Foram determinadas funções de variáveis como o número atômico e elementos da matriz de densidade que aproximam expoentes variacionalmente otimizados de bases mínimas de orbitais tipo-Slater de átomos em moléculas. Um dos conjuntos de funções corresponde à inclusão de correlação eletrônica (MP2) e potencial efetivo de caroço. No outro conjunto, tais efeitos não foram incluídos. Para a otimização variacional, foram utilizadas cerca de 400 moléculas, contendo átomos do hidrogênio ao argônio, cerca de 2200 expoentes (com potencial efetivo de caroço), e cerca de 3600 expoentes (sem potencial efetivo de caroço). Os orbitais tipo-Slater foram representados por expansões STO-8G. O erro médio na energia molecular devido ao uso dos expoentes aproximados para definir os orbitais atômicos é cerca de mil vezes menor que o erro correspondente devido ao uso da base mínima de orbitais tipo-Slater. / Functions of variables such as density matrix elements and atomic number that give approximate values of variationally optimized exponents for minimal basis sets of Slater-type orbitals were developed. One set of functions includes electronic correlation (MP2) and effective core potential. In the other set such effects are not included. Some 400 molecules, composed of atoms from hydrogen to argon, some 2200 exponents (with effective core potential), and some 3600 exponents (without effective core potential), were used in the variational optimization. Slater-type orbitals were represented by STO-8G expansions. The average molecular energy error due to the use of approximate exponents to define atomic orbitals is close to a thousand times smaller than the corresponding error due to the use of the minimal basis set of Slater-type orbitals.

Foram determinadas funções de variáveis como o número atômico e elementos da matriz de densidade que aproximam expoentes variacionalmente otimizados de bases mínimas de orbitais tipo-Slater de átomos em moléculas. Um dos conjuntos de funções corresponde à inclusão de correlação eletrônica (MP2) e potencial efetivo de caroço. No outro conjunto, tais efeitos não foram incluídos. Para a otimização variacional, foram utilizadas cerca de 400 moléculas, contendo átomos do hidrogênio ao argônio, cerca de 2200 expoentes (com potencial efetivo de caroço), e cerca de 3600 expoentes (sem potencial efetivo de caroço). Os orbitais tipo-Slater foram representados por expansões STO-8G. O erro médio na energia molecular devido ao uso dos expoentes aproximados para definir os orbitais atômicos é cerca de mil vezes menor que o erro correspondente devido ao uso da base mínima de orbitais tipo-Slater. / Functions of variables such as density matrix elements and atomic number that give approximate values of variationally optimized exponents for minimal basis sets of Slater-type orbitals were developed. One set of functions includes electronic correlation (MP2) and effective core potential. In the other set such effects are not included. Some 400 molecules, composed of atoms from hydrogen to argon, some 2200 exponents (with effective core potential), and some 3600 exponents (without effective core potential), were used in the variational optimization. Slater-type orbitals were represented by STO-8G expansions. The average molecular energy error due to the use of approximate exponents to define atomic orbitals is close to a thousand times smaller than the corresponding error due to the use of the minimal basis set of Slater-type orbitals.

Orbital angular momentum (OAM) is a property of light that is widely used for applications in bioimaging, optical communication and optical manipulation, but is mainly limited to the infrared and visible spectra. Developing a table-top source of Extreme Ultraviolet (XUV) light containing an arbitrary amount of OAM is yet to be achieved. We accomplish this by exploiting high-harmonic generation (HHG), a process whereby an infrared pump beam produces high order harmonics. We experimentally demonstrate the conservation of OAM in HHG by measuring harmonics of order n containing n times the OAM of the pump (n = 11, 13, 15 in our experiment). These results agree with our theoretical model. We also show theoretically how to manipulate the HHG process to impart an arbitrary amount of OAM to the di fferent harmonics. We hence show the way to a table-top and flexible source of XUV light containing orbital angular momentum.

Cubesats are picosatellites that have a mass of less than 1.3kg and have a shape of acube. As a result of their low cost of development and launch, cubesats are gainingpopularity in industry and academia. These satellites are also a cost-efective way forspace technology demonstrations. University of Würzburg has a longstanding cubesatprogram started with the launch of UWE-1 in 2005. This was followed by UWE-2 andUWE-3. Several technologies were tested and validated using the UWE platform. Thelast mission UWE-3 has successfully tested an attitude control system.In the next mission, UWE-4 will demonstrate an orbit control system. Being a picosatellite as small as this one (10 x 10 x 10cm 3 and 1kg) brings new challenges intodi↵erent aspects of satellite design, development, control and operation. The orbit con-trol of such a satellite is one of the problems that should be tackled. Being such a smallsatellite means having less propellant mass and much smaller thrusters than conventionalsatellites. These should be addressed in the orbit control. UWE-4 will take advantage of four NanoFEEP thrusters, on one side. Because of theiraccuracy and functionality, these thrusters can be used to implement a continuous thrustsystem. They are also a good choice because of their low energy usage. This work startswith the preparation that was needed to implement a control system. Then explains thestate of the art for continuous thrust control systems. Implements two di↵erent methods,based on perfect control and discusses the outcome. It discuses the limiting factors, likefuel mass, available electrical energy and their e↵ect on the controller performance andconcludes with recommendation for the future researches. / UWE-4

Magister Chirurgiae Dentium - MChD / Introduction: Maxillofacial and oral surgeons often encounter challenges when choos-ing an appropriate surgical access for patients who sustained periorbital and orbital trauma. There are various surgical approaches/incisions (transcutaneous and transcon-junctival) used to access the periorbital skeletal framework. However, there is no consen-sus in the literature regarding the aesthetical outcome of these approaches/incisions. Complications of the lower lid such as entropion, ectropion, retraction of lower lid, scar-ring, oedema of lid, canthal mal-position and chemosis are associated with these ap-proaches. Surgeons are posed with these challenges and aim for best aesthetic outcomes and low post-operative complications. Aim: The aim of this study was to compare aesthetic outcome of the transcutaneous ap-proach (subtarsal) to that of the transconjunctival approach when managing orbital trauma. Objectives: The objectives were to compare the aesthetic outcomes between the trans-conjunctival and transcutaneous (subtarsal) approach; to assess unwanted clinical out-comes, such as scaring, lid malposition (ectropion, entropion, scleral show), lid oedema, chemosis, haematoma, ecchymosis, wound dehiscence, infection and canthal malposition for the two approaches. Methodology: Twenty-two patients were enrolled in this study, 11 of which underwent “transconjunctival incision”, and 11 underwent "subtarsal incision". A high quality dig-ital photograph of each patient’s face was taken at specified time periods up to nine months after surgery. Ten Maxillofacial and Plastic surgeons were instructed to rank or-der the 22 photographs applying Q-sort scaling. Results: Eleven patients underwent the transconjunctival (retroseptal) incision. Ten of which had pure blowout fractures and one had a zygomatic complex fracture. Of the 11, seven were black Africans, two were Caucasians and two mixed race. There were four males and seven females in the transconjunctival incision group. The remainder of the 22 underwent the transcutaneous (subtarsal) incision. Six of the 11 were black Africans and five mixed race. There were nine males and two females in the tranconjunctival group. In this group, two patients had pure blowout fractures and nine had zygomatic complex fractures. Scars were visible in the subtarsal group after six months in seven out of the 11 cases (63.6%), but all the scars were rated as mild on the modified Vancouver Scar Scale. Scle-ral show was noted after six months in four of the 11 cases with the subtarsal approach and in two of the 11 cases with the transconjunctival approach. Only one case of ectropion was seen with both approaches and only one case of entropion was noted in the transcon-junctival group. According to the findings of the study, both approaches were found to have good aesthetic outcomes. Results from the expert rating showed a high-quality rank of 96.8% for the transconjunctival incision versus 90.5% for the subtarsal incision. Conclusion: Both approaches demonstrated good aesthetic results. The transconjunctival incision was associated with scleral show and entropion, while the subtarsal incision was more associated with scar formation. However, when performed meticulously, both inci-sions can provide aesthetically pleasing results.

The purpose of this study is to determine the characteristics of the solar cosmic ray flux. This report describes the design and construction of a cosmic ray detector system used in this study and describes the analysis of the data obtained from these systems.

Currently, the Low Earth Orbit (LEO) space environment contains a growing number of orbital debris objects. This growing orbital debris population increases collision probabilities between both orbital debris and functioning satellites. A phenomenon known as Kessler Syndrome can be induced if these collisions occur. Kessler Syndrome states that these collisions can lead to an exponential increase in the orbital debris population, which could dangerously impede future space missions. Current literature outlines the necessity of stabilizing the near-Earth environment debris population and introduces the concept of active debris removal (ADR). The use of ADR on five orbital debris objects per year was found to be a requirement to achieve stability within the orbital debris population. A viable mission architecture is henceforth explored to utilize ADR for near-future execution to further develop research for orbital debris mitigation missions. The larger orbital debris objects are found in many different orbital regimes and are primarily composed of spent rocket bodies and retired satellites. Different orbital debris ranking schemes have been developed based on the population density in these different regimes, which are linked to higher collision probabilities. Using these ranking schemes, a set of target objects are selected to be investigated for this mission design that was composed of target objects with similar orbital characteristics that were not launched by the Commonwealth of Independent States (CIS) to minimize legal barriers. Different ADR capture and removal methods are inspected to find the optimal methods for this mission. An Analytical Hierarchy Process (AHP) has been used to assess these different methods, which utilizes comparisons of the different methods among a set of weighted criteria. A net capture method with a low thrust chemical engine for removal is identified as the optimal ADR method. The use of a laser detumbling system is also selected to stabilize target objects with a high rotation rate. A rendezvous and deorbit orbital analysis are conducted using both a low fidelity tool (for preliminary results) and a high fidelity tool (for more precise results). The rendezvous analysis is used to select a mission architecture that was composed of two different chaser satellites which rendezvous with the five different target objects by taking advantage of nodal precession. The deorbit analysis investigates different decay timelines and found the delta-v estimates that would be required to deorbit the target objects within the same year that they were captured in. These two orbital analyses provide valuable insight to the mission timeline, delta-v estimates, and approximate mass requirement for the chaser satellite and deorbit kits. The results of the target selection process, ADR selection process, and the rendezvous and deorbit analyses are meant to provide an initial concept and analysis for a near-future ADR mission. These approximate results provide insight and information to further develop orbital debris mitigation research to help solve the orbital debris population growth challenge for future space missions. / Master of Science / Currently, the near Earth space environment contains a growing number of space debris. This growth in the orbital debris population increases the likelihood of collisions with orbital debris, functioning satellites, and launch vehicles. These collisions can generate a chain of events that could exponentially increase the population of orbital debris, which at some scale could become a major obstacle for future space missions. Researchers have introduced the concept of active debris removal (ADR), which in simulations has been shown to help stabilize the growth of orbital debris. The use of ADR to remove as low as five orbital debris objects per year has been found to be sufficient to stabilize debris growth. A viable mission architecture using ADR technologies that can be implemented in the near future is henceforth explored to further develop research for orbital debris missions. The larger orbital debris objects are found in many different areas in space and are primarily made up of used rocket bodies and retired satellites. Different ranking schemes have been developed by researchers for these larger orbital debris objects based on the population density within these areas in space, which are linked to the chance of a collision. Using these ranking schemes, a set of orbital debris objects are selected to be targeted for this mission design. This set of selected target objects have similar orbital characteristics and the political/legal barriers that could be present during removal are minimal. An ADR mission is composed of two primary components, a capture method and a removal method, which are inspected to find the optimal methods for this mission. A decision-making technique, called an Analytical Hierarchy Process (AHP), has been used to assess these different methods. The AHP compares different capture and removal methods using a set of weighted criteria. A net capture method with small thrusters for removal is identified as the optimal ADR method. Additionally, the use of a laser system is selected to stabilize target objects that may be rotating too quickly for capture. An analysis on different mission architectures is conducted using both a low fidelity tool (for preliminary results) and a high fidelity tool (for more precise results). A mission architecture composed of two different "chaser" satellites which rendezvous with and deorbit the five different target objects is selected. The analysis used on the selected mission architecture provides valuable insight to the mission timeline, fuel estimates, and approximate mass requirements. The results of the target selection process, ADR selection process, and the mission architecture analysis are meant to provide an initial concept and introduce possible requirements for a nearfuture ADR mission. These approximate results provide information to further develop research that can help us solve the orbital debris population growth challenge for future space missions.

The main purpose of this thesis is to develop a search strategy for space debris that are in the geosynchronous orbit (GEO) region. The search strategy is not an effort to find the object initially but rather if found one time to aid in finding it again within a small time frame. This was a request from NASA Johnson Space Center Orbital Debris Program Office through the MODEST, Michigan Orbital Debris Survey Telescope, program. A single definitive search pattern was not found, however depending on the COEs of the orbit specific search strategy can be employed. These search strategies are far from perfect and can be improved upon with more rigorous testing as well as a larger data sample. Another goal is to look for correlation between the orbital parameters and the errors in the predicted right ascension (RA) and the declination (DEC). This was accomplished by varying the different orbital parameters by ±10% individually while holding the other parameters constant. This showed some correlation existed between some parameters and their errors, in particular there was correlation between a variation in right ascension of ascending node (RAAN) and the value of RAAN itself. The correlation found was that with the higher the value of RAAN the larger the RMS error.

Introduction: Myasthenia gravis (MG) is an immune-mediated disorder affecting the neuromuscular junction. Weakness of the extraocular muscles (EOMs) occurs frequently in MG and typically responds to immune therapies similarly to the non-ocular muscles. Susceptible individuals with the ophthalmoplegic subphenotype of MG (OP-MG), which occurs almost exclusively in acetylcholine receptor positive MG (AChR-MG), may manifest treatmentresistant extraocular muscle weakness despite the use of standard immune therapies. The pathogenetic mechanisms involved in the development of treatment-resistant ophthalmoplegia in MG are still unknown and no effective treatment currently exists. Aim: To investigate the molecular-genetic pathogenesis of the OP-MG subphenotype. Methods: Triangulation of data from clinical observations, review of MG muscle biopsy histopathology, gene expression studies in OP-MG patient-derived orbital muscles (AChR-MG) and bioenergetic studies in highly specialised perimysial ocular fibroblasts of these OP-MG cases was used to identify the underlying pathogenetic mechanisms of OP-MG and to verify previous hypotheses generated by next generation sequencing studies. Results: Myasthenic ophthalmoparesis may persist despite immune therapies in 40% of cases in the first year of immune treatment. Delay to diagnosis of MG and therefore initiation of treatment (>1 year) was an unfavourable prognostic factor for resolution of ophthalmoparesis and suggested that with prolonged weakness, pathological changes may occur at the level of the muscle. Review of the literature documenting histopathology in MG muscle biopsies showed that neurogenic atrophy and features of mitochondrial stress, which may be secondary consequences of functional denervation and reduced contractility, are frequently observed in MG muscle biopsies and the EOMs may be particularly susceptible, demonstrating features of fatty and fibrocellular replacement of myofibres. Gene expression studies performed in the orbital muscles of OP-MG and non-MG control cases supported the hypotheses of previous unbiased genomic studies showing that genes harbouring OP-MG associated gene variants may be involved in a dysregulated network of genes including genes in pathways involved in atrophy signalling, muscle contractility and mitochondrial homeostasis. Several genes were significantly downregulated in the OP-MG orbital muscles compared with controls. MicroRNAs which are biological regulators of gene expression, were hypothesized to be a potential pathogenetic mechanism causing downregulation of these genes in OP-MG orbital muscles and several microRNAs highly expressed in EOMs were associated with the significantly repressed genes in OP-MG orbital muscle using available data in public microRNA databases. Preliminary dynamic bioenergetic assays in perimysial ocular fibroblasts derived from the EOM myotendons of OP-MG and non-MG control cases suggested that regulation of mitochondrial homeostasis may be altered in the context of MG. Conclusion: Gene expression analyses in patient-derived orbital muscles support the hypotheses of previous genomic studies suggesting that pathogenetic mechanisms involving pathways relating to muscle atrophy, contractility and mitochondrial homeostasis may by triggered in the EOMs in the context of MG. Dysregulation of these pathways is likely to impact EOM regeneration in the context of MG-induced complement-mediated attack as well as contractility in this specialized muscle allotype with a high firing rate. These complex aberrant molecular-genetic interactions may contribute to persistent ophthalmoplegia despite adequate immune therapies in OP-MG cases.

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