A Summary of the Scientific Theories of Heat A pre-human species (Homo erectus) used fire for cooking and heat at least 500,000 years ago (maybe as long as 790 000 years ago), even though we have understood the science of heat for less than 200 years. The early Greeks thought fire (heat) was one of four basic elements, and as one of the four basic elements, it was contained in all substances. Scientists realized that there were more than 4 elements. Heat was then determined to be an invisible liquid called phlogiston. However, when some substances were burned, the ashes weighed more than the original substance. Where did this extra weight come from? By the late 1700’s the caloric theory of heat emerged. Caloric was said to be a massless fluid that occupied all substances. It could not be created, nor destroyed, but it could flow from one substance to another (always from warm to cold). A “calorie” was later defined as “the amount of caloric that would increase the temperature of 1g of substance, by 1oC”. Count Rumford’s Hypothesis was introduced when he was making cannons. Boring holes in metal made very hot shavings and drill bits. He realized that heat was the equivalent to energy. German physician Julius Robert Mayer found evidence to support Rumford’s hypothesis while making observations during a blood letting “treatment”. James Prescott Joule (1818-1889) receives credit for discovering the mechanical equivalent of heat. His developments lead us into the physics of heat and energy. The SI unit of energy,…
unemployed, 38% had serious illnesses, and 93% were single (chapter 1, page 65).
Men were more than twice as likely as women to die in the Chicago heat wave (once we control for age with a statistical age-adjustment procedure), but women represented 45 % of total victims (chapter1, page 77).
The map of the Chicago community areas that experienced the highest heat-related death rates shows that the community areas hit hardest is concentrated on the South and West sides of the city, the historic Black Belt…
Heat Transfer from Extended Surfaces
Convective heat transfer theory relies on the assessment of the convective heat transfer coefficient, h, whose value depends upon both the properties of the fluid it characterizes and the circumstances under which convection is occurring. In this laboratory experiment, the value of the convective heat transfer coefficient for air at room temperature was determined empirically…
Real-Life Applications of Heat – Heat Energy and Transfer
Abstract: This reflective essay addresses heat energy and transfer and how they are used in real-life applications – from the natural world to modern human technology. This essay shows that heat is very important to nearly everything in life and how it is used nearly everywhere.
“Heat energy (or just heat) is a form of energy which transfers among particles in a substance (or system) by means of kinetic energy…
The reasonable ways to reduce the heat
losses from windows
Bachelor Thesis of Energy System
Supervisor: Taghi Karimipanah
The window insulation always plays an important role in building design and thermal
comfort, it is one of the main parts needed to be optimized in building envelop.
Window insulation is a basic element which can decide the insulation capacity. The
large heat loss from the window is the main part of wasting…
determining the overall heat transfer coefficient of the system and to perform a heat balance over the evaporator. The experiment was carried out by measuring the mass flow rate of the inlet water and the condensate, temperature of the inlet water, condensate before it passes the steam trap and the surface area of the evaporator. The collected data were used to find the enthalpies of the steam and water at suitable conditions from the steam table. The values were used to calculate the heat flow rates and…
The Heat Treatment of Steel
Engineering 45 (Material Science)
We observed how the properties of 4140 steel vary with the heat treatment to investigate the
impact they would have on a design project. We prepared six specimens with three different heat
treatments, Annealed (O), quenched and tempered (QT), and Normalized/ As-Received
(Norm/AR) and each were tensile tested using the universal testing machine (UTM) along with a…
Heat and Energy
February 7, 2013
The purpose of this paper is to discuss how the study of heat relates to the kinetic energy theory of matter. I will discuss what heat and temperature are, the relationship between them and their differences. I will provide examples of the various properties of a substance that will determine its heat capacity and various sources of heat.
In the 1840s scientists understood that heat was not just a substance but a…
The weather is becoming progressively warmer and accordingly, the risk of developing heat illnesses becomes higher. These emergencies are preventable if proper precautions are taken. A person in excellent condition can succumb to a heat illness if the person ignores warning signs, however, children, elderly, and obese people are at an even higher risk. If the problem isn't addressed, heat cramps (loss of salt from profuse sweating) can lead to heat exhaustion (dehydration), and…
To perform a Jominy end-quench test in order to observe heat treatment hardening and prepare the hardenability curve for a steel bar.
Steel is the most important engineering and construction material; it accounts for approximately 80 % of all metals produced. Steel has attained this degree of prominence because it combines strength, ease of fabricability into many shapes, and a wide range of properties along with low cost. Also it is possible to give a wide…
equipment, which is called Geothermal Heat Pump (GHP) can be used in any building like school, hotel and highly efficiency in today’s world. The principle of GHP is that can either transfer the heat source or cool source. In other words, a geothermal heat pump has the ability to move the source from one space to another space (EERE 2011). There are many facilities such as air conditioning, refrigerator, and ventilation that they all can use of geothermal heat pump as heating or cooling system. It…