Dissertations / Theses on the topic 'Fossil'
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Voronin, O. A. "Fossil fuels." Thesis, Sumy State University, 2014. http://essuir.sumdu.edu.ua/handle/123456789/45212.
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One of the most discussed global problems nowadays is using fossil fuels. For the past hundred years we have come to relying more on that power source. It facilitates the industrial revolution and helps to turn the Western world into what it is today. On the contrary, unwise consumption of resources will cause a lot of problems in future. The fact is that we are running out of this resource considerably quickly. However, it will not happen tomorrow we are not able to rely on that source of energy to power our economy any more.
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Van, Dijk D. E. "Contributions to knowledge of some Southern African fossil sites and their fossils." Thesis, Stellenbosch : University of Stellenbosch, 2001. http://hdl.handle.net/10019.1/2988.
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Thesis (MSc (Botany and Zoology. Palaeontology))--University of Stellenbosch, 2001.The fossil sites and fossils reported here range from the Archaean to the Recent. Information is presented on the circumstances of the discovery of some fossil sites in Southern Africa. A number of fossil sites, some of which can no longer be studied, are photographically recorded. Some recorded sites were relocated, while failure to locate others is noted. The assemblages at selected fossil sites are compiled, including some additions to their floras and faunas. Certain individual fossils are illustrated and discussed. Techniques which are not standard are outlined.
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Van, Dijk D. E. "Contributions to knowledge of some Southern African fossil sites and their fossils /." Link to the online version, 2000. http://hdl.handle.net/10019/3561.
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Helton, Cory. "The Re-Introduction of Fossil Springs' Flow to Fossil Creek in Three Possible Scenarios." Arizona-Nevada Academy of Science, 2003. http://hdl.handle.net/10150/296620.
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Mounce, Ross. "Comparative cladistics : fossils, morphological data partitions and lost branches in the fossil tree of life." Thesis, University of Bath, 2013. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.642021.
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In this thesis I attempt to gather together a wide range of cladistic analysis of fossil and extant taxa representing a diverse array of phylogenetic groups. I use this data to quantitatively compare the effect of fossil taxa relative to extant taxa in terms of support for relationships, number of most parsimonious trees (MPTs) and leaf stability. In line with previous studies I find that the effects of fossil taxa are seldom different to extant taxa – although I highlight some interesting exceptions. I also use this data to compare the phylogenetic signal within vertebrate morphological data sets, by choosing to compare cranial data to postcranial data. Comparisons between molecular data and morphological data have been previously well explored, as have signals between different molecular loci. But comparative signal within morphological data sets is much less commonly characterized and certainly not across a wide array of clades. With this analysis I show that there are many studies in which the evidence provided by cranial data appears to be be significantly incongruent with the postcranial data – more than one would expect to see just by the effect of chance and noise alone. I devise and implement a modification to a rarely used measure of homoplasy that will hopefully encourage its wider usage. Previously it had some undesirable bias associated with the distribution of missing data in a dataset, but my modification controls for this. I also take an in-depth and extensive review of the ILD test, noting it is often misused or reported poorly, even in recent studies. Finally, in attempting to collect data and metadata on a large scale, I uncovered inefficiencies in the research publication system that obstruct re-use of data and scientific progress. I highlight the importance of replication and reproducibility – even simple re-analysis of high profile papers can turn up some very different results. Data is highly valuable and thus it must be retained and made available for further re-use to maximize the overall return on research investment.
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Kandiel, Hussein. "En jämförelse av förnybara och fossila drivmedel. : A comparison of renewable fuels against fossil fuels." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-119909.
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Rapporten har skrivits för BioFuel Regions räkning i syfte att beskriva och sammanfatta kunskapsläget för ett antal förnybara drivmedel jämfört med dess fossila motsvarighet. De biodrivmedel som har analyserats är fordonsgas, DME och el. Först gjordes en analys av bensin och diesel vilket fungerade som en referens mot respektive biodrivmedel. Värdekedjan (råvara, produktion, distribution, fordon, regelverk och marknadskraft) har analyserats. Lika så har den miljömässiga påverkan, de ekonomiska förutsättningarna, den framtida utvecklingspotential och förutsättningar i norra Sverige gåtts igenom för de olika bränslena. I dagsläget dominerar fossila drivmedel för marknaden i både världen och Sverige. I Sverige stod andelen biodrivmedel i transportsektorn för ca 12 % år 2014. Det har satts upp mål om att denna siffra ska öka till mer än 80 % för att Sverige ska vara fossiloberoende till år 2030. Förutsättningarna för att ett drivmedel ska etableras på marknaden och vara konkurrenskraftigt är att alla länkarna i värdekedjan (råvara, produktion, distribution, fordon, regelverk och marknadskraft) är uppfyllda och kan visa potential. Regelverket kring biodrivmedel är en av flera avgörande faktorer då det kan begränsa, eller främja utvecklingen. Regelverket är viktigt för att säkerställa en hållbar produktion av drivmedlen genom hela kedjan. Exempelvis kan utsläppsminskningen av ett visst drivmedel vara stort vid själva användningen av det men utsläppen vid framtagningen av råvaran så stora att det inte kan klassas som hållbart. I Sverige styrs biodrivmedel i dagsläget av lagar under drivmedelsdirektivet Elbilar har inget eget regelverk, men påverkas av en mängd lagar och förordningar som rör el och fordon i allmänhet. DME används idag i så liten skala att det i dagsläget inte finns några specifika regelverk för dessa drivmedel. Livscykelanalysen visar att BioDME från biomassa släpper ut mindre växthusgaser (9 g CO2/km) än bensin och diesel som släpper ut 165 respektive 158 g CO2/km. För biogas som producerats med restprodukter jämförs med fossila drivmedel är reduktionen ca 80-90 % (Börjesson et al., 2013). Enligt Elforsks beräkningar släpper en elbil 112 g/km CO2 även om den endast drivs med marginalel, vilket fortfarande innebär lägre utsläpp än genomsnittutsläppet från bensinbilar. Tittar man på genomsnittet i Europa ser man att utsläppen från elbilar ligger på 63 g/km vilket är mindre än hälften jämfört med den genomsnittliga bensinbilen. Räknar man på den genomsnittliga elen i Sverige blir utsläppen 1,5 g/km. Möjligheterna för att Sverige ska nå målet om en fossiloberoende fordonsflotta finns. Denna studie visar att det finns tillgänglig teknik för produktion och fordon samt en bred råvarubas, men att det för vissa drivmedel saknas ett utbyggt distributionssystem. Dessutom krävs en tydlighet i regelverk och politiska incitament för att övertyga marknaden. Ingen av de drivmedel som studerats kan fasa ut hela den fossila fordonsflottan ensamt. Därför är varje drivmedel viktigt för att fylla i övergången till en fossilfri fordonsflotta.
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Hatamian, Abdol Hamid. "Fossil energy and the environment." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243723.
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Turner-Walker, Gordon Howard. "The characterisation of fossil bone." Thesis, Durham University, 1993. http://etheses.dur.ac.uk/5700/.
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This research presents a multi-disciplinary approach to the analysis of ancient bones, in which many different chemical and physical analytical techniques were applied to a relatively small sample of human and animal bones from different depositional environments. The results of these analyses indicate that the principle mechanisms responsible for diagenetic alteration of buried bones are chemical hydrolysis of bone collagen and microscopic tunnelling by saprophytic micro-organisms. These mechanisms, either independently or together, result in an increase in the porosity of the bone at a microscopic scale from a value of approximately 20 percent in fresh bone up to as much as 65 percent in some archaeological bones. There is no evidence that the hydrolysis of collagen in buried bones directly affects the mineral component of bone, although the breaking of the intimate association between the collagen molecules and the bone apatite crystallites exposes the crystallites to potential dissolution and recrystallization by percolating ground water. Disruption of the collagen-apatite bond has been recognised in optical microscopy of thin sections by loss of the characteristic birefringence seen in unaltered bone when viewed in polarised light. The birefringence in histologically normal bone results from the strongly anisotropic orientation of the bone mineral crystallites imposed by their association with the highly organised collagen fibrils. Loss of birefringence as a result of diagenetic activity is attributed to a randomising of the orientation of crystallites after hydrolytic degradation of the collagen molecule. With progressive loss of collagen the relative calcium and phosphorus contents of fossil bones have been found to increase in proportions close to those of stoichiometrically correct hydroxyapatite. Microscopic and mineralogical studies have suggested that changes in the crystallinity of buried bones may be attributed to the presence of well-ordered crystals of hydroxyapatite in the pore structures of the bones and that these derive from dissolution and re-precipitation of the original bone apatite. However the elemental and isotopic composition of these re-precipitated apatites may not reflect that of the original bio mineral due to the incorporation of strontium, uranium fluoride etc. from the environment. Dissolution of bone mineral can, in most cases, be associated with the action of micro-organisms, many of which are known to favour low pHs and secrete organic acids as a by-product of their metabolism. Although micro-organisms isolated from buried bones produce collagen degrading enzymes (collagenases) these enzymes are too large to enter the spaces between the bone apatite crystallites and are therefore unable to attack the collagenous matrix of undegraded bone. Before micro-organisms can utilise bone collagen, the bone matrix must first be demineralized to expose the collagen fibrils or the collagen must be degraded by hydrolysis into shorter lengths that then escape via disrupted regions of the surrounding crystallites. Analysis of the strengths of modem and fossil bones has demonstrated a near logarithmic relationship between tensile strength and porosity. In addition, plots of strength vs porosity and strength vs nitrogen content are bimodal, indicating that two mechanisms are involved in the degradation of fossil bones. The microscopic and chemical analyses suggest that these mechanisms are chain scissioning of collagen and tunnelling by micro-organisms. Microscopic studies show that surface adsorption of 'humic acids' and metal ions are responsible for the colouration of fossil bones. Analysis of the total lipid extract of fossil bones contain cholesterol and cholesterol degradation products. Fossil cholesterol represents a potentially important and unique resource for palaeodietary studies. Conversely, this research has demonstrated that studies of ancient DNA are compounded by inhibition by compounds from the soil and contamination by modem DNA. Fossil bones in anoxic or wateriogged soils are readily colonised by sulphate-reducing bacteria and these bacteria are responsible for the deposition of iron sulphide in the form of pyrite framboids in pore spaces in the bone. On exposure to atmospheric oxygen, these pyrite framboids oxidise to sulphuric acid which in turn attacks bone apatite, resulting in the formation of vivianite (Fe(_3)(PO(_4))(_2).8H(_2)O) and gypsum (CaSO(_4).2H(_2)O). Crystallization and hydration of these minerals frequently disrupt the physical integrity of the bone specimens. Finally this research indicates potential regimes for the conservation of fossil bone specimens together with the archaeological or environmental evidence preserved within them.
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Muscente, Anthony Drew. "Contributions to Exceptional Fossil Preservation." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/79659.
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Exceptionally preserved fossils—or fossils preserved with remains of originally non-biomineralized (i.e. soft) tissues—constitute a key resource for investigating the history of the biosphere. In comparison to fossils of biomineralized skeletal elements, which represent the majority of the fossil record but only a fraction of the total diversity that existed in the past, exceptionally preserved fossils are comparatively rare because soft tissues are rapidly destroyed in typical depositional environments.
Assemblages of such fossils, nonetheless, have received special attention among scientists in multiple fields of Earth and life sciences because they represent relatively 'complete' windows to past life. Through such windows, researchers are able to reconstruct original biological features (e.g. soft tissue anatomies) of extinct organisms and to describe the structures and compositions of ancient soft-bodied paleocommunities. To accomplish these goals, however, researchers must incorporate background information regarding the pre- and post-burial histories of exceptionally preserved fossils. In this context, my dissertation focuses on the environmental settings, diagenetic conditions, geomicrobiological activities, and weathering processes, which influence the conservation of original biological features within exceptionally preserved fossils and control their occurrences in time and space. An improved understanding of these critical factors involved in exceptional fossil preservation will ultimately our advance our knowledge regarding the history of the biosphere and the Earth system as a whole.
Each chapter of original research in this dissertation includes an innovative and distinct approach for studying exceptional fossil preservation. The second chapter describes environmental and geologic overprints in the exceptional fossil record, as revealed by a comprehensive statistical meta-analysis of a global dataset of exceptionally preserved fossil assemblages. Moving from global to specimen-based perspectives, the second and third chapters focus on minerals (products of geomicrobioloigcal, diagenetic, and weathering processes) and carbonaceous materials replicating exceptionally preserved fossils. The third chapter examines the causes of preservational variations observed among organophosphatic tubular shelly Sphenothallus fossils in the lower Cambrian of South China using an experimental approach. (Although Sphenothallus is not an exceptionally preserved fossil sensu stricto, its conservation of original organic matrix tissues in South China provides key insights into the preservation of carbonaceous material within fossils.) Lastly, the fourth chapter presents data acquired using various in situ nanoscale analytical techniques to test the hypothesis that microstructures within exceptionally preserved microfossils of the Ediacaran Doushantuo Formation of South China are some of the oldest putative cylindrical siliceous demosponge spicules in the fossil record. Collectively, these chapters describe environmental, authigenic, diagenetic, and weathering processes that affect exceptional fossil preservation, and highlight innovative methods and approaches for testing major paleobiologic and geobiologic hypotheses regarding exceptionally preserved fossils.Ph. D.
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Overby, Steven T., and Daniel G. Neary. "Travertine Geomorphology of Fossil Creek." Arizona-Nevada Academy of Science, 1996. http://hdl.handle.net/10150/296999.
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Coulomb, Renaud. "Fossil fuels and climate policy." Paris, EHESS, 2013. http://www.theses.fr/2013EHES0137.
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Cette thèse étudie les interactions entre la régulation des émissions de C02 et l'extraction de combustibles fossiles. Elle aborde diverses questions: quel est le sentier optimal d'extraction de ces combustibles? Quelle taxe carbone optimale mettre en œuvre ? Quand déployer les technologies de capture et de séquestration du carbone (CCS) ou les renouvelables ? Quels sont les effets de la taxation optimale du carbone sur les profits des producteurs de combustibles fossiles? Dans les cinq chapitres de cette thèse, nous explorons des modèles d'extraction de ressources à la Hotelling, suivant Chakravorty et al. (2006b). Le modèle de base est modifiée en fonction des questions posées, et les changements concernent la contrainte environnementale (un plafond sur la concentration de C02 et / ou une fonction de dommages), la disponibilité de la technologie CCS et son champ d'application, la durée de vie des infrastructures énergétiques non-polluantes, la dilution naturelle du C02 dans l'atmosphère (constante, proportionnelle au stock, ou négligeable), et l'existence de plusieurs ressources polluantes. La première partie étudie l'utilisation optimale et le déploiement de la CCS et des énergies renouvelables, quand un plafond sur la concentration de C02 est introduit. La deuxième partie traite de la taxation optimale du carbone et l'utilisation de la CCS lorsque les dommages marginaux augmentent avec le stock de C02 et qu'un plafond est introduit. La dernière partie étudie comment les propriétaires d'une ressource épuisable polluante (pétrole, gaz) peuvent bénéficier de la taxation du carbone si cette ressource est (ou sera) en concurrence avec une ressource plus polluanteThis thesis studies the interactions between carbon regulation and fossil fuels extraction. It addresses various questions: what is the optimal extraction path of polluting fossil fuels? What is the optimal carbon tax to implement? When investing in Carbon Capture and Starage technology (CCS) systems and carbon-free power plants? What are the impacts of optimal carbon taxation on profits of fossil fuels owner s? In a11 of the five chapters of this dissertation, we explore Hotelling-like models, close to Chakravorty et al. (2006b ). In these models, utility comes from the consumption of energy resources and the accumulation of C02 i n the atmosphere is regulated. At least two energy resources and carbon-emitting exhaustible resource and a carbon free renewable one, are available. The baseline model is modified throughout this dissertation, and changes concern: the environmental constraint (a carbon cap over C02 concentration and/or a damage function), the availability of CCS technology and its field of application, the duration of clean capital (CCS systems renewables plants) , the natural dilution (constant, proportional to the stock, or negligible) and the existence of several polluting resources. The first part studies the optimal use and deployment of carbon capture and renewables, when an environmental regulation is imposed through a cap over the C02 concentration. The second part deals with the optimal carbon taxation and carbon capture when marginal damages increase with the carbon stock and a carbon cap over the C02 concentration is set. The last part studies how owners of an averagely carbon-emitting resource (oil, gas) can benefit from carbon taxation
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Gustafsson, Emmy, and Caroline Olsson. "Fossil åkermarks synlighet i LIDAR : fossil åkermarks visuella potential iförhållande till vanliga typer av marktäcket." Thesis, Högskolan Kristianstad, Fakulteten för naturvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-20541.
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Uppmärksamheten och intresset för LIDAR data har blivit stort under 2000-talet. Som en väletablerad fjärranalysmetod uppvisar den resultat att studera och den kritisk frågan är ”Hur bra är egentligen resultatet att studera?”. I flera tidigare publiceringar infinner sig ofta en okritisk och positiv inställning till tekniken. Fördelaktiga resultat framhävs istället för helhets kritiska granskningar. Tidigt i processen finns det en rad olika aspekter, som kan utgöra störningsmoment. Hur inskanningen av LIDAR gemoförs, samt efterbehandlingens process. Den valda fornlämningstypen fossil åkermark, kan bli problematisk. Den fossila åkermarkens komplexa systemen kan med felaktiga visualisering döljas. Att kombinera höjdmodeller utifrån Hillshade och Slope förhindrar att den fossila åkermarkens system döljs. En annan aspekt att ta i beräkning är vegetationen. I vår frågeställning vill vi undersöka hur vanliga marktyper påverkar synligheten. Vi valde att utgå från Naturvårdsverkets marktäckesdata och har där tittat på tre olika marktyper. Granskog (utanför våtmark), Ädellövskog (utanför våtmark) och Temporärt ej skog (utanför våtmark). Av de tre marktyperna uppvisar Temporärt ej skog (utanför våtmark) svårigheter i samband med visualiseringen, kvalitén för markytan i höjdmodellaren skiftar avsevärt. Granskog (utanför våtmark) har möjligheter, däremot kan resultaten vara skiftande. Ädellövskog (utanför våtmark) har enklast material att tolka, med tydliga lämningar som tidigare inte vart registrerade hos FMIS.The attention and interest in LIDAR data has grown considerably during the 2000s. As a well-established distance analysis method, it presents results to study and the critical question is "How good is the result to study?". I several previous publications there often is an uncritical and positive attitude to the technology. Beneficial results are emphasized instead of critical reviews of the whole technology. Early in the process, there are several different aspects, which can be disruptive moments. How the scan of LIDAR is organized, as well as the post-treatment process. The chosen ancient type of fossil arable land can be problematic. The complex systems of the fossil farmland can be hidden with incorrect visualization. Combining altitude models based on Hillshade and Slope prevents the fossil farmland system from being concealed. Another aspect to consider is vegetation. In our question we want to investigate how common types of vegetation affect visibility. We chose to use the Swedish Environmental Protection Agency's ground cover data and have looked at three different vegetation types. Spruce forest (outside wetland), Nobel deciduous forest (outside wetland) and Temporary non forest (outside wetland). Of the three vegetation types, Temporary non forest (outside wetland) presents difficulties in visualization, the quality of the ground surface in the height model varies considerably. Spruce forest (outside wetlands) has opportunities, however the results can be varied. Noble deciduous forest (outside wetland) has the simplest material for interpreting, with remains that have not previously been registered with FMIS.
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Brandon, Sara. "Discovery of bald cypress fossil leaves at the Gray Fossil Site, Tennessee and their ecological significance." Digital Commons @ East Tennessee State University, 2013. https://dc.etsu.edu/honors/145.
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This study focuses on fossil Taxodium leaves found at the Gray Fossil Site in northeastern Tennessee where many 7-4.5 million year old plants and animals have been recovered. Identification of the leaves is based on comparison of leaf morphology and confirmed by leaf anatomy. The ecological implications of the fossil are discussed to understand the paleoecology and paleoclimate at the Gray site. It is concluded that the fossil plant along with many other plants lived by a large sinkhole lake under a little warmer-than-today’s climate condition.
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Dibenedetto, Joseph Nicholas. "Paleoclimatological implications of fossil tortoise bones." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2008. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Ekström, Kristin, Ida Johansson, and Agnes Lind. "Mässan - en fossil eller framtidens mötesplats?" Thesis, Linnéuniversitetet, Institutionen för marknadsföring (MF), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-31490.
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Syftet med denna uppsats är att identifiera samt analysera karaktärsdrag, trender och potentiell utveckling för mässan som verktyg för relationsbyggande B2B. Vi har i denna uppsats valt att göra en kvalitativ studie med en induktiv ansats med deduktiva inslag. Detta då vi ville få en djupare förståelse för ämnet snarare än att se till det bredare perspektivet. Insamlingen av empiriskt material skedde genom sex intervjuer med personer som arbetar med att marknadsföra sitt företag på mässor. Tre intervjuer genomfördes personligen, två via videokonferens och en via telefon. Genom analysarbetet har vi identifierat att mässan har stor betydelse för relationsbyggande mellan företag. Detta speciellt då den fungerar som ett verktyg som underlättar för företag att underhålla befintliga relationer samt skapa nya. Vi har även identifierat en trend som indikerar på att företag mer specifikt väljer ut vilka mässor de ska närvara vid, där en definierad målgrupp värderas högt för att företagens budskap ska nå fram. Vi har kommit fram till att virtuella mässor bör fungera som ett komplement snarare än ersätta den traditionella mässan eftersom det personliga mötet är av stor vikt inom B2B. Generationsskiften på arbetsmarknaden bidrar till att andra förhållningssätt till teknologi kommer att råda. Detta gör att företag måste förstå vikten av de förändringar som sker och agera därefter.
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Hemsley, Alan Richard. "The ultrastructure of fossil spore exines." Thesis, Royal Holloway, University of London, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493795.
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Harley, Madeline Margaret. "Palm pollen and the fossil record." Thesis, University of East London, 1996. http://roar.uel.ac.uk/1274/.
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Previously published descriptions of the pollen morphology of the Palmae are reviewed and discussed. The earliest macro fossil records for palms are summarised, while a more detailed review is given of the fossil records of palmlike pollen. Selected literature relating to pollen sharing some similarities to palm pollen in other monocotyledonous families are briefly reviewed, and the fossil pollen records for these families are examined. A brief chronological account of earlier systematic treatments of the palms is provided, as well as an outline of the systematic treatment of the family used in the present account. The pollen morphology of 1150 collections, representing 765 species of palms,f rom all but seveno f the currentlyr ecognisedg enera,h asb eene xamýined, as well as dispersedp alm-likef ossil pollen from the middle Eoceneo f the Isle of Wight, and of Java. Iii silit pollen of fossil palm flowers from the Messel oil shales (Germany)a re describedP. ost meiotic tetrad stageh asb eens tudiedf or representatives peciesin all subfamiliese xceptingt he PhytelephantoideaeP.o llen morphologyo f both recenta nd fossil pollen is describedf rom light, scanning electrona nd, selectivelyf rom transmissione lectronm icroscopy,w hile tetrad resultsa re from light and scanninge lectronm icroscopy.F ull detailso f preparation methods,t erminologya nd databaseus sedf or pollen morphological,f ossil and tetrad studies are given. Seventeena perturet ypes,p lus numerouss ubtypesa, nd twelve exine types with numerous subtypes are identified. The aperture types are shown to be broadly separablein to two groupsw hich are associatedw ith either simultaneous (tetrahedralt etrads)o r successive(t etragonalt etrads)m icros porogenessi. In generalt heset wo groups supportp resents ystematico pinion regardingt he subfamilies.S uccessivem eiosisi s dominanti n subfamiliesC alamoideaea nd Nypoideaew hile, with somer are exceptionss, imultaneousm eiosisp redominates in the remainingf our subfamiliesC: oryphoideaeC, eroxyloideaeA, recoideaea nd PhytelephantoideaeP.o llenu ltrastructurei s treatedi n detail only for simple tectate exines where it is important for further definition. Six types and a number of subtypesa re described.T he systematicd istributionso f aperturea nd exine types are summarisedA. trend towardsl arger pollen is noted, with the smallest pollen occurring in the least specialised subfamily, the Coryphoideae, while very large-sized pollen are characteristic of subfamily Phytelephantoideae. Monosulcate, disulcate and zonosulcate pollen are described from fossil material and closest affinities with recent palms suggested. Pollen morphology of recent palms is summarised and discussed, and compared with pollen of selected monocotyledonous families. The bearing of pollen data on recent palm systematics is considered at various levels from subfamily to species. Angiosperm pollen evolution is re-considered and evolutionary pathways for palm pollen aperture types and exine types are suggested. In the light of recent pollen morphology for the family the fossil record of palm pollen is re-evaluated. Some widely accepted affinities are challenged while previously unconsidered affinities are suggested, particularly for the mid- Cretaceous. The need is emphasized for future fossil pollen studies to look critically for pre Late Cretaceous palm-like monosulcates, which would be more informative of the early history of the family than the apparently highly evolved, easily recognisable Spini. -onocolpiles of the Late Cretaceous. Palaeogeography, environment and distribution of fossil records and depositional environment are discussed. Probable evolutionary pathways of pollen morphology, including pollen tetrad data which suggests imultaneousra thert han successivem eiosisa s the plesiomorphics tate,o ffer further evidencet hat the palmsa re indeeda n ancient group, and support the hypothesis that the palms may have originated in South America and Africa (West Gondwana)in the Late Jurassic or early Cretaceous, prior to the complete separation of these continents.
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Sheu, Elysia J. (Elysia Ja-Zeng). "Hybrid solar-fossil fuel power generation." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78189.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 83-92).
In this thesis, a literature review of hybrid solar-fossil fuel power generation is first given with an emphasis on system integration and evaluation. Hybrid systems are defined as those which use solar energy and fuel simultaneously, thus excluding the viable alternative of solar thermal plants which use fossil fuels as backup. The review is divided into three main sections: performance metrics, the different concentrated solar receiver technologies and their operating conditions, and the different hybridization schemes. In addition, a new linear combination metric for analysis of hybrid systems, which considers trade-off of different metrics at the fleet level, is presented. This metric is also compared to alternative metrics from multi-objective optimization. Some previous work only evaluates the hybrid cycle at a certain point in time, which can be misleading as this evaluation would not take into account certain aspects of hybrid cycle such as fluctuating solar supply. Furthermore, almost all previous work designs the hybrid solar-fossil fuel systems for a certain point in time and then evaluates the performance of the system for an entire year. By not taking into account fluctuating solar supply and selling price of electricity in the design of the system, the best possible annual performance of the hybrid cycle may not be reached. Second, an analysis of solar reforming as the integration method for the hybrid cycle is presented, in particular steam reforming of methane. Two solar reforming systems are analyzed: one with a parabolic trough and the other with a solar tower. From the analysis, it is determined that parabolic troughs are not suitable for steam reforming due to the relatively low operating temperatures. The tower reformer system is integrated with a standard combined cycle, and the design and operation of the hybrid cycle is optimized for highest work output for a fixed fuel input and solar collector area (essentially optimizing for maximum cycle efficiency). A heuristic two step procedure is used for the optimization due to the limitation of the optimizer which cannot simultaneously optimize both design and operation. From the optimization, it is determined that the tower reforming integration method is a promising integration option in that this type of hybrid cycle yields high incremental solar efficiencies and also satisfies the linear combination metric for efficiency and CO₂ emissions (i.e., the analyzed hybrid cycle has a higher efficiency for a fixed CO₂ emissions compared to a linear combination of solar only and fossil fuel only cycles).
by Elysia J. Sheu.
S.M.
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Weaver, Sarah Anne. "Fossil poetry : Tennyson and Victorian philology." Thesis, University of Cambridge, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708871.
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Matthews, Elizabeth, Tom Cain, Grant Loomis, Jerome Stefferud, and Rich Martin. "Fossil Creek: Restoring a Unique Ecosystem." Arizona-Nevada Academy of Science, 1995. http://hdl.handle.net/10150/296468.
Full textAbstract:
From the Proceedings of the 1995 Meetings of the Arizona Section - American Water Resources Association and the Hydrology Section - Arizona-Nevada Academy of Science - April 22, 1995, Northern Arizona University, Flagstaff, Arizona
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Herman, Julie D. "Fossil preservation and the effects of groundwater leaching on fossils in the Yorktown Formation (Upper Pliocene), Virginia." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/90972.
Full textAbstract:
Patterns of fossil diagenesis caused by groundwater leaching provide insight into how shells are altered. This study analyzes fossils in unconsolidated terrigenous sediments from the Virginia Coastal Plain, unlike previous studies conducted mostly in carbonate terranes. The vertical and lateral distribution of diagenetic states was mapped in an outcrop (63 m by 2.1 m) of the Yorktown Formation. A paleostream channel located at one end was incised during the Pleistocene and filled with sediments of the Shirley Formation. The Tabb Formation unconformably overlies the outcrop. Acidic groundwater caused the observed patterns of fossil and sediment diagenesis. These patterns include zones of fossil alteration, diagenetic stratification of the sediment, and fossil diagenesis on a microstructural level.
Groundwater movement, controlled by the presence of the paleochannel, caused diagenetic alteration or complete dissolution of the fossils, and possibly caused precipitation of fine-grained iron oxyhydroxides. All carbonate material in the vicinity of the paleochannel is completely dissolved away, although iron oxyhydroxide coatings of fossils remain. Away from the paleochannel Crepidula fornicata (gastropod; aragonite), Ostrea sp. (bivalve; calcite), Balanus sp. (barnacle; calcite), and bryozoans (calcite) are found in parallel zones of alteration that dip toward the paleochannel and cut across horizontal sedimentologic and fossiliferous layers.
Groundwater also leached the Yorktown sediments. This alteration caused a diagenetic stratification of the sediment, with unaltered greenish-gray silty fine sand along the base of the outcrop, overlain by leached yellowish-brown silty fine sand and areas of concentrated iron oxyhydroxides.
The preservation of both aragonitic and calcitic shells was affected by groundwater movement. Original aragonitic shell material is found as chalky, uncrystallized specimens or neomorphosed shells, or is completely dissolved with only molds or ghosts remaining. Neomorphosed specimens typically consist of calcite-replaced shell material with pockets of original aragonite, and sparry calcite filling empty shell cavities. Original calcitic shell material is either chalky or unaltered. Chalky shells range from relatively hard to soft and pasty. Crepidula shells of intermediate chalkiness tend to separate into thin flakes, caused by dissolution along growth surfaces. Chalkiness of pasty shells is caused by dissolution of shell material (without recrystallization) and not simply loss of organic matrix. SEM photos of Crepidula reveal the more porous and leached appearance of chalky shells in contrast with hard; unaltered shells. The presence of chalky aragonitic and calcitic shells indicates that chalky textures are, to some degree, independent of mineralogy and microstructure.M.S.
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Oberg, Danielle. "Fossil Moles from the Gray Fossil Site, TN: Implications for Diversification and Evolution of North American Talpidae." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etd/3394.
Full textAbstract:
The Gray Fossil Site (GFS) is one of the richest Cenozoic terrestrial localities in the eastern United States. This study describes the first talpid specimens recovered from the GFS. Using measurements and comparisons of dental and humerus morphology, I identify 4 talpids (Parascalops nov. sp., Quyania cf. Q. europaea, Mioscalops (= Scalopoides) sp., and an unidentified stem desman) occurring at the GFS. Humeral morphology has been used to diagnose talpid species and study relationships. A geometric morphometric analysis showed that humerus shape is highly reflective of locomotor ecology in extant talpids and allows ecological inferences for fossil talpids. Hierarchical cluster analysis using morphometric data allowed examination of similarity among taxa and helped to secondarily verify taxonomic designations for the GFS taxa. The resulting phenogram showed strong similarity to the most up-to-date molecular cladogram and actually matched phylogenetic relationships substantially better than any morphological cladistic analyses to date.
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Evans, F. J. (Fiona Jocelyn). "Taxonomy, palaeoecology and palaeobiogeography of some palaeozoic fish of Southern Gondwana." Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/50460.
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Thesis (PhD)--University of Stellenbosch, 2005.ENGLISH ABSTRACT: The fossiliferous Waaipoort Formation (Witteberg Group, Cape Supergroup), Ganikobis Formation (Dwyka Group, Karoo Supergroup) and Whitehill Formation (Ecca Group, Karoo Supergroup) span a protracted period interrupted by a +-45Ma glacial event. This Late Carboniferous glacial event resulted in a prolonged hiatus in sedimentation as well as significant erosion in many southern continents of Gondwana. This study demonstrates how the glacial episode affected faunal composition and changes in palaeoecology in southern Gondwana across this time period. The Waaipoort shows the highest overall faunal diversity with relatively high palaeoniscoid diversity within Ganikobis and Whitehill Formations. This study is unique in correlating Early Carboniferous - Early Permian fish fauna of South Africa and Namibia specifically, as well as other parts of southern Gondwana, and includes maps of possible fish migration routes. This study attempts to refine the body of disjointed knowledge on the taxonomy and distribution of the fish fauna surrounding this period in southern Gondwana. Three new Waaipoort taxa are recognised, and several reassigned. Earlier work on Late Carboniferous fish from Southern Africa has been updated herein to incorporate recent collections. This has allowed the recognition of up to 15 new palaeonoscoid taxa, some of which are endemic to this region. Several new taxa are recognised within the Whitehill Formation fish fauna and a new lectotype for Palaeoniscum. capensis is presented. Detailed taphonomic and sedimentological studies (with 6 lithologs) of fossil localities visited in this broad-based study verify the correlation, and impart information often lost or ignored in pure palaeontological studies on the palaeoecology or palaeoenvironment of the fauna. Systematic relationships discussed here also serve to strengthen the palaeobiogeographical correlations between the Gondwanan continents.
AFRIKAANSE OPSOMMING: Die fossie1draende Waaipoort Formasie (Witteberg Groep, Kaap Supergroep), Ganikobis Formasie (Dwyka Groep, Karoo Supergroep) en Whitehill Formasie (Ecca Groep, Karoo Supergroep) strek oor 'n uitgebreide tydvak wat 'n periode van vergletsering van ongeveer 45 miljoen jaar insluit. Hierdie Laat Karboon ystyd het sedimentasieprosesse lank onderbreek en beduidende erosie in baie van die suidelike kontinente van Gondwana veroorsaak. Die huidige studie toon hoe die vergletsering die faunistiese samestelling en veranderings in die paleo-ekologie van suidelike Gondwana beinvloed het. In totaal toon die Waaipoort die grootste faunistiese diversiteit, terwyl 'n relatief hoe diversiteit ook onder die Palaeoniscoidei van die Ganikobis en Whitehill Formasies voorkom. Hierdie studie is uniek insoverre dit spesifiek data oor die Vroee Karboon - Vroee Perm visfauna van Suid-Afrika en Namibie, asook ander gebiede van suidelike Gondwana korrelleer en kaarte van moontlike migrasieroetes insluit. Die navorsing poog om die groot hoeveelheid losstaande inligting oor die taksonomie en verspreiding van die visfauna in suidelike Gondwana te verwerk en te verfyn. Drie nuwe taksa is uit die Waaipoort geidentifiseer en 'n verdere aantal is geherklassifiseer. Vroeer navorsing oor die Laat Karboon-visse van Suider-Afrika is bygewerk in die lig van resente versamelings. Dit het die herkenning van tot 15 nuwe taksa onder die Palaeoniscoidei, waarvan sommige endemies aan hierdie streek is, moontlik gemaak. 'n Aantal nuwe taksa word onder die visfauna van die Whitehill Formasie aangeteken, saam met 'n nuwe lektotipe van Palaeoniscum capensis. Gedetailleerde tafonomiese en sedimentologiese analises van die vindplekke wat tydens hierdie studie ondersoek is en wat 6 vertikale profiele insluit, ondersteun hierdie korrelasie. Sodoende stel dit inligting beskikbaar wat dikwels gedurende suiwer paleontologiese studies oor die paleo-ekologie of paleo-omgewing van die fauna verlore sou gaan of geignoreer sou word. Die sistematiese verwantskappe wat hier bespreek word dien ook om die paleobiogeografiese ooreenkomste tussen die Gondwana-kontinente te versterk.
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Lena, Alex. "Le fossile, précepteur de l'épistémologie de la paléontologie : pour une historiographie du vivant." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1182/document.
Full textAbstract:
Le fossile est le siège incontournable de la connaissance du passé du vivant et par conséquent de celui du présent.Il est épistémologiquement a-phénoménal, non-expérimentable, incomplet et historique. Cette nature épistémologique occasionne des contraintes importantes dans la manière de fabriquer l'histoire du vivant pour le paléontologue : l'historiographie du vivant. Comment,le fossile comme objet naturel et sa nature épistémologique vont-ils contraindre le processus épistémologique de la paléontologie et en définitive l'historiographie du vivant ?The fossil is the essential seat of the knowledge of the past living beings and consequently of that of the present. It is epistemologically a-phenomenal, non-experimental, incomplete and historical. This epistemological nature causes important constraints in the way of making the history of the living beings for the paleontologist: the historiography of the living. How does the fossil as a natural object and its epistemological nature constrain the epistemological process of paleontology and ultimately the historiography of life?
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O'Brien, Jane, and n/a. "Tertiary fossil wood in South Eastern Australia." University of Canberra. Applied Science, 1999. http://erl.canberra.edu.au./public/adt-AUC20060821.132803.
Full textAbstract:
Palaeobotany illuminates past environments by relating the fossilised species to
the existing geological conditions. This has previously been done with fossilised
leaves and spores but not with fossilised wood.
The recovery of a significant quantity of wood from an area of Tertiary sediments
in New South Wales, enabled the used of fossilised wood as a
palaeoenvironmental tool. Tertiary sedimentary deposits of south eastern
Australia are diverse lithologically, occupy distinct areas and are limited in vertical
and horizontal extent. However, samples in museum collections together with
samples from field work and descriptions of fossil wood from previous researchers
enabled an analysis of the fossil wood.
The geological and palaeontological aspects of the fossil wood were considered
for each specimen. Only specimens with precise information concerning location
and description of the sedimentary deposits in which the specimens were found
were investigated. Lithology, sedimentary structures and the relationship with
surrounding geological units were also considered.
The samples were then classified and identified. It was possible to identify fossil
wood to Family level by comparison with existing taxa. In the majority of cases,
identification to species level was not possible due to the lack of detail in the
specimen and because features such as colour cannot be used with fossilised
specimens. With Australian fossilised wood, a systematic nomenclature based on
structure observed within the palaeotaxa, would be more relevant. Comparisons
of cell structures with previous work on palaeoenvironmental indicators was found
to be possible.
Fossil wood has two uses. Firstly, as a local environmental indicator, usually in
conjunction with sedimentological data, assessing the rate and direction of water
flow, types of depositional environments and localised floral assemblages.
Secondly, as an indicator of regional climate. Within any one particular time
period, comparisons between the cellular structures of wood found in different
parts of south eastern Australia show gross changes in cell size, mean growth ring
size and vessel size, which enabled generalisations about climate for each epoch
in the Tertiary.
Palaeoclimatic indicators from the wood concurred with previous climatic
interpretations based on palynology and sedimentology. Cool conditions during
the Palaeocene were clearly indicated by small cells and small growth rings which
gradually increased throughout the remainder of the Tertiary. Several areas e.g.,
Dargo High Plains, where cold conditions existed in isolation could be clearly
distinguished. This corresponds with the gradual northward movement of the
Australian plate with consequent increasing temperatures on the mainland.
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Good, Jennifer E. "Fossil Fuel Subsidies: Impacts and Reform Strategies." Scholarship @ Claremont, 2013. http://scholarship.claremont.edu/cmc_theses/687.
Full textAbstract:
This thesis uses cross-country panel regressions to identify the effects of fossil-fuel subsidies for both oil importers and oil exporters on GDP growth, industry growth, crowding out of government expenditures in education, health, and infrastructure, government debt, carbon dioxide emissions, inequality and poverty. Fossil-fuel subsidies are found to be associated with lower levels of growth and industry growth, less government expenditure on health and education, poorer infrastructure quality, more government debt, and higher rates of carbon dioxide emissions. No relationship is found between fossil fuel subsidies and poverty and inequality. These results confirm the arguments of those that argue that fossil-fuel subsidies should be rationalized.
However, removing subsidies is politically challenging. In order to identify strategies for fossil fuel reform, the successful reform efforts of Indonesia and Turkey are examined. These cases are then used to draw lessons for governments undertaking subsidy reform. The key strategies used were to exempt some regions, groups, or fuels from reform, use funds from subsidy removal for social safety nets and other poverty alleviation programs, time the reforms strategically, and communicate clearly to the public the reason for reform and how the funds will be used. These lessons are applied to countries in the developing Middle East and North Africa, including Egypt, Jordan, Syria, Algeria, Tunisia, and Morocco.
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Adams, Tegan Joan. "Chasing fossil fuels in the food system." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/37198.
Full textAbstract:
A carbon tax has already been introduced in British Columbia, Canada. It is likely that other carbon regulations will come into play across the globe shortly. In all likelihood, with the introduction of a domestic agreement pricing emissions, there will be border tax adjustment or other similar policy response proposed. For example, as the European Union (EU) enters the next development phases for their Emissions Trading System, a border adjustment on GHG emissions, also known as a “Border Carbon Adjustment” (BCA) (Fisher and Fox 2009) is being considered. It may work to displace concerns related to domestic competitiveness and carbon leakage from the trade of outsourced goods (including for example food, clothing and cars). In the absence of an international agreement to account for monitoring, pricing or capping GHG emissions, Canada’s response to GHG emissions or Carbon regulations is challenging policy makers. This thesis explores the feasibility of implementing a BCA on a sample of whole foods imported to Canada. It uses numerical industry trade data to create a snapshot of hypothetical Carbon Tariff estimates that reflect GHG emissions from the production and transport of a sample of whole foods imported to Canada. It investigates methods for accounting GHG emissions, trade legalities in the food system and the idealized characteristics of BCA design; it concludes by suggesting a BCA or any other policy tool reliant on GHGe accounting standards could not easily or effectively be implemented as a worthwhile or counteracting response to potential undesirable effects of domestic carbon regulations in any country at this time (2011). Finally, this paper recommends future research in the areas of GHGe accounting standards, food system transparency, product labeling and municipal policy tools as means of reducing GHGe from food production, while avoiding the repercussions of carbon regulations.
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Stern, Benjamin. "Biomineral lipids in living and fossil molluscs." Thesis, University of Newcastle Upon Tyne, 1996. http://hdl.handle.net/10443/1713.
Full textAbstract:
It has been proposed that geochemical and biomolecular palaeontological information can be obtained from biomineral associatedli pids. The location of lipidic material within the inorganic structureo f molluscan shells has previously been unknown, with important implications for long term survival of lipids and post-depositional contamination from the environment. Discrete experimental stages have been investigated and the different mechanical and chemical methods combined for the removal of contaminating material prior to the release and analysis of surficial, intercrystalline and intracrystalline lipids. Three extraction protocols have been compared using Recent Patella vulgata shells. Sequential stages of cleaning and extraction treatments identify n-alkanes, cholesterol (free and bound) and bound fatty acids. The n-alkanes are indigenous to the shell, but laboratory contamination can be significant, and highlights the need for experimental blanks. Bound fatty acids are extracted from intercrystalline and intracrystalline fractions. Cholesterol is extracted throughout the sequential methodology. The extraction of these compounds after extensive cleaning treatments illustrates the protective role of the inorganic biomineral. An experimental protocol for sequentially extracting protected lipids from the shells of Recent molluscs has been tested to distinguish the indigenous shell lipids from laboratory contamination and postdepositional ingress. The use of a calcium carbonate blank reveals the phthalate plasticisers extracted from the shells are due to laboratory contamination. Pristane, phytane and free fatty acids were rarely extracted which limits their use for interpretation. The n-alcohols, bound fatty acids, ß-hydroxy fatty acids, cholesterol and other steroids are extracted from the shells in higher yields than the calcium carbonate blanks and are considered indigenous to the shells. Multivariate statistical analysis is used to compare the distributions of bound fatty acids and steroids extracted from different shell locations with the reported fatty acids and steroids for the soft tissues of the same species. The reported values for the soft tissues were used to indicate the original shell lipid composition. The shells lack the unsaturated bound fatty acids reported in the soft tissues. The saturated bound fatty acids of Littorina littorea shells also differ in the carbon number distributions to the reported saturated fatty acids of the soft tissues. Surficial shell extracts are characterized by steroidal ketones, representing sterols which have been oxidised by the cleaning treatments used. The steroids from both intercrystalline and intracrystalline shell locations in Littorina littorea are most similar to the soft tissues. However, the intercrystalline steroids are different to the intracrystalline steroids which may indicate a different original composition. Potential Class level phylogenetic differences between the shells of Recent molluscs are revealed by their steroidal and bound saturated fatty acid compositions. The bivalves (n=3) have bound saturated fatty acids with a carbon number maximum of C16 whilst the gastropods (n=8) have a maximum of C16 or C18 and exhibit higher yields. ß-hydroxy fatty acids may indicate phylogenetic differences below the Class level for the Gastropoda. Principal component statistical analysis of the shell steroidal composition indicates differences at the Class level. Steroidal markers indicating the dietary intake have been found in the shells. The application of a methodology for the sequential extraction of lipids from molluscan shells has been used in a preliminary analysis of shell material for the presence of hydrocarbon pollutants. The shell nalkanes require comparison of carbon number distributions and yields with an experimental calcium carbonate blank to ensure indigeneity. Different n-alkane distributions within two Artica islandica shell samples are attributed to the different sampling locations. Differences between Patella vulgata and Littorina littorea shells from the same environment have also been observed, indicating different n-alkane uptake by different species. Polyaromatic hydrocarbons and sterane biomarkers reported to be present in the soft tissues of Patella vulgata exposed to the Braer oil spill have been searched for in the shells of an exposed sample. These compounds have not been detected. No increase in the shell n-alkane yields or similarity in carbon number distribution with the spilt oil is observed. This suggests no hydrocarbon incorporation or deputation pathway into the shell. Quaternary aged mollusc shells yield n-alkanes, n-alcohols, bound fatty acids and cholesterol. These have been extracted from both intercrystalline and intracrystal line locations within the shells. When compared with the extracts from Recent shells the yields of these lipids from fossil shells are significantly lower. The n-alkanes extracted from Quaternary shells are dominated by laboratory contamination, although some indigenous intracrystalline n-alkanes have been extracted. The bound fatty acids from intercrystalline sites within the fossils maintain their carbonn umber distribution but decreasein yields with increasinga ge; no diagenetic products were observed. The previously reported phylogenetic distinctions based on the bound fatty acids betweent he gastropodsa nd bivalves are maintainedf or fossils. However,t he information obtained from this analysis is limited by the small diversity of lipid distributions found in these fossil shells.
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Clegg, Heather. "Biomolecules in recent and fossil articulated brachiopods." Thesis, University of Newcastle Upon Tyne, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334162.
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Exton, Samantha Jane. "Natural selection in fossil and recent molluscs." Thesis, University of Liverpool, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366482.
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O'Dea, Aaron. "Environmental inferences using recent and fossil bryozoans." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302204.
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Yunt, Mehmet 1975. "Steam temperature regulation in fossil power plants." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/89876.
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Li, Derek Z. "Statistical analysis of correlated fossil fuel securities." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/69516.
Full textAbstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 36).
Forecasting the future prices or returns of a security is extraordinarily difficult if not impossible. However, statistical analysis of a basket of highly correlated securities offering a cross-sectional representation of a particular sector can yield information that is potentially tradable. Securities related to the fossil fuels industry are used as the basis of a practical application to two distinct forecasting techniques. The first method, forecasting using conditional multivariate Gaussian statistics, was shown to yield, in a relative sense, the best results for those securities which exhibited a high correlation with the rest of the basket. For the second method, principal component analysis was done on a basket of commodity futures to reveal a small number of dominant factors governing the movements of the portfolio. Autoregressive models were then applied to both the factors and futures, but results showed both to be essentially Markov processes.
by Derek Z. Li.
S.B.
34
Leitch, A. "Studies on living and fossil Charophyte oosporangia." Thesis, University of Bristol, 1986. http://hdl.handle.net/1983/f34206b6-5fa4-48a4-958e-e8aae5e75a2d.
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Allison, P. A. "The taphonomy of soft-bodied fossil biotas." Thesis, University of Bristol, 1987. http://hdl.handle.net/1983/0ae5c2b2-cfb9-473b-beef-7b5034401d4f.
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Ng, Kok Siew. "Decarbonised polygeneration from fossil and biomass resources." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/decarbonised-polygeneration-from-fossil-and-biomass-resources(e3b9e6d2-9716-44ca-b775-0ffe88fb47f1).html.
Full textAbstract:
Utilisation of biomass resources and CO2 abatement systems in currently exploited fossil resource based energy systems are the key strategies in resolving energy sustainability issue and combating against global climate change. These strategies are affected by high energy penalty and high investment. Therefore, it is imperative to assess the viability of these energy systems and further identify niche problem areas associated with energy efficiency and economic performance improvement. The current research work has two parts. The first part presents techno-economic investigation of thermochemical conversion of biomass into the production of fuels (Fischer-Tropsch liquid or methanol) and electricity. The work encompasses centralised bio-oil integrated gasification plant, assuming that the bio-oil is supplied from distributed pyrolysis plant. Bio-oil is a high energy density liquid derived from biomass fast pyrolysis process, providing advantages in transport and storage. Various bio-oil based integrated gasification system configurations were studied. The configurations were varied based on oxygen supply units, once-through and full conversion configurations and a range of capacities from small to large scale. The second part of this thesis considers integration of various CO2 abatement strategies in coal integrated gasification systems. The CO2 abatement strategies under consideration include CO2 capture and storage, CO2 capture and reuse as well as CO2 reuse from flue gas. These facilities are integrated into cogeneration or polygeneration systems. The cogeneration concept refers to the production of combined heat and power while polygeneration concept is an integrated system converting one or more feedstocks into three or more products. Polygeneration is advocated in this work attributed to its high efficiency and lower emission. Furthermore, it can generate a balanced set of products consisting of fuels, electricity and chemicals. It is regarded as a promising way of addressing the future rapidly growing energy demands. A holistic approach using systematic analytical frameworks comprising simulation modelling, process integration and economic analysis has been developed and adopted consistently throughout the study for the techno-economic performance evaluation of decarbonised fossil and bio-oil based systems. Important design methodology, sensitivity analysis of process parameters and process system modifications are proposed. These are to enhance the efficiency as well as lower the economic and environmental impacts of polygeneration systems. A shortcut methodology has also been developed as a decision-making tool for effective selection from a portfolio of CO2 abatement options and integrated systems. Critical and comprehensive analyses of all the systems under considerations are presented. These embrace the impact of carbon tax, product price evaluation and recommendations for sustainability of low carbon energy systems.
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Liu, Liping. "Chinese fossil Suoidea : systematics, evolution and paleoecology." Helsinki : University of Helsinki, 2003. http://ethesis.helsinki.fi/julkaisut/mat/geolo/vk/liping/.
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Schubert, Blaine W., and Jim I. Mead. "Gray Fossil Site: 10 Years of Research." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etsu_books/67.
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MAKAPEDUA, DAISY MONICA. "Genic characterization of "Living Fossil" Latimeria menadoensis." Doctoral thesis, Università Politecnica delle Marche, 2011. http://hdl.handle.net/11566/241984.
Full textAbstract:
I celacantiformi sono fossili viventi che costituiscono il probabile anello mancante
tra pesci e tetrapodi. Ad oggi sono state identificate solo due specie superstiti di celacanti,
quella africana, Latimeria chalumnae, e la specie indonesiana, Latimeria menadoensis.
Due esemplari di Latimeria menadoensis, una femmina ed un maschio,
recentemente catturati nella parte settentrionale del mare di Sulawesi (Maggio 2007 e
Settembre 2009) sono stati analizzati in un progetto di collaborazione di ricerca tra
l’Università Politecnica delle Marche e la Sam Ratulangi University di Manado (Indonesia).
Il contenuto di DNA (C-value) di Latimeria menadoensis (3.47 pg/cell), misurato con
la citofluorimetria di flusso è molto prossimo ai valori del contenuto di DNA della Latimeria
chalumnae precedentemente riportati. La metilazione del DNA è stata valutata con
cromatografia liquida ad alta pressione (HPLC): la percentuale di citosine metilate (5mC)
raggiunge l’1.25% e la percentuale di GC il 41.8%. Latimeria menadoensis presenta un
elevato C-value e un basso valore di metilazione rispetto a quelli degli altri pesci.
I geni 18S rDNA e l’istone 3 (H3) sono stati sequenziati ed analizzati a partire dal
DNA genomico. Le sequenze hanno confermato la stretta relazione evolutiva tra la specie
indonesiana e la specie africana. Entrambi i geni sono stati usati per costruire alberi
filogenetici in cui i due celacanti, L. menadoensis e L. chalumnae, appaiono vicini ai
tetrapodi. Inoltre, al fine di rendere l’analisi più precisa anche l’H3 di Protopterus
aethiopicus (un pesce polmonato africano) e di Polypterus senegalus (bichir) sono stati
determinati.
Per comprendere meglio le relazioni tra Latimeria ed i tetrapodi, inoltre, sono state
valutate le sequenze di due specifici mRNA, la vitellogenina AB (precursore del vitello) e
DMRT1 (un fattore di trascrizione coinvolto nel differenziamento sessuale). Gli alberi
filogenetici di queste due parziali sequenze di mRNA mostrano ancora la stretta relazione
tra L. menadoensis ed i tetrapodi.
Le sequenze del celacanto fanno luce su caratteristiche utili per decifrare i genomi
dei tetrapodi fornendo al contempo un punto d’osservazione privilegiato per indagare la
storia evolutiva.Coelacanthiformes are living fossils that constitute the likely missing link between fishes and tetrapods. Nowadays, there have been identified only two extant species of coelacanths, the African one, Latimeria chalumnae, and the Indonesian species, Latimeria menadoensis. Two specimens of Latimeria menadoensis, a female and a male, recently captured in northern Sulawesi Sea (May 2007 and September 2009) were analyzed in a research collaboration between the Università Politecnica delle Marche and the University of Sam Ratulangi in Manado (Indonesia ). The DNA content (C-value) of Latimeria menadoensis measured by Flow Cytometry (3.47 pg/cell) is quite similar to the DNA content of Latimeria chalumnae previously reported. The DNA methylation was evaluated by High Performance Liquid Chromatography (HPLC): the percentage of cytosine methylated (5mC) was 1.25% and the percentage of GC was 41.8%. Latimeria menadoensis has a high C-value and a low methylation level respect to other fishes. 18S rDNA and histone (H3) genes were sequenced and analyzed from the genomic DNA. The sequences confirmed the close evolutive relationship between the Indonesian and the African species. Both the genes were used to build phylogenetic trees in which the two coelacanths, L. menadoensis and L. chalumnae, appear close to tetrapods. In order to set a more precise analysis, also the histone (H3) gene of Protopterus aethiopicus (an African lungfish) and Polypterus senegalus (Bichir) has been determined. To better understand the relationship between Latimeria and the tetrapods, two specific mRNA sequences, vitellogenin AB (the yolk precursor) and DMRT1 (a transcription factor involved in sexual differentiation), were also evaluated. The phylogenetic trees of these two partial mRNA sequences show again a close relationship of L. menadoensis to tetrapods. The coelacanth sequences shed light on characteristics that are useful for deciphering features of tetrapod genomes, and also provide a unique vantage point for viewing the evolutionary history.
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Svedberg, Stefan. "The impact of fossil and non-fossil energy consumption on economic growth : -Evidence from a pooled mean group analysis." Thesis, Umeå universitet, Nationalekonomi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-172393.
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This paper investigates the causal relationship between economic growth and fossil and nonfossil energy consumption while controlling for human and physical capital in a panel of 74 countries over 1990 to 2017. The global sample was divided into four categories according to the World Bank income classifications: low-income, lower-middle income, upper-middle income, and high-income. The purpose of the income level subsamples was to further analyze the role of the country’s income level in the nexus between energy consumption and economic growth. This paper uses panel unit root and cross-sectional independence testing and employs the Pooled Mean Group estimator. The main results in this paper reveal (1) bidirectional causality between fossil energy consumption and economic growth for the low income and lower-middle income countries; (2) unidirectional causality from economic growth to fossil energy consumption for the high income and upper-middle income countries. In terms of nonfossil energy consumption, the results are more mixed; there is (3) unidirectional causality from economic growth to non-fossil energy consumption for the low-income and upper-middle income countries; (4) bidirectional causality between non-fossil energy consumption and economic growth for the lower-middle income countries; and (5) unidirectional causality from non-fossil energy consumption to economic growth for the high-income countries. These results have several policy implications that are discussed.
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Paulus, Faydre L. "Determining the relations between canine crown height and root basal diameters and root length implications for the hominin fossil record /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4291.
Full textAbstract:
Thesis (M.A.) University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (May 20, 2007) Vita. Includes bibliographical references.
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Eriksson, Martin. "Investigating fossil fuel utilization and the potential of reducing fossil fuels for heating in companies : The case of Gävleborg County." Thesis, Högskolan i Gävle, Energisystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-22965.
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Fossil fuels constitute roughly 80 % of the world’s energy supply and of this amount oil makes up almost one third. The combustion of these fossil fuels leads to increasing levels of greenhouse gases, causing a warming of the earth through the so called greenhouse effect. Because of this, several environmental and energy goals have been established by both the European Union and Sweden. The purpose of this thesis was to investigate how the use of fossil fuels can be reduced in companies that use oil for heating, in Gävleborg County. The thesis was divided into four problems to be solved. First, the companies that fit this description was identified by contacting energy advisors at municipalities. The second task was to investigate how willing these companies were to change to some other form of heating, which meant creating and sending a survey to them. It was also investigated what other aspects can affect a companies’ decision making, both technical and behavioural. The technical aspects meant listing and discussing some of the technical difficulties that can hinder a company from changing heating technology. Behavioural aspects were investigated using the comments left on the survey as well as research on the topic of barriers and driving forces that can affect companies. The final task was to estimate the reduction in CO2 emissions that could be achieved. This was done with data for the companies that answered that they wanted to change to some other form of heating and assumption regarding to the amount of emissions from different fuels. It was found that 95 companies use oil in Gävleborg County and 26 of these companies answered the survey to some extent, although results were only based on 24 of these answers. On the question of whether companies could consider changing to a different heating system, the same number (nine) that said “yes” also said “no”. There were many reasons for a company not wanting to change. Technical difficulties might be proximity to district heating net, not being able to install heat pumps, lacking infrastructure for biomass supply or being too close to a densely populated area to use biomass. Even so, it was concluded that for every company there is a possible technical solution. Behavioural aspects were also found to be numerous. Some companies answered that their reason for not changing was not owning their working facility and seeing the heating need as being too low to justify an investment. The research collected stated that lack of time, lack of money and having other priorities are important barriers. Meaning that to help companies change heating system, financial aid should be given, for example in the form of subsidies and soft loans. It can also be important to provide consulting assistance and informing companies of energy related issues and the benefits of dealing with them. The other answers to the survey varied a lot. The amount of oil used varied from 5 MWh to over 125000 MWh. The companies could also consider changing to all the optional heating systems, though district heating and heat pump were the most chosen with eight each. Ten companies said that they needed consultation and the same number said that they didn’t need it. Ten companies also said that they needed investment support and eight said that they did not need it. It was estimated that greenhouse gas emissions could be lowered by approximately 28900 tons, for the companies that took part in the survey. Two companies could also consider installing solar heating and assuming that this replaces 20 % of the total heating demand, a further reduction of roughly 1030 tons of greenhouse gas emissions is achieved. Based on past research, it was concluded that it is possible to reduce the consumption of fossil fuels in a region or company. This might come in the form of lowering overall energy use or replacing oil with biofuels. The responses to the survey also show that there is some interest in the companies asked. Even though they might have answered that they did not want to change heating, they did at least answer the survey.
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Ando, Tatsuro, and n/a. "New Zealand fossil penguins : origin, pattern, and process." University of Otago. Department of Geology, 2007. http://adt.otago.ac.nz./public/adt-NZDU20080204.140701.
Full textAbstract:
Penguins are middle- to large-sized sea birds and are widely distributed in the Southern Hemisphere. They have completely lost the capability for the aerial flight, but are highly efficient wing-propelled swimmers and divers. They have a long fossil record over 60 million years, and their origin could possibly extend back to the late Cretaceous. This study aims to elaborate the course of penguin evolution and driving force of changes based on fossil records of penguins. Numerous fossil penguin specimens have been collected and studied from New Zealand, Antarctica, South America, Australia, and Africa. Studies on fossil penguins have spanned about 150 years history since Huxley (1859).
Previous works on fossil penguins have achieved excellent results, but at the same time, left considerable confusion on taxonomy and anatomical interpretation, mainly because of the poor nature of the penguin fossils in early studies. Examination of newly found materials and updated evaluation of previously studied materials are needed, using modern methods.
During about 150 years of fossil penguins study since Huxley1859, more than 40 genera and 70 species have been described. The number of specimens listed in the published literature amounts to more than 1300. Chapter II reviews all those fossil penguins in a summarised and consistent style, aiming to present the taxonomy used in this study as a primary and essential resource for research. The chapter also provides other information on fossil penguins, such as geological data and an assessment of the skeletal association of the specimens referred to a species.
Chapter III introduces the osteology of penguins, by describing and comparing the skeletal characteristics and variation of both extant and fossil species. Though previous works on penguins osteology are extensive, the interpretation of the homology, and resulted terminology, are occasionally inappropriate, or incorrect, because of the highly-specialised structure. Many of the new, yet undescribed, fossils prompt a comprehensive update of those previous studies, to understand the nature of morphological variation in penguins, and to correct or clarify confusion in previous works.
The New Zealand fossil penguin fauna is one of the most significant for fossil penguin studies, but there are many undescribed fossil penguin specimens. Chapter IV provides accounts of such materials. Chapter IV also reviews previously-described New Zealand fossil penguins, usually re-evaluated using new materials. This chapter includes reassessment of the controversial, first-described fossil penguin Palaeeudyptes antarcticus, description of an enigmatic new species (Pakudyptes hakataramea gen. et sp. nov.) which could elucidate the evolutionary pattern of the penguin wing, description of new materials of Platydyptes revealing a unique structure and functional interpretation, and redescriptions with functional interpretation of Pachydyptes and Archaeospheniscus.
Published relationships within penguins have not been adequately discussed but stated within rather rough frameworks, so that the relationships within penguins were unclear. Chapter V provides an explicit framework for the phylogeny of penguins. Osteology-based cladistic analysis was performed to seek out the relationships within penguins, using observations on both extant and fossil penguins. There are several important grades in penguin history, which are structurally distant from each other. Results also agree with the published views in which the extant penguins form a rigid group, but Simpson�s subfamily groupings are only partly supported. A postulated phylogenetic tree includes all known fossil penguin taxa including un-named ones.
Chapter VI, as a synthesis of contents of previous chapters, provides a broad interpretation of penguin evolution through the Cenozoic: origin, body size increase, demise of 'giant penguins', and the emergence of modern penguins. The chapter gives a global picture of the interaction of penguins, pinnipeds, cetaceans, and temperature and sea-level change. Two main sections are: 'Origin of penguins' and 'Evolutionary process of penguins.' The loss of aerial flight and increase of body size were possibly triggered by the K/T mass extinction event which drastically reduced the predatory pressure for early penguins. The 'giant penguins' survived until the Late Oligocene but declined as the oceans modernised, and new forms of whales with advanced feeding function appeared. There is controversy about appearance of modern penguins. The fossil-based hypothesis (relatively recent origin for crown-penguins) contradicts the molecular-based one (ancient origin for crown penguins), though 'hard evidence' at present does not easily refute either hypothesis.
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May, John R. (John Robert) 1978. "Sustainability of electricity generation using Australian fossil fuels." Monash University, Dept. of Chemical Engineering, 2003. http://arrow.monash.edu.au/hdl/1959.1/9537.
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Ou, Jenq-Jang. "The combustion of fossil and waste solid fuels." Thesis, Imperial College London, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308074.
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Long, Sarah Louise. "Aspects of cementation in recent and fossil Brachiopoda." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246325.
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Tarver, James Eric. "The importance of fossil taxa within macroevolutionary studies." Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.535484.
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Thomas, Ceri-Wyn. "Decoding the fossil record of early metazoan development." Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.546189.
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Gill, Fiona Luise. "Fossil cold seep communities in the Caribbean region." Thesis, University of Leeds, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417885.
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Wright, Joanna L. "Fossil terrestrial trackways : function, taphonomy and palaeoecological significance." Thesis, University of Bristol, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389379.
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