Dissertations / Theses on the topic 'Hydroida'
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Watson, Jeanette Esther, and mikewood@deakin edu au. "Studies on Australian hydroids the genus eudendrium and the fauna of the seagrass amphibolis." Deakin University. School of Science, 1990. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20050825.121035.
Full textKunovjánek, Miroslav. "Studium vodivosti PVA membrán, obsahujících alkalické hydroxidy." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-234580.
Full textČech, Ondřej. "Vliv namáhání alkalických akumulátorů na jejich parametry." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217856.
Full textKopecký, Filip. "Možnosti využití odpadních slévárenských písků." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2013. http://www.nusl.cz/ntk/nusl-216991.
Full textMoore, M. A. "The effect of lithium hydroxide on the nickel hydroxide electrode." Thesis, University of Newcastle Upon Tyne, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379735.
Full textBrumbaugh, Daniel Robert. "The evolution of modular adaptation : experimental studies of dispersal and growth in the marine colonial hydroid, Aglaophenia struthionides /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/5233.
Full textCharles, E. A. "The effects of cobalt hydroxide addition on the nickel hydroxide electrode." Thesis, University of Newcastle Upon Tyne, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254070.
Full textNavrátil, Jan. "Určení vlivu iontů ve struktuře hydroxidu nikelnatého." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218391.
Full textPavlík, Ondřej. "Neutralizace kyselých roztoků." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230828.
Full textFahy, Eoin. "Polyketide derived metabolites from the marine hydroid Garveia annulata." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/27071.
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Lengheden, Annelie. "Periodontal implications of calcium hydroxide treatment." Stockholm : Dept. of Oral Diagnosis, Karolinska Institutet, 1994. http://books.google.com/books?id=zfJpAAAAMAAJ.
Full textMavis, Bora. "Homogeneous Precipitation of Nickel Hydroxide Powders." Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2003. http://www.osti.gov/servlets/purl/822049-urdfie/native/.
Full textPublished through the Information Bridge: DOE Scientific and Technical Information. "IS-T 2111" Bora Mavis. 12/12/2003. Report is also available in paper and microfiche from NTIS.
Ibrahim, Ahmed Abdellatif Hamed. "Jambe Humanoïde Hydraulique pour HYDROïD." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLV038.
Full textHuman body has always been an inspiration for engineers and scientists from all fields all over the world. One of the most interesting topics in the last decade was humanoid robots. Humanoid robots represent the most complex robotic systems. They provide greater mobility in rough and unstructured terrain than the normal wheeled vehicles. In the future, humanoid robots are expected to be employed for a variety of dangerous tasks in fields like rescue operations, assisting elderly people, education and humanitarian demining. The work achieved in this dissertation is performed on the humanoid hydraulic robot HYDROïD. It is hydraulically actuated humanoid featuring 52 active degrees of freedom and is designed to perform highly dynamic tasks like walking, running and jumping. Hydraulic power was chosen for this robot since hydraulic actuators have an excellent power to weight ratio and naturally absorb impact force peaks during different activities. The objective of this dissertation is to contribute toward the development of ahighly dynamic robotic ankle and knee mechanisms. A new ankle mechanism islooked for in order to tackle the drawbacks raised by the performances achievedwith the original old ankle mechanism. Lower leakage and friction rates areachieved in addition to a pressure optimization for the ankle joints. Moreover, anew solution for optimizing the weight of hydraulic actuators is applied on theknee mechanism of the robot. Such solution includes the usage of light compositematerial technology to achieve optimized weight and performance for the joint.In order to apply control methodologies on the ankle and knee mechanisms,inverse geometrical model for the both mechanism are presented. Position controlis used to control the joints angles of the ankle and the knee mechanisms. Finally,the conclusions and the future perspectives are presented in the last chapter
Morse, Valerie Jane. "The regulation and origin of bioluminescence in the hydroid obelia." Thesis, Cardiff University, 2013. http://orca.cf.ac.uk/53880/.
Full textRovnaníková, Markéta. "Studium a modelování karbonatace betonu." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2012. http://www.nusl.cz/ntk/nusl-233351.
Full textŘihák, Lukáš. "Vliv aditiv na vlastnosti elektrodových hmot pro alkalické akumulátory." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217860.
Full textRůžička, Tomáš. "Vliv iontů hliníku ve struktuře hydroxidu nikelnatého na vlastnosti elektrod." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218707.
Full textFusek, Petr. "Nové elektrodové struktury pro alkalické akumulátory." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-218936.
Full textJanečka, Marek. "Vliv uhlíkových materiálů na kladnou elektrodu Ni-Cd akumulátorů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219496.
Full textChladil, Ladislav. "Studium jevů limitujících životnost sekundárních článků Ni-Zn." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-233640.
Full textMasue, Yoko. "Adsorption, desorption, and stabilization of arsenic on aluminum substituted ferrihydrite." Texas A&M University, 2004. http://hdl.handle.net/1969.1/3343.
Full textTronolone, Valquiria Baddini. "Estudo faunístico e da distribuição das hidromedusas (Cnidaria, Hydrozoa) da região compreendida entre Cabo Frio (RJ) e Cabo de Santa Marta Grande (SC), Brasil." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/41/41133/tde-09102008-134819/.
Full textBrazil has an extensive marine coast of over 9.200 km. However, the taxonomical, biogeographical and ecological knowledge of the organisms present in coastal and neritic waters is scanty. Although the gelatinous plankton constitutes one of the main groups of pelagic predators, is abundant and relatively large, in size, it is usually underestimated in number and importance by the traditional sampling methods. Hydrozoa are one of the most numerous and common groups in this planktonic community. Among the works on hydromedusae, only some included extensive areas of the Brazilian continental shelf, although sampling of oceanographic expeditions, as the ones accomplished by the Instituto Oceanográfico of the Universidade de São Paulo (IO-USP), are available for study. The goal of this study is to survey the hydromedusae species collected by two oceanographic expeditions by the Brazilian vessel carried out by IO-USP along the continental shelf between Cabo Frio (RJ) and Cabo de Santa Marta Grande (SC) (South Brazil Bight - SBB), in 1991 and 2001: Sardinha 1 and PADCT 2. The diversity and geographic distribution of the hydromedusae fauna were analyzed. Data were interpreted trying to infer correlations in the distribution of the species with the characteristic water masses present in the area (Coastal Water - CW; Tropical Water - TW; South Atlantic Central Water - SACW). The distribution data were also used in a Parsimony Analysis of Endemicity (PAE), to verify possible endemic areas of the species. From the 155 samples a total of 51,808 hydromedusae specimens were found, belonging to 20 species/morphotypes: 10 Anthoathecata; 5 Leptothecata; 3 Trachymedusae; 2 Narcomedusae. The diversity and abundance of the species were lower in the samples of PADCT 2 when compared to Sardinha 1. All of the species had already been recorded for the Brazilian coast; however, some had their geographical distributions enlarged. Liriope tetraphylla and Aglaura hemistoma were the most frequent and abundant species in the samples of the Sardinha 1 and PADCT 2, respectively. There are indications that the geographical distributions of some species are associated, as Aglaura hemistoma and Corymorpha gracilis; Solmundella bitentaculata and the pair Aglaura hemistoma-Liriope tetraphylla; Turritopsis nutricula and Proboscidactyla ornata, the last association usually occurring when both species are abundant. The relative low number of hydromedusae species found in SBB can be consequence of the sampling method, which did not aim at the gelatinous plankton. However, among the 20 identified species/morphotypes are the most frequent species already recorded for SBB, as Aglaura hemistoma, Liriope tetraphylla, Rhopalonema velatum, Solmundella bitentaculata and Turritopsis nutricula.. Some species distributions are associated to specific water masses like Turritopsis nutricula, Niobia dendrotentaculata, Proboscidactyla ornata, Solmundella bitentaculata and Corymorpha gracilis in a mixture of SACW and CW. Most individuals of Liriope tetraphylla and Eucheilota duodecimalis were related to the exclusive presence of CW, while the majority of Aglaura hemistoma and Rhopalonema velatum individuals were associated with SACW or TW+SACW, respectively. Two areas were identified in a Parsimony Analysis of Endemicity (PAE), the first located between 50 and 200 m deep and predominance of SACW, with the presence of Bougainvillia carolinensis, Dipurena sp. and the predominance in abundance of Corymorpha gracilis, Ectopleura dumortieri, Niobia dendrotentaculata, and Proboscidactyla ornata. The second area was characterized by high abundance of Rhopalonema velatum, being located east of the 200 m bathymetric line, along the occurrence of TW (main water mass) and SACW (secondary water mass).
Liauw, Christopher Mark. "Influence of surface modification of aluminium hydroxide on the processing and mechanical properties of aluminium hydroxide/polypropylene composites." Thesis, Manchester Metropolitan University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359468.
Full textSezgiker, Korhan. "Production Of Nano Alumoxane From Aluminum Hydroxide." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/3/12611533/index.pdf.
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m) to submicron sizes. This process was followed by the glycothermal ageing step, and organic derivative of boehmite was obtained. The amorphous particles thus obtained were further treated mechanochemically in a high energy ball mill with organic chemicals like acetic acid, methoxy acetic acid, stearic acid and L-lysine. After this step the observed sizes of the particles were as low as 10-100 nm. The effects of organic molecules used in each step were studied by FTIR spectroscopy and their effectiveness in exfoliation of hydroxide layers were identified with dynamic light scattering from processing solutions dispersed in aqueous medium. Moreover, in each step, structural analyses were carried out by XRD.
Padovani, Michela. "Thiophosphates : Co(III) and hydroxide catalysed hydrolysis." Thesis, University of Sheffield, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401241.
Full textMarkland, Charles Ivor. "Novel aspects of layered double hydroxide chemistry." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:a3494026-6f43-4696-9ff4-7e3040fe7958.
Full textMassaro, Fernanda Cristina. "Estudos ecotoxicológicos com Hydra viridissima (Cnidaria: Hydrozoa)." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/18/18139/tde-25072006-134025/.
Full textHydras are the main freshwater representatives of phylum Cnidaria, and when exposed to toxic substances they can display gradual changes in the body structure, whose expression allows determining the lethal and sub-lethal doses of a toxic substance. In the present study, the native species Hydra viridissima was cultured in the laboratory in order to determine its population and individual growth, the time of duplication of the population and its generation time. This species was also submitted to acute toxicity tests with the reference substances potassium dichromate and sodium sulfide, and also to toxicity tests with samples of water and/or sediment of reservoirs of the state of São Paulo, aiming to use this species as organism-test for ecotoxicological studies. The main results were an individual growth rate (k) of 0.43; the maximum length of the hydra column was 2.53 mm and the generation time averaged 6.6 '+ OU -' 1.5 days. This species presented an intrinsic rate of population growth (r) of 0.0468 for the adjusted curve and a time of duplication of the population of 14.8 '+ OU -' 2.63 days. H. viridissima has a sensitivity range for potassium dichromate varying between 2.8 mg/L and 4.3 mg/L, with a mean value of 3.55 mg/L. This species is more sensible to this substance than other species widely used in toxicity tests, including Hydra attenuata. The sensitivity range of H. viridissima to sodium sulfide varies between 17.76 mg/L and 26.08 mg/L, with a 'LC IND.50'-96h of 21.92 mg/L. A reduction or loss of toxicity to this substance was observed during the test accomplishment. The water and sediment samples of Lobo, Barra Bonita and Promissão reservoirs were not toxic, nevertheless the sediment of Rasgão reservoir was toxic to the hydras. It was concluded that H. viridissima is easy to culture in the laboratory, has a good performance in the culture conditions tested and suffers gradual morphological changes under toxic conditions, being, therefore, a potential test-organism for ecotoxicological studies
Louw, Linda-Ann. "The synthesis of aluminium hydroxide and oxyhydroxide." Master's thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/9564.
Full textBeta alumina is a ceramic with the ability to conduct certain ions. It is conventionally formed through the high temperature solid state reaction of α-alumina with soda and lithia, which results in a mixture of β- and β"-alumina phases. To maximise the amount of β"-alumina formed, a second heat treatment step is required. Beta alumina may also be synthesised directly from the various aluminium hydroxide ( Al(OH)₃ ) and aluminium oxyhydroxide (AIOOH) polymorphs. The particular oxygen sublattice of the starting material is critical in determining which phases of beta alumina are formed. Boehmite and bayerite are known to yield pure β"-alumina. In this investigation, the differences in structure and the identification of the polymorphs is discussed. A review of the methods of synthesis and concomitant mechanisms of reaction proposed in the literature are presented. Of these, the synthesis of boehmite and bayerite are investigated experimentally. Attempts to synthesise boehmite at ambient conditions resulted in the formation of pseudoboehmite, and confirmed that boehmite can only be formed by the introduction of a hydrothermal step. However, it was possible to form bayerite at ambient conditions by sμnple chemical reaction. Control of the reaction pH and the removal of inhibiting ions were found to facilitate the formation of well crystallised bayerite. Although the factors governing the successful synthesis of bayerite need further investigation, the possibility of a direct synthesis route for β"-alumina has been demonstrated. Finally, the synthesis of β"-alumina by the solid state reaction of the hydroxide and oxyhydroxide polymorphs was successfully completed.
Schibeci, Mark. "Hydroxide speciation in highly alkaline aluminate solutions." Thesis, Schibeci, Mark (1998) Hydroxide speciation in highly alkaline aluminate solutions. Honours thesis, Murdoch University, 1998. https://researchrepository.murdoch.edu.au/id/eprint/50269/.
Full textPica, Daniela. "Morphology and ecology of Stylasteridae (Cnidaria, Hydrozoa)." Doctoral thesis, Università Politecnica delle Marche, 2013. http://hdl.handle.net/11566/242735.
Full textStylasteridae is one of the two hydroid families having hard, calcareous skeleton. The stylasterids are polymorphic hydroids having two different kinds of polyps lodged in pores. The distribution of the pores over the coenosteum and their shapes are features strictly related to the genera. All the polyps of a colony are connected by a network of coenosarcal canals that densely perforate the coenosteum. The morphology of the stylasterid skeleton was finely investigated for the first time using the X-ray computed microtomography technique (μCT). The utility of this technique for the non-destructive study of coral morphology was showed, demonstrating the benefit of the integrated analysis of pictures produced by X-ray μCT and the traditional SEM techniques in coral taxonomy. Indeed the combined results allow the identification of morphological characters that otherwise could be misidentified or even could pass unnoticed. The observation of post-larval specimens belonging to several species that when adult show pores arranged in rows, in cyclostystems or without coordination revealed that they invariably produce a primary cyclosystem. These data lead to the hypothesis that the cyclosystem represents the pore organisation of the family ancestor or that this organisation provides greater protection to the young gastrozooid by the dactylozooids. The present study reports also the first detailed description of the growth stages of two Distichopora species showing the formation of a primary cyclosystem and the description of the growth process from primary cyclosystem to adult pore organisation. From the reproductive point of view a preliminary survey was carried out about the morphology of the reproductive structures and the development of the gonophores of four Indonesian species. In addition for the first time a detailed description, at ultrastructural level, of some steps of the spermatogenesis up to spermatozoa differentiation in a Distichopora species was provided. The study of the associated fauna showed the first evidence of stylasterids associated to goose barnacles. Moreover the survey concerning the association between sponges and stylasterid corals reveled no specific association and generally the recorded sponges bore only the dead portion of the colonies not enveloped by living epithelium and lacking the coenosteal stolon network.
Hofírková, Linda. "Lomová houževnatost kompozitu s polymerní matricí." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228671.
Full textDumitru, Paul. "Influence of surface modification of magnesium hydroxide on the processing and properties of a thermoplastic elastomer/magnesium hydroxide composite." Thesis, Manchester Metropolitan University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326440.
Full textRaymond, Carole Lesley. "Coatings for magnesium hydroxide fillers in polyethylene compounds." Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/26868.
Full textGeswindt, Theodore Earl. "The reactions of osmium (VIII) in hydroxide medium." Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/960.
Full textTam, Kawai 1969. "Neutralization of an acidic effluent using magnesium hydroxide." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=26426.
Full textJordan, Stephanie Louise. "The characterization and reactivity of calcium hydroxide surfaces." Thesis, Brunel University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296213.
Full textLakin, Nicholas Mark. "Electronic and microwave spectroscopy of indium(I) hydroxide." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259963.
Full textGondal, Shahla. "Carbon dioxide absorption into hydroxide and carbonate systems." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for kjemisk prosessteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-27125.
Full textMangano, Valentina. "Studies of some properties of hydroxide-catalysis bonds." Thesis, University of Glasgow, 2018. http://theses.gla.ac.uk/30938/.
Full textMergler, Bianca Isolde. "Enterocyte uptake of nanoparticulate iron(III) oxo-hydroxide." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610413.
Full textGreen, Vicki C. "CO2 Recovery by Scrubbing with Reclaimed Magnesium Hydroxide." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378196688.
Full textCoelho, Helena Isabel Soares Dinis. "Microphytobenthos vs Hydrobia: trophic coupling in estuarine environment." Doctoral thesis, Universidade de Aveiro, 2010. http://hdl.handle.net/10773/3632.
Full textOs estuários são ambientes complexos, biologicamente diversos e muito importantes no que respeita à produtividade primária. As zonas intertidais destes ecossistemas são ocupadas por organismos que possuem uma elevada capacidade de sobrevivência e adaptação face às variadas e rápidas alterações nos factores ambientais (tais como temperatura, salinidade, conteúdo hídrico, etc.). As cadeias tróficas com origem no ecossistema estuarino bentónico são essencialmente herbívoras, regulando o fluxo de energia desde o fundo sedimentar e através do ecossistema. Nas áreas estuarinas intertidais a produção primária é essencialmente suportada pelo microfitobentos (MPB). Estas comunidades de microalgas bênticas constituem uma importante fonte de matéria orgânica e são por si só a principal fonte alimentar para as populações de Hydrobia. Neste contexto, a interacção MPB - Hydrobia é um modelo-chave na investigação da cadeia trófica estuarina de origem bentónica, actuando como um importante canal de transporte de energia para os níveis tróficos superiores, especialmente se considerarmos que Hydrobia é uma importante presa para peixes, aves e caranguejos. O presente estudo tem por objectivos gerais: i) a investigação do controlo ambiental (particularmente da luz e do teor em água do sedimento) e endógeno na migração vertical do MPB e ii) a identificação e potencial utilização de marcadores tróficos (pigmentos e ácidos gordos) úteis à investigação da interacção MPB – Hydrobia em laboratório e em condições naturais, considerando a existência de uma elevada plasticidade trófica por parte da Hydrobia e a elevada densidade populacional que estes organismos podem apresentar. A primeira fase de investigação resultou na comparação do papel dos estímulos ambientais e do controlo endógeno nos padrões de comportamento migratório vertical do microfitobentos, demonstrando a existência de um controlo essencialmente endógeno na formação e desintegração do biofilme superficial. A regulação e manutenção da biomassa à superfície do sedimento são claramente controladas pela variação dos factores ambientais, em especial da luz, cuja presença é essencial à formação total do biofilme microalgal à superfície do sedimento intertidal. Foi proposta uma nova abordagem metodológica com vista à estimativa nãodestrutiva do teor de água de sedimentos intertidais vasosos , possibilitando o estudo da influência da acção do vento no conteúdo hídrico dos sedimentos e o consequente impacto da dessecação na comunidade microfitobêntica. Observou-se que a dessecação provoca efeitos limitantes não só na biomassa superficial mas também na actividade fotossintética dos biofilmes microfitobênticos, conduzindo à diminuição da produtividade primária. No que respeita à dinâmica trófica da interacção MPB - Hydrobia foi estabelecido o uso do pigmento feoforbide a, quantificado nas partículas fecais da fauna, como marcador trófico que permite estimar a quantidade de biomassa de microalgas (clorofila a) incorporada pelos organismos animais.Para tal foi investigada e comprovada a existência de uma relação significativa entre a concentração de feopigmentos excretados e a concentração de clorofila a ingerida. Estes estudos foram desenvolvidos numa primeira fase à escala diária, considerando os efeitos dos ciclos sazonais, dia-noite e maré, e depois com a validação em condições naturais, numa escala mensal. A taxa de ingestão média de indivíduos de H. ulvae varia ao longo do dia, com o máximo em torno dos períodos diurnos de maré baixa, o que pode estar relacionado com a disponibilidade de MPB. As taxas de ingestão (TI) de H. ulvae variam ainda em função da estação do ano (TI verão > TI primavera) e em função da densidade de indivíduos (> densidade, < ingestão). Verificou-se um efeito negativo na concentração de clorofila disponível após herbívoria independentemente da densidade de indivíduos. Finalmente, a comparação dos perfis de ácidos gordos de H. ulvae provenientes de diferentes habitats com os perfis de potenciais fontes alimentares permitiu demonstrar que os ácidos gordos são ferramentas úteis na identificação do habitat ocupado por estes organismos. No entanto, apesar da ocupação de diferentes habitats e da integração de múltiplas fontes de produção primária na sua dieta foram sempre observados significativos níveis de ácidos gordos específicos de microalgas (em particular diatomáceas), reforçando o papel importante das comunidades de microalgas bênticas na dieta das populações de H. ulvae.
Estuaries are biologically diverse and form complex environments, which play an important role on the global primary productivity of aquatic environments. Intertidal areas of estuaries are inhabited by organisms with a strikingly capability to survive and to be adapted to frequent and fast changes in several environmental factors (such as temperature, salinity, water content, etc.). Grazing food chains are common in intertidal mudflats regulating the flow of nutrients and energy from the bottom throughout the estuarine ecosystem. Within intertidal estuarine areas the primary production was predominantly supported by microphytobenthos (MPB). These benthic microalgae assemblages are an important source of organic matter and are a main food source for Hydrobia populations. The MPB - Hydrobia interaction is a key model for the estuarine grazing food chain, acting as a significantly channel of energy to higher trophic levels, since Hydrobia is an important prey item for fish, birds and crabs. The present work addressed: i) the environmental (namely light and sediment water content) and the endogenous control of the vertical migration by microphytobenthos, and ii) the identification and the potential use of trophic markers (pigments and fatty acids) to establish this relationship under laboratory and natural conditions, considering that H. ulvae showed significant trophic plasticity and that mud snails could reach extremely high densities. The role of exogenous cues and endogenous control of the patterns of vertical migratory behavior of intertidal MPB biofilms were compared, showing that the formation and disintegration of the biofilm is endogenously-controlled. The regulation and maintenance of the microalgal biomass at the sediment surface is dependent on the variation of environmental factors, namely light, which is essential for the full formation of the MPB biofilm. A new methodological approach was proposed to estimate the water content of muddy intertidal sediments, enabling the study of the influence of wind on the hydric level of the sediment and the consequent impact of desiccation on the MPB biomass. This investigation showed that desiccation might be responsible to cause important limiting effects on biomass and photosynthetic activity of intertidal MPB biofilms, reducing the primary productivity. Regarding the trophic dynamics of the interaction MPB - Hydrobia, it was established the use of the pigment pheophorbide a, present on Hydrobia ulvae faecal pellets, as a trophic marker to estimate the amount of microalgal biomass incorporated, as chlorophyll a, by benthic macrofauna. A significant relationship between egested pheopigments and ingested chlorophyll a was investigated and validated. These studies were firstly developed on a daily scale, considering the effects of seasonal, tidal and day-night cycles, followed by a validation under natural conditions, on a monthly scale. The mean ingestion rate of H. ulvae individuals varied along the day, with the maximum around the diurnal low tide periods, which may be related with MPB availability. H. ulvae mean ingestion rate (IR) also varies seasonally (IR summer > IR spring) and depending on mud snails density (> density, < ingestion). There was a negative effect on chlorophyll concentration available after grazing, independently of H. ulvae density. Finally, the comparison of fatty acid profiles of mud snails from different habitats with the ones from potential food sources allowed identifying fatty acids as a useful tool to indicate H. ulvae habitat. Although the occupation of different habitats and the integration of multiple primary food sources on mud snails diet, significant inputs of fatty acids specific of microalgae (namely diatoms) were always found, which reinforce the important role of MPB on the diet of H. ulvae populations.
FCT; FSE - SFRH/BD/23720/2005
Harrison, Hollie. "The electrodialysis of lithium sulphate to lithium hydroxide." Thesis, Harrison, Hollie (2018) The electrodialysis of lithium sulphate to lithium hydroxide. Honours thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/40456/.
Full textKaddissy, Josiane. "Hydrogen production from irradiated aluminum hydroxide and oxyhydroxide." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS253/document.
Full textDihydrogen production is a critical issue for the current management of nuclear wastes. One potential source of hydrogen generation is the radiolysis of hydrated mineral phases encountered in the nuclear waste transportation and storage casks. We chose to study aluminum hydroxide (Al(OH)3) (Bayerite) and oxyhydroxides (AlOOH) (Boehmite) as model compounds. The determination of molecular hydrogen production was evaluated with respect to structure and particle size at room temperature and after annealing. In order to have a better understanding of the mechanisms and to identify the precursors of molecular hydrogen, we studied the irradiation defects and their stabilities using Electron Paramagnetic Resonance (EPR). The effect of adsorbed water and structural water on the molecular hydrogen production was studied. Different radiation sources were used such as Gamma radiation, electron beam radiations and heavy ions. In the last part, preliminary results related to the impact of impurities on hydrogen production are presented
Špičák, Petr. "Studium hydroxidů a oxidů kovů ve vodných roztocích." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-233539.
Full textIqbal, Muhammad Ahsan. "Layered double hydroxide based smart protective coating systems." Doctoral thesis, Università degli studi di Trento, 2021. http://hdl.handle.net/11572/302211.
Full textIqbal, Muhammad Ahsan. "Layered double hydroxide based smart protective coating systems." Doctoral thesis, Università degli studi di Trento, 2021. http://hdl.handle.net/11572/302211.
Full textMiranda, Thaís Pires. "Faunística e distribuição geográfica de hidróides bentônicos (Cnidaria, Hydrozoa) do sudoeste do Atlântico." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/41/41133/tde-24022010-183145/.
Full textIncreasing on faunistic and taxonomic knowledge is essential for reliable inferences on the geographical distribution and, consequently, on areas of endemism. This knowledge is incipient for the marine realm, including southwestern Atlantic, and particularly poor for cnidarians. The main goal of this study was (1) to survey the fauna of benthic hydroids from the region between Cabo Frio (Brasil) and Terra do Fogo (Argentina), and (2) to infer the geographic distribution of the surveyed species, aiming to propose areas of endemism. A total of 181 morphospecies of hydroids was recorded, 10 species are new records (Aglaophenia trifida, Antennella secundaria, Cryptolarella abyssicola, Filellum contortum, Lafoea coalescens, Lovenella gracilis, Macrorhynchia grandis, ?Nemertesia ciliata, Sertullarella leiocarpa e Zygophylax sibogae) and 9 are endemic species (Corymorpha januarii, Ectopleura obypa, Eudendrium caraiuru, Hydractinia uniformis, Lytocarpia canepa, Parascyphus repens, Plumularia insignis, Ralpharia sanctisebastiani, Symplectoscyphus magellanicus) for the area. Species richness slightly decreases along higher latitudes and along deeper waters (below 100 and 1000m isobaths). A PCA analyses has demonstrated that the substrata, Algae, Hydrozoa, Mollusca, Porifera and Rock showed a higher number of morphospecies of hydroids. Cluster analysis resulted in three faunistic groups: (1) Brazilian-coastal, (2) Uruguayan-Argentinean and (3) and oceanic group continuous along the entire surveyed area. Concerning areas of endemism, NDM-VNDM analyses resulted in two main coastal areas of endemism on the Brazilian coast (between 22-24°S 43-46°W and between 26-29°S 48- 49°W), and PAE resulted in four areas of endemism for the studied area: (1) coastal area in Brazil or Argentina; (2) a coastal and continuous area along Brazil and Argentina; (3) an oceanic and continuous area; (4) a Rio de La Plata area. Our results have shown that faunal affinities between Brazilian deep fauna and Argentinean shallow water fauna might be related to the marine fronts present in the southwestern Atlantic. Moreover, analyses exclusively including hydroid species with medusa in the life cycle resulted in more limited areas of endemism closer to the coast than those analyses exclusively including hydroids species with fixed gonophores. These results contradict the classical paradigm associating the presence of medusa and higher dispersive capabilities of the species.
Shimabukuro, Vanessa. "As associações epizóicas de Hydrozoa (Cnidaria: Leptothecata, Anthoathecata e Limnomedusae): I) Estudo faunístico de hidrozoários epizóicos e seus organismos associados; II) Dinâmica de comunidades bentônicas em substratos artificiais em São Sebastião, SP." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/41/41133/tde-29082007-145731/.
Full text2.1 The associations between animal groups and species of sponges are relatively well known and described in the literature. Of all the cnidarian groups, the most diverse associations with sponges are found among the hydrozoans. In this study, 117 species of epizoic hydroids were found on two classes of sponge substrates (Hexactinellida and Demospongiae). The biological aspects of the interactions between hydrozoans and sponges were discussed in this chapter. 3.1 Many studies describe the association between cnidarians and other organisms, even other cnidarians. In this study, 211 species of epizoic hydroids were found on two classes of cnidarian substrates (Anthozoa and Hydrozoa). The biological aspects of the interactions between hydrozoans and other cnidarians were discussed in this chapter. 4.1 The Phyllum Mollusca is one of the main groups that hydrozoans have ecological associations. On soft-bottom environments, the shells are an alternative for the organisms that need hard susbtrates to settle and grow. In this study, 143 species of epizoic hydroids were found on two classes of mollusc substrates (Bivalvia and Gastropoda). The biological aspects of the interactions between hydrozoans and molluscs were discussed in this chapter. 5.1 The polychaetes are abundant in different habitats and can be associated with many animals, even hydroids. In this study, 57 species of epizoic hydroids were found on two orders of polychaetes substrates (Aciculata and Canalipalpata). The biological aspects of the interactions between hydroids and polychaetes were discussed in this chapter. 6.1 The crustacean can be used as substrates, being their bodies and appendages overgrown by hydroid polyps. Another form of association found in the literature is indirect: the polyps grow over the gastropod shells occupied by hermit crabs. In this study 72 species of epizoic hydroids were found using two classes of Crustacea (Maxillopoda and Malacostraca) as substrates. The biological aspects of the interactions between hydroids and crustaceans were discussed in this chapter. 7.1 The bryozoan colonies grow on many substrates like rocks, algae, shells, crustaceans, ascidians, hydroids, and are important fouling members that grow on artificial substrates. However, they can also serve as substrate for other animals, even hydroids. In this study, 103 species of epizoic hydroids were found on two classes of bryozoan substrates (Gymnolaemata and Stenolaemata). The biological aspects of the interactions between hydroids and bryozoans were discussed in this chapter. 8.1 The most common commensal organisms of ascidians cited in the literature are copepods, molluscs, polychaetes, nemertines and there are records of endosymbiotic hydroids. The associations between ascidians and hydroids were listed in this study, and 51 species of epizoic hydroids were found on three orders of ascidian substrates (Aplousobranchia, Phlebobranchia e Stolidobranchia). The biological aspects of the interactions between hydroids and ascidians were discussed in this chapter. 9.1 Studies on the colonization of artificial substrates are quite common in the literature. In this study, we used ceramic panels in São Sebastião, SP, in order to observe the hydroid epizoic community and their animal substrates. Twenty-five species of epizoic hydroids were found on substrates of Porifera, Cnidaria, Mollusca, Arthropoda (Crustácea), Annelida (Polychaeta), Bryozoa and Chordata (Ascidiacea). The groups of substrates defined by the correspondence analysis seem to be related to the morphological features of the substrates, and the biological and temporal factors seem to influence the ecological succession of the experimental panels.
Máca, Tomáš. "Modifikace hydroxidu nikelnatého pro zlepšení jeho elektrochemických vlastností v alkalických akumulátorech." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-233682.
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