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The aim of this study was to test a predictive model of the geomorphological and sedimentological effects of floods resulting from the sudden drainage of ice-dammed lakes (jokulhlaups). A process-based, conceptual model for channel and sedimentary characteristics was tested within a jokulhlaup routeway near Sondre Stromfjord, west Greenland. River channel change resulting from a jokulhlaup monitored in 1987 was studied in three channel types along the flood routeway: deltaic, high gradient bedrock-controlled, and low gradient confined valley sandur. Flood powers, sediment supply and channel resistance to erosion were found to vary considerably between the channel types. Consequently, amounts of channel change and the character of the sedimentary record showed extreme variation. In addition, parts of the jokulhlaup channel which experienced backwater effects may have experienced two sediment transport peaks. Variations between the character of deposits found within each of the three channel types reflect local differences in sediment supply, stream power and channel resistance to erosion. Deposition in the delta and the sandur records sedimentation related to a number of jokulhlaups, whilst the spillway and the bedrock-confined channel provide a record of the action of the last jokulhlaup as low stage deposits, as well as that of the earliest flood events as high stage deposits. This study has shown that it is possible to predict the morphology of channel macroforms. The internal structure of these macroforms is strongly dependent upon both the amount and character of sediment supplied to the channel during a jokulhlaup. The more detailed the knowledge of the controlling variables for any one channel, the more detailed the resulting predictions are. At present, the model concerns only the products of turbulent, Newtonian, water floods. It may, however, be possible to predict thresholds marking the transition to non-Newtonian flows where sediment supply conditions and hydrograph characteristics are known. The model may also be used in reverse to reconstruct the magnitude and frequency of former jokulhlaups where sufficient geomorphological and sedimentary evidence is available.

Core flooding is a commonly used experimental procedure in the petroleum industry. It involves pressurizing a reservoir rock and flowing fluid through it in the laboratory. The cylindrical rock, called a core, can be cut from the reservoir during a separate core drilling operation or a formation outcrop. A core flooding apparatus suitable for matrix acidizing was designed and assembled. Matrix acidizing is a stimulation technique in which hydrochloric acid (HCl) is injected down the wellbore below formation fracture pressure to dissolve carbonate (CaCO3) rock creating high permeability streaks called wormholes. The main components of the apparatus include a continuous flow syringe pump, three core holders, a hydraulic hand pump, two accumulators, a back pressure regulator, and two pressure transducers connected through a series of tubing and valves. Due to the corrosive nature of the acid, the apparatus features Hastelloy which is a corrosion resistant metal alloy. Another substantial feature of the apparatus is the ability to apply 3000psi back pressure. This is the pressure necessary to keep CO2, a product of the CaCO3 and HCl reaction, in solution at elevated temperatures. To perform experiments at temperature, the core holder is wrapped with heating tape and surrounded by insulation. Tubing is wrapped around a heating band with insulation to heat the fluid before it enters the core. A LabVIEW graphical programming code was written to control heaters as well as record temperature and pressure drop across the core. Other considerations for the design include minimizing footprint, operational ease by the user, vertical placement of the accumulators and core holders to minimize gravity effects, and air release valves. Core floods can be performed at varying injection rates, temperatures and pressures up to 5000psi and 250 degF. The apparatus can handle small core plugs, 1’’ diameter X 1’’ length, up to 4’’ X 20’’ cores. The equipment description includes the purpose, relevant features, and connections to the system for each component. Finally documented is the procedure to run a core flooding test to determine permeability and inject acid complete with an analysis of pressure response data.

Följande arbete behandlar möjliga lösningar för hantering av SYN flooding, en Denial-of-Service-attack mot tjänster som använder TCP för kommunikation över datanätverk. Ett flertal olika skyddsmetoder, med varierande ansatser, identifieras, beskrivs och undersöks. Även möjligheter att kombinera dessa analyseras. Det visas att genom att implementera existerande skydd, samt kombinera flera av dessa begränsas hotet från SYN flooding avsevärt. Rekommendationer presenteras dessutom för hur organisationer bör gå tillväga för att säkra tjänster som riskerar att utsättas för SYN flooding-attacker genom att implementera skydd nära tjänsten först  samt  därefter ytterligare lager allt längre ut i nätverket.

An experimental study on flooding with steam and water in a large diameter vertical tube was conducted. This research has been performed to provide a better prediction of flooding in a pressurized water reactor (PWR) pressurizer surge line to be used in reactor safety codes. Experiments were conducted using a 3-inch (76.2 mm) diameter tube 72 inches (1.83 m) long with subcooled water and super-heated steam at atmospheric pressure as the working fluids. Water flows down the inside walls of the tube as an annulus while the steam flows upward in the middle. The water flow rates ranged from 3.5 to 12 gallons per minute (GPM) (0.00022 to 0.00076 m^3/s) and the water inlet temperature was approximately 70 degrees C. The steam inlet temperature was approximately 110 degrees C. The size of the test section as well as the flow ranges of the working fluids was determined based on a scaling analysis of a PWR pressurizer surge line. Two distinct trends were observed in the data. It was found that for water flow rates below 6 GPM (0.00038 m3/s) the amount of steam required for flooding to occur decreases with an increasing water flow rate. For water flow rates above 6 GPM the amount of steam required for flooding to occur increases with an increasing water flow rate. In addition, axial water temperature data was collected. Axial water temperatures have not been recorded in previous flooding experiments with steam and water. A new correlation for predicting flooding with steam and water was proposed. This correlation was an improvement from previous correlations because it included the amount of steam condensation. Incorporation of steam-water mass exchange promotes a better prediction of behavior in reactor systems. This data for flooding with steam and water in a large diameter vertical tube can lead to a mechanistic model for flooding.

Between 1850 and 1922, agriculturalists built 1,700 kilometers of levees to convert 250,000 hectares of tidal marsh to farmland where the San Joaquin and Sacramento Rivers enter the San Francisco Bay (the Delta). Drained, farmed and isolated from the water channels, the organic soils behind the levees subsided to elevations as low as 8 meters below sea level, turning "levees" into "dams" that hold back water constantly. Engineers built water transfer projects in the mid-20th century, transferring water from the south Delta to 25 million Californians who now rely on the "dams" accidentally converted into supply channels. In 1972, however, a levee failure caused a salt-water intrusion into the Delta, raising the prominence of the polemic Peripheral Canal which, if built would replace the levees in the trans-Delta water transport role. Levee failures in 2004 (the Delta) and 2005 (New Orleans) have re-ignited the debate, fueled by comments made by public officials who warned that the Delta levees posed more risk of failure than did the pre-Katina Louisiana levees. This background motivates two research questions: What are the social perspectives regarding levee failures of the experts managing the Delta; and what is the history of levee failures that might support their perspectives? The research employed Q-Method to identify and describe four social perspectives: Delta Sustainers, Abandon the Levees, Levee Pragmatists, and Multi-Purpose Levee Advocates. A critical element underlying differences among the perspectives revolved around the perceived history of failures of Delta levees. This dissertation employed semi-structured interviews, archival record searches, and historic map and aerial photograph comparisons to compile a history of 265 levee failures since 1868, many of which are referenced to location, segment, and levee type. In addition, the dissertation compiled a list of emergency repairs and successful flood-fights. The history of failures indicates that important levees of the Delta have performed significantly better than previously identified. Sharing these social perspectives and research results among the key actors addressing Delta issues may lead to improved consensus decisions.

An experimental study has been conducted to compare the effect of steam injection and caustic steam injection in improving the recovery of San Ardo and Duri heavy oils. A 67 cm long x 7.4 cm O.D (outer diameter), steel injection cell is used in the study. Six thermocouples are placed at specific distances in the injection cell to record temperature profiles and thus the steam front velocity. The injection cell is filled with a mixture of oil, water and sand. Steam is injected at superheated conditions of 238oC with the cell outlet pressure set at 200 psig, the cell pressure similar to that found in San Ardo field. The pressure in the separators is kept at 50 psig. The separator liquid is sampled at regular intervals. The liquid is centrifuged to determine the oil and water volumes, and oil viscosity, density and recovery. Acid number measurements are made by the titration method using a pH meter and measuring the EMF values. The interfacial tensions of the oil for different concentrations of NaOH are also measured using a tensionometer. Experimental results show that for Duri oil, the addition of caustic results in an increase in recovery of oil from 52% (steam injection) to 59 % (caustic steam injection). However, caustic has little effect on San Ardo oil where oil recovery is 75% (steam injection) and 76 % (caustic steam injection). Oil production acceleration is seen with steam-caustic injection. With steam caustic injection there is also a decrease in the produced oil viscosity and density for both oils. Sodium hydroxide concentration of 1 wt % is observed to give the lowest oil-caustic interfacial tension. The acid numbers for San Ardo and Duri oil are measured as 6.2 and 3.57 respectively.

In intermittently connected mobile networks (ICMNs), where most of the time there does not exist a complete path from source to destination, or such a path is highly unstable and may change or break after it has been found (or even while being found). This kind of environment may apply to wildlife tracking sensor networks or military networks, and node on this network must find a route and communicate with other nodes by the way of moving, because the base station is too far away or destroying. In order to achieve this purpose, researchers have suggested using flooding-based routing schemes. Although these ways have high probability of delivery, but they waste a lot of network resources. This thesis proposes a routing protocol in ICMNs named Spray and Hop, and it has adopted a kind of mechanism which is named Spray. The method can reduce network overhead, and broadcast efficiently at the same time by using one name little control packages named forwarding token. In addition, in order to improve the success rate of delivery, we still apply a kind of composite Utility-based mechanism. This mechanism is to select the next best candidate relay node through node's own information, not utilizing the way of direct transmission. Spray and Hop mechanism has highly scalability, that is, this mechanism has good performance in dense and sparse networks, and does not need extra network information. Simulation results show that Spray and Hop has good performance in packet transmissions and end-to-end delay indeed, comparing to other flooding-based mechanisms.

<p>Följande arbete behandlar möjliga lösningar för hantering av SYN flooding, en Denial-of-Service-attack mot tjänster som använder TCP för kommunikation över datanätverk. Ett flertal olika skyddsmetoder, med varierande ansatser, identifieras, beskrivs och undersöks. Även möjligheter att kombinera dessa analyseras. Det visas att genom att implementera existerande skydd, samt kombinera flera av dessa begränsas hotet från SYN flooding avsevärt. Rekommendationer presenteras dessutom för hur organisationer bör gå tillväga för att säkra tjänster som riskerar att utsättas för SYN flooding-attacker genom att implementera skydd nära tjänsten först  samt  därefter ytterligare lager allt längre ut i nätverket.</p>

The goal of this research was to study the effect of salinity on the waterflood of initially oil-wet clay-rich sand packs. Two one-foot long sand packs with 8% initial water saturation and 50% porosity were aged in crude oil for two weeks and flooded with either a low salinity (1000 ppm NaCl, pH 6.3) or a high salinity (20000 ppm CaCl, 20000 ppm MgCl, 20000 ppm NaCl, 20000 PPM KCl, pH 6.2) brine. 1D low salinity floods yield an incremental oil recovery of 15% and a significant change in the relative permeability. Initial breakthrough brine analysis showed that the low salinity flood results in more cation exchange activity compared to the high salinity case. A pH change of up to 1.4 point was witnessed for the high salinity case whereas the low salinity case had a 1.1 point pH change. The pH stayed below 7 in both low salinity and high salinity cases. The relative permeability of the low salinity case indicates a more water-wet state than that of the high salinity flood. The 2D study focused on capturing the movement of the water saturation fronts in transparent 2D sand packs via digital recordings. Two-dimensional sand packs of the oil-aged clay-rich sands were constructed in plastic quarter 5-spot models. Secondary water floods were performed. Low salinity flooding yielded higher oil recovery at breakthrough than the high salinity case. There was more areal bypassing in the case of low salinity flooding. It was difficult to pack the 2D cells uniformly which affected the water floods. / text