Love and Ferris Wheels Just Go Together

Love and Ferris Wheels just go together!

“…Look at our small town spinning around
We got our feet dangling high off the ground
Can you believe, baby, how good it feels
Falling in love on a Ferris wheel? Falling in love…”

Ferris Wheel, written by Michael Sarver. (C) 2010 Dream Records

February 14 is not only Valentine’s Day, but also National Ferris Wheel Day! It is the birth date of George W. G. Ferris, Jr. and he is credited for creating the first large, steel amusement ride – the Ferris Wheel.

chicagoFerriswheelImage
The 1893 Ferris Wheel

That first Ferris Wheel was unveiled in the summer of 1893 at Chicago’s World Columbian Exposition. It was the first international exposition held in the United States and the committee wanted an engineering marvel that would overshadow France’s Eiffel Tower. Having recently ridden a fifty-foot wooden “observation roundabout,” which had been built and soon would be patented by William Somers, Ferris was inspired to enter the competition with his paper-napkin drawing of an enormous park ride. The constructed 45-foot axle-wheel powered by two 1,000 horsepower steam engines was supported by two 140-foot steel towers and it carried thirty-six wooden cars 264 feet high into the air – taller than any existing buildings!

Since the original Ferris Wheel, the world has continually been trying to out-do it. In 1897, a copy of the original was erected in Prater Park, Vienna , Austria and became the longest running Ferris wheel in history.  In 1904 the Ferris wheel was again the centerpiece of the World’s Fair, this time in St. Louis. The Texas Star was built in Italy and shipped to Dallas, Texas in 1985. It was, at that time, the tallest operating Ferris wheel at 213 feet (that is 52 feet shorter than the original 1893 wheel).

The London Eye, at 443 feet, opened to the public in 2000. The Singapore Flyer, at 541 feet, became the tallest Ferris wheel in in the world in 2008. The 682 foot tall Beijing Great Wheel was supposed to be built in 2009-2010, but the parent company went into receivership and it was never completed.

High_Roller_FerrisWheel

The original Ferris Wheel had 36 cabins and each one was able to carry 60 people for a total of 2,160 people per ride. There were fancy wire chairs for 38 passengers and five large plate glass windows. The cabins were 24 feet long, 10 feet high and weighed 26,000 pounds. A conductor rode in each cabin to allay fears and answer questions.

Currently, the world’s largest Ferris wheel – or Observation Wheel – is the High Roller in Las Vegas across from Ceasars Palace. It is 550 feet tall, 107 feet taller then the London Eye. In contrast to the original Ferris Wheel each of the 28 cabins is 225 square-feet and weighs approximately 44,000 pounds. Each cabin has a diameter of 22 feet and includes 300 square feet of glass. It also has 8 flat-screen televisions and an iPod dock. The High Roller is lit by 2,000 LED lights which have multiple lighting options.  Looking for that special Valentine’s Day destination wedding? You can book a VIP cabin on the High Roller and have the wedding of your dreams!

Find the nearest Ferris Wheel and maybe, just maybe, fall in love?

 

References:

Circles in the Sky: The Life and Times of George Ferris. ENGN TA 140 .F455 W45 2009

Circles in the Sky

LINQ Hotel and Casino, High Roller FAQ ; http://www.caesars.com/linq/high-roller/faq/

Wikipedia, High Roller (Ferris Wheel) ; http://en.wikipedia.org/wiki/High_Roller_%28Ferris_wheel%29

Hyde Park Historical Society Newsletter, “The Big Wheel,” Spring 2000 ;

 

Standards

In 1978, the American Society for Testing Materials (ASTM) formed the F24 committee to create standards for the design, testing, manufacturing, and operation of amusement park rides. http://purl.lib.uiowa.edu/ASEDL

  • Standard Practice for Ownership, Operation, Maintenance, and Inspection of Amusement Rides and Devices, ASTM F770, Sept. 1, 2013 (4 pages)
  • Standard Practice for Measuring the Dynamic Characteristics of Amusement Rides and Devices, ASTM F2137, Aug. 1, 2013 (7 pages)
  • Standard Practice for Design of Amusement Rides and Devices, ASTM F2291, Aug. 1, 2013 (52 pages)

Celebrating Weatherpeople!

John Jeffries
John Jeffries Source: Wikipedia

Because the weather has a significant impact on our daily lives, National Weatherperson’s Day recognizes the scientists who track our major storms and atmospheric climate changes. The day commemorates the birth of John Jeffries who was born in Boston in 1745. He was a Harvard graduate and surgeon who became fascinated with observing the weather. Beginning in 1774, he daily measured and recorded the weather in Boston. Then, in 1784, he made a historical balloon flight across the English Channel to observe atmospheric conditions up close.

Weather balloons, anemometer cups and rain gauges have since been replaced with earth-orbiting satellites and computer-aided atmospheric modeling used for gathering data to predict long- and short-term meteorological events which will significantly impact our global atmosphere in terms of ozone levels and and movement of storms. The National Oceanic and Atmospheric Administration (NOAA) is the United States governmental body responsible for monitoring and forecasting the weather and conducting meteorological research. NASA, too, is instrumental in researching and mapping atmosopheric changes using telescopes and space stations.

Take a moment and think of your favorite and trusted meteorologist…big hint…she is your very own engineering librarian.

 

 

 

 

Satellite Weather Radar Source: IIHR
Satellite Weather Radar Source: IIHR Hydroscience & Engineering University of Iowa

References

infoplease: meteorology

infoplease: weather balloon

National Oceanic and Atmospheric Administration http://www.noaa.gov/

National Aeronautics and Space Administration http://www.nasa.gov/

Meteorological Technology World Expo 2015 http://www.meteorologicaltechnologyworldexpo.com/

 

 

Atmospheric Change book cover
Atmospheric Chemistry and Global Change Engineering Library QC879.6 .A85 1999

Books

Atmospheric chemistry and global change. New York: Oxford University Press, 1999. Engineering Library QC879.6 .A85 1999

Wallace, John M. Atmoshperic science: an introductory survey, 2d edition. Boston: Elsevier Academic Press, 2oo6. Engineering Library FOLIIO QC861.3 .W3 2006

Understanding Weather and Climate, 6th edition. Engineering Library QC861.3 .A38 2013. Engineering Library QC861.3 .A38 2013

 

 

Paper Engineering

Come and see the exhibit on Paper Engineering at the Lichtenberger Engineering Library. Paper Engineering, closely allied with chemical engineering, deals with application of math, chemistry, physics, and engineering to the pulp and paper industry; design and analysis of equipment and processes used in the manufacture of paper.1 The fascinating part of paper engineering is paper art including pop-up books, miniature books and origami (paper folding).

AliceAlice’s Adventure in Wonderland from the University’s Special Collections is a pop-book made by a pop-up book artist and paper engineer, Robert Sabuda. Before Alice came to the Engineering Library, her knee was fixed by the University Libraries Conservation Lab.

Amazing miniature books in the exhibit case are also from the University’s Special Collections. These miniature books are selected from the Charlotte M. Smith Collection.2 The suitcase is beyond cute! Inside there are three tiny books (in the white circle container), a magnifying glass to read them and larger copies of these tiny books.miniature book set

Among these miniature books in the exhibit case, you may be interested in seeing picture books: a children’s calendar in the Meiji period (over 100 years ago), the Tale of Genji (源氏物語) and Accordion to zither : a musical ABC.

Stop by and find more!

References

1 Paper Science and Engineering at the University of Wisconsin Stevens Point. Retrieved from https://www.uwsp.edu/papersci/Documents/NewFiles/Recruiting%20Panels2.pdf

2 The Charlotte M. Smith Collection of Miniature Books. Retrieved from http://www.lib.uiowa.edu/sc/smith/

Drones are taking off

Source: Make: Technology on Your Time Volume 37: Drones Take Off!
Source: Make: Technology on Your Time Volume 37: Drones Take Off! January 31, 2014 Available in the UI Lichtenberger Engineering Library periodicals section

As you take your final exam, you may find yourself shopping last minute for your family’s holiday gifts. Don’t despair. There is a day for that. December 18th is Free Shipping Day; a one-day, online-shopping event when thousands of merchants offer free shipping with delivery by Christmas Eve.1

So how do your packages go over the river and through the woods to arrive at your grandmother’s house in less than a week? Current delivery methods include carefully choreographed and computerized warehouse management structures as well as expedited ground and air express shipping services. Now, another method is rapidly taking off: commercial drones.

Typically, drones are associated with clandestine military operations. However, a year ago Amazon announced that it is developing aerial robotic technology to fly packages directly to a person’s doorstep.2 “Drones ‘will change the way we conduct some of our existing business in the not-too-distant future, but more importantly, will create completely new and world-changing applications we haven’t even thought of yet,’ said Jeff Lovin, a Woolpert senior vice president.”3

What is required to make this happen? The Federal Aviation Administration, the government agency responsible for all aircraft flying in the United States airspace, must approve of their safety. “The key safety element is to prevent drones from colliding with other aircraft, or with people on the ground. That means ensuring ways for other aircraft to detect and avoid drones, and for drones to land safely if they lose contact with remote pilots.”4

Because of the high demand for developing commercial, unmanned aerial vehicles (UAVs), the FAA is pressured to expedite rules and regulations. In a letter to the FAA, Amazon said its indoor testing of drones must now move outdoors “to practice in real-world conditions.” Paul Misener, the company’s vice president of global public policy, said the company might move its research abroad if the FAA does not act quickly. With a Congressionally mandated deadline of September 2015 looming large, the government agency has set up six test sites across the country and given exemption status to a few companies in order to learn more about how the technology works.5

What if you miss Free Shipping Day? Perhaps purchase your own Parrot AR.Drone 2.0 and personally deliver your gifts in record time.

Planning and Decision Making for Aerial Robots book cover
Bestaoui Sebbane, Yasmina. Planning and Decision Making for Aerial Robots. New York: Springer, 2014. Engineering Library TL718 .B47 2014

References

1About Free Shipping Day

2Amazon Unveils Futureristic Plan: Delivery by Drone December 2, 2013 (Source: 60 Minutes CBS News website)

3FAA Lets 4 companies Fly Commercial Drones (Source: USAToday.com, December 10, 2014)

4Ibid

5FAA’s Treatment of Amazon Proves Congress Must Act or Companies Will Take Drone Research Abroad (Source: Forbes.com, December 10, 2014)

 

 

Learn More

Association for Unmanned Vehicle Systems International

Bestaoui Sebbane, Yasmina. Planning and Decision Making for Aerial Robots. New York: Springer, 2014. Engineering Library TL718 .B47 2014

Commercial Drones (Source: Popular Science website)

Unmanned Aircraft Systems (Source: Federal Aviation Administration website – FAA.gov)

“60 Minutes” reports on the uncertainty of regulating drones March 14, 2014 (Source: YouTube)

Get Cooking; Saturday is Microwave Oven Day

Radarange
Raytheon’s Radarange. Source: How the microwave oven became a super success (http://www.marketingvp.com/guests/globe/oven.htm)

In 1942, while Dr.Percy Spencer was testing a magnetron, a candy bar in his pocket melted. This was Dr. Spencer’s ‘aha moment’ when he realized that radioactive beams can cook food. The Raytheon Company filed a patent application for Spencer’s invention on October 8, 1945. Then the company built the first commercially available microwave oven calling it the Radarange. It debuted in 1947 standing six feet tall and weighing over 700 pounds.1

Obviously, this behemoth model did not become popular in the average American home. However, during the 1970s, smaller “electronic ovens” started to make their way into the ordinary kitchen. At first, they were used reticently because the radioactive waves were considered harmful. However, the convenience of microwave cooking outweighed the fear factor. During the 1980s, the market was saturated with microwave cookbooks and products such as microwave bacon trays. Even Dire Straits references the kitchen appliance in Money for Nothing. Today’s average microwave cooks between 1000-1200 watts and is America’s sweetheart appliance for fast and convenient defrosting of frozen foods, rewarming of leftovers, or popping of corn. Bon appétit!

How does a microwave oven work? “A microwave oven produces high-frequency electromagnetic waves. Passing through food, the waves reverse polarity billions of times a second. The food’s water molecules also have polarity, and they react to each change by rapidly reversing themselves. Friction results, heating the water and cooking the food.2 For a visual explanation, watch the video, “How a Microwave Oven Works” by Bill Hammack from the Department of Chemical & Biomolecular Engineering, University of Illinois at Urbana-Champaign.

References

US Patent 2495429
Spencer, Percy L. Method of treating foodstuffs. U.S. Patent 2,495,429, filed October 8, 1945, issued January 24, 1950.

1 National Microwave Day (December 6, 2009)

2 Langone, John. How Things Work: Everyday Technology Explained. Washington D.C.: National Geographic Society, 2006, p.14. Engineering Library T47 .L2923 2006

3 Spencer, Percy L. Method of treating foodstuffs. U.S. Patent 2,495,429, filed October 8, 1945, issued January 24, 1950. Source: Google Patents

Books and Standards

Crupi, Giovanni, Editor. Microwave De-Embedding: From Theory to Applications. Waltham, MA: Elsevier/Academic Press, 2014. Engineering Library TK7876 .M53 2014

Hwang, Ruey-Bing. Periodic Structures: Mode-Matching Approach and Applications in Electromagnetic Engineering. Singapore: Wiley, 2013. Engineering Library TK872.F5 H93 2013

Maas, Stephen A. Practical Microwave Circuits. Boston: Artech House, 2014. Engineering Library (on order)

Pozar, David M. Microwave Engineering, 3rd. Hoboken, NJ: J. Wiley, 2005. Engineering Library TK7876 .P69 2005

Rohde, Ulrich L. RF/Microwave Circuit Design for Wireless Applications, 2nd. Hoboken, NJ: Wiley, 2013. Engineering Library TK7876 .R65 2013

Subcommittee F02.15 on Chemical/Safety Products microwave oven standards (Source: ASTM)

Need a Lift?

Motorized Inventory Robot Patent
Mountz, Michael C, et al. Inventory system with mobile drive unit and inventory holder. U.S. Patent 7,402,018, filed October 14, 2004, issued July 22, 2008.

December 1st is Cyber Monday, a day created by marketing companies to persuade people to shop online the first Monday after Thanksgiving. Employees returning to their desks after the holiday, stuffed full of turkey, are considered prime to shop on their high-speed internet connections at work. Warehouses, such as Amazon, are stocked to the brim with merchandise, and according to the Wall Street Journal, its order-fulfillment plans for this year’s holiday season will involve 10,000 robots. “Hugging the floor like a Roomba, and about the size of a big suitcase, these bright-orange bots lift and carry shelf-stacks of merchandise to warehouse workers who pack items for shipping. The idea is that it’s easier for the humans to stay in one place rather than tromp around a cavernous facility.”1, 2

Kiva Systems, now owned by Amazon Inc., has been engineering automated guided vehicles (AGVs) since the early 2000s.3 But as early as the 1970s, robotic lifts were being developed. In 1976, a self-propelled “Wheeled vehicle adapted to turn on the spot” with a load-carrying body or platform was issued by the US Patent Office.4

Basic components of an electric forklift. Source: en.wikipedia.org
Basic components of an electric forklift. Source: en.wikipedia.org

However, before the days of high tech, and still widely used, manual and motorized fork lifts move heavy items from one place to another. The first fork truck was the two-wheeled hand truck made of wrought iron axles and cast iron wheels Then, “in 1906, an official of the Pennsylvania Railroad at Altoona, Pennsylvania added storage battery power to a baggage wagon, producing what was probably the first powered platform truck. The controls were placed so that the operator had to walk out in front.” Between 1913 and 1919, trucks were engineered to lift small cranes both horizontally as well as vertically and forks and rams were introduced.”6

The Industrial Truck Association represents the manufacturers of powered and non-powered industrial trucks (forklifts) who do business in the United States, Canada and Mexico. It assumes responsibility for the Safety Standards for Low and High Lift Trucks as well as the Safety Standard for Driverless, Automatic Guided Industrial Vehicles and Automated Functions of Manned Industrial Vehicles.7,8

References

1 “Amazon’s Warehouse Robots, at Work and Play,” by Rob Walker. Yachoo! Tech, November 20, 2014.

2 “Amazon Robots Get Ready for Christmas,” by Greg Bensinger. The Wall Street Journal, November 19, 2014.

3 Mountz, Michael C, et al. Inventory system with mobile drive unit and inventory holder. U.S. Patent 7,402,018, filed October 14, 2004, issued July 22, 2008. Source: Google Patents

4 Folco Zambelli Gian Matteo, “Wheeled vehicle adapted to turn on the spot.” U.S. Patent 3,938,608, filed January 18, 1974, issued February 17, 1976. Source: Google Patents

5 “History of the Fork Truck” by Rick Leblanc. Packaging Revolution, October 17, 2011.

Excellence in Warehouse Management book cover6 Emmett, Stuart. Excellence in warehouse management : how to minimise costs and maximise value. Chicheser, West Sussex, England : Hoboken, NJ : Wiley, 2005. Engineering Library HF5485 .46 2005

7 Safety Standard for Low Lift and High Lift Trucks. ANSI/ITSDF B56.1-2012 (Revision of ANSI/ITSDF B56.1-2009) (PDF)

8 Safety Standard for Driverless, Automatic Guided Industrial Vehicles and Automated Functions of Manned Industrial Vehicles. ANSI/ITSDF B56.5-2012. (Order from ITSDF.org)

9 Steering a New Course” by Jack Maxwell. Standardization News, ASTM International.

A Real Life Game of Monopoly

HISTORY

Rich Uncle Pennybags
It’s National Play Monopoly Day!
Monopoly Patent Image
Darrow, Charles B. Board game apparatus. U.S. Patent 2,026,082, filed August 31, 1935, issued December 31, 1935.

Ironically, it was during the American Depression when Monopoly, a game of wealth and finance, became popular. Charles Darrow devised of a buying and selling real estate game with Atlantic City’s street names. He sold each hand-painted oil-cloth game for $4. When it caught on, and he could not keep up with the demand for manufacturing, he wrote Parker Brothers. The company initially rejected the board game citing it as too long and complicated, but eventually, Robert Barton, the president of the company, bought the rights to the game and registered the Monopoly® trademark in 1935. Thus, Darrow became the first inventor of games to become a millionaire.

INFRINGEMENT

Board Game Patent by Lizzie Maggie.
Magie, L. J. Game Board. U.S. Patent 748,626, filed March 23, 1903, issued January 5, 1904

Although Darrow is credited for the game’s invention, history shows that Elizabeth “Lizzie” Magie was issued a similar game patent in 1903. The Landlord’s Game,a practical demonstration of the present system of land-grabbing with all its usual outcomes and consequences,” was not widely manufactured and published until 1906 when she and two followers of Henry Goerge, an American political economist, established the Economic Game Company of New York. They wanted the game to demonstrate Henry George’s philosophy that people own value for what they create not for land which belongs to everyone. In 1910, Lizzie submitted her game to Parker Brothers for its consideration but was declined. Yet, word of the game spread. It is widely believed that Charles Darrow infringed upon Lizzie Magie’s patent, and in 1935, Robert Barton held a secret meeting with Darrow reaching a settlement agreement granting Parker Brothers worldwide rights in order to release Darrow from legal costs that he would incur defending the origin of the game.

The Landlord's GameWhat did Ms Magie get out of the deal? In a January 1936 interview with the Washington D.C. Evening Star, when asked how she felt for receiving only $500 for her patent and no royalties ever, she replied that it was okay “if she never made a dime so long as the Henry George single tax idea was spread to the people of the country.”

REFERENCES

1. McCorquodale, Duncan, et al, editors. Inventors and Inventions. London : Black Dog, 2009. p. 75 Engineering Library FOLIO T48 .I58 2009

2. Mag-ie, L.J. Game-board. U.S. Patent 748,626, filed March 23, 1903, issued January 5, 1904.

2. Darrow, Charles B. Board game apparatus. U.S. Patent 2,026,082, filed August 31, 1935, issued December 31, 1935.

3. Monopoly Game History, Landlord’s Game History

4. How Henry George’s Principles Were Corrupted Into the Game Called Monopoly

5. Henry George Source: http://en.wikipedia.org/wiki/Henry_George

6. George, Henry. Progress and Poverty, New York : Robert Schalkenbach Foundation, c1879, 1955 Main Library HB171 .G27 1955

7. There is nothing new under the sun, Mrs. Elizabeth Magie Phillips, headmistress and proprietor of the Henry George School of Social Science, in Clarendon, Val, is convinced, she said yesterday. The Washington Post [Washington D.C.] 28 Jan 1936: 13 Source: ProQuest News & Newspapers

How Cool Is This

In honor of Clean Out Your Refrigerator Day, celebrated on November 15th, you may want to know how your refrigerator operates.

Early Twentieth Century Refrigerator
The one-millionth Frigidaire refrigerator is proudly displayed as it comes off the assembly line in Dayton, Ohio, in 1929. Photograph: AP

HISTORY

Refrigerators are a modern invention. Until the advent of wide-scale electricity, keeping food cold had been a challenge for civilizations. Even as late as the 1800s, ice continued to be the major method for cooling. However, in 1848, Alexander Twining experimented with vapor-compression refrigeration allowing mechanical cooling to be applied in the meat packing and brewing manufacturing industries from the 1870s through the 1890s. Then in 1895, a German engineer, Carol von Linde, designed a process for the mass-scale production of domestic operating cooling units.1 By 1921, the first Frigidaire came off an assembly line at the Delco Light Plant of General Motors. That same year, 5,000 refrigerators were manufactured for home use.2

Einstein refrigerator patent image
Albert Einstein and Leo Szilard. Refrigeration. U.S. Patent 1,781,541, filed December 16, 1927, issued November 11, 1930 [6]
OPERATION

All refrigerator models work on the same principle: as the gas phase of matter expands, it takes up heat from the environment and converts the thermal energy to other forms of energy. This is called the Carnot cycle.3 In refrigerators, a gas is compressed and under pressure is changed to liquid. A compressor forces the liquid, or coolant, through a series of tubes or coils where it vaporizes, removing heat from the surrounding environment (i.e., from inside the refrigerator). A pump that is run by a motor sucks up the warmed gas, compresses it into liquid again, and sends it to the condenser for another bout of cooling.4 In the early twentieth century, refrigerators used methyl chloride, sulphur dioxide, or ammonia gas, all of which are toxic and caused several injuries and fatalities when leaked into homes.

Einstein and Szilard
Albert Einstein and Leo Szilard

INVENTION

For this reason, Albert Einstein had the idea to improve its safety. In 1926, he partnered with Leo Szilard, a Hungarian-American physicist, who had published his dissertation on thermodynamics and had knowledge of patent engineering. Together they set out to improve the mechanical compressors and eliminate the toxic gases. “The Einstein-Szilard fridge used pressurized ammonia, butane and water… and no moving parts — thereby eliminating the possibility of seal failure…One of the components the two physicists designed for their refrigerator was the Einstein-Szilard electromagnetic pump, which had no moving parts, relying instead on generating an electromagnetic field by running alternating current through coils. The field moved a liquid metal, and the metal, in turn, served as a piston and compressed a refrigerant.”5

In 1930, freon was introduced as an economically favored refrigerant gas. However, with environmental concerns over climate change and the impact of freon and other chlorofluorocarbons on the ozone layer, it maybe time for another reinvention. “Green refrigeration” is being explored. Two groups in the UK, Malcom McCullough of Oxford, is designing a solar-powered fridge as an alternative energy source, and Camfridge Ltd, in Cambridge, is researching gas-free alternatives.Also, a team of Canadian-Bulgarian researchers are looking into magnetic cooling.8

So as you toss out the carton of milk which expired two weeks ago, think how you might improve upon Einstein’s cooling appliance.

REFERENCES

1. McCorquodale, Duncan, et al, editors. Inventors and Inventions. London : Black Dog, 2009. p. 32 Engineering Library FOLIO T48 .I58 2009

2. Langone, John. How Things Work: Everyday technology explained. Washington D.C. : National Georgraphic Society, 2006, pages 18 – 19. Engineering Library T47 .L2923 2006

3. The Carnot Cycle (Source: MIT)

4. Wearing, Judy. Edison’s Concrete Piano: Flying Tanks, Six-Nippled Sheep, Walk-On-Water Shoes and 12 Other Flops from Great Inventors. Toronto : ECW Press, 2009, pages 231 – 232 Engineering Library T47 .W42 2009

5. The Story of Einstein’s Refrigerator by Jennifer Ouellette, December 5, 2010

6. Einstein, Albert and Szilard, Leo. Refrigeration. U.S. Patent 1,781,541, filed December 16, 1927, issued November 11, 1930. (Source: Google Patents)

7. Wearing, Judy. Edison’s Concrete Piano: Flying Tanks, Six-Nippled Sheep, Walk-On-Water Shoes and 12 Other Flops from Great Inventors. Toronto : ECW Press, 2009. pages 239 – 240. Engineering Library T47 .W42 2009

8. Magnetic Cooling Enables Efficient, ‘Green’ Refrigeration, June 19, 2014. (Source: Phys.org)

9. Standard Specification for Reach-in Refrigerators, Freezers, Combination Refrigerator/Freezers, and Thaw Cabinets. ASTM F2520-05 (2012) (Source: ASTM International)

10. Pham, Hung. Lower-GWP Refrigerants in Refrigeration. ASHRAE-D-ANRC12-17. (Source: TechStreet)

11. Energy-Efficient Refrigerator Prototype Test Results [microform]. Washington, D.C. : U.S. Environmental Protection Agency, Office of Atmospheric and Indoor Air. EPA-430-R-94-011, June 1994. Main Media Collection Microfiche EP 4.2:R 25/3