Shape and size of rocks are important physical characteristics of aggregates used in engineering and for interpretation of the genesis of naturally occurring sediment. Several image processing programs are available for measure the size and shape of various types of objects. The accuracy and reproducibility of results of a new imaging method and new matlab based 3D imaging program has been studied. 3D results are obtained by coupling two images of particles one of their largest and one of the smallest projected areas. The accuracy of results depends on the focal length used for imaging as well as the positioning of particles in the view field.

No description available.

Porous Wall Hollow Glass Microspheres (PWHGMs) were developed by the Savannah River National Laboratory. What makes these microspheres unique is the interconnected porosity spread throughout their wall allowing various materials to travel from the surface to the hollow interior. With their characteristic porosity, the PWHGMs are a great tool for encapsulating or filtrating different materials. Unfortunately, there is little information available on the mechanical properties of PWHGMs. The main goal of this research was to develop a method to crush individual microspheres and statistically analyze the results. One objective towards completing this goal was to measure the microsphere diameter distribution. Microsphere diameter is a major factor affecting strength as well as the Weibull parameters. Two different methods, microscopy counting and laser light scattering, used in the research yielded similar distributions. The main objective of this research was to analyze the crush strength of individual microspheres. Using nanoindentation, data were collected to analyze the crush strength of PWHGMs in uniaxial compression. Nanoindentation data were used to analyze how the strength of the PWHGMs changes through the different stages of production and at different diameter ranges. Data for 3M commercial microspheres were compared to ARC microspheres. Most data were analyzed using a statistical technique known as the two parameter Weibull analysis. The data indicated that the strength generally decreased as the microsphere diameter increased. Scattering in the data was nearly the same across all sample sets tested. Results indicated that the PWHGMs were weaker than the ARC hollow glass microspheres (HGMs). This is primarily due to the addition of wall porosity in the PWHGM. / Master of Science

Atlantic Meridional Overturning Circulation (AMOC) is a vital process that transfers heat and nutrients throughout the world's oceans, helping to regulate global climate and support marine ecosystems. The timing and nature of the shift to modern AMOC, and especially to deep-water formation in the North Atlantic, has been a topic of ongoing study, with the Eocene-Oligocene Transition (EOT, ~34 Ma) as a potential focal point of this shift. However, the role played by abrupt EOT cooling and Antarctic glaciation in North Atlantic circulation remains unclear. Improved constraints on Paleogene circulation will provide insight into the sensitivity of AMOC to perturbations in global climate, which is particularly relevant in light of contemporary climate change. To examine deep North Atlantic circulation response to the EOT we obtained grain-size data from the terrigenous fraction of the mud-dominated sediments of the Southeast Newfoundland Ridge contourite drift complex at IODP Site U1411, which is interpreted to have formed under the influence of the Deep Western Boundary Current. We analyzed 195 samples that span 150 m of stratigraphy from 36-26 Ma. The main objective was to use the 'sortable silt' fraction (10-63 µm) to generate a record of relative change in bottom-current intensity. These data are complemented with a record of the abundance and size of lithogenic sand (>63 µm). Here we present the first physical proxy record of abyssal current intensity in the North Atlantic, from late Eocene to mid Oligocene. Invigoration of North Atlantic deep circulation occurred gradually (over Myr timescales), with no significant changes linked temporally to the EOT. We infer that deep circulation in the North Atlantic was not sensitive to the abrupt global cooling and Antarctic glaciation associated with the EOT. Rather, our data suggest that changes in North Atlantic circulation were likely governed by longer-term processes related to the opening of key tectonic gateways, such as the Greenland-Scotland Ridge in the North Atlantic, and the Drake and Tasman Passages in the Southern Ocean. Additionally, we identify a significant mid-Oligocene invigoration of North Atlantic abyssal circulation, which climaxes around 27.9 Ma, and is coeval with a decrease in atmospheric CO2. / Master of Science / Atlantic Meridional Overturning Circulation (AMOC) is a vital process that transfers heat and nutrients throughout the world’s oceans, helping to regulate global climate and support marine ecosystems. However, AMOC has not always existed as we know it, and different modes of ocean circulation have operated in Earth’s past. The timing and nature of the shift to the modern form of AMOC/global ocean circulation has been a topic of ongoing study. The Eocene-Oligocene Transition (EOT, ~34 million years ago), a period of intense global cooling and Antarctic ice sheet growth, is thought to be a potential focal point of this shift to modern ocean circulation. However, the role played by abrupt EOT cooling and Antarctic glaciation in the evolution of ocean circulation remains unclear, especially in the North Atlantic. Understanding how and why ocean circulation has changed in more recent geologic time (within the past 65 million years), and ultimately evolved into its modern state, will help us understand the processes which led to, and now maintain, Earth’s modern climate state, as well as provide insight into the sensitivity of AMOC to perturbations in global climate, which is particularly relevant in light of contemporary climate change. To examine the response of ocean circulation in the North Atlantic to climate changes at the EOT, we obtained grain-size data from the mud-dominated sediments of the Southeast Newfoundland Ridge contourite drift complex at IODP Site U1411, which is interpreted to have formed under the influence of the Deep Western Boundary Current. Contourite drifts are massive sediment build-ups on the ocean floor, which are formed due to bottom-currents depositing large amounts of sediment in one area. Therefore, contourite drift deposits can hold valuable records of bottom-current activity over millions of years. We analyzed 195 samples that span 150 m of stratigraphy from 36-26 Ma (Ma = millions of years ago). The main objective was to use the ‘sortable silt’ fraction (10-63 µm) to generate a record of relative change in bottom-current intensity. These data are complemented with a record of the abundance and size of sand (>63 µm). Here we present the first physical proxy record of abyssal current intensity in the North Atlantic, from late Eocene to mid Oligocene. We find that invigoration of North Atlantic deep circulation occurred gradually (over million-year timescales), with no significant changes linked temporally to the EOT. We infer that deep circulation in the North Atlantic was not sensitive to the abrupt global cooling and Antarctic glaciation associated with the EOT. Rather, our data suggest that changes in North Atlantic circulation were likely governed by longer-term processes related to the opening of key tectonic gateways, such as the Greenland-Scotland Ridge in the North Atlantic, and the Drake and Tasman Passages in the Southern Ocean. Additionally, we identify a significant midOligocene invigoration of North Atlantic abyssal circulation, which climaxes around 27.9 Ma, and coincides with a decrease in atmospheric CO₂.

Η λεπτομερής ιζηματολογική ανάλυση των αποθέσεων της τομής Μακρυλιά, έδειξε την ύπαρξη τουλάχιστον 5 κύκλων ιζηματογένεσης με αυξανόμενο προς τα πάνω κοκκομετρικό μέγεθος που αναπτύχτηκαν σε ένα περιβάλλον υφαλοκρηπίδας. Η κύρια λιθολογία είναι αμμούχος πηλός και τα ιζήματα μεταφέρθηκαν ως ομογενές αιώρημα. Το ποσοστό του ανθρακικού ασβεστίου είναι χαμηλό και τείνει αυξανόμενο προς τα πιο αδρομερή κλάσματα. Το ποσοστό του οργανικού υλικού έδειξε την παρουσία αρκετών δειγμάτων με αυξημένο οργανικό υλικό προτείνοντας την ύπαρξη εν δυνάμει μητρικών πετρωμάτων για την γένεση υδρογονανθράκων. Η σχέση μεταξύ του ανθρακικού ασβεστίου και οργανικού υλικού είναι κύρια αρνητική προτείνοντας ανοξικές συνθήκες. Η βιοστρωματογραφική ανάλυση έδειξε Πλειοκαινική ηλικία των ιζημάτων που αποτέθηκαν σε εναλλασσόμενες οξικές – ανοξικές συνθήκες. Από τα παραπάνω αποτελέσματα και περνώντας υπόψη τα υπάρχοντα αποτελέσματα των ιζημάτων που περιβάλλουν την περιοχή μελέτης φαίνεται πως οι μελετηθείσες αποθέσεις συγκεντρώθηκαν σε μια ρηχή με ήσυχα νερά ενδο-ορεινή λεκάνη στα περιθώρια της κύριας λεκάνης της Ιεράπετρας. / Detailed sedimentological analysis, in Makrylia cross-section deposits, showed at least five coarsening-upward cycles developed in a shelf environment. The main lithology is sandy silt and sediments transported as homogenous suspension in a low energy environment that deposited in a shallow water basin. Calcium carbonate (CaCO3) is low and tends to increase to the coarse-grained clasts. Organic carbon (TOC) ratio showed the presence of many high content samples in TOC suggesting potential hydrocarbon source rocks. There is mostly a negative relation between CaCO3 and TOC introducing generally anoxic conditions. Biostratigraphy analysis showed a Pliocene age for the studied deposits in alternating conditions with oxic- anoxic events. According to the above results and taking into account previous results from the surrounding sediments it seems that studied deposits accumulated in a shallow, low energy, intra-mountain basin at the margins of the main Ierapetra basin.

Neste trabalho avaliou-se o comportamento coloidal de suspensões nasais contendo micropartículas de celulose (MCC-NaCMC) com o objetivo de desenvolver um produto genérico compatível com o produto referência de mercado. As propriedades reológicas destas formulações possuem alta influência nos atributos críticos de qualidade do produto, como uniformidade de dose, devido sedimentação durante estocagem em prateleira, e também na performance in-vitro/ in-vivo. Realizaram-se testes com diferentes concentrações de MCC-NaCMC e diferentes parâmetros de processo (tempo e taxa de cisalhamento) utilizando um planejamento de experimentos (DoE) de superfície de respostas através de um modelo composto central. As respostas avaliadas foram tamanho de partículas (quantidade em porcentagem de partículas menores que 1µm e D90) através da técnica por difração a laser e viscosidade/tixotropia através de um reômetro rotacional. Influências significativas dos três fatores e efeitos sinérgicos entre eles nas respostas analisadas foram observadas. Desta maneira foi possível obter respostas próximas ao do produto referência de mercado através deste mapeamento. Observou-se também uma alta correlação entre as respostas, pois este estudo mostrou que o tamanho das partículas coloidais controla a viscosidade e tixotropia das dispersões coloidais. Este trabalho mostrou a significativa influência das etapas de processo no comportamento coloidal das formulações. Idealmente o processo deveria ser monitorado por medidas reológicas, porém este controle é inviável devido ao tempo para a reestruturação do sistema (24 horas). Portanto, a melhor alternativa seria o monitoramento do processo por análise de tamanho de partículas online. / In this work, the colloidal behavior of nasal suspensions containing cellulose microparticles (MCC-NaCMC) was evaluated, in order to develop a generic product compatible with the brand-name product. The rheological properties of these formulations have high influence on the critical quality attributes of the product, such as dose uniformity, due to sedimentation during shelf life, and also on in-vitro/in-vivo performance. Tests were performed with different concentrations of MCC-NaCMC and different process parameters (time and shear rate) using a Design of Experiments (DoE) with response surface by central composite design. The responses evaluated were particle size (amount in percentage of particles smaller than 1m and D90) by means of laser diffraction, and viscosity / thixotropy using a rotational rheometer. Significant influences of the three factors and synergic effects among responses were observed. Through this mapping it was possible to obtain nearby responses to the brand-name product. There was also a strong correlation between the responses, because the size of colloidal particles controlled the dispersion viscosity and thixotropy. This study showed the significant influence of the process steps on the colloidal behavior of the formulations. Ideally the process should be monitored by rheological measurements, but this control is not feasible due to the time required for the system rebuilding (24 hours). Therefore, the best alternative would be monitoring the process by the online particle size analysis.

Neste trabalho avaliou-se o comportamento coloidal de suspensões nasais contendo micropartículas de celulose (MCC-NaCMC) com o objetivo de desenvolver um produto genérico compatível com o produto referência de mercado. As propriedades reológicas destas formulações possuem alta influência nos atributos críticos de qualidade do produto, como uniformidade de dose, devido sedimentação durante estocagem em prateleira, e também na performance in-vitro/ in-vivo. Realizaram-se testes com diferentes concentrações de MCC-NaCMC e diferentes parâmetros de processo (tempo e taxa de cisalhamento) utilizando um planejamento de experimentos (DoE) de superfície de respostas através de um modelo composto central. As respostas avaliadas foram tamanho de partículas (quantidade em porcentagem de partículas menores que 1µm e D90) através da técnica por difração a laser e viscosidade/tixotropia através de um reômetro rotacional. Influências significativas dos três fatores e efeitos sinérgicos entre eles nas respostas analisadas foram observadas. Desta maneira foi possível obter respostas próximas ao do produto referência de mercado através deste mapeamento. Observou-se também uma alta correlação entre as respostas, pois este estudo mostrou que o tamanho das partículas coloidais controla a viscosidade e tixotropia das dispersões coloidais. Este trabalho mostrou a significativa influência das etapas de processo no comportamento coloidal das formulações. Idealmente o processo deveria ser monitorado por medidas reológicas, porém este controle é inviável devido ao tempo para a reestruturação do sistema (24 horas). Portanto, a melhor alternativa seria o monitoramento do processo por análise de tamanho de partículas online. / In this work, the colloidal behavior of nasal suspensions containing cellulose microparticles (MCC-NaCMC) was evaluated, in order to develop a generic product compatible with the brand-name product. The rheological properties of these formulations have high influence on the critical quality attributes of the product, such as dose uniformity, due to sedimentation during shelf life, and also on in-vitro/in-vivo performance. Tests were performed with different concentrations of MCC-NaCMC and different process parameters (time and shear rate) using a Design of Experiments (DoE) with response surface by central composite design. The responses evaluated were particle size (amount in percentage of particles smaller than 1m and D90) by means of laser diffraction, and viscosity / thixotropy using a rotational rheometer. Significant influences of the three factors and synergic effects among responses were observed. Through this mapping it was possible to obtain nearby responses to the brand-name product. There was also a strong correlation between the responses, because the size of colloidal particles controlled the dispersion viscosity and thixotropy. This study showed the significant influence of the process steps on the colloidal behavior of the formulations. Ideally the process should be monitored by rheological measurements, but this control is not feasible due to the time required for the system rebuilding (24 hours). Therefore, the best alternative would be monitoring the process by the online particle size analysis.

Στόχος της παρούσας διατριβής είναι η μελέτη των ιζηματολογικών και γεωχημικών χαρακτηριστικών του νεογενούς σχηματισμού Μετόχια στην νήσο Γαύδο με κατεύθυνση την αναζήτηση πιθανών μητρικών πετρωμάτων υδρογονανθράκων. Στο πρώτο κεφάλαιο γίνεται βιβλιογραφική ανασκόπηση της γεωλογίας της περιοχής μελέτης καθώς και γενικότερα της λεκάνης Μεσσαρά-Γαύδου, περιγραφή της τομής δειγματοληψίας και τέλος της γεωδυναμικής και παλαιογεωγραφικής εξέλιξης της ευρύτερης περιοχής. Στο δεύτερο κεφάλαιο καταρχήν πραγματοποιείται μια επιγραμματική αναφορά των συνθηκών που απαιτούνται για την γένεση πεδίων υδρογονανθράκων και κατόπιν δίνεται έμφαση στα χαρακτηριστικά του οργανικού υλικού που εγκλωβίζεται στα ιζήματα και στον τρόπο δημιουργίας των μητρικών πετρωμάτων. Στο τρίτο κεφάλαιο περιγράφονται οι γεωχημικές αναλύσεις που πραγματοποιήθηκαν. Το κεφάλαιο αυτό χωρίζεται σε δυο μέρη. Στο πρώτο περιγράφεται η ανάλυση ανθρακικού ασβεστίου και τα αποτελέσματα της. Στο δεύτερο μέρος παρουσιάζονται βιβλιογραφικά δεδομένα του ολικού οργανικού άνθρακα από την περιοχής της Μεσσαρά και τα αποτελέσματα της ανάλυσης του ολικού οργανικού άνθρακα καθώς και τα χαρακτηριστικά του οργανικού υλικού που προέκυψαν από την παρούσα διατριβή. Στο τέταρτο κεφάλαιο γίνεται μια περιγραφή των μεθόδων κοκκομετρικής ανάλυσης που χρησιμοποιήθηκαν, η σύγκριση των μεθόδων, τα αποτελέσματα και η σύγκριση των αποτελεσμάτων που προέκυψαν. Τέλος στο πέμπτο κεφάλαιο παρουσιάζονται τα αποτελέσματα της παρούσας διατριβής. / The aim of this thesis is to study the sedimentological and geochemical characteristics of the Neogene Metochia formation on the island of Gavdos towards the exploration for potential hydrocarbon source rocks. The first chapter is a review of the geology of the study area and generally the geology of the Messara-Gavdos basin, a description of the sampling section and the geodynamic and paleogeographic evolution of the area. In the second chapter a brief review of the conditions required for the genesis of hydrocarbons fields is provided, and then the characteristics of the organic material trapped in sediments and how source rock being creating, is emphasised. In the third chapter the geochemical analysis don are described. This chapter is divided into two parts. First part describes the analysis of the total calcium carbonate and the results obtained. Second part presents bibliographical data for total organic carbon from Messara area samples and the results of the total organic carbon analysis derived from this thesis, as well as the characteristics of organic material of the studied samples. The fourth chapter describes the grain-size analysis methods used in this thesis, a comparison of these methods, the results obtained and a comparison of them. Finally in the fifth chapter the outcomes of this thesis are presented.

Η εργασία αυτή έχει ως σκοπό τη συλλογή και την εργαστηριακή επεξεργασία ενός α-ριθμού δειγμάτων από τη νοτιοδυτική Κρήτη και συγκεκριμένα από τον Πλάτανο. Τα δείγματα μελετήθηκαν εργαστηριακά με τη μέθοδο του ανθρακικού ασβεστίου, του ορ-γανικού υλικού με τιτλοδότηση και της κοκκομετρίας με κόσκινα (για τα πιο ανδρομε-ρή κλάσματα)και με πιπέττες (για τα λεπτόκοκκα κλάσματα). Τα αποτελέσματα που προκύπτουν φανερώνουν το περιβάλλον και τις συνθήκες απόθεσης των δειγμάτων της περιοχής, τις διαδικασίες μεταφοράς και απόθεσης, την περιεκτικότητα τους σε CaCO3 και TOC. Στην συνέχεια, εφόσον είναι γνωστοί αυτοί οι παράγοντες σε συνδι-ασμό με τη γενικότερη γεωλογία της περιοχής μπορούμε να εξετάστηκαν οι πιθανότη-τες που υπάρχουν να σχηματιστούν οι υδρογονάνθρακες, να αποθηκευτούν αλλά και να μεταναστέψουν. / Sedimetological analysis of 42 samples, sieve and pipette grain size analysis in rela-tion with statistical analysis, from a cross-section from Platanos basin in NW Crete island, shows that sedimentation took place in a shelf environment with low energy, where sediments transported through suspension. Depositional conditions changed during sedimentation, with changes in depositional depth from shallower to deeper. The main lithology is sandy clay and from the samples is seen that the fraction of clay has small values. TOC analysis showed that organic matter ranges from 0% to 2.38%. The presence of TOC values, more than 0.5%>, suggest that the studied de-posits could be source rocks under special conditions. CaCO3 analysis, with values from 34,87to 87,47, with an average 53.3%, indicate rapid sedimentary conditions. Comparison between TOC-CaCO3 seems to show that majority of samples are negative with low TOC and CaCO3 showing increased oxidative environment condi-tions sedimentation. At least 3 cases where we have increased TOC could character-ize the relationship as positive. Where high rates of both indicators show the oxidiz-ing conditions of the environment to maintain the high rate of organic carbon may be due to the high rate of sedimentation in a quickly plunge basin. Finally, in the heterolithic phase where most changes occur in the rates of both indicators also confirm the alternation of lithology showing strong variation of depth due to sedi-mentation apparently of tectonic activity. In this case it could and the correlation mentioned above to be connected with the change of tectonic regime in the passage from the phase of clay in heterolithic phase

Λαμβάνοντας υπόψη ιζηματογενείς δομές και υφές, και την βιοστρωματογραφία κατα-λήγουμε στο συμπέρασμα ότι η ιζηματογενής ακολουθία κατά μήκος της νότιας ακτής της Ζακύνθου από το χωριό Κερί μέχρι και τη χερσόνησο του Άγιου Σώστη έχει επη-ρεαστεί από ισχυρή τεκτονική δραστηριότητα, παράγοντας τουλάχιστον τέσσερις κύ-κλους με αυξανόμενο κοκκομετρικό μέγεθος προς τα πάνω. Η παρουσία της ακολου-θίας Bouma και των οριζόντων ολίσθησης συστήνουν ένα βαθύ θαλάσσιο περιβάλλον απόθεσης. Η κοκκομετρική ανάλυση έδειξε μια σταδιακή πλήρωση του κάθε κύκλου ιζηματογένεσης, αλλά και ολόκληρης της περιοχής. Επιπροσθέτως, η ανάλυση του TOC και του CaCO3 έδειξε ότι υπάρχει μια σχέση του ποσοστού τους με το περιβάλ-λον απόθεσης, καθώς και ότι υπάρχουν αρκετά καλές πιθανότητες για ανάπτυξη μη-τρικών πετρωμάτων με μέτρια έως καλή δυνατότητα γένεσης υδρογονανθράκων. / Taking into account sedimentary structures and textures, and biostratigraphy we conclude that the sedimentary sequence along the southern coast of Zakynthos is-land from Keri village as far as Ag. Sostis peninsula was influenced by strong tec-tonic activity, producing at least four coarsening upward cycles. The presence of Bouma sequence and slump horizons within the studied sediments introduce gener-ally deep sea depositional conditions. Grain size analysis showed a gradual upward swallowing of depositional conditions both to each cycle and general to the whole area. In addition, TOC and CaCΟ3 analysis showed that there is a relation of their content with the depositional conditions and moreover there are quite enough condi-tions for the development of source rocks with fair to good hydrocarbon generation.