3,761 research outputs found
Soil detritivore functioning in heterogeneously contaminated soils
Full text linkVerhoef, H.A. [Promotor]Berg, M.P. [Copromotor]Faber, J.H. [Copromotor
Through arthropod eyes : gaining mechanistic understanding of calcareous grassland diversity
Full text linkContains fulltext :
ToosvanNoordwijk.pdf (Publisher’s version ) (Open Access)Radboud Universiteit Nijmegen, 26 augustus 2014Promotores : Siepel, H., Bonte, D. Co-promotores : Berg, M.P., Remke, E.S.251 p
What's up down there?: Climate change effects on subarctic springtail communities and their role in carbon turnover
Full text linkCornelissen, J.H.C. [Promotor]Berg, M.P. [Copromotor
The use of plant litter and soil fauna traits in a mechanistic assessment of litter decomposition under global change
Full text linkAerts, M.A.P.A. [Promotor]Berg, M.P. [Copromotor
Living on the edge: Resource availablity and macroinvertebrate community dynamics in relation to sand nourishment
Full text linkAerts, M.A.P.A. [Promotor]Berg, M.P. [Copromotor]Bodegom, P.M. van [Copromotor
Living logs: Tree trait effects on decomposition and associated invertebrate diversity
Full text linkCornelissen, J.H.C. [Promotor]Berg, M.P. [Promotor]Hefting, M.M. [Copromotor
Detergency in Liquid CO2
No full textIn this dissertation we study Detergency in liquid Carbon Dioxide. Detergency is the cleaning performance of additives, surfactants in particular, in washing fluids. Liquid CO2 is under consideration, for environmental and toxicological reasons, to replace perchloro-ethylene as the solvent in textile dry cleaning technology. Inherent problems of such a transition were confronted with the methodology of chemical engineering design. The Basic Cycle of Design (BCD) approach was used as a pathway for designing a detergent. The BCD also establishes the structural framework of the thesis, which can, therefore, be read as records from a successful product engineering project, in which an effective detergent has been designed for a new dry cleaning solvent. The Dynamic Detergency Model (DDM), which succeeds to explain the role of surfactants in the washing operation, is used as a rational starting point for the design of a detergent in liquid CO2. According to this model, such a surfactant must be: sparingly soluble in the solvent, surface-active and able to form micelles in the solution. The different experiments carried out (solubility, interfacial-tension and dye solubilisation measurements), show that a number of molecules of the homologous polyoxyethylene/alkane series, generally described by the shorthand formula CiEj did indeed behave as surfactants and can be then considered detergents for liquid CO2. In the technical evaluation of the detergents, at laboratory as well as at semi-pilot scale, high washing performances were obtained. They are, indeed, as good for dry cleaning textiles as the present perchloro-ethylene (Perc) technology.Applied Science
On the organization of ecosystems: ecological autocatalysis in African savannas
No full textEnvironmental Biolog
Indução e controle da embriogenese somatica in vitro na goiabeira serrana (feijoa sellowiana Berg)
Full text linkDissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro de Ciencias BiologicasNo presente trabalho estudaram-se as condições para o estabelecimento, multiplicação e maturação de linhagens celulares embriogenéticas in vitro, a conversão dos ES e a produção de sementes sintéticas, a partir de embriões zigóticos (EZ) de Feijoa sellowiana Berg. Testaram-se também as formulações salinas LPm, MS e WPM, fontes e níveis de aminoácidos e pulsos de 2,4-D. Avaliações histoquímicas e histológicas foram feitas para caracterizar os processos morfogenéticos in vitro. A maior percentagem de indução e o maior número de ES ocorreram nos acessos 101 e 50-4. A formulação salina LPm, adicionada de 2,4-D e Gln, resultou em valores elevados de indução embriogenética. A adição de Asn, Gln ou Arg ao meio LPm resultou em valores elevados de indução e produção de ES. Pulsos de duas semanas com 2,4-D proporcionaram valores comparativos de indução e produção de ES, àqueles obtidos com pulsos de 4 e 8 semanas. Sementes em maturação fisiológica e armazenadas a 4° C por 12 meses, mantiveram alto potencial de indução e produção de ES. Linhagens celulares embriogenéticas foram estabelecidas, multiplicadas e mantidas com alto potencial embriogenético. A dinâmica de crescimento das suspensões celulares revelou um incremento de 21,7 vezes, após 50 dias em meio de cultura LPm contendo 2,4-D e 2iP e quando repicadas para o meio basal geleificado foram induzidas à maturação. A conversão de ES em plântulas foram obtidas em meio basal LPm contendo BAP e/ou GA3. A conversão das sementes sintéticas em plantulas ocorreu em tratamentos contendo KNO3. Estudos histoquímicos e histológicos demonstraram a evolução dos processos morfogênicos in vitro
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