The Master's thesis deals with the determination of measurement method of deflection the axis of the optical beam from its ideal position, which is caused by action of force of strong winds affecting the positional stability of the building or supporting structure (tower) used for placement of FSO links'heads. The thesis informs the readers about the other causes of deflection of beam axis in a real environment, about methods of determining the position of the beam axis in the plane perpendicular to the beam axis and the basic properties and parameters of the Gauss beams, including the phenomenon of diffraction on the output aperture of the laser transmitter.

The economic cost of a static design is nowadays very often the decisive factor during a tender. This work deals with the economic cost of designing the ceiling construction of a polyfunctional building. The work shows three design options regarding the second boundary condition. The decisive factor is the deflection under the masonry constructions. The deformation of the ceiling construction cannot be allowed to cause cracks in the masonry partitions. The aim of this work is the comparison of the economic cost of the possible design options.

This thesis deals with product design rotating camera crane with variable length telescopic arm. Proposed maximum arm length is 6 [m] with a maximum weight capacity of the camera 8 [kg]. The work deals with the various structural units associated mainly with the issue of the telescopic arm. In individual sections detail the construction of the camera head developed deformation and stress analysis of a telescopic jib.

This diploma thesis deals with issues in machining of thin-walled components. Its first part describes materials used in the aircraft industry. Then it focuses on issues associated with the prediction of deflections of a rib wall during machining. Later on it focuses on different methods and strategies of thin-walled part milling. The diploma thesis also describes an experiment of manufacturing thin-walled components in the form of ribs and evaluation parameters such as roughness, perpendicularity and straightness deviations, width of the rib and force loading of a cutting tool as measured by various gages. The final part is devoted to a calculation of the specific cutting force and its comparison with its theoretical value.

Thin films have become very important in the past years as there is a tremendous increase in the need for small-scale devices. Thin films are preferred because of their electrical, mechanical, chemical, and other unique properties. They are often used for coatings, and in the fabrication of Microelectronic devices and Micro-electro Mechanical Systems (MEMS). Internal (residual) stress always exists when a thin film is employed in the device design. Residual and thermal stresses cause membrane bow, altering the anticipated dynamic response of a membrane-based MEMS design. The device may even become inoperable under the high stresses conditions. As a result, the stresses that act upon the membrane should be minimized for optimum operation of a MEMS device. In this research, the fabrication process parameters leading to low stress silicon nitride films were investigated. Silicon nitride was deposited using Plasma Enhanced Chemical Vapor Deposition (PECVD) and the residual stresses on these films were determined using a wafer curvature technique. By adjusting the silane (SiH4) and nitrogen (N2) gas flow rates, and the radiofrequency (RF) power; high quality silicon nitride films with residual stress as low as 11 MPa were obtained. Furthermore, an analytical study was also conducted to explore the effect of thermal stresses between layers of thin films on the MEMS device operation. In this thesis, we concentrated our efforts on three layers of thin films, as that is the most commonly encountered in a membrane based MEMS device. The results obtained from a parametric study of the membrane center deflection indicate that the deflection can be minimized by the appropriate choice of materials used. In addition, our results indicate that thin films with similar coefficient of thermal expansion should be employed in the design to minimize the deflection of the membrane, leading to anticipated device operation and increased yield. A complete understanding of the thermal and residual stress in MEMS structures can improve survival rate during fabrication, thereby increasing yield and ultimately reducing the device cost. In addition, reliability, durability, and overall performance of membrane-based structures are improved when substrate curvature and membrane deflection caused by stresses are kept at a minimum.

Recently, the railway pavement structure system, as an integral part of the transport infrastructure, has been under fast development in some countries such as China, Turkey, and some European Union countries, particularly for the use of high-speed trains. In designing and constructing the railway pavement structure, it is necessary to take into account the infrastructure demand of the High-Speed Railway Lines (HSRL). Compared to traditional railway trains, HSRL can cause more significant problems to the ballast or base layer of commonly used ballasted railway pavements. The deteriorated ballast or base layer may further result in substructure degradation that may cause safety issues and catastrophic accidents. As a consequence, heavy goods or high-speed trains will affect railway efficiency. As a countermeasure, a railway pavement structure may be reinforced by geosynthetic materials in the ballast or base layer. In the literature, however, there is still a need to quantify the effect of geosynthetic materials, geogrid in particular, on the mechanical responses of railway pavement structures to HSRL loads, which is necessary knowledge in supporting the selection of appropriate material and placement location of geogrid. Therefore, the goal of this study is to investigate how a geogrid reinforcement layer can change the essential characteristics of a ballasted railway pavement structure, with focus on the material type and placement location of geogrid that can help minimize the rate of deterioration of the railway pavement structure system. This research attempts to validate the advantage of geogrid reinforcement through numerical simulation in a realistic railway setting. All technical literature on the use of geogrids in the railway system has been studied. A three-dimensional (3D) finite element model was constructed for the numerical simulation, in which three different types of geogrid placed at two different locations (i.e., within the ballast layer, between the ballast and the sub-ballast layer) within a railway pavement structure were analyzed under a range of vertical wheel loads. Therefore, four possible applications of geogrid reinforcement systems (G0: no-reinforcement; G1: reinforced with geogrid having the lowest density and Young’s modulus; G2: reinforced with geogrid having the intermediate Young’s modulus and density; G3: reinforced with geogrid having the highest density and Young’s modulus) were modeled to represent different situations in ballasted railway systems. Railway mechanical responses, such as vertical surface deflection, maximum principal stress and strain, and maximum shear stress were analyzed and compared among the four geogrid reinforcement scenarios and under four vertical wheel load levels (i.e., 75, 100, 150 and 200 kN). The advantages of such geosynthetics in ballast are indicated by result difference in the mechanical responses of railway pavement structures due to the use of different geogrid materials. The results also show that the reinforced structures have lower vertical surface deflection, lower maximum shear stress at the interface of sleeper and ballast, and maximum principal stress at the bottom of the ballast layer than a non-reinforced railway pavement structure. Consequently, the addition of geogrid into the ballast layer, and between the ballast and sub-ballast layer has been shown to reduce critical shear and principal stresses and vertical surface deflection in a ballasted railway pavement structure. Besides that, the results of the analysis confirm that geogrid reinforced layers exhibit higher resistance to deformation than the non-reinforced layers.

ROBEX is a unique research project combining Airbus Defence and Space’s robotics expertise with deep-sea exploration technology to discover more about the most extreme environments environments known to man. As a part of this project, a deep-sea glider called MOTH, is under development with the objective to determine whether gliders can be used as a platform for bathymetric and electromagnetic soundings of the seafloor as well as for new water column research. This master’s thesis aims to design and implement the MOTH glider’s control system. The glider will have an independent emergency system, a power unit, an on-board computer (OBC), actuators, navigation sensors and scientific measurement instruments which can be swopped between missions and are connected via remote terminal units. The selected OBC is a Linux embedded Axotec GX-6300 with RS232 and CAN bus interfaces, as selected in the electrical architecture, and the chosen operative system is Linux Debian. The glider communicates with GNS/Iridium antenna and also has an ethernet cable link for ground station operations and a future option of an acoustic transceiver. To control actuation, the glider is equipped with a rudder, a left and a right wing flap, a moveable mass and a buoyancy tank. It travels in sawtooth patterns and is therefore always descending, ascending or transitioning during operation and at times ascending all the way to the surface to transmit and receive data via satellite communication. A model based feedback controller for longitudinal control has been programmed based on the equations of motion described in this report. The modelled longitudinal trajectory is as desired until a transition point is reached, the model is, presumable because of the uncertainty of the model parameters, unstable as the actuators are unable to correct the pitch angle. An AHRS navigation sensor emulator and an OBC emulator have been programmed to simulate the communication between these two and the emulated system is well operating both as a continuous stream and for polling data. The emulator and the pitch controller, when updated parameter values are available, will be used for simulation and verification tests in the laboratory environment. The ROBEX alliance will, if the objectives with the MOTH glider are met, continue to design gliders with the aim to increase the maximum duration time and speed in order to reach greater depths of the oceans.

Tissue-papper eller mjukpapper är material som används för hygienändamål och finns tillgängligt som toalettpapper, hushållspapper och näsdukar. Beroende på vilken typ av tissue-papper som tillverkas anpassas egenskaper genom bland annat val av fibrer och kemikalier. Problemet som finns idag är att vissa mjukpapper brister i kvalitet vilket exemplifieras med att de rivs sönder i längden och inte vid perforeringen. Mjukpapper kan även gå sönder efter toalettbesöket. Detta leder till ökat produktsvinn och miljöbelastning. Som en del i att försöka minska miljöbelastningen och optimera egenskaperna hos papper har en studie genomförts inom ramen för ett mekaniskt forskningsprojekt som drivs av forskargruppen ”Mechanics and materials” på Örebro universitet. I detta arbete har fyra olika typer av mjukpapper studerats. Under arbetet har de olika pappersprodukternas omslutningsförmåga, det vill säga deras kontaktvinkel, vid tryck undersökts och analyserats. Vidare har även nedböjningen vid belastning undersökts teoretiskt. Syftet med arbetet var att undersöka ifall det fanns en koncis metod för att mäta omslutningen med, som en del i det större forskningsprojektet. Som verktyg används en objektiv fingerliknande sensor för att se en möjlig korrelation med mätmetoden. Resultatet visade att metoden var koncis och hade en korrelation med den objektiva fingerliknande sensorns utslag. Till fortsatt arbete rekommenderas ytterligare tester på pappersprodukterna för att utföra en noggrann statistisk analys. Även ytterligare kopplingar till pappersprodukternas egenskaper kan ge en djupare förståelse av hur materialet böjer sig vid belastning. / Tissue paper or soft paper are materials used for hygiene purposes and are available as toilet paper, kitchen paper and handkerchiefs. Depending on the variety that is manufactured, properties are adapted based on, among other things, the choice of fibers and chemicals. The problem that exists today is that some tissues lack quality, which is exemplified by the fact that they are torn in the long run and not during the perforation. Tissue can also break after the toilet visit. This leads to increased product waste and environmental impact. As part of trying to reduce the environmental impact and optimize the properties of paper, this report is written within the constraints of a mechanical science project by the research group called “Mechanics and materials” on Orebro university. In this project, four different types of tissue have been studied. During the work, the enclosing ability of the various paper products, its contact angle, has been examined and analyzed under pressure. Furthermore, the deflection under load has also been investigated theoretically. The purpose of the work was to investigate whether there was a concise method to measure the coverage, as part of the larger research project. An objective finger-like sensor is used as a tool to see a possible correlation with the measurement method. The results showed that the method was consistent and had a correlation with the objective finger-like sensor result. For further work, further tests on the paper products are recommended to perform a thorough statistical analysis. Further connections to the properties of the paper products can also provide a deeper understanding of how the material bends under load.

The aerospace industry endeavours to improve modern aircraft capabilities in efficiency, endurance, and comfort. One means of achieving these goals is through new enhancements in aerodynamics. Increased wing aspect ratio is an example of further improving efficiency. However, this comes with new challenges including possibly adverse aero-elastic and aero-servo-elastic (ASE) phenomena. New computational methods and tools are emerging and there is a need for experimental data for validation. University of Victoria’s Centre for Aerospace Research (UVic CfAR) set out to design a 20kg ASE demonstrator using a remotely piloted aircraft (RPA). This aircraft was designed with the intent of exploring coupling between aero-elastic modes including coupling between the short period aerodynamic mode and the first out-of-plane elastic mode of the wing. This thesis discuses the implementation of instrumentation designed and integrated into the ASE RPA demonstrator to monitor the deformation of the elastic wing in-flight. A strain based measurement technique was selected for integration into the ASE aircraft. This choice was made for several reasons including its reliability regardless of outdoor lighting, relatively lightweight processing requirements for real time applications, and suitable sampling bandwidth. To compute the wing deformation from strain, a method, sometimes referred to as strain pattern analysis (SPA), utilizing linear combinations of reference modal shapes fit against the measured strain, was used. Although this method is not new, to the author’s knowledge, it is the first practical application to a reduced scale RPA demonstrator. The deformation measurement system was validated against a series of distributed static load tests on the ground. Distributed load cases along the wing demonstrated good out-of-plane measurement performance. A case where only load is applied near the root of the wing resulted in the largest error in part as the mode shapes generated are less suited to approximate the resulting shape. In general errors in out-of-plane displacement at the end of the flexible wing portion can be expected to be less than 5%. The displacement at the tip of the wing can be as great as 11% for the left wing whereas the right wing is 4.7%. This suggest an asymmetry between the left and right wings requiring specifically tuned FE models for each to achieve best results. Twist angles presented in tests were relatively small for accurate comparison against the reference measurement, which was relatively noisy. Generally, the deformation measurement by SPA technique followed the same twist behaviours as the reference. A twist case, unlikely to be seen in flight, provided some insight into twist measurement robustness. The work presented is merely a small step forward with many opportunities for further research. There is room for improvement of the FE model used to generate the mode shapes in the strain pattern analysis. Initial efforts focused on the flexible spar portion of the wing. With more work improvements could be achieved for the estimation of the rigid wing. Additionally, there was some asymmetry between each wing semi-span, and with some focus on the left wing its results could be improved to at least match that of the right wing. A real-time implementation was not completed and would be particularly interesting for use as feedback for flight control. Study of load alleviation techniques may benefit. Another topic of study is the combination of this method with other measurements, such as accelerometers, to provide improved performance state estimation through sensor fusion. / Graduate

Individuals who suffer from depression can be stigmatized by labeling and resort to negative stigma coping orientations such as secrecy and withdrawal, resulting in internalized self-stigma. Self-stigma can have negative effects such as low self-esteem, low self-efficacy, isolation, and feeling like a failure. Guided by modified labeling theory, the purpose of this study was to fill a gap in the literature on predictors of two orientations (challenging and deflecting) of positive stigma coping. Challenging stigma involves taking action, and deflecting is a cognitive strategy; both are used to positively cope with the stigma of mental illness. Predictors included symptom severity, depression literacy, stereotype awareness, treatment seeking, social support, and stigma sentiments in a sample of undergraduates (N = 195). Results from a canonical correlation found that individuals with high scores on deflecting and, simultaneously, low scores on challenging tended to have high scores on stigma sentiments and low scores on both symptom severity and treatment seeking. Analyzed in independent regressions, challenging was significantly predicted only by symptom severity (+), while deflecting was predicted by symptom severity (-), depression literacy (+), and stigma sentiments (+). These findings reinforce the potential for individuals who suffer from depression to address stigma using healthier and more affirming coping orientations. Implications for positive social change include a decrease in self-stigma regarding depression, less negative stigma coping, an increased awareness of how depression stigma affects individuals who suffer from the disorder, and a decrease in the social stigma of depression. Educators and practitioners can apply this information in academia, counseling, and clinical practice.