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Smith, Toby Russell. "Impact crater particulates : microscopic meteoritic material surrounding meteorite craters /." Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/5434.
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Karlsson, Paola. "How human are the Crakers? : A study about human identity in Margaret Atwood’s Oryx and Crake." Thesis, Linnéuniversitetet, Institutionen för språk och litteratur, SOL, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-13547.
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This essay has handled the subject of humanity in Oryx and Crake by Margaret Atwood. The aim of the thesis was to argue that the Crakers developed into human beings with help of their teachers. This was made by researching different aspects in humanity such as human identity, language, religion, life and death and how these traits of humanity were developed. The development of the Crakers’ identities has also been discussed with regards to teachers, teaching and the relation between power and knowledge meaning how the Crakers’ teachers helped them or tried to prevent them from growing into humans. The relation between power and knowledge shows how the teacher holds power over his pupils since he decides what he will teach them. The results revealed that the Crakers became as human as they could be without being born human through teaching and acquiring traits that are known to be human.
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Karlsson, Paola. "How human are the Crakers? : A study about human identity in Margaret Atwood's Oryx and Crake." Thesis, Linnéuniversitetet, Institutionen för språk och litteratur, SOL, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-13232.
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This essay has handled the subject of humanity in Oryx and Crake by Margaret Atwood. The aim of the thesis was to argue that the Crakers developed into human beings with help of their teachers. This was made by researching different aspects in humanity such as human identity, language, religion, life and death and how these traits of humanity were developed. The development of the Crakers‟ identities has also been discussed with regards to teachers, teaching and the relation between power and knowledge meaning how the Crakers‟ teachers helped them or tried to prevent them from growing into humans. The relation between power and knowledge shows how the teacher holds power over his pupils since he decides what he will teach them. The results revealed that the Crakers became as human as they could be without being born human through teaching and acquiring traits that are known to be human.
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Kukkonen, S. (Soile). "Small impact craters in crater counting:evolution studies of the eastern Hellas outflow channels, Mars." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526218779.
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Abstract Crater counting is a method which allows us to estimate the surface ages of the planetary bodies, from which the sampling and sample delivery to laboratories on Earth are difficult or impossible. Because the number of craters on a surface unit increases over the time the surface has been exposed to space, old, geologically stable units have more craters than young and active units. When the crater production rate as a function of time is known, the absolute age of the surface unit can be determined based on its crater density. The purpose of this thesis is to investigate the role of small impact craters in crater counts to find out how modern very high-resolution space images can be utilized in age determination of planetary surfaces. The thesis focuses on how reliable crater count based datings are, if only small craters and counting areas are used in age determination. The research is carried out by utilizing crater counts on the outflow channels of Dao, Niger, Harmakhis and Reull Valles, which all are located in the eastern rim region of the Hellas impact basin, on the southern hemisphere of Mars. Crater counts are performed mainly based on the images of ConTeXt Imager (CTX) and High Resolution Imaging Science Experiment (HiRISE) aboard Mars Reconnaissance Orbiter (MRO). The results show that small craters are a very valuable tool to get information about the surface age. Instead of the size-range of counted craters, or the size of counting areas, results are dependent on the variability and scale of the surface modification history. The more variable or larger scale the modification history is, the larger surface area and wider crater diameter range are typically needed to achieve comprehensive age estimations. The crater counts on the eastern Hellas outflow channels support the earlier theories according to which the valles formed during a relatively short time interval, ~ 3.4–3.7 Ga ago. The existence of terrace structures and smaller tributary channels indicate that the outflow channels were filled by several pulses of liquids. The major fluvial activity ended no later than ~ 0.8–1.9 Ga ago, and it was probably controlled by the activity of nearby highland volcanoes. Soon after the declined fluvial activity, the outflow channels were covered by ice-rich deposits. The major reason for this was probably the changed climatic conditions, although in places e.g. impact cratering seems to have contributed to the emplacement of the deposits. The region as a whole was also resurfaced several times because of changes in local climate conditions. The most significant of the resurfacing processes seem to be the episodes of thin ice-rich mantling deposits, the most recent of which dominated the regional modification less than 10 Ma ago. In addition, the region has experienced eolian activity during the last 1 MaOriginal papers The original publications are not included in the electronic version of the dissertation. Kostama, V.-P., Kukkonen, S., & Raitala, J. (2017). Resurfacing event observed in Morpheos basin (Eridania Planitia) and the implications to the formation and timing of Waikato and Reull Valles, Mars. Planetary and Space Science, 140, 35–48. https://doi.org/10.1016/j.pss.2017.04.001 Kukkonen, S., & Kostama, V.-P. (2018). Modification history of the Harmakhis Vallis outflow channel, Mars, based on CTX-scale photogeologic mapping and crater count dating. Icarus, 299, 46–67. https://doi.org/10.1016/j.icarus.2017.07.014 Kukkonen, S., & Kostama, V.-P. (2018). Usability of small impact craters on small surface areas in crater count dating: Analysing examples from the Harmakhis Vallis outflow channel, Mars. Icarus, 305, 33–49. https://doi.org/10.1016/j.icarus.2018.01.004 Kukkonen, S., & Kostama, V.-P. (2018). Mapping and dating based evolution studies of the Niger Vallis outflow channel, Mars. Planetary and Space Science, 153, 54–71. https://doi.org/10.1016/j.pss.2017.12.012 Korteniemi, J., & Kukkonen, S. (2018). Volcanic Structures Within Niger and Dao Valles, Mars, and Implications for Outflow Channel Evolution and Hellas Basin Rim Development. Geophysical Research Letters, 45(7), 2934–2944. https://doi.org/10.1002/2018gl077067 http://jultika.oulu.fi/Record/nbnfi-fe201902226008
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Rishmawi, Sima. "Tip-over stability analysis of crawler cranes in heavy lifting applications." Thesis, Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/55033.
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Cranes are often the most conspicuous machines on a construction site. This is due to their large size, in addition to the important role they have in transporting heavy payloads vertically and horizontally. There are two major families of construction cranes: tower cranes and mobile cranes. Mobile cranes that are mounted on tracks are a subgroup referred to as ``crawler cranes''. Crawler cranes are widely used on construction sites, and are a backbone of the United States construction industry, thus a detailed study of these cranes' behavior is essential. This research studies the tip-over stability of crawler cranes in heavy-lifting applications. Two major applications are discussed: crawler cranes using movable counterweights and crawler cranes in tandem lifting.
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Liu, Shaobin. "Characterization, geographic distribution, and number of upper Eocene impact ejecta layers and their correlations with source craters." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 15.46 Mb., 308 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3220787.
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Martellato, Elena. "THE IMPORTANCE OF BEING A CRATER: A TOOL IN PLANETARY SURFACE ANALYSIS AND DATATION." Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3425336.
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This PhD thesis has been realized within the project of STC/SIMBIOSYS, the stereo channel composing the imaging system on board of the BepiColombo mission to Mercury and providing the global mapping in stereo mode of the Hermean surface. As the aim of this work is supporting the definition of the scientific requirements of STC, the impact craters have been recognized as the surface structure to be investigated, being the most important and common landform of any planetary body with a solid surface, but meanwhile far to be yet completely understood.
This thesis addresses to explore the importance of impact crater structure as a tool in investigating a variety of aspects of planetary bodies, whose remote sensing data is the only available information. Earth as well can take advantage from studying such a rarely occurring, complicated and highly dynamic process, as the combining effects of erosion, tectonics and volcanism can hide impact structures.
The first theme turns to impact craters not as an individual entity, but as a population of features on planetary surfaces, in particular Mercury. The cratering records, being the result of a long–repeated meteorite bombardment history, can be used to infer surface age after the application of a chronological model to statistical analysis. The data recently acquired by the MESSENGER mission during its three flybys with this planet were the starting point to study two new basins, i.e. Raditladi and Rachmaninoff. The MPF chronological model has been adopted to derive the crater retention age for these basins, whose impact events turned out to occur well after the LHB, posing some puzzles to the current impactor sources in the inner Solar System. In addition, Rachmaninoff interior plains could be emplaced in a very recent period (360 Ma ago), suggesting a long–lasting volcanism up to recent time, and hence a revision to our current knowledge on the thermal state of the planet is proposed
The second theme of my thesis addresses the investigation of the impact formation process. The current understanding of impact cratering as a whole has come from a suite of experimental, morphological, analytical and numerical studies. However, shocks codes represent one of the only feasible methods for studying impact craters, as they can simulate a large span of conditions beyond the reach of experiments, in addition to analyze the individual effect of any parameters acting during the impact event.
I have used iSALE shock code to simulate two craters, coming from a completely different environment, the Earth and one asteroid, recently observed by a space mission. In the first case, the knowledge of the surrounding area where the structure is located allowed to study in detail the impact crater collapse mechanism that origins a large crater. On the other hand, the good relatively knowledge of the formation of a simple crater allowed to investigate the composition and the structure of the asteroid. In both cases, the numerical modelling of the impact process has demonstrated to be a powerful tool to deepen our comprehension on the Solar System.Questa tesi di dottorato è stata realizzata nell’ambito del progetto di STC/SIMBIOSYS, il canale stereo appartenente al sistema di imaging che a bordo della missione spaziale BepiColombo avrà l’obiettivo di fornire la mappatura globale della superficie di Mercurio in modalità stereo. Poiché lo scopo di questa tesi è di supportare la definizione dei requisiti scientifici della stereo camera, lo studio dei crateri da impatto è stato selezionato come argomento fondamentale. I crateri da impatto sono infatti la più importante e più diffusa morfologia su qualsiasi corpo planetario dotato di una superficie solida, ma allo stesso tempo non ancora completamente compresi. Questa tesi vuole esplorare l’importanza dei crateri da impatto come tool nell’investigazione di una varietà di aspetti riguardanti i corpi planetari, dei quali si hanno a disposizione solo un numero esiguo di informazioni. Tuttavia, anche nel caso della Terra, per la quale si possiede una grande quantità di dati, lo studio di questo processo altamente dinamico può portare ad una migliore conoscenza del nostro pianeta e delle forze che tutt’ora lo modellano. Il primo tema di questa tesi riguarda lo studio dei crateri da impatto non come un’entità singola, ma una popolazione di oggetti presenti sulle superfici planetarie, in particolare quella di Mercurio. La craterizzazione su di una superficie è il risultato di una lunga storia di bombardamento meteoritico, e può essere quindi usato per derivare l’età di quella superficie, se si applica un modello cronologico basato sull’analisi statistica dei crateri. I dati recentemente acquisiti dalla missione MESSENGER durante i suoi tre flyby con questo pianeta sono stati l’incipit per lo studio di due nuovi bacini, Raditladi e Rachmaninoff. Si è quindi adottato il modello cronologico MPF per derivare l’età in cui si sono formati questi due bacini. Il risultato di questa analisi è che entrambe le strutture si sono originate in un periodo successivo all’LHB, ponendo interrogativi sulle attuali sorgenti di impattori, considerando la notevole dimensione di queste due strutture d’impatto. Inoltre, le piane interne di Rachmaninoff potrebbero essere molto giovani (360 Ma fa), suggerendo un prolungato vulcanismo, e, a sua volta, una revisione delle nostre attuali conoscenze sullo stato termico di questo pianeta. Il secondo tema di questa tesi riguarda lo studio del processo di formazione di un impatto. La nostra attuale comprensione di un evento di impatto viene principalmente da studi sperimentali, morfologici, analitici e numerici. Tuttavia, gli shock code rappresentano l’unico procedimento che permette sia di esplorare condizioni non raggiungibili in laboratorio, sia di capire l’influenza di ciascuna variabile durante il processo di impatto. In questa testi, si è usato iSALE per simulare due crateri, provenienti da due ambienti molto diversi, il nostro pianeta e un asteroide recentemente osservato da una missione spaziale. Nel primo caso, la buona conoscenza della regione dove è collocato il cratere ha permesso di approfondire il meccanismo che sta alla base del collasso di un cratere di grandi dimensioni. Invece, nel secondo caso, era il processo di formazione ad essere meglio conosciuto, dal momento che si trattava di una struttura semplice, e quindi la simulazione numerica è stata finalizzata a investigare la possibile composizione e struttura superficiale di questo asteroide. In entrambi i casi, la modellizzazione numerica del processo di impatto si è dimostrato un capace tool per migliorare la nostra conoscenza del Sistema Solare.
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Cramer, Karla B. "Impact of constructivism via the biological sciences curriculum study (BSCS) 5E model on student science achievement and attitude." Montana State University, 2012. http://etd.lib.montana.edu/etd/2012/cramer/CramerK0812.pdf.
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The investigation involved implementing constructivist instruction via the Biological Sciences Curriculum Study 5E Instructional Model to determine its' impact on student achievement and attitude. The study included 68 seventh grade Life Science students of average to above average achievement at a community based K-12 school in Florence, Montana. Treatment was implemented during a six week biome unit in which student achievement was assessed through the Evaluation Association Measured Academic Progress and summative assessments. Student attitude was evaluated through the Test of Science Related Attitudes and learning preference surveys, pre- and post-treatment. The effectiveness of constructivism approach to instruction on achievement via the BSCS 5E Instructional Model in the science classroom was not conclusively supported by data.
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Silva, Dailto 1960. "A mobilidade dos elementos traço e geração de fusão félsica na crosta durante o impacto de meteoritos : implicações para a evolução da crosta hadeana." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287218.
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Orientadores: Carlos Roberto de Souza Filho, Cristiano de Carvalho LanaTese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociências
Made available in DSpace on 2018-08-23T13:22:26Z (GMT). No. of bitstreams: 1 Silva_Dailto_D.pdf: 6673922 bytes, checksum: ad586d69e4694b3e81cab5a383dfef3f (MD5) Previous issue date: 2013
Resumo: A pesquisa foi realizada na cratera de impacto de meteorito de Araguainha (Goiás / Mato Grosso, Brasil) e compreendeu três desenvolvimentos científicos principais. O primeiro engloba a petrografia e geoquímica de rochas graníticas parcialmente fundidas do núcleo da cratera de impacto. Foi possível separar, por petrografia e posicionamento geográfico, os litotipos do granito preservado (GP) dos litotipos de fusão (granito parcialmente fundido (GPF), veios de fusão (VF) e capa de fusão (CF)). Contudo, estes litotipos apresentam características geoquímicas muito semelhantes para elementos maiores, menores, traços e terras raras. O diagrama que se mostrou o melhor discriminante entre os litotipos de fusão e os granitos preservados foi o Th/U x TiO2, que indica enriquecimento relativo na razão Th/U nos granitos. O granito preservado é também rico em quartzo e apresenta empobrecimento em elementos como Ti, Zr, Ce, Y, Eu, Nb e elementos terras raras. Essas características permitem postular uma possível influência hidrotermal na geração dos litotipos de fusão. O segundo desenvolvimento aborda a mobilidade dos elementos traço e geração de fusões félsicas na crosta terrestre durante o impacto de meteoritos e implicações para a evolução da crosta Hadeana. Nesse caso, o processo de acresção crustal por impacto pode ser um mecanismo complementar, capaz de explicar uma importante modificação da crosta terrestre Hadeana ocorrida entre 3.9-4.5 Ga. O terceiro desenvolvimento trata dos efeitos do impacto na indução de fusão incongruente da crosta da Terra, tendo como base a fusão da biotita. O estudo mostrou que a biotita pré-impacto é distinta daquela pós-impacto, com texturas, estrutura e quimismo contrastantes. Demonstrou-se que até 9% do granito de Araguainha é produto de cristalização a partir da quebra da biotita. A biotita funde incongruentemente durante o processo de impacto, produzindo uma fusão aluminosa, que preenche bolsões e rede de fraturas nas rochas. Impactos do tamanho de Araguainha ou maiores são capazes de gerar volumes substanciais de fundidos aluminosos na crosta
Abstract: The focus of this PhD thesis is on granitic targets impacted by meteorites and felsic melting generation in the crust during impacts. Key features of the Araguainha impact crater (Goiás / Mato Grosso, Brazil) were employed as a control. Field, petrographic and analytical data collected in the study area were grouped into three, central scientific developments. The first comprises the petrography and geochemistry of partially melted granitic rocks observed in the core of the Araguainha crater. The work shows that it is possible to separate, by petrography and geographical positioning, preserved granite rocks from melt rock types, such as the partially melted granite (GPF), the melted veins (VF), and the melted caps (CF). These rock types have very similar geochemical characteristics regarding major, minor, trace and rare earth elements. However, melt rock types are readily discriminated from preserved granites in Th/U x TiO2 scatergrams; granites show relative enrichment in the ratio Th/U. Another noteworthy feature is that the preserved granite rich in quartz is depleted in Ti, Zr, Ce, Y, I, Nb and REE, indicating a possible influence of hydrothermal systems in the formation of melt products. The second development provides clues on the mobility of trace elements and generation of felsic melts in the crust during the meteorite impact, and implications for the evolution of the Hadean crust. It is argued that process of crustal accretion by impacts may have been one of the mechanisms that can explain important modification of the Earth's crust during the Hadean (3.9-4.5 Ga). The third development deals with the effects of shock-induced incongruent melting within Earth's crust, using the case of biotite melting. It was demonstrated that pre-impact and pos-impact biotites found in Araguainha show distinct textures, structures and chemistry. Results show that up to 9% of Araguainha granite is a product of magma crystallization from breakdown of biotite. The biotite melts incongruently during the impact process, producing an aluminous fusion, which fulfills pockets and fracture networks of the rocks. Impacts of the size of Araguainha or larger seem to be capable of generating substantial amounts of aluminous melt in the crust
Doutorado
Geologia e Recursos Naturais
Doutor em Ciências
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Vasconcelos, Marcos Alberto Rodrigues. "Caracterização geofísica da estrutura de impacto de Araguainha, MT/GO." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/14/14132/tde-17052007-105856/.
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Araguainha é a maior e mais bem exposta cratera complexa da América do Sul, formada em sedimentos horizontais da Bacia do Paraná. Sua portentosa estrutura com aproximados 40 km de diâmetro e 25 km de cavidade transiente revela um contraste negativo de densidade e susceptibilidade magnética na região do soerguimento central. Esta feição permite inferir um limite de propriedade física entre o Núcleo Central Soerguido (NCS) e o Embasamento Granítico Soerguido (EGS), que por sua vez apresenta baixa razão de Koenigsberger. A caracterização geofísica de Araguainha é sustentada por modelamento 2,5D com base em informações gravimétricas, aeromagnéticas e magnéticas terrestres, o que permite classificá-la como uma estrutura concêntrica e simétrica, com profundidade média do embasamento a 1,0 km, exceto para a borda sul, que apresenta soerguimento mais acentuado. A interface embasamento/sedimento é seccionada por pares espelhados de falhas radiais que surgem no estágio de modificação da cratera. Estas estruturas rúpteis conferem as maiores profundidades à região da bacia anelar e promovem constricção dos sedimentos com tensão horizontal radial. A observação e interpretação destas deformações permitem caracterizar Araguainha como uma estrutura de impacto de domínio rúptil-dúctil.Araguainha is the largest and the best-exposed complex crater of South America, formed in horizontal sediments of the Paraná Basin. Its portentous structure with 40 km in diameter and 25 km of transient cavity reveals a negative contrast of density and magnetic susceptibility in the central uplift. That feature allows to infer a limit of physical property between the uplifted central core and the uplifted granite basement, which shows a low Konigsberger?s ratio. The geophysical characterization of Araguainha is sustained by 2,5D modeling with gravity, aeromagnetic, and ground magnetic information and It allows to classify it as a concentric, symmetrical structure, with average basement depth of 1.0 km, except in the southern rim, that shows a bigger uplift. The basement/sediment interface is cut by specular pairs of radial faults that appears in the modification stage of the crater. These brittle structures are responsible for the biggest depths in the annular basin region, and they promote a sediment constriction with horizontal radial tension. The observation and interpretation of these deformations allow to characterize Araguainha as an impact brittle-ductile domain structure.
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Vaughan, Joshua Eric. "Dynamics and control of mobile cranes." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24736.
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Thesis (Ph.D.)--Mechanical Engineering, Georgia Institute of Technology, 2009.Committee Chair: William Singhose; Committee Member: John-Paul Clarke; Committee Member: Kok-Meng Lee; Committee Member: Patricio Vela; Committee Member: Rhett Mayor.
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Booth, Philip. "Cracker etiquette : stories from somebody's South." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001473.
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Vermeesch, Peggy Marie-Therese. "Geophysical modelling of the Chicxulub crater." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429105.
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Cramer, Katharina [Verfasser]. "Multivariate Ausreißer und Datentiefe / Katharina Cramer." Aachen : Shaker, 2003. http://d-nb.info/1179022327/34.
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De, Waal Arthur William. "Development of a crane load software application for electric driven overhead travelling bridge cranes in accordance with SANS 10160-6:2010." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6622.
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Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2011.ENGLISH ABSTRACT: Electric driven overhead travelling bridge cranes (EOHTC) form a vital part of industrial plants where heavy objects require moving. Overhead travelling cranes aid in production by allowing an uninterrupted work process on the ground while heavy loads are moved to their required locations. Various factors need consideration in determining the loads induced by an EOHTC on its support structure. In order to design such a support structure, the designer must understand and take into account the various loads that the support structure will be subject to during its lifetime. The procedure for determining the loads induced by the EOHTC on its support structure is laid out in the SANS 10160-6:2010 code of practice. This document was published in June 2010 and as a result very few worked examples exist to test the coherence of the procedure. This thesis presents an investigation into the procedure for determining the actions induced by overhead travelling bridge cranes adopted in the SANS 10160-6:2010 code of practice. The investigation was conducted by developing a software application to automatically determine the necessary crane actions needed for the design of the crane support structure, given certain input parameters. The motivation behind this was to have a tool that can calculate the crane induced loads automatically. And by developing such a tool the procedure given in the code of practice is better understood. The Java programming language was used to code the calculations with an object oriented programming approach (OOP). NetBeans, the integrated development environment for developing with Java was used to generate the required graphical user interface of the application. In addition, a Microsoft Excel calculation sheet was also developed for the purpose of comparison and verification. Whilst developing the software application, it was found that the model for the acceleration or deceleration of the crane was specific for four wheel cranes only. This model was then extended to accommodate eight and sixteen wheel cranes and incorporated into the algorithm architecture of the application. The application was successfully completed and verified using benchmarked examples.
AFRIKAANSE OPSOMMING: Elektriese oorhoofse brugkrane vorm ‘n belangrike deel van baie nywerheidsprosesse, waar dit gebruik word om swaar laste in die nywerheidsaanleg te verskuif. Oorhoofse brugkrane voeg waarde by die produksie lyn deur te sorg dat die werksproses op die grond onversteurd voortgaan terwyl swaar laste na hul vereiste posisies verskuif word. Verskillende faktore moet in ag geneem word om die nodige kraanlaste te bepaal. Hierdie laste word benodig om die kraan se ondersteuningstruktuur te ontwerp. Die ontwerper moet die nodige kundigheid hê en moet ook die verskeie laste in ag neem wat die ondersteuningstruktuur gedurende sy leeftyd sal dra. SANS 10160-6:2010 verskaf riglyne vir die bepaling van die laste wat deur oorhoofse brugkrane uitgeoefen word. Hierdie dokument is in Junie 2010 gepubliseer dus bestaan daar min uitgewerkte voorbeelde om die korrektheid van die riglyne te toets en toepassing te demonstreer. Hierdie proefskrif ondersoek die riglyne vir die bepaling van oorhoofse brugkraan aksies soos uiteengesit in die SANS 10160-6:2010. Die navorsing is uitgevoer deur middel van die ontwikkeling van ‘n sagteware toepassing wat die nodige oorhoofse brugkraanlaste automaties bepaal, gegee sekere invoer waardes. Die rede hiervoor was om ‘n hulpmiddel te ontwikkel vir die outomatiese bepaling van oorhoofse brugkraan. Deur die bogenoemde hulpmiddel te ontwikkel word die riglyne, soos gegee in die kode beter verstaan. Java is gebruik as programmeringstaal waar die objek geörienteerde programeringstyl toegepas was. Die geintegreerde ontwikkelingsomgewing vir ontwikkeling met Java, naamlik NetBeans is gebruik om die nodige gebruikers koppelvlak op te bou. ‘n Microsoft Excel sigblad is ook ontwikkel vir kontrolerings doeleindes. Gedurende die ontwikkeling van die sagtewarepakket is dit bevind dat die lasmodel vir die versnelling of vertraging van die oorhoofse brugkraan slegs op vierwiel krane van toepasing is. Hierdie lasmodel is dus uitgebrei om agt- en sestienwiel krane ook te bevat. Die lasmodel aanpassing is dan ook in die program se algoritme-argitektuur ingebou. Die sagteware toepassing is suksesvol ontwikkel en gekontroleer met ‘n maatstaf voorbeeld.
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Murata-Seibt, Hiromi [Verfasser], Johannes [Akademischer Betreuer] Cramer, Manfred [Akademischer Betreuer] Speidel, Johannes [Gutachter] Cramer, and Manfred [Gutachter] Speidel. "Die Entwicklung der japanischen Kunstmuseumsarchitektur / Hiromi Murata-Seibt ; Gutachter: Johannes Cramer, Manfred Speidel ; Johannes Cramer, Manfred Speidel." Berlin : Technische Universität Berlin, 2019. http://d-nb.info/1192370600/34.
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Wu, Rui. "Integration of Orbital and Ground Data for Martian Crater Mapping: A Methodological Study at Santa Maria Crater." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1345439055.
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Nayfeh, Nader Ali. "Adaptation of Delayed Position Feedback to the Reduction of Sway of Container Cranes." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/9698.
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Cranes are increasingly used in transportation and construction. increasing demand and faster requirements necessitate better and more efficient controllers to guarantee fast turn-around time and to meet safety requirements. Container cranes are used extensively in ship-to-port and port-to-ship transfer operations.
In this work, we will extend the recently developed delayed position feedback controller to container cranes. In contrast with traditional work, which models a crane as a simple pendulum consisting of a hoisting cable and a lumped mass at its end, we have modeled the crane as a four-bar mechanism.
The actual configuration of the hoisting mechanism is significantly different from a simple pendulum. It consists typically of a set of four hoisting cables attached to four different points on the trolley and to four points on a spreader bar. The spreader bar is used to lift the containers. Therefore, the dynamics of hoisting assemblies of large container cranes are different from that of a simple pendulum. We found that a controller which treats the system as a four-bar mechanism has an improved response.
We developed a controller to meet the following requirements: traverse an 80-ton payload 50 m in 21.5 s, including raising the payload 15 m at the beginning and lowering the payload 15 m at the end of motion, while reducing the sway to 50 mm within 5.0 s at the end of the transfer maneuver. The performance of the controller has been demonstrated theoretically using numerical simulation. Moreover, the performance of the controller has been demonstrated experimentally using a 1/10th scale model. For the 1/10th scale model, the requirements translate into: traverse an 80 kg payload 5 m in 6.8 s, including raising 1.5 m at the beginning and lowering 1.5 m at the end of motion, while reducing the sway to 5 mm in under 1.6 s. The experiments validated the controller.Master of Science
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Oevermann, Heike [Verfasser], Hans-Rudolf [Akademischer Betreuer] Meier, Johannes [Akademischer Betreuer] Cramer, Hans-Rudolf [Gutachter] Meier, and Johannes [Gutachter] Cramer. "Historische Industriekomplexe in der Stadt / Heike Oevermann ; Gutachter: Hans-Rudolf Meier, Johannes Cramer ; Hans-Rudolf Meier, Johannes Cramer." Weimar : Bauhaus-Universität Weimar, 2020. http://d-nb.info/1226371779/34.
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Ak, Aykagan. "Berth and quay crane scheduling problems, models and solution methods /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26652.
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Thesis (Ph.D)--Industrial and Systems Engineering, Georgia Institute of Technology, 2009.Committee Chair: Erera, Alan L.; Committee Member: Ergun, Ozlem; Committee Member: Savelsbergh, Martin; Committee Member: Tetali, Prasad; Committee Member: White III, Chelsea C.. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Helde, Andreas. "Noncommutative Gröbner bases in Polly Cracker cryptosystems." Thesis, Norwegian University of Science and Technology, Department of Mathematical Sciences, 2009. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9928.
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We present the noncommutative version of the Polly Cracker cryptosystem, which is more promising than the commutative version. This is partly because many of the ideals in a free (noncommutative) algebra have an infinite Gröbner basis, which can be used as the public key in the cryptosystem. We start with a short brief of the commutative case which ends with the conclusion that the existence of "intelligent" linear algebra attacks ensures that such cryptosystems are left insecure. Further, we see that it is hard to prove that noncommutative ideals have an infinite reduced Gröbner basis for all admissible orders. Nevertheless, in chapter 4 we consider some ideals for which it seems infeasible to realize a finite Gröbner basis. These are considered further in a cryptographic setting, and there will be shown that one class of ideals seems more promising than the others with respect to encountering attacks on the cryptosystem. In fact, at the end of this thesis we are proposing a way of constructing a cryptosystem based on this class of ideals, such that any linear algebra attack will not be successful. However, many of the results are on experimental level, so there remains a serious amount of research in order to conclude that we have found a secure cryptosystem.
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Collins, Gareth S. "Numerical modelling of large impact crater collapse." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414838.
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Davies, Heather Louise. "Quaternary palaeolimnology of a Mexican crater lake." Thesis, Kingston University, 1995. http://eprints.kingston.ac.uk/20583/.
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La Piscina de Yuriria is a small (0.75 Km2), hydrologically closed crater lake situated in the Neovolcanic Axis of Central Mexico (20013'N, 100008'W, 1740m a.s.l.). The water level has fluctuated markedly over the last decade and, at present, has a chemical composition of Na-C03-CI type. It represents a highly evolved water body modified by evaporative concentration and dissolution of the salt crust produced during desiccation in 1987. Water reappeared in the basin during 1991 and was very shallow and anoxic. The lake basin is known to have been occupied by man since -3,100 yr BP and so provides an excellent opportunity to examine the nature and relative importance of anthropogenic disturbance and naturally induced climatic change. The record for a single 14.3m core (YC2) from La Piscina de Yuriria extends back -26,600 yr BP with the dating control provided by 16 radiocarbon dates. The project used a variety of techniques to reconstruct the palaeolimnology of the lake including: (i) ostracods; faunal assemblage analyses; trace-element and stable oxygen and carbon isotope analyses; (ii) Sedimentological analyses; mineralogical analyses; grain-size analyses; X-Ray diffraction; stable oxygen and carbonisotope analyses of fine-grained carbonate; Laser ablation lCP-MS; (iii) Sediment geochemistry. A number of moist and dry phases have been identified, through the core, which are controlled primarily by variations in precipitation/evaporation (PIE) ratios over La Piscina de Yuriria. A number of periods of catchment disturbance have also been identified which occured under both moist and dry conditions. The base of the core (-26,600 yr BP) reflects the most arid phase with stable conditions within the catchment. At 25,000 yr BP freshwater flowed into a salt filled basin with a second phase of moist conditions at 22,200 yr BP. The onset of drier conditions at 20,000 yr BP resulted in a pronounced phase of catchment erosion. The dry period continued and intensified between 19,000 and 14,700 yr BP. During this period two wet events were identified at 17,000 and 15,000 yr BP. Dry conditions resumed between -12,100 and 11,500 yr BP and were then replaced by moist conditions. Between -12,000 and -7,000 yr BP conditions appeared to be generally unstable, alternating between dry and wet phases. Between 8,000 and -3,000 yr BP conditions were more moist. A short-lived dry event occurred at -3,300 yr BP, which resulted in renewed catchment disturbance. Dry conditions were identified between-2,500 yr BP and -900 yr BP where a short-lived wet event produced: stable catchment conditions. Catchment disturbance resumed and continued toward the top of the core reflecting slightly drier conditions than during the moist event. The record is dominated by a strong climatic signal which does not appear to have been masked by anthropogenic effects during the last 3,100 yr BP. Comparison of the events identified in the core, with other sites within the Neotropics, suggests that many of the climatic changes occurred on a regional scale.
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Wallis, David. "Modelling impact crater morphology with orthogonal polynomials." Thesis, University of Kent, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342267.
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Weston, Peter. "Tar destruction in a Coandă tar cracker." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/8241/.
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Increasing the utilisation of bioenergy systems has the potential to become a vital component in the struggle to maintain and fulfil global energy demands. In particular, biomass gasification can offer a solution to the ‘Energy Trilemma’, and provide an affordable, reliable and carbon neutral technology. The limiting factor hampering the progression of biomass gasification power plants is tar. Tars formed during the thermal breakdown of biomass, condense and foul downstream equipment, causing reliability issues and damaging energy conversion equipment, such as engines and turbines. Treating tar through partial oxidation offers tar destruction without waste and soot, as well as maintaining the heating value of the tar in the producer gas. Coandă burners which are fuelled by more conventional fuels have been proven to operate close to, and below, stoichiometric conditions; as such, these devices were prime for further investigation. The main objective of this research project was to develop a small-scale system which utilises a novel Coandă burner for tar destruction. An experimental rig consisting of a wood pellet pyrolyser, which produced a gas loaded with tar, and a Coandă tar cracker, was designed, constructed and operated in order to determine the effectiveness of the process, with respect to tar reduction. The principal experimental program was divided into two phases, so that comparisons of the tar composition, before and after treatment, could be formed. In the first experimental phase, wood pellets were pyrolysed at a range of temperatures between 500 and 800ºC. The pyrolysis products (gas, tar and char) were analysed. As the pyrolysis temperature increased from 500 to 800ºC there was a decrease in the yield of gravimetric tar in the sampled gas from 78.59 to 16.55 g/Nm3. In the second phase the tarry gas was treated by the Coandă tar cracker. The Coandă tar cracker was shown to be effective at significantly reducing the tar content in the product gas. The yield of key tar components in the treated gas was reduced for all tested pyrolysis temperatures. For example; when the pyrolysis temperature was 800ºC; the yields of benzene, toluene and naphthalene were reduced by over 90% and the gravimetric tar yield by 88%. The success of the tar cracker can be attributed to the high flame temperature (>1000ºC) and the addition of oxygen which leads to the production of a greater proportion of radicals in the flame which initiate tar destruction reactions.
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Perälä, Jesper. "Pit Craters of Arsia Mons Volcano, Mars, and Their Relation to Regional Volcano-tectonism." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-255563.
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Pit crater and pit crater chains associated to the volcano Arsia Mons on Mars have been mapped to analyse their spatial pattern and to conclude about their formation. For the mapping, high resolution satellite data gathered during the Mars Express mission were used. The spatial distribution of the pit craters was then compared with typical patterns of magmatic sheet intrusions within volcanoes as they are known from Earth. The results show that the pattern of the mapped pit craters and pit crater chains are in good agreement with these sheet intrusions and are therefore likely related to Martian sheet intrusions.Kollapskratrar och kraterkedjor relaterade till vulkanen Arsia Mons på Mars har karterats för att analysera deras spatiala mönster och för att komma till slutsatser för deras tillblivelse. Högupplösta satellitbilder tagna av Mars Express-sonden har använts för karteringen. Fördelningen av de karterade kraterkedjorna jämfördes med typiska fördelningar av magmatiska gångbergarter från vulkaner på jorden. Resultaten visar att fördelningen av kollapskratrar och kraterkedjor överensstämmer enligt förväntningarna och påvisar en relation mellan kollapskratrar och magmatiska gångbergarter på Mars.
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Fujioka, Daichi. "Tip-over stability analysis for mobile boom cranes with single- and double-pendulum payloads." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37162.
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This thesis investigated a tip-over stability of mobile boom cranes with swinging payloads. Base and crane motion presents a tip-over problem. Attaching complex payloads further complicates the problem. They study began with a single-pendulum payload to analyze a tip-over stability characteristics under different conditions. A simple tip-over prediction model was developed with a goal of limiting a computational cost to a minimum. The stability was characterized by a tip-over stability margin method. The crane's tip-over stability was also represented by the maximum possible payload it can carry throughout the workspace. In a static stability analysis, mobile boom crane was assumed to be stationary, thus with no payload swing. The study provided basic understanding on the relationship between tip-over stability and boom configuration. In a pseudo-dynamic stability analysis, the method incorporated payload swing into the analysis by adding estimated maximum payload swing due to motions. To estimate the angles, differential equations of motions of payload swings were derived. The thesis extended the study to a double-pendulum payload. The maximum swing angles estimated in the single-pendulum case were directly applied to the double-pendulum case. To validate the analytical methods, a full dynamic multi-body simulation model of a mobile boom crane was developed. The predictions from the previous analysis were verified by the simulation results. The prediction model and the analytical methods in the thesis provide a significant tool for practical application of tip-over stability analysis on mobile boom cranes. The experimental results increase the confidence of the study's accuracy.
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Nasr, Imen. "Algorithmes et Bornes minimales pour la Synchronisation Temporelle à Haute Performance : Application à l’internet des objets corporels." Electronic Thesis or Diss., Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLY007.
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La synchronisation temporelle est la première opération effectuée par le démodulateur. Elle permet d'assurer que les échantillons transmis aux processus de démodulation puissent réaliser un taux d'erreurs binaires le plus faible.Dans cette thèse, nous proposons l'étude d'algorithmes innovants de synchronisation temporelle à haute performance.D'abord, nous avons proposé des algorithmes exploitant l'information souple du décodeur en plus du signal reçu afin d'améliorer l'estimation aveugle d'un retard temporel supposé constant sur la durée d'observation.Ensuite, nous avons proposé un algorithme original basé sur la synchronisation par lissage à faible complexité.Cette étape a consisté à proposer une technique opérant dans un contexte hors ligne, permettant l'estimation d'un retard aléatoire variable dans le temps via les boucles d'aller-retour sur plusieurs itération. Les performances d'un tel estimateur dépassent celles des algorithmes traditionnels.Afin d'évaluer la pertinence de tous les estimateurs proposés, pour des retards déterministe et aléatoire, nous avons évalué et comparé leurs performances à des bornes de Cramèr-Rao que nous avons développées pour ce cadre. Enfin, nous avons évalué les algorithmes proposés sur des signaux WBANTime synchronization is the first function performed by the demodulator. It ensures that the samples transmitted to the demodulation processes allow to achieve the lowest bit error rate.In this thesis we propose the study of innovative algorithms for high performance time synchronization.First, we propose algorithms exploiting the soft information from the decoder in addition to the received signal to improve the blind estimation of the time delay. Next, we develop an original algorithm based on low complexity smoothing synchronization techniques. This step consisted in proposing a technique operating in an off-line context, making it possible to estimate a random delay that varies over time on several iterations via Forward- Backward loops. The performance of such estimators exceeds that of traditional algorithms. In order to evaluate the relevance of all the proposed estimators, for deterministic and random delays, we evaluated and compared their performance to Cramer-Rao bounds that we developed within these frameworks. We, finally, evaluated the proposed algorithms on WBAN signals
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Wimmel, Robin [Verfasser], Johannes [Akademischer Betreuer] Cramer, Johannes [Gutachter] Cramer, and Klaus [Gutachter] Kreiser. "Architektur osmanischer Karawanseraien : Stationen des Fernverkehrs im Osmanischen Reich / Robin Wimmel ; Gutachter: Johannes Cramer, Klaus Kreiser ; Betreuer: Johannes Cramer." Berlin : Technische Universität Berlin, 2016. http://d-nb.info/1156183898/34.
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Gressel, Saskia [Verfasser], Patrick [Akademischer Betreuer] Cramer, Patrick [Gutachter] Cramer, and Markus [Gutachter] Bohnsack. "Multi-omics analysis of transcription kinetics in human cells / Saskia Gressel ; Gutachter: Patrick Cramer, Markus Bohnsack ; Betreuer: Patrick Cramer." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://d-nb.info/1209738465/34.
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Chee, Yenlai. "Remote sensing analysis of cratered surfaces Mars landing hazard assessment, comparison to terrestrial crater analogs, and Mars crater dating models /." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2007. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Pacioni, Giorgio. "Materia oscura nella galassia nana sferoidale Crater 2." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13796/.
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Le galassie nane sferoidali sono tipi di galassie peculiari sia a livello strutturale, avendo una complessa popolazione stellare di cui risulta ancora difficile delineare le fasi evolutive, sia per quanto riguarda le proprietà cinematiche. In particolare dagli studi effettuati sulla loro dispersione di velocità lungo la linea di vista (σ_los ), tali galassie sembrano essere caratterizzate dalla presenza di massicci aloni di materia oscura.
Nel contesto delle galassie nane sferoidali, Crater 2 rappresenta per il momento un unicum. Sebbene si conoscano dSphs di dimensioni simili, nessuna di loro presenta una luminosità così debole, e una σ_los così bassa, come quelle mostrate da Crater 2.
In questa tesi è stato costruito un modello per studiare la distribuzione di materia oscura in un sistema non collisionale in equilibrio dinamico, mediante l’analisi di Jeans per sistemi a simmetria sferica, ed è stato applicato a Crater 2 (limitandosi al caso isotropo).
La risoluzione delle equazioni di Jeans a simmetria sferica ha richiesto la scrittura di un codice in C++, e per testarne l’efficienza `e stato applicato al caso della sfera di Hernquist isotropa. Da questo test è emerso che il
programma è in grado di riprodurre il profilo di σ_los discostandosi dal profilo analitico con un errore del tutto trascurabile, il che conferma l’affidabilità del codice. Per Crater 2 sono stati scelti un profilo di Plummer per descrivere la distribuzione spaziale stellare. Si è assunto che il potenziale gravitazionale sia generato da un alone di materia oscura sferico per cui sono stati adottati il profilo NFW e profili con core a tripla legge di potenza. In entrambi i casi si ottengono buoni fit della σ_los. Inoltre è stato mostrato come la materia oscura sia nettamente dominante sulla quantità di massa deducibile dalla luminosità misurata di Crater 2, a qualunque raggio, assumendo un rapporto massa-luminosità tipico per le popolazioni stellari delle galassie nane sferoidali.
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Leven, William Franklin. "Approximate Cramer-Rao Bounds for Multiple Target Tracking." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10507.
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The main objective of this dissertation is to develop mean-squared error performance predictions for multiple target tracking. Envisioned as an approximate Cramer-Rao lower bound, these performance predictions allow a tracking system designer to
quickly and efficiently predict the general performance trends of a tracking system.
The symmetric measurement equation (SME) approach to multiple target tracking
(MTT) lies at the heart of our method. The SME approach, developed by Kamen
et al., offers a unique solution to the data association problem. Rather than deal directly with this problem, the SME approach transforms it into a nonlinear estimation
problem. In this way, the SME approach sidesteps report-to-track associations.
Developing performance predictions using the SME approach requires work in several areas: (1) extending SME tracking theory, (2) developing nonlinear filters for SME tracking, and (3) understanding techniques for computing Cramer-Rao error bounds in nonlinear filtering. First, on the SME front, we extend SME tracking theory by deriving a new set of SME equations for motion in two dimensions. We also develop
the first realistic and efficient method for SME tracking in three dimensions. Second,
we apply, for the first time, the unscented Kalman filter (UKF) and the particle filter
to SME tracking. Using Taylor series analysis, we show how different SME implementations affect the performance of the EKF and UKF and show how Kalman filtering degrades for the SME approach as the number of targets rises. Third, we explore the Cramer-Rao lower bound (CRLB) and the posterior Cramer-Rao lower bound (PCRB)
for computing MTT error predictions using the SME. We show how to compute performance predictions for multiple target tracking using the PCRB, as well as address confusion in the tracking community about the proper interpretation of the PCRB for tracking scenarios.
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Dolan, Daniel J. "Structural Evolution of Martin Crater Thaumasia Planum, Mars." Thesis, California State University, Long Beach, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10606452.
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A detailed structural map of the central uplift of Martin Crater in western Thaumasia Planum, Mars, reveals highly folded and fractured geology throughout the 15-km diameter uplift. The stratigraphy in the central uplift of the crater has been rotated to near vertical dip and imaged by high-definition cameras aboard the Mars Reconnaissance Orbiter (MRO). These unique factors allow individual geologic beds in Martin Crater to be studied and located across the length of the uplift.
Bedding in Martin Crater primarily strikes SSE-NNW and dips near vertically. Many units are separated by a highly complex series of linear faults, creating megablocks of uplifted material. Faulting is dominantly left-slip in surface expression and strikes SW-NE, roughly perpendicular to bedding, and major fold axes plunge toward the SW. Coupled with infrared imagery of the ejecta blanket, which shows an “exclusion zone” northeast of the crater, these structural indicators provide strong support for a low-angle impactor (approximately 10–20°) originating from the northeast.
Acoustic fluidization is the prevailing theoretical model put forth to explain complex crater uplift. The theory predicts that uplifted megablocks in craters are small, discrete, separated and highly randomized in orientation. However, megablocks in Martin Crater are tightly interlocked and often continuous in lithology across several kilometers. Thus, the model of acoustic fluidization, as it is currently formulated, does not appear to be supported by the structural evidence found in Martin Crater.
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Wearne, Olivia, and oliviawearne@hotmail com. "Crater Lake: A Study of the Monster Within." RMIT University. Creative Media, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20081209.160136.
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Mills, Keely. "Ugandan crater lakes : limnology, palaeolimnology and palaeoenvironmental history." Thesis, Loughborough University, 2009. https://dspace.lboro.ac.uk/2134/13219.
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This thesis presents the results of contemporary limnological and palaeolimnological investigations of a series of crater lakes in order to reconstruct the palaeoenvironmental history of western Uganda, East Africa. The research examines questions of spatial and temporal heterogeneity of climate changes in the context of growing human impacts on the landscape over the last millennium. Sediment records from two lakes, Nyamogusingiri and Kyasanduka within the Queen Elizabeth National Park (QENP) were investigated to look at the long term records of climate and environmental change (spanning the last c. 1000 years). Five shorter cores across a land-use gradient were retrieved to assess the impact of human activity on the palaeoenvironmental record over the last ~150 years. High-resolution (sub-decadal), multiproxy analyses of lake sediment cores based on diatoms, bulk geochemistry (C/N and δ13C) and sedimentary variables (loss-on-ignition, magnetic properties and physical properties) provide independent lines of evidence that allow the reconstruction of past climate and environmental changes. This multiproxy approach provides a powerful means to reconstruct past environments, whilst the multi-lake approach assists in the identification and separation of local (e.g. catchment-scale modifications and groundwater influences) and regional effects (e.g. climatic changes). The results of a modern limnological survey of 24 lakes were used in conjunction with diatom surface sediment samples (and corresponding water chemistry) from 64 lakes across a natural conductivity gradient in western Uganda (reflecting a regional climatic gradient of effective moisture) to explore factors controlling diatom distribution. The relationships between water chemistry and diatom distributions were explored using canonical correspondence analysis (CCA) and partial CCA. Variance partitioning indicated that conductivity accounted for a significant and independent portion of this variation. A transfer function was developed for conductivity (r2jack = 0.74). Prediction errors, estimated using jack-knifing, are low for the conductivity model (0.256 log units). The final model was applied to the core sediment data.This study highlights the potential for diatom-based quantitative palaeoenvironmental reconstructions from the crater lakes in western Uganda. Sedimentary archives from the Ugandan crater lakes can provide high-resolution, annual to sub-decadal records of environmental change. Whilst all of the lakes studied here demonstrate an individualistic response to external (e.g. climatic) drivers, the broad patterns observed in Uganda and across East Africa suggest that the crater lakes are indeed sensitive to climatic perturbations such as a dry Mediaeval Warm Period (MWP; AD 1000-1200) and a relatively drier climate during the main phase of the Little Ice Age (LIA; c. AD 1500-1800); though lake levels in western Uganda do fluctuate, with a high stand c. AD 1575-1600). The general trends support the hypothesis of an east to west (wet to dry) gradient across East Africa during the LIA, however, the relationship breaks down and is more complex towards the end of the LIA (c. AD 1700-1750) when the inferred changes in lake levels at Nyamogusingiri and Kyasanduka are synchronous with changes observed at Lakes Naivasha (Kenya) and Victoria and diverge from local lake level records (from Edward, Kasenda and Wandakara). Significant changes in the lake ecosystems have occurred over the last 50-75 years, with major shifts in diatom assemblages to benthic-dominated systems and an inferred increase in nutrient levels. These changes are coincident with large sediment influx to the lakes, perhaps as a result of increasing human activity within many of the lake catchments.
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Martins, Luciana Moreira. "Análise do transcriptoma de Podalia orsilochus (Cramer, 1775)." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-26082016-103637/.
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Os insetos são capazes de sobreviver em diversos ecossistemas do planeta e, mesmo estando constantemente expostos à ameaça de infecção microbiana, permanecem livres de infecções na maior parte do tempo. Essa capacidade de sobrevivência aliada à larga distribuição dos insetos em regiões totalmente diferentes tem estimulado a pesquisa de novos agentes terapêuticos nesta classe devido à descoberta de diversos componentes de mecanismos inespecíficos de combate à infecção, sendo possível sua aplicação no controle de diversas doenças. Todavia, apesar de um grande número de moléculas de defesa ter sido identificado a partir de vários insetos, pouca informação sobre suas aplicações está disponível. Desta forma, o presente trabalho elucida o perfil transcriptômico geral e dos genes de defesa do tegumento de Podalia orsilochus durante sua fase larval. Como consequência, os transcritos e os dados obtidos permitirão o auxílio em pesquisas posteriores, seja para comparação, citação, conhecimento biológico e das respostas de defesa ou das relações de filogenia do animal.The insects are able to survive in diverse ecosystems on earth, and even being constantly exposed to the threat of microbial infections, remain free of infection for most of the time. This survivability combined with the wide distribution of insects in totally different regions has stimulated the search for new therapeutic agents in this class due to the discovery of several components of nonspecific mechanisms to fight infection, and possible implementation in the control of various diseases. However, despite a large number of defense molecules have been identified from various insects, little information is available on their applications. Thus, this paper elucidates the general transcriptomic profile and integument of defense gene Podalia orsilochus during their larval stage. As a result, the transcripts and the data obtained will aid in further research, to compare, reference, biological knowledge and defense or animal phylogeny relationships.
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Rai, Tapan S. "Infinite Groebner Bases And Noncommutative Polly Cracker Cryptosystems." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/26504.
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We develop a public key cryptosystem whose security is based on the intractability of the ideal membership problem for a noncommutative algebra over a finite field. We show that this system, which is the noncommutative analogue of the Polly Cracker cryptosystem, is more secure than the commutative version. This is due to the fact that there are a number of ideals of noncommutative algebras (over finite fields) that have infinite reduced Groebner bases, and can be used to generate a public key. We present classes of such ideals and prove that they do not have a finite Groebner basis under any admissible order. We also examine various techniques to realize finite Groebner bases, in order to determine whether these ideals can be used effectively in the design of a public key cryptosystem.
We then show how some of these classes of ideals, which have infinite reduced Groebner bases, can be used to design a public key cryptosystem. We also study various techniques of encryption. Finally, we study techniques of cryptanalysis that may be used to attack the cryptosystems that we present. We show how poorly constructed public keys can in fact, reveal the private key, and discuss techniques to design public keys that adequately conceal the private key. We also show how linear algebra can be used in ciphertext attacks and present a technique to overcome such attacks. This is different from the commutative version of the Polly Cracker cryptosystem, which is believed to be susceptible to "intelligent" linear algebra attacks.Ph. D.
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Harvey, Samuel Vernon. "Thermal History of the Chesapeake Bay Impact Crater." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/9980.
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Anomalously high groundwater salinities exist within the syn-impact sediment of the Chesapeake Bay impact crater, including an unexplained brine. This brine may be the result of phase-separation of seawater that occurred within the syn-impact sediments as underlying deformed and possibly melted basement rock cooled following impact. The 85 km wide crater has been described as a complex peak-ring crater; created 35.8 million years ago in the then submerged unconsolidated sediments of the Atlantic Coastal Plain and now completely buried by post-impact sediments. An annular trough with relatively undisturbed basement surrounds a ~38 km diameter inner basin with a peak ring and central uplift. The basement surface within the inner basin was modified by the impact and is projected to be approximately 1.6 km below sea level.
Geothermometry and advective and conductive heat flow modeling was performed to characterize a possible post-impact hydrothermal system. Thermal maturity and radiogenic techniques were used to estimate the temperature history of the crater sediments. Core samples from one borehole just outside the crater, two within the annular trough, and one shallow borehole within the inner basin were examined. Numerical heat and fluid flow models were developed using a range of likely sediment parameters and basal heat flow values to determine if phase-separation temperatures were likely to have occurred, and to evaluate what affect, if any, lithostatic overpressures may have had on post-impact cooling.
Geothermometry results indicate that no detectable thermal anomaly exists within the syn or post-impact sediments at these boreholes; however, no data are available within the deep inner basin where temperatures were likely to have been higher. Samples from existing boreholes suggest that sediment are organically immature and likely were never heated above ~40°C for a geologically significant period of time. These results support apatite He (U/Th) and previously published apatite fission track radiogenic ages indicating no Cenozoic resetting. Heat flow simulations indicate that a high temperature (>400°C) hydrothermal system could have existed within the inner basin and not caused any measurable effect on thermal maturity in the annular trough and shallow portion of the inner basin. Results also indicate that phase-separation could have occurred in the syn-impact sediments using reasonable estimates of basal heat flow, permeability, thermal conductivity, and porosity values, and that overpressures resulting from rapid deposition of syn-impact sediments dissipate within a few thousand years and are not an important heat transport mechanism.Master of Science
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Gustafsson, Jacob. "Impactites from the Hiawatha crater, North-West Greenland." Thesis, Stockholms universitet, Institutionen för geologiska vetenskaper, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-187412.
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The recent discovery of the 31-km-wide Hiawatha impact crater has raised unanswered questions about its age, impactor and highly unusual organic carbon component. Previous research suggests a fractionated iron meteorite impactor, a probable maximum 3–2.4 Ma impact age and a possible Younger Dryas impact age. The first objective in this study has been to investigate a possible link between the Cape York meteorites and the Hiawatha impact crater by comparing the chromium isotopic signature in chromite from a Cape York meteorite with the chromium isotopic signature in potential chromite from the Hiawatha impactor. The second objective has been to investigate a possible Hiawatha signature in the Younger Dryas deposits from Baffin Bay. The third objective has been to study the organic carbon component in impactites derived from the Hiawatha impact crater. Heavy mineral grains were separated from glaciofluvial sediment which contains Hiawatha impactite grains. Not a single chromite grain was found and the possible link to the Cape York meteorites could not be tested. The petrographic examination of Younger Dryas marine deposits resulted in absence of impact-related Hiawatha grains. A petrological investigation revealed that organic carbon was likely found in five of six variably shocked impactites derived from the Hiawatha impact crater. The character of the organic carbon varies between the samples and also within individual samples. Vitrinite reflectance measurements of the organic carbon in two impactites yielded low reflectance values compared to charcoalification experiments of wood. Organic particles with different reflectance in the same sample suggest that the particles had different impact histories prior to settling and becoming a rock. Diagnostic conifer cellular texture was found in at least one of the samples. The character of the organic particles in the impactites supports the suggestion in a previous study that the sources of the Hiawatha organic carbon component are unmetamorphosed surficial deposits containing dead conifer tree trunks and fine-grained layered clay and organic matter. In this study it is concluded that the apparent absence of chromite in the examined glaciofluvial sediment sample corroborates the significance of previous research which suggests that the Hiawatha impactor was an iron meteorite. The apparent absence of impact related grains in the Younger Dryas deposits suggests that although a Younger Dryas age for the Hiawatha impact crater is less likely now, the possibility remains open. The organic carbon with diagnostic conifer cellular texture in the Hiawatha impactites corroborates the conclusion in a previous study that the Hiawatha impact-related organic carbon component stems from local, thermally degraded conifer trees with a probable age of ca. 3–2.4 Ma. It is also concluded that the relatively low reflectance values of the organic carbon in the Hiawatha impactites seem to be related to the short duration of the high-temperature excursion during the hypervelocity impact event.
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Caldwell, Nelson, Matthew G. Walker, Mario Mateo, Edward W. Olszewski, Sergey Koposov, Vasily Belokurov, Gabriel Torrealba, Alex Geringer-Sameth, and Christian I. Johnson. "Crater 2: An Extremely Cold Dark Matter Halo." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/623952.
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We present results from MMT/Hectochelle spectroscopy of 390 red giant candidate stars along the line of sight to the recently discovered Galactic satellite Crater 2. Modeling the joint distribution of stellar positions, velocities, and metallicities as a mixture of Crater 2 and Galactic foreground populations, we identify similar to 62 members of Crater 2, for which we resolve a line-of-sight velocity dispersion of sigma(nu los) = 2.7(-0.3)(+0.3) km s(-1) and a. mean velocity of
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Potter, Ross William Kerrill. "Numerical modelling of basin-scale impact crater formation." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/9322.
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Understanding of basin-scale crater formation is limited; only a few examples of basin-scale craters exist and these are difficult to access. The approach adopted in this research was to numerically model basin-scale impacts with the aim of understanding the basin-forming process and basin structure. Research was divided into: (1) investigating early stage formation processes (impactor survivability), (2) investigating later stage formation processes (excavation and modification) and basin structure, and (3) constraining an impact scenario for the largest lunar crater, the South Pole-Aitken Basin. Various impact parameters were investigated, quantifying their effect on the basin-forming process. Simulations showed impactor survivability, the fraction of impactor remaining solid during the impact process, greatly increased if the impactor was prolate in shape (vertical length > horizontal length) rather than spherical. Low (≲15 km/s) impact velocities and low impact angles (≲30 ) also noticeably increased survivability. Lunar basin-scale simulations removed a significant volume of crustal material during impact, producing thinner post-impact crustal layers than those suggested by gravity-derived basin data. Most simulations formed large, predominantly mantle, melt pools; inclusion of a steep target thermal gradient and high internal temperatures greatly influenced melt volume production. Differences in crustal thickness between simulations and gravity-derived data could be accounted for by differentiation of the voluminous impact-generated melt pools, predicted by the simulations, into new crustal layers. Assuming differentiation occurs, simulation results were used to predict features such as transient crater size for a suite of lunar basins and tentatively suggest lunar thermal conditions during the basin-forming epoch. Additional simulations concerned the formation of the South Pole-Aitken Basin. By constraining simulation results to geochemical and gravity-derived basin data, a best-fit impact scenario for the South Pole-Aitken Basin was found.
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Bray, Veronica J. "Impact crater formation on the icy Galilean satellites." Thesis, Imperial College London, 2009. http://hdl.handle.net/10044/1/4355.
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The possible existence of liquid water beneath the ice crusts of Ganymede and Europa makes these bodies of great scientific interest as the accessibility of the oceans has implications for astrobiology and future human exploration of the solar system. Study of the cratering trends on these bodies provides one means of assessing the depth of the ice layer above the sub-surface oceans. This work combines observational and numerical modelling data to develop a quantitative model for impact cratering in pure H₂O ice. Topographic profiles of craters on Ganymede are presented and used to construct scaling trends, which are then compared to similar trends for the Moon and Mars in order to assess differences in the cratering process in rock, ice and ice-rock mixes. The progression of central peak and central pit crater morphology as crater diameter increases, is used to develop a paradigm for central peak collapse and pit formation on Ganymede. These observed cratering trends are used to test the results of hydrocode simulation of impact cratering. These simulations were used to determine an appropriate material strength model, and its specific parameters, for the simulation of impact crater formation in un-layeredice. This optimal strength model is then applied to impact cratering in a layered ice and water target. The results from this numerical modelling are compared to the Europan cratering trends and used to estimate the thickness of Europa's ice crust.
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Cramer, Kirsten [Verfasser]. "Die transorale laserchirurgische Kehlkopfteilresektion bei Larynxkarzinomen / Kirsten Cramer." Köln : Deutsche Zentralbibliothek für Medizin, 2011. http://d-nb.info/1011001829/34.
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Kloberdanz, Christine Marie. "Geochemical analysis of the Monturaqui Impact Crater, Chile." Thesis, University of Iowa, 2010. https://ir.uiowa.edu/etd/835.
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Sorensen, Khalid Lief. "A Combined Feedback and Command Shaping Controller for Improving Positioning and Reducing Cable Sway in Cranes." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6853.
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Bridge and gantry cranes are crucially important elements in the industrial complex; they are used in many areas such as shipping, building construction, steel mills, and nuclear facilities, just to name a few.
These types of systems tend to be highly flexible in nature, generally responding to commanded motion with oscillations of the payload and hook. The response of these systems to external disturbances, such as wind, is also oscillatory in nature. Often, the oscillations of the hook and payload have undesirable consequences. For instance, precise manipulation of payloads is difficult when cable sway is present. Oscillation of the hook can also present a safety hazard. For these reasons, the ability to successfully negate these detrimental dynamics can result in improved positioning, quicker settling time, and improved safety.
This thesis addresses the dynamic properties of bridge and gantry cranes in an effort to develop a control scheme that enables strides to be made in these areas of positioning, efficiency, and safety.
The fundamental advancement arising from this thesis is the development of a control scheme that enables precise positioning of the payload while motion and disturbance-induced oscillations are eliminated. A command generation technique uniquely suited for reducing oscillation in low-frequency flexible systems is examined and utilized in the control. The control scheme is implemented on a 10-ton bridge crane for validation purposes.
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Nasr, Imen. "Algorithmes et Bornes minimales pour la Synchronisation Temporelle à Haute Performance : Application à l’internet des objets corporels." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLY007/document.
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La synchronisation temporelle est la première opération effectuée par le démodulateur. Elle permet d'assurer que les échantillons transmis aux processus de démodulation puissent réaliser un taux d'erreurs binaires le plus faible.Dans cette thèse, nous proposons l'étude d'algorithmes innovants de synchronisation temporelle à haute performance.D'abord, nous avons proposé des algorithmes exploitant l'information souple du décodeur en plus du signal reçu afin d'améliorer l'estimation aveugle d'un retard temporel supposé constant sur la durée d'observation.Ensuite, nous avons proposé un algorithme original basé sur la synchronisation par lissage à faible complexité.Cette étape a consisté à proposer une technique opérant dans un contexte hors ligne, permettant l'estimation d'un retard aléatoire variable dans le temps via les boucles d'aller-retour sur plusieurs itération. Les performances d'un tel estimateur dépassent celles des algorithmes traditionnels.Afin d'évaluer la pertinence de tous les estimateurs proposés, pour des retards déterministe et aléatoire, nous avons évalué et comparé leurs performances à des bornes de Cramèr-Rao que nous avons développées pour ce cadre. Enfin, nous avons évalué les algorithmes proposés sur des signaux WBANTime synchronization is the first function performed by the demodulator. It ensures that the samples transmitted to the demodulation processes allow to achieve the lowest bit error rate.In this thesis we propose the study of innovative algorithms for high performance time synchronization.First, we propose algorithms exploiting the soft information from the decoder in addition to the received signal to improve the blind estimation of the time delay. Next, we develop an original algorithm based on low complexity smoothing synchronization techniques. This step consisted in proposing a technique operating in an off-line context, making it possible to estimate a random delay that varies over time on several iterations via Forward- Backward loops. The performance of such estimators exceeds that of traditional algorithms. In order to evaluate the relevance of all the proposed estimators, for deterministic and random delays, we evaluated and compared their performance to Cramer-Rao bounds that we developed within these frameworks. We, finally, evaluated the proposed algorithms on WBAN signals
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Nilsson, Henrik, and Anders Svensson. "Automated Mobile Cranes." Thesis, Högskolan i Halmstad, Akademin för informationsteknologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-29479.
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Rose, Arnd [Verfasser], Johannes [Akademischer Betreuer] Cramer, Johannes [Gutachter] Cramer, and Cord [Gutachter] Meckseper. "Frühchristliche Propyläen : Herkunft, Gestalt und Entwicklung des Bautyps in Spätantike und Frühmittelalter / Arnd Rose ; Gutachter: Johannes Cramer, Cord Meckseper ; Betreuer: Johannes Cramer." Berlin : Technische Universität Berlin, 2017. http://d-nb.info/1156178312/34.
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Rose, Arnd Verfasser], Johannes [Akademischer Betreuer] [Cramer, Johannes Gutachter] Cramer, and Cord [Gutachter] [Meckseper. "Frühchristliche Propyläen : Herkunft, Gestalt und Entwicklung des Bautyps in Spätantike und Frühmittelalter / Arnd Rose ; Gutachter: Johannes Cramer, Cord Meckseper ; Betreuer: Johannes Cramer." Berlin : Technische Universität Berlin, 2017. http://nbn-resolving.de/urn:nbn:de:101:1-201804161795.
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