...The Mpemba effect describes the phenomenon that hot water may freeze faster than cold. To precisely state what is Mpemba impact, begin with two containers of water, same in shape, and with same amounts of water. The only difference is the water temperature one is at a higher temperature than the water in the other. cool two containers, using the exact same cooling process for both containers. In some conditions at first warmer water will freeze first. It means the Mpemba effect happens. Here's the proof. Say that it takes 10 minutes to freeze the initially cooler water starts at 30°C , while the initially warmer water starts out at 70°C. Now the initially warmer water needs more cooling time to get to get down to 30°C, then it needs 10 more minutes to freeze. So since the initially warmer water has to do everything that the initially cooler water has to do, plus a little more, it will take at least a little longer. Somehow, the hot water must be able to lose its heat faster than the cold water. Evaporation- Theoretical calculations have shown that evaporation can explain the Mpemba effect if you assume that the water loses heat solely through evaporation . When the initially warmer water cools to the initial temperature of the initially cooler water, it may lose significant amounts of water to evaporation. The reduced mass will make it easier for the water to cool and freeze. Then the initially warmer water can freeze before the initially cooler water, but will make less...
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...Comparison and Contrast Essay Hot and Cold Weather Comparisons Albert Weyant COMM/215 - Essentials of College Writing September 15, 2012 Dr. Nancy Reynolds Hot and Cold Weather Hot and cold climates will be discussed and the different comparisons between them. I will state my opinions and objectives pertaining to the two climates. The differences I will discuss are the climates, activities, and locations. Millions of people prefer to use the two different climates to accommodate themselves when the climates are in a comfortable temperature for them. Each year many lives are lost because of heat stroke and flu. The numbers are not very close. Four times as many people die from flu than heat stroke related deaths. Some prefer hot over cold and some, cold over hot. The differences between hot and cold are extreme. People have their own reasoning for the preferences. The first difference between Hot and Cold Weather are the climates The American Heritages, “the long-term prevalent weather conditions of an area, determined by latitude, position relative to oceans or continents, altitude, etc.,” describe climate. (2005). Climate, described by Merriam-Webster, is, “the non-specialist, climate means expected or habitual weather at a particular place and time of year. To the specialist...
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...Khristle Joy Hutalla BSBA 2301 Questions 1. In the case study, we referred to the systems being developed and used as decision support systems. However, we also identified various artificial intelligence (AI) technologies. How can a decision support system incorporate and use AI technologies such as pattern recognition? - Artificial Intelligence (AI) tools and techniques can aid in the diagnosis of disease states and assessment of treatment outcomes, so AI can be used by a decision support system as pattern recognition to analyze healthcare data and generate a representation of knowledge and make a decision support. One of this AI technologies tools is the Artificial Neural Networks which work much like the human brain and have the ability to learn from training data and store knowledge in the network. It maps relationship between inputs and the corresponding expected outputs. Neural networks have found the majority of their application in time series prediction, signal processing, and financial forecasting and especially in health care as pattern recognition. 2. At the Mayo Clinic, patients are given opt-in and opt-out rights concerning whether or not their information is used in the system that determines the most appropriate therapies given the specific patient profile. So far, 95 percent of the patients have opted to have their information included in the system. (This is the notion of opting in.) Why do you believe that 5 percent of the patients have opted out...
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... Table of Contents: Nomenclature. Pg. 3 Introduction and Background Pg. 4 Experimental Methodology Equipment and Apparatus Pg. 6 Experimental Procedures Pg. 7 Results Pg. 8 Analysis and Discussion……………………………………………………………………..Pg. 11 Summary and Conclusions Pg. 12 References Pg. 13 Appendices Pg. 14 Nomenclature Symbol | Term | Units | A | Heat transfer surface area for the tubes | Inches2 (in2) | Cp | Heat Capacity | J/(mol*K) | F | Correction Factor | __ | | Heat | W | c | Cold Side Heat Duty | W | H | Hot Side Heat Duty | W | Shell Side | Hot Side | __ | T | Temperature | Celsius | ∆T | Change in Temperature | Celsius | Tube Side | Cold Side | __ | ∆Tlm | Log mean temperature difference | Kelvin (K) | U | Heat Transfer Coefficient | W/(K*in2) | V | Volume | L | ṁH | Hot water flow rate | L/min | ṁC | Cold water flow rate | L/min | 1.0 Introduction and Background A heat exchanger is a device designed to efficiently transfer thermal energy from one fluid to another fluid, which can be a liquid or a gas [1]. These fluids do not mix or come into direct contact with each other. Even though all heat exchangers do the same job of passing heat from fluid to fluid, there are various types that work in many different ways. The two most common types of heat exchangers are the shell-and-tube and plate/fin. In shell-and-tube heat exchangers, one fluid...
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...Temperature and Response time measurement Abstract In this experiment, a Resistive Thermal Device (RTD) and thermocouple were calibrated for first order measurement. Then, the response times of the RTD and thermocouple sensors were calculated. After performing this experiment, it was found that the time constants for the RTD were found to be -78.7 for cold to hot and 17.39 for hot to cold. The time constants for the thermocouple were found to be 3.519 for cold to hot and 2.64 for hot to cold. The rise times for the RTD were found to be 7.39 for cold to hot, and 7.9 for hot to cold. The rise times for the thermocouple were found to be 1.14 for cold to hot, and 1.27 for hot to cold. The error band for the RTD was found to be ±.0075, and the error band for the thermocouple was found to be ±.3887. Nomenclature T Time τ Time Constant E Error Band INTRODUCTION A Resistive Thermal Devices is a sensor used to measure the temperature by correlating the resistance of the RTD element with temperature. An RTD most commonly consists of a length of fine coiled wire wrapped around a glass or ceramic center. The element of the RTD is made of a pure material so its resistance can be calculated at various temperatures [1]. A thermocouple is that consists of two conductors which produce a voltage proportional to a temperature difference between either end of the pair of conductors. This allows for the measurement of the temperature at broad ranges...
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...Hot packs are used to soothe stretched out or injured muscles. You are probably wondering what a hot pack is; a device that you put on a sore spot and that device starts to become warm. You can get hot packs from where you get your groceries, online, pharmacies, etc. Inside of the hot pack are sodium acetate crystals which trigger the device to become warm. This process is called exothermic, meaning release of heat/energy. Hot packs can potentially soothe your injuries or sore spots. Hot packs and cold packs are different devices, but they can be used to heal/soothe the same sore spot or injury on your body. When you first activate a hot pack it takes time for it to actually start to get warm. When you place the hot pack into warm/hot water the heat flow is usually high temperature to a low temperature, when the water has reached the hot pack. There is a balance of systems for the hot pack. Cold packs are the opposite of a hot pack but can do the same thing as a hot pack, which is heal an injury. Cold packs and hot packs are different, but both types of packs can heal you....
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...Calculations: In order to calculate the initial temperature of the hot water less complicated calculations find mass of cold water, and mass of mixed water are done by subtracting the total mass of (mixed or cold )waters and cup combined by the mass of the cup alone. Equation 1 Mass of Water and cup – Mass of cup = Mass of water Ex. From calculating mass of mixed water trial 1 139.786 g of mixed water and cup -15.436 g of cup = 124.35 g of mixed water 90.334 g of cold water and cup -15.436 g of cup = 74.898 g of cold water Another less complicated calculation was done to find the mass of hot water Equation 2 Mass of Mixed water-mass of cold Water = mass of Hot Water Ex. From trial 1 124.35 g of mixed water - 74.898 g of cold water=49.452 g of hot water Next in order to calculate the initial temperature of the hot water without being able to measure it with a thermometer the Calorimetry equation 3 must be used. Equation 3 q=m×C ×∆T * q is the heat change of the system (joules, J) * m is the mass(grams, g) * ∆T is the Temperature change, Tfinal-TinitialC * C is the specific heat for that substance(Jg ° C) After calculating the Heat change of the system using equation one we can use equation two ; The law of conservation of energy which states that while energy can be converted or transferred, it is not created or destroyed. Equation 4 qsystem + qsurroundings=0 Or qsystem = -qsurroundings Therefore if the heat change of the surroundings...
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...COLORS Expression Every people has its own way of saying things -- its own special expressions. Many everyday American expressions are based on colors. Red is a hot color. Americans often use it to express heat. They may say they are “red hot” about something unfair. When they are "red hot" they are very angry about something. The small hot-tasting peppers found in many Mexican foods are called “red hots” for their color and their fiery taste. Fast, loud music is popular with many people. They may say the music is “red hot” -- especially the kind called Dixieland jazz. Pink is a lighter kind of red. People sometimes say they are “in the pink” when they are in good health. The expression was first used in America at the beginning of the 20th century. It probably comes from the fact that many babies are born with a nice pink color that shows that they are in good health. Blue is a cool color. The traditional blues music in the United States is the opposite of red hot music. Blues is slow, sad and soulful. Duke Ellington and his orchestra recorded a famous song -- “Mood Indigo” -- about the deep blue color, indigo. In the words of the song: “You ain’t been blue till you’ve had that Mood Indigo.” Someone who is blue is very sad. The color green is natural for trees and grass. But it is an unnatural color for humans. A person who has a sick-feeling stomach may say she feels “a little green.” A passenger on a boat who is feeling very sick from high waves may look...
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...us or to our body, the message that sent to the brain, from our 4 experiment I’m going to choose and discuss the following 3: 1st –I’m going to take a piece of very coarse sandpaper and I’m going to rub my index for f\a few times very gently, and count rate its coarseness on a scale from 1 (very soft) to 7 (very coarse). 2nd - I’m going to take a cup with water added sugar and another cup of regular drinking water, I’m going to take a sip and swished around in my mount for couple second and after I’m going to drink the regular water and see what type of sensor adoption experience I’m going to have. 3rd- I’m going to take 3 bowls each has waters inside the 1st bowl hot water, 2nd bowl cold water and the 3rd bowl with lukewarm water, I’m going to put my right hand inside the cold water bowl, my left hand in the hot water I’m going to leave my hands like 3 minutes and after the 3 minutes I’m going to put my both hands in lukewarm water and I’m going to explain what I felt, what was my sense (Kent Van Cleave,2014 para 2 to 13). My experiment results are. The 1st experiment that I choose is the sensor of the sandpaper experiment, I took coarse sandpaper and I did the following I rubbed my index very gently from 1 to 7, the first couple times tis start bothering my fingers, but after I felt less coarse than the first time and what I adopt from my experiment was that my sense adoption got use to the coarse of the sand paper. The 2nd experiment that I’m...
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...Benefits of Hot Water Bottles Do you remember when your mum used to place a hot water bottle in the middle of your bed ready for bedtime? Bet, like many, a hot water bottle is not amongst the must-have items in homes nowadays and if that is the case then why not? Hot water bottles are not just for warming bedsheets on a cold winter’s night, they have so many more benefits. Period Pains Most women will agree that the worst part of being a woman is the period pains they suffer every month – some worse than others. Those in the know, thanks to mothers, aunts, grandmothers, reach for a hot water bottle and hug it tight. The warmth from the hot water bottle acts in the same way as placing a hot flannel on a painful part of our bodies. Both help to take away the pain and discomfort. Backache Back pain can be particularly painful and for regular suffers adding some heat to the afflicting areas brings some much needed relief. The heat from a hot water bottle stimulates the blood flow and encourages the healing nutrients in our body to gather around the affected area of the back. Toothache For those who have ever had a toothache know the pain can be excruciating and trying to find something that will alleviate some of the pain makes the situation worse. Adding some heat to the cheek will help bring some relieve, but don’t go putting a red hot water bottle straight onto your face. If possible, try using one that is covered or wrap the hot water bottle in a pillowcase...
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...School of Mechanical and Design Engineering Dublin Institute of Technology Bachelor of Engineering Technology in Mechanical Engineering Laboratory 2 Plate Heat Exchanger Assignment Robert O’Donovan Student Number: C12756051 Due Date: 24/10/2014 Lecturer: Jim Ffrench Dublin Institute of technology Bolton Street, Dublin 1. I. Abstract Heat exchangers are a piece of process equipment used for heat transfer between two media. The media do not come into direct contact and there is no mixing. Heat is transported from the hot medium to the cold medium by way of a heat conducting partition. In this experiment, we analysed the working principle of parallel and counter flow. We observed different fluid temperatures, fluid flow rates and how this affected the heat exchangers performance. Calculations were needed to determine the variation of the two configurations. There are some possible percentage errors that need to be considered in the experiment, these include the tube changeover from parallel to counter flow, the fluid loss will have an effect on the readings. Also if the unit is not allowed enough time to stabilise when changing the flow rates, the readings will not be accurate. 1"Vh"(L/min) Parallell"flow Counter"flow Vs U"= U"= 3"Vc"(L/min) 2.9"W/m 2 K 3.5"W/m 2 K The percentage difference between the U values is 20.6 %. II. Table of Contents 1. INTRODUCTION ...............
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...over a piece of very coarse sandpaper a few times and rate its coarseness on a scale from 1 (very soft) to 7 (very coarse). After a minute or two, rub the same finger over the paper and again rate its coarseness. Did your perception of the coarseness change? How? Record your reaction. In experiment 2 we will Prepare one cup with sugar water and one with fresh water. Take a sip of the sugar water and swish it around in your mouth for several seconds without swallowing it. Gradually, it should taste less sweet. (Dispose of the sugar water) Taste from the cup containing fresh water. Did the taste of the fresh water surprise you? How? Record your reaction. Finally experiment 3 we will Fill 3 medium-sized bowls as follows: Bowl 1 – with very hot (but...
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...motivate our employees and carry out an external environmental analysis. After a discussion, our group decided to open a company in the beverage industry as we are passionate about coffee. We spent two weeks doing our respective research before finalizing on the name of our company as well as the management functions. The three parts of this assignment was split equally among the five of us. Through this assignment, we have gotten a better grasp of the four functions of business management. 3.0 Introduction- background of the company Hot & Cold Company is a newly launched coffee company in beverage industry. Currently, we have a café that sells beverages and light food. It is a partnership between Quek Li-Ann, Wong Jing Yee, Lim Cheng Ching, Nasirah bt. Hakim and Goh Kar Yun. All five of us are passionate for coffee. Thus, we decided to turn our passion into a money-making business. The company is named as ‘Hot & Cold’ as both hot and cold coffees are delicious in their own ways. We want to offer our customers the best of both worlds. Our target market are students and working people as our company can provide leisure time for them to relax and improve their relationships among partners and friends. 4.0 4.1 Planning The planning of the company will be setting out the vision and mission. The mission of our company is to provide our consumers with specially brewed coffee at a reasonable price. We will provide a clean and comfortable environment inclusive of a close and...
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...Sugar Water and Fresh Water- I took one cup and put two teaspoons of sugar in with fresh water and stirred it. In the second cup I only put fresh water in it. I then took the cup with sugar water in it and took a sip and swished it around in my mouth. I noticed that I could feel my taste buds were stimulating but after a few seconds they became less stimulated. When I had tasted the fresh water and swished it around, I noticed that I tasted a hint of salt. It surprised me because I wasn’t expecting to taste salt beings that I didn’t add any to the water. So I believe that the fresh water had more of an affect over the sugar water. Experiment 3 with Cold, Hot and Lukewarm Water- I placed three bowls on the table. In the right bowl I added cold water. In the right bowl I had added very hot water and in the middle bowl I added lukewarm water. I placed my right hand in the bowl on the right and...
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...Desert There are two types of deserts Hot and Cold Where is the Desert located? • Covers about one fifth of the Earth’s land surface • Most Dry deserts are cold deserts • Most are near the Tropic Of Cancer or the Tropic of Capricorn • And also near the Artic Part of the Earth Climate Average Precipitation: Hot and Dry deserts have very little rainfall /short periods between long rainless periods 5cm is usually the amount of rain the desert gets Average Temperature: Hot Deserts: extreme temperature is 20 degrees to 25 degrees C Average ranges from 43.5 to 49 degrees C 5 Cold Deserts: • In the winter the cold deserts temperature is 2 degrees to 40 C and in the summer the temperature is 21 degrees to 26 degrees C • The Hot dry deserts are warm throughout the Fall and Spring seasons and very hot during the summer Animals • Borrowers • Mourning Wheatears Hot Deserts • Horned Vipers • Cactus Ferruginoug Pygmy Owl • Antelope • Ground Squirrels Cold Deserts • Jack Rabbits • Kangaroo Rats Adaptions • The Kangaroo Rat gets water from the food it eats • The Kangaroo Rat also has a cheek pouch which stores food while searching for shelter • The Cactus Ferruginoug Pygmy Owl adapts by sleeping in cactus during the winter Plants • Turpentine Bush • Prickly Pears • Brittle Bush • Shrubs • Short Woody Trees Adaptions • The ability to store water for long periods of time • And...
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