Agricultural production in Monterey County, California is a multi-billion dollar industry. Near the coast, seawater intrusion has threatened to degrade the groundwater quality due to over-pumping of the aquifer. The Monterey Regional Water Pollution Control Agency (MRWPCA), in partnership with the Monterey County Water Resources Agency, has provided recycled water since 1998 to over 12,000 acres of prime agricultural farmland in the northern Salinas Valley in an effort to reduce groundwater removal. The dominant soil types in the region are clay loam and clay soils, which are both susceptible to sodium (Na) accumulation and water infiltration problems. Recycled water blended with well water is used to irrigate cool season vegetables (i.e., artichokes, broccoli, Brussels sprouts, celery, cauliflower, and lettuce) and strawberries. A long-term study was implemented by MRWPCA to monitor salinity levels in commercial vegetable fields because of grower concerns that salts in the recycled water would have long term effects on soil quality. Accumulation of salts over time would make the soil less productive. Soil salinity levels were monitored at three Control and three Test Sites beginning in the spring of 2000. The Control Sites received well water, and the adjacent Test Sites received an approximate 2:1 blend of recycled and well water, respectively. Control and Test Sites were paired based on location to compare the same soil, crop, drainage systems, and farming practices. The soil was sampled three times per year from all sites: spring (before planting), mid-summer after harvest of the first crop, and late fall after the second crop harvest. Composites of four cores were collected at each site from the zero to 36-inch depth at 12-inch intervals. Each 12-inch interval soil sample was analyzed for pH, electrical conductivity (ECe), extractable cations (Na+, Ca2+, Mg2+, and K+) and extractable anions (Cl-, NO3-, and SO4-). After 10 years of monitoring, the data showed that using recycled water blended with well water at the Test Sites increased the ECe of the soil profile from 2.1 to 2.5 dS/m and increased the sodium adsorption ratio (SAR) from 3.0 to 3.9. The data also showed that using well water at the Control Sites increased the ECe of the soil profile from 1.4 to 2.6 dS/m and the change in SAR was negligible. The Test and Control Sites were significantly different for ECe and SAR, which was expected considering a higher salt content in the recycled water compared to the well water. The significant differences for ECe and SAR were associated with the significant differences in soil Na+ levels between the Test and Control Sites. The SAR and ECe of soil samples from all sites were in a range acceptable for vegetable production. The use of recycled water for irrigation of cool season vegetables and strawberries in the study area has not shown an indication of degraded soil productivity. Based on vegetable production and the slow increase of salts in the soil, recycled water can be used for long-term irrigation with proper management.

Orientador: Aparecido Donizete Rossi / Banca: Karin Volobuef / Banca: Luciana de Campos / Resumo: No conjunto de lendas galesas intitulado O Mabinogion (séc. XIV-XV) encontram-se histórias que remetem ao passado pagão das tribos celtas que habitavam a Grã-Bretanha, registradas e modificadas após o processo de cristianização e a influência da estética medieval. O presente trabalho analisa três de suas proeminentes personagens femininas que provavelmente um dia possuíram status divino, Rhiannon, Aranrhod e Blodeuwedd, a partir tanto do estudo da cultura celta quanto dos arquétipos sob a perspectiva junguiana. Através dessas análises, discute-se conceitos e interpretações do sagrado feminino, da construção da inferioridade social feminina e do papel do mito e das artes na revisão e reconstrução dessa identidade, dialogando com os estudos feministas. / Abstract: In the group of Welsh legends called The Mabinogion (XIV-XV centuries) are found stories that relate to the pagan past of the Celtic tribes that inhabited Great Britain, registered and modified after the process of Christianisation and the influence of medieval aesthetics. This dissertation analyses three of its prominent female characters that probably once had divine status, Rhiannon, Aranrhod and Blodeuwedd, considering both the characteristics of Celtic culture and the study of the archetypes in Jungian perspective. Through these analyses, concepts and interpretations for the sacred feminine, the construction of female's social inferiority and the part myhts and art can play at the revision and reconstruction of this identity are discussed, dialoguing with feminist studies. / Mestre

[Truncated abstract] Salinity and waterlogging interact to reduce the growth of most crop and pasture species. Species that are productive on saline-waterlogging land are needed for Australian farming systems. One option is Lotus tenuis, a perennial legume widely grown for pasture in the flood-prone and salt-affected Pampa region of Argentina. To identify mechanisms responsible for the adverse interaction between salinity and waterlogging, Lotus tenuis with a reputation for tolerance was compared with L. corniculatus, the most widely cultivated Lotus species. The physiology of salt and waterlogging tolerance in L. tenuis (4 cultivars) was evaluated, and compared with L. corniculatus (3 cultivars). Overall, L. tenuis cultivars accumulated less Na+ and Cl-, and more K+ in shoots than L. corniculatus cultivars, when exposed to 200 mM NaCl for 28 d in aerated or in anoxic (stagnant agar) solutions. In a NaCl dose response experiment (0 to 400 mM NaCl in aerated solution), Lotus tenuis (cv. Chaja) accumulated half as much Cl- in its shoots than L. corniculatus (cv. San Gabriel) at all external NaCl concentrations, and about 30% less shoot Na+ in treatments above 250 mM NaCl. Ion distributions in shoots were determined for plants at 200 mM NaCl; L. tenuis (cv. Chaja) accumulated about half as much Cl- in old leaves, young leaves and stems, compared with concentrations in L. corniculatus (cv. San Gabriel). There were not, however, significant differences between the two species for Na+ concentrations in the various shoot tissues under aerated NaCl treatment. '...' Therefore, during early stages of exposure to salinity, L. tenuis accumulated a higher proportion of total Na+ in the roots under combined stagnant-plus-NaCl treatment (55% versus 39% for L. corniculatus). Na+ transporters, particularly those relying on H+ gradients across membranes, which in turn require adequate ATP levels, could be impaired under O2 deficits that inhibit respiration. To study the effect of O2 deficiency on a Na+ transporter, an NHX1-like gene was cloned from L. tenuis and identity established via sequencing and yeast complementation studies. Real-time qPCR showed expression of NHX1 in L. tenuis roots increased under stagnant-plus-NaCl treatment, whereas it was reduced in L. corniculatus. Thus, maintaining O2 transport to roots, together with up-regulation of an NHX1-like gene for Na+ accumulation in vacuoles, contributes to tolerance of L. tenuis to combined salinity and waterlogging stresses. This study highlights the importance of minimising Cl- transport to shoots as a mechanism of salt tolerance and has identified a CCC-like gene in L. tenuis as a candidate for mediating root-to-shoot Cl- transport. Under combined stagnant-plus-NaCl treatment, control of Na+ transport is another mechanism contributing to tolerance in these Lotus species. Enhanced root aeration in L. tenuis maintains root Na+ transport processes, such as accumulation in vacuoles via NHX1-like genes, to diminish xylem loading to the shoot. Overall, this thesis has contributed new knowledge on the potential of Lotus tenuis as a saltland pasture and has significantly enhanced current understanding on the mechanisms of salinity and waterlogging tolerance in plants.

Hoy en día la monitorización del medio ambiente es una necesidad en todo el mundo, principalmente debido a la gran cantidad de gases tóxicos que emiten diariamente las industrias, como son óxidos de nitrógeno, dióxidos de azufre, vapores de benceno, y especies causantes de malos olores como los vapores de amoniaco o que indirectamente aumentan la concentración de ozono. Entre los dispositivos con capacidad de detectar trazas de gases se encuentran los sensores de gases de estado sólido, y sus principales ventajas se hallan en su tamaño reducido, su bajo coste comparado con las técnicas convencionales de detección de gases, la posibilidad de mostrar resultados en tiempo real y la portabilidad.Entre los óxidos metálicos existentes para la detección de gases tóxicos se cuenta el TiO2, SnO2 y el WO3. Estos materiales permiten detectar trazas de óxidos de nitrógeno (NO y NO2), sulfuro de hidrógeno, monóxido de carbono, vapores de amoniaco, hidrocarburos y oxígeno. Uno de los nuevos materiales que se estudia desde hace relativamente poco tiempo para ser utilizado como capas activas en la obtención de sensores químicos de gases capaces de trabajar a bajas temperaturas son los nanotubos de carbono(CNTs).El objetivo principal de esta tesis fue fabricar sensores capaces de detectar trazas de gases (como fueron NO2, CO, NH3 y O2 entre otros) trabajando a bajas temperaturas. Para ello se utilizaron los nanotubos de carbono. Éstos han mostrado tener muy buenas propiedades físicas y electrónicas, por ejemplo, dependiendo de su quiralidad y diámetro pueden tener un comportamiento eléctrico tipo semiconductor o metálico.Para mejorar la dispersión y sensibilidad de los nanotubos de carbono ante los gases, éstos se funcionalizaron aplicando una descarga en un plasma de radio frecuencia. Óxidos metálicos tales como el WO3, SnO2 y el TiO2, fueron mezclados (a diferentes proporciones respecto al peso) con nanotubos de carbono funcionalizados; la temperatura de trabajo estudiada típicamente varió entre 25 y 150ºC, utilizando como gas portador el aire. Los materiales utilizados como capas activas fueron obtenidos disolviéndolos o agitándolos en glicerol (utilizado como vehículo orgánico), luego se sometieron a un proceso de secado y recocido, y finalmente fueron depositados sobre sustratos para evaluar sus propiedades de sensado ante diferentes trazas de gases tóxicos. Dos métodos de depósito de capas fueron utilizados. El primero de ellos fue el drop-coating. Éste es un método que se emplea en el depósito de capas gruesas de óxidos metálicos. La evaporación térmica es el segundo método y hace posible depositar capas finas de óxidos metálicos sobre un sustrato con tamaños de grano muy pequeño.Las capas activas que contaron únicamente con nanotubos de carbono de paredes mútiples (MWCNTs) funcionalizados con oxígeno como material sensitivo fueron capaces de detectar trazas de gases de NO2 y CO operando a temperatura ambiente, aunque cuando estos nanotubos contaron con nanoclusters en sus paredes, las sensibilidades mejoraron ligeramente (aunque no fueron superiores al 20 %). El inconveniente que estos materiales tienen radica en la velocidad de respuesta y de recuperación, especialmente cuado trabajan a temperatura ambiente.Entre los aportes más interesantes de esta tesis se encuentra el mostrar que las capas híbridas nanotubos de carbono / óxido metálico (WO3, SnO2 o TiO2) tienen una gran sensibilidad a diferentes trazas de gases operando a temperatura ambiente. Las mejores respuestas fueron obtenidas utilizando los materiales híbridos MWCNTs/SnO2. La cantidad de nanotubos mostró ser muy importante, debido a que si la proporción de nanotubos con respecto al óxido metálico es muy alta, la resistencia de la capa activa del sensor es muy baja y los cambios de resistencia debido a la detección del gas no son muy apreciables. / The world-wide concern for environmental safety demands the monitoring of the emission of hazardous gases into the atmosphere. In this context, metal oxide-based sensors could be a key device, provided their power consumption could be dramatically reduced. Semiconductor oxides that can be produced by mature thin or thick-film technologies have been widely studied and employed as low-cost sensing elements for the detection and monitoring of hazardous gases. They show high sensitivity to a wide spectrum of gases, fast response time and fair long-term stability.Among the existing metal oxides, TiO2, SnO2 and WO3 have proved to be promising for gas sensing applications. Several studies have shown that it can be used for the detection of nitrogen oxides (NO and NO2), hydrogen sulphide, carbon monoxide, ammonia vapours, hydrocarbons and oxygen. Carbon nanotubes (CNTs)-based gas sensors have proved to work well at room temperature, which reduces the power consumption of the device and enables the safer detection of flammable gases.The objective of this thesis has consisted in the design and fabrication of gas sensors for detecting gas traces (like NO2, CO, NH3 y O2 amongst others) operating the sensors at temperatures between 25 and 150°C. Carbon nanotubes, depending of their chirality and diameter, show an electronic structure that can be either metallic or semiconducting. In practice it is difficult to obtain only semiconducting nanotubes from as-grown samples, which are typically mixtures of both metallic and semiconducting CNTs.Functionalisation of nanotubes with other chemical groups on the sidewalls is attempted to modify the properties required for an application in hand. For example, chemical modification of the sidewalls may improve the adhesion characteristics of nanotubes in a substrate and make functional composites. Uniform functionalisations either with oxygen or hydrogen were applied to the as-provided CNTs in order to graft functional groups at their surface and to improve their dispersion and surface reactivity. In this thesis, we study and compare the performance in gas sensing of hybrid materials consisting of functionalized multiwall carbon nanotubes dispersed in a metal oxide matrix. Three different metal oxides namely SnO2, WO3 and TiO2 were considered. An adequate mixture of the components was obtained by dissolving them in glycerol (employed as organic vehicle). The sensing films were dried in order to burn out the organic vehicle and after that annealed in ambient atmosphere.Plasma treatment was found to improve the sensing potential of MWCNT. Oxygen plasma functionalisation of MWCNT proved to play an important role in their responsiveness to ammonia and nitrogen dioxide. The presence of oxygen at the surface of MWCNT was found to increase their sensitivity to NO2, and CO (But did not exceed 20%). Nevertheless, nanotubes show a slow recovery process (especially when they work at room temperature), which can prevent their use in several situations.It is well known that metal oxide sensors are usually operated at temperatures well above 250°C. In this thesis, we have shown that the addition of a suitable quantity of MWCNTs in a metal oxide film can lower the sensor operating temperature. Sensors based on SnO2/MWCNTs hybrid films operated at room temperature showed the higher sensitivity towards NO2 in the ppb range, among the different materials studied. The response mechanism is fully reversible, since the sensors can recover their baseline resistance after each exposure to pollutant gases. Our results suggest that there is an optimum amount of carbon nanotubes to be added to each particular metal oxide in order to enhance responsiveness.

This thesis tests an approach to delivering affordable housing for rural Wales, through the design and development of a system of homegrown, re-engineered timber components for self build. Recent studies and policy have demonstrated an acute shortage of affordable housing in rural Wales. Consequently, the Welsh Assembly Government has committed to deliver an additional 6,500 homes in the period 2007 - 11. However, there remains significant concern regarding the long term, sustainable delivery of affordable rural housing. This dissertation proposes a solution to this need, based on the readily available resource of homegrown softwood. Sitka Spruce has become the primary production crop of the Welsh woodlands. It is rarely used in the construction industry due to its propensity to distort and instead is utilised in low value industries, including low grade carcassing timber. It is proposed that through an innovative and radical approach, homegrown timber resources can offer a high quality, locally sourced and sustainable modern method of construction. In this study, a system of engineered homegrown timber components is designed, prototyped and tested as a self build construction solution for affordable housing in the diverse physical, social and economic context of rural Wales. Design led studies, including a ‘Pattern Book’ of house types, and realised prototypical constructions are used to inform and interrogate the proposed components and construction methodology. The primary objective of these investigations is to examine the applicability and appropriateness for self build construction. Finally, through the construction of a whole house prototype, a system of homegrown timber components and an approach to its assembly is proposed. Although limitations remain with this proposal, it has been possible to demonstrate that there is significant opportunity for an innovative, self build construction system using homegrown timber resources, to offer an efficient and sustainable solution for affordable housing in rural Wales.

Global energy consumption is rising and the relative contribution of lighting in buildings to that total is also increasing. In offices, the dominant form of lighting is fluorescent, but this will soon be surpassed in terms of performance by LED lighting, which are already starting to be more widely used. Considering that most buildings and offices are of older building stock, this presents a great opportunity for making energy savings by using more efficient light sources within offices. This thesis investigates the application of LEDs as a retrofitting solution to existing fluorescent lighting systems and assesses their potential to provide an equivalent lighting environment with no adverse effects on performance and investigates their impact on space conditioning load demands and CO2e emissions on a range of case study buildings in the UK. Savings in lighting cannot only be made through reduced electrical consumption, but also through space conditioning loads, by reduced lighting heat gains. Currently used lighting technology is reaching its limit of performance, whereas LEDs offer the potential to meet energy saving targets with their rapidly improving performance. LEDs emit most of the heat generated to the back of a luminaire, rather than directly to the occupied space and this can lead to reduced heat gains and thus savings on space cooling demand loads, in addition to the electrical savings due to higher efficacies, for operating them. In this thesis, simulation software were reviewed that would allow for the lighting specification of custom LED replacement luminaires and assessment of their thermal performance. Methodologies were developed on simulating their light output and designing custom LED replacement luminaires with the use of RADIANCE, thus providing a novel use for this extensively used and validated software. For validation purposes a test room was used where custom LED replacement luminaires were fitted and measured for their performance, where good agreement in predicted and measured results was found. A visual performance study was also conducted using a range of age groups, to ascertain if there is a difference in task based performance on paper and VDU screens between fluorescent lighting and LED lighting, in an office environment. Subjective opinions on preference between the two light sources was also investigated. An assessment of space conditioning load demands was performed on five case study buildings, where custom LED luminaires were specified to retrofit the existing fluorescent lighting. Results showed lighting levels and distribution in each building could be replicated with good agreement, offering a cooling load demand reduction, however with an increase in heating load demand. In terms of CO2e emissions, the use of LED lighting instead of fluorescent also proved to be beneficial, providing reductions in emissions.

This research examines the concept of identity of place using the town centre of Kuantan, Malaysia as a case study. Identity in this research is defined as the qualities of a place that are recognised or recalled as being distinct from other places by the people. The aim is to investigate the elements and qualities associated with the identity of the town centre as perceived by its residents. The objectives of the research is to identify the elements associated with identity of the town centre as perceived by the residents. Secondly is to establish the qualities that are associated with identity of the town centre. The third objective is to examine the variation in residents' perception of elements and the qualities associated with identity according to their socio-cultural background. Finally, is to examine the variation in residents' perception of elements and qualities associated with identity between different parts of the town centre. The research adopted a mixed methodology using both the quantitative and qualitative method in data collection and analysis. The quantitative approach adopted a survey using a questionnaire on a sample of the town centre's residents. A total of 330 residents from the residential areas located within the town centre boundaries were involved in the sample survey. The data collected by the survey are the resident's perception of the town centre's environment and the profile of its residents. The survey data was processed using the SPSS Pc+ and analysed using descriptive statistics, namely frequencies and percentages. A cross-tabulation table was also used to identify the elements perceived by the different ethnic groups, gender and age groups that make up the composition of the respondents. The qualitative approach adopted four techniques that is focused interview, sketch map task, photo recognition interview and visual survey (field observations and recording). A total of thirty residents were involved in the interview. The data collected from this second phase was analysed qualitatively. The focused interview and photo recognition interview were taped recorded and transcribed. Analysis of the interview were based on the recurrent themes and categories that appeared in the transcripts. The findings of the research is a culmination of the cross analysis between the two different approaches. There are four main findings of the research. Firstly, there are three types of physical elements that are distinctive to the residents, that is physical structures (namely buildings, urban spaces (such as streets) and landscape features. Secondly, the characteristics of distinctive physical elements are influenced by the physical appearance, activities and the meanings and associations attached to the elements. The third finding is that there is no significant variation between the socio cultural groups in terms of elements perceived to be distinctive and that the slight variation is on the level of details observed. Of the three socio cultural factors observed, it is found that age group have more variation in perception of distinctive elements than the other two factors, especially between the youngest and the oldest group of residents. Finally, there is some variation in residents' perception of identity between different parts of the town centre. The variation observed is that residents perceived the older town centre as having a stronger identity than the newer town centre. From the research findings, several urban design and planning implications were suggested that influenced the distinctiveness of the town centre. The implications are with regards to decisions on the enhancement of path networks, development of landmarks, enhancement of nodes and entrances and conservation of the old town centre. Suggestions for further research and the implications for existing theories were also discussed. It is implied from this research that such guidelines would increased the distinctiveness of elements and places in the town centre. This consequently enhances the identity of the town centre to its residents.

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [86]-98).

Techn. Universiẗat, Diss., 1999--Berlin.

Techn. Universiẗat, Diss., 2000--Darmstadt.