152 research outputs found
Technical, economic, and environmental assessment of integrating solar thermal systems in existing district heating systems under Jordanian climatic conditions
Like most other similar institutions in Jordan, Jordan University of Science and Technology relies on a diesel-fired boiler that supplies a district heating system for space heating on campus. Different solar collector area scenarios were considered for both evacuated tube collector and parabolic trough collector technologies. The MATLAB package was utilized, and a code was developed using hourly irradiance and ambient temperature data which represented the average values for the last three years. The results show promising benefits at all levels. Technically, a high solar fraction of 0.84 can be achieved without the need for energy storage. Environmentally, potential reduction in carbon dioxide emission of 1,600 tons can be realized annually. Economically, the discounted payback period was calculated for each case studied. It turned out that the best value was 3.4 years for the case of 4,000 m2 evacuated tube collector and that parabolic trough collector technology is superior to evacuated tube collector technology although it has a higher initial cost
A bottleneck investigation at escalator entry at the Brisbane central train station
© 2016 ATRF, Commonwealth of Australia. All rights reserved. Escalators are an essential for passenger’s movements through multi-level rail station concourse environments. Despite the access benefits that escalators provide, they can make travel time longer and pose some challenges when bottlenecks appear at entry. Studying the passenger behaviour of bottlenecks at escalator entrances is essential for planning, designing and control of engineering transportation systems. In this paper we investigate passenger route choice behaviour while approaching an escalator-stair infrastructure set at Brisbane Central train station. A model of an escalator entry bottleneck is formulated. The developed model can explain the queuing characteristics of the bottlenecks and can be readily used to predict congested state occurrence at escalator entry bottleneck. Accurate prediction of bottlenecks occurring around escalators and the estimation of escalator capacity are obtained based on real field data collected from Brisbane Central train station. Results have provided significant insights and computational tools for understanding many features of escalator bottlenecks. Remarkably, escalator capacity at bottleneck points affects the duration and severity of the congested period
Writing Problems of Non- English Students
To be a good writer is one of the most difficulties that faces most of students who are majoring in English. It is known that writing skill is an important for educational, business and personal fields. This paper will spot the lights on EFL learners’ writing difficulty of Jordanian students at university of Jordan /Aqaba branch and the teachers’ concerns and efforts to explore and the nature of the students’ errors of first year students. These errors which are usually investigated may reflect poor linguistic competence on different levels including phonological awareness and knowledge of orthography, vocabulary, morphology and semantics relationship, and mental orthographic images. (Apl and Masterson, 2001; Apeh, Masterson and Nissen, 2004)
Eliot’s Approach to Ethical Poetry as a Case Study The Love Song by J. Alfred Prufrock
This study aims at showing the ethical approaches in T.S. Eliot’s poetry. I argue that Eliot’s poetry is loaded with ethical approaches that characterized the era in which he lived. Also, the significance of this study arises from the fact that ethics have become buried in modern life. I, among others, feel we need it urgently these days to survive in a nice manner.In The Love Song of J. Alfred Prufrock, readers are shocked to notice male man has become or is viewed as being less productive and lacking decision-making, exactly another copy of Hamlet. The Love Song of J. Alfred Prufrock reflects the feelings of emasculation, not feminism, experienced by many men as they returned home from World War I to find women empowered by their new role as wage earners. Prufrock (2009), unables to make a decision, watches women wander in and out of a room, “talking of Michelangelo” (p.14), and elsewhere admires their downy, bare arms.
An effort-based model for pedestrian route choice behaviour
University of Technology Sydney. Faculty of Engineering and Information Technology.This research proposes a novel effort-based theoretical framework for the pedestrian route choice problem to discover principles that pedestrians use to select their routes. A pedestrian chooses their route by optimising certain criteria, such as distance, time, and effort. Several possible criteria that could be used to predict the route choices of a pedestrian are re-assessed. In most cases, the common criteria of a pedestrian route choice are route length and travel time. Effort is proposed as an additional criterion, which indicates metabolic energy expenditure.
The basic principle and a methodology are proposed for route choice based on the least effort that a pedestrian may consume during travel between destinations. The followed deterministic approach assumes that the perceived utility of a route is deterministic and that pedestrians will only choose the route that features minimum average cost.
A mathematical formulation for solving the pedestrian route choice problem utilising the concept of physical effort is introduced. We compare our effort-based model against time and distance based models and validate against the Brisbane dataset. We demonstrate that our method has higher performance efficiency than the models that exist in the state-of-the-art and thereby the model justifies optimal pedestrian behaviour when choosing a route in a congested environment.
Our discussion concludes with an overview of how our approach could be used by rail service providers to optimise operations and improve customer experience. It is contended that the entire behaviour of an individual is subject to effort minimization. Hence, the pedestrian route choice problem is formulated as a constrained non-linear optimization problem whose objective function is the effort consumed while moving from current position to destination over the route.
This doctoral research is a part of research project entitled “Integrated Passenger Behaviour, Train Operations Diagnostics, and Vehicle Condition Monitoring System”, which aims to consolidate foundation technology for the sensing and perception functions of a system that can monitor passenger behaviour and operational characteristics of passenger trains as they arrive at crowded stations using low-cost multi-sensor network. The Brisbane Central Rail Train Station is selected for a case study for validation of the developed model
Thermal shock resistance of yttrium aluminium oxide Y3Al5O12 thermal barrier coating for titanium alloy
The high strength-to- weight ratio of titanium alloys allows their use in jet engines. However, their use is restricted by susceptibility to oxidation at high temperatures. In this study, the possibility of increasing the operating temperature of titanium alloys through using Yttrium Aluminum Oxide (YAG) as a thermal barrier coating material for Ti-6Al-4V substrate is studied. The study concludes that YAG can be utilized to increase the operating temperature of Ti-6Al-4V titanium alloy from around 350 °C to 800 °C due to its low thermal conductivity and phase stability up to its melting point. In addition, its lower oxygen diffusivity in comparison with the standard YSZ material will provide a better protection of the titanium substrate from oxidation. In this work, coating was created using atmospheric plasma spray. X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) were used to examine coatings' composition and structure. The coating was characterized by thermal shock test, Vickers hardness test and adhesion strength test. X-ray diffraction indicated that the coating was of a partially crystalline Y3Al5O12 composition. The coating was porous with excellent thermal shock resistance at 800 oC, with a Vickers micro-hardness of 331.35 HV and adhesion strength of 17.6 MPa
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