Heating Definition and 590 Threads

Is it possible to approximate the amount of heating in tissue (and other materials) due to electromagnetic radiation?

Hello new to the site and i usually don't post questions but after a few days searching I answered a few and found many more I'm hoping someone here can help. Background for project: Looking to preheat my RC (remote control) nitro motors to 200-220'F prior to starting the break-in process.i...

Needed some guidance for my circuit: Have a circuit consisting of a microcontroller + SSR relay + load (heaters)...issue is when the temperature reaches cutoff the heaters are not getting stopped and temp. keeps on increasing... I have a connection of outputs from microcontroller into...

So, I'm a student working on a M.S. Environmental Science. I just took a test, the course is Mechanisms in the Environment, and got a question marked wrong that I believe is a correct answer. The question was, paraphrased, Can ozone formation in the mid to upper stratosphere heat up the...

HI there, I have a thought question. Normally when we wish to warm up food in a microwave oven, common sense tells us that the lid of the plastic containter (or container of whatever material) should be off, so that the microwave can reach the food. Just wondering...if the lid is on, ie...

1. A cylinder with thermally insulated walls contains a movable frictionless thermally insulated piston. On each side of the piston are n moles of an ideal gas. The initial pressure (P_0), volume (V_0), and temperature (T_0) are the same on both sides of the piston. The value for (gamma) is 1.5...

I'm wondering about what's going on in an effect I've noticed with heating pads (as well as electric mattress pads). Try this experiment: take an ordinary heating pad (one of those flat rectangular things about 1 foot by 1.3 feet with an electric plug), plug it in, and have a friend sit...

Homework Statement If the following substances were heated what gas would be given off and what solid would remain? strontium carbonate, zinc carbonate, and iron carbonate. Homework Equations N/A The Attempt at a Solution So I presume carbon dioxide would be given off and the 3...

Hi there, I have been doing research on a lil private project of my own, and am looking for some help. Would it make sense to use nichrome wire to build a heating element that will heat to 80-100 degrees? It seems that nichrome is great for heating way way past that temperature. I want to...

Homework Statement If the specific heat capacity of water from an experiment is smaller than its actual value, does it mean more heat is lost to the surroundings? If the heat is emitted by a wire into a cup of water and the change in temperature is measured, does it mean that the change in...

I have heard about this term called radiant flooring, i don't know exactly what it is can anyone here explain me about radiant flooring.

I have problem in calculating heating time of Lube Oil ( SAE 40 ). There is a tank of Lube Oil ( SAE 40) of 19000 liters at 20° C. this oil has to be heated up from 20° C to 40° C with help of a heater of 85 kW through which oil flows at 4800 liter/hour and back to tank. How much time it...

Hi I need a heating element, 5 cm x 5 cm, to heat up a chip. Temperature range 293 - 373 Kelvin Anyone know what to go for?

Hello, I am new to this forum, I thought you guys could send me in the right direction. what I am trying to do is heat water with a wind turbine. the turbine produces 3 phase wild AC with voltage of 0 to 270V. related to wind speed. I am aware of the general practices with wind turbines-...

Just out of curiosity, has anyone ever heard of using sodium thiosulfate pentahydrate (liquid crystals) as a viable method of heating a house? I'm doing a project on this now and it seems hugely inefficient due to the massive amounts of crystals that would be needed to produce enough energy to...

Regarding a 12v source, is there a way to calculate how much energy is required to maintain a certain temperature through an element? Meaning if you want to maintain an element temperature of 35 F how much energy will it consume using 12v? How will the ambient temperature affect this equation...

In regard to (tile) radiant floor heating, a professional is needed to come and install a heat-conducting plastic mat with wire lattice-work, hook it up to the home’s electrical system, and then do the standard grout and tile work etc. I was wondering what the possibility would be to produce...

Homework Statement An oil-filled radiator is used to maintain the temperature of a room at 21C when the outside temperature is 10C. The radiator has a surface area of 1.5 m2, and a surface temperature of 70C. Given that the radiator is made of a metal with a thermal conductivity 80...

Homework Statement A 750-MW power plant sends its power out on a 475,000 V high-voltage line. If the total resistance of the line is 0.65 Ω, what percentage of the power is lost due to resistive heating? Homework Equations i have NO idea but maybe... P(loss)=I²R P(loss)=^v²/R...

I want to find the increase in the temperature of a resistor due to joule heating. I mean that if we apply some electrical power to a resistor then the electrical energy is converted to heat energy due to joule heating. The heat energy will increase the temperature of the resistor. Is it...

Homework Statement I have two problems. What is Delta U, Delta H, q, and w for the Reversible heating of an ideal gas at constant P. Also, what are these values for the Reversible cooling of an ideal gas at constant V. Homework Equations The Attempt at a Solution For the...

Homework Statement A toaster with a Nichrome heating element has a resistance of 70 ohms at 20oC and an initial current of 1.6 A. When the heating element reaches its final temperature, the current is 1.39 A. What is the final temperature of the heating element? Homework Equations V=IR...

if we heat semiconductors, so that the energy provided is more than threshold energy will they generate a current?

When I heat up, for example, a sweet potato in the microwave, how is the heating process affecting the nutritional aspects of the sweet potato? Heat affects enzymes, proteins, vitamins and whatever else. Does the heat render them useless? I heard vitamin C is destroyed in the pasteurization...

Say I want to put a bottle of water in the microwave and heat it up. How do I determine the pressure in the bottle as a relation to the temperature of the water? Assuming that there is a headspace of air between the liquid and the bottle cap. Is it dependant on the volume of the air space? ie...

hi all I am trying to use a circuit of NiCr wire to heat a surface. I have setup my circuit using parallel 'branches' of NiCr connected to a bus so that voltage is equal across each branch. I am an undergrad EE so I get electrical aspect, but have little knowledge of the thermo. My...

We are testing an Air Handling Unit, we need to raise the internal temperature by 30 degrees to pass the test, but cannot exceed an energy input of 500W. It is a completely sealed unit. We have four fans constantly running, consuming 384W. Firstly, how can I work out what temperature they...

Hi, I want to electrically heat a uniform block of a known material to a high temperature (about 2000 K). I want to get a rough idea of how much electrical energy I need to supply to raise the material to this temperature so as to gauge what apparatus I will need. How would I go about this...

This is an oversimplification of a practical problem I am currently trying to design for. Suppose, we have a very long cylinder closed at both ends which contains water at a given pressure P1 and temperature T1. P1 and T1 are such that water is in a compressed state (subcooled). One end of...

I have experimented the converse of Newton's law of cooling, i.e. the rate of heating of a cold body is directly proportional to the deficient temperature when the difference in temperatures is small and the states of the system remain the same.

Suppose the temperature in your room is 25 °C with 100% humidity. You are feeling very hot and sweating a lot. Most of the sweat does not evaporate on your body, it just drips onto the ground. If you switch on the heating in your room, would you feel more comnfortable? It seems to me that by...

Hi! In a book it said that it can be clearly seen from the interatomic potential (such as the Lennard Jones) that when a solid is heated it expands. Please explain how is it exactly manifested by the interatomic potential graph?

COMSOL RF module: urgent Hi i am a new user to comsol RF module. Actually I a want to model the heating of a material using IR waves... can i use the RF module (which illustrates microwave heating as an example) to model the IR heating...do we have options to change the frequency of wave from...

Ok so my question is about hot water in a home Lets say that I take a shower a shower and i use 20 gallons of water at 105* F If the hot water in my tank is at 140*F and my cold water comes in at 50*F how much of hot (140*F) water did i use? How much cold (50*F) Water did i use? Now...

Homework Statement A thin square tungsten foil, 10mm x 10mm, is supported in the centre of a vacuum chamber by thin wires which have negligible thermal conductance. A cooled shield surrounds the foil such that its initial temperature is -37 C. Two parallel slits, 1\mum wide and 1mm long...

Why are the heat coefficients for constant pressure and constant volume different? What is the physical reason?

Let's say there is a water based heating device that has 3/4" connection nipples. The pipe that leads to the device is 5/4". If one ignores pressure- and head loss, does it make any difference how far from the device the pipe reduces from 5/4" to 3/4" ?

Bit Stumped at the moment... I am attempting to design a system to take advantage of the solar energy available this summer, but am struggle to get the equation correct. Broken down, i have an aluminium pipe with water running thorugh it, which will gain energy from solar radiation, but...

Hi PF, I watched a video on youtube about a physics professor who asked some questions at the end of the video but didn't answer them. One really interested me. If you have a plane aluminum plate with a very little hole say in its center and you heat the whole plate. What happens to the size...

energy heating a home? Homework Statement During 2 hours one winter afternoon, when the outside temperature was 4° C, a house heated by electricity was kept at 20° C with the expenditure of 42 kwh (kilowatt·hours) of electric energy. (a) What was the average energy leakage in joules per...

I remember reading before that hydrogen gas is "transparent" to gamma rays. What does this mean? I know it has something to do with the gamma rays not heating the hydrogen. Also, would Xenon gas be transparent to gamma rays?

Hello. I'm planning on building a green house in my garden with a wind powered heating element to help sustain higher temperatures. I live in a windy area (North Sotland) so wind prevolance is no problem. Would an element be the best way to this or are there better methods of converting...

Just a question about heating compressed air.. I know generally how hot air works.. You heat it and particles expand and creates lift. So my question is, Does heating compressed air provide any lift? if so how much in relation to normal air? eg if I had 100m^3 of air heated to 120C...

I work for a contractor and we're currently discussing drains on the roof of a building, and whether they should have electric cable heating around them. It gets cold here and snow does accumulate on the roof. Under what circumstances should cables be used and not? Pros / cons?

I have read that some Scientists do not believe that the emissions from industry, power stations, transportation etc is the ultimate cause for a global warming scenario & they can't put there finger on another cause. Of course science is the study of what we don't know rather than what we do...

Hi Heat generated by the conductor because of DC is i*i*R where i is the current and R is the resistance. Does anybody know the heat generated by the same conductor for an AC? For example frequency 5kHz, DC resistance-20 ohms, RMS current is 3A.. How do we calculate this? I do not...

Hi I am living in a 2 bedroom house with base bord heaters but i have also purchesed 3 oil space heaters, my landlord since has givin me a bogus eviction notice because of to much humididiy in the air, his fault really for nothin ensuring propor ventalation when repairing the house but my...

Is the corona heating problem with only Sun? Or all stars having this problem? i.e. outer layer of all stars have high temperature than its immediate inner layer?

I want to make a heated steering wheel for my car using hand warmers from a snowmobile. The power source is 12 VDC and the resistance is 10.0 ohms using 25 watts on the low setting and 19.6 ohms using 35 watts on high. That is for one handwarmer, I figure I will need about 20 of them. Will...

Homework Statement A 2.5kW electric kettle takes 3 mins to raise the temperature of 1.2kg of water from a temperature of 20 degrees C to a temperature of 100 degress. The specific heat capacity of water is 4.2kJ/(kg K) Homework Equations So far I know that we're either using P=vit ot...