Proceedings of the 3rd International Conference of Teaching and Learning (ICTL 2011)
INTI International University, Malaysia
MULTIPHASE FLOW RECONSTRUCTION BY PORTABLE
CAPACITANCE TOMOGRAPHY: PBL APPLICATION
IN LABORATORY CLASSROOM FOR
ENGINEERING EDUCATION
Elmy Johana Mohamad1, Mimi Mohaffyza Mohamad2,
Ruzairi Abdul Rahim3 and Omar.M Faizan4
1,2,4
Universiti Tun Hussien Onn Malaysia
( elmy@uthm.edu.my, 2mimi@uthm.edu.my, 4mdfaizan@uthm.edu.my)
3
Universiti Technology Malaysia (ruzairi@fke.utm)
1
ABSTRACT
Laboratory has traditionally been an important part engineering education and it plays an integral part in
connecting the learned knowledge to promote problem solving proficiency. There is currently a worldwide
interest in improving the quality of engineering education and in some instances governments have intervened to
assess the quality of teaching and learning across the spectrum of subjects. This research described how Problem
Based Learning (PBL) can be applied in engineering education in laboratory classroom. A portable capacitance
tomography system (PCTS) for real-time imaging of multiphase flows is developed and presented in this work.
The Electrical Capacitance Tomography (ECT) is a new approach technology on multiphase flow meter.
Integrating PBL with laboratory work and engineering education pedagogy including assessment and evaluation
strategies is of an increased emphasis for educators. This paper describes the application of PBL in an
undergraduate preliminary engineering education course with an emphasis on student learning.
KEYWORDS
PBL, Engineering education, Laboratory classroom, Pedagogy, Student learning, ECT, PCTS
INTRODUCTION
There is currently a worldwide interest in improving the quality of engineering education and
in some instances, governments have intervened to assess the quality of teaching and learning
across the spectrum of subjects [1].Globally, attention is increasingly being paid to the
quality of teaching and learning in higher education. Higher education teaching is becoming
more professionalized with some countries setting up accreditation bodies to ensure
competencies [2]. Problem-based learning (PBL) is a teaching strategy that leads students to
learn to learn and encourages students to develop critical thinking and problem-solving skills
that they can carry for life. [3] PBL is the search for solutions to life’s messy problems. PBL
is an emerging teaching approach which has taken its prominence in tertiary education in
recent years [14]. The quality of student learning is directly not exclusively related to the
quality of teaching but the first and most promising way to improve learning is to improve
teaching writes [4].
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Proceedings of the 3rd International Conference of Teaching and Learning (ICTL 2011)
INTI International University, Malaysia
EXPERIMENTAL INSTRUMENT
The approach of this work is aimed to support the local higher educational institutions'
laboratory to have multipurpose instruments ECT flow-meter used to monitor multiphase
liquid in our local laboratory institutions. The question is how the multiphase liquid material
(water/gas and gas/oil) be reliably monitored without a separate flow measurement
instrument in our educational laboratory today? The current existing flow measuring
instrument at our local laboratory institutions is non-multiphase flow. It is bulky and not
portable and not user friendly. The system can only measure the component material (gas or
liquid) separately and need to fill into some sort of tank or vessel to measure the volume or
weight. The flow-meter that was used not able to visualize the feature of flow regime and and
it is difficult to see what is within them. Thus introducing the electrical capacitance
tomography (ECT) flow-meter, the multipurpose instruments are able to monitor the
multiphase liquid. It is also portable and easy to install. This multiphase flow-meter is the
new features for experimental instruments educational laboratory for teaching and learning in
higher education institutions especially for Electrical or Chemical Engineering course. The
compilation of the new ECT Flow-meter makes the most complete combination for flow
instrument compare the existing system that is currently used in local higher institution
Laboratory. This product is a new invention which is able to produce the image of the crosssectional slices of the investigated pipe in real time manner and visualize the multiphase
liquid inside closed pipe (water, oil and gas). Thus it will reduce the cost of purchasing,
operating and maintaining compared to existing instrument which needs to be purchased
individually, and may cost to the operation and maintenance.
The instrument gives the opportunity for the instructor or lecturer to apply the PBL module
for teaching and learning and students to learn and gain knowledge throughout the system
part by part as shown below:
(a) Microcontroller Programming
 Synchronizing the operation of circuit and Collecting data using
(b) Computer Programming
 Development of a real time image reconstruction using a computer – using Visual
Basic
(c) Sensor Modelling
 Development of on-board sensing plate to combine a sensor and its sensing
electronics together on a single module.
(d) Signal Conditioning Circuit
 Development of the signal switching circuit and signal conditioning circuit
(e) Signal processing
 Interfacing the sensors with computer, which are digitization of sensor readings and
the gateway of data transferring to PC
Electrical capacitance tomography (ECT) system is useful for obtaining information on the
spatial distribution of a mixture of dielectric materials inside a vessel [5]. This research is
aimed to obtain real-time monitoring on the composition for the liquid mixture in conveying
oil pipelines. A sixteen electrodes sensor array was developed and mounted symmetrically on
the outer surface of an insulating vertical pipeline. The new approach of this portable system
is to allow flexibility of the system to be assembled and moved from a pipeline to another.
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Proceedings of the 3rd International Conference of Teaching and Learning (ICTL 2011)
INTI International University, Malaysia
The system is designed to be able to assemble in different diameter sizes of pipeline and
flexibility of numbers of electrode's sensor usage depending to different size of pipeline
without the need to redesign the electrode's sensor. The sensor could be worked
independently. Universal Serial Bus technology (USB) is used for the data transferring in
order to provide the high data transfer rates to PC. A microcontroller works as the
centralization control unit to support full-speed USB data transfer rate. The information
obtained in the PC will be reconstructed using the linear back projection (LBP) algorithm. By
using these techniques, it can be used to measure the flow rate and the concentration of
material distribution through pipelines. These techniques give a better understanding of the
flow through the plant.
Figure 1: The multipurpose instruments in
laboratory which able to monitor multiphase liquid
Figure 2: ECT Flow meter Experimental Instrument
Multipurpose experimental instruments are useful for teaching and learning in higher
education level laboratory in related course, for example:
 Instrumentation
 Signal processing
 Microcontroller
 Electronics
 Computer Programming
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Proceedings of the 3rd International Conference of Teaching and Learning (ICTL 2011)
INTI International University, Malaysia
PROBLEM BASED LEARNING IN ENGINEERING EDUCATION
PBL is an emerging teaching approach which has taken its prominence in tertiary education
in recent years [6]. [7] PBL crosses a broad spectrum of instructional patterns, from total
teacher control to more emphasis on self-directed student inquiry. In PBL the teacher
instructor becomes the facilitator to provide resources and guidance to students as they
develop content knowledge and problem-solving skills. The first is the acquisition of factual
knowledge. The second is the mastery of general principles or concepts that can be
transferred to solve similar problems, and third, the acquisition of prior examples that can be
used in future problem-solving situations of a similar nature. Pedagogical element played an
important role to combine two elements in learning in PBL; instructive and constructive [8].
Instructive aligns with the classical instructional methods include lectures, demonstrations,
writing term papers, preparing lab reports, and taking written examinations while
constructivist teachers and administrators will collaborate with peers, researchers and their
own students to make sense of the teaching/learning process in their own contexts.
In PBL, the instructors become the facilitator to provide resources and guidance to students
as they develop content knowledge and problem-solving skills. [10] has stated that there are
three roles for PBL. The first is the acquisition of factual knowledge. The second is the
mastery of general principles or concepts that can be transferred to solve similar problems,
and third, the acquisition of prior examples that can be used in future problem-solving
situations of a similar nature. Finally, PBL in engineering education for laboratory classroom
comprises four components as illustrated in Figure 1.
PBL
Reflective
practice
Constructivist
learning
Collaborative &
Cooperative learning
Self learning
Figure 3: PBL in Laboratory Classroom
Reflection is defined as a specific interaction between objects and phenomena that constitutes
reflected objects within a dedicated medium of reflection. The most complicated type of
reflection is the psychological reflection [11]. [12] writes the plethora of material associated
with reflective practice has resulted in a diversity of labels, terms such as problem-based
learning, situation learning, experiential learning, action learning, critical reflection, critical
pedagogy, narrative enquiry, reflection in action, despite the differences in nomenclature
these forms of reflective practice indicate an epistemology of practice, which places technical
problem solving within a broader context of reflective inquiry. Through integrating theory
and practice, [13] indicates how a variation on PBL also referred to as the situation based
learning can be used to help students reflect critically upon issues of practice.
Constructivism is a philosophical view on how we come to understand or know [14]. In
constructivist learning, collaboration is important, as knowledge is socially constructed. [15]
describes that "Constructivist classrooms cannot be created through transmittal forms of staff
development. Rather than receiving "knowledge" from "experts" in training sessions, teachers
and administrators will collaborate with peers, researchers and their own students to make
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Proceedings of the 3rd International Conference of Teaching and Learning (ICTL 2011)
INTI International University, Malaysia
sense of the teaching/learning process in their own contexts. Students engaged in engineering
education, by and large, are interpreting, analysing, discovering, evaluating, acting and
problem solving. Cooperative learning focuses on the product, relating more to foundational
knowledge, and can be seen as the teacher oriented whereas collaborative learning focuses on
the process, sees knowledge as authenticated by the learning community and is learnercentered. According to [16], collaborative learning sharing of authority and acceptance of
responsibility consensus building through cooperation deals with individual group members'
abilities and contributions, in contrast to competition. Cooperative learning is defined by a set
of processes, which help people interact together in order to accomplish a specific goal or
develop an end product which is usually content specific. [17]
Self-directed learning (SDL) is defined in very diverse ways within the adult and workplace
education and vocational training literature. Some definitions associate self-directed learning
with tightly circumscribed activities, like programmed learning. Others are much more openended, emphasizing autonomous or independent learning on virtually any topic by almost any
means [18]. Conceptual framework of the early literature on self-direction [19] and [20]
assert orientation of self-directed learning in which the learner plans and initiates the learning
process. "self-directed learning describes a process in which individuals take the initiative,
with or without the help of others, in diagnosing their learning needs, formulating learning
goals, identifying human and material resources for learning, choosing and implementing
appropriate learning strategies, and evaluating learning outcomes." .
Normally, in classroom lecture, PBL will use learning strategies using library resources,
general reference text, participating in class and working with groups. It will take more time
for the lecturer, instructor and students to finish the task. This strategy is improper for
laboratory classroom. In the laboratory, students need to finish the task given in limited time.
Integrating pedagogical method, instructive and constructive, with PBL elements, the PBL
approach can be conducted in the laboratory as a new learning strategy.
APPLICATION OF PBL IN THE LABORATORY
PBL is a teaching strategy that leads students to learn to learn and encourages students to
develop critical thinking and problem-solving skills that they can carry for life. [21] PBL is
the search for solutions to life’s messy problems [22] PBL crosses a broad spectrum of
instructional patterns, from total teacher control to more emphasis on self-directed student
inquiry. Patterns of power and control of decision-making are affected by what [16] calls
“recapturing”. It is a shift from the traditional didactic teaching where the core knowledge
discovery process lies almost entirely in the hands of the learner rather than the teacher.
There are few inquiries why PBL needs in the laboratory classroom. Table 1 described the
inquiry should be answered.
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Proceedings of the 3rd International Conference of Teaching and Learning (ICTL 2011)
INTI International University, Malaysia
Table 1: PBL Inquiry
What do we know about the subject?
What do we want/need to find out about it
How will we go about finding out?
What do we expect to learn? What have we learned?
How we apply what we have learned to other subjects? To our personal lives?
What new questions do we have following our inquiry?
Engineering graduates facing the fast changing work environment, in addition must cope with
continual technological and organizational change in workplace [9]. The practice of real work
situation is practical task in laboratory. The normal approach the instructor prepares the
worksheet of the experiment and the guideline of the learning module and students will work
with the procedure until the class end. In this new approach, it will help the instructor conduct
the class with PBL material prepared. PBL allowed instructor to work in close contact with
students. Table 2 illustrates the procedures how this topic can be taught using the PBL
approach. This is the summary of guideline for instructor to conduct PBL in laboratory.
Table 2: Instructor Guide
FAQ1
ECT Technology
FAQ2
Applications
FAQ3
Capacitance measurement
FAQ4
Capacitance sensors for ect
FAQ5
Calibration and normalisation
FAQ6
Concentration models
FAQ7
FAQ8
Ect image format
Obtaining a permittivity image from the capacitance
measurements (Basic Image Reconstruction)
Advanced image reconstruction methods
FAQ9
Instructors will provide students a lab sheet for each task which they had to complete.
Students need not come to the lab on fixed schedule; they can do their experiments according
to their own schedule. That is the difference between the traditional methods of laboratory
current practice, and PBL is that students can complete the task and it will save the official
time in lab. Table 3 illustrates the difference between traditional methods and PBL
environment in engineering education.
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Proceedings of the 3rd International Conference of Teaching and Learning (ICTL 2011)
INTI International University, Malaysia
Table 3: Comparison of Traditional and PBL Environment
Traditional Methods
PBL environment
Instructor assumes role of expert or formal
authority.
Faculty member is a facilitator, guide, co-learner,
mentor, coach.
Faculty members tend to work independently
Faculty members work in teams together and with others
from outside the discipline.
Faculty structure is supportive and flexible.
Faculty members are involved in changing the
instructional culture though the development of
assessment tools that is congruent with PBL principles,
including peer review.
Faculty members transmit information to learners.
Students take responsibility for learning, creating
partnerships with Teachers
Faculty members organize course content into
lectures based on discipline content.
Faculty members develop learning scenarios designed
to empower students to seek information and to
integrate what they find.
Student motivation is enhanced through providing
scenarios from real life, and thereby activating prior
knowledge.
Students are viewed as passive recipients of
information.
.
Faculty members support students, encouraging
initiative, guiding learning to enable students to transfer
knowledge
Students work mostly independently and often in
isolation.
Students interact with faculty and peers, thus facilitating
the provision of immediate feedback and leading to
remediation and improvement.
Students absorb, transcribe, memorize, and repeat
information to accomplish content-specific tasks
such as tests, exams, and quiz.
Faculty members design course materials based on
case scenarios, thus creating flexible learning
environments for students.
Learning is individualistic and competitive.
Students experience learning in a collaborative and
supportive environment.
Students look for the “right answer” in order
tosucceed in an exam-driven context.
Faculty members discourage one “right answer”,
assisting students to frame questions, formulate learning
issues, and explore alternatives.
Performance is measured on content-specific
tasks.
Students identify, analyze, and resolve learning issues
using knowledge from previous experiences and
learning, not relying solely on recall.
Grading is summative and the instructor is the only
evaluator.
Students evaluate their own contributions as well as
those of other group members.
Lectures are based on one-way communication
with information being conveyed to a student
group.
Students work in groups of varying sizes to approach the
required learning task.
Students acquire and apply knowledge in a variety of
contexts.
Students discover resources with faculty guiding them to
the best information.
Students seek useful and relevant knowledge to be able
to apply into the future
(Abdallah, 2004, Baptiste, 2003)
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Proceedings of the 3rd International Conference of Teaching and Learning (ICTL 2011)
INTI International University, Malaysia
CONCLUSION
The fabricating of the sensor's electrodes, designing the signal conditioning circuit, switching
circuit and function generator circuit had been described. In short, a portable non-invasive
sensor system is designed and fabricated, because there is no mechanical interaction between
the fluid in the measurement plane and the electrodes. The system is designed so that it does
not use cables to connect the electrodes and the signal conditioning circuit. This eliminates
the cable noise. Other than that, stray immune capacitance measuring circuit is implemented
so that the circuit measures only the standing capacitance between the electrodes without
affected by stray capacitance in the circuit. A new concept that every sensing module has its
own microcontroller control unit has been applied. Thus, the sensing module is used can be
selected. The handling gripper can be designed based on a diameter of the pipeline will be
used.
Using PBL in engineering education instruction, especially in the laboratory classroom is
new approach and new features for experimental instrument's educational laboratory for
teaching and learning in higher-education institutions, especially for Electrical or Chemical
Engineering course. The product is the new features for experimental instrument's
educational laboratory for teaching and learning in higher-education institutions, especially
for Electrical or Chemical Engineering course. There is currently worldwide interest in
improving the quality of engineering education and in some instances, governments have
intervened to assess the quality of teaching and learning across the spectrum of subjects.
Globally, attention is increasingly being paid to the quality of teaching and learning in higher
education. The pedagogical environment in much engineering education still remains
predominantly instructive in that, regardless of the discipline, where as in a decentralized era,
an age of which knowledge is available to anyone, anywhere, at anytime professional life
merges to work and learning. Classical instructional methods view students as relatively
passive recipients. Professors teach and students learn. Engineering education through PBL
provides intellectual maturity by allowing students to become independent learners, not only
acquiring knowledge about what they know but also making them aware what they do not
know hence keeping their expectations real and protecting them from what they do not know.
REFERENCES
[1] Heywood J, (1995), “Toward the Improvement of Teaching Quality in Engineering
Education”, Proceedings of the ASEE/IEEE FIE Conference, Proceedings Editor, Dan
Budny, Robert Herrick
[2] Devlin, M. (2007), “The scholarship of teaching in Australian higher education: A
national imperative”, Keynote address at the Vice-Chancellors Colloquium, The
University of the Sunshine Coast, Queensland Australia, May 30, 2007.
[3] Fogarty R., (1998), “Problem Based Learning, a collection of articles”, Hawker
Brownlow Australia.
[4] Angelo, T A., Cross, K. P. (1993), “Classroom assessment techniques: A handbook for
college teachers”, San Francisco: Jossey Bass Higher and Adult Education Series ,427
pp.1
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Proceedings of the 3rd International Conference of Teaching and Learning (ICTL 2011)
INTI International University, Malaysia
[5] Yang,W.Q., Spink,D.M., Gamio,J.C. and Beck,M.S. , “Sensitivity Distributions of
Capacitance Tomography Sensors with Parallel Field Excitation.” Meas. Sci. Technol.
Vol 8: 562-569, 1997.
[6] Yeo, R. (2005), “Problem-based learning: a suitable approach in tertiary education?”, in
Tan, K.,Mok, J., Lee, M. and Ravindran, R. (Eds), “Problem-based Learning: New
Directions and Approaches”, Teinasek Centre for Problem Based Learning, Singapore,
pp. 93-113.
[7] Barell J (1998), “Problem Based Learning, an inquiry approach”, Hawker Brownlow
Education, Australia
[8] Reeves T C., Laffey J M., (1999), “Design, Assessment, and Evaluation of a Problembased Learning Environment in Undergraduate Engineering”, Higher Education
Research & Development, Vol. 18, No. 2, pp.219
[9] Abdullah M.Hasna (2004), “Problem Based Learning in Engineering Design”, Abu
Dhabi Men’s College.
[10] ConleyM, Livingstone A, Meharg S., (2006), “Collaborative Problem-based Learning in
a Peacekeeping Environment: The Role of the Pearson Peacekeeping Centre in
International Peacekeeping Training”, Presented at the 6th International Conference on
Knowledge, Culture and Change in Organisations, Prato, Italy, July 10-14.
[11] Bedny. G Z., Karwowski W, Jeng O J, (2004), “The situational reflection of reality in
activity theory and the concept of situation awareness in cognitive psychology”, Theory
Issues in Ergonomics Science, July–August, vol. 5, no. 4, 275–296
[12] Hard L, Taffe R, (1995),“Problem based learning: the experience for early childhood
students in the bed early childhood at Charles Sturt University”, research and
development in PBL, Edited P little, M Oswald, G Ryan, Sydney, volume 3.
[13] Dockett, S, Tegael, K (1993), “But we was just turtles; situation-based learning in early
childhood teacher training”, Australia journal of early childhood 18, 3, pp. 43-48
[14] Savery, J. R., Duffy, T. M., (1995), “Problem based learning: an instructional model and
its constructivist framework”, Educational Technology, 35 (5), pp.31-38.
[15] Sparks, D, Hirsh, S. (2000), “A new vision for staff development, Activating and
Engaging Habits of Mind”, Edited by Costa A. L. and Bena Kallick by Association for
Supervision and Curriculum Development.
[16] Panitz, T (1996), A Definition of Collaborative vs Cooperative Learning, De Liberations.
[17] Whatley J, Bell F, (2003), “Discussion Across Borders: Benefits for Collaborative
Learning”, Educational Media International, 40:1, pp.139-152.
[18] Gerber R, Lankshear C, Larsson S , Svensson L, (1995), “Self-directed learning in a
work context, Education and Training”, Volume 37 · Number 8, pp. 26–32
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INTI International University, Malaysia
[19] Knowles, M. S. (1975), “Self-directed learning: A guide for learners and teachers”,
Prentice Hall, Englewood Cliffs, New Jersey.
[20] Zimmerman, B.J. (1990), “Self-regulated learning and academic achievement: an
overview”, Educational Psychologist, 25(1), pp. 3-17.
[21] Fogarty R., (1998), “Problem Based Learning, a collection of articles”, Hawker
Brownlow Australia.
[22] Barell J (1998), “Problem Based Learning, an inquiry approach”, Hawker Brownlow
Education, Australia
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