Rozprawy doktorskie na temat „Drag”

This thesis explores drag as a fascinating performance medium with a rich and complex history. The thesis is presented as intertextual, comprising two parts: a body of creative works and a written paper. Drag as a male cross-dressing performance is documented to contextualise contemporary drag as an important LGBTIQA+ performance medium. During gay liberation, drag had been a form of entertainment with a defiant socio-political ethos used for resistance, fun & survival. The question set out in the paper is: how can a theory of drag explore drag as a site of carnival to elucidate new ways of looking at sex, gender & sexual orientation? Drag is proposed as a carnivalesque performance framed as a conceptual lens viewing drag as grotesque carnival, initially theorised by Russian writer Mikhail Bakhtin, who explained carnival as having roots in pagan ritual where there is a dissolution of order, the destabilising of boundaries, and an abandonment of rules. As drag is a cross-dressing transformation simultaneously embodying the representation of both sexes, the drag persona is a form of carnivalesque mask, and this is explored as a metaphysical experience linked to ancient theatre, occult ritual, & grotesquery. For gay culture, artistic risk-taking and a radical rethinking of drag created the emergence of a grotesque aesthetic caused by a state of community grief, anxiety, and fear amid mass death from HIV/AIDS. This era also created conditions for the emergence of a queer identity, as a call to arms in the fight against HIV/AIDS and homophobia. Queer and queer theory is used in this thesis to explore a novel way of reimagining drag. A chapter is dedicated to Ballroom culture, a drag-centred movement started by LGBTIQA+ Black & Latino communities in the US. The exploration of the Carnival Drag Grotesque in this thesis will offer a deeper insight into a fascinating medium, steeped in ancient ritual & tainted with its own polemics, bringing drag to a material/mystical nexus.

For over the thirty years, drag performance has been examined for its utility to subvert or reinforce traditional gender roles. Many of these examinations have focused on performances that emphasize subversion and separated drag into two categories: the progressive drag that subverts, and the regressive drag that reinforces. While this approach has provided a wealth of understanding about drag performance and gender roles, drag can be examined without separating its subverting/reinforcing aspects. If drag is seen as the consideration of a given gender performing the not given gender, then another consideration can be made to the subverting performing the reinforcing. This new consideration, referred to here as the divine, can provide new utility for drag performance and its role in understanding gender.

This thesis describes the Drag language. Drag is a general purpose, gradually typed, lexically scoped, and multi-paradigm pro- gramming language. The essence of Drag is to build the abstract syntax trees of the programs directly and interactively. Our work includes the language specification and a prototype program. The language specification focuses on the syntax, the semantic model, and the type system. The prototype consists of an interactive editor and a compiler that targets several plat- forms, among which we focus on the LLVM platform in this thesis.

Air intake related aerodynamic aspects of an air breathing cruise missile are analyzed. A method for thrust and drag accounting is established, and, based on that, a partial simulation model for the thrust and intake spillage drag force of the missile is developed. The model combines wind tunnel data with analytical data. The intake spillage force has two components, pre entry force and cowl force. The pre entry force can be computed relatively easily, while the cowl force depends strongly upon actual intake geometry and no general method exists. An approximate cowl force is computed based on available data. The accuracy of the cowl drag results is difficult to predict, as no complete theoretical model is available, and the partial models published cite no accuracy limits. The cowl drag results need further verification through wind tunnel tests or CFD analysis. However, spillage force results are produced that are in the magnitude of 30% of total drag, which is expected. Also, dependencies on known variables and trends are as expected. Finally, flight test profiles in order to validate the model are suggested.

Since the publication of Mother Camp: Female Impersonators in America in 1972, drag performance has been an object of fascination for many French and Anglo-American queer and feminist theorists. Employing an intersectional, transfeminist approach, I explore central preoccupations traversing diverse theories of drag, focusing particularly on three issues: the relationship between drag and performativity, the assumption that a drag performer’s gender differs from the gender they perform on stage, and the positioning of drag as necessarily either subversive or reactionary. Analysing the flaws and benefits of these conceptual trends as they appear in a representative selection of French and Anglo-American queer and feminist theoretical texts, I challenge the perception of drag as subverting or upholding the status quo, suggesting that this understanding creates reductive generalisations and cannot account for the diversity and complexity of many current drag scenes. Further, I contest the definitional focus on a presumed opposition between the gender of the performer and the gender they perform on stage. Although a performer’s gender can shape their experience and understanding of drag performance, the focus on this presumed opposition erases certain performers’ identities and distracts from what is actually happening on stage. While my first two chapters concentrate on selected queer and feminist theorizations of drag performance, my final chapter considers the relationship between Butlerian gender parody, intramural parody, and extramural satire in Rachilde’s Monsieur Vénus, Virginia Woolf’s Orlando, and Monique Wittig’s Le Corps lesbien. Here, I develop the frame of ‘textual drag’ to describe the interactions of these forms of parody and satire in these texts, while highlighting their authors’ interrogations of norms of gender performance, gender identity, and embodiment. I then conclude by demonstrating how existing insights into drag performance can be combined with my own findings to create a particularizing, transfeminist approach to drag.

Thesis (Ph. D.) -- University of Maryland, College Park, 2004.
Thesis research directed by: Physics. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

Denna uppsats handlar om gymnasieelevers anpassning till olika texttyper i skrift. Uppsatsens frågeställningar är: 1.) Vilka berättande drag återfinns i gymnasieelevers argumenterande texter? 2.) Har gymnasieelevers medvetenhet om den argumenterande texttypen något samband med det betyg som de får på uppgiften?Hypotesen som framläggs är att det förekommer fler berättande drag i texter med lägre betyg, eftersom målen för högre betyg kräver en medvetenhet om olika texttyper.Undersökningen är utförd på debattinlägg skrivna av 20 gymnasieelever, uppgift B1 i det nationella kursprovet i Svenska B vårterminen 2012 Dit vinden blåser (Skolverket 2012b). Utifrån förekomsten eller avsaknaden av fyra berättande drag, utvalda av uppsatsens författare, klassificeras elevtexterna enligt hur väl de uppfyller den argumenterande texttypen. Kriterierna gäller pronomenval, inledning, personliga exempel och ordval.Resultatet av undersökningen visar på att förekomsten av berättande drag återfinns i elevtexter på samtliga betygsnivåer. De berättande dragen i elevtexterna är mest frekventa i de elevtexter som inte har uppnått ett godkänt resultat, det finns lika många berättande drag i G-elevtexterna som i VG-elevtexterna och det är lägst antal berättande drag i MVG-elevtexterna. Därmed verifieras hypotesen.

This thesis is motivated by the application of active flow control on the cabin of trucks, thereby providing a new means of drag reduction. Particularly, the work presented strives to identify how plasma actuators can be used to reduce the drag caused by the detachment of the flow around the A-pillars. This is achieved by conducting numerical simulations, and is part of a larger project that also includes experimental. The effect of plasma actuators is modeled through a body force, which adds very little computational cost and is suitable for implementation in most CFD solvers. The spatial distribution of this force is described by coefficients which have been optimized against experimental data, and the model was shown to be able to accurately reproduce the wall jet created by a single plasma actuator in a no-flow condition. A half cylinder geometry - a simplified geometry for the A-pillar of a truck - was used in a preliminary Large Eddy Simulation (LES) study that showed that the actuator alone, operated continuously, was not sufficient to achieve a significant reduction of the drag. Nevertheless, a significant drag reduction was obtained by simply increasing the strength of the body force to a higher value, showing that this type of actuation remains relevant for the reduction of drag. In the course of finding ways to improve the efficiency of the actuator, dynamic mode decomposition was investigated as a post-processing tool to extract structures in the flow. Such structures are identified by their spatial location and frequency, and might help to understand how the actuator should be used to maximize drag reduction. Thus a parallel code for dynamic mode decomposition was developed in order to facilitate the treatment of the large amounts of data obtained by LES. This code and LES itself were thereafter evaluated in the case of a pulsating channel flow. By using the dynamic mode decomposition it was possible to accurately extract oscillating profiles at the forcing frequency, although harmonics with lower amplitude compared to the turbulence intensity could not be obtained.
Denna avhandling behandlar tillämpningen av aktiv strömningskontroll för lastbilshytter, vilket är en ny metod för minskning av luftmotståndet. Mer i detalj är det övergripande målet att visa på hur plasmaaktuatorer kan användas för att minska luftmotståndet orsakat av avlösningen runt A-stolparna. In denna avhandling studeras detta genom numeriska simuleringar. Arbetet är en del av ett projekt där även experimentella försök görs. Effekten av plasmaaktuatorer modelleras genom en masskraft, vilket inte ger nämnvärd ökning av beräkningstiden och är lämplig för implementering i de flesta CFD-lösare. Den rumsliga fördelningen av kraften bestäms av koefficienter vilka i detta arbete beräknades utifrån experimentella data. Modellen har visat sig kunna återskapa en stråle nära väggen med god noggrannhet av en enskild plasmaaktuator för en halvcylinder utan strömning. Samma geometri - en halvcylinder som här används som förenklad geometri av A-stolpen på en lastbil - användes i en preliminär LES studie som visade att enbart aktuatorn vid kontinuerlig drift inte var tillräckligt för att uppnå en signifikant minskning av luftmotståndet. En signifikant minskning av luftmotståndet erhölls genom att helt enkelt öka styrkan på kraften, vilket visats att denna typ av strömningskontroll är relevant för minskning av luftmotståndet. I syfte att förbättra effektiviteten hos aktuatorn, studerades dynamic mode decomposition, som ett verktyg för efterbehandling för att få fram flödesstrukturer. Dessa strukturer identifieras genom deras rumsupplösning och frekvens och kan hjälpa till att förstå hur aktuatorerna bör användas för att minska luftmotståndet. En parallelliserad kod för dynamic mode decomposition utvecklades för att underlätta efterbehandlingen av de stora datamängder som fås från LES-beräkningarna. Slutligen, utvärderades denna kod och LES-beräkningar på ett strömningsfall med pulserande kanalflöde. Metoden, dynamic mode decomposition, visade sig kunna extrahera de oscillerande flödesprofilerna med hög noggrannhet för den påtvingade frekvensen. Övertoner med lägre amplitud jämfört med turbulensintensiteten kunde dock inte erhållas.

QC 20150312

The addition of a minute amount of polymer or surfactant additive to a turbulent fluid flow can result in a large reduction in the frictional drag in pipes and channels. Over the past decades, numerous studies have been carried out on drag reducing additives (DRA). DRA have been successfully applied for potential benefits in various industrial processes, including oil well operations, heating and cooling water circuits, marine and biomedical systems. The use of additives to enhance flow in petroleum pipelines has received the greatest attention due to its great commercial success in reducting cost and energy consumption. Although this effect has been known for almost half a century, the detailed mechanism of drag reduction have still not been clearly identified and is still a subject of ongoing controversy. The aim of this thesis is to develop an understanding of the role of drag reducing agents and to explain the nature of drag reduction mechanism. This could have an impact on the design of efficient pumping systems, the design of drag-reducing agent that are more stable over time, and the modeling of mixing processes that could be an important consideration in designing practical systems
L'ajout d'une quantité infime d'un polymère ou d'un additif tensioactif à un flux turbulent de fluide peut causer une forte diminution de la friction dans les tuyaux et les canalisations. Ces dix dernières années, de nombreuses études ont été réalisées sur les agents réducteurs de friction (ARF). Les ARF sont utilisés pour leurs effets bénéfiques dans de nombreux procédés industriels, tels que l'extraction de pétrole, le chauffage et le refroidissement de circuits de circulation d'eau ainsi que dans des systèmes marins et biomédicaux. L'utilisation d'additifs pour améliorer l'écoulement dans les canalisations de pétrole a été particulièrement étudiée, en raison de son succès commercial en terme de réductions de couts et de consommation d'énergie. Bien que l'action de ces additifs est connue depuis presque cinquante ans, le mécanisme détaillé de la réduction des frictions n'a pas été clairement identifié et est encore sujet à controverses. Le but de cette étude est d'apporter une explication au rôle de ces agents en matière de réduction des frictions, et d'expliquer la nature ce mécanisme. Les résultats présentés ici peuvent influencer significativement la conception des systèmes de pompes, le développement d'agent réducteurs de friction plus stables ainsi que la modélisation de procédés mixtes qui pourraient devenir une considération majeure dans le design de systèmes réels

Thesis (Honors)--Ohio State University, 2005.
Title from first page of PDF file. Document formattted into pages: contains vii, 81 p.; also includes graphics. Includes bibliographical references (p. 81). Available online via Ohio State University's Knowledge Bank.

Thesis (M.S. in Aeronautical Engineering) Naval Postgraduate School, December 1993.
Thesis advisor(s): Howard, Richard M. ; Sweeney, III, Joseph W. "December 1993." Includes bibliographical references (p. 97). Also available online.

Thesis (M.S. in Applied Physics) Naval Postgraduate School, March 1999.
"March 1999". Thesis advisor(s): Andres Larraza, Bruce C. Denardo. Includes bibliographical references (p. 27-28). Also available online.

Thesis (Honors)--Ohio State University, 2006.
Title from first page of PDF file. Document formatted into pages: contains 36 p.; also includes graphics. Includes bibliographical references (p. 31-32). Available online via Ohio State University's Knowledge Bank.

An experimental investigation has been undertaken in a wind tunnel to study the induced airflow and drag reduction capability of AC glow discharge plasma actuators. Plasma is the fourth state of matter whereby a medium, such as air, is ionized creating a system of electrons, ions and neutral particles. Surface glow discharge plasma actuators have recently become a topic for flow control due to their ability to exert a body force near the wall of an aerodynamic object which can create or alter a flow. The exact nature of this force is not well understood, although the current state of knowledge is that the phenomenon results from the presence of charged plasma particles in a highly non-uniform electric field. Such actuators are lightweight, fully electronic (needing no moving parts or complicated ducting), have high bandwidth and high energy density. The manufacture of plasma actuators is relatively cheap and they can be easily retrofitted to existing surfaces. The first part of this study aims at characterising the airflow induced by surface plasma actuators in initially static air. Ambient air temperature and velocity profiles are presented around a variety of actuators in order to understand the nature of the induced flow for various parameters such as applied voltage, frequency, actuator geometry and material. It is found that the plasma actuator creates a laminar wall jet along the surface of the material on which it is placed. The second part of the study aims at using plasma actuators to reduce skin-friction drag in a fully developed turbulent boundary layer. Actuators are designed to induce spanwise forcing near the wall, oscillating in time. Thermal anemometry measurements within the boundary layer are presented. These show that the surface plasma can cause a skin-friction drag reduction of up to 45% due to the creation of streamwise vortices which interact with, and disrupt the near-wall turbulence production cycle.

This is the first holistic study of English cross-dressed performers. It will situate drag performers within their cultural context in order to establish how their concerns, motivations, employment, communities, friendships, self-perception and artistic ambitions impact on their performances. Furthermore, it utilises performance and ethnographic analysis of a number of artistes to demonstrate how modern drag politicises communities and forms an accessible critique of social roles. Furthermore, it aims to reunite Queer Theory with the realities of its effects on society. The first chapter establishes the study’s position within the overarching framework of Queer Theory. A troupe of drag performers are examined in light of Judith Butler’s theories of performativity to elucidate how the social aspects of gender can be developed. Then, Kate Bornstein’s work is used to illustrate how individuals can use these identities as a conscious method of self-development. Following this, the second chapter explores the social role drag performers have, sometimes inadvertently, chosen. Developing the theories of the interrelationship between belief, LGBTQ sexuality and otherness purported by Kate Bornstein, it asserts the educational and social role that can be taken by drag performers. The third chapter focuses on the messages that these LGTBQ shaman (a theory developed from Laurence Senelick’s work) convey to their community via performance. Case studies illustrate how the performers tailor their acts to politicise their often apathetic audiences. This work is extrapolated in the fourth chapter, which focuses on the community-wide Pride Parade performances. The Rabelaisian carnivalesque is used to argue that the carnivals encourage the audience to review their gender development, revitalising the culture. Finally, the fifth chapter demonstrates how these differing theoretical strands enable televised drag performance to challenge censure by questioning ‘otherness’ itself. This is achieved with reference to horror theory, camp and the performances of Danny La Rue, amongst others, and the cultural impact of the programme Little Britain (2003). The thesis demonstrates that drag is, in fact, a dialogue that can engage and politicise mainstream culture.

The primary motivation for this work was to predict the conditions that would yield minimum drag for a small Ram-Air Turbine used to provide a specified power requirement for a small flight test instrument called the Boundary Layer Data System. Actuator Disk Theory was used to provide an analytical model for this work. Classic Actuator Disk Theory (CADT) or Froude’s Momentum Theory was initially established for quasi-one-dimensional flows and inviscid fluids to predict the power output, drag, and efficiency of energy-extracting devices as a function of wake and freestream velocities using the laws of Conservations of Mass, Momentum, and Energy. Because swirl and losses due to the effects of viscosity have real and significant impacts on existing turbines, there is a strong motivation to develop models which can provide generalized results about the performance of an energy-extractor, such as a turbine, with the inclusion of these effects. A model with swirl and a model with losses due to the effects of viscosity were incorporated into CADT which yielded equations that predicted the performance of an energy-extractor for both un-ducted and ducted cases. In both of these models, for this application, additional performance parameters were analyzed including the drag, drag coefficient, power output, power coefficient, force coefficient, and relative efficiency. For the un-ducted CADT, it is well known that the wake-to-freestream velocity ratio of 1/3 will give the maximum power extraction efficiency of 59.3%; this result is called the Betz limit. However, the present analysis shows that reduced drag for a desired power extraction will occur for wake-to-freestream velocity ratios higher than the value of 1/3 which results in maximum power extraction efficiency. This in turn means that a turbine with a larger area than the smallest possible turbine for a specified power extraction will actually experience a lower drag. The model with the inclusion of swirl made use of the Moment of Momentum Theorem applied to a single-rotor actuator disk with no stators, in addition to the laws of Conservation of Mass, Momentum, and Energy from the CADT. The results from the model w/swirl showed that drag remains unchanged while power extracted decreases with the addition of swirl, with swirl effects becoming more severe for tip speed ratios below about 5. As for CADT, reduced drag for a specified power extraction can be achieved when the wake-to-freestream velocity ratio is higher that than which provides maximum power extraction efficiency. The model w/losses due to viscosity incorporated the losses into the Conservation of Energy relationship. The results from the model w/losses showed that there is a distinct wake-to-freestream velocity ratio at which minimum drag for a specified power output is achieved, and that this velocity ratio is usually—but not always—higher than that for which the power extraction efficiency is a maximum. It was concluded that a lower drag for a specified power output of an energy-extractor can usually be achieved at a wake-to-freestream velocity ratio higher than that which produces the v maximum power extraction efficiency. The latter condition, known as the Betz limit for CADT, and which defines the minimum size for a turbine to provide a specified power extraction, is therefore not the correct target design condition to achieve lowest drag for a small Ram-Air Turbine to power BLDS.

Coronal Mass Ejections (CMEs) are considered to be one of the most energetic events in the heliosphere. Capable of inducing geomagnetic storms on Earth that can cause damage to electronics, a pillar which the modern society we live in leans heavily upon. Being able to accurately predict the arrival of CMEs would present us with the ability to issue timely warnings to authorities and commercial actors, allowing for protective measures to be put in place minimizing the damage. In this study the predicted arrival times and speeds from the Drag Based Model (DBM) and Drag Based Ensemble Model (DBEM) were compared to observational data from a set of 12 events containing fast, Earth-directed Halo CMEs and their corresponding shocks. Although DBM was developed to model CME propagation, varying some parameters allow it to be used for estimating shock/sheath arrival. The results presented in this study indicate that on average DBM performs best when the drag-parameter γ is in the range 0.2 ≤ γ ≤ 0.3. However the variability in the results show that determining a universal value of γ for fast CMEs does not increase the consistency in the model's performance. For completeness, further investigation is needed to account for not only halo CMEs. This will allow to test broader range of variation in the DBEM input parameters.

A drag study was conducted on an oblate ellipsoid body in the Virginia Tech Stability Wind Tunnel. Two-dimensional wake surveys were taken with a seven-hole probe and an integral momentum method was applied to the results to calculate the drag on the body. Several different model configurations were tested; these included the model oriented at a 0° and 10° angle of attack with respect to the oncoming flow. For both angles, the model was tested with and without flow trip strips. At the 0° angle of attack orientation, data were taken at a speed of 44 m/s. Data with the model at a 10° angle of attack were taken at 44 m/s and 16 m/s. The high speed flow corresponded to a length-based Reynolds number of about 4.3 million; the low speed flow gave a Reynolds number of about 1.6 million. The results indicated that the length-squared drag coefficients ranged from around 0.0026 for the 0° angle of attack test cases and 0.0035 for the 10° angle of attack test cases. The 10° angle of attack cases had higher drag due to the increase in the frontal profile area of the model and the addition of induced drag. The flow trip strips appeared to have a tiny effect on the drag; a slight increase in drag coefficient was seen by their application but it was not outside of the uncertainty in the calculation. At the lower speed, uncertainties in the calculation were so high that the drag results could not be considered with much confidence, but the drag coefficient did decrease from the higher Reynolds number cases. Uncertainty in the drag calculations derived primarily from spatial fluctuations of the mean velocity and total pressure in the wake profile; uncertainty was estimated to be about 16% or less for the 44 m/s test cases.
Master of Science

Denna systematiska litteraturstudie handlar om definitioner av psykopatiska drag hos barn och ungdomar. Denna studie ämnar redovisa hur psykopatiska drag kan yttra sig, om de är knutna till arv eller miljö samt huruvida dessa personlighetsdrag hos barn och ungdomar är tillfälliga eller bestående. Riskbedömningsinstrument som PCL: YV och APSD samt aktuell forskning kring genetiska och sociala förklaringar till psykopatiska drag hos barn och ungdomar är inkluderat. Psykopatiska drag hos barn och ungdomar är ett kontroversiellt ämne. Studiens huvudsakliga frågeställning är; kan psykopati identifieras hos barn och ungdomar?
This systematic literature study discusses definitions of psychopathic traits in children and adolescents. We aim to clarify how psychopathic traits are expressed, if they are connected to inheritance or upbringing as well as if these personality traits are temporary or persistent. Risk assessments such as PCL: YV and APSD and current research about possible genetic and social explanations to psychopathic traits in childhood and adolescence is included. Psychopathic traits in childhood is a controversial subject. Our main questions is; can psychopathy be identified in children and adolescents?

Bibliography: leaves 71-74
This thesis deals with the airflow over a double trailer Gull Wing truck, with a view to reducing the drag of the truck. To investigate the flow over the truck, a 1:20 scale double trailer truck model was designed and constructed from chipboard for wind tunnel experiments. The overall size of the model is 1100 mm long, 130 mm wide and 215 mm high. A same scale numerical model was also built for computational simulations.

One of the governing sources of energy loss in a modern day jet engine is attributed to surfacedrag. This energy loss can be divided into friction loss and to surface geometry loss. Thefriction loss is the shear stress the fluid experience due to a no slip condition at the wall, whilethe surface geometry loss is due to pressure drop when the fuel passes an obstacle.The objective of this work is to study the drag coefficient of a plate for different types ofmilled tracks and for different kinds of flow conditions. The theories used to calculate thedrag coefficient are based on the momentum thickness theory including shear stress- andpressure integration. The computations were carried out with ANSYS CFX assuming a ShearStress Transport 𝑘 − 𝜔 turbulence model. The steady state flow conditions tested are varyingboundary layer thicknesses, milled track heights, milled track widths, Reynolds numbers overthe milled track height, Reynolds numbers over the plate length and free-stream angle ofattack. By knowing what affects the drag coefficient for different types of milled tracks, morepractical models can be developed making the prediction of surface drag inside the jet enginemore accurate.This report has resulted in a formula that predicts the drag coefficient for different types ofmilled surfaces. The formula is derived from the assumption that the CFD results on ANSYSCFX are correct. A physical test has not been made to verify those results, however this has tobe done to prove that this formula is valid.

This Thesis examines the mechanical response of large objects -called intruders or anchors that are embedded into a granular packing and subjected to dynamic loadings. By using a numerical approach based on a discrete element method, the study focuses on a canonical test comprising a plate-shaped intruder, placed horizontally and being uplifted vertically. The research is articulated into three projects. The first project considers steady and quasi-static loading conditions, whereby the intruder is uplifted at a constant velocity. Its purpose is to validate the numerical method against previously established models for the maximum drag force, also known as uplift capacity. Incidentally, this project establishes to what extent it is possible to downscale/upscale the size of the intruder relative to the grain size. This result is important as most laboratory and numerical tests, starting from those presented in this study, are performed with object-to-grain size ratios much smaller than real applications. The second project considers the mobility response under cyclic loading, whereby the object is subjected to a cyclic uplift force. A series of numerical tests exploring a range of loading frequency and magnitude reveals the existence of three possible mobility responses. The object can either move up steadily, not move up at all or exhibit a creep trajectory. Furthermore, this study points out a phenomena of elasto-inertial resonance inducing a fluidisation of the packing even at low loading magnitudes. The third project considers loading patterns including some acceleration of the object. This reveals a new contribution to the drag force, which we named “inertial drag”. We show that this contribution results from gradual mobilisation and acceleration of grains in the packing above the object. We further find that achieving a complete grain mobilisation takes a finite period of time, controlled by the elasto-inertial stress propagation from the object to the free surface. These three projects highlight fundamental differences between the drag force in quasi-static loading and dynamic loading conditions. A number of analytical models, built from identified micro-mechanical processes, are proposed to rationalise these effects

The freight rail industry is essential to the US infrastructure and there is significant motivation to improve its efficiency. The aerodynamic drag associated with transport of commodities by rail is becoming increasingly important as the cost of diesel fuel increases. For intermodal railcars a significant amount of aerodynamic drag is a result of the large distance between containers that often occurs and the resulting pressure drag resulting from the separated flow that results due to their non-streamlined shape. This thesis reports on research that has been done to characterize the aerodynamic drag on intermodal train builds and allow their builds to be optimized for fuel efficiency. Data was obtained through wind tunnel testing of G-scale (1/29) models. Drag on these models was measured using a system of isolated load cell balances and the wind tunnel speed was varied from 20 to 100 mph. Several common intermodal scenarios were explored and the aerodynamic drag for each was characterized. These scenarios were the partial loading of containers on rail cars, the influence of the gap between containers, the use of a streamlined container near the front of the train, and the inclusion of semi-trailers on railcars. For each case multiple build configurations were tested and the drag results were compared to determine the optimal build for each scenario.

Il presente lavoro ha ad oggetto l’analisi del fenomeno giuridico della covendita, che, come noto, si è diffuso nella prassi negoziale italiana attraverso il recepimento di talune fattispecie negoziali nate e sviluppatesi negli ordinamenti anglosassoni. In particolare, l’attenzione viene rivolta alle cc.dd. clausole di drag along (o “trascinamento”), le quali si inseriscono nell’ambito delle pattuizioni negoziali che comportano un obbligo di covendita. Le ragioni della scelta di tale tema di ricerca risiedono nella diffusione di questo tipo di clausole nella disciplina dei rapporti societari. In effetti, la redazione di clausole che dispongono un obbligo di covendita rappresenta ormai una tecnica negoziale ampiamente diffusa nella pratica dei negozi acquisitivi di partecipazioni sociali. La clausola di drag along è normalmente inserita all’interno di patti parasociali stipulati laddove venga effettuata un’acquisizione da cui risulti una società partecipata da una pluralità di investitori. Tuttavia, con sempre maggior frequenza, e nell’ambito di una certa tendenza alla “migrazione dal parasociale al sociale” quale effetto della nuova disciplina dei patti parasociali introdotta dalla riforma del diritto societario, questo genere di clausole viene inserito direttamente negli statuti delle società di capitali. Il recepimento a livello statutario della clausola di trascinamento ha posto numerosi interrogativi in ordine alla relativa natura giuridica, validità ed efficacia. In particolare, gli aspetti che hanno costituito oggetto di maggiore attenzione da parte della dottrina e della giurisprudenza sono costituiti dalla collocazione sistematica della clausola statutaria di trascinamento e dalle relative condizioni di validità alla luce dei principi inderogabili dell’ordinamento societario. Un profilo che, invece, non è stato adeguatamente approfondito attiene alla natura “sociale” o “parasociale” di una siffatta clausola statutaria. Si tratta, peraltro, di un aspetto non secondario, atteso che, come cerca di dimostrare il presente lavoro, l’inserimento della clausola di trascinamento all’interno dello statuto sociale non sembrerebbe implicare di per sé il riconoscimento alla medesima di un valore “sociale” e, dunque, imporne automaticamente la valutazione della validità alla stregua del diritto societario. In questa prospettiva, il presente lavoro procede, innanzitutto, ad una ricognizione delle clausole che vengono generalmente ricondotte nel genus della covendita: e ciò, segnatamente, al fine di ricostruire i tratti tipologici delle clausole di drag along, così da distinguerle dalle altre tecniche negoziali ricomprese nell’istituto della covendita. In particolare, si cerca di individuare l’ambito di applicazione di una siffatta clausola e gli interessi economici che essa è in grado di soddisfare. L’indagine compiuta dimostra che la clausola di drag along è di regola estranea alla sfera dell’ordinamento sociale e abitualmente inserita in patti parasociali stipulati da soci di società a struttura chiusa che presentano un elevato grado di investimenti specifici, in ragione della sua inerenza a specifiche operazioni di acquisizione societaria, caratterizzate dal normale interesse dei soci paciscenti alla massimizzazione del valore delle proprie partecipazioni sociali e dal fisiologico disinteresse degli stessi a vincolare i soci presenti e futuri ad un determinato assetto negoziale. Successivamente, alla luce dei risultati raggiunti, obiettivo del lavoro è quello di dimostrare che la clausola statutaria di drag along può assumere carattere sociale o parasociale a seconda del caso concreto. In particolare, tale verifica, compiuta attraverso l’esame dei vari criteri di distinzione del sociale dal parasociale elaborati dalla dottrina e dalla giurisprudenza, porta a ritenere che, al fine di riconoscere un rilievo sociale alla clausola statutaria di drag along, sia necessario che la stessa – oltre ad essere formulata in modo impersonale – soddisfi un ulteriore requisito: e, cioè, sia idonea a rispondere ad interessi sociali, destinati a soddisfare un’esigenza dell’ente o, indistintamente, dei soci in astratto, e non miri, invece, a gestire unicamente specifici rapporti tra soci. Infine, vengono esaminate le conseguenze che derivano sul piano qualificatorio e disciplinare a seconda che la clausola statutaria di drag along assuma, nel caso concreto, carattere “sociale” o “parasociale”. In particolare, l’indagine cerca di dimostrare, da un lato, che, contrariamente a quanto solitamente si ritiene, il patto parasociale di trascinamento – così come la clausola statutaria di drag along di natura parasociale – non pare essere, a rigore, un patto che disciplina le condizioni di “circolazione” delle partecipazioni, ma un patto che regola le condizioni di “investimento” e di “disinvestimento” nella società, essendo normalmente volto a tutelare l’interesse di tutti i soci paciscenti alla massimizzazione del valore delle partecipazioni sociali; dall’altro lato, che la struttura funzionale della clausola statutaria di drag along di carattere sociale presenta delle analogie rispetto alla struttura funzionale degli istituti giuridici del riscatto azionario e dell’esclusione del socio di s.r.l., dovendosi pertanto ritenere valida nella misura in cui sia compatibile con il principio dell’equa valorizzazione della partecipazione obbligatoriamente dismessa che si ricava dagli artt. 2437 sexies e 2473 bis c.c.
The present work relates to the legal analysis of the phenomenon of co-sale, which, as noted, it is common practice in negotiating through the implementation of certain Italian case negotiating created and developed in the Anglo-Saxon legal systems. In particular, attention is paid to cc.dd. drag along clauses (or "drag"), which are part of the negotiating stipulations that imply an obligation of co-sale. The reasons for the choice of research topic that reside in the spread of such clauses in the discipline of corporate relationships. In fact, the wording of clauses that have an obligation to co-sale is now negotiating a technique widely used in the practice of shopping acquisitive of shareholdings. The drag along clause is normally included in shareholders' agreements concluded when an acquisition is made, which result in a company owned by several investors. However, with increasing frequency, and within a certain tendency to "migrate from the parasocial to social" as a result of the new discipline of shareholders' agreements introduced by the reform of company law, such clauses are inserted directly into the statutes of the company capital. The implementation of the statutory provision at the drag posed numerous questions as to its legal, valid and effective. In particular, the aspects that have been the subject of increased attention by the doctrine and jurisprudence are constituted by the systematic position of the statute and the drive conditions of its validity in the light of the overriding principles of corporate order. A profile, however, has not been adequately thorough regards the "social" or "parasocial" of such a statute. It is, however, an important aspect, since, as this paper seeks to demonstrate, the inclusion of the clause in the bylaws do not drag would seem to imply the recognition of itself to the same value of a "social "and, therefore, automatically impose the same way as the evaluation of the validity of corporate law. In this perspective, this work proceeds, first, a survey of the clauses that are generally traced in the genus of the co-sale, and this, in particular, in order to reconstruct the typological features of the drag along clauses, so as to distinguish them from other negotiating techniques covered in the institution of co-sale. In particular, it seeks to identify the scope of such a clause and the economic interests that it is able to satisfy. The investigation carried out shows that the drag along clause is generally alien to the sphere of social order and usually included in shareholders' agreements concluded by shareholders of companies with a closed structure with a high degree of specific investments, because of its inherent specific corporate acquisitions, characterized by normal partners' interest in maximizing the value of their shareholdings and physiologically the same selflessness to bind the shareholders present and future negotiations to a specific structure. Later, in the light of the results achieved, goal of the work is to demonstrate that the statute can take to drag along social or agreement depending on the case. In particular, the verification process, accomplished through the examination of the various criteria of social distinction by the agreement drawn up by the doctrine and case law, leads to the belief that in order to recognize a social relevance to the statute of drag along, it is necessary that the same - as well as being formulated in an impersonal way - to fulfill an additional requirement: it is, is likely to respond to social interests, to meet a need or entity, without distinction of members in the abstract, and is not intended, however to handle only specific relationships between members. Finally, we examined the consequences on the level and discipline depending on whether the statute assumes drag along, in this case, "social" or " parasocial ". In particular, the survey seeks to demonstrate, firstly, that, contrary to what is usually considered the shareholders 'drag - as well as the statute of nature to drag along' agreement - does not seem to be, strictly speaking, a covenant governing the conditions of "circulation" of the investments, but a pact that regulates the conditions of "investment" and "disinvestment" in society, being generally aimed at protecting the interest of all shareholders to maximize the value of equity, on the other hand, the functional structure of the statute to drag along for social presents similarities with respect to the functional structure of legal institutions and the exclusion of equity of redemption partner srl, having to therefore be considered valid to the extent that both compatible with the principle of fair value of the investment which is made mandatory abandoned by the articles 2437 sexies e 2473 bis c.c.

Il presente lavoro ha ad oggetto l’analisi del fenomeno giuridico della covendita, che, come noto, si è diffuso nella prassi negoziale italiana attraverso il recepimento di talune fattispecie negoziali nate e sviluppatesi negli ordinamenti anglosassoni. In particolare, l’attenzione viene rivolta alle cc.dd. clausole di drag along (o “trascinamento”), le quali si inseriscono nell’ambito delle pattuizioni negoziali che comportano un obbligo di covendita. Le ragioni della scelta di tale tema di ricerca risiedono nella diffusione di questo tipo di clausole nella disciplina dei rapporti societari. In effetti, la redazione di clausole che dispongono un obbligo di covendita rappresenta ormai una tecnica negoziale ampiamente diffusa nella pratica dei negozi acquisitivi di partecipazioni sociali. La clausola di drag along è normalmente inserita all’interno di patti parasociali stipulati laddove venga effettuata un’acquisizione da cui risulti una società partecipata da una pluralità di investitori. Tuttavia, con sempre maggior frequenza, e nell’ambito di una certa tendenza alla “migrazione dal parasociale al sociale” quale effetto della nuova disciplina dei patti parasociali introdotta dalla riforma del diritto societario, questo genere di clausole viene inserito direttamente negli statuti delle società di capitali. Il recepimento a livello statutario della clausola di trascinamento ha posto numerosi interrogativi in ordine alla relativa natura giuridica, validità ed efficacia. In particolare, gli aspetti che hanno costituito oggetto di maggiore attenzione da parte della dottrina e della giurisprudenza sono costituiti dalla collocazione sistematica della clausola statutaria di trascinamento e dalle relative condizioni di validità alla luce dei principi inderogabili dell’ordinamento societario. Un profilo che, invece, non è stato adeguatamente approfondito attiene alla natura “sociale” o “parasociale” di una siffatta clausola statutaria. Si tratta, peraltro, di un aspetto non secondario, atteso che, come cerca di dimostrare il presente lavoro, l’inserimento della clausola di trascinamento all’interno dello statuto sociale non sembrerebbe implicare di per sé il riconoscimento alla medesima di un valore “sociale” e, dunque, imporne automaticamente la valutazione della validità alla stregua del diritto societario. In questa prospettiva, il presente lavoro procede, innanzitutto, ad una ricognizione delle clausole che vengono generalmente ricondotte nel genus della covendita: e ciò, segnatamente, al fine di ricostruire i tratti tipologici delle clausole di drag along, così da distinguerle dalle altre tecniche negoziali ricomprese nell’istituto della covendita. In particolare, si cerca di individuare l’ambito di applicazione di una siffatta clausola e gli interessi economici che essa è in grado di soddisfare. L’indagine compiuta dimostra che la clausola di drag along è di regola estranea alla sfera dell’ordinamento sociale e abitualmente inserita in patti parasociali stipulati da soci di società a struttura chiusa che presentano un elevato grado di investimenti specifici, in ragione della sua inerenza a specifiche operazioni di acquisizione societaria, caratterizzate dal normale interesse dei soci paciscenti alla massimizzazione del valore delle proprie partecipazioni sociali e dal fisiologico disinteresse degli stessi a vincolare i soci presenti e futuri ad un determinato assetto negoziale. Successivamente, alla luce dei risultati raggiunti, obiettivo del lavoro è quello di dimostrare che la clausola statutaria di drag along può assumere carattere sociale o parasociale a seconda del caso concreto. In particolare, tale verifica, compiuta attraverso l’esame dei vari criteri di distinzione del sociale dal parasociale elaborati dalla dottrina e dalla giurisprudenza, porta a ritenere che, al fine di riconoscere un rilievo sociale alla clausola statutaria di drag along, sia necessario che la stessa – oltre ad essere formulata in modo impersonale – soddisfi un ulteriore requisito: e, cioè, sia idonea a rispondere ad interessi sociali, destinati a soddisfare un’esigenza dell’ente o, indistintamente, dei soci in astratto, e non miri, invece, a gestire unicamente specifici rapporti tra soci. Infine, vengono esaminate le conseguenze che derivano sul piano qualificatorio e disciplinare a seconda che la clausola statutaria di drag along assuma, nel caso concreto, carattere “sociale” o “parasociale”. In particolare, l’indagine cerca di dimostrare, da un lato, che, contrariamente a quanto solitamente si ritiene, il patto parasociale di trascinamento – così come la clausola statutaria di drag along di natura parasociale – non pare essere, a rigore, un patto che disciplina le condizioni di “circolazione” delle partecipazioni, ma un patto che regola le condizioni di “investimento” e di “disinvestimento” nella società, essendo normalmente volto a tutelare l’interesse di tutti i soci paciscenti alla massimizzazione del valore delle partecipazioni sociali; dall’altro lato, che la struttura funzionale della clausola statutaria di drag along di carattere sociale presenta delle analogie rispetto alla struttura funzionale degli istituti giuridici del riscatto azionario e dell’esclusione del socio di s.r.l., dovendosi pertanto ritenere valida nella misura in cui sia compatibile con il principio dell’equa valorizzazione della partecipazione obbligatoriamente dismessa che si ricava dagli artt. 2437 sexies e 2473 bis c.c.
The present work relates to the legal analysis of the phenomenon of co-sale, which, as noted, it is common practice in negotiating through the implementation of certain Italian case negotiating created and developed in the Anglo-Saxon legal systems. In particular, attention is paid to cc.dd. drag along clauses (or "drag"), which are part of the negotiating stipulations that imply an obligation of co-sale. The reasons for the choice of research topic that reside in the spread of such clauses in the discipline of corporate relationships. In fact, the wording of clauses that have an obligation to co-sale is now negotiating a technique widely used in the practice of shopping acquisitive of shareholdings. The drag along clause is normally included in shareholders' agreements concluded when an acquisition is made, which result in a company owned by several investors. However, with increasing frequency, and within a certain tendency to "migrate from the parasocial to social" as a result of the new discipline of shareholders' agreements introduced by the reform of company law, such clauses are inserted directly into the statutes of the company capital. The implementation of the statutory provision at the drag posed numerous questions as to its legal, valid and effective. In particular, the aspects that have been the subject of increased attention by the doctrine and jurisprudence are constituted by the systematic position of the statute and the drive conditions of its validity in the light of the overriding principles of corporate order. A profile, however, has not been adequately thorough regards the "social" or "parasocial" of such a statute. It is, however, an important aspect, since, as this paper seeks to demonstrate, the inclusion of the clause in the bylaws do not drag would seem to imply the recognition of itself to the same value of a "social "and, therefore, automatically impose the same way as the evaluation of the validity of corporate law. In this perspective, this work proceeds, first, a survey of the clauses that are generally traced in the genus of the co-sale, and this, in particular, in order to reconstruct the typological features of the drag along clauses, so as to distinguish them from other negotiating techniques covered in the institution of co-sale. In particular, it seeks to identify the scope of such a clause and the economic interests that it is able to satisfy. The investigation carried out shows that the drag along clause is generally alien to the sphere of social order and usually included in shareholders' agreements concluded by shareholders of companies with a closed structure with a high degree of specific investments, because of its inherent specific corporate acquisitions, characterized by normal partners' interest in maximizing the value of their shareholdings and physiologically the same selflessness to bind the shareholders present and future negotiations to a specific structure. Later, in the light of the results achieved, goal of the work is to demonstrate that the statute can take to drag along social or agreement depending on the case. In particular, the verification process, accomplished through the examination of the various criteria of social distinction by the agreement drawn up by the doctrine and case law, leads to the belief that in order to recognize a social relevance to the statute of drag along, it is necessary that the same - as well as being formulated in an impersonal way - to fulfill an additional requirement: it is, is likely to respond to social interests, to meet a need or entity, without distinction of members in the abstract, and is not intended, however to handle only specific relationships between members. Finally, we examined the consequences on the level and discipline depending on whether the statute assumes drag along, in this case, "social" or " parasocial ". In particular, the survey seeks to demonstrate, firstly, that, contrary to what is usually considered the shareholders 'drag - as well as the statute of nature to drag along' agreement - does not seem to be, strictly speaking, a covenant governing the conditions of "circulation" of the investments, but a pact that regulates the conditions of "investment" and "disinvestment" in society, being generally aimed at protecting the interest of all shareholders to maximize the value of equity, on the other hand, the functional structure of the statute to drag along for social presents similarities with respect to the functional structure of legal institutions and the exclusion of equity of redemption partner srl, having to therefore be considered valid to the extent that both compatible with the principle of fair value of the investment which is made mandatory abandoned by the articles 2437 sexies e 2473 bis c.c.

The drag approximations done in the initial design phase needed to be verified. A model of the aircraft has been analyzed with CFD and results examined to see how accurate the estimations were. A step by step analysis was made and then a simulation was run. The drag results of the CFD analysis did not meet the goal of the initial design study. Several reasons for this are discussed. The analysis shows that the aircraft design works well aerodynamically but also shows a few areas where the design can be improved.

Det approximerade värdet på luftmotståndet som gjordes I den preliminära designfasen behövde verifieras. En flygplansmodell har analyserats med CFD och resultaten har undersökts för att se hur exakta antagandena var. En analys gjordes steg för steg och slutligen har en simulering utförts. Det uppmätta luftmotståndet motsvarade inte målet i den preliminära designfasen. Flera olika anledningar till detta diskuteras. Analysen visar att denna flygplansdesign fungerar bra aerodynamiskt men identifierar också en del punkter på vilken den kan förbättras.

The aim of this thesis was to contribute to the development of an objective, evidence-based international classification system for para-swimmers by quantifying the effect of physical impairment on passive and active drag. The thesis comprises five studies. Study 1 identified a significant relationship between normalised passive drag and the para-swimmers’ International Paralympic Committee (IPC) Class, but an inconsistent difference in normalised passive drag between adjacent classes. High within-class variability in passive drag indicates that the current classification system does not always differentiate clearly between swimming groups. Study 2 found that anthropometric features of para-swimmers, such as height and body mass, differed significantly between IPC Classes, whereas Shoulder Width, Chest Depth, Shoulder Girth and Torso Girth did not. A weak correlation existed between para-swimmers’ anthropometry and their passive drag, which indicates that other factors, such as impairment type, may be more important predictors of passive drag than anthropometry. Study 3 revealed that certain impairments, such as double-leg amputation above knee level, may predispose a para-swimmer to a relatively high passive drag which disadvantages them in competition. Study 4 compared two methods of estimating active drag during front crawl swimming: the Naval Architecture Based Approach (NABA) and the Active Towing Method (ATM). The means were not statistically different. Using a sensitivity analysis, the NABA was identified as the more reliable method of assessing active drag. Study 5 found that active and passive drag of elite para-swimmers are highly correlated but no relationship existed between active drag and International Paralympic Committee S Class (IPC S Class), indicating that factors other than impairment level may be more important in determining active drag. The relationships discovered between drag, IPC Class, anthropometry and impairments will contribute to the development of the future IPC Classification system.

Viscoelastic fluids are non-Newtonian fluids exhibiting both viscous and elastic properties. Many fluids of practical importance (polymers, surfactants, mucus, shampoos etc.) display viscoelastic effects to different degrees under a wide range of flow conditions and thus, these fluids present a variety of problems. In this work, we study two problems at very different flow conditions in viscoelastic fluids: a) the effect of swimming gait on bio-locomotion and b) characterizing the drag reducing fluids used for gravel-packing operations in the petroleum industry. For the first problem, we give formulas for the swimming of simplified two-dimensional bodies at low Reynolds numbers in complex fluids using the reciprocal theorem. By way of these formulas, we calculate the swimming velocity due to small-amplitude deformations on the simplest of these bodies, a two-dimensional sheet, to explore general conditions on the swimming gait under which the sheet may move faster, or slower, in a viscoelastic fluid compared to a Newtonian fluid. We show that in general, for small amplitude deformations, a speed increase can only be realized by multiple deformation modes in contrast to slip flows. Additionally, we show that a change in swimming speed is directly due to a change in thrust generated by the swimmer. Later, we work with viscoelastic additives (xanthan and a zwitterionic viscoelastic surfactant, VES), widely used as drag reducers for gravel-packing applications. While the behavior of xanthan is well characterized in the literature, much less is known about the VES characteristics, despite widespread use. We performed a number of rheological tests and flow-loop experiments on VES solutions to understand the structural characteristics to make better process predictions. Unlike xanthan, which displays typical viscoelastic liquid characteristics, VES displays elastic gel-like behaviour. The gel-like behaviour suggests long and relatively unbreakable chain lengths of the wormlike micelles in the VES at room temperature leading to gelation by entanglement. Also, a shear-thickening behaviour of VES samples at higher shear rates is observed, possibly as a result of shear-induced structures. Finally, we present a novel representation scheme to depict the flow-loop results relating the rheological characterization while observing drag reduction.
Applied Science, Faculty of
Graduate

Satellite formation flying is a very promising field for future space missions as it holds many advantages over the common monolithic satellite. However, in order for the formations to be effective, a formation maintenance scheme is required to overcome perturbations arising from different sources. In this thesis the effect of atmospheric drag on a formation is examined. To do so the Schweighart and Sedwick equations, which describe the motion of a spacecraft, called deputy spacecraft, relative to another spacecraft, referred to as the chief spacecraft, placed in a circular orbit, are modified to account for atmospheric drag. The modified equations keep the effects arising from the oblateness of the Earth, known as the J2 effects, which were included in the model proposed by Schweighart and Sedwick. A similar set of equation is then developed for satellite formations placed in orbits of small eccentricity. A formation maintenance scheme which uses differential atmospheric as a means of control is then introduced. Numerical simulation results showing the evolution of formations through time with and without active control are also provided.
Le vol de satellite en formation est un domaine très prometteur pour de futures missions spatial étant donnés les nombreux avantages que cette technologie détient le satellite monolitique commun. Toutefois, pour que ces formations soient efficaces, un système de maintenance de formation est nécessaire pour surmonter les perturbations provenant de multiples sources. Dans cette these, l'effet du freinage atmosphérique sur une formation est examiné. Pour ce faire, les equations de Schweighart et Sedwick, qui décrivent le mouvement d'un engin spatial, appelé meneur, relative à un autre engine, nommé suiveur, place sur une orbite circulaire, sont modifiées pour tenir compte du freinage atmosphérique. Les equations modifiées conservent les effets découlant du fait que la Terre n'est pas parfaitement sphérique, connus comme les effets J2, qui sont inclus dans le modèle proposé par Schweighart et Sedwick. Un ensemble d'équations similaire est ensuite développé pour des formations de satellites placées sur des orbites de petites eccentricités. Un système de maintenance de formation qui utilise le freinage atmosphérique comme moyen de contrôle est introduit. Des resultats de simulations numériques montrant l'évolution dans le temps de formations avec et sans contrôle sont également fournis.

This thesis is the outcome of a practice-based research project into contemporary formations of gender and sexuality through the study of drag performance. It is composed of two elements, the film Dragging the Past (presented on a DVD) and this written text. The film offers a multi-layered view of the drag performances in Koukles Club, Athens, Greece. The written thesis offers sociological analysis of articulations of self, from both performers and audiences. The purpose of this thesis was to investigate productions of the self through the process of viewing, engaging, and performing in a drag show, and also to examine the ways in which subjects negotiate their gender during this process. Moreover, this study illuminates the deployment of drag narratives, by both drag performers and members of the audience, as tools to create a desired self, always in relation to the other. A visual ethnography, that uses participant observation and video elicitation as key methods to gather empirical data, provides the foundation for this study. The ethnographic ‘I’ of the researcher combines with participants in the field and ‘together’ they produce ethnographic knowledge. Video elicitation interviews capture narratives of embodiment and competition; both film and text reflect that visual methods offer new perspectives on the way subjects form their gender and sexuality. This study reveals productions of particular kinds of subjects, specifically those that perform gender in relation to the other, while engaged in the process of competition and embodiment (incarnation), while also interrupting and disrupting the other. These themes proved to be central to the narratives participants deployed to perform the self. Furthermore, this thesis demonstrates that photographs and the act of mirroring are important to the forming of gender and sexuality, as they become tools for the production of the self.

In this thesis measurements are presented of the frictional drag between two closely spaced but electrically isolated two dimensional electron gases, where the momentum transfer from a current in one layer is measured as a voltage in the adjacent layer. The drag measurement has been applied to this bilayer system under a number of different conditions. Firstly, at zero magnetic field and at temperatures comparable to the Fermi temperature, a new interlayer coupling mechanism is measured. The experimental traces are compared to a recent theory of the plasmon enhancement of the interlayer Coulomb coupling, which is shown to account for the observed behaviour. The drag is used to probe the bilayer plasmon modes, and it is shown that calculations in the random phase approximation provide an over estimate of the plasmon energies, which are reduced by many-body correlations. The fit to experiment is improved for calculations where the intra-layer exchange interaction is included in the Hubbard approximation. Next, the drag is measured in the presence of a magnetic field at temperatures sufficient to smear the Landau level structure. It is shown that the discrete energy spectrum of the electronic states leads to an enhancement of low energy scattering, which favours single particle Coulomb scattering as the dominant interlayer coupling. When the temperature is lowered into the QH regime, it is shown that the drag is more sensitive to the spin-splitting of the Landau levels than single layer transport measurements. It is also shown that the localised states in the Landau level tails, should be included in the theoretical models. A novel electron-hole symmetry applies to the interlayer scattering in this regime, and a scattering mechanism is suggested involving interedge scattering within each layer via localised states.

Гречко, Д. С. Серверний додаток розвиваючої гри «Drag&Win» : дипломна робота : 121 Інженерія програмного забезпечення / Д. С. Гречко; керівник роботи Білоус І. В. ; Національний університет «Чернігівська політехніка», кафедра інформаційних технологій і програмної інженерії. – Чернігів, 2020. – 62 с.
Об'єкт розробки являє собою серверну частину додатку системи розвиваючої гри Drag&Win. Метою розробки є одержання системи, що значно спрощує роботу додавання, редагування та видалення даних. Крім того, система забезпечує синхронізацію з клієнтською частиною та вільне масштабування команди контент менеджерів. У ході розробки була створена працездатна серверна частина інформаційно-комп'ютерної система, складовими частинами якої є: - база даних; - панель адміністратора; - сервер. Виконання роботи проводилося відповідно до поставлених вимог. Подальший розвиток роботи можливо у бік ускладнення бази даних з метою збільшення обсягу збережених даних, ускладнення функціоналу для системи та створення додаткової вихідної документації. Робота має практичну цінність.
The object of development is a system of server application for the developmental game Drag & Win. The purpose of the development is to obtain a system that greatly simplifies the work of adding, editing and deleting data. Synchronization with the client part and free scaling of the team. During the development, a working information and computer system was created, the components of which are: – database; – admin panel: – server. The work was performed in accordance with the requirements. Further development of work is possible in the direction of complicating the database in order to increase the amount of stored data, complicate the functionality for the system and create additional source documentation. The work has practical value.

Клієнтська частина розвиваючої гри Drag&Win : дипломна робота : 121 Інженерія програмного забезпечення / М. С. Нікітенко ; керівник роботи Білоус І. В. ; Національний університет «Чернігівська політехніка», кафедра інформаційних технологій і програмної інженерії . – Чернігів, 2020. – 61 с.
Розроблюваний програмний продукт – це клієнтська частина для розвиваючої гри Drag&Win, який спрямований для розвитку дітей і дорослих та покращення рівня ерудиції. Результатом роботи є реалізація таких можливостей додатку:  підтримка операційної системи IOS та Android;  нараховування балів за правильні відповіді;  прораховування кількості життів в одній ігровій сесії;  створення зручного путівник для нових користувачів;  введення основних одиниць ваги (кілограмів або фунтів);  введення звукових ефектів;  можливість користувача додатку поділитися досягненнями;  режим гри, який працює без використання інтернету; Для реалізації системи використовувались інструментальні засоби JetBrains WebStorm 2019.1. Можливе подальше покращення функціоналу додатку.
Qualification work of the bachelor, 60 p., 21 images, 14 sources, 1 supplement. The developed software product is the customer part for the Drag&Win educational game, which is aimed at the development of children and adults and improving the level of erudition. The result is the implementation of the following features of the application:  support for IOS and Android operating systems;  accrual of points for correct answers;  counting the number of lives in one game session;  creating a user-friendly guide for new users;  introduction of basic units of weight (kilograms or pounds);  introduction of sound effects;  the ability of the application user to share achievements;  game mode that works without the use of the Internet; JetBrains WebStorm 2019.1 tools were used to implement the system. It is possible to further improve the functionality of the application.

The distribution of lift between the wing and tail surfaces of a conventional aircraft is examined in order to determine the combination that would produce the minimum drag for a given lift. Further, the center of gravity (CG) position which gives the desired lift distribution and at the same time, maintains aircraft trim is determined. Furthermore, a classic set of non-linear equations of motion for longitudinal flight is reduced to a set of linear equations by linearization. The location of the CG of the aircraft is then changed and a linear feedback control law is used to retain the dynamic characteristic (flying qualities) of the airplane. The response of the aircraft to an external disturbance such as a gust (modeled with a stochastic process) is studied in terms of drag versus CG position. Finally, it is shown that the position of the CG for minimum drag should be determined with consideration of the expected atmospheric turbulence.
Master of Science

A research effort aimed at enhancing ACSYNT, a computer program for aircraft conceptual design, has necessitated the development of methods for predicting inlet drag. Originally, the drag of only one inlet type, the variable-geometry conical inlet, could be calculated within ACSYNT. This prompted the present research which resulted in the creation of a modular suite of subroutines that extend the capability of ACSYNT. Using this new source code, ACSYNT can now predict the drag of subsonic and supersonic pitot inlets, fixed- and variable-geometry conical inlets, and two-dimensional supersonic inlets. Even though the requirement of computational efficiency has necessitated that many simplifications be made in the analysis, the drag calculations have a sound physical basis. The semi-empirical methods have been extracted from a number of sources based on an extensive literature survey, and these have been enhanced to encompass the full range of inlet operating conditions. The effectiveness of the methods has been demonstrated by comparing some results of the predictions to published data.
Master of Science

In the last twenty or so years the results of theory and experiment have produced much information on the characteristics of gas-surface interactions relevant to a satellite in hyperthermal free-molecular flow. This thesis contains reviews of the rarefied gas dynamics applicable to satellites and has attempted to compare existing models of gas-surface interaction with contemporary knowledge of such systems. It is shown that a more natural approach would be to characterise the gas-surface interaction using the normal and tangential momentum accommodation coefficients, igma' and igma respectively, specifically in the form igma = constant , igma' = igma'0 -igma'1sec i where i is the angle subtended between the incident flow and the surface normal and igma,igma'0 and igma'1 are constants. Adopting these relationships, the effects of atmospheric lift on inclination, i, and atmospheric drag on the semi-major axis, a, and eccentricity, e, have been investigated. Applications to ANS-1 (1974-70A) show that the observed perturbation in i can be ascribed primarily to non-zero igma'1 whilst perturbations in a and e produce constraint equations between the three parameters. The numerical results seem to imply that a good theoretical orbit is achieved despite a much lower drag coefficient than anticipated by earlier theories.