A theory is presented for the calculation of the pressure distribution and lift for arbitrary thick airfoils fitted with normal upper surface spoilers in two dimensional incompressible flow. Airfoil shape and angle of attack and spoiler location and height are arbitrary and unrestricted. The theory uses a sequence of conformal transformations from a basic flow past a circle, with one or two sources on that part of the circle corresponding to the surface of the airfoil and spoiler exposed to the wake. The flow inside the separating streamlines is ignored, and the upper surface pressure downstream of the spoiler is taken as an empirical parameter, assumed constant. The sources in the wake permit satisfaction of Kutta conditions with the desired pressure at the spoiler tip and airfoil trailing edge. Features of the theory include good prediction of loading distribution, a finite wake width and a pressure distribution on the separating streamlines decreasing asymptotically towards the free stream value at infinity. The theoretical predictions are compared with lift and pressure measurements on a Joukowsky airfoil of 11% thickness and 2.L\% camber, and with lift measurements on a 14% thick Clark Y airfoil. Both airfoils were tested through a range of angle of attack with spoilers of 5 and 10% chord height, each at several locations. Good agreement is found. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

An experimental study has been carried out on an airfoil with slotted flap and spoiler using Joukowsky profiles. Pressure distributions were measured as functions of angle of attack, flap deflection angle, spoiler size and inclination. The results are uncorrected for wind tunnel wall effects but the data base is available to carry out the corrections. The results will be used to compare with predictions of a theoretical model, yet to be worked out, which combines work previously done by Williams, Jandali, Parkinson and Yeung. This theory will involve the potential flow about a two-element 'near'-Joukowsky airfoil system. The secondary airfoil is a simulated slotted flap. Various size spoilers are introduced to the system at arbitrary angles of inclination using methods proposed by Parkinson and Yeung. The experimental results are qualitatively reasonable and some interesting effects are observed. The behaviour of spoilers, when used with slotted flaps at various deflection angles, corresponds well with requirements of aircraft in approach or landing situations. Similarly, the use of slotted flaps alone provides the high lift at low angle of attack which is beneficial to aircraft taking off. Some recommendations are proposed for further testing with this equipment. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

No description available.

Do terrorist organisations have an effect on the sustainability of peace agreements? In this paper, I investigate the potential consequences of including armed non-state actors in peace agreements. Specifically, I focus on the most controversial type of actor: terrorist organisations and how they affect the sustainability of peace agreements. I utilise a unique dataset covering all intrastate peace agreements and designated terrorist organisations between 1998 – 2011, and employ a survival analysis through a cox proportional hazard model. I find strong evidence suggesting that the presence of terrorist organisations – both in conflicts and in peace agreements – have a significantly destabilising effect on the sustainability of peace agreements. I also find evidence which suggest that more complex power sharing arrangements could be a viable option to combat the destabilising effect of terrorist actors, although this effect might not be as strong in peace process agreements.

With the advent of steerable, ram air parafoil canopies, aerial payload delivery has become a viable alternative for situations involving remote or undeveloped areas, hostile environments, or otherwise inaccessible locations. Autonomously guided systems utilizing such steerable, ram air canopies are typically controlled by symmetric and asymmetric deflection of the canopy trailing edge. Although these systems have demonstrated substantial improvement in landing accuracy over similarly sized unguided systems, their low number of available control channels and limited ability to alter vehicle glide slope during flight makes them highly susceptible to atmospheric gusts and other unknown conditions near the target area. This research aims to improve landing accuracy in such adverse conditions by replacing the standard trailing edge deflection control mechanism in favor of upper surface canopy spoilers. These spoilers operate by opening several spanwise slits in the upper surface of the parafoil canopy thus forming a virtual spoiler from the stream of expelled pressurized air. In particular, estimation of steady-state vehicle flight characteristics in response to different symmetric and asymmetric spoiler openings was determined for two different small-scale test vehicles. Additionally, improvements in autonomous landing accuracy using upper surface spoilers in a combined lateral and longitudinal control scheme was investigated computationally using a high fidelity, 6-DOF dynamic model of the test vehicle and further validated in actual flight experiments with good results. Lastly, a novel in-canopy bleed air actuation system suitable for large-scale parafoil aircraft was designed, fabricated, and flight-tested. The in-canopy system consists of several small, specifically designed wireless winch actuators mounted entirely inside the parafoil canopy. Each in-canopy actuator is capable of opening one or more upper surface canopy spoilers via a unique internal rigging structure. This system demonstrates not only the applicability of bleed air spoiler control for large-scale autonomous parafoil and payload aircraft, but also provides the potential for significant savings in size, weight, and cost of the required actuation hardware for currently fielded systems.

As the Congolese conflict marks the 20th year, and the peace process 17 years, the apparent question is why is the search for peace in the DRC proving elusive? Spoilers and other impediments to the peace process in the DRC have been studied and UN peacekeepers have been operational in the country for nearly seventeen years, but the conflict continues. This study therefore seeks to understand the potential of UN peacekeeping to hinder the peace process in the DRC, and the United Nations Organization Stabilization Mission in the Democratic Republic of the Congo (MONUSCO) constitutes a study case. MONUSCO has been in operation for six years today succeeding the United Nations Organization Mission in the Democratic Republic of Congo (MONUC), and is still operating. Inasmuch as it looks early to gauge whether MONUSCO is contributing to progress or hindering the peace process in the DRC, this study focuses on the practices of UN peacekeepers under MONUSCO and their potential to delay peace initiatives. Using secondary data as the main source of information, i.e., books, articles, journals, news, UN reports and resolutions, triangulation and Game Theory, especially the Prisoners’ Dilemma Analytical Framework derived from the Prisoners’ Dilemma Game Matrix, this study finds that the Stabilization Mission is inconsistent, i.e., UN peacekeepers are performing controversial tasks: use of force to protect civilians, engaging in battles to neutralize armed militias and investigation of war crimes and human rights, tasks that have generated resentment from the FARDC/Kinshasa government and the armed militias, making the search for peace a one actors responsibility [MONUSCO’s task]. A clear indication that MONUSCO is hindering the peace process in the DRC. The thematic analysis details five (5) themes and indicates that; cooperation is problematic, use of force to protect civilians is controversial, there is a mismatch between doctrine and practice, i.e., deviation of UN peacekeeping from the basic principles, the justice dilemma, and an understanding of peace as absence of war and fighters. The thesis concludes that practices of MONUSCO need revisiting, dialogue should be encouraged, revision of peacekeeping principles and accurate timing of interventions, so as to enhance progress in the search for peace in DRC. / <p>This thesis is a true representation of my artistic academic work, written passiantely and informed with logical interpretation of other authors' perepectives, i.e., it is a deskstudy. It took me 10 weeks to produce this piece of work which adds to the ongoing debate on the Congolese process and UN peacekeeping in the DRC and other parts of the world. Written in Linnaeus University, Småland Sweden. </p> / Masters Thesis

Some peace processes are tainted by more violence than the actual conflict, sometimes worsened by spoilers. Although spoilers pose a threat to the writing or lasting of peace agreements, they do not always succeed, and instead, peace can flourish. Despite this, the effects of spoiling violence on society have not been thoroughly explored. Research suggests that criminal violence thrives in the post-war period, this paper aims to answer the research question: How do spoilers affect post-war criminal violence? As spoilers instil insecurity, the hypothesis is that post-war criminal violence will increase within a state if the peace agreements have experienced outside spoiling. To investigate this, a Structured Focused Comparison approach is employed, comparing two cases, El Salvador and Sierra Leone. However, this paper was unable to find support for the proposed causal relationship between outside spoiling and post-war criminal violence. Further research is needed to understand how spoilers affect both the peace process and criminal violence.

This dissertation addresses the breakthrough of the multi-reel feature film in the United States, and the significance of this process within the wider context of the American film industry and culture in the 1910s. The purpose is to provide a new, and more comprehensive analytical framing of the topic, and to enhance our understanding of how a new central commodity, i.e. the multi-reel feature film, changed the conditions for film exhibition and reception. The introduction links the breakthrough of the multi-reel feature film to an array of film-historical transformations unfolding in the US around the same time. A critical assessment of previous scholarly work dealing with the early feature is also provided. Part I analyzes how the breakthrough of the multi-reel feature film was negotiated within the trade and by contemporary commentators. The result is a multi-perspective framing of the topic that highlights the complexity of these cultural negotiations and the uncertainty over cinema’s possible futures. Part II shifts attention to film culture and film exhibition in Philadelphia around 1914. The objective of this case study, largely based on newspaper sources, is to examine how the increasingly common multi-reel feature film was integrated into and/or changed the existing film culture in the city. The main conclusion is that experimentation and diversity rather than smooth transitions characterized the local response to the emergence of features. Part III deepens the investigation of local diversity by offering a case study of one particular film: The Spoilers (Selig Polyscope Co., 1914). The conditions of the film’s historical reception are outlined, and particular attention is given to the film’s role in the Americanization of the feature film market.

Spoilers are in everyday life often seen as something to be strictly avoided. Nonetheless, earlier studies researching short stories found that spoilers can enhance the enjoyment of a story, rather than destroying it. At the same time, there are studies that have reached opposite results, but the placement and style of the spoiler may affect how it is received. When it comes to games there are no, or only a few, studies on the subject. When unspoiled, players generally choose non-aggressive options, but they are also strongly influenced by what role the character they play has in the narrative. The spoiler can upset this. By knowing what may happen players act differently, as well as thinking about the story in other ways than unspoiled players do. / <p>Artefakten gjordes tillsammans med Siri Åhman som skrev arbetet <em>Wait I'm Him Now - Identification and Choice in Games with More Than One Protagonist. </em>Åhman ändrade dock mycket i artefaktens uppbyggnad för att få den att passa hennes frågeställning bättre.</p>