Non-continuous and variable rate processes: Optimisation for energy use

The need to develop new and improved ways of reducing energy use and increasing energy intensity in industrial processes is currently a major issue in New Zealand. Little attention has been given to optimisation of non-continuous processes in the past, due to their complexity, yet they remain an essential and often energy intensive component of many industrial sites. Novel models based on pinch analysis that aid in minimising utility usage have been constructed here through the adaptation of proven continuous techniques. The knowledge has been integrated into a user friendly software package, and allows the optimisation of processes under variable operating rates and batch conditions. An example problem demonstrates the improvements in energy use that can be gained when using these techniques to analyse non-continuous data. A comparison with results achieved using a pseudo-continuous method show that the method described can provide simultaneous reductions in capital and operating costs

Theology, News and Notes - Vol. 43, No. 02

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1125/thumbnail.jp

Integrating trans-disciplinary approaches: joined-up working in urban regeneration.

This paper questions the relationship between biodiversity, planning and governance and highlights physical and organizational barriers that can prevent change. Trans-disciplinary approaches to evaluating biodiverse urban environments are discussed and analysed with particular reference to the role of environmental public art and community engagement projects within urban regeneration. Public art has been integrated into the regeneration of cities. Public artists are capable of delivering interesting ‘greening projects’ that involve local communities in the processes. Such projects appeal to local authorities because they are perceived to address objectives within authority¹s social and environmental policies. An illustrative study is provided: a multidisciplinary team were commissioned to map four miles of the Leeds/Liverpool canal as part of Liverpool Biennial’s Urbanism 2009. The team, led by an artist and a plant ecologist, collected data over six months in the spring and summer of 2009. This data included measurements of the biodiversity of the area, recording and categorising human activity, patterns of dog fouling, ‘landscape preference’ using selected canal-side landscapes, and detailed data on the ‘barrier constructs’ (fencing, walls etc) along the canal which link back to patterns of human activity and can be further related to aesthetics and environmental psychology. The conclusions were that this stretch of urban waterway is an ecological gem within an area of urban deprivation, but for the gem to attract people from across all demographics - to enjoy and foster ongoing use and respect for the environment, changes need to occur in the way that agencies and professionals work together. This vision can only realistically be achieved if professionals from all relevant agencies work collectively, pooling resources and expertise. A series of recommendations for action are suggested: it is not so much about community cohesion - a sense of community in the built environment - but cohesion amongst agencies and professionals

Discriminating cool-water from warm-water carbonates and their diagenetic environments using element geochemistry: the Oligocene Tikorangi Formation (Taranaki Basin) and the dolomite effect

Fields portrayed within bivariate element plots have been used to distinguish between carbonates formed in warm- (tropical) water and cool- (temperate) water depositional settings. Here, element concentrations (Ca, Mg, Sr, Na, Fe, and Mn) have been determined for the carbonate fraction of bulk samples from the late Oligocene Tikorangi Formation, a subsurface, mixed dolomite-calcite, cool-water limestone sequence in Taranaki Basin, New Zealand. While the occurrence of dolomite is rare in New Zealand Cenozoic carbonates, and in cool-water carbonates more generally, the dolomite in the Tikorangi carbonates is shown to have a dramatic effect on the "traditional" positioning of cool-water limestone fields within bivariate element plots. Rare undolomitised, wholly calcitic carbonate samples in the Tikorangi Formation have the following average composition: Mg 2800 ppm; Ca 319 100 ppm; Na 800 ppm; Fe 6300 ppm; Sr 2400 ppm; and Mn 300 ppm. Tikorangi Formation dolomite-rich samples (>15% dolomite) have average values of: Mg 53 400 ppm; Ca 290 400 ppm; Na 4700 ppm; Fe 28 100 ppm; Sr 5400 ppm; and Mn 500 ppm. Element-element plots for dolomite-bearing samples show elevated Mg, Na, and Sr values compared with most other low-Mg calcite New Zealand Cenozoic limestones. The increased trace element contents are directly attributable to the trace element-enriched nature of the burial-derived dolomites, termed here the "dolomite effect". Fe levels in the Tikorangi Formation carbonates far exceed both modern and ancient cool-water and warm-water analogues, while Sr values are also higher than those in modern Tasmanian cool-water carbonates, and approach modern Bahaman warm-water carbonate values. Trace element data used in conjunction with more traditional petrographic data have aided in the diagenetic interpretation of the carbonate-dominated Tikorangi sequence. The geochemical results have been particularly useful for providing more definitive evidence for deep burial dolomitisation of the deposits under the influence of marine-modified pore fluids

Morphological change in Newfoundland caribou: Effects of abundance and climate

The demographic and environmental influences on large mammal morphology are central questions in ecology. We investigated the effects of population abundance and climate on body size and number of male antler points for the La Poile and Middle Ridge caribou (Rangifer tarandus, L. 1758) herds, Newfoundland, Canada. Across 40 years and 20-fold changes in abundance, adult males and females exhibited diminished stature as indicated by jawbone size (diastema and total mandible length) and the number of antler points at the time of harvest. Associations between jawbone size and population abundance at birth were consistently negative for both herds, both sexes, and all age classes. Large-scale climate patterns, as measured by the North Atlantic Oscillation in the winter prior to birth, were also negatively associated with jawbone size. Declines in male antler size, as measured by the number of antler points, were not well predicted by either abundance or climate, suggesting other factors (e.g., current, rather than latent, foraging conditions) may be involved. We conclude that these morphological changes indicate competition for food resources

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Practical Extensions to Cycle Time Approximations for the G=G=m-Queue With Applications

Abstract-Approximate closed form expressions for the mean cycle time in a -queue often serve as practical and intuitive alternatives to more exact but less tractable analyses. However, the -queue model may not fully address issues that arise in practical manufacturing systems. Such issues include tools with production parallelism, tools that are idle with work in process, travel to the queue, and the tendency of lots to defect from a failed server and return to the queue even after they have entered production. In this paper, we extend popular approximate mean cycle time formulae to address these practical manufacturing issues. Employing automated data extraction algorithms embedded in software, we test the approximations using parameters gleaned from production tool groups in IBM's 200 mm semiconductor wafer fabricator. Note to Practitioners-We develop extensions to intuitive closed-form approximations for the mean cycle time in queueing networks. Such approximations can be used to analyze the tradeoffs between equipment utilization and cycle time in a manufacturing facility. The extensions incorporate issues of practical import that have not been modeled in the literature and were motivated by the inability of existing models to accurately describe the performance of manufacturing in IBM's 200 mm semiconductor wafer fabricator. The utility of our extensions is that, using automated data collection systems, we are able to well model production tools and elucidate the sources of cycle time. Index Terms-Production management, queueing analysis, semiconductor device manufacture