Many officers in the field rely on breath alcohol testing devices to determine the blood alcohol concentration (BAC) in drunken-driving suspects. In this article, we will examine the scientific principles and technology behind the Breathalyzer and other breath alcohol testing devices. Contents ...
Interestingly, the expression of the results as a percentage of positive cells (Figure 3a) may not allow to evidence the increase in HLA-DR expression, as also observed by Vallhov et al [21]. A high expression of MHC-II molecules is inherent to the MoDCs model [11]. Hence, it ...
During this reaction, the reddish-orange dichromate ion changes color to the green chromium ion when it reacts with the alcohol; the degree of the color change is directly related to the level of alcohol in the expelled air. To determine the amount of alcohol in that air, the reacted mixt...
The energy packets that this electron is most likely to emit fall right around a wavelength of 590 nanometers. This wavelength corresponds to yellow light. If you run sodium light through a prism, you don't see a rainbow -- you see a pair of yellow lines....
aFor stimulated emission to occur, medium must have some molecules in an excited state. But consider the thermal population of the excited state at room temperature if the wavelength of emission is 694 nm. 为了受激发射能发生,媒介在受激态必须有有些分子。 如果放射波长是694毫微米,但考虑受激态的...
light excites fluorescence within molecules in the specimen. The objective lens collects the fluorescent-wavelength light produced. This fluorescent light passes through the dichroic mirror and a barrier filter (that eliminates wavelengths other than fluorescent), making it to the eyepiece to form the ...
This might be jarring to non-astronomers, but it’s a visual cue that speeds up research: Black star cores indicate there’s no useable data to investigate. (Every star has a particular brightness. Knowing how bright a star is and its distance can help researchers determine the amount of ...
An optical regenerator consists of optical fibers with a special coating (doping). The doped portion is "pumped" with a laser. When the degraded signal comes into the doped coating, the energy from the laser allows the doped molecules to become lasers themselves. The doped molecules then emit...
All forms of EM radiation reside on the electromagneticspectrum, which ranks radiation from lowest energy/longest wavelength to highest energy/shortest wavelength. The higher the energy, the stronger, and therefore more dangerous, the radiation. The only difference between a radio wave and a gamma ...
These faster-movingmoleculesmove into the surrounding air. For a moment, the region next to the drumhead has a greater-than-normal concentration of air molecules — it becomes a region of compression. As the faster-moving molecules overtake the air molecules in the surrounding air, they collide...