutdinov, V. M., Bannasch, R., Belolaptikov, I. A., Bogorodsky, D. Y., … Demidov, S. V. (2015). Search for neutrino emission from relic dark matter in the sun with the Baikal NT200 detector. Astroparticle Physics, 62, 12-20. doi:10.1016/j.astropartphys.2014.07.006Akerib, D. S., Araújo, H. M., Bai, X., Bailey, A. J., Balajthy, J., Bedikian, S., … Bradley, A. (2014). First Results from the LUX Dark Matter Experiment at the Sanford Underground Research Facility. Physical Review Letters, 112(9). doi:10.1103/physrevlett.112.091303Agnese, R., Anderson, A. J., Asai, M., Balakishiyeva, D., Basu Thakur, R., Bauer, D. A., … Bowles, M. A. (2014). Search for Low-Mass Weakly Interacting Massive Particles with SuperCDMS. Physical Review Letters, 112(24). doi:10.1103/physrevlett.112.241302Agnese, R., Anderson, A. J., Asai, M., Balakishiyeva, D., Basu Thakur, R., Bauer, D. A., … Brandt, D. (2014). Search for Low-Mass Weakly Interacting Massive Particles Using Voltage-Assisted Calorimetric Ionization Detection in the SuperCDMS Experiment. Physical Review Letters, 112(4). doi:10.1103/physrevlett.112.041302Angle, J., Aprile, E., Arneodo, F., Baudis, L., Bernstein, A., … Bolozdynya, A. I. (2011). Search for Light Dark Matter in XENON10 Data. Physical Review Letters, 107(5). doi:10.1103/physrevlett.107.051301Aprile, E., Alfonsi, M., Arisaka, K., Arneodo, F., Balan, C., Baudis, L., … Bokeloh, K. (2012). Dark Matter Results from 225 Live Days of XENON100 Data. Physical Review Letters, 109(18). doi:10.1103/physrevlett.109.181301Angloher, G., Bento, A., Bucci, C., Canonica, L., Erb, A., von Feilitzsch, F., … Zöller, A. (2014). Results on low mass WIMPs using an upgraded CRESST-II detector. The European Physical Journal C, 74(12). doi:10.1140/epjc/s10052-014-3184-9Bernabei, R., Belli, P., Cappella, F., Cerulli, R., Dai, C. J., d’ Angelo, A., … Ye, Z. P. (2008). First results from DAMA/LIBRA and the combined results with DAMA/NaI. The European Physical Journal C, 56(3), 333-355. doi:10.1140/epjc/s10052-008-0662-yAalseth, C. E., Barbeau, P. S., Colaresi, J., Collar, J. I., Diaz Leon, J., … Fast, J. E. (2013). CoGeNT: A search for low-mass dark matter usingp-type point contact germanium detectors. Physical Review D, 88(1). doi:10.1103/physrevd.88.012002Agnese, R., Ahmed, Z., Anderson, A. J., Arrenberg, S., Balakishiyeva, D., Basu Thakur, R., … Brink, P. L. (2013). Silicon detector results from the first five-tower run of CDMS II. Physical Review D, 88(3). doi:10.1103/physrevd.88.03110
Improved dark matter search results from PICO-2L Run 2
New data are reported from a second run of the 2-liter PICO-2L C3F8 bubble chamber with a total exposure of 129 kg-days at a thermodynamic threshold energy of 3.3 keV. These data show that measures taken to control particulate contamination in the superheated fluid resulted in the absence of the anomalous background events observed in the first run of this bubble chamber. One single nuclear-recoil event was observed in the data, consistent both with the predicted background rate from neutrons and with the observed rate of unambiguous multiple-bubble neutron scattering events. The chamber exhibits the same excellent electron-recoil and alpha decay rejection as was previously reported. These data provide the most stringent direct detection constraints on weakly interacting massive particle (WIMP)-proton spin-dependent scattering to date for WIMP masses < 50 GeV/c(2).The PICO Collaboration thanks SNOLAB for their exceptional laboratory space and technical support. We also thank Fermi National Accelerator Laboratory (Contract No. DE-AC02-07CH11359) and Pacific Northwest National Laboratory for their support. This work is supported by the National Sciences and Engineering Research Council of Canada (NSERC), the Canada Foundation for Innovation (CFI), the National Science Foundation (NSF) under the Grants No. PHY-1242637, No. PHY-0919526, No. PHY-1205987, and No. PHY-1506377 and by the U.S. Department of Energy under Award No. DE-SC-0012161. We also acknowledge the support of Department of Atomic Energy (DAE), Government of India, under the Center of AstroParticle Physics II project (CAPP-II) at Saha Institute of Physics (SINP); the Czech Ministry of Education, Youth and Sports (Grant No. LM2011027); the Spanish Ministerio de Economia y Competitividad, Consolider MultiDark (Grant No. CSD2009-00064) and DGAPA-UNAM through grant PAPIIT No. IA100316.Amole, C.; Ardid RamÃrez, M.; Arnquist, I.; Asner, DM.; Baxter, D.; Behnke, E.; Bhattacharjee, P.... (2016). Improved dark matter search results from PICO-2L Run 2. Physical Review D. 93(6):1-5. https://doi.org/10.1103/PhysRevD.93.061101S1593
Dark matter search results from the PICO-60 CF3I bubble chamber
New data are reported from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 36.8 kg of CF3I and located in the SNOLAB underground laboratory. PICO-60 is the largest bubble chamber to search for dark matter to date. With an analyzed exposure of 92.8 livedays, PICO-60 exhibits the same excellent background rejection observed in smaller bubble chambers. Alpha decays in PICO-60 exhibit frequency-dependent acoustic calorimetry, similar but not identical to that reported recently in a C3F8 bubble chamber. PICO-60 also observes a large population of unknown background events, exhibiting acoustic, spatial, and timing behaviors inconsistent with those expected from a dark matter signal. These behaviors allow for analysis cuts to remove all background events while retaining 48.2% of the exposure. Stringent limits on weakly interacting massive particles interacting via spin-dependent proton and spin-independent processes are set, and most interpretations of the DAMA/LIBRA modulation signal as dark matter interacting with iodine nuclei are ruled out.The PICO Collaboration would like to thank SNOLAB and its staff for providing an exceptional underground laboratory space and invaluable technical support. We acknowledge technical assistance from Fermilab's Computing, Particle Physics, and Accelerator Divisions and from A. Behnke at IUSB. We thank V. Gluscevic and S. McDermott for useful conversations and their assistance with the DMDD code package. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award No. DE-SC-0012161. Fermi National Accelerator Laboratory is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359. Part of the research described in this paper was conducted under the Ultra Sensitive Nuclear Measurements Initiative at Pacific Northwest National Laboratory, a multiprogram national laboratory operated by Battelle for the U.S. Department of Energy. We acknowledge the National Science Foundation for their support including Grants No. PHY-1242637, No. PHY-0919526, and No. PHY-1205987. We acknowledge the support of the National Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI). We thank the Kavli Institute for Cosmological Physics at the University of Chicago. We were also supported by the Spanish Ministerio de Economia y Competitividad, Consolider MultiDark CSD2009-00064 Grant. We thank the Department of Atomic Energy (DAE), Government of India, under the project CAPP-II at SINP, Kolkata. We acknowledge the Czech Ministry of Education, Youth and Sports, Grant No. LM2011027.Amole, C.; Ardid RamÃrez, M.; Asner, DM.; Baxter, D.; Behnke, E.; Bhattacharjee, P.; Borsodi, H.... (2016). Dark matter search results from the PICO-60 CF3I bubble chamber. Physical Review D. 93(5):1-14. https://doi.org/10.1103/PhysRevD.93.052014S114935Komatsu, E., Dunkley, J., Nolta, M. R., Bennett, C. L., Gold, B., Hinshaw, G., … Wright, E. L. (2009). FIVE-YEARWILKINSON MICROWAVE ANISOTROPY PROBEOBSERVATIONS: COSMOLOGICAL INTERPRETATION. The Astrophysical Journal Supplement Series, 180(2), 330-376. doi:10.1088/0067-0049/180/2/330Jungman, G., Kamionkowski, M., & Griest, K. (1996). Supersymmetric dark matter. Physics Reports, 267(5-6), 195-373. doi:10.1016/0370-1573(95)00058-5Bertone, G., Hooper, D., & Silk, J. (2005). Particle dark matter: evidence, candidates and constraints. Physics Reports, 405(5-6), 279-390. doi:10.1016/j.physrep.2004.08.031Feng, J. L. (2010). Dark Matter Candidates from Particle Physics and Methods of Detection. Annual Review of Astronomy and Astrophysics, 48(1), 495-545. doi:10.1146/annurev-astro-082708-101659Goodman, M. W., & Witten, E. (1985). Detectability of certain dark-matter candidates. Physical Review D, 31(12), 3059-3063. doi:10.1103/physrevd.31.3059Bolte, W. J., Collar, J. I., Crisler, M., Hall, J., Holmgren, D., Nakazawa, D., … Vieira, J. D. (2007). Development of bubble chambers with enhanced stability and sensitivity to low-energy nuclear recoils. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 577(3), 569-573. doi:10.1016/j.nima.2007.04.149Behnke, E., Collar, J. I., Cooper, P. S., Crum, K., Crisler, M., Hu, M., … Tschirhart, R. (2008). Spin-Dependent WIMP Limits from a Bubble Chamber. Science, 319(5865), 933-936. doi:10.1126/science.1149999Behnke, E., Behnke, J., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Cooper, P. S. (2011). Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two LiterCF3IBubble Chamber. Physical Review Letters, 106(2). doi:10.1103/physrevlett.106.021303Behnke, E., Behnke, J., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Conner, A. (2012). First dark matter search results from a 4-kgCF3Ibubble chamber operated in a deep underground site. Physical Review D, 86(5). doi:10.1103/physrevd.86.052001Archambault, S., Aubin, F., Auger, M., Behnke, E., Beltran, B., Clark, K., … Zacek, V. (2009). Dark matter spin-dependent limits for WIMP interactions on 19F by PICASSO. Physics Letters B, 682(2), 185-192. doi:10.1016/j.physletb.2009.11.019Archambault, S., Behnke, E., Bhattacharjee, P., Bhattacharya, S., Dai, X., Das, M., … Zacek, V. (2012). Constraints on low-mass WIMP interactions on 19F from PICASSO. Physics Letters B, 711(2), 153-161. doi:10.1016/j.physletb.2012.03.078Felizardo, M., Girard, T. A., Morlat, T., Fernandes, A. C., Ramos, A. R., Marques, J. G., … Marques, R. (2014). The SIMPLE Phase II dark matter search. Physical Review D, 89(7). doi:10.1103/physrevd.89.072013Amole, C., Ardid, M., Asner, D. M., Baxter, D., Behnke, E., Bhattacharjee, P., … Broemmelsiek, D. (2015). Dark Matter Search Results from the PICO-2LC3F8Bubble Chamber. Physical Review Letters, 114(23). doi:10.1103/physrevlett.114.231302Duncan, F., Noble, A. J., & Sinclair, D. (2010). The Construction and Anticipated Science of SNOLAB. Annual Review of Nuclear and Particle Science, 60(1), 163-180. doi:10.1146/annurev.nucl.012809.104513Glaser, D. A., & Rahm, D. C. (1955). Characteristics of Bubble Chambers. Physical Review, 97(2), 474-479. doi:10.1103/physrev.97.474Seitz, F. (1958). On the Theory of the Bubble Chamber. Physics of Fluids, 1(1), 2. doi:10.1063/1.1724333Collar, J. I. (2013). Applications of anY88/BePhotoneutron Calibration Source to Dark Matter and Neutrino Experiments. Physical Review Letters, 110(21). doi:10.1103/physrevlett.110.211101Behnke, E., Benjamin, T., Brice, S. J., Broemmelsiek, D., Collar, J. I., … Cooper, P. S. (2013). Direct measurement of the bubble-nucleation energy threshold in aCF3Ibubble chamber. Physical Review D, 88(2). doi:10.1103/physrevd.88.021101Archambault, S., Aubin, F., Auger, M., Beleshi, M., Behnke, E., … Behnke, J. (2011). New insights into particle detection with superheated liquids. New Journal of Physics, 13(4), 043006. doi:10.1088/1367-2630/13/4/043006Wilson, W. B., Perry, R. T., Charlton, W. S., Parish, T. A., & Shores, E. F. (2005). SOURCES: a code for calculating (α,n), spontaneous fission, and delayed neutron sources and spectra. Radiation Protection Dosimetry, 115(1-4), 117-121. doi:10.1093/rpd/nci260Mei, D.-M., & Hime, A. (2006). Muon-induced background study for underground laboratories. Physical Review D, 73(5). doi:10.1103/physrevd.73.053004Aharmim, B., Ahmed, S. N., Andersen, T. C., Anthony, A. E., Barros, N., Beier, E. W., … Biller, S. D. (2009). Measurement of the cosmic ray and neutrino-induced muon flux at the Sudbury neutrino observatory. Physical Review D, 80(1). doi:10.1103/physrevd.80.012001Agostinelli, S., Allison, J., Amako, K., Apostolakis, J., Araujo, H., Arce, P., … Barrand, G. (2003). Geant4—a simulation toolkit. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 506(3), 250-303. doi:10.1016/s0168-9002(03)01368-8Allison, J., Amako, K., Apostolakis, J., Araujo, H., Arce Dubois, P., Asai, M., … Chytracek, R. (2006). Geant4 developments and applications. IEEE Transactions on Nuclear Science, 53(1), 270-278. doi:10.1109/tns.2006.869826Aubin, F., Auger, M., Genest, M.-H., Giroux, G., Gornea, R., Faust, R., … Storey, C. (2008). Discrimination of nuclear recoils from alpha particles with superheated liquids. New Journal of Physics, 10(10), 103017. doi:10.1088/1367-2630/10/10/103017Yellin, S. (2002). Finding an upper limit in the presence of an unknown background. Physical Review D, 66(3). doi:10.1103/physrevd.66.032005Lewin, J. D., & Smith, P. F. (1996). Review of mathematics, numerical factors, and corrections for dark matter experiments based on elastic nuclear recoil. Astroparticle Physics, 6(1), 87-112. doi:10.1016/s0927-6505(96)00047-3Fitzpatrick, A. L., & Zurek, K. M. (2010). Dark moments and the DAMA-CoGeNT puzzle. Physical Review D, 82(7). doi:10.1103/physrevd.82.075004Fitzpatrick, A. L., Haxton, W., Katz, E., Lubbers, N., & Xu, Y. (2013). The effective field theory of dark matter direct detection. Journal of Cosmology and Astroparticle Physics, 2013(02), 004-004. doi:10.1088/1475-7516/2013/02/004Anand, N., Fitzpatrick, A. L., & Haxton, W. C. (2014). Weakly interacting massive particle-nucleus elastic scattering response. Physical Review C, 89(6). doi:10.1103/physrevc.89.065501Gresham, M. I., & Zurek, K. M. (2014). Effect of nuclear response functions in dark matter direct detection. Physical Review D, 89(12). doi:10.1103/physrevd.89.123521Gluscevic, V., Gresham, M. I., McDermott, S. D., Peter, A. H. G., & Zurek, K. M. (2015). Identifying the theory of dark matter with direct detection. Journal of Cosmology and Astroparticle Physics, 2015(12), 057-057. doi:10.1088/1475-7516/2015/12/057Akerib, D. S., Araújo, H. M., Bai, X., Bailey, A. J., Balajthy, J., Bedikian, S., … Bradley, A. (2014). First Results from the LUX Dark Matter Experiment at the Sanford Underground Research Facility. Physical Review Letters, 112(9). doi:10.1103/physrevlett.112.091303Aprile, E., Alfonsi, M., Arisaka, K., Arneodo, F., Balan, C., Baudis, L., … Bokeloh, K. (2012). Dark Matter Results from 225 Live Days of XENON100 Data. Physical Review Letters, 109(18). doi:10.1103/physrevlett.109.181301Agnese, R., Anderson, A. J., Asai, M., Balakishiyeva, D., Barker, D., Basu Thakur, R., … Bowles, M. A. (2015). Improved WIMP-search reach of the CDMS II germanium data. Physical Review D, 92(7). doi:10.1103/physrevd.92.072003Aprile, E., Alfonsi, M., Arisaka, K., Arneodo, F., Balan, C., Baudis, L., … Bokeloh, K. (2013). Limits on Spin-Dependent WIMP-Nucleon Cross Sections from 225 Live Days of XENON100 Data. Physical Review Letters, 111(2). doi:10.1103/physrevlett.111.021301Aartsen, M. G., Abbasi, R., Abdou, Y., Ackermann, M., Adams, J., Aguilar, J. A., … Bai, X. (2013). Search for Dark Matter Annihilations in the Sun with the 79-String IceCube Detector. Physical Review Letters, 110(13). doi:10.1103/physrevlett.110.131302Tanaka, T., Abe, K., Hayato, Y., Iida, T., Kameda, J., Koshio, Y., … Nakahata, M. (2011). AN INDIRECT SEARCH FOR WEAKLY INTERACTING MASSIVE PARTICLES IN THE SUN USING 3109.6 DAYS OF UPWARD-GOING MUONS IN SUPER-KAMIOKANDE. The Astrophysical Journal, 742(2), 78. doi:10.1088/0004-637x/742/2/78Choi, K., Abe, K., Haga, Y., Hayato, Y., Iyogi, K., Kameda, J., … Nakahata, M. (2015). Search for Neutrinos from Annihilation of Captured Low-Mass Dark Matter Particles in the Sun by Super-Kamiokande. Physical Review Letters, 114(14). doi:10.1103/physrevlett.114.141301Khachatryan, V., Sirunyan, A. M., Tumasyan, A., Adam, W., Bergauer, T., Dragicevic, M., … Frühwirth, R. (2015). Search for dark matter, extra dimensions, and unparticles in monojet events in proton–proton collisions at s = 8 TeV. The European Physical Journal C, 75(5). doi:10.1140/epjc/s10052-015-3451-4First results on dark matter annihilation in the Sun using the ANTARES neutrino telescope. (2013). Journal of Cosmology and Astroparticle Physics, 2013(11), 032-032. doi:10.1088/1475-7516/2013/11/032Demidov, S., & Suvorova, O. (2010). Annihilation of NMSSM neutralinos in the Sun and neutrino telescope limits. Journal of Cosmology and Astroparticle Physics, 2010(06), 018-018. doi:10.1088/1475-7516/2010/06/018Avrorin, A. D., Avrorin, A. V., Aynutdinov, V. M., Bannasch, R., Belolaptikov, I. A., Bogorodsky, D. Y., … Demidov, S. V. (2015). Search for neutrino emission from relic dark matter in the sun with the Baikal NT200 detector. Astroparticle Physics, 62, 12-20. doi:10.1016/j.astropartphys.2014.07.006Busoni, G., De Simone, A., Morgante, E., & Riotto, A. (2014). On the validity of the effective field theory for dark matter searches at the LHC. Physics Letters B, 728, 412-421. doi:10.1016/j.physletb.2013.11.069Buchmueller, O., Dolan, M. J., & McCabe, C. (2014). Beyond effective field theory for dark matter searches at the LHC. Journal of High Energy Physics, 2014(1). doi:10.1007/jhep01(2014)025Aad, G., Abbott, B., Abdallah, J., Abdel Khalek, S., Abdinov, O., … AbouZeid, O. S. (2015). Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at s = 8 TeV with the ATLAS detector. The European Physical Journal C, 75(7). doi:10.1140/epjc/s10052-015-3517-3Aad, G., Abbott, B., Abdallah, J., Abdel Khalek, S., Abdinov, O., … AbouZeid, O. S. (2015). Search for dark matter in events with heavy quarks and missing transverse momentum in p p collisions with the ATLAS detector. The European Physical Journal C, 75(2). doi:10.1140/epjc/s10052-015-3306-zRoszkowski, L., Austri, R. R. de, & Trotta, R. (2007). Implications for the Constrained MSSM from a new prediction forb→sγ. Journal of High Energy Physics, 2007(07), 075-075. doi:10.1088/1126-6708/2007/07/075Bernabei, R., Belli, P., Cappella, F., Caracciolo, V., Castellano, S., Cerulli, R., … Ye, Z. P. (2013). Final model independent result of DAMA/LIBRA–phase1. The European Physical Journal C, 73(12). doi:10.1140/epjc/s10052-013-2648-7Chang, S., Weiner, N., & Yavin, I. (2010). Magnetic inelastic dark matter. Physical Review D, 82(12). doi:10.1103/physrevd.82.125011Barello, G., Chang, S., & Newby, C. A. (2014). A model independent approach to inelastic dark matter scattering. Physical Review D, 90(9). doi:10.1103/physrevd.90.094027Kim, S. C., Bhang, H., Choi, J. H., Kang, W. G., Kim, B. H., Kim, H. J., … Yue, Q. (2012). New Limits on Interactions between Weakly Interacting Massive Particles and Nucleons Obtained with CsI(Tl) Crystal Detectors. Physical Review Letters, 108(18). doi:10.1103/physrevlett.108.181301Collar, J. I. (2013). Quenching and channeling of nuclear recoils in NaI(Tl): Implications for dark-matter searches. Physical Review C, 88(3). doi:10.1103/physrevc.88.035806Bernabei, R., Belli, P., Montecchia, F., Nozzoli, F., Cappella, F., Incicchitti, A., … Zhang, Y. J. (2007). Possible implications of the channeling effect in NaI(Tl) crystals. The European Physical Journal C, 53(2), 205-213. doi:10.1140/epjc/s10052-007-0479-0Bozorgnia, N., Gelmini, G. B., & Gondolo, P. (2010). Channeling in direct dark matter detection I: channeling fraction in NaI (Tl) crystals. Journal of Cosmology and Astroparticle Physics, 2010(11), 019-019. doi:10.1088/1475-7516/2010/11/019BERNABEI, R., BELLI, P., d’ ANGELO, S., DI MARCO, A., MONTECCHIA, F., CAPPELLA, F., … YE, Z. P. (2013). DARK MATTER INVESTIGATION BY DAMA AT GRAN SASSO. International Journal of Modern Physics A, 28(16), 1330022. doi:10.1142/s0217751x1330022
Carbon nanotubes synthetized from gaseous products of waste polymer pyrolysis and their application
This work is dedicated to the synthesis of carbon nanotube from pyrolysis gases obtained by plastics. Virgin and waste plastics (polyethylene, polypropylene, polystyrene, polyamide, polyvinyl-chloride, municipal plastic waste) were used as raw materials and fed into a horizontal tubular reactor and pyrolyzed without catalyst at 560–570 °C. Raw materials could be transformed into 14–32% gases and 15–44% pyrolysis oils, depending on the type of raw materials. Pyrolysis of municipal plastic waste produced the highest gas yield, while pyrolysis of virgin polypropylene gave the highest oil yield. Gases were passed through a chemical vapour deposition reactor, where they were transformed into carbon nanotubes at 700 °C in a semi-continuous rotating reactor with 0.5 h reaction time. To enhance the transformation of pyrolysis gases into carbon nanotubes (CNTs), Fe and Co based catalysts were used. Both gaseous and oil products of pyrolysis were investigated by gas-chromatography. The produced CNTs were added as reinforcement into a commercial low density polyethylene matrix using heated two roll mill and then specimens for testing were manufactured. Especially the reinforcing effects of carbon nanotube were investigated through the measuring of tensile and Charpy impact properties of the CNTs-LDPE polymers
Opioid binding profile of morphiceptin, Tyr-MIF-1 and dynorphin-related peptides in rat brain membranes
Opioid properties of several morphiceptin- (Tyr-Pro-Phe-Pro-NH2), Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2) and dynorphin-derivatives were characterized in rat brain in vitro receptor binding assay and in electrically stimulated longitudinal muscle strip preparation of guinea pig ileum. In the case of morphiceptin-related peptides, an excellent correlation was found between the [3H]-naloxone binding displacement data and the agonist potencies determined in the bioassay. The ‘turning point’ was the C-terminal amidation in the tri- and tetrapeptide pairs in both series. Tyr-MIF-1 derivatives showed weak affinity in the opioid receptor binding assay and none of them had any remarkable effect in the bioassay either as agonist or antagonist. The dynorphin A(1–10)-peptides modified at positions 5 and 8 retained their affinity with Pro5-, Pro8-, and Ala8- substituents, whereas some loss of affinity was observed in the case of Gly8-Dyn A(1–10)