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Structural Relationships between the Exshaw Thrust and Heart Mountain syncline, Exshaw, AlbertaLeGresley, Eric 04 1900 (has links)
<p> Displacement transfer between faults and folds has been extensively documented in the Rocky Mountains as an explanation for structural variability along strike producing seemingly similar overall shortenings. A series of subparallel imbricate thrusts and an associated syncline in the Southern Canadian Front ranges at Heart Mountain has been mapped at a scale of 1:16,667. Megascopic, mesoscopic and microscopic evidence supports the contention that the folding observed at Heart Mountain occurred synchronously with thrusting as the result of displacement transfer from the adjacent thrust. </p> <p>Numerical dynamic analyses (NDA) suggest that twinning of calcite grains occurred very early in the deformational history in response to a regional stress field orientation of 246/03, 340/02, and 159/84 for o 1, o2 , and 03 respectively in the Exshaw plate. Megascopic and mesoscopic fabrics indicate similar results. Ambiguous NDA results for the Heart Mountain Syncline are explained using neutral surface folding theories rather than flexural slip theories generally proposed for folding within the Front Ranges. Neutral surface folds are consistent with the deformational model (displacement transfer) proposed. </p> <p>An orthogonal fracture system is pervasive throughout the thesis area. Observations indicate that fractures are oriented parallel and perpendicular to the strike of the Rocky Mountains. Their development is inferred to have taken place in the same regional stress field thought to be responsible for twinning, with fracture opening occurring after the relaxation of tectonic stresses and the removal of substantial amounts of overburden. </p> / Thesis / Bachelor of Science (BSc)
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Poly(acrylonitrile/methyl acrylate) copolymers and clay nanocomposites : structural and property relationshipsZengeni, Eddson 12 1900 (has links)
Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2009. / Thesis submitted in partial fulfillment of the requirements for the degree
of Master of Science (Polymer Science)
at University of Stellenbosch. / ENGLISH ABSTRACT: The preparation of poly(acrylonitrile/methyl acrylate) [poly(AN-co-MA)] copolymers and
poly(AN-co-MA)/clay nanocomposites, via emulsion polymerization, their characterisation,
and the relationships between their molecular structures and physical properties are described.
The copolymer composition was varied, and the properties of the products were analysed and
correlated to copolymer composition.
The free volume properties of the copolymer were dependent on the glass transition
temperature (Tg), which is dependant on the copolymer composition. The copolymer
crystallinity decreased with increasing MA content. The decrease in crystallinity and increase
in both o-Ps lifetime and o-Ps intensity with decreasing Tg was caused by the enhanced chain
mobility brought about by the incorporation of methyl acrylate.
The poly(acrylonitrile-co-methyl acrylate)/clay nanocomposites with 60% AN:40%
MA (mol:mol) ratio were prepared using montmorillonite clay modified via adsorption, using
2-acrylamido-2-methyl-1-propanesulphonic acid (AMPS), via in-situ intercalation
polymerization. The poly(AN-co-MA)/clay nanocomposites with different clay loadings
showed no difference in morphology. They exhibited improved thermomechanical properties
and higher thermal stability than the neat copolymers.
The melt rheology results of these nanocomposites showed an improved storage
modulus as well as increased shear thinning behaviour with increasing clay content. However,
the nanocomposites exhibited long-time relaxation behaviour and their chemical structures
evolved during analysis. This was attributed to cyclisation reactions taking place at the
temperature used during the oscillatory tests.
The sorption isotherms of water vapour in these nanocomposites followed a dualmode
sorption behaviour (BET type II mode). Hysteresis was observed in sorption/desorption
isotherms of these nanocomposites. The equilibrium water uptake was higher in the nanocomposites compared to the neat copolymers, and it increased with increasing clay
content, especially at high water activities (0.8).
Although diffusion and permeability decreased with increasing clay content the
solubility increased due to the hydrophilic nature of the clay. Despite the decrease in diffusion
and permeability parameters the free volume hole radius of the nanocomposites remained constant, but a slight decrease in free volume hole number was observed. / AFRIKAANSE OPSOMMING: Die bereiding van poli(akrilonitriel/metielakrilaat) [poli(AN-ko-MA)] kopolimere en
poli(AN-ko-MA)/klei nanosamestellings deur middel van emulsiepolimerisasie, hul
karakterisering asook die ooreenkoms tussen hul molekulêre strukture en fisiese eienskappe is
beskryf. Die kopolimeersamestelling is gevarieer, en eienskappe is geanaliseer en dan
gekorreleer met die kopolimeersamestelling.
Die vrye-volume eienskappe van die kopolimeer was afhanklik van die
glasoorgangstemperatuur (Tg) wat weer afhanklik is van die kopolimeersamestealling. Die
kristalliniteit van die kopolimeer het verminder met die hoeveelheid MA teenwoordig. Die
afname in kristalliniteit en toename in beide die o-Ps leeftyd en o-Ps intensiteit met afname in
Tg is veroorsaak deur die beter kettingbeweegbaarheid wat veroorsaak is deur die byvoeging
van metielakrilaat.
Die poli(akrilonitriel-ko-metielakrilaat)/klei nanosamestellings met 60% AN:40% MA
(mol:mol) verhouding is berei deur die gebruik van montmorillonietklei, gemodifiseer deur
die adsorpsie van 2-akrielamido-2-metiel-1-propaansulfoonsuur (AMPS) deur middel van 'n
in-situ interkaleringspolimerisasie. Die poli(AN-ko-MA)/klei nanosamestellings het, ten spyte
van die verskillende hoeveelhede klei wat gebruik is, geen verandering in morfologie getoon
nie. Hulle het wel beter termodinamiese eienskappe en hoër termiese stabiliteit as die
oorspronklike kopolimere getoon.
Die smeltreologie resultate van hierdie nanosamestellings het ‘n beter stoormodulus
getoon, sowel as toenemende skuifverdunningsgedrag met 'n verhoogde klei inhoud. Tog het
die nanosamestellings lang tyd-ontspanningsgedrag getoon en die chemiese struktuur het
verander tydens analise. Dit word toegeskryf aan die sikliese reaksies wat plaasvind by die
temperatuur wat gebruik is tydens die ossillatoriese toetse.
Die sorpsie isoterme van waterdamp in hierdie nanosamestellings het ‘n dubbel-styl
sorpsiegedrag gevolg (BET tipe II styl). Histerese is waargeneem in sorpsie/desorpsie isoterme van hierdie nanosamestellings. Die ewewig in wateropname van die
nanosamestellings was hoër as vir dié van die oorspronklike kopolimere en dit het toegeneem
met 'n toenemende klei inhoud, veral by hoë humiditeit (0.8).
Al het die diffusie en deurlaatbaarheid afgeneem met 'n toename in die klei inhoud,
het die oplosbaarheid toegeneem as gevolg van die hidrofiliese karakter van die klei. Ten
spyte van die afname in diffusie en deurlaatbaarheidsparameters, het die radius van die vryevolume
openinge van die nanosamestellings konstant gebly, maar ‘n klein afname in die aantal vrye-volume openinge is gevind.
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Nyhetsjournalistik : En studie om Aftonbladets nyhetsjournalistiks möjligheter att leva upp till objektiv samhällsgranskning / News journalism : A study of the journalists at the newspaper Aftonbladet opportunities to live up to objective scrutiny of society.Mattsson Ottosson, Margareta, Tuomi, Topias January 2010 (has links)
The purpose of this study has been to find out what possibilities the journalists at the newspaper Aftonbladet have to live up to the proposed ideas and values that defines journalism, as well as how these values are presented to the readers. With this as a starting-point we have studied what kind of society Aftonbladet presents to its readers as well as how this society is supposed to work and also what it`s like. To be able to answer this question we have first researched through theories and earlier studies, literature about journalism, media science, semiotics, history and laws. With the help of the investigation we found fitting tools to perform the analysis. With the theory as groundwork we have, through the qualitative approach analyzed seven news articles from seven Aftonbladet newspapers during one week. Our study shows that the Afonbladet’s journalists have not been able to present occurrences in society in a correct and impartial manner - because they exaggerate insignificant details and neglect to show real attention to serious societal structures by using sensationalism, dramatization and a very superficial approach to the stories that they are conveying. We have also been able to establish that it is impossible for journalists to follow up and live up to the ideals of journalism. Not only that, it’s also impossible for them to live up to the ideals that the Aftonbladet as a newspaper has assigned for itself. A probable explanation for this is that the journalism field is characterized by high productivity and demands that the news are supposed to be easily understood and have a specific news value. All of this combined amounts to that a lot of times the journalism becomes accentuated, one sided and simplified, all to lure readers every day because Aftonbladet’s main income comes from single copy sales.
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