Re: Stuff and Nonsense Unleashed
« Reply #1563 on: Jun 2nd, 2017, 7:18pm »
" I don't see anything in the description that would form a basis of a battery electrolyte."
I don't know, Hal. Does this help?
One of the most important properties of water is its ability to dissolve a wide variety of substances. Solutions in which water is the dissolving medium are called aqueous solutions. For electrolyte, water is the most important solvent. Ethanol, ammonia, and acetic acid are some of the non-aqueous solvents that are able to dissolve electrolytes.
Electrolytes Substances that give ions when dissolved in water are called electrolytes. They can be divided into acids, bases, and salts, because they all give ions when dissolved in water. These solutions conduct electricity due to the mobility of the positive and negative ions, which are called cations and anions respectively. Strong electrolytes completely ionize when dissolved, and no neutral molecules are formed in solution.
For example, NaCl, HNO3, HClO3, CaCl2 etc are strong electrolytes. An ionization can be represented by,
NaCl(s) = Na+(aq) + Cl-(aq)
Since NaCl is an ionic solid (s), which consists of cations Na+ and anions Cl-. No molecules of NaCl are present in NaCl solid or NaCl solution. The ionization is said to be complete. The solute is one hundred percent (100%) ionized. Some other ionic solids are CaCl2, NH4Cl, KBr, CuSO4, NaCH3COO (sodium acetate), CaCO3, NaHCO3 (baking soda).
Small fractions of weak electrolytes' molecules ionize when dissolve in water. Some neutral molecules are present in their solutions. For example, ammonia, NH4OH, carbonic acid, H2CO3, acetic acid, CH3COOH, and most organic acids and bases are weak electrolytes. The following ionization is not complete,
H2CO3(aq) = H+(aq) + HCO3-(aq)
In a solution, H2CO3 molecules are present. The fraction (often expressed as a %) that undergos ionization depends on the concentration of the solution.
On the other hand, ionization can be viewed as an equilibrium established for the above reaction, for which the equilibrium constant is defined as
[H+] [HCO3-] K = --------- [H2CO3]
where we use [ ] to mean the concentration of the species in the [ ]. For carbonic acid, K = 4.2x10-7. You can generalize the definition of K here to give the equilibrium constant expression for any weak electrolyte.
Water is a very weak electrolyte. The ionization or autoionization of pure water can be represented by the ionization equation,
H2O = H++ OH- and the equilibrium constant is,
[H+] [OH-] K = ----------- [H2O]
For pure water, [H2O] is a constant (1000/18 = 55.6 M), and we often use the ion product, Kw, for water,
Kw = K [H2O] [H+] [OH-]
The constant Kw depends on temperature. At 298 K, Kw = 1x10-14. If there is no solute in water, the solution has equal concentrations of [H+] and [OH-].
[H+] = [OH-] = 1x10-7, and pH = - log [H+] = 7.
Note that only at 298 K is the pH of water = 7. At higher temperatures, pH is slightly less than 7, and at lower temperature, the pH is greater than 7.
A fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction of positively charged hydrogen ions with oxygen or another oxidizing agent. Fuel cells are different from batteries in requiring a continuous source of fuel and oxygen or air to sustain the chemical reaction, whereas in a battery the chemicals present in the battery react with each other to generate an electromotive force (emf). Fuel cells can produce electricity continuously for as long as these inputs are supplied.
The first fuel cells were invented in 1838. The first commercial use of fuel cells came more than a century later in NASA space programs to generate power for satellites and space capsules. Since then, fuel cells have been used in many other applications. Fuel cells are used for primary and backup power for commercial, industrial and residential buildings and in remote or inaccessible areas. They are also used to power fuel cell vehicles, including forklifts, automobiles, buses, boats, motorcycles and submarines.
There are many types of fuel cells, but they all consist of an anode, a cathode, and an electrolyte that allows positively charged hydrogen ions (protons) to move between the two sides of the fuel cell. The anode and cathode contain catalysts that cause the fuel to undergo oxidation reactions that generate positively charged hydrogen ions and electrons. The hydrogen ions are drawn through the electrolyte after the reaction. At the same time, electrons are drawn from the anode to the cathode through an external circuit, producing direct current electricity. At the cathode, hydrogen ions, electrons, and oxygen react to form water. As the main difference among fuel cell types is the electrolyte, fuel cells are classified by the type of electrolyte they use and by the difference in startup time ranging from 1 second for proton exchange membrane fuel cells (PEM fuel cells, or PEMFC) to 10 minutes for solid oxide fuel cells (SOFC).
Re: Stuff and Nonsense Unleashed
« Reply #1564 on: Jun 2nd, 2017, 9:47pm »
Well Done, Cadet!
Air Force cadet creates bulletproof breakthrough
By Kelly David Burke, Alicia Acuna Published June 02, 2017
Air Force Academy cadet creates bulletproof substance
Air Force cadet Hayley Weir had an idea that turned out to be a game changer. "It was just the concept of going out there and stopping a bullet with something that we had made in a chemistry lab."
The 21-year-old Weir approached Air Force Academy Assistant Professor Ryan Burke with the idea. He was skeptical.
"I said, 'I'm not really sure this is going to work, the body armor industry is a billion-plus-dollar industry," he noted.
Weir's idea was to combine anti-ballistic fabric with what's known as a shear thickening fluid to create a less heavy material to use in body armor. She demonstrated the principle to Burke by combining water and cornstarch in a container and asking the professor to jam his finger into the paste-like goo.
"I jam my finger right into this bowl, and I almost broke my finger! Hayley's laughing because I've got this finger that I'm shaking and I'm saying, 'You know, that's pretty impressive stuff.'"
Convinced, Ryan worked with Weir for several months in a small lab at the Air Force Adacemy in Colorado Springs. They were helped and advised by Dr. Jeff Owens, Senior Research Chemist at the Air Force Civil Engineer Center at Tyndall Air Force Base in Florida.
They tried combining several different ingredients to come up with the exact formula for the shear thickening fluid, and the correct way to layer it with ballistic fibers.
"The pieces are not new," Weir explains, "everything that we've used in there has been researched (before) in some capacity for ballistics protection."
They tested their combinations on the firing range, failing time and again, until one day their quarter-inch thick design repeatedly stopped a round fired from a 9mm handgun.
Weir and Ryan's excitement was tempered by the range safety officer who pulled his .44 Magnum and told them bluntly, "This will fail."
Ryan says, "We loaded it in and it stopped it. And it stopped it a second time, and then a third time."
They realized they had hit on something special, that could potentially lighten the average 26-pound body armor kit worn by servicemen in the field by as much as two thirds.
"This is something that our competition doesn't have right now," Weir explained. "And with this advantage our soldiers, if they wear this body armor, will be able to move faster, run farther, jump higher."
Body armor for the military and first responders may not be the only thing that can be improved by the new fabric. It could possibly be used to reduce or replace the thick metal plates that protect military aircraft, tanks and other vehicles.
"And there's some significant gravity and weight behind that," Ryan said. "And what it could mean for people like my friends who are still active duty in the military, that are going downrange, serving overseas."
A patent for the as yet unnamed design is pending, and if money is ultimately made, the Air Force will share the profits with Weir, Ryan and Owens.
"It doesn't feel like it's that great of an achievement," Weir muses, "just because it's been something that we've enjoyed doing."
The Air Force believes it is definitely a great achievement. They are providing the newly graduated 2d Lt Weir with a full-ride scholarship to Clemson University, where she will earn her Master of Materials Science and Engineering, before returning to the Air Force to continue her work.
Re: Stuff and Nonsense Unleashed
« Reply #1571 on: Jun 3rd, 2017, 4:53pm »
CRS-11 Begins with Spectacular Launch from Historic Pad
5:34pm EST, June 3, 2017
Nearly three tons of research gear, supplies and hardware are on their way to the International Space Station following the liftoff this evening of a SpaceX Falcon 9 rocket with a Dragon cargo spacecraft. The launch marked the 100th time a mission launched from Launch Complex 39A at NASA’s Kennedy Space Center in Florida. Launch occurred at 5:07 p.m. to cap a smooth countdown. Now in orbit with its twin solar arrays open to generate power for the spacecraft systems, the Dragon is on course to rendezvous with the space station Monday, June 5.