Dynamic ocular thermography

The ability to measure ocular surface temperature (OST) with thermal imaging offers potential insight into ocular physiology that has been acknowledged in the literature. The TH7102MX thermo-camera (NEC San-ei, Japan) continuously records dynamic information about OST without sacrificing spatial resolution. Using purpose-designed image analysis software, it was possible to select and quantify the principal components of absolute temperature values and the magnitude plus rate of temperature change that followed blinking. The techniques was examined for repeatability, reproducibility and the effects of extrinsic factors: a suitable experimental protocol was thus developed. The precise source of the measured thermal radiation has previously been subject toe dispute: in this thesis, the results of a study examining the relationships between physical parameters of the anterior eye and OST, confirmed a principal role for the tear film in OST. The dynamic changes in OST were studied in a large group of young subjects: quantifying the post-blink changes in temperature with time also established a role for tear flow dynamics in OST. Using dynamic thermography, the effects of hydrogel contact lens wear on OST were investigated: a model eye for in vivo work, and both neophyte and adapted contact lens wearers for in vivo studies. Significantly greater OST was observed in contact lens wearers, particularly with silicone hydrogel lenses compared to etafilcon A, and tended to be greatest when lenses had been worn continuously. This finding is important to understanding the ocular response to contact lens wear. In a group of normal subjects, dynamic thermography appeared to measure the ocular response to the application of artificial tear drops: this may prove to be a significant research and clinical tool.

Controlled study into the effectiveness of individual client-centred counselling for young offenders in residential care

This study is toe first documented account in the British Isles of an evaluation of the effectiveness of client-centred counselling with young offenders in secure residential care. It is a test of Rogers' (1957) position on the 'necessary and sufficient' conditions of therapeutic personality change within a counselling relationship. Forty teenage male offenders, the subjects of Training School Orders, were randomly allocated in equal numbers to either an experimental or control group. Boys in the experimental group received weekly individual sessions of client-centred counselling over a seven month period. Boys in the control group received no formal counselling but were shown to have similar intellectual, personality, socio-economic and criminal backgrounds to those in the experimental group. It was hypothesised that counselled subjects would show more positive outcomes than control subjects over a range of measures relating to criminal behaviour and self-conception. The results indicated that the counselled subjects had a significantly lower rate of offending and a srnaller range of offences over a mean follow-up period of 2.5 years. They were also licensed from the institution significantly earlier and spent less time in custody during a one year follow-up after counselling was completed. Self-conception measures gave less clear-cut results. The direction of change towards better adjustment favoured the counselled subjects but the magnitude was often small. Those counselled subjects with most positive behaviour change tended to have significantly improved self-evaluation, less self/ideal self discrepancy and more variation on 'actual' self concept compared to pre-counselling. The results are discussed in the context of client-centred theory, methodological adequacy of the experimental design, and their application to the future treatment of young offenders in secure residential care.

Discrete element modelling of a rotating drum and drum granulation

This thesis reports the results of DEM (Discrete Element Method) simulations of rotating drums operated in a number of different flow regimes. DEM simulations of drum granulation have also been conducted. The aim was to demonstrate that a realistic simulation is possible, and further understanding of the particle motion and granulation processes in a rotating drum. The simulation model has shown good qualitative and quantitative agreement with other published experimental results. A two-dimensional bed of 5000 disc particles, with properties similar to glass has been simulated in the rolling mode (Froude number 0.0076) with a fractional drum fill of approximately 30%. Particle velocity fields in the cascading layer, bed cross-section, and at the drum wall have shown good agreement with experimental PEPT data. Particle avalanches in the cascading layer have been shown to be consistent with single layers of particles cascading down the free surface towards the drum wall. Particle slip at the drum wall has been shown to depend on angular position, and ranged from 20% at the toe and shoulder, to less than 1% at the mid-point. Three-dimensional DEM simulations of a moderately cascading bed of 50,000 spherical elastic particles (Froude number 0.83) with a fractional fill of approximately 30% have also been performed. The drum axis was inclined by 50 to the horizontal with periodic boundaries at the ends of the drum. The mean period of bed circulation was found to be 0.28s. A liquid binder was added to the system using a spray model based on the concept of a wet surface energy. Granule formation and breakage processes have been demonstrated in the system.

HTHP syngas cleaning concept of two stage biomass gasification for FT synthesis

The EU intends to increase the fraction of fuels from biogenic energy sources from 2% in 2005 to 8% in 2020. This means a minimum of 30 million TOE/a of fuels from biomass. This makes technical-scale generation of syngas from high-grade biomass, e.g. straw, hay, bark, or paper/cardboard waste, and the production of synthetic fuels by Fischer-Tropsch (FT) synthesis highly attractive. The BTL concept (Biomass to Liquids) of the Karlsruhe Research Center, labeled bioliq, focuses on this challenge by locally concentrating the biomass energy content by fast pyrolysis in a coke/oil slurry followed by slurry conversion to syngas in a central entrained flow gasifier at 1200C and pressures above 4MPa. FT synthesis generates intermediate products for synthetic fuels. To prevent the sensitive catalysts from being poisoned the syngas must be free of tar and particulates. Trace concentrations of H2S, COS, CS2, HCl, NH3, and HCN must be on the order of a few ppb. Moreover, maximum conversion efficiency will be achieved by cleaning the gas above the synthesis conditions. (T>350C, P>4MPa). The concept of an innovative dry HTHP syngas cleaning process is presented. Based on HT particle filtration and suitable sorption and catalysis processes for the relevant contaminants, an overall concept will be derived, which leads to a syngas quality required for FT synthesis in only two combined stages. Results of filtration experiments on a pilot scale are presented. The influence of temperature on the separation and conversion, respectively, of particulates and gaseous contaminants is discussed on the basis of experimental results obtained on a laboratory and pilot scale. Extensive studies of this concept are performed in a scientific network comprising the Karlsruhe Research Center and five universities; funding is provided by the Helmholtz Association of National Research Centers in Germany.

An investigation into the adoption and implementation of electronic commerce in Saudi Arabian small and medium enterprises

Saudi Arabian Small and Medium Enterprises (SMEs) will face fierce competition from new entrants to local markets as a result of their accession to the Word Trade Organisation (WTO), and electronic commerce (e-commerce) technologies can reinforce SME’s competitive edge. This study investigates the state of e-commerce adoption and analyses the factors that determine the extent to which SMEs in Saudi Arabia are inclined towards deploying e-commerce technologies. This could assist future firms in designing effective implementation projects. Seven SMEs’ e-commerce adoption levels are studied as a case. The Technology-Organization-Environment (TOE) framework was used as the major source of inspiration in our analysis of e-commerce adoption amongst Saudi SMEs. In addition to advancing research on e-commerce in Saudi Arabia, this chapter also highlights several directions for future inquiry and implications for managers and policymakers.

An investigation into the adoption and implementation of electronic commerce in Saudi Arabian small and medium enterprises

Saudi Arabian Small and Medium Enterprises (SMEs) will face fierce competition from new entrants to local markets as a result of their accession to the Word Trade Organisation (WTO), and electronic commerce (e-commerce) technologies can reinforce SME's competitive edge. This study investigates the state of e-commerce adoption and analyses the factors that determine the extent to which SMEs in Saudi Arabia are inclined towards deploying e-commerce technologies. This could assist future firms in designing effective implementation projects. Seven SMEs' e-commerce adoption levels are studied as a case. The Technology-Organization-Environment (TOE) framework was used as the major source of inspiration in our analysis of e-commerce adoption amongst Saudi SMEs. In addition to advancing research on e-commerce in Saudi Arabia, this chapter also highlights several directions for future inquiry and implications for managers and policymakers.

Balance ability in 7- and 10-year-old children:associations with prenatal lead and cadmium exposure and with blood lead levels in childhood in a prospective birth cohort study

OBJECTIVES: Most studies reporting evidence of adverse effects of lead and cadmium on the ability to balance have been conducted in high-exposure groups or have included adults. The effects of prenatal exposure have not been well studied, nor have the effects in children been directly studied. The aim of the study was to identify the associations of lead (in utero and in childhood) and cadmium (in utero) exposure with the ability to balance in children aged 7 and 10 years. DESIGN: Prospective birth cohort study. PARTICIPANTS: Maternal blood lead (n=4285) and cadmium (n=4286) levels were measured by inductively coupled plasma mass spectrometry in women enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) during pregnancy. Child lead levels were measured in a subsample of 582 of ALSPAC children at age 30 months. MAIN OUTCOME MEASURES: Children completed a heel-to-toe walking test at 7 years. At 10 years, the children underwent clinical tests of static and dynamic balance. Statistical analysis using SPSS V.19 included logistic regression modelling, comparing categories of ≥ 5 vs <5 µg/dL for lead, and ≥ 1 vs <1 µg/L for cadmium. RESULTS: Balance at age 7 years was not associated with elevated in utero lead or cadmium exposure (adjusted OR for balance dysfunction: Pb 1.01 (95% CI 0.95 to 1.01), n=1732; Cd 0.95 (0.77 to 1.20), n=1734), or with elevated child blood lead level at age 30 months (adjusted OR 0.98 (0.92 to 1.05), n=354). Similarly, neither measures of static nor dynamic balance at age 10 years were associated with in utero lead or cadmium exposure, or child lead level. CONCLUSIONS: These findings do not provide any evidence of an association of prenatal exposure to lead or cadmium, or lead levels in childhood, on balance ability in children. Confirmation in other cohorts is needed.

Prenatal alcohol exposure and childhood balance ability:findings from a UK birth cohort study

OBJECTIVE: To investigate the association of prenatal alcohol exposure with balance in10-year-old children. DESIGN: Population-based prospective longitudinal study. SETTING: Former Avon region of UK (Southwest England). PARTICIPANTS: 6915 children from the Avon Longitudinal Study of Parents and Children who had a balance assessment at age 10 and had data on maternal alcohol consumption. OUTCOME MEASURES: 3 composite balance scores: dynamic balance (beam-walking), static balance eyes open, static balance eyes closed (heel-to-toe balance on a beam and standing on one leg, eyes open or closed). RESULTS: Most mothers (95.5%) consumed no-to-moderate amounts (3-7 glasses/week) of alcohol during pregnancy. Higher total-alcohol consumption was associated with maternal-social advantage, whereas binge drinking (≥4 units/day) and abstinence were associated with maternal social disadvantage. No evidence was found of an adverse effect of maternal-alcohol consumption on childhood balance. Higher maternal-alcohol use during pregnancy was generally associated with better offspring outcomes, with some specific effects appearing strong (static balance eyes open and moderate total alcohol exposure at 18 weeks, adjusted OR 1.23 (95% CI 1.01 to 1.49); static balance eyes closed and moderate total alcohol exposure at 18 weeks, adjusted OR 1.25 (95% CI 1.06 to 1.48). Similar results were found for both paternal and postnatal maternal alcohol exposure. A Mendelian-randomization approach was used to estimate the association between maternal genotype and offspring balance using the non-synonymous variant rs1229984*A (ADH1B) to proxy for lower maternal alcohol consumption; no strong associations were found between this genotype/proxy and offspring balance. CONCLUSIONS: No evidence was found to indicate that moderate maternal alcohol consumption in this population sample had an adverse effect on offspring balance at age 10. An apparent beneficial effect of higher total maternal alcohol consumption on offspring balance appeared likely to reflect residual confounding.

Balance ability of 7 and 10 year old children in the population:results from a large UK birth cohort study

OBJECTIVE: The literature contains many reports of balance function in children, but these are often on atypical samples taken from hospital-based clinics and may not be generalisable to the population as a whole. The purpose of the present study is to describe balance test results from a large UK-based birth cohort study. METHODS: Data from the Avon Longitudinal Study of Parents and Children (ALSPAC) were analysed. A total of 5402 children completed the heel-to-toe walking test at age 7 years. At age 10 years, 6915 children underwent clinical tests of balance including beam-walking, standing heel-to-toe on a beam and standing on one leg. A proportion of the children returned to the clinic for retesting within 3 months allowing test-retest agreement to be measured. RESULTS: Frequency distributions for each of the balance tests are given. Correlations between measures of dynamic balance at ages 7 and 10 years were weak. The static balance of 10 year old children was found to be poorer with eyes closed than with eyes open, and poorer in boys than in girls for all measures. Balance on one leg was poorer than heel-to-toe balance on a beam. A significant learning effect was found when first and second attempts of the tests were compared. Measures of static and dynamic balance appeared independent. Consistent with previous reports in the literature, test-retest reliability was found to be low. CONCLUSIONS: This study provides information about the balance ability of children aged 7 and 10 years and provides clinicians with reference data for balance tests commonly used in the paediatric clinic.