Thermal and exergetic analysis of the Goswami cycle integrated with mid-grade heat sources

This paper presents a theoretical investigation of a combined Power and Cooling Cycle that employs an Ammonia-Water mixture. The cycle combines a Rankine and an absorption refrigeration cycle. The Goswami cycle can be used in a wide range of applications including recovering waste heat as a bottoming cycle or generating power from non-conventional sources like solar radiation or geothermal energy. A thermodynamic study of power and cooling co-generation is presented for heat source temperatures between 100 to 350 °C. A comprehensive analysis of the effect of several operation and configuration parameters, including the number of turbine stages and different superheating configurations, on the power output and the thermal and exergy efficiencies was conducted. Results showed the Goswami cycle can operate at an effective exergy efficiency of 60-80% with thermal efficiencies between 25 to 31%. The investigation also showed that multiple stage turbines had a better performance than single stage turbines when heat source temperatures remain above 200 °C in terms of power, thermal and exergy efficiencies. However, the effect of turbine stages is almost the same when heat source temperatures were below 175 °C. For multiple turbine stages, the use of partial superheating with Single or Double Reheat stream showed a better performance in terms of efficiency. It also showed an increase in exergy destruction when heat source temperature was increased

Phenotypic screen for oxygen consumption rate identifies an anti-cancer naphthoquinone that induces mitochondrial oxidative stress.

A hallmark of cancer cells is their ability to reprogram nutrient metabolism. Thus, disruption to this phenotype is a potential avenue for anti-cancer therapy. Herein we used a phenotypic chemical library screening approach to identify molecules that disrupted nutrient metabolism (by increasing cellular oxygen consumption rate) and were toxic to cancer cells. From this screen we discovered a 1,4-Naphthoquinone (referred to as BH10) that is toxic to a broad range of cancer cell types. BH10 has improved cancer-selective toxicity compared to doxorubicin, 17-AAG, vitamin K3, and other known anti-cancer quinones. BH10 increases glucose oxidation via both mitochondrial and pentose phosphate pathways, decreases glycolysis, lowers GSH:GSSG and NAPDH/NAPD+ ratios exclusively in cancer cells, and induces necrosis. BH10 targets mitochondrial redox defence as evidenced by increased mitochondrial peroxiredoxin 3 oxidation and decreased mitochondrial aconitase activity, without changes in markers of cytosolic or nuclear damage. Over-expression of mitochondria-targeted catalase protects cells from BH10-mediated toxicity, while the thioredoxin reductase inhibitor auranofin synergistically enhances BH10-induced peroxiredoxin 3 oxidation and cytotoxicity. Overall, BH10 represents a 1,4-Naphthoquinone with an improved cancer-selective cytotoxicity profile via its mitochondrial specificity

From little things, big things grow: trends and fads in 110 years of Australian ornithology

Publishing histories can reveal changes in ornithological effort, focus or direction through time. This study presents a bibliometric content analysis of Emu (1901–2011) which revealed 115 trends (long-term changes in publication over time) and 18 fads (temporary increases in publication activity) from the classification of 9,039 articles using 128 codes organised into eight categories (author gender, author affiliation, article type, subject, main focus, main method, geographical scale and geographical location). Across 110 years, private authorship declined, while publications involving universities and multiple institutions increased; from 1960, female authorship increased. Over time, question-driven studies and incidental observations increased and decreased in frequency, respectively. Single species and ‘taxonomic group’ subjects increased while studies of birds at specific places decreased. The focus of articles shifted from species distribution and activities of the host organisation to breeding, foraging and other biological/ecological topics. Site- and Australian-continental-scales slightly decreased over time; non-Australian studies increased from the 1970s. A wide variety of fads occurred (e.g. articles on bird distribution, 1942–1951, and using museum specimens, 1906–1913) though the occurrence of fads decreased over time. Changes over time are correlated with technological, theoretical, social and institutional changes, and suggest ornithological priorities, like those of other scientific disciplines, are temporally labil

The Effect of Multi-Combination Freight Vehicles in Urban Traffic

The use of heavy vehicles that are capable of carrying increased loads has continued to increase rapidly. Such vehicles, such as B-Doubles, Road-Trains and other large sized vehicles, are termed here as Multi-Combination Vehicles (MCV). Significant economic benefits result from the use of such innovative vehicles, which are able to carry up to twice the payload of standard semi-trailers. Those benefits, however, need to be traded-off against the potentially negative impacts on other road users, such as additional delays in urban areas. The research detailed here will deliver an increased understanding of some of those impacts by investigating models which can be used to estimate delays to other road users. Preliminary results from adding small numbers of MCV for a freeway section and an intersection demonstrated a significant adverse impact on the performance of the network. These results imply higher passenger car equivalent values than those commonly used for MCV. Further research is being conducted, including calibrating the input parameters and performing the same network simulations on other microsimulation packages to compare the results

Towards A Methodology To Evaluate Public Transport Projects

The document is intended to form the basis for the development of the Public Transport Evaluation (PTE) Framework, which is be used in practice by planning agencies and transport operators in Queensland. The main underlying aim is to be able to answer the question: What does the community get for each $ spent on Public Transport (PT) projects? The full community benefits of PT investment and recurring operating fare box subsidies are often difficult to identify and quantify, either in monetary or other units. This is mainly due to the nature of the externalities involved (eg. reduced road space requirements; reduced road based congestion, environmental impacts and energy consumption; increased access for non-car owning households; etc.). Such quantification is necessary for strategy/project evaluation and to justify investments in PT initiatives to the community at large. Currently, the levels of consistency and uniformity in the procedures for the evaluation of road projects are not matched in the evaluation of PT projects ands strategies. The lack of a structured evaluation methodology is, in part, due to the level of complexity of impacts and affected groups. Compared to public transport, road projects tend to have fewer impacts and affect fewer groups. The complex nature of potential impacts is directly related to the range (eg. economic, financial, environmental, social; direct/indirect) and affected groups (users, non-users, as well as government and private operators). The main benefits of a common evaluation framework include: Potential to improve the quality of investment and policy decisions; Ability to compare projects across transport portfolio on a consistent basis; Help the ‘value for money’ arguments for PT projects; Identify affected groups and impacts; Identify trade-offs between gainers and losers; and Help design specific evaluation studies to assess the degree to which claimed benefits have been/are being achieved. The framework proposed here is intended as a user-friendly spreadsheet based tool which can be used to assess individual projects or strategies within a comprehensive and consistent basis, using Queensland related evaluation parameter values where appropriate. Currently, an EXCEL based prototype for the framework has been built. The following main components make up the framework: • Project/Strategy definition – the user specifies the project or strategy using a suggestion typology; • Identification of impacts – the system suggests impact types likely to apply based on project definition and the user finalises impact list; • Before & After input data (or conditions ‘with’ and ‘without’ project)– this relates to road and PT link data on volumes, patronage, speeds and other data needed for impact assessment. The affected road and PT links or segments are identified separately to allow a reasonable level of disaggregation of impacts. At this stage, the user has the option of using estimates given default values and relationships (eg; speed/flow curves to obtain estimates of delay impact on road traffic) or input his/her own estimates independently arrived at; • Impact quantification – for each impact type, the user can opt to make use of default parameters applicable in Queensland , to quantify impacts; and • Summary outputs are shown by main impact type to enable sensitivity analysis results to be easily compared. Two methods are primarily used for in road and public transport project evaluation, namely: cost benefit analysis and multi-criteria analysis. For some impacts, such as equity, environmental effects and regional development, there is no consensus on their incorporation or quantification in money terms. Other issues that require careful consideration in an evaluation methodology include: • The measure used to reflect public transport ridership. This can have a major influence on the results, since a number of the impacts are estimated on the forecast ridership estimates; • The life of the project. Some benefits are long term and hard to quantify with certainty, resulting in the evaluation being less robust as the life of the project is extended; • The implementation risk factors. Some measures, such as the likelihood of successful implementation or difficulty of construction, should be considered; • The definition of the base case and the geographic scope of the evaluation; and • The evaluation method used should not focus on a final Net Present Value (NPV) or single ‘best’ solution. This approach may exclude: non-quantifiable benefits; uncertainty in the cost and benefit estimates; and alternative weighting of the project objectives. Thus, an evaluation methodology needs to cater for sensitivity analysis, including the impact of changes in the weighting factors for each objective

Modelling tolls: values of time and elasticities of demand: a summary of evidence

This report summarises a review which was prepared as part of a study conducted for the Queensland Department of Main Roads (QDMR) and the Brisbane City Council (BCC) into future transport infrastructure options for Brisbane. The provision of additional cross-river links and the issues associated with the possible use of tolls as the pricing of those links are of special interest in the study. The Transport Research Consortium at QUT has been asked to contribute to this study by: (a) Reviewing values of time used in demand modelling. Particular emphasis should be placed on the most appropriate values to be used when conducting traffic assignment (analysis of traffic flows using specific paths in the road network); (this is dealt with in Appendix A). Currently, the Brisbane strategic transport model (BSTM) uses a single value of time for all road users. This value is used to obtain generalised costs of travel and hence to assign an Origin-Destination (O-D) vehicle trip matrix to the road network. Ideally, to estimate the extent of traffic re-assignment due tolls being introduced on specific links, different values of time should apply to: • different tripmakers to reflect differences in income levels; • different trip purposes – ‘business’ trips and all other trips being the most common distinction made. In this way, commercial vehicle trips, for example, would use a different value of time for assignment purposes. • different trip distances to reflect the different elasticities of demand to tolls for different trip lengths. The literature surveyed points to a wide range of VTT used for modelling purposes. However, 40% to 50% of average wage rates seems to be widely accepted for non- ‘business’ trips (where ‘business’ trips are those made during employers’ time). The latter tend to be valued at higher rates of up to 80%-100% of the wage rate. With the current Australian weekly average wage of around $22/hr., this would translate into values of time of between$9-$11/hr. and$18-$22/hr. for ‘business’ trips. The Brisbane Strategic Transport Model uses a single value of time of$12/hr. (b) Reviewing the evidence on the elasticities of demand for road tolls in urban networks from elsewhere and reporting on the appropriateness of transferring the results to Brisbane; The use of tolls to finance capital expenditure on road facilities offers an opportunity to include a component of the toll which can be used to reflect congestion related topics. Road user charges or tolls for the use of congested road space has long been seen by economists as the preferred option to allocate scarce resources efficiently. Such charges have been made politically acceptable when the revenues obtained have been used to fund improvements in public transport services and facilities. A range of toll elasticities was found in the literature. It would appear that elasticities of between -0.2 and –0.3 could be used in Brisbane as average values. However, there is a wide range of values found for different trip purposes, income levels and overall trip costs. In addition, the availability of alternative routes which are attractive enough, in terms of levels of service, will have a significant impact on elasticities of demand for tolled roads. The main options used to undertake traffic assignment with toll estimation remain as put forward in QT (1993), namely: • Use conventional assignment techniques with generalised costs and treat the toll as an additional cost on a specific link, using an assumed value of time for all drivers; • Use multi-class assignment with each vehicle class having a different assumed value of time. Values of time for different trip purposes can be used to reflect differences in drivers’ perceptions. This option also allows for different toll rates by vehicle class. This option could also see the use of more detailed modelling techniques based on logit type ‘diversion’ curves. This allows for different classes of vehicle or trip purposes to be modelled separately with the probability of using the tolled facility given by a function of the generalised cost difference between it and its next best alternative. Whilst there have been advances in the way in which the main software transport planning packages deal with the modelling of tolls, the basic options and their data requirements remain as outlined in QT (1993). The needs identified in that report related to specific surveys to obtain up-to-date data on drivers perceptions of time and operating costs, still remains

Performance measures used in transit contracts: Review of evidence

This report has summarised the work undertaken at QUT as part of a research project sponsored by the Federal Transit Administration in the US. The project was administered by the US Transportation Research Board of the National Research Council, under TCRP Project G-6: 'A Guidebook for Developing a Transit Performance-Measurement System'. Kittelson and Associates Inc. acted as the principal investigators and other participants included Urbitran Inc., LKC Consulting Services, MORPACE International, Inc. and Yuko Nakanishi. The stated objective of this research is: 'to produce a practical, user-friendly guidebook that will assist transit system managers in developing a performance-measurement system that uses traditional and nontraditional performance indicators and measures to address customer-oriented and community issues.' As well as an extensive literature review, a total of 19 transit planning agencies and operators were interviewed for the overall project, regarding the performance measures currently in use. The results are available in the form of several project reports, which are currently in draft form, including: • TCRP G-6: A guidebook for developing a transit performance measurement system: Literature Review, September 2001; • TCRP G-6: A guidebook for developing a transit performance measurement system: Interim Report, December 2001; and • TCRP G-6: A guidebook for developing a transit performance measurement system: Performance measure summary, December 2001. As part of the team working on the project QUT reviewed a number of existing transit performance based contracts in several countries. This report deals with the review of evidence from agencies and operators. The summary provided here is based on documents obtained from agencies and operators, as well as on personal communication with a number of individuals in 12 organisations in Australia, US, UK, Norway and South Africa

Minimising the Conflict Between Rail Operations and Infrastructure Maintenance

This paper presents a method aimed at reducing the conflict between the trains and track maintenance by the short-term scheduling of the maintenance and the required resources. The risk of delays to the trains and maintenance is incorporated in the process of developing the maintenance timetable. The problem is formulated as a binary integer non-linear programming problem, with the following heuristics techniques applied: Simulated Annealing; Local Search; Multiple Local Search; and Tabu Search. The most appropriate solution method to solve the short-term maintenance scheduling problem as formulated here is found to be Simulated Annealing. Sensitivity analysis is conducted to examine the effects of variation in the input parameters, such as different priorities for the railway company

Tracing Tourism Translations: Opening the black box of development assistance in community-based tourism in Viet Nam

Tourism is a lens that provides unique insights into the social, cultural, political and economic processes operating in specific environments. In this study, the lens is directed at community-based tourism initiatives in northern Viet Nam that have been ‘facilitated’ by international development agencies. The potential of tourism as a tool for development is gaining increased recognition and popularity around the globe, despite widespread criticism in the academic literature based on the poor record of success. In Viet Nam, community-based tourism initiatives are increasingly being established with assistance from international development agencies, as a means of diversifying agricultural livelihoods in the hope of alleviating poverty. Based on six weeks of ethnographic fieldwork in northern Viet Nam, this research joins only a handful of tourism studies that have used actor-network theory (ANT) as a methodological approach for studying tourism. This thesis therefore provides an important contribution to the emerging dialogue on the potential of ANT to inform new understandings about tourism, as well as opening the black box of development-assisted community-based tourism in Viet Nam. This research uses Callon’s (1986b) phases of translation to identify the actors in community-based tourism in Viet Nam, exploring the roles, relationships and strategies (per)formed by these actors as they attempt to enact CBT actor-networks. A discourse analysis shows how dominant discourses around knowledge and power homogenize groups such as host communities and tour operators, in ways that legitimise the interventions and actions of other actors, such as development agencies and government institutions. Exploring the dominant discourses around CBT opens a window into spaces within the actor-network of CBT where the workings of the actor-network are prescribed, taken for granted, and thus appear stable. However there are also spaces where the actor-networks are constantly negotiated, where meaning is contested and relationships between actors are fluid and dynamic. Out of these negotiated spaces agency emerges, and actor-networks are reconfigured as power relations shift and actors are transformed. This thesis explores some of these prescribed and negotiated spaces, showing the impact of specific power relations on material CBT outcomes and providing new understandings to inform development policy and practice