The research of the neutron induced Single Event Effect (SEE) at aircraft altitudes or at ground level are very important since the neutron radiation is able to cause serious errors or damages on electronic components and system. TheWeapons Neutron Research (WNR) facility at Los Alamos Neutron Science Center (LANSCE), and ANITA (Atmospheric-like Neutrons from thIck TArget) facility at The Svedberg Laboratory (TSL) both provide spallation neutron source for radiation testing of electronic components. A local beam monitoring system was successfully developed by S. Platt and L. Zhang in the University of Central Lancashire for measuring neutron dosimetry during accelerated SEE testing of electronic devices with using silicon photodiode. However, such silicon photodiode is sensitive to gamma-ray as well. For above reasons, characterization of neutron and gamma fields at spallation neutron sources used for accelerated SEE testing has become the purpose of this work. Monte Carlo calculation of radiation fields at spallation neutron source was used to characterize neutron and gamma energy spectra for accelerated single event effect testing. Geant4 (GEometry ANd Tracking version 4) toolkit, using Monte Carlo method, was used to simulate a preliminary model of spallation neutron source at LANSCE (ICE House, WNR) and TSL (ANITA) for understanding physical mechanisms of neutron and gamma interactions with matter. At first, two preliminary spallation neutron sources on basis of WNR (ICE House) and ANITA facilities were modeled with using two intra-nuclear cascade models (bertini, binary) provided by Geant4 reference physics lists. The result of neutron spectrum with binary INC model agrees well with LANSCE measurement data and independent calculation results in each case. In this computation, gamma dose rates at WNR and ANITA were calculated, and gamma dose rate from the simulation is consistent with the ANITA measurement results. The results of photon energy spectra with using Geant4 toolkit presents a continuum between 0.1MeV and 10MeV, and the annihilation peak at 0.5MeV. However, calculation results of neutron spectrum at ANITA facility with using binary INC model match ANITA measurements less well in absolute neutron yield above 20MeV, which is likely due to the missing geometry components in preliminary spallation neutron source simulation. A more complex model of ANITA facility was constructed with adding bending magnet, shielding components, detector system, and collimator, which makes modelling as realistically as possible. The discrepancy in absolute neutron yield between simulation results and measurements data has improved at Standard User Position (SUP) of ANITA facility, in contrast with the preliminary modelling of ANITA neutron source. At the same time, a new position referred as Close User Position (CUP) was investigated in order to compare with ANITA measurement informed by Monte Carlo N-Particle eXtended (MCNPX) simulation results. The neutron spatial distribution, radius effect for neutrons, neutron beam profiles, and time of flight spectra were calculated at the SUP and CUP positions for different collimator apertures of 3 cm, 10.2 cm, and 30 cm, respectively. A comparison of simulated neutron beam profiles folded with 238U (n, f) cross-section with ANITA measurements at the SUP and CUP-TOF positions was used for validating improved ANITA neutron source modelling. The neutron beam profiles in the horizontal direction were predicted with using Geant4, which filled the gap of geometrical limitation at ANITA facility for accelerated single event effect testing. It is the first time to predict gamma dose rate at the SUP and CUP positions for 3 cm, 10.2 cm, and 30 cm collimators with using Geant4 modelling of ANITA neutron source. In addition, the gamma dose rate at the SUP position is consistent with ANITA measurement data. Finally, the gamma yield, photon spatial distribution, dose rate against energy are considered for gamma field at the SUP and CUP positions, which have contributed to understand and analyse gamma interactions with matter.

Preterm birth and the premature infant have been predominately studied from clinical perspectives. The experiences of parenting a preterm child and the experiences of staff directly involved in the care of preterm infants have been studied much less. Additionally, less is known about the meaning of experiences around the preterm infant’s discharge from the neonatal unit and life at home thereafter. This study addresses these gaps identified in research and aims to generate a deeper understanding of the meanings, and lived experiences of NICU-to-home transition from multiple perspectives: mothers and fathers, and neonatal staff. This is a Heideggerian hermeneutic phenomenological study of the experiences of Maltese parents of preterm infants and, of neonatal staff of NICU-to-home transition. Using purposive sampling, open interviews were conducted with 9 mother-father dyads of preterm infants and 12 neonatal staff that included midwives, nurses and doctors working on the only neonatal unit in Malta. A modified vignette technique based on the parents’ interviews was used to stimulate reflective talk with the staff. A longitudinal design was adopted for data collection from the parents: at 1 month, 3 months and 6 months after discharge of their baby from the unit. The research process including analysis of the data was guided by van Manen (1990). The parents’ experiences of NICU-to-home transition are represented through four main themes: ‘Shadowed by fading clouds of uncertainty’, ‘Reaching out’, ‘Watching vigilantly’ and ‘Living the new family’. In addition, three main themes emerged from the staff data: ‘Acknowledging good practice’, ‘Realising limits’ and ‘Awakening to needed improvements in care’. Findings indicate that, in the longer term in the home setting, parents translated their parenting approaches through the norms of neonatal unit routines and practices. Staff findings revealed that care focuses primarily on producing technically prepared parents in infant care which arises out of their sense of responsibility towards the babies’ wellbeing that extends to after being discharged from the neonatal unit. A further in-depth interpretation and synthesis of the findings was undertaken drawing on the philosophy of Heidegger (1962). This revealed ‘oscillating realities’ between parents’ and staff experiences, particularly in the degree to which they endeavoured to solicitude which ‘leaped in’ or ‘leaped ahead’, and the extent to which technocratic ways of Being permeated their relationships to each other and to the babies. Implications of the findings and suggestions for further research are presented.

The impetus for the research undertaken in this dissertation hinges on concern for the low priority status attached to aesthetic issues in public deliberation on matters concerning environmental and ethical issues. Although interconnected reasons are identified for the prevalence of this attitude a principal reason is the tendency to assume a conventional understanding of aesthetic value as primarily concern for visual or formal appearance, a consequence of which is that it is treated as of superficial significance only to be considered after more pressing issues have been addressed, for example, economic ones. A ifirther concern, however, is the prevalence in environmental theory/ethics to take a similar view in the way that aesthetic value tends to be considered an unsuitable basis on which to establish an environmental ethic or as of only partial significance in environmental protection and management. While contextualist theorists in environnental aesthetics have made significant contributions in redressing this attitude the discipline is divided between two schools of thought namely scientific cognitivists and non-cognitivists. In arguing against the cognitivist position I develop and advance a non-cognitive approach that focuses on the relational dimension of aesthetic experience and value. Relationship, though largely implicit or assumed in non-cognitive accounts, is undeveloped theoretically particularly as a locus of value in itself I contend that aesthetic value communicates the quality and merit of the relations that given things embody and express. I illustrate how a relational approach raises issues of identity and meaning; issues that are not addressed in environmental theory or mainstream axiological approaches. The significance of the approach rests in its practical and theoretical implication particularly as it bears on the concept of nature; of natural and unnatural value; on issues of beauty, ugliness and sacredness and on the culture/nature dualism predominant in environmental thinking and practice. Moreover, and importantly, a relational approach to aesthetic value extends the reach of environmental aesthetics from a focus on the evaluation of our physical surroundings to a broader, more inclusive view of 'environment' such that its 'reach' can be shown to have ethical import, for example, in issues concerning biotechnological practices.

Intermediate phases in two non-ionic polyoxyethylene surfactantiD20 systems - nonaethylene glycol mono (1 1-oxa-14,18,22,26-tetramethylheptacosyl) ether (C30E09) and hexaethylene glycol n-hexadecyl ether (C15E05) have been studied. Both systems have a rhombohedral mesh phase with the space group symmetry R3m, and model calculations show this phase to consist of hexagonally arranged pores in a surfactant bilayer. The formation of this phase is driven by the need to introduce curvature into the interface as the temperature decreases and hydration of the ethylene oxide headgroups increases. In the C30E09 system a small angle neutron scattering study on a 42 wt.% sample has allowed the epitaxial relationship between the lower temperature hexagonal (H1) phase and the mesh intermediate phase, with the (10) planes of the H 1 phase becoming the (001) planes of the mesh phase. The concentration interval of 48 - 62 wt.% of the C 1 6E06 system has been studied using optical microscopy, 2H nuclear magnetic resonance, and small angle scattering in order to establish the detailed phase behaviour. On cooling from the lamellar phase, the phase sequence observed is defected lamellar, mesh intermediate, Ia3d cubic, and hexagonal plus gel. On heating from the hexagonal plus gel phase region, the intermediate and cubic phase observed upon cooling is replaced by an Ia3d cubic phase region. The mesh intermediate forms when the water filled defects of the higher temperature defected lamellar phase correlate between the surfactant layers. The C16E06 system has been perturbed by the inclusion of either the shorter chain surfactant hexa-ethylene glycol mono n-dodecyl ether (C12EO6) or the oil octadecane (C 1 81-138). The addition of C12E05 promotes aggregate structures with more curved interfaces, and the intermediate mesh phase is eliminated in favour of the Ia3d cubic phase. The addition of C181-138 swells the surfactant bilayers and promotes flatter interfaces, but does not stabilise the intermediate phase, as only small additions of oil suppress this phase.

Streptomyces clavuligerus was grown in nutrient-limited defined media in laboratory scale fermenters using continuous and batch culture methods. Cephamycin C was produced in all fermentations. Clavulanic acid was produced in carbon- and nitrogenlimited continuous culture and in carbon- and phosphate-limited batch culture. Low levels of intracellular guanosine 5'-diphosphate 3'-diphosphate (ppGpp) were detected at D= 0.02 h' in continuous culture in all media. Low levels of intracellular guanosine 5 '-diphosphate 3 '-monophosphate (ppGp) were detected at D=0.02 if' in carbon- and nitrogen- limited media. ppop was not detected under phosphate limitation at any dilution rate. Increased production of cephamycin C was observed at D=0.02 If' under nitrogen limitation coinciding with the detection of elevated levels of ppGpp, ppGp and ATP. Increased production of clavulanic acid was observed at D=0.02 If' under carbon limitation coinciding with the detection of elevated levels of ppGpp and ppGp. There was no correlation between dilution rate and basal levels of either ppGpp or ppGp in any growth-limiting medium. ppGpp was produced at low levels in carbon- and nitrogen-limited batch fermentations prior to the detection of cephamycin C and clavulanic acid in the medium. High levels of ppGpp were detected under phosphate limitation immediately prior to the transcription of cas, the gene encoding clavaminate synthase. High levels of ppGp were detected in all batch fermentations following a downturn in nitrogen and carbon levels and immediately prior to the detection of isopenicillin N synthetase (IPNS). ppGp was detected following nutrient shifidown by amino acid depletion and was not produced via degradation of ppGpp. The results point to a possible role for ppGpp in the regulation of clavulanic acid synthesis under phosphate limitation only, and a potential role for ppGp in the regulation of cephamycin C production in Streptomyces clavuligerus.

The effect of damage on carbon-fibre reinforced poly(aryl suiphone) by a solvent of the type used by BAe Military Aircraft Division as a paint stripper has been investigated together with the effect of fibre waviness upon the mechanical strength of carbon-fibre reinforced poly(aryl suiphone). Mathematical models for solvent effects were derived and comparison was made with the practical results obtained both from tension loading and three-point loading in bending. Good agreement between the theoretical and test results has been observed. It was found that solvent damage is minimal on the tensile behaviour of (90,0)s laminates but caused a reduction in the strain at failure in (0,90)s laminates. Theoretical models were developed for fibre waviness, where the waviness is in the plane of the ply. The theoretical results are compared to the results of tensile testing. It is reported that, contrary to the work of others, fibre waviness can have a marked affect on laminate behaviour in tension and, for a wave ratio of 0.1, can cause the load at failure in cross-plied laminates to be reduced to only 24% of the the load at failure in an equivalent laminate free of fibre waviness. Specimens were put through heating and cooling cycles in order to reduce residual stresses. Estimates of the value of these stresses were based upon the curvature of asymmetric laminates. The results compared favourably with published values for similar materials. Various 'protective' coats were investigated to reduce the amount of solvent damage. One protective coat was found to give reduced damage with increasing coats. Test results were compared to those obtained from (i) The Tsai-Hill failure criterion, (ii) The Han-Smith maximum shear stress criterion. The test results were found to be in good agreement with both criteria when failure did not occur at positions containing fibre waviness. When failure occurs at fibre waviness it is demonstrated that if the exact point of failure within fibre waviness is known then corrections can be made to the test results. When the corrections were made there was good agreement between test results and both criteria.

Despite being Britain's most extensive semi-natural habitat, less research has been carried out on blanket mires than on many other habitats. This is possibly a result of their relative inaccessibility, since they are mainly confined to upland areas in England and Wales and remoter parts of Scotland; also to their apparent abundance, given that they cover significant portions of the landscape. Blanket mires in Britain cover approximately 1.5-2 million hectares; studies have documented substantial losses and up to ninety percent of blanket mires in Britain have been adversely affected. Literature on blanket mires suggests that poor management is one of the key issues for this habitat together with a lack of financial resources and commitment by the Government to protect and conserve sites adequately. The range of land uses of blanket mires is complex and includes agriculture, conservation, recreation, water catchment, grouse and deer management and forestry. These various uses have led to conflict among certain groups and a number of uses have had a detrimental effect on this habitat. Often the value of blanket mires has been overlooked even though this habitat, as part of natural ecosystem process, can provide functions and services such as wildlife interest and hydrological supply systems. A gap has been identified in the current literature on blanket mires, which suggests that research into the broader issues of strategy and management of this habitat, by organisations, landowners and farmers, has not been undertaken. Interview data have been obtained from organisations, landowners and farmers involved with blanket mire management and assessed by interpretational analysis. The research has been carried out both at a national level in Britain and at a local level with a case study of the Forest of Bowland in Lancashire. The local case study has been related to the wider context of blanket mire management and conservation. A total of fifty four in-depth interviews were undertaken in order to gain information on the views, perspectives and experiences of those involved with blanket mire management. How blanket mires are valued has a significant impact on how peatlands are conserved and for what reason. This research reveals that, in order to be effective, organisations will have to have a clear vision of what end point they are working towards and devise practical sategies that are flexible enough to incorporate the distinctiveness of different blanket mire areas.

The binary surfactant system nona (ethylene glycol) mono-( 11 -oxa- 14,18.22,26-tetramethylheptacosylether) in heavy water has been investigated using deuterium nuclear magnetic resonance, optical polarising microscopy and small angle scattering techniques. The phase diagram has been established and the phases encountered exist for the most part from 24 to 60% surfactant by weight. Above and below these concentrations exist isotropic and lamellar phases respectively. The phase diagram features three main phases, a hexagonal phase of circular rods, a lamellar phase and an intermediate phase. The length of the alkyl chain is shown to be the most important factor in stabilising intermediate phases in preference to the bicontinuous cubic phases usually encountered between hexagonal and lamellar phases in shorter chain homologues. A nematic phase has also been observed in the water penetration scan. The intermediate phase is extensive, ranging from 32 to 60% surfactant by weight and is about 5°C wide. It has a body centred tetragonal mesh structure, comprised of layers of surfactant with regularly spaced holes which are also correlated between the layers, the hole of one layer overlapping the intersection of the layer below. As the concentration is decreased, from 60% to 30% (surfactant by weight) this correlation relaxes. The actual form of the aggregate appears to be elliptical rods (ellipticity - 1.7) joined four by four to form the basis of the mesh structure. A simplified version of the model based on circular rods joined by cube junction regions has been used to quantitatively investigate this phase. The results from this crude model produce results very close to those anticipated and produces results to within 2% of those generated using a more sophisticated model. This system is unusual in that the nature of the interaction between aggregates appears to be dominated by a single interaction - 'headgroup overlap force. This arises from the repulsive pressure experienced by the headgroups penetrating from the aggregate interface and also between headgroups on the same aggregate.