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In this article the authors present the transient thermal analysis for a developed thermal linear actuator based on wax paraffin used to drive the cells of a Braille device. A numerical investigation of transient heat transfer phenomenon during paraffin melting and solidification in an encapsulated recipient has been carried out using the ANSYS v.12 software. The researchers offer data on the heat distribution in the proposed model of the actuator as well as on the material properties required for these applications and provide the opportunity to identify new problems specific to thermal actuation, such as the heater properties and the cooling process of the active material in the structure of the Braille cell. (Contains 1 table and 8 figures.)

In order to interpret laboratory experimental data, undergraduate students are used to perform linear regression through linearized versions of nonlinear models. However, the use of linearized models can lead to statistically biased parameter estimates. Even so, it is not an easy task to introduce nonlinear regression and show for the students that this is the best approach. In this work linear and nonlinear regressions are statistically compared in a simple heat transfer laboratory experiment.

A project that involves the numerical simulation of transport phenomena is an excellent method to teach this subject to senior/graduate chemical engineering students. The subject presented here has been used in our senior/graduate course, it concerns the study of natural convection heat transfer between two concentric, horizontal, saturated porous cylinders. The different stages involved to successfully solve this project are the writing of appropriate conservation equations and boundary conditions, the choice of scaling parameters to render the equations dimensionless, the writing of a numerical code to solve these equations and finally the interpretation of the obtained results. Upon completion, the student should have a good working knowledge of natural convection heat transfer, vector analysis, and CFD.

This paper is aimed at describing an experiment involving flame-front movement across the fuel package located within long enclosures and associated heat transfer mechanism. There is a growing interest in incorporating safety education in the chemical engineering curriculum, especially in relation to "facility siting." This experiment is designed for engineering students to appreciate the threat posed to the building structural safety as well as occupant safety due to the fire within the enclosure and at different locations and times.

The second law of thermodynamics has various formulations. There is the "Clausius formulation," which can be stated in a very intuitive way: "No process is possible whose sole result is the transfer of heat from a cooler to a hotter body." There is also the "Kelvin-Plank principle," which states that "no cyclic process exists whose sole result is the absorption of heat from a reservoir and the conversion of all this heat into work" [emphasis added] (since this would require perfect energy conversion efficiency). Both these statements can be presented to physics students in a conceptual manner, and students' "everyday" experiences will support either statement of the second law of thermodynamics. However, when the second law of thermodynamics is expressed using the concept of entropy (?S = 0, for a closed system), most first-year physics students lack any direct experimental experience with this parameter. This paper describes a calculation of the increase in entropy that can be performed while completing three traditional thermodynamics experiments. These simple and quick calculations help students become familiar and comfortable with the concept of entropy. This paper is complementary to prior work where classroom activities were developed to provide insight into the statistical nature of entropy.

In his interesting and informative book "Is That a Fact?," Joe Schwarcz avers that pigs do not sweat and the saying "sweating like a pig" originates in iron smelting. Oblong pieces of hot iron, with a fancied resemblance to a sow with piglets, cool in sand to the dew point of the surrounding air, and hence water condenses on the "pig." But this explanation, which the author had seen on the Internet, lacks a few caveats. It implies that molten iron, solidifying and cooling, anywhere, anytime, accretes liquid water, as if this were a special property of cooling iron. The true fact is that iron's thermophysical properties are not conducive to dew formation, and maximum dewfall is a fraction of a millimeter, it is difficult to envision a big, fat iron pig slathered in sweat after a hard night of cooling, even outside a smelter. Absent evidence to the contrary, "sweating like a pig" strikes the author as irony, meaning straining to do something to no effect.

In the New England region, where temperatures range from below 0 to over 100 degrees, heating and cooling can present a major opportunity to improve sustainability statistics of a campus. Overt changes such as improving windows come to mind, but recent advancements in boiler technology and strategies for working with the heat of the sun and the cool of the earth can provide powerful means of reducing emissions quickly. With the 2020 deadline to hit objectives for the Presidents' Climate Leadership Commitments, which were created by the American College & University Presidents' Climate Commitment in 2007, something as mundane as a campus boiler system can help colleges meet climate goals and offer hands-on research at the intersection of environmental studies and engineering, the author argues.

Earth science has a part to play in broadening students' learning experience in physics. The Earth Science Education Unit presents a range of (free) workshops to teachers and trainee teachers, suggesting how Earth-based science activities, which show how we understand and use the planet we live on, can easily be slotted into normal science lessons. Waves and resonance, for example, are illustrated by earthquakes, electromagnetic induction is used to design seismometers, metal detectors and wind turbines, and thermodynamics is illustrated by heat exchangers used for space heating. The "Earth Physics" workshops, which show how to set up the activities within a physics lesson, have been well received by teachers. (Contains 1 table, 7 figures and 3 online resources.)

A roller coaster ride comes to an end. Magnets on the train induce eddy currents in the braking fins, giving a smooth rise in braking force as the remaining kinetic energy is absorbed by the brakes and converted to thermal energy. In this paper an IR camera was used to monitor the temperature of the first braking fin, before, during and after the passage of a train. In addition, the resulting acceleration of the train was modelled and compared to accelerometer data for the Kanonen roller coaster in Liseberg. The results were used to model the distribution of temperature increase over the braking fins. Finally, the cooling of the fins after the passage of the train was analysed and compared to the IR data. (Contains 7 figures and 5 footnotes.)

Digital storage oscilloscopes (DSOs) are now easily available to undergraduate laboratories. In many cases, a DSO can replace a data-acquisition system. Seven such experiments/demonstrations are considered: (i) families of "I-V" characteristics of electronic devices (bipolar junction transistor), (ii) the "V-I" curve of a high-temperature superconductor (critical currents), (iii) the speed of electromagnetic waves and losses (in a coaxial cable), (iv) diffraction patterns (one and two slits), (v) the photoelectric effect (the Einstein equation), (vi) two variants of the Franck-Hertz experiment (with a Franck-Hertz tube from PHYWE and with a thyratron), and (vii) the structure of the video signal. All the experiments are performed without a computer or additional software. An exception is the experiment with a coaxial cable, where it is necessary to build graphs of the results obtained. (Contains 8 figures.)

Thermoacoustic instability is defined as the excitation of acoustic modes in chambers with heat sources due to the coupling between acoustic perturbations and unsteady heat addition. The major objective of this paper is to achieve accurate theoretical results in a thermoacoustic heat transfer process. We carry out a detailed heat transfer analysis aimed at determining the stability-instability border of the thermoacoustic system. In this paper, we present a project type of physical examination and modelling task. We employed an electrically heated Rijke tube in our thermoacoustic project work. The aim of our project is to help our students enlarge their knowledge about thermodynamics, mainly about thermoacoustics, and develop their applied information technology and mathematical skills. (Contains 4 figures.)

Climate change and the projected depletion of fossil energy resources pose multiple global challenges. Innovative technologies offer interesting possibilities to achieve more sustainable outcomes in the energy production sector. Local, decentralized alternatives have the potential to sustain livelihoods in rural areas. One example of such a venture has emerged around heating businesses in rural Finland, and is referred to as heat entrepreneurship. Heat entrepreneurship entails a system where a local forest owner, usually a farmer, provides heat to a small community or local building, such as a school. Heat is produced using local forest resources that would otherwise be unutilized. The purpose of this study is to examine heat entrepreneurship as a potential sustainable alternative for energy production and its multifunctionality. The data was collected by interviewing 15 heat entrepreneurs in the area of Central Finland. The study demonstrates how multifunctional farming-related energy production can provide more sustainable livelihoods for farmers by increasing social, economic and environmental sustainability. This is achieved by diversifying farmers' economic options, enhancing rural areas economically, increasing farmers' social networks and well-being and, to some extent, by boosting local environmental capital. However, the study also points to differences among the farmers and sustainability trade-offs, suggesting for the need to better acknowledge the local perceptions in policy-making. (Contains 2 tables and 1 figure.)

The recent introduction of inexpensive high-speed cameras offers a new experimental approach to many simple but fast-occurring events in physics. In this paper, the authors present two simple demonstration experiments recorded with high-speed cameras in the fields of gas dynamics and thermal physics. The experiments feature vapour pressure effects as well as adiabatic cooling observed upon opening a bottle of champagne. The authors also give simple qualitative and quantitative descriptions of the underlying physics. (Contains 7 figures.)

We present a sensitive diffusion cloud chamber which does not require any radioactive sources. A major difference from commonly used chambers is the use of a heat sink as its bottom plate. The result of a performance test of the chamber is given. (Contains 8 figures.)

Bulbs are considered to be very inefficient sources of light. Bulbs give light and heat. As we use them for a long time, especially in winter, a large part of the heat produced by bulbs lowers the power consumption of the heating system. In this paper the problem of the real efficiency of a bulb is solved when both the lighting and heating effects of illumination of the interior of buildings are taken into account. It is analysed from the viewpoints of the energy consumed and the price of that energy. The real efficiency of bulbs and the savings obtained by replacing them with fluorescent lamps are calculated for various locations. (Contains 4 tables.)

A simple low-cost experiment for undergraduate students to determine the characteristics of a negative temperature coefficient of resistance thermistor is presented. The experiment measures the resistance-temperature and voltage-temperature characteristics of the thermistor. Results of the resistance-temperature experiment are used to determine the sensitivity index of the thermistor material. The experimental sensitivity index of the thermistor material is found to be close to the one from the datasheet of the manufacturer. Two voltage-temperature measurement circuits are tested experimentally, namely the Wheatstone bridge circuit and the operational amplifier (Opamp) bridge circuit. The Wheatstone bridge circuit produces a better sensitivity than the Opamp bridge circuit. The best linearity is obtained with a modified Opamp bridge circuit at an expense of reducing the sensitivity. The low cost of the experimental setup makes it suitable for implementation in universities with very limited resources, especially in developing countries. (Contains 11 figures.)

A recipe is a great way to learn about the procedure and the variables (or "ingredients") involved. Cookbooks are comforting and valuable: They're easy to follow, and people know what they'll get. The problem is that cookbook labs end just when things get interesting. The excitement of science is in understanding the discovery and pursuing the questions that arise--a reasonable definition of inquiry. Lab experiments fall on a spectrum from cookbook to open inquiry with guided inquiry somewhere in the middle. Experiments that progress from scaffolded to open investigations give the teacher a range of options and the student a path leading from a structured to a more adventurous experience. The best labs clearly define the procedure, include meaningful scientific content, and ask interesting questions. This article discusses four labs--centered on the science of heat transfer--that define the procedure, include meaningful scientific content, and ask interesting questions. The simple extensions described lead to more complex issues and opportunities for inquiry. (Contains 7 figures.)

Thermal cameras are useful tools for use in scientific investigation and for teaching scientific concepts to students in the classroom. Demonstrations of scientific phenomena can be greatly enhanced visually by the use of this cutting-edge technology. (Contains 7 figures.)

The implementation of an automated system based on the hot-wire technique is described for the measurement of the thermal conductivity of liquids using equipment easily available in modern physics laboratories at high schools and universities (basically a precision current source and a voltage meter, a data acquisition card, a personal computer and a high purity platinum wire). The wire, which is immersed in the investigated sample, is heated by passing a constant electrical current through it, and its temperature evolution, "[delta]T", is measured as a function of time, "t", for several values of the current. A straightforward methodology is then used for data processing in order to obtain the liquid thermal conductivity. The start point is the well known linear relationship between "[delta]T" and ln("t") predicted for long heating times by a model based on a solution of the heat conduction equation for an infinite lineal heat source embedded in an infinite medium into which heat is conducted without convective and radiative heat losses. A criterion is used to verify that the selected linear region is the one that matches the conditions imposed by the theoretical model. As a consequence the method involves least-squares fits in linear, semi-logarithmic (semi-log) and log-log graphs, so that it becomes attractive not only to teach about heat transfer and thermal properties measurement techniques, but also as a good exercise for students of undergraduate courses of physics and engineering learning about these kinds of mathematical functional relationships between variables. The functionality of the experiment was demonstrated by measuring the thermal conductivity in samples of liquids with well known thermal properties. (Contains 1 table and 3 figures.)

This exploratory study in a classroom setting investigates first graders' (age 7-8 years, N = 25) ability to perform analogical reasoning and create their own analogies for two irreversible natural phenomena: mixing and heat transfer. We found that the children who contributed actively to a full-class discussion were consistently successful at making analogical comparisons between known objects provided by a researcher and that some of the children could come up with their own analogies for the abstract natural phenomena with which they interacted. The use of full-class and small-group settings, shared laboratory experiences of the phenomena and children's drawings as different kinds of scaffolding was found to be helpful for the children's analogical reasoning. As an implication for science education, self-generated analogies are put forward as a potential learning tool within a constructivist approach to education.

We introduce the photoacoustic educational system (PAES), by which we can identify which gas causes the greenhouse effect in a classroom (Kaneko "et al" 2010 "J. Chem. Educ." 87 202-4). PAES is an experimental system in which a pulse of infrared (IR) is absorbed into gas as internal energy, an oscillation of pressure (sound) appears, and then we can measure the absorptance of IR by the strength of sound. In this paper, we construct a simple mathematical model for PAES which is equivalent to the CR circuit. The energy absorption of an IR pulse into gas corresponds to the charge of a condenser and the heat diffusion to the outside corresponds to the energy dissipation by electric resistance. We analyse the experimental results by using this simple model, and check its validity. Although the model is simple, it explains phenomena occurring in PAES and can be a good educational resource. (Contains 4 footnotes and 10 figures.)

A procedure modelling ideal classical and quantum gases is discussed. The proposed approach is mainly based on the idea that modelling and algorithm analysis can provide a deeper understanding of particularly complex physical systems. Appropriate representations and physical models able to mimic possible pseudo-mechanisms of functioning and having predictive validity are developed. (Contains 3 tables, 4 footnotes and 7 figures.)

This article describes engaging students in two simple observations to address the concepts of changes of states, heat, temperature, and molecular potential and kinetic energy. It also discusses how these concepts can enable students to further explore and understand interesting and significant phenomena and research in multiple areas of science. (Contains 4 figures.)

We construct a thermometer exploiting the electric resistance of the filament of a small lamp used in micro-illumination settings. The instrument may guarantee a response time better than 10 ms, i.e. much faster than commercial thermocouples or other quite expensive devices. This makes our thermometer a useful one in several processes which are characterized by a rapid time evolution. (Contains 1 table and 6 figures.)

Heat transfer is widely taught in secondary Earth science and physics. Researchers have identified many misconceptions related to heat and temperature. These misconceptions primarily stem from hunches developed in everyday life (though the confusions in terminology often worsen them). Interactive computer simulations that visualize thermal energy, temperature distribution, and heat transfer may provide a straightforward method for teaching and learning these concepts. Through interacting with visual representations of the concepts and observing how they respond to manipulations, the misconceptions may be dispelled more effectively. This paper presents a new educational simulation tool called Energy2D developed to explore this idea.

Summer brings to mind the joys of vacation and spending time outdoors. The author looks forward to the summer months, particularly June--that's when they hold Junior Naturalist Camp at the Fairchild Tropical Botanic Garden in Coral Gables, Florida. While she enjoys each day of camp, one in particular really brings out her inner student--Solar Energy Day. The Sun is a universal object with endless possibilities for exploration, and on Solar Energy Day, students learn more about it through books, crafts, and investigations. Even though they're located in sunny South Florida, the activities they use can be implemented across the globe and with students of all ages. This article describes the solar activities they use in more detail and provides a model for teachers who wish to replicate these activities in their classrooms. (Contains 1 figure and 7 online resources.)

Glazing can be optimized to enhance passive solar heating and daylight harvesting by exceeding the prescriptive limits of the energy code. This savings can be garnered without the high cost of external overhangs or expensive glazing products. The majority of savings from solar glazing are attributable to the increase in solar heating and secondarily to daylight illumination. Glazing with high solar gains can have a compelling advantage over code-compliant conventional glazing with low solar gains. In this article, the author discusses how solar glazing can benefit schools, and offers tips for school construction.

As energy costs continue to rise, many schools and universities are considering energy-saving solutions, including solar heating options, to lower costs and to attract students and staff that support environmentally friendly practices. However, administrators and facility engineers should take several issues into account before pursuing a solar heating system. Understanding the process of installing solar thermal systems can help schools determine whether it will meet needs now and into the future.

The objective of the study was to determine the hydrodynamics of the two stage counter-current cascade wet scrubbers used during incineration of medical waste. The dependence of the hydrodynamics on two main variables was studied: Inlet air flow rate and inlet liquid flow rate. This study introduces a new wet scrubber operating features, which are liquid accumulation, together with a detailed analysis of liquid-to-gas ratio and pressure drops. Liquid accumulation at the base of each scrubber helps to prevent the gas from short circuiting to the scrubber solution feed tanks. It was observed that liquid accumulation increases linearly with inlet scrubbing liquid flow rate beyond 0.2 L/s in the absence of flue gas flow. When flue gas is flowing into multistage wet scrubber the accumulation level increases abruptly starting from inlet scrubbing liquid of 0.45 L/s and stabilizes at accumulation level of 0.1 m beyond 0.75 L/s. Increasing the flue gas flow rate increases the minimum inlet scrubbing liquid flow rate at which initial accumulation was observed. The outlet scrubbing solution flow rate and liquid accumulation in the bottom of the scrubber increase as the inlet liquid flow rate increases. Beyond inlet liquid flow rate of 0.75 L/s, the outlet liquid flow rate does not increase any more, the wet scrubber enters flooding range, whereby, the volume of accumulated liquid increases faster with inlet scrubbing liquid flow rate. The maximum liquid-to-gas ratio was observed to be 1.9 L/m[superscript 3] and the minimum liquid-to-gas ratio was 0.1 L/m[superscript 3]. Based on liquid accumulation and minimum flooding conditions, the operating liquid-to-gas ratio was recommended to be 0.6 to 1.9 L/m[superscript 3], while the allowable inlet liquid flow rate ranged between 0.45 and 0.75 L/s, giving a constant accumulation of scrubbing liquid in the wet scrubber. The pressure drop across the wet scrubber remained constant at lower flow rate and increased linearly beyond U[subscript g] = 5 m/s. The maximum pressure drop of the multistage wet scrubber was 75 kPa. (Contains 10 figures and 1 table.)

Evaporation and boiling are both terms applied to the change of a liquid to the vapour/gaseous state. This article argues that it is the formation of bubbles of vapour within the liquid that most clearly differentiates boiling from evaporation although only a minority of chemistry textbooks seems to mention bubble formation in this context. The importance of bubble formation is used to explore a much deeper, albeit a largely qualitative, explanatory basis of a number of interrelated phenomena. These include the fixed boiling point of liquids at a constant external pressure, the effect of pressure changes and of dissolved substances on boiling point, and nucleation, superheating and bump-boiling. (Contains 1 table, 2 boxes, 1 note, and 3 figures.)

When engineers design heat-pump-based geothermal heating systems for homes and other buildings, they can use coil loops buried around the perimeter of the structure to gather low-grade heat from the earth. As an alternative approach, they can drill well casings and store the summer's heat deep in the earth, then bring it back in the winter to warm the buildings. To understand how heat can be stored in the earth and how it propagates through soil, this article presents four interesting experiments that teachers and their students can carry out using a relatively simple apparatus consisting of a wooden box, some inexpensive accessories, and various types of soil. (Contains 3 figures.)

Maybe it's the peculiar way they walk or their cute little suits, but students of all ages are drawn to penguins. To meet younger students' curiosity, the authors adapted a middle-school level, penguin-themed curriculum unit called Save the Penguins (Schnittka, Bell, and Richards 2010) for third-grade students. The students loved learning about penguins that live all over the world and in various climates. This three-day interdisciplinary science unit allows students to explore their own ideas about penguins, temperature, and heat. The students even used engineering to design miniature dwellings to protect models of South African penguins from climate change and attacks by gulls. Specifically, the objectives of the unit are for students to (1) describe where penguins live, some features of warm and cold climate penguins, and the climate issue affecting penguin populations; (2) compare the temperatures for each given sample of material and describe which materials prevent heat transfer the best; (3) construct a small shelter for a penguin-shaped ice cube so that at least half the penguin mass remains after being placed in a thermal oven for 20 minutes; and (4) describe that heat travels more slowly through some materials than others and that light is reflected by some colors and absorbed by others to make the material hot. The authors used the 5E Learning Cycle model (BSCS 1989) to achieve these objectives because it is a proven method of teaching science. (Contains 3 figures, 2 resources and 5 online resources.)

Evaporation of a small glass of ethylic alcohol is studied both experimentally and through an elementary thermal physics approach. For a cylindrical beaker and no air flow in the room, a simple quadratic relation is found between the evaporation time and the mass of evaporated liquid. This problem and the obtained results offer excellent possibilities for simple student experiments and for testing basic principles of thermal physics. As an example, we use the obtained results for estimating the value of the Boltzmann constant from evaporation experiments. (Contains 1 table and 4 figures.)

When an ice cube floating on water in a container melts, it is said in some textbooks that the water level does not change. However, as pointed out by Lan in a recent work, when the buoyant force from a less dense fluid resting above the waterline is taken into account, one should expect a detectable "increase" in the volume of water. Here in this work, by noting that the melting process itself reduces the water temperature, which in turn "reduces" its volume, we show that the thermal contraction of water can override the volume increase predicted by Lan. (Contains 1 figure and 6 footnotes.)

An alloy is an intimate association of two or more metals, with or without a definite composition, which has metallic properties. Heterogeneous alloys, such as tin-lead (Sn/Pb) solders, consist of a mixture of crystalline phases with different compositions. A homogeneous alloy with a unique composition having the lowest possible melting point is called a eutectic. A binary eutectic alloy is a mixture of two metals with a well-defined composition that melts at the lowest temperature of any composition of the mixture. The purpose of this project was to study the thermal properties of various compositions of Sn/Pb alloys. The conclusions from this work were as follows: (i) the eutectic composition was found to be 62 wt % Sn with a melting temperature of 183[degree]C; (ii) as the Sn and Pb compositions decreased from 100%, the alloy melting temperature also decreased; and (iii) by measuring the differential scanning calorimetry (DSC) peak melting point of the Sn/Pb alloy, the alloy composition can be obtained from the constructed binary phase diagram. Overall, the DSC provided a method of analysis for the determination of a binary alloy composition of Sn/Pb and the construction of a simple binary phase diagram. (Contains 1 table and 4 figures.)

The project models the conductive heat loss through the ceiling of a home. Students are led through a sequence of tasks from measuring the area and insulation status of a home to developing several functions leading to a net savings function where the depth of insulation is the input. At this point students use calculus or a graphing utility to determine the optimal savings. Extensions to air conditioning savings and a present values of future savings are also included.

In undergraduate chemical thermodynamics teachers often include equations and view manipulations of variables as understanding. Undergraduate students are often not able to describe the meaning of these equations. In chemistry, enthalpy and its change are introduced to describe some features of chemical reactions. In the process of measuring heat at constant pressure, work is often disregarded. Therefore, we investigated how undergraduate students describe expansion work and technical work in relation to enthalpy and its change. Three empirical studies (n[subscript tot] = 64, n[subscript tot] = 22, n[subscript tot] = 10) with undergraduate chemistry students taking their first or fifth chemistry course at two Swedish universities were conducted. Questions on enthalpy and its change, internal energy and its change, heat and work were administered in questionnaires, exam questions, hand-ins and interviews. An analytical matrix was developed and qualitative categories with respect to pressure and volume were formed. The results indicate that work in general and even more so expansion work and technical work are difficult processes to describe and relate to the definition and formula of enthalpy change. Work is mainly described without reference to pressure and volume. The properties of volume are more likely to be described correctly than the properties of pressure. The definition of enthalpy change at constant pressure is generalised to constant volume/varying pressure cases. This study gives further insight into the way in which students use pressure and volume as they describe expansion work and technical work as well as the contextual correctness of these descriptions. The matrix and categories can be used by researchers, teachers and students. (Contains 5 tables and 1 figure.)

This case study of the University of Toronto Sustainability Office's energy conservation project, Rewire, explores the implementation of a social marketing campaign that encourages energy efficient behavior. Energy conservation activities have reached approximately 3,000 students and staff members annually, and have saved electricity, thermal energy, and water. Rewire helped develop an "ethic of sustainability" on campus, conferred legitimacy on student and staff environmental leaders, and has catalyzed other environmental activities. (Contains 1 table and 2 footnotes.)

This article deals with a brief biographical sketch of Joseph Fourier, his first celebrated work on analytical theory of heat, his first great discovery of Fourier series and Fourier transforms. Included is a historical development of Fourier series and Fourier transforms with their properties, importance and applications. Special emphasis is made to his splendid research contributions to mathematical physics, pure and applied mathematics and his unprecedented public service accomplishments in the history of France. This is followed by historical comments about the significant and major impact of Fourier analysis on mathematical physics, probability and mathematical statistics, mathematical economics and many areas of pure and applied mathematics including geometry, harmonic analysis, signal analysis, wave propagation and wavelet analysis. Special attention is also given to the Fourier integral formula, Brownian motion and stochastic processes and many examples of applications including isoparametric inequality, everywhere continuous but nowhere differentiable functions, Heisenberg uncertainty principle, Dirichlets' theorem on primes in arithmetic progression, the Poisson summation formula and solutions of wave and diffusion equations. It is also shown that Fourier coefficients c[subscript n](t) in the Fourier expansion of a scalar field psi(theta, t) satisfy equations of the simple harmonic motion.

The aims of this study were to determine the underlying conceptual structure of the thermal concept evaluation (TCE) questionnaire, a pencil-and-paper instrument about everyday contexts of heat, temperature, and heat transfer, to investigate students' conceptual understanding of thermal concepts in everyday contexts across several school years and to analyse the variables--school year, science subjects currently being studied, and science subjects previously studied in thermal energy--that influence students' thermal conceptual understanding. The TCE, which was administered to 515 Korean students from years 10-12, was developed in Australia, using students' alternative conceptions derived from the research literature. The conceptual structure comprised four groups--heat transfer and temperature changes, boiling, heat conductivity and equilibrium, and freezing and melting--using 19 of the 26 items in the original questionnaire. Depending on the year group, 25-55% of students experienced difficulties in applying scientific concepts in everyday contexts. Years of schooling, science subjects currently studied and physics topics previously studied correlated with development of students' conceptual understanding, especially in topics relating to heat transfer, temperature scales, specific heat capacity, homeostasis, and thermodynamics. Although students did improve their conceptual understandings in later years of schooling, they still had difficulties in relating the scientific concepts to their experiences in everyday contexts. The study illustrates the utility of using a pencil-and-paper questionnaire to identify students' understanding of thermal concepts in everyday situations and provides a baseline for Korean students' achievement in terms of physics in everyday contexts, one of the objectives of the Korean national curriculum reforms. (Contains 9 tables and 1 figure.)

The physics and chemistry education literature has grappled with an appropriate definition for the concept of heat for the past four decades. Most of the literature promotes the view that heat is "energy in transit" or "involves the transfer of energy" between the system and surroundings because of a difference in temperature. Given that many undergraduate students are not learning the concept of heat in physics and chemistry alone, the goal of this investigation is to explore the conceptions of heat as presented in textbooks from across the science disciplines. An analysis of the definitions of heat from physics, chemistry, the biological sciences and the earth sciences showed a significant variation in the definitions within a discipline and between the disciplines. Specifically, the physics and chemistry textbooks used "energy in transit" or "transfer of energy" definitions (Class I), whereas textbooks from other disciplines typically used definitions which relate heat to "molecular kinetic energy" (Class II) or they used a hybrid of Class I and II definitions. Although a universal definition of heat across disciplines may not be possible (or even desirable), we suggest that discrepancies in definitions be acknowledged and clearly communicated to students. (Contains 1 table, 2 figures, and 5 notes.)

An evaporator-type cryogenic heat exchanger is designed and built for introducing fluid-solid heat exchange phenomena to undergraduates in a practical and efficient way. The heat exchanger functions at liquid nitrogen temperature and enables cooling of N[subscript 2] and He gases from room temperatures. We present first the experimental results of various parameters which characterize the heat exchanger (efficiency, number of transfer units, heat exchange coefficient, etc) as a function of the mass flow rate of the gas to be cooled. An analysis of the "Nu-Re" diagram is also presented. All experiments were conducted with N[subscript 2] gas. The scope of this tool is readily extended to research purposes. (Contains 9 figures and 1 table.)

In this paper, some heat transfer characteristics through a sample that is uniformly heated on one of its surfaces by a power density modulated by a periodical square wave are discussed. The solution of this problem has two contributions, comprising a transient term and an oscillatory term, superposed to it. The analytical solution is compared to the experimental results obtained by using the approach first proposed by Angstrom, which has become a well-known thermal wave experimental procedure used for the determination of thermal diffusivity. A number of conclusions are drawn from this comparison, which highlight the need to carefully consider the experimental setup employed when carrying out this type of measurement. The results may be of interest to those dealing with heat transfer problems, thermal characterization techniques and/or involved in the teaching of partial differential equations at undergraduate or graduate level. (Contains 12 figures and 1 table.)

One physical science topic that is difficult for middle school students is the transfer of thermal energy: Research indicates many have trouble understanding that thermal energy naturally transfers from the "warmer" object to the "colder" object until both objects reach the same temperature (Driver et al. 1994; Keeley, Eberle, and Tugel 2007). This article presents a short and cost-effective lesson the author has developed to help middle-grade students learn about National Science Education Standard 5-8 Content Standards concerning the transfer of thermal energy (NRC 1996). The lesson comprises three activities: a predict-share-observe-explain (PSOE) sequence of instruction that elicits students' conceptions and piques their interest in learning about heat transfer (Stepans 1996); an investigation into convection; and a follow-up, whole-class discussion of kinetic and thermal energy to solidify understanding. (Contains 2 figures.)

An Internet search for why objects, especially humans, cool more rapidly in water than in air, both at the same temperature, and by how much, yields off-the-cuff answers unsupported by experiment or analysis. To answer these questions in depth requires a smattering of engineering heat transfer, including radiative transfer, and the different thermophysical properties of the two fluids. The correct ratio for humans is closer to 2 than to 10, and if this were not so, swimming in cool water could be fatal.

This study addresses a controversial issue in the adiabatic piston problem, namely that of the piston being adiabatic when it is fixed but no longer so when it can move freely. It is shown that this apparent contradiction arises from the usual definition of adiabatic condition. The issue is addressed here by requiring the adiabatic condition to be compatible with the invariance of total entropy under a system-surroundings interchange. This paper also strengthens some recently published ideas concerning the concepts of heat and dissipative work, and is primarily intended for teachers and graduate students, as well as for all who are interested in this fascinating problem. (Contains 1 figure.)