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Purpose Throughout an aircraft development process, the conceptual design phase is an extremely important milestone; hence, the quality and success of this step directly affect the overall cost and lead time of the project. Because of this fact, the purpose of this study is to provide outputs and suggestions to the designing engineer regarding the requirements for reducing overall design time as well as costs and creating an ideal design at the early phases of the project by optimizing the aircraft development process. Design methodology approach The system has been prepared parametrically and presents some performance specifications for the aircraft in the early phases of the design, for example, coefficients for lift CL as well as drag CD and weight as well as fuel estimations. The software uses a combination of well-known design techniques within just one platform in contrast to many other applications. Because of this feature, it is not needed to use different sub-platforms which would require an appropriate environment and even though would lead to complications with regard to the connectivity. The system also presents relevant information about the aircraft performance like velocity versus load factor (V-n) diagrams, maximum turn rate of climb, turn rate and climb angle graphs in contrast to many other open-source conceptual design platforms. Findings In this study, authentic General Dynamics F-16 Fighting Falcon and McDonnell Douglas F-15 Eagle data were used as input to the system, and advanced geometric and/or performance graphs were obtained and compared to the literature where a good agreement of the results was observed. These results with regard to the aircraft performance are typically product specific and quite rare in the literature. These data obtained by use of the software during the aircraft design are, thus, of major interest, especially for the design of new aerospace platforms. In this study, all of these graphs (especially the remarkable V-n diagram) are obtained on one platform. Originality value The aircraft conceptual design and analysis system software provides information and suggestions regarding the requirements for reducing the overall design time, reducing the design costs and creating an optimized design at the early phases of a project by optimizing the aircraft development process within just one convenient, that is, user friendly, platform, where it uses a combination of varying methodologies. Besides presenting one interface, which is quite typical for conceptual design tools, it allows applications of methods like vortex lattices and finite differences for obtaining aerodynamic performance parameters.

Dispersion and distribution of graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) in polymer matrices without the use of any functionalization and application of conventional procedures such as mixing or sonication does not display the full potential of the fillers due to agglomeration which limits the use of the corresponding nanomaterials. Contrarily, varying GNP and CNT based fillers were integrated to an aerospace grade epoxy resin, which has a high curing temperature of 180 °C and is commonly used as matrix to manufacture structural parts, by use of three-roll milling in this study. This procedure is of major interest for industrial applications, especially for the aerospace sector, since the process is scalable and works for resins with high curing temperatures. Microstructure and thermal properties of the nanocomposites were investigated. Moreover, mechanical and electrical performances were studied. Results show that certain fillers yield multifunctional properties, i.e. enhanced flexural strength up to 64±41 % in combination with low electrical resistivity with orders of magnitude of ∼10−1−10−2 Ωm in comparison to the electrical resistivity of the epoxy being 109 Ωm.

Objectives:The ongoing coronavirus disease 2019 (COVID-19) pandemic, which was initially identified in December 2019 in the city of Wuhan in China, poses a major threat to worldwide health care. By August 04, 2020, there were globally 695,848 deaths (Johns Hopkins University, https://coronavirus.jhu.edu/map.html). A total of 5765 of them come from Turkey (Johns Hopkins University, https://coronavirus.jhu.edu/map.html). As a result, various governments and their respective populations have taken strong measures to control the spread of the pandemic. In this study, a model that is by construction able to describe both government actions and individual reactions in addition to the well-known exponential spread is presented. Moreover, the influence of the weather is included. This approach demonstrates a quantitative method to track these dynamic influences. This makes it possible to numerically estimate the influence that various private or state measures that were put into effect to contain the pandemic had at time t. This might serve governments across the world by allowing them to plan their actions based on quantitative data to minimize the social and economic consequences of their containment strategies.Methods:A compartmental model based on SEIR that includes the risk perception of the population by an additional differential equation and uses an implicit time-dependent transmission rate is constructed. Within this model, the transmission rate depends on temperature, population, and government actions, which in turn depend on time. The model was tested using different scenarios, with the different dynamic influences being mathematically switched on and off. In addition, the real data of infected coronavirus cases in Turkey were compared with the results of the model.Results:The mathematical study of the influence of the different parameters is presented through different scenarios. Remarkably, the last scenario is also an example of a theoretical mitigation strategy that shows its maximum in August 2020. In addition, the results of the model are compared with the real data from Turkey using conventional fitting that shows good agreement.Conclusions:Although most countries activated their pandemic plans, significant disruptions in health-care systems occurred. The framework of this model seems to be valid for a numerical analysis of dynamic processes that occur during the COVID-19 outbreak due to weather and human reactions. As a result, the effects of the measures introduced could be better planned in advance by use of this model.

The aim of this thesis is the construction of a pseudogap Anderson impurity model, i.e. an Anderson impurity model with the dispersion relation e(k) = k^z, z > 0 for the host instead of the standard Anderson impurity model with dispersion relation e(k) = k for the host. We note that the Anderson impurity model is an integrable continuum model for which the coordinate Bethe approach is known so far. Since the column-to-column transfer matrix does not exist in the continuum, the finitely many non-linear integral equations for the description of thermodynamics could not be directly determined. Bortz, Klümper and Scheeren showed that there is a different lattice model with the same regimes as in the phase diagram of the Anderson impurity model. With respect to the regimes the models were considered as equivalent and the finitely many non-linear integral equations for the lattice model were derived. In this thesis, our first goal is to embed the standard Anderson impurity model into a lattice model. As an appropriate model, the Hubbard model with integrable impurity emerges. For this reason, we generalize known results of the Hubbard model. After that our goal is that this lattice model yields the Anderson impurity model with all parameters in a continuum limit. Then we want to use the limit for the description of the thermodynamics by performing it for the infinite set of thermodynamic Bethe ansatz equations as well as for the finitely many non-linear integral equations. The latter represents a new result. In this thesis, we also develop a method to perform the limit for the Hamiltonian. By embedding the Anderson impurity model in a lattice model, it is now possible to perform modifications on the lattice that serve to change the dispersion relation of the host. These modifications are thus carried out at the level of the Hubbard model. After performing the established continuum limit, this provides the desired pseudogap Anderson impurity model, whose Hamiltonian we can specify. Through the generalization on the lattice, it is possible to fully describe the thermodynamics of this newly constructed model with a finite number of non-linear integral equations. Therefore the aim of this thesis is the construction of a Anderson impurity model with modified density of states and the exact description of the thermodynamics with Bethe ansatz techniques.

Crime prevention and community safety are issues that the Swedish government constantly have to struggle with. With different working conditions, priorities and budgets for each region and municipality, such tasks could turn into colossal challenges if the right solutions aren’t taken. In the last couple of years the government has together with the police and crime-preventing council (Brottsförebyggande rådet) issued a number of publications encouraging the municipal councils to cooperate with police, governmental bodies and local civil actors. The motive being that crime-preventive reforms and measures only work if all actors act like a coherent body, from planning to implementation of policies. These publications have also advocated the use of several crime-preventive methods when planning such reforms. The goal with this essay is to examine the incorporated crime-prevention methods such as the control theory and structural change theory. Questions to be answered are also about the measures taken and levels of cooperation in the two municipalities of Örebro and Karlstad. This has been done through the lens of the qualitative method because we were interested in studying the subject on different levels. To do so we have performed four interviews with one municipal commissioner from each municipality, one security coordinator in Karlstad and a local area police in Örebro. We have also studied several documents related to the empirical material. The conclusion has been that there are similarities regarding the usage of crime-prevention methods but that the implementation of measures differs regarding community safety and long-term effects to provide a safe environment for the citizens