Submitted by Nadir Basilio (nadirsb@uninove.br) on 2017-04-05T15:26:13Z No. of bitstreams: 1 Aleixo Fernandes.pdf: 1781746 bytes, checksum: d0d61f658fd80fa11dcf43275790349f (MD5) / Made available in DSpace on 2017-04-05T15:26:13Z (GMT). No. of bitstreams: 1 Aleixo Fernandes.pdf: 1781746 bytes, checksum: d0d61f658fd80fa11dcf43275790349f (MD5) Previous issue date: 2016-12-16 / This thesis seeks to explain how moderators of satisfaction - reputation and involvement - act on the willingness to pay more and loyalty. These moderators were chosen because they are recognized in the literature as components which relates with cognitive and emotional elements that make up the satisfaction. The purpose of this study is to explain the influence of reputation and involvement variables on the relationship between satisfaction (independent), loyalty to the brand, and the willingness to pay more (dependent) for after-sales service. The gap that this study seeks to fill is to demonstrate to what extent consumer satisfaction with after-sales service contributes important aspects to the companies' market results. To this end, it aims to answer how the company's reputation and consumer involvement influence the effect of consumer satisfaction on loyalty and the desire to pay more. This quantitative study uses a survey to obtain data. After the collection, regressions were performed with the objective of verifying how the interaction between the variables occur. Of the 9 hypotheses constructed, 4 were confirmed, 2 were partially confirmed and 3 could not be verified. An unexpected result is that the response of the willingness to pay more as a function of satisfaction was linear, whereas the theory suggests that it should be non-linear. At the end, limitations, academic and managerial contributions as well as suggestions for future research are presented. / Esta dissertação busca explicar como dois fatores moderadores da satisfação do consumidor – reputação e envolvimento – agem sobre a disposição de pagar mais e a lealdade. Estas moderadoras foram escolhidas por serem reconhecidas na literatura como componentes que se relacionam com os elementos cognitivos e emocionais que compõem a satisfação. O objetivo deste estudo é explicar a influência das variáveis: reputação e envolvimento na relação entre satisfação (antecedente), lealdade em relação à marca e à disposição de pagar mais (consequentes) pelo serviço de pós-venda. A lacuna que este estudo busca preencher é demonstrar em que medida a satisfação do consumidor, com serviço de pós-venda, contribui com aspectos importantes para o resultado mercadológico das empresas. Para isso pretende responder como a reputação da empresa e o envolvimento do consumidor influenciam o efeito da satisfação desse sobre a lealdade e a disposição de pagar mais. Este é um estudo quantitativo que utiliza um survey para a obtenção de dados. Após a amostra coletada, regressões foram realizadas com o objetivo de verificar como a interação entre as variáveis ocorrem. Das 9 hipóteses construídas, 4 foram confirmadas, 2 foram parcialmente confirmadas e 3 não puderam ser confirmadas. Um resultado não esperado é que a resposta da disposição de pagar mais em função da satisfação se mostrou linear, enquanto a teoria aponta que deveria ser não linear. Ao final são apresentadas limitações, contribuições acadêmicas e gerenciais, bem como sugestões de pesquisas futuras.

<p></p><p>In the grain handling and processing industry, dust emission and accumulation are major concerns for the safety of workers and for explosion risks. Dust emission and accumulation locations highly depend on the facility design and equipment used for handling and processing. To prevent an explosive atmosphere, monitoring the amount of dust accumulated or dispersed is extremely important. However, methods of measuring the dust concentration require the installation of equipment. The Occupational Safety and Health Administration (OSHA) regulations and National Fire Protection Association (NFPA) standards restrict the thickness of dust layers on floors for fine powder materials such as starch. The objective of this dissertation was to better understand the rate of dust layer accumulation, dust suspension patterns, and the optical properties of suspended dust. For this purpose, The Discrete Phase Model (DPM) was combined with a Computational Fluid Dynamics Model (CFD) and the hybrid model was used to model dust dispersion. Dust dispersion patterns under pressure, such as primary explosions or leakage from equipment, were simulated using the unsteady CFD-DPM approach. The particle-wall interaction based on energy conservation was also introduced in this model. Both one-time and continuous dust dispersion in an enclosed chamber were simulated to mimic secondary explosions and the dust emission from processing equipment. In addition, the light extinction property of suspended dust was studied as a method of measuring suspended dust concentration. </p> <p>For a one-time dust dispersion incident, the predicted dust concentration agreed with the simulation result for the trial conducted at a dust injection velocity of 2 m/s with injection rates of 0.05 and 0.10 kg/m³ and at a dust injection velocity of 10 m/s with an injection rate of 0.05 kg/m³. The dust concentration in the entire chamber increased with dust injection velocity and the mass of injected dust. As dust injection velocity increased, dust spread out and formed a larger explosive dust cloud. However, the dust concentration inside the chamber was non-uniform. Considering the minimum explosive concentration, the largest explosive cloud was created at a dust injection velocity of 10 m/s with an injection rate of 0.10 kg/m³. Explosive concentrations of dust were found somewhere in the chamber for all dispersion rates. At an injection velocity of 10 m/s with an injection rate of 0.10 kg/m³, the predicted dust concentration was 10% more than the measured dust concentration. Thus, this model is suitable for dilute dust particle dispersion flows, where the volume fraction of particles is less and only a single particle layer settles.</p> <p>Continuous dispersion was simulated to determine the suspended dust concentration and particle deposition patterns. Dust was dispersed for 30 s at dispersion rates of 2, 4 and 6 g/min at a dust injection velocity of 2 m/s. The dust concentration increased at a constant rate after a few seconds of dispersion, regardless of the dust dispersion rate. Most dust particles were deposited near the dust dispersion nozzle. Large particles were more affected by gravitational force and inertia compared with small particles, which traveled with airflow and settled behind the nozzle. The dust accumulated close to the dispersion nozzle faster than behind the nozzle location. However, specific attention must be paid to small particles, because they are more likely to cause an explosion, as their minimum explosive concentration is lower than that of large particles.</p> <p>The light extinction coefficients of cornstarch, grain dust, and sawdust were measured using a two-target method. The suspended dust concentration was measured using a calibrated laser instrument. The light extinction coefficient was linearly related to the suspended dust concentration. The correlation coefficient between the light extinction coefficient and suspended dust concentration depended on particle size, particle shape, and chemical properties. </p> <p>Controlling dust cloud generation and minimizing the concentration and volume of dust clouds are some key measures to prevent dust explosions. The mathematical models developed in this study to predict dust dispersion, suspension, and rate of settling will help solve a few of the challenges in the particulate material handling and processing industry. This method of measuring the light extinction coefficient can be applied development of a dust safety monitoring system. The result presented in this dissertation will help the industry prevent the formation of an explosive atmosphere.</p><br><p></p>

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Bereavement is painful at any time of life. For young children experiencing bereavement, grandmothers are often the first line of defense. Grandmothers are frequently called upon when their family members experience an out-of-order death, and while they are willing to provide care, grandmothers don't always know the best way forward. This qualitative study sought to learn more about the grief experiences of 22 grandmothers who had lost a family member prematurely through semi-structured interviews and Interpretive Phenomenological Analysis. Findings suggest (a) grandmothers experience layered grief in that they grieve the loss of the family member, experience the pain of the surviving family members, and their own pain; (b) grandmothers experience invisible grief as their feelings are not often revealed to or recognized by their family members; (c) grandmothers experience confusion in knowing how to help and attend to their family members who are bereaved. These difficulties seem related to the family relationships, the connection to the person who died (their own child or an in-law child or grandchild), what they are grieving, and their ability to develop new roles and relationships during the bereavement period.

Manufacturing management and operations place heavy emphasis on monitoring and improving production performance. This supervision is accomplished through strategies of manufacturing performance management, a set of measurements and methods used to monitor production conditions. Over the last thirty years the most prevalent measurement of traditional performance management has been overall equipment effectiveness, a percentile summary metric of a machine's utilization. The technologies encapsulated by Industry 4.0 have expanded the ability to gather, process, and store vast quantities of data, creating opportunity to innovate on how performance is measured. A new method of managing manufacturing performance utilizing Industry 4.0 technologies has been proposed by McKinsey & Company and software tools have been developed by PTC Inc. to aid in performing what they both call digital performance management. To evaluate this new approach, the digital performance management tool was deployed on a Festo Cyber-Physical Lab, an educational mock production environment, and compared to a digitally enabled traditional performance management solution. Results from a multi-day production period displayed an increased level of detail in both the data presented to the user and the insights gained from the digital performance management solution as compared to the traditional approach. The time unit measurements presented by digital performance management paint a clear picture of what and where losses are occurring during production and the impact of those losses. This is contrasted by the single summary metric of a traditional performance management approach, which easily obfuscates the constituent data and requires further investigation to determine what and where production losses are occurring.

The purpose of this thesis is to examine applications of thermal and laser-based methods to monitor airborne particulates in underground coal mines. Specifically, coal and mixed mineral mine dust, as well as, diesel particulate matter (DPM). These particulates have historically, and continue to have, significant health impacts on underground miners. Chapters 1 and 2 of this thesis concentrate on using a novel method of thermogravimetric analysis (TGA) to characterize respirable coal and mixed mineral mine dust and presents the results of this method being applied to samples collected in Appalachia coal mines. Appalachia has been a geographic "hotspot" for the rise in occupational lung disease amongst underground coal miners, which began in 1990's after decades of steady decline. This has led researchers to propose there could be something unique about the respirable dust composition in Appalachia coal mines, which resulted in the surge of lung disease cases; however, the knowledge base regarding the actual composition of respirable coal mine dust is limited. The results of this thesis show that most of the mass fraction of respirable Appalachia coal mine dust is not coal, but rather carbonates and non-carbonate minerals (i.e. silica and silicates). These findings are significant as many researchers now suspect silica and silicates to be the true culprit in the occupational lung disease of coal miners. DPM presents an additional occupational health hazard to underground coal miners where diesel equipment is used and is difficult to monitor due to its complex nature. In underground metal/non-metal mines, airborne DPM is regulated and monitored using carbon surrogates. However, due to the potential interference from coal-sourced carbon, DPM in coal mines is monitored only by taking samples at the tailpipe of each piece of equipment. This thesis aims to investigate the potential for a laser-based instrument, the FLIR Airtec, to be used in underground coal mines. In particular, what effect the coal dust will have on the instrument, as it measures DPM by way of elemental carbon (EC). The results of this study show that while the Airtec will not over-estimate coal-sourced EC, there could be some sampling artifacts associated with its operation in coal mines, which may inhibit its effectiveness. / Master of Science

Diesel particulate matter (DPM) is comprised of two main fractions, organic carbon (OC) and elemental carbon (EC). DPM is the solid portion of diesel exhaust and particles are submicron in size typically ranging from 10 to 1000 nanometers. DPM is a known respirable hazard and occupational exposure can lead to negative health effects. These effects can range from irritation of the eyes, nose, and throat to more serious respirable and cardiovascular diseases. Due to the use of diesel powered equipment in confined airways, underground mine environments present an increased risk and underground mine works can be chronically overexposed. Current engineering controls used to mitigate DPM exposure include cleaner fuels, regular engine maintenance, ventilation controls, and enclosed cabs on vehicles. However even with these controls in place, workers can still be overexposed. The author's research group has previously tested the efficacy of a novel, fog-based scrubber treatment for removing DPM from the air, in a laboratory setting. It was found that the fog treatment improved DPM removal by approximately 45% by number density compared to the control trial (fog off). The previous work stated thermal coagulation between the fog drops and the DPM, followed by gravitational settling of the drops to be the likely mechanisms responsible for the DPM removal. The current work investigated the efficacy of the fog treatment on a larger scale in an underground mine environment, by using a fogging scrubber to treat the entire exhaust stream from a diesel vehicle. A total of 11 field tests were conducted. Based on measurements of nanoparticle number concentration at the inlet and outlet of the scrubber, the fog treatment in the current work showed an average improvement in total DPM removal of approximately 55% compared to the control (fog off) condition. It was found that the treatment more effectively removed smaller DPM sizes, removing an average of 84 to 89% of the DPM in the 11.5, 15.4, and 20.5 nanometer size bins and removing 24 to 30% of the DPM in the 88.6, 115.5, and 154 nanometer size bins. These observations are consistent with expectations since the rate of coagulation between the DPM and fog drops should be greater for smaller diameters. Further analysis of the DPM removal was aided by the development of a mechanistic model of the fogging scrubber. The model uses the inlet data from the experimental tests as input parameters, and it outputs the outlet concentration of DPM for comparison to the experimental outlet data. Results provided support for the notion that DPM removal relies on DPM-fog drop coagulation, and subsequent removal of the DPM-laden drops as opposed to DPM removal by diffusion or inertial impaction of DPM directly to the walls. The model results suggest that inertial impaction of these drops to the scrubber walls is likely much more important than gravitational settling. Moreover, the ribbed geometry of the tubing used for the scrubber apparatus tested here appears to greatly enhance inertial impaction (via enhancement of depositional velocity) versus smooth-walled tubing. This is consistent with previous research that shows particle deposition in tubes with internally ribbed or wavy structures is enhanced compared to deposition in tubes with smooth walls. / Master of Science / Diesel particulate matter (DPM) describes the solid portion of diesel exhaust. These particles are in the nanometer size range (10-1000nm) and can penetrate deep within the lungs presenting a serious health hazard. Because of the use of diesel powered equipment in confined spaces, DPM presents an occupational hazard for underground mine workers. Even with the use of cleaner fuels, regular engine maintenance, proper ventilation, and enclosed vehicle cabs, workers can still be over exposed. Previous work has shown that a water fog treatment can help to remove DPM from the air in a laboratory setting. This removal is due to the DPM particles attaching to the drops, followed by the drops settling out of the air due to gravity or impacting the walls of a tube. To explore a full scale exhaust treatment, a fogging scrubber was built using a fogger and a long tube, and was tested in an underground mine on vehicle exhaust. Experimental results showed that the fog treatment was effective at removing DPM from the exhaust. On average, the fog improved DPM removal by about 55% compared to when the treatment was not employed (fog off). To better understand the mechanisms responsible for DPM removal in the scrubber, a computer model was generated. The model uses the inlet parameters from the field tests, such as inlet DPM and fog concentration and tube geometry, and predicts the scrubber outlet DPM concentration. The model results suggest that the primary way that DPM is removed from the system is by combining with fog drops, which then hit the scrubber tube walls. This effect is probably enhanced by the ribbed structure of the scrubber tubing used here, which may be important for practical applications.

Exposure to diesel engine exhaust is linked to chronic and acute illness. In underground mines, workers can be exposed to high concentrations for extended periods of time. Therefore, Mine Safety and Health Administration (MSHA) enforces personal exposure and engine emission limits. These regulations target just the solid portion of diesel exhaust, known as diesel particulate matter (DPM). The majority of DPM mass is attributed to particulate organic carbon (POC) and elemental carbon (EC). Total carbon (TC) is the sum of POC and EC and currently used as the surrogate to represent DPM as a whole. The NIOSH Method 5040 is the standard sample collection and analysis procedure. It outlines collection of submicron particulate matter samples on a quartz filter then measurement of POC and EC using a thermal-optical analysis. Error in DPM measurement occurs when volatile organic carbon (VOC) sorbs onto the particulate matter deposit and filter resulting in a positive sampling artifact. To correct for this, a dynamic blank method with two quartz filters (i.e., primary and secondary) in tandem is used. However, the accuracy of the dynamic blank correction method is dependent on equal sorption of VOC onto each filter. Observed instances of higher VOC on the secondary filter result in underestimated POC measurements and in some cases negative POC. The work presented in this thesis investigates the sources of VOC interference in particulate matter sampling and possible solutions. Three existing datasets containing information from blank samples and laboratory and field DPM samples were analyzed to look into instances of higher VOC sorption onto the secondary filter. Negative total POC results were limited to blank samples, but negative results for the POC of individual isotherms were observed in blank and DPM samples. A follow-up study looked into the possibility of sampling materials as a source of VOC that preferentially sorbs onto the secondary filter. Blank samples were assembled to test five sampling materials (i.e., two types of sample cassette, cellulose support pads, impactor cassettes, and impactors). In addition, sample storage conditions (i.e., temperature and duration) were tested for their impact on VOC sorption. It was discovered that all of the sample materials tested contributed VOC and, as expected, higher storage temperatures and longer storage durations increase the amount of VOC. Preferential sorption onto the secondary filter was observed in most conditions as well. A field study explored thermal separation of VOC and POC as a possible alternative to the dynamic blank correction method. Two sets of DPM samples were collected from two locations in an underground stone mine and one set of ambient particulate matter samples was collected from a highly trafficked truck stop. The temperature of 175°C was used for this preliminary investigation. The effectiveness of a temperature separation may depend on sample location. To better understand VOC and POC evolution characteristic, further testing with a wide range of sample mass and composition as well as different temperatures is suggested. It seems unlikely that a correction method using a separation temperature would be more effective than the standard dynamic blank in occupational DPM monitoring. The work presented in this thesis highlights the difficulty in accurately measuring POC. / Master of Science / Diesel Particulate matter (DPM) is the solid portion of diesel exhaust and can cause chronic and acute illness. Underground miners can regularly be exposed to high concentrations of DPM over long periods of time, therefore DPM must be monitored. Total Carbon (TC) is the sum of particulate organic and elemental carbon (POC and EC) and is used as the surrogate measurement to represent DPM. The standard method of DPM sample analysis is subject to volatile organic carbon (VOC) interference, therefore a dynamic blank correction is used. However, in some cases, the dynamic blank over- or under-corrects. This thesis presents studies to better understand the source(s) of VOC interference and possible solutions. Three existing datasets containing information from blank samples and laboratory and field DPM samples were investigated for instances of VOC interference resulting in an overcorrection. Such instances were limited to blank and low mass samples. A field study looked into the possibility of sampling materials as a source of VOC that may cause overcorrection when using the dynamic blank method. Blank samples were assembled to test five sampling materials as well as various sample storage conditions. It was discovered that all of the sample materials tested contributed VOC and, as expected, higher storage temperatures and longer storage durations increase the amount of VOC. A second field study explored thermal separation of VOC and POC as a possible alternative to the dynamic blank correction method. Two sets of DPM samples were collected from two locations in an underground stone mine and one set of ambient particulate matter samples was collected from a highly trafficked truck stop. The temperature of 175°C was used for this preliminary investigation. Results indicate that the effectiveness of temperature separation may depend on sample concentration and composition. To better understand VOC and POC evolution characteristic, further testing with a wide range of sample mass and composition, as well as, different temperatures is suggested. The work presented in this thesis highlights the difficulty in accurately measuring POC.

Le premier chapitre de cette thèse traite de l'importance des échelles temporelles et spatiales dans le contexte des systèmes vivants. J'y décris également les principaux composants de la réponse mécanique des cellules vivantes. Après ce chapitre introductif, le deuxième chapitre est dédié à la réponse mécanique des cellules évaluée avec l'AFM et en particulier, son aspect dynamique. Je présente d'abord l'analyse des courbes force-indentation, puis je propose une méthode alternative pour l'étude de la rhéologie cellulaire qui est basée sur l'excitation multifréquence du levier par bruit thermique. La DPM est l'objet du troisième chapitre où je revisite la méthode d'extraction de phase en utilisant la transformation en ondelette à deux dimensions. Ensuite je montre comment la DPM peut être utilisée pour caractériser les fluctuations temporelles et la morphologie de différents types de cellules du sang et de cellules adhérentes. Finalement, le chapitre quatre est un chapitre de conclusion où je fais une synthèse des résultats obtenus. Par exemple, je montre que, en comparaison avec des cellules saines, les cellules leucémiques subissent des changements morphologiques qui sont accompagnés par un comportement mécanique plus rigide et plus élastique. Cela indique que dans cet exemple la transformation cellulaire n'est pas seulement donnée par son cortex mais aussi par son cytosquelette et son couplage avec le noyau / In the first chapter of this thesis I discuss the importance of spatial and temporal scales in living systems, and I review the main components involved in the mechanical response of living cells. After this introductory chapter, the second one is dedicated to evaluating the mechanical response of single-cells with AFM, and in particular, its dynamical aspect. I present the analysis of force-indentation curves without any assumption on the linearity of the system, contrary to more typical analysis based on Sneddon’s or Hertz models. Then, I propose an alternative method to study the cell rheology based on the multi-frequency excitation of the cantilever by thermal noise. DPM is discussed on chapter three. I revisit the phase recovery method using the 2D wavelet transform, and I show how DPM can be used to characterize the temporal fluctuations and the morphology of different types of blood cells and adherent cells. Finally, chapter four is a conclusion chapter where I summarise our results by comparing healthy and pathological immature blood cells. For instance I show that, in comparison to healthy cells, leukaemic cells undergo morphological changes that are accompanied by a stiffer and more elastic behaviour. Altogether, our results indicate that this cell transformation involves the whole cytoskeleton and its coupling to the nucleus rather than simply the cell cortex