Web-Based Courseware in Teaching Laboratory

Global J. of Engng. Educ., Vol.4, No.1 Printed in Australia

© 2000 UICEE

Web-Based Courseware in Teaching Laboratory-Based Courses* Vincent G. Gomes Bruce Choy Geoff W. Barton Jose A. Romagnoli Department of Chemical Engineering, The University of Sydney, Sydney, NSW 2006, Australia

Educational hypermedia offers flexible access to information, supports convenient learning styles, and provides a number of teaching advantages. The student’s desire to learn can be enhanced by involving them in the education process and by presenting the course material in an attractive manner to encourage student participation. A well-implemented multimedia curriculum is an effective tool in technical education. Detailed mathematical models and simulations of pilot-plants have been developed in order to create virtual plants. Students can be trained to operate and test these virtual plants in order to learn about their behaviour. Student assignments and projects based on these simulated process plants provide self and group learning opportunities at a pace comfortable to the students. This paper reviews a case study in the setting up of simulated process plants for such flexible learning.

INTRODUCTION

The student’s desire to learn can be enhanced by involving them in the education process and by presenting the course material in an attractive manner to encourage their participation. For example: combining text, sound, graphics, interactivity and motion to animate technical concepts helps students understand concepts and enables them to do far more than through listening alone. Thus, a well-implemented hypermedia-enhanced curriculum could be an effective tool in technical education. The task must be perceived by students to be relevant to their needs as future professionals, and must include their direct involvement with problem solving and exploring possible options in plant conceptualization, design and operation. To overcome these difficulties, we have developed a computerbased instruction system with real-world case studies for teaching a laboratory-based course offered to third-year chemical engineering students.

Our industries face stiff competition in the current progress towards globalisation of the economy, as manufacturers search for new ways to increase production at a lower cost with higher quality. To address these challenges, industries need highly skilled personnel tuned to modern technology. However, rising costs, reduced budgets, difficulties in retaining high quality students and lack of technical and laboratory resources are some of the challenges that beset engineering education. Further exigencies include timetable clashes and time constraints within a flexible semesterised system offering multiple options. Therefore, innovative teaching methods are necessary to circumvent some of these problems. An essential factor in student learning is motivation. Studies [1,2] note the limitations of traditional classroom teaching in today’s changing environment. * A revised and expanded version of a keynote address presented at the 2nd Asia-Pacific Forum on Engineering and Technology Education, held in Sydney from 4 to 7 July 1999. This paper was awarded the UICEE silver award by popular vote of Conference participants, for the greatest contribution to the field of engineering education.

WEB-BASED LEARNING A major shortcoming with conventional engineering education is the exigency of providing equipment and laboratory tools caused by rising costs and infra65

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structure requirements. Besides the difficulties in managing and maintaining pilot-scale units, additional problems arise in upgrading these facilities to continue providing leading edge education. We contend that it is now partly possible to facilitate higher level learning in practice-oriented courses with the availability of affordable computers and supporting software. Our early experience shows that in a highly dynamic and technologically fast-moving environment, web-based laboratory work may be a suitable option for sus-tainably providing high-level skills to engineering students. From its inception, the web was recognized as a lowcost, flexible, and platform-independent means for information exchange. In its infancy, web-based education relied on the distribution of static pages. In this delivery mode, the only advantages the web offered over its Internet predecessors, such as the News Groups and Gopher servers, were ease of use and the ability to embed graphical content. However, the current interactivity available with a web-based system provides significant advantages over these early versions. As the World Wide Web (WWW) evolves into an important instructional platform, educational hypermedia is gaining increasing attention. Hypermedia is made up of nodes that can contain text, graphics, audio, video, even entire programs, and is an open system that allows users to read from, append or write materials to shared structures. Consequently, educational hypermedia provides flexible means of accessing instructional information and supports various learning styles. From an instructional perspective, a critical feature of hypermedia is that it provides a non-sequential information presentation that differs markedly from the text-based material used in conventional instructional systems. Sound structures and learning guidance, however, are as important as is navigational freedom. A hypermedia learning system must be able to assist students in determining their learning performance levels. A hierarchical learning environment may help students not only during non-sequential information searches and browsing, but also during knowledge construction and integration [3-6]. Thus, hypermedia courseware has the potential to offer distributed, interactive, student-centred learning. Students will have greater flexibility and control to study when and where they desire. The courseware will be interactive, adaptive and responsive to the pedagogical needs of the students. Classroom instruction can be transformed from primarily lecturer-based to predominantly student-centred. It is a wellestablished fact that students tend to retain more

by interactive doing and reading. Coupled with hypermedia, the methodology of student learning is set to undergo fundamental transformations.

LABORATORY EXPERIENCE A part of our newly organised Senior Year (i.e. third year) laboratory course is conducted with the help of web-based courseware. The new format has been stimulated by our changing student profiles with a greater demand for enrolment in combined degrees (with inevitable timetable clashes) and due to our need to optimise teaching costs. Additional motives include being able to provide updated facilities, to place greater emphasis on student participation, to improve the integration between theory and practice, to achieve flexibility in learning modes and to enhance student motivation. The laboratory projects are run in several phases. As operating actual pilot-scale experiments is both timeconsuming and expensive, students are required to conduct experiments only after learning the relevant theory, performing simulation work and planning experiments in detail. Discussions with their partners and with a staff mentor provide additional information. To further consolidate the knowledge gained, students are required to further interact with computer simulations, run test cases and undertake data analysis.

Pilot-Plants Figure 1 shows a schematic of the various experimental components of this scheme. Essentially the following industrially relevant process pilot-plants located in our Department were integrated for hypermedia navigation:

• • • •

A heat exchanger rig; A distillation column; A twin-reactor system; A cooling tower.

The units are fully instrumented and interfaced to advanced monitoring and control systems. The construction of these virtual plants was supported by a grant from the NeTTL (New Technologies in Teaching and Learning) group in the University of Sydney. The arrangement enables modular inclusion of additional units and flexible upgrading. The interfacing layer from the control system of both the actual pilot-plants and the virtual process plant simulations was developed in Citect (a commercial software package widely used for process monitoring, developed by Ci Technologies). Preliminary interface designs have been developed in G2 (a widely used commercial expert system

Web-Based Courseware...

Points of Access Chemical Engineering Pilot Plants

Twin-reactor System

Spiral Heat Exchanger

Undergraduate Computing Laboratories

Course Material 1

Research and Teaching Laboratories

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Course Material 2

Distillation Column Advanced Monitoring and Control System (Supervisory and DCS)

Simulated TwinReactor System

Course Material 3

Lecture Theatres

Cooling Tower

Interactive Interface

Course Material 4

Simulation Design and Virtual Control System

Simulated Distillation Column

"Virtual" Chemical Enigneering Plants

Remote Training Facilities

Simulated Spiral Heat Exchanger

Simulated Cooling Tower

Figure 1: Web connections to pilot-plants (both physical and virtual). and real-time process-monitoring package by Gensym). One aspect of these designs is that the students see identical monitoring and control interfaces, regardless of whether the data source is the physical pilot-plant or the virtual pilot-plant. This interactive interface allows ease of transition from the courseware material to implementations on the actual pilot-plants. Among notable features of our pilot-plants are that they are:

• scaled-down versions of real production units; • instrumented for process measurements i n t e r faced for computer process control. The main features of our virtual-plants are that they provide:

• computer simulations accessible on the web; • nterface designs developed in G2 (Gensym); • instrumentation interface via Citect (Ci Technologies); • identical monitoring and control interfaces as the pilot plants themselves. After the preparatory stages, students are allowed a single block of time (typically six hours) to complete their actual experiments. If the experiments are not successful, the students have a choice of going back to virtual experimentation to analyse what might have gone wrong. When a student fails to elicit meaningful

data from actual experiments, he/she may end up simply frustrated. On the other hand, the experience with preparation, planning, virtual experiments, real experiments and mentoring provide a range of learning opportunities for students with a range of styles of learning. This allows consolidation of total effort for valuable learning outcomes. Students are also encouraged to find limitations in the pilot-plant and the software used, and to suggest ways of improving upon them. Thus, instead of blind trials and pre-occupation with obtaining meaningful data from a laboratory facility, the focus is on analysis and thinking, rather than the purely mechanistic aspects of experimentation. In this manner, the students gain not only practical skills but also insight and analytical skills, which are the higher level goals to be achieved in an education system.

PROBLEMS AND CONSTRAINTS The infrastructure requirements of hypermedia courseware are extensive. Significant initial time must be invested in preparing the courseware which may include computer programs, hypertexts, graphics, animation and audio components where appropriate, with an adaptive tutoring and presentation system. Significant hardware investment is necessary in addition to the network requirements. To support

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student-centred learning, students must have access to the hypermedia at distributed convenient locations. These points must have multimedia computers capable of reliably providing access to the course material. There is an additional significant cost associated with maintaining the network and hardware infrastructure necessary to support hypermedia. It must be noted that students may become disoriented in the structures of some hypermedia courseware because of multiple navigational choices. After navigating for a while, orienting themselves in hyperspace and aiming for goal nodes may become difficult. Cognitive overhead usually occurs when a student needs to remember the relationships implied by the links between nodes in addition to understanding the content of the nodes. Thus, introducing hypermedia material brings up courseware navigation issues, as well as courseware construction issues. Our strategy in circumventing some of these problems has been as follows:

• design courseware to use the computer facilities currently available within campus;

• design hypermedia structures with help facilities

AN EXAMPLE: HEAT EXCHANGER RIG The primary aim of this experiment is to evaluate the performance of shell-and-tube heat exchangers that are widely used in industry in heating and cooling applications. The main tasks for the experimenter include the evaluation of control performance and the comparison of experimental results for heat transfer and pressure drop with theory and with published correlations. The actual pilot-scale heat exchanger rig installed in the laboratory is shown in Figure 2. The rig comprises two heat exchangers of the shell-and-tube type, a fluid holding tank, pumps for fluid circulation, piping, valves and fittings. In this rig, a fluid stream is heated by steam supplied by a boiler in one heat exchanger. Subsequently the heated fluid is cooled in the other heat exchanger using cooling water supplied by the cooling tower. The process fluid stream is then returned to the holding tank and is recirculated in a closed-loop. Specifications for the the actual heat exchanger hardware are: Tubes:

to assist students in their learning;

• enable goal-oriented navigation by students; • allow dynamic adjustment of information presented; • enable ease of updating the information provided. Our recent experiences with web-based supplementation to laboratory work for a heat exchanger system is given below.

Shell:

Tubes: 96; Pitch: 16mm square Material: copper Outside tube diameter: 9.5mm Tube length 1780mm Tube sheet thickness: 25mm Material: Cusilman bronze Inside diameter: 195mm Baffles: 34, 51mm centres Baffle type: 38mm cut-off Nozzle: 25mm BSP.

Figure 2: Views of the actual heat exchanger rig.

Web-Based Courseware... The rig is monitored using a range of process instrumentation (pressure gauges, thermocouples and flow meters). The rig allows the specification of setpoints for control of process variables. All measurements taken on the exchanger are fed into a Honeywell TDC 3000 Distributed Control System. The data are displayed on the TDC 3000 console terminal located in the control room. Typical measurements comprise:

• inlet and outlet temperatures of the fluid streams; • pressure drops across the heat exchangers; • hot and cold water flow rates. Typical calculations comprise:

• Estimation of the maximum heat loss from the rig; • Rate of heat loss from the hot stream (Qh) and heat gain by the cold stream (Qc);

• Log-mean temperature difference (LMTD) estimation and the heat exchanger performance factor (Ft) based on the measured inlet and outlet temperatures. • Estimation of the film and overall heat transfer coefficients using Kern’s and Bell’s methods [7]. The virtual pilot-plant comprises computer simulations of the actual process plant. These simulations are based on mathematical models we

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developed to describe the process [7][8]. The virtual heat exchanger specifications are:

• • • • •

All hardware information Process flow diagram Mathematical models Computer programs Interactive user interfaces

On familiarising themselves with heat transfer theory, the students use the virtual heat exchanger pilot-plant to consolidate the theory learnt and to train themselves in the operation of the rig. The virtual plant also allows manipulation of process stream flow rates and temperatures to study their effect on the unit performance prior to running actual experiments. Figure 3 shows the simulated virtual pilot-plant in process flow diagram (PFD) format, which is displayed on the computer screen. This allows students to visualise the actual configuration of the experimental rig with its measurement and control schemes. The desired set-points can be specified on the virtual plant followed by conducting virtual experiments and monitoring of the process. The students are required to execute simulation of real-time dynamic responses to set-point changes in input process variables. The corresponding changes

Figure 3: A view of the virtual plant heat exchanger rig.

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in manipulated and controlled variables are then monitored in the form of graphical traces (as shown in Figure 4), and tables which may be further analysed in order to deduce the necessary system behaviour parameters and heat exchanger performance indicators. Thus a set of results are obtained for virtual experiments which are later compared with results from actual experiments.

OUTCOMES This preparatory phase provides students with confidence and familiarity in relation to rig operation and guides them in understanding the underlying heat transfer theory. The students then plan for experimental work based on the knowledge gained. Following the actual experiments, students return to the simulation to check the agreement (or disagreement) between experiments and theory, to analyse their results and to explain any discrepancies. In our experience, the training and learning phases with our hypermedia courseware allow for:

• • • • • • •

practice and training before experimenting with the physical plant; opportunities for what-if analyses; deeper exploration without pilot-plant experimental time-limit pressures; self-directed learning; focus on analysis and thinking; distributed use via remote computers; availability at times convenient to students.

CONCLUSIONS Computer simulations of pilot-scale process plants in the Department of Chemical Engineering, University of Sydney, have been packaged to provide a suite of virtual plants suitable for web-based navigation. This has been developed to allow a seamless transition between the physical and virtual pilot-plants. It is intended that these simulations be used for student training before operation of the physical plants, thus improving the quality of laboratory work and making optimum use of the limited time and resource available. Further, this arrangement helps reduce equipment breakdown (due to improper operation) and reduces the associated maintenance costs. Students navigating in hypermedia enjoy convenience and flexibility. However, the problems of disorientation and cognitive overhead should be carefully addressed. An important feature of hypermedia environments is that they are dynamically updated, in the sense that the courseware and the links are adjusted regularly as new material becomes available.

Figure 4: Dynamic responses to virtual experiments. With greater emphasis on student involvement, enhancement of student motivation, provision of selfdirected learning opportunity and focus on analysis and thinking, this approach has the potential for providing deep-learning that is of value to both industry, academia and society.

REFERENCES 1. McKeachie, W., Teaching Tips: A Guide for the Beginning College Teacher. Lexington, MA: Heath (1986). 2. Rigden, J.S., Holcomb, D.F. and Di Stefano, R., The introductory physics project. Physics Today, 46, 32-37 (1993). 3. Swafford, M.L., Graham, C., Brown, D.J. and Trick, T.N., Mallard: asynchronous learning in two engineering courses. Proc. of the FIE Annual Conference, IEEE (1996). 4. Oakley, B., Helping faculty develop new asynchronous learning environments. Proc. of the FIE Annual Conference, IEEE (1996). 5. Carver, C.A. and Biehler, M.A., Incorporating multimedia and hypertext documents in an under-graduate curriculum. Proc. of Frontiers in Education Conf., San Jose, USA, 87-92 (1994). 6. Carver, C.A. and Gregory, J.E., Networked hyper-media in undergraduate curriculum. Proc. of ED-MEDIA, Conf. on Educational Multi media and Hypermedia, Graz, Austria, 139144 (1995). 7. Hewitt, G.F., Shires, G.L. and Bott, R., Process Heat Transfer. Boca Raton: CRC Press: Begell House (1994).

Web-Based Courseware... 8. Stephanopoulos, G., Chemical Process Control: An Introduction to Theory and Practice. Englewood Cliffs, NJ: Prentice-Hall (1984).

BIOGRAPHIES Vincent Gomes received his MEng. and PhD degrees from McGill University, Montreal, and his BTech degree in Chemical Engineering from IIT. He is currently a Senior Lecturer at the Department of Chemical Engineering and Program Manager of the Australian Key Centre for Polymer Colloids at the University of Sydney. He has industrial experience working in the petrochemical, and pulp and paper industries. His research interests include polymer engineering, sorption and reaction processes and pollution prevention. He has a strong interest in University teaching issues. Bruce Choy is a lecturer in the Department of Chemical Engineering at the University of Sydney. His currentresearch interests are in process systems engineering and environmental fate and transport. Bruce is a member of the Engineering Faculty’s Teaching and Learning committee and has a keen interest in the use of technology in university teaching. Geoff Barton was born in London, England, in 1949. He received both BE and PhD degrees in Chemical

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Engineering from the University of Sydney, Australia. He has worked for both the UKAEA (Harwell) and the CSIRO (Melbourne), as well as being involved in a wide range of collaborative and consulting work with a diverse range of industry sectors. Since 1997, he has been Associate Dean for Undergraduate Studies in the Faculty of Engineering, and as such has been heavily involved with the on-going restructuring of the Engineering program. He has a strong interest in making teaching and learning more rewarding experiences for all concerned. Jose Romagnoli was born in Bahia Blanca, Argentina, in 1948. He received the Bachelor degree and the PhD degree in chemical engineering from the Universidad Nacional del Sur, Argentina, in 1973 and the University of Minnesota, Minneapolis, in 1980, respectively. Since 1980 he has been a Researcher at CONICET (National Council for Research in Science and technology), Argentina and a full professor, Department of Chemical Engineering, Universidad del Sur. He was a Visiting Associate Professor at the University of Minnesota and at the University of California, Davis during the academic years 1987-88 and 1988-89, respectively. He now holds the Joint Orica-University of Sydney Chair of Process Systems Engineering at the University of Sydney. His current research interests include process dynamics and robust linear and nonlinear control.

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nd

Proceedings of the 2 Asia-Pacific Forum on Engineering and Technology Education edited by Zenon J. Pudlowski Participants from over 20 countries came together at the University of Sydney, Australia, nd between 4 and 7 July 1999, for the 2 Asia-Pacific Forum on Engineering and Technology Education. Issues debated included those of globalisation, specifically the impact of globalisation on engineering and technology education; the impact of, and responses to, rapidly changing technology and production processes; and the status, quality and importance of engineering and technology education, all of the above in the context of recent economic difficulties in the Asia-Pacific region. This volume of proceedings includes 78 papers categorised in distinct sections, each section headed by a lead paper thought to be most representative of the area under discussion. Topics covered include the following: · · · · · · · · · · · · ·

Promoting engineering & technology in schools Vocational education and training The impact of new technology on the effective training of engineers and technologists Multimedia in engineering and technology education Current issues, trends and innovations in engineering and technology education Management of engineering & technology education and engineering management education Social and philosophical aspects of technology and its impact on modern societies Distance education, open learning and related issues Academia/industry collaboration programs Continuing education needs of engineers and technologists Engineering & technology education in other countries Effective methods in training engineers & technologists Engineering & technology education programs

The papers have been reviewed by independent international peer referees, ensuring their high quality and the value of the Proceedings for some time to come. To purchase a copy of the Proceedings, a cheque for $A100 (+ $A10 for postage within Australia, and $A20 for overseas postage) should be made payable to Monash University UICEE, and sent to: Administrative Officer, UICEE, Faculty of Engineering, Monash University, Clayton, Victoria 3800, Australia. Tel: +61 3 990-54977 Fax: +61 3 990-51547