Background A perforation in the nasal septum can cause symptoms such as bleeding, obstruction, crusts and pain, and can be a challenge to treat. Surgery is the treatment of choice, but disease, size of the perforation, or the patient’s wish may contradict surgery. A custom-made silicone obturator is a successful treatment option, but little is known how this treatment affects the microbial flora. The purposes of this thesis were (i) to investigate the microbial flora around symptomatic nasal septal perforations before treatment, (ii) during and after a 12-month treatment period with a custom-made obturator, (iii) to compare the microbial flora around symptomatic perforations with the flora from the same area of the septum in healthy individuals, (iv) to investigate the microbial colonization of the silicone obturator, and (v) also to investigate the water sorption, solubility and if the wettability of silicones are affected by water. The hypotheses were (i) that the bacterial flora around symptomatic perforations would not differ from that found in healthy individuals, apart from a possible presence of Helicobacter pylori; (ii) the bacterial flora would change in composition during the course of treatment and that microorganisms and proteins could be seen on the surface of the silicone obturators; (iii) a material that has adsorbed water would also show an increase in wettability and the surface free energy of the material.  Methods Twenty-seven patients and 101 healthy individuals volunteered. Swabs were made around the rim of the perforation, or on the septum in the locus Kisselbachi area in the healthy individuals. Bacteria and fungi were isolated and identified with standard laboratory techniques. A biopsy of the granulated tissue at the perforation was taken and cultivated for Helicobacter pylori. Swabs were also taken three, six and twelve months after inserting the obturator. The obturator was analysed after being used twelve months in the nose.  Seven silicones were tested for water sorption and solubility according to ISO standards 1567:1999 and ISO 10477:2004. The change in wettability was examined by measuring the contact angle with a contact goniometer at various stages of the sorption/solubility test. Results Staphylococcus aureus was present in 88% of the untreated patients. With treatment a significant reduction of S. aureus occurred to 54.5% (p<0.05). In the healthy group S. aureus was present in 13% of the subjects. No Helicobacter pylori could be cultivated from the biopsies taken of the granulated tissue at the perforation. The flora round the untreated perforation was dominated by S. aureus with few other bacterial species detected. In the healthy group there was a diversified flora with both aerobic and anaerobic bacteria. SEM revealed a rough surface on the silicone obturator and crazing of the silicone surrounding the pigment granules. Both bacteria and proteins could be seen on the obturators in SEM. Candida albicans was detected in one obturator, but not in the mucosal swab at the corresponding time. That patient had, however, been treated for Candida in the nose six months prior to the last visit in the study. Wettability was affected but did not increase with amount of adsorbed water. Some materials showed an increase and some a decrease in the surface-free energy. The tested addition silicones showed little sorption and solubility. Conclusions The patients with symptomatic perforations of the nasal septum had a bacterial flora totally dominated by S. aureus. The massive presence of S. aureus around symptomatic perforations may have an impact on the persistence of the granulated and inflamed tissue present in symptomatic perforations, thus forming a vicious circle with bleeding and crustation. S. aureus dominance in the mucosa surrounding symptomatic perforations was diminished by using a custom-made obturator. The microbial flora became more diversified with the treatment, although not resembling the flora in healthy individuals. The microbial flora of the obturators was similar, but not the same as the corresponding mucosal flora. The discovery of Candida in the obturator of a patient who had been treated for Candida in the nose six months earlier suggests that obturators need to be exchanged when fungal infections are being treated to prevent the fungus from re-infecting the patient at a later stage. The silicone had a rough surface and a poor wettability, both aspects favours colonization of microorganisms. The silicone was negatively affected by the colouring pigments, this should be considered when colouring is not necessary. The slight, but existing solubility of silicones emphasises the importance of using medical grade silicones that are more purified than industrial silicones.

In this master thesis, a system has been designed that is used to detect the perforation holes on a film in a line-scanning film scanner. The film scanner is used to scan regular film taken by high-speed cameras during tests of for example missile launches or vehicle crash tests. The system consists of a PLD that detects the perforation holes on the film using a signal from a digital line-scanning CCD camera. A main issue has been to make the detection procedure robust and independent of the different types of films encountered in real life situations. The result from the detection is used to generate control signals to the film speed regulation mechanism inside the film scanner that then regulates the velocity of the film. To make the detection and regulation more sensitive, a part-of-line precision has been developed to calculate where, inside a line, the actual hole is positioned. The system has been programmed in VHDL, synthesized, implemented and fitted into a Xilinx Spartan (XCS10-3-PC84) Field Programmable Gate Array (FPGA). The implementation has been simulated but not in real hardware.

In this thesis, it is aimed to determine the ballistic limit thicknesses of ST-37 steel plates under oblique impact of bullets having hard steel core (DIN 100Cr6 at 61-62 HRc) by using both experimental and numerical methods. In experimental part, angles of attack of the bullets are changed from 0 to 70 degrees by 10 degrees increments. Bullet velocities are measured for each shot just before the impact and they are found to be between 790-830 m/s. The minimum plate thickness that is not perforated and the maximum plate thickness that is perforated are determined by conducting three shots for each angle of attack - plate thickness combination. After the monolithic case, for some angles, layered plate combinations are also investigated. In the numerical analysis part, Johnson Cook constitutive and failure models are used together with the data obtained from literature. Experiments are simulated numerically by using a commercial non-linear explicit hydrocode software package, ANSYS AUTODYN. Results of the numerical simulations and the experimental findings are presented in tabular and graphical forms and then compared to each other.

In order to evaluate the productivity of methane hydrate (MH) by the depressurization method, Japan Oil, Gas and Metals National Corporation and Natural Resources Canada carried out a full scale production test in the Mallik field, Mackenzie Delta, Canada in April, 2007. An extensive wire-line logging program was conducted to evaluate reservoir properties, to determine production/water injection intervals, to evaluate cement bonding, and to interpret MH dissociation behavior throughout the production. New open hole wire-line logging tools such as MR Scanner, Rt Scanner and Sonic Scanner, and other advanced logging tools such as ECS (Elemental Capture Spectroscopy) were deployed to obtain precise data on the occurrence of MH, lithology, MH pore saturation, porosity and permeability. Perforation intervals of the production and water injection zones were selected using a multidisciplinary approach. Based on the results of geological interpretation and open hole logging analysis, we picked candidate test intervals considering lithology, MH pore saturation, initial effective permeability and absolute permeability. Reservoir layer models were constructed to allow for quick reservoir numerical simulations for several perforation scenarios. Using the results of well log analysis, reservoir numerical simulation, and consideration of operational constraints, a MH bearing formation from 1093 to 1105 mKB was selected for 2007 testing and three zones (1224-1230, 1238-1256, 1270-1274 mKB) were selected for injection of produced water. Three kinds of cased-hole logging, RST (Reservoir Saturation Tool), APS (Accelerator Porosity Sonde), and Sonic Scanner were carried out to evaluate physical property changes of MH bearing formation before/after the production test. Preliminary evaluation of RST-sigma suggested that MH bearing formation in the above perforation interval was almost selectively dissociated (sand produced) in lateral direction. Preliminary analysis using Sonic Scanner data, which has deeper depth of investigation than RST brought us additional information on MH dissociation front and dissociation behavior.

The objective of this study is to investigate the penetration and perforation resistance of alumina ceramics against kinetic energy projectiles. There are several different mechanisms by which a target can fail when it is subjected to impact of a projectile and these may occur singly or in combinations of two or more. The presence of large number of penetration and failure mechanisms makes the investigation of the perforation very difficult. Because of this difficulty, the analytical investigations of penetration and perforation processes usually assume one type of failure mechanism. One of these analytical investigations is reviewed and it is seen that this analytical model is capable of predicting after impact parameters reasonably accurately. A parallel investigation of this problem is also been carried out numerically by using Autodyn hydrocodes. Numerical study is capable of simulating the main changes in ceramic/steel composite target during penetration process of kinetic energy projectile. Results of analytical and numerical investigations are parallel to each other. A set of experiments was carried out for checking the results of analytical and numerical calculations with the experimental data.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Este trabalho tem por finalidade o estudo teórico e experimental de avaliação da degradação em postes de madeira utilizados em redes de energia elétrica. Com base em ampla revisão bibliográfica, de dados climáticos de várias cidades do Estado de São Paulo e resultados de ensaios de perfuração controlada realizadas em campo, em vários municípios do Estado de São Paulo, apresenta um modelo de apodrecimento de madeira em contato com o solo, identificando quais as cidades são mais e menos agressivas à madeira nestas condições, propondo a simplificação deste modelo, facilitando sua utilização na previsão da vida útil de madeiras em contato com o solo, predizendo o grau de deterioração destes. O modelo proposto se mostrou bastante adequado, dando uma boa previsão da deterioração de postes nas diversas regiões do Estado. / The purpose of this paper is the theoretical and experimental study of evaluation of timber deterioration in used poles in nets of electric energy. Basing on ample bibliographical reviews of climatic data of some cities in the State of São Paulo and results of controlled perforation testing done in field, in some cities of the State of São Paulo, it presents a model of timber decay in contact with the ground, identifying which cities are more aggressive or less aggressive to the wood in these conditions, proposing the simplification of this model, facilitating its use in the forecast of the timber service life in contact with the ground, predicting the degree of deterioration in them. The proposed model proved to be sufficiently adequate giving a good forecast of the pole deterioration in several regions of the State.

Presented are approximate finite strip methods for use in predicting elastic buckling strength of cold-formed steel columns. These methods were developed by examining elemental behavior of cross-sections in eigen-buckling analyses and validated using a large database of finite element rack-type columns with perforation patterns. The influence of perforations is accounted by reduced thicknesses related to the plate buckling coefficient and transverse web rotational stiffness in the prediction of local and distortional buckling respectively. Global buckling prediction including the influence of perforations uses critical elastic loads of an unperforated section multiplied by the ratio of weighted to gross cross-sectional moment of inertia for flexural buckling and the ratios of weighted to gross cross-sectional warping torsion constant and weighted to gross St. Venant torsional constant for flexural-torsional buckling. Concern for end-user was given and methods are presented in a way for incorporation into governing design standards. Data to support these findings are available at http://hdl.handle.net/10919/23797 / Master of Science

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