A question about temperature

[_Simon_]

<p>Hey all!</p><p>&nbsp;I just became a member of this forum but I have been reading other peoples post for some time now and I find them to be very interesting.</p><p>I have a question though. And forgive me if this has ben asked before. </p><p>In many Sci-fimovies when people are exposed to the vacuum of space without any suits they instantly freeze up like popsicles. I find this to be somewhat unbelievable. What i mean is if space is vacuum then what is there to keep the cold temperature?</p><p>&nbsp;I was watching "Sunshine" the other day and the same thing happened there. Now, I dont have an education in space-science so forgive me if this question seems a bit ignorant. =)&nbsp;</p><p>&nbsp;</p><p>And I also want to point out that English is not my first language if you&acute;re wondering about my spelling.</p><p>&nbsp;Take care! </p> <div class="Discussion_UserSignature"> </div>

 

[neuvik]

<p>Welcome to SDC Simon.</p><p>&nbsp;&nbsp; If a human was exposed to the vacumm of space it would not freeze immediately.&nbsp; A vaccum is the perfect insulator because theres next to nothing in which heat can transfer. &nbsp; So the body would actually "cook" itself to an extent since the body has no way to cool itself. &nbsp; Unprotected skin exposed to the light of the sun would suffer sun burns, and further increase in body temperature.&nbsp;&nbsp; </p><p>In a vacuum water spontaneous converts to a vapor, So I'm guess the eyes, muscles, organs, mouth, and other soft tissue will have a hard time and bloating occurs.</p><p>&nbsp;</p><p>heres some reading</p><p>http://science.howstuffworks.com/suitless-space-walk1.htm</p> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">I don't think I'm alone when I say, "I hope more planets fall under the ruthless domination of Earth!"</font></strong></p><p><font color="#0000ff">SDC Boards: Power by PLuck - Ph**king Luck</font></p> </div>

 

[_Simon_]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Welcome to SDC Simon.&nbsp;&nbsp; If a human was exposed to the vacumm of space it would not freeze immediately.&nbsp; A vaccum is the perfect insulator because theres next to nothing in which heat can transfer. &nbsp; So the body would actually "cook" itself to an extent since the body has no way to cool itself. &nbsp; Unprotected skin exposed to the light of the sun would suffer sun burns, and further increase in body temperature.&nbsp;&nbsp; In a vacuum water spontaneous converts to a vapor, So I'm guess the eyes, muscles, organs, mouth, and other soft tissue will have a hard time and bloating occurs.&nbsp;heres some readinghttp://science.howstuffworks.com/suitless-space-walk1.htm <br /> Posted by neuvik</DIV><br /></p><p>Thank you for the response and the link. That cleared things up. But the answer led me to another question. Does the sunbeams lose strength the further away from the sun they travel? I understand that the quantity of beams decreases but the beam itself, is it as dangerous to be exposed to it if floating in space just outside earth compared to a distance further away from the sun? &nbsp;</p> <div class="Discussion_UserSignature"> </div>

 

[neuvik]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thank you for the response and the link. That cleared things up. But the answer led me to another question. Does the sunbeams lose strength the further away from the sun they travel? I understand that the quantity of beams decreases but the beam itself, is it as dangerous to be exposed to it if floating in space just outside earth compared to a distance further away from the sun? &nbsp; <br /> Posted by _Simon_</DIV></p><p>There quantity of the beams don't really diminish per say.&nbsp; This is a very in depth question and way out of my hobbyist type expertise.&nbsp; But I'll give it a whirl.</p><p> &nbsp; Solar radiation, does not need a medium in which to travel.&nbsp; But for sake of argument the amount of energy does diminish on objects at a distance from the sun.</p><p> &nbsp; The Solar irridence does diminish with distance.&nbsp; However without goin into quantum mechanics for the really long range stuff, I'll give you what I sort of know.&nbsp; Hopefully a more knowledgeable member can swing by and give a better explanation.&nbsp;&nbsp; </p><p>Solar Irridance can be calculated for a planet with the equation: </p><p>S = S* cos(z)(R/r)^2&nbsp; </p><p>Where S is solar irradiance at the "begening of the atmosphere," S* is the solar isolation average, &nbsp; Z is the solar zenith angle, and (R/r) is the sun to planet distance.</p><p>&nbsp;Thats a very basic equation; and the break downs for cos(z) and (R/r) have specific information needed based on the object in question.</p><p>&nbsp;</p><p>I didn't talk about the thermodynamics of solar radiation, because that also has a lot of variables. The energy and transfer rate can be calculated on a surfrace area macroscopically with the Stefan-Boltsmann law. &nbsp;</p><p>&nbsp;</p><p>I hazard to guess on which area of our solar system, if any is a better place to experiance a vacuum; but I'd say I'd want to be closer to earth. &nbsp;&nbsp; However I should think that being immerised in a vacuum in Plutos region would increase the time at which the body will freeze.&nbsp; </p> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">I don't think I'm alone when I say, "I hope more planets fall under the ruthless domination of Earth!"</font></strong></p><p><font color="#0000ff">SDC Boards: Power by PLuck - Ph**king Luck</font></p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thank you for the response and the link. That cleared things up. But the answer led me to another question. Does the sunbeams lose strength the further away from the sun they travel? I understand that the quantity of beams decreases but the beam itself, is it as dangerous to be exposed to it if floating in space just outside earth compared to a distance further away from the sun? &nbsp; <br />Posted by _Simon_</DIV></p><p>There really is no such thing as a "beam" from the sun.&nbsp; You can think of the sun as a hot sphere that emits radiation outward in a radial direction.&nbsp; The intensity of that radiation is inversely proportional to the area over which it is distributed.&nbsp; So the nearer you are to the sun the more intense is the heat.&nbsp; An individual photon of light has a specific amount of energy and that does not change with distance.&nbsp; The number of photons that strike a surface drops and the inverse of the square of the distance.</p><p>Consider a spherical shell with the center at the center of the sun.&nbsp; That shell will be uniformly irradiated by the sun, just because of symmetry.&nbsp; The area of the shell is 4pi * radius^2.&nbsp; So the intensity of the light/heat being received is inversely proportional to the square of the distance from the center of the sun.</p><p>In space there is no loss of heat due to conduction because a vacuum cannot conduct heat.&nbsp; But heat can be absorbed or lost through radiation.&nbsp; Heat is radiated at a rate that varies with the 4th power of absolute temperature.&nbsp; The sun is very hot, so objects exposed to direct sunlight are readily heated.&nbsp; But most of space is very cold, the background temperature being only about 2.72K so objects at normal room temperatures radiate heat very quickly to that background and cool quickly.&nbsp; So an object in space is likely to be quite warm on sides facing the sun and cool on surfaces that look out towards deep space.&nbsp; Somewhere in between for objects pointed towards Earth, if in low Earth orbit.&nbsp; </p> <div class="Discussion_UserSignature"> </div>

 

[aphh]

<p>It has not been verified, that a human could only survive some 10 - 15 seconds in space without a spacesuit. It could be in the minutes. Even if you lost consciousness, you might still be recoverable.</p><p>All of the sources claim that one's fluids would immediately boil in the vacuum of space. However, your fluids would not be directly subject to the vacuum on space, as a human being is basically a tight closed container. You have internal pressure also created by muscles and blood circulation packed tightly inside a thick skin. That would not go away in space and would keep your fluids from boiling instantly.</p><p>Obviously without air pressure around you, your body would start to expand. If you exhaled just before you exited the spacecraft without a pressure suit, a lung rupture could occur. It is important to inhale just before exiting the craft.</p><p>So the problems in space would be related to the temperature extremes plus cosmic radiation. As there is no air in space you could not control your attitude in space without mechanical aid. Hence if your face pointed to sun when you exited the craft, you could not turn your body around to try to distribute the heat from the sun evenly. This would quickly become a problem.</p><p>The famous scene where Dave makes if from the pod back to the spacecraft without a pressurized suit could very well be realistic. You could survive space without boiling your fluids. Nobody has first hand information, so it is largely speculation.&nbsp;</p>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>It has not been verified, that a human could only survive some 10 - 15 seconds in space without a spacesuit. It could be in the minutes. Even if you lost consciousness, you might still be recoverable.All of the sources claim that one's fluids would immediately boil in the vacuum of space. However, your fluids would not be directly subject to the vacuum on space, as a human being is basically a tight closed container. You have internal pressure also created by muscles and blood circulation packed tightly inside a thick skin. That would not go away in space and would keep your fluids from boiling instantly.Obviously without air pressure around you, your body would start to expand. If you exhaled just before you exited the spacecraft without a pressure suit, a lung rupture could occur. It is important to inhale just before exiting the craft.So the problems in space would be related to the temperature extremes plus cosmic radiation. As there is no air in space you could not control your attitude in space without mechanical aid. Hence if your face pointed to sun when you exited the craft, you could not turn your body around to try to distribute the heat from the sun evenly. This would quickly become a problem.The famous scene where Dave makes if from the pod back to the spacecraft without a pressurized suit could very well be realistic. You could survive space without boiling your fluids. Nobody has first hand information, so it is largely speculation.&nbsp; <br />Posted by aphh</DIV></p><p>Maybe you could enlighten me as to the physiology that protects your lungs in that situation.</p><p>As I thought I understood it, there is not much between the lungs and the pressure of the environment through the nasal cavities and the nose.&nbsp; In that case an inflated or partially inflated lung ought to empty through the nose to the vacuum.&nbsp; That would expose all of the small blood vessels in the the lungs to a vacuum or near vacuum.&nbsp; At that point I would expect any gasses in the blood to come out of solution (as happens to divers experiencing the bends). I would not be surprised if that caused massive hemorrhaging as capillaries ruptured.</p><p>What prevents this scenario from occurring?<br /></p> <div class="Discussion_UserSignature"> </div>

 

[neuvik]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>What prevents this scenario from occurring? <br /> Posted by DrRocket</DIV></p><p>Hollywood...duh.&nbsp;</p> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">I don't think I'm alone when I say, "I hope more planets fall under the ruthless domination of Earth!"</font></strong></p><p><font color="#0000ff">SDC Boards: Power by PLuck - Ph**king Luck</font></p> </div>

 

[derekmcd]

<p>This link seems to provide a fairly comprehensive description:</p><p>http://www.sff.net/people/geoffrey.landis/vacuum.html</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[aphh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This link seems to provide a fairly comprehensive description:http://www.sff.net/people/geoffrey.landis/vacuum.html <br /> Posted by derekmcd</DIV></p><p>This is rather significant information and topic, as the vacuum during a space mission is always a possibility. Maybe the astronauts could train for vacuum incidents and become hardened, like free-divers become hardened for extreme depths? </p>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This link seems to provide a fairly comprehensive description:http://www.sff.net/people/geoffrey.landis/vacuum.html <br />Posted by derekmcd</DIV></p><p>Interesting article.&nbsp; But it did not quite answer my question.&nbsp; Unless there is a mechanism that I don't understand (a distinct possibility) the higher pressure in the lungs will immediately vent through the nasal passages and the nose to the ouside vacuum, limited only by the available flow area.&nbsp; I don't see how you hold your breath under those circumstances.&nbsp; And once the lungs are at zero pressure I don't know what holds the tiny blood vessels together under the presssure of the gasses that would be coming out of solution.&nbsp;&nbsp; Maybe that is what is going on during the 9 or so seconds before loss of consciousness.</p><p>In any case it looks like the only credible outcome is death, and pretty quickly. <br /></p> <div class="Discussion_UserSignature"> </div>

 

[Mee_n_Mac]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Interesting article.&nbsp; But it did not quite answer my question.&nbsp; Unless there is a mechanism that I don't understand (a distinct possibility) the higher pressure in the lungs will immediately vent through the nasal passages and the nose to the ouside vacuum, limited only by the available flow area.&nbsp; I don't see how you hold your breath under those circumstances.&nbsp; And once the lungs are at zero pressure I don't know what holds the tiny blood vessels together under the presssure of the gasses that would be coming out of solution.&nbsp;&nbsp; Maybe that is what is going on during the 9 or so seconds before loss of consciousness.In any case it looks like the only credible outcome is death, and pretty quickly. <br />Posted by <strong>DrRocket</strong></DIV><br /><br />How about pinching your nose and closing your mouth.&nbsp; Might live for a few more seconds that way.&nbsp; Better close your eyes too, their surface will&nbsp;flash freeze pretty quickly I'd think.&nbsp; Don't know what you'd do with your ear drums .... <div class="Discussion_UserSignature"> <p>-----------------------------------------------------</p><p><font color="#ff0000">Ask not what your Forum Software can do do on you,</font></p><p><font color="#ff0000">Ask it to, please for the love of all that's Holy, <strong>STOP</strong> !</font></p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>How about pinching your nose and closing your mouth.&nbsp; Might live for a few more seconds that way.&nbsp; Better close your eyes too, their surface will&nbsp;flash freeze pretty quickly I'd think.&nbsp; Don't know what you'd do with your ear drums .... <br />Posted by mee_n_mac</DIV></p><p>Actually the article indicates that if you did that, the pressure differential between the lungs and the thorax would result in tissue rupture going that direction.&nbsp; In fact it suggests that such a strategy is counter-productive.&nbsp; I hadn't thought avout the eyes, but a 1-atmosphere pressure drop across the eyeball would not do you any good either.&nbsp; I'm not sure about the flash freezing, but moisture ought to evaporate pretty quickly. &nbsp;It looks like your basic lose-lose situation.<br /></p> <div class="Discussion_UserSignature"> </div>

 

[derekmcd]

I wonder if your lungs collapse after the air escapes thus protecting the capillaries?&nbsp; I would also guess that it would be a natural instinct to close your eyes as a defense mechanism as soon as your brain realizes they are in jeopordy.&nbsp; It certainly wouldn't be anything like Arnold in 'Total Recall'.<br /> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I wonder if your lungs collapse after the air escapes thus protecting the capillaries?&nbsp; I would also guess that it would be a natural instinct to close your eyes as a defense mechanism as soon as your brain realizes they are in jeopordy.&nbsp; It certainly wouldn't be anything like Arnold in 'Total Recall'. <br />Posted by derekmcd</DIV></p><p>I don't know.&nbsp; They might, but that is a hell of a way to protect the capillaries.&nbsp; Basically it seems that vacuums are bad for you.&nbsp; Avoid them.</p><p>That probably means that one ought not attempt an intellectual discussion with a politician.<br /></p> <div class="Discussion_UserSignature"> </div>

 

[a_lost_packet_]

Everything I have seen discussed concerning sudden exposure to vacuum includes emptying the lungs of as much air as possible to prevent a sudden and violent release.&nbsp; Close your eyes, empty your lungs and cross your fingers.&nbsp; Bending over and kissing your butt goodbye would probably be a good idea if you are fond of it as you might only have a couple of minutes of agony before you're unconscious. <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[nimbus]

Trying to move your eardrums one way or another (as during a flight) by pinching your nose and blowing against them can have the air trying to exit via your eyes. &nbsp;So they would be a leak.. And IIRC there's the eustachian tubes, though I don't know how strong/weak the barrier in these is. <div class="Discussion_UserSignature"> </div>

 

[skeptic]

<p>This is a very good question and one which I became aware of while reading Robert Heinlein's 'Have Spacesuit Will Travel' about 45 years ago.&nbsp; Yes space is an insulator so an object in space cannot get rid of heat by conduction or convection, only by radiation.&nbsp; If the object doesn't produce heat of it's own it will eventually reach equilibrium when the heat it radiates equals the heat it absorbs.&nbsp; In deep space that temperature would be close to absolute zero. </p><p>I have wondered how the space station gets rid of it's heat.&nbsp; I presume it has quite a few instruments aboard that generate substantial heat.&nbsp; It must also pick up heat from the sun and being near the earth means that the heat it radiates towards the earth must be about equal to what it receives from the earth. Does anyone here have any about how our satellites cool themselves?</p><p>&nbsp;</p><p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Hey all!&nbsp;I just became a member of this forum but I have been reading other peoples post for some time now and I find them to be very interesting.I have a question though. And forgive me if this has ben asked before. In many Sci-fimovies when people are exposed to the vacuum of space without any suits they instantly freeze up like popsicles. I find this to be somewhat unbelievable. What i mean is if space is vacuum then what is there to keep the cold temperature?&nbsp;I was watching "Sunshine" the other day and the same thing happened there. Now, I dont have an education in space-science so forgive me if this question seems a bit ignorant. =)&nbsp;&nbsp;And I also want to point out that English is not my first language if you&acute;re wondering about my spelling.&nbsp;Take care! <br /> Posted by _Simon_</DIV><br /></p>

 

[lukman]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Interesting article.&nbsp; But it did not quite answer my question.&nbsp; Unless there is a mechanism that I don't understand (a distinct possibility) the higher pressure in the lungs will immediately vent through the nasal passages and the nose to the ouside vacuum, limited only by the available flow area.&nbsp; I don't see how you hold your breath under those circumstances.&nbsp; And once the lungs are at zero pressure I don't know what holds the tiny blood vessels together under the presssure of the gasses that would be coming out of solution.&nbsp;&nbsp; Maybe that is what is going on during the 9 or so seconds before loss of consciousness.In any case it looks like the only credible outcome is death, and pretty quickly. <br />Posted by DrRocket</DIV><br /><br />Regarding pressure differential, we dont need to go too far for an&nbsp;example.&nbsp;Many commercial airplanes&nbsp;experienced explosive decompression only at only several thousands of meter above sea level. Some accidents are: BOAC Flight 781, South African Airways Flight 201 (suspected), Aloha Airlines Flight 243, China Airlines Flight 611, Japan Airlines Flight 123.</p><p>I dont understand Pressurisation/Decompression very much, so i also have a question, which is more severe, human at&nbsp;1 atm pressure being exposed to a vacum, or a diver adapted to 100m undersea, suddenly have to experience 1 atm.</p> <div class="Discussion_UserSignature"> </div>

 

[aphh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Does anyone here have any about how our satellites cool themselves?&nbsp; <br /> Posted by skeptic</DIV></p><p>Don't forget, that a orbiting satellite spends roughly 45 minutes in the Sun and 45 minutes in the dark during one orbit.&nbsp; Also, the sun facing angle of a satellite is called Beta-angle. If the 45 minutes of direct sunlight is too much, the satellite changes attitude so that the other side faces sun.&nbsp;</p>

 

[aphh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>or a diver adapted to 100m undersea, suddenly have to experience 1 atm. <br /> Posted by lukman</DIV></p><p>This would be lethal. It is true that deep sea divers do not breathe air, but a mixture of helium/oxygen, so no nitrogen bubbles could be formed in the circulation of the diver.</p><p>Despite lack of nitrogen, I'm sure a rapid change of 100 atm -> 1 atm would be really unhealthy.</p><p>It must be noted, that the best free divers can sustain this. Nobody really knows how.&nbsp;</p>

 

[aphh]

<p>I just today read about a recent accident, where the diver was working in the depth of 50 metres when his air supply stopped working and he had to make a emergency surfacing without stops. He survived.</p><p>The article said that the danger in a emergency surfacing is rapid lowering of pressure, that could rupture lungs. If compressed air is used (not recommended down in 50 metres), nitrogen bubbles form in the circulation during emergency surfacing, which is extremely dangerous aswell.&nbsp;</p>

 

[Cygnus_2112]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This is a very good question and one which I became aware of while reading Robert Heinlein's 'Have Spacesuit Will Travel' about 45 years ago.&nbsp; Yes space is an insulator so an object in space cannot get rid of heat by conduction or convection, only by radiation.&nbsp; If the object doesn't produce heat of it's own it will eventually reach equilibrium when the heat it radiates equals the heat it absorbs.&nbsp; In deep space that temperature would be close to absolute zero. I have wondered how the space station gets rid of it's heat.&nbsp; I presume it has quite a few instruments aboard that generate substantial heat.&nbsp; It must also pick up heat from the sun and being near the earth means that the heat it radiates towards the earth must be about equal to what it receives from the earth. Does anyone here have any about how our satellites cool themselves?&nbsp; <br /> Posted by skeptic</DIV></p><p>&nbsp;</p><p>All spacecraft have radiators. They usually placed on the spacecraft. 90 -180 degrees from the sun&nbsp; The panels on the ISS that are 90 degrees to the solar arrays are radiators. Theyre are two sets on radiators consisting of 3 panels each on the truss that bracket the modules.&nbsp; They are at about a 45 dgress angle. </p><p>http://spaceflight1.nasa.gov/gallery/images/shuttle/sts-124/hires/s124e010042.jpg</p><p>&nbsp;</p><p>The shuttle has huge radiators that deploy when the payload bay doors are open. &nbsp; </p>

 

[Cygnus_2112]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Don't forget, that a orbiting satellite spends roughly 45 minutes in the Sun and 45 minutes in the dark during one orbit.&nbsp; Also, the sun facing angle of a satellite is called Beta-angle. If the 45 minutes of direct sunlight is too much, the satellite changes attitude so that the other side faces sun.&nbsp; <br /> Posted by aphh</DIV></p><p>&nbsp;</p><p>Spacecraft have to have heaters and radiators to cope with the temp differences of "day and night".&nbsp; Even when in the sun, spacecraft have heaters on the shaded parts, because most spacecraft can't change attitude because requirements dicate that a sensor or antenna must be pointed in a certain directions </p>

 

[neilsox]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;Spacecraft have to have heaters and radiators to cope with the temp differences of "day and night".&nbsp; Even when in the sun, spacecraft have heaters on the shaded parts, because most spacecraft can't change attitude because requirements dicate that a sensor or antenna must be pointed in a certain directions <br />Posted by Cygnus_2112</DIV><br />If I recall correctly Apolo 13 got cold when nearly all the systems failed and thus stopped producing waste heat. With normal systems operating, the radiators need to dispose of waste heat to avoid cooking the astronauts when in sunlight.</p><p>Likely a&nbsp; naked human&nbsp;without a space suit would rotate fast enough to keep body temperature, not much colder than the side facing the sun. Black skin or dull dull black clothing would absorb more heat from the sun.</p><p>It would be important to exhale as the pressure dropped. My guess is Dr Rocket is correct, minor lung damage would occur almost imediately due to near vacuum inside the lungs. Keeping eyes closed would reduce eye damage.&nbsp;Holding one's breath might be helpful after the lungs were almost empty of air.&nbsp;I'll guess 5 minutes of hard vacuum would mean not even intensive care could prevent death&nbsp;within an hour. A pressure drop of 1/2 atmosphere in one second might produce death in about one&nbsp;more second. A sudden change is very damaging. &nbsp;Neil</p>