Refrigeration Refrigeration is defined as “The process of removing heat from an
enclosed space, or from a substance, to lower its pressure.” (First
website given in bibliography) In simpler terms, it is removing heat
from states of matter in order to keep them cooler. The basic need
for refrigeration is to cool food and beverages, as they often get
spoilt if the temperature is high. Before actual refrigerators and
other such mechanical systems were introduced, it was very common for
people to cool their food with ice and snow. These materials were
either gathered from the mountains, or were provided locally. For
most of history, cellars were holes dug into the ground, covered with
ice and lined with either wood or straw.
The first known artificial system of refrigeration was demonstrated by
William Cullen in 1805; however, he did not use it for any practical
purpose. It was not till later when Oliver Evans, an American
inventor, designed the first actual refrigeration machine in 1948. As
more years past by, it was built and brought to life.
The scientific principle behind how a refrigerator actually works is
quite basic. The refrigerator uses the evaporation of a liquid to
absorb heat. This liquid is often known as the refrigerant, and when
used in the refrigerator, evaporates at a fairly low temperature.
This causes the cold temperatures within. It is based on physics, and
the 2nd law of thermodynamics. A liquid is vaporized through
compression, which requires kinetic energy. This draws the energy
needed from the direct area; causing a loss in energy and then it
Ruth Schwartz Cowan wrote “How the Refrigerator Got Its Hum” in 1983. It was included in the section, “Failed Machines” of her book. I never thought about why most refrigerators are electric. We have owned gas stoves and dryers, but never a gas refrigerator. Gas appliances cost more upfront, but are inexpensive to run over time. Personally, I would rather have gas appliances than electric and believe many other people would too; however, there are major factors that caused the gas refrigerator to fail.
An Investigation Into How the Thickness of Insulation Affects the Time a Drink Takes to Cool Down
The Effect of Temperature on the Rate of Respiration in Yeast There are two types of respiration in yeast: Aerobic: [IMAGE] Anaerobic: Glucose [IMAGE] Carbon dioxide + ethanol + energy Respiration is controlled by enzymes, which are proteins which speed up one or more biological reactions. Within any cell many chemical reactions are going on at any one time. Yeast has many different types of enzymes that speed up respiration. Prediction I predict that as temperature increases, the rate will also increase, until a certain optimum temperature, after which, the rate will decrease until the rate is zero as respiration has stopped completely. Reason
Standard Air Conditioner There are a number of standard air conditioner systems that are available on the market. One is a unitary system. The one room air conditioners sit in a window or wall opening, with interior controls. A large house or building may have several units, permitting each room to be cooled separately. Another type is the basic central air conditioning unit, which offers whole house-house cooling. It is usually a large, loud, mechanism that sits outside of the home. Although these standard air conditioners may be effective, they come with drawbacks. According to the U.S. Department of Energy, Americans spend $22 billion a year and use more than 183 billion kilowatt-hours of electricity to cool their homes with standard air conditioning. Also those air conditioners release about 100 million tons of carbon dioxide into the air annually -- two tons for each home that has one.
Cellular respiration is an important function for the body to obtain energy (Citovsky, Lecture 18). There are two types of cellular respiration; aerobic conditions and anaerobic conditions. Aerobic conditions are the cellular respiration occurred with oxygen while anaerobic conditions are cellular respiration occurred without oxygen. The most common cellular respiration is aerobic conditions where oxygen were supplied for phosphorylation (Campbell et al., pg 177). In human body, anaerobic conditions occurred when muscle cells are overworked and oxygen is depleted before it could be replenished (Citovsky, Lecture 19). This is a common phenomenon during exercise. The accumulation and production of lactic acid from anaerobic cellular respiration has been always a cause of muscle sore from intense exercise (Campbell et al., pg. 179).
In warmer climates such as Egypt they used techniques as evaporative cooling, “if water is placed in shallow trays during the cool tropical nights, its rapid evaporation can cause ice to form in the trays, even if the air does not fall below freezing temperatures”. Although refrigeration developed in the 18th century it wasn’t until the mid-19th century when the first refrigerator built using vapor technology was build by American John Gorrie in 1844. A few years later commercial refrigeration was introduced as well as vapor compression technology which was the beginning of our modern refrigeration. Later that century ammonia was popularized as the evaporation chemical in refrigeration. All the trials and tribulations of refrigeration where all stepping stones to the 20th century and the introduction of modern refrigeration as we know it
In March of 1989, a discovery was made that rocked the scientific world. Stanley Pons and Martin Fleischman had announced that they were able to create and sustain a cold fusion process. After intense media attention, and corresponding interest in future test, the subject seemed to have faded away. Future tests proved inconclusive, and when the quick promise of easy energy didn’t materialize, most quickly forgot the subject. Little is said about the continuing research in the scientific community to further our understanding of the free energy enigma. Is it science fiction, on the border of legitamete science, or is it a practical field worthy of serious attention?
Norbert Rillieux invented the triple effect vacuum evaporator. The "triple effect" is for the multiple things that the system does all at the same time. The "vacuum" is for the vacuum of air that is used in the system, and the "evaporator" is for the sugarcane liquid syrup that is heated and evaporated into regular sugar. The actual system is somewhat complicated, so please see the picture that is provided.
Also, when we put the insulation cans in warn water the water heated up the can. And lastly, in the insulated can experiments, both cooling and heating, when the cans temperature was changed it in turn changed the air temperature
Possible effects and some examples are pain in stomach, heat stroke, asthma or other allergy symptoms. So this technology is really useful for keeping our homes clean and healthy. The dehumidifier has an incredible design which solves the main issue really well; most dehumidifiers have a fan compressor, reheater, compressing cooler coils, and a reservoir. And here are how these components are broken down into three individual steps to work together and solve the issue. Firstly, a fan from a dehumidifier collects and drags air (with large amounts of moisture) into the machine. Then, as the air is being brought through, it approaches a section of the dehumidifier called the cooled coils. These coils are designed to perform the process of condensation to drag moisture away from the air that is passing through. The moisture would remain on the coils and eventually drip into the dehumidifier reservoir. Finally, the air inside the machine would be reheated and exhausted back to the room.
Willis Haviland Carrier invented the first air conditioner in 1902. This was designed to boost the working process control in a printing plant. Carrier’s invention controlled temperature and humidity. The low heat and humidity helped keep the paper dimensions and ink alignment the same. Later his invention was used to populate productivity in the workplace. The Carrier Air Conditioning Company of America developed for the increasing demands. Gradually, air conditioning was used to help increase comfort in homes and cars. Residential sales increased rapidly in the 1950's.
Therefore, the relationship between pressure drop and boil-up rate means that more volume of vapour educed per unit time results in more restriction of the holes in the sieve tray and that caused by passing of vapour through the liquid on top of the tray. Hence, the higher the velocity, the higher the boil-up rate and so does the overall pressure drop.
If you’ve ever seen the Austin Powers movie I’m sure you remember the part where they cryogenically freeze Austin and then thirty years later thaw him out to save the world. While we all know Austin Powers isn’t real, I’m sure you wondered if this freezing could be done in real life. Today we will look at what exactly cryonics is, what businesses claim to provide it, the procedure and its risks.
In thermodynamics Refrigeration is the major application area, in which the heat is transferred from a lower temperature region to a higher temperature region. The devices which produce refrigeration are known as Refrigerators and the cycle on which it operates are called refrigeration cycles. Vapour compression refrigeration cycle is the most regularly used refrigeration cycle in which the refrigerant is alternately vaporized and condensed and in the vapor phase it is compressed. Gas refrigeration cycle is the well-known refrigeration cycle in which cycle refrigerant remains in the gaseous phase throughout the cycle. Cascade refrigeration are the other refrigeration cycles discussed in this chapter; absorption refrigeration is the one more refrigeration cycle which is used where the refrigerant is dissolved in liquid before it is compressed. One more refrigeration in which refrigeration is produced by passing the electric current through two dissimilar materials is called as the thermoelectric refrigeration.