When you think about it, the friction between the blood cells, plasma and the inside of the arteries can’t be very big. Even a small increase in the frictional coefficient between these surfaces would increase the amount of work you heart has to do to a ridiculous level. For a long time the existence of the endothelial glycocalyx layer, a layer of molecules bound to the walls of the blood vessels (made of endothelial cells), has been known about. These molecules are mostly the protein glycocalyx and form a layer about a micrometre thick. Only when direct comparisons were drawn between experiments in simulated blood vessels and actual ones was the importance of this layer for vascular biology understood.
There are many aspects of humans that makes our species unique among animals. Our intelligence is clear but from that stems our language and empathy. We also have acute mechanical abilities, our standing upright and our incredible stamina are also unique aspects of being human. But most of all, of course, is our opposable thumbs. They grant us the ability to perform such delicate manipulation that so many tasks, such as the typing I’m doing right now, become simple when really it’s a whole more complicated than we ever really think about. It is unsurprising, therefore, that people who have suffered spinal cord damage report that restoration of arm and hand functions is what they desire most. Important for spinal damage, and even more so for amputation, the brain-computer interface so that the control of a robotic replacement can be optimised is essential.
Surface plasmons are the oscillating electrons that exist in a metals surface. They get excited very easily by any light that is incident on the metal. It is possible for an electromagnetic wave in the visible or infrared to be formed in interface between a metal and a dielectric (such as the air). This wave is called a surface plasmon polariton and can be produced when energy energy is provided in a direction parallel to the metal’s surface. These waves are very important for both research and technology especially their tendency to travel along the surface much like light travels along an optical fibre.
Alloys are the mixture of metals. Nothing can ever be so simple that it’s summed up in a single sentence however. Most of the alloys you will have heard of, steel, solder and so forth are all called multiphase alloys. In fact almost all alloys that are used in some industrial context are multiphase. A single phase alloy is produced by melding together two elements into a solid solution, a minor component distributed uniformly amongst the crystal structure of the major component. This can only happen when the two materials already have the same crystal structure and are similar in size. The resulting alloy has it’s own completely uniform crystal structure, which can be useful, but doesn’t offer the same strength as multiphase alloys where the different crystal structure between the phases prevents the layers of metallic atoms separating.
Out of all methods of energy collection we have solar could be argued to be the most direct. Gathering energy directly from the Sun would be wonderful and especially efficient if the form you want that energy in is heat. Of course the biggest disadvantage is apparent, the fact the Sun only shines for half the day and unless you wish to add motorised technology to the panels to rotate them the incident light will only be optimal for a few hours a day. As a result, solar thermal energy storage is possibly the most important technology to develop for solar energy. What is the point in having the most efficient solar panel when there is nowhere for the energy to go when produced.
Seismic secondary waves, like every other kind of transverse wave, can be polarised. Seismic waves are actually just a specific terranean example of elastic waves. But to imagine the polarisation or even the waves themselves to be similar to that of a light wave would be a mistake. The polarisation of all waves is a whole lot more complicated than simply limiting the orientation of the waves passing through a point and waves in solid materials need extra consideration as they hold polarisation properties not found in other wave types.
In this post published a few days ago I talked about the potential for terahertz spectroscopy to analyse the chemical properties of drugs.
Today’s instead looks at the possible uses in computer and technology development for terahertz radiation. Of course for any communication system modulation of the wave that’s transferring the message is important. It may have crossed the reader’s mind at some point, the question of why sound waves cannot be radiated from aerials despite a frequency existing within them. This is because at the frequency of 15kHz, the upper range of audio frequencies, the energy radiated from an aerial is basically zero. The phrase “radio frequencies” was coined because it’s literally frequencies which are high enough for radio waves to be noticeably produced. In order to actually radiate sound energy, you need to create a wave of higher frequency, called the carrier wave, that mimics the wave you want to transmit. The diagram above shows the two most common ways of doing this, AM for amplitude modulated has a carrier wave that matches amplitude with the signal while frequency modulated has a higher frequency at the peaks than at the troughs.