News Interviews: Clayman and Heritage’s The News Interview

News interviews: Clayman and Heritage’s ‘The News Interview

Rhetorische Elemente als Bestandteile moralischer Kommunikation (eine Forschungsskizze zur Sendereihe 'Das Wort zum Sonntag')

UuStB Koeln(38)-960106058 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Superdiffusive Cusp-Like Waves in the Mercuric Iodide Precipitate System and Their Transition to Regular Reaction Bands

We report a two-dimensional (2D) reaction-diffusion system that exhibits a superdiffusive propagating wave with anomalous cusp-like contours. This wave results from a leading precipitation reaction (wavefront) and a trailing redissolution (waveback) between initially separated mercuric chloride and potassium iodide to produce mercuric iodide precipitate (HgI2) in a thin sheet of a solid hydrogel (agar) medium. The propagation dynamics is accompanied by continuous polymorphic transformations between the metastable yellow crystals and the stable red crystals of HgI2. We study the dynamics of wavefront and waveback propagation that reveals interesting anomalous superdiffusive behavior without the influence of external enhancement. We find that a transition from superdiffusive to subdiffusive dynamics occurs as a function of outer iodide concentration. Inner mercuric concentrations lead to the transition from the anomalous cusp-like to cusp-free regular bands. While gel concentration affects the speed of propagation of the wave, it has no effect on its shape or on its superdiffusive dynamics. Microscopically, we show that the macroscopic wave propagation and polymorphic transformations are accompanied by an Ostwald ripening mechanism in which larger red HgI2 crystals are formed at the expense of smaller yellow HgI2 crystals. © 2014 American Chemical Society.Mansour AA, 2011, PHYS REV E, V84, DOI 10.1103-PhysRevE.84.026107; Al-Ghoul M, 2001, J PHYS CHEM A, V105, P8053, DOI 10.1021-jp011158o; Al-Ghoul M, 2012, J PHYS CHEM A, V116, P4427, DOI 10.1021-jp300163f; Antal T, 1998, J CHEM PHYS, V109, P9479, DOI 10.1063-1.477609; Badr L., 2009, J PHYS CHEM A, V113, P6581; Berenstein I, 2008, PHYS REV E, V78, DOI 10.1103-PhysRevE.78.025101; CORNELL S, 1991, PHYS REV A, V44, P4826, DOI 10.1103-PhysRevA.44.4826; CROSS MC, 1993, REV MOD PHYS, V65, P851, DOI 10.1103-RevModPhys.65.851; DAS I, 1989, J PHYS CHEM-US, V93, P7269, DOI 10.1021-j100357a047; DAS I, 1990, J PHYS CHEM-US, V94, P8968, DOI 10.1021-j100389a023; DAS I, 1991, J PHYS CHEM-US, V95, P3866, DOI 10.1021-j100162a078; Deutsch A., 2005, CELLULAR AUTOMATON M; Fernandez-Garcia G, 2008, EUR PHYS J-SPEC TOP, V165, P169, DOI 10.1140-epjst-e2008-00860-2; FIELD RJ, 1972, J AM CHEM SOC, V94, P8649, DOI 10.1021-ja00780a001; GALFI L, 1988, PHYS REV A, V38, P3151, DOI 10.1103-PhysRevA.38.3151; Greenwell HC, 2006, J CRYST GROWTH, V294, P53, DOI 10.1016-j.jcrysgro.2006.05.048; Grzybowski B., 2009, CHEMISTRY IN MOTION; Hantz P, 2002, PHYS CHEM CHEM PHYS, V4, P1262, DOI 10.1039-b107742b; Hantz P, 2000, J PHYS CHEM B, V104, P4266, DOI 10.1021-jp992456c; Hilal N, 2003, CHEM PHYS LETT, V374, P183, DOI 10.1016-S0009-2614(03)00726-7; Horvat S, 2005, J CHEM PHYS, V123, DOI 10.1063-1.1943409; Hostettler M, 2003, HELV CHIM ACTA, V86, P1410, DOI 10.1002-hlca.200390126; Hostettler M, 2001, CHIMIA, V55, P541; Hostettler M, 2002, ACTA CRYSTALLOGR B, V58, P903, DOI 10.1107-S010876810201618X; Hostettler M, 2005, CR CHIM, V8, P147, DOI 10.1016-j.crci.2004.06.006; JEFFREY GA, 1967, INORG CHEM, V6, P396, DOI 10.1021-ic50048a048; Kapral R., 1995, CHEMICAL WAVES AND P; Kleber W., 1968, KRIST TECH, V3, P65, DOI 10.1002-crat.19680030109; KOO YE, 1990, MOL CRYST LIQ CRYST, V183, P187, DOI 10.1080-15421409008047455; Koza Z, 1996, PHYS REV E, V54, pR1040, DOI 10.1103-PhysRevE.54.R1040; Lagzi I, 2012, LANGMUIR, V28, P3350, DOI 10.1021-la2049025; LARRALDE H, 1992, PHYS REV A, V46, P855, DOI 10.1103-PhysRevA.46.855; Leger C, 1999, J PHYS CHEM B, V103, P5841, DOI 10.1021-jp990486+; Liesegang R, 1896, NATURWISS WOCHENSCHR, V10, P353; Meinhardt H., 2009, THE ALGORITHMIC BEAU; Muller SC, 2003, J PHYS CHEM A, V107, P7997, DOI 10.1021-jp030364o; Murray J. D., 2002, MATHEMATICAL BIOLOGY, V2; NOSZTICZIUS Z, 1991, J PHYS CHEM-US, V95, P6575, DOI 10.1021-j100170a038; Panfilov AV, 2007, P NATL ACAD SCI USA, V104, P7922, DOI 10.1073-pnas.0701895104; Paoletti MS, 2006, PHYS REV LETT, V96, DOI 10.1103-PhysRevLett.96.124101; Sultan R, 1996, J PHYS CHEM-US, V100, P16912, DOI 10.1021-jp960958+; Sultan R, 2001, PHYSICA D, V157, P241, DOI 10.1016-S0167-2789(01)00303-7; Taitelbaum H, 1996, PHYS REV E, V54, P5942, DOI 10.1103-PhysRevE.54.5942; Taylor AF, 2002, PROG REACT KINET MEC, V27, P247; Tinsley MR, 2013, J PHYS CHEM A, V117, P12719, DOI 10.1021-jp4095479; Vanag VK, 2001, SCIENCE, V294, P835, DOI 10.1126-science.1064167; van Baalen G, 2000, COMMUN MATH PHYS, V210, P145, DOI 10.1007-s002200050775; Volford A, 2007, LANGMUIR, V23, P961, DOI 10.1021-la0623432; von Kameke A, 2010, PHYS REV E, V81, DOI 10.1103-PhysRevE.81.066211; WOOD PM, 1985, J CHEM PHYS, V82, P1924, DOI 10.1063-1.448376; ZAIKIN AN, 1970, NATURE, V225, P535, DOI 10.1038-225535b0; ZRINYI M, 1991, J PHYS CHEM-US, V95, P1618, DOI 10.1021-j100157a0221