AMPLITUDE-VERSUS-ANGLE ANALYSIS AND WIDE-ANGLE-INVERSION OF CROSSWELL SEISMIC DATA IN A CARBONATE RESERVOIR

Crosswell data set contains a range of angles limited only by the geometry of the source and receiver configuration, the separation of the boreholes and the depth to the target. However, the wide angles reflections present in crosswell imaging result in amplitude-versus-angle (AVA) features not usually observed in surface data. These features include reflections from angles that are near critical and beyond critical for many of the interfaces; some of these reflections are visible only for a small range of angles, presumably near their critical angle. High-resolution crosswell seismic surveys were conducted over a Silurian (Niagaran) reef at two fields in northern Michigan, Springdale and Coldspring. The Springdale wells extended to much greater depths than the reef, and imaging was conducted from above and from beneath the reef. Combining the results from images obtained from above with those from beneath provides additional information, by exhibiting ranges of angles that are different for the two images, especially for reflectors at shallow depths, and second, by providing additional constraints on the solutions for Zoeppritz equations. Inversion of seismic data for impedance has become a standard part of the workflow for quantitative reservoir characterization. Inversion of crosswell data using either deterministic or geostatistical methods can lead to poor results with phase change beyond the critical angle, however, the simultaneous pre-stack inversion of partial angle stacks may be best conducted with restrictions to angles less than critical. Deterministic inversion is designed to yield only a single model of elastic properties (best-fit), while the geostatistical inversion produces multiple models (realizations) of elastic properties, lithology and reservoir properties. Geostatistical inversion produces results with far more detail than deterministic inversion. The magnitude of difference in details between both types of inversion becomes increasingly pronounced for thinner reservoirs, particularly those beyond the vertical resolution of the seismic. For any interface imaged from above and from beneath, the results AVA characters must result from identical contrasts in elastic properties in the two sets of images, albeit in reverse order. An inversion approach to handle both datasets simultaneously, at pre-critical angles, is demonstrated in this work. The main exploration problem for carbonate reefs is determining the porosity distribution. Images of elastic properties, obtained from deterministic and geostatistical simultaneous inversion of a high-resolution crosswell seismic survey were used to obtain the internal structure and reservoir properties (porosity) of Niagaran Michigan reef. The images obtained are the best of any Niagaran pinnacle reef to date.

Experimentally and coupled CFD/CSD assisted structural and aeroelastic modelling of the Javelin UAV outboard wing section

This study presents the procedure followed to make a prediction of the critical flutter speed for a composite UAV wing. At the beginning of the study, there was no information available on the materials used for the construction of the wing, and the wing internal structure was unknown. Ground vibration tests were performed in order to detect the structure’s natural frequencies and mode shapes. From tests, it was found that the wing possesses a high stiffness, presenting well separated first bending and torsional natural frequencies. Two finite element models were developed and matched to experimental results. It has been necessary to introduce some assumptions, due to the uncertainties regarding the structure. The matching process was based on natural frequencies’ sensitivity with respect to a change in the mechanical properties of the materials. Once experimental results were met, average material properties were also found. Aerodynamic coefficients for the wing were obtained by means of a CFD software. The same analysis was also conducted when the wing is deformed in its first four mode shapes. A first approximation for flutter critical speed was made with the classical V - g technique. Finally, wing’s aeroelastic behavior was simulated using a coupled CFD/CSD method, obtaining a more accurate flutter prediction. The CSD solver is based on the time integration of modal dynamic equations, requiring the extraction of mode shapes from the previously performed finite-element analysis. Results show that flutter onset is not a risk for the UAV, occurring at velocities well beyond its operative range.

Time Orientation in Organizations: Polychronicity and Multitasking

This dissertation consists of four studies examining two constructs related to time orientation in organizations: polychronicity and multitasking. The first study investigates the internal structure of polychronicity and its external correlates in a sample of undergraduate students (N = 732). Results converge to support a one-factor model and finds measures of polychronicity to be significantly related to extraversion, agreeableness, and openness to experience. The second study quantitatively reviews the existing research examining the relationship between polychronicity and the Big Five factors of personality. Results reveal a significant relationship between extraversion and openness to experience across studies. Studies three and four examine the usefulness of multitasking ability in the prediction of work related criteria using two organizational samples (N = 175 and 119, respectively). Multitasking ability demonstrated predictive validity, however the incremental validity over that of traditional predictors (i.e., cognitive ability and the Big Five factors of personality) was minimal. The relationships between multitasking ability, polychronicity, and other individual differences were also investigated. Polychronicity and multitasking ability proved to be distinct constructs demonstrating differential relationships with cognitive ability, personality, and performance. Results provided support for multitasking performance as a mediator in the relationship between multitasking ability and overall job performance. Additionally, polychronicity moderated the relationship between multitasking ability and both ratings of multitasking performance and overall job performance in Study four. Clarification of the factor structure of polychronicity and its correlates will facilitate future research in the time orientation literature. Results from two organizational samples point to work related measures of multitasking ability as a worthwhile tool for predicting the performance of job applicants.

Proton Form Factor Puzzle and the CEBAF Large Acceptance Spectrometer(CLAS) Two-Photon Exchange Experiment

The electromagnetic form factors are the most fundamental observables that encode information about the internal structure of the nucleon. The electric ($G_{E}$) and the magnetic ($G_{M}$) form factors contain information about the spatial distribution of the charge and magnetization inside the nucleon. A significant discrepancy exists between the Rosenbluth and the polarization transfer measurements of the electromagnetic form factors of the proton. One possible explanation for the discrepancy is the contributions of two-photon exchange (TPE) effects. Theoretical calculations estimating the magnitude of the TPE effect are highly model dependent, and limited experimental evidence for such effects exists. Experimentally, the TPE effect can be measured by comparing the ratio of positron-proton elastic scattering cross section to that of the electron-proton $\large(R = \frac{\sigma (e^{+}p)}{\sigma (e^{-}p)}\large)$. The ratio $R$ was measured over a wide range of kinematics, utilizing a 5.6 GeV primary electron beam produced by the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. This dissertation explored dependence of $R$ on kinematic variables such as squared four-momentum transfer ($Q^{2}$) and the virtual photon polarization parameter ($\varepsilon$). A mixed electron-positron beam was produced from the primary electron beam in experimental Hall B. The mixed beam was scattered from a liquid hydrogen (LH$_{2}$) target. Both the scattered lepton and the recoil proton were detected by the CEBAF Large Acceptance Spectrometer (CLAS). The elastic events were then identified by using elastic scattering kinematics. This work extracted the $Q^{2}$ dependence of $R$ at high $\varepsilon$ ($\varepsilon > $ 0.8) and the $\varepsilon$ dependence of $R$ at $\langle Q^{2} \rangle \approx 0.85$ GeV$^{2}$. In these kinematics, our data confirm the validity of the hadronic calculations of the TPE effect by Blunden, Melnitchouk, and Tjon. This hadronic TPE effect, with additional corrections contributed by higher excitations of the intermediate state nucleon, largely reconciles the Rosenbluth and the polarization transfer measurements of the electromagnetic form factors.

EVIDENCE FOR MECHANICAL STRAINS INFLUENCE IN OSTEOPHYTE DEVELOPMENT

Purpose: Osteophytes are osteo-cartilaginous metaplastic tissue outgrowths of bone capped by cartilage usually found in degenerative and inflammatory joint disease. The presence and degree of maturity of osteophytes, along with joint space narrowing, are the main radiographic criteria for diagnosis and grading osteoarthritis (OA). Although osteophytes are known for being anatomic signs of advanced OA, they can occur in non-symptomatic joints, in joints with no other observable alterations, and in early stage OA. It remains unclear if they develop from molecular, physiological and/or mechanical stimuli. We hypothesized that mechanical strains play a role in osteophyte development. The overall objective of this thesis was to find evidence that osteophytes are influenced by mechanical strains. Methods: The first project was to develop a mechanically-induced osteophyte animal model. One single impact load that was reported to induce moderate joint damage was applied to the periosteum of the rat knee. Animals were sacrificed at four time points to characterize the evolution of damaged tissue and the joint by histology. A second study using human mature hip osteophytes was conducted to evaluate if mature osteophyte presented histological signs of proliferating and developmental processes. The histological characterization of mature osteophyte was used to compare findings of the mechanically-induced osteophyte in the animal model to validate the use of this rodent model in studying some aspect of osteophyte development of human. Lastly, a detailed three-dimensional (3D) radiological morphometric analysis was performed on microscopic computed tomography (µCT) scanned femoral heads collected from total hip arthroplasty patients presenting mature hip osteophytes. Quantitative morphometric measures of osteophytes internal structure was compared to three regions of the femoral head of known quality of organisation and mechanical constraint. Results and Conclusion: Osteophyte can be mechanically induced by a single load impact to the joint periosteum, indicating that a moderate trauma to the periosteal layer of the joint may play a role in osteophyte development. Mature osteophytes have proliferation, developing and remodelling zones and have trabecular structures. Mechanically-induced osteophytes and mature osteophytes presented similar histological composition. Mature osteophytes have organized internal structure. These results provide evidence that mechanical strain can influence osteophyte development.

La produzione ceramica dell'abitato di Mursia (Pantelleria). Interazioni tra comunità costiere della Sicilia e del Mediterraneo centrale tra Bronzo Antico e Bronzo Medio

La ricerca di dottorato affronta lo studio della cultura materiale dell’abitato dell’età del Bronzo di Mursia (isola di Pantelleria) attraverso l’analisi della produzione ceramica. In particolare, sono analizzati gli aspetti che permettono di ampliare l’inquadramento culturale del sito, sia nella sua articolazione interna che nei rapporti con le coeve comunità del Mediterraneo centrale nella prima metà del II millennio a.C. La ricerca inizia con l’illustrazione delle recenti prospettive di studio della Preistoria del Mediterraneo, un tema al centro di un intenso dibattito incentrato sul riconoscimento delle identità culturali e sul ruolo delle reciproche interazioni, con particolare attenzione all’età del Bronzo. Al complesso archeologico di Mursia viene riconosciuto un carattere di eccezionalità per la spettacolare conservazione dei resti archeologici dell’abitato e della necropoli monumentale, oggetto di indagine negli ultimi decenni da parte dell’Università di Bologna e dell’Università Suor Orsola Benincasa di Napoli. Le ricerche hanno consentito di mettere in luce ampie porzioni dell’abitato e di poter esaminare con elevato dettaglio la cultura materiale in rapporto alle modalità insediative diversificate nello spazio e nel tempo. L’approfondimento della ricerca del dottorato verte sullo studio dei manufatti ceramici come strumento privilegiato per definire l’identità culturale della comunità di Mursia, attraverso gli aspetti della produzione artigianale, le abitudini di preparazione e consumo dei cibi e il significato funzionale o simbolico/estetico di alcune categorie vascolari. Rispetto a precedenti presentazioni del contesto di Mursia, la ricerca di dottorato ha enfatizzato, all’interno dell’abbondante produzione ceramica, la presenza di alcune classi con decorazioni incise e impresse che per quantità e caratteri di originalità divengono un elemento aggiuntivo nella definizione della facies di Mursia. Le stesse ceramiche incise e impresse presentano elementi di affinità con una serie di produzioni vascolari coeve nell’area del Mediterraneo centrale, consentendo di affrontare il tema delle interazioni tra diversi contesti insulari

An efficient Jeans modelling of axisymmetric galaxies with multiple stellar components

Dynamical models of stellar systems represent a powerful tool to study their internal structure and dynamics, to interpret the observed morphological and kinematical fields, and also to support numerical simulations of their evolution. We present a method especially designed to build axisymmetric Jeans models of galaxies, assumed as stationary and collisionless stellar systems. The aim is the development of a rigorous and flexible modelling procedure of multicomponent galaxies, composed of different stellar and dark matter distributions, and a central supermassive black hole. The stellar components, in particular, are intended to represent different galaxy structures, such as discs, bulges, halos, and can then have different structural (density profile, flattening, mass, scale-length), dynamical (rotation, velocity dispersion anisotropy), and population (age, metallicity, initial mass function, mass-to-light ratio) properties. The theoretical framework supporting the modelling procedure is presented, with the introduction of a suitable nomenclature, and its numerical implementation is discussed, with particular reference to the numerical code JASMINE2, developed for this purpose. We propose an approach for efficiently scaling the contributions in mass, luminosity, and rotational support, of the different matter components, allowing for fast and flexible explorations of the model parameter space. We also offer different methods of the computation of the gravitational potentials associated of the density components, especially convenient for their easier numerical tractability. A few galaxy models are studied, showing internal, and projected, structural and dynamical properties of multicomponent galaxies, with a focus on axisymmetric early-type galaxies with complex kinematical morphologies. The application of galaxy models to the study of initial conditions for hydro-dynamical and $N$-body simulations of galaxy evolution is also addressed, allowing in particular to investigate the large number of interesting combinations of the parameters which determine the structure and dynamics of complex multicomponent stellar systems.

Study of the rotational state of Titan using radio tracking data of the Dragonfly mission

Our solar system contains an impressive amount of celestial bodies. For example Saturn posses a huge variety of natural satellites, the diversity in size and physical proprieties of which might amaze imagination. The observational data gathered in 30 years range of deep space missions revealed, that some of these bodies can hide subsurface oceans under their crust. The water, as we know, serves as a fundamental base for a possible appearance of life. This statement is quite exited for the scientific society and serves as a reason for studying so called ”ocean worlds”. In order to detect the celestial bodies with the hidden subsurface ocean, one of the key aspects is the study of their rotational state, which is strongly coupled with the body internal structure. It can be done through the various techniques mentioned in Chapter 1. The main goal of the thesis is the study of rotational state of Titan, whose interior structure expectedly contains liquid ocean layer under its icy crust. Titan is the largest moon of Saturn and it is the second largest moon in the solar system in general. This natural satellite is of particular scientific interest, because it is one of a kind which has substantial atmosphere. The present work was done using radio tracking data of the Dragonfly mission which is one of the next NASA’s missions destined for Titan selected as a part of the New Frontiers Program in 2019. The detailed characteristic of the Dragonfly regarding the landing site and mission lifetime was reported in Chapter 2. The radio-tracking communication link from Titan side was performed using Dragonfly X band transponder according to the schedule tracking opportunity. From Earth side according to the mission, Deep Space Station 25 which is a part of NASA’s Deep Space Network was considered. Only Doppler data was used for studying Titan rotational state, even though there are other reliable techniques described in Chapter 3, that in general could be implemented.

Graphite for lithium-ion batteries: mineral analysis and global Material Flow Analysis

Graphite is a mineral commodity used as anode for lithium-ion batteries (LIBs), and its global demand is doomed to increase significantly in the future due to the forecasted global market demand of electric vehicles. Currently, the graphite used to produce LIBs is a mix of synthetic and natural graphite. The first one is produced by the crystallization of petroleum by-products and the second comes from mining, which causes threats related to pollution, social acceptance, and health. This MSc work has the objective of determining compositional and textural characteristics of natural, synthetic, and recycled graphite by using SEM-EDS, XRF, XRD, and TEM analytical techniques and couple these data with dynamic Material Flow Analysis (MFA) models, which have the objective of predicting the future global use of graphite in order to test the hypothesis that natural graphite will no longer be used in the LIB market globally. The mineral analyses reveal that the synthetic graphite samples contain less impurities than the natural graphite, which has a rolled internal structure similar to the recycled one. However, recycled graphite shows fractures and discontinuities of the graphene layers caused by the recycling process, but its rolled internal structure can help the Li-ions’ migration through the fractures. Three dynamic MFA studies have been conducted to test distinct scenarios that include graphite recycling in the period 2022-2050 and it emerges that - irrespective of any considered scenario - there will be an increase of synthetic graphite demand, caused by the limited stocks of battery scrap available. Hence, I conclude that both natural and recycled graphite is doomed to be used in the LIB market in the future, at least until the year 2050 when the stock of recycled graphite production will be enough to supersede natural graphite. In addition, some new improvement in the dismantling and recycling processes are necessary to improve the quality of recycled graphite.

Characterization of Mars rotational dynamics from Doppler tracking of the InSight lander

In the last decades the evolution of radio science has made it possible to infer the atmosphere composition, the surface and the internal structure of the planets. Since the arrival of the first landers on Mars it was possible to make accurate measurements of the dynamics of this planet; in this thesis we will focus on InSight, considering the data disclosed by the JPL relative to the period from November 26th, 2018 to August 15th, 2021. In particular, the Doppler and Range measurements conducted by the RISE (Rotation and Interior Structure Experiment) will be analyzed. Since the accuracy of these measurements was improved significantly the effects due to the atmosphere of Mars might be measured so it should thus be possible to obtain a better estimate of the parameters characterizing the rotational dynamic of Mars. A large part of this study will therefore be dedicated to the study, modeling, implementation and analysis of the atmosphere of Mars, in both its components: troposphere and ionosphere. Once the complete model of Mars had been built, i.e. including the atmosphere, it was then possible to analyze the residuals, obtained between the data of the measurements carried out and the values predicted by the developed model, in order to obtain an estimate of the rotational dynamic of Mars.

Construction and detectors’ characterization of a new detection system for FAMU Experiment

From 2010, the Proton Radius has become one of the most interest value to determine. The first proof of not complete understanding of its internal structure was the measurement of the Lamb Shift using the muonic hydrogen, leading to a value 7σ lower. A new road so was open and the Proton Radius Puzzle epoch begun. FAMU Experiment is a project that tries to give an answer to this Puzzle implementing high precision experimental apparatus. The work of this thesis is based on the study, construction and first characterization of a new detection system. Thanks to the previous experiments and simulations, this apparatus is composed by 17 detectors positioned on a semicircular crown with the related electronic circuit. The detectors' characterization is based on the use of a LabView program controlling a digital potentiometer and on other two analog potentiometers, all three used to set the amplitude of each detector to a predefined value, around 1.2 V, set on the oscilloscope by which is possible to observe the signal. This is the requirement in order to have, in the final measurement, a single high peak given by the sum of all the signals coming from the detectors. Each signal has been acquired for almost half of an hour, but the entire circuit has been maintained active for more time to observe its capacity to work for longer periods. The principal results of this thesis are given by the spectra of 12 detectors and the corresponding values of Voltages, FWHM and Resolution. The outcomes of the acquisitions show also another expected behavior: the strong dependence of the detectors from the temperature, demonstrating that an its change causes fluctuations in the signal. In turn, these fluctuations will affect the spectrum, resulting in a shifting of the curve and a lower Resolution. On the other hand, a measurement performed in stable conditions will lead to accordance between the nominal and experimental measurements, as for the detectors 10, 11 and 12 of our system.

Development and testing of a safety module for diagnostics and protection from hazards in secondary woodworking machinery

The main theme covered by this dissertation is safety, set in the context of automatic machinery for secondary woodworking. The thesis describes in detail the project of a software module for CNC machining centers to protect the operator against hazards and to report errors in the machine safety management. Its design has been developed during an internship at SCM Group technical department. The development of the safety module is addressed step by step in a detailed way: first the company and the reference framework are introduced and then all the design choices are explained and justified. The discussion begins with a detailed analysis of the standards concerning woodworking machines and safety-related software. In this way, a clear and linear procedure can be established to develop and implement the internal structure of the module, its interface, and its application to specific safety-critical conditions. Afterwards, particular attention is paid to software testing, with the development of a comprehensive test procedure for the module, and to diagnostics, especially oriented towards signal management in IoT mode. Finally, the safety module is used as an anti-regression tool to initiate a design improvement of the machine control program. The refactoring steps performed in the process are explained in detail and the SCENT approach is introduced to test the result.

Accudire l’umanità. Proposta di traduzione, analisi e commento del racconto breve di fantascienza cinese Shanyang Renlei di Liu Cixin.

The main topic of this thesis is the italian translation from Chinese of the 2005 short science fiction story, Shanyang Renlei 赡养人类 (known as For the Benefit of Mankind/The Wages of Humanity in English), by Liu Cixin 刘慈欣, the leading figure in contemporary Chinese science fiction, and the analysis of the major problems and challenges encountered during the translation. In terms of its internal structure, the thesis is divided into four chapters. The first chapter is an introduction both for science fiction enthusiasts and laypersons. Thus, it starts with the very concept of “science fiction”; then it analyzes some of the most relevant definitions of the genre throughout the years, with particular attention to the one proposed by Darko Suvin; lastly, it presents a brief but thorough excursus that goes all the way through the origins and development of science fiction in the West and of kehuan xiaoshuo in China, so that the readers can have a glimpse into their similarities and differ-ences as they evolved. The second chapter focuses on Liu Cixin himself and his works. After a short account of the novels and short stories that are considered the most representative of the three creative phases of his career as a science fiction author, with a section dedicated to his opus magnum, the trilogy Diqiu Wangshi 地球往事 (Remembrance of Earth’s Past), the chapter then goes on to analyze the most characteristic features and themes of his narrative style. The chapter ends with a detailed description of the plot of Shanyang Renlei and an in-depth look at the thematic content of the story. Chapters Three and Four presents, respectively, the Italian translation of the short story, and the thorough analysis of some of the most interesting and challenging issues that have arisen during the translation, along with an illustration of the corresponding strategies and solutions.

Roof structure internal, Raun Raun Theatre, Goroka

View of carved king post.

Roof structure, internal, PNG Coffee Industry Board Office and Warehouse, Goroka

View to underside of roof with steel beam and insulation.