This study aims at uncovering the formation mechanism of the recent bright gully deposits observed on Mars in order to assess the viability of liquid water involvement. I use a high resolution topography model as input into a kinematic model to assess whether or not a dry granular flow could form the bright gully deposits seen in Hale Crater. I investigate a dry mechanism due to the difficulty of producing water on the martian surface under present-day pressure and temperature conditions. I examine a range of particle sizes, flow thicknesses, and upslope initiation points to examine how these parameters affect the run-out distances of flows. The results show that multiple combinations of parameters could produce flows that travel to within the observed deposits' boundaries. The results suggest that the recent bright gully deposits are not evidence of recent liquid water on the surface of Mars.

A complete understanding of the cooling process when hot rolling steel is essential to understanding how the quality of the steel is connected to the cooling. This is why it is of great interest to simulate this process. However traditional CFD methods are too expensive in terms of CPU time. Knowing that video games successfully simulate fluids in reasonable time, those methods could be useful for simulating the cooling process in steel manufacturing. This would mean a loss in accuracy that could be acceptable. In this thesis different methods used for fluid simulations have been studied. The Smoothed Particle Hydrodynamics (SPH) method has been chosen. The method has been implemented for simulating the cooling process in MATLAB, which is a matrix operation based programming tool. Convincing results have been achieved for a big scale, but problems still remain for an implementation on a small scale.

This dissertation consists of three essays on the impact of non-market financial flows in developing countries. The first essay answers two questions. First, to what extent are remittances (as private transfers) differentiable from grants (as public transfers) in their effects on capital formation and growth? Second, how might the motivations to remit inform the nature of the relationship between remittances and growth? Using a sample of four developing countries, results suggest that remittances and grants, in fact, do behave differently. Remittances have no significant relationship with investment for all but one country (remittances are positively correlated with growth for Bangladesh). Grants’ impact on investment is negative in Egypt, positive in Pakistan and Syria and insignificant in Bangladesh. Migrants’ motivations to remit are found to be different across countries. Enlightened self-interest motivation to remit is the most likely cause of growth impacts in Egypt. A combination of self-interest and enlightened self-interest explains the growth impact in Bangladesh. Finally, a combination of migrants’ altruistic behavior and self-interest attitude explains the growth impact in Pakistan and Syria. The second essay demonstrates the allocation of foreign aid between consumption and investment with special emphasis on the importance of reverse flows in developing countries. Using a panel of 61 countries from 1980 to 2006, results indicate that, on average, 23 to 25% of any increase in foreign aid has been directed towards financing reverse flows. 78% was consumed and an insignificant amount was invested. Additional investigation suggests that almost 50% of aid is used for reverse flows in Sub-Saharan Africa, 19% in the Americas and 16 to 20% in North Africa, Asia and the Pacific. The third essay examines how remittances are allocated between consumption, investment and reverse flows in developing countries. Using a panel of 36 countries from 1980 to 2006, results suggest that almost 80% of any increase in remittances/GDP was consumed. With respect to investment, remittances had to statistically discernable effect on rate of investment. Additionally, 20% of any increase in remittances was diverted as reverse flows and contributed neither to increase consumption nor to investment.

No description available.

A particle tracking velocimetry (PTV) system is used to investigate the turbulent properties at the free surface of shallow shear flows and a shallow vortex street (VS) wake flow. The resolution of the PTV system enables information to be gathered regarding the large-scale turbulent structure of these flows, and also enables analysis to proceed in both the temporal and spatial domains. Statistical tools such as the probability density function (PDF), autocorrelation and power spectral density (PSD) are utilised to characterise the turbulent properties at the flow surface. Two supercritical flows and one subcritical shallow shear flow are analysed. Taylor's frozen turbulence hypothesis is shown to be valid for these flows, and the integral length scales indicate that 2D isotropic structures with scales larger than the flow depth are present at the free surface. Such large-scale structures at the free surface are consistent with observations from dye visualisation experiments and with "spiral eddies" identified by Kumar, et al (1998). The longitudinal extent of near and intermediate wake fields for the shallow VS wake flow is well defined by the integral wake length scale specified by v.Carmer (2005). The near wake region is characterised by high rates of exchange between the mean flow and large-scale 2D coherent structures (2DCS). In the intermediate field, the rate of decay of the turbulent stress components greatly diminishes as the 2DCS are stabilised and dissipated under the action of bed friction. Multiple peaks are observed in the power spectral density of the turbulent fluctuations. The periodic shedding of 2DCS behind the circular cylinder is characterised by an energy peak at a Strouhal number of 0.21, and further energy peaks are observed in the near-wake region. The PSD estimates are consistent with the findings of v.Carmer (2005) in which a -5/3 decay law to high frequencies is observed, and no evidence of an inverse energy cascade is present.

There's a big demand for activated carbon in Ghana, it's used for the country's mining industry as well as in a multitude of other applications. Currently all activated carbon is imported despite the fact that the country has a large supply of agricultural waste that could be used for its production. This study focuses on activated carbon production from oil palm kernel shells from the nations palm oil industry. Earlier research points to a set of specific conditions needed for the production. The pyrolysis process produces biochar from the biomass and the process is set to take place for 2 h at 600  °C after a initial heating of 10 °C/min. The activation process then produces the activated carbon from the biochar and is set to take place for 2 h at 850 °C with a heating rate of 11.6 °C/min. Two reactors are designed to meet the desired conditions. The reactors are both set up to use secondary gases from diesel burners to heat the biomass. The heating is accomplished by leading the hot gases in an enclosure around a rotating steel drum that holds the biomass. To improve the ability to control the temperature profile in the biomass two outlet pipes are set up on top of the reactor, one above the biomass inlet and one above the biomass outlet. By controlling how much gas that flows to each outlet both the heating rate and the stability of the temperature profile can be controlled. The secondary gas inlet is set up facing downwards at the transition between the heating zone (area of initial heating) and the maintaining zone (area of constant temperature). The two reactors are modeled the physics simulation software COMSOL Multiphysics. Reference operating parameters are established and these parameters, as well as parts of the design, are then changed to evaluate how the temperature profile in the biomass and biochar can be controlled. A goal area was set up for the profile in the biomass where it was required to maintain a temperature of between 571.5 and 628.5 °C after the initial heating to be seen as acceptable. Similarly a goal area was set for the biochar between 809 °C and 891 °C after the initial heating. It's found from the simulations that the initial design of the reactors work well and can be used to produce the desired temperature profiles in the biomass and biochar. Furthermore it's concluded that the initial design for the pyrolysis reactor can be improved by having the gas outlet pipe situated by the biomass inlet face downwards instead of upwards. The redesign improves the overall efficiency of the reactor by increasing the heating rate and maintained temperature. The evaluation of the operating parameters led to the conclusion that the secondary gas inlet temperature effects the temperature profile to a greater extent than the gas mass flow in both reactors thereby making them more energy efficient. The increase in efficiency comes with a drawback of more unstable temperature profile. If the temperature profile becomes too unstable it will include temperatures that are too high or too low to be seen as acceptable. / Det finns en stor efterfrågan på aktivt kol i Ghana, det används dels i landets gruvnäring men även för en mängd andra applikationer. Idag importeras allt aktivt kol, trots att landet har stora mängder restprodukter från jordbruk som skulle kunna användas för produktion av aktivt kol. Det här arbetet fokuserar på produktion av aktivt kol från oiljepalmskärnor från landets palmoljeindustri. Tidigare forskning påvisar en mängd specifika förhållanden som krävs för produktionen. Pyrolysprocessen producerar biokol från biomassa och som mål för processen sätts att den ska hålla 600 °C i två timmar efter en uppvärmningstakt av 10 °C/min. För aktiveringsprocessen som sedan producerar aktivt kol från biokolet sätts målet till att hålla en temperatur av 850 °C med en uppvärmningstakt av 11.6 °C/min. Två reaktorer designas för att skapa dom efterfrågade förhållandena. Reaktorerna värms av sekundärgas från dieselbrännare för att värma biomassan och biokolet. Värmningen sker genom att den värma sekundärgasen leds runt en roterande ståltrumma genom vilken biomassan flödar. För att kunna ha en bra kontroll av temperaturprofilen i biomassan så används två utloppsrör för gasen på reaktorernas ovansida. Genom att kontrollera gasflödet till respektive utloppsrör kan både uppvärmningstakt och stabiliteten hos temperaturen justeras. Sekundärgasens inloppsrör placeras på reaktorns undersida och riktas mot övergångszonen mellan uppvärmning och stabilisering. Reaktorerna modelleras i fysiksimuleringsprogrammet COMSOL Multiphysics 4.3b. I COMSOL simuleras driften och de parametrar som påverkar den evalueras genom att varieras mot ett referensvärde. Temperaturprofilens målområde i pyrolysreaktorn sätts till att hålla en temperatur mellan 571.5 och 628.5 °C för pyrolysen och efter uppvärmningen, om temperaturprofilen går utanför målområdet så klassas den som oacceptabel. För biokolet i aktiveringsreaktorn sätts ett liknade mål till att det ska hålla mellan 809 °C och 891 °C efter uppvärmningen. Resultaten från simuleringarna visa att reaktorernas design fungerar som önskat och att dom kan producera dom önskade temperaturprofilerna. Det visas även att designen för pyrolysreaktorn kan förbättras ytterligare genom att sätta det främre utloppsröret för sekundärgasen på reaktorns undersida istället för dess ovansida. Förändringen leder till en effektivare värmeöverföring till biomassan samt höjer dess temperatur genom hela reaktorn. Analysen av driftparametrar som flöde och temperatur av sekundärgas, visar att dess temperatur påverkar processerna till en mycket större grad än dess massflöde. Genom att höja temperaturen kan flödet sänkas och hela processen blir mer energieffektiv, dock så leder det till en ökad instabilitet inom målområdet och om instabiliteten blir för stor så börjar temperaturprofilen gå ur målområdet.

The lower continental slope of Morocco’s west coast consists of Triassic-age salt manifested in the form of diapirs, tongues, sheets, and canopies, and both extensional and compressional structures that result from salt movements. Salt diapirism and regional tectonics greatly influenced a broad spectrum of depositional processes along the margin. Mapping of a 1064-km2 (411-mi2) seismic survey acquired in the Safi Haute Mer area reveals that Jurassic to Holocene salt mobilization has induced sedimentation that manifests itself in gravity slumps and slides and debris flows. An east-west–trending structural anticline located downdip of the salt-influenced region, was activated during the Atlas uplift (latest Cretaceous) and shaped much of the lower continental slope morphology from Tertiary time until present. The largest of the mass transport deposits (MTC) is a 500-m (1640-ft)-thick Cretaceous-age unit that spans an area of up to 20,000 km2 (7722 mi2). Seismic facies composing the MTC are (1) chaotic, mounded reflectors; (2) imbricated continuous to discontinuous folded reflector packages interpreted to represent internal syn-depositional thrusts; and (3) isolated, thick packages of continuous reflectors interpreted to represent transported megablocks (3.3 km2 [1.3 mi2]). The latter show well preserved internal stratigraphy. The MTCs originated from an upslope collapse of a narrow shelf during the earliest phases of the Alpine orogeny. Seismic geomorphologic analysis of the non-salt-deformed sections reveal numerous linear features that are interpreted as migrating Mesozoic-age deepmarine sediment waves. Three styles of sediment waves have been identified. These include: (1) type J1—small (less than 17 m thick) and poorly imaged, Jurassic in age, ridges that have wavelengths of up to 12 km and crest-to-crest separations of less than 1 km; (2) type K1—early Aptian constructional sediment waves (~110 m thick) that appear to show some orientation and size variations which suggest an influence on currents by salt-influenced seafloor topography, and (3) type K2—latest Albian and earliest post-Albian sediment waves exhibiting wave heights of 40 m and crest-to-crest separations of 1 km, that are continuous across the entire study area and show evidence of up-slope migration.

This dissertation consists of three essays on the impact of non-market financial flows in developing countries. The first essay answers two questions. First, to what extent are remittances (as private transfers) differentiable from grants (as public transfers) in their effects on capital formation and growth? Second, how might the motivations to remit inform the nature of the relationship between remittances and growth? Using a sample of four developing countries, results suggest that remittances and grants, in fact, do behave differently. Remittances have no significant relationship with investment for all but one country (remittances are positively correlated with growth for Bangladesh). Grants’ impact on investment is negative in Egypt, positive in Pakistan and Syria and insignificant in Bangladesh. Migrants’ motivations to remit are found to be different across countries. Enlightened self-interest motivation to remit is the most likely cause of growth impacts in Egypt. A combination of self-interest and enlightened self-interest explains the growth impact in Bangladesh. Finally, a combination of migrants’ altruistic behavior and self-interest attitude explains the growth impact in Pakistan and Syria. The second essay demonstrates the allocation of foreign aid between consumption and investment with special emphasis on the importance of reverse flows in developing countries. Using a panel of 61 countries from 1980 to 2006, results indicate that, on average, 23 to 25% of any increase in foreign aid has been directed towards financing reverse flows. 78% was consumed and an insignificant amount was invested. Additional investigation suggests that almost 50% of aid is used for reverse flows in Sub-Saharan Africa, 19% in the Americas and 16 to 20% in North Africa, Asia and the Pacific. The third essay examines how remittances are allocated between consumption, investment and reverse flows in developing countries. Using a panel of 36 countries from 1980 to 2006, results suggest that almost 80% of any increase in remittances/GDP was consumed. With respect to investment, remittances had to statistically discernable effect on rate of investment. Additionally, 20% of any increase in remittances was diverted as reverse flows and contributed neither to increase consumption nor to investment.

No description available.

No description available.