The Kilogram is Being Redefined
“How is the Kilogram being redefined?”
A massive shift has just happened in the physics community. For over a century our measurement for the kilogram has been based off an official block sealed in vaults below Paris. However, after many decades of work and false starts, a committee has convened to redefine the kilogram based not on an artifact of nature but instead on Plank’s constant. As a result we now have a truly uniform system of fundamental units!
How ‘Invisible Wires’ Could Improve Solar Cell Efficiency
“How can we solve the silicon wire reflectivity problem in solar cells?”
We know that PV modules have a transmission wire reflectivity problem. But some research coming out of Stanford University could change this entirely. Instead of relying upon wires to channel electrons away from the silicon semiconductors, what if we were to use gold sheets with holes in them, and tiny silicon towers on top to redirect sunlight away from the gold sheet and into the holes? This way the maximum amount of sunlight can be absorbed and reflectivity can be minimized. This is just a small example of How ‘Invisible Wires’ Could Improve Solar Cell Efficiency.
Image Credit https://news.stanford.edu
How Adding Fins can Achieve Better Thermal Management
“How can adding fins help thermal management?”
In engineering, objects can overheat from a variety of operations. As a result, they will need some form of thermal dissipation. But how can we do this? Well, let’s use our engineering mindsets to find out. We know that if we add more surface area to an object, then it will be more exposed to the surrounding atmosphere. And if it is more exposed, then more heat transfer will take place. So what if we were to make our system more conductive by adding fins? This is the fundamental idea of How Adding Fins can Achieve Better Thermal Management.
“How do buildings react to temperature changes?”
We have a conundrum. Temperatures change throughout the day, but inside a building it’s supposed to stay constant. And since some buildings are better about it than others, how can we quantify this phenomenon? Well, since this concept is a lot like inertia, Architectural Engineers have decided to call this Thermal Mass.
Hydrogen Production through Electrolysis
“How can we produce hydrogen using electricity?”
Hydrogen is an amazing material. However, extracting it can be quite difficult. One way to do it is to take an anode and a cathode separated by an electrolyte and a membrane. The water will react at the anode to produce oxygen and positively charged hydrogen ions. The electrons will flow through the circuit and the hydrogen ions will move across the membrane to the cathode side. They will then meet and recombine to form hydrogen molecules. This way, we can Produce Hydrogen using Electrolysis. Since the only thing that needs to be added to the system is electricity, if our grid is powered by renewables then we can have a carbon neutral method of hydrogen production!
Image credit Department of Energy
“How can we calculate the specific energy for humid air?”
Air can vary a lot in both temperature and humidity. And sometimes, we would like to know the specific energy for humid air under constant pressure at a reference temperature ignoring the effects of condensation. To do this, we can calculate by the Sigma Heat S = 17.86 (kj/kg) + 1.05 (kj/kg)*t + W(2501 (kj/kg) + 1.884(kj/kg)*t), where t is the dry-bulb temperature of the air (in °C), and W is the specific humidity of the air (no unit). The Sigma Heat equation is commonly used in mining engineering to calculate the temperature regulation of mine air.
“Can a thermodynamic process be so slow that it’s almost static?”
Thermodynamic processes can happen over any period of time. Sometimes they happen so slowly that they almost seem to be static. These Quasistatic Processes are often used in analysis of Iso-Processes due to their stable nature.