Development of microwave reflected type moisture meter for wooden cross-arms

A simple, cheap, accurate, portable and easy to operate microwave reflected type moisture meter has been developed to determine the moisture content and consequently to assess the quality of the in service wooden cross-arms. The investigation shows that the dielectric properties of the Chengal wood are dependent on the moisture content (MC) at microwave frequencies. The moisture in wood contributes in two different forms, one below fiber saturation point (FSP) and the other above FSP. Both dielectric constant and dielectric loss factor for Chengal wood increases slowly when the Me increases from zero up to FSP and increases rapidly with MC above FSP. Investigation was made to find the optimum conditions for the sensor design. The optimum condition for best sensitivity of the sensor was determined through experimental and theoretical methods. It was found out that the sensitivity can be controlled by thickness of protective cover and the optimum thickness is about 1 mm. The investigation to find out the minimum thickness of the cross-arms section to avoid interference was discussed. It was found that the minimum thickness for the cross-anns to reach a semi-infinite length was about 50mrn. The operating principles of the sensor are based on the plane wave propagation theory and the dielectric mixture theory. The details of Weiner's mixture model were discussed and it was used as the theoretical model to predict and convince the experimental results. In the actual service condition, moisture content of Chengal wooden cross-arms varied within certain range. For decayed wood, its MC varying between Equilibrium moisture content (EMC) to about 45% of dry basis and the sound wood MC between EMC to about 30% of dry basis. It was quite hard for the cross-arms to achieve higher level ofM C. Once the cross-arms achieve a higher level ofMC, it may take about 20 hours to return to EMC level. The densities of severely decayed, partly decayed and sound wood were different from each other even from the same species of wood. The densities were found to vary between 680kgm-3 to 820kgm-3. The reflected power signal for severely decayed, partly decay and sound wood at EMC were less than 0.05, 0.05 to 0.10 and 0.13 to 0.15 respectively. It was found that the microwave reflected type sensor can determine the decay stage of the wooden cross arms at EMC. A HP-basic program was written to develop the meter scale for microwave moisture meter. The meter scale contains two types of reading. They are MC reading and stage of decay reading. The mean error were 2.3% and 1.1% for severely decayed and sound wood respectively and the maximum error were found to be 5.4% and 3.9% respectively

Synthesis and characterization of ceria nanomaterials.

Cerium dioxide or ceria, CeO2, has been widely used in industry as catalyst for automotive exhaust controls, chemical mechanical polishing (CMP) slurries, and high temperature fuel cells because of its unique metal oxide properties. This well-known rare metal oxide has high thermal stability, electrical conductivity and chemical diffusivity. Proper synthesis method requires knowledge of reaction temperature, concentration, and time effects on the synthesis. In this work, ceria nanomaterials were prepared via the hydrothermal method using a Teflon autoclave. Cerium nitrate solution was used as the source and three different precursors: NaOH, H2O2, and NH4OH were used as the oxidizing agents. CeO2 nanoplates, nanocubes and nanorods were produced and studied using transmission electron microscopy (TEM), BET specific surface area, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Through characterization, CeO2 nanomaterials showed the presence of mixed valence states (Ce3+ and Ce4+) through XPS spectra. Deconvolution was performed to investigate the ratio of Ce3+/Ce4+ concentration in the synthesized CeO2 nanostructures. Nanocubes showed a higher Ce3+ concentration. CeO2 nanomaterials were found to be mesoporous. Nanoplates synthesized with H2O2, and NH4OH were found with surface areas of 95.11 m2/ g and 62.07 m2/ g, respectively. Nanorods and nanocubes showed surface areas of 16.77 m2/ g and 16.55 m2/ g, respectively. The prepared ceria nanoplates, nanocubes and nanorods had crystallite size in the range of 5-25 nm and pore size range of 7-15 nm. XRD spectra confirmed that the peaks were indexed to the cubic phase of CeO2 with fluorite structure and with an average lattice parameter, 5.407 Å. Higher Ce3+ concentration and exposed surface of crystalline planes suggest that nanorods are better catalyst for CO oxidation and oxygen storage capacity (OSC)

Evidence-based enteral feeding for preterm or low birth weight infants : systematic review of the use of protein hydrolysate formula

Infants born preterm, especially those born very preterm, are at elevated risk of mortality and morbidity secondary to organ immaturity and exposure to intensive and invasive care practices and procedures. Although care and outcomes for preterm infants have improved substantially over the past forty years, major challenges remain including the need for better strategies to prevent or treat complications such as necrotising enterocolitis and severe infection. These complications are the most common causes of death and disability after the early neonatal period for preterm infants and are associated with life-long health consequences and costs.This thesis first presents an overview of the epidemiology, causes, and risk factors for preterm birth, and a summary of the interventions for improving outcomes for preterm infants. I then describe the current understanding of the pathogenesis of necrotising enterocolitis, its impact on growth and development, and the evidence-base for interventions to prevent this condition. This discussion focusses on nutritional strategies, and particularly on how the timing and type of enteral feeding affects gut physiology and health, feed tolerance, and the risk of necrotising enterocolitis in preterm infants.The main body of the thesis consists of a Cochrane review of a specific enteral feeding option for preterm infants – the use of formula containing hydrolysed protein rather than standard formula. This costly strategy has become widely adopted in high-income countries based on perceptions that protein hydrolysate formulas are tolerated better by the immature gastro-intestinal tract, and are less likely to lead to complications including necrotising enterocolitis. Using Cochrane methods, we conducted the first systematic review of the evidence-base for this intervention. We found ten eligible randomised controlled trials (total participants 600). Meta-analyses did not show any significant differences in feed intolerance or necrotising enterocolitis, calling into question current policies and practice in neonatal units in high-income countries

ERP projects : an examination of the factors influencing additional unplanned effort in the project life-cycle

Includes bibliographical references (leaves 125-143).For over a decade, ERP systems have been the target of significant amounts of investment in organisations. Some have reaped the benefits anticipated while others struggle to achieve the required level of success. In fact, based on available statistics, numerous organisations have faced problems in keeping their allocated budget and time schedules on track often facing the threat of failure, escalation or significant redirection in their projects. As a result, organisations are seen to spend what can be termed as additional unplanned effort (AUE) in order to try and achieve a certain level of success given budget and time constraints. Using the concept called AUE, derived from topics such as ERP project success and failure, the ERP life-cycle framework and critical success factors (CSFs) relevant to the life-cycle phases, this study attempted to investigate the factors that influence AUE in the phases ofthe ERP life-cycle which in this study consist of the pre-implementation and implementation phases specifically. A sub-objective was also to investigate the possible influence that the presence of factors, responsible for escalation of commitment (EoC) in IT projects, have on AUE in ERP projects. Based on a qualitative mUltiple case-study of 5 ERP projects at different organisations, results showed that there are several factors that influence AUE in satisfying CSFs in each phase of the life-cycle. Particularly, in the pre-implementation phase, factors such as the justification for ERP adoption, the formalisation of an ERP vision, the finalisation of an ERP package choice, the stability of organisational structure, the organisation and flow of the acquisition process, the nature of market conditions and the type of internal and external partnership were found important in influencing AUE in that phase. In the implementation phase factors such as the formalisation of an implementation strategy, the management of organisational momentum and resistance to change, the maintenance of external partnership relationships, conditions external to the organisation, the nature of the organisation and the management of project factors were found important

Buyers-to-shoppers ratio of shopping malls: A probit study in Hong Kong

Buyers-to-shoppers ratio (i.e. conversion rate) has long been one of the commonly adopted metrics in assessing retail performance of shopping malls, but it is almost always relied on interviews, consumer surveys, and questionnaires. These methods are intrinsically problematic in ascertaining the trustworthiness of the responses. This paper is probably the first objective study on the buyers-to-shoppers ratio based on actual observations in shopping malls in Hong Kong. A probit model is used to study factors affecting the ratio. The results show that consumer-surveys seriously over-estimate the ratio. © 2010 Elsevier Ltd.postprin

The effect of Al(NO3)3 concentration on the formation of AuNPs using low temperature hydrothermal reaction for memory application

Distribution of gold nanoparticles (AuNPs) on a substrate becomes crucial in nanotechnology applications. This work describes a route to fabricate AuNPs directly on silicon substrates by using an aluminum template in hydrothermal reaction at 80°C for 1 h. The effect of aluminum nitrate (Al(NO3)3) concentration in the hydrothermal bath was investigated. The properties of AuNPs were studied using field-emission scanning electron microscope (FESEM), x-ray diffractometer (XRD) and semiconductor characterization system (SCS). Two distinct sizes of AuNPs were observed by FESEM. XRD analysis proved the formation of AuNPs directly on the substrate. AuNPs were embedded between polymethylsilsesquioxane (PMSSQ) in order to investigate their effect on memory properties. The sample grown in 0.1 M Al(NO3)3 exhibited the largest hysteresis window (2.6 V) and the lowest Vth (2.2 V) to turn ‘ON’ the memory device. This indicated that good distribution of FCC structure AuNPs with 80±4 nm and 42±7 nm of large and small particles produced better charge storage capability. Charge transport mechanisms of AuNPs embedded in PMSSQ were explained in details whereby electrons from Si are transported across the barrier by thermionic effects via field-assisted lowering at the Si-PMSSQ interface with the combination of the Schottky and Poole Frenkel emission effect in Region 1. Trapped charge limited current (TCLC) and space charge limited current (SCLC) transport mechanism occurred in Region 2 and Region 3

Gmunu: Paralleled, grid-adaptive, general-relativistic magnetohydrodynamics in curvilinear geometries in dynamical spacetimes

We present an update of the General-relativistic multigrid numerical (Gmunu) code, a parallelized, multi-dimensional curvilinear, general relativistic magnetohydrodynamics code with an efficient non-linear cell-centred multigrid (CCMG) elliptic solver, which is fully coupled with an efficient block-based adaptive mesh refinement modules. Currently, Gmunu is able to solve the elliptic metric equations in the conformally flat condition (CFC) approximation with the multigrid approach and the equations of ideal general-relativistic magnetohydrodynamics by means of high-resolution shock-capturing finite volume method with reference-metric formularise multi-dimensionally in cartesian, cylindrical or spherical geometries. To guarantee the absence of magnetic monopoles during the evolution, we have developed an elliptical divergence cleaning method by using multigrid solver. In this paper, we present the methodology, full evolution equations and implementation details of our code Gmunu and its properties and performance in some benchmarking and challenging relativistic magnetohydrodynamics problems

Rotordynamics Analyses of a Modified Hydraulic Power Recovery Turbine

Case StudiesProblem Statement, Machine Information, Torsional Model & Assumption, Torsional Response & Results, Tuning Methods, Field Validation, Conclusio