Nerdy Science Blog

Paul Steen, a professor of chemical and biomolecular engineering, and Michael Vogal, a formal postdoctoral associate, developed a palm-size device that possibly allowed human to walk on walls by using water surface tension as an adhesive bond.  The device was developed at Cornell University and the research was published in Feb 1’s Proceedings of the National Academy of Sciences.

The invention was inspired by beetle native to Florida which can stick itself to a leaf 100 times more than its own weight.  Scientists applied the rapid adhesion mechanism they found to develop a device that can be used on shoes, gloves, or other possible tools you can think of to stick and unstick heavy things to walls.  The device is made of holes in orders of microns on flat plate with a liquid reservoir at bottom and porous layer at the middle.  With the help of 9-volt battery, water will be pumped to produce droplets to the top layer of the device and the droplets’ surface tension will grip another surface.

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Researchers from Oregon State University, Cornell University and the University of North Carolina published their work in Proceedings of the National Academy of Sciences showing the effect of herbivores and omnivores on the prevalence of barley and cereal yellow dwarf viruses.  It is found that grazers such as deer, rabbits and feral pigs actually help to spread plant disease, which is contrary with findings that suggested grazers actually contain or reduce disease.  Elizabeth Borer, an assistant professor of zoology at OSU explained their study is about the interaction of plant pathogens with the complexity of natural ecosystems.  Any small change in the elements of ecosystems can cause butterfly effects with seemingly unrelated diseases, and these changes can be caused by climate change, species population, human manipulation, etc.  One obvious example is that the increase of white-footed mice population is correlated to the increase of Lyme disease risk in humans.  Although the grazers increase the amount of annual grasses, these grasses are preferred by the aphids which transmitted the viral plant disease.

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Thomas Midgley, Jr was born to an immigrant inventor who came from London. He was born in Beaver Falls, Pennsylvania and grew up in Ohio. Midgley then graduated from Cornell University in the year of 1991 holding a PhD in mechanical engineering. As a fresh graduate, he worked various jobs before joining the research team of Charles Kettering’s Lab, based in Dayton, Ohio.

Thomas Midgley was a good chemist, solving some of the most challenging chemical problems of his day. It all started with the ‘knocking’ problem.

Kettering, the company that Midgley was working for, produces small kerosene engine to generate electricity for home-lighting on farms. The problem was that the fuel did not burn properly in the engine. It ignited prematurely when the piston of the cylinder compressed the fuel and air, making the engine to produce a ‘knock’. The lab asked Midgley to search for a solution so that the fuel could be less volatile. In other words, his job would be to make the fuel less likely to ignite while being compressed, thus producing less ‘knocking’. Midgley started his experiment by dyeing the fuel red, hoping that it would then absorb more heat and knock less. The method didn’t work and Midgley continued with another idea of mixing iodine with kerosene. The result produced less knock. After several random experiments to find the correct mixed, Midgley decided to find a more systematic way in searching for the correct compound for the antiknock additive. He then turned to the Periodic Table. Since then, his experiments began to follow a pattern. He first tried Tellurium, which successfully halted the premature ignition but later on gave up on it due to the garlic smell which was produced by the compound. He then ventured into trying Tetraethyl tin and later on metallic lead. On December 9 of 1921, tetraethyl lead was produced, delivered and the one-cylinder engine in the laboratory ran without any knocking. Thomas Midgley had found his correct antiknock compound after 6 years of researching.

Midgley only took 3 days to make his next contribution to the world. This time, Midgley developed Freon. He was commissioned to find a safer refrigerant as most refrigerators during his time used chemicals like ammonia and sulphur dioxide as refrigerants. These refrigerants, which when leaked out, could kill people.

Freon is a trade name which contains different chemical compounds, a combination of chlorine, fluorine and carbon, which was then known as CFC. During his presentation of this compound to the American Chemical society, he inhaled the gas, and exhaled the cold air over a candle – which then went out. In this demonstration, he showed everybody that this new invention was non-toxic, colorless, odorless and nonflammable. Since then, the compound was widely used in refrigeration systems.

Even thou Thomas Midgley had solved some of the very challenging problems of his time, his inventions, although brilliant, had caused problems later on.

The tetraethyl lead developed by Midgley as an antiknocking agent in petrol turned out to be an air pollutant. The level of lead in the air increased as the number of vehicles using leaded petrol increased during the 20th century. Lead that accumulates has neurotoxic effects even at low levels, resulting in antisocial behavior and low IQ. The effects on children are even worse. It damages nervous connections, causes brain and blood disorders. Long term exposure could cause colic-like abdominal pains and nephropathy. It is also linked to schizophrenia.

Due to such adverse effects, many countries banned the use of leaded petrol, replacing the agent with other different agents. After the ban, the health risks were successfully removed.

CFCs which was Thomas Midgley 2nd invention, is capable of damaging protective layer of the ozone around the earth.

The earth is protected by a layer of gas, named the ozone gas, O3. This ozone layer could absorb most of the ultraviolet light produced and transmitted to the earth by the sun. Excessive exposure to ultraviolet radiation is bad for living things. Overexposure could cause sunburn and skin cancers (for example malignant melanoma). It may also results in certain health effects on the eye and immune system. All the UV radiation could damage collagen fibers, accelerate aging and destroy vitamin A in the skin. UVB light could cause direct damage to the human DNA, thus resulting in mutation, which can then turn into cancerous growths.

Today, there are various daily items that we use which contain CFC. Air conditioners, refrigerators, hair spray and even medical products contain CFC. These gases rise into the air and start to react with the ultraviolet light. Oxygen starts to bind with the CFC instead of another O2 compound (Oxygen has a stronger attraction to chlorine compared to another oxygen atom), producing a new oxygen molecule and a new chlorine atom. The new molecule produced by the reaction is called a ClO (chlorine monoxide), which is useless for us. It doesn’t function like the ozone layer which blocks the UV rays. These new chlorine monoxides have the ability to bind with another Oxygen atom to produce another new oxygen molecule and a chlorine atom. This process moves on, until the chlorine break apart thousands more ozone molecules.

The thinning of the ozone can already be seen from the satellite view of the North Pole and the South Pole as early as 1991. Such thinning has already occurred over the US. After the effects of CFC were known, there were international co-operation to reduce usage of such chemicals. Unfortunately, it would take a long time for the ozone to be restored to its pre-Midgley levels.

During Midgley’s time, he had served as vice president in Ethyl Gasoline Corporation (1923), vice president for Kinetic Chemicals (1930), and as a director of Ethyl Dow Chemical Company (1933). He was also a director of Ohio State University Research Foundation from 1940 to 1944. When he was 51, Midgley suffered from poliomyelitis. He then invented a system of ropes, hoists and pulleys to help himself in and out of bed. He got tangled up in the ropes and died.