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Wang, Qing Min. "Calamitic liquid crystals based on metalloporphyrins." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364297.
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Baldwin, Rodney James. "Charge Transport Properties of Reactive Calamitic Liquid Crystals." Thesis, Queen Mary, University of London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487771.
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Polymerisable liquid crystalline semiconductors, referred to as reactive mesogens (RMs), consist of rr-conjugated cores with reactive end groups decoupled by an aliphatic spacer. These can be polymerised within a mesophase, maintaining the self-assembled mesophase morphology and charge transport characteristics. By successfully maintaining desirable charge transport properties in polymerised films, these molecular systems can be used in organic electronic applications such as charge transport layers in organic light emitting diodes and field effect transistors. We present a systematic study in collaboration with Merck Chemicals Ltd (UK), of the effect of reactive end groups on charge transport in calamiti9' liquid crystals (RMs) using the time-of-flight (TOF) technique. Several different compounds were synthesised with a variation in both the LC mesogenic core group and the functional end groups. The introduction of reactive end groups in most cases affects the mesophase charge transport compared to the non-reactive LC mesophase transport. This manifests itself as a reduction in mobility, varying from a factor of four in the best case, to as large as two orders of magnitude. In the best systems studied, however, the reactive end group effect on the transport, compared to the nonreactive mesophase transport, is negligible. Polymerised reactive mesogens do maintain long-range transport, with comparable mobilities to those of the phase in which they were polymerised ·over a broad temperature range, including room temperature. The temperature independent hole and electron mobility found in polymerised systems is explored using the Holstein small polaron model in the nonadiabatic limit, yielding the relevant polaron binding energies and bandwidths. In addition to this the Bassler Gaussian Disorder Model is applied to the data yielding the relevant energetic disorder parameters.
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De, Luca Marc Dominic. "Molecular dynamics simulations of calamitic and discotic liquid crystals." Thesis, Sheffield Hallam University, 1997. http://shura.shu.ac.uk/3187/.
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Significant progress has been made in recent years in modelling liquid crystal phases using the Monte Carlo and molecular dynamics simulation techniques. We describe the technique of molecular dynamics in the microcanonical ensemble that we have used in simulations of liquid crystal systems. A review and discussion of some of the important simulations that have been performed to date on non-spherical hard particle models, soft anisotropic single site models, and realistic atom-atom based models is presented. We report the results of molecular dynamics simulation studies of a system of particles interacting via an anisotropic potential proposed by Luckhurst and Romano, scaled by part of the well depth formulation employed by Gay and Berne. The resultant hybrid Gay-Berne Luckhurst-Romano (HGBLR) potential has an approximately spherical hard core with anisotropic long range attractive interactions with a dependency on the intermolecular vector joining a pair of sites. The spherical hard core nature of individual HGBLR centres notwithstanding we have parameterised single-site HGBLR centres to represent both calarnitic and discotic mesogens. Both systems are shown to exhibit a range of mesophases on cooling from the isotropic liquid to form a crystal, including uniaxial-nematic and columnar-like phases. Unlike previous hard particle studies these ordered phases obtain because of the presence of the long range attractive interactions. A comparison between the different structures formed with the two different parameterisations is presented including graphical representations of the simulation cell . In order to more closely represent the short range anisotropic interactions of real mesogens, a 3-HGBLR-site model has been parameterised to represent the mesogen para-terphenyl. Details of the parameterisation are discussed. Two versions of this model, a twisted central site 3-HGBLR-site site model obtained from a molecular mechanics minimum energy conformation of para-terphenyl, and an all coplanar 3-HGBLR-site site model have been studied using the molecular dynamics technique. The resultant models are found to be biaxial unlike previous anisotropic single site studies utilising soft potentials. Both models appear to exhibit a variety of uniaxial and biaxial mesophases but inclusion of the twisted site appears to promote the formation of biaxial phases. A comparison of the two models is made.
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Kloess, Petra Sabine. "Siloxane head groups and spacers in calamitic liquid crystals." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242294.
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Chakraborty, Susanta. "Phase transitions in Binary mixtures of calamitic and Bent-Core-Mesogens." Thesis, University of North Bengal, 2019. http://hdl.handle.net/123456789/2847.
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Shen, Xiaodong. "Study of molecular order and dynamics in calamitic and discotic liquid crystals by ²H NMR." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0028/NQ32889.pdf.
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Liu, Xiao-Hua. "Calamitic octahedral manganese(I) and rhenium(I) metallomesogens and side chain liquid crystalline poly(ferrocenylsilanes)." Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264433.
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Su, Xiaolu. "Engineering, Synthesis, and Characterization of New Multi-lamellar Liquid Crystalline Molecular Architectures based on Discotic and Calamitic π-Conjugated Mesogens." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066392/document.
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Grace à leurs propriétés d’auto-réparation et d’auto-organisation, les matériaux pi-conjugués liquide-cristallins (LCs) présentent un grand intérêt pour l’élaboration de matériaux semi-conducteurs à hautes performances. Ils peuvent être utilisés pour différents types d’applications en électronique organique telles que les cellules solaires (OPV), les diodes électroluminescentes (OLED) et les transistors à effet de champs (OFET). Dans ce travail, nous avons conçu et préparé une nouvelle famille de LCs combinant des entités pi-conjuguées de type calamitique et discotique au sein d’une architecture moléculaire unique. Plus particulièrement, nous avons imaginé trois différentes architectures telles que des dyades et triades linéaires et des triades ramifiées, incluant des dérivés discotiques de pérylène ou de triphénylène et des dérivés calamitiques de terthiophène, de benzothienobenzothiophène ou encore de pyromellitique. L’objectif était d’étudier leurs comportements liquide-cristallins et leurs propriétés d’auto-organisation et de transport de charges.Les résultats obtenus ont montré que ces matériaux donnent des auto-assemblages complexes formant des arrangements multi-lamellaires de bicouches, dans lesquelles les entités calamitiques et discotiques présentent une organisation dans le plan. De plus, en choisissant judicieusement les entités pi-conjuguées calamitiques et discotiques (type-p ou type-n), nous avons démontré que ce type de matériaux auto-organisés peut présenter des propriétés de transport de charge ambipolaire en formant des chemins distincts pour chaque type de charge (trou et électron) par nano-ségrégation de ces entités de type p et de type nDue to their self-healing ability and their self-organization property, pi-conjugated liquid crystals (LCs) are materials of great interest to prepare high performance semiconducting materials. They can be used in different types of organic electronic applications such as solar cells (OPV), Organic Light-Emitting Diodes (OLED) and Organic Field-Effect Transistors (OFET). In this work, we were interested in designing and preparing a novel family of LCs combining π-conjugated discotic and calamitic moieties in a unique molecular architecture. More particularly, we designed three different molecular architectures based on a linear dyad, triad and a branched triad, which include discotic triphenylene or perylene and calamitic terthiophene, benzothienobenzothiophene or pyromellitic moieties. The objective was to study their liquid crystalline behaviors and their self-organization and charge transport properties.Based on our results, we demonstrated that these materials can form complex self-assemblies in the bulk such as multi-lamellar arrangements presenting bilayered lamellar phases with in-layer organization of both calamitic and discotic species. In addition, based on the appropriate choice of the disk- and rod-like π-conjugated cores (p-type or n-type), we showed that this kind of self-organized materials could exhibit ambipolar charge transport properties, presenting a spontaneous nanosegregation of p-type and n-type entities in bulk, and leading to well-defined distinct conductive channels for each type of charge carriers (hole and electron)
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Castiglione, Andrea. "Liquid crystalline macromolecular architectures based on regioregular poly(3-alkylthiophene) as backbone and calamitic mesogens as side-groups : towards ambipolar materials." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066693.
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Très récemment, le potentiel des semi-conducteur organiques (OSC) ambipolaires à attiré l'attention par de nombreuses applications technologiques. Dans le domaine de la microélectronique organique, l'un des obstacles majeurs pour le développent des OSC est le design de systèmes capables de transporter à la fois les électrons et les trous. Les matériaux semi-conducteurs ambipolaires ordonnés, peuvent répondre à cette problématique. Dans ce contexte nous avons développé la synthèse et la caractérisation d'une architecture macromoléculaire originale, fondée sur l'association d'un polymère semi-conducteur régiorégulier d'une part, avec des molécules ?-conjuguées cristal liquides ayant la propriété de s'auto-organiser spontanément d'autre part. Afin d'améliorer les propriétés mésomorphes et électroniques de ce système macromoléculaire, une gamme de composés différant par (i) la nature chimique du groupement pendant et (ii) le dégrée de polymérisation moyen du polymère à été synthétisée. La présence d'une mesophase a été confirmée pour chacun de ces composés par diffraction des rayons X et une mesophase de type lamello-lamellaire, présentant une alternance de couches électron-donneur ou électron-accepter à également pu être mis en évidenceVery recently ambipolar organic semi-conductors (OSC) have gaining attention for their potential use in numerous technologically relevant applications. Representative technological examples are the area of organic microelectronics where patterning of p- and n-channel semiconductors is one of the major hurdles for the implantation of OSC in organic complementary logic circuit. To achieve this objective, well-ordered ambipolar semiconducting materials are needed. In this work we investigated the self-organization and the electronic properties of a series of side chain liquid crystal (SCLC) semiconducting polymers where: (i) the backbone is a π-conjugated polymer and (ii) the side-groups are π-conjugated calamitic mesogens. We present our results on the design, synthesis, and structural characterization of this new liquid crystal regioregular poly(3-alkylthiophene) polymer family post-functionalized with side-on calamitic moieties. The parameters of these materials are: (i) the chemical nature of the side-group moieties and (ii) the degree of polymerization. As a result we will show that this strategy leads to the supramolecular self-assembly of this SCLC semiconducting polymer in a peculiar lamello-lamellar mesophase, where the two different lamellas present two different electronic properties, such as electron donor and electron acceptor behaviors
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Biswas, Soma. "EFFECT OF LINKER CHEMISTRY AND TERMINAL SUBSTITUENTS ON THE LIQUID CRYSTALLINE PROPERTIES OF BIS(AZOBENZENE) MESOGENS." Thesis, The University of Arizona, 2008. http://hdl.handle.net/10150/193436.
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Azobenzene upon photochemical E/Z isomerization changes both its shape and size. The E-azobenzene moiety falls in the class of calamitic liquid crystalline mesogens, producing a wide variety of mesophases. Two series of linear bis(azobenzene) compounds, one with phenyl benzoate linkage and the other with benzyl benzoate linkage were synthesized. The termini of these molecules ranged from a dodecyloxy chain to hydrophobic amphiphilic dendrons up to first generation. We determined the effects of both the linkages and generation number on the mesogenic properties of these compounds. Our results show that the mesogenic behavior of these bis(azobenzene) compounds are highly dependent on the linkages between individual azobenzenes and that for the bis(azobenzene) compounds of the phenyl benzoate series, generation number had an effect on the liquid crystalline mesophase of the compounds
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Tamba, Maria Gabriela [Verfasser], W. [Akademischer Betreuer] Weißflog, and R. [Akademischer Betreuer] Zentel. "Design of liquid crystal dimers and trimers : synthesis and characterization of novel systems containing bent-core and calamitic mesogenic units / Maria Gabriela Tamba. Betreuer: W. Weißflog ; R. Zentel." Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2014. http://d-nb.info/1069814741/34.
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Naresh, Shakya Man. "Studies of Electronic Transport in Novel Smectic and Discotic Liquid Crystalline Organic Semiconductors." Kent State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=kent1289418142.
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Ogilvie, Megan Jacqueline 1979. "Ocean fertilization : ecological cure or calamity." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/39431.
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Thesis (S.M. in Science Writing)--Massachusetts Institute of Technology, Dept. of Humanities, Program in Writing and Humanistic Studies, 2004.Vita.
Includes bibliographical references (leaves 35-41).
The late John Martin demonstrated the paramount importance of iron for microscopic plant growth in large areas of the world's oceans. Iron, he hypothesized, was the nutrient that limited green life in seawater. Over twenty years later, Martin's iron hypothesis is widely considered to be the major contribution to oceanography in the second half of the 20th century. Originating as an ecosystem experiment to test Martin's iron hypothesis, iron fertilization experiments are now used as powerful tools to study the world's oceans. Some oceanographers are concerned that these experiments are catapulting ocean science into a new era. The vast stretches of ocean play a key role in the global carbon cycle, and thus in regulating Earth's climate. Some scientists, engineers and international policy makers claim that dissolving iron in the ocean will help stop global warming. Adding large amounts of iron to the oceans may drastically increase the amount of carbon dioxide that phytoplankton can capture from the atmosphere, thereby reducing the most common greenhouse gas. But intentional iron fertilization over great expanses of the ocean may have unintended consequences for the world's largest ecosystem. The open ocean is one of the planet's last frontiers and a part of the global commons. As such, using the open ocean as a means to solve the complex problem of global warming raises deep questions about how humans think of and use the Earth. The question remains: Should humans use the ocean as a means to regulate a changing climate?
by Megan Jacqueline Ogilvie.
S.M.in Science Writing
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May, Shoshanna. "Fitness and genetic diversity in Bufo calamita populations." Thesis, University of Sussex, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505908.
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The aims of this DPhil were the characterisation of major histocompatibility complex class II β loci in the amphibian species Bufo calamita, determination of fitness of four Bufo calamita populations and measurement of genetic diversity at both microsatellite loci and MHC class II β loci. The genetic diversity at microsatellite loci is considered to be neutral to selection and the genetic diversity seen at MHC loci is adaptive. Fitness in the four populations was measured using the known larval fitness traits age at metamorphosis, growth rates and survival. A 114 base pair section of MHC class II loci was characterised in this study. It was shown here that the diversity at neutral microsatellite markers was negatively correlated with adaptive MHC class II variation. No correlation was found between microsatellite HE and the larval fitness traits growth rate, survival and age at metamorphosis. However, MHC class II diversity was found to be associated with survival, and individuals that were heterozygous at both MHC loci had a significantly higher chance of survival than individuals homozygous at one or both of the two loci. A separate part of this DPhil project was the population genetics of six Irish Bufo calamita populations. The genetic structure was investigated using nine polymorphic microsatellite markers. It was found that all populations had similar and moderate levels of genetic diversity, comparable with those on the coast of north-west England. Toad populations were substantially differentiated, implying little migration between sites within historical times. Phylogenetics and estimates of divergence times supported the hypothesis that populations on the north coast of Dingle separated from those around Castlemaine Harbour many thousands of years ago, and are not recent introductions.
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Sommer, Heather J. "Of Crimes and Calamities: Marie Antoinette in American Political Discourse." Miami University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=miami1532967916465092.
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Larsson, Matilda. "Inventering av Strandpadda (Bufo calamita) 2012 på Balgö och inom Varbergs kust." Thesis, Högskolan i Halmstad, Ekologi och miljövetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-21574.
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Ghosh, Tirthankar. "Natural Calamities, Economy and Ecology: A Study on Northern Bengal during the Second half of the Nineteenth Century and First half of the Twentieth Century." Thesis, University of North Bengal, 2018. http://ir.nbu.ac.in/handle/123456789/2788.
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Godfrey, Lisa Pitcher. "Mining the Colorado Plateau: the Story of Calamity Mesa 1910-19." DigitalCommons@USU, 1991. https://digitalcommons.usu.edu/etd/4469.
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This thesis was written to outline the history of five stone houses, which have survived almost a century of mining activity. The houses are located on a barren mesa, called Calamity, in southwestern Colorado. This work was funded by the Bureau of Land Management, Department of the Interior, in order to explore the possibility of designating this site as a National Historic Site.
Men and women lived and worked on this and the surrounding mesas for most of the twentieth century. The lives of the families, the men, women, and children who lived and worked on Calamity Mesa, provided the context for the entire period. These people formed nebulous communities on what could only be called a twentieth-century frontier.
I used several methods for this study, including oral interviews with surviving miners and their families, company and government officials, mining engineers, and medical personnel involved in studies concerning the effects of radiation exposure. Government publications, local newspapers, and personal papers of several individuals were also researched. Through the use of these methods I further developed the history of the period, by focusing on Calamity Camp and the lives of the men and women who lived and worked there.
The miners who came to Calamity Mesa extracted the carnotite ore from sandstone beds. Originally, miners searched for radium, desired for its illusory cure for cancer. Then they sought vanadium, which was used as a strengthening agent for steel during both world wars . Finally, their goal was uranium, a key component for the production of nuclear weapons and energy.
The search for these minerals brought, many working class men and women to the Colorado Plateau. They brought their families to Calamity Mesa and lived in whatever shelter they could find. The stone houses, lived in by generation after generation of miners and their families, who came searching for carnotite, provided a permanence to Calamity Mesa throughout this period.
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Fiorot, Guilherme Henrique [UNESP]. "Mitigação de riscos e catástrofes naturais: análise numérico-experimental de roll waves evoluindo em canais inclinados." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/88863.
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As corridas de lama e os deslizamentos de terra, corriqueiros nas épocas de chuvas, vêm sendo observados e despertando atenção na mídia e órgãos públicos em função do número crescente de vítimas registrado. Trata-se de eventos naturais que atingem, cada vez mais, núcleos soci- ais vulneráveis. Esta dissertação de mestrado faz uma abordagem mecanicista destes eventos, modelados matematicamente como escoamentos em canais inclinados. Quando colocados em condições favoráveis de inclinação e vazão, este tipo de escoamento pode constituir um domínio propício à propagação de instabilidades na sua superfície livre que, eventualmente, podem vir a se tornar um tipo específico de ondas denominado na literatura de roll waves. Estas ondas, de comprimento de onda e amplitude bem definidos, são especialmente afetadas pelas caracte- rísticas do escoamento e do fluido. As lamas (soluções hiperconcentradas de matriz argilosa) constituídas quando daqueles eventos naturais são caracterizadas como fluidos fortemente não- newtonianos do tipo Herschel-Bulkley (COUSSOT; PIAU, 1994; SANTOS, 2003). Em termos de fluidos-tipo (aqueles usados em laboratório), duas vertentes são tratadas: a proposta do uso do carbopol como fluido representativo das lamas (fluido não-newtoniano); e a proposta da glice- rina (fluido newtoniano). Um modelo matemático representativo do fenômeno é apresentado, proposto por Ferreira (2007). Nele o respectivo modelo reológico é inserido na parte viscosa das equações de Cauchy e, após adimensionalização das variáveis e promediação das equações, culmina com uma equação diferencial de primeira ordem que é resolvida numericamente. Os parâmetros que envolvem o equacionamento são discutidos em função da sensibilidade das características das roll waves. Uma segunda abordagem traz a...
Mudflows and landslides, common in the rainy season, have been noticed and attracted media and public departments attention due to the increasing amount of victims recorded. This disser- tation provides a mechanistic approach of those events, mathematically modeled as flows in in- clined open channels. When disposed in favorable conditions of slope and flow, this type of flow can become a suitable domain to the propagation of instabilities on its free surface that even- tually may turn out to be a specific type of waves called by the literature as roll waves. These waves, well-defined in wavelength and amplitude, are particularly affected by the characteris- tics of flow and fluid. The muddy materials (hyper-concentrated solutions of clay) which take place on those natural events are characterized as highly non-Newtonian fluids like Herschel- Bulkley (COUSSOT; PIAU, 1994; SANTOS, 2003). Concerning the test-fluids (those employed on laboratory), two lines are explored: the utilization of carbopol as representative fluid for muds (non-Newtonian fluid); and the employment of glycerin (Newtonian fluid). A mathematical model representing the phenomenon is presented, proposed by Ferreira (2007). The proper rhe- ological model is inserted into the viscous part of Cauchy’s equations and, after transferring to dimensionless variables and averaging the equations, the model culminates with a first-order differential equation which is solved numerically. The parameters involving the equation are discussed due to the sensitivity of the characteristics of roll waves to them. A second approach brings the direct numerical simulation through FLUENT software as an attempt to validate the models. Based on the great lack of information concerning realistic measurements of this phe- nomenon in the literature, it was sought, in this work... (Complete abstract click electronic access below)
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Nicolle, Philip David. "The environmental physiology of Bufo bufo L. and Bufo calamita Laur. tadpoles." Thesis, Liverpool John Moores University, 1989. http://researchonline.ljmu.ac.uk/4987/.
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Using spawn collected from the north Merseyside sand dune system, the effects of temperature on growth, development, metabolism and metamorphosis in B. bufo and B. calamita tadpoles were investigated, together with a limited study on the effects of L-thyroxine. The effects of density on growth, developteI1t and metamorphosis were examined. Physiological and behavioural effects of B. bufo tadpoles on B. calamita tadpoles were also studied. B. calamita spawn and tadpoles survive at higher temperatures than B. bufo. Below20°CB. bufo spawn, and below 15°Ctheir t.adpcl.es, develop at a greater rate than B. calamita. B. calamita spawn and tadpoles' growth and development is faster at higher temperatures. B. calamita tadpoles have higher metabolic rates than B. bufo across the temperature range 15-30°C. Faster rates of metabolism and development in B. calamita result in smaller tadpoles and toadlets than B. bufo. B. calamita may compensate for this with increased metamorphic efficiency in terms of energy. It is speculated that differences in tadpole thyroid physiology could account for observed differences. metamorphic efficiency was greatest, and rates of development and growth maximised/at the tadpoles' preferred body temperature. Increased density reduced growth-and developteI1t of tadpoles, but influenced different stages in the two species. metamorphosis in all B. bufo tadpoles was delayed, whereas in B. calamita a proportion of the population metamorphosed apparently unaffected by increased density. The responses of tadpoles to temperature and density were related to the species' preferred spawning environments. In the presence of B. bufo tadpoles, B. calamita growth, development and metabolism was suppressed. The pattern of development and timing of metamorphosis in B. calamita became similar to that of B. bufo. Inhibition was not relieved by L-thyroxine, and did not effect tadpole behaviour. Mass specific food consumption was increased. It is speculated that the inhibitor is a parasite or a substance which affects assimilation.
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Maazouz, Samira. "Etude des interactions entre l'Hyménoptère Braconidé Cotesia sesamiae (Cameron, 1906), le virus de la polyédrose nucléaire de Sesamia calamistis Hampson, 1910, Lepidoptera, Noctuidae, le virus de la polyédrose nucléaire de Mamestra brassicae (Linnaeus, 1758), Lepidoptera, Noctuidae et deux virus de polyédroses cytoplasmiques de Sesamia calamistis chez les chenilles de Sesamia calamistis." Montpellier 2, 1991. http://www.theses.fr/1991MON20030.
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Le travail presente relate une description detaillee de la biologie de sesamia calamistis et de cotesia sesamiae. Les caracteristiques generales des baculovirus et des reovirus d'insectes sont egalement decrites. Pour effectuer son developpement chez la chenille de s. Calamistis, c. Sesamiae est associe a un systeme de cellules geantes ou teratocytes qui assurent sa nutrition. Les teratocytes derivent de la membrane embryonnaire de l'uf de c. Sesamiae. L'action pathogene du virus de polyedrose nucleaire de s. Calamistis et de deux virus de polyedroses cytoplasmiques de s. Calamistis a ete etudiee. Une interaction negative est constatee entre le virus de polyedrose nucleaire de s. Calamistis et les deux virus de polyedroses cytoplasmiques de s. Calamistis. Elle se traduit par le developpement des deux polyedroses cytoplasmiques de s. Calamistis. Elle se traduit par le developpement des deux polyedroses cytoplasmiques et l'inhibition de la polyedrose nucleaire. Par opposition, le virus de polyedrose nucleaire de mamestra brassicae n'est pas inhibe. La coexistence du virus de polyedrose nucleaire de m. Brassicae et de c. Sesamiae chez les chenilles de s. Calamistis a ete etudiee. Le developpement de c. Sesamiae n'est pas directement affecte par le virus de polyedrose nucleaire de m. Brassicae. C. Sesamiae meurt quand son hote infecte meurt d'une dose elevee de virus de polyedrose nucleaire. C. Sesamiae reussit a effectuer un developpement complet chez des chenilles infectees avec une dose faible de virus de polyedrose nucleaire
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Ek, Karolina. "Strandpaddan (Epidalea calamita) – från starkt hotad till nära utrotad : Åtgärder som förändrar nischer." Thesis, Karlstads universitet, Fakulteten för humaniora och samhällsvetenskap (from 2013), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-80529.
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Människan har påverkat landskapet i över 1500 år. Mellan 1870 och 2010 har 99,7% av seminaturella höängar förlorats i Sverige. Detta påverkar många arter som idag kategoriseras som hotade. Även faktorer så som förändrad markanvändning och det industriella jordbruket har påverkat arter negativt. Människans markanvändning resulterar i skapandet av nya nischer som gynnar vissa arter och missgynnar andra. Strandpaddan (Epidalea calamita) är en av arterna som missgynnas av nya nischer. År 2000 och 2005 kategoriserades arten som starkt hotad (EN). Naturvårdsverket införde åtgärdsprogram med syfte att vända på den negativa trenden i strandpadde populationerna. Sedan det första åtgärdsprogrammet trädde i kraft år 2000 har en rad åtgärder vidtagits för att bevara arten i de aktuella utbredningsområden som omfattar Blekinge, Blekinge, Skåne och Västra Götaland. Åtgärderna som ansågs ha högst verkan var ny grävning av småvatten eller fördjupning av befintliga småvatten och växthävd genom bete eller röjning. Populationerna i de två undersökta länen, Skåne och Blekinge, visar positiva trender och verkar ha ökat något sedan år 2004. År 2020 har statusen för arten därför ändrats till nära hotad (NT). Dessa förändringar i populationer sker tack vare de nya nischerna som är speciellt anpassade för strandpaddan då den inte kunde själv kunde anpassa sig efter förändringarna av människans markanvändning.
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Donnelly, Kristin. "To Fight Calamity or Forfeit Humanity: Coping with the Terror of Total Termination." Thesis, The University of Arizona, 2010. http://hdl.handle.net/10150/146913.
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Previous research in TMT reveals that mortality salience (MS; or a death reminder) increases pro-social giving tendencies and consumerism, both serving to shield death-related concerns. However, little is known about resoponse to the extinction of humanity, which may to some degree operate as a mortality reminder. Using global warming as an extinction prompt, we will investigate the effects of communal extinction on preferences for environmentally-friendly products that may combat the extinction threat. Preferences for eniromentally friendly aspects of consumer products as influenced by the experimental manipulation is predicted to be moderated by individual differences in locus of control. Internal locus of control was predicted to generate greater value for environmentally-friendly characteristics that have been socially valued to minimize global warming. Because external locus of control involves a perception of diminished personal influence on the external world, global mortality salience was predicted to trigger a decreased concern for ―green‖ product characteristics among individuals subscribing to this viewpoint. However, we found Mortality Salience to be the biggest catalyst for favoring green-oriented consumer items above and beyond the extinction prompt of Global Warming.
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Oromí, Farrús Neus. "Latitudinal and altitudinal variation of life history traits in natterjack toads (Bufo calamita): genetic adaptation vs. phenotypic plasticity." Doctoral thesis, Universitat de Lleida, 2011. http://hdl.handle.net/10803/51584.
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Ribas, Palom Anna. "Natura, societat i calamitat. Una aproximació a les inundacions històriques de la ciutat de Girona." Doctoral thesis, Universitat Autònoma de Barcelona, 1994. http://hdl.handle.net/10803/4985.
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Brady, Lee Damien. "Adaptation to a variable environment : tadpole development strategies in the natterjack toad (Bufo calamita)." Thesis, University of Kent, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297399.
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Nuñgulu, Agostinho Tchivange Nandjunge. "Monitorização das espécies de brocas do milho em Angola. Gestão das suas populações com recurso a plantas-isco e plantas repelentes." Doctoral thesis, ISA/UL, 2014. http://hdl.handle.net/10400.5/9260.
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Doutoramento em Engenharia Agronómica - Instituto Superior de AgronomiaStem borers (Insecta: Lepidoptera) in Africa emerge as a major biotic constraints to cereal production. The distribution of species depends on the region and the losses tend to be higher in altitude. For the monitoring of species of stem borers in Angola were used sex pheromone traps for Busseola fusca, Chilo partellus and Sesamia calamistis that were installed in Cavaco, Alto Kapaka, Cela, Chianga and Humpata. To study the management of populations of stem borers using the push-pull system were held in Huambo tests, using as attractive plant Pennisetum purpureum and as repellent plant Desmodium uncinatum. It was found that the three species monitored were present at all sites sampled B. fusca was the dominant species in Chianga, Cela and Alto Kapaka and S. calamistis in Cela and Cavaco. In capturing the pheromone B. fusca ‘Pherobank’ was significantly more effective than pheromone ‘Insect Science’. The incidence of attacks of borers in maize ranged between 86.2% in the control and 14.4% in the treatment maize x P. purpureum x D. uncinatum. For the four years of trials the average production increase in treatment that used attractive and repulsive plants was 340.6%, compared to maize alone
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MEMOLA, ANNA TERESA. "ASSICURAZIONE DEI RISCHI DA CATASTROFE NATURALE: SCENARIO ITALIANO E REALTÀ STRANIERE." Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/233254.
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THE THESIS, WITH A COMPARATIVE APPROACH, EXAMINES THE ISSUE OF THE INSURANCE OF NATURAL CATASTROPHES IN ITALIAN LAW AND DOCTRINE.THE AUTHOR DEALS WITH THE MAIN SOLUTIONS AVAILABLE ON THE INSURANCE MARKET AND EXPOSES THE MAIN DIFFICULTIES OF THE STATE TOWARDS NATURAL CATASTROPHES DAMAGES.
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Kuhn, Wolfgang. "Kreuzkröte (Bufo calamita) und Wechselkröte (Bufo viridis) eine Mischpopulation am südlichen Rand ihres Verbreitungsgebietes in Bayern /." [S.l.] : [s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=962144878.
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Denton, Jonathan Simon. "The terrestrial ecology of the natterjack, Bufo calamita(Laurenti), and the common toad, Bufo bufo (Linnaeus)." Thesis, University of Sussex, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334029.
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Maffei, Jacopo. "Rilevamento e studio petrografico del Complesso di M. Calamita (Elba SE) nella zona di Spiaggia di Remaiolo." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14041/.
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Lo scopo del lavoro di tesi consiste nello studio petrografico, dalla scala dell’affioramento a quella della sezione sottile, di rocce di basamento cristallino soggetto a metamorfismo e
deformazione polifasiche. La zona di studio è la Spiaggia di Remaiolo, Elba SE. Questo settore da un punto di vista
geologico fa parte del Complesso di M. Calamita, all’interno dell’Unità di Porto Azzurro. Gli affioramenti studiati mostrano diversi eventi metamorfici: il basamento metamorfico Ercinico e le sue coperture mesozoiche subiscono una sovraimpronta metamorfica Alpina di età Oligo-Miocenica correlabile alla strutturazione della catena dell’Appenino Settentrionale. Successivamente le rocce subiscono un’ulteriore sovraimpronta
termometamorfica Mio-Pliocenica legata all’intrusione del plutone La Serra-Porto Azzurro. Il lavoro di campagna ha comportato un rilevamento di dettaglio per creare una Carta degli affioramenti (Allegato 1) e prelevare dei campioni rappresentativi delle litologie. Il lavoro di laboratorio si è svolto su 6 sezioni sottili, realizzate con i campioni prelevati in campagna, tramite l’ausilio del microscopio ottico a luce polarizzata.
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Davis, C. A. "The population dynamics of the Natterjack Toad (Bufo calamita Laur.) in the north Merseyside sand-dune system." Thesis, Liverpool John Moores University, 1985. http://researchonline.ljmu.ac.uk/5561/.
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Gomes, Laura Sofia Silva. "Valorização das espécieis condimentares Calamitha nepeta, Mentha cervina, Mentha pulegium e Mentha spicata: potencial nutracêutico dos seus extratos aquosos." Master's thesis, Universidade de Évora, 2019. http://hdl.handle.net/10174/27692.
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Neste projeto, selecionaram-se quatro espécies aromáticas e condimentares da
família Lamiaceae, Calamintha nepeta, Mentha cervina, Mentha pulegium e Mentha
spicata, para preparação de extratos aquosos, extratos de hidrodestilação (EHD) e
extratos de planta fresca (EPF), e avaliação das suas propriedades antioxidantes e
neuroprotetoras.
Os EHD apresentaram maior conteúdo em fenóis e flavonoides do que os EPF. O teste
de letalidade em A. salina revelou baixa toxicidade para os extratos. Os EHD
apresentaram maior potencial antioxidante para captar radicais livres, proteger a
oxidação lipídica e evitar a oxidação do ferro hémico. Os EHD revelaram também maior
atividade inibitória dos sistemas enzimáticos de catalases (CAT), glutationo
peroxidases (GPx), acetilcolinesterases (AChE) e butirilcolinesterases (BChE). Os EHD
destas plantas condimentares revelaram-se promissores no combate do stress
oxidativo, com potencial aplicação nas indústrias alimentar e/ou farmacêutica; Flavouring herbs Calamintha nepeta, Mentha cervina, Mentha pulegium
and Mentha spicata valorisation: nutraceutical potential of aqueous
extracts.
Abstract:
In this project, four aromatic and flavouring species of Lamiaceae family, Calamintha
nepeta, Mentha cervina, Mentha pulegium and Mentha spicata were selected to
prepare their aqueous extracts, hydrodistillation extracts (EHD) and fresh plant extracts
(EPF), to evaluate their antioxidant and neuroprotective properties.
Extracts were rich in bioactive compounds and EHD had higher phenol and flavonoid
content. A. salina lethality test showed low toxicity of extracts. EHD showed higher
antioxidant potential to scavenge free radicals, protect lipid oxidation and prevent the
hemic iron oxidation. EHD presented higher inhibitory activity of catalases (CAT),
glutathione peroxidases (GPx), acetylcholinesterases (AChE) and butyrylcholinesterases
(BChE) enzyme systems. Results showed that EHD from these flavouring herbs are
promising extracts against oxidative stress with potential application in the food and/or
pharmaceutical industries.
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Faucher, Leslie. "Histoire évolutive de deux espèces d’amphibiens pionnières, le Pélodyte ponctué et le Crapaud calamite, en milieu fortement anthropisé." Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10159/document.
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La perte et la fragmentation des habitats générées par les activités humaines érodent la diversité génétique intra-spécifique, entrainant l’extinction de populations chez de nombreuses espèces. Paradoxalement, des habitats artificiels comme les terrils du nord de la France favorisent l’installation de populations sauvages. Néanmoins leur localisation au sein d’un paysage très anthropisé interroge sur la pérennité des populations qu’ils hébergent. Cette étude visait à étudier la diversité génétique neutre des populations de Bufo calamita et Pelodytes punctatus, deux espèces d’amphibiens établies dans le bassin houiller et dans des habitats littoraux plus sauvages. Des approches de génétique des populations ont permis de décrire les effets de différents processus micro-évolutifs sur les niveaux de diversité génétique, depuis le processus biogéographique de colonisation des terrils jusqu’au régime d’appariement dans une population, en passant par une analyse multi-espèces de la connectivité paysagère. Les populations de B. calamita du bassin houiller présentent de forts niveaux de diversité génétique pouvant résulter d’introductions d’individus de diverses localités. Toutefois, dans le bassin houiller, une forte différenciation génétique s’observe chez les deux espèces. Cela s’explique au moins en partie par la présence de barrières aux flux de gènes entre populations qui, à long terme, pourrait compromettre le maintien des populations. Enfin, le succès reproducteur inégal des mâles de B. calamita, qui pourrait induire des baisses de niveau diversité génétique intra-population, semble associé à une compétition entre mâles et implique plusieurs stratégies d’appariementsHuman activities induce habitat loss and fragmentation that have an erosive effect on the level of intraspecific genetic diversity, decreasing the individual fitness and jeopardizing populations’ adaptive capability. Conversely, new human-made areas, such as spoil heaps of northern France, can provide suitable habitats for pioneering species. Spoil heaps being part of a highly human-fragmented landscape, the likelihood of population persistence is questioned given the scarcity of suitable habitats and the occurrence of potential barriers to dispersal. We studied the intraspecific genetic diversity of two anurans, Pelodytes punctatus and Bufo calamita, located in coalfield areas and semi-natural coastal habitats. We focused on the effects of micro-evolutionary processes of genetic drift and gene flow in shaping genetic structure. We studied (i) the biogeographical history of colonization of coalfield areas in B. calamita, (ii) the landscape connectivity using a multispecies approach, and (iii) the evolutionary determinants of variance in breeding success in B. calamita. In coalfield areas, B. calamita populations showed high levels of genetic diversity suggesting several independent colonization events. Nonetheless, marked local genetic discontinuities were observed within coalfield areas for both species, suggesting occurrence of environmental barriers impeding gene flow that may compromise population viability. Within a B. calamita population, we observed a polygynous mating system involving a possible decrease in genetic diversity. Our results suggested that variance in male mating success was linked to male-male competition and may imply distinct mating strategies
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Minting, Peter. "An investigation into the effects of Batrachochytrium dendrobatidis (Bd) on natterjack toad (Bufo calamita) populations in the UK." Thesis, University of Sussex, 2012. http://sro.sussex.ac.uk/id/eprint/41270/.
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The chytridiomycete Batrachochytrium dendrobatidis (Bd) is a parasite which has been blamed for amphibian declines across the world. This study was designed to investigate the effects of Bd on natterjack toads (Bufo calamita), following the discovery of Bd populations of this species in the UK. The effect of Bd on natterjack toads was assessed by fieldwork and experiments. Wild adult natterjacks were tagged and repeatedly tested for Bd during 2009-2011. Captive adults and juveniles from infected populations were also tested in response to changes in environmental conditions. Swabs were used to collect Bd DNA from the skin of study animals. Swabbing did not reliably diagnose infection but the quantity of Bd DNA in swabs (Bd score) provided an indication of infection activity. Immersion in water appeared to trigger Bd zoospore emergence from the skin, resulting in an increase in the likelihood of Bd detection and increases in Bd score. Bd dynamics in natterjack populations were also influenced by salinity. Natterjacks in the UK are found mainly in coastal habitat, where ponds are often inundated by high tides. Adults captured in brackish water were less likely to test positive than those caught in fresh water. Bd isolated from coastal natterjacks was killed in vitro by a salinity equivalent to 50% seawater. The isolate grew fastest at low salinities, suggesting that it may have become adapted to brackish conditions. Despite this adaptation, tidal inundation may be sufficient to disinfect ponds and limit Bd transmission. Capture-mark-recapture (CMR) data from adult natterjacks revealed a weak negative correlation between Bd score and survival in the wild. Males had higher Bd scores than females but survival did not differ between sexes and there was no correlation between Bd score and growth. An experiment showed BD could kill natterjacks if infection activity was boosted by wet conditions. However only 6% of wild adults recorded Bd scores in excess of a mortality threshold derived from this experiment. Many adults and juvenile natterjacks can tolerate Bd infection and act as reservoirs of this pathogen. Despite detection of Bd in at least 14 UK natterjack populations by 2011, no mass mortalities of adult natterjacks have been reported and spawning has continued at all sites. Bd does not appear to have a major effect on natterjacks but this situation may not persist and vigilance should be maintained. Bd isolated from natterjack toads in this study belomgs to a global panzootic lineage (GPL) of Bd which Farrer et al (2011) claim has achieved a global distribution as a result of human activities.
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McGrath, Anna. "Quantitative assessment of conservation management approaches for rare British fauna : a case study of the natterjack toad Bufo calamita." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511849.
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Bratus, Antonio. "MONITORAGGIO DI DISSESTI FRANOSI CON METODOLOGIA INTEGRATA BASATA SULL'USO DI SISTEMA RADAR INTERFEROMETRICO TERRESTRE (GBSAR)." Doctoral thesis, Università degli studi di Trieste, 2015. http://hdl.handle.net/10077/10925.
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2013/2014L’analisi critica del monitoraggio di frane con l’utilizzo dell’interferometria radar da terra è stata lo scopo di questa tesi di dottorato di ricerca in geoscienze. Il progetto prende lo spunto dalla possibilità di poter coniugare le esigenze di una struttura preposta al monitoraggio di dissesti franosi, la disponibilità di tecnologie innovative non invasive e la loro fattibilità nel contesto regionale. L’idea di poter utilizzare ed analizzare criticamente i risultati di una serie di monitoraggi è stata quindi presa come linea guida per questo ciclo di dottorato di ricerca in geoscienze. Nell’ambito delle opere di prevenzione da calamità naturali, il Servizio geologico della Regione Autonoma Friuli Venezia Giulia, di cui l’autore è un componente, ha ritenuto di attivare il monitoraggio di tre frane ubicate nel territorio di competenza con l’utilizzo di misure di superficie eseguite con tecnologie basate sull’uso del sistema radar interferometrico con lo scopo di identificare delle zone caratterizzate da movimenti di versante, così da: • integrare le conoscenze pregresse sulla determinazione della forma ed estensione della massa in movimento nonché della distribuzione di pressioni e sforzi; • determinare gli spostamenti differenziali dell’area di frana; • stimare il campo di velocità e la sua interrelazione con fattori esterni quali piogge o temperatura; I siti individuati per questo piano di monitoraggio sono caratterizzati da diverse tipologie di dissesto e di condizioni al contorno. La loro designazione è stata fatta seguendo questo criterio guida. Considerando l’eterogeneità del territorio regionale sono stati scelti: • Ligosullo (UD): il sito in oggetto è rappresentato dal centro urbano di Ligosullo, caratterizzato da un fenomeno di instabilità generalizzato con tassi di deformazione dell’ordine di alcuni cm/anno; • Cimolais (PN): Il sito in oggetto è rappresentato una parete rocciosa, caratterizzata da fenomeni localizzati di crollo; • Erto e Casso, località La Pineda (PN): il sito in oggetto è rappresentato da una parte dell’accumulo di una paleo frana del monte Salta. Caratterizzato da una zona calanchiva in evoluzione, caratterizzata da frane superficiali diffuse. I motivi che hanno individuato il radar interferometrico terrestre come principale metodo di monitoraggio sono legati alle principali caratteristiche della tecnica, ovvero: • sistema remoto che consente di misurare spostamenti del fronte instabile senza la necessità teorica di installare riflettori artificiali e quindi di accedere direttamente alla zona instabile; • capacità di fornire mappe di spostamento dell’intero versante; • misure in near real time: è possibile elaborare i dati acquisiti in maniera automatica e fornire i risultati in tempo quasi reali (con pochi minuti di ritardo rispetto all’acquisizione); • misure in qualsiasi condizione meteorologica, sia di giorno che di notte grazie all’uso di un sistema radar; • misure ad elevata accuratezza (tra il decimo di millimetro ed il millimetro in funzione della distanza) nate dall’applicazione della ricerca spaziale, che consente di determinare l’entità dello spostamento di un oggetto confrontando le informazioni di fase delle onde elettromagnetiche riflesse dall’oggetto in diversi istanti di tempo.
XXVI Ciclo
1970
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Hamadoun, Abdoulaye. "Contribution a l'etude de la dynamique des populations de sesamia calamistis hmps (lepidoptera-noctuidae) au mali : relations trophiques avec ses plantes -hotes cultivees." Paris 6, 1989. http://www.theses.fr/1989PA066230.
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La dynamique des populations de s. Calamistis et les degats qu'il provoque sur les principales cultures du mali ont ete etudies a kogoni. Des variations importantes des populations larvaires sont observees en fonction de l'espece cultivee, de la variete, du stade phenologique en 1986 et 1987. Les periodes de vols les plus importants se situent: de fin juillet a debut aout, en deuxieme quinzaine de septembre et d'octobre. Les pertes de rendement sont faibles sur le mil et le sorgho, tandis qu'elles sont elevees sur le mais. Les analyses biochimiques des grains des plantes hotes ont revele des teneurs en composes glucidiques et azotes variables suivant l'espece et meme la variete cultivees. L'evaluation de divers facteurs morphometriques et biologiques ont montre que les tiges de mais sont plus favorables aux chenilles que celles du mil ou du sorgho ou du milieu meridique. Par complementation de la cysteine au milieu meridique, des effets positifs ont ete observes sur certains parametres du ravageur alors que sur d'autres, ils sont nuls. Les principales enzymes revelees chez les chenilles de 5eme stade, elevees sur milieu meridique sont l'invertase, le maltase et dans une moindre mesure l'amylase
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Feather, Catherine Anne. "Creativity or calamity : what does the future hold? : an examination of teacher's understandings of creativity in a sample of South African schools." Master's thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/6963.
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Bibliography: leaves 91-101.Technological progress, organisational change and intensified global competition have driven a shift from manual work to 'thinking' jobs that emphasise a whole new range of skills. It is no longer enough for students to show that they are capable of passing public examinations, for to thrive in an economy defined by the innovative application of knowledge they must be able to do more than absorb and feedback information. Learners and workers must draw on their entire spectrum of learning experiences and apply what they have learned in new and creative ways (Seltzer and Bentley 1999). To help equip our learners with the attitudes and abilities that will enable them to meet future problems creatively and inventively (Parnes 1970) we need a curriculum that acknowledges the importance of creativity, as well as teachers who are able to recognise and encourage creative behaviour in their classrooms. In the absence of any formal guidance in this regard, this thesis is an attempt to find out if teachers have the broad and accurate understanding of creativity necessary to do this successfully. To achieve this aim an open-ended questionnaire was compiled and distributed to a number of teachers in a range of teaching contexts. Responses were then analysed qualitatively using a method known as the Constant Comparative Method proposed by Glaser and Strauss (1976). An interactive model of creativity (and thus, one which took into consideration the creative product, the creative person, the creative process and the creative environment) was used to structure the questionnaire and to judge the responses. Using the literature as a yardstick it was determined that, at least on an individual basis, these teachers have an extremely narrow understanding of creativity. It was also evident that there were Significant differences in understanding across contexts. This is an issue that needs to be addressed with some urgency if we intend to be at all successful in our attempts to educate for creativity in this country. A shared understanding of this term needs to be ensured - not assumed - something that could be achieved through the provision of a broad and inclusive set of guidelines.
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Di, Veroli Veronica <1990>. "Salvaguardia, gestione e valorizzazione del patrimonio culturale immobile esposto a rischi da calamità naturali ed ambientali: il caso di Civita di Bagnoregio (VT)." Master's Degree Thesis, Università Ca' Foscari Venezia, 2017. http://hdl.handle.net/10579/9736.
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Nell’elaborato viene analizzato il caso studio di Civita di Bagnoregio, frazione dell’omonimo comune in provincia di Viterbo, denominata ormai la “Città che Muore” a causa dei progressivi crolli che stanno interessando da secoli la rupe tufacea su cui il borgo si erge, e che hanno concorso alla riduzione progressiva della superficie dell’abitato ed al suo spopolamento.
Successivamente ad una prima fase di presentazione del borgo secondo un profilo storico-geografico ed un’analisi dei fenomeni di dissesto si procede ad analizzare gli strumenti e le strategie di gestione del rischio correlato. Partendo da un quadro generale inerente il Patrimonio Culturale italiano potenzialmente soggetto a rischio idrogeologico e sismico si procede con l’analisi di monitoraggio e prevenzione del caso in esame, proseguendo con l’analisi degli interventi di consolidamento che hanno interessato il borgo e con un’esposizione delle tecnologie e delle banche dati attualmente disponibili per il monitoraggio e la prevenzione del rischio. L’elaborato poi analizza le attuali strategie di gestione del territorio, tenendo in considerazione l’impatto del turismo e la valorizzazione del borgo da parte degli enti competenti coinvolti nella sua amministrazione. Viene analizzata infine la recente candidatura di Civita di Bagnoregio come Paesaggio Culturale UNESCO, valutando le implicazioni dell’ammissione del borgo tra i Patrimoni dell’Umanità e le possibili ricadute sul territorio e sulle peculiarità socio-economiche che lo caratterizzano.
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Ngondjo, Georges. "Effet d'un apport de silice sur la diminution de la sensibilité du riz à l'infestation par les foreurs des tiges : Chilo zacconius Bleszynski et Sesamia calamistis Hampson." Montpellier 2, 1986. http://www.theses.fr/1986MON20078.
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A partir de cinq couples d'insectes adultes, on a realise un elevage intensif assurant une production totale de plus de 6000 larves en continu. Elles ont servi a infester des plantes a differents stades de leur developpement et provenant de plusieurs varietes. On a pu aussi determiner que les infestations realises au stade de gonflement sont les plus devastatrices. Dans le but d'augmenter la teneur des tiges en silice et en calcium, on a introduit de la silice, soit extraite de cendres de balles de riz, de pouzzolane ou d'un residu riche en silice, soit sous forme pulverente en amendement du sol: on obtient une diminution des forts degres d'infestation en liaison avec une augmentation significative de la teneur en silice et en calcium de la tige.
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Ngondjo, Georges. "Effet d'un apport de silice sur la diminution de la sensibilité du riz à l'infestation par les foreurs des tiges Chilo Zacconius Bleszynski et Sesamia calamistis Hampson." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37600003d.
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Ugolini, Celine. "The Resilience of New Orleans : Assessing a History of Disasters 1718-1803." Thesis, Bordeaux 3, 2014. http://www.theses.fr/2014BOR30077.
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La Nouvelle Orléans fut fondée en 1718 sur un sol qui est désormais connu pour être instable. En 1719, peu après sa construction initiale, la ville fut inondée. Le premier ouragan qui détruisit la ville date de 1722. D’autres tempêtes dévastatrices suivirent et imposèrent la reconstruction de cette ville naissante. Les colons français qui ont construit La Nouvelle Orléans n’avaient aucune expérience du climat de la Louisiane ni des tempêtes et inondations répétitives. Les dégâts liés aux catastrophes naturelles furent si fréquents que les premières décennies de l’histoire de la ville se résument au difficile travail de reconstruction. L’assistant de l’ingénieur de la ville, Adrien de Pauger, fut le premier à proposer un système de jetées qui aurait pu résoudre le problème de la formation des bancs de sable. Mais ses plans n’ont pas été mis en œuvre. Reconstruire une ville que les français venaient juste de fonder présenta un défi dès le début. Le déficit démographique engendra l’envoi de criminels et autres indésirables venant de France. Ces derniers finirent par jouer un rôle crucial dans la construction, puis la reconstruction de la ville. Ce projet examine les défis que les premiers Néo-Orléanais ont dû affronter, et leur adaptation nécessaire a un environnement inhospitalier. Malgré les nombreuses craintes que les habitants quittent leur ville afin de se réfugier dans des terres plus élevées, ou bien de retourner en France, ces derniers ont su montrer leur résilience et leur attachement a cette ville, de la même manière que cela s’est produit après l’ouragan Katrina en 2005. D’autres villes environnantes, comme La Balise, ont connu un sort différent. La Balise disparut après de nombreux ouragans alors que la capitale de la Louisiane de l’époque fût constamment reconstruite. Cette thèse traite des premières années de chaos et de destruction de La Nouvelle Orléans. Par ailleurs elle montre comment la ville a survécu aux nombreux ouragans, incendies et autres catastrophes, avant d’évoluer du statut d’une commune fragile à celui d’une ville robusteNew Orleans, Louisiana, formerly La Nouvelle Orléans, was founded in 1718 on what is known today to be unstable land. Shortly after its initial construction, a flood in 1719 devastated the city. Several other strong storms quickly followed and forced reconstruction upon the nascent Crescent City. The French colonists who built La Nouvelle Orléans had no experience with either Louisiana’s climate or repetitive tropical storms and flooding. Damage from disasters occurred so frequently that the difficult work of reconstruction characterized the city’s first few decades. Assistant City Engineer Adrien de Pauger was the very first person to plan for a jetty system for the city. La Nouvelle Orléans could have benefited from solving its sandbars issues had this venture been conducted the way Pauger had envisaged. Rebuilding for a city that the French had just recently built presented a challenge from the start. The lack of population of the area generated the sending of criminals and other unwanted individuals from the mother country. These ended up taking an active part in the construction and reconstruction process. This research examines the early challenges confronting New Orleanians and their necessary adaptation to an inhospitable environment. Despite concerns that residents would leave their city to seek safer living conditions on higher land or move back to the home country as some did, early New Orleanians displayed a resilience similar to that found in the aftermath of Katrina. Other local settlements, such as La Balise, had a different fate and disappeared as a result of recurring hurricanes whereas the then capital of Louisiana always rebuilt after each disaster. The study will discuss the city’s early years of chaos and destruction, and how La Nouvelle Orléans struggled to overcome hurricanes, fires, and disease, before evolving from a fragile settlement to a stronger city
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Erasmus, Annemie. "Response of selected non-target Lepidoptera, Coleoptera and Diptera species to Cry1Ab protein expressed by genetically modified maize / Annemie Erasmus." Thesis, North-West University, 2010. http://hdl.handle.net/10394/4105.
Full textAbstract:
The environmental impacts of genetically modified (GM) crop plants such as Bt (Bacillus
thuringiensis) maize have not yet been fully assessed in South Africa. Bt maize designed
to express Bt endotoxin for control of Busseola fusca (Fuller) (Lepidoptera: Noctuidae)
and Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) is planted on approximately
1.103 million hectares in South Africa. The monitoring of GM crops after release is
important in order to assess and evaluate possible environmental effects. No risk
assessment for Bt maize was done in South Africa before its release in 1998 and no
targeted post-release monitoring of possible resistance development or impact on non-target
species have been done. Awareness has risen in South Africa through research
highlighting the possible effects GM crops may have. The aim of this study was to
determine, through feeding experiments, the effects of Bt maize on selected non-target
Lepidoptera, Coleoptera and Diptera species that occur in maize agro-ecosystems in
South Africa. Results provide information for use in future risk assessment studies on Bt
maize and indicate which species could possibly be of importance in post-release
monitoring of Bt maize. Priority insect species were identified and laboratory- and semifield
experiments were conducted to evaluate the effect of Bt maize on these species. In
the light of the reportedly lower toxicity of Bt maize to certain noctuid borers, the effect
of Bt maize was evaluated on Sesamia calamistis (Hampson), Agrotis segetum (Denis &
Schiffermüller), and Helicoverpa armigera (Hubner). Feeding studies were also
conducted to determine the effect of Bt maize on non-target Coleoptera, i.e.
Heteronychus arator Fabricius (Coleoptera: Scarabaeidae) and Somaticus angulatus
(Fahraeus) (Coleoptera: Tenebrionidae). The effect of indirect exposure of the stem borer
parasitoid Sturmiopsis parasitica (Curran) (Diptera: Tachinidae) to Bt toxin was
evaluated to determine if there is any effect when it parasitizes Bt-resistant B. fusca
larvae that have fed on Bt maize. Results from the study conducted with S. calamistis
indicated that Bt maize of both events (Bt11 and MON810) were highly toxic to S.
calamistis. The behavioural characteristic of S. calamistis to feed behind leaf sheaths and
to enter stems directly did not result in escape of exposure to the toxin. Larval feeding on
leaf sheaths therefore resulted in the ingestion of sufficient toxin to kill larvae before they entered maize stems. Results showed that the effect of Cry1Ab toxin on the biology of A.
segetum larvae and moths were largely insignificant. Whorl leaves were observed to be
an unsuitable food source for H. armigera larvae and larval growth was poor. No larvae
survived to the pupal stage on any of the Bt maize treatments. When feeding on maize
ears H. armigera larval mass increased on non-Bt maize whereas no increase occurred on
Bt maize. The feeding study conducted with Coleoptera showed that the effect of Bt
maize on H. arator and S. angulatus was insignificant and no differences were observed
in any of the parameters measured for the two species. Although not always significant,
the percentage parasitism of Bt-consuming host larvae by S. parasitica was always higher
compared to host larvae that fed on non-Bt maize. It could be that Bt toxin affects B.
fusca fitness to such an extent that the immune systems of host larvae were less effective.
The different parameters tested for S. parasitica indicated only one case where fly
maggots originating from diapause host larvae feeding on non-Bt maize had a greater
mass compared to host larvae that fed on Bt maize. The same applied to S. parasitica
pupal length. For other parameters tested there were no significant differences. Sesamia
calamistis is stenophagous and occurs in mixed populations with other borer species. It
was therefore concluded that the ecological impact of local extinctions of S. calamistis
caused by Bt maize is not expected to be great. Bt maize will most likely not have any
significant effect on the control of A. segetum under field conditions. The feeding study
conducted with H. armigera quantified the effects of Bt maize on this species and
provided important information on the potential of Bt maize as protection against this
polyphagous pest. However, the likelihood of H. armigera becoming an important
secondary pest is high. It can be concluded that the Cry1Ab toxin targeting lepidopteran
pests will not have adverse effects on H. arator or S. angulatus. Although some adverse
effects were observed on S. parasitica mass and pupal length it is most likely that this
will not contribute to adverse effects in the field, but that there rather be synergism
between Bt maize and S. parasitica. An ecological approach was followed in which the
potential effects of exposure of priority species to Bt toxin in maize was investigated. A
series of selection matrixes were developed in which each of the above mentioned
species was ranked for its maximum potential exposure to Bt toxin by assessing it
occurrence, abundance, presence and linkage in the maize ecosystem. Through the use of these selection matrixes, knowledge gaps were identified for future research and to guide
the design of ecologically realistic experiments. This study contributes to knowledge
regarding the possible effects of Bt maize on the most economically important non-target
pests in South Africa. There is, however, a need to evaluate other non-target species in
feeding studies, as well as in field studies. From this study it can be concluded that some
species can be eliminated from further testing since Bt maize had no adverse effect while
more research have to be conducted on other species.Thesis (Ph.D. (Environmental Science)--North-West University, Potchefstroom Campus, 2010.
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Andersson, Susanna. "Diversitet av amfibier och förhållandet mellan gruppens reproduktiva framgång och evertebrater knutna till dammar." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-42721.
Full textAbstract:
Inledning: Småvatten som dammar har försummats i bevarande-och övervakningsstrategier där fokus har lagts på större sötvattensmiljöer. Kunskap om småvattens roll i bevarandet av biologisk mångfald är bristfällig men studier har visat att dammar kan försörja fler arter, fler unika arter och mer ovanliga arter än sjöar, floder och vattendrag. I Sverige är 100 av 240 rödlistade sötvattensorganismer knutna till småvatten, där de flesta är arter av evertebrater men inkluderar även 38 % arter av den svenska amfibiefaunan. För att säkra den svenska amfibiefaunan måste faktorerna som missgynnar faunan, framförallt de hotade arterna, bli kända. Att bedöma vattenmiljöer lämpade för framgångsrik reproduktion hos amfibier kan vara komplicerad med hjälp av instrumentmätningar och vattenprover då kemiska parametrar i vattnet är ostabila. Alternativt kan man studera sötvattenslevande makroevertebrater där sammansättning, förekomst eller frånvaro kan indikera om miljön är utsatt för stressfaktorer. Utdikningar, övergödning och introduktion av invasiva arter har missgynnat amfibiefaunan genom minska reproduktionslokaler och skapa spridningsbarriärer. I Skånes region, som har högst diversitet av groddjur, har hundratals vatten återskapats för amfibier men behovet att fortsätta med naturvårdsinsatser kvarstår. Syfte: Med denna studie önskar jag lyfta vikten av att bevara och återskapa dammar för amfibier. Studien fokuserar på artrikedom hos amfibier, hotade arter samt reproduktiv framgång hos dessa. Studien omfattar 15 dammar fördelade över tre områden i Skåne. I två områden har flera dammar återskapats för att gynna amfibiefaunan och genom att följa upp kolonisering av dessa och utvärdera reproduktiv framgång, önskar jag bidra med lärdom om naturvårdsinsatsers effektivitet. De två områdena kommer även att jämföras med ett referensområde där inga omfattande naturvårdsinsatser har genomförts. Kemi- och fysikaliska parametrar kommer mätas i dammarna men även makroevertebrater i vattnet kommer att studeras för att se om det finns ett samband mellan dammar med framgångsrik reproduktion hos amfibier och förekomsten av makroevertebrater. Frågorna som ska besvaras är 1) vilket område är mest artrikt? 2) Har naturvårdsinsatserna i relation till referensområdet gynnat hotade arter? 3) Skiljer sig sammansättningen av vattenkemiska parametrar åt mellan dammar med framgångsrik reproduktion hos Anura med dammar utan framgångsrik reproduktion? 4) Skiljer förekomst, diversitet, sammansättning av evertebrater samt andelen rovinsekter åt mellan dammar med framgångsrik reproduktion hos Anura med dammar utan framgångsrik reproduktion? Metod: Projektområdet begränsades till sydöstra Skåne. Två områden, Ravlunda och Högestad valdes ut efter vetskapen om att omfattande naturvårdsinsatser utförts i områdena med syftet att gynna amfibier. Markanvändningen i områdena skiljer sig åt där Ravlunda är ett aktivt skjutfält och i Högestad drivs bland annat jord- och skogsbruk. Det tredje området, Referensområdet, bestod av spridda dammar runt Ravlunda skjutfält. Här hade inga naturvårdsinsatser utförts i syftet att gynna amfibier. Amfibier och deras utvecklingsstadium inventeras under säsongen när gruppen är som mest aktiv i vattenmiljön. Utvalda kemi-och fysikaliska mätningar tas med hjälp av mätinstrument och vattenprover analyseras i laboratorium. Evertebrater samlas in genom håvning för att beräkna Shannons diversitet index och Average score per taxon (ASPT) index. Andelen rovinsekter beräknas från antalet larver av Odonata och individer från familjerna Dytiscidae och Notonectidae. Variansanalyser kommer utföras för att identifiera skillnader mellan områdena och korrelationsanalyser utförs för att identifiera samband mellan evertebrater och framgångsrik reproduktion hos amfibier. Non-metric multidimensional scaling analyser kommer utföras för att identifiera hur lokalerna förhåller sig till varandra i sammansättning av vattenkemi samt sammansättning av familjer och fördelning hos evertebrater. Resultat: Högestad var det mest artrika området. Där var signifikant skillnad i antalet individer av hotad art mellan Ravlunda och de andra områdena. Naturvårdsinsatserna bedömdes gynnat hotad art i Ravlunda men inte i Högestad. Korrelationsanalysen visade inget samband mellan framgångsrik reproduktion och index-beräkningarna. Slutsats: Naturvårdsinsatser i syftet att bevara den svenska amfibiefaunan och dess hotade arter kan vara framgångsrik om man lägger alla bitar i pusslet rätt, för det är många faktorer som spelar in för att insatser ska bli både effektiva och framgångsrika. Att fortsätta med uppföljningar av naturvårdsinsatser efter att projekttiden är slut är viktigt för att kunna ta lärdom om vilka metoder som skapar bäst förutsättningar för stabila populationer hos amfibier.
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Paiva, Daniela Rabelo Costa Ribeiro. "As descrições da cidade de Lisboa: escrita, poder e sociedade no Portugal dos Filipes." reponame:Repositório Institucional da UFF, 2013. https://appdesenv.uff.br/riuff/handle/1/216.
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Portugueses ou estrangeiros, os autores que dedicaram os seus escritos à cidade de Lisboa foram muitos. Sendo que, os escritos se tornaram mais expressivos durante a União Ibérica. O incentivo que os Filipes ofereceram às atividades de impressão e o desenvolvimento da história urbana em toda Europa ajudam a compreender melhor essa produção, que ainda pode ser explicada pela própria condição de Lisboa na época. Quando Portugal foi incorporado à monarquia católica, os reis Filipes optaram por não residir em sua principal cidade. Desta sorte, a antiga residência dos Avís perdeu seu status de corte régia e aos poucos se viu transformar em uma simples capital de província. A historiografia identificou a ausência real como tônica para se compreender o período. A proposta da pesquisa de dissertação é avaliar em que medida a retórica de uma Lisboa sem Rei está presente nas representações feitas sobre a cidade, em especial as descrições que tiveram maior repercussão na época. E também identificar outros elementos que compõem o seu imaginário, como as adversidades vivenciadas pela urbe, guerras, epidemias e crises de abastecimento, que marcaram o cotidiano dos citadinos e merecem projeção historiográfica.
Portuguese or foreign, the authors who have dedicated their writings to Lisbon were many. And these writings became more expressive during the Iberian Union. The incentive offered to the Phillips activities and development urban history throughout Europe to help better understand this production, which can still be explained by the condition of Lisbon at the time. When Portugal was incorporated into the catholic monarchy, the kings Phillips opted not reside in its main city. Thus, the ancient residence of Avis lost her royal status cutoff saw and slowly transform into a simple provincial capital. The historiography identified the absence as tonic for understanding the period. The proposed dissertation research is to assess the extent to which the rethoric of a Lisbon without king is present in the representations made about the city, especially the descriptions that had the greatest impact at the time. And also identify other elements that make up your imagination, as the adversities experienced by the metropolis, war, epidemics and supply crises that marked the daily lives and deserve historiographical projection.
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Moyal, Pascal. "Les foreurs du maïs en zone des savanes de Côte d'Ivoire : données morphologiques, biologiques, écologiques : essais de lutte et relation plante-insecte." Paris 6, 1986. http://www.theses.fr/1986PA066488.
Full textAbstract:
Le maïs cultivé en zones de savanes de Côte d'Ivoire est attaqué par 5 espèces de Lépidoptères foreurs qui s'attaquent soit a la tige, soit a l'épi, soit aux deux. Étude de la chétotaxie larvaire des différents foreurs, de l'habitus des stades préimaginaux, de la morphologie et de la biologie de Mussidia nigrivenella. Résultats de l'étude des fluctuations des populations de ces foreurs. Mise en évidence de l'efficacité de la deltaméthrine en concentré émulsifiable a 15 grammes de matière active à l'hectare. Iimpact des divers insectes sur le rendement et calcul d'équations de régression reliant la perte de rendement a l'attaque
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Li, Ssu-Yeh, and 李思燁. "Designed and synthesized with calamitic mesogens." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/87187650214807020258.
Full textAbstract:
碩士國立中央大學
化學研究所
98
In this thesis, we investigated the relationship between inter-molecular interactions and mesomorphic properties through substitution partial structures. All compounds were characterized by 1H, 13C-NMR spectroscopy and element analysis. The phase behaviors of these compounds were studied by polarized optical microscopy (POM), differential scanning calorimetry (DSC), powder X-ray diffraction (XRD). Ligand 2a were derivated from salicyladimines. Pd2+ and VO2+ ions formed mononuclear complexes (1a, 1b), whereas, Cu2+ ion formed binuclear complexes (1c) . Series 2a, 1a and 1b exhibited SmA phase. We also compared mesomorphic properties with similar structures. Ligand 4a were derivated from unsymmetric pyrazoles. Froming four coordination complexes (3a) with Cu2+ ions, whereas, Al3+ ions fromed six coordination complexes (3b). Ligands and complexes exhibited smectic phase. Compared with similar structures, we proved that it is helpful for formation of mesophase by increasing rigid core proportion. Finally, series 6a and 6b were oxadiazole and thiadiazole derivatives. 6a exhibited a short range of nematic (N) or smectic C (SmC) mesophases. The thiadiazole derivatives, 6b, formed nematic (N), smectic A (SmA) and smectic C (SmC) phases over a wide range of temperatures.
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Chou, Shih-Yu, and 周世祐. "Calamitic heterocyclic pyrazoles formed by 1,5-bis(4-alkoxyphenyl)-l,3,5-pentanetriones." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/26770058482258289706.
Full textAbstract:
碩士國立中央大學
化學研究所
96
In this thesis, we report the synthesis, characterization and mesomorphic properties of a series of new mesogenic derivatives based on pyrazole structureies. All compounds were characterized by 1H, 13C-NMR spectroscopy and elemental analysis. The phase behaviors of these mesogenic compounds were characterized and studied by differential scanning calorimeter (DSC) and polarization optical microscope. In the serie, a new type of mesogenic compounds derived from heterocyclic pyrazoles were prepared and studied. The compounds of Tpz-Cn, exhibited smectic phases, as expected for their rod-like structures, compounds of Tpz-2Cn, exhibited columnar hexagonal phases, as expected for their discotic-like structures. The metal complexes, Tpz-2Cn-Ni, formed by reacting the pyrazoles with NiCl2 are exhibited columnar hexagonal phases too.
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Weng, Hsiao-Tun, and 翁筱惇. "Synthesis and Mesogenic Properties of Novel Bent-shaped and Calamitic Liquid Crystals." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/08177663020497976791.
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