Orientador: Alexandre Dal Pai / Banca: Roberto Lyra Villas Bôas / Banca: Francisco Sérgio dos Santos / Resumo: O presente trabalho apresenta o desenvolvimento e implantação de um sistema de aquisição de dados de temperatura, em um silo de armazenamento de grãos, carregado com milho. Os dados foram coletados no silo por um sistema Arduíno ao qual são acoplados os sensores de temperatura. Após a leitura os dados são transmitidos via rádio e exibidos em tempo real em uma tela de computador criada especificamente para que o usuário do sistema consiga identificar os pontos de medição rapidamente. Essa informação é importante para subsidiar o operador do sistema na tomada de decisão sobre intervir ou não no processo de aeração dos grãos para manter a qualidade do produto armazenado. Os dados coletados são armazenados e podem compor uma série histórica do comportamento da temperatura dos grãos durante o armazenamento, bem como serem utilizados em pesquisas acadêmicas. A parte experimental deste trabalho, corroborou para a validação do mesmo. O sistema contou com 12 sensores distribuídos dentro do silo, e as leituras foram realizadas com intervalo de 15 minutos no período entre 16 de julho e 18 de outubro de 2018. Nesse período foram coletados 104640 medidas de temperatura, que permitiram realizar diversas análises. Foi verificado que o sistema pode ser usado para avaliar como foi o comportamento térmico dos grãos e quais foram as reações do milhos depois de atuações para diminuição da temperatura. A partir da variação de temperatura entre o volume do silo sem grãos e com a presença dos mesmo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This paper presents the development and implementation of a temperature data acquisition system in a grain storage silo loaded with corn. Data were collected in the silo by an Arduino system to which the temperature sensors are coupled. After reading the data is transmitted by radio and displayed in real time on a computer screen specifically designed so that the system user can identify the measuring points quickly. This information is important to support the system operator in deciding whether or not to intervene in the grain aeration process to maintain the quality of the stored product. The collected data are stored and can compose a historical series of grain temperature behavior during storage, as well as being used in academic research. The experimental part of this work corroborated its validation. The system had 12 sensors distributed inside the silo, and the readings were taken with a 15-minute interval between July 16 and October 18, 2018. During this period 104640 temperature measurements were collected, which allowed to perform various analyzes. It was verified that the system can be used to evaluate how was the thermal behavior of the grains and what were the reactions of the corn after actions to decrease the temperature. From the temperature variation between the volume of the silo without grains and with their presence it is possible to estimate the volume occupied by the grain in it. / Mestre

Structural equation modelling (SEM) is carried out with the aim of testing hypotheses on the model of the researcher in a quantitative way, using the sampled data. Although SEM has developed in many aspects over the past few decades, there are still numerous advances which can make SEM an even more powerful technique. We propose representing the nal theoretical SEM by a Bayesian Network (BN), which we would like to call a Probabilistic Structural Equation Model (PSEM). With the PSEM, we can take things a step further and conduct inference by explicitly entering evidence into the network and performing di erent types of inferences. Because the direction of the inference is not an issue, various scenarios can be simulated using the BN. The augmentation of SEM with BN provides signi cant contributions to the eld. Firstly, structural learning can mine data for additional causal information which is not necessarily clear when hypothesising causality from theory. Secondly, the inference ability of the BN provides not only insight as mentioned before, but acts as an interactive tool as the `what-if' analysis is dynamic. / Mini Dissertation (MCom)--University of Pretoria, 2018. / Statistics / MCom / Unrestricted

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The study evaluated the psychometric properties of the Spanish version of the Obsession with COVID-19 Scale (OCS) in 214 police and members of the armed forces (M age = 29.33 years, SD = 11.28). The one-dimensionality and satisfactory reliability of OCS were confirmed with confirmatory factor analysis, Item Response Theory analysis, Cronbach’s alpha, and McDonald’s omega. The scale is useful for identifying individuals with low levels of persistent and disturbing thoughts about COVID-19. COVID-19 obsession was associated with COVID-19 fear, anxiety, and depression. The OCS is suitable for investigating the psychological impact of COVID-19 on members of the police and armed forces.

>Magister Scientiae - MSc / Pletmos Basin is a Mesozoic half graben located in the southern part of South Africa and has undergone numerous tectonic changes which involve alteration of structure and reworking of sediments. Clay diagenesis has become a more prominent factor affecting the quality of the tight shaly sandstone reservoirs in the southern Pletmos Basin. The present study focused on Block 11a as a primary area of interest .The tight sandstone reservoirs encountered in the four wells, viz. Ga-Q1, Ga- Q2, Ga-Z1 and Ga- E2 were studied using four different methods to incorporate and infer the overall diagenetic effect on the reservoirs, caused by materials of argillaceous origin. The methods adopted in the present research are formation evaluation using wireline logs and calibration of core data using Interactive Petrophysics software, thin section petrography, X-Ray Diffraction (XRD) and, Scanning Electron Microscope (SEM) along with Energy Dispersive X-Ray Spectroscopy (EDS). The availability of core samples were limited to wells Ga- Q1 and well Ga- Z1. Four reservoirs within the Cretaceous age were identified in each well and the best reservoirs were associated with facies B and D. / 2022-04-30

The novel method herein proposed, aims to study Deoxyribonucleic acid (DNA) and Rad51 repair protein in its resting state after their interaction by using a combination of biological preparation and physical measures. Rad51 is a highly conserved protein; it is involved in eukaryotes genome stability and can interact with single strand (ss) and double strands (ds) DNA. In our work, a droplet of the solution containing the dsDNA/Rad51 complexes was deposited on micro-fabricated super-hydrophobic substrates (SHS) to obtain self-organized and suspended fibers. The silicon-based SHS were designed to incorporate a regular circular array of pillars and to maintain a high contact angle with the drop. The samples were let dehydrate at controlled temperature and humidity conditions. At the end of the buffer evaporation process, non-suspended material and salt excess are concentrated on the top of a few micro-pillars in a limited area (drop residual) of the device while ordered and self-assembled DNA/Rad51 fibers are suspended between micro-pillars. To find the ideal conditions to obtain and suspend the nucleic acid/protein complexes, several parameters were investigated: saline buffer, DNA and protein concentrations were widely titrated and showed a significant effect on the biomolecule suspension on SHS. The samples were then preliminarily checked by microscopy techniques and then described by the Raman spectra acquired. Several techniques were used: optical microscopy, Energy Dispersive X-Ray Spectroscopy (EDAX), Scanning Electron Microscopy (SEM) and Raman Spectroscopy. Protein expressions, DNA suspension, micro-fabrication and characterization were all performed in KAUST Core Labs and Structural Molecular Imaging Light Enhanced Spectroscopies (SMILEs) Lab. The novel approach presented in this work is highly multidisciplinary and comprises physical measurements (Raman spectroscopy and EM imaging), chemistry and biology. In future the method can be used further expanded supporting the data with HRTEM direct imaging to elucidate the nucleic acids/proteins behavior in the multiple phases of the genome repair processes. Also, it and can serve as a fingerprint of the biological molecules involved in biological interactions, their localization and structural characterization, providing a new tool for structural analysis, screening and diagnostics.

Studies with primary focus on Viking age gilding techniques in Scandinavia has not been carried out since the sixties. During the past 50 years knowledge about prehistoric gilding techniques and traces of them in the archeological material, as well as the usage of natural sciences within archaeology, has developed considerably. The aim of this thesis was to revisit the topic of gilding and shed new light on Viking age metalworking in Scandinavia with focus on gilding techniques. The second aim was to determine the possibilities and limitations of the study of gilding with a non-destructive methodology. The surfaces of 13 metal objects, four of which are indigenous and the rest are imported goods, were analyzed with SEM-EDS. The chemical compositions of the gilded layers as well as the underlying silver- or copper alloys were analyzed. Furthermore, observations of micro morphological structures were carried out on the gilt surfaces. Interpretations of both chemical compositions and micro morphology were carried out in order to identify what technique or techniques have been used for gilding. The results show that two of artefacts have not been gilded at all, five of them have been fire gilded and the results of the remaining six objects are inconclusive mainly due to lacking reference data. It can be concluded that further research regarding the aging of gilt surfaces on gilded artefacts, more specifically the loss of mercury in fire gilded surfaces over time, needs to be carried out.

Objective: This study was conducted to compare the shear bond strengths, patterns of bond failure and enamel surfaces after debonding two ceramic brackets (ClearVu and Radiance Plus) and one standard metal bracket (Mini Uni-Twin). Background: Ceramic brackets are an esthetic alternative to metal brackets. The mean shear bond strength of ceramic brackets is significantly greater than for metal brackets. Excessive bond strength can result in pain upon debonding, damage to the bracket or permanent damage to the enamel including flaking, cracks or tooth fracture. Numerous studies have evaluated techniques to reduce the risk of enamel damage when debonding ceramic brackets, including the use of debonding pliers. Debonding pliers produce a concentrated stress within the adhesive, resulting in cohesive failures within the resin or adhesive failures outside the resin. Methods: A total of 75 caries-free extracted human premolar teeth were randomly divided into 3 groups: ClearVu ceramic bracket (TP Orthodontics, LaPorte, IN), Radiance Plus ceramic bracket (American Orthodontics, Sheboygan, WI) and Mini Uni-Twin metal bracket (3M Unitek, Monrovia, CA). The Instron Universal Testing Machine Model 8841 with a customized jig with a bracket removing plier was used to debond the brackets. The teeth were microscopically evaluated to determine the location of bond failure. Selected teeth were evaluated with the scanning electron microscope to evaluate for enamel cracks and tear-outs. Results: A one-way ANOVA was created and no significant differences in shear bond strength were discovered between the three groups. Using a chi-square test of independence it was determined that the brackets all possessed a different ARI score. After examining the standardized residuals, we found that Radiance Plus Ceramic bracket and ClearVu Ceramic bracket were both likely to have favorable bond failure patterns, compared to the Mini Uni-Twin Metal bracket. Radiance Plus was most likely to debond at the bracket-adhesive surface, with a majority or all of the adhesive on the tooth after debond. Teeth with unfavorable bond failure patterns (ARI score of 0 or 1) were evaluated with the scanning electron microscope. 11% of the total teeth in the study had enamel damage, including cracks and tear-outs. 62.5% of these teeth were from the ClearVu ceramic bracket group. Conclusions: Our results show that both Radiance Plus ceramic bracket and ClearVu ceramic brackets are comparable to the gold standard metal bracket used in this study, the Mini Uni-Twin, in terms of shear bond strength. Radiance Plus ceramic bracket had the most favorable bond failure pattern, but shattered more during debonding. ClearVu ceramic bracket had the most enamel damage when evaluated with the scanning electron microscope. American Orthodontics’ Radiance Plus Ceramic bracket is the recommended bracket of those studied.

At voestalpine Precision Strip AB, the slitting process is used frequently. Slitting is a commonly applied manufacturing technique during sheet metal processing that aims to split large coils of sheet metal into narrower widths. The coiled sheets are uncoiled and transferred to a slitter, where they pass between rotating circular knives that produce long and straight cuts, splitting the wide sheet into desired widths. However, during operation, their slitting knives are occasionally damaged. This means that the knives must be replaced, which wastes both time and money.   The goal of this project is therefore to examine the damage of a degraded slitting knife. A scanning electron microscope (SEM) is used to analyse the fracture surface and the microstructure of the knife. Further analysis of the knife is a Vickers hardness test to determine the knife’s hardness. Moreover, finite element (FE) simulations of the slitting process are performed in FE software Abaqus to understand the stresses that the knives are subject to during operation. The results show that the Mises stress reaches a maximum value of around 2250 MPa, which is approximately 75% of the materials yield stress in compression.   The SEM images show clear signs of smooth cleavage zones in the fracture area, indicating that the knife has failed by a brittle fracture. Furthermore, the images reveal possible signs of fatigue. The hardness test proved that the knife is very hard with a hardness of 802,2 HV. Plenty of carbides were revealed by the microstructure test – mainly two types. MC vanadium carbides and M6C carbides mainly consisting of tungsten and molybdenum, which explains the hardness of the knife.   To draw further conclusions on the damage of slitting knives in the future, there needs to be proper documentation of the slitting process. This involves taking note of the knife setup, the sheet material and its thickness, as well as the lifetime of the knives as failure occurs.

The focus of much marketing research for the past two decades has been on the role of consumption in consumers’ lives. Relationships with products, brands, and favorite possessions have captured the interest of researchers and practitioners. More recently the concept of brand love has emerged to describe the lengths to which some consumers will go to maintain relationships with certain consumed objects. But is consumer love contained only to favorite brands or might there be different types of love as in interpersonal relationships? This dissertation presents a case for the development of one type of consumer love – customer chemistry, the consumer process of forming a positive, environmentally-derived attachment to a retailer. Because the concept of customer chemistry is new, this dissertation employs a methodical approach necessary for building theory. Essay One (Chapter Two) explores the reactions of consumers to a select group of retailers. Through analysis of their reactions to various retail servicescapes, the researcher draws conclusions regarding the levels of importance that consumers place on specific elements of the retail experience. Essay Two (Chapter Three) delineates the bridging laws that allow for theory development. Conclusions from the previous essay inform the creation of a model that describes the customer chemistry process and allows for prediction of specific antecedents and outcomes. The model is tested using structural equation modeling (SEM). With customer chemistry established empirically, Essay Three (Chapter Four) explores the purpose that customer chemistry serves in consumers’ lives. Modified consumer life histories describe customer chemistry in the context of life narratives, suggesting that customer chemistry plays an important role in identity construction. While the concept of consumption serving an identity creation purpose for consumers is not new, the idea that a place (in this case, a retail store) can serve that purpose is unique to this research. This dissertation argues for a better understanding of consumers’ relationships with loved retailers and suggests several avenues for future research. The surface ofa broad phenomenon has only been scratched, but important groundwork is laid for the development of a rich stream of research, one that can benefit researchers, practitioners, and consumers.

<p> Lower Cretaceous Mannville Group sandstones of Alberta were deposited in non-marine and marginal environments. A shallow sea transgressed several times over the study area and left evidence of tidal action. The proportion of rock fragments increases from Lower Mannville to Upper Mannville sandstones due to the uplifting of strata to the west. </p> <p> Observed petrographic and SEM textures indicate that authigenic pyrite, quartz and calcite cements were precipitated in that order followed by the dissolution of carbonate material and feldspar grains with the simultaneous precipitation of kaolinite and quartz. The secondary (or dissolution) porosity is the result of an influx of acidic pore waters. This secondary porosity is best developed in the Ellerslie Sandstone because its remnant intergranular porosity and permeability are superior to the porosity and permeability in the overlying sandstones. The present degree of diagenesis in the sandstones is largely controlled by the permeability of the rock. </p> / Thesis / Bachelor of Science (BSc)