995 resultados para Chemical Cleaning


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Maintenance of bridge structures is a major issue for the Queensland Department of Main Roads. In the previous phase of this CRC project an initial approach was made towards the development of a program for lifetime prediction of metallic bridge components. This involved the analysis of five representative bridge structures with respect to salt deposition (a major contributor to metallic corrosion) to determine common elements to be used as “cases” - those defined for buildings are not applicable. The five bridges analysed included the Gladstone Port Access Road Overpass, Stewart Road Overpass, South Johnstone River Bridge, Johnson Creek Bridge and the Ward River Bridge.

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The aim of this work was to investigate ultrafine particles (< 0.1 μm) in primary school classrooms, in relation to the classrooms activities. The investigations were conducted in three classrooms during two measuring campaigns, which together encompassed a period of 60 days. Initial investigations showed that under the normal operating conditions of the school there were many occasions in all three classrooms where indoor particle concentrations increased significantly compared to outdoor levels. By far the highest increases in the classroom resulted from art activities (painting, gluing and drawing), at times reaching over 1.4 x 105 particle cm-3. The indoor particle concentrations exceeded outdoor concentrations by approximately one order of magnitude, with a count median diameter ranging from 20-50 nm. Significant increases also occurred during cleaning activities, when detergents were used. GC-MS analysis conducted on 4 samples randomly selected from about 30 different paints and glues, as well as the detergent used in the school, showed that d-limonene was one of the main organic compounds of the detergent, however, it was not detected in the samples of the paints and the glue. Controlled experiments showed that this monoterpene, emitted from the detergent, reacted with O3 (at outdoor ambient concentrations ranging from 0.06-0.08ppm) and formed secondary organic aerosols. Further investigations to identify other liquids which may be potential sources of the precursors of secondary organic aerosols, were outside the scope of this project, however, it is expected that the problem identified by this study could be more widely spread, since most primary schools use liquid materials for art classes, and all schools use detergents for cleaning. Further studies are therefore recommended to better understand this phenomenon and also to minimize school children exposure to ultrafine particles from these indoor sources.

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The macerals in bituminous coals with varying organic sulfur content from the Early Permian Greta Coal Measures at three locations (Southland Colliery, Drayton Colliery and the Cranky Corner Basin), in and around the Sydney Basin (Australia), have been studied using light-element electron microprobe (EMP) analysis and micro-ATR–FTIR. Electron microprobe analysis of individual macerals reveals that the vitrinite in both the Cranky Corner Basin and Drayton Colliery (Puxtrees seam) samples have similar carbon contents (ca. 78% C in telocollinite), suggesting that they are of equivalent rank. However, the Cranky Corner coals have anomalously low vitrinite reflectance (down to 0.45%) vs. the Drayton materials (ca. 0.7%). They also have very high organic S content (3–6.5%) and lower O content (ca. 10%) than the equivalent macerals in the Drayton sample (0.7% S and 15.6% O). A study was carried out to investigate the impacts of the high organic S on the functional groups of the macerals in these two otherwise iso-rank, stratigraphically-equivalent seams. An iso-rank low-S coal from the overlying Wittingham Coal Measures near Muswellbrook and coals of slightly higher rank from the Greta Coal Measures at Southland Colliery near Cessnock were also evaluated using the same techniques to extend the data set. Although the telocollinite in the Drayton and Cranky Corner coals have very similar carbon content (ca.78% C), the ATR–FTIR spectra of the vitrinite and inertinite macerals in these respectively low S and high S coals show some distinct differences in IR absorbance from various aliphatic and aromatic functional groups. The differences in absorbance of the aliphatic stretching bands (2800–3000 cm−1) and the aromatic carbon (CC) peak at 1606 cm−1 are very obvious. Compared to that of the Drayton sample (0.7% S and 15% O), the telocollinite of the Cranky Corner coal (6% S and 10% O) clearly shows: (i) less absorbance from OH groups, represented by a broad region around 3553 cm−1, (ii) much stronger aliphatic C–H absorbance (stretching modes around 3000–2800 cm−1 and bending modes around 1442 cm−1) and (iii) less absorbance from aromatic carbon functional groups (peaking at 1606 cm−1). Evaluation of the iso-rank Drayton and Cranky Corner coals shows that: (i) the aliphatic C–H absorbances decrease with increasing oxygen content but increase with increasing organic S content and (ii) the aromatic H to aliphatic H ratio (Har/Hali) for the telocollinite increases with (organic) O%, but decreases progressively with increasing organic S. The high organic S content in the maceral appears to be accompanied by a greater proportion of aliphatic functional groups, possibly as a result of some of the O within maceral ring structures in the high S coal samples being replaced.

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Chemical and physical restraints are frequently used in the intensive care unit (ICU) to control agitated patients and to prevent self-harm and unplanned extubations. Published work relating to the numerous issues of the care and treatment strategies for these patients remains conflicting and unclear. Literature regarding sedation and chemical restraint reveals a trend towards management with lighter sedation, use of sedation assessment tools and sedation protocols. It remains unclear which treatment is best for agitated and delirious patients, and the evidence on the effect of sedation is conflicting. A large portion of the literature on the use of physical restraint is from general hospital wards and residential homes, and not from the ICU environment. The purpose of this paper is to provide a summary of the existing literature on the use of physical and chemical restraints in the ICU setting. In Part 1 of this two-part paper, the evidence on chemical and physical restraints is explored with specific focus on definition of terms, unplanned

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An important goal of the care for the mechanically ventilated patient is to minimize patient discomfort and anxiety. This is partly achieved by frequent use of chemical and physical restraints. The majority of patients in intensive care will receive some form of sedation. The goal and use of sedation has changed considerably over the past few decades with literature evidencing trends toward overall lighter sedation levels and daily interruption of sedation. Conversely, the use of physical restraint for the ventilated patient in ICU differs considerably between nations and continents. A large portion of the literature on the use of physical restraint is from general hospital wards and residential homes, and not from the ICU environment. Recent literature suggests minimal use of physical restraint in the ICU, and that reduction programmes have been initiated. However, very few papers illuminate the patient's experience of physical and chemical restraints as a treatment strategy. In Part 1 of this two-part review, the evidence on chemical and physical restraints was explored with specific focus on definitions of terms, unplanned extubation, agitation, delirium as well as the impact of nurse–patient ratios in the ICU on these issues. This paper, Part 2, examines the evidence related to chemical and physical restraints from the mechanically ventilated patient's perspective.

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A membrane filtration plant using suitable micro or ultra-filtration membranes has the potential to significantly increase pan stage capacity and improve sugar quality. Previous investigations by SRI and others have shown that membranes will remove polysaccharides, turbidity and colloidal impurities and result in lower viscosity syrups and molasses. However, the conclusion from those investigations was that membrane filtration was not economically viable. A comprehensive assessment of current generation membrane technology was undertaken by SRI. With the aid of two pilot plants provided by Applexion and Koch Membrane Systems, extensive trials were conducted at an Australian factory using clarified juice at 80–98°C as feed to each pilot plant. Conditions were varied during the trials to examine the effect of a range of operating parameters on the filtering characteristics of each of the membranes. These parameters included feed temperature and pressure, flow velocity, soluble solids and impurity concentrations. The data were then combined to develop models to predict the filtration rate (or flux) that could be expected for nominated operating conditions. The models demonstrated very good agreement with the data collected during the trials. The trials also identified those membranes that provided the highest flux levels per unit area of membrane surface for a nominated set of conditions. Cleaning procedures were developed that ensured the water flux level was recovered following a clean-in-place process. Bulk samples of clarified juice and membrane filtered juice from each pilot were evaporated to syrup to quantify the gain in pan stage productivity that results from the removal of high molecular weight impurities by membrane filtration. The results are in general agreement with those published by other research groups.

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The ISSCT Process Section workshop held in Réunion 20–23 October 2008 was attended by 51 delegates from 10 countries. The theme was Green cane impact on sugar processing. The workshop provided a valuable and timely opportunity to review and discuss the impact on factory operations and performance from a green cane supply that could include significant levels of trash. It was particularly relevant to those mills that were considering options to boost their biomass intake for increased co-generation capacity. Several of the speakers related their experiences with processing ‘whole of crop’ cane supplies through the factory. Speakers detailed the problems and increased losses that were incurred when processing cane with high trash levels. The consensus of the delegates was that the best scenario would involve a cane-cleaning plant at the factory so that only clean cane would be processed through the factory. The forum recommended that more research was required to address the issues of increased impurities in the process streams associated with high trash levels. Site visits to the two factories and a cane-delivery station were arranged as part of the workshop.

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A major challenge of the 21st century will be to generate transportation fuels using feedstocks such as lignocellulosic waste materials as a substitute for existing fossil and nuclear fuels. The advantages of lignocellulosics as a feedstock material are that they are abundant, sustainable and carbon-neutral. To improve the economics of producing liquid transportation fuels from lignocellulosic biomass, the development of value-added products from lignin, a major component of lignocellulosics, is necessary. Lignins produced from black liquor through the fractionation of sugarcane bagasse with soda and organic solvents have been characterised by physical, chemical and thermal means. The soda lignin fractions have different physico-chemical and thermal properties from one another. Some of these properties have been compared to bagasse lignin extracted with aqueous ethanol.

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