357 research outputs found
A project based approach to learning for first year engineering students
Support for transition from Leaving Certificate and entry to college for 1st year engineering students
can be difficult to achieve. This new course offers an innovative project based approach to learning for
1st years with an introduction to design to build confidence in student ability and give motivation in
research and discovery skills. The project takes place in small groups and relies heavily on
presentation, group and individual skills. The Mechanical and Manufacturing and the Electronic
Engineering Schools at Dublin City University offered this new module for all first year Engineering
Students in 2006. The course entitled, âProject and Laboratory Skillsâ was an immediate success with
increased participation and retention rates and a high level of academic success in assessment. This
paper highlights the overall module concepts, teaching and learning outcomes and the resources
required for such a module
Personal reflections of a 1st year postgraduate student
Undertaking a postgraduate research degree can be a very exciting and daunting experience. The aim of this paper is to relate some of the experiences and reflections of a first year postgraduate engineering student. There have been other articles written on the PhD experience, however I believe that this paper offers insights into the industry based project experience, the benefits and drawbacks of multiple supervisors, and it offers the perspective of a student on an early point of the postgraduate learning curve
Pharmaceutical water systems and the 6D rule: a computational fluid dynamics analysis
The problem o f piping system dead-legs are frequently encountered in high purity water systems throughout the pharmaceutical and semi-conductor industries. The installation of a pipe tee in sterile process pipework often creates a stagnant dead-leg zone which can result in the formation of bio-film and compromise the entire system. Considerable basic research is required to address the lack of understanding of this problem and to assist during design, manufacture, installation and operation of these critical systems. This study involves the application o f CFD (computational fluid dynamics) techniques to the study of turbulent flow in Pharmaceutical pipe teejunctions.
Numerical models have been developed to initially study divided turbulent flow in a range of standard Pharmaceutical tee-j unctions and then to study dead-leg flow. Numerical predictions were compared with previously presented experimental results based on Laser Doppler Velocimetry. Turbulent models such as the k - e and Reynolds Stress model (RSM) were used to analyse the flow. Dye injection studies highlighted the lack of penetration o f the dead-leg and complex branch flow patterns for both sharp and round entry tees. Hydrogen bubble techniques gave clear evidence of the presence of a slow rotating vortex at entry to each branch and the presence of stagnation zones throughout the dead-legs.
The effect o f mainstream velocity and loop to branch ratios on dead-leg flow patterns was analysed. Stagnation zones were identified within each branch and the presence of a slow rotating cell within the dead-leg resulted in a lack of exchange of mainstream fluid from the distribution to the branch. The 6D-rule was found to be industrially irrelevant. 1 to 2D configurations should be used to avoid stagnation. No configuration resulted in high wall shear stress within the branch and a reduction in branch to loop diameter increased branch stagnation. There was no evidence of exchange of fluid between the loop and branch and all configurations had some quiescent (dormant/inactive) water
Chemical event tracking using a low-cost wireless chemical sensing network
A recently developed low-cost light emitting diode (LED) chemical sensing technique is integrated with a Mica2Dot wireless communications platform to form a deployable wireless chemical event indicator network. The operation of the colorimetric sensing node has been evaluated to determine its reproducibility and limit of detection for an acidic airborne contaminant. A test-scale network of five similar chemical sensing nodes is deployed in a star communication topology at fixed points within a custom built Environmental Sensing Chamber (ESC). Presented data sets collected from the deployed wireless chemical sensor network (WCSN) show that during an acidic event scenario it is possible to track the plume speed and direction, and estimate the concentration of chemical plume by examining the collective sensor data relative to individual sensor node location within the monitored environment
Automatic reaction to a chemical event detected by a low-cost wireless chemical sensing network
A test-scale wireless chemical sensor network (WCSN) has been deployed within a controlled Environmental Chamber (EC). The combined signals from the WCSN were used to initiate a controllable response to the detected chemical event. When a particular sensor response pattern was obtained, a purging cycle was initiated. Sensor data were continuously checked against user-defined action limits, to determine if a chemical event had occurred. An acidic contaminant was used to demonstrate the response of the sensor network. Once the acid plume was simultaneously detected by a number of wireless chemical sensor nodes, an automatic response action, which was the purging of the EC with clean air, was initiated and maintained for a period of time until the WCSN indicated that normal status had been re-established
The optimisation of a paired emitter-detector diode optical pH sensing device
With recent improvements in wireless sensor network hardware there has been a concurrent push to develop sensors that are suitable in terms of price and performance. In this paper a low cost gas sensor is detailed, and significant improvements in sensor characteristics have been achieved compared to previously published results. A chemical sensor is presented based on the use of low cost LEDs as both the light source and photodetector, coupled with a sensor slide coated with a pH sensitive colorimetric dye to create a simple gas sensor. Similar setups have been successfully used to detect both acetic acid and ammonia. The goal of this work was to optimise the system performance by integration of the sensing technique into a purposely deigned flowcell platform that holds the colorimetric slide and optical detector in position. The reproducibility of the sensor has been improved through this arrangement and careful control of deposited film thickness. The enhanced reproducibility between sensors opens the potential of calibration-free measurement, in that calibration of one sensor can be used to model the characteristics of all sensors in a particular batch
Fouling of a plate heat exchanger by cheese whey solutions
A plate heat exchanger rig was developed at Dublin City University to study fouling of plate heat exchangers using cheese whey solutions. The rig consisted of an Alfa-Laval plate heat exchanger, 316 stainless steel pipework, pressure and temperature measurement and was temperature controlled with all information logged via an Anville data acquisition system.
Cheese whey solutions of various concentration were passed through the plate heat exchanger for periods of up to four hours. The effect of flowrate, temperature, whey concentration and cleaning on fouling resistance were investigated. Increasing the processing temperature was found to increase the rate of fouling Maximum deposition on the plates of the heat exchanger was found to occur at low whey flowrates Increasing whey concentration was found to increase the rate of fouling. An induction period was noted and asymptotic fouling found to occur at low flowrates and high temperatures. Cleaning of the plates of the heat exchanger was found to significantly affect the rate of fouling
The âmiracleâ of Fatima: Media framing and the regeneration of a Dublin housing estate
This article examines media coverage of one local authority housing estate in Dublin with a difficult past. Fatima Mansions was built between 1949 and 1951 as part of a government policy to re-house the cityâs poor. The estate enjoyed a relatively unremarkable history up until the 1970s. A heroin problem developed in the estate in the 1980s and contributed to its negative media construction, such that by the end of the 1990s the estate was widely viewed as being in crisis. Beginning in the early 2000s and recently completed, a major regeneration project has seen the estate transformed with the potential finally to dislodge the negative stereotyping embedded in the estateâs past. An empirical analysis of two media spaces that represented this change process shows how the media tuned into the change agenda promoted by local residents, in the process widening its frame of reference and allowing for representations with a more positive valence. The article argues that media representations of social problems may not be authoritative and media agenda-setting is more provisional and open ended than is commonly assumed
The âmiracleâ of Fatima : Media Framing and the regeneration of a Dublin Housing Estate (NIRSA) Working Paper Series. No. 47
This paper examines media coverage of one local authority housing estate in Dublin city with a difficult past. Fatima Mansions was built in the late 1940s and enjoyed an unremarkable history up until the 1970s. A heroin problem developed in the estate in the 1980s and contributed to its negative media construction. Beginning at the end of the 1990s and continuing to the present, a regeneration project worked hard to dislodge earlier interpretations of the estate. A qualitative analysis of different media spaces that represented this change process shows how the media tuned into it and that earlier negative meaning-making in the late 1990s was later displaced by visual imagery, audio recordings and textual accounts with a more positive valence. The paper argues that media representations of social problems may not be authoritative and media agenda-setting is more provisional and open-ended than is commonly assumed
Autonomous greenhouse gas measurement system for analysis of gas migration on landfill sites
This paper describes the design, development and
validation of an autonomous gas sensing platform
prototype for monitoring of the greenhouse gases, methane
(CH4) and carbon dioxide (CO2). The deployment
undertaken for validation of the developed prototype
monitored landfill gas migration to perimeter borehole
wells on a landfill site. Target gas concentrations were
captured via infrared gas sensors tuned for each target gas
and data reported to an offsite data collection point at 12
hour intervals. This bespoke platform and the
accompanying data recording and interface software
provide a flexible alternative to the presently employed
labor intensive, manual monitoring routines. This
successful trial brought about a change in the management
of the trial sites gas extraction system
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