Tunable thermal expansion in framework materials through redox intercalation

Thermal expansion properties of solids are of fundamental interest and control of thermal expansion is important for practical applications but can be difficult to achieve. Many framework-type materials show negative thermal expansion when internal cages are empty but positive thermal expansion when additional atoms or molecules fill internal voids present. Here we show that redox intercalation offers an effective method to control thermal expansion from positive to zero to negative by insertion of Li ions into the simple negative thermal expansion framework material ScF3, doped with 10% Fe to enable reduction. The small concentration of intercalated Li ions has a strong influence through steric hindrance of transverse fluoride ion vibrations, which directly controls the thermal expansion. Redox intercalation of guest ions is thus likely to be a general and effective method for controlling thermal expansion in the many known framework materials with phonon-driven negative thermal expansion

Carrot floral development and reproductive biology

The defining characteristic of the botanical family of Apiaceae (former Umbelliferae) is the inflorescence. The flowers aggregate in terminal umbels that may be commonly compound, often umbelliform cymes. Likewise, flowers of the carrot are clustered in flat, dense umbels, partially with zygomorphic petals at the edges. Carrot producers and consumers mainly consider the vegetative phase namely the storage root as vegetable. Nevertheless, the reproductive phase is an important topic for genetic research, for breeding new cultivars and seed production. Hence, an improved knowledge on the genetic control mechanisms of reproduction such as flowering time, flower development and architecture, pollen fertility and male sterility as well as seed set are of essential importance. The chapter reviews key steps on carrot floral development and reproductive biology especially under consideration of the comprehensive genomic data set recently obtained from carrot.Fil: Linke, Betina. Humboldt-Universität zu Berlin; AlemaniaFil: Alessandro, Maria Soledad. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; ArgentinaFil: Galmarini, Claudio Romulo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Nothnagel, Thomas. Institute for Breeding Research on Horticultural Crops; Alemani