Syftet med projektet var att ta fram en rekylsimulator till användning vid torrträning i skidskytte för att tillföra mer realism till träningsformen. Projektet hade som mål att testa ut komponenter till simulatorn, designa ett fäste samt att både genom mätningar och användartester verifiera den framtagna simulatorns validitet. För att med god reliabilitet testa de ingående komponenterna byggdes en testrigg där upprepade tester kunde utföras. Ett fäste togs även fram och itererades på tills en slutgiltig lösning erhölls. De två verifieringsstegen hann ej utföras och de ingående komponenterna uppvisade ej heller egenskaper som är nog väl överensstämmande med uppmätta värden för att garantera goda chanser till en lyckad simulering. I testerna förekom det även problem med den sensor som användes vilket innebar en viss osäkerhet kring erhållna värden. Över lag krävs mer arbete för att finna bättre komponenter, men även för att testa löningsprincipen och dess giltighet / The purpose of the project was to develop a recoil simulator for use in dry training in biathlon to add more realism to the practice. The project aimed to evaluate components of the simulator, design a mounting for the rifle and to verify the validity of the developed simulator through both measurements and user tests. In order to test the constituent components with good reliability, a test rig was constructed where repeated reliable measurements could be performed. A mounting was also designed and iterated upon until a final solution was obtained. The two verification steps were not performed, due to time constraints and the components also did not show properties that were well enough in accordance with measured values to guarantee good chances of a successful simulation. In the tests, there were also problems with the sensor used, which meant there was some uncertainty about the obtained values. In general, more work is required to find better components, but also in order to test the principle and its validity. / <p>2022-07-01</p>

As it becomes more important to replace fossil fuels with alternative fuels, biofuels like ethanol are becoming more commercially used. The increased use of ethanol brings good influences such as lower impact on the environment. However, the use of ethanol can also bring negative effects regarding corrosion of metals. In the automotive industry aluminium has been seen affected by a novel very aggressive corrosion phenomenon, alcoholate corrosion. This master thesis investigation has investigated the effect of a few parameters of importance for alcoholate corrosion; water, temperature, time and pressure. The aluminium alloys AA6063 and A380 have been investigated and the capacity of five different surface treatments of AA6063 has been tested to observe if they inhibit the effect of alcoholate corrosion.   Throughout the experiments the water dependence of alcoholate corrosion has showed to be of large importance for the corrosion process. An increase in water content will postpone the start of alcoholate corrosion or prevent corrosion to occur.  A correlation between temperature and time has been observed. Higher temperatures results in a shorter time period of exposure before alcoholate corrosion occurs, and vice versa. The effect of different pressures was investigated and showed no effect on alcoholate corrosion when using pressurisation with the inert nitrogen gas.   All surface treatments revealed a capacity to protect the aluminium alloy against alcoholate corrosion to different extent. The electroless nickel plating seemed to prevent alcoholate corrosion while the Keronite coating seemed more sensitive to this form of corrosion.

Ecological restoration has the potential to provide a multitude of benefits, such as conserving biodiversity and supporting natural-resources dependent livelihoods. Tropical dry forests (TDFs) occur in densely populated human-modified landscapes in the tropics and are susceptible to degradation, making them an important biome to restore when degraded. TDFs are also socio-ecological systems, where local people rely on the forest for subsistence and livelihoods and effectively manage them for desire outcomes. People’s reliance on TDFs necessitates restoration projects to take into account more than biophysical and abiotic considerations when they are designed. In this decade of restoration, while there is the much-needed impetus to restore degraded land, to achieve enduring and just outcomes at large spatial scales, restoration projects need to more intentionally address local considerations, such as traditional land tenure systems and livelihood strategies, and goals such as socio-economic development. At the same time, to guide restoration efforts and realistically forecast the consequences of these efforts in the future, there is a need for rapid and accurate assessment tools to quantify the impact of restoration on biodiversity and people at several time steps. In Chapter 1, I use India, a country with high biophysical potential for restoration, as a case study to demonstrate a people-centric approach for identifying restoration opportunities. I find that there is a large overlap between areas of high biophysical restoration potential and high poverty, indicating potential and need to pursue restoration in a manner that addresses both ecological and social goals. In Chapter 2, I study a commonly adopted livelihood strategy, seasonal migration, in forest-dependent communities in India. I find that households in more agricultural and prosperous districts experience lower rates of migration but are more sensitive to climatic variability than households in poorer districts. In Chapter 3, I examine the impact of ecological restoration of a tropical dry forest in central India (CI). I find no significant difference in the cumulative number of bird species detected, but a significant difference in bird communities across the sites. In the lower frequencies dominated by birds and insects, I find that restored sites were positively associated with acoustic space occupancy in comparison to unrestored and low Lantana density (LLD) sites. In Chapter 4, I study the combined socio-ecological outcomes of restoration in the same sites in CI. I find that in the absence of alternative, people rely on Lantana camara, an invasive shrub, for subsistence and livelihoods, in the form of firewood and farm boundaries. I do not find any significant effect of restoration or LLD on people’s perception of ease of forest use, except for the distances covered for grazing, an important indicator of restoration success in this landscape. Finally, I also find that restoration is not associated with any significant changes in soundscapes in the higher frequency ranges dominated by insects and bats. Taken together, my chapters contribute to a greater understanding of the potential for restoration to meet social and ecological goals, the vulnerability of the livelihoods of people living on forest-fringes of TDFs to climate variability and expected and unexpected socio-ecological outcomes of restoration.

Human tear film is an accessible biospecimen rich with useful biological information. As tear protein biomarkers for both ocular and systemic diseases have been identified in tears, efforts are being made to create point-of-care tests useful for clinical diagnoses. However, there are significant obstacles to tear diagnostics, including inadequate sampling methods and biomarkers with insufficient sensitivity and specificity. Furthermore, tear film diagnostics are particularly challenging for dry eye disease (DED) patients, where low tear volume makes sampling more difficult and the multifactorial nature of DED makes identifying the exact pathological subtype very complex. As soft contact lenses (SCLs) are designed for optimal ocular surface interaction and concentrate proteins on the eye regardless of tear volume, we hypothesized that we could improve tear sampling methods for research and diagnostic purposes. We further hypothesized that we could identify new and existing and DED biomarkers using SCL tear film sampling. To begin, we demonstrate SCL sampling in vitro and then compare SCLs to other current tear sampling methods in vivo. Objectively, we observe that SCLs do not show signs of ocular surface irritation, regardless of previous SCL use. We also see that SCLs sample similar types and amounts of proteins relative to other methods. Subjective assessments of tear sampling methods are also made by subjects. Our results indicate that training and experience in tear sampling are key components which may significantly impact subject experience as well as the tear type collected. Next, we optimized our tear sampling method by comparing different SCLs materials in search of an ideal lens. Our data show that certain combinations of SCL materials and mass spectrometry (MS) sample preparation methods can lead to significant polymer contamination in MS. Furthermore, we observe individual protein binding specificity based on SCL chemistry. Our experiments reveal etafilcon A and verofilcon A lenses as the optimal SCL materials for tear film sampling. Finally, a pilot study in DED candidates using SCL sampling confirms the presence of previously reported biomarkers in DED subjects as well as identifies new biomarkers for future validation studies. We also correlate clinical metrics to biochemical findings and identify correlations between tear film homeostasis and pathologic phenotypes. Ultimately, these studies demonstrate SCL sampling is an advantageous alternative to current tear film sampling methods, useful for biomarker discovery, and potentially, clinical diagnostics.

No description available.

The understanding of diversification of intraspecific lineages can shed light on speciation processes and ultimately biogeographic patterns across multiple spatial and temporal scales. In this dissertation I investigated the geographical and ecological factors promoting diversification across the South American dry diagonal biomes (i.e. Cerrado, Chaco, and Seasonally Dry Tropical Forests - SDTFs), through a coupled approach between multilocus phylogeographic and geospatial methods, in the larger context of interpreting the consequences of the resulting patterns for the conservation of biodiversity and evolutionary processes. In Chapter 1 I evaluate biogeographic hypotheses previously proposed and emphasize that the dry diagonal biomes are particularly biodiverse and biogeographically complex, but poorly studied and under protected. I also propose testable predictions for the subsequent chapters and future diversification studies. In the subsequent chapters I adopt a biodiversity prediction approach based on estimating palaeodistributions and habitat stability surfaces to formulate and test spatially explicit diversification hypotheses based on squamate richness and phylogeography. In Chapter 2 I identify historically stable areas of SDTFs and in Chapter 3 I found that the historical climatic stability is a good predictor of Cerrado squamate richness. In Chapter 4 I use a multilocus dataset to estimate the phylogenetic relationships among described species of the lizard genus Phyllopezus (Phyllodactylidae), distributed across the ‘dry diagonal’ biomes. In Chapter 5 I used a dense sampling design focused in the species complex P. pollicaris (more individuals, localities, and markers), and coalescent phylogeographic methods to test the relative influences of Tertiary geomorphological vs. Quaternary climatic events on diversification in this lizard. I found unprecedented levels of cryptic genetic diversity, deep phylogeographic structure, and diversification dating back to at least the Neogene with persistence across Quaternary fluctuations. My dissertation emphasizes that patterns of diversification across the ‘dry diagonal’ biomes are much more complex than previously proposed and reflect the primary influence of geologically old processes. Evidence of allopatric and ecological speciation between lineages that coincide with genetic clusters associated with each of the biomes, contradicts early views that the biomes would have a shared diversification history. These patterns illustrate that low-vagility complexes, characterized by strong structure and pre-Pleistocene divergences, represent ideal radiations to investigate broad biogeography of associated biomes. Future studies should investigate patterns of temporal and spatial congruence across co-distributed taxa, and integrate morphological and further ecological data to refine species limits, taxonomy, and patterns of trait evolution across these radiations.

The Greenland ice sheet is an area of great interest to the scientific community due to its role as an important bellwether for the global climate. Satellite-borne scatterometers are particularly well-suited to studying temporal changes in the Greenland ice sheet because of their high spatial coverage, frequent sampling, and sensitivity to the presence of liquid water. The dry snow zone is the largest component of the Greenland ice sheet and is identified as the region that experiences negligible annual melt. Due to the lack of melt in the dry snow zone, backscatter was previously assumed to be relatively constant over time in this region. However, this thesis shows that a small seasonal variation in backscatter is present in QuikSCAT data in the dry snow zone. Understanding the cause of this seasonal variability is important to verify the accuracy of QuikSCAT measurements, to better understand the ice sheet conditions, and to improve future scatterometer calibration efforts that may use ice sheets as calibration targets.This thesis provides a study of the temporal behavior of backscatter in the dry snow zone of the Greenland ice sheet focusing on seasonal variation. Spatial averaging of backscatter and the Karhunen-Lo`eve transform are used to identify and study the dominant patterns in annual backscatter behavior. Several QuikSCAT instrumental parameters are tested as possible causes of seasonal variation in backscatter in the dry snow zone to verify the accuracy of QuikSCAT products. None of the tested parameters are found to be related to seasonal variation. Further evidence is given that suggests that the cause of the seasonal variation is geophysical and several geophysical factors are tested. Temperature is found to be highly related to dry snow backscatter and therefore may be driving the seasonal variation in backscatter in the dry snow zone.

Two studies were conducted to determine the relative effect of various combinations of antioxidants on vitamin A oxidation and isomerization in nonfat dry milk (NDM). In the first study, one lot of pasteurized unfortified skim milk was divided, fortified with vitamins A and D and one of 11 antioxidant treatments, and spray dried. A control batch from the same lot was also fortified with vitamins A and D and spray dried. Samples were analyzed for total vitamin A bioactivity after zero, one, and two weeks of storage. After two weeks at 50°C, the only NDM samples that did not experience significant vitamin A loss were those treated with butylated hydroxytoluene, either alone at 0.57 ppm or at 0.29 ppm in combination with 250 ppm ascorbic acid. The control sample was significantly different from both of these treatments, and retained only 17% of its original retinol activity equivalents. Isomer composition changed over the two weeks of storage, with an increase of the 13-cis, 9,13-di-cis and the 9-cis isomers as well as a decrease in the all-trans isomer. In the second study, two lots of pasteurized, vitamin A & D fortified, condensed skim milk were divided into four batches, three of which were spiked with an antioxidant treatment: 250 ppm ascorbic acid + 1 ppm propyl gallate, 250 ppm ascorbic acid + 1 ppm butylated hydroxyanisole, or 2 ppm propyl gallate; the fourth batch was a control. Each of the eight batches was homogenized, spray dried and stored in the absence of light at 30°C for 3 months. Vitamin A and riboflavin were analyzed before spray drying, and after 0, 1, 2, 4, 6, 8, 10, and 12 weeks. Two treatments had significant higher vitamin A than the control, the 250 ppm ascorbic acid + 1 ppm butylated hydroxyanisole treatment and the 2 ppm propyl gallate treatment. Limited vitamin A degradation occurred in all samples during the study timeframe, although the overall degree of retinol isomerization began and remained high in all samples, with cis isomers accounting for approximately 23% of the total μg of retinol after 12 weeks. There were no significant differences in riboflavin content between any of the antioxidant treatments and no significant degradation in riboflavin over time. Antioxidants appear to be an effective means of reducing vitamin A oxidation and isomerization in nonfat dry milk. Butylated hydroxytoluene in combination with ascorbic acid was the most effective antioxidant blend observed. Antioxidants may be less effective at protecting against degradation of vitamin A if isomerization has already taken place.

No description available.

In the construction of highways, airports, and other structures, the compaction of soils is needed to improve its strength. In 1933 Proctor developed a laboratory compaction test to determine the maximum dry density of compacted soils, which can be used for specifications of field compaction. The Compaction of soils is influenced by many factors, the most common are the moisture content, the soil type and the applied compaction energy. The objective of this research is the analysis of the maximum dry density values based on the soil classification and characterization. The method of choice in the determination of the maximum dry density from different soils was the Standard Proctor Test following the procedure for the standard Proctor test as is explained in ASTM Test Designation D-698. From this investigation, the maximum dry density of eight types of sands was obtained, the sands were classified by using the Unified Soil Classification System. The influence on the maximum dry density of the type of sands, type of fines, amount of fines and distribution of the grain size was determined, followed by a sensitivity analysis that measured the influence of these parameters on the obtained maximum dry density. The research revealed some correlations between the maximum dry density of soils with the type of fines, the fines content and the Uniformity Coefficient. These correlations were measured and some particular behavioral trends were encountered and analyzed. It was found that well-graded sands have higher maximum dry density than poorly graded when the soils have the same fines content, also it was encountered that plastic fines tend to increase the maximum dry density.