Dry Sliding of Nitrided NiTiHf

The unlubricated friction and wear properties of the superelastic material NiTiHf, treated by either gas nitriding or plasma nitriding, have been investigated. Pin-on-disk testing of the studied materials was performed at sliding speeds from 0.01 to 1 m/s at normal loads of 1, 5, or 10 N. For all of the studied friction pairs (NiTiHf pins vs. nitrided disks) over the given parameters, the steady-state coefficients of friction varied from 0.7 to 1.6, and those of the control (NiTiHf on NiTiHf) varied from 0.5 to 1.2. Pin wear factors ranged from approximately 10^?6 against the NiTiHf and plasma-nitrided disks to approximately 10^?4 for the gas-nitrided disks. The plasma-nitrided disks provided wear protection in several cases and tended to wear by adhesion. The gas-nitrided treatment generated the most pin wear but essentially no disk wear except under the most severe of the studied conditions (1 N load and 1 m/s sliding speed). The results of this study are expected to provide guidance for design of aerospace components such as gears and fasteners.     

Prediction of metabolic clusters in early-lactation dairy cows using models based on milk biomarkers

The aim of this study was to describe metabolism of early-lactation dairy cows by clustering cows based on glucose, insulin-like growth factor I (IGF-I), free fatty acid, and β-hydroxybutyrate (BHB) using the k-means method. Predictive models for metabolic clusters were created and validated using 3 sets of milk biomarkers (milk metabolites and enzymes, glycans on the immunogamma globulin fraction of milk, and Fourier-transform mid-infrared spectra of milk). Metabolic clusters are used to identify dairy cows with a balanced or imbalanced metabolic profile. Around 14 and 35 d in milk, serum or plasma concentrations of BHB, free fatty acids, glucose, and IGF-I were determined. Cows with a favorable metabolic profile were grouped together in what was referred to as the “balanced” group (n = 43) and were compared with cows in what was referred to as the “other balanced” group (n = 64). Cows with an unfavorable metabolic profile were grouped in what was referred to as the “imbalanced” group (n = 19) and compared with cows in what was referred to as the “other imbalanced” group (n = 88). Glucose and IGF-I were higher in balanced compared with other balanced cows. Free fatty acids and BHB were lower in balanced compared with other balanced cows. Glucose and IGF-I were lower in imbalanced compared with other imbalanced cows. Free fatty acids and BHB were higher in imbalanced cows. Metabolic clusters were related to production parameters. There was a trend for a higher daily increase in fat- and protein-corrected milk yield in balanced cows, whereas that of imbalanced cows was higher. Dry matter intake and the daily increase in dry matter intake were higher in balanced cows and lower in imbalanced cows. Energy balance was continuously higher in balanced cows and lower in imbalanced cows. Weekly or twice-weekly milk samples were taken and milk metabolites and enzymes (milk glucose, glucose-6-phosphate, BHB, lactate dehydrogenase, N-acetyl-β-d-glucosaminidase, isocitrate), immunogamma globulin glycans (19 peaks), and Fourier-transform mid-infrared spectra (1,060 wavelengths reduced to 15 principal components) were determined. Milk biomarkers with or without additional cow information (days in milk, parity, milk yield features) were used to create predictive models for the metabolic clusters. Accuracy for prediction of balanced (80%) and imbalanced (88%) cows was highest using milk metabolites and enzymes combined with days in milk and parity. The results and models of the present study are part of the GplusE project and identify novel milk-based phenotypes that may be used as predictors for metabolic and performance traits in early-lactation dairy cows.     

Real-Time business data acquisition: How frequent is frequent enough?

Effective data acquisition for business process monitoring has become a critical element in today’s business world. While the need for monitoring is generally agreed upon by both re- searchers and practitioners alike, the means and mechanisms are often vague. This is especially salient with the fast growing availability of various technologies to monitor in real-time through recent advances such as the Internet of Things (IoT) with specific emphasis on Radio-Frequency IDentification (RFID) and associated sensor networks. This study is motivated by the lack of published literature in data acquisition and analytics that specifically addresses sufficient real-time data acquisition for effective managerial monitoring. As a step in addressing this void, we review and extend existing literature in this general area by studying various requirements and information sources that relate to effective management monitoring. We then design an exploratory study to evaluate current managerial monitoring needs and the importance of automated data collection technologies. Results from this study show that the most important latent factor that influences an organization’s information need is its dynamic competitiveness, and consequently, companies with a dynamic supply chain would need a faster transaction and operations data system. The second important latent factor is the behavioral performance, which renders it essential to have a human-centric data system. This study provides evidence for the significance in adopting technologies such as RFID and other IoT systems for real-time monitoring in highly dynamic organizations and offers guidelines for analytical technology adoption for various industries.     

Pressurised flash drying of Yallourn lignite

A previously developed 1D model of lignite drying for pulverised lignite feeding into a conventional pulverised fuel boiler during the coal milling process is applied to lignite in an entrained flow configuration at elevated pressure. A combustor fired with diesel and air was used to produce a flue gas at 800 °C and 10 atm to flash dry Yallourn lignite at a nominal feed rate of 725 kg/h along a 50 m duct. A coal feeder arrangement was also developed which provides a simple positive feeding device for feeding against a back pressure. The feeder takes as an input coal which is nominally <50 mm and discharges it as a finely divided product with a mean particle size of approximately 1.0-1.5 mm. The comparison between model predictions and measured temperature profiles for the flue gas and final moisture content of the dried coal product showed excellent agreement. Coal moisture was reduced from 67 wt% to between 30 and 40 wt%, depending upon on the coal feed rate and particle size. The small variation in the final outlet temperature observed between the model and experimental results is due to heat losses from the exposed duct work to the environment.     

Cardenolide fingerprint of monarch butterflies reared on common milkweed,Asclepias syriaca L.

Monarch butterfly,Danaus plexippus (L.), larvae were collected during August 1983 from the common milkweed,Asclepias syriaca L., across its extensive North American range from North Dakota, east to Vermont, and south to Virginia. This confirms that the late summer distribution of breeding monarchs in eastern North America coincides with the range of this extremely abundant milkweed resource. Plant cardenolide concentrations, assayed by spectrophotometry in 158 samples from 27 collection sites, were biased towards plants with low cardenolide, and ranged from 4 to 229 g/ 0.1 g dry weight, with a mean of 50 g/0.1 g. Monarch larvae reared on these plants stored cardenolides logarithmically, and produced 158 adults with a normally distributed concentration range from 0 to 792 g/0. l g dry butterfly, with a mean of 234 g/0.1 g. Thus butterflies increased the mean plant cardenolide concentration by 4.7. The eastern plants and their resultant butterflies had higher cardenolide concentrations than those from the west, and in some areas monarchs sequestered more cardenolide from equivalent plants. Plants growing in small patches had higher cardenolide concentrations than those in larger patches, but this did not influence butterfly concentration. However, younger plants and those at habitat edges had higher cardenolide concentrations than either older, shaded, or open habitat plants, and this did influence butterfly storage. There were no apparent topographical differences reflected in the cardenolides of plants and butterflies. Twenty-eight cardenolides were recognized by thin-layer chromatography, with 27 in plants and 21 in butterflies. Butterflies stored cardenolides within the more polar 46% of the plantR _d range, these being sequestered in higher relative concentrations than they occurred in the plants. By comparison with published TLC cardenolide mobilities, spots 3, 4, 9, 16, 24 or 25, 26, and 27, may be the cardenolides syrioside, uzarin, syriobioside, syriogenin, uzarigenin, labriformidin, and labriformin, respectively. Cochromatography with cardenolide standards indicated that desglucosyrioside did not occur in the plants but did occur in 70% of the butterflies, and aspecioside was in 99% of the plants and 100% of the butterflies. The polar aspecioside was the single most concentrated and diagnostic cardenolide in both plants and butterflies. ButterflyR _d values were dependent on those of the plant, and both showed remarkable uniformity over the range of areas sampled. Thus contrary to previous reports,A. syriaca has a biogeographically consistent cardenolide fingerprint pattern. The ecological implications of this for understanding the monarch's annual migration cycle are significant.     

Maintaining the security of supply in the Australian national electricity Market with higher levels of renewable energy

This paper examines security of supply concerns in an Australian electricity market under transition and considers potential policy pathways to address them. It details the current state of Australia’s electricity industry, considers the extent to which supply security in the electricity sector may be considered a public good, and examines the features likely to impact on the efficacy of current and potential future market designs.     

Environmental performance of a naturally ventilated city centre library

To tackle climate change it is essential to reduce carbon dioxide emissions. To this end, it is important to reduce the energy demands of non-domestic buildings. Naturally ventilated buildings can have low energy demands but the strategy is difficult to implement in deep plan, urban locations. The Frederick Lanchester Library at Coventry University, UK, incorporates natural ventilation, daylighting and passive cooling strategies. By using lightwells and perimeter stacks to supply and exhaust air, it can be ventilated by natural means despite its deep plan form and sealed façade. This paper describes the building and presents the energy consumption and the internal temperatures and CO₂ levels recorded in 2004/2005. The building's performance is compared to the original design criteria and good practice guidelines. Recommendations for the design of such buildings are made and the likely performance in other UK cities is assessed. It is concluded that the building uses under half the energy of a standard air-conditioned building and yet, in summer, can keep the interior comfortable and up to 5 °C below ambient. The design would perform equally well in the typical weather conditions experienced at 13 other UK cities, but not in London. It is concluded that deep-plan, naturally ventilated buildings with sealed facades, if well designed, could maintain thermal comfort in all but a very few UK locations, whilst consuming much less energy than even good practice standards.     

Observations on the changes in nitrate concentrations along streams in seven upland moorland catchments in Northeast Scotland

River water has been sampled under baseflow conditions in both summer and winter at c. 250-m intervals along the length of each of seven rivers in northeast Scotland, and the nitrate contents have been determined. The resultant data have been examined in the context of the nitrogen saturation hypothesis. Capacity of the catchment soils to retain nitrate was generally minimal in winter. Although biological uptake of nitrate was evident in summer, in the upper part of each catchment substantial nitrate leaching still occurred. The phenomenon was most marked in water draining from hill peats, except where these were conspicuously waterlogged. The results are discussed in the context of possible nitrogen saturation effects on upper catchment slopes.     

Maxwell and the science of colour

This non-technical review of Maxwell's contributions to the quantitative theory of colour was presented at a symposium in Aberdeen to celebrate the 150th anniversary of his appointment as professor of natural philosophy at Marischal College. Maxwell maintained his interest in the science of light and colour from his childhood to the last decade of his life. He lavished the same care and imagination on these studies as he did on his epochal contributions to electromagnetism and statistical physics.