Thermodynamics Course Research Articles

On illustrating Carnot’s general proposition by means of reversible Stirling engines

Carnot’s general proposition, also referred to as one of Carnot’s principles, states that the work producing potential of heat—harvested by reversible heat engines—is independent of the working fluid and of engine internal details, being only a function of the temperatures of the reservoirs with which the engine exchanges heat. This concept, usually presented in introductory thermodynamics courses to ME students in the context of the second law of thermodynamics before entropy is introduced, is customarily proven by contradiction, i.e., by a violation of the second law, using second law concepts and abstractions such as ‘thermal reservoirs’ and ‘reversible engines’, without concrete examples, even though Carnot’s proposition mentions concrete things such as working fluids and engine internal details. This work proposes to document the usage of different reversible Stirling engine models that take the engine arrangement down to engine constructive parameters, crankshaft angles, and the like, as well as fluid properties into account towards illustrating the validity of Carnot’s general proposition without using entropy.

The Effect of Blended Learning Problem-Based Instruction Model on Students’ Critical Thinking Ability in Thermodynamic Course

The course of thermodynamics is one of the subjects whose material content consists of real theory and practice and the use of formulas. Therefore, in the application of this course is a need to apply a learning model that is able to help students find and solve problems and be able to explain their findings in achieving the basic competencies of thermodynamics course. The learning model is a Problem Based Instruction learning model based on Blended Learning. This study aims to improve the critical thinking skills of pre-service physics teacher as a result of using Problem Based Instruction based on Blended Learning in the course of thermodynamics. Retrieval of data in this study was conducted on third semester students of physics education study programs that take Thermodynamics course. This research was conducted in September-October 2019. The research method used is quasi-experimental. Quasi-experiments are research carried out on a single group of students. Data analysis in this study used a one-party t-test. The results showed that (1) the application of the Problem Based Instruction learning model based on Blended Learning can improve students’ critical thinking skills, (2) Students’ responses to the application of the Problem Based Instruction learning model based on Blended Learning get a very happy category of ongoing learning.

Active Learning Approach for an Intuitive Understanding of the Boltzmann Distribution by Basic Computer Simulations

The Boltzmann distribution lies at the heart of essentially all of statistical thermodynamics. In most textbooks, this distribution is introduced either ad hoc or it is mathematically derived by constrained entropy optimization using the method of Lagrange multipliers. Unfortunately, when students enroll in a statistical thermodynamics course, many are not familiar with this method from their prerequisite calculus courses. The recent availability of powerful computational devices for essentially all students provides an alternative way to explore the origin of qualitative and quantitative aspects of the Boltzmann distribution. Here we demonstrate a straightforward simulation approach to obtain an intuitive understanding of this distribution. We also make available concise and easily understandable computer programs in MATLAB and Python, providing an opportunity for an active learning experience of this fundamental law.

Control over Kinetic and Thermodynamically Driven Pathways of Crystallization to Yield Cofacial and Slipped-Stack Dimers in Single Crystals.

Control over the molecular packing in the solid state is of utmost importance in regulating the bulk optical properties of organic semiconductors. The electronic coupling between the molecules makes it possible to improve the properties of the bulk materials. This work reports an example of control over the selective formation of polymorphic single crystals of donor-acceptor-type small-molecule compound 25TR by 1) kinetic or 2) thermodynamic course of crystallisation to yield slipped stack (S) and cofacial (C) dimers in the single crystals. The distinct optical characteristics of the C-dimer and S-dimer are summarised. Both forms show significant excitonic interactions in the solid state, and the S-dimeric form has strong yellowish orange fluorescence, whereas the C-dimeric form is non-fluorescent in the crystalline state. DFT calculations and differential scanning calorimetric experiments revealed that the C-dimer polymorph is the thermodynamically stable form with a free energy offset of 0.43 eV in comparison with the S-dimer. Interestingly, the thermodynamically driven non-fluorescent single crystal was found to be convertible to its fluorescent form irreversibly by thermal trigger. The charge-carrier-transport characteristics of these two polymorphs were computed by using the Marcus-Hush formalism. The computations of the charge-carrier-transport behaviour revealed that the S-dimer (25TR(R) ) is ambipolar, whereas the C-dimer (25TR(Y) ) is predominantly n-type.

Redesigning a commercial combined cycle in an undergraduate thermodynamics course: Connecting theory to practical cycle design

Due to various reasons, the concepts of thermodynamics are not easy to grasp for undergraduate students. One of the major reasons is that the students are mostly unfamiliar with the thermodynamics devices discussed in the courses. Offering courses with experiments is an effective approach to solve this issue. However, it is not practical or possible for universities to own devices that operate at high temperatures and with high pressure fluids. With the cooperation of a nearby electric company, undergraduate students of a thermodynamics course from the Department of Mechanical Engineering measured thermal performances of a commercial combined cycle and its sub-systems at the President University. After learning about the theory of thermal cycles, the students analyzed the thermal performances of actual thermodynamics cycles. Subsequently, they analyzed the thermal efficiency improvements when reheating or regeneration is applied to the simple Rankine cycle in the combined cycle. At the end of the course, the students gave presentations before the electric company’s management and engineering personnel, akin to professional engineers. This course is structured to familiarize undergraduate students with thermodynamics cycles and devices.

An Evaluation of a Pilot Study of the Personal Tutoring Programme in Improving Skills Development at the University of Trinidad and Tobago

Personal tutoring provides professional skills development and support to students as they matriculate through their respective university programmes. Recently, there has been a growing trend of students facing academic difficulties in their first year of undergraduate study at the University of Trinidad and Tobago (UTT) which have impacted on student retention rates. This paper shares the experiences of a pilot study of the Personal Tutoring Programme (PTP) launched in term 2 (January to May) of the 2018 academic year, at the UTT where five hundred and thirty-two (532) students along with forty-eight (48) personal tutors (PTs) engaged in activities that promoted academic and social support. During term 2, PTs met with their assigned tutees at least once per week. The evaluation of the PTP in skills development was based primarily on pass rates of term 2 courses in the Certificate of Applied Engineering (CAE) and Bachelor of Applied Science Common Year I (BASc Common Yr I). These programmes are used as entry requirements to specialized diploma and bachelor level programmes at UTT. Within the BASc Common Yr I, there were marked improvements in the Engineering Thermodynamics course while in the CAE programme, there were marked improvements in the Applied Engineering Mathematics II course with 100% pass rates in two campuses where it was offered. Student feedback was indicative of the positive impact of the PTP which improved students pass rates with engineering courses that traditionally were difficult for them. Overall the PTP contributed to the holistic development of the students.

Understanding entropy through a discussion of exergy

Entropy is an extremely important physical quantity in thermodynamics. However, students studying thermodynamics commonly find it difficult to understand entropy. In most thermodynamics textbooks, there is only a microscopic explanation of the physical meaning of entropy, with a lack of a macroscopic interpretation. This lack is far from sufficient for people who are more concerned about the macroscopic engineering applications of entropy. In this study, we comparatively analyse entropy and exergy to explain the macroscopic physical meaning of entropy based on the concept of exergy. That is, entropy is a measure of the unavailable energy of a system during reversible heat interaction with the environment. Based on this physical interpretation of entropy, we have answered three questions that students may raise when learning about the concept of entropy. In addition to theoretical derivation, we also try to use several examples from daily life to help readers better understand the macroscopic physical meaning of entropy. Finally, through a questionnaire survey, we learned about students’ evaluations and their understanding of an engineering thermodynamics course. We have also learned whether the students prefer entropy or exergy and the reasons for their preference, as well as what aspects regarding the contents and methods the students would prefer the lecturer to improve upon when teaching entropy and exergy. The results of this work can make it easier for students to understand the physical quantity of entropy. Additionally, the results of the questionnaire analysis can be of a certain reference value for the instructions of an engineering thermodynamics course.

Influence of Peer Learning on Students’ Academic Performance (The Case of 2010 E.C for the Course Chemical Thermodynamics at Assosa University)

Peer teaching is a suite of practices in which peers instruct each other in a purpose driven, meaning full interaction. Many universities are facing challenges due to the increasing number of young people attending higher education. Learning is enhanced when it is more like a team effort than a solo race. This study explores how peer learning influences the academic performance of students and it also resolves the negative attitude of teachers and students on the active teaching learning process. It increases student’s social interaction as well as subject matter knowledge. The study was conducted in Assosa university Chemistry department second year students on chemical thermodynamics course. The data was analyzed by using percentage and mean using tables. The tolls of data collection were mainly questionnaires, interview and observations. As peer learning is implemented frequently, the score of the student was increased. Students will learn from one another because in their discussion of the content, cognitive conflicts will arise, inadequate reasoning will be exposed, and higher-quality understanding will emerge. Finally, this finding recommends that in most chemistry courses, a team work is important to increase the academic performance of students and it could be applicable.

A New Educational Thermodynamic Software to Promote Critical Thinking in Youth Engineering Students

This article presents the application of a new educational thermodynamic software called MOLECULARDISORDER, based on graphical user interfaces created in Matlab® to promote critical thinking in youth engineering students, by means of the energy and entropy balance application in different systems. Statistics of the results obtained by the youth students are shown to determine the influence of the software in a regular course in thermodynamics to promote critical thinking. Two case studies were done by the students, where parameters such as temperature of the fluid and metal surfaces, pressure of the system, mass of the fluid and solid, volume, and velocity of the fluid are used to obtain output variables such as enthalpy, entropy, changes in entropy, entropy production, and energy transfer in the chosen system. Four cognitive skills were considered to evaluate the cognitive competencies of interpreting, arguing and proposing, and interacting with the different graphical user interfaces; these cognitive skills (CS) were argumentative claim (CS1), modeling (CS2), interpreting data/information (CS3), and organization (CS4). Student´s T-test was used to compare the degree of difficulty of each criterion. The case studies were evaluated first without using the software and then with the use of the software to determine the significant effect of the software quantitatively. A population of 130 youth students was taken to perform the statistical analysis with a level of significance of 5%. With the help of the software, the students obtained an improvement when performing case study 1 since the p-value obtained was 0.03, indicating that there are significant differences between the results before and after taking the software. The overall averages of the grades for case study 1 had an increase after using the software from 3.74 to 4.04. The overall averages for case study 2 were also higher after taking the software from 3.44 to 3.75.

Pengembangan Instrumen Skala Berpikir Reflektif untuk Mengukur Level Kemampuan Berpikir Reflektif Mahasiswa Calon Guru Fisika

The purpose of this study is to develop a reflective thinking scale instrument to measure the level of reflective thinking ability of prospective physics students. This research method used the DDR (Design Development Research) method with the Tools and Research model. The reflective thinking scale developed is a modification of the Reflective Thinking Kember which consists of 24 items each consisting of 6 definitions. The level of Kember reflective thinking namely; 1) Habitual Actions, 2) Understanding, 3) Reflective, 4) Critical Reflective. The research sample was 138 prospective physics teacher students who had taken thermodynamics courses. Data analysis techniques in this study used the CVR (Content Validity Ratio) for content validation analysis, Product Moment Correlation (construct validity test), Cronbach alpha (Reliability) and Confirmatory Factor Analysis to find a model match. The results show that the instrument is valid, reliable and the Goodness of Fit index. It is therefore denied that the instruments developed are valid, reliable and suitable for measuring the level of reflective thinking ability..

Using Virtual Laboratory to Improve Pre-service Physics Teachers’ Creativity and Problem-Solving Skills on Thermodynamics Concept

Virtual laboratories have been developed in this study as an alternative to the limited equipment of physics experiments. This study aims to examine the effectiveness of virtual lab models to improve creativity and problem-solving skills for prospective physics teachers. The research and development have been divided into 3 phases namely, preliminary study, design development, and model testing. Model testing was performed on two groups of thermodynamic courses using a pre-test post-test control group design. The instruments that have been used are creativity tests and problem-solving tests in the form of essays. Instruments of creativity include verbal and figural aspects. Each data was analyzed using t-test and normalized gain score. The results showed that there was an increase in creativity and problem-solving skills in both groups. The creativity of students of the experimental group was higher than the control group. Student problem-solving skills in the two groups differed significantly. The experimental group has a higher problem-solving ability than the control group. This suggested that the developed virtual lab model proved to improve the creativity and problem-solving skills ability of prospective physics teachers.

Формування самоосвітньої компетентності майбутніх учителів фізики в сучасному освітньому просторі

The development of the competence-based approach is facilitated by the renewal of the educational space through the active implementation of information and communication technologies (ICTs). The professional training of graduates of higher educational institutions, the development of their ability of continuous professional self-improvement, self-development acquire special importance under conditions of dynamic changes occurring in the modern educational space, which should be ensured by their highly developed self-educational competence. The purpose of the study was to implement the project-based technology using ICTs while training future teachers of Physics as a condition for the formation of their self-educational competence within the modern educational space. The experimental research work on the formation of the designated competence was conducted on the platform of the Faculty of Physics and Mathematics (Ushynsky University). The project-based method, using ICT, was used as a method facilitating the formation of the self-educational competence. The developed multimedia complex was applied in the experimental group (EG), when developing the course in molecular physics and thermodynamics, and the following project tasks were performed: to independently find a demonstration material on a certain topic of lectures in the Internet and to demonstrate it on an interactive whiteboard at lecture sessions with the help of multimedia tools. Certain topics for the project work were selected from the course program, the laws and phenomena that can not be realized using the existing demonstration equipment were demonstrated by means of multimedia. The project-based activity substantially increased the EG students’ experience in comparison with the CG (control groups) ones’ due to the deepening, expansion, generalization, consolidation and revision of the educational material as well as its practical application. It was concluded that the implementation of the projects contributes to the formation of secondary school teachers’ self-educational competence which facilitates the development of the future Physics teacher’s ability to independently manage his / her teaching / learning activities, generate ideas, and predict their solution. Keywords: self-education competence, a future teacher of Physics, a project-based activity.

On the Logic of a Prior Based Statistical Mechanics of Polydisperse Systems: The Case of Binary Mixtures.

Most undergraduate students who have followed a thermodynamics course would have been asked to evaluate the volume occupied by one mole of air under standard conditions of pressure and temperature. However, what is this task exactly referring to? If air is to be regarded as a mixture, under what circumstances can this mixture be considered as comprising only one component called “air” in classical statistical mechanics? Furthermore, following the paradigmatic Gibbs’ mixing thought experiment, if one mixes air from a container with air from another container, all other things being equal, should there be a change in entropy? The present paper addresses these questions by developing a prior-based statistical mechanics framework to characterise binary mixtures’ composition realisations and their effect on thermodynamic free energies and entropies. It is found that (a) there exist circumstances for which an ideal binary mixture is thermodynamically equivalent to a single component ideal gas and (b) even when mixing two substances identical in their underlying composition, entropy increase does occur for finite size systems. The nature of the contributions to this increase is then discussed.

Modeling student pathways in a physics bachelor’s degree program

Physics education research has used quantitative modeling techniques to explore learning, affect, and other aspects of physics education. However, these studies have rarely examined the predictive output of the models, instead focusing on the inferences or causal relationships observed in various data sets. This research introduces a modern predictive modeling approach to the PER community using transcript data for students declaring physics majors at Michigan State University (MSU). Using a machine learning model, this analysis demonstrates that students who switch from a physics degree program to an engineering degree program do not take the third semester course in thermodynamics and modern physics, and may take engineering courses while registered as a physics major. Performance in introductory physics and calculus courses, measured by grade as well as a students' declared gender and ethnicity play a much smaller role relative to the other features included the model. These results are used to compare traditional statistical analysis to a more modern modeling approach.

Pre-Class Tutorial (PCT): an instructional strategy to improve pre-service physics teachers’ understanding about P-V-T-S diagrams in thermodynamic course

The Pre-Class Tutorial has been used to successfully improve the deep conceptual understanding and skills to draw and interpret the P-V-T-S diagrams in Thermodynamic Courses. This study was motivated by the previous research findings that students encounter the lack of conceptual understanding to draw and interpret the P-V-T diagrams to describe thermal process and Cycles of Ideal Gas. The analysis of the academic responses at written test shows that some of the students’ conceptual difficulties as follows. First, the biggest difficulty in each P-V, P-T, V-T and T-S diagram is to draw an adiabatic process. Second, the percentage of students who answer the P-V diagram correctly is higher than those who answer the P-T, V-T and T-S diagram. Third, Students prefer understanding thermal processes with their unique characteristic, such as isobaric with constant pressure, isotherm with constant temperature, and isochoric with volume constant. Finally, the lack of understanding the concept of P-V-T-S diagram also affects students’ understanding of various thermal cycles. Based on these findings, we developed the pre-class tutorial that facilitates students either to construct their own concepts to draw and interpret the P-V-T-S diagram. The descriptive method was used to involve 88 third-years students of Physics Education Department. The increased conceptual understanding was identified from the average of students’ achievement score on the instrument test. The findings showed that the use of pre-class tutorial effectively improves students’ conceptual understanding of the draw and interpret the P-V-T-S diagrams to describe thermal process and Cycles.

Management of Learning Technique on Lesson Termodinamika on Department Mechanical Engineering Maritime Inonesia Academy Medan

This research is a development research to develop the design of the right learning technique in the process of learning on the subject of Thermodynamics at the Department of Mechanical Engineering Academy of Indonesia Maritime Medan. The population in this study is all students in the Department of Mechanical Engineering, while the research sample used is the students who are active in taking thermodynamics courses that is as much as 4 classes (100 people) in the second half (even) Academic Year 2017/2018. The method used in this research is the method of Research and Development, while the techniques in data retrieval used is through observation, documentation, interviews, and questionnaires. All the techniques in data collection in this class are used to see the success in the learning process. From the results of research and discussion conducted, learning techniques show that student learning outcomes tend to be high. The average value of student learning outcomes is 87.71. As many as 100% of students can pass the threshold for thermodynamics course that is ≥ 60. There are 2% of students are categorized enough, 6% of students are categorized capable and 92% of students are categorized as very capable. Keywords: Management Learning Technique, Thermodynamics and Learning Outcomes DOI : 10.7176/JEP/10-2-06

ThermoState: A state manager for thermodynamics courses

ThermoState: A state manager for thermodynamics courses

Collaborative Projects with simulation assignments in mechanical engineering thermodynamics courses

In the undergraduate engineering classroom, some level of collaborative learning can be employed to enhance learning. Separately, enhancements in curriculum may include the use of computer technology to provide interactivity. The present study explores a new approach to facilitate learning of an engineering thermodynamics course and seeks to address the question: “What are the impacts of a themed Collaborative Project (CP) with a simulation component, on students and their understanding of thermodynamics?”. This approach was implemented into a sophomore-level thermodynamics course at a private university in the New England area of the United States. Over the duration of the semester, the clean water-themed CP required students to: solve thermodynamics problems linked to this theme; use thermodynamics fundamentals to check the results of clean water-related thermo-fluid simulations conducted using COMSOL Multiphysics® software; and ultimately, use thermodynamics to develop a device to clean water. This approach has the potential benefit not only of demonstrating various uses of thermodynamic analysis but also in preparing career-ready students who are better capable of strategically utilizing engineering software in tandem with their fundamental engineering backgrounds. Results presented include select student work, student perceptions as per surveys, and comparison of changes in average final exam grades as compared to previous courses. While students shared limited enthusiasm in utilizing the software, they expressed that they understood thermodynamics, and they performed better on final exam questions. This study follows up on a previous effort, which revealed various benefits for students who experienced such a CP.

Students’ Task Understanding during Engineering Problem Solving in an Introductory Thermodynamics Course

Understanding problems or tasks is a critical step in any problem-solving activity and the heart of self-regulated learning. When encountering a problem, students draw upon information available in the environment, along with knowledge, concepts, and perceptions derived from prior learning experiences, to interpret the demands of the task. Interpretation of tasks is, therefore, a key determinant of the goals set while learning, strategies selected to achieve those goals, and the criteria used to self-assess and evaluate outcomes. The purpose of this study is to better understand engineering students’ self-regulation in task interpretation processes while engaged in problem solving in an introductory engineering thermodynamics course. Two research questions guided the study: (1) What are the gaps, if any, between the instructor’s and students’ interpretation (explicit and implicit task features) of a problem-solving task?; and (2) How do students’ task interpretation (explicit and implicit) change after engaging in self-evaluation of their problem-solving processes? One hundred twelve (112) second year engineering undergraduates voluntarily participated in the study. Analysis of the data collected revealed a significant difference between the instructor’s and students’ task interpretation of the assigned problems. Furthermore, the analysis showed that students’ had a higher ability to identify the explicit parts of problem tasks than implicit ones. Students were able to grasp 63 to 77 percent and 39 to 49 percent, respectively, of the explicit and implicit information that was presented to them while engaged in problem-solving activities.

COMPARISON OF STUDENT PERFORMANCE WHEN SOLVING A THERMODYNAMIC CYCLE AFTER IMPLEMENTING AN ALTERNATIVE TEACHING METHOD

Abstract –First-year engineering students at the University of Manitoba take a thermodynamics course. The summer instructor taught the course differently from the fall and winter terms. He combined tutorials with lectures to introduce active learning to the course, implemented an online problem library and increased the number of term tests.
 Students in the summer 2016 term were given a similar thermodynamic cycle question in their final exam as students in the winter 2016 term. Student performance inthe cycle question was compared in order to evaluate the effectiveness of the new teaching method.
 Both groups had similar question averages with generally similar question score histograms. However, winter students scored an average of 10% below their GPA, while summer students scored an average of 1% below their GPA. The difference between these averages is statistically significant (97.5% confidence). These results suggest that the new teaching approach leads to better student performance when solving thermodynamic cycles.