<p> We study the Coulomb effect on the proton-proton low-energy scattering parameters when all other effects are represented by a separable potential.</p> <p> For this purpose, we present a formulation for the scattering of two particles via a separable potential. We treat the same problem when any potential, particularly a Coulomb potential or a separable potential, is added to the separable potential. The properties of scattering from a separable potential plus a (local or non-local) potential lead us to the possibility of obtaining a one term separable potential equivalent to a two term separable potential, and a model for the nuclear potential as a sum of a separable potential and a non-separable potential.</p> <p> We determine, to the first order in Me^2/β where β^-1 is the range of the separable potential, the parameters for Yamaguchi's and Naqvi's separable potentials from proton-proton scattering data. We use these parameters to calculate the low-energy proton-proton scattering parameters when the Coulomb interaction is removed. Our results show that the shape dependence of these parameters are somewhat larger than obtained by Heller et al in their investigation on local potentials. Implications of our results concerning the charge symmetry and charge independence of the nuclear forces are discussed.</p> / Thesis / Master of Science (MSc)

Renewed interest in returning to the Moon, emboldened by recent directives and missions by NASA, has necessitated the establishment of lunar infrastructure to support continuous human presence. With that, the objective of making this return more cost effective has gained significant importance. Low energy lunar transfers are more efficient ways to reach the Moon than the traditional Hohmann-type transfer. These trajectories leverage the multi-body gravitational effects to reduce overall delta-v requirements, in some cases removing the capture delta-v completely. While the time of flight for these transfers can be much longer than a Hohmann-type transfer, the chaotic design space of these transfers can enable large changes in arrival conditions at the Moon for small changes in initial conditions. Many investigations of these transfers take place in simplified dynamical models, such as the Planar Circular Restricted Three Body Problem, with very few higher-fidelity models being implemented. This approach is good to understand the dynamics of these trajectories as well as provide initial guesses for higher-fidelity models; but approximating the dynamics heavily make these models less applicable to mission design. This thesis aims to investigate the application of a higher-order model to simulate these trajectories. STK Astrogator was used to recreate the NASA GRAIL trajectory; and from the recreated trajectory, a nominal trajectory absent of mid-course corrections was established. This nominal trajectory was used to perform parametric and variational studies of departure and arrival conditions as well as compare to a nominal trajectory in a reduced-fidelity model. An investigation into the post launch correction burn requirements following launch vehicle under-performance was completed. Utilizing low energy transfers proved beneficial to adjusting arrival conditions for low delta-v requirements. All arrival inclinations are reasonably achievable for around 255 m/s. Using 255 m/s as a baseline, right ascension of the ascending node could be reached in a 40 degree range and argument of periapsis in a 50 degree range. Lunar insertion arrival can be varied by 7 hours on either side for less than 80 m/s. Trans-lunar injection epoch can be varied by 7 hours on either side of nominal departure for less than 4 m/s. Orbit radius and initial velocity are the most expensive errors to correct. These trajectories can be tuned to reduce the overall mid-course correction delta-v requirement for differing arrival inclinations if other orbital elements are relaxed. A relationship between placement of post-launch correction maneuver for velocity or radius errors was found. Comparing the trajectory in STK to the Inclined Bi-Elliptic Restricted Four Body problem, revealed that timing of the trajectory is variable while keeping the same arrival and departure conditions. However, solar radiation pressure cannot be ignored for more accurate simulation of these trajectories. This investigation has shown that low energy lunar transfers are a viable method to reach the Moon and their chaotic nature can be leveraged to relax restrictions in the design space. / Master of Science / Returning to the Moon has become a more important goal within the space industry. This has required more cost-efficient ways to reach the Moon; an important cost savings being fuel. Traditional ways to reach the Moon required large amounts of fuel to be expended to remain around the Moon after launch. Low energy lunar transfers aim to reduce fuel usage while still reaching the Moon, although they take much longer to reach their destination. Fuel and energy have direct comparisons and are used to evaluate these transfers. These transfers are highly susceptible to changes in their trajectory making them ideal for transferring to the Moon in different orientations. These changes can be made using very little fuel, allowing for more resources to be brought to the Moon. Navigating these transfers to the Moon require an accurate model of space for mission design.

The pathomechanism of migraine attacks is not understood well, however, is currently believed to be a brain disorder. Migraine is a multifactorial disorder that needs to be investigated in multiple research areas to shed light into its mechanism and find ways to treat it effectively. Migraine episodes come from one or many things at the same time, and such vary from person to person. However, sufficient evidence in recent studies show there is a strong relationship between genetics with patients having specific genes that may be responsible for the disease or a genetic sequence passed down through generations in families, especially in the case of migraine with aura. Several genes including P/Q type calcium channel gene mutations, Na+ /K+ pump ATP1A2 malfunctions and Na+ gated voltage channel Nav 1.1 have been implicated with familial hemiplegic migraines with aura (Samsam 2012). Additionally, insulin resistance has been shown to be a very prevalent factor in migraine patients, but more research has yet to be done to support such claim. Also, many studies suggest the possibility of migraine attacks occurring due to a lack of energy in the patient´s brain. Meaning that exhaustion of the brain can also lead to a migraine episode. In this thesis, we investigated the genetic causes of migraine and reviewed the recent genes implicated in the pathomechanism of migraines. Further, we explored several articles that investigated the metabolic changes that occur in the brain during a migraine attack and looked for reasons behind such changes.

<p> Wireless communication technologies, such as cellular ones, Bluetooth, and WiFi, are fundamental for today’s and tomorrow’s communication infrastructure. Networks based on those technologies are or will be increasingly deployed in many critical domains, such as critical infrastructures, smart cities, healthcare, and industrial environments. Protecting wireless networks against attacks and privacy breaches is thus critical. A fundamental step for the security and privacy of these networks is ensuring that their protocols are implemented as mandated by the standards. These protocols are however quite complex and unfortunately, the lack of secure-by-design approaches for these complex protocols often induces vulnerabilities in implementations with severe security and privacy repercussions. For these protocols, the standards are thousands of pages long, written in natural language, describe the high-level interaction of the protocol entities, and most often depend on human interpretation—which is open to misunderstanding and ambiguity. This inherently entails the question of whether these wireless protocols and their communication equipment implement the corresponding standards correctly or whether the implementations introduce vulnerabilities that can have severe consequences.</p>

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The Internet of Things (IoT) is an umbrella term for smart things connected to the Internet.Precision agriculture is a related concept where connected sensors can be used to facilitate, e.g. more effective farming. At the same time, Bluetooth has been making advancements into IoT with the release of Bluetooth Low Energy (BLE) or Bluetooth smart as it is also known by. This thesis describes the development of a Bluetooth Low Energy moisture- and temperature sensor intended for use in an agricultural wireless sensor network system. The sensor was evaluated based on its effectiveness in agricultural environments and conditions such as weather, elevation and in different crop fields. Bluetooth Low Energy was chosen as the technology for communication by the supervising company due to its inherent support for mobile phone accessibility.Field tests showed that the sensor nodes were largely affected by greenery positioned betweentransmitter and receiver, meaning that these would preferably be placed above growing crops foreffective communication. With ideal placement of the sensor and receiving unit, the signal wouldreach up to 100 m, meaning that a receiving unit would cover a circle area with radius 100 m.Due to Bluetooth being largely integrated in mobile devices it would mean that sensor data couldeasily be made accessible with a mobile app, rather than acquiring data from an online web server.

Today’s data centers (DCs) consume up to 3% of the energy produced worldwide, much of which is wasted due to over-cooling and underutilization of IT equipment. This wastage in part stems from the lack of real-time visibility of fine-grained thermal distribution in DCs. Wireless sensing is an ideal candidate for DC monitoring as it is cost-effective, facility-friendly, and can be easily re-purposed. In this thesis, we develop LEMoNet, a novel low-energy wireless sensor network design for monitoring co-location DCs. It employs a two-tier network architecture and a multi-mode data exchange protocol to balance the trade-offs between low power consumption and high data reliability. We have evaluated the performance of LEMoNet by deploying custom-designed sensor and gateway nodes in a SHARCNET DC at A.N. Bourns Science Building. We show experimentally that LEMoNet achieves an average data yield of over 98%. Under normal operations with one temperature and one humidity reading every thirty seconds, the battery lifetime of LEMoNet sensor nodes is projected to be 14.9 years on a single lithium coin battery. / Thesis / Master of Science (MSc)

Preoperative optimization of patients with obesity prior to non-bariatric surgery through weight loss interventions may significantly improve perioperative outcomes and decrease healthcare resource utilization associated with this increasingly prevalent patient population. Ultimately, very low energy diets and bariatric surgery have the potential to become a cornerstone of pre-habilitation protocols for patients with obesity undergoing elective operations for both benign and malignant disease processes. Further adequately powered prospective study is warranted. / Background: Improved preoperative weight loss strategies for patients with obesity undergoing major non-bariatric surgery are necessary. As such, this research program focusing on evaluating different preoperative weight loss interventions, namely very low energy diets (VLEDs) and bariatric surgery, for patients with obesity undergoing major non-bariatric surgery was developed. Methods: The first chapter is a systematic review evaluating the use of preoperative VLEDs reported according to PRISMA. Medline, EMBASE, CENTRAL, and PubMed were systematically searched from inception through to July 2021. Articles were included if they evaluated VLED utilization prior to non-bariatric surgery. Pairwise meta-analyses using inverse variance random effects were performed. The second chapter is a retrospective study investigating the impact of a history of bariatric surgery on patients undergoing surgery for colorectal cancer. Adult patients undergoing resection for colorectal cancer from 2015-2019 were identified from the National Inpatient Sample (NIS). Patients were stratified according to their history of bariatric surgery. Propensity score matching with 4:1 nearest-neighbor matching was performed. Results: In Chapter 1, 13 studies with 395 patients with obesity receiving VLEDs preoperatively in preparation for non-bariatric surgery were included. Adherence with VLEDs ranged from 94- 100%. Mean preoperative weight loss ranged from 3.2-19.2kg. Patients using VLEDs had decreased intraoperative blood loss (MD 305.20mL, 95%CI 208.18-402.23, p<0.00001). In Chapter 2, 1,197 patients without prior bariatric surgery and 376 patients with prior bariatric surgery were included. Patients with prior bariatric surgery had an absolute reduction of 6.5% in overall in-hospital postoperative morbidity (19.1% vs. 25.6%, p<0.0001) and a $5,256 decrease in hospitalization cost ($70,344 vs. $75,600, p=0.034). iv Conclusion: These studies support the use of preoperative weight loss techniques for patients with obesity prior to non-bariatric surgery. VLEDs and bariatric surgery have the potential to become cornerstones of pre-habilitation protocols for patients with obesity undergoing elective operations. Further adequately powered prospective study is warranted. / Thesis / Master of Science (MSc) / Preoperative weight loss strategies for patients with obesity undergoing major non- bariatric surgery are becoming a necessity given the ubiquitous nature of obesity in our current surgical patient population. The first chapter is a systematic review and meta-analysis evaluating the use of preoperative very low energy diets (VLEDs) prior to non-bariatric surgery for patients with obesity. After screening nearly 800 citations and including 13 studies, this review identified that while currently available evidence is heterogenous, preoperative VLEDs are safe, well tolerated, and effectively induce preoperative weight loss in patients with obesity undergoing non-bariatric surgery for both benign and malignant disease. The second chapter is a population- level retrospective study investigating the impact of a history of bariatric surgery for weight loss on patients undergoing surgery for colorectal cancer. The findings from this study suggested that bariatric surgery prior to surgery for colorectal cancer may be associated with decreased postoperative morbidity and healthcare resource utilization.

A comparative study between the techniques Bluetooth Low Energy and Bluetooth Classic has been performed in cooperation with Saab AB with the purpose to determine which technique is best suited for transmission of data between an Android unit and an embedded system. The parameters that has been analyzed are throughput, energy efficiency and susceptibility. The study has been performed in accordance with the method Design Science Research and has therefore produced an artefact in the form of a system that has been evaluated in an experiment where performance parameters have been measured and analyzed. The results show that BLE is more robust in environments with a high level of noise and can handle lower SNR levels than BR/EDR; 3 dB vs 7,5 dB. If enough transfer speed is reached, BLE would also give the best energy efficiency and if the specified maximum throughput is reached, BLE would, according to this study, have more than double the energy efficiency as BR/EDR. BLE is, according to most measures, preferable from Bluetooth version 5 and is future-proof but BR/EDR still provides the highest throughput.