It is estimated that at least one tenth of the population have some form of needle phobia. That is the arrant fear of injections and the associated hypodermic syringes to the point where it seriously hampers medical procedures. There have even been reported cases of people actually dying of fright (more accurately drop in blood pressure) as the physiological result of their fear. One solution which may help, though not particularly designed with this problem in mind, is the microneedle.
Technology progression is quite amazing. If you told someone a few hundred years ago that bolts would one day not be needed to hold two pieces of metal together they wouldn’t believe you. The entire concept of welding or adhesives strong enough to do so is so far beyond them. Ultrasonic welding is the next step up from this. Needing no soldering metal, bolt, adhesive or any traditional connection ultrasonic welding is used mostly on plastics but can also be used to join different metals together provided the sheets are thin enough.
A lot of focus has been given, and for good reason, towards understanding how individual atoms arrange physically in a space (not outer space but a space) to form a molecule. Many mechanisms have been proposed and many experiments done with the result that our quantitative knowledge about how molecules arrange is quite high. A place where we know no where near as much, would be the topic of how colloidal systems (solutions but with the solute being formed from much larger particles up to 1000 nm in diamter) manage to arrange to create useful materials.
Transition metals are defined as any metal with an incomplete d-subshell. In other words one particular electron layer isn’t quite complete which opens a wide range of properties granted by variable electron configurations mostly focused on in chemistry through the three Cs of catalyst, colour and complex. For physics we love looking at the properties of transition metal oxides due to an increased stability which makes working with them easier. The cuprates, all the metal oxides containing copper, are particularly interesting as they have shown superconductivity and other electronic properties. Of course when we want to study what gives cuprates their properties it is best to study something very similar in many ways but with one clear distinct difference.
Using electromagnetic radiation to probe matter is such an inherent part of physics that it comes up in every branch and every subject. Whether it’s the interaction between charges, understanding crystal structures, monitoring chemical reactions or logging the compounds found in foodstuff there is always spectroscopy. One of more common techniques is called pump-probe spectroscopy. A laser pulse of only a few hundred femtoseconds is split into two sections. The stronger is sent first and is called the pump and it is this pump which excites the matter being studied into a energetic state. Then along comes the probe pulse which records various optical properties of the matter. Normally the delay on the probe is varied in order to see how the relaxation occurs in the material.
In 2014 the Nobel prize for physics was given to three men whose combined work was the production of a blue light emitting diode. The reason that this was such a special achievement was the fact that when the blue LED is covered by a colour conversion layer made of various phosphors it can have an eventual output of white light. This is obviously ideal for almost all artificial lighting as white light is mirrors that which is produced by the Sun. Phosphors in general work by absorbing the incident blue light and then radiating light of a lower frequency through the promotion and relaxation of atomic electrons. However there is a problem. Although LEDs have only improved in reliability, energy efficiency and lifetime over the course of their development the phosphors used have remained limited to rare earth metals and their ions.
Galling is a type of wear that happens when two materials (normally metals) are tightly pressed together before one of them suddenly slides. This results in layers of metal being unevenly torn off one surface and adhering to the other. The galled material will appear pock marked or gouged and the galling material will have received patches of its partner stuck to it.