Currently the "Pump and Dump" method employed by Exploration and Production (E&P) companies in deepwater is simply not enough to control increasingly dangerous and unpredictable shallow hazards. "Pump and Dump" requires a heavy dependence on accurate seismic data to avoid shallow gas zones; the kick detection methods are slow and unreliable, which results in a need for visual kick detection; and it does not offer dynamic well control methods of managing shallow hazards such as methane hydrates, shallow gas and shallow water flows. These negative aspects of "Pump and Dump" are in addition to the environmental impact, high drilling fluid (mud) costs and limited mud options. Dual gradient technology offers a closed system, which improves drilling simply because the mud within the system is recycled. The amount of required mud is reduced, the variety of acceptable mud types is increased and chemical additives to the mud become an option. This closed system also offers more accurate and faster kick detection methods in addition to those that are already used in the "Pump and Dump" method. This closed system has the potential to prevent the formation of hydrates by adding hydrate inhibitors to the drilling mud. And more significantly, this system successfully controls dissociating methane hydrates, over pressured shallow gas zones and shallow water flows. Dual gradient technology improves deepwater drilling operations by removing fluid constraints and offering proactive well control over dissociating hydrates, shallow water flows and over pressured shallow gas zones. There are several clear advantages for dual gradient technology: economic, technical and significantly improved safety, which is achieved through superior well control.

Two kinds of tsunami models are used in this thesis to simulate tsunami propagation in the ocean. One is the linear dispersion tsunami model developed by Port and Airport Research Institute (PARI), Japan. The other is COrnell Multigrid COupled Tsunami model (COMCOT) developed by the School of Civil and Environmental Engineering, Cornell University, that carries on the tsunami run-up computation to the nearshore region. Two kinds of tsunami models have the same mechanism of initial wave profile, which is the vertical seabed displacement as the initial tsunami profile proposed by Mansinha and Smylie (1971). Both models describe the tsunami by the same shallow water equations. At first, the feasibility of the PARI model is established by comparing with the record in Maldives during the South Asia tsunami in December 2004. Then, the COMCOT model in applied to the Pingtong earthquake in December 2006 and is validated by comparing with the tidal station records. Possible submarine fault activities around Taiwan and the Western Pacific ring is simulated by the The PARI model based on moment magnitude scale (¢Ûw) close to the South Asia tsunami. Seven sources are chosen: the Hokkaido, the East Japan, the Ryukyu Islands, the Guishan Island in Taiwan, the Fukien of mainland China, the Luzon Island and the New Guinea. The results suggest the northeast and southwest part of Taiwan have potential tsunami risk. Finally, we simulate the fault activity between Taiwan and Luzon islands by the COMCOT model. The inundation area extends northward to the Tso-Ying and San-Min districts, eastward to the Siao-Gang district and Fengshan city. The Kaohsiung harbor can resist tsunami hazard for moment magnitude scale (¢Ûw) up to 7.58 with maximum wave height of 5.5 meters.

Numerical modeling of shallow microtidal semi-enclosed estuaries requires the effective simulation of physical processes with a wide range of temporal and spatial scales. In theory, application of sufficient grid resolution in both the horizontal and vertical should result in a reasonable simulation. However, in practice, this is not the case. Fully resolving the finest scales can be computationally prohibitive, and various algorithmic assumptions can break down at fine resolutions, leading to spurious oscillations in the solution. One method of simulating inherently cross-scale phenomena is to use multimodel approaches in which domain decomposition is used to divide the region into multiple subregions, each modeled by different submodels. These submodels are coupled to simulate the entire system efficiently. In general, the different models may involve different physics, they may be dimensionally heterogeneous or they may be both physically and dimensionally heterogeneous. A reduction in computational expense is obtained by using simpler physics and/or a reduced dimension model in the submodels. In this research, we look at the particular case of modeling shallow bays containing narrow, deep ship channels. In order to accurately model bay circulation, a model should capture the effect of these spatially localized navigational channels. Our research shows that modeling techniques currently used to simulate such systems using 2 dimensional or coarse resolution 3 dimensional estuary models misrepresent wind driven surface circulation in the shallow bay and tide driven volume fluxes through the channel. Fully resolving the geometry of the ship channel is impractical on all but large parallel computing clusters. We propose a more efficient method using the multimodel approach. This approach splits the estuary into a shallow bay region and a subsurface ship channel region. By separating the physical domain into two parts in this way, simpler models can be used that are targeted at the different physical processes and geometries dominant in each region. By using a low resolution 3D model (SELFE) in the shallow bay region, coupled through appropriate interface conditions with a 2D laterally averaged model, the effects of the ship channel on bay circulation are accurately represented at a fraction of the computational expense. In this research, this coupled model was developed and applied to an ideal shallow bay- ship channel system. The coupled model approach is found to be an effective strategy for modeling this type of system. / text

Many problems in shallow water acoustics require accurate predictions of the acoustic field in space and time. The accuracy of the predicted acoustic field depends heavily on the accuracy of the inputs to the propagation model. Oceanographic internal waves are known to introduce considerable temporo-spatial variability to the water column, subsequently affecting the propagation of acoustic waves. As a result, when internal waves are present, errors in model inputs can significantly degrade the accuracy of the predicted acoustic field. Accurate temporo-spatial predictions of the acoustic field in the presence of internal waves therefore depend largely on one's ability to accurately prescribe the water column properties for the acoustic model. This work introduces a data-driven oceanographic model, named the evolutionary propagated thermistor string (EPTS) model, that captures the temporo-spatial evolution of the internal wave field along a fixed track, thereby permitting prediction of temporal fluctuations in the acoustic field. Simultaneously-measured oceanographic and acoustic data from the Office of Naval Research Shallow Water 2006 experiment are utilized in this work. Thermistor measurements, recorded on four oceanographic moorings spaced along the continental shelf, provide the data from which the EPTS model constructs the internal wave field over a 30 km track. The acoustic data were acquired from propagation measurements over a co-located path between a moored source and a vertical line array. Acoustic quantities computed in the model space, such as received level, depth-integrated intensity, and scintillation index are directly compared to measured acoustic quantities to evaluate the fidelity of the oceanographic model. In addition, a strong correlation is observed between the amplitude of the internal wave field and acoustic intensity statistics at a distant receiving array. It is found that the EPTS model possessed sufficient fidelity to permit the prediction of acoustic intensity distributions in the presence of nonlinear internal waves. / text

There is growing evidence that young adult readers frequently fail to create exhaustive textbased representations as they read. Although there has been a significant amount of research devoted to age-related effects on text processing, there has been little research concerning this so-called shallow processing by older readers. This dissertation uses eye tracking to explore age-related effects in shallow processing across different levels of text representations. Experiment 1 investigated shallow processing by older readers at the textbase level by inserting semantic anomalies into passages read by participants. Older readers frequently failed to report the anomalies, but no more frequently than did younger readers. The eye-fixation behaviour revealed that older readers detected some of the anomalies sooner than did younger readers, but had to allocate disproportionately more processing resources to looking back to the anomalies to achieve comparable levels of detection success as their younger counterparts. Experiment 2 examined age-related effects of shallow processing at the surface form by inserting syntactic anomalies into passages read by older and younger adults. Older readers were less likely to detect syntactic anomalies when first encountering them relative to younger readers and engaged in increased regressive fixations to the anomalies. However, older readers with high iii reading comprehension skill were able to use their familiarity with text content to increase their likelihood of syntactic anomaly detection. Experiment 3 investigated the role of aging on shallow processing of the temporal dimension of the situation model. No age-related differences reporting the anomalies were found. The eye-fixation behaviour revealed that older readers with high working memory capacity detected some anomalies sooner than did younger readers; however, they had to allocate increased processing resources looking back to the anomalies to achieve comparable levels of detection as younger readers. Together, the results demonstrate that older readers are susceptible to shallow processing, but no more so than younger readers when they can rely on their linguistic skill or their existing knowledge to help reduce processing demands. However, older readers appear to require additional processing time to achieve comparable levels of anomaly detection as younger readers.

Lake Ellesmere/Te Waihora is one of New Zealand’s largest coastal, brackish water lakes. It has nationally significant wetland bird populations and is regionally important for iwi. The lake regularly experiences fluctuations in water level, resulting in a continually expanding and contracting littoral zone. This study investigated the impacts of these water level changes on the ecology of the lake. Water chemistry results collected over 12 months, confirm the lake is hypertrophic, due to high nutrient (nitrogen and phosphorus) concentrations resulting in high chlorophyll a levels and low water clarity. Water chemistry conditions were collected at five locations around the lake and showed marked spatial variation, with the eastern most end (Kaituna Lagoon) having generally the best water quality and lowest salinity (mean 4.9 ppt). Mean concentrations of total nitrogen ranged from 1.63 to 2.4 mg/L, chlorophyll a from 50 to 148 ug/L and total suspended solids from 151 – 248 mg/L. Seasonally, highest nutrient concentrations (mean, total nitrogen = 2.625 mg/L, dissolved reactive phosphorus = 0.059 mg/L and total phosphorus = 0.365 mg/L) occurred in late summer months (February – March), slightly decreasing but remaining high throughout winter. The benthic invertebrate community was surprisingly diverse, Crustacea (Paracorophium excavatum), Oligochaeta, Mollusca (Potamopyrgus antipodarum) and Chironomidae (Chironomus zealandicus) were dominant community members in the littoral zone, although 24 other taxa were collected. At high water levels, taxonomic richness increased in the eulittoral zone, while decreasing in the mid-littoral and lower littoral zones. In contrast, density decreased with higher water level in the eulittoral and mid-littoral zones, while increasing in the lower littoral zone. Benthic invertebrate communities appeared to be adapted to periods of intermittent dewatering, and even sustained dewatering under cooler temperatures. Despite the relatively high diversity of benthic invertebrates, invertebrate predators are generally absent from the lake. My results suggest multiple factors and interactions from predation pressure, salinity and lack of macrophytes are likely responsible for the absence of predatory invertebrates such as damselfly (Xanthocnemis zealandica) and dragonfly (Procordulia grayi) larvae. The lack of significant relationships between water quality variables and water level, and the positive relationship between chlorophyll a and salinity, suggests that current lake opening events do not have a positive effective on either water quality or phytoplankton biomass in Lake Ellesmere/Te Waihora. However, the current lake opening regime seems to be favourable to benthic invertebrate survival in the littoral zone, as the lake is predominantly open over winter when temperatures are lower, reducing the risk of desiccation. Anthropogenic activities which modify hydrodynamic and water quality conditions can potentially have a large negative impact on the structure and diversity of the littoral invertebrate community as well as flow on effects through the lake food web. Based on results from this study, I suggest a minimum lake level at Taumutu of 0.6 m during the months from November – April in order to protect benthic invertebrate communities in the eulittoral zone from extensive loss of habitat, extreme temperature and reduced risk of desiccation. Having a minimum set at ~0.6 m would provide sufficient littoral zone habitat for the lakes extensive bird life and fish populations. In addition, immediate efforts are needed into reducing nutrient loads into the lake, through improved farm management (nutrient and stocking budgets) and riparian fencing. Furthermore, physical and chemical water quality properties would benefit from an increased water level over summer months, by reducing water temperatures, diluting readily available nutrient concentrations and potentially reducing phytoplankton (and potentially toxic cyanobacterial) blooms.

In this thesis proposals for different designs of a borehole thermal energy storage (BTES) have been developed for the building DN-huset in Stockholm, Sweden. To build a BTES results in savings in energy costs by approximately 44 %, i.e. 2 million Swedish crowns annually. Furthermore, a BTES would reduce the annual environmental impact with roughly 75-157 tonnes of CO2 equivalents per year, depending on how the electricity consumption’s environmental impact is estimated. The payback period is about 11 years, including the warm-up period that is necessary before commissioning the BTES. The savings in environmental impact and operating costs are a result of energy being reused. During the summer heat is stored in the bedrock beneath the building for retrieval about half a year later in the winter, when there is a heating demand. In addition to developing proposals for different BTES designs the thesis also examines the influence of certain design parameters, conservative choices and operating conditions.

There is growing evidence that young adult readers frequently fail to create exhaustive textbased representations as they read. Although there has been a significant amount of research devoted to age-related effects on text processing, there has been little research concerning this so-called shallow processing by older readers. This dissertation uses eye tracking to explore age-related effects in shallow processing across different levels of text representations. Experiment 1 investigated shallow processing by older readers at the textbase level by inserting semantic anomalies into passages read by participants. Older readers frequently failed to report the anomalies, but no more frequently than did younger readers. The eye-fixation behaviour revealed that older readers detected some of the anomalies sooner than did younger readers, but had to allocate disproportionately more processing resources to looking back to the anomalies to achieve comparable levels of detection success as their younger counterparts. Experiment 2 examined age-related effects of shallow processing at the surface form by inserting syntactic anomalies into passages read by older and younger adults. Older readers were less likely to detect syntactic anomalies when first encountering them relative to younger readers and engaged in increased regressive fixations to the anomalies. However, older readers with high iii reading comprehension skill were able to use their familiarity with text content to increase their likelihood of syntactic anomaly detection. Experiment 3 investigated the role of aging on shallow processing of the temporal dimension of the situation model. No age-related differences reporting the anomalies were found. The eye-fixation behaviour revealed that older readers with high working memory capacity detected some anomalies sooner than did younger readers; however, they had to allocate increased processing resources looking back to the anomalies to achieve comparable levels of detection as younger readers. Together, the results demonstrate that older readers are susceptible to shallow processing, but no more so than younger readers when they can rely on their linguistic skill or their existing knowledge to help reduce processing demands. However, older readers appear to require additional processing time to achieve comparable levels of anomaly detection as younger readers.

Coastal and shallow lakes are often subjected to eutrophication due to nutrients from catchment farming activities. Lake Ellesmere (Te Waihora) is a hyper-eutrophic lake which has gained recent attention because of concerns over its ecological health and fishery status. This study investigated the benthic ecology of the lake by extensive spatial and temporal sampling. Eight littoral sites were sampled on a single occasion, and 20 benthic sites were sampled once per season for one year. Water chemistry conditions, substrate and invertebrate communities varied significantly around the lake. Salinity, pH, DO and seston were primarily affected by freshwater inputs from inflow streams and salt water intrusion due to the lake opening to the sea. On these occasions, salinity reached 32 ‰ at the lake outlet. The lake invertebrate community was depauperate, comprising of only two species of invertebrate predators restricted to the littoral zone and eight benthic invertebrate taxa, dominated by oligochaetes, amphipods and chironomids. Benthic invertebrate abundances also reflect the dominant local substrate, where oligochaetes and chironomids preferred areas of silt substrate, whereas Potamopyrgus preferred harder substrate. Stable isotope and gut analysis determined that the primary food sources within the lake were phytoplankton and algae. Macrophytes provided a minimal contribution to the food web, possibly relating to the change in status from a clear water, macrophyte dominated lake to a turbid, phytoplankton dominated condition since the Wahine Storm in 1968. Isotope analysis also showed that the lake food web was markedly different in its carbon values from food webs of its inflow streams and nearby marine source. However the lake food web did show a marine-derived carbon signature. A mesocosm experiment testing the effect of common lentic predators on the abundance of the lake chironomid Chironomus zealandicus, showed that if invertebrate predators were present in the lake they could markedly reduce the abundance of the pest prey species. This study highlights that the frequent re-suspension of bottom sediments, lake level fluctuation resulting in wetting and drying of littoral zones, and the management of the lake opening to the sea all have an effect on the benthic ecology of Te Waihora.

Since the last three decades, several studies have been conducted related to improvement in bearing capacity of pavements, embankments, and shallow foundations resting on geosynthetic reinforced soil. Most of the work has been carried out on single layer soil e.g., sand or clay layer only. Very few studies are available on a double layer soil system; but no study is available on the local soil of Carbondale, Illinois. The present study investigates the physical and engineering properties of a local soil and commonly available sand and improvement in the bearing capacity of a local soil for a rectangular footing by replacing top of the local soil with sand layer and placing geogrids at different depths. Seven tests on the model footing were performed to establish the load versus settlement curves of unreinforced and reinforced soil supporting a rectangular foundation. The improvement in bearing capacity is compared with the bearing capacity of the local soil and double layer unreinforced soil system. The test results focus on the improvement in bearing capacity of local soil and double layer unreinforced soil system in non-dimensional form i.e., BCR (Bearing Capacity Ratio). The results obtained from the present study show that bearing capacity increases significantly with the increasing number of geogrid layers. The bearing capacity for double layer soil increases, by placing three inch sand layer at the top of local soil, was not significant. The bearing capacity of the local soil increased at an average of 7% with three inches sand layer. The bearing capacity for the double layer soil increases with an average of 16.67% using one geogrid layer at interface of soils (i.e., local soil and sand) with u/B equal to 0.67. The bearing capacity for the double layer soil increases with an average of 33.33% while using one geogrid in middle of sand layer having u/B equal to 0.33. The improvement in bearing capacity for double layer soil maintaining u/B equal to 0.33 and h/B equal to 0.33; for two, three and four number geogrid layer were 44.44%, 61.11%, 72.22%, respectively. The results obtained from this research work may be useful for the specific condition or similar type of soil available anywhere to improve the bearing capacity of soil for foundation and pavement design.