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The purpose of this study was to explore the preferred information sources and delivery channels for farm-related information among selected northeast Texas farmers and describe these results in a manner which might enable the Texas AgriLife Extension Service and other agriculture-focused entities better position themselves to address the needs of their clientele. An instrument was developed and mailed to (N = 290) randomly selected farmers from existing Extension mailing lists in four northeast Texas counties: Bowie, Rains, Rusk and Shelby. Participants had the option of responding online or via return mail. The highest ranking interpersonal information sources were other farmers, AgriLife Extension personnel, and seminars/workshops. The lowest ranking interpersonal information sources were agricultural lenders/bankers and private consultants. The highest ranking print-based information sources were agricultural newspapers and farm magazines. The lowest ranking print-based information sources were publications from non-governmental farm organizations and daily or weekly newspapers. Respondents were neutral on the usefulness of television and radio as information sources. The Internet was the only electronic information source agreed to as useful by responding farmers. The lowest ranking electronic media source was social media. The most common type of contact between farmers and the Texas AgriLife Extension Service was reading an Extension publication monthly, followed by a yearly visit to the Extension office. Farmers were satisfied with the quality of the agriculture related materials and programs provided by the Texas AgriLife Extension Service and were likely to recommend the agency to others. The majority (91.6%) of respondents had not heard of the national Extension website eXtension and only 4 respondents (2.5%) had reported using the website before. Respondents felt that eXtension would increase the accessibility of Extension programming, should be publicized more by local Extension offices, and would make Cooperative Extension more popular. Internet use among farmers was found to be influenced by age, highest level of education attained, Internet connection type, and other electronic devices used. Perceptions about AgriLife Extension were found to be influenced by Innovativeness Category, primary occupation, gender, and other electronic devices used. Findings in this study support the Uses and Gratifications Theory of media use.

Mobile data traffic is growing exponentially due to the popularization of smart phones, tablets and other data traffic appliances. One way of handling the increased data traffic is to deploy large antenna arrays at the base station, also known as Massive MIMO. In Massive MIMO, the base station having excessive number of transmit antennas, can achieve increased data rate by spatial-multiplexing terminals into the same time-frequency resource. This thesis investigates Massive MIMO in LTE in a single-cell deployment with up to 100 base station antennas. The benefits of more antennas are investigated with single-antenna terminals in a typical urban environment. The terminal transmitted sounding reference signals (SRS) are used at the base station to calculate channel state information (CSI) in order to generate an MRT precoder. With perfect CSI, the results showed that the expected terminal SINR depends on the antenna-terminal ratio. It was also showed that with spatial-multiplexed terminals and 100 base station antennas, the maximum cell throughput increased 13 times compared with no spatial-multiplexed terminals. Channel ageing causes inaccuracy in the CSI, the thesis showed that the variation in terminal SINR increased rapidly with less frequent SRS transmissions. When having moving terminals at 3 km/h, the difference between the 10th and 90th SINR percentile is 1 dB with an SRS transmission periodicity of 20 ms, and 17 dB with an SRS transmission periodicity of 80 ms. With 100 base station antennas and moving terminals at 3 km/h with an SRS periodicity of 20 ms, the maximum cell throughput decreased with 13% compared to when the base station has perfect CSI. The result showed that the maximum cell throughput scaled linearly with the number of base station antennas. It also showed that having the number of spatial-multiplexed terminals equal to the number of antennas is a reasonable assumption when maximizing the cell throughput.

The LHCb experiment (CERN) will offer a precise hadronic probe with which to study CP violation, rare decays and possible New Physics (NP) effects occurring in the b-system. Contained within the vast physics program is a dedicated and intense effort to measure the CP violating weak mixing phase, βs. This phase, observable in the neutral Bs-system, presents a sensitive indicator to NP occurring at the TeV scale. This phase appearing through the theoretically clean ¯b → ¯cc¯s quarklevel transition, can be measured precisely using Bs → J/ψφ decays. The analysis of Bs → J/ψφ decays requires using its decay angular information to separate out the CP eigenstates. The sensitivity to βs can then be extracted from the angular differential rates for this mode. This thesis presents the selection and reconstruction of this decay channel, analysis of the background specific to this channel and the method for fitting the data to extract βs. Previous studies within the collaboration have shown the βs sensitivity using a reduced angular expression for the decay rates. By studying the full angular expression, we find both a quantitative and qualitative improvement in the precision with which βs is obtained: the precision improves by approximately 20%, from ± 0.027 to ± 0.022 radians. In addition, we find it is possible to extract the b-tagging parameter from data itself, which aids to minimise the overall systematic effect. This thesis, in preparation for data taking at the LHCb, presents this expected improvement in measuring βs.

The thesis discusses the channel modelling and relay techniques in powerline communications (PLC) which is considered as a promising technology for the Smart Grid communications, Internet access and home area network (HAN). In this thesis, the statistical PLC channel characteristics are investigated, a new statistical channel modelling method is proposed for the in-door PLC. Then a series of the relay protocols are suggested for the broadband communications over power grid. The statistical channel modelling method is proposed to surmount the limits of the traditional deterministic PLC channel models such as multipath model and transmission line model. To develop the channel model, the properties of the multipath magnitudes, interval between the paths, cable loss and the channel classification are investigated in detail. Then, each property is described by statistical distribution or formula. The simulation results show that the statistical model can describe the PLC channels as accurate as deterministic models without the topology information which is a time-consuming work for collecting. The relay transmission is proposed to help PLC adapting the diverse application scenarios. The protocols covers the main relay aspects which include decode/amplify forwarding, single/ multiple relay nodes, full/half duplex relay working mode. The capacity performance of each protocol is given and compared. A series of the facts which improve the performance of the PLC networks are figured out according to simulation results. The facts include that the decode-and-forward is more suitable for the PLC environment, deviation or transforming station is better location for placing relay node and full duplex relay working mode help exploiting the capacity potential of the PLC networks. Some future works are pointed out based on the work of statistical channel model and relay. In the last part of this thesis, an unit based statistical channel model is initialled for adapting various PLC channel conditions, a more practical relay scenario which contains multiple data terminals is proposed for approaching the realistic transmission scenario. At last, the relay for the narrowband PLC Smart Grid is also mentioned as future research topic.

The application of geological and geophysical methods on the Ionian Island of Kefalonia has provided a new-found basis by which to test the hypothesis that Ancient Ithaca, the home of Odysseus as described in Homer’s epic the Odyssey, a subject which has perplexed academics for centuries. Although popular belief places Odysseus’ homeland on Ithaki, a small mountainous island lying to the east of Kefalonia, its location does not fit Homer’s descriptions of Ancient Ithaca since it is described as a “low-lying” island lying “furthest to the west” (facing dusk not dawn). Being land-locked and connected to the rest of Kefalonia by a narrow (6 km x 2 km) isthmus called the Thinia valley, the Paliki Peninsula of Western Kefalonia provides a better geographical fit. However, it has generally been dismissed as a candidate for Ancient Ithaca since it is not an island today and the topography of the connecting isthmus rises to a height of c. 200 m along the centre of the Thinia valley. Despite these obstacles and based on a quote by the ancient geographer Strabo made around 1 BC, Bittlestone et al. (2005) proposed that during the Mycenaean Era an ancient seaway (“Strabo’s Channel”) could have existed where Thinia stands today and the valley’s present topography is due to landslide deposition which eventually closed the seaway. This thesis presents the results of a 3-year geological, geomorphological and geophysical investigation of “Strabo’s Channel”. The investigation was carried out using a survey programme of complimentary non-invasive geophysical techniques calibrated by 17 shallow sedimentary cores and combined with surface geological mapping and geomorphological observations. In addition to a helicopter-mounted electromagnetic (HEM) survey acquired for Northern Paliki, gravity measurements were taken across the Thinia isthmus, and resistivity and seismic refraction surveys were carried out at strategic sites. Marine shallow seismic reflection surveys were also undertaken in the coastal areas adjacent to the isthmus to chart postglacial transgression into these shallow coastal areas and to reconstruct the paleo-geography of Northern Paliki since the Last Glacial Maximum (LGM) (c. 21 500 BP). The survey area is sited in the Pre-Apulian isopic zone of the Hellenide thrust belt which represents a structurally-inverted passive continental margin subsequently affected by foreland contraction and overprinted by neotectonic (outer-arc) deformation resulting from African-Eurasian plate collision. The results showed that the geology and geomorphology of Thinia was far more complicated than originally believed. The bedrock geology records the Cretaceous-Quaternary evolution of an extensional-compressional regime brought about through the foreland-migration of the Hellenide fold-and-thrust deformation in the Early Miocene which reactivated earlier south-easterly-dipping extensional faults. The peninsula was affected by further Late Quaternary, Holocene and recent neotectonic deformation caused by the formation of the dextral Kefalonia Transform Fault (KTF) and slope failure resulting from the generation of steep slopes. The shallow marine seismic reflection survey showed clear differentiation between the tectonised “pre-Holocene” and onlapping postglacial sediments separated by a prominent erosional surface associated with the LGM sea level lowstand of -120 m. The survey detected a buried drainage valley deeply-incised into the pre-Holocene of the Gulf of Argostoli indicating that a major glacial river drained from Thinia during this lowstand. During postglacial sea level rise this valley was infiltrated by marine waters to form a ria, flooding two large glacial lakes which acted as depocentres for postglacial sediments. While the prevalence of slope collapse of the steep valley sides in Thinia favoured the idea that “Strabo’s Channel” was infilled through repeated deposition of landslide debris, the presence of bedrock at the surface of Thinia ruled out the possibility that the present valley topography was built-up through Late Holocene deposition of landslide material between Kefalonia and Paliki. The onshore tests confirmed the presence of a thick deposit of steeply-dipping and tectonised marine sediments within the valley. Biostratigraphic analysis of core samples dated these as Early Miocene to Early Pleistocene (Gelasian) indicating marine waters existed along the valley until at least 1.80 million years ago, an order of magnitude younger than previously reported in the area. However, no new independent sediment younger than Early Pleistocene was retrieved in the cores obtained for this study despite the findings of an earlier borehole which appeared to contain Late Quaternary and Holocene marine fauna (Ehux). The geophysical surveys and cores failed to detect the sides or bottom of a channel or evidence of substantial clastic debris within the proposed channel route thus ruling out the possibility that a buried marine-level channel which extended from “sea-to-sea” had existed during the Late Bronze Age. One strategic area of investigation was the upland site of a suspected paleo-lake (Lake Katachori) which overlapped the proposed route of Strabo’s Channel at ~170 m elevation. Although the presence of freshwater algae within the upper few metres confirmed a lacustrine environment, the geophysical and core evidence showed it was shallow (6 m thick) and was sited on steeply easterly-dipping Plio-Pleistocene sediments uplifted to ~170 m above sea level. The occurrence of freshwater algae admixed with uppermost Plio-Pleistocene sediments probably represents a basal reworked basal lag deposit thus, implying departure from marine depositional setting occurred in Thinia sometime after the Gelasian (1.80 Ma). Coring at Livadi Marsh suggested that while the marsh was flooded during the Bronze Age to a depth of c. 1.2 m, making it a candidate for Ancient Ithaca’s harbour, no significant coseismic uplift appears to have occurred since the Late Bronze Age. Current coastal position was due to progradation and aggradation of marsh sediments with no more than 1.2m of coseismic uplift. The lack of Holocene-Late Quaternary sediment relating to an uplifted marine channel and the presence of Lake Katachori may tentatively be explained through the uplift and westwards translation of the sediments of central Thinia through establishment of a contractional-extensional linked gravity driven rotational slip linking the listric “Agia Ioanni Fault” with the Atheras Thrust. The boreholes detected shear-thrusting and steep dips within the Miocene and Plio-Pleistocene marl sediments demonstrating that the area experienced strong tectonic dislocation which is in favour of this model however further tests are required to investigate this and whether it could feasibly have occured in the required timescale.

Convection in a Boussinesq fluid confined by a annular channel fast rotating about a vertical axis and uniformly heated from below, is one of our concerns in this thesis. An assumption that the channel has a sufficiently large radius in comparison with its gap-width is employed, so that the curvature effect can be neglected. The aspect ratio of the channel has great influence on the convective flow in it. Guided by the result of the linear stability analysis, we perform three-dimensional numerical simulations to investigate the convective flows under three different types of aspect ratios, which are namely the moderate or large aspect ratios, the very small aspect ratios and the moderately small aspect ratios. Also, we numerically study how convection in the channel is affected by inhomogeneous heat fluxes on sidewalls, which is a simple simulation of the thermal interaction between the Earth's core and mantle. Convection and dynamo action in a rapidly rotating, self-gravitating, Boussinesq fluid sphere is the other concern. We develop a finite element model for the dynamo problem in a whole sphere. This model is constructed by incorporating dynamo equations with globally implemented magnetic boundary conditions to a whole sphere convection model, which is also presented here. The coordinate singularity at the center usually encountered when applying the spectral method is no longer an obstacle and no nonphysical assumptions (i.e. hyper-diffusivities) are used in our model. A large effort has been made to efficiently parallelize the model. Consequently, it can take the full advantage of modern massively parallel computers. Based on this dynamo model, we investigate the dynamo process in a sphere and find that self-sustaining dynamos are more difficult to obtain in a sphere than in a spherical shell. They are activated at relatively high Rayleigh numbers. Moreover, the magnetic fields generated are not dipole-dominant, different from those generated in most dynamo simulations.